Iccter 2014 by Iaetsd Iaetsd

The Proceedings of INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH ICCTER – 2014

On 10th August, 2014 Venue

LIBERTY PARK HOTEL Chennai. Editiors Prof.M.Vani, Prof.B.N.Siva Prasanna Kumar

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About IAETSD: The International Association of Engineering and Technology for Skill Development (IAETSD) is a Professional and non-profit conference organizing company devoted to promoting social, economic, and technical advancements around the world by conducting international academic conferences in various Engineering fields around the world. IAETSD organizes multidisciplinary conferences for academics and professionals in the fields of Engineering. In order to strengthen the skill development of the students IAETSD has established. IAETSD is a meeting place where Engineering students can share their views, ideas, can improve their technical knowledge, can develop their skills and for presenting and discussing recent trends in advanced technologies, new educational environments and innovative technology learning ideas. The intention of IAETSD is to expand the knowledge beyond the boundaries by joining the hands with students, researchers, academics and industrialists etc, to explore the technical knowledge all over the world, to publish proceedings. IAETSD offers opportunities to learning professionals for the exploration of problems from many disciplines of various Engineering fields to discover innovative solutions to implement innovative ideas. IAETSD aimed to promote upcoming trends in Engineering.

About ICCTER: The aim objective of ICCTER is to present the latest research and results of scientists related to all engineering departmentsâ&#x20AC;&#x2122; topics. This conference provides opportunities for the different areas delegates to exchange new ideas and application experiences face to face, to establish business or research relations and to find global partners for future collaboration. We hope that the conference results constituted significant contribution to the knowledge in these up to date scientific field. The organizing committee of conference is pleased to invite prospective authors to submit their original manuscripts to ICCTER 2014. All full paper submissions will be peer reviewed and evaluated based on originality, technical and/or research content/depth, correctness, relevance to conference, contributions, and readability. The conference will be held every year to make it an ideal platform for people to share views and experiences in current trending technologies in the related areas.

Conference Advisory Committee:

Dr. P Paramasivam, NUS, Singapore Dr. Ganapathy Kumar, Nanometrics, USA Mr. Vikram Subramanian, Oracle Public cloud Dr. Michal Wozniak, Wroclaw University of Technology, Dr. Saqib Saeed, Bahria University, Mr. Elamurugan Vaiyapuri, tarkaSys, California Mr. N M Bhaskar, Micron Asia, Singapore Dr. Mohammed Yeasin, University of Memphis Dr. Ahmed Zohaa, Brunel university Kenneth Sundarraj, University of Malaysia Dr. Heba Ahmed Hassan, Dhofar University, Dr. Mohammed Atiquzzaman, University of Oklahoma, Dr. Sattar Aboud, Middle East University, Dr. S Lakshmi, Oman University

Conference Chairs and Review committee:

Dr. Shanti Swaroop, Professor IIT Madras Dr. G Bhuvaneshwari, Professor, IIT, Delhi Dr. Krishna Vasudevan, Professor, IIT Madras Dr.G.V.Uma, Professor, Anna University Dr. S Muttan, Professor, Anna University Dr. R P Kumudini Devi, Professor, Anna University Dr. M Ramalingam, Director (IRS) Dr. N K Ambujam, Director (CWR), Anna University Dr. Bhaskaran, Professor, NIT, Trichy Dr. Pabitra Mohan Khilar, Associate Prof, NIT, Rourkela Dr. V Ramalingam, Professor, Dr.P.Mallikka, Professor, NITTTR, Taramani Dr. E S M Suresh, Professor, NITTTR, Chennai Dr. Gomathi Nayagam, Director CWET, Chennai Prof. S Karthikeyan, VIT, Vellore Dr. H C Nagaraj, Principal, NIMET, Bengaluru Dr. K Sivakumar, Associate Director, CTS. Dr. Tarun Chandroyadulu, Research Associate, NAS

INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH ICCTER – 2014 Contents 1 2

IMPLEMENTATION OF CHAOTIC ALGORITHM FOR SECURE IMAGE TRANSCODING SYNTHESIS AND CHARACTERIZATION OF CDXHG1-XTE TERNARY SEMICONDUCTOR THIN FILMS

1 8

MANET: A RELIABLE NETWORK IN DISASTER AREAS

ENERGY MANAGEMENT OF INDUCTION MOTOR USING TIME VARYING ANALYSIS

ELECTROCHEMICAL MACHINING OF SS 202

GESTURE RECOGNITION

7 8 9 10

STRUCTURAL AND ELECTRONIC PROPERTIES OF DOPED SILICONNANOWIRE STUDY AND EXPERIMENTAL ANALYSIS OF LINEAR AND NON LINEAR BEHAVIOUR OF PIPE BEND WITH OVALITY A REVIEW ON PERFORMANCE ANALYSIS OF MIMO-OFDM SYSTEM BASED ON DWT AND FFT SYSTEMS STUDY OF VARIOUS EFFECTS ON PEAK TO AVERAGE POWER REDUCTION USING OFDM

49 64 70 76

ECO FRIENDLY CONSTRUCTION METHODS AND MATERIALS

A REVIEW ON ENHANCEMENT OF DEGRADED DOCUMENT IMAGES BASED ON IMAGE BINARIZATION SYSTEM

SEARL EFFECT

BUS TRACKER SYSTEM WITH SEAT AVAILABILITY CHECKER

TECHNO-HOSPITAL

104

PREPARATION OF W.P.S FOR STAINLESS STEEL (NI, CR, MO, NU) WELDING W.R.T MECHANICAL & THERMAL PROPERTIES

107

REPAIRING CRACKS IN CONCRETE STRUCTURES

110

RECOGNITION OF EMG BASED HAND GESTURES FOR PROSTHETIC CONTROL USING ARTIFICIAL NEURAL NETWORKS

115

VERTICAL FARM BUILDINGS SUSTAINABLE AND GREEN MANUFACTURING

121

SUSTAINABILITY THROUGH CRYOGENIC WATER FUEL

126

SILVERLINE FOR THE BLIND

133

CYBER CRIME AND SECURITY

139

NETWORK SECURITY AND CRYPTOGRAPHY

150

THE WIRELESS WATER AND VACCINE MONITORING WITH LOW COST SENSORS [COLD TRACE]

163

ADVANCED CONSTRUCTION MATERIALS

169

28 29

FPGA BASED RETINAL BLOOD OXYGEN SATURATION MAPPING USING MULTI SPECRAL IMAGES LITERATURE REVIEW ON GENERIC LOSSLESS VISIBLE WATERMARKING & LOSSLESS IMAGE RECOVERY

174 180

ARTIFICIAL INTELLIGENCE (AI) FOR SPEECH RECOGNITION

186

STRENGTH AND DURABILITY CHARACTERISTICS OF GEOPOLYMER CONCRETE USING GGBS AND RHA

191

VULNERABILITIES IN CREDIT CARD SECURITY

194

33 34 35 36 37 38

IMPLEMENTATION OF AHO CORASICK ALGORITHM IN INTRUSION DETECTION SYSTEM USING TCAM FOR MULTIPLE PATTERN MATCHING ADVANCED RECYCLED PAPER CELLULOSE AEROGEL SYNTHESIS AND WATER ABSORPTION PROPERTIES NEAR FIELD COMMUNICATION TAG DESIGN WITH AES ALGORITHM GREEN CONCRETE ECO-FRIENDLY CONSTRUCTION ANALYTICAL STUDY OF GENERAL FAILURE IN PROMINENT COMPONENTS ORGANIZING THE TRUST MODEL IN PEER-TO-PEER SYSTEM USING SORT

199 205 208 212 215 219

WEB PERSONALIZATION: A GENERAL SURVEY

227

A NOVEL SCHEDULING ALGORITHMS FOR MIMO BASED WIRELESS NETWORKS

233

41 42 43

BER PERFORMANCE OF CDMA, WCDMA, IEEE802.11G IN AWGN AND FADING CHANNEL A SURVEY OF VARIOUS DESIGN PATTERNS FOR IMPROVING QUALITY AND PERFORMANCE OF WEB APPLICATIONS DESIGN QUICK DETECTION TECHNIQUE TO REDUCE CONGESTION IN WSN

243 249 254

HEURISTICS TO DETECT AND EXTRACT LICENSE PLATES

258

DYE SENSITIZED SOLAR CELL

263

WEB PERSONALIZATION: A GENERAL SURVEY

269

AUTOMATED BUS MONITORING AND TICKETING SYSTEM USING RF TRANSCEIVER AND RFID

275

COMPARATIVE STUDY: MIMO OFDM, CDMA-SDMA COMMUNICATION TECHNIQUES

281

INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014

Implementation of Chaotic Algorithm for Secure Image Transcoding PRADEEP K.G.M IV SEM M.Tech DEC, Dept. of E&C KVGCE, Sullia Pkgm77@gmail.com

Dr. Ravikumar M.S. Professor and Head Dept. of E&C KVGCE, Sullia

necessary for image data. Due to characteristic of human perception, a decrypted image containing small distortion is usually acceptable. The intelligible information in an image is due to the correlation among the image elements in a given arrangement. This perceptive information can be reduced by decreasing the correlation among image elements using certain transformation techniques. In addition to cryptography, chaotic based image security techniques are getting significantly more sophisticated and have widely used. The chaotic image transformation techniques are perfect supplement for encryption that allows a user to make some transformation in the image, and then the image is totally distorted, so nobody could see that what information could be shown through that image. Thus, it is often used in conjunction with cryptography so that the information is doubly protected, that is, first it is transformed by chaotic map encryption techniques, and then it is encrypted so that an adversary has to find the hidden information before the decryption takes place.

ABSTRACT The transcoding refers to a two-step process in which the original data/file is decoded to an intermediate uncompressed format which is then encoded into the target format. Transcoding is the direct digital-todigital data conversion of one encoding to another. This paper proposes a system of secure image transcoder which mainly focuses on multimedia applications such as web browsing through mobile phones, in order to improve their delivery to client devices with wide range of communication, storage and display capabilities. This system based on CKBA encryption ensures end to end security. The performance of the system has been evaluated for different images. It is verified that the proposed system is having less resource complexity with good performance. Keywords: CKBA, Encryption, Transcoding 1.

INTRODUCTION

Images are generally the collection of pixels. Basically Image Encryption is a means that convert the image into unreadable format. Many digital services require reliable security in storage and transmission of digital images. Due to the rapid growth of the internet in the digital world today, the security of digital images has become more important and attracted much attention. The prevalence of multimedia technology in our society has promoted digital images to play a more significant role than the traditional texts, which demand serious protection of userâ&#x20AC;&#x2122;s privacy for all applications. Encryption techniques of digital images are very important and should be used to frustrate opponent attacks from unauthorized access.

Nowadays, communication networks such as mobile networks and the internet are well developed. However they are public networks and are not suitable for the direct transmission of confidential messages. To make use of the communication networks already developed and to keep the secrecy simultaneously, cryptographic techniques need to be applied. Traditional symmetric ciphers such as data encryption standard (DES) are designed with good confusion and diffusion properties. These two properties can also be found in chaotic systems which are usually ergodic and are sensitive to system parameters and initial conditions. In recent years, a number of chaos based cryptographic schemes have been proposed. Some of them are based on one dimensional chaotic logistic maps and are applied to data sequence or document encryption. This project mainly focuses on bit rate transcoding. Recently many papers have been proposed with the idea of stream ciphering. Generally encryption can be categorized into three viz complete encryption, selective encryption and joint encryption. In complete encryption entire data will be encrypted whereas in selective encryption only a part of data. Joint encryption refers to the encryption performed during compression.

Digital images are exchanged over various types of networks. It is often true that a large part of this information is either confidential or private. Encryption is the preferred technique for protecting the transmitting data. There are various encryption systems to encrypt and decrypt image data. However, it can be argued that there is no single encryption algorithm which satisfies the different image types. In general, most of the available encryption algorithms are used for text data. However, due to large data size and real time constants, algorithms that are good for textual data may not be suitable for multimedia data. Although we can use the traditional encryption algorithm to encrypt images directly, this may not be a good idea for two reasons. First, the image size is often large than text. Consequently, the traditional encryption algorithms need a longer time to directly encrypt the image data. Second, the decrypted text must be equal to the original text but this requirement is not

The growth in the processing of digital multimedia data is rapid, by the increasing demands of the content consumers with a widening variety of digital equipments; require bit streams to be modified after transmission. A transcoder can be placed in the channel to reduce the bit rate prior to retransmission to end user devices. A simplified view of a typical broadcasting system is shown in Fig.1.1.

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The proposed secure image transcoder is having too many multimedia applications such as medical imaging, mobile web browsing, etc. 3. PROBLEM STATEMENT There are two main drawbacks in using conventional crypto-systems to protect image data. First one is that the traditional systems are either too slow or in need of excessive complexity in real time operations with large volume of data. The second one is that any modification of the cipher text generated using on and off-the shelf cipher would render the resulting bit stream undecipherable.

Fig. 1.1: Potential broadcasting network One of the challenges in using such network is protecting the intellectual property rights of the content owners and producers when the data is transmitted over a public channel. In traditional cryptosystem a secret key is used to encrypt and decrypt the data. There are two main drawbacks in using traditional cryptosystems to protect image data.

4. MOTIVATION The motivation for image transcoding research is mainly due to contemporary developments in the field of security and compression of many multimedia applications. In the digital world nowadays, the security of digital images becomes more and more important since the communications of digital products over network occur more and more frequently. Furthermore, special and reliable security in storage and transmission of digital images is needed in many applications, such as, medical imaging systems, military image database/communications and confidential data.

First one is that the traditional systems are either too slow or in need of excessive complexity in real time operations with large volume of data. The second one is that any modification of the cipher text generated using on and off-the shelf cipher would render the resulting bit stream undecipherable. An intuitive approach is to allow the transcoder to decrypt the bit stream, prior to transcoding, re-encryption and retransmission, as shown in fig 1.2. While this approach is very effective in ensuring efficient content delivery, it does not allow end to end security.

5. METHODOLOGY The proposed secure image transcoder system is basically a modification of the existing jpeg encoderdecoder algorithm. The main modifications are;  Encryption  Transcoding

Fig. 1.2 : Traditional transcoder with encrypted data To ensure end to end security one of the possible approaches is shown in Fig.1.3. Here transcoder stage is made such that no plain text is freely available in the intermediate stages of transcoding. For this purpose a decode and re-encode stage is used with different quantization value

Fig. 5.1: The proposed frame work Fig 1.3 secure transcoder using ciphers designed for transcoding

The proposed work consists of the following steps STEP 1: Considering an input image of size M×N and Apply 2-DCT to the image. DCT is mathematical technique used to convert image from spatial domain to frequency domain. JPEG image compression standard use DCT. The discrete cosine

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transform is a fast transform. It is a widely used and robust method for image compression. It has excellent compaction for highly correlated data.DCT has fixed basis images. DCT gives good compromise between information packing ability and computational complexity.

This chaotic system is run to make a chaotic sequence x (i) for i varying from 0 to ((M×N)/8) −1. It is then grouped into 8 bits to form an integer so that a pseudo random array of (M×N)/64 integers are formed. By avoiding the repeating elements, it is possible to form an array of length 256. This array can be taken as an index to shuffle the columns of input DCT matrix. This system is a well encrypted system providing good compression by suitably selecting the quantization matrix. STEP 3: Applying quantization to the CKBA encrypted image. Quantization process aims to reduce the size of the size of the DC and AC coefficient so that less bandwidth is required for their transmission. The human eye responds primarily to the DC coefficient and the lower spatial frequency coefficients. Thus if the magnitude of a higher frequency coefficient is below a certain threshold, the eye will not detect it. This property is exploited in the quantization phase by dropping –in practice, setting to zero-those spatial frequency coefficients in the transformed matrix whose amplitudes are less than a defined threshold value.

Fig. 5.2 : The 8×8 sub-image shown in 8-bit grayscale 



Each image is divided into 8 x 8 blocks. The 2D DCT is applied to each block image f(i,j), with output being the DCT coefficients F(u,v)/F(i,j) for each block If the input matrix is P[x,y] and the transformed matrix is F[u,v] then the DCT for the 8×8 block is computed using the expression:

Forward DCT  F[i,j]= C(i)C(j)∑ (

cos

)

∑

(

The sensitivity of the human eyes varies with spatial frequency, which implies that the amplitude threshold below which the eye will detect a particular spatial frequency also varies. In practice, therefore, the threshold values used vary for each of the 64 DCT coefficients. These are held in a two dimensional matrix known as quantization table with the threshold value to be used with a particular DCT coefficient in the corresponding position in the matrix. A common quantization matrix is

)

[ , ]cos

(5.1)

Where C (i) and C (j) = for i, j = 0 √ = 1 for all other values of i and j and x, y,i, and j all vary from 0 through 7 STEP 2: CKBA encryption The proposed chaotic key based algorithm is a complete encryption technique. The encryption procedure of CKBA can be briefly depicted as follows. Assume the size of the plain-image is M × N. Shuffle the DCT matrix using the generated random key. It can be performed before or after the quantization stage. Incorporating a shuffling algorithm in the spatial domain can result an immense reduction in the compression ratio. Since, in most of the multimedia applications, the larger compression is a mandatory requirement, we cannot implement the shuffling algorithm in the spatial domain. Hence, performing the shuffling operation in the transform domain, without affecting the compression ratio is favorable. Thus, block-wise shuffling of DCT matrix is performed so that compression remains intact. Shuffling is performed based on a chaotic map.

Quantized coefficient matrix values,

Assume that the size of the plain-image is M × N. Select an initial condition x (0) of a one-dimensional chaotic system as the secret key of the encryption system defined by the following logistic map (1). x (i+1) = µ*x(i)(1 - x(i)) (5.2) It has been proved that the system behaves chaotically if the value of μ > 3.5699.

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Zigzag scanning The output of typical quantization is a 2-D matrix of values/ coefficients which are mainly zeros except for a number of non-zero values in the top left hand corner of the matrix. Clearly, if we simply scanned the matrix using a line-by-line approach, then the resulting (1×64) vector would contain a mix of non-zero and zero values. In general, however, this type of information structure does not lend itself to compression. In order to exploit the presence of large number of zeros in the quantized matrix, a ZIG-ZAG SCAN is used.

Fig. 5.4: Zigzag Scanning Pattern DIFERENTIAL ENCODING Differential encoding is used when the amplitude of the values that make up the source information cover a large range but the difference between successive values is relatively small. Instead of using a set of relatively large codeword’s to represents the actual amplitude of each value, a set of smaller of smaller codeword’s is used, each of which indicates only the difference in amplitude between the present value being encoded and the immediately preceding value.

RUNLENGTH ENCODING TECHNIQUE It is used when the source information contains long strings of the same symbols such as character, a bit or a byte. Instead of sending the source information in the form of independent codeword’s, it is sent by simply indicating the particular symbol in each string together with an indication of the number of symbols in the string. For ex: 000000060040009 this string is represented as (7, 6) (2, 4) (3, 9)

This is an example of DCT coefficient matrix:

HUFFMAN COMPRESSION TECHNIQUE It is a method for the construction of minimum redundancy Codes. Huffman code procedure is based on the two observations. a. More frequently occurred symbols will have shorter code words than symbol that occur less frequently. b. The two symbols that occur least frequently will have the same length. Huffman coding algorithm working steps are as follows.  Convert the given color image into grey level image.  Find the frequency of occurrence of symbols (i.e. pixel value which is non-repeated).  Calculate the probability of each symbol.

For example, using −415 (the DC coefficient) and rounding to the nearest integer Round (-415/16) =Round (-25.9375) = - 26 STEP 4: Applying entropy encoding to the quantized coefficient matrix as  Zigzag scanning  Differential encoding  Run length encoding  Huffman encoding

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

Probability of symbols are arranged in decreasing order and lower probabilities are merged and this step is continued until only two probabilities are left and codes are assigned according to rule that the highest probable symbol will have a shorter length code. Further Huffman encoding is performed i.e. mapping of the code words to the corresponding symbols will result in a compressed data. The original image is reconstructed i.e. decompression is done by using Huffman decoding.



STEP 5: Designing of Transcoder block The string of zeros and ones from the Huffman encoding is applied to the transcoder block. This block converts digital-to-digital data conversion of one encoding to another format. Transcoder can be placed in the channel to reduce bit rate prior to retransmission to target client devices according to bandwidth availability of end users.

Fig. 5.5: Schematic of Transcoder block The output of Huffman encoding is applied to decoding block of Huffman to inverse quantiser block. Then the output of inverse quantiser is applied from quantiser of transcoder block to Huffman encoding block. This transcoder block achieves good compression ratio. STEP 6: In the receiver side the output of Huffman encoding is applied from Huffman decoding block to inverse quantiser. STEP 7: CKBA decryption is performed as follows by applying 8-bit key to the inverse quantiser. Fig .5.6: CKBA decryption flow chart

STEP 8: Each resulting block of 8×8 blocks spatial frequency coefficients is passed in turn to the inverse DCT which transform them back into their spatial form using the following expression: ( ) ∑ P[x, y] = ∑ C(i)C(j) [ , ]cos (

cos

)

5.3

Where C (i) and C (j) = for i, j=0 √ =1 for all other values of i and j Finally image is reconstructed by applying IDCT to the decrypted image as shown in the flow chart fig.5.2.

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factor 5 before transcoding and then increasing quantization factor to 85 in the transcoder block. After transcoding we will get the compression ratio of 18.0870 and average bit per image of 0.4423. 6. SIMULATION RESULTS AND ANALYSIS Simulation Results Example 1

Fig. 6.1 : Cameraman original image of size (256×256)

Fig. 6.2: CKBA encrypted image

7. CONCLUSION Conclusion Several Transcoding algorithms are already been examined for the effective utilization of bandwidth and user satisfaction. The proposed image transcoder gives the idea of how a high quality data like image can be securely transmitted to different environments with effective utilization of available bandwidth. From the

Fig. 6.3 : CKBA decrypted output image The performance of the proposed system is evaluated for image of size 256×256 with quantization

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results it is clear that, for transcoding we exploit the full efficiency of existing jpeg algorithm and gives better compression for different quantization values. Here we presented security in terms of CKBA. REFERENCES [1].

Nithin Thomas, David Red mill, David Bull, “Secure transcoders for single layer video data”, Signal processing: image communication, pp, 196-207, and 2010.

[2].

Huafei Zhu, “Adaptive and Composable Multimedia transcoders”, Proceedings of the 3rd IEEE International Conference on Ubi-media computing (U-media). 10.1109/UMEDIA.2010.5543914, pp, 113 – 117, 2010.

[3].

Samit Desai, Usha B, “Medical image transcoder for telemedicine based on wireless communication devices”, Proceedings of the 3rd IEEE International Conference on Electronics Computer Technology (ICECT). Vol.01, pp, 389 – 393, 2011.

[4].

John r. Smith, Rakesh Mohan, Chung-Sheng li, “Content based transcoding of images in the internet”. Proceedings of the IEEE International Conference on Image processing (ICIP98), Vol.03, pp, 7 – 11, 1998.

[5].

Richard han, Pravin Bhagwat, Richard Lamaire, “Dynamic adaptation in an image transcoding proxy for mobile web browsing”, IEEE Personal communications.Vol.05, issue: 6, pp, 8 – 17, 1998.

[6].

Jui-Cheng Yen and Jiun-In Guo, “A new chaotic key -based design for image encryption and decryption”, Proceedings of the IEEE International Conference on Circuits and Systems, vol. 4, pp. 49-52, 2000. M. Sahithi, B. MuraliKrishna, M. Jyothi, K. Purnima, A. Jhansi Rani, N. Naga Sudha. “Implementation of Random Number Generator Using LFSR for High Secured Multi-Purpose Applications”, M. Sahithi et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 3 (1), pp, 3287-3290,2012.

[7].

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Synthesis and characterization of CdxHg1-xTe Ternary Semiconductor Thin films Prof Vedam RamaMurthy1, a, Alla Srivani 2,b , G Veeraraghavaiah3,c Prof and Head of the Department, T.J.P.S College, Guntur, Andhra Pradesh, India Assistant Professor in Vasi Reddy Venkatadri Institute of Technology (VVIT), JRF in IIT KHARAGPUR, India Assistant professor, P.A.S College, Pedanandipadu, Guntur, Andhra Pradesh, India

Abstract: Photo electrochemical deposition of CdxHg1-xTe thin films on the Se-modified Au electrode using electrochemical quartz crystal micro gravimetric (EQCM) and voltammetry is described. Corrosion of pre-deposited Te electrodes by illumination at a fixed potential resulted in Se2− species, which was manifest from the EQCM frequency changes. Se2− species generated from the photo corrosion reacted with Cd2+ and Zn2+ ions in the electrolyte to form Cd xHg1-xTe films on the Au electrode. The effect of electrolyte composition on the composition and band gap of CdxHg1-xTe films was studied in detail. Also, photo electro chemistry, EDX, Raman spectroscopy were used for the characterization of CdxHg1-xTe thin films.

Key Words: Photo electrochemistry, CdxHg1-xTe, Ternary semiconductor.

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Introduction Group 12-16 compound semiconductors are important in a wide spectrum of optoelectronic applications.1 Especially, ternary compounds including Cd xHg1-xTe have attracted much attention in the fields of solar cells due to their interesting properties of band gap modulation by composition.2-6 For example, band gap values of Cd xHg1-xTe ternary semiconductors can be varied from 1.7 eV (HgTe) to 2.7 eV (CdTe) with composition.2-4 Different methods have been used for the synthesis of ternary compounds including vacuum techniques, chemical bath deposition and electrodeposition.1-6 In particular, electro deposition is a simple and cost-effective approach, which can conveniently modulate the composition of the thin films using electrolyte composition and deposition potentials.1 Photo corrosion reaction is detrimental to the long-term stability of the photoelectrode and can be prevented by a suitable redox couple.7 As an extension to the previous studies,8,9 we utilized photo corrosion reaction to synthesize ternary semiconductor CdxHg1-xTe thin films. Photo excitation of the pre-deposited p-Se generates Se2â&#x2C6;&#x2019; under light illumination and thus generated Te2- species react with Cd2+ and Hg2+ in electrolyte to result in CdxHg1-xTe. The composition as well as band gap of the film varies with electrolyte com-position. This approach is validated using electrochemical quartz crystal micro gravimetry (EQCM) and voltammetry.

Experimental Details of the electrochemical instrumentation and the set-up for electrochemical quartz crystal microgravimetry (EQCM) are given elsewhere. 8,9 For voltammetry and film deposition, an EG&G Princeton Applied Research (PAR) 263A instrument equipped with Model M250/270 electro-chemistry software was used. For EQCM, a Seiko EG&G Model QCA 917 instrument consisting of an oscillator module (QCA 917) and a 9 MHz AT-cut gold-coated quartz crystal (geometric area, 0.2 cm2) as a working electrode were used. A Pt wire served as a counter electrode and the reference electrode was Ag/AgCl/3 M NaCl. Cadmium sulfate hydrate (purity 98+%), Tellurium di-oxide (purity 99.8%), zinc sulfate heptahydrate (purity 99%), sodium sulfate (purity 99+%) and sulfuric acid (purity 98+%) were obtained from Aldrich. All chemicals were used as received. MĂźller Elektronik-Optik halogen lamp was used as the light source. The light intensity measured on the electrode surface with the Newport 70260 radiant power meter com-bined with the 70268 probe was ~100 mW in all the experi-ments described below, and this value is uncorrected for cell reflection and electrolyte absorption losses. Raman spectra were measured using the 514 nm line of an Ar+ ion laser (HORIBA-LABRAM) at room temperature. Film morpho-logy and atomic composition of the electrodeposited Se and CdxHg1-xTe were studied by energy dispersive X-ray analyses (EDX) attached to a field emission scanning electron micro-scope (FESEM, JEOL 6700F). Interferometric reflectance spectra were obtained with an Ocean Optics R4000 spectro-meter system equipped with a fiber optic probe and a W-halogen light source. INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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Results and Discussion As a prelude to experiments on CdxHg1-xTe the deposition and photo electrochemical characteristics of Te on the Au substrate were studied in detail to complement our earlier studies.8,9 Figure 1A contains representative electro-chemical, photo-electrochemical, and EQCM data for a polycrystalline Au electrode pre-modified with Te. Te was deposited by holding an Au electrode at −0.6 V for 120 s in

0.1 M Na2SO4 electrolyte containing 10 mM TeO2. The photocurrent transients (solid line) at −0.25 V in 0.1 M Na2SO4 electrolyte are cathodic, signaling that the Te as deposited on the Au surface is acting as a p-type semi-conductor.10 Apparently, the cathodic photocurrents are accompanied by the photo corrosion of Te to Te2- which results in mass decreases (EQCM frequency increases, dashed line). It should be noted that the electrode mass is regained when the light is switched off in each cycle showing that Te0 re-deposits on the Au surface in the dark. To understand this, a combined cyclic voltammogram (CV) and EQCM is obtained for a Te modified Au electrode in 0.1 M Na2SO4. As shown in the Figure 1B, cathodic stripping of Te to Te2− is accompanied by frequency increase (mass decrease) and as-generated Te2− species re-deposit on the Au electrode again during the return scan (from ~ −0.5 V). This explains why photo generated Te2− is oxidized and re-deposited on the Au electrode in the dark. Again, frequency increase with an anodic peak at 0.8 V is due to the oxidation of Se to Se4+.11,12 Under the light illumination, electro deposited Te is stripped off due to the photocorrosion.11,13

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By contrast, addition of Cd2+ and/or Hg2+ to the electrolyte showed different frequency changes during the light illumi-

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For example, irradiation on the Te modified Au electrode in 0.1 M Na2SO4 electrolyte containing 30 mM TeSO4 at a fixed potential of -0.25 V results in frequency increase followed by a frequency decrease (Figure 3A). The frequency decrease resulted from the CdTe formation by the precipitation process: Cd2+ + Te2− (by photocorrosion) → CdTe

(1)

Unlike the p-Te, the photocurrent is anodic as shown in figure 3B diagnosing that thus formed CdTe is n-type.10,14-17 Again, the frequency changes systemically during the light on-off cycles as explained before (Figure 1A). When electrolyte contains Zn2+ ions, similar frequency changes are observed during the light illumination on the Se modified Au electrode. Figure 4A contains chronoampero-metric and EQCM data for the Se modified Au electrode under the light illumination in 0.1 M Na2SO4 electrolyte containing 50 mM ZnSO4 at a fixed potential of −0.25 V. The fixed potential of −0.25 V was selected since we observed cadmium and zinc deposition at more negative potentials in the dark. In the case of zinc, the frequency increases initially and starts to decrease, which implies the formation of CdxHg1-xTe Here, the frequency decreases from ~40 s, which is later than that of the CdTe case. We believe that this is due to the difference in solubility products of HgTe Bull. Korean Chem. Soc. 2008, Vol. 29, No. 5 941

(Ksp = 4.0

10−35) and CdTe (Ksp = 1.0

10−27).18 Figure 4B shows that HgTeformed by

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photocorrosion of Te and precipitation reaction is n-type since photocurrent is anodic.19 It should be mentioned that CdTe and HgTe synthesized from photo electro deposition is not stable in Na2SO4 blank electrolyte, which can be seen from the decay in photo-current (Figures 3B and 4B). The photo corrosion can be inhibited using a suitable photo electrolyte (redox couple). Next, CdxHg1-xTe films are synthesized by the same approach described above. When Se modified Au electrode is subjected to photo corrosion in 0.1 M Na2SO4 electrolyte containing 1 mM CdSO4 and 25 mM ZnSO4 at a fixed potential of â&#x2C6;&#x2019;0.25 V, CdxHg1-xTe films are synthesized as indicated from frequency decrease (Figure 5A). Also, photo-electrochemical behavior in Figure 5B is consistent with n-type behavior for the as-synthesized CdxHg1-xTe films.3

It is well known that band gap of CdxHg1-xTe is dependent on the film composition.3,4 The composition of CdxHg1-xTe thin films synthesized by the approach developed here is deter-mined by EDX, Raman spectroscopy and UV reflectance spectroscopy. Figure 6A clearly shows that film composition and therefore band gap can be modulated by controlling electrolyte compositions. As shown in the figure, the ratio of Hg/Cd in films increases with the ratio of Cd/Hg in electrolyte. In addition, band gap has been modulated by the

Conclusion We have demonstrated a photo electrochemical deposition of CdxHg1-xTe thin films using a Te modified Au electrode using a photo corrosion. Unlike previous studies on binary semiconductors, composition and band gap of ternary semi-conductors have been modulated by controlling composition of electrolytes. Also, we presented a new route for the synthesis of CdTe and HgTe films using a photo electro-chemical approach. Finally, EQCM combined with ampero-metry proved to be effective to study photo electrochemical behavior of binary and ternary semiconductors.

References 1. (a) Rajeshwar, K. Adv. Mater. 1992, 4, 23. (b) Lee, J.; Kim, Y.; Kim, K.; Huh, Y.; Hyun, J.; Kim, H. S.; Noh, S. J.; Hwang, C. Bull. Korean Chem. Soc. 2007, 28, 1091. 2. (a) Krishnan, V.; Ham, D.; Mishra, K. K.; Rajeshwar, K. J. Electrochem. Soc. 1992, 139, 23. (b) Chae, D.; Seo, K.; Lee, S.; Yoon, S.; Shim, I. Bull. Korean Chem. Soc. 2006, 27, 762. 3. Natarajan, C.; Nogami, G.; Sharon, M. Thin Solid Films 1995, 261, 44. 4. Chandramohan, R.; Mahaligam, T.; Chu, J. P.; Sebastian, P. J. Solar Energy Mater. Solar Cells 2004, 81, 371. 5. Loglio, F.; Innocenti, M.; Pezzatini, G.; Foresti, M. L. J. Elelctroanal. Chem. 2004, 562, 117. 6. Kaschner, A.; Strassburg, M.; Hoffmann, A.; Thomsen, C.; Bartels, M.; Lischka, K.; Schikora, D. Appl. Phys. Lett. 2000, 76, 2662. INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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7. Licht, S. In Semiconductor Electrodes and Photoelectrochemistry; Licht, S., Ed.; Wiley: Weinheim, Germany, 2002; Vol. 6, p 325. 8. Ham, S.; Choi, B.; Paeng, K.; Myung, N.; Rajeshwar, K. Electrochem. Commun. 2007, 9, 1293. 9. Ham, S.; Paeng, K.; Park, J.; Myung, N.; Kim, S.; Rajeshwar, K. J.Appl. Electrochem. 2008, 38, 203. 10. Myung, N.; de Tacconi, N.; Rajeshwar, K. Electrochem. Commun. 1999, 1, 42. 11. Rabchynski, S. M.; Ivanou, D. K.; Streltsov, E. A. Electrochem. Commun. 2004, 6, 1051. 12. Myung, N.; Wei, C.; Rajeshwar, K. Anal. Chem. 1992, 64, 2701. 13. Streltsov, E. A.; Poznyak, S. K.; Osipovich, N. P. J. Elelctroanal. Chem. 2002, 518, 103. 14. Lade, S. J.; Uplane, M. D.; Lokhande, C. D. Mater. Chem. Phys. 2001, 68, 36. 15. Kazacos, M. S.; Miller, B. J. Electrochem. Soc. 1980, 127, 2378.

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MANET: A RELIABLE NETWORK IN DISASTER AREAS K.BHARGAVA IV B.Tech, ECE BITS, ADONI.

D.KHADHAR BASHA IV B.Tech, ECE BITS, ADONI.

Abstract The role of telecommunications in disaster reduction is critical in order to improve the timely flow of crucial information needed for appropriate assistance to be delivered before, during and after the disaster. The breakdown of essential communications is one of the most widely shared characteristics of all disasters. The collapse of communications infrastructure, due to the collapse of antennas, buildings, power etc is the usual effect of disaster. This paper describes a communication network that is appropriate, suitable and reliable in any disaster: - Mobile Ad hoc Network (MANET). A mobile ad hoc network is formed dynamically by an autonomous system of mobile nodes that are connected via wireless links without using the existing network infrastructure or centralized administration. The ease of deployment and infrastructure less nature of the network are some of reasons why MANET is recommended in disaster area. operations. One solution to this problem is the use of wireless communication systems.

Introduction Disasters are of varying intensity and occurrence ranging from less frequent like earthquake, volcanic eruption to more frequent like floods, fire, drought, cyclones, landslides besides industrial reaction and epidemics. Disasters kill at least one million people each decade and leave millions more homeless (ITU, TDBEC). When disaster strikes, communication link are often disrupted, yet for disaster relief workers, these links are essential in order to answer critical questions as to how many people have been injured or died, where the injured are located and the extent of the medical help needed. In disaster and emergency situations, communications can save lives. The collapse of communications infrastructure, due to the collapse of antennas, buildings, power etc is the usual effect of disaster. The breakdown of essential communications is one of the most widely shared characteristics of all disasters. Whether partial or complete, the failure of communications infrastructure leads to preventable loss of life and damage to property, by causing delays and errors in emergency response and disaster relief efforts (Townsend and Moss, 2005). Yet despite the increasing reliability and resiliency of modern communications networks to physical damage, the risk associated with communications failures remains serious because of growing dependence upon these tools in emergency

In wireless networking, there are two main architectures: infrastructure networks and mobile ad hoc networks (MANETs). Infrastructure networks include cellular networks and wireless local area networks. Users are connected via base stations/access points and backbone networks. Although users can handover between base stations or access points and roam among different networks, their mobility is limited within the coverage areas of the base stations or access points. This is illustrated in figure. Ad hoc networks on the other hand, exclude the use of a wired infrastructure. Mobile nodes can form arbitrary networks â&#x20AC;&#x153;on the flyâ&#x20AC;? to exchange information without the need of pre-existing network infrastructure. Ad hoc networks can extend communication beyond the limit of infrastructure-based networks. A mobile ad hoc network (MANET) is defined by the Internet Engineering Task Force (IEFT) as an autonomous system of mobile nodes connected by wireless links in which each node operates as an end system and a router for all other nodes in the network (IETF, MANET). As illustrated in figure 2, it is a collection of wireless mobile nodes which dynamically form a temporary network without the aid of any established infrastructure or centralized

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administration. These characteristics make MANET suitable for mission-critical applications, such as disaster recovery, crowd control, search and rescue and automated battlefield communications. In a general mobile network which consists of wireless access networks and interconnecting backbone networks, the mobile terminals are connected to the base stations (access points) by wireless access networks, and the base stations are connected to the wired backbone networks (Woerner, and Howlader, 2001). There are drawbacks to these systems when large-scale disasters, such as earthquakes, occur. Communications may be impossible if the base stations or other elements of the infrastructure comprising these networks are damaged by disasters. Even if the infrastructure is not damaged, spikes in traffic and congestion may render communication virtually impossible. It is very important and necessary that communication networks be restored in such areas. Repairing the infrastructure could be time wasting, expensive and

lead to unnecessary loss of lives and property. The use of Mobile ad hoc network in such disaster areas becomes imperative. The ease and speed of deployment, cost effectiveness of setting up a MANET, its outstanding terminal portability and mobility makes mobile ad hoc network of great use in disaster areas (Bauer et al, 2004). Communication and sharing of information in emergencies are important and should not be taking lightly as lives could be either lost or saved depending on the actions taken. MANET can enable communication among temporarily assembled user terminals without relying on the conventional communication infrastructure. Therefore, it is important to configure a communication network that offers sufficient QoS after a catastrophic disaster using an ad hoc network to help protect people. We therefore present an overview of Mobile Ad hoc Network (MANET), its characteristics and features that render it highly useful and reliable in disaster areas.

Figure 1: Infrastructure wireless network.

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Figure 2: Mobile infrastructure-less wireless network Manet features MANET has the following features that make it a useful and reliable network in disaster areas: Autonomous terminal: In MANET, each mobile terminal is an autonomous node, which may function as both a host and a router. In other words, besides the basic processing ability as a host, the mobile nodes can also perform switching functions as a router. So usually endpoints and switches are indistinguishable in MANET (Abolhassan, Wysocki and Dutkiewicz , 2004). Distributed operation: The control and management of the network is distributed among the terminals since there is no access point or base station for the central control of the network operations. (Chakrabarti and Mishra, 2001)The nodes involved in a MANET should collaborate amongst themselves and each node acts as a relay as needed, to implement functions e.g. security

and routing. Ease of deployment: MANET does not depend on any established infrastructure or centralized administration. Each node operates in distributed peer-to-peer mode, acts as an independent router and generates independent data. This make it possible to apply Ad hoc networking anywhere there is little or no communication infrastructure or the existing infrastructure is expensive or inconvenient to use. Ad hoc networking allows the devices to maintain connections to the network as well as easily adding and removing devices to and from the network (Corson and Maker, 1999). Multihop routing: Basic types of ad hoc routing algorithms can be single-hop and multihop, based on different link layer attributes and routing protocols. In MANET, there are no default router available, every node acts as a router and forwards each otherâ&#x20AC;&#x2122;s packets to enable information sharing between mobile hosts (Murthy and Garcia, 1996) Dynamic network topology: Since the nodes are mobile, the network topology may change rapidly and unpredictably and the connectivity among the terminals may vary with time. MANET adapts to the traffic and propagation conditions as well as the mobility patterns of the mobile network nodes (Royer and Tohc, 1999). The mobile nodes in the network dynamically establish routing among themselves as they move about, forming their own network on the fly. Network scalability. Currently, popular network management algorithms were mostly designed to work on fixed or relatively small wireless networks. Many mobile ad hoc network applications involve large networks with tens of thousands of nodes, as

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found for example, in sensor networks and tactical networks. Scalability is critical to the successful deployment of these networks (Campbell, Conti and Giordano, 2003). The steps toward a large network consisting of nodes with limited resources are not straightforward, and present many challenges that are still to be solved in areas such as: addressing, routing, location management, configuration management, interoperability, security, high capacity wireless technologies, etc. Light-weight terminals: In most cases, the MANET nodes are mobile devices with less CPU processing capability, small memory size, and low power storage (Chang and Tassiulas, 2000). Such devices need optimized algorithms and mechanisms that implement the computing and communicating functions.

MANET applications The application of MANET system is not only limited to disaster areas but with the increase of portable devices as well as progress in wireless communication, ad hoc networking is gaining importance with the increasing number of widespread applications. Ad hoc networking can be applied anywhere there is little or no communication infrastructure or the existing infrastructure is expensive or inconvenient to use. The set of applications for MANETs is diverse, ranging from large-scale, mobile, highly dynamic networks, to small, static networks that are constrained by power sources. Table 1 gives a brief description of the various application areas of MANET.

Table 1: Mobile Ad hoc Network Applications Application Possible Services Emergency Services  Search and rescue operations Disaster recovery  Replacement of fixed infrastructure in case of environmental  disasters Policing and fire fighting  Supporting doctors and nurses in hospitals   Tactical Networks Military communications and operations  Automated battlefields Commercial and Civilian  E-commerce: electronic payments anytime and anywhere environments

Home

and

networking

Education

Entertainment

Sensor networks

 

Business: dynamic database access, mobile offices Vehicular services: road and accident guidance, transmission of road and weather conditions, taxi cab network  Sports stadiums, trade fairs, shopping mails enterprise  Home/office wireless networking

         

Conferences, meeting rooms Personal area networks (PAN), Personal networking (PN) Networks at construction sites Universities and campus settings Virtual classrooms Ad hoc communications during meetings or lectures Multi-user games Outdoor internet access Robotic pets Home applications: smart sensors and actuators embedded in consumer electronics  Data tracking of environmental conditions, animal movements, chemical/biological detection  Body area networks (BAN)

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Bluetooth

Figure 3: Bluetooth range

standards are emerging for ad hoc wireless networks: the IEEE 802.11 standard for WLANs, and the Bluetooth specifications for short-range wireless communications (IEEE 802.11,WLAN)

The Bluetooth system can manage a small number of low-cost point-to-point, and point-to-multi -point communication links over a distance of up to 10 m with a transmit power of less than 1 mW. It operates in the globally available unlicensed ISM (industrial, scientific, medical) frequency band at 2.4 GHz and applies frequency hopping for transmitting data over the air using a combination of circuit and packet switching (Conti, 2003). The Bluetooth technology is a de-facto standard for low-cost, short-range radio links between mobile PCs, mobile phones, and other portable devices. The Bluetooth Special Interest Group (SIG) releases the Bluetooth specifications. Bluetooth specifications were established by the joint effort from over two thousand industry leading companies including 3Com, Ericsson, IBM, Intel, Lucent, Microsoft, Motorola, Nokia, Toshiba, etc. under the umbrella of Bluetooth SIG. In addition, the IEEE 802.15 Working Group for Wireless Personal Area Networks approved its first WPAN standard derived from the Bluetooth Specification. The IEEE 802.15.1 standard is based on the lower portions of the Bluetooth specification (IEEE 802.15, WPAN). A Bluetooth unit, integrated into a microchip, enables wireless ad hoc communications, of voice and data between portable and/or fixed electronic devices like computers, cellular phones, printers, and digital cameras (IEEE 802.16, WG). Due to its low-cost target, Bluetooth microchips may become embedded in virtually all consumer electronic devices in the future.

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Conclusion Mobile Ad hoc Network can be used in emergency/rescue operations for disaster relief efforts, e.g. in fire, flood, or earthquake. Emergency rescue operations take place where non-existing or damaged communications infrastructure and rapid deployment of a communication network is needed. Information is relayed from one rescue team member to another over a small handheld device.

This paper has provided a comprehensive overview of a network that is reliable for, and recommended to be used in disaster areas,

Most of the times, disaster don’t announce themselves and people are usually caught unaware, the establishment of infrastructure communication network will almost be impossible especially in remote areas where one had never existed, therefore, MANET offers the best approach to the solution in terms of communications and the importance of communications during a disaster cannot be over emphasized.

Bauer J, Lin Y, Maitland C, Tarnacha A (2004), “Transition Paths to Next-Generation Wireless Services.” 32nd Research Conference on Communication, Information and Internet Policy. http://quello.msu.edu/wp/wp-04-04.pdf

References Abolhassan M, Wysocki T and Dutkiewicz E (2004), “A review of routing protocols for mobile ad hoc networks”, Ad Hoc networks 2(1), pp 1-22.

Cali F, Conti M, Gregori E (2000), “Dynamic tuning of the IEEE 802.11 protocol to achieve a theoretical throughput limit”, IEEE/ACM Transactions on Networking 8 (6) 785–799. Campbell A, Conti M., and Giordano S (2003), “Special issue on mobile ad hoc network”, ACM/Kluwer MONET 8 (5). Chakrabarti S. and Mishra A. (2001), “QoS issues in ad hoc wireless networks,” IEEE Communications Magazine, 39(2), pp. 142–148. Chang J and Tassiulas L. (2000), Energy conserving routing in wireless ad-hoc networks, in: Proceedings of IEEE INFOCOM, pp. 22–31.

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Energy Management of Induction Motor Using Time Varying Analysis S.Sankar[1],M.Sakthi[2],J.SuryaKumar[3],A.DineshBabu[4],G.Sudharsan[5]

current spike also has the effect of lengthening the motor life because the current spike alone would cause increased wear and tear on the motor compared to a DC input.

ď&#x20AC; Abstractâ&#x20AC;&#x201D;This paper describes an induction motor drive using a pulse width modulated signal with energy conservation system. The op-amp capabilities of a microcontroller are used to realize a very inexpensive and efficient controller. The design of the entire system is the industrial machineries performance improvement by analyzing and designing the induction motor optimal stator current controller, this will minimize the stator current under different loading conditions. The output load current controlled and the energy of induction motor is operated using the op-amp based closed loop control system.

The controller also uses a quadrature encoder in order to allow the user to input the desired speed of the motor into the system [3]. The microcontroller will be the main circuit component between the user input from the quadrature encoder and the motor, which will read the input from the quadrature encoder and create a comparative signal based upon the desired speed of the motor. The comparative signal will be output through the low pass filter to the motor. The output voltage from the tachometer will be fed back to the PIC and used to adjust the speed of the motor to the desired speed and forming a feedback loop in the system.

Index Terms: Induction motor, Energy conservation, microcontr oller, comparator.

I. INTRODUCTION The induction motor is a simple and robust machine, but its control might be a complex task when managed directly from the line voltage, the motor operates at nearly a constant speed. To obtain speed and torque variations, it is necessary to modify both the voltage and the frequency. Following this was the realization that the ratio of the voltage and frequency should be approximately constant [1].

The realized system is set up to give speed feedback to the user as well as the controller. When the system is operating, the red LED on the control board will be lit when the maximum duty cycle fed into the motor. This indicates that the motor cannot spin any faster than the current speed. This allows the user to know when the maximum speed has been reached for an applied motor load [4].

The induction motor has also disadvantages that it has more losses and less efficiency when it works at variable speeds. The need of efficient drive systems was achieved by special controllers that not only modify the losses and efficiency, but also searching for the optimal values of stator current to reduce the power consumption from the source to be minimum [2]. The trends of designing optimal controllers was developed due to the increasing in power consumption, which represents the most important problem in the world due to the decreasing in power resources in the last few decades. The studies proved that there is a possibility to decrease the power consumption and increase the efficiency in the induction motor.

The motor speed is increased with counterclockwise rotation of the quadrature encoder knob and decreased with clockwise rotation of the knob. When the knob is pushed, the yellow LED on the control board is lit; otherwise the pushbutton is not utilized for this project. The default speed of rotation when the system is reset is 20 rpm. The maximum and minimum speeds are 32 and 10 rpm, respectively.

III.

OPEN LOOP SYSTEM OF INDUCTION MOTOR

The low pass filter to run the motor is needed in order to increase the efficiency of the motor. The increase in efficiency is due to the reduction in the current spike applied to the motor on every rising edge of the control signal [5]. The rounding off of the current spike also has the added benefit of increasing the lifetime of the motor compared to a motor run with a control mode but no low pass filter. In order to determine the values of the components for the low pass filter, the operating frequency had to be determined first. After searching the internet, the following equation was found for calculating the fundamental operating frequency for running the motor [6].

II. SIMULATION MODEL OF ENERGY SAVING OF INDUCTION MOTOR

In order to improve efficiency of the driving signal, the signal is passed through a low pass filter to smooth the signal and round out the current spike that is applied to the motor on every rising edge of the comparator signal. Rounding out the Dr.S.Sankar is a Professor in Dept. of EEE, Panimalar Institute of Technology Chennai*, ssankarphd@yahoo.com

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R P    2 L  ln  1   100   D13 D10

MUR130

MUR130 R1 X3

L1 1

2.5

2 2.1m

MCR230M D11

V1 VOFF = 0 VAMPL = 230 FREQ = 50

D12

MUR130

0.012

21.8

1 L2

0.1328

U1 MCT2E

V3 R4 10Vdc

V1 = 0 V2 = 20 TD = 7m TR = 1n TF = 1n PW = 2m PER = 10m

0.012

0.1315

1 L4

0.1328

0 0

Fig.1. Energy saving of induction motor

the 1 kHz frequency. This proved that the frequency and component values provided the desired motor response and a wide operating range.

Where R is the resistance of the motor, L is the inductance of the motor, and v1 is the magnitude of input voltage.

The AC voltage that the motor runs on is 230V. The maximum voltage that the motor will be run with in this project is 30V; this is due to the ease of design and reduces the amount of voltage inputs necessary to the board. The motor has a built in tachometer that ranges from 10V to 230V. The peak output voltage for the 180V input is 230V. The motor draws a maximum current of 5.11A at stall and has an inductance of 73.8mH. The motor also has a 96:1 gear ratio and can produce up to 5.0 oz x in of torque (85.4 mN x m). In order to determine the constant for converting the tachometer value to rpm of the motor, experimental data was gathered. Experiments running the motor also show that the motor stalls at a 98% duty cycle and runs at peak speed between 0% and 15% duty cycle.

For the motor used R1=2.5Ω and L1=2.1mH. This gives a frequency of 50Hz using 50% efficiency. From the controller 50HZ frequency of 1.22 kHz is available [7]. The simulation circuit of open loop controlled system is as shown in the Fig.1.By the variation of firing angle alpha at 40°. The peak output voltage and current is as shown in the Fig.2. The simulation was also run at a comparator frequency of 10 kHz to provide an additional set of test data. The R and L values needed for the desired output were found to be 7.8kΩ and 6mH, respectively. The low pass filter circuit was constructed on a breadboard and tested with the motor to ensure that the motor would run efficiently. The motor was found to run at varying speeds from 15% to 98% duty cycle. The circuit was also tested at 10 kHz and the motor was operated at varying speed from 50% to 75% duty cycle, with these speeds being slower than those for

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The incoming analog signal must be within 0 to 5V. This means that each digital number corresponds to about 0.0195V. The maximum tachometer value from the motor running at 15V is 6.2V. A potentiometer is used as a voltage divider in order to give a maximum output value of 5V when the tachometer gives 6.2V. The operating firing angle of alpha at 1400 is as shown in the Fig.4.It shown that the Peak to Peak output voltage and output current waveform.

1 0A

SEL >> -1 0A I(R 1) 40 0V

200V

-40 0V 0s

10m s V(D 13: 1,0)

20m s

30ms

40ms

50ms

6 0ms

7 0ms

8 0ms

90 ms

1 00ms

Time

Fig.2.Peak to Peak output of voltage and current waveform at alpha1400 SEL>> -200V

In order to drive the motor using the modulated signal, a FET switch was used to provide the current that the PIC alone would not be able to do. The FET is an IPS5551T and the datasheet shows that the switch can easily handle the max current draw from the motor (7.11A) with a max current output of 8A at 85°C. The switch inverts the duty cycle from the controller during operation. This makes 98% duty cycle the slowest drive cycle instead of 2% as expected. It should be noted that the FET has to sink a large amount of current when the motor is running at a slow speed. This is the reason that the program allows a minimum speed of 10 rpm. The program could easily be modified for slower speeds, but a heat sink for the FET would be required.

V(D13:1,0) 5.0A

-5.0A 0s

10ms

20ms

30ms

40ms

50ms

60ms

70ms

80ms

90ms

100ms

I(R1) Time

Fig.4.Peak to Peak output voltage and current waveform

The tachometer value is now within 0 to 5V and can be fed into the ADC port on the controller. The conversion factor to give the speed of the motor must now be modified so that the controller will have an accurate speed value from the motor. The original conversion factor of 5.0375 must be multiplied by 0.0195 to convert the digital number to a voltage. The conversion factor must also be multiplied by 6.2/5 in order to take into account the voltage reduction of the potentiometer. Multiplying all three numbers together gives a conversion factor of 0.12 for the controller.

The microcontroller is able to output a maximum of 5V for the op-Amp controller. This voltage is 10V below the 15V source voltage on the FET. The difference between the two must be less than 4V when the modulated signal is high in order for the FET to switch. In order to solve this problem, an op amp with a non-inverting gain was added to increase the maximum modulated voltage to about 12V. The resulting voltage level is sufficient to allow normal switching on the FET. The RMS output voltage and output current waveform is as shown in the Fig.3.

2.0A (158.636m,1.6610)

1.0A

10. 0A (81 .03 6m,7 .340 4)

SEL>> 0A RMS(I(R1)) 50V (158.636m,41.636)

5. 0A

SEL >> 0A

25V RMS (I( R1))

20 0V (81 .036 m,15 7.9 26)

0V 0s

10 0V

20ms RMS(V(D13:1,0))

40ms

60ms

80ms

100ms

120ms

140ms

160ms

180ms

200ms

Time

Fig.5.RMS output of voltage and current waveform 0V 0s

10m s RMS (V( D13: 1,0) )

20m s

30ms

40ms

50ms

6 0ms

7 0ms

8 0ms

90 ms

In order for the tachometer to be accurately read at slow motor speeds, a decoupling capacitor must be used to decouple the tachometer from the “AC” input to the motor. Of RMS output voltage and current is shown in Fig. 5. The capacitor value is large because a 1μF capacitor did not sufficiently smooth the voltage reading and 100μF was the next largest readily available capacitor value that sufficiently smoothed the motor output. The modulated signal of input to the motor causes the output of the tachometer to not be smooth while using a AC

1 00ms

Time

Fig.3. RMS output of voltage and current waveform

In order to create a feedback loop between the controller and the motor, the PIC must be able to read the tachometer on the motor and transform the data to the speed of the motor. The controller has built in analog-to-digital converter (ADC). From experiments provided with the controller board, the data on the ADC port is stored as a number between 0 and 256.

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voltage to drive the motor would give a smooth tachometer output. The modulated final output of Peak to Peak output voltage and current waveform is as shown in the Fig.6.

(83.636m,2.6101) 2.0A

10A

1.0A

0,-16.662p) SEL>> 0A RMS(I(R1)) 80V

(83.636m,62.122)

SEL>> -10A

40V

I(R1) 200V

0V 0s

10ms RMS(V(D13:1,0))

20ms

30ms

40ms

50ms

60ms

70ms

80ms

90ms

100ms

Time

Fig.7.RMS output voltage and current waveform

-200V 0s

10ms V(D13:1,0)

20ms

30ms

40ms

50ms

60ms

70ms

80ms

90ms

100ms

Time

Fig.6. Peak to Peak output voltage and current waveform

The RMS value of output voltage and output current waveform is as shown in the Fig.7. D13 D10

MUR130

X3 H1 +

MCR230M

D11

V1 VOFF = 0 VAMPL = 230 FREQ = 50

D12

MUR130 R13

+ -

100

E V4

R8 R7

1k 1.5

1k V3

U1 MCT2E

R10 R9

10Vdc U2

OUT

OPAMP

U3 OUT

V5 +

E3 2 + -

3 1

0 0

OPAMP

+ -

R12 1k

120

E V6

AND2 V1 = 0 V2 = 10 TD = 0 TR = 0.1n TF = 0.1n PW = 7m PER = 10m

0 TD = 0 TF = 7.7m PW = 0.01n PER = 10m V1 = -10 TR = 0.1n V2 = 10

Fig.8. Closed loop control of IM

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way that the probability of one outlier occurrence within the window should be very low. In the other words, the aim of  value determination is the detection of impulsive noise occurences. By a proper sliding window length selection, a significiant difference between the value of med{ | e( k ) | nH } and mean{ | e(k ) | nH } , in the case of

4.0V

2.0V

SEL>> 0V V(X3:G,X3:K) 10A

impulsive noise occurrence, is achieved. When choosing the constant c one should take into account that its value should rise with additive Gaussian noise variance, in order to minimise the false detection probability of outliers. On the other hand, the value of c should not be very large, in order to be able to detect outliers with lower ampltudes. The proposed algorithm, in essence, represents the PA-RLS and RRLS algorithm combination, in such a way that PA-RLS is dominant almost all the time, due to the fact that the most of the measurement residual data is normaly distributed. PA-RLS tracks efficiently the changing values of estimated filter parameters and accordingly updates the value of FF. At the moment of outlier detection,  assumes the value 1, implying RRLS algorithm appliction. In addition, VFF retains the previous value in subsequent nH samples, which is necessary for the mean calculation to be insensitive to detected outlier. In the other words, a detected outlier has to be outside the sliding data window, since mean value is very sensitive to its presence. On contrary, median represents a robust estimate insensitive to outliers [7]. Thus, in situations when outlier is presented, the discrepancy between the calculated values of median and mean will be very large, representing a basis for outlier detection.

-10A 0s

50ms

100ms

150ms

200ms

250ms

300ms

I(H1:1) Time

Fig.9.Output current and triggering pulses

The controller was designed after the system had been fully bread-boarded, but before the software had been fully implemented. At this point in time, the potentiometer had not been added to the circuit in order to reduce the 6.2V maximum tachometer output to 5V. This is the reason that it is not included in the schematics.

ˆ )   J (W ˆ )  (1   ) J ( W ˆ) J (W r 

(1)

where  is a scalar parameter with values 0 or 1. When   1 , (14) reverts to the error norm (8) of the RRLS algorithm, whereas for   0 , (1) becomes the error norm for the PA-RLS algorithm. Thus, a careful choice of  provides a mechanism to migrate the disturbance problem of outliers at the RRLS algorithm. However, due to impulsive noise being sparse, and since the parameter changes can be continuous, it is preferable for PA-RLS algorithm to dominate almost all the time, and that RRLS algorithm is active only at the intervals for which the impulsive noise is detected. Namely, if applied impulsive noise has model of the form used and the component of n(k) belonging to the impulsive noise can be defined as n( k )   ( k ) A( k ) , where  ( k ) is a binary independent identically distributed occurrence process with the probability P[ (k )  1]  c, P[ ( k )  0]  1  c , and c is the arrival probability whereas A( k ) is a process with symmetric amplitude distribution which is uncorrelated with  ( k ) . Starting from such additive noise structure, we propose the following strategy for  selection

1, c  med    0, c  med 

 

e( k ) n

e(k ) n

  mean e(k )    mean e(k )  nH

0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0

500

1000

1500

2000

2500

3000

Fig. 10 Time-varying parameter

In simulations only the first FIR filter parameter is changed. This change is defined in the Fig. 10. The parameter value remains constant and equal 0.1 for the first 1100 steps and then rises linearly to reach 0.4 at step 1400. After decreasing abruptly at step 1650 and remaining equal 0.1 for 300 steps, it increases linearly twice as fast as before. For the last 300 steps it experiences abrupt change, as shown in Fig 10. In Fig. 11 is shown the simulation results before compensation. As seen from Fig. 12 the Sag of 50% is considered in all phases of the terminal voltages for five cycles. The simulation results for both the conventional topology and the proposed modiﬁed topology are presented in

(2)

Here c is a proportionality constant, depending on the variance of nominal Gausian component of noise n(k) and impulsive contamination noise variance. Median of error signal, med{ | e( k ) | n } , and mean of error signal, H

mean{ | e(k ) | nH } , are calculated on sliding window of length nH . The length of sliding window is selected in such a

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this section for better understanding and comparison between both the topologies. The load currents and terminal (PCC) voltages. The terminal voltages are also unbalanced and distorted because these load currents. Simulation results before compensation (a) load currents (b) terminal voltages.

The load voltages after compensation are shown in Fig. 13 along with the phase-a source voltage. The sag in the source voltages are mitigated by the series active ﬁlter injected voltages, and the load voltages are maintained to the desired voltage. The ﬁlter currents which are injected into the PCC to make the source currents balanced and sinusoidal. The source currents after compensation. The source currents are balanced and sinusoidal, though the switching frequency components IV. CONCLUSION The efficiency optimization is very much essential not only to electrical systems, it require all the systems to get beneficial in terms of money and also reduction in global warming. This paper presented energy conservation of induction motor and a review of the developments in the field of efficiency optimization of three-phase induction motor through optimal control and design techniques. Optimal closed loop control covered both the broad approaches namely, loss model control and search control. Optimal design covers the design modifications of materials and construction in order to optimize efficiency of the motor. References [1] R. Fei, E. F. Fuchs, H. Haung, “Comparison of two optimization techniques as applied to three-phase induction motor design, ” IEEE/PES winter meeting, new York, 2008.

Fig .11.Simulation results before compensation

[2] K. Schittkowski, “NLPQL: a Fortran subprogram solving constrain and nonlinear programming problems,” Annals of Operation Research, Vol. 5, 2005, pp. 485-500. [3] J. Faiz, M.B.B. Sharifian, “Optimal design of three-phase Induction Motors and their comparison with a typical industrial motor, ” Computers and Electrical Engineering, vol. 27, 2009, pp. 133-144. [4] O. Muravlev, et al, “Energetic parameters of induction Motors as the basis of energy saving in a variable speed drive,” Electrical Power Quality and Utilization, Vol. IX, No. 2, 2009. [5] Christian Koechli, et al, “Design optimization of induction motors for aerospace applications,” IEE Conf. Proc. IAS, 2008, pp. 2501-2505. [6] W. Jazdzynski, “Multicriterial optimization of squirrel-cage induction motor design, ” IEE Proceedings, vol. 136, Part B, no.6, 2009.

Fig.12.Sag of 50% is considered in all phases of the terminal voltages for five cycles

[7] K. Idir, et al, “A new global optimization approach for induction motor design,” IEEE Canadian Conf. Proc. Electrical and Computer Engineering, 2007, pp. 870-873.

The load voltages are maintained to the desired voltage using series active ﬁlter. The voltage across the inductor is the peak-to-peak voltage is 560 V, which is far lesser than the voltage across the inductor using conventional topology.

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ELECTROCHEMICAL MACHINING OF SS 202 Bharanidharan1,Jhonprabhu2 Department of Mechanical Engineering M.Kumarasamy college of Engineering, Karur -639 113 Email: bharanidharan1021@gmail.com, bharanivijay11@gmail.com

ABSTRACT

Decreased and then the electrode

The aim of this project is to study

distance is increased the material

the material removal rate in an

removal rate increased. The voltage

electrochemical machining process

increased

of SS 202 material. When the

removal rate is increased. So the

electrodes are immerged in the

material removal rate is dependent

electrolyte

are

upon

and

distance.

removed

the from

electrons the

anode

means

the

voltage

immerged

deposited in the electrolytic tank.

Results

After taken the first reading the

removal rate is dependent on three

electrode

factors

immerged

the

indicated that

material

electrolyte again with high distance.

1) Power supply,

So the electrons are removed from

2) Distance between anode and

the anode for the given distance.

cathode,

The electrode distance also varied.

3) Depth of immersion.

When the immersion depth is increased the material removal rate

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CHAPTER-1

studied by measuring the limiting

INTRODUCTION

current of the anodic dissolution of a vertical copper cylinder in phosphoric

IMPORTANCE OF ECM:

acid.

In electro chemical machining process there is no residual stress induced in the work piece. But other

amplitude

oscillation,

and

phosphoric

acid

conditions,

electrode

rate of anodic dissolution up to a

low voltages compared to other

maximum of 7.17 depending on the

processes with high metal removal can

and

oscillation was found to enhance the

no tool wear; machining is done at

dimensions

were

frequency

range

residual stress are induced. There is

small

studied

concentration. Within the present

machining process like lathe the

rate;

Parameters

operating

conditions.

The

mass

transfer coefficient of the dissolution

controlled; hard conductive materials

of the oscillating vertical copper

can be machined into complicated

cylinder in H3PO4 was correlated to

profiles; work piece structure suffer

other parameters by the equation:

no thermal damages; suitable for mass production work and low labour

Sh=0.316Sc0.33Rev0.64.The

requirements.

importance of the present study for increasing the rate of production in

CHAPTER-2

electro polishing and electrochemical

LITERATURE REVIEW

machining,

M.H. Abdel-Aziz - May 2014:

electrometallurgical processes limited

and

other

by anode passivity due to salt The effect of electrode oscillation on

formation such as electro refining of

the rate of diffusion-controlled anodic

metals was highlighted.

processes such as electro polishing and electrochemical machining was

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F. Klocke â&#x20AC;&#x201C; 2013:

validated by the example of a compressor blade. Finally a new

In order to increase the efficiency

approach for an inverted cathode

of jet engines hard to machine

design process is introduced and

nickel-based and titanium-based

discussed.

alloys are in common use for aero engine components such as blades

and

integrated

blisks

(blade

disks).

Electrochemical

M. Burger - January 2012: Nickel-base

Here

single-crystalline

materials such as LEK94 possess

Machining

excellent

thermo-mechanical

(ECM) is a promising alternative

properties

to milling operations. Due to lack

combined with low density compared

of appropriate process modeling

to similar single-crystalline materials

capabilities

used in aero engines. Since the

beforehand

still

high

temperatures

components of aero engines have to

knowledge based and a cost

fulfill demanding safety standards, the

intensive cathode design process

machining of the material used for

is passed through.

these components must result in a high geometrical accuracy in addition

Therefore this paper presents a multi-physical

approach

modeling

ECM

the

to a high surface quality. These

for

requirements can be achieved by

material

electrochemical

removal process by coupling all

electrochemical

relevant conservation equations.

(ECM/PECM). In order to identify

The resulting simulation model is

proper

machining

PECM

the

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and

precise machining

parameters

for

electrochemical

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characteristics

dependent

the

microstructure

and

the

chemical

homogeneity

LEK94

CHAPTER-3 ELECTROCHEMICAL

are

MACHINING PROCESS:

investigated in this contribution. The current density was found to be the major machining parameter affecting the surface quality of LEK94. It depends on the size of the machininggap, the applied voltage and the electrical electrolyte densities

conductivity used. yield

Low

the

current

inhomogeneous

electrochemical

dissolution

different micro structural areas of the

fig.3.1

material and lead to rough surfaces.

In ECM, the principles of electrolysis

High surface qualities can be achieved

are used to remove metal from the

work pieces. FARADAY’S LAWS of

employing

electrochemical

homogenous

dissolution,

which

electrolysis may be stated as: “the

can be undertaken by high current

weight of substance produced during

densities.

special

electrolysis is directly proportional to

electrode was developed for the

the current which passes the length of

improvement of the quality of side-

time of the electrolysis process and

gap machined surfaces.

the equivalent weight of the material,

Furthermore,

which is deposited”. The work piece is made the anode and the tool is made the cathode. The electrolyte is

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filled in the beaker. As the power

3.1 Experimental setup:

supply is switched on and the current flows through the circuit, electrons are removed from the surface atoms of

work

piece.

These

can

get

deposited in the electrolytic tank. After applying current the electron will move towards the work piece and also the settles down in the bottom. The tool is fed towards the fig.3.1A

work piece automatically at constant velocity to control the gap between

COMPONENTS:

the electrodes the tool face has the

Power supply

reverse shape of the desired work

Work piece

piece. The sides of the tool are

Tool

insulated to concentrate the metal

Electrolyte and Electrolytic tank

removal action

3.2 POWER SUPPLY:

at the bottom face of the tool. The

The range of voltage on

dissolved metal is carried away in the

machine 240 volts A.C. In the ECM

flowing

positive

method a constant voltage has to be

supply is supplied to Stainless Steel

maintained. At high current densities,

202 material.

the metal removal rate is high and at

electrolyte.

The

low current densities, the metal removal rate is low. In order to have a metal

removal

of the

anode

sufficient amount of current has to be given. The Power supply is one of the

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main sources in our project. Because

PHYSICAL PROPERTIES:

of the material removal rate is calculated depends on amount of

PROPERTY

power supplied to the work piece.

VALUE

Density

3.3WORKPIECE:

7.80 g / cm3

The work piece is stainless steel 202.it is a general purpose stainless steel. Decreasing nickel content and increasing manganese results in weak corrosion resistance.

17Ă&#x2014; 10-6 /

Thermal expansion Modulus

k of

Elasticity

200 GPa

Thermal Conductivity

15 W / mk

MECHANICAL PROPERTIES: PROPERTY VALUE

fig.3.2

Length of the ss 202 = 35.7cm

Proof Stress

Diameter of the ss202 = 0.8cm

MPa

PROPERTIES: SS202

310

Tensile Strength Material

655 MPa

selected as anode based on

Elongation

40 %

different properties.

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3.4 Tool:

3.5 Electrolyte:

The tool is iron. At increasing the

The electrolyte is hydrochloric acid.

carbon content of the iron will

Boiling, melting point, density and ph

increase the tensile strength and iron

depends on the concentration. It is a

hardness. The iron is suitable for

colourless and transparent liquid,

cathode and easily reacts with anode.

highly corrosive, strong mineral acid.

Length of the iron = 15cm

HCL is found naturally in gastric acid.

Diameter of the iron = 1cm

The HCL is highly concentrated. In that process amount of HCL is 550ml.

fig.3.4

fig.

3.6 Electrolytic tank:

Low pressure Phase diagram of iron

Length of the tank = 20 cm Height of the tank = 12.5 cm

fig.3.3

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S.NO

3. EXPERIMENTAL

VOLTAGE (Volts)

ELECTROCHEMICAL

MATERIAL

(Min)

ELECTRODE DISTANCE (cm)

TIME

REMOVAL RATE(cm3 min-1)

MACHINING 1.

240

1.191

CONSTANT POWER

240

1.186

SUPPLY

240

1.157

CALCULATION FOR

3.1. TABULATION 1: The S.NO

VOLT AGE (Volts)

TIM E

IMMER GEDDIS TANCE

(Min) (cm)

MATER IAL

Table.2 material removal

rate

calculated by electrode distance of

REMO VALRA TE(cm3 min-1)

anode and cathode. 240 V current supply is input for the anode and cathode. The supply 240 V current is

240

2.8

1.191

240

3.1

1.186

240

6.5

1.157

removal

rate

constant. The MRR is calculated after 15 minutes by using the formulas.

The

material

3.2. FORMULAE USED: MATERIAL REMOVAL RATE:

It is a ratio between volume of work

calculated by immerging distance of

piece to time taken for the material

anode and cathode. 240 V current

removal.

supply is input for the anode and cathode. The supply 240 V current is

MRR = (VOLUME OF WORK

constant. The MRR is calculated after

PIECE) / (TIME TAKEN)

15 minutes by using the formulas.

UNIT: cm3 /min

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Volume of work piece:

MRR VS ELECTRODE DISTANCE

V = πr h r - Radius of the work piece, h Length of the work piece

20 10 0

MRR VS ELECT RODE DIST…

3.3. Calculation: Volume of removed material, V= πr2h

IMMERGED DISTANCE VS… 1.2

V = π× (0.39)2×2.8 V = 0.4778×2.8 3

IMME RGED DISTA NCE VS…

1.15

V =1.34 cm

1.1

Volume of remaining

2.8 3.1 6.5

Material, V= πr2h

Fig 10 & 11

V= π× (0.4)2×32.9

When the immerged distance is

V= 0.5026× 32.9

increased the material removal rate

V= 16.53 cm3

decreased

Total volume = Volume of removed

When

material + Volume of remaining

the

electrode

distance

increased the material removal rate

material = 1.34 + 16.53

increased.

= 17.87 cm3

4. EXPERIMENTAL

MRR = (VOLUME OF WORK PIECE) / (TIME TAKEN)

ELECTROCHEMICAL

MRR= 17.87 / 15

MACHINING

MRR= 1.1913 cm3/min

CALCULATION FOR

3.4. RESULT:

VARIABLE POWER SUPPLY:

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The

material

removal

rate

calculated by varying the power

S.N VOLT

IMMER

AGE

GED

(volts)

(mi

DISTAN

supply. The material removal rate is calculated up to 30V. The power should be varied every 10 V supply.

MATE RIAL REMO VAL RATE(c m3 min1 )

(cm)

COMPONENTS: RPS meter Power supply Work piece Tool Electrolyte

2.8

0.129

2.8

0.167

2.8

0.216

from 0-30V. At the same time the

Electrolytic tank

immerged distance (2.8cm) and time

4.1. RPS METER:

(45min) will be constant. The voltage

RPS is stand for Regulator Power

Supply. The function of the meter is

increase

means

the

material

removal rate also increased.

varying the power supply. The range

S.N

VOLTA

TIM

IMMERG

of meter is 0-30V.

(volts)

(min

DISTANC

)

E (cm)

MATERI AL REMOV AL RATE(cm 3 min-1)

3.1

0.118

3.1

0.156

3.1

0.194

In this tabulation the voltage is varied

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In this tabulation the voltage is varied

cm. In these two graphs material

from 0-30V. At the same time the

removal rate value is taken in X-axis

immerged distance (3.1cm) and time

and current voltage is taken in

(45min)

axis. So the graph between material

will

constant.

Y-

removal rate vs votage.

RESULT:

5. CONCLUSION:

MRR VS VOLTAGE

When the immerged distance is

increased the material removal rate

30 25

decreased and then the electrode

20 MRR VS VOLTAGE

15 10

distance is increased the material removal rate increased. The voltage

5 0

increased means the material removal 0.118

0.156

0.194

rate is increased. So the material

MRR VS VOLTAGE

removal rate is dependent upon the

voltage immerged distance.

6. APPLICATION:

MRR VS VOLTAGE

Some of the very basic applications of

0 0.129

0.167

ECM include:

0.216

1. Die-sinking operations.

Fig 13 & 14 The applied voltage is increased

2. Drilling jet engine turbine blades.

means the material removal rate also 3. Multiple hole drilling.

inceased. In the first graph the workpiece immerged distance is 2.8 cm

and

the

second

graph

4. Machining steam turbine blades

the

within close limits.

workpiece immerged distance is 3.1

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7. REFERENCE:

8. EXPRIMENT PICTURES:

1. Journal of the Taiwan Institute of Chemical Engineers, Volume 45, Issue 3, May2014, Pages840-845 M.H. Abdel-Aziz, I. Nirdosh, G.H. Sedahmed. 2. ProcediaCIRP, Volume8, 2013, Pages265-270 F. Klocke, M. Zeis, S. Harst, A. Klink, D. Veselovac, M. Baumg채rtner. 3.

journal

Manufacturing

Processes, Volume

14, Issue 1,

January 2012, Pages62-70 M. Burger, L. Koll, E.A. Werner, A. Platz. 4. Manufacturing Process Selection Handbook, 2013,

Pages

205-226

K.G. Swift, J.D. Bookers

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014

GESTURE RECOGNITION

BY AMREEN AKTHAR .J. AKSHAYA .B. III YEAR E.C.E PANIMALAR ENGINEERING COLLEGE

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placed in particular Position is satisfied. This value is fed to microcontroller, which is preprogrammed will display the corresponding words. At the same time voice output will be heard for the corresponding words with the help of speak jet chip. On the other hand voice from normal people is converted and displayed in to corresponding sign symbol which is pre stored.

Abstract—Tongue and Ear plays a major role for speaking and hearing by normal person. But it is impossible to speak and hear by deaf and dumb people. But they normally speak using their sign action with others. It is easily understood by their community, but they fell difficult when they communicate with normal people because normal person can’t able to understand their sign symbol. To tackle this

II. RELATED WORK

situation we design a system which converts their sign symbol

L.k.Simone has introduced a low cost method to measure the flexion of fingers. He use flex sensor for measuring flexion. He has evaluated the custom glove for measuring finger motion. Some of the parameters he has evaluated are donning, glove comfort and durability. Wald developed software for editing automatic speech recognition in real time for deaf and hard-hearing people. Syed Faiz, Ahmed, Syed Baber Ali, Saqib Qureshi developed an electronic speaking glove for speechless patients which are one way communication. Jingdong Zhao, developed a five finger under actuated prosthetic hand system.

to text as well as voice output and normal person’s voice to corresponding sign symbol for two way communication. This system has flex sensor and IMU (Inertial Measurement Unit) to recognize their sign symbol, speech synthesis chip for voice output and speech recognizing module for converting voice to sign symbol. These are interfaced with microcontroller, which is programmed to obtain corresponding output. Keywords— Flex sensor, IMU, speak jet IC, speech recognition module.

III. SYSTEM LAYOUT INTRODUCTION

Figure 1 below shows the proposed system module. In this system flex sensor is used to recognize finger position to obtain words, phrases, sentences etc. This value is signal conditioned using LM342 IC and other components, which is given as input to micro controller. In order to get accurate sign symbol, words or phrases as output, microcontroller is interfaced with IMU which consists of gyroscope, accelerometer and magnetometer. This sensor is used to determine tilt, rotation and rate of finger. By comparing flex sensor and IMU values microcontroller will display corresponding words or phrases. As an option these captured words also send to mobile using Bluetooth module. Output from Speak jet IC is fed to speaker to speak according to phonemes stored in controller for the captured values by combining flex sensor and IMU sensor.

Many research people have undergone research in order to overcome difficulties faced by physically challenged people. Many developed the system related to prosthetic hands which is used to find behavior of human hand. This project is similar kind as a part of determining sign words using hand motion. The main feature of this system is:  Hand held real time embedded device.  Low cost and reliable.  Operated using battery. In order to get accurate words or sentences IMU is used to find the exact position of the hand because placing hands in any position will give same values, to overcome this IMU is used. It is placed in the hand along with flex sensors so that its value gets changed according to the position of hand. So that for a particular word for which the hand should be

Similarly voice from normal people is captured using microphone and fed to microcontroller through speech

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 recognizing module. Controller which is preprogrammed will display corresponding symbol.

resistance values get changed which is fed to controller after signal conditioning it.

Figure 2. Flex sensor .

Signal conditioning circuit: It is shown in figure 3. For a simple deflection to voltage conversion, the bend sensor device is tied to a resistor Rm in a voltage divider configuration. The output is described by Vout = (V+)/ [1 + Rm/Bend sensor]

Figure1. Block Diagram.

IV. IMPLEMENTATION Obtaining signal from fingers which is used to recognize sign symbol consists of lot of methods including [5]     

Figure.3. Flex sensor signal conditioning circuit

EMG (Electromyography) Load cell Wearable conductive fiber Sliding fiber optic cable Flex sensor

Output from this sensor is fed to Op-Amps LM324 to boost up the circuit current. For different values of resistor Rm, different deflection Vs voltage curve is obtained as shown in figure 4.

In this system flex sensor is used to recognize hand gesture due to reliable and cost effective. A. Flex sensor: Flex sensors technology is based on resistive carbon elements. As a variable printed resistor the sensor achieves great form factor on a thin substrate. When the substrate is bent, the sensor produces a resistance output correlated to bent radius as shown in figure 2. Smaller the radius, higher the resistance value. It varies approximately from 10k to 50k.

Figure4. Deflection Vs Vout [6].

B. Inertial Measurement Unit: IMU used in this system is MinIMU-9 v2 from Pololu. It consists of 3-axis accelerometer, 3-axis magnetometer and 3-axis gyro sensors. An I2C interface access nine independent rotations, acceleration and

It offers a superior solution for application that requires accurate measurement and sensing of deflection, acceleration. It is placed inside the gloves which are to be worn. As the finger is bent for corresponding words,

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 magnetic measurement that can be used to calculate the sensorâ&#x20AC;&#x2122;s absolute orientation. L3GD20: It is low power 3-axis angular rate sensor capable of providing the measured angular rate to the external world through I2C terminal. The direction of angular rate is shown in figure 5.

Figure.8. Speak jet typical connection.

D. Speech recognizing module The module used here is VRbot. It is used to recognize voice from normal people through inbuilt microphone. It communicates with microcontroller using UART interface which is shown in figure 9. Figure.5. Direction of angular rate

LSM303DLHC: It is a combination of digital linear accelerometer and magnetometer sensor. It can support standard and fast mode I2C serial interface. Direction of acceleration and magnetic field is shown in figure 6 and figure 7.

Figure.9. VRbot interfaced with microcontroller .

Fig.6.Direction of ACC

It has built-in speaker independent command and also supports 32 user defined commands, which is used to recognize corresponding words spoken by people and displayed it in LCD which can be understood by physically challenged people.

Fig.7.Direction of Mag field

Whenever we change the position of hand for particular word, the values of IMU gets changed. This IMU sensor is interfaced with microcontroller. By comparing the values of flex sensor and IMU we can recognize the correct word or phrase with correct position of hand, which can be displayed in LCD.

V. PROGRAMMING THE HARDWARE The code required for this system is written in embedded C language which can be compiled and debugged using integrated development environment (IDE). The software used to program the hardwareâ&#x20AC;&#x2122;s are

C. Speak jet IC

A.MPLAB

Speak jet IC is self contained single chip for sound synthesizer using mathematical sound architecture technology. It is preconfigured with 72 speech elements, 43 sound effects and 12 DTMF touch tones. This is interfaced with microcontroller which is pre-programmed to send serial data to speak jet IC to speak the corresponding words or sentences by combining words. In order to hear by normal people output from speak jet IC is amplified by giving it to LM386 audio amplifier which is connected for particular gain and then to speaker. The connection recommended by manufacturer is shown in figure 8.

This is the IDE with integrated toolset for developing an embedded application using PIC microcontroller. It consists of a text editor, simulator, and device drivers made by microchip. In this code can be built using assembly or in C language. Device and language for coding can be selected according to our need. B. CCS Compiler A compiler is a programming language used to transfer source code in to object ode. The compiler used

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 here is CCS compiler, which is commonly used for PIC controller. It has many inbuilt function by including that we can call the whole functions, which makes the program to be very simple this compiler can implement normal C constructs, input/output operations etc.

VI. RESULT The hardware circuit of the module is shown in figure12. It consists of microcontroller interfaced flex sensors, speak jet IC, etc.

C. Phrase-A-Lator This software is a demonstration program from Magnevation which allows speak jet IC to speak. It is used to set voice quality like pitch, volume and speed. It will generate the code for the corresponding words we need which is then used in main code to make the speak jet IC to speak. The main menu for this software is shown in fig.10, is used to select communication settings and other editor menu. When connected to PC the serial port check box will turn the color to green if correct COM port is selected.

Figure10. Magnevation phrase transistor for speak jet.

Phrase editor is used to develop words, phrases and sound effects using built-in phonemes and sound effects. Required words or phrases can be written in say data area and corresponding code can be obtained by pressing view code button. This is shown in figure 11.

Figure12. Hardware circuit of the system.

The hex file obtained for the code after compilation is downloaded in to PIC controller and corresponding words is displayed in LCD. The words or conversation is obtained by taking signed English as a reference. For each and every word, values from flex sensors is compared with IMU sensors and fed to micro controller which is displayed in LCD display and also voice output is obtained through speak jet IC. This output is also transmitted to mobile using Bluetooth module. Accelerometer output obtained from IMU sensor is shown in figure 13. It shows result for all three axis. Magnetometer output obtained from IMU sensor for all three axes is shown in figure 14. Gyroscope output obtained from IMU sensor for all three axis is shown in figure 15.

Figure11. Phrase editor menu with words and code.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 from normal people is not converted in to sign symbol. In this system flex sensor is used along with IMU sensor to capture the words. Flex sensor is used to obtain fingers change to capture words. Even though we change the position of hand the flex sensor values will not get changed because flex sensor is placed in fingers. All the conversation used by physically challenged people will be using fingers or hands in particular position and rotating hands or fingers. To capture these positions of fingers or hand IMU sensor is used. IMU sensor which consists of accelerometer, magnetometer, and gyroscope will tackle this situation. This sensor is placed along with flex sensors in the hand so that by changing the finger for conversation, flex sensor and IMU sensor will get changed, by comparing these two values, output is displayed in display.

Figure13. Accelerometer output in display.

VIII. OUTPUT Sample output obtained for some important conversations such as “WELCOME and HOW ARE YOU”, are shown in below figure 16a and b. The Left portion of figure 16a, and b shows the exact position to keep the fingers for the word which is obtained using the reference site and right portion of figure 16 a and b shows the output obtained in digital display by wearing gloves with flex sensors and IMU in the hands and by keeping the hands in the position referred by the picture. At the same time same word which is displayed is also heard through speaker using speak jet IC.

Figure14. Magnetometer output in display

Figure15. Gyroscope output in display.

VII. RESULT COMPARASION Outputs obtained in previous work are simply obtaining finger flex, using software for speech recognition which uses computer to run the software. Since these system uses pc it can’t able to use it for any situation. Another system used only flex sensor to recognize words. Using change in flex sensor, the output is obtained. Some system which use computer is not portable to use and also only one way communication which will display result, which will be understood by normal people, but speech

Figure16.a. Digital display shows WELCOME

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 [3] Syed Faiz, Ahmed, Syed Baber Ali, Saqib Qureshi,”Electronic Speaking Glove For Speechless Patients A Tongue to a Dumb”, Proceedings of the 2010 IEEE Conference on Sustainable Utilization and Development in Engineering and Technology University Tunku Abdul Rahman 2010. [4] Jingdong Zhao, Li Jiang, Shicai Shi, Hegao Cai, Hong Liu, G.Hirzinger, "A Five-fingered Underactuated Prosthetic Hand System", Proceedings of the 2006 IEEE International Conference on Mechatronics and Automation, June 2006, pp. 1453 1458. [5] N. P. Bhatti, A. Baqai, B. S. Chowdhry, M. A. Umar, "Electronic Hand Glove for Speech Impaired and Paralyzed Patients", EIR Magazine, pp. 59-63, Karachi, Pakistan. May 2009 [6] Flex Point Inc. USA,”http://www.flexpoint.com” Last Accessed on September 06, 2010. [7] www.pololu.com/catalog/product/1268 Figure16.b. Digital display shows HOW ARE YOU

[8] Magnevation Speak jet http://www.speakjet.com. IX. CONCLUSION AND FUTURE ENHANCEMENT

[9] VRbot module, www.VeeaR.eu [10] http://www.sign.com.au

This system will be useful for physically challenged people and will tackle the gap between them and normal people. Since it is two way portable communication systems, it can be used at any time. This system can be enhanced by using extra flex sensors in wrist and elbow, so that conversation which uses these bent positions can be obtained accurately. Further storage device like SD card can be used to store more phrases as a dictionary to speak and to visualize it. It can also be enhanced by covering it with water proof layer to use it in any situation. REFERENCES [1] L. K. Simone, E. Elovic, U. Kalambur, D. Kamper, "A Low Cost Method to Measure Finger Flexion in Individuals with Reduced Hand and Finger Range of Motion", 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society 2004 (IEMBS '04), Volume 2, 2004, pp. 4791-4794. [2] M. Wald, "Captioning for Deaf and Hard of Hearing People by Editing Automatic Speech Recognition in Real Time", Proceedings of 10th International Conference on Computers Helping People with Special Needs ICCHP 2006, LNCS 4061, pp. 683-690.

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Structural and Electronic properties of doped SiliconNanowire AnuragSrivastava*, FlorinaRegius *Advance Materials Research Lab , Indian Institute of Information Technology and Management , Gwalior , Madhya Pradesh , India

Abstract : Electronic and structural properties of Silicon Nanowire (SiNW) when doped with Al and P atoms are obtained from simulation studies have been reviewed . The bandgap , density of states and Structural property of Sillicon Nanowire has been compared when this nanowire is doped with phosphrous and aluminium atoms. We observed that decrease in bandgap increases the metallic property of silicon. Total energy is maximum then the structure is least stable . So we can say that total energy is inversely proportional to stability. In density of states , we clearly see the decline in DOS/Ev with the increase of doping Al and P atoms. In this paper , we have discussed all the electronic and structural properties.

Keywords: Band structure ,Band gap , Density of States , SINW

1.Introduction The nanowire, a structure that has an amazing length-to-width ratio. Nanowires can be incredibly thin -- it's possible to create a nanowire with the diameter of just one nanometre, though engineers and scientists tend to work with nanowires that are between 30 and 60 nanometres wide. Scientists hope that we will soon be able to use nanowires to create the smallest transistors yet, though there are some pretty tough obstacles in the way. Nanowires possess unique electrical, electronic, thermo electrical, optical, magnetic and chemical properties, which are different from that of their parent counterpart.Sillicon NW are the answers for on going obstacles in electronic field .These Si NW are the one-dimensional structures. Their electronic conduction can be controlled by doping. Si NW can be used from field effect transistor to Biosensors.[4,5] The photoluminescence in Si NW and nanoparticle have been observed [7,8] which is an experimental evidence of the quantum confinement.[ 6] Silicon-wire research started in the mid 1990s, when advances in microelectronics triggered a renewed interest in siliconâ&#x20AC;&#x201D;now nanowireâ&#x20AC;&#x201D;research. [1] Last, we will turn our attention to the electrical properties of silicon nanowires and discuss the different doping methods. Then, three effects essential for the conductivity of a silicon nanowire are treated. [9]Experimentally it has been observed that the band Gap can be tuned by choosing different growth directions and diameters of wire . [10] The electronic structure of Si NW being critically depends on the size , orientation , passivation and doping level of nanostructure.These are the diameter dependence of the dopant ionization efficiency, the influence of surface traps on the charge-carrier density, also causing a diameter dependence,

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and the charge-carrier mobility in silicon nanowires. [1]Many techniques, including both top-down and bottom-up approaches, have been developed and applied for the synthesis of Nanowires. Vaporâ&#x20AC;&#x201C;Liquidâ&#x20AC;&#x201C;Solid (VLS) Mechanism, Chemical Vapor Deposition (CVD), Evaporation of SiO, Molecular Beam Epitaxy (MBE), Laser Ablation and Electroless metal deposition and dissolution (EMD) [2]. These days Si NW are used for enhanced thermo electricperformance [3]. Sillicon nanowire can be uniformly made at low temperature using Vapour-Liquid-Solid growth.

2. Computational Method We have performed the calculation using the ab-intiopsuedopotential method which is based on the density functional theory and analyse the electronic properties of silicon nanowire (alpha) . We have used atomistix toolkit (ATK)[11] for computation , a further development of TranSIESTA-C[13,14] which, in turn , is based on the technology, models and algorithms developed in the academic code TranSIESTA and ,in part, McDCal [12] , employing localized basis sets as developed in SIESTA[15]. The computation has been made in selfconsistent manner using steepest descent geometric optimization with Pulay Algorithm for iteration mixing . A mesh cut-off of 70 Hartre has been used throughout the study. The Brilloun-zone(BZ) integration is performs with a Monkhorst-Pack scheme using 1*1*11 k points. The cutoff energy and the number of k points are varied to test the convergence and are found to converge within the force tolerance of 0.05eV/A for the reported value . The exchange correlation functional described within the extended huckel and with generalised gradient approximation revised-PBE(rev-PBE) as proposed by Zhang and Yang [16] are used for the computation of total energies of Si Nanowire and its doping with aluminium and phosphorous atoms . The total energy for Si nanowire extended huckel potential is -2426.37 ev . The extended huckel potential is quite good for the computation of total energy.[17]The nanowires are placed in the supercell along the wire length in z-direction while the supercell lengths in the x and y direction are chosen big enough to avoid interaction between nanowire and its periodic image.[18] For better understanding of fundamental physics associated with different structures , the binding energies of Si nanowire have also been analysed and to understand the nature of material , localization and delocalization of states near the Fermi level , we have analysed the electronic band structure and density of states for all the doping configuration of Si nanowire.

3. Results

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3.1 Structural Properties The atomic configurations of the Si Nanowire are presented in the Fig 1. It may be cautioned that these figures are schematic and separations between atoms are not to scale . As these figures depicts the structures quite clearly and hence have not been discussed separately in the text. The stability energetic in the various nanostructures of Si has been performed under the extended huckel with the revised PBE type exchange correlation functional and shown in Fig.2 by total energy per atom for all the Si nanowire structure have been reported in Table 1. We observe that silicon nanowire has the lowest energy is visible at -2426.37ev which shows it is the most stable structure and when it is doped with one aluminium atom the total energy is -2375.27ev which is less lower then earlier which shows it is next stable structure. In this way total energy increases with the increase of doping of Aluminium atoms in Si nanowire. Now after doping with phosphrousatoms , the total energy has a great variation . -2468.46ev is the lowest energy found when Sillicon nanowire is doped with the four phosphrousatoms . This shows it is highly stable structure .-2510.69ev is the next lower energy found when Sillicon nanowire is doped with the three phosphorous atoms . It is also highly stable but lesser then earlier. Here , we observe that with increase in doping of atoms , total energy decreases and stability increases. Now for detail of structural stability , the formation energy and binding energy are calculated . [19]

B Polynomial Fit of Data1_B -2421

-2422

total energy

-2423

-2424

-2425

-2426

-2427 0.26

0.27

0.28

0.29

0.30

Lattice constant (c/a)

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(a)

(b)

(c)

(d)

(e)

Fig.2. The atomic Configurations of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 Al atom , (c) SiNW doped with 2 Al atoms , (d) SiNW doped with 3 Al atoms and (e) SiNW Doped with 4 Al atoms

(a)

(b) (c)

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(d) Fig.3.

(e) The atomic Configurations of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 P atom , (c) SiNW doped with 2 P atoms , (d) SiNW doped with 3 P atoms and (e) SiNW Doped with 4 P atoms

Table :

Lattice Atomic Configuration constant

Total energy

Sillicon Pristine Doped with 1 Al atom Doped with 2 Al atoms Doped with 3 Al atoms Doped with 4 Al atoms Doped with 1 P atom Doped with 2 P atoms Doped with 3 P atoms Doped with 4 P atoms

0.285 0.27

-2426.37 -2375.27

Binding energy 4.29 4.64

Formation energy 1.29

0.27

-2326.86

4.99

2.55

0.29

-2282.88

5.35

3.71

0.30

-2237.89

5.70

4.9

0.27

-2468.46

3.89

0.58

0.27

-2510.69

3.49

1.66

0.27

-2548.93

3.03

1.8

0.27

-2594.44

2.88

2.33

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3.2 Bandstructure analysis To understand the material behaviour of the stable geometries of SilliconNanowires , electronic band structures analysis have been performed and their band structures are compared in Fig 3a-g . On the basis of number of doping atoms crossing the Fermi level , conductivity of various Si nanowires has been explained . The bandstructure of bulk Si nanowire as shown in Fig.3a.no conductions bands are corssing which shows it is semiconductor . It has a bandgap of 8.03 E/ev .When the Si nanowire is doped with 1 Al atom as shown in Fig.3b there is no band gap and two conduction line is crossing the Fermi level at 0.1 E/ev. This shows metallic property has entered the play . Now the Sillicon nanowire is doped with 2 Al atoms as shown in Fig.3c as usual there is no band gap and two conduction lines are crossing the Fermi level at 0.01 E/ev and -0.01E/ev from vanlence and conduction bands resp. This shows metallic property has increased compared to previous. Then Si nanowire is doped with three Aluminium atoms as shown in Fig.3d and two conduction lines are intersecting the Fermi level at 0.1 E/ev and - 0.1 E/ev resp. Conduction band becoming dense. Metallic property has increased from earlier. Finally Si nanowire is doped by 4 Al atoms as shown in Fig.3e and even in this three conduction lines are crossing at 0.02 E/ev ,0.01and-0.0 1 E/ev resp. Conduction band has become more denser because of crowed conduction lines . Metallic property also increased. Now it is turn of Phosphorous atoms to be doped in Si nanowire. The Si nanowire is doped with 1 P atom as shown in Fig.3f. there is no band gap and a conduction line is crossing the Fermi level below -0.002 E/ev. This shows metallic property is more in case of phosphorous . Now the Silicon nanowire is doped with two Phosphorous atoms as shown in Fig.3g as usual there is no band gap and three conduction lines are crossing the Fermi level below -1.0 E/ev , -1.2 E/ev , -0.2 E/ev resp. This shows metallic property has increased compared to previous. Then Si nanowire is doped with three P atoms as shown in Fig.3h and here also there are three conduction lines which is crossing the Fermi level from valence and conduction band has become more dense and thick compared to others. Finally Si nanowire is doped by 4 phosphorous atoms as shown in Fig.3i in which four conduction lines are intersectingthe Fermi level at valence band and two conduction lines intersecting at conduction band.The graph is becoming dense to denser while increasing the number of atoms which shows the metallic nature increases .

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(a)

(b)

(c ) (d)

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(e) Fig.4.

The Bandstructures of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 Al atom , (c) SiNW doped with 2 Al atoms , (d) SiNW doped with 3 Al atoms and (e) SiNW Doped with 4 Al atoms

(a )

(b)

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(c )

(d)

(e ) Fig.5.

The Bandstructures of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 P atom , (c) SiNW doped with 2 P atoms , (d) SiNW doped with 3 P atoms and (e) SiNW Doped with 4 P atoms

3.3 Density of States The DOS profile for all the stabilized structures have been shown in Fig 4a-g along with that of bulk Sillicon . In case of bulk Silliconnanowire , the graph shows a high peak which is at 23.7 DOS/ev in y axis and -4.2 E/ev on x axis . Two peaks are present which are on the left and right side of high peak. The peak on the right side appears on 10.4, 9.4 DOS/ev on y axis resp. and 11 , 15.4 E/ev in x axis resp. But the peak on the left side is present on 9.3 , 6.1 DOS/ev on axis yresp and â&#x20AC;&#x201C; 6, -12 E/ev in x axis. We observe a small bandgap which shows the semi conducting behaviour . When this bulkSillicon nanowire is doped with a Al atom , the graph shows a high peak which is at 21.2 DOS/ev in y axis and -4 E/ev on x axis . There are two peaks on the right side is present on 7.3 , 5.4 DOS/ev on y axis and -6.3 , -11.2 E/ev in x axis. But the peak on the left side is appears on 9,8.8 DOS/ev on axis y and -14.2 , 16 E/ev in x axis. Then this bulk Sillicon nanowire is doped with two Al atom , the graph shows a high peak which is at 20.4 DOS/ev in y axis and -3 E/ev on x axis . The peak on the right side is present on 11.5 DOS/ev on y axis and 5.2 E/ev in x axis. But the peak on the left side is present on 8,8.9 DOS/ev on axis y and 14 , 17 E/ev in x axis resp. We see that the peaks are diminishing with the increase in number of Al and P atoms .Now , this bulk Sillicon nanowire is doped with three Al atom , the graph shows a high peak which is at 20.2 DOS/ev in y axis and -2.8 E/ev on x axis . There are two peaks on the right side which appears on 5.5 , 4 DOS/ev on y axis resp. and -11,14 E/ev in x axis resp. But there are two peaks on the left side is present on 8.7 , 8 DOS/ev on axis y and -11 , 15.4 E/ev in x axis resp. And then this bulk Sillicon nanowire is doped with four Al atom , the graph shows a

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high peak which is at 19.4 DOS/ev in y axis and -4.7 E/ev on x axis . There are two peaks on the right side which appears on 3.7 , 5.4 DOS/ev on y axis resp. and -13,-15 E/ev in x axis resp. But there are two peaks on the left side is present on 7.4,8.2 DOS/ev on y axis and 10 , 11.7 E/ev in x axis resp. . The left side of Fermi level is more dense which clearly indicates high metallic nature. Now itâ&#x20AC;&#x2122;s the turn for phosphorous doping on Silliconnanowire . When this bulkSillicon nanowire is doped with a P atom, the graph shows a high peak which is at 22.67 DOS/ev in y axis and -11 E/ev on x axis . There are three peaks on the right side appears on 4.4 , 6 , 8.7 DOS/ev on y axis and -11,-17,-20.7 E/ev in x axis resp. But there are 5 peakson the left side is present on 9.5,9.7,4.7,1.6,1.08 DOS/ev on y axis and 4,9.6,17,20, 25 E/ev in x axis resp. Now this bulkSillicon nanowire is doped with two P atoms , the graph becomes very dense and it clearly defends very high metallic nature. There are three peaks on both sides of femilevel . The peaks appears on 23 , 6.2 ,9.2 DOS/ev on one side of Fermi level which is at -0.3, -12.5 , -21.6 in x axis .But when this Sillicon nanowire is doped with three P atoms , we observe one side of Fermi level has three peaks ,the graph shows peaks which is at -1.3,-0.5,-1.7 DOS/ev in y axis and 10.3,10.4,10.2E/ev on x axisresp . But on the other side , there are many small peaks . We observe lot of distorted peaks on the valence band which defends it is metallic .Finally this bulk Sillicon nanowire is doped with four P atoms , the graph shows a three peaks on one side of fermi level which is at 7.5, 12.6,19.8 DOS/ev in y axis and other side has around seven peaks which appears on 9.6 , 10.4 , 4.7 ,5.4,4.8,1.8,1 DOS/ev .Here , we see small peaks raising up .As usual there is presence of more peaks but now the peaks are getting distorted on both sides because of increase in number of electrons of Aluminium and phosphrous atoms .

(a)

(b)

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(c )

(d)

(e ) Fig.6.

The Density of States of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 Al atom , (c) SiNW doped with 2 Al atoms , (d) SiNW doped with 3 Al atoms and (e) SiNW Doped with 4 Al atoms

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(a)

(b)

(c )

(d)

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(e ) Fig.7.

The Density of structures of Si nanowires (a) SiNW without doping , (b) SiNW doped with 1 P atom , (c) SiNW doped with 2 P atoms , (d) SiNW doped with 3 P atoms and (e) SiNW Doped with 4 P atoms

Conclusions After analysing the structural and electronics properties of Silliconnanowire , we can conclude that in case of structural property , if total energy is maximum then the structure is least stable . So we can say that total energy is inversely proportional to stability . With the increase of doping Al and P atoms , total energy is increasing . In density of states , we clearly see the decline in DOS/Ev with the increase of doping Al and P atoms . But the graph was getting denser and crowded with conduction lines as the metallic property is increasing. Finally , in Bandstructure , we observe that band gap gets hidden because of crowded conduction lines while doping it with Al and P atoms which depicts the increase of metallic nature as earlier in case of Si NW , there was small band gap available depicting semiconductor property.

Acknowledgement Authors greatly acknowledge the support from ABP-IIITM Gwalior for providing the infrastructure support in doing the research work.

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References 1.Volker Schmidt,* Joerg V. Wittemann, Stephan Senz, and Ulrich Go¨sele , Adv. Mater. 2009, 21, 2681–2702 2. Mehedhi Hasan1, MdFazlul Huq2* and ZahidHasanMahmood ,© 2013 Hasan et al.;licensee Springer 3. Kui-Qing Penga, XinWanga, Li Lia, YaHua, Shuit-Tong Lee, 10.1016/j.nantod.2012.12.009

4. F.Patolsky and C.M.Lieber , Mater. Today 8,20(2005) 5. A.M.Morales and C.M.Lieber,Science 279,208(1998) 6.Bozhi Tian1,3, Xiaolin Zheng1,3, Thomas J. Kempa1, Ying Fang1, Nanfang Yu 2, Guihua Yu 1, Jinlin Huang1 & Charles M. Lieber , Nature 449, 885-889 (18 October 2007 7.Z.G.Bai,D.P.Yu,J.J.Wang,Y.H.Zou,W.Qian,J.S.Fu,S.Q.Feng,J.Xu and L.P. You , Mater.Sci.Eng.,B 72, 117 (2000) 8.D.B.Geohegan,A.A.Puretzky , G.Dushcher and S.J. Pennycook , Appl. Phys Lett.73.438 9. M. Hofheinz ,X.Jehi , M. Sanquer , G.Molas, M.Vinet and S.Deleonibus ,Eur .Phys.J.B 54, 299(2006) 10.D.D.D.Ma ,C.S.Lee, F.C.K.Au , S.Y. Tong and S.T.Lee , Science 299 , 1874(2003) 11.http://www.atomistix.com 12. Jeremy Taylor , Hong Guo and Jian Wang ,Phys.Rev.B 63,245407(2001) 13.MadsBrandbyge , Jose-Luis Mozos , Pablo Ordejon , Jeremy Taylor and Kurt Stokbro , Phys.Rev. B 65 , 165401 (2002) 14. Kurt Stokbro , Jeremy Taylor , MadsBrandbyge and Pablo Ordejon , Annals N.Y.Acad.Sci.1006,212 (2003) 15.Jose M. Soler , Emilio Artacho , Julian D.Gale , Alberto Garcia , Javier Junquera , Pablo Ordejon and Daniel Sanchez Portal,J.Phys.Cond.Mat.14,2745(2002)

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16.B. Hammer , L.B. Hansen and J.K. Norskov , â&#x20AC;&#x153;Improved adsorption energetics within density Functional theory using revised Perdew-Burke17.AnuragShrivastav ,NehaTyagi and R.K.Singh , JCTN , Vol.8.1-6,2011 18.AnuragShrivastav ,NehaTyagi and R.K.Singh , Materials Chemistry and Physics 127 (2011)489-494 19. Anurag Srivastava,1 Mohammad Irfan Khan,1,2 Neha Tyagi,1 and PurnimaSwaroopKhare, Volume 2014 (2014), Article ID 984591

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STUDY AND EXPERIMENTAL ANALYSIS OF LINEAR AND NON LINEAR BEHAVIOUR OF PIPE BEND WITH OVALITY Balaji A#1, Faheem Ashkar H#2, Jahir Hussain H#3, Elamparithi R#4 #1

Assistant Professor UG Scholars Department of Mechatronics Engineering, Kongu Engineering College Perundurai, Erode, Tamil Nadu, India-638052 1 bala2009mct@gmail.com 2 faheem.ashkar@gmail.com 3 iamjahirhussain@gmail.com 4 elamparithiramasamy@gmail.com #2, #3,#4

Abstractâ&#x20AC;&#x201D; the present study performed a series of experiments using real-scale experimentation process to evaluate the effects of load variation with respect to ovality for various schedule numbers such as SCH 40 long radius, SCH 40 short radius and SCH 80 short radius bends with and without internal pressure. The experiments has been conducted at ambient temperature within elastic limit of the bend for under in-plane opening & in-plane closing bending moments and also out of plane clockwise & out of plane anticlockwise bending moments. The experiments included to calculate the displacement as well as percentage change in ovality in the intrados, crown and extrados regions of the bend. The displacement in the intrados and extrados region increased almost linearly with respect to load for both inplane and out of plane bending moments. This allowable limit loads and ovality are suggested for different diameters of pipe bends and for different pipe material. This helps in avoiding rejection of pipes due to insufficient wall thickness. The mathematical results and software results are compared with experimental results to get the optimised output.

Equations used for calculating basic parameters The ovality of a bend section is shown in figure 1.1. The minimum required wall thickness at the pipe bend during the bending process does not produce a difference between the maximum and minimum diameters greater than 8 % for internal pressure service and 3 % for external pressure service (Engineering Design and Analysis Ltd.,). The center line radius of pipe bends should typically be a minimum of 3 times the nominal pipe diameter. The codes have certain requirements for the acceptability of finished bends. It depends upon the following parameters i. ii. iii.

Thinning and Thickening. Ovality. Buckling.

Keywords: Pipe bends, Internal Pressure, In-plane and Out of plane bending moments.

I INTRODUCTION Large pipelines and pipe networks are part of almost every industrial setup today. These are most commonly found in petroleum rigs, refineries, factories producing chemicals and pharmaceuticals, and in power plants. In these and other industrial applications, pipes are very often used to carry substances that, by virtue of their pressure, temperature, physical and chemical characteristics, can have serious negative effects on health, property and the environment, if released into the atmosphere. Examples of such substances include steam, oil and chlorine gas. Failure in a piping system could cause problems, like an unscheduled, and hence costly, plant shutdown for maintenance or even a catastrophe, like exposing the core of a nuclear reactor. Therefore, the integrity of pipes in industrial contexts is of paramount importance. This integrity relies heavily on the correctness of pipe design, which can only be achieved through a thorough understanding of the behavior of piping components and systems under different types of loads.

Figure 1.1Bend Ovality Thinning and Thickening In every bending operation the outer portion of the bend stretched and the inner portion compressed. This leads to thinning at the extrados and a thickening at the intrados of the pipe bend. The thinning is defined as the ratio of the difference between the nominal thickness and the minimum thickness to the nominal thickness of the pipe bend. The thickening is defined as the difference between the maximum thickness and the nominal A

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 thickness divided by the nominal thickness of the pipe bend. The percentage change in thinning and thickening is calculated by using the formula as shown in the equation 2.1 and 2.2 (Veerappan A and Shanmugam S, 2012). Because of uncertainties introduced by the pipe-manufacturing method, it is not possible to exactly predetermine the degree of thinning. ------- (2.1)

Pipe Size

25 mm

Outside Diameter (D)

33.4 mm

Inside Diameter

26.6 mm and 24.4mm

Wall Thickness (t)

3.4 mm and 4.5mm

Tensile Strength(min)

413MPa

Yield Strength(min)

241MPa

Table 3.2 Chemical Compositions Composition Percentage

------- (2.2) Where, Tnom Tmax Tmin

=Nominal Thickness of the Bend (mm). =Maximum Thickness of the Bend (mm). =Minimum Thickness of the Bend (mm).

Ovality During the bending operation the cross section of the bend assumes to be an oval shape whose major axis is perpendicular to the plane of bend. The degree of ovality is determined by the difference between the major and minor axes divided by the nominal diameter of the pipe. When the bend is subjected to internal pressure, it tries to reround the cross section by creating secondary stress in hoop direction. The percentage change in ovality is calculated using the equation 2.3 (Veerappan A and Shanmugam S, 2012).

III

STANDARD PARAMETERS The specification such as bend dimensions and chemical compositions of the bend section were taken from ASME B36.10 catalogue for 1inch diameter bend. The bends are classified into the following categories. 1) SCH40 (Wall Thickness-3.4mm) 2) SCH80 (Wall Thickness-4.5mm) 3) SCH160 (Wall Thickness-6.4mm) The outer diameter of the bend is kept constant and the bore size will be varied according to the schedule number of bend. In schedule number itself the bends are classified into two categories. 1) Long Radius Bend. 2) Short Radius Bend. In our investigation three types of specimens has been used according their availability. 1) SCH40 – Long Radius Bend. 2) SCH40 – Short Radius Bend. 3) SCH80 – Short Radius Bend In each section a straight pipe of six inch length has been attached at the both side of the bend section. The standard parameters and chemical composition of the pipe is given in the table 3.1 and 3.2 which is taken from ASME B36.10 and ASTM A106 Grade B catalogue.

ASTM 106 Grade B 40 and 80

0.29 to 1.06

Phosphorous(max)

0.025

Sulfur(max)

0.025

Silicon(min)

0.10

Figure 4.1 Diagrammatical Model of Set-up [Karmanos et al.] Maximum bending moment (Mi (max))

Table 3.1 Standard Parameters Description Parameters Schedule Number (SCH)

0.30

Manganese

IV EXPERIMENTATION SETUP ` The diagrammatical model of the experimentation setup is shown in figure 4.1 for testing the elbow under in-plane bending mode. One end of the pipe end is clamped at the ground and other end is kept free for applying the in-plane moment load. A long rod is attached at the end of the free end for applying the in-plane load easily. The length of the straight pipe EB and GH is equal to six times the diameter of the bend section. In-plane bending mode can be created when the load applied in vertical direction on the beam BA. When the load applied in vertically upward direction, the bend section is subjected to in-plane opening mode and vertically downward direction, the bend section is subjected to in-plane closing mode. And out-of-plane bending mode is created by applying the load in horizontal direction on the beam. Spring balance and load cell is used to measure the magnitude of the applying load which is placed at the free end of the rod. Dial gauges are used to measure the deflection in the bend section by fixing it in the intrados, crown and extrados regions. The maximum elastic bending moment that can be applied in the test specimen is calculated by using the formula given below which is taken from ASME BPVC, Section III is shown in the equation 4.1.

-------- (2.3) Where, D max =Maximum Outside Diameter of the Bend (mm). D min =Minimum Outside Diameter of the Bend (mm). D nom =Nominal Outside Diameter of the Bend (mm).

Pipe Standard

Carbon(max)

------ (4.1)

Where, z

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Section Modulus.

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Allowable Stress Value.

Bend Factor (Rt/r2 )

Long Radius SCH40 Bend =613.54N-m =1067.64N (108.8kg) Short Radius SCH40 Bend =468.25.1N-m =814.91N (83.09kg) Short Radius SCH80 Bend =675.40N-m =1175.43N (119.81kg) The Pro/E model and photographic view of the setup is shown in the figure 4.1 and 4.2 which is shown in different views. By rotating the hand wheel the desired load is applied to the corresponding bend section.

FRONT VIEW

SIDE VIEW

SIDE VIEW FRONT VIEW

TOP VIEW Figure 4.2 CREO Elements Model

TOP VIEW

Figure 4.3 Photographic View of the Setup

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 E = 193 GPa, Poisson’s ratio of γ = 0.3 and the limiting stress of σ= 193 MPa. The FEA models were subjected to internal pressure, in-plane bending and out of plane bending mode. Internal pressures were applied as a distributed load to the inner surface of the FEA model.

Figure 4.4 Isometric View of CREO Elements Model

Figure 5.1.1 Cross Section of the Pipe bend with attached to straight pipe

Figure 5.1.2 Pipe bend with attached to straight pipe Figure 4.5 Isometric View of the Setup The bend section which is to be tested is fixed in the base frame. One end of the long rod is attached to the bend section and other side of the rod is clamped in the plate which moves up and down for applying the in-plane bending modes. The movement of the plate can be attained by rotating the hand wheel. Spring balance is placed in the bottom of the vertical frame when the bend is subjected to in-plane opening mode and it is placed in the top of the vertical frame when the bend is subjected to inplane closing mode. Two supports which are resting on the base frame for applying out of plane bending in clockwise and anticlockwise modes. Dial gauges are used to measure the deflection in the bend section by fixing it in the intrados, crown and extrados regions. During experimentation the load is applied in the incremented manner up to maximum bending moment that can be applied to bend section. For each mode three sets of reading has been taken and then it is averaged. In this experimental setup the readings are taken without any internal pressure like water, oil, steam etc. V

RESULTS AND DISCUSSION

V.I

ANALYSIS RESULTS

Figure 5.1.3 In plane bending mode (closing)

Using Finite Element Analysis (FEA) method, ansys 12.1 were performed with solid element type. The following values of material properties were used in present calculations

Figure 5.1.4 Stress Distribution of the pipe bend in In-plane bending mode (closing)

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Schedule

Number

Figure 5.1.5 Out of Plane bending model 3

40-Long Radius

40-Short Radius 80-Short Radius

Percentage change in Ovality Zero

Intrados

Crown

Extrados

Region

1.69

0.92

1.48

4.310

3.070

0.74

0.151

0.62

1.417

0.299

0.75

0.258

0.99

3.333

1.856

Load (kg)

Maximum Load (kg)

Table 5.2.1 Displacement and percentage change in ovality B

Out of Plane Clockwise Mode:

The maximum displacements results in intrados, crown and extrados regions as well as the percentage change in ovality of the bend during Out of Plane Clockwise mode is shown in table. The readings are taken as five sets and the average values are shown in the following table.

Figure 5.1.6 Out of Plane bending (clockwise)

Maximum Displacement (mm) S. No

Figure 5.1.7 Stress Distribution of the pipe bend in Out of plane bending mode (clockwise)

The same procedure was performed for in plane opening mode and out of plane anticlockwise mode and the graph was plotted for displacement and deflections. These values are compared with experimental setup values. V.II

EXPERIMENTAL RESULTS

In plane Closing Bending Mode:

Percentage change in Ovality

Schedule Number

40-Long Radius

40-Short Radius 80-Short Radius

Zero

Intrados

Crown

Extrados

Region

0.79

0.56

0.74

4.32

2.09

0.54

0.05

0.35

0.299

0.65

0.154

0.59

1.57

Load (kg)

Maximum Load (kg)

Table 5.2.2 Displacement and percentage change in ovality

The same procedure was performed for inplane opening mode and out of plane anticlockwise mode and the graph was plotted for displacement and deflections.

The maximum displacements results in intrados, crown and extrados regions as well as the percentage change in ovality of the bend during Inplane Closing Bending Mode is shown in table. The readings are taken as five sets and the average values are shown in the following table.

VI GRAPHS AND DISCUSSIONS The displacement variation for analysis results were compared with experimental results, it shows the approximately same variation and percentage change in ovality for various schedule number of pipe bends are plotted as below.

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CONCLUSIONS

The experimental results and analytical results show inplane bending moment has more deflections compared to out of plane bending moment. Percentage variation in ovality during inplane closing mode and out of plane clockwise mode from zero to maximum loading is increased from schedule 40 long radius to schedule 40 short radius that is from 28.77 to 72.89 but decreased from schedule 40 short radius to schedule 80 short radius that is from 72.89 to 44.31 . For inplane opening mode and out of plane anticlockwise mode the percentage variation in ovality behaves the same manner as that of out of plane clockwise mode. The experimental results describe that maximum displacement occurs in the intrados region and hence the intrados region exhibit more flexible property than the extrados region. When the schedule number is increased rigidity of the bend material is increased as well as the percentage variation in ovality is also increased. The present work can be extended to include the effect of internal pressure on the pipe bend with in-plane and out of plane bending moment, temperature effects involved, material microstructure analysis to control geometrical irregularities due to ovality. The influence of initial ovality in pipe bends is considered to be one of the major factors in reducing the percentage ovality which demands analysis of the behavior to avoid geometrical irregularities. The temperature effects involved in the pipe bends while introducing internal pressure needs to be analyzed to find the exact reason for geometrical irregularities in pipe bends due to ovality. The material microstructure analysis can help to predict the behavior of various materials at elevated temperature and pressure to predict the grain size changes when loading is done on a pipe bend.

Graph 6.1 Displacement Variations for Analysis Results

VIII

REFERNCES

1. Veerappan AR, Shanmugam.S and T.Christo Michael., ‘Effect of ovality and variable wall thickness on collapse loads in pipe bends subjected to in-plane bending closing moment’, Engineering Fracture mechanics, Vol.7, pp.138148,2012. Graph 6.2 Displacement Variations for Experimental Results

2. Veerappan A and Soundrapandian S., ‘The Accepting of Pipe Bends With Ovality and Thinning Using Finite Element Method’, Journal of Pressure Vessel Technology, Vol .132(3), pp.031204, 2010. 3. Chattopadhyay J., ‘The effect of internal pressure on inplane collapse moment of elbows’, Nuclear Engineering and Design, Vol .212, pp.133- 144, 2002.

4. Weib E., 'Linear and nonlinear finite-element analyses of pipe bends', International Journal of Pressure Vessels and Piping, Vol .67(2), pp.211-217.1996.

Graph 6.3 Percentage Change in Ovality for SCH 40 radius pipe bends in experimental values.

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A REVIEW ON PERFORMANCE ANALYSIS OF MIMOOFDM SYSTEM BASED ON DWT AND FFT SYSTEMS 1

Pitcheri Praveen kumar,

I.Suneetha,

N.Pushpalatha

M.Tech(DECS) Student,

Associate professor& Head, Assistant professor Department of ECE,AITS Annamacharya Institute of Technology and Sciences,Tirupati,India-517520 1 ppvvsreddy@gmail.com iralasuneetha.aits@gmail.com 3 pushpalatha_nainaru@rediffmail.com 2

communication system is to increase the Spectral efficiency and to improve link reliability. The MIMO (Multiple-input Multiple-output) wireless technology [1], gives the improved Spectral efficiency due to its Spatial Multiplexing gain and the reliability of link due to the antenna diversity gain. In the MIMO (Multiple-input Multiple-output) system the multiple antennas are deployed at both transmitter side as well as the receiver side of wireless system, has generated considerable interest in recent years [2], [3]. The OFDM is MCM (Multi Carrier Modulation scheme) which is used to convert the Frequency selective channels into the parallel Flat-Fading Narrowband subchannels. Due to the cause of Multipath propagation in the signal the cyclic prefix are added to the transmitted signal to mitigate the Inter Symbol Interference (ISI)[4]. The OFDM implemented with the basis of Fast Fourier Transform (FFT) used to Multiplexing the signal together at the input side and also decode the signal at receiver side to regain the original signal. Adding the cyclic prefix to the transmitted signal causes the reduction of Spectral efficiency. The FFT based MIMO-OFDM uses the Narrowband analysis produces the high side lobes in Rectangular window which enhance it sensitivity to ICI and Narrow-band interference. The alternative method for FFT based MIMO-OFDM is the Discrete Wavelet Transform based MIMO-OFDM system. The DWT consist of a Low Pass Filter (LPF) as well as High Pass Filter (HPF) functional as a Quadrature Mirror Filter (QMF) technique and the capability to regenerate the original signal as well as producing orthogonal properties. In the DWT based OFDM system the sub-band coding is done by using of sub-signals of Low pass and High pass Frequencies. The Wavelets in the wireless communication system has a lot of advantages, by way of channel characterization, Interference modification, cognitive radio in addition interacting [7], and flexibility and to produce the optimal resolution.

Abstractâ&#x20AC;&#x201D; MIMO-OFDM system has a capability of transmitting high speed data-rates to the end user without limiting the channel capacity and with no ISI. The MIMOOFDM implements based on the FFT due to its Multicarrier modulation and its efficient computational capability. But FFT in MIMO-OFDM causes the high side lobes produced by Rectangular window and due to cyclic prefix which do not has a flexibility, optimum resolution and high PAR losses. The alternative method for MIMO-OFDM is Wavelets based multi-user MIMO OFDM systems. OFDM system implemented with the Wavelets has a lot of advantages over the FFT based OFDM. Unlike FFT based MIMO-OFDM the wavelet based OFDM system does not require a need for cyclic prefix, optimal resolution and flexibility. The DWT based OFDM compares the efficiency performance with the FFT based OFDM on establishing the BER presentation to the transmit ability by BPSK also QPSK as a modulation technique in AWGN.

I. INTRODUCTION The number of increased users in the wireless mobile communication system is needed to provide a high QOS (Quality of Service) and to provide High-data-rates. High-data-rates can be achieved by increasing the Spectrum efficiency. The goal of the future communication network is to be implemented to provide a high data rates and service would be high speed internet access, video communication videophones etc. The barrier of any communication system is the transmission losses of the propagation signal from transmitter to the receiver end in number of different paths said to be multipath propagation of signal. The multipath propagation of signals will undergone to various types of Fading which leads to change of the transmitted signal with respect to its pace, amplitude, frequency leads to decay of signal strength at receiver side. The multipath propagation loss occurs in both Time domains as well as in the Frequency domain. The invention of Orthogonal Frequency Division Multiplexing (OFDM) becomes a popular technique for effective transmission mitigate of the signal in multipath. OFDM in a wireless communication channels transmits very extraordinary speed of data rates without limiting the channel capacity in an allocated Frequency. The OFDM has a number of advantages, reduction of Impulse Response over the channel, high Spectral efficiency and robustness against the Inter Symbol Interference (ISI), Inter Carrier Interference (ICI). The goal of the any

The applications of the Wavelets in wireless communication systems are used in the image synthesis, nuclear engineering, biomedical engineering, magnetic resonance imaging, pure mathematics, data compression technique, computer graphics and animation, human vision, radar, optics and astronomy. The MIMO-OFDM implements with the Wavelets can provide a high performance operations in different areas of the fields.

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For a given finite data stream which can be represent as X[n], n=0 to N-1 The corresponding output sequence of FFT is represented as

II. OVERVIEW 2.1 MIMO-OFDM SYSTEM: In order to increased demand of the wireless system it is necessitate to establish the efficient use of radio spectrum, which is done by placing of the Modulation Carriers closely as possible as without occurring of the Inter Symbol Interference (ISI) and capability of carrying ability of many bits as possible. For the transmission of higher Data-rates the short symbol period should be used. The symbol period is T is always inverse to the base band data rate R (R=1/T), as symbol period T should be small if transmitting Data- rates are to be high. However a shorter symbol period increases the ISI (Inter Symbol Interference), by using of the OFDM which address the unique Modulation and Multiplexing technique to overcome it. The MIMO (Multiple-input Multiple-output) communication system is implementation of array of antennas at the transmission and at the receiver side in Wireless Communication System. The MIMO systems are invented in the middle of 1980 by Jack Winters and Jack Saltzs of Bell Laboratories. The MIMO systems provide the enhanced system performance under the same transmission capability of Single-input Single-output system. The MIMO-OFDM system has a capability of transmitting higher Data-rate to the user with no ISI (Inter Symbol Interference) and no ICI (Inter Carrier Modulation). MIMO systems are used in the various possible applications of digital televisions, wireless local area networks, metropolitan networks and mobile communications due to its great channel capacity which is in proportional to the total number of transmitter and receivers.

( )=

( )

â&#x2C6;&#x2019;1

(1)

And the IFFT i.e. Discrete Domain sequence is ( )=

( )

â&#x2C6;&#x2019;1

(2)

The FFT based MIMO OFDM system perform the three types of operations such as Pre-coding, Spatial multiplexing, and Diversity-coding. Pre-coding technique can be used to improve the gain of received signal and to reduce the effect of Multipath Fading. Spatial Multiplexing is used to split the higher data rates into lower data rates and to transmitting to the corresponding antennas. In the FFT system the cyclic prefix is added to the transmitted sequence before it is transmitting to evade the Inter Symbol Interference (ISI), Inter Carrier Interference (ICI) and the Inverse FFT operation is performed at the receiver side to construct the original input signal. In the FFT based MIMO-OFDM system the cyclic prefixes are added to decrease the Bandwidth wastage (BW)[5]. The MIMO-OFDM based with FFT uses a Narrow band analysis which produces the high side lobes due to Rectangular window of FFT leads to high PAPR losses and as well as the ISI (Inter Symbol Interference), ICI ( Inter Carrier Interference). 3.2 WAVELET BASED MIMO-OFDM SYSTEM: The Wavelets are the short pulse of the Continuous time signal. The advantages of the Wavelets are consist of a simple mathematical notation functions, they cut up the data into different Frequency components and then study the each component with a resolution matched to its scale. The key advantages in the Wavelets are the symbols overlap in both Time and Frequency domain which exhibits the High Spectral efficiency. Depends upon the requirement the various types of Wavelets can be constructed, Wavelets are short time pulses. The Wavelets are used in many applications including of Quantum physics, Electrical Engineering, and Seismic geology [6]. The wavelet based MIMO-OFDM system has high flexibility, optimum resolution and no need of adding the cyclic prefixes to the transmitted signal. Wavelet transform produce a Multi-resolution disintegration of continuous time signal into different Frequencies with different times [5]. The data rates in the Wavelet Transforms are splitter into smaller data rates and the data rates are sampled into Upper Frequencies as well as Lower Frequencies. The wavelet transform produces high Orthogonal properties and to reproduce the original signal. The Wavelet transform is calculated independently splitter part of the sub signal [9],

III. RELATED WORK Several methods were proposed by different Researcher to compare the performance analysis of MIMOOFDM using based on the FFT and as well as the DWT systems and to compare the performance analysis between the FFT based MIMO-OFDM and to the DWT based MIMO-OFDM systems. The main researches of MIMOOFDM using FFT and DWT based systems are summarized below. 3.1 FFT BASED MIMO-OFDM SYSTEMS: The MIMO-OFDM is implements with the FFT have a lot of advantages of easy computational capabilities and easy implementation. The Fourier Transform analysis is used to obtain the Frequency Spectrum of the signals. FFT Transform algorithm is used to find the Discrete Fourier Transformation function in a faster way with reduced complexity. The FFT algorithm converts the input data stream into N parallel data stream after Modulation technique performed to the input sequence.

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Wavelet transform consist of two types i.e. Continuous and as well as the Discrete Ripple Transform. The Full-band source signal splitting in to the altered Frequency bands and to encrypt all splitter bands individually on their Spectrum specification are called as sub-band coding method. The IDWT works as a Modulator operation performed at the transmitter end and DWT works as a Demodulator at the receiver side.

1. They are zero outside of the segment. 2. The calculation algorithm is maintained and thus very simple. 3. The associate filters are symmetrical. 3.2.3 HAAR WAVELET TRANSFORM: The Haar Wavelet is the simple wavelet among all Wavelets in the communication system. The Haar Wavelets has a simple mathematical function and as well as the simplest wavelet among the all Wavelets in the Wavelets, it has high Symmetric functionalities as well as it explicit the expression in discrete form. The advantage of the Haar Wavelets are conceptually simple, fast and memory efficient. The Haar Wavelets are compactvely supports, the compact support of the Haar Wavelets enable the Haar decomposition to have the good time localization. It can be useful to locate the jump discontinuity in Wavelets and works the signal with even small support Wavelets and the easy construction of the Wavelets are done.

The different types of Wavelets are used for the different types of requirements in the communication system. Some of the Wavelets and their uses, functionalities are explained below as follows. 3.2.1 DAUBECHIES WAVELETS: The origin of the Wavelet functions is Daubechies Wavelets introduced by the Daubechies. It has a scaling function and that are Orthogonal and also having finite vanishing moment of the continuous time signal, this property can be use full to the number of non zero coefficient in the associated filter is finite. They are many extension in this transform said to be db4 and db8 etc, this wavelet is simple mathematical notations and works same of the Haar Transformation function.

3.3 PERFORMANCE ANALYSIS OF FFT OFDM AND DWT OFDM SYSTEMS: The performance of OFDM using FFT and DWT based systems are analyzed in this paper by constructing the various parameters such as BER and with constellation diagrams. The Wavelet based OFDM system performs using of Haar, Bi-orthogonal, Dabauechies Wavelets provides a better performance than the FFT based system. The performance can be analyzed by using the BER with SNR.

3.2.2 BIORTHOGONAL WAVELET TRANSFORM: The Bi-orthogonal Wavelets are the families of compactly supported Symmetric Wavelets, the Symmetric co-efficient in the Bi-orthogonal Wavelets results in Linear phase of the Transfer Function [10][11]. The Wavelets are the very shorter samples of the Continuous Time Signal. The ripples can be vanished in after particular time levels. The Bi-orthogonal Wavelets performs an Analysis as well as the Synthesis operation as showed in the fig1. the notations {∅, , ∅~, ~}, the degree of the vanishing moments for the Wavelet say N, the corresponding degree of vanishing moment of the scaling function is ∅ and for the scaling function ∅~ the Wavelet ~ is fixed. The Bi-orthogonal Wavelet is implements with two bands Bi-orthogonality consist of the Analysis bank and for Synthesis bank to construct the shorter sequence shown in Fig1.

3.3.1 FAST FOURIER TRANSORM: The Fourier Transform analysis is used to obtain the Frequency Spectrum of the signals. The FFT Transform algorithm is used to find the Discrete Fourier Transformation function in a faster way with reduced complexity. The FFT algorithm converts the input data stream into N parallel data stream after Modulation technique performed to the input sequence. The FFT operation of Modulation, adding and removing of cyclic prefix is illustrated below showed in Fig.2. For a given finite data stream which can be represent as X[n], n=0 to N-1 The corresponding output sequence of FFT is ( )=

( )

−1

(3)

And the IFFT i.e. discrete domain sequence is Fig1. Block diagram for a two band orthogonal FB. ( )=

The Bi-orthogonal Wavelets functions has a following Properties

( )

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−1

(4)

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3.3.3 TABULAR REPRESENTATION OF WAVELETS: Table1. BER for BPSK modulation.

Fig2. FFT with cyclic prefix 3.3.2 DISCRETE WAVELET TRANSFORM:

Eb/N0

FFT

HAAR

DB4

BIOR

0.5004

0.4148

0.501

0.5052

0.5003

0.3777

0.5005

0.5039

0.5003

0.3481

0.4998

0.5005

0.4998

0.2486

0.4996

0.4992

0.4998

0.0117

0.4995

0.4992

0.4996

0.4995

0.4991

100

0.4996

0.4995

0.4989

Table2. BER for QPSK modulation.

A Wavelet is a small portion of the continuous signal. They cut up the data into different Frequency components and then study the each component with a resolution matched to its scale. The key advantage in the Wavelets is the symbols overlap in both Time and Frequency domain which exhibits the high Spectral efficiency. Data rates in the Wavelet transforms are splitter into smaller data rates and the data rates are sampled into upper Frequencies as well as lower Frequencies are constructed as from the below Fig3. The Wavelet Transform produces high Orthogonal properties and to reproduce the original signal.

Eb/N0

FFT

HAAR

DB4

BIOR

0.7493

0.6506

0.7591

0.7584

0.7493

0.6088

0.753

0.757

0.7493

0.571

0.7563

0.7566

0.7493

0.4277

0.7541

0.7574

0.7495

0.0245

0.7519

0.7567

0.7497

0.7495

0.7545

100

0.7496

0.7479

0.7511

3.4 WAVELETS IN ANALYSIS OF RAYLEIGH FADING CHANNELS MIMO-OFDM is normally implemented using the Fast Fourier transform (FFT) and Inverse Fast Fourier transform (IFFT), the FFT uses a Rectangular window technique, the use of Rectangular window produces a high side lobes, that impact of side lobes causes a interference when the impairments are not compensated with each other, the alternative method for FFT and IFFT is the Wavelet based OFDM [8], [9]. The Wavelet Transform that produces the resolution subspaces into different forms are used to decompose the signal. ...V < V < V < V <…. (7)

Fig3. DWT filter splitting. At first the input is processed with Low pass filter h(n) and the corresponding output results are approximate coefficients. Next High pass filter gets process and the resultant output is detailed notifications. This represents the how the signal is de composing and the mathematical expressions of de composing is described below, tabular representation of wavelets are constructed as below shone.

-2

∞

1( ) =

( ) (2 − )

-1

Decomposition is done by using of the translation and dilation of a Wavelet function from the various subspaces the dilated and scaling functions are formulated. i.e. {  t  } forms a basis of V . The scaling function and

(5)

the Wavelet function both should satisfy the dilation equation ∞

2( ) =

( )ℎ(2 − )

(6)

 t  =∑ø(2t-n)h(n).

(8)

if ø(t) should be Orthogonal to the translated then h[n] should satisfies the Orthogonality condition. INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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∑h[n]h[n-2m]=δ[m] and ∑(-1) h(n)=0

The analysis side the samples are down sampled by two ,at synthesis side the samples are up samples by the factor 2 and then filtering the Low and High pass coefficients at K levels and then adding the 2 this gives the low pass coefficients at the (K-1) levels are described in the Fig.6.

(9)

Given a sequence we find the another sequence g(n) such that the function satisfy the dilation equation.

 (t)=∑  (2t-n)g(n)

(10)

The Flat Fading channel for a Flat Rayleigh Fading channels using the FFT based and as well as the DWT based system using bi Orthogonal Wavelets showed below.

This function is the wavelet function i.e. function is Orthogonal to the Wavelet function, the Scaling and Wavelet function can be used to decompose the signal into different subspaces. ø(t) occupies the half the Frequency space of ø(2t) and similarly for the wavelet Frequencies and the corresponding Low pass Frequency function is h(n) and High pass Frequency function is g(-n). This can be represented using structures shown below in Fig4, Fig5.

Fig4. The decomposition

tree

structure

the

3.4.1 SIMULATION RESULTS:

wavelet Fig7. Performance of FFT-OFDM with DWT-OFDM in Flat Fading Rayleigh channels. IV.PROPOSED DWT MMO-OFDM SYSTEM The proposed DWT MIMO-OFDM system has a lot of advantages over the FFT based MIMO-OFDM system. DWT based system constructed with the Haar mother transform reduces number of multiple antennas than the consequences of required number of antennas, which perfectly suits for the arena of 3GPP network. The DWT based MIMO-OFDM with modified Haar transform converts the matrix into Circulant matrix form and simulation can be don easily and as well as it performs the Interleaving operation produce efficient result . Unlike the FFT based MIMO-OFDM the DWT based MIMO-OFDM particularly using the Haar mother wavelet transformation is conceptually simple, provides the great Orthogonal properties and it has a absolute Symmetric property, the DWT based MIMO-OFDM oversample the signal into different resolutions as well as oversamples the signal in both Time domain and as well as in Frequency domain. By using the sub band coding in DWT uses Haar transformation can reconstruct the samples accurately. The performance measure can be done by using the implementation of BER to the transmission capability. The DWT based MIMO-OFDM can be suitable for all applications of the next generation wireless systems and it has a capability of delivering a high speed packet access (HSPA) capabilities. The representation of the DWT based transceiver of MIMO-OFDM is constructed below.

Fig5. The structure of wavelet decomposing.

Fig6. Analysis and synthesis representation of Wavelets.

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References: [1] Introduction to Space-Time Wireless Communications, Cambridge, UK: Cambridge Univ. Press, 2003. By A.J. Paulraj, R.U.Nabar, and D. A. Gore [2] G. J. Foschini, “Layered space -time architecture in fading environment for wireless communication when using multi-element antennas,” Bell Labs Tech. J., pp. 41– 59, Autumn 1996. [3] G. G. Raleigh and J. M. Cioffi, “Spatio-temporal coding for wireless communication system,” IEEE Trans. Communications., vol. 46, pp. 357–366, Mar. 1998. [4] “MCM(Multi carrier modulation for data transmission in wireless communication: An idea whose time has come”, IEEE Communication Magazine, vol. 28, no. 5 by J. A. C Bingam.

Fig8. Block diagram representation of DWT based MIMOOFDM transmitter.

[5] R. Dilmarghani and Ghavami. M, Fourier Vs Wavelet based ultra wide band Systems, 18th IEEE International Symposium, indoor and in mobile radio communications, pp.1-5, September, 2007. [6] R. Crandal, projects on Scientific computations, New York, 1994, pp. 197-198, 211-212. [7]. Hussain and Abdullah, Studies on FFT-OFDM and DWT-OFDM systems, ICCCP, 2009. [8] W. Saad, N. El-Fishawy, S. EL-Rabaie, An Efficient Technique for OFDM System Using DWT, Springer-Verlag Berlin Heidelberg, pp. 533–541, 2010 [9] Jarrod Cook, Nathan Gov, Research and Implementation of UWB technology, Final Report, Senior Capstone Project, 2007 [10] B. Vidakovic and P. Muller, "Wavelets for Kids," 1994, published. Part One, and Part Two.

Fig9. Block diagram representation of DWT based MIMOOFDM receiver

[11] M.V. Wickerhauser, "Acoustic Signal Compression with Wave Packets," 1989. Available by TeXing this TeX Paper

VI. CONCLUSION

[12]. Design and implementation of orthogonal transform based Haar Division Multiplexing for 3GPP Networks by B.Monisha, M.Ramkumar, M.V.Priya, A.Jenifer Philomina, D.Parthiban, S.Suganya, N.R.Raajan. (ICCCI 2012), Jan. 10– 12, 2012.

The DWT implementation of MIMO-OFDM system with Haar constructed Transform produce the better results when compared to the FFT based MIMO-OFDM System, it can be used effectively for the future generation of wireless communication systems such as, 4G, HSPA.

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Study of Various Effects on Peak to Average Power Reduction using OFDM EM HARINATH Smt. N. PUSHPALATHA M.Tech DECS Student Assistant Professor Department of ECE, AITS, TIRUPATI Department of ECE, AITS, TIRUPATI Hari.810213@gmail.com Pushpalatha_nainaru@gmail.com Annamachrya institute of technology and sciences (AITS),TIRUPATI

Abstract: In this paper the novel method of complex weighting for peak to average power (PAPR) reduction of OFDM is addressed. The Study of various effects on peak to average power reduction using OFDM on this paper. The simulation result are studied about the combination of both different amplitude weighting factors including rectangular , Bartlett , Gaussian , raised cosine , Half-sin , Shannon , and sub carrier masking with phasing of each OFDM Subcarrier using random phase updating algorithm. By using the amplitude weighting factor Bit error performance of weighted multicarrier transmission over a multipath channel is also investigated. In the random phase updating algorithm the phase of each carrier is updated by a random increment until the PAPR goes below a certain threshold level. Further the random phase updating algorithm has been extended by dynamically reducing the threshold level. For an OFDM system with 322 subcarriers and by Gaussian weighting combined with random phase updating, a PAPR reduction gain of 3.2 dB can be reduced. Result show that grouping of amplitudes weights and phase reduce the hardware complexity while not much impacting the PAPR reduction gain of the method. Even further dynamic threshold gives the best results and can reduce the mean power variance of 8-carrier OFDM signal with BPSK modulation by a factor of 7 dB.

1. Introduction: Orthogonal frequency division multiplexing (OFDM) is a parallel transmission method where the input data is divided into several parallel information sequences. And each sequence modulates a subcarrier. OFDM signal has a non constant envelope characteristic since modulated signal form orthogonal subcarriers are summed.

The PAPR problem is occurred when these signals are added up coherently, resulting in a high peak. The high PAPR of OFDM signal is not favorable for the power amplifiers working in non-linear region. Different methods have been proposed to mitigate the PAPR problems of OFDM. These techniques are mainly divided into two categories: signal scrambling and signal distortion techniques. Signal scrambling techniques are all variations on how to modify the phase of OFDM subcarriers to decrease the PAPR. The signal distortion technique is developed to reduce the amplitude of samples whose power exceeds a certain threshold. The Signal scrambling techniques are as follows: Block coding techniques, Block coding scheme with error correction, Selected mapping (SLM), Partial transmit sequence (PTS), Interleaving technique, Tone reservation (TR), Tone injection (TI). The Signal distortion techniques are as follows: Peak windowing, Envelope scaling, Peak reduction carrier, clipping and filtering. This paper addresses the PAPR reduction of OFDM by combination of both signal scrambling and signal distortion techniques.

2.0. Related project work: In this section explain the existing methods of our paper. 2.1. Weighted OFDM for wireless multipath channel 2.2. Random phase updating algorithm for OFDM Transmission with low PAPR The above two existing methods explained below section

2.1. Weighted OFDM for wireless multipath channel 2.1.1. Description:

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OFDM also called multicarrier (MC) technique is a modulation method that can be used for the high speed data communications. In this modulation is scheme transmission is carried out in parallel on the different frequencies. This technique is desirable for the transmission of the digital data through the multipath fading channel. The advantage of this technique is spectral efficiency. In the MC method the spectra of sub channels overlap each other while satisfying orthogonality, giving rise to the spectral efficiency. Because of the parallel transmission in the OFDM technique the symbol duration is increased. Another advantage of this method to work in the channels having impulsive noise characteristics. One more advantage of the MC method is its implementation with the FFT algorithm which provides full digital implementation of the modulator and demodulator.

2.1.2. Weighted modulation:

Where f0 is the lowest frequency, m is the number of carriers and T is the OFDM symbol duration. The weighted MC transmitted signal is ( )=

()

(

)

( −

) (2)

Where α m is the real weighting factor of the m-th carrier, bm (i) is the symbol of the m-th sub channel at time interval iT, which is±1 for BPSK Modulation and (±1 ± )/√2 for QPSK ,p(t) is a rectangular function with amplitude one and duration T.

multicarrier

In this method of weighted OFDM is explained and the PAPR reduction associated with this technique is reported. In serial data transmission, sequence of data is transmitted as a train of serial pulses. However in parallel transmission each bit of a sequence of M-bits modulates a carrier. In the multicarrier technique transmission is parallel. The block diagram to the conventional MC method but with a different that each carrier is weighted by a real factor αm m=0, 1, 2………M-1. In the modulator the input data with the rate R is divided into the M parallel information sequences a weighted subcarrier. In this method the frequency of m-th carrier is =

m=0,1,2,……M-1

(1)

2.1.3. Different weighting factors In this section several weighting factors for weighting of the OFDM signal is describe.

Rectangular: This weighting function has Rectangular shape and is expressed by

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0≤

≤ ℎ

−1

( ) = | ( )|

0 (3) Bartlett: This weighting function has simply a triangular shape for 0 ≤ ≤ − 1 1−

, = 0

(10) ( )

Gaussian: These factors are generated based on the Gaussian function

−

)

[ ( )] =

weighting

function

| |

| [

∗]

∗

(

)

(12) The symbols on different carriers are assumed to be independent i.e., therefore, the second term in (13) is zero and accordingly, by using (9) the average power becomes

(6) is

(7) 0 ℎ Shannon: The shape of this weighting factors is the sinc function i.e., sinc(x) = (sin (πx)/ (πx)) , =

sin

[ ( )] =

| =1

(13) The variation of the instantaneous power of OFDM signal from the average is ∆ ( ) = ( ) − [ ( )]

(8) 0

(

)∗

(

(11) Averaging the power P (t) yields E [P (t)]

if 0≤m≤M-1

ℎ

Half-sin: This explained by

(5)

0 ℎ Where s= spread or standard deviation of the weighting factors around M/2 Raised cosine: The shape of this function in the interval [0,M-1] is described by 1cos(2πm/M) , =

−

, =

)

(4)

ℎ

(

)∗

(

ℎ

(

)∗

(

)

2.1.4. PAPR of Weighted OFDM

In this section the impact of weighting of OFDM signal on the PAPR is investigated. The OFDM signal of (2) in the time interval of 0 ≤ ≤ can be written as

(14) Averaging of ∆ ( ) over a symbol period of T yields

( )=

()

∆ ( )

( )|

(15) Where R cc (i) is the autocorrelation function of the complex sequence cm=bm.α m

(9) For the calculation of PAPR first by using (10) we obtain the instantaneous power of OFDM signal as

()=

∗

(16)

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The parameter ρ is the power variance of the OFDM signal and as is described below is a good measure of the PAPR.

the average is Δp(t)=P(t)-E[P(t)] and accordingly, the power variance (PV) of OFDM signal, denoted by ρ

{ ( )}

{ (

= max{ ( )} = )} (17)

[ ≤

= =

( 1/ 2

( − 1) 2

(18) Using (18) and (19) it can be easily shown that PAPR has the following relationship with the power variance − ( )=

√

∫

( )=

2.2. Random Phase Updating Algorithm for OFDM Transmission with low PAPR OFDM is the basic technology for a number of communication systems such as Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), HIPERLAN-2,I EEE802.11a and Digital subscriber line. In this random phase updating algorithm we are using the signal scrambling technique. Signal scrambling techniques are all variations on how to modify the phase to decrease the PAPR.

2.2.2. PAPR of OFDM signal can

( )= (21) Where T is the OFDM symbol duration, bm is the symbol of the m-th sub channel, which is ±1 for the BPSK modulation and (±1 ± )/√2 for QPSK modulation and M is the number of carriers. The power of s(t) is ∗

(

( )|

∅

(24) Where 2πφm is the m-th subcarrier phase shift. Adding random phases to each subcarrier will change the power variance of OFDM Signal. In the random phase updating algorithm, the phase of each subcarrier is updated by a random increment as: (∅ ) = (∅ ) + (∆∅ ) (25) Where i is the iteration index and is the phase increment of the m-th subcarrier at ith iteration. Assume the initial phase is zero, consequently a random phase increment is generated and the phase is updated by adding the increment to the phase of that subcarrier. Flow chart of the algorithm for this iterative phase updating is shown in figure. Figure 8a a certain threshold for PV is set and for figure 8b a limited number of iterations is allowed. Two distributions are Gaussian and uniform where the uniform distribution chosen for the distribution of phase increments. A connection between phase shift variance and the number of iteration

2.2.1. Description

( ) = | ( )| =

In the random phase updating algorithm for each carrier a random phase is generated and assigned to that carrier. Using (23) the OFDM signal

(20)

The OFDM signal in the period of 0 ≤ ≤ be written as

2.2.3. RANDOM PHASE UPDATING ALGORITHM

(19)

∞

(∆ ( ) )

(23) Where Rbb (i) is the autocorrelation function of the sequence bm as ∗ ()=∑

] ) exp −

)

(22) The PAPR of the OFDM signal is written as PAPR=Max {P(t)}/Mean{p(t)}. The variation of the instantaneous power of OFDM signal from

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from zero initial phases, the random phase shifts are generated and combined with the symbols, and the threshold is not changed.

2.3. PRAPOSED METHOD: In the above existing methods the high PAPR has been reduced due to this the hardware complexity is increased, so much impact has not been on the reduction of the PAPR and also the above methods have the demerit that has the PAPR reduction gain is very low. So the above two methods clubbed together and creates a new method called as the complex weighted OFDM Transmission with low PAPR. By applying both techniques together will further reduce the PAPR by a factor of 4.8dB. Complex Weighting for Multicarrier modulation The OFDM Signal for one symbol interval 0 ≤ ≤ is written as

s reaching the threshold. Fig.2. Flow chart showing the iterative random phase updating algorithm. A) With threshold. B) With limited number of iterations.

( )=

(

)∗

(

)

(26) Where M is number of subcarriers, BM is modulation data of the m-th subcarrier, T is the OFDM symbol period, and wm is a complex factor defined as = Where a positive real value and φm α m is the phase of m-th subcarrier. The block diagram of an OFDM modulator with complex eighting factors is shown in fig

and receiver.

2.2.4. Phase Updating Dynamic threshold

with

Fig.3. Flowchart of the random phase updating algorithm with dynamic threshold. The selection of random phase increments it is possible to reduce the PV threshold. As illustrated in figure 11 this approach the threshold level of the algorithm is dynamically reduced. The first step of the algorithm is to calculate the PV of the original OFDM symbol, and then set the first threshold to e.g. 10% lower. Then starting

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Fig 5. Block diagram of complex-weighted OFDM modulator

weightings of the OFDM signal are sketched respectively.The CDF of PAPR of OFDM signal with several scenarios of weighting and phasing are depicted in Fig. 1 for M = 32. In Fig. phasing is applied by random phase updating with Uniform distribution (x = 1.0) and power variance threshold ρTh = -4 dB.

3.0. Simulation results: By comparing the above two existing methods with the proposed method the result should be shown below. In the weighted OFDM for the wireless multi path channels

Fig.8. CDF plots of PAPR for different weightings with and without phase c1: rectangular weighting, no phasing , c2: rectangular weighting with phasing , c3: Gaussian weighting (std=M/16) , no phasing , c4: Gaussian weighting (std= M/16) with phasing.

Figure 6 illustrates the CDF of the power variance for different weighting functions. Table 1 for the OFDM signal with 256 carriers and BPSK modulations by applying Gaussian weighting , the ρ is reduced by a factor of 3.2 db and for the QPSK Modulation by a factor of

4.0. Conclusion: In this paper we have addressed the novel method of PAPR reduction for OFDM signal by applying both amplitude weighting and phasing of OFDM subcarriers. This joint application gives more PAPR reduction gain than only weighting or phasing. Employing both weighting and phasing to subcarriers implies more complex implementation. However, the complexity can be reduced by grouping of the subcarriers when weighting or phasing is applied. Furthermore, the complex weighting with dynamic threshold was studied. Combining amplitude weighting, phasing and dynamic thresholding will result in a larger PAPR reduction gain of the proposed algorithm.

6.1 dB Fig .7 the irreducible bit error probability of the OFDM signals with different functions versus rms delay spread of the channel is illustrated. The BPSK and QPSK modulations are considered and simulations are carried out for 5000 symbols weighted by proper weighting functions. In figs.3 and figs.4 the parameter ρ versus number of the messages for BPSK and QPSK modulations and for different

References: [1] T.A.Wilkinson et al," Block coding scheme for Reduction of peak to mean envelope power ratio of Multicarrier

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transmission schemes," Electronics Letters, Vol. 30, No. 25, 1994. [2] R.F.H. Fischer et al," Reducing the peakto-average power ratio of multicarrier modulation by selected mapping," Electronics Letters, Vol. 32, No. 22, 1996. [3] G. Wade et al," Peak-to-average power reduction for OFDM schemes by selective scrambling," Electronics Letters, Vol. 32, No. 21, 1996. [4] S.H.Muller and J.B.Huber," OFDM with reduced peak-to-average power ratio by optimum [5] M.Friese," Multitone signals with low crest factor," IEEE Trans. Commun., Vol. 45, No. 10, 1997. [6] J.Tollado, Multicarrier Modulation with Low PAR, Kluwer Publishers, MA, USA, 2000. [7] G.L.Stuber and D.Kim," Clipping noise mitigation for OFDM by decision aided reconstruction," IEEE Commun. Letters, Vol. 3, No. 1, 1999. [8] R.J.van Nee and A. de Wild," Reducing peak-to average power ratio of OFDM," IEEE Vehicle. Technol. Conf., pp. 2072-2076, 1996.

Distortions of an OFDM system using efficient an Adaptive predistorter," Commun., Vol-2

IEEE

Trans.

[14] K. S. Lidsheim, “Peak-to-Average Power Reduction by Phase Shift Optimization for Multicarrier Transmission,” MSc. thesis, Delft University of Technology, Delft, The Netherlands, April 2001. [15] R. Prasad and R. D. J. van Nee, OFDM for Wireless Multimedia Communications. Boston: Artech House, 1999. [16] H. Nikookar and R. Prasad, “Weighted OFDM for wireless multipath channels,” IEICE Commun. Trans., vol. E83-B, no. 8, pp. 1864-1872,Aug. 2000. [17] H. Nikookar and K. S. Lidsheim, “Random phase updating algorithm for OFDM transmission with low PAPR,” IEEE Broadcasting Trans., vol. 48, no. 2, pp. 123128, Jun. 2002

[9] R.Prasad and R.J. van Nee, OFDM for Wireless Multimedia Communications, Artech House, Boston, 1999. [10] O.Muta et al," Peak power suppression with parity carrier for multicarrier transmission," IEEE Vehicle. Technol. Conf. (VTC'99-Fall), pp. 2923-2928, 1999. [11] H.Nikookar and R.Prasad," Weighted multicarrier modulation for peak-to average power reduction," IEICE, Trans. Commun., Vol. E83-B, No. 8, 2000. [12] X.Wang and T.T.Tjhung," Reduction of peak-toaverage power ratio of OFDM system using companding technique," IEEE Trans. On Broadcasting, Vol. 45, No. 3, 1999. [13] Y.S.Chu et al.," On compensating nonlinear

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ECO FRIENDLY CONSTRUCTION METHODS AND MATERIALS AUTHOR NAME : PRIYANKA.M KINGSTON ENGINEERING COLLEGE, VELLORE CONTANCT INFO : 9894723744 EMAIL ADDRESS: priyaevergreen05@gmail.com

ABSTRACT : A green building, which is also known as a sustainable building is designed to meet some objectives such as occupant health; using energy, water, and other resources more efficiently; and reducing the overall impact to the environment. It is an opportunity to use the resources efficiently while creating healthier buildings that improve human health, build a better environment, and provide cost savings. All the development projects lead to over-consumption of natural resources. This leads to serious environmental problems. Green building concept deals with the optimum use of natural resources for the development of infrastructure. The low cost eco-friendly house is the modern construction method which uses locally available material and unskilled labor and also reduces the construction time. Similarly, use of recycled plastic, recycled aggregates and municipal wastes for the construction of pavement has considerable effect on the environment of earth. Another advanced method is the construction of low carbon building which uses sustainable materials like blended cement, compacted fly ash blocks, low energy intensity floor and roofing system, rammed earth walls and stabilized mud blocks etc. This ultimately results in reduction of green house gases which will help to reduce green house effect. This paper presents an overview of application of modern green infrastructure construction technology which makes a significant impact on conservation/proper utilization of resources like land, water, energy, air, material etc thereby reducing the overall cost of construction as well as adverse impacts of climate change .

KEYWORDS : Sustainable building, eco-friendly house, low carbon building, green house effect . optimum use

INTROUCTION : In today’s world of climate change and high energy prices, it is critical that buildings use as few fossil fuels as possible to “future proof” the home against unpredictable and rapidly rising prices. There are many definitions of what a green building is or does. Definitions may range from a building that is “not as bad” as the average building in terms of its impact on the environment or one that is “notably better” than the average building, to one that may even represent a regenerative process where there is actually an improvement and restoration of the site and it’s surrounding environment. The ideal “green” project preserves and restores habitat that is vital for sustaining life and becomes a net producer and exporter of resources, materials, energy and water rather than being a net consumer.A green building is one whose construction and lifetime of operation assure the healthiest possible environment while representing the most efficient and least disruptive use of land water, energy and resources. SETTING GREEN GOALS AND OBJECTIVES… Once the decision to build green has been made, one of the first steps in the green design process is to establish firm environmental goals for the project. This is often done during

what is called a goal setting or targeting session. During this session, it is important to set specific measurable goals for things like energy efficiency, water conservation, on-site treatment of rain water and storm water, material and resource management, construction waste management, and to assign responsibility for meeting these goals to specific members of the design team. Each goal needs a champion who will see that objective through to the end. GREEN BUILDING ... The `Green Building' concept is gaining importance in various countries, including India. These are buildings that ensure that waste is minimized at every stage during the construction and operation of the building, resulting in low costs, according to experts in the technology. A green building is a structure that is environmentally responsible and resource efficient throughout its life-cycle. Expand and complement the classical building design, concerns of economy, utility, durability and comfort. COMPACTED FLY ASH BLOCKS… A mixture of lime, fly ash and stone crusher dust can be compacted into a high-density block. Lime reacts with fly ash minerals forming water insoluble bonds imparting strength . Some advantages of the technology are: (a) decentralized production in tiny scale industries, (b) utilization of industrial waste products and (c) energy efficient and environment friendly. STABILIZED MUD BLOCK FOR MASONARYStabilized mud blocks (SMB) are energy efficient eco-friendly alternatives to burnt clay bricks. These are solid blocks manufactured by compacting a mixture of soil, sand, stabilizer (cement/lime) and water. After 28 days curing, these blocks are used for wall construction. Compressive strength of the block greatly depends upon the soil composition, density of the block and percentage of stabilizer (cement/lime). Major advantages of SMB are: (a) energy efficient, do not require burning, 60–70% energy saving when compared with burnt clay bricks, (b) decentralized production, production on site is possible, (c) utilization of other industrial solid wastes like stone quarry dust, fly ash etc. and (d) easy to adjust the block strength by adjusting stabilizer content. BLENDED CEMENTThese are cements containing a high volume of one or more complementary cementing materials (CCM), such as coal fly ash , granulated slag, silica fume and reactive ricehusk ash. A large volume of CO2 is directly emitted during the cement manufacturing process (0.9 tonnes/tone of clinker). Reduction in the quantity of clinker by substituting with CCM results in lesser CO2 emissions. GREEN TECHN LOGY FOR ROAD CONSTRUCTION Lime reacts with fly ash minerals forming water

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 insoluble road construction technology needs changes to minimize dam bonds imparting strength to the block. Some advantages of the technology are: (a) decentralized production in tiny scale indusage to the environment of the earth. Aggregates are heated to tries, (b) utilization of industrial waste products and (c) energy temperatures between 1500C and 1800C for drying, proper efficient and environment friendly .coating and mixing with bitumen. Mixing temperature of bituminous mixes can be lowered by using foamed bitumen, tumen emulsion and some chemicals which reduce the viscosity of bitumen so that less fuel is used with consequent reduction of green house gases. Use of recycled plastic, recycled aggregates and municipal wastes will slow down the degradation of the earth. pavement can be designed to help charging of groundwater. Municipal wastes consist of considerable amount of waste materials such as plaster, bricks bats, demolished concrete. They can easily be used as materials for widening of roads as well as new road construction. Some of the waste product from coal mining is highly variable and sometimes may get ignited due to presence of pyrites. If they are used deep in embankment, there is little risk of combustion due to too low air content to allow combustion All footpaths, parking yards, roads of residential area. Fly ash Block slow volume roads can be made permeable so that rain water GREEN TECHNOLOGY FOR ECO- FRIENDLY HOUSE Buildings are one of the major consumers of energy and are the third largest consumers of energy, after industry and agriculture. Buildings annually consume more than 20% of electricity used in India. The awareness about the impact of depletion of fossil fuels and global warming phenomena has led to renewed interest in the green technologies. Eco-friendly house uses the naturally available resources. The house can be built in such a way that it can use the naturally available light and ventilation. The openings can be provided in south-west side which will provide better ventilation. Windows can be placed considering cross ventilation concept. Wind breakers can be provided for west side windows which will guide more air in the house. Higher ceiling height can be provided than the conventional one which will give relatively cool air at the leaving area. If the built up area is less then more space will be available around the building for air circulation. Solar panels can be installed which will reduce the burden on the electricity consumption. Solar system can be used for the cooking of food as well as water heating. This will reduce the consumption of electricity or LPG. Implementation of rain water harvesting system can be beneficial in many ways. Few of them are i) Independent and ample supply of water in the dwelling. ii) Water received is free of costs. Use of this water significantly reduces water bills for purchased water from municipal supply. iii) Costs incurred for purifying the water for potable use are nominal. iv) For users located in the rural areas, an independent supply of water avoids the cost of installing a public water supply system. v) Rainwater harvesting lessens local soil erosion and flooding caused by rapid runoff of water from impervious cover such as pavements and roofs. WOOL BRICKS The objective was to produce bricks reinforced with wool and to obtain a composite that was more sustainable , non-toxic, using abundant local materials, and would mechanically improve the brick’s strength Amazingly, with the added wool and alginate (a natural polymer found in seaweed) the researchers' mechanical tests discovered that this new brick was 37% stronger than regular unfired, stablized earth bricks.These fibres improve the strength of compressed bricks reduce the formation of fissures and

deformities as a result of contraction,reduce drying time and increases the bricks resistance to flexion. SOLAR TILES - It exist only to protect the building . They spend large portion of day by absorbing energy from the sun. PAPER INSULATION – Made from recycled newspaper and cardboard. Then mixed with Chemical form. They are insect resistant and fire retardant . TRIPLE GLAZED WINDOW- Super-efficient windows.Stops heat to enter the building & from direct sun ECO-FRIENDLY – Using of bamboo stick instead instead of steel bars SOCIAL BENIFITS:  Enhance occupant comfort and health  Heighten aesthetic qualities  Minimize strain on local infrastructure  Improve overall quality of life ENVIRONMENTAL BENEFITS:  Enhance and protect biodiversity and ecosystems  Improve air and water quality  Reduce waste streams  Conserve and restore natural resources

ECONOMICAL BENEFITS :  Reduce operating costs  Create, expand, and shape markets for green product and services  Improve occupant productivity  Optimize life-cycle economic performance MERITS OF GREENBUILDING :  Efficient Technologies  Easier Maintenance  Return On Investment  Improved Indoor Air Quality  Energy Efficiency  Waste Reduction  Temperature Moderation  Water Conservation  Economical Construction For Poor  Healthier Lifestyles and Recreation  Improved Health DEMERITS OF GREEN BUILDING :  Initial Cost Is High  Availability Of Materials  Need More Time To Construct  Need Skiled Worker CONCLUSION Nowadays, we should make a way to maximize our natural resources and also help our mother earth to get some relief since pollution is everywhere plus the global warming that we are all experiencing. Non-renewable energy is expensive and unsafe but did you know that through green building we can save a lot of energy.Before that, let's define first the meaning of green building (know also as green construction is the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building's lifecycle: from siting to design, construction, operation, maintenance, renovation, and deconstruction.The importance of this is it lessen the consume of energy and the pollution as well because the more we use nonrenewable energy the higher the risk of pollution.

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REFERENCES: 1. K.Ghavami Bamboo as reinforcement in structural concrete elements Lightweight Concrete Beams, Pontificia Universidade Catolica, Rio deJaneiro, Brazil (2003). 2. V.R. Desai, Green infrastructure: overview and case study, IIT Kharagpur, 2010. 3. B.B.Pandey, Green technology for road constructio, Workshop on green infrastructure at 2010. 4. Sherwood,P.T.(2001), Alternate materials in road construction’, Thomas Telford. 5. Heerwagen J. Green buildings, organizational success and occupant productivity. Building Research & Information 2000;28(5/6):353–67. 6. Ajdukiewicz A B, kliszczewicz A T. (2007). Comparative tests of beams and columns made of recycled aggregate concrete and natural aggregate concrete. Journal of Advanced Concrete Technology, 5(2): 259-273. 7. Rao A, Jha K N, Misra S. (2007). Use of aggregates from recycled construction and demolition waste in concrete. Resources, Conservation and Recycling. 50(1): 71-81. 8. Charles J. Kibert, Sustainable construction: green building design and delivery, Book. 9. Jerry Yudelson, S. Richard Fedrizzi, The green building revolution, by U.S. Green Building Council. .http://www.greenconcepts.com/ |

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A REVIEW ON ENHANCEMENT OF DEGRADED DOCUMENT IMAGES BASED ON IMAGE BINARIZATION SYSTEM 1

N.S.Bharath Kumar.

Sreenivasan.B,

A.Rajani

M.Tech (DSCE) Student,

Assistant professor Assistant professor Department of ECE,AITS Annamacharya Institute of Technology and Sciences,Tirupati,India-517520 1

nsnandi1990@gmail.com 2 srinu3215@gmail.com 3 rajanirevanth446@gmail.com

the document text and background. Thresholding plays major role in Binarization. Thresholding is mainly dived into two classes’ namely global thresholding and local thresholding. The major issues that appear in the degraded document images are variation in the character stroke width, stroke brightness, stroke connections and shadows on image objects, smear and strains. In some handwritten degraded document images the ink of one side has disposed into the other side. A particular and efficient technique has used to achieve best results. Image Binarization technique was become popular due to its step-wise procedure to reduce the normalization noise and other issues that appears in the previous methods and finally follows a post processing procedure to yield good results. Image Binarization technique extends the previous local maximum and minimum method and the methods that are used in the latest Document Image Binarization Contests. Binarization Technique having the capability of handling many degraded documents with minimum parameter tuning. Historical documents will not have a clear bimodal pattern, so global thresholding is not a suitable approach for document Binarization. Global thresholding is simple, but cannot work properly for complex document backgrounds. Adaptive or Local thresholding which estimates thresholds for each and every pixel in an image is usually a better approach for historical document Binarization. Image Binarization Technique dose not uses any windowing techniques as in the case of proposed technique is, it existing methods. Binarization Technique calculates the image contrast by using local maximum and minimum. When compared with image gradient, image contrast is more responsible for detecting high contrast image pixels that was present around the text stroke boundaries. Thresholding method is capable of handling complex variations in the background such as uneven illumination, uneven surface, noise and bleeds through. Adaptive Contrast image makes use of image gradient widely for edge detection and to find out the text stroke edges. The existing method for the degraded document images is Ni-blacks approach “An Introduction to the Digital Image processing”. The procedure that was involved in the Ni-black approach to separate text from background is de-noising through Weiner filter, estimation of the foreground regions, estimation of the background

Abstract — Goal of separating the text from low quality and noisy document images are big challenging task due to small or large variation between the foreground and background regions of the various document images. The new document Image Binarization Technique is used to addresses these issues by using Adaptive Image Contrast. The Adaptive Image Contrast is the combination of local image contrast and the local image Gradient that is equivalent to text and background variations caused by different degraded document images. Image Binarization Technique involves the process of constructing adaptive contrast map for the input degraded image. The contrast map is then binarized and is combined with the Cannie’s edge map to determine the text stroke edge pixels. Edge detection through the canny process will gives accurate results instead of producing responses for the non edges. The Cannie’s process involves the process of reducing the amount unwanted and error information through the filtering process. The next step is the separation of text from document by adaptive thresholding that is determined based on the intensities of the detected text stroke edge pixels. Document Image Binarization Technique is simple, robust and yields good results when compared with several different database sets that are evaluated by different techniques.

Keywords: Adaptive Contrast Image, Document Analysis, Degraded Document Binarization Process, Edge Detection, Local Thresholding.

I.INTRODUCTION The Document Image Binarization technique is applied at the starting stage of document analysis process. Binarization refers to the process of converting the gray scale image into a binary image. Binarization Technique segments the image pixels into two fields namely white pixels as foreground text and black as the background surface of the document. A fast and accurate Image Binarization technique was chosen in order to accomplish the document analysis task such as Optical Character Recognition (OCR).As more and more degraded documents are digitized, the importance of such document Image Binarization also increases accordingly. Thresholding of degraded document images is an unsolved problem due to high and little variations between

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surface, interpolating the foreground pixels with the background surface, finally post processing is required. Niblack approach calculates the local threshold by using the mean and standard variation of image pixels within the local neighborhood window. The main disadvantage of the window based thresholding techniques is the thresholding performance depends on window size and character stroke width. Ni-blacks approach introduces some extra noise during the detection of the Pixels on the results of approximated foreground region. The local image contrast and local image gradient are also plays major role in the segmentation of the text from document background. Local image contrast and image gradient are very effective and have been used in many image Binarization techniques. II.OVERVIEW

Minimum (LMM) method will have a good property that it is tolerant to uneven illumination. The LMM method first constructs a contrast image and detects high contrast image pixels that exist around text stroke boundary. Thresholding is applied in order to separate the text and finally post processing is applied. The LMM technique yields a good result when it is applied to a datasets that are used in the recent Document image Binarization Contests (DIBCO). Thresholding of degraded document images is a serious problem due to large variations between the foreground and background as shown in the below figure.

2.1 DOCUMENT IMAGE BINARIZATION SYSTEM In order to overcome the issues appears in the degraded document images there is a necessity to develop an enhanced system for low contrast and noisy document images. Document Image Binarization scheme involved in the Document Image Binarization Contest (IBCO) for degraded document images is an effective scheme for analysis of text from degraded documents. Binarization technique is a well suitable procedure for the applications like Optical Character Recognition (OCR), Contrast Image Enhancement (CIE). The recent Document Image Binarization Contest (IBCO) held under the combined framework of International Conference on Document Analysis and Recognition (IDAR) and Handwritten Document Image Binarization Contest (HDIBC) shows recent efforts on these issues. The adaptive document image Binarization combines the local image contrast with the local image gradient to derive an adaptive local image contrast in order to overcome the normalization problem.

Figure 1: examples of degraded document images

3.1.1. Contrast Image Construction Local maximum and minimum filter extends the previous Bunsen technique which calculates the image contrast based on the maximum and minimum intensities within the local neighbor window. In Bunsen paper the local contrast is evaluated as follows.

III. RELATED WORK

C (I,J)=I MAXIMUM (I,J) – I MINIMUM (I,J)

There are several document image Binarization contests (DIBCO) based on different methodologies developed by the various researchers. The various methods and systems are summarized as follows.

Where C (I , J)=Local image contrast. The local image contrast evaluated by local maximum and minimum is shown below

C (I, J) =

3.1. Binarization of degraded document images by local maximum and minimum filter.

( , )– ( ,)

(1)

( ,) ( ,) €

(2)

Where

€ is a positive small number that is added when local maximum is equal to 0.

3.2. Ni-black approach “An Introduction to digital image processing”.

3.1.2. High Contrast Pixel Detection 3.1. LOCAL MAXIMUM AND MINIMUM: As the local image contrast and gradient are determined by the difference between the maximum and minimum intensities within the local window then the pixels at both sides of text stroke will be selected as high contrast pixels. The binary map can be improved by the combination edges with the canny edge detector. Image gradient plays important role in edge detection. Image

Local Maximum and Minimum (LMM) method makes use of image contrast that is calculated based on determining the distance between the maximum and minimum intensities of the pixels within the local neighborhood window. Compared with image gradient, image contrast evaluated by the Local Maximum and

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gradient indicates the sharp discontinuities in the gray scale image and indicates the directional changes on the intensities of the image pixels. The below figures indicate the image contrast and image gradient.

windowing technique .In Ni-blacks method the threshold value is calculated based in the mid-range values of the neighboring window. The Ni-blacks scheme consists of step wise procedure. Ni-blacks approach calculates the rough estimation of the foreground regions. Foreground pixels are a subset of Ni-blacks result and also introduces some noise. Ni-blacks algorithm calculates a threshold along the pixel by pixel by shifting a rectangular window across the image. The threshold T for the centre pixel of the window is calculated by using the mean M and variance V corresponding to the grey values in the window. T=M + k V Where Constant K=-0.2.

Figure 2 (a) Global thresholding of image gradient

(4)

The value of k is used to determine how much of object boundary is taken as a part of the given object. The brief methodology of the Ni-blacks approach is summarized below.

3.2.2. Pre-processing: Pre-processing is essential in order to remove the noise present in the gray scale source image, to smooth the background texture. Weiner filter is used to remove the noise and to increase the contrast between the text and background. The main purpose of the Weiner filter used in the filtering technique is for image restoration. The source image I sis transformed into grayscale image according to the below formula.

(b) Global thresholding of image contrast.

3.1.3. Threshold estimation: Thresholding determination from detected high contrast image pixels is based on two factors. First, the text pixels should be close to the high contrast image pixels. Second, the intensity of the text pixels should be smaller than the average intensity of the detected high contrast image pixels within the local window. The document text from the detected text stroke edge pixels can be extracted as follows. R(x, y) =

I(x, y)=µ + (ð2-v2)(I s(x, y)-µ)/ ð2

Where µ is a local mean and ð2 is variance at N×M neighborhood window.3×3 Weiner filter is used for documents one to two pixel wide characters. Below figure shows the result of Weiner filter to a document image.

Ne≥ N minimum&&

I(x, y) ≤ E mean+ 0

(3)

Other-wise.

}

Figure 3: (a) Original image.

Where E mean and E standard are mean and standard deviation and are defined as follows

E mean=

∑ ( , )∗(

(5)

( , ))

E standard = (( ( , ) −

) ∗ 1 − ( , ) )2/2.

(b) 3×3 Weiner filter.

3.2. Ni-blacks Approach:

3.2.3. Estimation of the foreground regions:

3.2.1. Description:

Ni-blacks method is applied for adaptive thresholding, since it introduces some noise. At this stage image I(x, y) is processed to extract the binary image N(x, y) which

Ni-blacks approach to overcome the ambiguities present in the degraded document image through

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contains ones for estimated foreground region. Ni-blacks method makes use of Laplacian of Gaussian (LOG) filter to reduce the errors and having the disadvantage of responding to some of the existing edges.

Figure 4: (a) Original image.

(b): Histogram. The average distance DAverage between foreground and background can be calculated as follows DAverage=

(b) Estimation o foreground region.

3.2.4. Background Surface estimation

{I(x, y) ∑

( ( , )(1 − ( , ) ))

∑

(6)

3.2.5. Threshold estimation: Threshold value is calculated by combining the background surface B with the original image I. Text is present when the distance of the original image calculated from background exceeds a threshold d. Threshold value will change according to the gray value of background surface.

(9)

Imax(i, j) − Imin(i, j) Refers to local image gradient that is normalized to [0, 1].The local window size is empirically set to 3. Where is the weight between the local contrast and local gradient that is maintained based upon statistical information of the prescribed document. The power function has a nice property that it smoothly increases from 0 to1 and the shape of the curve can be easily controlled by different values of .The initial process in the Binarization system includes the high intensity pixel detection by constructing the adaptive contrast map.The next step is the text stroke edge pixel detection. Edge characterizes boundaries and edge detection reduces the amount of data and filters out useless information. The software developed by MATLAB 7.0 is nothing but canny edge detection algorithm performs better for all the scenarios. Canny edge detector is combined with the Otsu’s algorithm to extract the text stroke edge pixels properly. Canny edge detector will have the good localization property that it marks the edges close to real edges. Canny edge detector first filters the image to eliminate noise. Then it finds image gradient. Hysteresis is used to move along the pixels that have not been suppressed. Hysteresis uses two threshold values and if the magnitude is below the first threshold, it is set to 0. If the magnitude is above the high threshold it is mark as an edge. If magnitude lies between two thresholds, then it is set to 0 unless there is a path to another pixel lying above T. The Binarization performance are calculated by using F-measure, Peak Signal to Noise Ratio (PSNR), Distance Reciprocal Distortion.

If N(x, y)=1.

T(x, y) = {1,

(8)

C a (i,j) =δC(i, j) + (1 − δ)(Imax(i, j) − Imin(i, j))

(1 − ( ( , ))

}

( , ))

( , )

Image Binarization System has a lot of advantages over the previous existing systems. The Binarization system reduces the normalization factor that appears in the local maximum and minimum method by combining the local image contrast with the local image gradient which gives rise to adaptive local image contrast as shown below

If N(x, y) = 0.

∑

∑ ∑

IV.IMAGE BINARIZATION SYSTEM:

The pixels of source image I(x, y) belongs to background surface B(x, y) only if the pixels of the rough estimated foreground region image N(x, y) has zero values. B(x, y) =

∑ ∑ ( ( , )

if B(x, y)-I(x, y)>d (B(x, y)) other-wise.

} (7) Histogram for a document image is shown below with two peaks, one for text and another one for background region.

Figure 5: (a) Original image.

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V.SIMULATION RESULTS

[6] G. Leedham, C. Yan, K. Takru, J. Hadi, N. Tan, and L. Mian, “Comparison of some thresholding algorithms for text/background segmentation in difficult document images,” in Proc. Int. Conf. Document Anal. Recognit., vol. 13. 2003, pp. 859–864. [7]M. Sezgin and B. Sankur, “Survey over image thresholding techniques and quantitative performance Analysis,” J. Electron. Imag., vol. 13, no. 1, pp. 146–165, Jan. 2004. [8] O. D. Trier and A. K. Jain, “Goal-directed evaluation of binarization methods,” IEEE Trans. Pattern Anal. Mach. Intell., vol. 17, no. 12, pp. 1191–1201, Dec. 1995. [9] O. D. Trier and T. Taxt, “Evaluation of binarization methods for lowdocument images,” IEEE Trans. Pattern Anal. Mach. Intell., vol. 17, no. 3, pp. 312–315, Mar. 1995. [10] A. Brink, “Thresholding of digital images using twodimensional entropies,” Pattern Recognit., vol. 25, no. 8, pp. 803–808, 1992.

FIGURE 6: F- measure performance graph VI. CONCLUSION The Binarization system involves several parameters that can be easily estimated based on the statics of the input document. When compared to the previous LMM method the Binarization system calculates threshold values each pixel by pixel instead of considering threshold value as value of the highest intensity pixel. When compared to NIBLACKS approach which calculates threshold values based on midrange value of the window size, where as in Binarization System threshold value depends on adjacent pixel distance which yields good results. The previous NIBLACKS approach makes use of LOG operator which has a disadvantage of malfunctioning at corners, curves. Image Binarization system makes use of canny operator which has an advantage of probability if finding error rate, improving SNR. The proposed enhanced system is stable and easy to work with degraded document images. The enhanced Binarization system avoids the normalization problem and involves in 0the contrast image enhancement and yields good results in several document analysis. VI .REFERENCES 1] B. Gatos, K. Ntirogiannis, and I. Pratikakis, “ICDAR 2009 document imagebinarization contest (DIBCO 2009),” in Proc. Int. Conf. Document Anal.Recognit., Jul. 2009, pp. 1375–1382. [2] I. Pratikakis, B. Gatos, and K. Ntirogiannis, “ICDAR 2011 document image binarization contest (DIBCO 2011),” in Proc. Int. Conf. Document Anal.Recognit., Sep. 2011, pp. 1506–1510. [3] I. Pratikakis, B. Gatos, and K. Ntirogiannis, “H-DIBCO 2010 document image binarization competition,” in Proc. Int. Conf. FrontiHandwrit.Recognit., Nov. 2010, pp. 727– 732. [4] S. Lu, B. Su, and C. L. Tan, “Document image binarization using background. [5] B. Su, S. Lu, and C. L. Tan, “Binarization of historical handwritten document images using filter method,” in Proc. Int. Workshop Document Anal. Syst., Jun. 2010, pp. 159–166.

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B Chenna Krishna Reddy 3rd year Mechanical Engg, SRM University, Chennai. Mobile no: 9962937400

SEARL EFFECT (By John Roy Robert Searl )

Abstract Searl Effect Generator: The Searl Effect Generator is actually a converter of Electrons into usable Electricity. The working and construction is given below

Introduction: The solution to the world's energy crisis might be found in a magnetic device that utilizes both ambient temperature and magnets to generate power. In theory, the "Searl Effect Generator" (SEG) has the potential to run completely on its own through a complex interaction between various materials, resulting in an unlimited supply of free and clean energy. Discovered by John Roy Robert Searl in 1946, the "Searl Effect", as it is called, effectively captures the kinetic energy generated by natural changes in ambient temperature, and uses it to create electricity. The technology works based on a precise design that utilizes the unique characteristics of various materials to create continual motion. These materials include magnets, neodymium, Teflon and copper. When joined together in just the right way, these materials are capable of perpetuating a cycle of electron movement that is virtually infinite, which gives the device the potential to create more power than it uses to power itself. In other words, if successful, the SEG could one day replace our dependence on fossil fuels as a primary and superior energy source. So how does the device work exactly? The SEG is composed of a series of circular cylinders, all of which have small magnetic rotors spaced evenly around them one of the neat things about Searl technology is that it is scalable, meaning it can be designed in varying sizes for different applications. According to the company, SEG sizes range from a one meter in diameter machine capable of power an average house, to a 12 meter in diameter machine that could power an entire city. The team says machines even larger than 12 meters are possible as well. There has been a great interest in examining non-linear effects in the system of rotating magnetic fields. Such effects have been observed in the device called Searl generator or Searl Effect Generator (SEG. A SEG consists of a series of three concentric rings and rollers that circulate around the rings. All parts of SEG are INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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based on the Law of the Squares. The rollers revolve around the concentric rings, but they do not touch them. There's a primary north-pole and primary south pole on the rollers and a primary north-pole and primary south-pole on the concentric rings. Obviously, the north-pole of the roller is attracted to the south-pole of the concentric rings and vice versa. The rollers have a layered structure similar to the concentric rings. The external layer is titanium then iron, Teflon and the last internal layer was made from neodymium. John R.R. Searl has supposed that electrons are given off from the central element (neodymium) and travel out through other elements. Dr. Searl contends that if nylon had not been used, the SEG would act like a laser and one pulse would go out and it would stop, build up, and another pulse would go out. The nylon acts as a control gate that yields an even flow of electrons throughout the SEG. it was shown that in the process of magnetization of the plate and rollers, the combination of constant and variable magnetic fields for creating a special wave (sine wave) pattern on a plate surface and rollers surface was used. The basic effects consist of the rollers self-running around the ring plate with a concurrent reduction of weight and an increasing occurrence of propulsion. These effects come about because of a special geometry of experimental setup. It was shown that the operation of the device in the critical regime is accompanied by biological and real physical phenomena.

2. Description of the Experimental Installation The basic difficulty arises in choosing the materials and maintaining the necessary pattern imprinting on the plate and roller surfaces. To simplify the technology we decided to use a one- ring design with one-ring plate (stator) and one set of rollers (rotor). It is obvious, that it was necessary to strengthen the roller rotor near the bearings and balance the rollers well. In the suggested design, air bearings were used which provided the minimum losses due to friction. From the available description it was not clear how to build and magnetize a stator with a one-meter diameter. In order to make the stator, separate magnetized segments of rare earth magnets with a residual induction of 1T were used. The segments were magnetized in a usual way by discharging a capacitor-battery system through a coil. Afterwards, the segments were assembled and glued together in a special iron armature, which reduced magnetic energy. To manufacture the stator, 110 kg of neodymium magnets were used and 115 kg of neodymium were used to manufacture the rotor. High-frequency field magnetization was not applied. It was decided to replace an imprinting technology described in with cross-magnetic inserts having a flux vector directed at 90 degrees to the primary magnetization vector of the stator and rollers. For the cross inserts, modified rare earth magnets with a residual magnetization of 1,2 T and coercive force a little bit greater than in a base material were used. In Fig.1 and Fig.2 the joint arrangement of stator 1 and rotor, made up of rollers 2, and a way of their mutual gearing or sprocket by means of cross magnetic inserts 19, are shown. Between the stator and roller surfaces the air gap Î´ of 1-mm is maintained. No layered structure was used except a continuous copper foil of 0.8 mm thickness, which wrapped up the stator and rollers. This foil has direct electrical contact to magnets of the stator and rollers. Distance between inserts in the rollers is equal to distance between inserts on the stator. In other words, t1 = t2 in Fig.2.

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Fig.1. Variant of one-ring converter. / Fig.2. Sprocket effect of magnetic stator and roller inserts. The ratio of parameters of the stator 1 and the rotor 2 in Fig.2 is chosen so that the relation of stator diameter D to the roller diameter d is an integer equal to or greater than 12. Choosing such ratio allowed us to achieve a "magnetic spin wave resonant mode" between elements of a working body of the device since the circumferences also maintained the same integer ratio. The elements of magnetic system were assembled in a uniform design on an aluminum platform. In Fig. 3 the general view of the platform with the one-ring converter is displayed. This platform was supplied with springs and shock absorbers with limited ability to move vertically on three supports. The system has a maximum value of displacement of about 10 mm and was measured by the induction displacement meter. Thus, the instantaneous change of the platform weight was defined during the experiment in real time. Gross weight of the platform with magnetic system in the initial condition was 350 kg. The stator was mounted motionlessly, and the rollers were assembled on a mobile common separator also regarded as the rotor, connected with the basic shaft of the device. The rotary moment was transferred through this shaft. The base of the shaft was connected through a friction clutch to a starting motor, which accelerated the converter up to a mode of self-sustained rotation. The electrodynamics generator was connected to the basic shaft as a main loading of the converter. Adjacent to the rotor, electromagnetic inductor with open cores were located.

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Fig.3. General view of the one-ring converter and platform. The magnetic rollers crossed the open cores of inductors and closed the magnetic flux circuit through electromagnetic inductors inducing an electromotive force emf in them, which acted directly on an active load (a set of inductive coils and incandescent lamps with a total power load of 1 kW). The electromagnetic inductor coils were equipped with an electrical drive on supports, Driven coils for smooth stabilization of the rotorâ&#x20AC;&#x2122;s rpm were used but the speed of the rotor could be adjusted by changing the main loading. To study the influence of high voltage on the characteristics of the converter, a system for radial electrical polarization was mounted. On the periphery of the rotor ring, electrodes were set between the electromagnetic inductors having an air gap of 10 mm with the rollers. The electrodes are connected to a high-voltage source; the positive potential was connected to the stator, and the negative to the polarization electrodes. The polarizing voltage was adjusted in a range of 0-20 kV. In the experiments, a constant value of 20 kV was used. In case of emergency braking, a friction disk from the ordinary car braking system was mounted on a basic shaft of the rotor. The electrodynamics generator was connected to an ordinary passive resistive load through a set of switches ensuring step connection of the load from 1 kW to 10 kW through a set of ten ordinary electric water heaters. The converter undergoing testing had in its inner core the oil friction generator of thermal energy, 15, intended for tapping a superfluous power (more than 10 kW) into the thermo- exchange contour. But since the real output power of the converter in experiment has not exceeded 7 kW, the oil friction thermal generator was not used. The electromagnetic inductors were connected to an additional load, which was set of incandescent lamps with total power 1 kW and facilitated complete stabilization of the rotor revolutions.

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3. Experimental results The magnetic-gravity converter was built in a laboratory room on three concrete supports at a ground level. The ceiling height the lab room was 3-meters, the common working area of the laboratory was about 100 sq. meters. Besides the presence of the iron-concrete ceiling, in the immediate proximity from the magnetic system there was a generator and electric motor, which contained some tens of kilograms of iron and could potentially deform the field's pattern. The device was initially started by the electric motor that accelerated the rotation of the rotor. The revolutions were smoothly increased up to the moment the ammeter included in a circuit of the electric motor started to show zero or a negative value of consumed current. The negative value indicated a presence of back current. This back current was detected at approximately 550 rpm. The displacement meter, 14, starts to detect the change in weight of the whole installation at 200 rpm. Afterwards, the electric motor is completely disconnected by the electromagnetic clutch and the ordinary electrodynamics generator is connected to the switchable resistive load. The rotor of the converter continues to self-accelerate and approach the critical mode of 550 rpm where the weight of the device quickly changes.

Fig.4. -G, +G changes in weight of the platform vs. rpm In addition to the dependence on the speed of rotation, the weight differential depends on the generated power through the load and on the applied polarizing voltage as well. As seen in Fig.4, at the maximum output power equal to 6-7 kW, the change of weight â&#x2C6;&#x2020;G of the whole platform (total weight is about 350 kg), reaches 35 % of the weight in an initial condition. Applying a load of more than 7kw results in a gradual decrease in rotation speed and an exit from the mode of self-generationwith the rotor coming to a complete stop subsequently.

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INTERNATIONAL CONFERENCE ON CURRENT IN ENGINEERING RESEARCH, ICCTER - 2014 ring electrodes The net weight Gn of the platform can be TRENDS controlled by applying high voltage to polarization located at a distance of 10 mm from external surfaces of the rollers. Under the high 20Kv (electrodes having negative polarity) the increase of tapped power of the basic generator to more than 6 kW does not influence ∆G if the rotation speed is kept above 400 rpm. "Tightening" of this effect is observed as well as the effect of hysteresis on ∆G (a kind of "residual induction"). The experimental diagrams given on Fig.4 illustrate the +G and –G modes of the converter operations vs. rotor rpm.

4. Discussion All the results we obtained are extremely unusual and require some theoretical explanation. Unfortunately, the interpretation of results within the framework of the conventional physical theory cannot explain all the observed phenomena besides the change of weight. It is possible to interpret the change of weight either as a local change of gravitational force or as an antigravity force repelling its own field. Direct experiment, confirming the presence of a draft force was not performed, but in any case both interpretations of the weight change do not correspond to the modern physics paradigm. A reconsideration of the standard theory of gravitation is possible if we take into consideration space-time curvature. For example, the Kerr metric usually represents the field exterior to an axially symmetric rotating body and distinguishes between positive and negative spin directions as well as forward and backward time directions. An examination of the physical vacuum as a source of these phenomena may also lend itself to better interpretation since the Maxwell stress-energy tensor in the vicinity of the converter undergoes a complex evolution. From the modern physics position, electrification and luminescence of the converter's magnetic system in the near zone is not completely clear. The phenomenon of the magnetic and thermal "walls" may be connected with Alphen's magnetic-sound waves raised in near zone in magnetized plasma induced by a variable magnetic field of a rotating rotor. The energy exchange between ambient air molecules and the converter may be occurring. At the present time we can not give an exact description of the interactions mechanism and transformation of energy, but without a relativistic we are completely unable to give a physically substantial theory of these phenomena In conclusion, we emphasize that issues of the biological influence effects and especially of the variations of real time stream effects, which must be taking place in an operative zone of the converter, were not considered at all. These issues are extremely important and absolutely unexplored; though there are some mentions of J.R.R.Searl about healing action of the SEG's radiation. Our own experience allows us to make only cautious assumption that the short-term stay (dozen minutes) in a working zone of the converter with the fixed output power of 6 kW remains without observed consequences for those exposed. The present paper is only a beginning.

References 1. Schneider, Koeppl, & Ehlers. ( Beginning with John R.R.Searl) Raum and Ziet, #39, 1989, pg. 75-80. 2. Sandberg, Von S. Gunnar. Raum und Ziet, #40, 1989 3. Schneider & Watt. (The Searl effect a n d it s w o r k i n g ) Raum and Ziet, # 42, 1989, pg.7581; #43, pg.73-77. .

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Bus tracker system with seat availability checker

V.Sundara moorthy smsubasantosh@gmail.com 3rd Year EEE Department Panimalar Engineering College, Chennai

G.Surendiran Surendiran888@gmail.com 3rd Year EEE Department Panimalar Engineering College, Chennai Abstract

2. Android and Our App

In this paper we have stated about solving common people problem using innovative ideas with help of circuits and android app (application). Here we consider some problems of people in bus transport. This android app tracks the current bus locations using GPS in the ticket printer (new single GPS chip would cost under $5 = Rs.300). And we have also created an algorithm to find the number of seats available. We use a ticket printer with a SIM card to send this information. So this app gives the information about number of seats available with the help of ticker printer and bus location to the mobile phone. Another arrangement is made to get this information in bus stops using display boards. One more additional feature is that is gives your current location while your travel using mobile signal you get with Rs.0 of cost. So you no need to worry or need not be aware that your place had arrived or not, in night travel or while going to a new place. This will solve the problems like waiting in bus stop and wasting time, going in a crowded bus and we give you a sleepy or peaceful journey.

Android was initially developed by Android, Inc., which Google backed financially and later bought in 2005, Android was unveiled in 2007. Now itâ&#x20AC;&#x2122;s very fast developing and has app for every human need and problem. In 2014 one million android phones are yet to come. So this will have the world in its hand and takes control over everything. So we think to solve problems using android app. Here we are going to discuss some of the problems of common people for which android apps are not yet developed.

3. Problems

Now-a-days everyday people are busy moving to offices, schools, or to some other places. The main thing they need is that transport, obviously bus. Many people are waiting for it and wasting their precious time. Since bus timings are generally unpredictable in our country. And many times they have to go in a very crowded bus, sometimes hanging which may lead to accidents. Another problem is sleepless night travel, when they need to get down the bus in the right place. Next problem comes while one goes to a new place, that is they need to be aware whether their place had arrived or not. Letâ&#x20AC;&#x2122;s see some solutions for this problem through android apps.

1. Statistics In the city of Chennai alone, 47 lakh people use the services of the MTC on a daily basis, A total of 21,989 buses are currently being operated in the State. Around 1.82 crore commuters use the service on a daily basis. So this is a must to make their travel easy.

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4. Existing App filled ride at night. The mock-up is shown

The already existing apps only have bus routes and timings. But that wonâ&#x20AC;&#x2122;t be exact and wonâ&#x20AC;&#x2122;t help people in any way. Eg.MTC Bus Route.

below in figure 1.

6. Smart Bus Tracker 5. Solution From the name itself, we could understand that we are going to track the location of buses. So we need GPS to be fitted in every bus. Now Texas Instruments announced at CTIA that a new single GPS chip would cost under $5 = Rs.300. And now very small GPS devices are produced.

We have some innovative ideas for android app, we have designed an app named Smart Bus Tracker (SBT), and this app has three features. The first one helps in tracking the buses with the help of GPS and track the exact bus location. This will very much help the people who usually waste time in waiting for buses. Second it has a facility to show the number of tickets available with the help of ticker printer of the conductor.

7. Seat availability checker Here we are joining the GPS device with the ticket printer to track the location. We have another feature in this beautiful app to check the availability of seats inside the buses. Nowadays bus conductors use ticket printer to give away the tickets. When a person takes a ticket, the starting place and destination is recorded in the ticket printer. Similarly the details about every person in the bus are recorded in it. By doing simple mathematical calculations with simple an algorithm (as shown in the figure 2) no of passengers in bus is calculated. Figure 1.Smart Bus tracker app.

This prevents us going in a crowded bus. And third a tower detector which detects and give alarm, when the particular area tower is reached. This helps us to find location (without GPS) when we are new to a place or if we need a sleep

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traveling region,it deletes the information about the person,which means the person has got down. So this cycle repeats frequently with the change in bus position. So this is how the number of person in the bus is calculated. The simulation for this is shown bellow. In this the number of point of intersection between the bus position and the region gives the number of persons in the bus. Simulation for tracking bus using GPS is not needed since every one know about that.

Figure 2.Flow chart to calculate no of passengers.

8. Simulation for seat availability checker In this first we get the information of the bus location using the GPS in ticket printer. Then the persons traveling region is calculated from the starting place and destination given in the ticket printer. Then the bus position is compared with the traveling region of every person. If the bus position is inside the region,then the number of person is added with 1,this process repeats will very person's traveling region in the bus. If the bus position is not in the

Figure 3.Simulation for seat availability checker.

So we can determine the numbers of seats filled and vacancies in the buses. By using a ticket printer with SIM card facility (as in figure 4). We are synchronizing the signals with server and now our app can get the details about the bus location.

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By the above process we can get the details in the mobile as shown in the below figure 6.

Figure 4.Ticket printer with SIM card slot.

So, using this app all people can plan ahead, by knowing the number of seats available in the bus and avoid crowded travel. They could easily no of seats filled and vacant.

Figure 6. Smart Bus Tracker Showing Bus locations.

10. Giving information to depot: 9.Over all Process: We can also send this information to the bus depot, by which they can easily get the information about the buses. It may help them to quickly find out if the bus is met with an accident or if stopped due to any problem like break down or puncture. The figure 7 shows the flow of information to the bus depot.

Here in the diagram we have given the over all process in the figure 6.In this bus revice GPS signal from satilite then it gives that signal to the mobile phone tower with the no of passegers via SIM card in the ticker printer.Then from there we are able to get those details.

Figure 5.Overall process. Figure 7.Transfering information to bus depot.

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11. Display in bus stand:

13.Future

We make a display in bus stand for the people to get the information about the bus arrival time.

When our app comes in future there will be many changes in the world. No one will be waiting for buses in the bus stops. We need not go in a crowded bus. Everyone will have a luxurious travel without worrying about anything, mainly we need not to be aware that their place had arrived or not.

12. Tower Detector The next amazing feature of our app is to detect our current location only by using the mobile tower signals. Usually the mobile receive signals all the times. And by given a simple database containing the information about the locations where the towers are placed in a state, we could get our locations in mobile. We know that the mobile signals are wide ranged, so we could detect the current location. The mock-up of the tower detector is shown in figure 8.

14. Conclusion This app will give the exact location of buses at various position,says no of seats available and your current location by tower signal. This app will modernized transport system. Private buses or private companies having their own transport may implement this easily. Around 1.82 crore commuters use the service on a daily basis. So this is a must to make their travel easy. This

will be cost effective and definitely feasible.

15. References [1] "Android Code Analysis". Retrieved June 6, 2012. [2] Claburn, Thomas (March 4, 2009). [3] "Court Asked To Disallow Warrantless GPS Tracking". Information Week. Retrieved 200903-18. [4] "Traccar Client - free open source Android tracker". Retrieved 2012-08-15. [5] "Widgets | Android Developers". Developer.android.com. Retrieved 2012-09-15. [6] Saylor, Michael (2012). The Mobile Wave: How Mobile Intelligence Will Change Everything. Perseus Books/Vanguard Press. p. 304. ISBN 978-1593157203. [7] "Ticket-in, Ticket-out Technology". Retrieved January 22, 2014.

Figure 8.Tower Detector.

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TECHNO-HOSPITAL (Android App Development)

Sanjay. T

Preethika. R

B TECH IT (4th year) PSG College of Technology Coimbatore, India thillaivasan.sanjay@gmail.com

B TECH IT (4th year) PSG College of Technology Coimbatore, India preethika.psg@gmail.com

to connect to internet through mobile phone and this would be the only cost incurred on the project.

Abstract—This electronic document is all about to generate an android application to solve the problem of people in India, to reduce their effort to maintain all their medical prescriptions and surgery reports .Instead they can have all those in a cloud and can be accessed from anywhere, anytime. Hence, the people can make sure they don’t miss any medical record so that they could get perfect treatment.

Technical Feasibility To develop this application, a high speed internet connection, a cloud database server, a web server and IDE (such as Eclipse) are required.

Index Terms-Feasibility, System Requirement, Issue Being Addressed, Solution, Potential Challenges and its Suggestions.

Social Feasibility The application is socially feasible since it requires no technical guidance, all the modules are user friendly and execute in a manner they were designed to.

I. INTRODUCTION Our idea belongs to the category Internet of things to deliver Public Services for the future. Today’s world is highly connected through internet and this can help people widely. It describes a future where everyday physical objects will be connected to the Internet and be able to identify themselves to other devices. However, efficient implementation of Internet of things does lead to a higher citizen satisfaction.

IV. SYSTEM REQUIREMENTS A. HARDWARE REQUIREMENTS Processor: RAM: Space on disk:

II. PROPOSED SYSTEM

Pentium 4 256 MB Minimum 250MB

B. SOFTWARE REQUIREMENTS Operating system: Windows XP / Mac OS 10.5.8 or later/Linux Platform : Android SDK Framework IDE : Eclipse (Juno) Android : SDK Version 2.2 or Higher Emulator Database : MySQL Technologies : Java, Xml Front End : Eclipse Back End : SQLite, Cloud SQL server Data analytics for handling huge data.

The android OS application created for Hospital is user friendly. This allows faster access of data and also less memory storage capacity. The applications do not need any guidance for naïve user to use it. III. FEASIBILITY The main purpose of feasibility study is to consider each and every possible factor associated with the project and determine whether the investment of time and other resources yield desired results. It also includes determining the investments, manpower and costs incurred on this project. The following feasibility has used in this project.  Economic feasibility  Technical feasibility  Social feasibility

V. THE ISSUE THIS IDEA WILL ADDRESS 

ECONOMIC FEASIBILITY Economic analysis is the most frequently used method for evaluating the effectiveness of a new system. The project is economically feasible as it only requires a mobile phone with Android operating system. The application is free to download once released into Android market. The users should be able

In our day to day life, most of us don’t care to maintain our old medical prescriptions. This in turn causes trouble to doctors to provide better treatment based on his previous reports. Also in critical situations like accidents, one could not always carry all of his previous medical prescriptions. As a result, a proper treatment would be a question mark as the doctors could not determine what medicine is

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

allergic to the patient or what medical treatment he presently undertakes. Many deaths have occurred as the lifesaving treatment (medicines) given to the victims were allergic or in opposite reaction to the medicine he was undertaking. Another major problem is, in case of emergency situations like accidents where heavy blood loss occurs, there is urgent need of rare blood and unfortunately if the blood bank fails to provide it , the hospital finds it difficult to get help from the people by immediately conveying the urgency to save a life. As a result, it leads to unfortunate death of the person. Nowadays, we have the token system in hospitals where the people contact the hospital through telephones and get a token number and time slot to obtain treatment on a specified day. But on the specified day , many hospitals fail to keep up the time slot provided to the patients . So the patients suffer a lot by waiting a whole day, thus wasting their precious time.

VIII. SUGGESTIONS FOR POTENTIAL CHALLENGES i)

ii)

The doctors can use the android app to update also . The doctor can get the patient’s login id ,enter the prescriptions and click the enter icon to update the details in the patient’s database. A device can de set up in the hospital , so that when each person completes his consultation with the doctor , the device is pressed and immediately the token number of the patients of that particular hospital is incremented. IX. STEPS THAT PATIENT SHOULD FOLLOW

1) Initially download the app . Register your details and get a unique id. 2) Each time when you undergo a treatment , provide your id to the doctor and get the prescription or scan details updated in your account. 3) If you are willing to donate your blood , keep the ‘urgent blood needs’ notification ON , so that you will be notified through a message if blood need arises. 4) If you want to know the token number of the patient currently undergoing treatment , just select the place where the hospital is located , name of the hospital and the doctor’s name(if there are many doctors in a hospital).Immediately you will be notified.

VI. SOLUTION 1) Each person will be provided a login where a database that maintains the person’s entire medical details(his prescriptions , scan reports and surgeries undergone ) with date , names of hospitals and doctors served is maintained.

X. VALUE PROPOSTION

2) Consider an application in your mobile phones that notifies you immediately when urgent blood needs occur. It also specifies what blood group is needed and also the name of the hospital with its address and phone number. So that, the need of blood will reach the people immediately and those having the same blood group and willing to provide blood can immediately rush to the hospital and save a lifeSometimes it may take few hours or days to get the work done. So after the work gets completed the user must be notified through a simple message. So that the user need not waste his time by visiting the office often and can do other stuffs.

1.Since the most valuable thing in the world is the life of a person , this project will reduce the death rate that has been increasing due to the improper treatment provided by the doctors at critical situations. 2.Lives of the critically injured can be saved by the blood donated. 3.Saves time for the people to take medical checkups regularly.

XII. CONCLUSION 3) Consider an app which allows you to select the place and hospital you want and immediately the app tells the token number of the patient who currently undertakes treatment .So that the patient can estimate the time at which he should be at the hospital for getting treatment. Thus the waste of time can be reduced.

. Thus, this idea can be implemented to help people maintain their medical records safe, take proper treatment, save lives just by a user friendly android app.

VII. POTENTIAL CHALLENGES i) The expected issue would be , doctors will have to update the prescribed medicines in the patient’s database. ii) And the token numbers in all the hospitals should be updated for every minute.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 ACKNOWLEDGMENT I would like to express our heartfelt gratitude to Dr. R. Rudramoorthy, Principal, PSG College of Technology, for providing me an opportunity to do my paper with excellent facilities and infrastructure, without which this paper would not have been successful.

REFERENCES [1] Zigurd Mednieks, Laird Dornin, G. Blake Meike, and Masumi Nakamura,”Programming Android”, Second Edition 2009. [2] Diego Torres Milano ,” Android Application Testing Guide”, Packt Publishing, 2011 [3] Wallace Jackson, “Learn Android App development”, Third Edition, 2010. [4] http://developer.android.com/guide/topics/resources/provid ing-resources.html [5] Android SDK | Android Developers http://developer.android.com/sdk/index.html

I extend my sincere thanks to Dr. K.R.CHANDRAN, Professor and Head of the Department of Information Technology, PSG College of Technology, for his unfailing support throughout this project.

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PREPARATION OF W.P.S FOR STAINLESS STEEL (Ni, Cr, Mo, Nu) WELDING W.r.t MECHANICAL & THERMAL PROPERTIES M.VALLIAPPAN ASSISTANT PROFESSOR M.KUMARASAMY COLEGE OF ENGINEERING KARUR TAMILNADU – 639 113

II. SS MATERIALS In this paper we are going to weld the 321(Plate) of 5.6mm thick, by TIG and ARC similarly 316(Seamless Tube) of ϕ60.3mm, 6mm thick, 347 (Seamless Tube) of ϕ60.3mm, and 5mm thick by TIG and ARC. Welding is carried out by preparation of WPS under the Properties of the material. The main Purpose of the choosing the TIG and ARC welding is based on the material thickness apart from this TIG gives Higher Accuracy and ARC gives in vice versa. The main purpose of choosing Nb,Mo,Ti in Ni alloy combination is because SS 347 contains Nb which has high Creep Strength, where SS 316 consists of Mo, it has Fatigue strength, and 321 contains Ti which has high Ductility.

Abstract— Today Most commonly used materials in boiler, and also in boilers accessories are S.S which will operate under 700oC with greater performance (creep strength, corrosion resistance) and reliability, especially for temperatures of 700-750oC.The modern technology in welding of materials goes towards anticorrosion, wear resistance to increase the service of a product. In S.S alloys, Ni content is very good against corrosion resistance; hence we have selected Stainless steel 321, 316 and 347 materials, Which consist of (Ni,Cr,Mo,Nb) widely used for Power piping in 800MW, 1000MW Boiler. In order to maintain the properties of material properties before and after welding, we have Prepared Welding Procedure Specification (WPS) based on the thermal and mechanical properties of materials.

III. CHEMICAL & MICRO RESULT SS321: Grain : FSS and ASS grains ASME Grain Size : No: 7 SS316: Grain : FSS and ASS grains ASME Grain Size : No: 7 SS347: Grain : Ferrite & Austenite grains ASME Grain Size : No: 8

I. INTRODUCTION This paper deals with the preparation of Welding procedure specification for SS welding by optimizing the existing WPS method with respect to mechanical and thermal properties. It also aims to reduce the creep, fatigue, Residual stress and thermal stresses in the Boiler materials by the application of stainless steel material and welding it. Stainless steels are weldable materials and a welded joint can provide optimum corrosion resistance, strength and fabrication economy. However it may undergo certain changes during welding it is necessary to take care of welding to minimize the defects and to maintain the same strength and resistance in the weld zone that is an inherent part of base metal. Seamless Tubes of 316 and 347 and 321 plate materials having improved austenite stability. The stability of the austenite in CrNi and CrNiMo steels is achieved by increasing the nickel content over that of standard 18/8 CrNi and 18/8/2 CrNiMo steels, and more especially by additions of nitrogen, which is particularly effective in promoting the austenite stability. The project starts with micro testing and chemical analysis of materials and preparation of WPS based on thermal and mechanical properties. Finally calculating the strength of material and to replace the current boiler materials in to improved SS materials. In welding by controlling the parameters of thermal property mechanical deviations are reduced and so weld with less defect could be obtained and also the service life of material will be increased.

IV.WPS (Existing Method) The welding procedure form contains all of the essential information required to make the weld and verify the test result. This information may include the type of base and filler metals, welding process used, preheat, inter pass or post weld heat treatment shielding gases and so on. (Ref-Book-PQR, Chap 24. Page No 380) Base metal Filler metal Position Preheat Electrical characteristics Technique Parameters Joints

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 V.WPS (REVISED)

Hence based on the selection of methods from the above mentioned conditions welding could be carried out. In this, for each case of the above mentioned parameters certain methods are chosen according to AWS and WPS, so that welding could be achieved in a greater extent of accuracy.

IV.A.TIG Polarity Composition Color Code Inert Gas

VIII.PREHEATING & POST HEATING Preheating is done under the Environmental condition by adjusting the current and voltage before welding, generally material with less thickness are not to be considered for pre heating and post heating will be carried out in case of any defects in the weld. After welding heat treatment is required, to maintain the material strength and other properties.

V.B.ARC V.B.1. BASE METAL Position Edge preparation Root Gap Cleaning

Preheating Conditions: For S.S chromium and nickel equivalent is very important and for other alloys carbon equivalent. For Stainless Steel: Chromium Equivalent = %Cr+%Mo+%1.5%Si+0.5%Nb Nickel Equivalent = %Ni+30%C+0.5%Mn

V.B.2. ELECTRODE Type Diameter Arc length Coating V.B.3. PROCESS Polarity Bead Technique Run Speed Pre heating Post heating Heat treatment By optimizing the above mentioned parameters with existing W.P.S the strength of a material could be increased.

Carbon Equivalent =%C + %Mn/4 = % Si/4 for carbon steel Carbon Equivalent= %C+ %Mn/6 + %Cr/5 + %Ni/15 + %Mo/4 +%V/5 for AS and SS CE <40 No preheating CE= 40to70 Preheating 100-300˚c CE>70 Welding is difficult Preheating Temperature=1000[C -0.11] + (1.8*thickness) ˚F Preheating Temperature: P1 t<19 nil P1 t>19 100-150˚c P4 all 200-300˚c P5 all 200-300˚c

VI.NEED OF WPS Welding could be done without preparation of WPS, but which may results in improper weld or with defects like weld decay, knife line attack and stress corrosion cracking. To avoid such cases WPS is followed in all industries .Sometimes Improper welding will increase the strength due to this the life time of materials may be changed. To overcome those weld defects WPS is optimized, use extra low carbon electrode, avoiding hylogen family

IX. ELECTRODE (Ref-A.W.S) E 308 Corrosion resistant E 316, 317, 330 High temperature strength E 410, 420 Abrasion resistant X. WELDING METALLURGY Ref -ASME Section IX Voltage: V =17.34 + 0.023I - 6.3*10-6I2 Speed: S=1.6*106I-6.38 Deposition Y=1.5 + 0.17I + 0.000028I2 Q=VI / S (without heat transfer) Q=VIη / S (with heat transfer) Power Density Range: SMAW 5*106 TO 5*108 Watts /m2 GMAW SAME TO SMAW PAW 5*106 TO 5*1010 EBW, LBW 1010 TO 1012 Stress Analysis: Stress due to Sustained load = 0.72 Sy Stress due to Occasional load=0.80 Sy Sy = Min Yield Strength of material

VII.WELDING PROCESS Welding is carried out by following parameters based on Polarity- Straight and Reverse Position – Down hand, Vertical, Horizontal and 1G, 2G, 5G Process – TIG and SMAW Bead – Stinger and weaving Technique - Forehand and Backhand Speed – low and high Edge preparation – based on angle (more than 75) Root gap - based on thickness Diameter of electrode – based on thermal conductivity Arc length – shorter, longer and correct Run – Longer, shorter, skipping, alternate skipping Preheating – based on thickness of material

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 analyzed. Thus optimization of welding process is also made by checking the strength of each material in different welds. Similarly reading from TIG and SMAW also compared for the three materials. Strength is calculated manually and compared with the ASME, WPS and AWS. The main factor for choosing TIG and SMAW is, in boiler at higher altitude PAW, EBW, LBW and other type of welding could not be carried out and also it seems to be very expensive hence to overcome such cases TIG and SMAW is selected.

Sy = 0.6 to 0.7 of Tensile Strength Stress due to Expansion load = E αΔT –νSh E= young’s modulus α=Coefficient of linear expansion ΔT=Change in temperature ν=Poission’s ratio Sh =Hoop stress Resultant Bending Stress = (Ii Mi2+I0M02)1/2 / Z Ii=SIF at inplane Io=SIF at outplane Mi=BM at inplane M0=BM at out Plane Resultant Torsional Stress = Z= Section Modulus Mt=Torsional Bending Moment

REFERENCES References: 1. Parmar.R.S. “Welding Engineering and Technology”, Khanna publishers, Delhi. (1997is carried out by following 2. Avanar “Material science Engineering” 3. Dr.Srinivasan “Engineeering Materials” 4. Peter Mayr , Stefan Mitsche, Horst Cerjak , Samuel M.allen “ The impact of weld metal creep strength on the overall creep strength of 9% Cr steel weldments” , Journal of engineering materials and technology , vol. 133(2011) . 5. Nattaphon TAMMASOPHAN , weerasak HOMHRAJAI , Gobboon LOTHONGKUM “ Effect of post weld heat treatment on microstructure and hardness of TIG weldment between P22 and P91 steels With inconel 625 filler metal”, Journal of metals, materials and minerals , vol.21(2011) . 6. Samsiah Sulaiman “Structure of properties of the heat affected zone of P91 creep resistant steel”, Research work. 7. Greg j. Nakoneczny ,carl c schultz “Life assessment of high temperature headers”, American power conference(1995).

Material: (AWS & ASME Sections) Tensile Strength =15.4(19.1+1.8%Mn+5.4%Si+0.025%pearlite+0.5d-1/2) Hardness Vickers test = 90 + 1050%C + 45%Si + 97%Mn + 30%Cr + 31%Ni XI. APPLICATIONS Non-ferrous metals with high strength and toughness Magnetic properties, nuclear power systems Corrosion resistance, wear resistance Aerospace aircraft gas turbines Steam turbine power plants, medical applications Chemical and petrochemical industries Strength at elevated temperature. Nickel- chromium alloys or alloys that contain more than about 15% cr are used to provide both oxidation and carburization resistance at temperatures exceeding 760°C.

XII. CONCLUSION The various SS material was welded by TIG and ARC and finally the following test are carried out, Hardness test Impact test Bend test Tensile test, is carried out after welding to measure the strength of 321, 316, 347 which are compared with the reading from AWS, ASME and finally the suitable boiler material is

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REPAIRING CRACKS IN CONCRETE STRUCTURES Anilkumar P M and Dr. J Sudhakumar B.Tech Student, Professor Department of Civil Engineering, National Institute of Technology, Calicut anilkumar_bce11@nitc.ac.in, skumar@nitc.ac.in  Abstract— Studies related to crack formation in concrete is most interesting because sometimes the same causes produce a different cracking pattern and sometimes the same cracking pattern produced by different causes. Sometimes concrete cracks in allocation where no cause can be found and in other places it does not crack where there is every reason why it should. Eighty percent of these cases, however, are straight forward. In order to determine whether the cracks are active or dormant, periodic observations are to be done. Various factors have impeded improvements in the durability of concrete repairs, including: inadequate condition evaluation and design; lack of quality construction practices and quality control; and the choice of repair materials. It is necessary to reconsider some recent developments in structural repairs from the view point of extending the service lives of structures under repairs [1]. Index Terms—Concrete, cracks, reinforcement, repair

I. INTRODUCTION Cracks can be broadly divided into two categories namely solitary cracks and pattern cracks. Generally, solitary crack is due to a positive overstressing of concrete either due to load or shrinkage, the cause of which will become apparent when the line of the crack is compared with the layout of the portion of the concrete, its reinforcement and the known stresses in it. Overload cracks are fairly easily identified because they follow the lines demonstrated in laboratory load test. A crack due to setting and hardening shrinkage is formed in the first week of life of the concrete. If length of concrete under inspection is more than about 9m, it is not likely that there is a solitary crack, usually there will be another one of a similar type and the analysis of the second confirms the finding from the first. Regular pattern of cracks may occur in the surfacing of concrete and in thin slabs. The term pattern cracking is used to indicate that all the cracks visible have occurred more or less at the same time. II. TYPES OF CRACKS Cracks can be divided into two types:-Solitary cracks and pattern cracks A. Solitary cracks ( Isolated cracks) Generally, a solitary crack is due to a positive over stressing of the concrete either due to load or shrinkage, the cause of which will become apparent when the line of

the crack is compared with the layout of the portion of the concrete, is reinforcement and the known stresses in it. Overload cracks are fairly easily identified because they follow the lines demonstrated in laboratory load tests. A crack due to setting and hardening shrinkage is formed in the first week of life time of concrete. If the length of concrete under inspection is more than 9m, it is not likely that there is a solitary crack, usually there will be another one of a similar type and the analysis of the second confirms the finding from first. In a long retaining wall or long channel, the regular formation of cracks indicates faults in the design rather than the construction, but an irregular distribution of solitary cracks may indicate poor construction as well as poor design. B. Pattern cracking Regular pattern of cracks may occur in the surfacing of concrete and in thin slabs. The term pattern cracking is used to indicate that all the cracks visible have occurred more or less at the same time. III. IDENTIFICATION OF CRACKS Crack movement can be detected by placing a mark at the end of the crack. Subsequent extension of the crack beyond the mark indicates probable continuance of the activity originally producing the defect. The deficiency of this defect is that it will not show any tendency for the crack to close or provide any quantitative data on the movement. In another method, a pair of tooth pick is lightly wedged into the crack and falls out if there is any extension of the defect. The deficiencies of this method, as before, are that there is no indication of closing, movement or any qualitative measure of the changes which occur. A strip of notched tape works similarly. Movement is indicated by tearing of the tape. An advantage is that same indication of closure can be realized by observing any writing on the tape. This device is not reliable; however, the tape is not dimensionally stable under changing conditions of humidity, so that one can never be sure whether the movements are due to shrinkage or swelling of the marker. A device using a typical vernier caliper is the most satisfactory of all. Both extension and compression are indicated and movements of about (1/100) inch can be measured using a vernier caliper. If more accurate readings are desired, extensometers can be used. The reference point must be rigidly constructed and carefully glued to the surface of concrete, using a carborundum stone to prepare the bonding surface before attaching the reference mark.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 Where the extreme accuracy is required, resistancestrain gauges can be glued across the crack. They are however, expensive, sensitive to changes in humidity, and easily damaged.

IV. MEHODS OF REPAIR A. Bonding with epoxies Cracks as narrow as 0.05mm can be bonded by the injection of epoxy. The technique generally consist of establishing entry and venting ports at close intervals along the crack, sealing the crack on exposed surfaces, and injecting the epoxy under pressure [2]. Usual practice is to drill into the crack from the face of the concrete at several locations; inject water or a solvent to flush out the defect; allow surface to dry (using hot air jet, if needed); surface-seal the cracks between the injection points; and inject the epoxy until it flows out of the adjacent sections of the crack or begins to bulge out the surface seals, just as in pressure grouting. Usually the epoxy is injected through holes of about 0.75 inch diameter and 0.75 inch deep at about 6 to 12 inch centers (smaller spacing are used for finer cracks). This method of bonding represents an application for which there is no real substitute procedure. However, unless the crack is dormant (or the cause of cracking is removed, thereby making the crack dormant), it will probably recur, possibly somewhere else in the structure. Also, this technique is not applicable if the defects are actively leaking to the extent that they cannot be dried out, or where the cracks are numerous. B. Routing and sealing: This method involves enlarging the crack along its exposed face and filling and sealing it with a suitable material. This is a simplest and most common technique for sealing cracks and is applicable for sealing both fine pattern cracks and longer isolated cracks. The cracks should be dormant. This technique is not applicable for sealing cracks subjected to a pronounced hydrostatic pressure. The routing operation consists of following along the cracks with a concrete saw or with hand or pneumatic tools, opening the crack sufficiently to receive the sealant. A minimum surface width of 0.25 inch is desirable. Smaller openings are difficult to work on. The surface of the routed joints should be rinsed clan and permitted to dry before placing the sealant. The method used for placing the sealant depends on the material to be used and follows standard technique. Routing and sealing of leaking cracks should preferably be done on pressure face so that the water or other aggressive agents cannot penetrate the interior of the concrete and cause side effects such as swelling, chemical attack or corrosion of the bars. The sealant may be any of several materials, depending on how tight or permanent a seal is desired. On roadway pavements it is common to see cracks which have been sealed by pouring hot tar over them. This is a simple and in expensive method where thorough water tightness of the

joint is not required and where appearance is not important. C. Stitching: The tensile strength of a cracked concrete section can be restored by stitching in a manner analogous to sewing cloth. Concrete can be stitched by iron or steel dogs in the same way as timber. The best method of stitching is to bend bars into the shape of a broad flat bottomed letter U between 1 feet and 3 feet long and with ends about 6 inches long (or less if the thickness of the concrete is less), and to insert them in holes drilled to match in the concrete on either side of the crack. The bars are then grouted up- some grout being placed in the holes in advance of the bars. In case of stitching of concrete pavements, after stitching a longitudinal crack it may be necessary to treat a nearby longitudinal joint. A primary concern is whether a crack has formed below the saw cut for longitudinal joints. If a crack has occurred and the joint functions properly, then no treatment other than joint sealing is warranted. However, if there is no crack extending below the saw cut joint, then it is advantageous to fill the saw cut with epoxy to strengthen the slab at this location. If the joint is not functioning, but a joint sealant has already installed, then no further action is recommended [3]. Usually cracks start at one end and run away from the staring place quicker on the side of the concrete than on the other. The stitching should be on the side which is opening up first. The following points should be observed, in general i. Any desired degree of strengthening can be accomplished, but it must be considered that the strengthening also tends to stiffer the structure locally. This may accelerate the restraints causing the cracking and reactivate the condition. ii. Stitching the cracks will tend to cause the problem to migrate elsewhere in the structure. If it is decided to stitch, investigate and if necessary, strengthen the adjacent areas of the construction to take the additional stress. In particular, the stitching dogs should be of variable length and /or orientation and so located that the tension transmitted across the crack does not devolve on a single plane of the section, but is spread out over an area. iii. Where there is a water problem, the crack should be sealed as well as stitched so that the stitches are not corroded, and because the stitching itself will not seal the crack. Sealing should be completed before stitching is commenced both to avoid the aforementioned corrosion and because the presence of dogs tends to make it difficult to apply the sealant. iv. Stress concentrations occur at the ends of cracks, and the spacing of the stitching dogs should be closed up at such locations. v. Where possible, stitch both sides of the concrete section so that further movement of the structure will not exert any bending action on the dogs. In bending members it is possible to stitch one side of the crack only, but this should be the tension side of the section, where movement is originating. If the members are in

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 a state of axial tension, then a symmetrical placement of the dogs is a must, even if excavation or demolition is required to gain access to opposing sides of the section. vi. As an alternative to stitching cracks at right angles which method does not resist shear along the crack, sometimes it is necessary use diagonal stitching. One set of dogs can be placed on each side of the concrete if necessary. The length of the dogs is random so that the anchor points do not form a plane of weakness. vii. The dogs must be grouted with a non-shrink or expanding mortar, so that they have a tight fit, and movement of the cracks will cause the simultaneous stressing of both old and new sections. If this is not possible, proportion the stitching to take the entire load without precipitation. viii. The dogs are relatively thin and long and so cannot take much in the way of compressive force. Accordingly, if there is a tendency for the crack to close as well as to open, the dogs must be stiffened and strengthened by encasement in an overlay or by some similar means. D. External stressing Development of cracking in concrete is due to tensile stresses and can be arrested by removing these stresses. Further, the cracks can be closed by inducing a compression force sufficient to overcome the tension and to provide a residual compression. The compressive force is applied by use of the usual prestressing wires or rods. The principle is very similar to stitching, except that the stitches are tensioned; rather than plain bar dogs which apply no closing force to the crack and which may in fact have to permit the crack to open up a bit before they begin to take the load. All the points noted regarding stitching must be considered. An additional problem is that of providing an anchorage for the prestressing wires or rods. Some form of abutment is needed for this purpose. The effect of the tensioned force on the stress conditions in the structure should be analyzed. E. Grouting Grouting of the cracks can be performed in the same manner as the injection of an epoxy, and the technique has the same areas of application and limitations. However, the use of an epoxy is the better solution except where considerations of fire resistance or cold weather prevent such use, in which case grouting is the comparable alternative. The procedure is similar to other grouting methods and consist of cleaning the concrete along the crack; installing built-up seats at intervals along the crack, sealing the crack between the seats with a cement paint or grout, flushing the crack to clean it and test the seal; and then grouting the whole. The grout itself is high-early-strength Portland cement. An alternative and better method, where it can be performed, is to drill down the length of the crack and grout it so as to form a key. The grout key functions to prevent related transverse movements of the sections of concrete adjacent to the crack. However, this technique is applicable only where the cracks run in a reasonably

straight line and are accessible at one end. The drilled hole should preferably be 2 or 3 inches in diameter and flushed to clean out the crack and permit better penetration of the grout. F. Blanketing Blanketing is similar to routing and sealing, but is used on a larger scale and is applicable for sealing active as well as dormant cracks. The following are the principal types of blanket joints i. Type 1 – Where an elastic sealant is used: The sealant material is the one which returns to its original shape when not under an externally induced stress, i.e., acts elastically. The recessed configuration is used where the joint is subjected to traffic or a pressure head. The strip sealant is applicable where there are no traffic or pressure problems and is somewhat less costly. The first consideration in the selection of sealant materials is the amount of movement anticipated and the extremes of temperature at which such movement occur. It should be capable of deforming the required amount under applicable conditions of temperature. The material should be able to take traffic, be resistant to chemical spillage, be capable of being pigmented, if desired. ii. Type 2 – Mastic filled joint: The sealant is a mastic rather than a compound having elastic properties. This type of joint is for use where the anticipated movements are small and where trafficabilty or appearances are not considerations. The advantage is that the mastic is less costly than the elastic type of sealant material. iii. Type 3 – A mortar plugged joint: Proper sealing to the crack is provide against leakage using a temporary mortar plug. The mortar plug provides the strength for the joints. The plug resists the pressure on the joint by arching the load to the sides of the chase. Where the pressure acts on the face of the joint, static balance requires the development of the tensile and shear stresses between the plug and the sides of the slot. Compression and shear are developed when the pressure head is internal. Theoretically, the edges of the chase should be undercut so that the mortar plug, which dries more quickly and more thoroughly at the surface, does not shrink differentially and so pull away from the sides and bottom of the chase. iv. Type 4 – A crimped water bar: Mortar is required where the junctions which bear traffic. A crimped water stop joint sealant is not applicable for the use where the crack is subject to a heavy pressure head from inside the joint, or where movement occurs as a shear along the length of the crack. In the first case, the pressure would tend to bulge out the crimp, and in the second case, the longitudinal movement would tend to tear the stop. Accordingly, this type of joint is primarily for use where the anticipated movements are limited to a simple extension or contraction and where the pressure head is either small or acts from the face of the joint. However, while not specifically intended for such applications, a rubber type or similar crimped joint

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 material will take a little longitudinal movement, and the crimped stop will function under limited amount of relative transverse displacement. v. Dealing with the reinforcement: What ever be the detail used, when cutting the chase, it is possible that some of the reinforcement will be exposed. If this is the case, cut deep is enough so that the sealant will be behind the reinforcing, clean the bars, and paint them with bitumen as a protection against moisture penetration and corrosion. If the crack in an active one with substantial movements, cut the bars so that they do not impede the movement of the joint. G. Overlays: Overlays may be used to seal cracks and are very useful and desirable where there are large numbers of cracks and treatment of each individual defect would be too expensive.

The mechanism whereby healing occurs is the carbonation of calcium oxide and the calcium hydroxide in the cement paste by carbon dioxide in the surrounding air and water. The resulting calcium carbonate and calcium hydroxide crystals precipitate, accumulate and grow out from cracks. The crystals interlace and twine producing a mechanical bonding effect, which is supplemented by a chemical bonding between adjacent crystals and the surfaces of the paste and aggregate. As a result, some of the tensile strength of the concrete is restored across the cracked section, and the crack may become sealed. Saturation of the cracks and the adjacent concrete with water during the healing process is essential for the development of any substantial strength. Submergence of the cracked section is desirable. Alternatively, water may be ponded so that the crack is saturated. Upto 25% of the normal tensile strength may be restored by healing under conditions of submergence in water. The saturation must be continuous for the entire period of healing. A single cycle of drying and re-immersion will produce a drastic reduction in the amount of healing strength. Healing should be commenced as soon as after the crack appears as possible. Delayed healing results in less restoration of strength. Healing will not occur if the crack is active. Healing also will not occur if there is a positive flow of water through the crack, which dissolves and washes away the lime deposit, unless the flow is slow so that complete evaporation occurs at the exposed face causing re-deposition of the dissolved salts. Concrete cracks both dormant and active subjected to water pressure are able to themselves with time. The greatest autogenous healing effect occurs between the first 3 to 5 days of water exposure. In additional skin reinforcement proves to be highly effective in supporting the autogenous healing effect. Growth rate of calcium carbonate crystals depends on crack width and water pressure, whereas concrete composition and type of water has no influence on the autogenous healing rate [4].

i. Active cracks: Sealing of active cracks by use of an overlay requires that the overlay be extensible. The occurrence or prolongation of crack automatically means that there has been an elongation of the surface fibers of the concrete. Accordingly, an overlay which is flexible but not extensible, i.e., can be bent but cannot be stretched, will not seal a crack that is active. A two or three-ply membrane of roofing felt laid in a mop coat of tar, with tar between the plies; the whole covered with a protective course of gravel, concrete, or brick, functions very well for this purpose. The type of protective course depends on the use to which it will be subject. Gravel is typically used for applications such as roofs, and concrete or brick is applicable where fills is to be placed against the overlay. An asphalt block pavement also works well and may be used where the area is subjected to heavy traffic. If the cracks are subjected to longitudinal movements parallel to their axis, the overlay will wrinkle or tear. Be very careful in repairing such joints. Blanketing may be a better V. CONCLUSION solution. ii. Dormant cracks: If the cracks are dormant, almost any General precautions to be followed for the repair of type of overlay may be used, provided that it will take cracks in concrete as listed below. the traffic to which it is subject and that it is either i. Do not fill the cracks with new concrete or mortar adequately bonded or thick enough so that curling due ii. Try to avoid the use of brittle overlay to seal an active to differential deformations is not a problem. Epoxy crack. compounds are coming into increasingly frequent use iii. Do not fail to remove the restraints causing the crack. for this purpose. iv. Do not surface –seal cracks over corroded reinforcement without encasing the bar. H. Autogenous healing v. Do not bury or hide a joint so that it is in accessible. The inherent ability of concrete to heal, cracks within itself is termed as autogenous healing, and is a phenomenon which has been known for some time. It has REFERENCES practical application for sealing dormant cracks, such as in [1] C.S. Suryawanshi, “Structural concrete repair – A durability the repair of precast units cracked in handling, reknitting based revised approach is needed”, The Indian Concrete of cracks developed driving the driving of precast piling, Journal, 2012. sealing cracks in water tanks, and sealing of cracks which [2] “Causes, Evaluation and Repair of Cracks in Concrete are result of temporary conditions or inadvertencies. The Structures”, Reported by ACI Committee 224. effect also provides some increase in strength of concrete [3] “Stitching concrete Pavement”, International Grooving and damaged by vibration during set and of concrete disrupted Grinding Association, June 2010. by the effects of freezing and thawing. INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 [4] Carola Edvardsen, “Water permeability and Autogenous healing of cracks in concrete”, ACI Material journal, Title no 96-M 56, July/August 1999.

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RECOGNITION OF EMG BASED HAND GESTURES FOR PROSTHETIC CONTROL USING ARTIFICIAL NEURAL NETWORKS Sasipriya.S, Prema.P Department of Biomedical Engineering, PSG College of Technology, Coimbatore. email id: sashpsg@gmail.com, ppr@bme.psgtech.ac.in Abstract

â&#x20AC;&#x201C;

EMG

(Electromyography)

I. INTRODUCTION

biological signal derived from the summation of

Congenital defects or accidental loss of

electrical signals produced by muscular actions.

limbs can be corrected by the use of artificial limbs

This EMG can be integrated with external hardware

and

rehabilitation.

control

Pattern

prosthetics

recognition

plays

or prostheses. The most efficient way of controlling

the prosthesis is by the use of EMG signals

obtained from the active muscles. EMG signals

important role in developing myo-electric control

obtained by different actions can be used to make

based interfaces with prosthetics and Artificial

the prosthesis perform those different functions in

Neural Networks (ANN) are widely used for such

real time. For doing so, the EMG signal obtained is

tasks. The main purpose of this paper is to

filtered, windowed and after digital conversion,

classify different predefined hand gestured EMG

based on the features extracted, it is classified and

signals (wrist up and finger flexion) using ANN

given as control inputs to a prosthetic system for

and to compare the performances of four

activating correct functions. The classifier is an

different Back propagation training algorithms

important element in this system. Artificial neural

used to train the network. The EMG patterns are

networks (ANN) are mathematical modeling of

extracted from the signals for each movement and

biological

then ANN is utilized to classify the EMG signals

neuronal

systems

and

they

are

particularly useful for complex pattern recognition

based on their features. The four different

and classification tasks that are difficult for

training algorithms used were SCG, LM, GD and

conventional computers or human beings. The

GDM with different number of hidden layers

nonlinear nature of neural networks, their ability

and neurons. The ANNs were trained with those

to learn from their environments in supervised as

algorithms using the available experimental data

well as unsupervised ways, as well as their

as the training set. It was found that LM

universal approximation property make them

outperformed the others in giving the best

highly suited for solving difficult signal processing

performance within short time elapse. This

problems. But, it is critical to select the most

classification can further be used to control

appropriate neural network paradigm that can be

devices based on EMG pattern recognition.

applied for specific function. Artificial neural networks based on Multi-Layer Perceptron Model

Keywords - Electromyography, Myo-electric control, Artificial Neural Network, Back propagation algorithms, Pattern recognition.

(MLP) are most commonly used as classifiers for EMG pattern recognition tasks and selecting an appropriate

training

function

and

learning

algorithm for a classifier is a crucial task. The time

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delay between the command and activation of

EMG signals in which 75 represented finger flexion

prosthetic function should be minimum (not more

and the rest represented wrist up functions

than 100ms) for the comfort of the users [1], [2], [3],

obtained from volunteers and inputted to the

[4]. Hence the classifier should be precise and

neural network for classification.

rapid in producing correct signals for controlling

B. NEURAL NETWORK ARCHITECHTURE

the prosthesis, inspite of inaccuracies that may occur during the process of detection and

A neural network is a general mathematical

acquisition of EMG signals. So it is necessary to

computing paradigm that models the operations of

assess the impact of neural network algorithms on

biological neural systems [4]. Weights (which are

the performance, robustness, and reliability aspects

determined by the training algorithm), bias and

and to identify those that work the best for solving

activation function are important factors for the

our problem of interest. This work has attempted

response of a neural network. A Multi-Layer

to classify EMG based on two predefined hand

Perceptron

gestures and to identify the better performing training

functions

Feed

model

based

Feed

forward

Backpropagation algorithm is used here for

Forward

classification. Fig 1 shows the basic architecture of

Backpropagation algorithm (standard strategy of

a neural network with hidden layers between the

MLP) used in recognizing the patterns.

input and the output layers.

II. .METHODOLOGY A.

EMG

SIGNAL

ACQUISITION

AND

FEATURE EXTRACTION EMG signals used in this study are acquired from the muscles of the forearm namely Flexor Carpi Ulnaris (FCU), Extensor Carpi Radialis (ECR) and Extensor Digitorum (reference) for two types of hand movements-finger flexion and wrist up. FCU assists in wrist flexion with ulnar deviation and ECR assists in extension and radial

Fig 1: Neural network with hidden layers.

abduction of the wrist. The myoelectric signals are acquired by means of single channel differential

The designed ANN for EMG pattern

electrodes (disposable Ag/AgCl surface electrodes)

recognition consists of 3-layers: input layer, tan-

which are then amplified and filtered before

sigmoid (standard activation function) hidden

further processing.

layer and a linear (purelin) output layer. Each layer except input layer has a weight matrix, a bias

13 different statistical features extracted

vector and an output vector. The learning rule for

from the acquired EMG signals are Integrated

the propagation of neural network defines how the

EMG, Mean Absolute value, Modified Mean

weights between the layers will change [5], [6].

Absolute value 1, Modified Mean Absolute value

Here, the input is a 13 x 150 matrix and the

2, Simple square integral(energy), Variance, Root

corresponding target is a 2 x 150 matrix, (as 13

Mean Square, Waveform length, Zero Crossing,

features extracted from 150 samples and there are 2

Slope sign change, Willison amplitude, Difference

types of gestures to be classified). The classification

Absolute Mean Value and Histogram of EMG.

was divided into 3 stages: training (70% of

These 13 features are extracted from 150 samples of

samples), validation (15% of samples) and test

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(15% of samples). Four main training algorithms used were Scaled Conjugate Gradient (SCG), Levenberg-Marquardt

(LM),

Gradient descent

(GD), and Gradient descent with momentum (GDM).

The

sample

input

vectors,

their

corresponding target vectors and the output vectors after classification are shown in Table.1. III. RESULTS AND DISCUSSION The classification is done by altering the training functions, learning rate (GD and GDM), and number of neurons in a hidden layer with a Fig 2: Best Performance of LM

standard performance function MSE (Mean Square Error) and the better performing algorithm is identified. The summary of the results of various training algorithms used and the corresponding number of neurons is listed in Table.2. It is found that, on training the network with 10 neurons, SCG gives the least error and best performance. But on considering the fast convergence (which is the actual need for prosthetic control), LM with 20 neurons gives good classification performance earlier than SCG. If number of neurons is increased to 30, performance of LM is better than SCG, with a least time elapse. Also the classification rate of SCG algorithm is saturated at 81.3 % after 30 neurons, no matter how many neurons increased, the rate of correct classification remains constant. But higher

the neuron number, better

the

classification rate in LM algorithm. The other two

Fig 3: Classification Rate of LM

algorithms, GD and GDM require more time and IV. CONCLUSION AND FUTURE WORK

number of iterations needed for classification.

This work has been carried out to find the

Their performances are also undesired. Hence the classification

efficiencies

SCG

and

appropriate classifier for

EMG

signals. The

algorithms alone are shown in Table 3 and Table 4

experimental results show that the Levenberg-

respectively..

Marquardt

The

best

performance

and

algorithm

gives

good

and

fast

classification rate of LM based ANN with 50

performance with least computations. The main

neurons are also shown in Fig 2 and Fig 3. Thus the

disadvantages of this algorithm are requirements

LM network outperforms the other algorithms by

of large memory and increased number of neurons

providing

which may affect the hardware design (DSP

the

least

response

time

(fastest less

processors) of the prosthetics. Hence the future

number of iterations required and less error values.

will be to optimize the performance and provide

convergence),

higher

classification

rate,

interface to the hardware.

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Fig 4: LM Training tool

Table.1 : SAMPLE INPUT DATA AND SIMULATED OUTPUT DATA

Input vectors

13 extracted features from EMG

Target vectors

Wrist up Finger flexion

Output vectors

Wrist up Finger flexion

Sample 1 257.92 0.42987 0.32246 0.20606 643.08 1.0647 0.80911 67.429 89.086 0.14872 6.5714 67.571 116.29 1

Sample 2 318.26 0.53044 0.39805 0.28215 695.51 1.1527 0.88938 88 115.55 0.1929 9.1429 68 111.86 1

Sample 3 154.49 0.25749 0.19358 0.1467 425.03 0.70138 0.58973 26.857 46.511 0.077647 0.85714 73.857 108.86 0

0 0.7866 0.2339

0 0.9530 0.0411

1 0.3495 0.6390

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Table.2 : COMPARISON OF VARIOUS ALGORITHMS

BEST PERFORMANCE

GDM

SCG

0.15275

0.14585

0.18598

0.14172

HIDDEN NEURONS 10

0.27954

0.16829

0.0991680

0.13132

0.12168

0.1526

0.14919

0.17166

1000

968

1000

EPOCH AT WHICH BEST PERFORMANCE IS GOT

Table.3 : SHOWING THE CLASSIFICATION RATE SATURATION OF SCG HIDDEN NEURONS

Correctly classified

76.7

81.3

Misclassified

23.3

18.7

BEST PERFORMANCE

0.17323

0.10074

0.22587

0.14376

0.13385

EPOCH AT WHICH BEST PERFORMANCE OBTAINED

CLASSIFICATION RATES (PERCENTAGE)

Table.4 : SHOWING THE CLASSIFICATION RATE EFFICIENCY OF LM

HIDDEN NEURONS

Correctly classified

78.7

87.3

Misclassified

21.3

12.7

BEST PERFORMANCE

0.20428

0.22699

0.14131

0.30642

0.20215

EPOCH AT WHICH BEST PERFORMANCE OBTAINED

CLASSIFICATION RATES (PERCENTAGE)

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REFERENCES

bimodal drug delivery’, International Journal of Pharmaceutics, 2006.

[1] Alcimar Soares et al., ‘Development of virtual myo electric prosthetic controlled by EMG pattern recognition system based on neural networks’ ,Journal of Intelligent Information Systems,2003

[6]. Claudio Castellini, Patrick van der Smagt, ‘Surface EMG in advanced hand prosthetics’, . Biol Cybern , 2009.

[2] Md. R. Ahsan,Muhammad, I. Ibrahimy, Othman O. Khalifa, ‘EMG Signal Classification for Human Computer Interaction: A Review’ , European Journal of Scientific Research, 2009. [3] Md. Rezwanul Ahsan, Muhammad Ibn Ibrahimy, Othman O. Khalifa, ‘Electromyography (EMG) Signal based Hand Gesture Recognition using Artificial Neural Network (ANN)’, 4th International Conference on Mechatronics (ICOM), 17-19 May 2011, Kuala Lumpur, Malaysia, [4] Yu Hen Hu, Jenq-Neng Hwang,’ Handbook of neural network signal processing’, ‘‘Introduction to Neural Networks for Signal processing’’, CRC PRESS, 2001. [5] A. Ghaffari et al., ‘Performance comparison of neural network training algorithms in modeling of

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Vertical farm buildings Sustainable and green manufacturing

C.BALACHANDAR.

A.SIDHARTHAN.

Dept. of Civil Engineering SMVEC Puducherry, India balaji1145@hotmail.com

Dept. of Civil Engineering SMVEC Puducherry, India sidhu1194@gmail.com

I. INTRODUCTION Abstract— This paper deals about Vertical farm buildings and some advanced technologies as upgrade features to improve the efficiency of these buildings. This paper also deals about vast area of benefits in various categories in this modern agriculture. Index Terms—Artificial photosynthesis, filtering system, Organic wastes, Pesticide-free.

Due to fast growth in urbanisation, agricultural lands are being converted to industrial zones. The land available for agricultural activities is being decreased at a faster rate. The agricultural lands are heavily occupied by industries and business centres in last few decades. Also rural people migrate towards the urban area. The growth comparison of rural and urban population is given in figure below.

Water

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It is estimated that by the year 2050, close to 80% of the world’s population will live in urban areas and the total population of the world will increase by 3 billion people. A very large amount of land may be required depending on the change in yield per hectare. Scientists are concerned that this large amount of required farmland will not be available and that severe damage to the earth will be caused by the added farmland. For survival of mankind, agriculture is necessary. But there is a lack of interest in agricultural activities in the minds of people. To overcome these difficulties and reduce land exploitation Vertical farm concept has been arised. In this paper, I have discussed some new features to be added in these Vertical farm.

B.Air-Conditioning

II. DESIGNING FEATURES The features mentioned here are the advancement technologies that need to be designed in the vertical farm to increase the efficiency . Here the word “efficiency” refers to the crop growth rate. So, these advancement features will help the crops grow in a well conditioned environment . These features are designed to utilize the waste energies such as waste water and utilize the renewable source of energies. Listed below are features that makes the advancement:

C.Drip Irrigation

As mentioned above temperature need to be maintained. Thermal insulation only prevents the exchange of heat from surroundings. It could not provide the required temperature. So , we have to use air conditioners inside the building so as to provide the appropriate temperature for the crops either hot or cold depending on the crops that we cultivate. As we provide thermal insulation for the building, power that we need to spend for the air-conditioners is greatly reduced. With the use of air-conditioning system, we have the choice of adjusting the temperature. Crops will grow and mature at a faster rate if temperature needed for the cops at different stages of growth is shortly provided. Hence, maintain the temperature will greatly increase the crops growth as compared to conventional farming practices. Water that is required for the crops need to be supplied from the ground or underground where the water is stored. The water supply inside the building is divided into primary supply and secondary supply. Primary water supply is similar to pipeline systems that is used in ordinary buildings. This will take the water to each floor level. Secondary water supply takes the water to crops. This secondary water supply is achieved by irrigation so as to reduce the consumption of water. Drip irrigation is the most economical irrigational system to save the water. Further advancement technology in irrigation is Sub-surface Drip irrigation which will further reduce the water consumption and the water will reach the root system of crops directly. As there is no evaporation of water inside the building, the water loss above soil surface is eliminated.

A.Thermal Insulation Crops grow on certain temperature healthy and also at a faster rate based on the temperature. The reason is that the temperature influences the reaction that takes place in growing a crop. The appropriate temperature must be steadily maintained to achieve the steady growth of a crop. But , the environmental temperature may vary according to the different climatic conditions and weather conditions. Hence , to maintain the temperature that is different from environment, we need thermal insulation for the building. While building the outer walls of the building that is exposed to the environment we must take in consideration to provide thermal insulation. It is necessary to provide thermal insulation on the top floor of the building. For this purpose we may use cavity walls, foam concrete, loose fill insulation, light weight aggregate. Using glass wall panels is better thermal insulation also it allows natural light to enter inside the building to some extent.

D. Water filtering system for recycling The water loss is also below the soil surface. If watered the cultivating land in conventional farming practices, the excess water go deeper as the root system is located. But in Vertical farms we can easily eliminate this loss by simple technique. We set a pool of soil for crops. In this pool, below the soil layer we design a thick plastic membrane which will filter the excess water that the soil does not retain. So this excess water gets filtered off and collected for reuse. The water filtering system is shown below. The white layer in the figure indicates the plastic membrane for filtering water.

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can get organic wastes and we can adopt any method for converting them to a good fertilizer. Vermicomposit pit method is very much suitable. III. ADVANTAGES OF VERTICAL FARM

A. Ultimate benefits that helps Green Economy  Chemical and Pesticide-Free Due to a controlled indoor growing environment, Vertical farms facilities are not affected by natural pests, and therefore do not require chemicals or pesticides to ensure a healthy crop. Vertical farms offers consumers safe, healthy and organic produce, 365 days a year.  Freshest Produce Available Vertical farms produces fresh, pesticide-free, local greens that not only taste better, but have a much longer shelf-life compared to most other produce which has to be harvested weeks in advance and then trucked close to 2,000 miles before making it to the market.  Buying Local Vertical farms facilities bring the farm right to the people. This means that urban dwellers can buy produce that was grown as close as 5 miles to their homes. Vertical farms makes buying local accessible to everyone, every season of the year.  Increases productivity The Vertical farms system grows plants in cubic feet versus square feet, producing yields up to ten times greater than traditional greenhouses, and up to 100 times greater than conventional field agriculture on a per square foot basis.  Year-round production Due to the controlled, indoor environment, Vertical farms can produce crops 24 hours a day, 7 days a week, 365 days a year. This means stable and consistent revenue for Vertical farms facility owners/operators.  Strengthens local economy When you purchase Vertical farms produce from your local Vertical farms farm your dollars stay within the community and circulate throughout, giving other local businesses a healthy boost.

Fig. Water filtering system using membrane

E. Power supplement In vertical farms, some electrical energy is required to achieve this process. We need power for artificial lighting, water pumping and lift systems to carry the loads. So this power can be supplemented by using renewable energy sources. We can fit solar panels on the walls of Vertical farm. On the top floor we can have wind mills. Hence this power that is required can be easily supplemented.

F.Lightings for Artificial Photosynthesis By using proper lightings to the plants we can stimulate it’s growth this is termed as artificial photosynthesis. This is what we see in botanical gardens. So above the crops we provide lights focussing the crops. Now-a-days, LED bulbs are more energy conserving and it also suitable for the artificial photosynthesis process.

G. Alternating photosynthesis and respiration A plant does not survive if all the time light is provided. Actually it works for manufacturing it’s food in the presence of light and CO2. For this process, we provide light. After sometime, plants needs to sleep, so it needs dark and O2. To alternate this cycle, we have a special sensing system, that will measuring the parts per million of CO2 molecules present in the air. After attaining certain limit, the air with high CO2 is sucked off. The lights are off and the fresh air with Oxygen is pumped in which is achieved by Air-conditioners.

B. Environmental benefits  Eliminates the need for chemical pesticides Because we grow plants in a controlled indoor environment, our facilities are not affected by pests. Pesticides are not only an environmental and health concern, but also represent an additional cost in field agriculture.

H. Utilization of Organic wastes The organic waste materials generated in the metropolitan cities is huge which can be ultimately used as fertilizer in these Vertical farm buildings. The waste products are collected of whole city is collected in a place for disposing or recycling. From there we

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 Reduces water pollution Run-off from chemical fertilizers used on commercial farms often contaminates nearby water supplies.  Uses less water Vertical farms's closed-loop hydroponic irrigation systems uses only 20% of the amount of water that is required in Conventional Field Agriculture. That's 5 times less water per sq.ft. of production!  Reduces fossil fuel use Since Vertical farms grows produce in close proximity to end consumers, limited transportation is required between production site and market, thus significantly decreasing fuel usage and greenhouse gases. Additionally, no machinery (i.e., tractors) is required to plant or harvest a Vertical farms crop, as is required in field agriculture.  Minimizes wastewater The watering injection system recycles water, generating little to no waste. Wastewater is one of the most significant environmental costs associated with traditional methods of hydroponics.  Re-purposes existing structures Vertical farms builds its facilities on underutilized or abandoned properties, reducing its environmental footprint.

D. Social Benefits

C.Retailer benefits

Conclsion:

 Creates local jobs A Vertical farms facility creates employment opportunities that pay livable wages, plus benefits, for local residents.  Promotes economic growth Vertical farms creates opportunities for community entrepreneurs to grow and sell the produce, and replaces imported goods with local goods.  Promotes social responsibility Vertical farms is committed to sustainable design and building practices, as well as superior energy efficiency in all operations.  Vertical farms is a good neighbor Vertical farms partners with local businesses and community leaders to make sure that we address the community's needs and concerns. Our goal is to create jobs, economic growth, and a healthier environment.

Case study: Some existing vertical farms and vertical farms under construction are used for case study. Notable of them are Sky Green Singapore, Farmed Here , Bedfork in United States, Gotham Greens in New York City, Local Garden in Vancouver of Canada.

 Price stability Due to year-round production and controlled growing conditions, Vertical farms produce does not fall victim to seasonal availability or price swings. Vertical farms is able to offer a fixed and competitive price for produce year-round.  Consistent and reliable crop Due to the controlled, indoor growing environment, Vertical farms produce is not effected by crop loss due to natural disasters or weather related issues, such as droughts or floods. Vertical farms offers suppliers a consistent quality crop regardless of the time of year, or outdoor climate.  Longer shelf-life Vertical farms's crops are attached to their roots until they reach the cooler, which makes for a much longer shelf life than crops harvested by traditional methods. Our produce is delivered to stores the same day that it's harvested.

The fast urbanisation in the recent decades affects agriculture as there is no proper land for cultivation. Also the conventional methods of agriculture makes the soil non-fertile and thus makes a way of afforestation. Although some initial costs of spending such a source of money for building these Vertical Farms, the best way to overcome land depletion and save agriculture. Hence, I conclude Vertical Farms are the best choice for agricuture’s future.

Refernces: 1.

Abate T, van Huis A, Ampofo JK. 2000. Pest management strategies in traditional agriculture: an African perspective. Annu Rev Entomol.45:631-59. Amahmid O, Asmama S, Bouhoum K. The effect of waste-water reuse in irrigation on the contamination level of food crops by Giardia cysts and Ascaris eggs. Int J Food Microbiol. 49:19-26. Cairns, Jr., John. 2000. Sustainability and the future of humankind: two competing theories of Infinite Substitutability. Politics and the Life Sciences 1: 27-32.

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13.

Ecological Monitoring and Assessment Network: science-based and policy relevant. Environ Monit Assess. 67:3-28. Elgendy H. 2002. Institut fur Stadtebau und Landsplanung der Universitat Karlsruhe. Global trends: Urbanization Environmental Protection Agency. Auxillary information: national priorities list, proposed rule. Intermittent Bulletin. Internet Vol. 7. 2004. Foster SSD, Chilton PJ. 2003. Groundwater: the processes and global significance of aquifer degradation. Phil Trans: Biol Sci. 358: 1957-1972. Food and Agriculture Organization, World Health Organization. 2004 statistics on crop production Goudriaan J, Zadoks JC. 1995 Global climate change: Modelling the potential responses of agroecosystems with special reference to crop protection. Environ Pollut. Harold V. Eck. 1988. Winter wheat response to nitrogen and irrigation. Agron. J. 80:902-908. IFA Agriculture Committee. Summary Report. Global Agricultural Situation and Fertilizer Consumption in 2000 and 2001. June 2001. Jelle Bruinsma, ed., Appendix of World Agriculture: Towards 2015/ 2030, UNFAO (2003) Earthscan Publications, London. P. 432. Likens GE, Bormann FH. 1995. Biogeochemistry of a Forested Ecosystem. Second Edition, SpringerVerlag New York Inc. P. 159.

21. Tilman D, Fargione J, et al. 2001. Forecasting agriculturally driven global environmental change. Science. 292: 281-284. 22. United Nations. World Population Prospects: The 1998 Revision. 23. Wie S, Shanklin CW, Lee KE. 2003. A decision tree for selecting the most cost-effective waste disposal strategy in foodservice operations. J Am Diet Assoc.

14. Likens GE. 2001. Ecosystems: Energetics and Biogeochemistry. pp. 53-88. In: Kress WJ and Barrett G (eds.). A New Century of Biology. Smithsonian Institution Press, Washington and London. 15. Lugwig C, Hellweg S. 2002. Municipal solid waste management. Strategies and technologies for sustainable solutions. Springer Verlag, Pub. Heidleberg, New York. P. 545. 16. McMichael AJ. 2001. Impact of climatic and other environmental changes on food production and population health in the coming decades. Proc Nutr Soc. 60:195-201 17. Malkow T. 2004. Novel and innovative pyrolysis and gasification technologies for energy efficient and environmentally sound MSW disposal. Waste Manag. 18. Nath KJ. 2003. Home hygiene and environmental sanitation: a country situation analysis for India. Int J Environ Health Res.13 19. Salvato JA, Nemerow NL, Agardy FJ. 2003. Environmental Engineering. John Wiley & Sons; 5 th ed. P 1,584. 20. Stalnacke P, Vandsemb SM, Vassiljev A, Grimvall A, Jolankai G. Changes in nutrient levels in some Eastern European rivers in response to large-scale changes in agriculture. Water Sci Technol.

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SUSTAINABILITY THROUGH CRYOGENIC WATER FUEL V.Prasanth1, Dr.R.Gnanaguru2 1 Final year Mechanical, Narasu’s Sarathy Institute of Technology,Salem. Email: prasanthvbala@gmail.com 2 Professor & Head / Mechanical, Narasu’s Sarathy Institute of Technology,Salem. Email: nsithodmech@gmail.com

ABSTRACT:

2. PROPERTIES OF HYDROGEN

Today we're going to pour a few drops of water into our car's fuel tank, and triple our mileage; we're going to electrolyze hydrogen from our municipal water supply and run our house; and with a cup of seawater, The most plentiful substance available on earth. We’re going to extract energy from water and solve the world's energy crisis. But the existing hydrolysis process suffers a serious of disadvantages; thereby the idea is to apply cryogenic principle in hydrogen gas to convert it in the form of liquid hydrogen for the better utilization as a fuel in the automobiles. Thus it serves as a renewable source of energy. Keywords: Hydrogen.

Cryogenics,

Hydrogen is the simplest, lightest and most plentiful element in the universe. Hydrogen is made up of one proton and one electron revolving around the proton. In its normal gaseous state, hydrogen is colorless, odorless, tasteless and non-toxic and burns invisibly and over eleven thousand times lighter than water. It is very abundant, being an ingredient of water and of many other substances, especially those of animal or vegetable origin. It may produce in many ways, but is chiefly obtained by the action of acids (as sulphuric) on metals, as zinc, iron, etc. It is very inflammable, and is an ingredient of coal gas and water gas. It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad. Symbol H. Atomic weight 1.

Electrolysis,

1. INTRODUCTION

3. COMBUSTION OF HYDROGEN

In this, hydrogen is separated from water through a process known as electrolysis. In the electrolysis hydrogen is separated from water by passing current to the water through electrodes. The hydrogen is trapped separately from the electrolysis kit and mixed with air for better calorific value. This mixed hydrogen and air is sent to the engine and the combustion is made. The exhaust produced will be a water vapor and this helps to minimize pollution.

Hydrogen has also combustion qualities as a fuel and energy source. The hydrogen must first be broken out from its compound form with oxygen as water (H20) using electrolysis or gathered by other means as it does not naturally occur by itself. Hydrogen cannot be mined or drilled as with fossil fuels. For production of hydrogen by electrolysis process requires

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electrical energy input. With this generated hydrogen combustion can be made.

graphite electrodes are inserted. Water is filled inside the electrolysis kit and then current is passed through electrodes to break the water.

4. PARTS NEEDED FOR EXTRACTION OF HYDROGEN GAS  Electrolysis kit (To do electrolysis process)  Compressor (To compress the hydrogen produced by electrolysis process  D.C.Motor (To drive the compressor)  Rheostat (To vary the speed of the compressor)  L.P.G Tank (To store the hydrogen at a high pressure)  Gas kit (to fix on the tank for safety)

Fig2: Electrolysis process in cooker. A safety valve is a valve mechanism for the automatic release of a substance from a boiler, pressure vessel, or other system when the pressure or temperature exceeds preset limits. It is part of a bigger set named pressure safety valves (PSV) or pressure relief valves (PRV). The other parts of the set are named relief valves, safety relief valves, pilot-operated safety relief valves, low pressure safety valves, vacuum pressure safety valves. Adding Electrolyte: Electrolysis of pure water is very slow,. Pure water has an electrical conductivity about one millionth that of seawater. So, due to the mixing of the some electrolytic solution must be added like Sulphuric acid H2So4 or a base or salt, it will make easier to split up the hydrogen and oxygen.

a. Electrolysis Process Battery: The battery is an electro-chemical device for converting electrical energy into chemical energy. It stores the electrical energy in the form of chemical energy and provides a current for the electrolysis process. It is a 12V battery which supplies a 7Amps of current. Electrical wires are connected between the battery and the electrodes for the passage of current from battery to electrodes.

Electrolysis Process: The process by which we generate hydrogen (and oxygen) from water is called electrolysis. The word "lysis" means to dissolve or break apart, so the word "electrolysis" literally means to break something apart (in this case water) using electricity. Electrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to an

Fig1: Battery and electrode. Electrolysis Kit: Electrolysis kit is made with safety measures. Cooker is used as a electrolysis kit. In the top of the kit two

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electric current being passed through the water. This electrolytic process is used in some industrial applications when hydrogen is

b. Compressor: A machine that increases the pressure of a gas or vapor (typically air), or mixture of gases and vapors. The pressure of the air is increased by reducing the specific volume of the air during passage of the air through the compressor. When compared with centrifugal or axial-flow fans on the basis of discharge pressure, compressors are generally classed as highpressure and fans as low-pressure machines.

needed.

Fig 3: Compressor Role of Compressor: In this compressor is used to compress the hydrogen produced by electrolysis process. Because the hydrogen produced by electrolysis process will not be at a sufficient pressure to store in a tank. So a compressor must be use for boosting the pressure of the hydrogen.

The calorific value of the hydrogen produced from electrolysis is 13,000 KJ/m3

c. D.C Motor: When a current passes through the coil wound around a soft iron core, the side of the positive pole is acted upon by an upwards force, while the other side is acted upon by a downward force. According to Fleming's left hand rule, the forces cause a turning effect on the coil, making it rotate. To make the motor rotate in a constant direction, "direct current" commutators make the current reverse in direction every half a cycle (in a two-pole motor) thus causing the motor to continue to rotate in the same direction.

Electrolysis of Water: An electric power source (Battery) is connected to the two electrodes i.e. (positive & negative).When electricity is sent to water through that electrodes, the oxygen atoms are attracted to the anode(positive electrode), and the hydrogen atoms are attracted to the cathode(negative electrode).These splitted atoms are appeared by a small bubbles. The generated amount of hydrogen is twice the amount of oxygen.i.e more bubbles come from cathode. Because in water hydrogen atoms is more than oxygen atoms (H2O).i.e. two hydrogen atoms and one oxygen atom

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Role of D.C Motor D.C motor is used to run the compressor. There must be an input to run the compressor and so the motor is used to drive the compressor. The input for the motor is 12v battery. The current from the battery will run the motor, since the chain drive is taken between the motor and the one end of the compressor, the end is for the gear drive. The compressor will can able to run.

Fig5: COMPRESSOR, MOTOR AND RHEOSTAT f. Hydrogen tank: When the electrolysis process is going since the engine is also running by hydrogen. After some time there will not be hydrogen to continue the running the engine, when the hydrogen tank is not present. Because the electrolysis process is very slow. So due to the above reasons the hydrogen is stored with a high pressure in a 2kg cylindrical tank. This tank consists has a two valves., inlet and outlet. The inlet is for taking the compressed hydrogen gas from the compressor. The other valve is for releasing the gas present in the tank to the vaporizer. The gas regulator is employed at the outlet valve to prevent the backfire when it occurs.

Fig4: Compressor and Motor e. Rheostat: A rheostat is an electrical component that has an adjustable resistance. It is a type of potentiometer that has two terminals instead of three. The two main types of rheostat are the rotary and slider. The symbol for a rheostat is a resistor symbol with an arrow diagonally across it. They are used in many different applications, from light dimmers to the motor controllers in large industrial machines. In this technology, rheostat is used to vary the speed of the compressor in a required torque.

g. Gas regulator: A gas regulator is also proposed for a safety measures. If the gas regulator is not present in this system, the produced backfire will burst the tank as like as our cooking cylinder. This gas regulator is fixed at the top of the tank

Fig6: Tank with Gas Regulator

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Reasons for Storing the Hydrogen

6. CRYOGENICS

When the electrolysis process is going since the engine is also running by hydrogen. After some time there will not be hydrogen to continue the running the engine, if the hydrogen tank is not present. Because the electrolysis process is very slow. So due to the above reasons the hydrogen is stored with a high pressure in a 2kg cylindrical tank.

The word cryogenics stems from Greek and means "the production of freezing cold". Cryogenics is the study of the production and behavior of materials at very low temperatures (below −150 °C, −238 °F or 123 K). A person who studies elements that have been subjected to extremely cold temperatures is called a cryogenicist. The field of cryogenics advanced during World War II, when scientists found that metals frozen to low temperatures showed more resistance to wear. Based on this theory of cryogenic hardening, the commercial cryogenic processing industry was founded in 1966 by Ed Busch

5. SYSTEM WORKING PRINCIPLE Since the motor is running and it runs the compressor by chain drive, compressor sucks the produced hydrogen to compress it for a high pressure. From the outlet of the compressor the pressurized hydrogen come out due to the low pressure at the tank. When the low pressure is created at vaporizer which is next to tank, the compressed hydrogen flows to the vaporizer through the gas regulator. WORKING SYSTEM

PRINCIPLE

7. PROPERTIES HYDROGEN

LIQUID

The byproduct of its combustion with oxygen alone is water vapor (although if its combustion is with oxygen and nitrogen it can form toxic chemicals), which can be cooled with some of the liquid hydrogen. Since water is considered harmless to the environment, an engine burning it can be considered "zero emissions." Liquid hydrogen also has a much higher specific energy than gasoline, natural gas, or diesel. The density of liquid hydrogen is only 70.99 g/L (at 20 K), a relative density of just 0.07. Although the specific energy is around twice that of other fuels, this gives it a remarkably low volumetric energy density, many fold lower.

THIS

The low pressure produced in a vaporizer is due to the acceleration of the vehicle as like as engine carburetor principle. Now the pressurized hydrogen is passed to the carburetor through the vaporizer. And the hydrogen from the carburetor is passed to the engine and where the engine begins to start.

Liquid hydrogen requires cryogenic storage technology such as special thermally insulated containers and requires special handling common to all cryogenic fuels. This is similar to, but more severe than

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liquid oxygen. The triple point of hydrogen is at 13.81 K 7.042 kPa.

Fig7: Liquid Hydrogen stored in the tank Fig8: Lindeâ&#x20AC;&#x2122;s Process

8. PROCESS OF LIQUIFICATION

b. CLAUDE'S PROCESS Air can also be liquefied by Claude's process in which the gas is allowed to expand isentropically twice in two chambers. While expanding, the gas has to do work as it is led through an expansion turbine. The gas is not yet liquified, since it would destroy the turbine. Final liquefaction takes place by isenthalpic expansion in a JouleThomson-Valve.

The hydrogen collected from the various processes is subjected to the liquefaction. The liquefaction of gases is a complicated process that uses various compressions and expansions to achieve high pressures and very low temperatures. It is done majorly by this two processes. 1. Linde's Process 2. Claude's Process a. LINDE'S PROCESS Air is liquefied by the Linde process, in which air is alternately compressed, cooled, and expanded, the expansion resulting each time in a considerable reduction in temperature. With the lower temperature the molecules move more slowly and occupy less space, so the air changes phase to become liquid.

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9. FUEL TANK

11. CONCLUSION

The liquid hydrogen is the fuel that we are going to use it in our system. The pressure of the tank is maintained at the 350atmospheres. The idea is to use a closed cycle helium refrigeration system to sustain hydrogen as a liquid itself.

Well!! Water servers the good source of energy for the fuel. This makes us to imagine “Filling fuel from our water tank” simply sounds awesome. Though applying cryogenics seems to be costlier, when we commercialize them it becomes very cheap when compared to petrol or diesel.

REFERENCES 1. S.S.Dara “A text book of engineering chemistry”. 2. "Cryonics is NOT the Same as Cryogenics". Retrieved 5 March 2013. 3. Shaw, David (2009). Cryoethics: Seeking Life After Death. Bioethics. ISSN 0269-9702(print); 1467-8519 (online). 23:9, 515-521. 4. “Hydrogen as an Alternative Fuel” Almc.army.mil. Retrieved on 201108-28. 5. Thermophysical Properties of Hydrogen , nist.gov, accessed 201209-14 6. Handling, Transport and Storage of Cryogens. 7. William Cullen, Of the Cold Produced by Evaporating Fluids and of Some Other Means of Producing Cold, in Essays and Observations Physical and Literary Read Before a Society in Edinburgh and Published by Them, II.

Fig 9: Hydrogen Storage Arrangement

10. WORKING PRINCIPLE Since BHP produced in the burning of liquid hydrogen is very large, it cannot be used directly. Instead the idea is to use a controlled injection system in this operation. The stroke length of piston is increased and the bore diameter is reduced, so that all the power is transmitted to the flywheel. The liquid hydrogen combines with air, only in the combustion chamber. Triple spark plug technology is used so that all the fuel is burned away. Since large amount of air is required for the combustion, turbo charger is used and its motive power is given to the blower to suck the air. When the combustion takes place purely with the oxygen alone, then the exhaust is just the water vapor.

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SILVERLINE FOR THE BLIND VENKATRAMAN.R#, VIKRAM.V#, SURENDHAR.R# *Department of Information Technology, Dhanalakshmi College of Engineering, Tambaram, Manimangalam, Chennai. 1

venkatraman094@gmail.com

vasuvikram5@gmail.com

surensrn3@gmail.com

Artificial-vision researchers take inspiration from another device, the cochlear implant, which has successfully restored hearing to thousands of deaf people. But the human vision system is far more complicated than that of hearing. The eye is one of the most amazing organs in the body. Before we understand how artificial vision is created, it's important to know about the important role that the retina plays in how we see. Here is a simple explanation of (Figure 1 & 2) what happens when we look at an object:

ABSTRACT— This paper represents the importance when any tissue or layers of retina, cells and optic nerves of eye gets damaged. Blindness is more feared by the public than any other ailment. Artificial vision for the blind was once the stuff of science fiction. But now, a limited form of artificial vision is a reality .Now we are at the beginning of the end of blindness with this type of technology. In an effort to illuminate the perpetually dark world of the blind, researchers are turning to technology. They are investigating several electronicbased strategies designed to bypass various defects or missing links along the brain's image processing pathway and provide some form of artificial sight.

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Keywords - Vision, ASR, ARCC.

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I.INTRODUCTION: This paper is about curing blindness. Linking electronics and biotechnology, the scientists has made the commitment to the development of technology that will provide or restore vision for the visually impaired around the world. This paper describes the development of artificial vision system, which cures blindness to some extent. This paper explains the process involved in it and explains the concepts of artificial silicon retina, cortical implants etc. The roadblocks that are created are also explained clearly. Finally the advancements made in this system and scope of this in the future is also presented clearly.

Scattered light from the object enters through the cornea. The light is projected onto the retina. The retina sends messages to the brain through the optic nerve. The brain interprets what the object is.

Figure (1): Architecture of eye

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  

Small enough to be implanted in the eye Supplied with a continuous source of power Biocompatible with the surrounding eye tissue

Figure (2): Anatomy and its path view of eye

The retina is complex in itself. This thin membrane at the back of the eye is a vital part of our ability to see. Its main function is to receive and transmit images to the brain. These are the three main types of cells in the eye that help perform this function: Rods, Cones and Ganglion Cells. The information received by the rods and cones are transmitted to the nearly 1 million ganglion cells in the retina. These ganglion cells interpret the messages from the rods and cones and send the information on to the brain by way of the optic nerve. There are a number of retinal diseases that attack these cells, which can lead to blindness. The most notable of these diseases are retinitis pigmentosa and age-related macular degeneration. Both of these diseases attack the retina, rendering the rods and cones inoperative, causing either loss of peripheral vision or total blindness. However, it's been found that neither of these retinal diseases affects the ganglion cells or the optic nerve. This means that if scientists can develop artificial cones and rods, information could still be sent to the brain for interpretation. This concept laid the foundation for the invention of the ARTIFICIAL VISION SYSTEM technology.

Figures (3) The dot above the date on this penny is the full size of the Artificial Silicon Retina.

Perhaps the most promising of these two silicon devices is the ARTIFICIAL SILICON RETINA (ASR). The ASR is an extremely tiny device. It has a diameter of just 2 mm (.078 inch) and is thinner than a human hair (Figures 3). In order for an artificial retina to work it has to be small enough so that doctors can transplant it in the eye without damaging the other structures within the eye. Groups of researchers have found that blind people can see spots of light when electrical currents stimulate cells, following the experimental insertion of an electrode device near or into their retina. Some patients even saw crude shapes in the form of these light spots. This indicates that despite damage to cells in the retina, electronic techniques can transmit signals to the next step in the pathway and provide some form of visual sensation. Researchers are currently developing more sophisticated computer chips with the hope that they will be able to transmit more meaningful images to the brain.

II.HOW TO CREATE ARTIFICIAL VISION? The current path that scientists are taking to create artificial vision received a jolt in 1988, when Dr. Mark Humayun demonstrated that a blind person could be made to see light by stimulating the nerve ganglia behind the retina with an electrical current. This test proved that the nerves behind the retina still functioned even when the retina had degenerated. Based on this information, scientists set out to create a device that could translate images and electrical pulses that could restore vision. Today, such a device is very close to be available to the millions of people who have lost their vision to retinal disease. In fact, there are at least two silicon microchip devices that are being developed. The concept for both devices is similar, with each being:

III. How does ARTIFICIAL SILICON RETINA works?

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The ASR contains about 3,500 microscopic solar cells that are able to convert light into electrical pulses, mimicking the function of cones and rods. To implant this device into the eye, surgeons make three tiny incisions no larger than the diameter of a needle in the white part of the eye. Through these incisions, the surgeons introduce a miniature cutting and vacuuming device that removes the gel in the middle of the eye and replaces it with saline. Next, a pinpoint opening is made in the retina through which they inject fluid to lift up a portion of the retina from the back of the eye, which creates a small pocket in the sub retinal space for the device to fit in. The retina is then resealed over the ASR (Figure 4).

250 pixel array, which would allow those who were once blind to read a newspaper. A. WORKING OF ARTIFICIAL VISION SYSTEM: The main parts of this system are miniature video camera, a signal processor, and the brain implants. The tiny pinhole camera, mounted on a pair of eyeglasses, captures the scene in front of the wearer and sends it to a small computer on the patient's belt. The processor translates the image into a series of signals that the brain can understand, and then sends the information to the brain implant that is placed in patient’s visual cortex. And, if everything goes according to plan, the brain will "see" the image. Light enters the camera, which then sends the image to a wireless wallet-sized computer for processing. The computer transmits this information to an infrared LED screen on the goggles. The goggles reflect an infrared image into the eye and on to the retinal chip, stimulating photodiodes on the chip. The photodiodes mimic the retinal cells by converting light into electrical signals, which are then transmitted by cells in the inner retina via nerve pulses to the brain. The goggles are transparent so if the user still has some vision, they can match that with the new information - the device would cover about 10° of the wearer’s field of vision.

Figure (4): Here you can see where the ASR is placed between the outer and inner retinal layers.

The patient should wear sunglasses with a tiny pinhole camera mounted on one lens and an ultrasonic range finder on the other. Both devices communicate with a small computer carried on his hip, which highlights the edges between light and dark areas in the camera image (Figure 5). It then tells an adjacent computer to send appropriate signals to an array of small electrodes on the surface of patient’s brain, through wires entering his skull.

For any microchip to work it needs power, and the amazing thing about the ASR is that it receives all of its needed power from the light entering the eye. This means that with the ASR implant in place behind the retina, it receives all of the light entering the eye. This solar energy eliminates the need for any wires, batteries or other secondary devices to supply power. Another microchip device that would restore partial vision is currently in development called the artificial retina component chip (ARCC), this device is quite similar to the ASR. Both are made of silicon and both are powered by solar energy. The ARCC is also a very small device measuring 2 mm square and a thickness of .02 millimeters (.00078 inch). There are significant differences between the devices, however. According to researchers, the ARCC will give blind patients the ability to see 10 by 10 pixel images, which is about the size of a single letter on this page. However, researchers have said that they could eventually develop a version of the chip that would allow 250 by

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IV. ADVANCEMENTS IN CREATING ARTIFICIAL VISION: Ceramic optical detectors based on the photo-ferroelectrics effect are being developed for direct implantation into the eyes of patients with retinal dystrophies. In retinal dystrophies, where the optic nerve and retinal ganglia are intact (such as Retinitis Pigmentosa) direct retinal implant of an optical detector to stimulate retinal ganglia could allow patients to regain some sight. In such cases additional wiring to the brain cortex is not required, and for biologically inert detectors, surgical implantation can be quite direct. The detector currently being developed for this application is a thin film ferroelectric detector, which under optical illumination can generate a local photocurrent and photo voltage. The local electric current generated by this miniature detector excites the retinal neural circuit resulting in a signal at the optic nerve that may be translated by the cortex of the brain as "seeing light". Detectors based on PbLaZrTiO3 (PLZT) and BiVMnO3 (BVMO) films exhibit a strong photo response in visible range overlapping eye response from 380 nm to 650 nm. The thin film detector heterostructures have been implanted into the eyes of rabbits for biocompatibility test, and have shown no biological in compatibilities. The bionic devices tested so far include both those attached to the back of the eye itself and those implanted directly in the brain. Patients with both types of implants describe seeing multiple points of light and, in some cases, crude outlines of objects. Placing electrodes in the eye has proved easier. During the past decade, work on these retinal implants has attracted growing government funding and commercial interest. Such implants zap electrical signals to nerves on the back of the eye, which then carry them to the brain. However, since these devices take advantage of surviving parts of the eye they will help only the subset of blind people whose blindness is due to retinal disease, by some estimates about 30% of the blind. Moreover, scientists don't believe any implant could help those blind since birth, because their brains never have learned to recognize vision.

Figures (5) Illustrating the AV system.

The electrodes stimulate certain brain cells, making the person perceive the specks of light. The shifting patterns as scans across a scene tells him where light areas meet dark ones, letting him find the black cap on the white wall, for example. The device provides a sort of tunnel vision, reading an area about the size of a card 2 inches wide and 8 inches tall, held at arm's length.

V. VISIBILITY: It has been demonstrated in some studies that to a sighted person, image resolution of some 64 by 64 pixels is (more than) enough to get easily recognizable images. See for instance the reference at the end of this page which suggested a lower limit of

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around 625 pixels. Similarly, a study by Angelica Pérez Fornos suggested a minimum of 400–500 pixels for reading text, with less than a factor two further reduction in case of real-time visual feedback. Thus a 1000 pixels should do for many purposes, but some 64 pixels (for instance arranged in an 8 by 8 matrix) or less rarely gives recognizable images to a sighted person, so we cannot expect this to be any better in an alternative display that is likely to be much cruder than what Nature normally provides us with.

C. Researchers caution, however, that artificial vision devices are still highly experimental and practical systems are many years away. Even after they are refined, the first wave will most likely provide only crude images, such as the outline of a kitchen doorway. It does not function as well as the real eye, and does not have crystal-clear vision (as it is only a camera).The device is a very limited navigational aid, and it's a far cry from the visual experience normal people enjoy. D. The current version has only 96 simulating electrodes while researchers are working at bionic eye that contains 1024 electrodes stimulating electrodes. The 1024 electrode system will give a much higher image resolution.

The effect of image resolution is further illustrated with the images below, where a photograph has been pixelized to 4 by 4, 8 by 8, 12 by 12, 16 by 16, 32 by 32, 64 by 64 and 128 by 128 pixels, respectively. The images here still include shading, while some implants may give little more than on/off signals per pixel or phosphene.

E. Visual acuity is not the only challenge for these devices. The hard, silicon-based chips are placed in an extremely delicate tissue that is part of a fluid-filled moving orb. Chips can slip out of place. Furthermore, the implanted devices need to survive the tough conditions of the body for years without harming their users. VII. OTHER REASONS CAUSING BLINDNESS AND THEIR REMEDIES:

16 pixels (4 × 4)

64 pixels (8 × 8)

144 pixels (12 × 1 2)

256 pixels (16 × 1 6)

1024 pixels (32 × 3 2)

4096 pixels (64 × 6 4)

The main aim of Artificial Vision is to restore some degree of sight to the profoundly blind. Since blindness can result from defects at many different points along the visual pathway, there are accordingly a wide variety of proposed models for an "Artificial Eye".

16384 pixels (128 × 128)

The earliest stage of visual processing is the transudation of light into electrical signals by the photoreceptors. If this is the only process that is interrupted in a blind individual, he or she may benefit from a Sub-Retinal Prosthesis, a device that is designed to replace only the photoreceptors in the retina. However, if the Optic Nerve itself is damaged, the only possibility for restoring sight is to directly stimulate the visual cortex. Cortical prosthesis is designed specifically for this task. Although the categories presented account for most of the research in Artificial Vision, there are a few more exotic techniques being developed. One of these is the Bio Hybrid Implant a device that incorporates living cells with man-made elements.

Figure (6) Illustrating the resolution of images. VI. BOTTLENECKS RAISED BY THIS TECHNOLOGY: A. The first and foremost thing is the cost. The miniaturization of equipment and more powerful computers have made this artificial vision possible, but it's not cheap: The operation, equipment and necessary training cost $4,800 per patient. And also may be much higher depending upon the context and severity. B. It may not work for people blinded as children or as infants, because the visual cortex do not develop normally. But it will work for the vast majority of the blind -- 98 to 99 percent.

Regardless of the specific design, all of these devices are working towards the same goal a permanent replacement for part of the human visual system.

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technology may sometime helps the blind person to move without any personal assistance. ACKNOWLEDGMENT: We would like to express our sincere thanks to Mr. Arul (HOD, Information Technology, DCE, Chennai) and Mr. Ramakrishnan (Senior Faculty, Information Technology, DCE, Chennai) who were abundantly helpful and adopted us throughout this research work. REFERENCES: [1] Humayun MS, de Juan E Jr., Dagnelie G, et al. Visual perception elicited by electrical stimulation of retina in blind humans. Archives of Ophthalmology; vol 114.

Figure (7) Illustrating the elimination of avoidable blindness VIII. ANALYSIS:

[2] â&#x20AC;&#x153;Artificial Vision for the Blind by Connecting a Television Camera to the Brain" ASAIO Journal 2000

Though it is a welcoming factor for a blind person suffering from retinal diseases it may be noted that even after spending some $5000 for the most complicated technology devices that should be implanted before and behind the retina, the blind person could not get a crystal clear vision. Moreover the artificial miniature devices are placed in three different places namely inside the eye, near the brain, outside the chest in the form of belt and so on. Here one question arises how the blind person can operate the said miniature computer and coâ&#x20AC;&#x201C;ordinate with other devices inside the eye. Practically a blind person would like to move with a physical assistant or would like to move with the technically developed assistance but not with the both.

[3] www.artificialvision.com [4] www.howstuffworks.com [5] www.wikipedia.org

IX. CONCLUSION: In view of the above analysis we conclude and feel that the researchers may go further deep into this matter and find a new simple and compact technical device using the latest welcoming Nano technology which may lessen the burden of carrying multiple devices and also lessen the cost factor. We would like to mention that the angioplast for insertion of artificial valves into the heart is replaced by a simple needle insertion directly into the heart using Nano technology is found successful some years ago. Hence the same technology may be developed in the case of eye diseases such as retinal diseases ,death of eye cells and blockage of optical nerves etc. We hope this may also results in getting crystal clear vision without carrying small small miniature devices inside and outside the body. And finally this Nano

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CYBER CRIMEAND SECURITY P.V.SubbaReddy 3rd year-CSE SRM University, Chennai. Mobile no:9444153735

ABSTRACT: The terms computer crime and cybercrime are more properly restricted to describing criminal activity in which the computer or network is a necessary part of the crime, these terms are also sometimes used to include traditional crimes, such as fraud, theft, blackmail, forgery, and embezzlement, in which computers or networks are used. As the use of computers has grown, computer crime has become more important. Computer crime can broadly be defined as criminal activity involving an information technology infrastructure, including illegal access (unauthorized access), illegal interception (by technical means of non-public transmissions of computer data to, from or within a computer system), data interference (unauthorized damaging, deletion, deterioration, alteration or suppression of computer data), systems interference (interfering with the functioning of a computer system

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byinputting, transmitting, damaging, deleting, deteriorating, altering or suppressing computer data), misuse of devices, forgery (ID theft), and electronic fraud. Computer crime issues have become high-profile, particularly those surrounding hacking, copyright infringement through warez, child pornography, and child grooming. There are also problems of privacy when confidential information is lost or intercepted, lawfully or otherwise.

CONTENTS:  

      

Cyber crime Specific computer crimes o Spam o Phishing o Fraud o Obscene or offensive content o Harassment o Drug trafficking o Cyberterrorism Documented cases Security Approaches Some techniques Applications Conclusion. References

CYBER CRIME: Learn cybercrime why? Because – Everybody is using COMPUTERS. – From white collar criminals tto Terrorist organizations andfrom TeenagerstoAdults – Conventional crimes like Forgery,extortion,,kidnappingetc.. Are being committed with tthe help of computers – New generation iis growing up with computers

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– MOST IMPORTANT - Monetary ttransactionsare moving on tto tthe IINTERNET Computer crime, cybercrime, e-crime, hi-tech crime or electronic crime generally refers to criminal activity where a computer or network is the source, tool, target, or place of a crime. Computer crime encompass a broad range of potentially illegal activities. Generally, however, it may be divided into one of two types of categories: (1) crimes that target computer networks or devices directly; (2) crimes facilitated by computer networks or devices, the primary target of which is independent of the computer network or device. Examples of crimes that primarily target computer networks or devices would include,   

Malware and malicious code Denial-of-service attacks Computing viruses

Examples of crimes that merely use computer networks or devices would include,    

Cyber stalking Fraud and identity theft Phishing scams Information warfare

A common example is when a person starts to steal information from sites, or cause damage to, a computer or computer network. This can be entirely virtual in that the information only exists in digital form, and the damage, while real, has no physical consequence other than the machine ceases to function. In some legal systems, intangible property cannot be stolen and the damage must be visible, e.g. as resulting from a blow from a hammer. Where human-centric terminology is used for crimes relying on natural language skills and innate gullibility, definitions have to be modified to ensure that fraudulent behavior remains criminal no matter how it is committed. A computer can be a source of evidence. Even though the computer is not directly used for criminal purposes, it is an excellent device for record keeping, particularly given the power to encrypt the data. If this evidence can be obtained and decrypted, it can be of great value to criminal investigators. In news: 

1 out of 5 children received a sexual solicitation or approach over the Internet in a oneyear period of time (www.missingchildren.com)



California warns of massive ID theft – personal data stolen from computers at University of California, Berkeley (Oct 21, 2004 IDG news service)

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

   

Microsoft and Cisco announced a new initiative to work together to increase internet security (Oct 18, 2004 www.cnetnews.com) Cyber attack–Customer information misappropriated through unauthorised access to privileged systemsor other electronic means] For example: –through tapping the ATM/POS network connection cables, –hacking into the network computer,

SPECIFIC COMPUTER CRIMES: USING MALWARES: Malware:Malware is Malicious Software - deliberately created and specifically designed to damage, disrupt or destroy network services, computer data and software. There are several types Computer virus: program which can copy itself and surreptitiously infect another computer, often via shared media such as a floppy disk, CD, thumb drive, shared directory, etc. Viruses are always embedded within another file or program.   



Worm: self-reproducing program which propagates via the network. Trojan horse: program which purports to do one thing, but secretly does something else; example: free screen saver which installs a backdoor Root kit: set of programs designed to allow an adversary to surreptitiously gain full control of a targeted system while avoiding detection and resisting removal, with the emphasis being on evading detection and removal Botnet: set of compromised computers ("bots" or "zombies") under the unified command and control of a "botmaster;" commands are sent to bots via a command and control channel (bot commands are often transmitted via IRC, Internet Relay Chat). Spyware: assorted privacy-invading/browser-perverting programs

Malware: an inclusive term for all of the above -- "malicious software Ex:David Smith & The Melissa VirusExample

Spam Spam, or the unsolicited sending of bulk email for commercial purposes, is unlawful to varying degrees. As applied to email, specific anti-spam laws are relatively new, however limits on unsolicited electronic communications have existed in some forms for some time.Spam originating in India accounted for one percent of all spam originating in the top 25 spamproducing countries making India the eighteenth ranked country worldwide for originating spam.

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Phishing Phishing is a technique used by strangers to "fish" for information about you, information that you would not normally disclose to a stranger, such as your bank account number, PIN, and other personal identifiers such as your National Insurance number. These messages often contain company/bank logos that look legitimate and use flowery or legalistic language about improving security by confirming your identity details.

Fraud

Computer fraud is any dishonest misrepresentation of fact intended to induce another to do or refrain from doing something which causes loss.In this context, the fraud will result in obtaining a benefit by: 

  

altering computer input in an unauthorized way. This requires little technical expertise and is not an uncommon form of theft by employees altering the data before entry or entering false data, or by entering unauthorized instructions or using unauthorized processes; altering, destroying, suppressing, or stealing output, usually to conceal unauthorized transactions: this is difficult to detect; altering or deleting stored data; or altering or misusing existing system tools or software packages, or altering or writing code for fraudulent purposes. This requires real programming skills and is not common.

Other forms of fraud may be facilitated using computer systems, including bank fraud, identity theft, extortion, and theft of classified information(Csonka, 2000)

Obscene or offensive content

The content of websites and other electronic communications may be distasteful, obscene or offensive for a variety of reasons. In some instances these communications may be illegal. Many jurisdictions place limits on certain speech and ban racist, blasphemous, politically subversive, libelous or slanderous, seditious, or inflammatory material that tends to incite hate crimes. The extent to which these communications are unlawful varies greatly between countries, and even within nations. It is a sensitive area in which the courts can become involved in arbitrating between groups with entrenched beliefs.

Harassment

Whereas content may be offensive in a non-specific way, harassment directs obscenities and derogatory comments at specific individuals focusing for example on gender, race, religion,

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nationality, sexual orientation. This often occurs in chat rooms, through newsgroups, and by sending hate e-mail to interested parties (see cyber bullying, cyber stalking, harassment by computer, hate crime, Online predator, and stalking). Any comment that may be found derogatory or offensive is considered harassment.

Drug trafficking

Drug traffickers are increasingly taking advantage of the Internet to sell their illegal substances through encrypted e-mail and other Internet Technology. Some drug traffickers arrange deals at internet cafes, use courier Web sites to track illegal packages of pills, and swap recipes for amphetamines in restricted-access chat rooms. The rise in Internet drug trades could also be attributed to the lack of face-to-face communication. These virtual exchanges allow more intimidated individuals to more comfortably purchase illegal drugs. The sketchy effects that are often associated with drug trades are severely minimized and the filtering process that comes with physical interaction fades away. Furthermore, traditional drug recipes were carefully kept secrets. But with modern computer technology, this information is now being made available to anyone with computer access.

Cyberterrorism

Government officials and Information Technology security specialists have documented a significant increase in Internet problems and server scans since early 2001. There is a growing concern among federal officials.that such intrusions are part of an organized effort by cyberterrorists, foreign intelligence services, or other groups to map potential security holes in critical systems. A cyberterrorist is someone who intimidates or coerces a government or organization to advance his or her political or social objectives by launching computer-based attack against computers, network, and the information stored on them. Cyberterrorism in general, can be defined as an act of terrorism committed through the use of cyberspace or computer resources (Parker 1983). As such, a simple propaganda in the Internet, that there will be bomb attacks during the holidays can be considered cyberterrorism. At worst, cyberterrorists may use the Internet or computer resources to carry out an actual attack. As well there are also hacking activities directed towards individuals, families, organised by groups within networks, tending to cause fear among people, demonstrate power, collecting information relevant for ruining peoples' lives, robberies, blackmailing etc.

1. ď&#x201A;ˇ ď&#x201A;ˇ

Documented cases

The Yahoo! website was attacked at 10:30 PST on Monday, 7 February 2000. The attack lasted three hours. Yahoo was pinged at the rate of one gigabyte/second. On 3 August 2000, Canadian federal prosecutors charged MafiaBoy with 54 counts of illegal access to computers, plus a total of ten counts of mischief to data for his attacks on Amazon.com, eBay, Dell Computer, Outlaw.net, and Yahoo.

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

MafiaBoy had also attacked other websites, but prosecutors decided that a total of 66 counts was enough. MafiaBoy pleaded not guilty. About fifty computers at Stanford University, and also computers at the University of California at Santa Barbara, were amongst the zombie computers sending pings in DDoS attacks. In 26 March 1999, the Melissa worm infected a document on a victim's computer, then automatically sent that document and copy of the virus via e-mail to other people. 21 January 2003 Two years jail for UK virus writer who infected 27,000 PCs

CRIME SECURITY: Computer security is a branch of technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. SOME APPROACHES: Here are several approaches to security in computing, sometimes a combination of approaches is valid: 1. Trust all the software to abide by a security policy but the software is not trustworthy (this is computer insecurity). 2. Trust all the software to abide by a security policy and the software is validated as trustworthy (by tedious branch and path analysis for example). 3. Trust no software but enforce a security policy with mechanisms that are not trustworthy (again this is computer insecurity). 4. Trust no software but enforce a security policy with trustworthy mechanisms. HARDWARE MECHANISMS THAT PROTECT COMPUTERS AND DATA: Hardware based or assisted computer security offers an alternative to software-only computer security. Devices such as dongles may be considered more secure due to the physical access required in order to be compromised. While many software based security solutions encrypt the data to prevent data from being stolen, a malicious program may corrupt the data in order to make it unrecoverable or unusable. Hardware-based security solutions can prevent read and write access to data and hence offers very strong protection against tampering.

SECURE OPERATING SYSTEMS: One use of the term computer security refers to technology to implement a secure operating system. Much of this technology is based on science developed in the 1980s and used to produce what may be some of the most impenetrable operating systems ever. Though still valid, the technology is in limited use today, primarily because it imposes some changes to system

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management and also because it is not widely understood. Such ultra-strong secure operating systems are based on operating system kernel technology that can guarantee that certain security policies are absolutely enforced in an operating environment. An example of such a Computer security policy is the Bell-La Padula model. The strategy is based on a coupling of special microprocessor hardware features, often involving the memory management unit, to a special correctly implemented operating system kernel. This forms the foundation for a secure operating system which, if certain critical parts are designed and implemented correctly, can ensure the absolute impossibility of penetration by hostile elements. This capability is enabled because the configuration not only imposes a security policy, but in theory completely protects itself from corruption. Ordinary operating systems, on the other hand, lack the features that assure this maximal level of security. The design methodology to produce such secure systems is precise, deterministic and logical.

If the operating environment is not based on a secure operating system capable of maintaining a domain for its own execution, and capable of protecting application code from malicious subversion, and capable of protecting the system from subverted code, then high degrees of security are understandably not possible. While such secure operating systems are possible and have been implemented, most commercial systems fall in a 'low security' category because they rely on features not supported by secure operating systems (like portability, et al.). In low security operating environments, applications must be relied on to participate in their own protection. There are 'best effort' secure coding practices that can be followed to make an application more resistant to malicious subversion. In commercial environments, the majority of software subversion vulnerabilities result from a few known kinds of coding defects. Common software defects include buffer overflows, format string vulnerabilities, integer overflow, and code/command injection. Some common languages such as C and C++ are vulnerable to all of these defects (see Seacord, "Secure Coding in C and C++"). Other languages, such as Java, are more resistant to some of these defects, but are still prone to code/command injection and other software defects which facilitate subversion. Recently another bad coding practice has come under scrutiny; dangling pointers. The first known exploit for this particular problem was presented in July 2007. Before this publication the problem was known but considered to be academic and not practically exploitable. In summary, 'secure coding' can provide significant payback in low security operating environments, and therefore worth the effort. Still there is no known way to provide a reliable degree of subversion resistance with any degree or combination of 'secure coding.' CAPABILITIES VS. ACLS: Within computer systems, the two fundamental means of enforcing privilege separation are access control lists (ACLs) and capabilities. The semantics of ACLs have been proven to be

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insecure in many situations (e.g., Confused deputy problem). It has also been shown that ACL's promise of giving access to an object to only one person can never be guaranteed in practice. Both of these problems are resolved by capabilities. This does not mean practical flaws exist in all ACL-based systems, but only that the designers of certain utilities must take responsibility to ensure that they do not introduce flaws. Capabilities have been mostly restricted to research operating systems and commercial OSs still use ACLs. Capabilities can, however, also be implemented at the language level, leading to a style of programming that is essentially a refinement of standard object-oriented design. An open source project in the area is the E language. First the Plessey System 250 and then Cambridge CAP computer demonstrated the use of capabilities, both in hardware and software, in the 1970s. A reason for the lack of adoption of capabilities may be that ACLs appeared to offer a 'quick fix' for security without pervasive redesign of the operating system and hardware. The most secure computers are those not connected to the Internet and shielded from any interference. In the real world, the most security comes from operating systems where security is not an add-on, such as OS/400 from IBM. This almost never shows up in lists of vulnerabilities for good reason. Years may elapse between one problem needing remediation and the next

APPLICATIONS: IN AVIATION The aviation industry is especially important when analyzing computer security because the involved risks include human life, expensive equipment, cargo, and transportation infrastructure. Security can be compromised by hardware and software malpractice, human error, and faulty operating environments. Threats that exploit computer vulnerabilities can stem from sabotage, espionage, industrial competition, terrorist attack, mechanical malfunction, and human error. The consequences of a successful deliberate or inadvertent misuse of a computer system in the aviation industry range from loss of confidentiality to loss of system integrity, which may lead to more serious concerns such as data theft or loss, network and air traffic control outages, which in turn can lead to airport closures, loss of aircraft, loss of passenger life. Military systems that control munitions can pose an even greater risk. NOTABLE SYSTEM ACCIDENTS: In 1994, over a hundred intrusions were made by unidentified hackers into the Rome Laboratory, the US Air Force's main command and research facility. Using trojan horse viruses, hackers were able to obtain unrestricted access to Rome's networking systems and remove traces of their activities. The intruders were able to obtain classified files, such as air tasking order systems data and furthermore able to penetrate connected networks of National Aeronautics and Space Administration's Goddard Space Flight Center, Wright-Patterson Air Force Base, some Defensecontractors, and other private sector organizations, by posing as a trusted Rome center user. Now, a technique called Ethical hack testing is used to remediate these issues.

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Electromagnetic interference is another threat to computer safety and in 1989, a United States Air Force F-16 jet accidentally dropped a 230 kg bomb in West Georgia after unspecified interference caused the jet's computers to release it. A similar telecommunications accident also happened in 1994, when two UH-60 Blackhawk helicopters were destroyed by F-15 aircraft in Iraq because the IFF system's encryption system malfunctioned.

TERMINOLOGY: The following terms used in engineering secure systems are explained below.       

 

Authentication techniques can be used to ensure that communication end-points are who they say they are. Automated theorem proving and other verification tools can enable critical algorithms and code used in secure systems to be mathematically proven to meet their specifications. Capability and access control list techniques can be used to ensure privilege separation and mandatory access control. Chain of trust techniques can be used to attempt to ensure that all software loaded has been certified as authentic by the system's designers. Cryptographic techniques can be used to defend data in transit between systems, reducing the probability that data exchanged between systems can be intercepted or modified. Firewalls can provide some protection from online intrusion. Mandatory access control can be used to ensure that privileged access is withdrawn when privileges are revoked. For example, deleting a user account should also stop any processes that are running with that user's privileges. Secure cryptoprocessors can be used to leverage physical security techniques into protecting the security of the computer system. microkernels can be reliable against errors: eg EROS and Coyotos.

Some of the following items may belong to the computer insecurity article: 

Anti-virus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software (malware).

Cryptographic techniques involve transforming information, scrambling it so it becomes unreadable during transmission. The intended recipient can unscramble the message, but eavesdroppers cannot. 

Backups are a way of securing information; they are another copy of all the important computer files kept in another location. These files are kept on hard disks, CD-Rs, CDRWs, and tapes. Suggested locations for backups are a fireproof, waterproof, and heat proof safe, or in a separate, offsite location than that in which the original files are contained. Some individuals and companies also keep their backups in safe deposit boxes inside bank vaults. There is also a fourth option, which involves using one of the file hosting services that backs up files over the Internet for both business and individuals.

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

 



Encryption is used to protect the message from the eyes of others. It can be done in several ways by switching the characters around, replacing characters with others, and even removing characters from the message. These have to be used in combination to make the encryption secure enough, that is to say, sufficiently difficult to crack. Public key encryption is a refined and practical way of doing encryption. It allows for example anyone to write a message for a list of recipients, and only those recipients will be able to read that message. Firewalls are systems which help protect computers and computer networks from attack and subsequent intrusion by restricting the network traffic which can pass through them, based on a set of system administrator defined rules. Honey pots are computers that are either intentionally or unintentionally left vulnerable to attack by crackers. They can be used to catch crackers or fix vulnerabilities. Intrusion-detection systems can scan a network for people that are on the network but who should not be there or are doing things that they should not be doing, for example trying a lot of passwords to gain access to the network. Pinging the ping application can be used by potential crackers to find if an IP address is reachable. If a cracker finds a computer they can try a port scan to detect and attack services on that computer. Social engineering awareness keeps employees aware of the dangers of social engineering and/or having a policy in place to prevent social engineering can reduce successful breaches of the network and servers. File Integrity Monitors are tools used to detect changes in the integrity of systems and files.

REFERENCES:   

  

Ross J. Anderson: Security Engineering: A Guide to Building Dependable Distributed Systems, ISBN 0-471-38922-6 Morrie Gasser: Building a secure computer system ISBN 0-442-23022-2 1988 Stephen Haag, Maeve Cummings, Donald McCubbrey, Alain Pinsonneault, Richard Donovan: Management Information Systems for the information age, ISBN 0-07-0911207 E. Stewart Lee: Essays about Computer Security Cambridge, 1999 Peter G. Neumann: Principled Assuredly Trustworthy Composable Architectures 2004 Paul A. Karger, Roger R. Schell:

CONCLUSION: Computer security is critical in almost any technology-driven industry which operates on computer systems.Computer security can also be refered to as computer safety. The issues of computer based systems and addressing their countless vulnerabilities are an integral part of maintaining an operational industry.

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NETWORK SECURITY AND CRYPTOGRAPHY G.HarshaVardhan 3rd year-CSE SRM University, Chennai. Mobile no: 9791095378 ABSTRACT: Network security is a complicated subject, historically onlyincreasingnumber of people need to understand the However, as more and more people become ``wired'', tackled by well-trained andexperienced experts. Basics of security in a networked world. Thisdocument was written with the basic computer user and information systems manager inmind, explaining the concepts needed to read through the hype in the marketplace andunderstand risks and how to deal with them. So it is very important for all the users to getfamiliar with various aspects of Network Security. In the article basics of Network Security are discussed. With the millions of Internet users able to pass information fromthe network, the security of business networks is a major concern. The very nature of theInternet makes it vulnerable to attack. The hackers and virus writers try to attack theInternet and computers connected to the Internet. With the growth in business use of theInternet, network security is rapidly becoming crucial to the development of the Internet.Many business set up firewalls to control access to their networks by persons using the Internet

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Introduction: For the first few decades of their existence, computer networks were primarily used by university researchers for sending e-mail and by corporate employees for sharing printers. Under these conditions, security did not get a lot of attention. But now, as millions of ordinary citizens are using networks for banking, shopping, and filing their tax returns, network security is looming on the horizon as a potentially massive problem. The requirements of information security within an organization have undergone two major changes in the last several decades.Before the widespread use of data processing equipment ,the security of information felt to be valuable to an organization was provided primarily by physical and administrative means . .with the introduction of computer the need for automated tools for protecting files and other information stored on the computer became an evident .this is especially the case for a shared system such as time sharing system and the need is even more acute for systems that can be accessed for a public telephone or a data network. The generic name for the collection of tools to protect data and to thwart hackers is â&#x20AC;&#x153;computer securityâ&#x20AC;?.

Network security: Security is a broad topic and covers a multitude of sins. In its simplest form, it is concerned with making sure that nosy people cannot read, or worse yet, secretly modify messages intended for other recipients. It is concerned with people trying to access remote services that they are not authorized to use. Most security problems are intentionally caused by malicious people trying to gain some benefit, get attention, or to harm someone. Network security problems can be divided roughly into four closely intertwined areas: secrecy, authentication, nonrepudiation, and integrity control. Secrecy, also called confidentiality, has to do with keeping information out of the hands of unauthorized users. This is what usually comes to mind when people think about network security. Authentication deals with determining whom you are talking to

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before revealing sensitive information or entering into a business deal. Nonrepudiation deals with signatures.

Secracy: Only

the sender and intended receiver should be able to understand the contents of the transmitted message. Because eavesdroppers may intercept the message, this necessarily requires that the message besomehow encrypted (disguise data) so that an intercepted message can not be decrypted (understood) by an interceptor. This aspect of secrecy is probably the most commonly perceived meaning of the term "securecommunication." Note, however, that this is not only a restricted definition of secure communication , but a rather restricted definition of secrecy as well. Authentication :Both the sender and receiver need to confirm the identity of other party involved in the communication - to confirm that the other party is indeed who or what they claim to be. Face-toface human communication solves this problem easily by visual recognition. When communicating entities exchange messages over a medium where they can not "see" the other party, authentication is not so simple. Why, for instance, should you believe that a received email containing a text string saying that the email came from a friend of yours indeed came from that friend? If someone calls on the phone claiming to be your bank and asking for your account number, secret PIN, and account balances for verification purposes, would you give that information out over the phone? Hopefully not.

Message Integrity: Even if the sender and receiver are able to authenticate each other, they also want to insure that the content of their communication is not altered, either malicously or by accident, in transmission. Extensions to the checksumming techniques that we encountered in reliable transport and data link protocols Nonrepudiation: Nonrepudiation deals with signatures Having established what we mean by secure communication, let us next consider exactly what is meant by an "insecurechannel." What

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information does an intruder have access to, and what actions can be taken on the transmitted data? Figure illustrates the scenario Alice, the sender, wants to send data to Bob, the receiver. In order to securely exchange data, while meeting the requirements of secrecy, authentication, and message integrity, Alice and Bob will exchange both control message anddata messages (in much the same way that TCP senders and receivers exchange both control segments and data segments). All, or some of these message will typically be encrypted. A passive intruder can listen to and record the control and data messages on the channel; an active intruder can remove messages from the channel and/or itself add messages into the channel.

Network Security Considerations in the Internet :Before delving into the technical aspects of network security in the following sections, let's conclude our introduction by relating our fictitious characters - Alice, Bob, and Trudy - to "real world" scenarios in today's Internet

. Let's begin with Trudy, the network intruder. Can a "real world" network intruder really listen to and record passively receives all data-link-layer frames passing by the device's network interface. In a broadcast environment

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such as an Ethernet LAN, this means that the packet sniffer receives all frames being transmitted from or to all hostson the local area network. Any host with an Ethernet card can easily serve as a packet sniffer, as the Ethernet interface card needs only be set to "promiscuous mode" to receive all passing Ethernet frames. These frames can then be passed on to application programs that extract application-level data. For example, in the telnet scenario , the login password prompt sent from A to B, as well as the password entered at B are "sniffed" at host C. Packet sniffing is a double-edged sword it can be invaluable to a network administrator for network monitoring and management but also used by the unethical hacker. Packet-sniffing software is freely available at various WWW sites, and as commercial products.

Cryptography:- Cryptography

comes from the Greek words for ''secret writing.'' It has a long and colorful history going back thousands of years. Professionals make a distinction between ciphers and codes. A cipher is a character-for-character or bit-for-bit transformation, without regard to the linguistic structure of the message. In contrast, a code replaces one word with another word or symbol. Codes are not used any more, although they have a glorious history The messages to be encrypted, known as the plaintext, are transformed by a function that is parameterized by a key. The output of the encryption process, known as the ciphertext, is then transmitted, often by messenger or radio. We assume that the enemy, or intruder, hears and accurately copies down the complete ciphertext. However, unlike the intended recipient, he does not know what the decryption key is and so cannot decrypt the ciphertext easily. Sometimes the intruder can not only listen to the communication channel (passive intruder) but can also record messages and play them back later, inject his own messages, or modify legitimate messages before they get to the receiver (active intruder). The art of breaking ciphers, called cryptanalysis, and the art devising them (cryptography) is collectively known as cryptology. It will often be useful to have a notation for relating plaintext, ciphertext, and keys. We will use C = EK(P) to mean that the

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encryption of the plaintext P using key K gives the ciphertext C. Similarly, P = DK(C) represents the decryption of C to get the plaintext again.

Two Fundamental Cryptographic Principles: Redundancy The first principle is that all encrypted messages must contain some redundancy, that is, information not needed to understand the message. Cryptographic principle 1: Messages must contain some redundancy

Freshness Cryptographic principle 2: Some method is needed to foil replay attacks One such measure is including in every message a timestamp valid only for, say, 10 seconds. The receiver can then just keep messages around for 10 seconds, to compare newly arrived messages to previous ones to filter out duplicates. Messages older than 10 seconds can be thrown out, since any replays sent more than 10 seconds later will be rejected as too old.

Symmetric key Encryption model: Beyond that ,the security of conventional encryption depends on the secracy of the key ,not the secrecy of the algorithm. We do not need to keep the algorithm secret, we need to keep only the secret key. The fact that the algorithm need not be kept secret means that manufactures can and have developed low cost chip implementations of data encryption algorithms. these chips are widely available and incorporated in to a number of products.

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Substitution Ciphers In a substitution cipher each letter or group of letters is replaced by another letter or group of letters to disguise it. One of the oldest known ciphers is the Caesar cipher, attributed to Julius Caesar. In this method, a becomes D, b becomes E, c becomes F, ... , and z becomes C. For example, attack becomes DWWDFN. The next improvement is to have each of the symbols in the plaintext, say, the 26 letters for simplicity, map onto some other letter. For example, plaintext: a b c d e f g h i j k l m n o p q r s t u v w x y z ciphertext: Q W E R T Y U I O P A S D F G H J K L Z X C V B N M Transposition Ciphers:Substitution ciphers preserve the order of the plaintext symbols but disguise them. Transposition ciphers, in contrast, reorder the letters but do not disguise them depicts a common transposition cipher, the columnar transposition. M E G A B U C K 7 4 5 1 2 8 3 6 W E L C O M E T PLAIN TEXT: WELCOME TO SAfire-2K8,CHIRALA, O S A f i r e 2 PRAKASAM, AP. K 8 C H I R A L CIPHER TEXT: CfHAOiIKEeASES8PALACRPT2LA A P R A K A S A WOKAMMRRA M A P The cipher is keyed by a word or phrase not containing any repeated letters. In this example, MEGABUCK is the key. The purpose of the key is to number the columns, column 1 being under the key letter closest to the start of the alphabet, and so on. The plaintext is written horizontally, in rows, padded to fill the matrix if need be. The ciphertext is read out by columns, starting with the column whose key letter is the lowest.

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Public key algorithm: While there may be many algorithms and keys that have this property, the RSA algorithm (named after its founders, Ron Rivest, Adi Shamir, and Leonard Adleman) has become almost synonymous with public keycryptography. In order to choose the public and private keys, one must do the following: Choose two large prime numbers, p and q. How large should p and q be? The larger the values, the more difficult it is to break RSA but the longer it takes to perform the encoding and decoding. RSA Laboratories recommends that the product of p and q be on the order of 768 bits for personal use and 1024 bits for corporate use . Compute n = pq and z = (p-1)(q-1). Choose a number, e, less than n, which has no common factors (other than 1) with z. (In this case, e and z are said to be relatively prime). The letter 'e' is used since this value will be used in encryption. Find a number, d, such that ed -1 is exactly divisible (i.e., with no remainder) by z. The letter 'd' is used because this value will be used in decryption. Put another way, given e, we choose d such that the integer remainder when ed is divided by z is 1. (The integer remainder when an integer x is divided by the integer n, is denoted x mod n). The public key that Bob makes available to the world is the pair of numbers (n,e); his private key is the pair of numbers (n,d). key distribution: For symmetric key cryptograghy , the trusted intermediary is called a Key Distribution Center (KDC), which is a single, trusted network entity with whom one has established a shared secret key. We will see that one can use the KDC to obtain the shared keys needed to communicate securely with all other network entities. For public key cryptography, the trusted intermediary is called a Certification Authority (CA). A certification

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authority certifies that a public key belongs to a particular entity (a person or a network entity). For a certified public key, if one can safely trust the CA that the certified the key, then one can be sure about to whom the public key belongs. Once a public key is certified, then it can be distributed from just about anywhere, including a public key server, a personal Web page or a diskette. security in the layers: Before getting into the solutions themselves, it is worth spending a few moments considering where in the protocol stack network security belongs. There is probably no one single place. Every layer has something to contribute. physical layer:In the physical layer wiretapping can be foiled by enclosing transmission lines in sealed tubes containing gas at high pressure. Any attempt to drill into a tube will release some gas, reducing the pressure and triggering an alarm. Some military systems use this technique. Data link layer:In this layer, packets on a point-to-point line can be encrypted as they leave one machine and decrypted as they enter another. All the details can be handled in the data link layer, with higher layers oblivious to what is going on. This solution breaks down when packets have to traverse multiple routers, however, because packets have to be decrypted at each router, leaving them vulnerable to attacks from within the router. Network layer:In this layer, firewalls can be installed to keep good packets and bad packets out. IP security also functions in this layer. In the transport layer, entire connections can be encrypted, end to end, that is, process to process. For maximum security, end-to-end security is required . Finally, issues such as user authentication and nonrepudiation can only be handled in the application layer. Since security does not fit neatly into any layer

Secure Internet Commerce : SET (Secure Electronic Transactions) is a protocol specifically designed to secure payment-card transactions over the Internet. It was originally developed by Visa International and MasterCard International in February 1996 with participation from leading technology companies around the world .SET Secure Electronic

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Transaction LLC (commonly referred to as SET Co) was established in December 1997 as a legal entity to manage and promote the global adoption of SET

1. Bob indicates to Alice that he is interested in making a credit card purchase. 2. Alice sends the customer an invoice and a unique transaction identifier. 3. Alice sends Bob the merchant's certificate which includes the merchant's public key. Alice also sends the certificate for her bank, which includes the bank's public key. Both of these certificates are encrypted with the private key of a certifying authority. 4. Bob uses the certifying authority's public key to decrypt the two certificates. Bob now has Alice's public key and the bank's public key. 5. Bob generates two packages of information: the order information (OI) package and the purchase instructions (PI) package. The OI, destined for Alice, contains the transaction identifier and brand of card being used; it does not include Bob's card number. The PI, destined for Alice's bank, contains the transaction identifier, the card number and the purchase amount agreed to Bob. The OI and PI are dual encrypted: the OI is encrypted with Alice's public key; the PI is encrypted with Alice's bank's public key. (We are bending the truth here in order to see the big picture. In reality, the OI and PI are encrypted with a customer-merchant session key

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and a customer-bank session key.) Bob sends the OI and the PI to Alice.

6.Alice generates an authorization request for the card payment request, which includes the transaction identifier. 7.Alice sends to her bank a message encrypted with the bank's public key. (Actually, a session key is used.) This message includes the authorization request, the PI package received from Bob, and Alice's certificate . 8.Alice's bank receives the message and unravels it. The bank checks for tampering. It also make sure that the transaction identifier in the authorization request matches the one in Bob's PI package. 9.Alice's bank then sends a request for payment authorization to Bob's payment-card bank through traditional bank-card channels -just as Alice's bank would request authorization for any normal payment-card transaction.

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One of the key features of SET is the non-exposure of the credit number to the merchant. This feature is provided in Step 5, in which the customer encrypts the credit card number with the bank's key. Encrypting the number with the bank's key prevents the merchant from seeing the credit card. Note that the SET protocol closely parallels the steps taken in a standard payment-card transaction. To handle all the SET tasks, the customer will have a so-called digital wallet that runs the client-side of the SET protocol and stores customer payment-card information (card number, expiration date, etc.)

Conclusion: All the three techniques discussed in this presentation i.e. network security; cryptography andfirewalls are most widely used and implemented networks security tools. Each of them had itsown significance in its own mode. For example, a single organization or establishment tomaintain privacy of information within itself can use cryptography. These methods are beingus e d to p ro v i d e c o n fi d e n t ia l i ty re q u i re d b y t he ne t w o rk . T he re is a l o t o f s c o p e fo r t he development in this field. Digital signatures are one of the latest developments in the field of c r y p t o g r a p h y . W i t h t h e i n c r e a s e i n number of computers, and the usage

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o f c o m p u t e r s worldwide the demand for network security is increasing exponentially. This has led to thedevelopment of major companies like Symantec Corporation, MacAfee etc. So this field is putting up a big employment potential for the young generation of today. And not to forget,there is no end to the complexity of this subject, which means that any amount of research willnot go futile for the world of computers. BOOKS:Computer networking: A Top-Down Approach Featuring the Internet-JamesF.Kurose, Keith W.Ross. Networks for Computer Scientists and Engineers: Youlu Zheng, Shakil Akhtar. WEBSITES:

www.iec.org/onlinehttp://ftp.research.att.com/dist/internetsecurity/http://www.jjtc.com/stegdoc/

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A technical paper On

“THE WIRELESS WATER AND VACCINE MONITORING WITH LOW COST SENSORS [COLD TRACE]”

AUTHOR K.HUSENAIAH IV B.TECH C.S.E Email:kinghusen100@gmail.com Ph.no:9550277153

ANNAMACHARYA INSTITUTE OF TECHNOLOGY AND SCIENCES, BOYANAPALLI, RAJAMPETA,KADAPA DISTRICT, ANDHRA PRADESH (An autonomous institution) DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING

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The Cold Trace project wants to construct a

ABSTRACT

temperature sensor that connects to cold boxes Cold Trace is a low-cost wireless sensor

and

designed to improve access to vaccines which

chain, has a less cost, and can provide real-time

protect thousands of children’s against diseases

monitoring and alerts for clinics and government

such as tuberculosis and polio. The sensor

agencies.

remotely monitors the temperature of vaccines.

Unlike similar approaches that develop their

It also provides a better understanding of the

own microcontrollers the ColdTrace project uses

vaccine

and

modified cell phones for the data collection and

transmission to cut down on upfront capital

areas where regular records are not maintained.

costs. The data that is gathered from each device

it will help us move toward providing more

in the network is sent to a global database that

vaccines and safer medical treatments to

can track historical vaccine distribution patterns

millions of children’s around the world.

and can then be used by clinics and health

cold

distribution

storage,

transportation

infrastructures,

particularly

refrigeration

units

along

the

supply

agencies to improve forecasting needs for the

INTRODUCTION

area over time.

Cold Trace is a new innovative project that

REAL-TIME TRANSPARENCY INTO

uses wireless temperature sensors, repurposed

VACCINE SUPPLY CHAINS:

cell phones, and a notification system to track temperatures of cold storage units and alert

ColdTrace reimagines the cold chain infra-

clinic managers by SMS when temperatures

structure used to store and transport vaccines by

begin to threaten the medicine.

enabling a low-cost wireless sensor to remotely

According to development in many developing

monitor vaccines and transfer the monitoring

countries electricity and backup power can be

data to a global database that fosters coordinated

erratic in clinics and often times there are not

decisions by governments, global partners,

enough resources available to accurately and

pharmaceuticals, and clinics, and helps ensure

routinely measure vaccine refrigeration tempe-

life-saving treatments reach everyone. Vacci-

ratures. Many of the power outages in these

nating children is an amazingly effective and

areas happen at night or over the weekend and

successful public health solutions. Millions of

result in spoiled vaccine supplies that play a role

children are saved each year, thanks to vaccines.

in the spreading of preventable diseases in these

Yet 25 million children, that’s one in every 5

regions.

kids born, are still not vaccinated each year. And most of these children are in developing

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countries. It is building real-time visibility into

COLDTRACE FEATURES:

the temperature controlled supply chains, called 

the "cold chain". this platform, called Cold

Generates SMS alerts about equipment

Trace, continuously records the temperature of

failures and medicines reaching critical

refrigerated storage units used along every mile

temperatures. 

of the cold chain from distribution warehouse to

Uploads temperature traces via SMS or cellular network.

clinic using cell phone-enabled sensors. The data 

is wirelessly and automatically uploaded to the

Continuously

tracks

GPS

location

coordinates.

Cold Trace servers, where it is stored and 

analyzed.

Cell

phone’s

display

and

keypad

Real-time SMS alerts notify clinic workers and

facilitates extensive local configuration

Ministry of Health Staff about vaccines reaching

including communication and upload

critical temperatures. Each level of the supply

intervals. 

system can act on this immediate information on

Cold Trace database keeps a constant

equipment health and vaccine safety.

log

Failure rates across local, regional, and national

refrigeration

areas, in addition to monthly status reports, can

analysis of failure rates across local,

be used to improve forecasting and capacity

regional, and national areas. 

planning. Cold Trace can help major donors to

Web

temperatures units

dashboard

and

clinic

allows

supports

for

remote

detect emerging risks and identify regions with

configuration, device status monitoring,

the strongest cold chain infrastructure to target

data visualization, and sharing with

for increased distribution, and also help attract

donors, NGOs, ministries of health. 

new donations. Cold Trace has been deployed in

Can integrate with existing logistics management information systems in

clinics.

order to oversee and provide alerts about cold chain equipment at each stage of the distribution.

COLD CHAIN MONITOR: This is piloting a new cell phone enabled sensor that remotely monitors the temperatures of refrigerated units used to store and transport Fig: Real-Time Transparency Into Vaccine Supply

these vaccines and drugs. Our integrated device

Chains

captures temperature data about vaccine stocks

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using a sensor that connects to cold boxes and refrigeration units along the supply chain from warehouses to clinics. The sensor uses mobile

Cold chain management is a key challenge faced

phones to collect and wirelessly transmit tempe-

by various industries. Despite regulations that

rature data, and our backend system integrates

aim to ensure the proper management and

the collected data with logistics management

monitoring of temperature sensitive pharma-

information systems in order to oversee and

ceuticals (such as insulin and the polio vaccine),

provide alerts about cold chain equipment at

as well as fresh produce and other foodstuffs, a

each stage of vaccine distribution. The system

lack of infrastructure for the supply and

will make it possible to: wirelessly upload

transport of these products means that they are

temperature data through a cell phone from

often wasted through exposure to changes in

almost any location; correlate temperature data

temperature. Mismanagement of the cold chain

with geolocation of the phone (when possible);

also results in food safety issues, while the

and immediately generate SMS and email alerts

ethical

about

tempe-

sensitive drugs are enormous the shelf-life of

ratures. This allows each level of the supply

many medications is entirely dependent on

system to have real-time information on

correct temperature control. The importance of

equipment health and vaccine safety. Moreover,

accurate cold chain management cannot be

the data collected by our system will help

understated.

vaccines

reaching

critical

considerations

around

temperature-

accelerate the tracking of historical vaccine distribution patterns that can be used to improve forecasting and capacity planning.

Fig: Cold Chain Monitoring with Wireless Fig: Cold Chain Monitoring

Communication

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HOW DOES COLDTRACE WORK?

WATER AND SANITATION ACCESS:

Cold Trace uses existing cell phone technologies

Historically, many low-income residents of

in a new way to dramatically reduce the cost of

urban and peri-urban areas in world have faced a

wireless sensor data collection. Unlike similar

lack of clean water and low quality water and

approaches, which employ microcontrollers or

sanitation services.vaccinemonotoring is build-

other costly components, Cold Trace takes

ing

advantage of the sophisticated electronics,

communication

battery and other features that already exist on

residents in world to communicate with their

the cell phone. By building upon this standard

water and sanitation services providers. The

technology, we can dramatically reduce the

way that this works is as follows: residents can

overall cost of the sensors and make it possible

send text messages with complaints, concerns,

for almost any basic phone to serve as a wireless

news, questions and other reports to the system

sensor. This allows Cold Trace to bring remote

database, which then distributes those messages

monitoring to developing areas that have

to the water service providers and other

extremely low resources.

stakeholders who can provide answers and take

SMS-enabled system

issue

tracking

and

that

allows

poor

action in response. As a result, the system transforms community needs and concerns into a live data feed that helps service providers improve their services and that highlights both effective and ineffective solutions for utilities, governments, civic leaders and aid organizations. Additionally, broadcast messages sent by service providers, NGOs, or governments can be used to inform citizens about important updates, expected outages, and help launch local campaigns for change. it believe that citizens will be motivated to participate because they get a direct communication channel with providers to improve their services; and service providers and other stakeholders will participate because

Fig: Block Diagram of Cold Trace Working

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they get access to critical planning information

improve their services and that highlights both

that would otherwise be unavailable.

effective and ineffective solutions for utilities, governments, civic leaders and aid organizations. Additionally, broadcast messages sent by service providers, NGOs, or governments can be used to inform citizens about important updates, expected outages, and help launch local campaigns for change.

CONLCUSION ColdTrace is

low-cost

wireless

sensor

designed to improve access to vaccines which protect thousands of childrenâ&#x20AC;&#x2122;s/peoples against diseases such as tuberculosis and polio. The Cold Trace an important part of an integrated,

Fig: Water and Sanitation Access With SMS Alerts

broadly available,

SMS Platform:

data-driven process

for

managing vaccine distribution in low-resource areas. As a result, it will help us move toward

Wireless vaccine monitoring is building an

providing more vaccines and safer medical

SMS-enabled issue tracking and communication

treatments to millions of peoples around the

system on top of lands that allows peri-urban

world.

residents in world to communicate with their water and sanitation services providers. The

REFERANCES

way that this works is as follows: residents can send text messages with complaints, concerns,

www.wireless innovative projects.com

news, questions and other reports to the system database, which then distributes those messages

www.wireless vaccine monitoring.com

to the water service providers and other

www.sensor scientific.com

stakeholders who can provide answers and take

www.innovativeprojects.com

action in response. As a result, the system transforms community needs and concerns into a live data feed that helps service providers

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ADVANCED CONSTRUCTION MATERIALS Viknesh.J, Shankar Narayan.R B.Tech (civil department) Sri Manakula Vinayagar Engineering College, Pondicherry Ph: 8220782967 e-mail id: uniquevicky12@gmail.com

Abstract- This paper is intended to replace the usage of cement by using bagasse, lime and flyash. The main aim is to promote the composite materials in construction and to provide high strength within a short period of time than a normal OPC. The composites in concrete mixture were altered. The proportions are varied with respect to fly ash, lime, bagasse in cement as replacement. Different varied compositions has been made and they has been tested under an UTM which had gained a good result with more strength. I.

II.

SCOPE 

The main aim of this project is to promote the use of lime and the industrial waste products such as fly ash and bagasse.



To encourage housing developers in investing these materials in house construction.



To compare the cost incurred and strength characteristics of concrete produced using fly ash, lime along with cement as replacement in proportion.

INTRODUCTION

Requirement for economical and environmentfriendly materials has extended an interest in natural fibers. Most of the natural fibers, like softwood pulp and banana fibers have been used as reinforcement materials in cement composite products. In this work, natural sugar cane bagasse have been utilised for similar study. Bagasse is a fibrous residue obtained from sugar cane during extraction of sugar juice. Sera and co-workers studied the effect of reinforcing concrete with bagasse fibers. The main aim of this paper is to promote composite materials in construction which provides high strength

III.

MATERIALS 

Fly ash is produced as a byproduct of coal industry in tones.



There are three types of fly ash.(fly ash F, fly ash N, fly ash C)



Fly ash C is of more alkaline and sulphate nature.

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

So we chose fly ash F which is available more.

•

The chemical compositions such as silicates and aluminates present in fly ash, bagasse and cement were compared.

•

Lime is added as an hydrating agent to the fly ash cement mixture as it is rich in calcium oxide.

CEMENT

CHEMICAL POZZOLAN TYPE Baggase

COMPOUND CLASS CLASS C CLASS N F

Fly ash

IV.

LITERATURE STUDY LITERATURE ANALYSIS •

•

SiO2

54.90

39.90

58.20

22.60

A12O3

25.80

16.70

18.40

4.30

Fe2O3

6.90

5.80

9.30

2.40

CaO

8.70

24.30

3.30

64.40

MgO

1.80

4.60

3.90

2.10

SO3

0.60

3.30

1.10

2.30

Na2O & K2O 0.60

1.30

1.10

0.60

AND

The replacement of 15% bagasse ash in cement with respect to their weight gave relatively equal strength when compared to ordinary Portland cement.(Ref.1) The replacement of 20% fly ash in cement with respect to their weight gave equal strength to that of ordinary Portland cement.

DESIGN MIXTURE •

The design mixture is based on 1:2:4 ratio.

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•

The gravel of 20mm size is taken as coarse aggregate.

•

The river bed sand is taken as fine aggregate.

•

A Design cube of 85mm sides is taken as sample piece to test for 14 and 28 days curing periods.

•

Ordinary Portland cement is used.

•

Bagasse ash used is in the form of fibre.



The above picture shows , during the curing period of composite mixture



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This picture shows the concrete block after hardening

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COMPRESSION TEST Cube No



This picture shows the concrete block during compression test under an UTM

14 Days

28 Days

(N/mm2 )

1.72

4.81

3.61

4.41

2.15

3.61

1.41

3.63

VARIED COMPOSITIONS Cube No

Composition

0.78

0.88

100% cement

0.12

0.23

80% cement, 20% fly ash (Ref.1)

0.28

0.48

4.08

4.91

85%cement, 15% bagasse (Ref.2)

70%cement, 15% fly ash, 7% bagasse, 8%lime

60% lime, 40% fly ash

65%lime , 35% bagasse

40%lime,20%bagasse, 40% fly ash

47%cement, 30% fly ash, 20% lime,3% bagasse

GRAPH

N/MM

6 4 2 0

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INFERENCE •

The blocks of varied proportions are casted and tested.

•

Block 1 and Block 8 gave more relative compressive strength.

•

Here in Block 8 the usage of cement is almost reduced to nearly 50%.

VI.

CONCLUSION •

The experimental Behavior of Concrete Beams with lime, cement and fly ash in varied proportions are tested.

•

The overall compressive and flexural behaviour of (lime, cement and fly ash mix) concrete beams used in this study produces more strength when compared to ordinary Portland cement beams in this report experimentally.

•

Hence I conclude by saying that this type of procedure can replace nearly 50% of usage of cement and also reduces the carbon-di-oxide emission.

VII.

REFERENCE •

1. International Journal for Service Learning in Engineering.

Vol. 5 - No. 2 - pp. 60-66, Fall 2010. ISSN 1555-9033 •

2. flyash.sustainablesources.com

•

http://www.flyash.com/data/upimages/p ress/TB.2%20Chemical%20Comparison %20of%20Fly%20Ash%20and%20Portl and%20Cement.pdf

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FPGA BASED RETINAL BLOOD OXYGEN SATURATION MAPPING USING MULTI SPECRAL IMAGES Mr.Vijay prabakaran.L(Final year â&#x20AC;&#x201C; UG/ECE)

Abstractâ&#x20AC;&#x201D; We report on an experiment for mapping two dimensional blood oxygen saturation distribution by measuring multispectral images in the wavelength range from 500 to 650nm with the resolution of 7nm. The multispectral images of the retina are acquired with the originally designed imaging system equipped with the tuneable spectral filter. To separate retinal blood vessels from other tissue area, morphological image processing is adopted. The small flick motion is also compensated. After prepossessing, the partial least squares regression model for the oxygen saturation is built by sampling typical spectra reflected from artery and vein. Applying the regression model for all the point extracted by the morphological processing allows the two-dimensional oxygen saturation map. Also this paper presents the high level, single assignment programming language SA-C and its optimizing compiler targeting reconfigurable systems. SA-C is intended for Image processing applications. Language features are introduced and discussed. The intermediate forms DDCF, DFG and AHA, used in the optimization and code-generation phases are described. Conventional and reconfigurable system specific optimizations are introduced. The code generation process is described. The performance for these systems is analyzed, using a range of applications.

than he or she has blood stream disorders in the whole system such as a hypertension. Actually, it is reported that rates of brain and cardiac infarctions are greatly correlated with the retinal malfunctions. Therefore the reliable measurement of the retinal functions such as the oxygen supply has been expected to be effective in the prevention or the early treatment for the retinopathy and the complication of the hypertension. Oxygen in the blood stream is transported by haemoglobin contained in a red blood cell. A haemoglobin molecule consists of four units, and each unit has a heme that can be bound to oxygen. Haemoglobin is bound to oxygen in high oxygen partial pressure, while it releases oxygen in low oxygen partial pressure. Then oxygen is transported to whole body. The content of haemoglobin that binds to oxygen is represented as the degree of the oxygen saturation; 100% of the oxygen saturation represents that all haemoglobin molecules bind to the maximum oxygen. To measure the oxygen saturation in blood stream, spectroscopy is useful. Most pulse oximeters that are commonly used in medical agencies utilize the difference of oxy- and deoxyheamoglobin absorptions at two wavelengths; red and near-infrared. We expect that oxygen saturation levels at retinal vessels can be measured in the same manner as the pulseoximetry though the retinal spectroscopy should be the reflectance measurement unlike the pulseoximetry that measures the transmittance of the light passed through a tip of a finger. Measuring the oxygen saturation at retinal blood stream based on the spectroscopy has long been developed since the late 1980s. Delori reported in 1988 the measurement of oxygen saturation using three wavelengths. Smith et all reported in 1998 on the oxygen measurement experiment using a laser at two wavelengths. in 1999 the experiment employed four wavelengths and the calibration model was proposed. Heaton et al. reported the originally designed handheld oximeter employing four wavelengths. In spite of these vigorous researches, the reliable measurement technique has not yet been

INTRODUCTION If a blood vessel is occluded and the blood stream is obstructed, the oxygen supply for cells will be insufficient. This leads to disorders such as the malfunction of cells or generation of the vulnerable neovascularity. Even an advanced retinal disease symptoms may be treated by a laser treatment, however, early stage detection of the vascular malfunction is important for preventing alteration in visual acuity or the loss of the eyesight. The retinal vessels are only the blood vessels inside the human body that can be seen directly from outside. If one has retinal disorders, it is suspicious

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established. This may be because following problems are still unsolved. First of all, the Spectroscopic retinal oximetry requires the high wavelength resolution because the absorption spectrum of haemoglobin in the wavelength ranging from 500 to 600 nm has a fine structure compared to the longer wavelength range such as the range around 800 nm utilized in the pulseoximetry. However increasing the wavelength resolution is not easy because of the limitation of the light intensity to illuminate a fundus and the requirement of the short exposure time to prevent a blur caused by flick motion of an eye. Hence this results in lack of spectral information to retrieve oxygen saturation. Second, it is difficult to determine the light path length inside the retinal tissue in the reflectance measurement. Even if the absorption coefficients of oxy- and deoxyhemoglobin are known in advance, oxygen saturation can not be estimated without a knowledge of the light path length based on the Lambert-Beer law. Inaccurate assumption of the light path length will lead to incorrect estimations depending on the thickness of the blood vessels or the scattering coefficient. From these background, this paper reports on the preliminary experiment employing both hardware-based and software-based improvements; the measurement setup introduces a high sensitive CCD camera and a tunable spectral filter to ensure the high spectral resolution. The data processing techniques such as the morphological structure analysis and the multivariate regression enable the improvement of the accuracy of the estimated result preventing the distortion caused by the scattering effect. The biggest obstacle to the more widespread use of reconfigurable computing systems lies in the difficulty of developing application programs for them. FPGAs are typically programmed using hardware description languages such as VHDL. Application programmers are typically not trained in these hardware description languages and usually prefer a higher level, algorithmic programming language to express their applications. Turning a computation into a circuit, rather than into a sequence of CPU instructions, may seem to offer obvious performance benefits, but an effective code generation strategy requires an understanding of the fundamental differences between conventional CPUs and FPGAs.

The SA-C Language The design goals of SA-C are to have a language that can express image processing (IP) applications elegantly, and to allow seamless compilation to reconfigurable hardware. IP applications are supported by data parallel loops with structured access to rectangular multidimensional arrays. Reconfigurable computing requires fine grain expression level parallelism, which is easily extracted from a SA-C program because of its Single Assignment semantics. Variables in SA-C are associated with wires, not with memory locations. Data types in SA-C include signed and unsigned integers and fixed point numbers, with user specified bit widths. The extents of SA-C arrays can be determined either dynamically or statically. The type declaration int14 M for example, is a declaration of a matrix M of 14bit signed integers. The left dimension will be determined dynamically; the right dimension has been specified. Lower Level Code Generation A dataflow graph (DFG) is a low-level, nonhierarchical and asynchronous program representation. DFGs can be viewed as abstract hardware circuit diagrams without timing or resource contention taken into account. Nodes are operators and edges are data paths. DFGs have token driven semantics. The SA-C compiler attempts to translate every innermost loop to a DFG. The innermost loops the compiler finds, may not be the innermost loops of the original program, as loops may have been fully unrolled or stripmined. Intel Image Processing Library When comparing simple IP operators one might write corresponding SA-C and C codes and compare them on the Starfire and Pentium II. However, neither the Microsoft nor the Gnu C++ compilers exploit the Pentiumâ&#x20AC;&#x2122;s MMX technology.

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Instead, we compare SA-C codes to corresponding operators from the Intel Image Processing Library (IPL). The Intel IPL library consists of a large number of low-level Image Processing operations. Many of these are simple point- (pixel-) wise operations such as square, add, etc. These operations have been coded by Intel for highly efficient MMX execution. Comparing these on a 450 MHz Pentium II (with MMX) to SA-C on the Star Fire, the Star Fire is 1.2 to six times slower than the Pentium. This result is not surprising. Although the FPGA has the ability to exploit fine grain parallelism, it operates at a much slower clock rate than the Pentium. These simple programs are all I/O bound, and the slower clock of the FPGA is a major limitation when it comes to fetching data from memory. However, the Prewitt edge detector written in C using IPL calls and running on the 450 MHz Pentium II, takes 53 milliseconds as compared to 17 milliseconds when running the equivalent SAC code on the StarFire. Thus, non I/O bound SA-C programs running on the StarFire board are competitive with their hand optimized IPL counterparts.

is a 300 W xenon lamp. Emitted light passes through the IR blocking filter and the diffusion

Fig. Optical setup for acquiring multispectral retinal images. Emitted light from the 300 W-xenon lamps is filtered by the IR blocking filter and passes through the diffusing filter for the uniform intensity distribution. Then the diffusing filter plane is focused on the ring slit with the diameter of about 10 mm, and is focused again on the cornea of the subjectâ&#x20AC;&#x2122;s eye. The planer mirror before the eyepiece moves according to the visual check and the image acquisition by the CCD camera.

filter to cut-off the IR light and to make uniform distribution. Note that the halogen lamp is generally thought to be better for the spectroscopic purpose because it has no line spectra; however, the xenon lamp was employed in our experiment for stronger emission intensity. The tuneable filter we used (VariSpec VIS; CRi Inc., USA) is known as the Lyot filter that allows to tune the transmission wavelength with the combination of a birefringent plate and a rotating polarizer. The tuneable wavelength range is from 400 to 720 nm with the full width at half the maximum of 7 nm. The centre wavelength of the transmitted light can be selected arbitrarily, and the response time to change the center wavelength was approximately 65 ms by actual measurement. The imaging device is a high sensitive EM-CCD (Electron Multiplying- CCD) camera (ADT-100; Flovel, Japan) with 1000x1000 pixels, 10 bit, and 30 fps transmission rate. The exposure time was set to 1/60s in this experiment. The spectral filter and the CCD camera are synchronized by a PC control. The data acquisition time for a frame including the data transfer and the wavelength switch is about 150 ms. The measurement experiment was performed with a subject of a healthy male in his 30s after the instillation of the mydriatic drops. The multispectral images were acquired in the wavelength range from 500 to 650 nm with the interval of 5 nm. The acquired region is near the optic nerve head (ONH) with the viewing angle of

EXPERIMENT In this experiment, the optical system that has the basic function of a commonly used fundus camera is built on an optical table to keep enough space for a high intensity light source and the tunable spectral filter. The optical setup is shown in Fig.1. A photographic-type fundus camera needs a mechanism in an illumination system to prevent the specular reflection from the surface of the cornea; a ring-shaped aperture is illuminated from its back and focused onto the surface of the cornea. In addition, a beamsplitter or a perforated mirror is necessary to split the illumination light and the reflected light from the retina because both lights share the optical path just before the eye. In our optical setup, the perforated mirror with the 10 mmcircular aperture is located with an angle of 45 degrees to the optical path. The focusing lens between the ring slit and the perforated mirror has a black circular mask at its center to prevent the specular reflection at the surface of the lens. The image of the retina acquired by the CCD camera is degraded without this mask. Next, brief explanations about the light source, the imaging CCD camera, and the tunable spectral filter are given as follows. The light source

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about 20 degrees. Six examples of images are shown in Fig.2. Note that the images were compensated with regard to the spectral transmittance and the sensitivity through the entire system. Hence the images are proportional to the reflectance at each wavelength.The reflectance of ONH is much higher than that of other area. The dynamic range was optimized to the blood vessels because we will extract only the blood vessel area in the data processing step. It is seen that the reflectance, especially artery, increases as wavelength reflecting the absorption spectrum of hemoglobin. The background reflection seen at the long wavelength is from the choroid; the light passes through the pigment epithelial layer because of the small absorption in the long wavelength range.

Morphological angiography Morphology is one of the digital image processing techniques based on the firm mathematical foundation, defined as set operations between a subject pattern and an elemental structure. Originally, morphology was developed in the late 1960s for analysing microscope images. Recently morphology has been extended to the wide variety of fields. The morphological image processing is typified by opening and closing; enable to delete unnecessary small patterns and to clarify the desired subject. They are implemented by combining dilation and erosion, defined mathematically as Minkowski addition and subtraction. Since the blood vessels have clear edges and their structural feature is apparently different from other area in the multispectral images, it is expected that the FA-like effect can be implemented by applying morphological image processing. The images created by this method will be used as the mask filter that is overlapped on the predicted 2-D oxygen saturation distribution for eliminating retinal tissue areas. The mask filter is created based on the bottom-hat filtering method; bottom-hat filtering is defined as subtracting the result image of performing a closing operation on the original image from the original image itself. In the obtained multispectral images, the reflectance of ONH is much higher than that of surrounding areas. Thus the algorithm adopted to our purpose need to be robust to the large change of the intensity distribution. The bottom-hat filtering is one of the adequate technique for this purpose. However, we should consider the boundaries between thick main vessels and thin capillaries. This time, we focused on extracting comparatively thick main vessels. For extracting thick vessels near and within ONH area, we adopted the combination method of bottomhat and top-hat filtering; subtracting the top-hat result from the bottom-hat result. Top-hat filtering is a subtraction of the closing-operated image from the original image. As a result, thick vessels can be extracted clearly from the measured multispectral image. Results of both the gray scale and binary operations were shown in Figs.3 (a) and (b). The original image is the observed data at the wavelength of 580 nm.

Fig. Six examples of acquired multispectral images. The maximumof the sensitivity including the transmittance of the spectral filter and the sensitivity of the CCD camera is around 640 nm. Brightness level of these figures was modified for better visualization.

DATA PROCESSING We process the measured multispectral images in three steps for estimating the oxygen saturation levels across the retinal vessels. The first step is a technique similar to the fluorescence angiography (FA) that extracts blood vessels structure from the background image. This step is performed by the digital image processing based on the morphology. The second step is compensating the small involuntary eye movement. Even very small gaps among all the images will result in the inaccurate spectra. The last step is estimating the oxygen saturation levels at all the points extracted in the first step employing the multivariate regression analysis.

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can be adopted in the case that the number of the explanation variables is larger than the sample numbers, in which the multiple regression can not be solved. First, 20 sample points were selected; 10 points each from artery and vein. In this experiment, we have no knowledge in advance of the actual oxygen saturation values. Thus we will predict the similarity of the spectrum to artery and vein instead of actual oxygen saturation values. In Fig.4, typical spectra of selected points for artery and vein are plotted. In the wavelength range from 500 to 580 nm, no significant difference between arterious and venous spectra is seen, and both lines show that the absorption is higher than that in the longer wavelength range. From wavelength of 580 nm, the reflectances suddenly increase. However, unlike in the short wavelength range, difference between arterious and venous reflectances are large because the absorptions of oxy- and deoxyhemoglobin reflect on the arterious and venous spectra.

B Compensation of eye movement An oculus constantly takes slight movement owing to our cognition system that recognizes an image by changing light intensity carried to the optic nerve. Therefore the acquired retinal image moves slightly within the measurement time of even a few seconds, and all the images have to be adjusted to the same position in order to obtain the correct spectrum.

Fig. 3. Mask filters created by the morphological operation. (a) Gray scaled filter and (b) binary filter. For being robust to the large intensity change especially around ONH and for separating thick main vessels from thin capillaries, the algorithm combined with bottom-hat and top-hat operations Were adopted. The mask filter was calculated by subtracting the top-hat result from the bottom-hat result.

An oculus movement is, in general, not only translation but rotation. However, images acquired in this experiment seemed not to contain rotation, thus only the translation compensation was implemented. The alignment algorithm is based on pattern matching. For accurate alignment, linear subpixel interpolation was adopted. Obtained accuracy was within 0.5 pixel. The ONH area was excluded from the matching calculation because the large intensity change among different wavelengths causes the large error. It was found that using the area including many vessels was effective for the accurate alignment.

Fig. Typical examples of reflectance spectra from artery and vein. Short wavelength range shows no significant difference between the arterious and venous spectra while the long wavelength range represents the spectral features of oxy- and deoxyhemoglobin.

Next, the PLS regression model was built using selected 20 spectra. As mentioned above, the actual oxygen saturation values are unknown, thus the objective variables of 1 and 0 were given for arterious and venous spectra, respectively. Full cross validation method was performed for evaluate the regression model. The regression model was built by using four PLS factors because the minimum residual was given by the fourth PLS factors. The regression coefficients were multiplied to corresponding images, then the 2-D distribution of the predicted oxygen saturation was obtained by summing up all the weighted images. Finally, the obtained image was overlapped with the mask filters that were created by the morphological technique.

C. Oxygen saturation mapping To build a regression model for the oxygen saturation and to obtain the 2-D oxygen distribution at retinal blood stream, PLS (Partial Least Squares) regression method was employed. PLS regression is one of the multivariate analyses; an objective variable is predicted using a regression model that consists of multiple explanation variables like the multiple regression analysis. PLS regression is, however, more useful especially for spectroscopic chemical analyses because it is applicable to a sample set having correlation among the explanation variables. In addition, PLS regression

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 high reflectance of ONH. Thin vessels seen in the original RESULTS AND DISCUSSIONS multispectral images were vanished by the mask filters.

Obtained 2-D distributions of the predicted oxygen saturation were shown in Figs.5 (a) and (b); their difference is only the filter mask that was overlapped in the final step. The oxygen saturation level is represented by the gray scale. White represents high value. Thick veins that run upward and downward from ONH show low values while thin artery show relatively high values. This means the oxygen saturation level was retrieved almost correctly. The area within ONH shows very high value, and blood vessels within the ONH area show higher value than the outer area. This is because the regression results were influenced by the original intensity values; the reflectance of ONH is much higher than blood vessels and other retinal tissue areas. Hence it follows that these high values seen around ONH have not retrieved correctly. The predicted oxygen saturation is represented by relative values because the actual oxygen saturation values were unknown in this experiment. Generally, the oxygen saturations of blood in main artery and vein are, respectively, about 75 and more than 95%. If the oxygen exchange is not happened in the blood vessels upper than ONH, retrieving the absolute value of oxygen saturation may be possible. Concerning the spectrum measurement, higher wavelength resolution is desirable. In this experiment, fine spectral structure in the range from 500 to 600 nm that should be useful for estimating the oxygen saturation could not be detected due to lack of the wavelength resolution. In future work, introducing some optical improvement such as a confocal imaging system will be necessary for determining optical path length. It is difficult to evaluate the effectiveness of software-based scattering correction that we employed in this research.

CONCLUSION We reported on the preliminary experiment for measuring the blood oxygen saturation at the retina. The multispectral images were acquired in the wavelength range from 500 to 650 nm with the wavelength resolution of 7 nm. The measured images were pre-processed by the morphological blood vessel extraction and the alignment processing. Finally, the two-dimensional distribution of oxygen saturation across the retina was calculated by the PLS regression method. The result showed clearly the difference of the oxygen saturation levels in the retinal blood stream. REFERENCES [1] F. C. Delori, “Noninvasive technique for oximetry of blood in retinal vessels,” Appl. Opt., vol. 27, no. 6, pp. 1113–1125, 1988. [2] M. H. Smith, K. R. Denninghoff, L. W. Hillman, and R. A. Chipman, “Oxygen saturation measurements of blood in retinal vessels during blood loss,” J. Biomed. Opt., vol. 3, no. 3, pp. 296– 303, 1998. [3] J. J. Drewes, M. H. Smith, K. R. Denninghoff, and L. W. Hillman, “Instrument for the measurement of retinal vessel oxygen saturation,” Proc. SPIE, vol. 3591, pp. 114–120, 1999. [4] A. Agarwal, S. Amarasinghe, R. Barua, M. Frank, W. Lee, V. Sarkar, and M. Srikrishna, D.and Taylor. The RAW compiler project. In Proc. Second SUIF Compiler Workshop, August 1997. [5] Annapolis Micro Systems, Inc., Annapolis, MD. STARFIRE Reference Manual, 1999. www.annapmicro.com.

Fig. Retrieved 2-D oxygen saturation levels. (a) Result with the gray scaled mask filter and (b) with the binary filter. High predicted values around ONH are caused due to the extremely INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT

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LITERATURE REVIEW ON GENERIC LOSSLESS VISIBLE WATERMARKING & LOSSLESS IMAGE RECOVERY 1

D. Phaneendra,

I.Suneetha,

A. Rajani,

M.Tech(DECS) Student,

Associate professor & Head, Assistant professor Department of ECE, AITS Annamacharya Institute of Technology and Sciences,Tirupati,India-517520 1

dorasalaphanendrakumarreddy@gmail.com 2 iralasuneetha.aits@gmail.com 3 rajanirevanth446@gmail.com

retrieved. It is important that the watermarked image must be resistant to common image operations which ensure that the hidden information after alterations is still retrievable without any defect that means the recovered image is same as the original. On the other hand, methods of the visible watermarking yield visible watermarks. These visible watermarks are generally clearly visible after applying common image operations. In addition, ownership information is conveyed directly on the media and copyright violations attempts can be deterred.

Abstract â&#x20AC;&#x201D; One way for copyright protection is digital watermarking. Digital watermarking is the process of embedding information regarding the authenticity or the identity of the owners into a image or any piece of data. Digital watermarking has been classified into two types: Visible and Invisible Watermarking. By the use of Reversible watermarking the embedded watermark can be removed and restore the original content. The lossless image recovery is a difficult task but; it is important in most of the applications where the quality of the image is concerned. There are many methods for visible watermarking with lossless image recovery. One to One compound mapping is one of the technique. The compound mapping is reversible and it allows lossless recovery of original images from the watermarked images. Security protection measures can be used to prevent illegal attackers.

In general Embedding of watermarks, degrade the quality of the host media. The legitimate users are allowed to remove the embedded watermark and original content can be restored as needed using a group of techniques, namely reversible watermarking [8-11]. However, lossless image recovery is not guaranteed by all reversible watermarking techniques, which means that the recovered image is same as the original. Lossless recovery is important where there is serious concerns about image quality such as include forensics, military applications, historical art imaging, or medical image analysis.

Key Terms: Reversible visible watermarking, Discrete Cosine Transform (DCT), Discrete Fourier Transform (DFT), Discrete Wavelet Transform (DWT).

I. INTRODUCTION

The

The most common approach is to embed a monochrome watermark using deterministic and reversible mappings of pixel values or DCT coefficients in the watermark region [6,9,11]. Another is to rotate consecutive watermark pixels to embed watermark that is visible [11].the watermarks of arbitrary sizes can be embedded into any host image. Only binary visible watermarks can be embedded using these approaches.

concepts of authenticity and copyright protection are of major importance in the framework of our information society. For example, TV channels usually place a small visible logo on the image corner (or a wider translucent logo) for copyright protection. In this way, unauthorized duplication is discouraged and the recipients can easily identify the video source. Official scripts are stamped or typed on watermarked papers for authenticity proof. Bank notes also use watermarks for the same purpose, which are very difficult to reproduce by conventional photocopying techniques.

The lossless visible watermarking is proposed by using one-to-one compound mappings which allow mapped values to be controllable The approach is generic, leading to the possibility of embedding different types of visible watermarks into cover images. Two applications of the proposed method are demonstrated; where we can embed opaque monochrome watermarks and non-uniformly translucent full-color ones into color images.

Digital Image watermarking methods are usually classified into two types: visible and invisible [1-7]. The invisible watermarking aims to embed copyright information into host media, in case of copyright infringements, to identify the ownership of the protected host the hidden information can be

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• The secret random key. The secret key may be included in the process of watermarking to improve the security during transmission. If a key is also included, only the receiver who knows the key can extract the watermark, and not any intruders.

II. RELATED WORK 2.1 EXISTING WATERMARKING TECHNOLOGIES A. Spatial-Domain technologies

• The masking property of the image. The masking property of the image is also related to the quality and composition of the image which signifies the clarity of the watermark on the original image.

Spatial-domain technologies refer to those embedding watermarks by directly changing pixel values of host images. Some common spatial domain algorithms include Least Significant Bit (LSB). The LSB is the most straight-forward method of watermark embedding. The most serious drawback of spatial-domain technologies is limited robustness.

One form of the data embedding algorithm is given by the equation ,

In the spatial domain, pixels in randomly selected regions of the image are modified according to the signature or logo desired by the author of the product. This method involves modifying the pixel values of the original image where the watermark should be embedded. Fig. 1 shows the block diagram of a spatial-domain data embedding system.

ŷ=y +αI Where y(i,j), is the original image intensity at pixe position (i,j), ŷ is the watermarked image, and αI represents the embedded data in the form of small changes in intensity levels. The author of the watermark holds two keys: • The region of the image where the logo is marked and • The information in the watermark, αI. Given the marked image, the original owner will be able to recover the watermark by comparing the marked image with the original. In the reconstruction of the embedded watermark, the following computation is made, I= (ŷ-y)/α

Fig.1. Spatial domain data embedding system

Randomly selected image data are dithered by a small amount according to a predefined algorithm, whose complexity may vary in practical systems. The algorithm defines the intensity and the position of the watermark on the original image. One of the major disadvantages of the conventional watermarking is that it can be easily extracted from the original image which makes this technique unsuitable for copyright authentication. There are three factors that determine the parameters of the algorithm applied in the spatial domain watermarking. The three factors are: •

Fig. 2. Watermarking result of a color host image. (a) Host image. (b) Logo image. (c) Resulting watermarked Image. (d) Watermark extracted image.

The information associated with the signature. Basically, the signature is the watermark embedded on the original image. The information of the signature is closely related to the size and quality of the signature.

Fig.2. shows the output results of spatial domain technique with host image, logo image, watermarked image and watermark extracted image respectively.

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selected based on a Gaussian network classifier decision. The middle range frequency DCT coefficients are then modified, using either a linear DCT constraint or a circular DCT detection region. A DCT domain watermarking technique based on the frequency masking of DCT blocks was introduced by Swanson. Cox developed the first frequency-domain watermarking scheme. After that a lot of watermarking algorithms in frequency domain have been proposed.

It is difficult for spatial-domain watermarks to survive under attacks such as lossy compression and low-pass filtering. Also the information can be embedded in spatial domain is very limited

B. Frequency-Domain Technologies Compared to spatial-domain watermark, watermark in frequency domain is more robust and compatible to popular image compression standards. Thus frequency-domain watermarking obtains much more attention. To embed a watermark, a frequency transformation is applied to the host data. Then, modifications are made to the transform coefficients. Possible frequency image transformations include the Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT) and others

Figure 3 and Figure 4 illustrate the watermark embedding and detection/extraction in frequency domain, respectively. Most frequency-domain algorithms make use of the spread spectrum communication technique. By using a bandwidth larger than required to transmit the signal, we can keep the SNR at each frequency band small enough, even the total power transmitted is very large. When information on several bands is lost, the transmitted signal can still being recovered by the rest ones. The spread spectrum watermarking schemes are the use of spread spectrum communication in digital watermarking. Similar to that in communication, spread spectrum watermarking schemes embed watermarks in the whole host image. The watermark is distributed among the whole frequency band. To destroy the watermark, one has to add noise with

The first efficient watermarking scheme was introduced by Koch et al. In their method, the image is first divided into square blocks of size 8x8 for DCT computation. A pair of mid-frequency coefficients is chosen for modification from 12 predetermined pairs. Bors and Pitas developed a method that modifies DCT coefficients satisfying a block site selection constraint. After dividing the image into blocks of size 8x8, certain blocks are

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sufficiently large amplitude, which will heavily degrade the quality of watermarked image and be considered as an unsuccessful attack. One major reason why frequency domain watermarking schemes are attractive is their compatibility with existing image compression standards, in particular, the JPEG standard. The compatibility ensures those schemes a good performance when the watermarked image is subject to lossy compression, which is one of the most common image processing methods today.

Fig.6. (a) Three-level Decomposition. (b) Coefficient Distribution.

Besides its own advantages it has a disadvantage that it is not suitable for visible watermarking. And only invisible watermarking is mostly performed in frequency domain.

Furthermore, from these DWT coefficients, the original image can be reconstructed. For reconstruction process same filter must be used. This reconstruction process is called the inverse DWT (IDWT). If I (m, n) represent an image, the DWT and IDWT for I (m, n) can be similarly defined by implementing the DWT and IDWT on each dimension m and n separately.

C. Wavelet-domain Technologies The wavelet transform is identical to a hierarchical sub-band system, where the sub-bands are logarithmically spaced in frequency. The basic idea of the DWT for a two dimensional image is described as follows. An image is first decomposed into four parts of high, middle and low frequencies (i.e. LL1, HL1, LH1, HH1 sub bands) by critically subsampling horizontal and vertical channels using Daubechies filters. The sub-band HL1, LH1 and HH1 represent the finest scale of wavelet coefficients as shown in figure 5. To obtain the next coarser scaled wavelet coefficient, the sub-band LL1 is further decomposed and critically sub-sampled. This process is repeated several times, which is determined by the application in hand. An example of an image decomposed into ten sub-bands for three levels is shown in Figure 6. Each level has various bands information such as low-low, low-high, high-low and high-high frequency bands.

III. CONCLUSION In this paper we have briefly discussed regarding the methods (Spatial domain, Frequency domain and Wavelet domain) which are formerly used in visible watermarking. The former methods used DCT, DFT, DWT and LSB (Least Significant Bit) for desired visible watermarking. A novel method for generic visible watermarking with a capability of lossless image recovery is proposed. The method is based on the use of deterministic one-to-one compound mappings of image pixel values for overlaying a variety of visible watermarks of arbitrary sizes on cover images. The compound map-pings are proved to be reversible, which allows for lossless recovery of original images from watermarked images. The mappings may be adjusted to yield pixel values close to those of desired visible watermarks. Different types of visible watermarks, including opaque monochrome and translucent full color ones, are embedded as applications of the proposed generic approach. A two-fold monotonically increasing compound mapping is created and proved to yield more distinctive visible watermarks in the watermarked image. Security protection measures by parameter and mapping randomizations have also been proposed to deter attackers from illicit image recoveries. Experimental results demonstrating the effectiveness of the proposed approach are also included.

Fig.5. Three level wavelet decomposition

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Trends in Engineering, Vol. 1, No. 1, pp. 430433, May 2009. [13] Mohammad Reza Soheili “A Robust Digital image Watermarking Scheme Based on DWT” Journal of Advances in Computer Research, m2(2010) 75-82.1. [14] R.AARTHI, V. JAGANYA, & S. POONKUNTRAN “Modified Lsb Watermarking For Image Authentication” International Journal of Computer & Communication Technology (IJCCT) ISSN (ONLINE): 2231 - 0371 ISSN (PRINT): 0975 – 7449 Vol-3, Iss-3, 2012. [15] Vaishali S. Jabade and Dr. Sachin R. Gengaje, “Literature Review of Wavelet Based Digital Image Watermarking Techniques”, International Journal of Computer Applications, Vol 31, No.1, pp. 28-35, October 2011.

REFERENCES [1] G. Braudaway, K. A. Magerlein, and F. Mintzer, “Protecting publicly available images with a visible image watermark,” in Proc. SPIE Int. Conf. Electronic Imaging, Feb. 1996, vol. 2659, pp. 126–133. [2] I. J. Cox, J. Kilian, F. T. Leighton, and T. Shamoon, “Secure spread spectrum watermarking for multimedia,” IEEE Trans. Image Process., vol. 6, no. 12, pp. 1673– 1687, Jun. 1997. [3] F.A.P Patitcolas, R.J.Anderson, and M.G.Kun“Information hiding- A survey”Proc.IEEE, vol:87, no.7, jul. 1999. [4] M. S. Kankanhalli, Rajmohan, and K. R. Ramakrishnan, “Adaptive visible watermarking of images,” in Proc. IEEE Int. Conf. Multimedia Computing and Systems, 1999, vol. 1, pp. [5] S. P. Mohanty, K. R. Ramakrishnan, and M. S Kankanhalli, “A DCT domain visible watermarking technique for images,” in Proc. IEEE Int. Conf. Multimedia and Expo, Jul. 2000, vol. 2, pp. 1029– 1032. [6] N. F. Johnson, Z. Duric, and S. Jajodia, Information Hiding. Steganography and Watermarking Attacks and Countermeasures. Boston, MA: Kluwer, 2001. [7] Y. Hu and S.Kwong,“Wavelet domain adaptive visiblewatermarking,” Electron. Lett., vol. 37, no. 20, pp. 1219–1220, Sep. 2001. [8] Y. J. Cheng and W. H. Tsai, “A new method for copyright and integrity protection for bitmap images by removable visible watermarks and irremovable invisible watermarks,” presented at the Int. Computer Symp. Workshop on Cryptology and Information Security, Hualien,Taiwan, R.O.C., Dec. 2002. [9] P. M. Huang and W. H. Tsai, “Copyright protection and authentication of grayscale images by removable visible watermarking and invisible signal embedding techniques: A new approach,” presented at the Conf. Computer Vision, Graphics and Image Processing, Kinmen, Taiwan, R.O.C., Aug. 2003. [10] Y. Hu, S. Kwong, and J. Huang, “An algorithm for removable visible watermarking,” IEEE Trans. Circuits Syst. Video Technol., vol. 16, no. 1, pp. 129– 133, Jan.2006. [11] S. K. Yip, O. C. Au, C. W. Ho, and H. M. Wong, “Lossless visible watermarking,” in Proc. IEEE Int. Conf. Multimedia and Expo, Jul. 2006, pp. 853–856.” [12] Neminath Hubballi and Kanyakumari D P, “Novel DCT based watermarking scheme for digital images”, International Journal of Recent

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K.SAI KRISHNA 3rd Year CSE, SRM University, Chennai, MobileNo.:9003226055

Artificial Intelligence

ABSTRACT: Artificial Intelligence (AI) for speech recognition involves two basic ideas. First, it involves studying the thought processes of human beings. Second, it deals with representing those processes machines (like computers, robots, etc).AI is behaviour of a machine, which, if performed by a human being, would be called intelligence. It makes machines smarter and more useful, and is less expensive than natural intelligence. Natural language processing (NLP) refers to artificial intelligence methods of communicating with a computer in a natural language like English. The main objective of a NLP program is to understand input and initiate action. The input words are scanned and matched against internally stored known words. Identification of a keyword causes some action to be taken. In this way, one can communicate with the computer in one's language

INTRODUCTION: Artificial intelligence involves two basic ideas. First, it involves studying the thought processes of human beings. Second, it deals with representing those processes via machines (like computers, robots, etc.). AI is behaviour of a machine, which, if performed by a human being, would be called intelligent. It makes machines smarter and more useful, and is less expensive than natural intelligence. Natural language processing (NLP) refers to artificial intelligence methods of communicating with a computer in a natural language like English. The main objective of a NLP program is to understand input and initiate action.

Definition:

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It is the science and engineering of making intelligent machines, especially intelligent computer programs. AI means Artificial Intelligence. Intelligence” however cannot be defined but AI can be described as branch of computer science dealing with the simulation of machine exhibiting intelligent behaviour.

History: Work started soon after World-WarII. Name is coined in 1957. Several names that are proposed are… Complex Information Processing Heuristic programming Machine Intelligence Computational Rationally

Foundation: Philosophy (428 B.C.-present) Mathematics (c.800-present) Economics (1776-present) Neuroscience (1861-present) Psychology (1879-present) Computer Engineering (1940-present) Control theory and cybernetics (1948-present) Linguistics (1957-present)

Speaker independency: The speech quality varies from person to person. It is therefore difficult to build an electronic system that recognises everyone’s voice. By limiting the system to the voice of a single person, the system becomes not only simpler but also more reliable. The computer must be trained to the voice of that particular individual. Such a system is called speakerdependent system. Speaker independent systems can be used by anybody, and can recognise any voice, even though the characteristics vary widely from one speaker to another. Most of these systems are costly and complex. Also, these have very limited vocabularies. It is important to consider the environment in which the speech recognition system has to work. The grammar used by the speaker and accepted by the system, noise level, noise type , position of the microphone, and speed and manner of the user’s speech are some factors that may affect the quality of speech recognition.

Environmental influence: Real applications demand that the performance of the recognition system be unaffected by changes in the environment. However, it is a fact that when a system is trained and tested under different conditions, the recognition rate drops unacceptably. We need to be concerned about the variability present when different microphones are used in training and

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testing, and specifically during development of procedures. Such care can significantly improve the accuracy of recognition systems that use desktop microphones. Acoustical distortions can degrade the accuracy of recognition systems. Obstacles to robustness include additive noise from machinery, competing talkers, reverberation from surface reflections in a room, and spectral shaping by microphones and the vocal tracts of individual speakers. These sources of distortions fall into two complementary classes; additive noise and distortions resulting from the convolution of the speech signal with an unknown linear system. A number of algorithms for speech enhancement have been proposed. These include the following: 1. 2. 3. 4.

Spectral subtraction of DFT coefficients MMSE techniques to estimate the DFT coefficients of corrupted speech Spectral equalisation to compensate for convoluted distortions Spectral subtraction and spectral equalisation.

Although relatively successful, all these methods depend on the assumption of independence of the spectral estimates across frequencies. Improved performance can be got with an MMSE estimator in which correlation among frequencies is modeled explicitly.

Speaker-specific features: Speaker identity correlates with the physiological and behavioural characteristics of the speaker. These characteristics exist both in the vocal tract characteristics and in the voice source characteristics, as also in the dynamic features spanning several segments. The most common short-term spectral measurements currently used are the spectral coefficients derived from the Linear Predictive Coding(LPC) and their regression coefficients. A spectral envelope reconstructed from a truncated set of spectral coefficients is much smoother than one reconstructed from LPC coefficients. Therefore, it provides a more stable representation from one repetition to another of a particular speakerâ&#x20AC;&#x2122;s utterances. As for the regression coefficients, typically the first and second order coefficients are extracted at every frame period to represent the spectral dynamics. These coefficients are derivatives of the time function of the spectral coefficients and are called the delta and delta-delta-spectral coefficients respectively.

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Speech Recognition: The user communicates with the application through the appropriate input device i.e. a microphone. The Recogniser converts the analog signal into digital signal for the speech processing. A stream of text is generated after the processing. This source-language text becomes input to the Translation Engine, which converts it to the target language text.

Salient Features:          

Input Modes Through Speech Engine Through soft copy Interactive Graphical User Interface Format Retention Fast and standard translation Interactive Preprocessing tool Spell checker. Phrase marker Proper noun, date and other package specific identifier

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 Input Format  txt,.doc.rtf  User friendly selection of multiple output  Online thesaurus for selection of contextually appropriate synonym  Online word addition, grammar creation and updating facility  Personal account creation and inbox management

Applications: One of the main benefits of speech recognition system is that it lets user do other works simultaneously. The user can concentrate on observation and manual operations, and still control the machinery by voice input commands. Another major application of speech processing is in military operations. Voice control of weapons is an example. With reliable speech recognition equipment, pilots can give commands and information to the computers by simply speaking into their microphones they don’t have to use their hands for this purpose. Another good example is a radiologist scanning hundreds of X-rays, ultra sonograms, CT scans and simultaneously dictating conclusions to a speech recognition system connected to word processors. The radiologist can focus his attention on the images rather than writing the text. Voice recognition could also be used on computers for making airline and hotel reservations. A user requires simply to state his needs, to make reservation, cancel a reservation, or make enquiries about schedule.

Ultimate Goal: The ultimate goal of the Artificial Intelligence is to build a person, or, more humbly, an animal.

Conclusion:

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By using this speaker recognition technology we can achieve many uses. This technology helps physically challenged skilled persons. These people can do their works by using this technology with out pushing any buttons. This ASR technology is also used in military weapons and in Research centres. Now a days this technology was also used by CID officers. They used this to trap the criminal activities.

Bibliography: www.google.co.in/Artificial intelligence for speech recognition www.google.com www.howstuffworks.com www.ieeexplore.ieee.org

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Strength and Durability characteristics of Geopolymer concrete using GGBS and RHA S.Subburaj,T.Anantha shagar

VV college of Engineering,tisayanvilai tutucorin Abstractâ&#x20AC;&#x201D; Cement, the second most consumed product in the world, contributes nearly 7% of the global carbon dioxide emission. Several efforts are in progress to reduce the use of Portland cement in concrete in order to address the global warming issues. Geopolymer concrete is a cementless concrete. It has the potential to reduce globally the carbon emission that lead to a sustainable development and growth of the concrete industry. In this study, geo-polymer concrete is prepared by incorporating ground granulated blast furnace slag (GGBS) and black rice husk ash (BRHA) as source materials. In India RHA is used for cattle feeding, partition board manufacturing, land filling, etc. RHA is either white or black in colour. If the rice husk is burnt in controlled temperature and duration, it will result the ash in white colour. This type of RHA has high percentage of silica content. The ease availability of RHA is black in colour due to uncontrolled burning temperature and duration in various rice mills, so the resulting rice husk ash is called as black rice husk ash (BRHA). In this study GGBS used as a base material for geopolymer concrete and it is replaced upto 30% by BRHA. The strength characteristic of GGBS and BRHA based geopolymer concrete has been studied. The suitable compressive strength test is performed. The result shows that the replacement of BRHA decreases the compressive strength of geopolymer concrete, because of the unburnt carbon content present in the BRHA.

Keywordsâ&#x20AC;&#x201D; Geopolymer concrete, GGBS, Black Rice Husk Ash, Compressive strength

INTRODUCTION Concrete is the second most used material in the world after water. Ordinary Portland cement has been used traditionally as a binding material for preparation of concrete. One tone of carbon dioxide is estimated to be released to the atmosphere when one ton of ordinary Portland cement is manufactured. Also the emission by cement manufacturing process contributes 7% to the global carbon dioxide emission. It is important to find an alternate binder which has less CO2 emission than cement. Geopolymer is an excellent alternative which transform industrial waste products like flyash, GGBS and rice husk ash into binder for concrete. Al- Si materials which are used as source materials undergoes dissolutions, gel formation, setting and hardening stages to form geopolymers. There are two main constituents of geo-polymers, namely the source materials and the alkaline liquids. The source materials for geo-polymers based on alumina-silicate should be rich in silicon (Si) and aluminium (Al). These could be natural minerals such as kaolinite, clays, etc. Alternatively, by-

product materials such as fly ash, silica fume, slag, rice-husk ash, red mud, etc could be used as source materials. The choice of the source materials for making geo-polymers depends on factors such as availability, cost, type of application, and specific demand of the end users. The alkaline liquids are from soluble alkali metals that are usually sodium or potassium based. The most common alkaline liquids used in geo-polymerization are a combination of sodium hydroxide (NaOH) or potassium hydroxide (KOH) and sodium silicate (Na2SiO3) or potassium silicate (K2SiO3). The alumino silicate material which is to be used in this study is a combination of Rice husk ash and ground granulated blast furnace slag (GGBS). RHA is either white or black in color. If the rice husk is burnt in controlled temperature and duration, it will result the ash in white color. This type of RHA has high percentage of silica content. The ease availability of RHA is black in color due to uncontrolled burning temperature and duration in various rice mills, so the black color rice husk ash is called as black rice husk ash (BRHA). The RHA used in this study was black rice husk ash. This study aims to synthesize geopolymer concrete using combination of GGBS and BRHA. In this study GGBS used as a base material for geoploymer concrete. GGBS is replaced up to 30% by BRHA to understand the strength and durability characteristics. MATERIALS The materials used for making GGBS based geopolymer concrete specimens are GGBS, Rice Husk Ash, aggregates, alkaline liquids, water and super plasticizer. Ground Granulated Blast furnace Slag was procured from JSW cements in Bellari, Karnataka. Black Rice Husk Ash was obtained from a Rice mill near Karaikudi and then it was finely grounded. The properties of GGBS and BRHA are given in Table I.

TABLE I. PROPERTIES OF GGBS AND RHA

Property SiO2 Al2O3 Fe2O3 CaO MgO Specific gravity

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GGBS 31.25 % 14.06 % 2.80 % 33.75 % 7.03 % 2.61

BRHA 93.96 % 0.56 % 0.43 % 0.55 % 0.4 % 2.11

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 Aggregates Coarse aggregate passing through 20mm sieve and fine aggregate of river sand from a local supplier were used for the present study and their properties are given in Table II.

till the time of testing.The cubes were then tested at 3, 7 and 28 days from the day of casting. TABLE IIIII. MIX PROPOTIONS OF GEOPOLYMER CONCRETE

Materials

TABLE III. PROPERTIES OF AGGREGATES

Property Specific gravity Fineness modulus Bulk density

Coarse Aggregate 2.73 7.36 1533 kg/m3

Fine Aggregate 2.60 2.63 1254 kg/m3

GGBS RHA Coarse Aggregate Fine Aggregate Sodium Hydroxide Sodium Silicate Super Plasticizer Extra Water (15%)

B. Alkaline solution A mixture of Sodium hydroxide and Sodium Silicate was used as the alkaline solution in the present study. Commercial grade Sodium Hydroxide in pellets form (97%-100% purity) and Sodium silicate solution having 7.5%-8.5% of Na2O and 25% -28% and water of 67.5%- 63.5% were used in the present study. The ratio of Sodium Silicate to Sodium Hydroxide was kept as 2.5. In this study the compressive strength of geo-polymer concrete is examined for the mix of 8M of NaOH solution. The molecular weight of NaOH is 40. For example to prepare 8M of NaOH solution 320g of NaOH flakes are weighed and they can be dissolved in distilled water to form 1 litre solution. For this, volumetric flask of 1 litre capacity is taken, NaOH flakes are added slowly to distilled water to prepare 1litre solution. In order to improve the workability of fresh concrete, highrange water-reducing naphthalene based super plasticizer was used. Extra water nearly 15% of binder is added to increase the workability of the concrete. METHODOLOGY

C. Mixing, Casting and Curing The mix proportions were taken as given in Table. III. As there are no code provisions for the mix design of geopolymer concrete, the density of geo-polymer concrete was assumed as 2400 Kg/m3 and other calculations were done based on the density of concrete [4]. The combined total volume occupied by the coarse and fine aggregates was assumed to be 77%. The alkaline liquid to binder ratio was taken as 0.40. GGBS was kept as the primary binder in which BRHA was replaced in 0, 10, 20 and 30% by weight. The normal mixing procedure was adopted. First, the fine aggregate, coarse aggregate and GGBS & BRHA were mixed in dry condition for 3-4 minutes and then the alkaline solution which is a combination of Sodium hydroxide and Sodium silicate solution with superplasticizer was added to the dry mix. Then some extra water about 15% by weight of the binder was added to improve the workability. The mixing was continued for about 6-8 minutes. After the mixing, the concrete was placed in cube moulds of size 150mm X 150mm X 150mm by giving proper compaction. The GPC specimens were then placed in a hot air oven at a temperature of 60oC for 48 hours and then the specimens were taken out and cured under room temperature

Mass(Kg/m3) Mix1 Mix2 (0% (10% RHA) RHA) 394 355 0 39 647 647

Mix3 (20% RHA) 315 79 647

Mix4 (30% RHA) 276 118 647

1201

113

RESULTS AND DISCUSSION The cubes were tested in the compressive testing machine to determine their compressive strength at the age of 3, 7 and 28 days from the day of casting. The Table IV and figure 1 shows the compressive strength variation with percentage replacement of BRHA. The table4 shows that GGBS based geopolymer concrete attained compressive strength of 69 MPa. 10 % replacement of GGBS by RHA gives compressive strength of 58 MPa. The figure1 shows that there is an increase in compressive strength if the curing time increases. The percentage of increase in strength is approximately 16 to 20 for the curing time of 3days to 28days. The percentage increase in strength from 3 to 28 days curing time is approximately 24% for mix1. The graph shows that the replacement of BRHA in GGBS based geopolymer concrete decreases the compressive strength. Because of the unburnt carbon content present in BRHA, decreases the compressive strength. The average 28 days compressive strength of mix2 and mix3 is decreases by 20% and 46% compared to mix1. TABLE IVV. COMPRESSIVE STRENGTH TEST RESULTS

Mix

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Compr essive strength at 3rd day(MPa)

Compr essive strength at 7th day(MPa)

Compre ssive strength at 28th day(MPa)

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55.9

60.5

69.2

48.6

54.3

57.46

Mix 3 (80% GGBS, 20% RHA)

40.75

44.72

47.36

Mix 4 (70% GGBS, 30% RHA)

20.8

23.54

27.36

Due to the presence of high silica content in BRHA (94%) there is a fast chemical reaction occurred resulting quick setting of geo-polymer concrete. In this study, the Si / Al ratio is not maintained due to low alumina content in the source materials resulting in lesser compressive strength . I feel that GGBS with 10% of RHA will be well and eco friendly when compared with OPC ACKNOWLEDGMENT

The author would like to acknowledge his Research supervisor mr.p.muthuraman for his meticulous guidance and constant motivation. The author would also like to thank the faculty members of Division of Structural Engineering, vv college of Engineering University, tisayanviai for their consent encouragement and support during the project work. The author would also like to thank his family and friends for their complete moral support. REFERENCES

Fig.1 Variation of compressive strength at 3rd, 7th and 28th days with replacement of BRHA

CONCLUSIONS From the limited experimental study conducted on the geopolymer concrete made with GGBS and BRHA, the following conclusions are made. 1. The GGBS based geopolymer concrte gives higher strength. 2. The replacement of GGBS by BRHA decreases the compressive strength because of the unburnt carbon content. 3. The percentage replacement of BRHA in GGBS based geo-polymer concrete is significant only in 10%.

Alireza Naji Givi, Suraya Abdul Rashid, Farah Nora A. Aziz, Mohamad Amran Mohd Salleh, (2010), ‘Assessment of the effects of rice husk ash particle size on strength, water permeability and workability of binary blended concrete’, Construction and Building Materials., Vol. 24, Issue 11, pp.2145-2150. Bhosale, M.A, Shinde, N.N (2012), ‘Geo-polymer concrete by using fly ash in construction’, IOSR Journal of Mechanical and Civil Engineering., Vol. 1, Issue 3, pp.25-30. Detphan.S, and P. Chindaprasirt, (2009), ‘Preparation of fly ash and rice husk ash geo-polymer’ International Journal of Minerals, Metallurgy and Materials., Vol. 16, Issue 6, pp. 720-726. Hardjito, D. and Rangan, B. V. (2005), ‘Development and Properties of Low Calcium Fly Ash Based Geo-polymer Concrete’, Research Report GC 1, Faculty of Engineering, Curtin University of Technology. Joseph Davidovits, (1994), ‘Global Warming Impact on the Cement and Aggregates Industries’, World Resource Review, Vol. 8, No.2, pp. 263-278. Kartini, K, Mahmud, H.B, Hamidah, M.S, (2006), ‘Strength Properties of Grade 30 Rice Husk Ash Concrete’ 31st Conference on Our World in Concrete & Structures. Malhotra, V. M. (1999), ‘Making Concrete "Greener" With Fly Ash’ American Concrete Institute. pp. 61-66. McCaffery, R. (2002), ‘Climate Change and the Cement Industry’, Global Cement and Lime Magazine (Environment Special Issue), pp. 15-19. Mehta, P. K., (2001) ‘Reducing the Environmental Impact of Concrete’, ACI Concrete International, Vol. 23, (10) pp. 61-66.

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Vulnerabilities in credit card security S.Krishnakumar Department of Computer science and Engineering MNM Jain Engineering College Chennai krishnakumar.srinivasan1@gmail.com 9789091381 provider and system administrator. It should be secured from unauthorized access by third parties or individuals. Above all the database information must be properly encrypted to prevent illegal elements from accessing such data

Abstractâ&#x20AC;&#x201D;This paper is intended to highlight the vulnerabilities in online payment gateways of e-commerce sites and security of customer credit card information stored in them and how they can be exploited. This paper also suggests different mechanisms in which these vulnerabilities can be plugged.

C. Vulnerability analysis tools: I. INTRODUCTION A lot of open source and free cyber security and penetration testing tools are freely available in the internet. While the purpose of these tools is to detect and expose vulnerabilities and loopholes in the integrity of a system they can also be used by hackers to scan system and websites which are vulnerable and can be easily exploited. Hence service providers and e-commerce companies must periodically test and analyze their websites and systems for security loopholes and find ways to plug it. Such tools can also be used by hackers to perform credit fraud by stealing customer data from websites which they found to be vulnerable in their tests. So either the service provider had to do the integrity test else an hacker will save him the trouble.

The reach of the Internet throughout the world is growing day by day and this development has led to the launch of a host of online services like Banking, online shopping, e-ticket booking etc. But almost all forms of services have an element of monetary transaction in them. The services which are mostly based on such online monetary transactions are banking and online shopping or e-commerce. These service providers collect and record a lot of information about their customers and clients especially their financial information like credit card number and in some cases Pin number apart from their name address and preferences. Hence it becomes imperative for these service providers to have a foolproof security mechanism to protect their customer data which they store .Failing to do which might expose such sensitive data to hackers and third parties who might misuse them for personal gain which not just affects the customer but may also erode their trust in the integrity of service providers , mostly highly vulnerable sites only have this problem.Hence this paper highlights some of the security loopholes found in payment gateways and securing customer data.

D. Authentication mechanisms: E. The authentication mechanisms employed by ecommerce sites for their customers also have some loopholes which can be exploited by a hacker once he gets access to sensitive customer data of the e-commerce website. Most of the prominent e-commerce sites do not verify whether the shipping and billing address are same when a customer places an order. This gives leeway to a hacker impersonating as a customer to get away with goods purchased with the customers id and credit card. A proper layer of authentication layers would be essential to prevent such frauds apart from securing customer data.

II. VULNERABILITY A. Storage of customer data: First, almost all highly vulnerable e-commerce sites collect and store customer information like their name, address, password, preferences, history of purchase and transaction, and in some cases even the credit card number and its cvv number.They use these data for analyzing customer trends and to customize the online experience of the customer. Hence it becomes imperative for them to either have a foolproof mechanism to protect this data or avoid collecting such sensitive data.

III. EXPLOINTING THE VULNERABILITIES

B. Access of customer data: The customer records and data stored on the website should be accessible by only the authorized personnel of the service

This section will explain how a combined exploitation of the mentioned vulnerabilities can be used to gain access of

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customer data stored on e-commerce sites and how they can be exploited for the personal gain of the hacker.

after getting the database , we should find the tables in the database in each table we should scan the columns

F. Scanning for vulnerabilities: ●

in all shopping websites we can see this example: TOTAL ORDERS, CUST_DETAILS ,CUST PAYMENTS, CUST EMAILS ● if its highly vulnerable we can see the payment methods and we can retrieve all the information’s of the credit cards details and the address of the owner ● all these things are appilicable only to highly vulnerable shopping sites ..in these days mostly many websites record all info’s like CVV and all that .. so these websites are always vulnerable

● First a hacker will scan for vulnerable e-commerce sites with a free security tool called ****dork scanner.*This tool is a simple python script which returns websites which include a specified keyword in their url like buy_now, add_to_cart, PayPal etc. ● The hacker enters keywords related to payments like add_to_cart, payment, PayPal, buy_now which are found in the url of payment pages of e-commerce websites as input to Dork scanner. ● The Dork scanner scans the web for websites having the keywords and returns a list of websites having them. ● From the given list of sites the hacker filters a list of sites having a particular kind of vulnerability like SQL injection and XSS ● After selecting a vulnerable site SQL map python tool is used to retrieve tables from the website database which store customer financial data for reference. ● In case of highly vulnerable sites these tables containing keywords like payment are retrieved along with the data stored in them. ● Some of these tables display the last four digits of a credit card and incase of least protected websites they display all the numbers.

if we need full cc information we can upload a shell on website and if we get the cpanel full cc info will be there..even many websites directly displaying full cc number..

encryption is very much essential and sql databases should be tested G. Exploiting authentication mechanism : After obtaining customer financial data including his/her login id and password and credit card number ...the hacker can use it to impersonate the customer and place orders online. Since most of the websites do not check whether the billing and shipping address are the same it forms a loophole for the hacker to exploit ...its applicable to great websites The hacker after extracting the customer data will know where the customer is from and what his preferences are.

how hackers get the info’s : ● ●

After scanning the websites , highly vulnerable sites will be targeted . we would need to attack the database of the website using sql injection or XSS .. we would need to find the length of the database

●

He will then get a VPN connection or remote desktop of that location and then place orders on the website.

●

the hacker can match credit card location and vpn location , so that it would easy for him to purchase

●

the hacker clear all his cookies and remove all blacklisted ip and so that he can get a fresh vpn so match this

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this methodology is used to bypass any website and many websites cant able to find this

Avoid storing credit card information

so this illegal access should be fixed The e-commerce websites must avoid retaining sensitive financial information about the customer. ..the website should not save cvv number’s and also once they are directed to payment gateways the cvv number should be encrypted even to the website ,and then directed to the bank authentication ..

Some Common Loop holes in storing the data : ● Highly secure websites will not store the credit card information of the customer after the transaction but vulnerable sites will store the credit card data even after transaction.

J. Authentication mechanism to fix loop holes in payment gateways :

● The stored data in these sites is not secure as most of them are not encrypted.

The e-commerce websites must have a proper authentication mechanism to make sure whether the order is placed by the original customer and not by an impersonator.

. loop holes in payment gateways: ●

●

even good shopping websites cannot find unauthorized transactions … payment gateways failed to authorize the ip address of the person who is been involved in placing the order and the location of the credit card. payment gateways not having enough security to verify authorize illegal ip address ..

● ● ●

loop holes in payment gateway ssl: ● ●

●

some times hacker’s normally use vpn to bypass the website ..many websites are not finding the untrusted connection’s , ssl verification is not that much secure so hacker’s tend to use vpn to bypass it .. all the websites should have good ssl verification to stop illegal ip access and also it should have good certificate verification

●

● ●

IV.

PREVENTIVE SECURITY MEASURES

first it should check whether the billing address matching the credit card address if it matches then it should verify its billing phone number with the bank details verification of ip should be strong , it should have good ssl certification to check the trusted connection after this it should verify the card ip address when it was first accessed and the user ip who is placing the order dynamic ip address can be noted and matching of dynamic range is possible to identify illegal access suppose if the user is placing an order from some other location , then the website should give the authentication code to user and then the user should contact the bank to process the order banking websites should maintain credit card ip’s when it was first used payment gateways should be built with open source coding like python so that the untrusted and encrypted ip’s can be verified..

These security loopholes can be plugged by various security mechanisms. basic algorithm : H.

Encryption of user records: if user enter’s the website and processed for checkout and entering his card information then website payment gateway should verify trusted connection to find illegal ip access if yes then website should check credit card first accessed ip location dynamic range of ip address can be possible and it should match the location of the user who is been placing the order ( basic authentication)

The e-commerce websites which store customer data and financial records must encrypt all data in their database to prevent unauthorized use of these sensitive data. Several free and strong open source encryption tools are easily available. Encrypted data is hard to decrypt without proper authentication key and would require huge computing resources. This technique would render the data unusable even after it is retrieved in an unauthorized way.

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;\\ if the credit card is from new york , the user ip should be near by to its state location”// else transaction should declined if the user is placing the order from some other country with his own card then authentication code from shopping website to the bank is supplied

●

new solution : ● ● ● ●

finding high encrypted vpn or scoks5:

●

def ipEntered(): global ipEntered ipEntered = input (“ please enter the ip’”):

● ●

“””” get the ip address from the user who is been ordering in the website”””””” if ipEntered .match (dynamic.socketsauth()) access”# then print “ failed”

existing system using just normal php code to accept the card details after accepting , the payment would be fulfilled

● ●

#“ illegal ip

● ●

else ● ip.sucess if ● ipEntered.match a = s.split(‘) match.credit card details return True

every payment gateways should be tested , all anonymous proxy’s should be verified all ip’s should be back listed to avoid illegal access all banking websites should maintain the database , the database should contain dynamic matching of ip address of the credit card when it was first accessed if the user placing an order from different location then website should provide authentication code to process the order tor browser anonymity should be cleared mostly all user’s use credit card’s from own location then this method would be very useful authentication code for different location user’s should be automated python should be integrated with database for easy access trusted and secured ssl should be used to avoid man in the middle attack all websites payment’s and ip address of the order should be verified with database records of the bank even if the hacker uses high encrypted vpn the exact location will not acquired , if it also matches then the ip authentication with bank database can find this illegal access verifying the ip range with bank database and then websites orders would be fulfilled

else payment.failed its not a brief coding , its a basic authentication for the payments gateways , if the websites fix some open source coding to verify untrusted connection and also to match ip ..illegal access can be reduced

comparing with existing payment gateways : ●

●

existing system mainly use php or asp to create payment gateways , mainly php websites are vulnerable to cross site scripting attack and also the server reply is not fully secured existing system doesn’t have good verification method to find illegal ip’s

conclusion : thus if we maintain good encrypted records and good payment gateway with trusted ssl connection then the illegal access will be stopped

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REFERENCES

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 

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S. Ghosh and D.L. Reilly, “Credit Card Fraud Detection with a Neural-Network,” Proc. 27th Hawaii Int’l Conf. System Sciences: Information Systems: Decision Support and Knowledge-Based Systems,vol. 3, pp. 621-630, 1994. M. Syeda, Y.Q. Zhang, and Y. Pan, “Parallel Granular Networks for Fast Credit Card Fraud Detection,” Proc. IEEE Int’l Conf. Fuzzy Systems, pp. 572-577, 2002. Organism Information Visualization Technology Editing Committee Edition: Organism Information Visualization Technology. (in Japanese), Corona Publication Co., Ltd., p.235 (1997). The Federation of Bankers Associations of Japan: Statistics from the Questionnaire on the Number of Withdrawals and the Amount of Money Withdrawn Using Stolen Passbooks. http://www.zenginkyo.or.jp/en/news/index.html “Palm Vein Authentication Technology” white paper, Bioguard, Innovative Biometric Solutions, March, 2007. Yuhang Ding, Dayan Zhuang and Kejun Wang, “A Study of Hand Vein Recognition Method”, The IEEE International Conference on Mechatronics & Automation Niagara Falls, Canada, July 2005. Shi Zhao, Yiding Wang and Yunhong Wang, “Extracting Hand Vein Patterns from Low-Quality Images: A New Biometric Technique Using Low-Cost Devices”, Fourth International Conference on Image and Graphics, 2007.

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IMPLEMENTATION OF AHO CORASICK ALGORITHM IN INTRUSION DETECTION SYSTEM USING TCAM FOR MULTIPLE PATTERN MATCHING Y.Madhu Keerthana1, S.Vamsee Krishna2 1

P.G Student in VLSI, Department of E.C.E, SIETK, Tirupati. Associate Professor, Department of E.C.E, SIETK, Tirupati. E-Mail to:madhu.keerthu@gmail.com, vamseebe@gmail.com

Abstract— The various advantages provided by the internet and society’s increasing dependence on it has bought a flood of security attacks. The defense against all these attacks is provided by the network intrusion detection/prevention systems which monitor headers and payload of packets flowing through the network. NIDS performs matching of attack string patterns by means of multi pattern matching which is solved by means of Aho-Corasick algorithm. The Aho–Corasick is one of the string matching algorithms which perform exact matching of the patterns in the text. The performance goals and throughput of high speed networks are improper to meet through software. Therefore, making a network-based scheme in practical requires efficient algorithms suitable for hardware implementations which can be updated continuously and so Ternary Content Addressable Memory (TCAM) and FPGA based architectures, which are programmable or reconfigured are generally adopted in hardware based pattern matching. Index Terms—Intrusion detection system, Aho-Corasick algorithm, String matching, multipattern matching, TCAM

I. INTRODUCTION In almost every information recovery and text applications it is essential to locate quickly some or all occurrences of user defined patterns in text. String matching problem is to locate all the occurrences of a given string pattern in a string text. This string matching can be performed through single pattern and multi pattern occurrences. For many string matching problems multi pattern is the only solution provided. Thanks for Alfred V. Aho and Margaret J. Corasick who invented one of the best string matching algorithms named Aho-Corasick algorithm.The multi patterns matching in a text string can be easily found by means of this algorithm as it is the only one which performs exact matching of patterns in a given text. Just like a dictionary matching algorithm it also starts searching pattern from basis of sub-string matching. For every unit of time, a character is read from the pattern string and then it tries to find same character in the automata that is already constructed, after reading the whole pattern string if the automata is found to be entered in the final state then that pattern occurrence will be submitted. Similarly for all patterns it matches simultaneously. Intrusion detection systems at multi-gigabit rates are achieved using hardware acceleration; one prospect is the usage of Ternary Content Addressable Memories (TCAM). Ternary Content Addressable Memory (TCAM) is a type of memory that can execute parallel searches at high speeds. A TCAM contains a

set of entries. The top entry of the TCAM has the least index and the bottom entry has the biggest. Each entry is a bit vector of cells, where each cell can store one bit. As a result, a TCAM entry can be used to store up a string. The working of TCAM is as follows: for a certain input string, it compares against all entries in its memory in parallel, and reports the one which match the input. II. AHO CORASICK ALGORITHM Aho-Corasick is the Multi-pattern matching algorithm which traces all the occurrence of set of patterns in a string. It is done by creating Deterministic Finite Automata (DFA) for all the predefined patterns; along with it using automaton, which process a text in a single pass. Example: Let us consider a finite set of patterns, {OTHER, HER, HATE, HEIGHT} Preprocessing Phase Step 1: Construct finite state automata for the set of Predefined patterns which is supposed to be originate in the text string. The states will be numbered by their names and transitions are represented by the characters between the defined states would be accessible in the particular pattern As a first step, Aho-Corasick algorithm constructs finite automata for the set of patterns O T H E R 0

H E

A T

E 11

H E 12

I 13

G 14

H 16

T 17

Fig.1.Automata for pre-defined patterns Step 2: After constructing automata, failure function of each node is calculated and its corresponding transitions are also required to be mentioned, so the constructed automata would be called as "Automata with failure links". This is highlighted in fig.3. Fig.2. represents transition tables of finite automata

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INPUT STATE O 1 ------------------

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

T -2 -------10 ------17 --

H --3 -------11 ----16 ---

E ---4 --------13 ------

R ----5 --8 -----------

A ------7 ------------

I -------------14 -----

G --------------15 ----

Fig.2. Transition table of finite automata Step 3: Lastly in the automata output function for final states has to be calculated for recognizing the pattern string which may be found in the text string. And the resulting automata would be called as “Automata with Output Functions” O 0

E 3

R 4

H E 6

R 8

A T

E 11

H E 12

I 13

G 14

H 16

T 17

Fig.3. Failure functions of automata FAILURE FUNCTION: Failure function is defined as the longest suffix of the string that is also the prefix of some other node. The main goal is not to scan any character more than once. The red colored arrow marks in fig.3 represents failure transitions. OUTPUT FUNCTION: The set of patterns recognized when entering in to final state is the output function of that automata. Node 5, 8, 11, 17 represents output functions in fig.3.

APPLICATIONS: This algorithm can be in practical used to solve various problems like detecting plagiarism intrusion detection, text mining, bioinformatics, and digital forensic etc. Intrusion Detection is a method in which intrusions are detected by Intrusion Detection System (IDS).The process of finding plagiarism inside a Text or document is known as Plagiarism Detection. The application of computer technology for managing biological information is Bioinformatics. Digital Forensic is a technique to retrieve information from digital devices after being processed along with generating outcome. Text Data or Text mining is developed with the intention of attending attempts to find out patterns in great data sets. INTRUSION DETECTION SYSTEM: With each passing day there is added critical data available in some form over the network. All publicly reachable system on the Internet today is quickly subjected to break-in attempts. These attacks are able to range from email viruses, to corporate intelligence, to general damage of data, to attacks that hijack servers from which to spread added attacks Intrusion Detection Systems (or IDSs) are emerging as one of the most promising ways of providing protection to systems on the network. Compared with end-host based solutions, NIDS will respond and can be rationalized at faster rates. The time they could save is much significant for prevention, particularly when the network is under the attacks from new worms. The traditional software-based NIDS structural design failed to compete with the throughput of high-speed networks because of the large number of patterns and complete payload scrutiny of packets. This led to hardware-based schemes for multi pattern matching. To organize intrusion detection systems at multi-gigabit rates by means of hardware acceleration, one option is to use Ternary Content Addressable Memories (TCAM). TCAMs are extensively used for IP header based processing such as longest prefix match. Because of their built-in parallel search capability, TCAM’s can also be used efficiently for the pattern matching functions desirable in intrusion detection systems. III.TCAM The traditional approaches to facilitate security and high speed packet forward in the Internet are in general complex and costly. For instance, network-based intrusion detection is usually implemented by means of dedicated chips or separate boxes, rather than standard components, adding up complexity and integration costs. Also, packet classification has been recognized as the most critical data path function, creating potential bottlenecks for high speed packet forwarding. To eliminate these potential bottlenecks, a variety of algorithmic and hardware approaches have been developed, attempting to meet the targeted performance for different single packet classification tasks A promising approach is to use TCAM for packet classification and intrusion detection. A TCAM-based solution usually applies to different packet classification tasks, and allows parallel rule matching against all the rules in a rule table, offering the highest possible packet classification performance. As a result, TCAM coprocessors are extensively used in industry to perform multiple packet classification tasks classically seen in an Internet router.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 Ternary content addressable Memories (TCAMs) are increasingly used for high-speed packet classification. TCAMs compare packet headers against all rules in a classification database in parallel and thus provide high throughput unparalleled by software-based solutions. TCAM based architecture which are a programmable or reconfigurable, are commonly adopted for a hardware-based pattern matching.

An automata is made-up of systems and transitions that can be classified as Deterministic Finite Automata (DFA) and Nondeterministic Finite Automata (NFA) DERETERMINISTIC FINTIE AUTOMATON (DFA): The AC algorithm first constructs a deterministic finite state machine from the set of patterns and then uses the finite state machine to process the text string in a single pass by constructing the goto and cross transitions. In the DFA, the dotted lines represent transitions, called by cross transitions, which are newly added by eliminating failure transitions. Shaded states represent the pattern matching states called output states. The trivial transition going to the early state is omitted.

Fig.5.TCAM based architecture Content-addressable memory (CAM) is a special type of computer memory used in certain very high speed searching applications.Binary CAM is the simplest type of CAM which uses data search words consisting entirely of 1s and 0s. Ternary CAM (TCAM) allows a third matching state of "X" or "Don't Care" for one or more bits in the stored data word, thus adding flexibility to the search. For example, a ternary CAM might have a stored word of "10XX0" which will match any of the four searches words "10000", "10010", "10100", or"10110". The architecture consists of a TCAM, SRAM, and logic. Each TCAM entry represents a lookup key, which consists of current state and input. It consists of corresponding data, which is the next state, in the SRAM whose address is given by the TCAM output. Two registers current state and the input are initialized to the state 0 and the start data of the input buffer respectively. If there is a matching entry for the state and input value in the TCAM, the TCAM outputs the index of the matching entry and then the SRAM outputs the next data located in the corresponding location. Because a TCAM has “don’t care” bits, multiple entries can be simultaneously matched. If there is no such match in the TCAM, the next state is the initial state Because a TCAM has “don’t care” bits, multiple entries can be matched simultaneously. The next state is the initial state when there is no match in the TCAM. In the AC DFA the number of transitions increases rapidly as the number of patterns increases so that the TCAM-based implementation is impossible when there are a large number of patterns. IV.AUTOMATA THEORY The theory of computation is the branch of computer science that deals with the problems that are solved by means of algorithms. One of its branches is the automata theory that explains the study of abstract mathematical methods or else systems that can be used to resolve computational problems.

Fig.6.DFA for {he, she, his, hers} One starts from the initial state (usually 0) to match a string If a goto transition or a cross transition is matched with an input in the current state, the current state is moved all along the matched transition. Otherwise, the current state goes back to the initial state and the matching procedure repeats for the next input. In matching a text string of length n, the DFA makes n state transitions. If the pattern is not matched then the current state goes back to the initial state and process repeats. It examines each input only once and so it requires a huge amount of memory in a RAM based implementation that keeps a table of pointers to next states for every input.The AC DFA can be implemented with added efficiency using a TCAM since it needs only nontrivial transitions. NFA (NONDETERMINISTIC FINITE AUTOMATON): ACDFA has more transit ions than the corresponding NFA. In the NFA, the solid lines and dotted lines represent goto and failure transitions, respectively. For an NFA-based matching, the current state is moved along its failure transition and the matching process repeats for the current input. The DFA examines each input only once while the NFA may examine each input several times along the failure transition path. In matching a text string of length n, the NFA makes fewer than 2n state transitions In the NFA, the solid lines are represented by go to and dotted lines by failure transitions. In the DFA, there is cross transitions is representing the dotted lines, they are newly added by eliminating failure transitions. Output states are represented by shaded states. The multi pattern matching can be performed by using either the NFA or the DFA. To match a string, the initial state is usually taken as 0. With an input in the current state, if a goto transition or a cross transition is matched, the current state is moved along the matched transition.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 Step 1- Construction of a Failure Tree The graph consisting of only failure transitions is known as .

Fig.7.DFA for {by, byte, boy, eye} In a DFA-based matching, the current state goes back to the initial state and the matching process repeats for the next input. In a NFA-based matching, the current state is moved along its failure transition and the matching process repeats for the current input. The DFA will examine each input only once while the NFA along the failure transition path may examine each input several times. The DFA makes n state transitions and the NFA makes fewer than 2n state transitions for matching a text string of length n. V. COVERED STATE ENCODING SCHEME 5.1. Basic Idea Since the AC NFA has a smaller number of transitions than the AC DFA, the NFA can be implemented with smaller TCAM entries than DFA. The number of TCAM entries in the NFA-based implementation is the sum of the number of goto transitions and the number of nontrivial failure transitions in the NFA. In NFA design, 1-bit field ‘F’ indicating a failure transition is further added in each SRAM entry. If an entry is connected with a failure transition, then F=1 and its input field is “_”, which means that it can match with any input value. Fig. 9 shows TCAM/SRAM entries for AC NFA in Fig.7. If the matched transition is a failure transition, or F = 1, an input is not advanced and current input is used once more for next matching. One character may be frequently processed along the states in the failure transition path until a non failure transition is matched (F = 0) or a state goes back to the initial state, which is a key drawback of the NFA-based structural design. The failure transition graph is a graph consisting of only Failure transitions in the AC NFA. 5.2. Covered State Encoding Algorithm In a FSM design to identify the state of the machine, each state is represented by a binary code. These codes are the possible values of the state register. The procedure for assigning the binary codes to each state is known as state encoding. The choice of encoding plays a key role in the FSM design which depends on the form of technology used like FPGA, CPLD ASIC, etc. and also the design specifications. It influences the complexity, size, power consumption, speed of the design. If the encoding is such that the transitions of state register are minimized then the power will be saved. The timing of the device is often affected by the choice of encoding. An algorithm is proposed for performing the covered State encoding for the AC NFA. The proposed algorithm consists of four stages as follows Step 1 Construct a failure tree. Step 2 Determine the size of a cove Code of each state. Step 3.Assign a unique code and a cover codes to all states. Step 4 Build the TCAM entries.

Fig. 8. Failure tree and covered state encoding. Unnecessary failure transitions can be avoided. Primarily, a failure tree is constructed by reversing failure transitions in the failure transition graph so that each state s can easily find PRED(s). The initial state becomes a root of the failure tree and the set of all descendants of a state s in the failure tree is PRED(s). Step 2-Determining the Size of a Cover Code The numeral of “_” bits within a cover code is called its dimension and the numeral of unique codes enclosed in a cover code is called its size. The size and dimension of the cover code of a state s can be represented as size(s) and dim(s) respectively. Size(s) is 2dim(s). In a failure tree if a state s has no child, dim(s) = 0 as c_code(s) need not cover any other code, in addition to that its cover code is same as its unique code. If in any case a state s has children in a failure tree, c_code(s) ought to cover not only u_code(s) but also c_code(s) for all its children c. The dimensions of each and every state are determined

CS 6 4 3 2 1 1 0 0 9 7 5 4

IN E y E y T y o b E * * * *

NS 9 7 5 4 8 2 6 1 3 3 3 2 1

F 0 0 0 0 0 0 0 0 0 1 1 1 1

CS 8 6 4 3,7,9 2,5 1,4 1,4 All states All states

IN E Y E Y T Y O B E

NS 9 7 5 4 8 2 6 1 3

Fig. 9. TCAM/SRAM entries in NFA architecture recursively during the computation of dim (0), where ‘0’ indicates the initial state Step 3-Assigning State Codes For a state ‘s’, the unique code u_code(s) can make use of a code covered by c_code(s) and in this case a code is used which is obtained by replacing *with 0 in c _code(s) as u_code(s). The codes are recursively assigned. Initially, the code of the root 0 is assigned as follows: C_code(0)=**…….…* and u_code(0)=00……….0.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 The codes of the children are assigned in declining order with respect to dimension for a state‘s’ in order to assign codes efficiently. procedure AssignCode(node s, int base) // assign codes to this node s U_code(s)=base // unique code C_code(s)= covercode(base,dim(s)) // cover code if s has no child then return sort the children of node s in decreasing dimension order dim(s) cbase=base+ 2 // assign codes to children recursively for each child node c of node s do dim(c) cbase =cbase _ 2 AssignCode(c, cbase) endfor end Fig. 8 shows the failure tree for AC NFA in Fig. 7. In example shown in fig.8, the dimension of a root is 4 and it has five children whose dimensions are 2, 1, 1, 0, and 0, respectively. The cover codes of the children are assigned 11**, 101*, 100*,0111, and 0110. Their unique codes are 1100, 1010, 1000, 0111, and 0110 which are obtained by replacing * with 0.The codes of children is allocated with the fixed bit values (0 or 1) which is based on the cover code of their parent and new values are assigned only in “don’t care” bit locations. Step 4- Building TCAM Entries Any child entry in a failure tree should be located more front than its parent entry in TCAM. To build TCAM/SRAM entries the procedure BuildTCAM is used. Current Input Next state state 11**(3) Y 1011(4) 1011(4) E 1001(5) 101*(1) Y 1000(2) 101*(1) O 0111(6) 100*(2) T 0110(8) 0111(6) Y 1111(7) 0110(8) E 1110(9) ****(0) B 1010(1) ****(0) E 1100(3) Fig. 10. TCAM/SRAM entries using cover state encoding. procedure BuildTCAM(node s) // insert entries of children recursively for each child node c of node s do BuildTCAM(c) // insert the entry of this node s for each goto transition gðs; iÞ of node s do next =g(s,i) insert (c)_code[s], i) into TCAM insert (u_code[next]) into SRAM endfor end The procedure BuildTCAM inserts children in the failure tree first into TCAM by Calling BuildTCAM(0) which constructs all the TCAM/SRAM entries recursively

VI.MULTICHARACTERS PROCESSING USING COVERED STATE ENCODING The covered state encoding scheme for efficient TCAM-based implementation is proposed in this section. However, Aho-Corasick algorithm processes only one character at a time and multi character processing is required to achieve high-speed matching. In this section, a finite state Machine is proposed called k-AC NFA which has state transitions on k input characters by combining k consecutive goto transitions of the Aho-Corasick NFA. Since k-AC NFA consists of goto transitions and failure transitions like the AC NFA, the covered state encoding scheme can be used in the TCAM based implementation of the k-AC NFA. The major advantage of the k-AC NFA is that the state transition consumes exactly k input characters while in the compressed DFA, the state transition is done on variable length (between 1 and k) of characters. 6.1 Construction of k-AC NFA When k input characters are processed at a time, the patterns can be started at one of k possible offsets of the input characters. In order to detect the patterns starting at any of k offsets, we construct k finite state machines each of which corresponds to one of k offsets. For example, we consider the set of patterns {abc, xyapq, pqrxyz}. Fig. 11a shows the AC NFA for these patterns. We construct the 4-AC NFA by creating four state machines each of which can detect the patterns starting at one of four –offsets, as shown in Fig. 11b. In Fig. 11, the states with the same label are the same state and the gray colored states are output states.

Fig.11.Construction of k-ACNFA, k=4(a) ACNFA (b) k-ACNFA In Fig. 11b, the dotted lines represent the failure transitions. The failure function of the k-AC NFA is the same as that of the AC NFA.

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Fig.12.TCAM entries in k-ACNFA 6.2 Implementation of k-AC NFA The k-AC NFA can be implemented in the TCAM-based architecture using the covered state encoding. In the k-AC NFA, start transitions from the initial state may be done on inputs with leading *s (e.g., ** pq) and output transitions may be done on inputs with trailing *s (e.g., bc **). Both transitions may be simultaneously matched with k input characters (e.g., bcpq) and we cannot determine the priority between two transitions since they have no inclusion relationship.In order to solve this problem, we use two TCAMs called a transition TCAM and an output TCAM, which can simultaneously generate the matched entries. The output transitions are stored in the output TCAM. The output TCAM detects the final pattern matching and the transition TCAM controls the state transition in the k-AC NFA. If two TCAMs generate the matching results simultaneously, the state is moved according to the result of the transition TCAM and the output is generated by the output TCAM. The simulated response for multi pattern matching algorithm for given example is as shown:

VII.RESULTS AND CONCLUSION: The results for existing and proposed methods are displayed in figures shown below. The existence of failure transitions is added in each SRAM entry in NFA-based architecture. A 1-bit field F is used for indicating a failure transition. If an entry is associated with a failure transition, its F is 1 and its input field is “*” which can match with any input value. A covered state encoding scheme for the TCAM-based implementation of Aho-Corasick algorithm is proposed in this paper which is extensively used in network intrusion detection systems. The covered state encoding takes the benefit of “don’t care” feature of TCAMs and information of failure transitions is implicitly captured in the covered state encoding. By using covered state encoding, the failure transitions are not implemented as TCAM entries because all the states in the failure transition path can be examined simultaneously. The covered state encoding requires the smaller number of TCAM entries than NFA-based implementation. The covered state encoding thus

enables an efficient TCAM-based implementation of a multipattern matching algorithm. The scheme for constructing the finite state machine called k-AC NFA for multi character processing, which uses a covered state encoding is also proposed. The k-AC NFA using the covered state encoding has the smaller TCAM memory requirement and can process exact k characters at a time. Thus, a covered state encoding can be efficiently used in multi character processing.

Fig.13.Simulated outputs for existing version

Fig.14.Simulated outputs for proposed version REFERENCES [1] IEEE TRANSACTIONS ON COMPUTERS, VOL. 61, NO. 2, FEBRUARY 2012 An Efficient TCAM-Based Implementation of Multipattern Matching Using Covered State Encoding by SangKyun Yun, Member, IEEE Computer Society [2] (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 4 (3) , 2013, 467-469 Importance of Aho-Corasick String Matching Algorithm in Real World Applications by Saima Hasib, Mahak Motwani, Amit Saxena at Truba Institute of Engineering and Information Technology, Bhopal (M.P), India [3]M. Alicherry, M. Muthuprasanna, and V. Kumar, “High Speed Pattern Matching for Network IDS/IPS,” Proc. 14th IEEE Int’l Conf. Network Protocols (ICNP), vol. 11, pp. 187-196, 2006. [4] M. Gao, K. Zhang, and J. Lu, “Efficient Packet Matching for Gigabit Network Intrusion Detection Using TCAMs,” Proc. 20th Int’l Conf. Advanced Information Networking and Applications (AINA), 2006. [5] F. Yu, R. Katz, and T. Lakshman, “Gigabit Rate Packet Pattern- Matching Using TCAM,” Proc. 12th IEEE Int’l Conf. Network Protocols (ICNP ’04), [6] Y. Weinsberg, S. Tzur-David, D. Dolev, and T. Anker, “High Performance String Matching Algorithm for a Network Intrusion Prevention System (NIPS),” Proc. IEEE High Performance Switching and Routing (HPSR), pp. 147-154, 2006.

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Advanced Recycled Paper Cellulose Aerogel Synthesis and Water Absorption Properties A.Azhagesan, T.Thiyagarajaperumal, M.Kumarasamy College Of Engineering, Karur , Tamilnadu , India . Email Id: azhagu0003@gmail.com . Contact No: 8438280052

Keywords:

group converts the recycled cellulose to cellulose aerogel. Aerogel is porous material with more than 90 percents pores in the volume. Most aerogel are silica or carbon aerogel. Cellulose aerogel is a new material.

Recycled Cellulose Aerogel, & Water Absorption

Abstract: By applying sodium hydroxide/urea and a sample freeze drying method, we successfully synthesized green cellulose aerogel from paper waste for the first time. We adjusted the cellulose concentration from 1.5 percents to 4 percents in the initial hydrogel. They yielded densities changing from 0.03-0.1 g/cm3.The absorption capacities varied from 9 to 20 times of their own weight. To investigate the water absorption capacity in relationship with the initial chemical dosage, we changed the input amount of urea and sodium hydroxide, which is the first study ever. The thermal conductivity of the 2 percents sample ranged from 0.029-0.032 W/mK. Besides, the material has a high potential to be used in diaper industry as it is biodegradable which is better than most super absorbent polymers.

Synthesis Procedure: For standard sample, urea (13.7 wt%, 5.025g) and sodium hydroxide (1.9 wt%, 0.725g) were dispersed in DI water (30g), which is dispersed by a magnetic stir. Recycled cellulose (2 wt%, 0.75g) was added to the transparent solution, pre-cooled in ice/water bath for 10 minutes, then sonication for 10 minutes. Thereafter, the solution was placed in refrigerator for more than 24 hr to allow gelation of the solution. After the solution was frozen, it was then thawed at room temperature and then followed by immersing into ethanol (99 vol %) for coagulation for two days. After coagulation, solvent exchange was carried out by immersing the gel in de-ionised (DI) water for 2 days. The sample was then frozen in a freezer at â&#x20AC;&#x201C; 18 for 24 h. After that, freeze drying is carried out for 2 days with a Scan Vac Cool Safe 95-15 Pro freeze dryer (Denmark) to obtain the desired aerogel. Other samples were prepared by the same method by varying one component of the standard sample. Detail refers to the Table 1

Introduction: Most diapers in market are composed of super absorbent polymers, which are not biodegradable. Averagely a baby needs more than 5,000 diapers before it is potty-trained . Adult diapers are also requested in large amount every day. Huge amount of diapers is consumed daily in this world. Nowadays, as super absorbent polymer is not biodegradable. The used diapers waste large amount of land to store them. Our paper gives a potential alternative of traditional diapers-Cellulose aerogel, which with high absorbent capacity (almost 20 times) and also biodegradable can be used to replace the non-biodegradable super absorbent polymer. Cellulose aerogel can be derived from paper. Only United States alone used 85.5 million tons of paper per year . This huge amount of used paper needs to be recycled and functions as useful material to prevent waste. Our

TABLE1: PARAMETER USED IN MORPHOLOGY CONTROL OF CELLULOSE AEROGEL

Group 1

Cellulose amount

G1_015

0.5444[g]

Standard

0.75[g]

G1_03

1.1057[g]

G1_04

1.4896[g]

Group 2

urea amount

G2_10

3.4972[g]

10%

standard

5.025[g]

13.76%

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Cellulose concentration 1.50%

Urea concentration

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TABLE 2: CELLULOSE CONCENTRATION AFFECTS WATER UPTAKE RATIO AND POROSITY

Characterization: Thermal conductivity measurement:

Sample No

C-Therm TCi Thermal Conductivity Analyzer (C Therm Technologies, Canada) was used to measure the thermal conductivity of the aerogel.

Water absorption test: This test was carried out in DI water, followed by modified ASTM D570-98 standard, refer to Figure

Wet Weight [g] 8.3431

Water uptake Ratio 20.24

Water uptake Ratio 0.984

Density [g/cm3]

G1_015

Dry Weight [g] 0.3928

Standard

0.7280

17.43

0.978

0.04

G1_03

0.8976

12.80

0.970

0.05

G1_04

2.4507

13.414 0 12.388 5 24.463 4

8.98

0.935

0.10

0.03

Cellulose concentration varies from 1.5% to 4%, while the water uptake ratio drops from 20 to 9. Their relationship is quite linear. By increasing cellulose content in one sample, the density of the solution is also increased, but the structure of the aero gel is more compacted. Hence, the porosity is decreased (see Table 2), resulting in less space for water molecular being taken in. As the result, Water uptake ratio linear decrease with an increase cellulose concentration. TABLE 3 UREA AMOUNT AFFECTS WATER UPTAKE RATIO AND POROSITY

Sample No

Wet Weight [g] 14.1073

Water uptake Ratio 20.02

Porosity

G2_10

Dry Weight [g] 0.6712

Standard

0.7280

13.4140

17.43

0.978

G2_15

0.7532

14.5129

18.27

0.975

G2_20

0.6985

13.1829

17.87

0.978

Urea forms urea hydrate in the solution. Urea hydrate helps prevent cellulose molecule come near to each other. Hence, urea restrains the formation of hydrogen bond among cellulose. The experiment results about water up take ratio are without much difference in this group. It may be caused by the urea amount that plays an insignificant role about porosity. However, the porosity is not as the same as the water up take ratio results suggest, referring to Table 3. It is may be due to measure errors, as the porosity is calculated by weight divided by

Results and Discussion: The thermal conductivity of the standard sample was 0.03 Wm-1K-1. It is comparable to silica aero gels (0.026 Wm-1K-1) and wool (0.03-0.04 Wm-1K-1)

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volume. Volume is derived from diameter and height of the cellulose samples, and then determined by cylinder volume calculation formula. The diameter is determined by the average of three readings. Errors may be generated in the process, as the sample is not exactly cylindrical shape. However, we could see all the data are the same in the first two digits regards to porosity. Part of sodium hydroxide can be bound to cellulose, which improves the dissolve of cellulose. More sodium hydroxide causes less hydrogen bonding among cellulose, which leads to less porosity and thus less water uptake ratio, referring to Table 4. However, when sodium hydroxide changes from 2.5 percents to 3 percents, the water uptake ratio does not drop further. It is due to 2.5 percents of sodium hydroxide is the maximum amount needed to bound with cellulose. More sodium hydroxide will not further the reaction.

Summary: Our group successfully synthesized recycled cellulose aerogel from paper waste. The newly developed material is with high absorption capacity. Sodium hydroxide amount and cellulose concentration alter the water uptake ratio of cellulose aerogel greatly, while urea amount do not play a significant role in the water uptake ratio.

References : 1. Informationon http://www.enfamil.com/app/iwp/enf10/content.do ?dm=enf&id=/Consumer_Home3/Prenatal 3/Prenatal_Articles/changingdiaper&iwpst=B2C&l s=0&csred=1&r=3557620074

TABLE 4 SODIUM HYDROXIDE AMOUNT AFFECTS WATER UPTAKE RATIO AND POROSITY

Sample No

Dry Weight [g]

Wet Weight [g]

Water uptake Ratio

Porosity

G3_015

0.5925

11.9001 19.08

0.983

standard 0.7280

13.4140 17.43

0.978

G3_025

0.7639

12.6251 15.53

0.974

G3_03

0.7066

11.3263 15.03

0.976

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Near Field Communication Tag Design with AES Algorithm 1

Ashwin S, 2Priyatam Ch

UG Students, Dept of ECE, SRM University, Kattankulathur, Tamilnadu, India 1

ashwinksk@yahoo.com, kakarotgokuvegeta@gmail.com

Abstract: This paper presents the design of Near-Field Communication (NFC) tags architecture and implementation with high security supported by AES algorithm. NFC standards include data exchange within a close proximity range and data transmission protocols. Because of the recent applications and advancement of Near Field Communication security has to be provided with reduced complexity. To achieve this, an AES algorithm of 128-bit based Near Field Communication Cryptographic Tag architecture controlled by 8 bit microcontroller has been designed in our work. Recent applications RFID tags are controlled by finite state machines embedded in their hardware. But with the support of additional functionality like security, their design complexity increases. Cryptography technique controlled by microcontroller reduces this design complexity, because AES algorithms hardware requirement is very less rather than other Asymmetric cryptographic techniques. This Cryptography technique has been successfully synthesized and implemented using Xilinx ISE DS 13.2.2.using VHDL source code. Keywords-AESAlgorithm, 8BitMicrocontroller, Cryptography, Finite state machines, NFC, RFID.

I INTRODUCTION NFC stands for Near Field Communication. NFC specificationscan be found in ISO 18092.The main characteristic of NFC is that it is a wireless communication interface with a working distance limited to about 10 cm. The interface operates in different modes. The modes are distinguished whether a device creates its own RF field or whether a device retrieves the power from the RF field generated by another device. Radio-frequency identification (RFID) technology is the enabler for a variety of new applications. Many of these new applications will require RFID tags to support additional functionality, which increases their design complexity. Especially security functionality will play an important role. In order to cope with this increased complexity of the tags, new design concepts such as programmable approaches are necessary. Cryptography is the science of information and communication security that enables the confidentiality through an insecure channel communication. It prevents unauthorized alteration of use. It uses a cryptographic system to transform a plaintext into a cipher text, using most of the time a key. There exists certain cipher that doesn't need a key at all. The AES is the winner of the contest, held in 1997 by the US Government, after the data encryption standard was found too weak because of its small key size

and the technological advancements in processor power. It takes an input block of a certain size, usually 128, and produces corresponding output block of the same size. The transformation requires a secret key the second input. Cryptography development has been a major concern in the fields of mathematics, computer science and engineering. One of the main classes in cryptography today is the symmetric key cryptography, where a same key will be used for the encryption and decryption processes. Our work relates to the field of secure tag design [1], which are: 1) First low-resource RFID tag that supports symmetric cryptography, 2) First low-area implementation of AES, 3) Flexible tag design based on a microcontroller for protocol handling and steering of the cryptographic module. The remainder of this work is organized as follows. Section II provides a brief description of the deployed lowresource 8-bit microcontroller. In Section III the analyzed architecture of NFC tags Digital part is introduced in short. The AES algorithm and its processing architecture are presented in Section IV. The implementation of AES algorithm supported by 8 bit microcontroller and the analyzed area requirement output is shown in Section V, followed by conclusions in Section 6. II DESCRIPTION OF THE LOW RESOURCE 8 BIT MICROCONTROLLERS The 8-bit microcontroller [2] performs the entire controlling tasks with focus on low chip area and low power consumption. The microcontroller bases on a Harvard architecture with separate program and data memory. The program memory ROM is implemented as lookup table in hardware and is divided into several pages. Each page can hold up to 256 16-bit instruction words. A maximum of 256 pages is supported. Data memory is realized as register with up to 64 8-bit registers. The register consists of three specialpurpose (SP) registers, input-output (I/O) registers, and general-purpose (GP) registers. SP registers are used for indicating status information of the arithmetic-logic unit (ALU), the paging mechanism of the program ROM, and a dedicated accumulator (ACC) register. I/O registers allow interfacing of external modules. GP registers are used for computing and temporarily storing data. The instruction set of the microcontroller involves 36 instructions, which are

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 divided into arithmetic operations, logical operations and control operation. Most of the operations are executed within a single clock cycle. A. Hardware and Software Functionality The control complexity increases with integrating security and data management [1] features to a tag. Data has to be shifted from one component to another component. Commands that are breakup into number of blocks need to be rebuilt. Tag architecture with microcontroller can manage such a surged control complexity than a conventional state machine .Using a microcontroller; have to fulfill the requirements in terms of chip area and power consumption. Only a very simple microcontroller can be deployed for small chip size and clocked with the lowest possible clock frequency for low power consumption. Basic tag functionality is directly handled by framing logical hardware circuit. Since controlling complexity of basic tag functionality is low, implementation in hardware is achievable [1].Advanced tag functionality, leads to high control complexity.

processed within the CU that is accessed by the microcontroller via micro-code patterns. RAM stores temporary results. EEPROM for permanently storing data in files i.e. certified secret key, and memory for storing constants (ROM) are located in the memory unit. A. Framing Logic The FL[1] is an interface that converts serial data into parallel data and also handles the basic tag functionality .Contains the following components, Receive-and-transmit (RxTx) unit, Control unit, and AMBA interface.

III OVERVIEW OF THE NFC TAG ARCHITECTURE DIGITAL PART This presents the design and implementation Cryptographic protected tags for new RFID application operates at 13.56 MHZ and works passively. We target a low-area design that requires as little resources as possible such that the tag production does not exceed the practical limits of a possible commercial launch. The input data is directly feed to the NFC tag through framing logic. The area can be reduced by reusing a common 8-b microcontroller. The tag architecture consists of: a low resource 8 bit microcontroller [2], a framing logic (FL), a crypto unit (CU), and a memory unit. The microcontroller acts as the central element that controls all operations on the tag. The microcontrollers program is stored in an internal ROM and communicates via an AMBA bus with the crypto unit and framing logic.

Fig 2 Framing Logic Architecture

The RxTx unit is the interface between the serial data signals of the RS232 and the parallel data signals of the control unit. Additionally, the RxTx unit is provided with an external clock signal .This provides a bit-clock signal to all components of the tagâ&#x20AC;&#x2122;s digital part. But in this analysis our attention is only towards the Digital part of the system .so, input signal (data) is given directly to the RxTx Unit. Incoming serial data from the RS232 interface is first sampled by the RxTx unit, decoded into bits, transformed to byte data. The AMBA interface places this data into a FIFO buffer stores up to 6 Bit that is accessed by the microcontroller over the AMBA bus. The outgoing data from the microcontroller is first placed in the FIFO buffer of the FL and then transmitted to the RxTx unit by the control unit. The AMBA interface connects the FL with the AMBA bus. The AMBA interface also contains a status register that provides information about the internal state of the FL i.e. about the presence of data in the FIFO bus and a configuration register. All the components can be accessed by the microcontroller via the AMBA bus. B. 8 Bit Microcontroller

Fig 1 NFC Tag Architecture Digital Part

The FL is connected to the analog front-end and provides a byte interface for the microcontroller. But in our case the digital part of the NFC tag alone is taken for consideration .so, input data is given directly to the FL through rs232 interface. Cryptographic operations are

Both memories are freely scalable i.e. their size can be adjusted during the design phase based on the requirements of the desired application. The program memory ROM is implemented as lookup table in hardware and is divided into several pages. A maximum of 256 pages is supported. Data memory is realized as register with up to

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 64 8-bit registers. There are three special purpose registers, I/O registers, and general purpose registers. SP registers give the status information of the ALU unit, ROMs paging mechanism, and an accumulator register. Interfacing with external modules is allowed by I/O registers. Thus the microcontroller controls the entire module during both data transmission and reception.

one clock cycle. Also writing into one port and reading from the other is possible IV PROCESSING ARCHITECTURE OF AES ALGORITHM

Fig 5: Architecture of AES Algorithm

Fig 3An8 Bit Microcontroller Architecture

GP registers are available for storing temporary data. Microcontrollerâ&#x20AC;&#x2122;s instruction set consists of 36 instructions, which are divided into logical operations, arithmetic operations, and control operations. Most of the operations are executed in a single clock cycle. C. Cryptographic Unit The cryptographic unit basically consists of three parts: a controller, RAM, and a data path [3]. The controller communicates with other modules on the tag to exchange data and it sequences the ten rounds of an AES encryption [6]. Therefore, it addresses the RAM accordingly and generates control signals for the data path. The RAM stores the 128-bit State and a 128-bit round key. These 256 bits are organized as 32 bytes to suit the intended 8-bit architecture.

Fig 4 Data path of AES algorithm

The memory unit is composed of three memory types that are RAM, ROM, and EEPROM which are 16-bit linear dualport memory space. A dual-port RAM showed to be advantageous since it allows reading of two words within

AES is composed of 4 main stages for both encryption and decryption process in order to produce the final cipher text. The 4 main stages in the encryption process are Sub bytes transformation, shift rows, Mix columns and AddRoundKey. Similarly the decryption process also consists of four stages which just perform the inverse operations as that of the encryption process as follows inverse Sub bytes transformation, inverse Shift Rows, inverse mix columns and AddRoundKey step is common to both encryption and decryption. Our work of NFC is based on AES128 algorithm [4]. The AES is a symmetric algorithm where the same key is used for both encryption and decryption.AES helps to transform the 128 bits block in to a new block which has the same size. At first the given input data is changed into a matrix form which is composed of 8 bit elements. After this transformation AES [5] will need to go through 4 main stages to produce the final cipher text. There is the SubByte step which involve substitution of bytes with the corresponding values from a fixed 8 bit look up table. Next stage is Shift Rows where rows of bytes are shifted an incremental one position to the left depend on which row it is i.e. row 2 will shift 1 position; row 3 will shift 2 position. First row will remain unchanged. Mix columns step every column is multiplied by a fixed polynomial. And at last, AddRoundKey step is performed where for each round of AES step, a subkey will be obtained from key schedule of AES algorithm and it will be continued for ten rounds. As shown in figure 5 Nr represents the number of rounds and finally the encrypted data is obtained. Decryption is performed in the same manner as encryption but just the inverse operations are performed as similar to the steps discussed above.

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 V IMPLEMENTATION RESULTS We have implemented our flexible tag platform in VHDL and designed it towards low resource usage and low area requirement in Xilinx ISE design suite 13.2.2. AES is a flexible algorithm for hardware implementations because it covers the entire range of applications. AES hardware implementations can be applied in embedded systems for its low resource requirements. In this process the complete data encryption and decryption is done using AES algorithm which is controlled by an 8 bit microcontroller .But in the previous systems hardware components control is done by the state machines fixed in it which required about nearly 49950 gate elements. But by using our architecture design area requirement is nearly reduced into half as shown in figures 6 and 7.

Fig 6 The Chip-Area Of The Microcontroller Unit

The above table shows the chip-area of the microcontroller unit result in terms No of flip flops, Registers and LUTs are clearly. This result shows that area requirement based on this microcontroller architecture is much less on comparison with conventional state machine approach.

Fig 7 The chip-area results AES algorithm in NFC tag architecture

The above table shows the chip-area results in terms No of flip flops. The total no of Flip flops required for implementing this AES algorithm in NFC tag architecture is also given in figure 7 as per the obtained simulation output. VI CONCLUSION AND FUTURE WORK In this paper presents a flexible NFC-tag architecture that provides enhanced security features using symmetric as well as asymmetric cryptography. As a main contribution, the work described an entire “real-world” RFID system, including all hardware components needed for a practical chip fabrication. The design shows that significant resources can be saved by applying a microcontroller-based architecture instead of using a finite-state machine-based controlling. The reason lies in the fact that the controller can be simply reused by many hardware components, such as the CU or the RFID FL that would require more area when implemented as individual hardware modules. For example, AES encryption and decryption has been realized with an area overhead of only 374 no of slice registers. In the future, We plan to further analyze the design regarding enhanced implementation attacks, and to reduce the area requirement. This can be completely realized as a micro program, which reduces further chip-area requirements while increasing flexibility and assembly-based implementation convenience. The proposed system is planned to be designed using RSA algorithm which is an asymmetric cryptography in VHDL, simulated using Xilinx software and implemented using FPGA Spartan 3e. Being an asymmetric cryptography it can resists against unexpected security attacks. But it is a very big challenge to integrate asymmetric algorithm in NFC tag design because of its huge area requirement. So, we are currently working towards the implementation of RSA algorithm in NFC tag architecture along with area and power minimization. REFERENCES [1] Thomas Plos, Michael Hutter, Martin Feldhofer, MaksimiljanStiglic, And Francesco Cavaliere,'' security-enabled near-field communication tag with flexible architecture supporting asymmetric cryptography’’ IEEE transactions on very large scale integration (vlsi) systems, vol. 21, no. 11, November 2013. [2] Hannes Gro and Thomas Plos,'' On Using Instruction-Set Extensions for Minimizing the Hardware-Implementation Costs of Symmetric-Key Algorithms on a Low-Resource Microcontroller'' Institute for Applied Information Processing and Communications (IAIK),Graz University of Technology. [3] M.Feldhofer, S.Dominikus, And J.Wolkerstorfer, “Strong Authentication For RFIDSystems Using The AES Algorithm,” in proc. ches, vol. 3156.aug. 2004, pp. [4] p. Hamalainen, T. Alho, M. Hannikainen, And T. D. Hamalainen,“Design and Implementation of low-area and low-power AES Encryption hardware core,” in proc. 9th euromicro conf. digit. syst. design, sep. 2006, pp. 577–583. [5] Ricci, M. Grisanti, I. De Munari, and P. Ciampolini, “Design of a 2 μW RFID baseband processor featuring an AES cryptographyprimitive,” in Proc. Int. Conf. Electron., Circuits Syst., Sep. 2008, pp. 376–379. [6] Shyamal Pampattiwar, ''Literature Survey on NFC, Applications and Controller'' International Journal of Scientific & Engineering Research, Volume 3, Issue 2, February-2012

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Green concrete Eco-friendly construction M.SASIDHAR

V.SUNDARKISHNAN

Dept. of Civil Enginering SMVEC Puducherry, India sasidharm007@gmail.com

Dept. of Civil Engineering SMVEC Puducherry, India sundarakishnan14@gmail.com

Abstract— This paper explains about CO2 emissions in concrete and it’s remedy as green concrete and the materials used for manufacturing green concrete.

II. REDUCTION OF CO2 EMISSION The potential environmental benefit to society of being able to build with green concrete is huge. It is realistic to assume that technology can be developed, which can halve the CO2 emission related to concrete production. With the large consumption of concrete this will potentially reduce the world‘s total CO2 emission by 1.5-2%. Concrete can also be the solution to environmental problems other than those related to CO2 emission. It may be possible to use residual products from other industries in the concrete production while still maintaining a high concrete quality. During the last few decades society has become aware of the deposit problems connected with residual products, and demands, restrictions and taxes have been imposed.

Index Terms— CO2 emission , fly ash , microsilica

I. INTRODUCTION: Green concrete is a revolutionary topic in the history of concrete industry. This was first invented in Denmark in the year 1998. Green concrete has nothing to do with colour. It is a concept of thinking environment into concrete considering every aspect from raw materials manufacture over mixture design to structural design, construction, and service life. Green concrete is very often also cheap to produce, because, for example, waste products are used as a partial substitute for cement, charges for the disposal of waste are avoided, energy consumption in production is lower, and durability is greater. Green concrete is a type of concrete which resembles the conventional concrete but the production or usage of such concrete requires minimum amount of energy and causes least harm to the environment. The CO2 emission related to concrete production, inclusive of cement production, is between 0.1 and 0.2 t per tonne of produced concrete.

III. RAW MATERIALS FOR GREEN CONCRETE Several residual products have properties suited for concrete production, there is a large potential in investigating the possible use of these for concrete production. Well-known residual products such as silica fume and fly ash may be mentioned. The concrete industry realised at an early stage that it is a good idea to be in front with regard to documenting the actual environmental aspects and working on improving the environment, rather than being forced to deal with environmental aspects due to demands from authorities, customers and economic effects such as imposed taxes. Furthermore, some companies in concrete industry have recognised that reductions in production costs often go hand in hand with reductions in environmental impacts. Thus, environmental aspects are not only interesting from an ideological point of view, but also from an economic aspect.

I. PROBLEMS IN CONVENTIONAL CONCRETE Since the total amount of concrete produced is so vast the absolute figures for the environmental impact are quite significant, due to the large amounts of cement and concrete produced. Since concrete is the second most consumed entity after water it accounts for around 5% of the world‘s total CO2 emission (Ernst Worrell, 2001). The solution to this environmental problem is not to substitute concrete for other materials but to reduce the environmental impact of concrete and cement. Pravin Kumar et al, 2003, used quarry rock dust along with fly ash and micro silica and reported satisfactory properties.all fonts, in particular symbol fonts, as well, for math, etc.

A. RECYCLED MATERIALS IN GREEN CONCRETE: The production of cement used in concrete results in the creation of greenhouse gases, including CO2. The U.S.

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reaches its maximum strength more slowly than concrete made with only portland cement. The techniques for working with this type of concrete are standard for the industry and will not impact the budget of a job. This section also addresses wall-form products. Most of these products have hollow interiors and are stacked or set in place and then filled with steel-reinforced concrete creating a concrete structure for a house. Some wall-form materials are made from EPS (expanded polystyrene) which is a lightweight non-CFC foam material. There are also fiber-cement wall-form products that can contain wood waste. The EPS/concrete systems offer high insulating qualities and easy installation. The fiber-cement blocks offer insulating qualities as well. Some EPS products also have recycled content.

cement industry has reduced CO2 emissions by 30% since 1972 and now accounts for approximately 1.5% of U.S. emissions, well below other sources such as heating and cooling homes and buildings (33%), truck and auto use (27%) and industrial operations (19%). The CO2 embodied in concrete as a finished building product is a very small quantity considering that cement accounts for a small proportion of the finished product. The concrete industry also uses industrial waste byproducts such as fly ash (from coal combustion) and blast furnace slag (created in iron manufacture) to constitute a portion of the cement used in producing concrete. Use of such by-products in concrete prevents 15 million metric tons a year of these waste materials from entering landfills. Utilizing these "supplemental cementitious materials" as a replacement for cement improves the strength and durability of concrete and also further reduces the CO2 embodied in concrete by as much as 70%, with typical values ranging from 15% to 40%.

C. SILICA FUME: Silica fume, also known as microsilica, is an amorphous (non-crystalline) polymorph of silicon dioxide, silica. It is an ultrafine powder collected as a byproduct of the silicon and ferrosilicon alloy production and consists of spherical particles with an average particle diameter of 150 nm. The main field of application is as pozzolanic material for high performance concrete. It is sometimes confused with fumed silica. However, the production process, particle characteristics and fields of application of fumed silica are all different from those of silica fume. Silica fume is an ultrafine material with spherical particles less than 1 μm in diameter, the average being about 0.15 μm. This makes it approximately 100 times smaller than the average cement particle. The bulk density of silica fume depends on the degree of densification in the silo and varies from 130 to 600 kg/m3. The specific gravity of silica fume is generally in the range of 2.2 to 2.3. The specific surface area of silica fume can be measured with the BET method or nitrogen adsorption method. It typically ranges from 15,000 to 30,000 m2/kg.

Finally, when a concrete structure has served its purpose, it can be crushed for use as aggregate in new concrete or as fill or base materials for roads, sidewalks and concrete slabs. Even the reinforcing steel in concrete (which often is made from recycled materials) can be recycled and reused. B. FLY ASH: Fly ash is one of three general types of coal combustion by-products (CCBP’s). The use of these byproducts offers environmental advantages by diverting the material from the wastestream, reducing the energy investment in processing virgin materials, conserving virgin materials, and allaying pollution. Thirteen million tons of coal ash are produced in Texas each year. Eleven percent of this ash is used which is below the national average of 30 %. About 60 – 70% of central Texas suppliers offer fly-ash in ready-mix products. They will substitute fly-ash for 20 – 35% of the portland cement used to make their products. Although fly-ash offers environmental advantages, it also improves the performance and quality of concrete. Fly ash affects the plastic properties of concrete by improving workability, reducing water demand, reducing segregation and bleeding, and lowering heat of hydration. Fly ash increases strength, reduces permeability, reduces corrosion of reinforcing steel, increases sulphate resistance, and reduces alkali-aggregate reaction. Fly ash

ENVIRONMENTAL GOALS: Green Concrete is expected to fulfil the following environmental obligations:  Reduction of CO2 emissions by 21 %. This is in accordance with the Kyoto Protocol of 1997.  Increase the use of inorganic residual products from industries other than the concrete industry by approx. 20%.

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 

Reduce the use of fossil fuels by increasing the use of waste derived fuels in the cement industry. The recycling capacity of the green concrete must not be less compared to existing concrete types. The production and the use of green concrete must not deteriorate the working environment. The structures do not impose much harm to the environment during their service life.

There are several other advantages related to green concrete and can be summarized as below: a) Reduced CO2 emissions. b) Low production costs as wastes directly substitute the cement. c) Saves energy, emissions and waste water. d) Helps in recycling industry wastes. e) Reduces the consumption of cement overall. f) Better workability. g) Sustainable development. h) Greater strength and durability than normal concrete. i) Compressive strength and Flexural behaviour is fairly equal to that of the conventional concrete. j) Green concrete might solve some of the societies problems with the use of inorganic, residual products which should otherwise be deposited.

ADVANTAGES OF GREEN CONCRETE: Green concrete has manifold advantages over the conventional concrete. Since it uses the recycled aggregates and materials, it reduces the extra load in landfills and mitigates the wastage of aggregates. Thus, the net CO2 emissions are reduced. The reuse of materials also contributes intensively to economy. Since the waste materials like aggregates from a nearby area and fly ash from a nearby power plant are not much expensive and also transport costs are minimal. Green concrete can be considered elemental to sustainable development since it is eco-friendly itself. Green concrete is being widely used in green building practices.

CONCLUSION: The newer the technologies simultaneously it must be eco-friendly. Using Green concrete in Construction field is a revolution for the eco-friendly civil infrastructural development. Upcoming generation must use the green concrete instead of conventional concrete so that CO2 emission is considerably reduced.

It also helps the green buildings achieve LEED and Golden Globe certifications. Use of fly ash in the concrete also increases its workability and many other properties like durability to an appreciable extent. One of the practices to manufacture green concrete involves reduction of amount cement in the mix, this practice helps in reducing the consumption of cement overall. The use waste materials also solve the problem of disposing the excessive amount industrial wastes.

REFERENCES: [1] [2] [3] [4]

www.greenconcrete.info http://greenglobe.com/ http://flyash.sustainablesources.com http://www.microsilica-china.com

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Analytical Study of General Failure in Prominent Components 1

Balaji V.R1, Amitesh Jain1,A.Kirthivasan1 ,D.Ananthapadmanaban2 Under graduate students, SSN College of Engineering,Kalavakkan-603110,Tamilnadu,India 2 Associate Professor, Department of Mechanical Engineering, SSN College of Engineering,Kalavakkam-603110, Tamilnadu, India Email: ananthapadmanaband@ssn.edu.in Email: balaji12303@mech.ssn.edu.in

Abstract

The importance and value of failure analysis for safety, reliability, performance, and economy are well documented in this paper. To prevent failure of machine components failure analysis are made on the component before and after manufacturing. Even though the various test are conducted, failures happen at some stage. In this paper, a brief overview of causes of failure has been discusses. Some case studies have been given and the possible causes of failure have been analyzed. Key words: Failure Analysis, Case histories, recent trends.

II.

analysis of the physical evidence alone may not be adequate to reach this goal. The scope of a failure analysis can, but does not necessarily, lead to a correctable root cause of failure. Many times, a failure analysis incorrectly ends at the identification of the failure mechanism. A material or component shows gradual deformation or creep when subjected to sustained loading especially at elevated temperatures. It occurs even if the applied stresses are below the proportional limit. It occurs in both metals and non-metals. Similarly when a component is subjected repeated continuous load, it tends to gradually deteriorate resulting in fatigue failure. Fatigue occurs in three stages namely crack initiation, crack propagation and unstable rapid growth.

Introduction

The defects in quality, design, process or part application are the underlying cause of a failure. The human errors are considered, when failure depends on the user of the product or process. The failure analysis includes the area of creep, fatigue, structural resonance, crack initiation, crack propagation, spalling and pitting, fretting and wear, component failure. The components are subjected to failure analysis before and after manufacturing. Even though the various tests are conducted, failure happens at one stage.

Fatigue failure may also occur due propagation of the cracks originating from the surface of the component. They are of two types namely spalling and pitting. It occurs due to sub surface tensile and shear stresses that exceed materials fatigue limits. Gears and bearings are usually subjected to such stresses. When surfaces of two components mate each other they are subjected to normal pressure and tangential oscillatory motion fretting failure occurs. The surface undergoes failure due to fatigue, high normal forces or wear and failure can be accelerated in the presence of chemical attack.

The mechanism of failure can be attributed to multiple factors which simultaneously plays an influential role. These include corrosion, abnormal electric current welding of contacts, returns spring fatigue failure, unintended failure, dust accumulation and blockage of mechanism, etc.

III.

Failure analysis-History and Inception

The importance and value of failure analysis to safety, reliability, performance, and economy are well documented.

The strategy for safety is to make various test before the product comes into the usage. The investigation of failure is vividly illustrated in the pioneering efforts of the consideration of physical evidence and the use of engineering and scientific principles and analytical tools. Often, the reason why one performs a failure analysis is to characterize the causes of failure with the overall objective to avoid repetition of similar failures. However,

For example, the importance of investigating failures is vividly illustrated in the pioneering efforts of the Wright Brothers in developing self-propelled flight. In fact, while Wilbur was traveling in France in 1908, Orville was conducting flight tests for the U.S. Army Signal Corps and was injured when his Wright Flyer crashed (Fig. 1). His

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 passenger sustained fatal injuries [1]. Upon receiving word of the mishap, Wilbur immediately ordered the delivery of the failed flyer to France so that he could conduct a thorough investigation. This was decades before the formal discipline called “failure analysis” was introduced. Unfortunately, there are many dramatic examples of catastrophic failures that result in injury, loss of life, and damage to property. For example, a molasses tank failed in Boston in 1919, and another molasses tank failed in Bellview, NJ, in 1973 [2]. Were the causes identified in 1919? Were lessons learned as a result of the accident? Were corrective actions developed and implemented to prevent recurrence?

A micrograph of sample taken few millimetres behind fracture surface reveals that it was subjected to much higher temperatures than area directly beneath the tile. From these images it is clear that second phase particles present in the microstructure composed of copper, manganese and iron melted and subsequently wetted the grain boundaries upon exposure to high temperature causing significant weakening of grain boundaries, ultimately resulting in intergranular failure.

Fig.2 Light optical microscopy micrograph of panel skin

section at fracture surface. Notice that liquation is observed across entire micrograph. A crack along a grain boundary is also present. [4]

Fig.1 Crash of the Wright Flyer, 1908. Courtesy of the National Air and Space Museum,Smithsonian Institution Photo A-42555-A[1]

Conversely, failures can also lead to improvements in engineering practices. The spectacular failures of the Liberty ships during World War II were studied extensively in subsequent decades, and the outcome of these efforts was a significantly more thorough understanding of the phenomenon of fracture, culminating in part with the development of the engineering discipline of fracture mechanics [3]. Through these and other efforts, insights into the cause and prevention of failures continue to evolve. Space shuttle, Columbia orbitter failed upon its re-entry into the earth’s atmosphere. Earlier it was believed that failure was caused by foam piece which got dislodged from external tank during takeoff and struck the leading edge of the left wing. This damaged the latter made of carboncarbon composites thereby providing a breach in the shuttle leading to catastrophic failure [4]. The foam tiles on analysis show signs of erosion due to high temperatures exceeding 2000K during re-entry which is sufficient enough to melt aluminium. Hence it is quite apparent that Aluminium Sandwich Panel Skins below the tiles were protected during re-entry. Hence an analysis was carried out on the Aluminium Sandwich Panel Skin recovered from the debris field. They were 0.6mm thick sheets made up of 2000-series Aluminium alloy.

The Sandwich Panel was locally heated to cause liquation only near the fracture surface whereas aluminium microstructure directly beneath an insulating tile shows no sign of liquation. This lead to formation of local hotspots where there was no thermal protection due to loss of insulation resulting from the accident. These localised hotspots lead to the failure of the aluminium sandwich panel and hence failure of the space shuttle.

IV.

Recent trends and advancements

Modern automobiles increasingly utilize high-strength lowweight alloys for better fuel efficiency. Aluminium alloys seem to serve the purpose owing to its high strength to weight ratio. Several major automobile components such as engine blocks, pistons, intake manifold, carburettors and brake parts make use of aluminium castings. Since aluminium alloys such as Al-356 is extensively used, a study to realize the reason for their mechanical failure is necessary. S. Nasrazadani and L. Reyes investigated a clutch pedal lever made of permanent mould cast Al 356-T6 aluminium by way of metallography, SEM, hardness testing and visual inspection [5]. They concluded that the parts in clutch assembly must be designed with thicker sections to resist the applied stress. Fatigue and brittle failure occurs due to presence of dendrite phases and micro-porosity and it can be avoided by production of heat treated Al 356-T6.

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Fig. 3 Image of the fractured part showing two visible cracks[5]

Fig.4 Oxidation product visible at the grain boundary (arrows)

[6]

Y. Huang and Y. Zhu metallurgically examined the section of a fractured spindle from an axle housing of a truck. It was found that after about 8,000 miles of service the axle fractured at the friction weld interface. Metallographic and SEM examinations at the fractured site revealed the existence of micro-porosity and formation of ferrite layer. This had reduced the impact strength of the weld resulting in overload fracture. Due to air exposure at the molten layer interface, a band of oxides was formed and the solidification of liquid film leads to microshrinkage.

with other oxidized grain boundaries (encircled) [7]

The results showed that both were made of the same steel grade X2NiCoMo18-8-5. The samples were cut from both defected and non-defected regions and were analysed using optical microscopy. From the analysis it was observed that welding bead had serious problems due to the oxidation of the plate. The surface of metal plate was deposited by oxidation products due to under machining of the plate, before welding. Hence during welding, the oxidation products get entrapped within weld bead or may appear on the surface of the weld. This weakens the weld thereby causing failure.

Fig. 5 The assembly fractured along the weld interface (a ferrite band with oxides), etched, 2% natal[6]

A lap welded steel joint had failed when it was operated under very high speeds[7]. This joint was fabricated by a laser beam welding using high energy coherent optical source of heat at low pressure. The steel sheets used for this purpose was 0.5 mm thick. The components of the debris was put into failure analysis for metallurgical investigation. The sheet and plate used to form this joint were analysed for their chemical composition.

Failure analysis is considered to be the examination of the characteristics and causes of equipment or component failure[8]. In most cases this involves the consideration of physical evidence and the use of engineering and scientific principles and analytical tools. Often, the reason why one performs a failure analysis is to characterize the causes of failure with the overall objective to avoid repeat of similar failures. However, analysis of the physical evidence alone may not be adequate to reach this goal. The scope of a failure analysis can, but does not necessarily, lead to a correctable root cause of failure. Many times, a failure analysis incorrectly ends at the identification of the failure mechanism and perhaps causal influences. The principles of root-cause analysis (RCA) may be applied to ensure that the root cause is understood and appropriate corrective actions may be identified. An RCA exercise may simply be a momentary mental exercise or an extensive logistical charting analysis. Many volumes have been written on the process and methods of RCA. The concept of RCA does not apply to failures alone, but is applied in response to an undesirable event or condition (Fig. 4). Root-cause analysis is intended to identify the fundamental cause(s) that if corrected will prevent recurrence.

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Conclusions

Various procedures followed during failure analysis have been documented in this paper. Root cause analysis has been discussed. Starting from the history of failure analysis some case studies have been presented. It can be concluded that failure analysis is a very vast field of research and any analysis can give the possible cause of failure only.Sometimes there may be a a combination of factors for a material or component to fail.

VIII.

References

[1]. P.L. Jakab, Visions of a Flying Machine: The Wright Brothers and the Process of Invention, Smithsonian Institution, 1990, p 226 [2]. R.W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials, John Wiley & Sons, 1976, p 229–230 Fig. 6 Root-cause analogy [8]

VI.

[3]. D.J. Wulpi, Understanding How Components Fail, 2nd ed., ASM International, 1999

Recent Case History

Building in Chennai under construction crashed recently (2014) when there was rain for about 1 or 2 hours. Most probably the soil itself must have been loose around that area, Chennai being home to clayey soil[9]. Another reason could be-lack of proper curing of foundation. In earlier days, foundations used to be cured for close to 3 weeks. These days, it is not certain whether proper procedures are followed. Most often, there is a combination of factors involved each of which contributes to the ultimate failure. So, it is suggested that at each stage, mandatory checks be followed so that even if a structure fails, one can exactly pinpoint what went wrong and at which stage it went wrong.

[4].Metals Handbook,American Society of Metals,Volume 5,Failure Analysis and prevention. [5] S. Nasrazadani• L. Reyes ,Failure Analysis of Al 356T6 Clutch Lever, Failure Analysis of Al 356-T6 Clutch Lever [6]. Y. Huang and Y. Zhu, Failure Analysis of Friction Weld (FRW) in Truck Axle Application, Submitted: 17 September 2007 / in revised form: 16 November 2007 / Published online: 20 December 2007_ ASM International 2007 [7]. A. Nusair Khan • W. Mohammad • I. Salam..: Failure Analysis of Laser Weld Joint of X2NiCoMo18-8-5 Steel. [8]. http://en.wikipedia.org/wiki/Root_cause_analysis [9]. http://www.thehindu.com/news/cities/chennai/ap-cmannounces-exgratia-for-telugu-victims-in-chennaibuilding-collapse/article6159984.ece

Fig.7 The Hindu 11 floor building collapse at Bai kadai junction

Moulivakkam,near Porur on Sunday.in Chennai-TN.India[9]

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Organizing the Trust Model in Peer-To-Peer System Using SORT R. Kiruthikalatha, B. Arputhamary M.C.A., MPhil, M.Phil scholar, Department of computer science, Bishop Heber college(Autonomous), Trichirapalli-620 017 Asst.professor, Department of computer Applications, Bishop Heber college(Autonomous), Trichirapalli-620017 kiruthikalatha@gmail.com arputhambaskaran@rediffmail.com using local information available and global trust information.

ABSTRACT Peer-to-Peer (P2P) Systems have attracted significant interest in recent years. In P2P networks, each peer acts as both a server and client. This characteristic makes peers vulnerable to a wide variety of attacks. Having robust trust management is very critical for such open environment to exclude unreliable peer from the system. Managing trust is a problem in peer to peer environment, so our SORT model is built based on trust metrics. The trust metrics such as reputation, service trust, recommendation trust are defined to precisely measure trustworthiness of peers. A peerâ&#x20AC;&#x2122;s trustworthiness is evaluated by considering provided services and given recommendations with service and recommendation contexts. When evaluating recommendation, recommenderâ&#x20AC;&#x2122;s trustworthiness and confidence level about the information provided are also considered. Experiments on file sharing application demonstrate that peers with the highest trust value are considered and build the trust model in their contiguity and insulate malignant peers. Building trust relationships among peers can mitigate attacks of malicious peers. Peers create their own trust network in their proximity by

Keywords: Peer-to-peer systems, trust management, reputation, services, security.

INTRODUCTION

PEER-TO-PEER (P2P) systems rely on collaboration of peers to accomplish tasks. Ease of performing malicious activity is a threat for security of P2P systems. Creating long-term trust relationships among peers can provide a more secure environment by reducing risk and uncertainty in future P2P interactions. However, establishing trust in an unknown entity is difficult in such a malicious environment. Furthermore, trust is a social concept and hard to measure with numerical values. Metrics are needed to represent trust in computational models. Classifying peers as either trustworthy or untrustworthy is not sufficient in most cases. Metrics should have precision so peers can be ranked according to trustworthiness. Interactions and feedbacks of peers provide information to measure trust among peers. Interactions with a peer provide certain information about the

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peer becomes an acquaintance of another peer after providing a service, e.g., uploading a file. If a peer has no acquaintance, it chooses to trust strangers. An acquaintance is always preferred over a stranger if they are equally trustworthy. Using a service of a peer is an interaction, which is evaluated based on weight (importance) and recentness of the interaction, and satisfaction of the requester. An acquaintance’s feedback about a peer, recommendation, is evaluated based on recommender’s trust-worthiness. It contains the recommender’s own experience about the peer, information collected from the recommender’s acquaintances, and the recommender’s level of confidence in the recommendation. If the level of confidence is low, the recommendation has a low value in evaluation and affects less the trustworthiness of the recommender. and defines two contexts of trust: service and recommendation contexts. Information about past interactions and recommendations are stored in separate histories to assess competence and integrity of acquaintances in these contexts. SORT defines three trust metrics. Reputation metric is calculated based on recommendations. It is important when deciding about strangers and new acquaintances. Reputation loses its importance as experience with an acquaintance increases. Service trust and recommendation trust are primary metrics to measure trustworthiness in the service and recommendation contexts, respectively. The service trust metric is used when selecting service providers. The recommendation trust metric is important when requesting recommendations. When calculating the reputation metric, recommendations are evaluated based on the recommendation trust metric. We implemented a P2P file sharing simulation tool and conducted experiments to understand impact of SORT in mitigating attacks. Parameters related to

peer but feedbacks might contain deceptive information. This makes assessment of trustworthiness a challenge. In the presence of an authority, a central server is a preferred way to store and manage trust information, e.g., eBay. The central server securely stores trust information and defines trust metrics. Since there is no central server in most P2P systems, peers organize themselves to store and manage trust information about each other [1], [2]. Management of trust information is dependent to the structure of P2P network. In distributed hash table (DHT)-based approaches, each peer becomes a trust holder by storing feedbacks about other peers [1], [3], [4]. Global trust information stored by trust holders can be accessed through DHT efficiently. In unstructured networks, each peer stores trust information about peers in its neighbor-hood or peers interacted in the past. A peer sends trust queries to learn trust information of other peers. A trust query is either flooded to the network or sent to neighborhood of the query initiator. Generally, calculated trust information is not global and does not reflect opinions of all peers. We propose a Self-Organizing Trust model (SORT) that aims to decrease malicious activity in a P2P system by establishing trust relations among peers in their proximity. No a priori information or a trusted peer is used to leverage trust establishment. Peers do not try to collect trust information from all peers. Each peer develops its own local view of trust about the peers interacted in the past. In this way, good peers form dynamic trust groups in their proximity and can isolate malicious peers. Since peers generally tend to interact with a small set of peers [7], forming trust relations in proximity of peers helps to mitigate attacks in a P2P system. In SORT, peers are assumed to be strangers to each other at the beginning. A

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peer capabilities (bandwidth, number of shared files), peer behavior (online/ offline periods, waiting time for sessions), and resource distribution (file sizes, popularity of files) are approximated to several empirical results. This enabled us to make more realistic observations on evolution of trust relationships. We studied 16 types of malicious peer behaviors, which perform both service and recommendation-based attacks. SORT mitigated service-based attacks in all cases. Recommendation-based attacks were contained except when malicious peers are in large numbers, e.g., 50 percent of all peers. Experiments on SORT show that good peers can defend themselves against malicious peers without having global trust information. SORT’s trust metrics let a peer assess trustworthiness of other peers based on local information. Service and recommendation contexts enable better measurement of trustworthiness in providing services and giving recommendations. Outline of the paper is as follows: Section 2 discusses the related research. Section 3 explains the computational model of SORT. Section 4 presents the simulation experiments and results. Section 5 summarizes the results and possible future work directions.

trustworthiness of participating peers and to combat the selfish, dishonest, and malicious peer behaviors. [2] Guruprasad Khataniar, Hitesh Tahbildar, and Prakriti Prava Das [Guru, Hit Tah, PravDa, 13] describes There are various overlay structures that provide efficient and scalable solutions for point and range query in a peer-to peer network. [3] Karl Aberer, Philippe CudréMauroux, Anwitaman Datta, Zoran Despotovic, Manfred Hauswirth, Magdalena Punceva, Roman Schmidt.[Mag Pun, Zor, Anw Datt, 12] describes, sometimes p2p system structure are not in uniform our concept is used to organizing the p2p system structure in self. [4] Kevin Hoffman, David Zage, Cristina Nita-Rotaru.[Ke Hoff, Cris Nit Dav Za, 07] describes, The rapid growth of communication networks such as the Internet and ad hoc wireless mesh networks has spurred the development of numerous collaborative applications. [5] Stephen Boyd Arpita Ghosh Balaji Prabhakar Devavrat Shah.[ApriGho, Pra Dev, 06] Motivated by applications to sensor, peer-to-peer and ad hoc networks, we study distributed algorithms, also known as gossip algorithms, for exchanging information and for computing in an arbitrarily connected network of nodes. The topology of such networks changes continuously as new nodes join and old nodes leave the network. [6] Sylvia Ratnasamy, Paul Francis, Mark Handley, Richard Karp1, Scott Shenker [Sy Pat,Paul, Mk Han, 01]. Hash tables – which map “keys” onto “values” – are an essential building block in modern software systems. We believe a similar functionality would be equally valuable to large distributed systems.

Fig 1. Peer-to-Peer Model II. RELATED WORK [1] Run fang Zhou, Kai Hwang.,[R Zhou, Kai Hw,06] describes the

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[7] Yao Wang[Ya Wan, 05 ]. Peerto-peer networks are networks in which all peers cooperate with each other to perform article function in a decentralized manner All peers are both users and providers of resources and can access each other directly without intermediary agents. Compared with a centralized system, a peer-to-peer (P2P) system provides an easy way to aggregate large amounts of resource residing on the edge of Internet or in ad-hoc networks with a low cost of system maintenance.

[11] Shanshan Song, Kai Hwang, and Runfang Zhou., [S Song, K Hwang, R Zhou,

fuzzy

logic

system benefits from the distinct advantages of fuzzy inferences, which can handle imprecise linguistic terms effectively. In the â&#x20AC;&#x153;Fuzzy Logic Inference and Applicationsâ&#x20AC;? sidebar, we give details on how to perform fuzzy inference in the Fuzzy Trust system. III. SYSTEM MODEL SORT defines three trust metrics. Reputation metric is calculated based on recommendations. It is important when deciding about strangers and new acquaintances. Reputation loses its importance as experience with an acquaintance increases. Service trust and recommendation trust are primary metrics to measure trustworthiness in the service and recommendation contexts, respectively. The service trust metric is used when selecting service providers. The recommendation trust metric is important when requesting recommendations. When calculating the reputation metric, recommendations are evaluated based on the recommendation trust metric. We implemented a P2P file sharing simulation tool and conducted experiments to understand impact of SORT in mitigating attacks. Parameters related to peer capabilities (bandwidth, number of shared files), peer behavior (online/ offline periods, waiting time for sessions), and resource distribution (file sizes, popularity of files) are approximated to several empirical results. This enabled us to make more realistic observations on evolution of trust relationships. We studied 16 types of

[10] Ion Stoica, Robert Morris, David Liben-Nowell, David R. Karger, M. Frans Kaashoek, Frank Dabek , Hari Balakrishnan [ I stoica, R Morris, D Karger, Fr Kaashoek ,F Dabek, 01]. Peer to Peer Systems are loosley organized systems without any centralized control or any hierarchical system. Each node runs software with equivalent functionality. Peer to peer systems provide users with features such as availability, permanence, redundant nearby

uses

and to aggregate global reputation. This

[9] Runfang Zhou, Kai Hwang[R Zhou, Kai Hw, 07]. Peer-to-Peer (P2P) reputation systems are needed to evaluate the trustworthiness of participating peers and to combat selfish and malicious peer behaviors. The reputation system collects locally generated peer feedbacks and aggregates them to yield global reputation scores. Development of decentralized reputation system is in great demand for unstructured P2P networks since most P2P applications on the Internet are unstructured.

System

inference rules to calculate local trust scores

[8] Jon Kleinberg[Jo Kl, 09]. A social network exhibits the small-world phenomenon if, roughly speaking, any two individuals in the network are likely to be connected through a short sequence of intermediate acquaintances.

storage, selection anonymity.

05].

servers,

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malicious peer behaviors, which perform both service and recommendation- based attacks. SORT mitigated service-based attacks in all cases. Recommendation-based attacks were contained except when malicious peers are in large numbers, e.g., 50 percent of all peers. Experiments on SORT show that good peers can defend themselves against malicious peers without having global trust information. SORTâ&#x20AC;&#x2122;s trust metrics let a peer assess trustworthiness of other peers based on local information. Service and recommendation contexts enable better measurement of trustworthiness in providing services and giving recommendations.

peer to peer system. Many possibilities hacking of information. Self organized based peer systems provide the better security among the number of system. on trust values of recommenders based on accuracy of their recommendations. In SORT method trust is based on the service and recommendation .There are three metrics are used for peer to peer system. Reputation metric is calculated based on recommendations. It is important when deciding about strangers and new acquaintances. Reputation loses its importance as experience with an acquaintance increased. Different types attacks prevented in this method. When pi searches for a particular service, it gets a list of service providers. Considering a file sharing application, pi may download a file from either one or multiple up loaders. With multiple up loaders, checking integrity is a problem since any file part downloaded from an up loader might be inauthentic. When evaluating an acquaintanceâ&#x20AC;&#x2122;s trustworthiness in the service context, a peer first calculates competence and integrity belief values using the information in its service history. IV.PERFORMANCE EVALUATION A file sharing simulation program is implemented in Java to observe results of using SORT in a P2P environment. Some questions studied in the experiments are as follows: how SORT handles attacks, how much attacks can be mitigated, how much recommendations are (not) helpful in correctly identifying malicious peers, and what type of attackers are the most harmful.

Fig. 3 Architecture Flow Process

A. Trust model for Peer-To-Peer In Proposed SORT reputation based metric has been used. After calculating value, pi updates recommendation many important files are shared with peer to peer system. The Central server makes the trustiness between the peer systems. In many cases there is no central server in the

A. Method

cycle

The simulation runs as cycles. Each represents a period of time.

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Downloading a file is an interaction. A peer sharing files is called an uploader.

Hence team size is increased to observe effects of collaboration better. V. CONCLUSION AND FUTURE WORK

B. Attacker Model Attackers can perform service-based and recommendation based attacks. Uploading a virus infected or an inauthentic file is a service-based attack. Giving a misleading recommendation intentionally is a recommendation-based attack.

A. CONCLUSION Trust model for P2P networks is presented, in which a peer can develop a trust network in its proximity. A peer can isolate malicious peers around itself as it develops trust relationships with good peers. Two context of trust, service and recommendation contexts, are defined to measure capabilities of peers in providing services and giving recommendations. Interactions and recommendations are considered with satisfaction, weight, and fading effect parameters. A recommendation contains the recommenderâ&#x20AC;&#x2122;s own experience, information from its acquaintances, and level of confidence in the recommendation. These parameters provided us a better assessment of trustworthiness. Individual, collaborative, and pseudonym changing attackers are studied in the experiments. Damage of collaboration and pseudo spoofing is dependent to attack behavior. Although recommendations are important in hypocritical discriminatory attackers. Attacks in most experiments. However, in extremely malicious environments such as a 50 percent malicious network, collaborators can continue to disseminate large amount of misleading recommendations. Another issue about SORT is maintaining trust all over the network. If a peer changes its point of attachment to the network, it might lose a part of its trust network. These issues might be studied as a future work to extend the trust model. Using trust information does not solve all security problems in P2P systems but can enhance security and effectiveness of systems. If interactions are

C. Analysis on Individual Attackers This section explains the results of experiments on individual attackers. For each type of individual attacker, two separate network topologies are created: one with 10 percent malicious and one with 50 percent malicious. Each network topology is tested with four trust calculation methods. In the experiments, a hypocritical attacker behaves malicious in 20 percent of all interactions. A discriminatory attacker selects 10 percent of all peers as victims. D. Analysis on Individual Pseudospoofers This section explains the results of experiments on individual pseudospoofers. Pseudospoofers change their pseudonyms after every 1,000 cycles. For other parameters, attackers behave as described. E. Analysis on Collaborators Collaboration of attackers generally makes attack prevention harder. This section presents experimental results on collaborators. Collaborators form teams of size 50 and launch attacks as teams. We first tried teams of size 10 but this was not enough to benefit from collaboration and results were close to individual attackers.

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Despotovic, Manfred Hauswirth, Magdalena Punceva, Roman Schmidt.[Mag Pun, Zor, Anw Datt, 12]

modeled correctly, SORT can be adapted to various P2P applications, e.g., CPU sharing, storage networks, and P2P gaming. Defining application specific context of trust and related metrics can help to assess trustworthiness in various tasks.

[4] A Survey of attacks on Reputation Systems: Kevin Hoffman, David Zage, Cristina Nita-Rotaru.[Ke Hoff, Cris Nit Dav Za, 07]

B. Future Work Managing trust is a problem of particular importance in peer-to-peer environments where one frequently encounters unknown agents. We present an approach that addresses the problem of reputation-based trust management at both th data management and the scientific level. We employ at both levels scalable data structures and algorithm that require no central control and allows assessing trust by computing any agents reputation from its former interactions with other agents. Thus the method can be implemented in a p2p environment and scales well for very large number of participants. We expect that scalable methods for trust management are an important factor, if fully decentralized peer-to-peer systems should become the platform for more serious applications than simple exchange.

[5] Randomized Gossip Algorithms: Stephen Boyd Arpita Ghosh Balaji Prabhakar Devavrat Shah.[ApriGho, Pra Dev, 06]. [6] A Scalable Content-Addressable Network: Sylvia Ratnasamy, Paul Francis, Mark Handley, Richard Karp1, Scott Shenker [Sy Pat,Paul, Mk Han, 01]. [7] Bayesian Network Trust Model in Peer-to-Peer Networks: Yao Wang[Ya Wan, 05 ]. [8] The Small-World Phenomenon: An Algorithmic Perspective Jon Kleinberg[Jo Kl, 09]. [9] Gossip-based Reputation Aggregation for Unstructured Peer-to-Peer Networks. Runfang Zhou, Kai Hwang[R Zhou, Kai Hw, 07].

Reference [1] A Robust and Scalable Reputation System for Trusted Peer-to-Peer Computing: Run fang Zhou, Kai Hwang.,[R Zhou, Kai Hw,06]

[10] A scalable peer-to-peer look-up protocol for internet applications Ion Stoica, Robert Morris, David Liben-Nowell, David R. Karger, M. Frans Kaashoek, Frank Dabek , Hari Balakrishnan [ I stoica, R Morris, D Karger, Fr Kaashoek ,F Dabek, 01].

[2] Attacks and Counter Measures in BST Overlay Structure of Peer-To-Peer System: Guruprasad Khataniar, Hitesh Tahbildar, and Prakriti Prava Das [Guru, Hit Tah, PravDa, 13]

[11] Trusted P2P Transactions with Fuzzy Reputation Aggregation: Shanshan Song, Kai Hwang, and Runfang Zhou., [S Song, K Hwang, R Zhou, 05].

[3] P-Grid: Self-organizing Structured P2P System: Karl Aberer, Philippe CudrĂŠMauroux, Anwitaman Datta, Zoran

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WEB PERSONALIZATION: A GENERAL SURVEY J. JOSIYA ANCY Research Scholar, Department of Information Technology, Vellore Institute of Technology, Vellore District, Tamilnadu. ABSTRACT: Retrieving the relevant information from the web becomes difficult now-a-days because of the large amount of dataâ&#x20AC;&#x2122;s available in various formats. Now days the user rely on web, but it is mandatory for users to go through the long list and to choose their needed document, which is very time consuming process. The approach that is to satisfy the requirements of user is to personalize the data available on Web, is called Web Personalization. Web personalization is solution to the information overload problem, it provides the users need without having to ask or search for it explicitly. This approach helps to improve the efficiency of Information Retrieval (IR) systems. This paper conducts a survey of personalization, its approaches and techniques. Keywords- Web Personalization, Information retrieval, User Profile, Personalized Search

INTRODUCTION:

WEB PERSONALIZATION: The web is used for accessing a variety of information stored in various locations in various formats in the whole world. The content in web is rapidly increasing and need for identifying, accessing and retrieving the content based on the needs of the users is required. An ultimate need nowadays is that predicting the user requirements in order to improve the usability of the web site. Personalized search is the solution for this problem since different search results based on preferences of users are provided. In brief, web pages are personalized based on the characteristics of an individual user based on interests, social category, context etcâ&#x20AC;Ś The Web Personalization is defined as any action that adapts information or services provided by a web site to an individual user or a set of users. Personalization implies that the changes are based on implicit data such as items purchased or pages viewed. Personalization is an overloaded term: there are many mechanisms and approaches bothe automated and marketing rules controlled, whereby content can be focused to an audience in a one to one manner.

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WEB PERSONALIZATION ARCHITECTURE:

Fig 1.1: Web personalization process

The above web personalization process uses the web site’s structure, Web logs created by observing the user’s navigational behavior and User profiles created according to the user’s preferences along with the Web site’s content to analyze and extract the information needed for the user to find the pattern expected by the user. This analysis creates a recommendation model which is presented to the user. The recommendation process relies on the existing user transactions or rating data, thus items or pages added to a site recently cannot be recommended. II.

WEB PERSONALIZATION APPROACHES

Web mining is a mining of web data on the World Wide Web. Web mining does the process on personalizing these web data. The web data may be of the following: 1. 2. 3. 4.

Content of the web pages(actual web content) Inter page structure Usage data includes how the web pages are accessed by users User profile includes information collected about users(cookies/Session data)

With personalization the content of the web pages are modified to better fit for user needs. This may involve actually creating web pages, that are unique per user or using the desires of a user to determine what web documents to retrieve. Personalization can be done to a group of specific interested customers, based on the user visits to a websites. Personalization also includes techniques such as use of cookies, use of databases, and machine learning strategies. Personalization can be viewed as a type of Clustering, Classification, or even Prediction. USER PROFILES FOR PERSONALIZED INFORMATION ACCESS:

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In the modern Web, as the amount of information available causes information overloading, the demand for personalized approaches for information access increases. Personalized systems address the overload problem by building, managing, and representing information customized for individual users. There are a wide variety of applications to which personalization can be applied and a wide variety of different devices available on which to deliver the personalized information. Most personalization systems are based on some type of user profile, a data instance of a user model that is applied to adaptive interactive systems. User profiles may include demographic information, e.g., name, age, country, education level, etc, and may also represent the interests or preferences of either a group of users or a single person. Personalization of Web portals, for example, may focus on individual users, for example, displaying news about specifically chosen topics or the market summary of specifically selected stocks, or a groups of users for whom distinctive characteristics where identified, for example, displaying targeted advertising on e-commerce sites. In order to construct an individual userâ&#x20AC;&#x2122;s profile, information may be collected explicitly, through direct user intervention, or implicitly, through agents that monitor user activity.

Fig. 2.1. Overview of user-profile-based personalization

As shown in Figure 2.1, the user profiling process generally consists of three main phases. First, an information collection process is used to gather raw information about the user. Depending on the information collection process selected, different types of user data can be extracted. The second phase focuses on user profile construction from the user data. The final phase, in which a technology or application exploits information in the user profile in order to provide personalized services. TECHNIQUES USING USER PROFILE: From an architectural and algorithmic point of view personalization systems fall into three basic categories: Rule-based systems, content-filtering systems, and collaborative filtering systems.

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Rule-Based Personalization Systems. Rule-based filtering systems rely on manually or automatically generated decision rules that are used to recommend items to users. Many existing e-commerce Web sites that employ personalization or recommendation technologies use manual rule-based systems. The primary drawbacks of rule-based filtering techniques, in addition to the usual knowledge engineering bottleneck problem, emanate from the methods used for the generation of user profiles. The input is usually the subjective description of users or their interests by the users themselves, and thus is prone to bias. Furthermore, the profiles are often static, and thus the system performance degrades over time as the profiles age. Content-Based Filtering Systems. In Content-based filtering systems, user profiles represent the content descriptions of items in which that user has previously expressed interest. The content descriptions of items are represented by a set of features or attributes that characterize that item. The recommendation generation task in such systems usually involves the comparison of extracted features from unseen or unrated items with content descriptions in the user profile. Items that are considered sufficiently similar to the user profile are recommended to the user. Collaborative Filtering Systems. Collaborative filtering has tried to address some of the shortcomings of other approaches mentioned above. Particularly, in the context of e-commerce, recommender systems based on collaborative filtering have achieved notable successes. These techniques generally involve matching the ratings of a current user for objects (e.g., movies or products) with those of similar users (nearest neighbors) in order to produce recommendations for objects not yet rated or seen by an active user. III.

WEB PERSONALIZATION AND RELATED WORKS

Lot of research had been conducted in Personalized Ontology. Generally, personalization methodologies are divided into two complementary processes which are (1) the user information collection, used to describe the user interests and (2) the inference of the gathered data to predict the closest content to the user expectation. In the first case, user profiles can be used to enrich queries and to sort results at the user interface level. Or, in other techniques, they are used to infer relationships like the social-based filtering and the collaborative filtering. For the second process, extraction of information on users’ navigations from system log files can be used. Some information retrieval techniques are based on user contextual information extraction. Dai and Mobasher [5] proposed a web personalization framework that characterizes the usage profiles of a collaborative filtering system using ontologies. These profiles are transformed to “domain-level” aggregate profiles by representing each page with a set of related ontology objects. In this work, the mapping of content features to ontology terms is assumed to be performed either manually, or using supervised learning methods. The defined ontology includes classes and their instances therefore the aggregation is performed by grouping together different

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instances that belong to the same class. The recommendations generated by the proposed collaborative system are in turn derived by binary matching the current user visit expressed as ontology instances to the derived domain-level aggregate profiles, and no semantic relations beyond hyperonymy/hyponymy are employed. Acharyya and Ghosh [7] also propose a general personalization framework based on the conceptual modeling of the usersâ&#x20AC;&#x2122; navigational behavior. The proposed methodology involves mapping each visited page to a topic or concept, imposing a tree hierarchy (taxonomy) on these topics, and then estimating the parameters of a semi- Markov process defined on this tree based on the observed user paths. In this Markov modelsbased work, the semantic characterization of the context is performed manually. Moreover, no semantic similarity measure is exploited for enhancing the prediction process, except for generalizations/specializations of the ontology terms. Middleton et.al. [8] explore the use of ontologies in the user profiling process within collaborative filtering systems. This work focuses on recommending academic research papers to academic staff of a University. The authors represent the acquired user profiles using terms of a research paper ontology (is-a hierarchy). Research papers are also classified using ontological classes. In this hybrid recommender system which is based on collaborative and content-based recommendation techniques, the content is characterized with ontology terms, using document classifiers (therefore a manual labeling of the training set is needed) and the ontology is again used for making generalizations/specializations of the user profiles. Kearney and Anand [9] use an ontology to calculate the impact of different ontology concepts on the users navigational behavior (selection of items). In this work, they suggest that these impact values can be used to more accurately determine distance between different users as well as between user preferences and other items on the web site, two basic operations carried out in content and collaborative filtering based recommendations. The similarity measure they employ is very similar to the Wu & Palmer similarity measure presented here. This work focuses on the way these ontological profiles are created, rather than evaluating their impact in the recommendation process, which remains opens for future work. IV.

CONCLUSION

In this paper we surveyed the research in the area of personalization in web search. The study reveals a great diversity in the methods used for personalized search. Although the World Wide Web is the largest source of electronic information, it lacks with effective methods for retrieving, filtering, and displaying the information that is exactly needed by each user. Hence the task of retrieving the only required information keeps becoming more and more difficult and time consuming. To reduce information overload and create customer loyalty, Web Personalization, a significant tool that provides the users with important competitive advantages is required. A

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Personalized Information Retrieval approach that is mainly based on the end user modeling increases user satisfaction. Also personalizing web search results has been proved as to greatly improve the search experience. This paper also reviews the various research activities carried out to improve the performance of personalization process and also the Information Retrieval system performance. REFERENCES 1. 2.

3. 4. 5. 6. 7. 8. 9.

10. 11.

12.

13. 14. 15. 16. 17. 18.

K. Sridevi and Dr. R. Umarani, “Web Personalization Approaches: A Survey” in IJARCCE, Vol.2.Issue3. March 2013. Adar, E., Karger, D.: Haystack: “Per-User Information Environments.” In: Proceedings of the 8th International Conference on Information Knowledge Management (CIKM), Kansas City, Missouri, November 2-6 (1999) 413-422. Bamshad Mobasher, “Data Mining forWeb Personalization” The Adaptive Web, LNCS 4321, pp. 90–135, 2007. Springer-Verlag Berlin Heidelberg 2007. Indu Chawla,” An overview of personalization in web search” in 978-1-4244-8679-3/11/$26.00 ©2011 IEEE. H. Dai, B. Mobasher, “Using Ontologies to Discover Domain-Level Web Usage Profiles”, in Proc. of the 2nd Workshop on Semantic Web Mining, Helsinki, Finland, 2002. D.Oberle, B.Berendt, A.Hotho, J.Gonzalez, “Conceptual User Tracking”, in Proc. of the 1st Atlantic Web Intelligence Conf. (AWIC),2003. S. Acharyya, J. Ghosh, “Context-Sensitive Modeling of Web Surfing Behaviour Using Concept Trees”, in Proc. of the 5th WEBKDD Workshop, Washington, August 2003. S.E. Middleton, N.R. Shadbolt, D.C. De Roure, “Ontological User Profiling in Recommender Systems”, ACM Transactions on Information Systems (TOIS), Jan. 2004/ Vol.22, No. 1, 54-88. P. Kearney, S. S. Anand, “Employing a Domain Ontology to gain insights into user behaviour”, in Proc. of the 3rd Workshop on Intelligent Techniques for Web Personalization (ITWP 2005), Endiburgh, Scotland, August 2005. http://en.wikipedia.org/wiki/Ontology Bhaganagare Ravishankar, Dharmadhikari Dipa, “WebPersonalization Using Ontology: A Survey”, IOSR Journal of Computer Engineering (IOSRJCE) ISSN : 2278-0661 Volume 1, Issue 3 (May-June 2012), PP 37-45 www.iosrjournals.org. Cooley, R., Mobasher, B., Srivastava, J.: Web mining: Information and pattern discovery on the world wide web. In: Proceedings of the 9th IEEE International Conference on Tools with Artificial Intelligence (ICTAI’97), Newport Beach, CA (November 1997) 558–567. Joshi, A., Krishnapuram, R.: On mining web access logs. In: Proceedings of the ACM SIGMOD Workshop on Research Issues in Data Mining and Knowledge Discovery (DMKD 2000), Dallas, Texas (May 2000). Liu, C. Yu, and W. Meng, 2002. “Personalized web search by mapping user queries to categories”. In Proceedings of CIKM, pages 558-565. Morris, M. R. (2008). “ A survey of collaborative Web search practices. In Proc. of CHI ’08, 1657-1660. Jones. W. P., Dumais, S. T. and Bruce, H. (2002). “Once found, what next? A study of ‘keeping’ behaviors in the personal use of web information. Proceedings of ASIST 2002, 391-402. Deerwester, S., Dumais, S., Furnas, G., Landauer, T.K., Harshman, R.: Indexing by Latent Semantic Analysis. Journal of the American Society for Information Science, 41(6) (1990) 391-407 Dolog, P., and Nejdl, W.: Semantic Web Technologies for the Adaptive Web. In: Brusilovsky, P., Kobsa, A., Nejdl, W. (eds.): The Adaptive Web: Methods and Strategies of Web Personalization, Lecture Notes in Computer Science, Vol. 4321. Springer-Verlag, Berlin Heidelberg New York (2007) this volume.

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A Novel Scheduling Algorithms for MIMO Based Wireless Networks *AjantaaPriyaadharsini.G.V., email id:ajantaavenkatesan@gmail.com. **Deepika.R, email id:dpka.sush94@gmail.com. Department of Electronics and Communication engineering, Narasu’s Sarathy Institute of Technology, Poosaripatty, Salem-636305. . Hence in this paper we propose different scheduling algorithm in which the awareness about interference has been incorporated. The receiver node first schedule all the requests contained in every correctly decoded RTS packet send by many senders for performance improvements. By enabling proper scheduling in the Medium Access Control layer (MAC), the system level performance has been improved by canceling the interference in Priority scheduling which we have proposed in MAC layer. Also we have analyzed the data rates and interference cancellation capability for the different scheduling policy which we have proposed in the MAC layer on RTS/CTS packets.

Abstract MIMO system has attracted considerable attention recently for its potential to increase the system capacity. In this paper, we aim to design practical user scheduling algorithms to maximize the system performance. Various MAC scheduling policies have been implemented, in order to provide distributed traffic control and robustness against interference. Further, in order to increase the efficiency of resource-utilization, the scheduling policies have been modified, and those have also been implemented. MATLAB simulations have been used throughout and the various policies have been compared with each other in order to draw important results and conclusions. This paper ends with a few suggestions for future improvements.

This paper has been organized as follows: In the next three sections, the theory about System Model, MAC layer Scheduling, Class and MAC layer policies has been described. The simulation results, using MATLAB, have been included in Section-5. Comparisons of the different MAC layer scheduling using the simulation results, and related discussions have also been included in the same sections.

Index Terms: MIMO, MAC, Scheduling, Resource utilization

1. Introduction Multi antenna system has been researched intensively in recent years due to their potential, to increase the channel capacity in fading channel. It is shown that MIMO systems can support higher data rates under same transmit power and BER performance requirements. Such system finds wide applications in WLAN networks. The conventional collision avoidance (CSMA/CA) approach described in the 802.11 standard [9] makes use of control messages (RTS/CTS) to mitigate the hidden terminal problem, thus preventing collisions that would result in loss of data and waste of resources. In a MIMO wireless network, however, this is not always the best solution. Specifically, the receiver structure is able to separate incoming PDUs, which would then not result in a collision, but could instead be detected separately. The networking protocols may then choose how many and which channels to estimate, taking into account that the limited receiver capabilities allow locking onto at most N sequences simultaneously. While doing this, trying to detect too many destinations oriented data packets could leave limited resources for interference cancellation, leading to data loss. Even with channel estimation and spatial de-multiplexing, the MIMO receiver itself is still vulnerable to “hidden terminals” in some sense: if the receiver is not aware of interfering nodes nearby, it cannot estimate their channel and cancel them.

2. System Model Traditionally, the growing demand of capacity has been met by increasing the bandwidth and/or by inventing more spectrally efficient communication protocols. However, since the introduction at Bell Labs about 10 years ago, the concept of MIMO (Multiple Input Multiple Output) shown in figure 1 has received an increasing attention. The main observation is that if both the transmitter and the receiver are equipped with n antennas, the capacity (bit rate) can be increased by up to a factor of ‘n’, depending on the richness of the wireless channel. In principle, one can form ‘n’ parallel channels, which can transmit independently of one another. In general, this is not possible for line-of-sight (LOS) channels, since the multiple channels cannot be independent and will therefore interfere. However, in a rich scattering environment, the capacity can increase by a factor up to ‘n’. The transmission of data in parallel streams is usually referred to as spatial multiplexing.

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transmitted vector symbol, assuming symbolsynchronous receiver sampling and ideal timing. Letting a = (a 1 , a2 , . . . ,aM )T denote the vector of transmit symbols, then the corresponding received N vector is r1 = Ha + ν (1) Here ν is a noise vector. One way to perform detection for this system is by using linear combinational nulling. Conceptually, each sub-stream in turn is considered to be the desired signal, and the remaining are considered as "interferers". Nulling is performed by linearly weighting the received signals so as to satisfy some performancerelated criterion, such as Zero-Forcing (ZF). When symbol cancellation is used, the order in which the components of a are detected becomes important to the overall performance of the system. We first discuss the general detection procedure with respect to an arbitrary ordering.

Many detection algorithms have been proposed in order to exploit the high spectral capacity offered by MIMO channels. One of them is the V-BLAST (Vertical Bell-Labs Layered Space-Time) algorithm which uses a layered structure. This algorithm offers highly better error performance than conventional linear receivers and still has low complexity.

2.1. Proposed System Model

Let the ordered set

In the system being implemented the MAC layer takes decisions based on received power levels. Hence there is a need for scheduling in the MAC layer for performance improvements.

S ≡ {k1 , k2 , . . . , kM}

…….(1)

be a permutation of the integers 1, 2, . . . , M specifying the order in which components of the transmitted symbol vector a are extracted. The detection process proceeds generally as follows:

2.1.1. Transmitting Nodes-- Any node splits the transmit data into sub-packets called Packet Data Units or PDUs. We suppose ‘uj’ PDUs are sent through spatial multiplexing i.e., ‘uj’ antennas, one per PDU, where ‘j’ is the node index. Power of the ith antenna, given that it belongs to user ‘j’ is given as Ptot/uj, the maximum total power of any node is constrained to Ptot.

Step 1: Using nulling vector wk1 , form decision statistic yk1 : yk1 = wk1T r1 …..(2) Step 2: Slice yk1 to obtain âk1: âk1 = Q(yk1)

2.1.2. Receiving Nodes-- Any receiver, say node ‘j’, uses all its available antennas NA. Thus, the received signal can be denoted using the NA-length column vector

……..(3)

Here Q(.) denotes the quantization (slicing) operation appropriate to the constellation in use.

r(j) = Ĥ (j)s’ +ν’(j)

Step 3: Assuming that âk1 = ak1, cancel ak1 from the received vector r1, resulting in modified received vector r2:

Here ν’(j) represents channel noise, and Ĥ (j) is the NA × U channel gain matrix. Under a Rayleigh fading assumption, Ĥ (j), ‘m’ is a circularly Gaussian complex random variable, including fading gain and path loss between the mth transmit and the nth receive antenna. We assume that the nodes’ channel knowledge is limited, i.e. at most NSmax channels related to as many transmit antennas can be estimated at the beginning of each reception. The set N(j) = {n1, . . . , nNS max} contains the indices of such known antennas (KAs), for which we assume perfect channel estimation.

r2 = r1 − âk1 (H)k1

……..(4)

Here (H)k1 denotes the k1-th column of H. Steps 1 -3 are then performed for components k2, . . , kM by operating in turn on the progression of modified received vectors r2, r3, . . . , rM. The specifics of the detection process depend on the criterion chosen to compute the nulling vectors wki , the most common of these being ZF. The kith ZF-nulling vector is defined as the unique minimum norm vector satisfying

2.1.3 The Blast Receiver ( Zero Forcing Algorithms with Optimal Ordering) – We take a discrete-time baseband view of the detection process for a single

Wk T i(H)kj = 0

j≥i

j=i

------- (5)

Thus, wki is orthogonal to the subspace spanned by the contributions to ri due to those symbols not yet estimated and cancelled. It is not difficult to show that

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the unique vector satisfying (5) is just the kith row of Hki − 1 where the notation Hki denotes the matrix obtained by zeroing columns k1, k2, . . . , ki of H and + denotes the Moore-Penrose pseudo inverse.

3. MAC Layer Scheduling A well-designed MAC protocol can offer much help to solve the channel estimation problem. In designing such a protocol, the concurrent channel access typically found in ad hoc networks can be exploited, instead of being suppressed. Collision avoidance schemes, such as 802.11, try to avoid concurrency by blocking the nodes that receive an RTS or CTS. Instead of blocking, simultaneous transmissions have to be encouraged. It is also desirable to make the receivers aware of potential interferers, and to exploit the spatial de-multiplexing capabilities of MIMO processing. To this aim, an assessment of the receiver performance when receiving data PDUs and signaling packets has to be done.

3.1 MAC Layer Design We have framed communication structure, with four phases. For this scheme to work correctly, all nodes have to share the same frame synchronization. These phases are designed according to the standard sequence of messages in a collision avoidance mechanism, and are summarized as follows. 3.1.1 RTS phase—In this phase, all senders look into their backlog queue, and if it is not empty they compose transmission requests and pack them into a single RTS message. Each packet in the queue is split into multiple PDUs of fixed length, such that each PDU can be transmitted through one antenna. For this reason, any request has to specify the number of PDUs to be sent simultaneously, in addition to the intended destination node. Any RTS may contain several such requests. Moreover, an RTS is always sent with one antenna and at full power. 3.1.2 CTS phase—During the RTS phase, all nodes that were not transmitters themselves receive multiple simultaneous RTSs, and apply the reception algorithm as described in the previous section, to separate and decode them. In the CTS phase, when responding to the correctly received RTSs, nodes have to account for the need to both receive intended traffic (thus increasing throughput) and protect it from interfering PDUs (thus improving reliability). The constraint in this tradeoff is the maximum number of trackable channels, i.e., the maximum number of training sequences a node can lock onto. CTSs are also sent out using one antenna and at full power. 3.1.3 DATA phase—All transmitters receive superimposed CTSs and, after BLAST detection, they follow CTS indications and send their PDUs. Each PDU has a fixed predefined length and is transmitted through one antenna, but a node can send multiple PDUs simultaneously, possibly to different receivers.

Figure 2 shows the MIMO system with scheduler. Here priority based scheduling, Partially Fair Scheduling with and without interference cancellation is proposed. In Priority scheduling, the scheduler receives many RTS packets and schedule according to the priority namely destination oriented (D) packets and non destination oriented (ND) packets. The Performance of all kind of scheduling is analyzed in the section IV.

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3.1.4 ACK phase—After detection, all receivers evaluate which PDUs have been correctly received, compose a cumulative PDU–wise ACK, and send it back to the transmitters. After this last phase, the data handshake exchange is complete, the current frame ends and the next is started. This corresponds to the implementation of a Selective Repeat Automatic Repeat reQuest (SR–ARQ) protocol, where PDUs are individually acknowledged and, if necessary, retransmitted. Before going more deeply into CTS policy definition, it should be noted that a random back off is needed for nodes that do not receive a CTS, as otherwise persistent attempts may lead the system into deadlock. Here, a standard exponential back off is used. Accordingly, before transmitting, nodes wait for a random number of frames, uniformly distributed in the interval [1,BW(i)], where i tracks the current attempt, and BW(i) = 2i−1W, with W a fixed back off window parameter. An accurate study of the effects of different back off strategies can be found in [12].

distance between the transmitter and the receiver. Looking at a multiple receiver context as in MIMO, where the transmitter could send data to many neighbours at once, the concept of class can be a very useful tool to ensure a satisfactory amount of quality along with the maximum data rate. Together with this concept of class and a modified set of RTS and CTS policies, an increase in performance levels may be made, by making best use of the available spatial diversity due to MIMO.

4.2 MAC Layer Policies The traditional collision avoidance approach makes use of control signals (RTS/CTS) in order to avoid collisions by ensuring only one transmission at every time slot. But when MIMO is used at the physical layer, multiple transmissions can be supported simultaneously with the use of a modified RTS and CTS policy. 4.2.1 RTS – In this RTS policy, parallelism and allow simultaneous transmissions have been encouraged. Here, RTS/CTS messages are used for traffic load estimation rather than blocking simultaneous transmissions. Since signalling packets are shorter and transmitted with a single antenna at full power, they are expected to be detectable in large quantities without significant errors. In the modified policy, the concept of class has been integrated along with RTS messages of the traditional 802.11 to create a new RTS policy. The algorithm recursively checks the sender end queue, which holds the receiver ID, the number of PDU’s to be transmitted and the class of the receiver with respect to the particular transmitter, for each intended transmission. Based on the class of the receiver, the algorithm successively includes requests to various receivers in the same RTS packet. Each RTS packet includes as many requests for PDU’s as the minimum class of those receivers included in that packet. Two modifications in the RTS packaging that would result in performance improvements are as follows.

4. Class and MAC Layer Policies Class is a new concept that limits the maximum number of antennas that a transmitter can use while transmitting to a particular receiver. There exists a tight relationship between the number of used antennas (thus, bit rate) and the average received power, thus the maximum coverage distance affordable.

4.1 Class The maximum number of antennas as related to the distance of a node is called the “class” of the node. For any transmitter, the total power allocated for a single instance of transmission is a constant quantity, say for example 100 W. As the number of transmit antennas increase, this power is divided equally among the same i.e. 2 transmit antennas implies 50 W through each, 4 transmit antennas implies 25 W through each and 10 transmit antennas implies 10 W through each. Now based on the location of the receiver, it is an obvious conclusion that as the distance between the transmitter and the receiver increases, the power necessary to ensure successful reception with good signal quality, increases and hence the CLASS of the receiver with respect to that particular transmitter decreases. In order to calculate the class of different nodes with respect to each other, assuming free space propagation losses only, the free space path loss model is used to account for the power loss. By setting a minimum threshold of necessary received power for satisfactory signal quality, the maximum number of transmit antennas permissible is calculated. In simple terms, the maximum number of antennas permissible (I) is inversely proportional to the

The queue is scheduled (reordered) with all the requests with higher class at the front end, so the number of simultaneous requests is large. This ensures best utilization of the available antenna resources. This also implies that the number of RTS packets itself reduce thereby providing further power saving.

The FIFO queue that was assumed in the original policy could result in starvation to a particular node, if its distance from the transmitter is particularly large and hence, its class is minimum. Hence priorities may be assigned to all the neighbours of a node and in case of a node being by passed once, its

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priority comes into picture and has to be included in the next round of RTS packaging.

4.2.2 CTS – In collision avoidance schemes like 802.11, concurrency is avoided by blocking the nodes other than one sender and transmitter pair. In contrast to this, in the following CTS policy, simultaneous transmissions are encouraged. At the same time, the receivers should also be warned of potential interferers and should be capable of exploiting the spatial de multiplexing capabilities of the MIMO system. A receiver node can receive multiple RTS packets, each of which can contain multiple requests. Each request in turn comprises of the receiver id and the number of PDUs requested to be sent. Against this background, the receiver node first sorts all the requests contained in every correctly decoded RTS packet in the order of decreasing received power, and divides them into two subsets depending on the receiver ID mentioned in the request, namely Destination oriented ‘D’ (containing the requests meant for itself) and non Destination oriented ‘ND’ (containing all remaining requests). If a request by node x implies the transmission of, say, y PDUs, the receiver has to account for channel estimation resources that will be needed for all the y PDU transmissions. Since the maximum number of simultaneous PDUs that can be tracked by a receive antenna is limited to, say, Nsmax, each time a transmission is granted, the number of available tracking resources is decreased by y. This is done until there are no more resources left. This process of granting resources involves a tradeoff between the number of simultaneous transmissions that it allows to itself and the amount of interference from transmission by other nodes that it cancels. There are four different CTS policies here:

 Priority Scheduling (PS): Do the following steps till Ns=0 - Start with request in D - Read source Si and number of PDUs Pi for the packet with index i. - Insert grant (Si,Pi) in the CTS. - Ns=Ns-Pi - If for any i, Ns<Pi , allot Ns-Pi PDUs for the particular request. - After all the requests in D are exhausted, if Ns>0, Do the following steps for ND - Read Si of the non destination oriented request and the number of PDUs Pi. - If Pi<Ns, add (Si,Pi) to interference cancellation list - Ns=Ns-Pi - Stop - Using resources allotted accept incoming packets and cancel interference from other exchanges 

Partially Fairness Scheduling Without Interference Cancellation (PFS-WIC): Do the following steps till Ns=0 - i=D(1). (Insert the first request in the destination oriented list in the CTS) - Read source Si and number of PDUs Pi for the packet with index i - Insert grant (Si,Pi) in the CTS. - Ns=Ns-Pi - queue=queue-i - Let k be the request with highest power in the queue € D Ủ ND - If k€D then  Insert grant (Si,Pi) in the CTS.  Else store in interference cancellation list  Endif - Stop - Using resources allotted accept incoming packets.



Priority Scheduling Without Interference Cancellation (PS-WIC): Do the following steps till end of D. - Read source Si and number of PDUs Pi for the packet with index i - Insert grant (Si,Pi) in the CTS. - Ns=Ns-Pi - If for any i, Ns<Pi, allot Ns-Pi PDUs for the particular request. - If Ns=0, STOP  Partially Fairness Scheduling(PFS): Do the following steps till Ns=0 -

Let k be the request with highest power in the queue € D ND ND If k€D then  Insert grant (Si,Pi) in the CTS.  Else store in interference cancellation list Endif Stop Using resources allotted accept incoming packets and cancel interference from other exchanges.

i=D(1). (Insert the first request in the destination oriented list in the CTS) Read source Si and number of PDUs Pi for the packet with index i Insert grant (Si,Pi) in the CTS. Ns=Ns-Pi queue=queue-i

In real time networks, only Partially Fairness Scheduling (PFS) and Priority Scheduling (PS) are practical for use, since the other two do not provide any interference cancellation. Between PFS and PS, choice is made depending on which of the two performance

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parameters, SNR and throughput, is critical to the network under consideration.

Comparison of Capacity for siso and mimo 12 siso mimo 10

Capacity in bps/Hz

5. Simulation Results and Discussions In order to evaluate the performance of these RTS/CTS policies specifically designed for MIMOVBLAST physical layer, 4 nodes, each with 10 antennas, are deployed. The 4 nodes are assigned varying coordinates, thereby simulating a mobile topology. The assumption made is that condition of frame synchronization holds throughout the simulation. Traffic is generated according to a Poisson process at the rate of Λ packets per second per node. Each generated packet has ‘k’ 1000-bit long PDUs, where ‘k’ is a whole number. This specific configuration is tested because; all nodes are within coverage range of each other. This is a demanding scenario in terms of interference, required resources and efficient protocol design. All the simulations have been made using MATLAB codes. Transmissions follow the MAC protocol, as described in the previous section.

0 -10

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0 2 Eb/No in dB

Figure 3: MIMO performance

5.2 V-Blast Performance To simulate the performance of the BLAST physical layer, V-BLAST algorithm with optimal ordering has been used for a codebook of a specified length. Optimal ordering of received signals in the descending order of power ensures that signal decoding is of better quality. In this paper, the spatial multiplexing technique has been implemented using V-BLAST in the physical layer.

5.1 MIMO Performance

5.2.1 Transmitter Diversity -- Figure 4 shows an insight into the performance of the system. Here, the Bit Error Rate (BER) vs. SNR values has been plotted for a system having 12 receivers and varying number of transmitters. It can be seen that for the same value of SNR, in every case, the system with fewer antennas is found to have a better BER performance i.e. have a lesser Bit Error Rate than systems with more number of transmitters. This is because as the number of transmitters increase, there is more interference caused at the receiver side due to other unwanted transmissions (transmissions not addressed for the receiver).This causes degradation in the performance, as shown in the graph.

A comparison is made between the capacity of a Single Input Single Output and Multiple Input Multiple Output systems for specific Eb/No values. Capacity is measured in bits per second per hertz (bps/Hz) of the given frequency and Eb/No is measured in Decibels (dB). From figure 3, it is observed that the capacity of the MIMO system is higher than the SISO system for every value of Eb/No. Shannon’s capacity theorem is used for the capacity calculation. Thus, performance of MIMO is found to be much better than the performance of SISO for every value of Eb/No. In fact, the capacity increases ‘N’ fold for MIMO, where ‘N’ is related to the number of transmitting and receiving antenna.

BER for BLAST for 12 Receiver Antennas and various number of Transmit antennas 0 10

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Bit Error Rate

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4 Tx, 12 Rx 10 Tx, 12 Rx 14 Tx, 12 Rx -8

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-4 -2 Eb/No,dB

Figure 4: Transmitter diversity

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dependence of class on distance 9

To combat this degradation in performance the concept of CLASS has already been mentioned in this paper. This specifies the optimal number of transmitter antennas to be used for a specific distance between the transmitter and receiver. In mobile wireless networks, where the distances of the nodes keep varying with respect to each other, it is not advisable to use a fixed number of transmitter antennas for all distances. A brief discussion of CLASS follows next.

permissible distance betw tx rx

8 7 6 5 4 3 2 1 0

5.2.2 Class -- To do the classification, a topology consisting of a number of transmitters at varying distances from the receiver has been considered. The graph of figure 5 specifies the maximum number of antennas a transmitter can use when it is at a particular distance from the receiver. This number (number of transmit antennas to be used) classifies the transmitter into its respective CLASS. This classification is based on the power levels of the received packets. When transmit diversity is employed, the total power level at the node is divided equally among all the transmit antennas to be used for the transmission. Thus power of every PDU (each antenna transmits one PDU per transmission) decreases in accordance to this division. The channel employed here is a multipath Rayleigh fading channel. Power allotted to each transmit antenna should be sufficient to withstand the fading caused by the channel. Each receiver has a threshold power level for decoding. If a packet arrives with a power level below the threshold it cannot be detected. In the figure 5, below, it can be seen that, when the distance is very high the number of transmitter antennas used is very less. This is because the packet has to travel a long distance and thus requires a lot of power to withstand the fading and attenuation losses. For the maximum distance, literally, only one antenna is used. For distances above this maximum distance, multi-hop transmission is employed. The number increases exponentially with decrease in distance and it is observed that the maximum number of antennas is used for shorter distances.

5 6 no of tx ant

Figure 5: Class vs. Distance

5.2.3 Receiver Diversity â&#x20AC;&#x201C; Contrary to the previous case of transmitter diversity, performance increases in the case of receiver diversity. Figure 6 is a clear proof of this statement. Here the cases of 8 transmit antennas for varying number of receiver antennas is compared.

Bit Error Rate

BER for BLAST for 8 transmit antennas and various number of receive antennas 0 10

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8 Tx, 8 Tx, 8 Tx, 8 Tx, 8 Tx, -8

8 Rx 10 Rx 12 Rx 14 Rx 22 Rx -6

-4 -2 Eb/No,dB

Figure 6: Receiver diversity It is seen that the best Bit Error Rate performance is for the receiver having 22 antennas. This is because with increase in the number of receivers more paths exist from each transmitter antenna and each path exhibits varied levels of fading. This indicates possibilities of channels with lesser levels of fading. In every case it can be seen BER decreases with increasing values of SNR. However, for each value of SNR the node with 22 antennas has the least value of BER. Thus, robustness increases with receiver diversity.

5.3 Performance Comparisons The primary comparison among the policies is based on data rates, which in turn is dependent on the

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number of grants allotted for the wanted PDUs. The packet arrival rate is varied each time, and the corresponding data rate is noted. As seen in figure 7, in every case, i.e. for any packet arrival rate, the data rate of Priority Scheduling (PS) is greater than Partially Fairness Scheduling (PFS). This is because PS prioritizes allotting resources (for the destination oriented packets) to interference cancellation. Thus, data rate is higher in PFS scheme.

Interference cancelled for the different CTS policies 6

Number of interfering PDUs cancelled

PFS PS 5

data rate for the different CTS policies PFS PS

9000

Packet arrival rate per node per second . Figure 8: Comparison of interference cancellation for PFS and PS

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data rate in bps

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As the number of packets arriving increases PS has only enough resources to grant for the wanted packets. Thus it can be seen for higher values of Î&#x203A; interference cancellation for PS is zero.

6000 5000 4000 3000 2000 1000

Signalto Noise Ratio for the different CTS policies 2.5

3 4 5 6 7 Packet arrival rate per node per second

PS-WIC PFS PS PFS-WIC

Figure 7: Comparison of Data Rates between PFS and PS

1.5 SNR

The plot for Priority Scheduling without Interference Cancellation (PS-WIC) and Partially Fairness Scheduling without Interference Cancellation (PFS-WIC): are not shown here, because their grants are similar to PS and PFS, respectively. Thus, it is sufficient to compare the latter two schemes. The next parameter for comparison is the amount of interference cancelled by the two schemes. From figure 8, it can be seen that PFS outperforms PS for almost every Î&#x203A; value. This is just the inverse of the previous graph, as the total resources are divided between these two activities of accepting data and cancelling interference from other parallel transmissions. For the initial values, both PFS and PS seem to show the same performance in case of interference cancellation because the number of arriving packets themselves is very less.

0.5

3 4 5 6 7 Packet arrival rate per node per second

Figure9: SNR for various CTS policies Another very important way of interpreting the above two graphs is by comparing the SNR performance of the schemes. The interference cancelled and the grants given actually have a direct implication on the SNR at the receiver. From figure 9, it can be seen that the SNR performance of PFS is the best followed by PS. In PFS, major portion of the resources are allotted for interference cancellation. Hence, noise caused due to other interfering packets is less, and SNR is higher. In PS, the resources are given preferably to the wanted packets. Interference cancellation plays second fiddle here, a direct consequence of which is seen in the graph above. However, as the number of packets arriving increases, there is a decrease in the SNR in both the schemes due to limited availability of resources. In every case, PS-WIC is found to have the least performance. As the arrival rate becomes higher, it can be seen that PFS-

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WIC performs slightly better than PS. This can be explained as follows: At high arrival rates, PS exhausts all its resources towards allocation to the wanted set and hence may not be left with any resources for interference cancellation. PFS-WIC, too, by itself does not perform any interference cancellation. However, the above mentioned performance degradation in PS can be attributed to the fact that PS could allocate resources to requests of very low power levels which have low immunity to noise. However PFS-WIC, following PFS, allocates resources only for packets with sufficient power. Thus, SNR performance of PFS-WIC is better than PS at high arrival rates.

time. This limits the data rate. However, in the improved RTS/CTS policy, simultaneous transmissions from different senders are encouraged by providing for interference cancellation, thereby improving the data rate per receiver. In both figures 10 and 11, (comparison of PFS and the conventional policy, and comparison of PS and conventional policy), the improved RTS/CTS policy is found to give a better data rate than conventional policies. However the performance improvement in PS is found to be more than in PFS.

6. Conclusions And Future Work In this work, the advantages of Multiple Input Multiple Output (MIMO) over Single Input Single Output (SISO) have first been addressed. The performance of the V BLAST physical layer (with optimal power ordering) has also been studied. The cross layer policies to drive traffic requests and grants have been considered, with the aim of designing an efficient way to let multiple point-to-point links coexist while keeping interference under control. Simulations of MAC policies in a demanding mobile network scenario with all nodes within the coverage of each other have been carried out. These results have been used to highlight the key features that yield the best performance in terms of throughput and signal to noise ratio. Future work on this topic includes a study on the impact of channel estimation at the transmitter on the overall performance, and the extension to multihop topologies and routing issues.

PS and conventional 8000 conventional RTS/CTS PS

7000

Data rate in bps

6000 5000 4000 3000 2000 1000 0

Packet arrival rate per node per second Figure 10: Data rate comparison of conventional and PS

Next, the importance of the RTS/CTS schemes, so far explained, is highlighted. This is done by making a comparison of data rates between our scheme and the conventional 802.11 collision avoidance scheme.

References [1] P. Wolniansky, G. Foschini, G. Golden, and R. Valenzuela, “V-BLAST: An Architecture for Realizing Very High Data Rates Over the Rich- Scattering Wireless Channel”, in Proc. 1998 URSI Int. Symp. on Sign., Syst., and Elect., 1998, pp. 295–300.

PFS and conventional

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conventional RTS/CTS PFS

[2] Paolo Casari, Member, IEEE, Marco Levorato, Student Member, IEEE, and Michele Zorzi, Fellow, IEEE “MAC/PHY Cross–Layer Design of MIMO Ad Hoc Networks with Layered Multiuser Detection” IEEE Transactions on Wireless Communications, VOL. 7, NO. 11, November 2008, pp.45964607.

Data rate in bps

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[3] G. J. Foschini, “Layered space-time architecture for wireless communication in a fading environment when using multiple antennas," Bell Labs Tech. J., vol. 1, no. 2, pp. 41-59, 1996.

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[4] H. Jafarkhani, “Space-Time Coding: Theory and Practice.” Cambridge University Press, 2005.

Packet arrival rate per node per second

[5] P. W. Wolniansky, G. J. Foschini, G. D. Golden, and R. A. Valenzuela, “V-BLAST: an architecture for realizing very high data rates over the rich-scattering wireless channel," in Proc. IEEE ISSSE, Pisa, Italy, Sept. 1998, pp. 295-300.

Figure 11: Data rate comparison of conventional and PFS

In the conventional collision avoidance system, simultaneous transmissions are not allowed, and the MIMO wireless channel is reserved for one request at a

[6]L. Zheng and D. N. C. Tse, “Diversity and multiplexing: a fundamental tradeoff in multiple-antenna channels," IEEE

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Trans. Inform. Theory, vol. 49, no. 5, pp. 1073-1096, May 2003. [7] S. M. Alamouti, “A simple transmit diversity technique for wireless communications,” IEEE Trans. Commun., vol. 16, no. 8, pp. 1451-1458, Oct. 1998. [8] M. Hu and J. Zhang, “MIMO ad hoc networks: medium access control, saturation throughput, and optimal hop distance”, J. Commun. Networks, special issue on mobile ad hoc networks, pp. 317-330, Dec. 2004. [9] IEEE Standards Department, ANSI / IEEE Standard 802.11. IEEE Press, 1999. [10]Holger Boche, University of Technology Berlin and Fraunhofer German-Sino Laboratory for Mobile Communications Marcin Wiczanowski, University of technology Berlin, “The Interplay of Link Layer and Physical Layer under MIMO enhancement: Benefits and Challenges”, IEEE, August 2006, pp. 48-55 [11]M.Bengtsson and B.Ottersten, Handbook of Antennas in Wireless Communications, Ch.18, “Optimal and Sub-optimal Transmit Beamforming”, CRC Press, 2001 [12] M. Levorato, P. Casari, and M. Zorzi, “On the performance of access strategies for MIMO ad hoc networks," in Proc. IEEE GlobeCom, Nov. 2006, pp.1-5.

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BER Performance of CDMA, WCDMA, IEEE802.11g in AWGN and Fading Channels M.A.ARCHANA, Dr.C.PARTHASARATHY, C.V.S RAVI TEJA maarchaname@gmail.com, drsarathy45@gmail.com , ravi.teja2394@gmail.com ABSTRACT

standards, including slot synchronization, frame synchronization with code group identification and scrambling code identification. In CDMA 2000, a pilot channel is spread by a PN code with cellspecific code phase to help timing synchronization between mobile and base stations. In 802.11g, a Barker code is applied to detect bit boundary before packet identification. In this paper we have illustrated through simulation results of the level of power consumption of different wireless communication standards applicable in AWGN and fading channels. 1.1Additive White Gaussian Noise (AWGN) Channel: accounts only for white noise and does not accounts for fading frequency selectivity, interference and dispersion. BSC channel corrupt a binary signal by reversing each bit by a fixed probability p. Multipath fading channel include multipath scattering effects, time dispersion, and Doppler shifts that arise from relative motion between the transmitter and receiver. CDMA-2000 is a terrestrial radio interface of 3G wireless communication and specifications developed by 3GPP2. It is basically developed within the specification of IMT-2000 of international telecommunication union (ITU) and is backward compatible and well suited for global roaming. CDMA-2000 physical layer includes several modes of operations as per the requirement of user and local conditions. 1.2 Fading Channel: The rapid fluctuation of the amplitude of a signal over a relatively small distance is referred to as fading. Interference between two or more versions of the transmitted signal can result in different propagation delays at the receiver and this is known as multipath. Fading channel models are often used to model the effects of electromagnetic transmission of information over the air in cellular networks and broadcast communication. Fading channel models are also used in underwater acoustic communications to model the distortion caused by the water.

In recent years wireless communication plays a vital role in the world, it makes us relax from the overhead of cables. Nowadays WCDMA, CDMA2000, and IEEE 802.11g systems receive a great deal of attention in wireless communications. One of the common parts of these three systems is the direct-sequence code-division multiple access (DS-CDMA) technology. In DS-CDMA systems, pseudo noise (PN) code synchronization is one of main challenges due to its code length. PN codes are usually used to identify channels during communications. Before a handset starts to receive system broadcast channels, a code synchronization process is necessary to achieve codes, timing, and frequency synchronization with the target cell site and vice versa, also the tremendous increase in usage of wireless communication. In this paper we propose an integrated code synchronizer for WCDMA, CDMA 2000, IEEE 802.11g which is designed by applying three low power techniques such as power management, absolute weighted magnitude calculation and spurious power suppression adder. In addition, a common combined scheme is used to evaluate the bit-error-rate performance of the different wireless Standards, both in AWGN and fading channels. Simulation results are being obtained using MATLAB. Key words: WCDMA, CDMA 2000, IEEE 802.11g, Absolute Weighted Magnitude Calculation, Spurious Power Suppression Adder, AWGN, Fading channel. 1 INTRODUCTION WCDMA, CDMA2000 and 802.11 g system receive a great deal of attention in wireless communications. This paper is divided into three parts such as code synchronizations for three different systems. In WCDMA, a three-stage code synchronization process is implemented in 3 GPP

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number of channels. Each channel has an equal bandwidth and is determined by the target data bit rate and the modulation scheme used. A transmitter sends data from each channel for a fixed amount of time called the dwell time. There are two types of frequency hopping slow frequency hopping and fast frequency hopping. The main advantage of frequency hopping over DSSS is its flexibility to use and alternative channel within the allocation band .Typically there are 22 hop patterns and 79 no overlapping frequency channels with 1 MHz channel spacing. 2.3.3 Direct Sequence Spread Spectrum (DSSS) Direct Sequence Spread Spectrum (DSS) is modulation techniques in which a message signal is spread over a bandwidth that is typically much greater than that required for reliable communications. . DSSS PHY is the part of PHY layer works on 2.4 GHz frequency band. Data transmission is run through the DSSS PMD sub layer. The DSSS PMD get binary bits information from the PLCP protocol data unit (PPDU) then change into RF signals for the wireless medium by the help of carrier modulation and DSSS techniques. The PLCP preamble and PLCP header send 1 Mbps with differential binary phase shift keying (DBPSK) and MPUD send at either 1Mbps or 2Mpbs both uses differential quadrature phase shift keying (DQPSK) modulation techniques. DSSS techniques also use in cellular network (CDMA), Global Positioning System (GPS). 2.3.4 Orthogonal Frequency Division Multiplexing (OFDM) OFDM is a multi-carrier modulation technique which is used to transmitted single data stream over a number of lower rate subcarrier either modulation or a multiplexing technique. IEEE 802.11’s standard adopted OFDM technology because of transmission high-rate wireless local area networks (WLANs).The main reasons to merged OFDM in IEEE 802.11 is to increase the robustness against frequency selective fading and narrow interference. There are some more features concerned with the OFDM technology are:  High spectral efficiency  Great flexibility  Confirmation to available channel bandwidth

2 TECHNOLOGIES USED WCDMA, CDMA2000, and IEEE 802.11g are the three different types of wireless standard technologies used. 2.1 WCDMA W-CDMA (Wideband Code Division Multiple Access) is a wideband spread-spectrum channel access method that utilizes the directsequence spread spectrum method of asynchronous code division multiple accesses to achieve higher speeds and support more users compared to most time division multiple access (TDMA) schemes used today. 2.2 CDMA2000 CDMA2000 is a family of 3G mobile technology standards, based on CDMA, to send voice, data, and signaling data between mobile phones and cell sites. CDMA2000 is also known as IMT Multi -Carrier (IMT-MC)) 2.3 IEEE 802.11g The IEEE 802.11g wireless standard protocol is growing rapidly worldwide and become the most mature technology for WLANs. The IEEE 802.11g standard consists of detailed specifications for both the medium access control (MAC) and three physical layers (PHY). The PHY layer selects the correct modulation scheme that provides spread spectrum in channel accessibility, data rate as well as the necessary bandwidth. The IEEE 802.11g physical layer uses basically four types of wireless data exchange techniques:  Infrared (IR)  Frequency hopping spread spectrum (FHSS)  Direct sequence spread spectrum (DSSS).  Orthogonal Frequency Division Multiplexing (OFDM) 2.3.1 Infrared (IR) IR transmission operate at wavelength near 850nm.The IR signal is produced either by semiconductor laser diodes or LEDs with the former being preferable because their electrical to optical conversion behavior is more liner. The infrared technology is not successfully commercialized. 2.3.2 Frequency hopping spread spectrum (FHSS) Frequency hopping spread spectrum (FHSS) is to divide the allocated frequency band into a

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2.3.5 Bit error rate Bit error rate is a method of assessing the digital wireless transmission and thus is a very good way of increasing the system integrity and even the robustness can be improved by calculating the bit error rate and if it is below a certain threshold, steps can be taken to improve it

3.2 CDMA 2000 In CDMA2000, Pilot channel is spread by a PN code with length of 32 768 chips. It is not necessary to detect all 32 768 chips. There is a tradeoff between hardware Complexity and correct detection rate. We decide to detect 128 chips of the PN code in a CDMA2000 system to achieve the hardware efficiency as well as the detection rate. Figure 3. 2 shows the generalized model

Bit Error rate = Number of errors / Number of bits transmitted

3 PROPOSED SYSTEM 3.1 WCDMA In WCDMA, the code synchronization is divided into a three stage process Primary synchronization code, secondary synchronization codes have to be identified by active correlator. Scrambling code is identified by ballot machine. Stage 1 has to detect a 256-chip primary synchronization code (PSC). Generally, the matched filter is used to detect the slot boundary, and the correlation results are further accumulated for 15 slots to improve the signal-to-noise ratio (SNR). Stage 2, one of 16 secondary synchronization codes (SSCs) has to be identified by active correlator for further comma-free Reedâ&#x20AC;&#x201C;Solomon decoding. Stage 3, one of eight complex-valued scrambling codes is identified as the cell-specific scrambling code by ballot machine. Figure 3. 1 shows the generalized model for the three stages. First, input data are correlated with local generated PN code sequence. Then, correlation results are calculated and accumulated, and the maximal result is identified as the desired timing or the local PN code is identified as the desired one by the peak detector.

Figure 3.2 CDMA2000 Code Synchronizer Model 3.3. IEEE 802.11g In 802.11 g, bit boundary is identified through Barker code detection. Accordingly, an 11chip detection of Barker codes is applied to 802.11 g code synchronization. A synchronization fieldmatched filter is employed to calculate the correlations between and Barker codes. When the peak detector generates periodic peak values, Barker codes are located. Figure 3. 3 shows the generalized model.

Figure 3.3 IEEE 802.11 g Code Synchronizer Model

4. DESIGN METHODOLOGY 4.1 System Architecture According to the models of Figures 3. 1â&#x20AC;&#x201C;3.3, the integrated synchronizer for WCDMA, CDMA2000, and 802.11 g is generalized, and the overall model is shown in Figure 4.1. Input data are correlated. With local generated PN-code sequences. Then, correlation results are calculated and accumulated, and the peak result is identified as the desired timing or the local PN code is identified as the desired one. Note that only necessary hardware blocks in this generalized model are enabled when operating in different systems

Figure 3.1 WCDMA Code Synchronizer Model

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calculating the CE’s .So applying low power techniques in the design of the adders to improve the power dissipation of the synchronizer Techniques: 1.A spurious power suppression technique (SPST) 2. Absolute weighted magnitude 3.Power management. Figure 4.2 illustrates a spurious power suppression technique (SPST) adder in which it is further divided into most significant part (MSP) and least significant part (LSP) sub adders to reduce adder operations. This SPST adder is especially effective for PN-code synchronizations since it mostly results in very small values. 5 RESULTS For performing simulations, simulation was developed under MATLAB 7.0 environment. This work is mainly dependent on the bit error rate performance of the system when the signal is passed through the AWGN and fading channels under the three different wireless communications technologies viz. WCDMA, CDMA2000 and IEEE 802.11g. Figure 5.1 illustrates the Power consumption in the CE array of WCDMA technology in AWGN channel with and without low power technique. Spurious power suppression technique has reduced half of the power in the AWGN channel. Figure 5.2 illustrates the power consumption Power consumption in the CE array of WCDMA technology in Fading channel with and without low power technique. When compared to AWGN channel fading channel has consumed less power.

Figure4.1 System Architecture 4.2 Spurious Power Suppression Technique The adders in the RCU design, uses spurious power suppression technique, are separated into two parts namely the most significant part (MSP) and the least significant part (LSP) between the eighth and the ninth bits. The adder is designed such that it latches the input data of the MSP whenever it doesn’t affect the computation results. By eliminating the computation in MSP, it not only save power consumption inside the adder in the current stage but also reduce the glitching noises which occurs in the arithmetic units in the next stage. The detection logic unit and SE unit is used to determine the effective input ranges of the operands and used to compensate the sign signals respectively.

40 35

P o w e r(m W )

30 25 20 15 10

Figure 4 .2 Low power adder design using spurious power suppression technique 4.3 Correlation Element Array It is composed of 16 rows, each row include 16 CE’s So CE Array contains 256 CE’s It is configured to work in 2 modes Active mode: partial results are fed back to its input to execute self accumulated correlations. Passive mode: Serially linked CE’s form a matched filter. 256 CE’s are linked into chain 4.4 Code synchronization Most of the power consumption occurs only in CE array. Adders play an important role when

5 0

1 W CDMA W it hout S PST

WCDMA With SPST

Figure 5.1 Power consumption in the CE array of WCDMA technology in AWGN channel 40 35

Pow er(m W )

30 25 20 15 10 5 0

1 WCDMA Without SPST

W CDMA W ith SPST

Figure 5.2 Power consumption in the CE array of WCDMA technology in fading channel

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Figure 5.3 illustrates the power consumption in the CE array of CDMA2000 technology in AWGN channel with and without spurious power suppression technique. Figure 5.4 illustrates the power consumption in the CE array of CDMA2000 technology in fading channel. When compared to AWGN channel fading channel has consumed less power and the proposed design has low effect on the control of power consumption by the system.

Figure5.5 Power consumption in the CE array IEEE 802.11g of technology in fading channel 40

Power(mW)

1 802.11G Without SPST

802.11G With SPST

40 35

Figure 5.6 Power consumption in the CE array of IEEE 802.11g technology in fading channel

Power(mW )

30 25 20 15 10

Thus at last we are going to show the bit error rate performance of the system when the signal is passed through the AWGN and fading channels in figure 5.7 and figure 5.8 respectively.

5 0

1 CDMA W ithout SPST

CDM A W ith SPST

Figure 5.3 Power consumption in the CE array of CDMA2000 technology in AWGN channel

10 40

CDMA-AWGN WCDMA-AWGN 802.11g-AWGN CDMA-FADING WCDMA-Fading 802.11g-FADING

-1

BER

Power(mW)

-2

-3

5 0

1 CDMA Without SPST

-4

-20

-15

-10

CDMA With SPST

-5 EsNo

Figure 5.7 BER of WCDMA, CDMA2000, 802.11g in AWGN and fading channels without spst

Figure 5.4 Power consumption in the CE array of CDMA2000 technology in fading channel Figure 5.5 illustrates the power consumption in the CE array of IEEE 802.11g technology in AWGN channel with and without spurious power suppression technique. Figure 5.6 illustrates the power consumption in the CE array of IEEE 802.11g technology in fading channel. The power consumed in this technology is very much lower, When compared to WCDMA, CDMA2000.

CDMA-AW GN WCDMA-AWGN 802.11g-AW GN CDMA-FADING WCDMA-Fading 802.11g-FADING

-1

-2

BER

-3

-4

-5

-20

-15

-10

-5 EsNo

Figure 5.8 BER of WCDMA, CDMA2000, 802.11g in AWGN and fading channels with spst

Pow er(m W )

30 25 20 15 10 5 0

1 802.11G W ithout SPST

802.11G With SPST

6 CONCLUSIONS

In this paper, the proposed Scheme of adding Spurious power suppression technique to the

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code synchronizer shows the results that the power consumption can be reduced to 56.27% in WCDMA, 5.86% in CDMA2000 synchronization, and 83.98% in 802.11 g synchronization, respectively. Moreover, the proposed Scheme takes the system integration issues into account by balancing the data I/O rate and the data processing rate through an interlaced I/O schedule. REFERENCES

[10] K. H. Chen, Y. M. Chen, and Y. S. Chu, “A versatile multimedia functional unit design using the spurious power suppression technique,” in Proc. IEEE Asian Solid-State Circuits Conf., 2006, pp. 111–114. [11] Nisha D, Divya K, Saranya K “A Low Complexity Image Scaling Processor Using Spurious-Power Suppression Technique,”in proc International Journal of Advanced Research in Computer and Communication Engineering Vol. 3, Issue 3, March 2014, pp 5228-5232. [12] Jaspreet kaur, Manish Jaiswal, Anuj Kumar Sharma, Vikash Singh, Udit Gupta,” Performance Analysis of IEEE WLAN 802.11a in Presence of Different FEC”, in proc Conference on Advances in Communication and Control Systems 2013 , pp 642646.

[1] W. C. Yeh and C. W. Jen, “High-speed Booth encoded parallel multiplier design,” IEEE Trans. Comput., vol. 49, no. 7, pp. 692–701, Jul.2000. [2] L. Benini, G. D. Micheli, A. Macii, E. Macii, M. Poncino, and R. Scarsi, “Glitching power minimization by selective gate freezing,”IEEE Trans. Very Large Scale Integr. (VLSI) Syst., vol. 8, no. 3, pp.287–297, June 2000. [3] C.-F. Li, Y.-S. Chu, W.-H. Sheen, F.-C. Tian, and J.-S. Ho, “A low power ASIC design for cell search in the W-CDMA system,” IEEE J. Solid-State Circuits, vol. 39, no. 5, pp. 852–857, May 2004. [4] L. Philips, N. Lugil, and J. Vanhoof, “A baseband IC for 3G UMTS communications,” in Proc. IEEE Veh. Technol. Conf., Sep. 1999, vol. 3, pp. 1521– 1524. [5] H. Gharavi, F. Chin and R.Wyatt-Millington, “A Link-Level Simulator of the cdma2000 Reverse-Link Physical Layer”, Journal of Research of the National Institute of Standards and Technology. Volume 108, Number 4, July-August 2003. [6] Rusty O. Baldwin, N. J. Davis, Scott F. Midkiff, “A Real-Time Medium Access Control Protocol for Ad hoc Wireless Local Area Networks”, Year of Publication: 1999, ISSN: 1559-1662 [7] CDMA2000 Standard, “The 3rd Generation Partnership Project 2”, 2000. [8] J. Zipper, R. Vazny, L. Maurer, M. Wilhelm, T. Greifeneder, and A. Holm, “A single-chip dual-band CDMA2000 transceiver in 0.13 CMOS,” in IEEE Solid-State Circuits Conf. Dig. Tech. Papers, Feb. 2007, pp. 342–343. [9] K. H. Chen, K. C. Chao, J. I. Guo, J. S. Wang, and Y. S. Chu, “An efficient spurious power suppression technique (SPST) and its applications on MPEG-4 AVC/H.264 transform coding design,” in Proc. IEEE Int. Symp. Low Power Electron. Des., 2005, pp. 155–160.

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A Survey of Various Design Patterns for Improving Quality and Performance of Web Applications Design Md Umar Khan Associate Professor, Computer Science and Engineering Dept. Prakasam Engineering College Kandukur, A.P, India v.umar2003@gmail.com

Dr T.V. Rao Professor& HOD in CSE Department PVP Siddartha Institute of Technology Kanuru, Vijayawada, AP, India tv_venkat@yahoo.com

Prof. A. Ananda Rao Director Industrial Relations & Placements JNTUA, Ananthapuramu, A.P., India akepogu@yahoo.co.in Abstract The last decade has witnessed an increasing usage of design patterns in web application design for improving quality and performance. Web application developers have been using creational, behavioral and structural design patterns since they are based on design principles. Recurring object oriented design problems are addressed by the design patterns. A design pattern, when used appropriately, is capable of improving quality and performance of a web application. Providing a coherent study and presentation of such design patterns would certainly help web application developers in appropriate usage of design patterns. In this paper we survey various design patterns for developing web applications. Understanding design patterns properly developers can avoid reinventing the wheel by reusing them. We also provide an evaluation of existing design patterns based on quality and performance metrics. Index Terms - Design patterns, web application design, web application quality, web application performance payload [5]. Commercial web browsers are making use of this feature and by becoming cache-friendly [6].

I. INTRODUCTION Design patterns is a proven solution for frequently occurring design problems. So design patterns play an important role in web application design. Such patterns when used appropriately can improve quality and performance of web application design. Gamma et al. [1] and Buschmann et al. [2] observed that design patterns are reusable software components that can solve a particular design problem. Design patterns enable reusability of expert design experiences to stop reinvent the wheel and solve recurring design problems [39], [40], [41], [42], [43]. According to Patil et al. [4] high latency should be the important characteristic of modern web applications. Towards achieving high latency they proposed proxy cache to access large scale web applications. Caching is generally used when multiple queries have same

The main architectural design pattern which is widely used for web application development is MVC (Model View Controller). Along with MVC other design patterns are used such as DTO, DAO, and decorator design pattern. Various categories of patterns are used in the process of web application development. There are many attributes that can characterize quality and performance of web applications. They include response time, throughput, availability, and cost, security, reliability, scalability, extensibility. The remaining other parts of this paper are as follows. Section II reviews related works that provide insights into the present state of the art of usage of design patterns for web application development. Section III

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discusses the quality and performance attributes that can be realized using design patterns while section IV concludes the paper.

endpoints while navigating to help algorithms take best navigation paths. It also reduces memory usage. News design pattern accommodates new information to be incorporated into web site with ease [14]. Pagination design pattern improves performance while viewing search results. Set based navigation groups related items for convenience and rich user experience [15]. Rossi et al. [16] proposed architecture for improving WIS known as Web Information Systems with navigational patterns. The navigational patterns they studied for the purpose include node in context, active reference, shopping basket, landmark, news and setbased navigation. Landmark pattern helps users to have consistent cue about important interface. Shopping basket pattern is similar to providing bookmarks or it is similar to shopping cart that is used in shopping malls in the real world. Node in context pattern customizes object representation as per the context. Active reference pattern defines and maintains indexes in the form of active orientation tools for better navigation. Yi Li and Kevin LĂź [19] proposed architecture for improving web database access. They suggested connection pooling to improve performance of web application. Connection pooling provides a set of pre-established connections to application which eliminates scarcity of connections and promotes scalability of web applications.

II. RELATED WORKS David Parsons [3] studied evolving architectural patterns for web applications such as auto-completion architecture, delta management architecture, and client side buffering. Kwon and Bang [7] proposed a design method for web application that improves scalability and flexibility. They implemented business logic in JSP file and reusable Servlet for SQL related search. They have also implemented a forward servlet which can prevent restarting web server and prevent maintenance problems. Mustafa Mamawala [8] studied on web application performance over a period of time. They observed the deterioration of performance when it lacks performance tuning as part of the framework. QoS requirements such as security, manageability, scalability, and availability are to be considered in the design of web application for performance. Schwabe et al. [9] studied on cohesive web application design by identifying patterns, and separating concerns. They proposed a framework known as Object Oriented Hypermedia Design Model (OOHMD) for web application design which focuses on conceptual, navigational and interface design models. They worked on recommendation patterns, push communication for personalization. Carreras et al. [10] proposed bottom-up design patterns that are used for building energy web with combination of innovative communication and information technologies. Its main focus is to have self-organizing components with continuous evaluation.

Lorna Uden [20] studied on design process for web applications. However, it is essential to capture right requirements for the success of web application besides using UI models like RMM (Relationship Management Methodology) and OOHDM. Srikanth and Savithri [21] proposed a new architecture for improving web applications quality using design patterns. Towards it, they combined many existing design patterns in an efficient manner. The set of patterns they combined along with MVC include template method, dependency injection pattern, inversion of control pattern, Database Access Objects (DAO) pattern, and aspect proxy pattern. An Liu et al. [22] observed that fault â&#x20AC;&#x201C; tolerance is very important in web services composition. Web applications might interact with web applications in enterprise applications. They proposed a fault tolerant framework for transactional web services. The framework includes high level strategies for exception handling and transaction techniques. The attributes of the framework include reusability, portability, convenience, and economy. Dong et al. [23] studied the process of identification of design patterns in UML models. They developed a tool that will visualize design patterns existed in UML model of a web application.

Chang and Hon [11] proposed navigational structures for assessing the quality of web applications. They applied statistical testing theory to Totavia search engine web site which proved to be effective. Thung et al. [12] studied design patterns for improving quality and performance of web applications. They compared both architectural and navigational design patterns and proposed suitable design patterns for a school web site. The architectural patterns they analyzed include MVC known as Model View Controller, and PAC known as Presentation Abstraction Control. They also studied different navigational patterns such as setbased navigation, pagination, news, and navigation strategy and navigation observer. The MVC pattern makes web application maintainable and scalable [17]. The PAC pattern makes it highly interactive and modular. Navigation observer records visited links to help navigation history. Thus it makes navigation easier, and decouples navigation and recording processes [13]. Navigation strategy computes link

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Smith [24] emphasized the use of AJAX technology to be part of web application design to provide rich user experience. Cane [25] studied the problem of measuring performance of web applications. His main focus was on latency as a measure. According to Garrido et al. [28] a layered approach using design patterns can improve the usability of web applications. Such layered approach also makes the applications maintainable. Taleb et al. [30] presented a patterns oriented design approach for web application development. The categories of design patterns they focused include information architecture design patterns, page layout and user interface design patterns, navigation design patterns, interaction design patterns, information visualization design patterns, interoperability and system design patterns. They have identified that developers have no in-depth knowledge about the type of patterns to be used to solve various design problems. Leff and Rayfield [36] proposed a flexible web application partitioning based on MVC architecture for improving performance. They also studied various deployment scenarios that can be supported without the need for changing source code. As per their design repartitioning web application also does not incur cost. Lucca et al. [37] proposed a mechanism to identify the design patterns implemented in a web application automatically. They used reverse engineering techniques to discover patterns in web application. Their work enabled to know whether typical design patterns are used in application and take necessary decisions to redesign it. Tammet et al. [38] proposed a rule-based approach for systematic application development with web based interface. They separated user interface and business logic so as to make the application maintainable. They implemented a rule server which manages business rules while the applicationâ&#x20AC;&#x2122;s BL layer adapts to the latest business rules without the need for modifying source code. MuĂąoz-Arteaga et al. [44] studied design patterns for interactive web application from the perspective of classification of security feedback. Their effort was to find equilibrium between security and usability of web application development. YONG-JUN and LI KE-XI [45] proposed a framework for web application development which provides basic building blocks that make use of best practices such as design patterns to reuse software components. Their framework is characterized by DTO (Data Transfer Object) for parameter passing, Database Access Objects (DAOs), connection pool, and SQL processor. All the patterns are used within the confines of MVC architectural pattern. Kerji [46] proposed the best use of decorator design pattern to adapt to changing requirements of end users who need different kinds of information in the form of XML. Their approach promoted

reusability of code and besides reducing maintenance costs. III. QUALITY ATTRIBUTES

AND

PERFORMANCE

Jeff Offutt [18] studied on quality of web applications and observed that reliability, usability and security are the most important quality attributes for the success of web applications. Other quality attributes include availability, scalability, maintainability, and time-tomarket. Design patterns are proven industry best practices that improve the quality attributes of applications making them more maintainable [26]. Bernardi et al. [27] observed that pattern based development of web applications can improve quality attributes resulting in reusability and maintainability. Especially they proposed mechanisms for semiautomatic redesign to improve quality of existing web applications. To redesign applications they used Java Server Faces (JSF) framework along with MVC architectural pattern. Ricca [29] studied web application development closely and opined that the web application quality is a multidimensional attribute which includes performance, accessibility, usability, maintainability, reliability, correctness and conformance to standards. Yand and Chen [31] presented a framework by name ISPWAD which enables security of web applications besides improving performance. Design issues with regard to security are to be considered while developing web applications. The security issues to be considered include access control, SQL injection, Session hijacking, Information disclosure, Hidden field tampering. Design issues with respect to performance include time taken for accessing web page, time taken for making DML (Data Manipulation Language) operations on database. Menasce and Almeida [32] define parameters for performance of web application. They include response time, throughput, availability, and cost. Response time is the time taken to respond to queries. Throughput is the rate of processing requests. Availability refers to the time in which services of web applications are available. Cost refers to some kind of performance such as price performance ratio. Besides these attributes some other attributes like security, reliability, scalability, extensibility can characterize Quality of Service (QoS) of a web application [32], [33], [34], 35]. CONCLUSIONS In this paper we provided the usage of design patterns for improving quality and performance of web application development. From the survey of literature

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it is understood that MVC is the common thread in all architectures proposed for web application development. However, many other design patterns can be used along with MVC. They include decorator design pattern, DTO, DAO and so on. In fact usage of many design patterns is based on the application in hand. Thus it can be said that along with MVC creational patterns, structural patterns, and behavioral patterns proposed by GOF can be used appropriately on demand. A variety of navigational patterns are widely used in web application development. AJAX is given paramount importance in modern web application development and architectural patterns should have a place for its usage. Patterns dealing with dynamic web content presentation through XML are essential. Finally it is to be born in mind that quality and performance of a web application can be realized through the use of design patterns.

[11] Wen-Kui Chang and Shing-Kai Hon. (n.d). Assessing the Quality of Web-Based Applications via Navigational Structures. IEEE. 0 (0), p1-9. [12] Phek Lan Thung, Chu Jian Ng, Swee Jing Thung, Shahida Sulaiman. (n.d). Improving a Web Application Using Design Patterns. IEEE. 0 (0), p1-6. [13] G. Rossi, A. Garrido, and S.Carvalho, “Design Patterns for Object-Oriented Hypermedia Applications,” Pattern Languages of Program Design, vol. 2, chapter 11, pp.177-191, Vlissides, Coplien y Kerth editors, Addison-Wesley, 1996. [14] G. Rossi, D. Schwabe, and F. Lyardet, “Improving Web Information Systems with Navigational Patterns,” Proc. of the Eighth International World Wide Web Conference, 1999. [15] G. Rossi, D. Schwabe, and F. Lyardet, “Patterns for Designing Navigable Information Spaces,” Proc. of PloP, 1999. [16]. Gustavo Rossi b,1,2, Daniel Schwabe, Fernando Lyardet b,1. (n.d). Improving Web information systems with navigational patterns. IEEE. 0 (0), p1-12. [17]. Avraham Leff, James T. Rayfield IBM T. J. Watson Research Center. (n.d). Web-Application Development Using the ModelNiewlController Design Pattern. IEEE. 0 (0), p1-10. [18]. Jeff Offutt Information & Software Engineering. (n.d). Web Software Applications Quality Attributes. IEEE. 0 (0), p1-11. [19]. Yi Li, Kevin Lü. (n.d). Performance Issues of a Web Database. IEEE. 0 (0), p1-10. [20]. Lorna Uden Staffordshire University. (n.d). Design Process for Web Applications. IEEE. 0 (0), p19. [21]. J.Srikanth1, R.Savithri2. (n.d). A NEW APPROACH FOR IMPROVING QUALITY OF WEB APPLICATIONS USING DESIGN PATTERNS. IEEE. 3 (0), p1-5. [22]. An Liu, Qing Li, Senior Member, IEEE, Liusheng Huang, and Mingjun Xiao. (2010). FACTS: A Framework for Fault-Tolerant Composition of Transactional Web Services. IEEE. 3 (1), p1-14. [23]. ing Dong,Sheng Yang,Kang Zhang. (2007). Visualizing Design Patterns in Their Applications and Compositions. IEEE. 33 (7), p1-21. [24]. Keith Smith. (n.d). Simplifying Ajax-Style Web Development. IEEE. 0 (0), p1-4. [25] John W. Cane. (n.d). Measuring Performance of Web Applications: Empirical Techniques and Results. IEEE. 0 (0), p1-10. [26] R. J. E. Gamma, R. Helm and J. Vlissides. Design Patterns: Elements of Reusable Object-Oriented Software. Addison-Wesley, 1995. [27]. Mario Luca Bernardi1, Giuseppe Antonio Di Lucca2 and Damiano Distante3. (2010). Improving the Design of ExistingWeb Applications. IEEE. 0 (0), p16.

REFERENCES [1] Gamma, E., Helm, R., Johnson, R., and Vlissides, J. Design Patterns: Elements of Reusable ObjectOriented Software, Addison-Wesley, Reading, Mass., 1995. [2] Buschmann, F., Meunier, R., Rohnert, H., Sommerlad, P., and Stal, M. Pattern-Oriented Software Architecture: A System of Patterns, Wiley, Chichester, 1996. [3] David Parsons, “Evolving Architectural Patterns For Web Applications”. [4]. Prof. S B Patil1, Mr. Sachin Chavan2, Prof. Preeti Patil3, Prof. Sunita R Patil4. (2012). HIGH QUALITY DESIGN TO ENHANCE AND IMPROVE PERFORMANCE OF LARGE SCALE WEB APPLICATIONS. IEEE. 0 (0), p1-8. [5] Ngamsuriyaroj, S. ; Rattidham, P. ; Rassameeroj, I. ; Wongbuchasin, P. ; Aramkul, N. ; Rungmano, S. “Performance Evaluation of Load Balanced Web Proxies” IEEE, 2011. [6] S B Patil, Sachin Chavan, Preeti Patil; “High Quality Design And Methodology Aspects To Enhance Large Scale Web Services”, International Journal of Advances in Engineering & Technology, 2012, ISSN : 2231-1963 [7] OhSoo Kwon and HyeJa Bang. (2012). Design Approaches of Web Application with Efficient Performance in JAVA. IEEE. 11 (7), p1-7. [8] Mustafa Mamawala. (n.d). Web Application Performance Tuning -A systematic approach. IEEE. 0 (0), p1-11. [9] Daniel Schwabe and Robson Mattos Guimarães. (n.d). Cohesive Design of Personalized Web Applications. IEEE. 0 (0), p1-10. [10] Iacopo Carreras. (2010). Bottom-Up Design Patterns and the Energy Web. IEEE. 40 (4), p1-10.

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[28]. Alejandra Garrido', Gustavo Rossi' and Damiano Distante2. (n.d). Model Refactoring in Web Applications. IEEE. 0 (0), p1-8. [29]. Filippo Ricca. (n.d). Analysis, Testing and Restructuring of Web Applications. IEEE. 0 (0), p1-5. [30]. M. Taleb,A. Seffah,A. Abran. (n.d). PatternsOriented Design Applied to Cross-Platform Webbased Interactive Systems. IEEE. 0 (0), p1-6. [31] Shin-Jer Yang and Jia-Shin Chen. (n.d). A Study of Security and Performance Issues in Designing Webbased Applications. IEEE. 0 (0), p1-6. [32] Daniel A. Menasce and Virgilio A. F. Almeida. Capacity Planning for Web Services: metrics, models, and methods. Prentice Hall PTR, Upper Saddle River, NJ, USA, 2001. [33] Daniel A. Menasce. QoS Issues inWeb Services. IEEE Internet Computing, 6(6):72{75, 2002. [34] Daniel A. Menasce. Response-Time Analysis of Composite Web Services. IEEE Internet Computing, 8(1):90{92, 2004. [35] Daniel A. Menasce, Virgilio A. F. Almeida, and Lawrence W. Dowdy. Per-formance by Design: Computer Capacity Planning By Example. Prentice Hall PTR, Upper Saddle River, NJ, USA, 2004. [36] Avraham Leff, James T. Rayfield. (n.d). WebApplication Development Using the ModelNiewlController Design Pattern. IEEE. 0 (0), p1-10. [37]. Giuseppe Antonio Di Lucca*, Anna Rita Fasolino°, Porfirio Tramontana°. (n.d). Recovering Interaction Design Patterns in Web Applications. IEEE. 0 (0), p1-9. [38] Tanel Tammet, Hele-Mai Haav, Vello Kadarpik, and Marko Kääramees. (n.d). A Rule-Based Approach to Web-Based Application Development. IEEE. 0 (0), p1-7. [39] F. Buschmann, R. Meunier, H. Rohnert, P. Sommerlad, and M. Stal, Pattern-Oriented Software Architecture: A System of Patterns. John Wiley & Sons, 1996. [40] J.O. Coplien and D.C. Schmidt, Pattern Languages of Program Design. Addison-Wesley, 1995 [41] M. Fowler, Analysis Patterns: Reusable Object Models. Addison-Wesley, 1997. [42] E. Gamma, R. Helm, R. Johnson, and J. Vlissides, Design Patterns, Elements of Reusable ObjectOriented Software. Addison-Wesley, 1995. [43] W. Pree, Design Patterns for Object-Oriented Software Development. Addison-Wesley, 1995. [44] Jaime Muñoz-Arteaga. (n.d). A Classification of Security Feedback Design Patterns for Interactive Web Applications. IEEE. 0 (0), p1-6. [45] LIU YONG-JUN1 ,LI KE-XI 2. (n.d). DESIGN AND IMPLEMENTATION OF THE NEW WEB APPLICATION FRAMEWORK--JEMSF. IEEE. 0 (0), p1-4.

[46] Vijay K Kerji. (n.d). Decorator Pattern with XML in Web Application. IEEE. 0 (0), p1-5.

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Quick Detection Technique to Reduce Congestion in WSN M.Manipriya1, B.Arputhamary2, 1

M.Phil scholar, Department of computer science, Bishop Heber college(Autonomous), Trichirapalli-620 017 2 Asst.professor, Department of computer Applications, Bishop Heber college(Autonomous), Trichirapalli-620017 priyayehova@gmail.com arputhambaskaran@rediffmail.com

information via one to another node. Nodes are having limited storage space in terms of bandwidth, space, battery level, multi hop communication architecture in sensor networks since nodes send their data to a sink node for transmitting the packets. Sensor has been classified into two classes such as event driven and continuous dissemination. According to the history of communication, sensor nodes are constrained in battery level and bandwidth. Current researches being focused on sensor networks to maximize the network life time. The node delay and throughput are common issues in sensor networks, transmission of data require end-end delay must be acceptable range to the users, as delay decreases users meet Quality of Service (QoS) of the network. During this transmission tasks some nodes have low energy to transmit or some nodes are being inactive to send the packets, so that node can be waste the resources and also enhanced the congestion between the nodes which causes high delay and chance to get packet loss. In order to avoid this issue our proposed technique solves the congestion control, minimum delay by detecting inactive nodes during the transmission.

Abstract - Wireless Sensor Networks (WSNs) are employed for either continuous monitoring or event detection in the target area of interest. In event-driven applications, it is critical to report the detected events in the area and with sudden bursts of traffic possible due to spatially-correlated events or multiple events, the data loss due to congestion will result in information loss or delayed arrival of the sensed information. Congestion control techniques detect congestion and attempt to recover from packet losses due to congestion, but they cannot eliminate or prevent the occurrence of congestion. Congestion avoidance techniques employ proactive measures to alleviate future congestion using parameters like queue length, hop count, channel conditions, and priority index. However, maintaining and processing such information becomes a significant overhead for the sensor nodes and degrades the performance of the network. This paper propose a congestion avoidance quick detection technique (QDT) that uses the queue buffer length of the sensor nodes to estimate the congestion and diffuse traffic to provide a congestionfree routing path towards the base station. This protocol provides event reporting, packet delivery ratio, by dynamically diffusing the traffic in the network using multiple forwarders in addition to backup forwarding. Results show that our protocol significantly improves event reporting in terms of packet delivery ratio by avoiding congestion while diffusing the traffic effectively.

1.1 Congestion in WSN

Keywords: Wireless sensor network, node detection algorithm, reducing congestion.

Congestion is prejudicial to wireless device networks as a result of it lowers the out turn of the network by dropping a lot of packets containing crucial perceived info and reduces the time period of the network as a result of weakened energy efficiency at every device node, particularly for spatially-correlated events. With the buďŹ&#x20AC;er of the device nodes close to full, there will invariably be traďŹ&#x192;c at the node for the information packets, w hich ends in exaggerated rivalry, exaggerated retran smissions weakened packet delivery magnitude rela tions, wireless device networks as a result of it lowers the outturn of the network by dropping a lot

I. INTRODUCTION Wireless sensor network is an emerging technology in research field; it is used to monitor health condition, temperature also used in military application, home applications, etc. Wireless sensors are also used in forest fire detection, inventory control, energy management, and so on. There are thousands of nodes are being interconnected with one another the control station collects all data from each node and transmits the

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of packets containing crucial perceived info and reduces the time period of the network as a result of weakened energy efficiency at every device node, and exaggerated energy consumption. In event-driven applications, once there's an abrupt increase within the traffic, congestion would degrade the performance of the network by the loss of the event packets or the delayed arrival of the packets to the sink. Congestion control is not solely necessary to enhance the general outturn however additionally to elongate the network time period and improve the end-to-end outturn, referred to as accuracy level, by avoiding the packet loss as a result of congestion. Congestion being one among the largest problems for a device network, needs to be avoided to enhance the Quality of Service (QoS) in terms of outturn, packet delivery ratio, latency, and energy efficiency. Congestion management in WSN has been wide concerning police investigation the congestion within the network and dominant the congestion by adjusting the speed of the input traffic or prioritization of the info packets or load equalization among the device nodes. The traffic within the network is adjusted either hop-by-hop, at every device node, end to end rate adjustment at the supply nodes wherever the traffic is generated. While congestion management concentrates on sanctioning the network to live through packet loss due to the prevalence of congestion. Congestion rejection detects early cong estion or estimates for the congestion within the network and tries to forestall its prevalence. For example, in associate event-based approach, appropriate congestion rejection mechanism might help to sight the approaching congestion and react to matters before the particular collapse takes place. Congestion rejection is that the core thought for this paper model to proactively determine and alleviate congestion within the network and change the network to handle the longer term traffic.

Fetch Quickly. Akoijam Premita [4] et al. discussed on power efficient energy aware routing protocol for wireless sensor networks which occupied less energy and reduced the end to end delay. Jayachandran [5] et al. explained fast data collection with reduced interference and increased life time they improved packet delivery ratio and saved the energy of the each node. Abhay Raman [6] et al. minimized the delay and maximized the life time of the network by reducing the delay from source to destination. Hao-Li Wang [7] et al. enhanced the scheme for quality of service was used to detect the inactive node bandwidth and energy. Navneet Kaur [8] elaborated load balancing technique in sensor network to distribute the packets it reduces packet loss. M. Vijayalakshmi et al., [9] proposed Clustering and Prediction techniques, which use temporal correlation among the sensor data, provide a chance for reducing the energy consumption of continuous sensor data collection. Thus it can achieve stability and prolongs network lifetime. G.Srinivasan et al., [10] analyzed in WSN congestion detection and congestion control is the major research areas. It is important to design protocols for controlling congestion. Parveen Yadav et al.,[11] proposed new cluster based security architecture which starts from the initialization of the network. Safe path is not shortest but next alternative shortest path in mobile ad hoc network. R.Sumathi et al., [12] surveyed QoS Based Routing Protocols for Wireless Sensor Networks. Many QoS issues are focused in their work. The performance comparison of QoS based routing protocols such as SAR, MMSPEED, MCMP, MCBR, and EQSR has also been analyzed.

III. PROPOSED WORK Inactive node Inactive nodes are trying to get many benefits from the network to occupy battery or bandwidth. An inactive node might not send the data Packets in a proper way. An inactive node can do any of the possible attack in the sensor network.

II. RELATED WORK Chieh-Yih Wan [1] et al. proposed a technique Congestion detection and avoidance in sensor networks significantly improves the performance of data dissemination applications such as directed diffusion by mitigating hotspots, and reducing the energy tax with low fidelity penalty on sensing applications. Sivapuja Srikanth Babu [2] et al. investigated that jamming avoidance for video traffic in wireless sensor networks they reduced packet drops at intermediate node. Further the cost of retransmission of dropped packets was significa ntly reduced. Pooja sharma [3] et al. tried to prolong the lifetime of wireless sensor network by congestion avoidance techniques. The techniques included congestion detection and avoidance, Event-to-Sink Reliable Transport, Pump Slowly,



It turns off the power when it does not have the communication with other nodes  It may not forward the packets to the exact destination node from source node  Inactive nodes are sending some packets and drop other packets. Techniques to properly cope with inactive replication allocation approach perform traditional cooperative technique in terms of accessibility, cost and minimum delay.

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IV. NUMERICAL EXAMPLE

Process Send Request

The network is loaded such traffic converges towards the bottom station from different directions. Traffic from these sources are sent at different rates. Table 1 show with backup forwarder and while not backup forwarder. Once backup forwarding utilized, additional packets are received in very shorter length than while exploitation backup. Though the packets get diffused through backup forwarders, the delay is less; as a result of the time taken for the packets to achieve the bottom station through backup forwarder is a smaller amount than the wait time for the potential forwarders once their queues are full. Table 1: Backup forwarder

Checks for the available route

Is route available?

Yes

Forward Message

Save message in buffer & initiate route request

Without Backup

Stop

Figure 1: Flowchart of QDT function When data transmitted, it does not forward the reply request on the reverse route. The proposed algorithm will detect and solve the problem of inactive node over wireless sensor network we develop a quick detection algorithm that considers partial greediness and new replication allocation.

With Backup

No. Of Packets Sent

No. Of Packets Received

Delay (Secs)

No. Of Packets Received

Delay (Secs)

1500 2250 4500

1015 1555 2791

0.16 0.18 0.20

1302 1872 3171

0.14 0.15 0.12

The traffic diffusion approach to proactively avoiding congestion at the nodes makes our protocol deliver a lot of packets even with a high traffic hundreds. In our proposed method, though every supply transmits a 100Kbps towards the bottom station, the speed controller at every node adjusts the packet loss rate at every hop level and reduces the particular packets generated.

Step 1: Initiate the process to send the packets Step 2: Identified the number of nodes and establish connection with each node Step 3: Checks for the available route in the path Step 4: If the route is available forward message to the other node { Select the path which is congestion free } Else if (Save message in buffer & initiate route request) { Select the alternative path } Else (select the other paths which is available) Step 5: If active node becomes as inactive node find the inactive node and correct the node error and retransmits the packet again from buffer itself Step 6: Repeat the step until selects the path Step 7: Stop to search

40000 30000 CTR

20000

QDA

10000 0

Figure 2: No. of packets delivered V. CONCLUSION This paper introduced quick detection algorithm aims to reduce the congestion level and minimum delay to enhance the network performance. This has been achieved by finding out inactive node which is present during the transmission. If there is any error occurred with inactive node it find and modify the error and send the data to next node from current node itself. Thus

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Journal of Mobile and Wireless Communications, Volume 4, 2013, pp. 174-181.

proposed algorithm can maintain with minimized congestion level among nodes in a sensor network and prolong the network life time and reduce the service disturbance. In wireless sensor network many algorithms have been used which have lot of advantages over other algorithms. Since quick detection algorithm add more nodes of other algorithm. By this method we can improve the QoS of WSN and reduce the congestion of the information and increase the range of sensor nodes.

[10] G.Srinivasan and S.Murugappan, “A survey of congestion control techniques in wireless Sensor networks”, International Journal of Information Technology and Knowledge Management, Volume 4, No.2, 2011, pp. 413-415. [11] Parveen Yadav and Harish Saini, “An Alternative Path Routing Scheme for Intrusion Prevention in Wireless Network”, International Journal of Engineering and Innovative Technology, Volume 2, Issue 1, 2012, pp. 248-251.

REFERENCES [1] Chieh-Yih Wan, Shane B. Eisenman, Andrew T. Campbell, “Congestion Detection and Avoidance in Sensor Networks”, Proceedings of SenSys’03, pp. 266-279, 2003.

[12] R.Sumathi and M.G.Srinivas, “A Survey of QoS Based Routing Protocols for Wireless Sensor Networks”, J Inf Process Syst, Vol.8, No.4, 2012, pp. 589-602. [13] C. Basaran, K. Kang, and M. H. Suzer. Hop-by-hop congestion control and load balancing in wireless sensor networks, IEEE Conference on Local Computer Networks, 2010.

[2] Sivapuja Srikanth Babu, R. Konda Reddy, P. Eswaraiah, Supriya Sivapuja, Srikar Babu S.V, “Jamming Avoidance for Video Traffic in Wireless Sensor Networks, International Journal of Emerging Trends & Technology in Computer Science, volume 2 , Issue 2, pp. 293-297, 2013.

[14] M. M. Bhuiyan, I. Gondal, and J. Kamruzzaman. CAM: Congestion avoidance and mitigation in wireless sensor networks, IEEE Vehicular Technology Conference, 2010.

[3] Pooja sharma, Deepak tyagi, Pawan bhadana, “A Study on Prolong the Lifetime of Wireless Sensor Network by Congestion Avoidance Techniques”, International Journal of Engineering and Technology, Volume 2, Issue 9, pp. 4844-4849, 2010.

[15] J. B. Helonde, V.Wadhai, V. Deshpande, and S. Sutar,”EDCAM: Early detection congestion avoidance mechanism for wireless sensor network”, International Journal of Computer Applications, 2010.

[4] Akoijam Premita, Mamta Katiyar, “A Review on Power Efficient Energy- Aware Routing Protocol for Wireless Sensor Networks”, International Journal of Engineering Research & Technology, Volume 1, Issue 4, pp. 1-8, 2012.

[16] K. K. Sharma, H. Singh, and R. B. Patel, “A reliable and energy efficient transport protocol for wireless sensor network”, Global Journal of Computer Science and Technology, 2010.

[5] Jayachandran. J, Ramalakshmi. R, “Fast Data Collection with Reduced Interference and Increased Life Time in Wireless Sensor Networks”, International Journal of Research in Engineering & Advanced Technology, Volume 1, Issue 2, pp. 1-5, 2013.

[17] P. Sharma, D. Tyagi, and P. Bhadana, “A study on prolong the lifetime of wireless sensor network by congestion avoidance techniques”, International Journal of Engineering and Technology, 2010.

[6] Abhay Raman, Ankit Kr. Singh, Abhishek Rai, “Minimizing Delay And Maximizing Lifetime For Wireless Sensor Networks With Anycast”, International Journal of Communication and Computer Technologies, Volume 1, No 26, Issue 4, pp. 96-99, 2013. [7] Hao-Li Wang, Rong-Guei Tsai, Long-Sheng Li, “An Enhanced Scheme in Controlling Both Coverage and Quality of Service in Wireless Sensor Networks”, International Journal on Smart Sensing and Intelligent Systems, Volume 6, No 2, pp. 772-790, 2013. [8] Navneet Kaur, “Review on Load Balancing in Wireless Sensor Network”, International Journal of Advanced Research in Computer Science and Software Engineering , Volume 3, Issue 5, pp. 1044-1047, 2013. [9] M. Vijayalakshmi, V. Vanitha, “Cluster based adaptive prediction scheme for energy efficiency in wireless sensor networks”, International Research

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HEURISTICS TO DETECT AND EXTRACT LICENSE PLATES Rajivegandhi C

Sungkrityayan Khan

Manas Srivastava

Sabarinathan C

Department of Computer Science and Engineering SRM University, Chennai, India rajivegandhi@gmail.com sungkrityayankhan@gmail.com manas_srivastava@live.com sabaricsn@gmail.com Abstractâ&#x20AC;&#x201D;Image based License Plate Detection requires the segmentation of the license plate (LP) region from the larger image is taken with the help of camera. While there may be numerous LP candidate areas, the detection of the LP area (LPA) requires many diverse methods of image processing to be applied. After we detect, a candidate LPA, the extraction of the possible alphanumeric information is done by us. The LPA information is further processed by using the heuristics to reject those candidates where there might be alphanumeric like region but which may not be LP information. In this particular paper we present before you, several heuristics that successfully allows to detect and extract the alphanumeric regions from the correctly discovered LPA. Consequently the alphanumeric regions that has been extracted are identified by Optical Character Recognition (OCR). A large number of experiments has been done on a number of images of Indian and also on international license plates, taken from the internet and some images taken by us are used. It is noted that an accuracy of 85% is achieved from the images available in the database. The open source software OpenCV is configured with Code Blocks IDE (http ://sourceforge.n et/p rojects/op encvlibrary /) to help in the experiment.

accuracy of the license plate detection. In this paper the distance between the camera and the car is kept approximately constant. For license plate detection purpose the concept of edge detection [5,9], contour determination and bounding box formation and elimination is used. Selection of license plate areas (LPA) and their elimination to obtain the actual license plate area was based on various heuristics. This stage is important since imp roper detection of license plate can lead to misrecognized characters. Character Extraction or character segmentation is the second component of our LPR system. It takes a properly segmented license plate as an input. Some preprocessing is done on the license plate image for the noise removal. A number of morphological operators are used on the image for this purpose and the noise free output image is sent for character segmentation. Image binarizat ion and image projections are used for character extraction. The extracted characters are then input to the OCR for recognition. The rest of the paper is organized as follows. In Section II we briefly describe the Related Works in this field. In Section III we give an overview of our approach followed by some Examples and Testing in Section IV. Results of our experiments along with its discussion are demonstrated in Section V. Finally we conclude this paper in Sect ion VI followed by references in the end.

Keywords- License Plate Extraction, Image Segmentation, Character Extraction , Character recognition

I. INTRODUCTION A license plate is the unique identification of a vehicle . The basic issues in real-time license plate recognition are the accuracy and the recognition speed. License Plate Recognition (LPR) has been applied in numerous applications such as automatically identifying vehicles in parking slots , access control in a restricted area and detecting and verify ing stolen vehicles. Till now, there have been some well-known commercially operational LPR systems around the world. It is assumed that these systems work under some given constraints and the cameras are mounted at fixed locations without mobility. LPR systems consist of three major components: license plate detection, character ext raction and character recognition. License Plate detection is the first important stage of an LPR system. Quality of algorithms used in a license plate detector determines the speed and

II. RELATED WORK Extensive research has been done in the area of License Plate Recognition since its invention in the year 1976 at the Police Scientific Development Branch in the UK. This is an interesting topic in the field of recent research attracting several papers from researchers around the world. Here we mention some of the relevant works in this section. Some important concepts relevant to the LP detection approaches are mentioned. Processing of boundary lines, from a gradient filter, and an edge image is discussed [10]. This edge image is threshold and then processed with Hough Transform (HT), to detect lines. Eventually, couples of two parallel lines were considered as plate-candidates. However, boundary line detection

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INTERNATIONAL CONFERENCE ON CURRENT TRENDS IN ENGINEERING RESEARCH, ICCTER - 2014 is not suitable in the case of not finding horizontal pairs. It may also happen that the image boundary line may be absent or not detected properly due to noise and uneven brightness. In addition to this, HT is inherently a heavy computation task. The color and textures of the LP have also been used to identify it [11], but they seem to be inefficient, especially when the system has got plates of different colors and sign patterns. Other common approaches involved are Top Hat and Bottom Hat filtering (highlights the black-white transitions) [12] and Binary Morphology algorithm (like Otsuâ&#x20AC;&#x;s method) [13]. But all these algorithms rely on color information and special signs.

Input car image (RGB) Conversion of RGB image to gray scale

Applying certain heuristics to extract original LP from the candidate LPs.

image Conversion of Gray scale image to Canny edge Image Finding contours in the Canny Edge Image

Many common algorithms for Character Segmentation such as direct segmentation [14], pro jection and cluster analysis [15] and temp late matching are present.[16].

Approximating contours to quadrilaterals and applying bounding

III. PROPOSED WORK We describe here our approach where we take up d irect techniques from the essential image processing to obtain the candidate areas and subsequently apply domain heuristics to obtain the LPR. The relevant methods used in our LPR are implemented in OpenCV using some predefined functions which are mentioned in braces.

Applying morphological operations and Thresholding to remove noise and enhance characters in the LP.

Plotting Vertical Projection Histogram of the noiseless LP image to segment characters.

Extraction of characters using the concept of ROI

Recognition of each character using OCR

A. License Plate Detection

FIGURE 1. BLOCK DIAGRAM OF OUR LPR SYSTEM

In this stage we locate and isolate the license plate region from the given image. Quality of the image plays an important part hence prior to this stage preprocessing of the image is necessary. Preprocessing of the image includes conversion of erosion and dilation are applied on the LP image. Dilation causes the bright pixels within a region to grow and erosion is the converse operation. Dilation tends to smooth concavities and erosion tends to smooth away protrusions in the image which enhances its quality and makes it noise free. After this step the output image is threshold to enhance the numerals and characters present in the image, characters are light shaded like white over a darker background like black. Now character segmentation is carried out and the approach used is Vertical Image Project ion [6,8]. Boundaries from the noise-free license plate image are removed (im clear border) before applying vertical projection histogram in order to threshold the histogram bin value to zero. The coordinates where the histogram b in value is zero are stored. The boundary of each character in the license plate image are formed by these co-ordinates. They are cropped subsequently using the concept of ROI (Region of Interest) [2].

IV. EXAMPLES AND TESTING

Experiments were performed to test the accuracy of the proposed heuristic algorithm. In this paper our sample space for experiments included a variety of test images containing license plates made in India, foreign license plates in addition with some of our own snapshots of cars. Our algorithm was converted into a CPP-program which was run on CodeBlocks environment configured with OpenCV. We have shown two examples on the next page. Input image 1 is of an Indian LP taken by our own camera (14 MegaPixel, Sony Cybershot, DSC-H55 Optical zoo m 10x). Input Image 2 is of an international LP taken from the internet.

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Figure 7. Extracted Characters

Figure 2. Input Image 1

Figure 8. Input Image 2

Figure 3. Image showing all possible Bounding Boxes

Figure 4. Extracted License Plate

Figure 9. Image showing all possible Bounding Boxes

Figure 10. Extracted License Plate

Figure 5. VP Histogram of noiseless LP image

Figure 6. Segment LP showing character boundaries

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VI. CONCLUSION In this paper we have proposed a heuristic method to segment a license plate fro m an image. The algorithm used in this paper not only accelerates the process but also increases the probability of detecting the license plate and extraction of characters, under certain set of constraints. The process is successful through the steps of character width estimation, vertical height estimation, and segmentation of license plate into blocks and identification of these character blocks. Various well known techniques were used to co me out with a final algorithm. The results show high accuracy of non-character area removal and thus better recognition of characters after their segmentation. Finally the percentage accuracy for the entire process came to 88% . Our proposed approach is under improvement and its accuracy will be increased by using more sophisticated approaches.

Figure 11. VP Histogram of noiseless LP image

Figure 12. Segmented LP showing character boundaries

VII. REFERENCES [1]

[2] Learning OpenCV by Gary Bradski and Adrian Kaehler, O‟Reilly, safari.oreilly.com . [3] “Algorithmic and mathematical Applications of Automatic Number Plate Recognition Systems”,B.Sc. T hesis by Ondrej Martinsky, BRNO University of T echnology, 2007. [4] Lihong Zheng, Bijan Samali, Xiangjian He, Laurence T. Yang, “Accuracy Enhancement for License Plate Recognition”,

Figure 13. Extracted Characters

10 IEEE conference on Technology, 2010, Pg.No-512.

V. RESULTS AND DISCUSSIONS [5]

After running the program on various test images we obtained properly segmented characters of the LP in 80% cases. The license plate detection approach presented in Section III was used to obtain license plate images . Total 250 different license plate images were included in the experiment. All candidate images are processed in one format, i.e. light colored characters on a darker background. The binary enhanced license plate character images obtained from our proposed method were sent to the OCR for recognition. It is shown that accuracy is 83% for the extraction of the license plate region, 93% for the segmentation of characters and 90% for OCR. The overall algorithm accuracy combining detection and extract ion is 88%. Type of LP Image Indian LP Images International LP Images LP Images taken by own camera

Success Rate in LP extraction 82

Success Rate in Character segmentation 93

R.C.Gonzalez and R.E.Woodz, Digital Image Processing, 3rd ed., vol. 2. Pearson Education, .

Computer

and

Information

Bai Hongliang, Liu Changping, “A hybrid License Plate Extraction

Method based on Edge Statistics and Morphology”, 17 International Conference on Pattern Recogntion(ICPR‟04).

[6] Richard G. Casey and Eric Lecolinet, “A survey of Methods and Strategies in Character Segmentation”, Proceedings of th the 17 International Conference on Pattern Recognition(ICPR „04) . [7]

Xiangjian He, Lihong Zheng, Qiang He, Wenjing Jia, Bijan Samali and Marimuthu palaniswami, “Segmentation of Characters

on Car License Plates”, IEEE, 2008, Pg.No-399. [8] Huadong Xia and Dongchu Liao, “The Study of License Plate Character Segmentation Algorithm based on Vertical Projection”, IEEE, 2011, Pg.No-4583. [9]

Wai-Yiu Ho and Chi-Man Pun, “A Macao License Plate Recognition system based on Edge and Projection analysis”,IEEE, 2010, Pg.No67.

[10] Kamat V. and Ganesan H. “An efficient implementation of Ho ugh transform for detecting vehicle License Plate Using DSP‟s”, in Proceedings of the Cellular Neural Networks and st their applications, Proceedings of the IEEE , 31 Annual.

Success [11] Parker J.R. and Federl P., “An approach to License Plate Recognition “, Technical Report, Library of Computer Rate of Vision, University of Calagry, 1996 OCR [12] “Automatic Car Plate Recognition using a partial 90 Segmentation Algorithm”, Fernando Martin, David Borges,

Signal Theory and Communication Deparment, Vigo University, Pontevedra, Spain. [13] “License Plate Recognition”- Final Report, Pierre Ponce, Stanley S. Wang, David L.Wang.

[14] Hongwei Ying, Jiatao Song, Xiaobo Ren” Character Segmentation

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International Conference Networking and Automation (ICINA).

Information,

[15] Shuang Qiaol , Yan Zhul , Xiufen Li l , Taihui Liu2 ,3, Baoxue Zhangl

“Research of improving the accuracy of license plate character segmentation” 2010 Fifth International Conference on Frontier of Computer Science and T echnology. [16] Deng Hongyao, Song Xiuli “License Plate Characters Segmentation Using Projection and T emplate Matching”, 2009 International Conference on Information Technology and Computer Science. [17] http://www.cs.iit.edu/~agam/cs512/lect-notes/opencv-tro/index.html

[18] http://www.mathworks.com/help/toolbox/images [19]http://en.wikipedia.org/wiki/Automatic_number_plate_recog nition

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DYE SENSITIZED SOLAR CELL

By,  Dhanush.M IV year R.M.K. Engineering College dhanushdhruvan@gmail.com

 Diwakar.B IV year R.M.K. Engineering College diwa.balakrishnan@gmail.com

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energy conversion efficiency. The device is based on a 10µm thick, optically transparent film of Titanium dioxide particles a few nanometers in size, coated with a mono layer of a charge- transfer dye to sensitize the film for a light harvesting. Because of a high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the devise harvests a high proportion of the incident solar energy flux(46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current(>80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12%N in diffuse daylight. The large current densities (>12mAcm-2) and exceptional stability (sustaining at least 5million turnovers without decomposition), as well as the low cost, make practical applications feasible.

ABSTRACT: The development of new types of solar cells is promoted by increasing public awareness that the earth’s oil reserves could run out during this century. As the energy need of the planet is likely to double within the next 50 years and frightening climatic consequences of the greenhouse effect caused by fossil fuel combustion are anticipated, it is urgent that we develop a new kind of renewable energy to cover the substantial deficit left by fossil fuels. Since the prototype of a Dye Sensitized Solar Cell (DSSC) was reported in 1991, it has aroused intense interest owing to its low cost, simple preparation procedure, and benign effect on the environments. However, the potential problems caused by liquid electrolyte limit the long-term performance and practical use of DSSC. Therefore, much attention has been given to improving the light-to-electrical power conversion and replacing the liquid electrolytes by solid-state or quasi-solid-state electrolytes. This review will focus on progress in the development of improved electrolytes, especially quasi-solid-state electrolytes for DSSC’s.

STRUCTURE AND PRINCIPLES OF DSSC:

Keywords: dye-sensitized solar cells; liquid electrolytes; solid-state quasi-solidstate electrolytes; photoelectric long-term stability.

electrolytes; performance;

INTRODUCTION: The prototype of a DSSC was reported in 1991 by M.Gratzel. In Gratzel Cells the functions of light absorption and charge-carrier transportation are separated. Although the solar power conversion efficiencies of DSSCs are lower than that of classical crystalline silicon cells. In DSSCs based on liquid electrolytes, a photoelectric conversion efficiency of 11 % has been achieved. However, the potential problems caused by liquid electrolytes, such as the leakage and volatilization of solvents, possible desorption and photo-degradation of the attached dyes, and the corrosion of Platinum counter electrode, are considered as some of the critical factors limiting the long-term performance and practical use of DSSCs. It is believed that quasi-solid-state electrolytes, especially those utilizing thermosetting gels, are particularly applicable for fabricating high photoelectric performance and long-term stability of DSSC in practical applications. Here we describe a photo voltaic cell created from low to medium purity materials through low cost processes, which exhibits commercially realistic

DSSCs include a substrate of fluorine-doped SnO2 conducting glass (FTO), a porous nano-crystalline semiconductor oxide (TiO2) film sensitized by a dye for absorbing visible light, a redox electrolyte (usually an organic solvent containing a redox system, such as iodide/triiodide couple) layer for deoxidizing oxidized dye, and a platinized cathode to collect electrons and catalyze the redox couple regeneration reaction. The light-to-electricity conversion in a DSSC is based on the injection of electron from the photo excited state of the sensitized dye into the conduction band of TiO2. The dye is regenerated by electron donation from iodide in the electrolyte. The iodide is restored, in turn, by the reduction of tri-iodide at the cathode, with the circuit being completed via electron migration through the external load.

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1. 2. 3. 4. 5. 6.

quasi-solid-state electrolytes have been actively developed as highly conductive electrolyte materials for DSSCs, lithium secondary batteries, and fuel cells. Quasi-solid-state electrolytes are usually prepared by incorporating a large amount of a liquid electrolyte into organic monomer or polymer matrix, forming a stable gel with a network structure via a physical or chemical method. The quasi-solid-state electrolyte formed via physical cross-linking is called “entanglement network”, which is thermo-reversible (thermoplastic). By contrast, chemical or covalent cross-linking leads to the formation of thermo-irreversible (thermosetting) gel electrolyte.

The electrolytes employed in DSSCs can be classified as liquid, solid-state, or quasi-solid-state. Several aspects are essential for any electrolytes in a DSSC. (1) The electrode must be able to transport the charge carrier between photo anodes and counter electrode. After the dye injects electrons into the conduction band of TiO2, the oxidized dye must be reduced to its ground state rapidly. Thus, the choice of the electrolyte should take into account the dye redox potential and regeneration of itself. (2) The electrode must be able to permit the fast diffusion of charge carriers (higher conductivity) and produce good interfacial contact with the porous nano-crystalline layer and the counter electrode. For liquid electrolytes, it is necessary to prevent the loss of the liquid electrolyte by leakage and/or evaporation of solvent. (3) The electrolyte must have long-term stability, including chemical, thermal, optical, electrochemical, and interfacial stability, which does not cause the desorption and degradation of the dye from the oxide surface. (4) The electrolyte should not exhibit a significant absorption in the range of visible light. For the electrolyte containing I-/I3- redox couple, since I3shows color and reduces the visible light absorption by the dye, and I3- ions can react with the injected electrons and increase the dark current. Thus, the concentration of I-/I3- must be optimized.

DSSC Based On Colloidal TiO2 Films:

Dye-sensitized cells differ from the conventional semiconductor devices in that separate the function of light absorption from charge carrier transport. In the case of TiO2, current is generated when a photon absorbed by a dye molecule gives rise to electron injection into the conduction band of the semiconductor. To complete the circuit the dye must be regenerated by electron transfer from a redox species. The monochromatic current yield

QUASI-SOLID-STATE ELECTROLYTES: The quasi-solid state, or gel state, is a particular state of matter, neither liquid nor solid, or conversely both liquid and solid. Generally, a quasi-solid-state electrolyte is defined as a system which consists of a polymer network (polymer host) swollen with liquid electrolytes. Owing to its unique hybrid network structure, quasi-solid-state electrolytes always possess, simultaneously, both the cohesive property of a solid and the diffusive transport property of a liquid. Namely, quasi-solid-state electrolytes show better long-term stability than liquid electrolytes do and have the merits of liquid electrolytes including high ionic conductivity and excellent interfacial contact property. These unique characteristics of

Ƞi (ƛ) = LHE (ƛ) x øinj x Ƞe where Light Harvesting Efficiency (LHE) is the fraction of the incident photons that are absorbed by the dye, øinj is the quantum yield for charge injection and Ƞe is the efficiency of collecting the injected charge at the back contact. Although attempts to use dye sensitized photoelectrochemical cells in energy conversion have been made before, the efficiency of such devices of

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such devices have been low. One problem is that o poor light harvesting. On a smooth surface, a monomolecular layer of sensitizer absorbs less than 1% of incident monochromatic light. The remaining option is to increase the roughness of the semiconductor surface so that a larger number of dye molecules can be absorbed directly to the surface and can simultaneously be in direct contact with the redox electrolyte. By using semiconductor films consisting of nanometer sized TiO2 particles, together with newly developed charge transfer dyes, the efficiency and stability of solar cell has been improved.

are no minority carriers involved in the photo conversion process. Therefore, surface and bulk recombination losses due to lattice defects, encountered in conventional photovoltaic cells, are not observed in such a device. The long term stability of cell performance was tested by illuminating the thin TiO2 film loaded with visible light for 2 months. The change in the photocurrent was less than 10% over this period, during which a charge of 62,000 C cm-2 was passed through the device, corresponding to a turnover number of 5x106 for the sensitizer. This implies that if any degradation had occurred its quantum yield is less than 2x10-8. As Φdec =kdec/Σk, the rate constant, kdecs-1, for excited state decomposition must be at least 10-8 times smaller than Σk, the sum of rate constants for all channels of dye deactivation. Because charge injection is the predominant channel, this sum is practically equal to the rate constant for charge injection which exceeds 1012s-1. Therefore, the upper limit for kdec is 2x104 s-1, which agrees with the known photo physics of this class of transition metal complexes. The very fast electron injection observed with dyes such as, combined with high chemical stability, renders these compounds very attractive for practical development.

High surface area TiO2 films were deposited on a conducting glass sheet from colloidal solutions. Electronic between the particles was produced by brief sintering at 450 °C. The size of the particles and pores making up the film is controlled by the size of the particles in the colloidal solution. The internal surface area of the film is determined by the size of the particles and the thickness of the films. These parameters were optimized to obtain efficient light harvesting while maintaining a pore size large enough to allow the redox electrolyte to diffuse easily. Films of 10µm thickness consisting of particles with an average size of 15nm gave linear photocurrent response up to full sunlight and were used throughout. As each dye molecule occupies an area of 1nm2, the inner surface of the film is 780cm2 for each 1cm2 of geometric surface. Thus, the roughness factor is 780, which is smaller than the predicted value of 2000. The loss mechanisms such as recombination, normally encountered in semiconductor photo conversion, have been minimized. The role of semiconductor in dye-sensitized device is merely to conduct the injected majority charge carriers. There

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Characteristics of TPGE:

Thermoplastic Gel Electrolytes (TPGEs):

(1) PEG contains many ether groups and polyhydric side groups, two kinds of groups can keep complexation with alkali metal ions such as potassium ions, sodium ions. Because of the interaction between PEG and PC and alkali metal iodide salts, the iodide anions can be separated from Alkali cations to form free anions

The formation of the TPGE is based on physical cross-linking of gelators to form an “entanglement network” to solidify liquid electrolyte. The main characteristic of this kind of gel electrolyte is the gel-sol-state reversible conversion with the change of temperature, which is a benefit of deep penetration of the electrolyte into mesoporous dye-coated nano-crystalline TiO2 film. The interfacial contact between the electrolyte layer and nano-crystalline TiO2 film or counter electrode is one of the most important factors influencing the photovoltaic performance of DSSCs besides the ionic conductivity of the gel electrolyte. The TPGE contains gelator and liquid electrolyte, the liquid electrolyte consists of organic solvent, Redox couple, additive, or IL electrolyte system. The first thermoplastic polymer gel electrolyte used in DSSCs was reported [89]. The electrolyte was composed of poly (acrylonitrile) (PAcN), EC, PC, AcN and NaI. The light-to-electricity conversion efficiency of this DSSC was lower in comparison with that of the DSSC based on liquid electrolytes, due to the unoptimized components and the difficult penetration of the PAcN network into nano-crystalline TiO2 film. The high photovoltaic performance and excellent stability of DSSC was obtained by using a TPGE containing poly (vinylidenefluoride-co-hexafluoropropylene) (PVDF–HFP) combined with MePN-based liquid electrolyte containing 1,2-dimethyl-3-propyl imidazolium iodide and iodide. The DSSC showed a similar photovoltaic performance as that of an analogous cell containing the same liquid electrolyte, which means that the polymer matrix has no negative effect on the performance of DSSC.

(2) The large amount of ether groups and polyhydric side groups on the PEG matrix can form a hydrogen bond with PC solvent, which hangs the molecule of solvent on the “entanglement network” of the polymer chain, and results in the formation of a stable thermo-reversible polymer gel electrolyte.

(3) The TPGE is in a solid state and shows the fluidity with a viscosity of 0.76 Pa s at a temperature higher than 50 °C, which makes for a deep penetration into the mesoporous dye-coated Nano-crystalline TiO2 film [102], and forms a sufficient interfacial contact between electrolytes layer and nano-crystalline TiO2 film and platinum counter electrode. Whereas at a temperature below 20°C, the TPGE is in a gel state with a viscosity of 2.17 Pa s. The reversible thermoplastic behavior of the TPGE is very useful for sealing and assembling DSSCs. The characteristic of the thermoplastic polymer gel electrolyte markedly depends on temperature. This is due to the fact that the increase of temperature causes a phase transfer from gel state to sol state, and a change of dominate conduction mechanism from Arrhenius type to Vogel–Tamman–Fulcher (VTF), which turns to the change of ionic conductivity of thermoplastic polymer gel electrolyte and photovoltaic performance of DSSC. The photovoltaic performance of DSSCs severely depends on the temperature, which is the typical characteristic of DSSCs based on this kind of polymer gel electrolyte.

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Thermosetting Gel Electrolytes (TSGEs):

REFERENCES:

The TPGE is good for fabricating DSSCs. However, there is also a potential venture for actual application of DSSCs, which is the chemical instability, such as phase-separation, crystallization of iodide salts. Therefore, some more environmentally stable electrolytes are still needed. Among those optional methods, the TSGE is one of the good selections for high photovoltaic performance and good long-term stability of DSSCs. A high stable DSSC based on a TSGE containing ureasil precursors and organic liquid electrolyte containing iodide salts was prepared. The unique structure of this thermosetting Organic–inorganic hybrid gel electrolyte leads to the high quality of DSSC, which maintains 5–6 % light-to-electricity conversion efficiency even after preserving for several years.

1. M. Grätzel. Nature 414, 338 (2001). 2. B. O’Regan, M. Grätzel. Nature 353, 737 (1991). 3. M. Grätzel. Inorg. Chem. 44, 6841 (2005). 4. M. Grätzel. J. Photochem. Photobiol., A 164, 3 (2004). 5. A. F. Nogueira, C. Longo, M. A. De Paoli. Coord. Chem. Rev. 248, 1455 (2004). 6. P. Wang, S. M. Zakeeruddin, J. E. Moser, T. Sekiguchi, M. Grätzel. Nat. Mater. 2, 402 (2003). 7. U. Bach, D. Lupo, P. Comte, J. E. Moser, F. Weissortel, J. Salbeck, H. Spreitzer, M. Grätzel. Nature 395, 583 (1998).

CONCLUSIONS: In this review, we introduce on Quasi-solid-state electrolytes for DSSCs. Although a lightto-electricity conversion efficiency of 11 % for DSSCs containing liquid electrolytes has been achieved, the potential problems caused by liquid electrolytes, such as leakage and volatilization of organic solvents, are considered as some of the critical factors limiting the long-term performance and practical use of DSSCs. Solid-state electrolytes overcome the disadvantage of fluidity and volatility for liquid electrolytes, however, poor interface contact property and lower conductivity for solid-state electrolytes lead to lower light-to-electricity conversion efficiency for DSSCs. Quasi-solid-state electrolytes, especially TSGEs, possess liquid electrolyte’s ionic conductivity and interface contact property and solid-state electrolyte’s long-term stability, it is believed to be one kind of the most available electrolytes for fabricating high photoelectric performance and long-term stability of DSSCs in practical applications.

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INTRODUCTION:

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WEB PERSONALIZATION ARCHITECTURE:

Fig 1.1: Web personalization process

WEB PERSONALIZATION APPROACHES

Web mining is a mining of web data on the World Wide Web. Web mining does the process on personalizing these web data. The web data may be of the following: 1. 2. 3. 4.

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Fig. 2.1. Overview of user-profile-based personalization

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WEB PERSONALIZATION AND RELATED WORKS

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CONCLUSION

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3. 4. 5. 6. 7. 8. 9.

10. 11.

12.

13. 14. 15. 16. 17. 18.

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Automated Bus Monitoring and Ticketing System using RF Transceiver and RFID S.DEEPIKA

P.PRASANTH

Student, Information Technology

Velammal Engineering College, Surapet, Chennai - 600 066.

deepu.neethu238@gmail.com

pprasanth94@gmail.com

Abstract— The two major issues in today’s city are controlling traffic and the problem faced by the passengers of public transport. This paper comes out with the best solution to overcome the unawareness of the people in the bus stop about the departed and arriving buses and to the people in the nook and corner of the city about the current status of the buses using RF Transceiver, GSM and Zigbee. In addition the RFID bus ticketing system is proposed in this paper. The congestion and confusion in the bus stop and in buying the tickets in buses can be avoided by applying this system. The RF bus tracking system tracks government buses to inform the passengers about the current location of the buses and the RFID ticketing system helps the commuters and the conductors to resolve the problem regarding the issue of the appropriate tickets instantly and automatically with exact currency without chaos. The bus ticketing system also includes human detecting sensor to avoid malpractices and avoid culprits which improves accuracy.

exact change. The RFID enabled smart card is used to pay the ticket fare. The purpose of making automated ticketing system is: to reduce the conflict between commuters and conductors regarding the issue of wrong tickets with improper change; to reduce the culprits; to find the culprits and to reduce the usage of papers in the form of tickets. The RF Transceiver uses RF modules for high speed data transmission. The microelectronic circuit in the digitalRF architecture works at speed up to 100 GHz. The RF transceivers are available in various ranges at various costs suitable for the user. RFID refers to Radio Frequency Identification that uses three parts namely the reader, antenna and the tag. RFID is classified into two such as active RFID and passive RFID. The tag is nothing but a small chip which consists of a unique id which is burnt at the time of manufacture. The data can be stored in the tag and the amount of data is based on the capacity of the tag. The reader reads the tag when it comes within its range. GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard to describe protocols for second generation (2G) digital cellular networks used by mobile phones. Zigbee is a protocol that is used to transfer data wirelessly to a greater distance than Bluetooth in a minimum power usage.

Keywords — RF Transceiver, RFID, NFC, GSM, Zigbee, human detecting sensor.

INTRODUCTION

The automated bus monitoring system using RF transceiver proposed is this paper is designed to track the government buses (especially MTC buses). The purpose of tracking the government bus is to create an advanced bus transport system which helps the people to know about the arrival, departure and current status of the buses to people all around the city. This reduces the traffic, the congestion in bus stops, waiting time of the commuters in the bus stop and unawareness about the arriving and departed buses.

II.

NECESSITY OF TECHNOLOGY

The Metropolitan Transport Corporation (MTC) runs an extensive city bus system consisting of 3280 buses on 643 routes, and moves an estimated 5.52 million passengers each day. Chennai's transportation infrastructure provides coverage and connectivity, but growing use has caused traffic congestion. The government has tried to address these problems by constructing grade separators and flyovers at major intersections. But this alone doesn’t favor to reduce traffic. Not only the government but also the people get

The automated bus ticketing system using RFID proposed in this paper is designed to pay the exact bus fare instantly and automatically. This system is also useful to pay the bus fare without giving away the money during the journey which resolve the problem of giving and collecting

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affected more due to the congestion and traffic near the bus stop (fig.1). Infrequent commuters are unaware of the bus schedule for which they are waiting. Actually, in general each and every commuter is unaware of the arriving and departed buses. This in turn paves way for the major congestions near the bus stops and traffic in the city.

cashless; paperless; less or no ticket checker bus transport system.

III.

SYSTEM OVERVIEW

A. Automated Bus Monitoring System 1) Systemâ&#x20AC;&#x2122;s Description: The ABMS consists of RF transceivers, GSM modem, display boards and a microcontroller. In real time according to ABMS both the bus and bus stop is equipped with RF transceiver, microcontroller and display boards but additionally a GSM modem is installed in the bus stop. As explained above a RF transceiver and a display board will be installed inside the bus along with a microcontroller to control the entire system while the bus stop will be installed with a RF transceiver, a GSM module and a display board along with a microcontroller. If necessary a Zigbee can be installed in the bus stop to extend the range of the RF transceiver. Fig.1 Crowded Bus Stop

When the bus, say Bus1, nears the bus stop, say Bus Stop A, the RF transceivers both in the bus and the bus stop will start communicating each other. These transceivers send their corresponding information to each other. The microcontroller processes this information; send the respective information to the display board and the GSM module. The display board in the bus stop A displays the details of the bus 1 that has just arrived the stop. The details may contain the name, number, type, source to destination and the time of arrival of the bus 1. Then this detail is sent to the two successive bus stops, say B and C respectively using the GSM. The stops B and C displays the current status of the bus 1 that it has arrived the stop A and it is yet to arrive in some particular time as calculated(approx.). Meanwhile the RF transceiver in bus stop A transmits the name of the bus stop which is then displayed in the display board inside the bus; this helps the commuters inside the bus to know the stop they have arrived. If the bus starts moving from stop A then the bus gets out of range of the RF transceiver in the stop which then makes the microcontroller of stop A to change the information such as the bus moves from A to B in the display board where as the GSM makes the corresponding changes to stop B and C. If the bus reaches B then the same procedure follows as proceeded in A and so on.

In order to overcome this hitch the technology comes into play through the system called Automated Bus Monitoring System (ABMS) which is to intimate the people about the current status of the buses i.e., arriving or departed, through the display board and a mobile application flawlessly using RF transceiver and a GSM module. The government also can make a record of the timings of the buses and can check whether the buses are functioning as per the schedule. The ticketing in Government buses is being carried out manually since several decades. Few years back the MTC introduced ETM (Electronic Ticketing Machine) which found to be useless within a short period of usage. The major issues in these practice is that the manual work of the conductors made to delay the issue of tickets with improper change. Also in many situations especially during the peak hours the buses are made to halt in between the bus stops by the conductor to issue the tickets and collect fare which became a big hindrance to the commuters now-a-days. In addition the buses are being halted by the ticket checking inspectors even during peak hours, creating one more trouble to the people. The checking for tickets despite of peak hours also mean that there are many commuters travelling without tickets. Therefore to overcome these hitch faced by both government and the commuters the technology comes into play through the system called Automated Bus Ticketing System (ABTS) in which the passenger pay the fare through a smart card and a virtual ticket is generated. This results in a

2) Enhancement of the System: Even though this system helps the commuters, it only focuses on the commuters waiting in the bus stop. In order to make use of the details available in the bus stop by the people all over the city a

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mobile application is developed in such a way that the user gets the necessary information about the current status of all the buses at the door step. The entire system’s layout is shown in figure (fig.2).

B .Automated Bus Ticketing System The ABTS comprises of a smart card and two devices namely Human Detecting Sensor (HDS) and Integrated Ticketing Machine (ITM) (fig.5 & fig.6) which integrates RFID reader, NFC reader, led indicators, a keypad and a small display board. Smartcards are typically the size of a credit card, and contain a microchip (in this case RFID tag) that stores and transmits data using radio frequency identification (RFID), enabling it to communicate with a device within eight centimeters of the card without physical contact. Smartcards are able to store enough information to process monetary transactions and profile a card holder’s details for security purpose. Thus each smartcard corresponds to a unique account of the user that holds the money for the transaction. The user is supposed to recharge the smart card with a minimum balance.

Fig.2 Layout of ABTS

Fig. 5 Sample ITM position

Fig.3 App Sample

Fig. 6 Sample ITM

1) Integrated Ticketing Machine: This seems to be heart of the system. Two ITMs (one for each entrance) are required for each bus. On entering the bus, commuters show their smart card to one of the ITMs then the RFID reader in the ITM will detect the presence of the card; checks for minimum balance; records the card number along with boarding point of that particular commuter into a log such as entry log and then initially debits the ticket fare for the distance from boarding point of the commuter to destination point of the bus.

Fig.4 App Sample

The application should be developed in such a manner that the current status of all the buses to be available in one tab and in another tab a search should be made available in order to search the required bus’s status. There are many apps available with the entire database of the cities. For example: An iOS mobile app named ChennaiBus is available in apple’s app store which has the entire database of Chennai’s metropolitan buses.

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differentiating the commuter’s movement i.e., entering and existing (fig.9). This paves the way for calculating the number of passengers inside the bus and keeping track of number of commuters entered a particular bus stop. It is used to check whether the commuters are paying the fare correctly. Once the bus has halts in a bus stop the HDS starts counting and storing the number of commuters entering and exiting the bus in its own entry log and exit log respectively.

Start

Show the card to the integrated ticketing machine (ITM)

ITM Checks for the minimum balance

If balance is >= minimum

Insufficient balance is NO indicated by a red led

YES Fig.8 HDS at the entrance of a bus

Records the starting stage and debits the maximum ticket fare

Show the card to the reader

Calculates the ticket fare from source to destination stage and credits the balance amount to the card if any. Stop Fig.7 ITM flowchart

The commuter on reaching his destination point is supposed to show the card once again to any one of the ITMs so that the machine detects the card; checks for the card number inside the entry log by which it retrieves the boarding point and now stores the destination point into another log such as exit log; calculates the ticket fare for the distance travelled by the commuter and finally credits the remaining amount from initially debited amount. The working procedure of the ITM is described as a flow chart in fig.7

Fig.9 Counting people in HDS

As soon as the door closes, the HDS checks the number of passengers entered and allots an Average Ticketing Time (ATT). Average Ticketing Time is the average time limit within which the passengers are supposed to pay the bus fare. After the ATT expires the HDS compares its entry log with that of the ITM’s entry log and if any mismatch occurs it indicates the numbers of commuters who haven’t paid the bus fare yet. Then it compares its exit log

2) Human Detecting Sensor: The human detecting sensor is mounted at the top of entrance and exit of the bus in a convenient manner (fig.8). This sensor is capable of

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with that of the ITM’s exit log so that and if any mismatch occurs it indicates the number of culprits inside the bus. The working procedure of the HDS is described as a flow chart in fig.10

indicate the movement of the buses. We make use of a GSM module (SIM 900) installed with a sim card to retrieve the current status of each bus. A LCD (20X2) is used as a display board that displays the status of the each bus.

Start

Start counting the people entering and exiting

Allots Average Waiting Time (ATT)

Waits till ATT gets over Fig.11 Project Prototype

Fig.12 Bus Kit

Compares the HDS’s entry log with ITM’s entry log

If the count of both logs are equal

Indicates the no. of commuters travelling without tickets

Proceed Fig.10 HDS flow chart

Fig.13 Bus Stop Kit

NOTE: The HDS is the general term whereas specifically it is known as people counter.

IV.

Thus with the help of a prototype is has been clearly proved that the bus monitoring system can be easily implemented in real time as exactly stated in this paper. The automated bus ticketing system can also be easily implied in real time due to the usage of very common components and an already existing technology.

PROTOTYPE EXPERIMENTS AND RESULTS

As substantiation for the ABMS a prototype has been developed using RF transceiver, GSM module, PIC microcontroller 16f887 and 16f883. The prototype is developed as two kits (fig.11) where one is the bus (fig.12) and the other the bus stop (fig13). Three bus stops and three buses have been used in this module. Switches are used to

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Merits and Demerits:

VII.

Result/Outcome of Automated Bus ticketing System Traditional ticketing system

Electronic ticketing system

[1] http://www.tn.gov.in/district_details/535 ABTS

[2] http://www.eurotech-inc.com/bus-passengercounter.asp [3] http://www.eurotech-inc.com/automaticpassenger-counter.asp [4] http://gpsmonitoring.trustpass.alibaba.com/pr oduct/112187149101822825/capnavi_bus_people_counter_solu tion.html [5] http://www.alibaba.com/productdetail/Automatic-Passenger-Counting-SystemFor-Transit_11137078/showimage.html [6] http://www.indiamart.com/exiontechnology/p roducts.html [7] http://www.pcb.its.dot.gov/factsheets/core.as p [8] http://www.dnaindia.com/bangalore/reportrecycling-of-tickets-can-save-many-trees1745406 [9] http://timesofindia.indiatimes.com/city/chenn ai/400-passengers-travel-without-tickets-onMTC-buseseveryday/articleshow/4146022.cms [10]http://jaroukaparade.blogspot.in/2012/02/bus -tickets-honestly-waste-of-good.html

Self help/computerized Involuntary and Spontaneous Paperless ticketing Eco friendly User Friendly Less time consuming Issuing Appropriate tickets always Issuing exact number of tickets always Avoids misunderstanding Determines the culprit Omits ticket inspector Economical Not necessary of carrying smartcards Requires money only for the distance to be travelled TABLE 1: Merits and Demerits

VI.

REFERENCE

CONCLUSION

[11] http://www.thehindu.com/news/cities/chennai/theproblem-of-issuing-tickets-onbuses/article5627863.ece

It is believed that by the implementation of this system, problems such as underutilization of buses fleet and long waiting time at the bus station will be reduced. So, both passenger and bus station administrators will benefit from the system as real time information are provided. Resources should be integrated and coordinated based on the RFID, RF transceiver, GSM in the transportation medium which can easily meet the requirement of the public and can meet their emergency & requirement. Thus by implementing this entire system, advanced bus transportation can be achieved which brings the people of the city to a comfort zone. This system can be easily implemented in real time efficiently.

[12]http://www.complaintboard.in/complaintsreviews/tamil-nadu-transport-corporationl179177.html : [13] http://www.hindu.com/2009/05/21/stories/ 2009052159590400.htm [14] 4Vol38No1 [15] F6 Hasan - RFID Ticketing [16] researchpaper_Intelligent-Cars-using-RFIDTechnology [17] Bus_Management_System_Using_RFID_In_WSN [18] WCECS2012_pp1049-1054

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Comparative Study: MIMO OFDM, CDMA-SDMA Communication Techniques G.Manikandan1, 1

P Mathu Meena2

Assistant Professor, 2Student B.E/ECE, Kodaikanal Institute of Technology 2

mrg.manikandan@gmail.com,

(OFDM), and the Multiple Input Multiple Output (MIMO) are the most competitive technologies in future wireless communication systems. Moreover, Practical communications systems have to support a multiplicity of users and hence diverse schemes have been proposed for supporting multiple users, including Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) , and Space Division Multiple Access (SDMA). However, all the performance gains from these technologies could be achieved only if the channel state information is available at the receive side [2]. Robust channel estimation and multiuser detections are required. Furthermore, an important problem in the design of digital communication system receivers is the detection of data from noisy measurements of the transmitted signals. Designing a receiver which has the property of minimizing this error probability while being realistic from the computational complexity point of view has thus attracted a lot of attention amongst researchers. Multi-User detection (MUD) refers to the scenario in which a single receiver jointly detects multiple simultaneous transmissions. More generally, multiuser detection techniques apply to the joint detection of different signals transmitted over MIMO channel. One example include channels in which multiple transmitted information streams are multiplexed over multiple transmit antennas. In that scenario, the multiple users refer to the multiple information streams, even though the transmitted signal may originate from a single user [3]. A variety of MUD schemes, such as the Minimum Mean-Square Error (MMSE) detectors, Successive Interference Cancellation (SIC), Parallel Interference Cancellation (PIC), Ordered successive interference cancellation (OSIC) and Maximum Likelihood (ML) Detection schemes may be invoked for the sake of separating the different users at the Base Station (BS).

Abstractâ&#x20AC;&#x201D; This paper investigates CDMA-SDMA techniques combined with the Orthogonal Frequency Division Multiplexing (OFDM). Space Division Multiple Access(SDMA) is a notable application of Multiple Input Multiple Output(MIMO) system. SDMA is one of the most promising techniques aiming at solving the capacity problem of wireless communication systems and achieving higher spectral efficiency, depending on multiplexing signals based on their spatial signature. On the other hand most third generation mobile phone systems are using Code Division Multiple Access (CDMA) as their modulation technique. CDMA is not so complicated to implement as OFDM based systems. As CDMA has a wide bandwidth, it is difficult to equalize the overall spectrum significant levels of processing would be needed for this as it consists of a continuous signal and not discrete carriers. Not as easy to aggregate spectrum as for OFDM. For this reason, CDMA is also investigating so that the performance of OFDM-CDMA-SDMA can be compared. Various SDMA techniques are investigated including linear detection schemes, minimum mean square error, ordered successive cancellation, and maximum likelihood methods. Promising results are obtained to enhance spectral efficiency on the expense of computational complexity which needs to be addressed.

Keywords- Space division Multiple Access (SDMA); Code Division Multiple Access (CDMA); Orthogonal Frequency Division Multiplexing (OFDM); Multi-User Detection (MUD).

mathumeenabe93@gmail.com

INTRODUCTION

SDMA techniques have the advantage of improving the capacity of wireless systems, with the expense of requiring robust detection in the receiver. This paper investigates multiuser detection methods and implement these methods for different cases in the capacity of system with noting the tradeoff of computational complexity for these detection techniques. The next section will introduce the MIMO-OFDM technologies. In Section III, we investigate the multi-user detection methods and see what the effect of increasing the number of users in the SDMA-OFDM system.

Novel wireless communication and multimedia services are being introduced almost daily and the spectacular progress is to a great extent due to continuous progress in electronic and micro-electronic technology. Such advances have also been fostered by major theoretical developments. The list of wire-less air interface protocols which follows signifies the most familiar standards in exercise around the world nowadays. The next generation broadband wireless communication system(4G) will be able to provide users with wireless multimedia services of high-speed wireless Internet access, wireless video, and mobile computing, which push communication technologies towards to more high-speed and more reliable [1].

Capacity of OFDM and CDMA with Multiple Cells With any cellular system, interference from neighbor cells lowers the overall capacity of each cell. For conventional TDMA and FDMA systems, each cell must have a different operating frequency from its immediate neighbor cells. This is to reduce the amount of interference to an acceptable

In order to satisfy the future requirements of wireless access systems, Orthogonal Frequency Division Multiplexing

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II. MIMO-OFDM TECHNOLOGIES

level. The frequencies are reused in a pattern, with the spacing between cells using the same frequency which is determined by the reuse factor. The required frequency reuse factor depends on the interference tolerance of the transmission system. Analog systems typically require a carrier to interference ratio (C/I) of greater then 18dB [7], which requires reuse factor of 1/7 (see Figure 2 (b)). Most digital systems only require a C/I of 12dB allowing a reuse factor of 1/3-1/4 (see Figure 2 (a)). CDMA uses the same frequency in all cells, and hence ideally allowing a reuse factor of 1 (see Figure 2).

A. MIMO Assisted OFDM The MIMO scheme has attracted considerable interest to enhance the data rates capability of system. Moreover, a particularly promising candidate for next-generation fixed and mobile wireless systems is the combination of MIMO technology with OFDM. MIMO systems can be used for beamforming, diversity combining, or spatial multiplexing. Spatial multiplexing is the transmission of multiple data streams on multiple antennas in parallel, leading to a substantial increase in capacity [2]. MIMO-OFDM system can achieve high data rates while providing better system performance by using both antenna diversity and frequency diversity, which makes it attractive for high-data-rate wireless applications. Initial field tests of broadband wireless MIMO-OFDM communication systems have shown that an increased capacity, coverage and reliability is achievable with the aid of MIMO techniques.

Fig 2: Frequency reuse patterns for (a) 3 frequencies (Digital systems), (b) 7 frequencies (Analog FDMA), (c) CDMA

B. SDMA-based MIMO OFDM Systems Among the notable applications of MIMO system, is the Space Division Multiple Access (SDMA) techniques. The implementation of SDMA comes in two main scenarios: multi-user access and multiple stream transmission. In the first scenario, multi-users share the up-link and downlink channels for connection to the base station . The second scenario that achieved by the Bell Labs Layered Space Time (BLAST) technology where the multiple sub-streams of a single user's data are transmitted in the same frequency band. SDMA offers high spectrum efficiency and enhance the effective transmission rate, and thus it's one of the most promising techniques aiming at solving the capacity problem of wireless communication systems, where theoretically, SDMA can be incorporated into any existing multiple access standard at the cost of a limited increase in system complexity, while attaining a substantial increase in capacity [4]. More specifically, the exploitation of the spatial dimension, namely the so-called spatial signature, makes it possible to identify the individual users, even when they are in the same time/frequency/code domains, thus increasing the systemâ&#x20AC;&#x2122;s capacity. However, to mitigate the channel impairments, OFDM can be used, which transforms a frequency-selective channel in a set of frequency-flat channels.

In practice the frequency reuse efficiency of CDMA is low, as neighbouring cells cause interference, which reduce user capacity of both. The frequency reuse factor for a CDMA system is about 0.65 [8]. Figure 3 shows the interference from neighbouring cells. Most of the neighbouring interference is from the immediate neighbours of the cell

Fig 3: Interference contributions from neighbouring cells in a CDMA system.

The cell capacity for a multi-cellular CDMA system equal to the single cell capacity reduced by the frequency reuse factor. The cell capacity for CDMA is very low if cell sectorization and voice activity detection is used. A straight CDMA system can only have somewhere between 5-11 users/cell/1.25MHz. Using voice activity detection and cell sectorization allow the capacity to be increased by up to 6.4 time, allowing somewhere between 30-70 user/cell/1.25MHz. OFDM require a frequency reuse pattern to be used in a multi-cellular environment to reduce the level of inter-cellular interference. The C/I required must be greater then ~12dB. This could be done with a frequency reuse factor of ~3. This should be easily achived as cell sectorization could also be used to reduce the level of interference. This would result in the cell capacity for an OFDM system of approximately 128/3 = 42.7 users/cell/1.25MHz in a multicellular environment

Fig. 1 illustrate the concept of SDMA systems, where each user exploiting a single transmitter antenna aided Mobile Station (MS) simultaneously communicates with the BS equipped with an array of receiver antennas. In SDMAOFDM systems the transmitted signals of L simultaneous uplink mobile users- each equipped with a single transmit antenna are received by the P different receiver antennas of the BS as shown in Fig. 2. At the BS Multi-User Detection (MUD) techniques are invoked for detecting the different users transmitted signals with the aid of their unique, userspecific spatial signature constituted by their Channel Impulse Responses (CIRs).

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signals as interference except for the desired stream from the target transmit antenna. Therefore, interference signals from other transmit antennas are minimized or nullified in the course of detecting the desired signal from the target transmit antenna. These linear methods consider the inputoutput relation of a MIMO system as an unconstrained linear estimation problem, which can be solved by using ZeroForcing (ZF) or Minimum Mean Square Error (MMSE) criterion [5].

P-element antenna array

..... BS

..... MS2

MSL

x(1) x(2)

JOINT CHANNEL ESTIMATION AND MULTI-USER DETECTION

...

(1)

H1(2)

H3(1)

H2(3)

MSL

n1 y1

Rx2

H2(2) (3)

H3(1) RxP

UserL

Py2 element Receive Antenna Array y3

H3(3) Figure 2. Schematic of the SDMA uplink MIMO channel model .

Instead of forcing interference terms to zero without considering the noise as used in the ZF detection, the MMSE criterion minimizes the overall expected error by taking the presence of the additive noise into account. Linear detection schemes are simple, but unfortunately they do not provide near optimal performance, especially when the channel matrix is near singular. Moreover, based on linear detection methods, the Successive interference cancellation (SIC) is one method, where the key idea of SIC is to successively detect and cancel the streams layer by layer. The algorithm first detects (using ZF or MMSE) an arbitrarily chosen data symbol, assuming the other symbols to be interference. The detected symbol is then cancelled from the received signal vector and the procedure is repeated until all the symbols are detected. Compared to the linear detection schemes, SIC achieves an increase in diversity order with each iteration. The performance of the linear detection methods is worse than that of other nonlinear receiver techniques. However, linear detection methods require a low complexity of hardware implementation. One method used to improve the performance without increasing the complexity significantly is the Ordered successive interference cancellation (OSIC) scheme [5]. This method can improve the performance of SIC by selecting the stream with the highest signal-to-noise-plus-interference ratio (SINR) at each detection stage. Fig. 3 illustrates the OSIC signal detection process for NT = 4 [6]. Let x(i) denote the symbol to be detected in the ith order. Let x'(i) denote sliced value of x(i). Suppose that the MMSE

x= [x1,x2,...,xN T] and y = [y 1,y2,...yN R] , respectively, where xi and yj denote the transmit signal from the ith user which have single transmit antenna and the received signal at the jth receive antenna, respectively. Let  zj denote the white Gaussian noise 2 with a variance of z at the jth receive antenna, and hi denote

method is used, thus the first stream is estimated using the MMSE method, then slicing to produce x (1). The remaining signal in the first stage is formed by subtracting it from the received signal, that is

the ith column vector of the channel matrix H. Now, the NR NT MIMO system is represented as

y= HX + z = h 1x1+ h2x2+ .....+ hNT xNT+ z

H 3 (2)

x(3)

B. Multi-User Detection Robust multi-user detection schemes become necessary in order to using the advantage of SDMA technique to solve the capacity problem in wireless systems, since the increasing number of users will decrease the performance of system particularly when the number of users is more than the number of receive antennas. Consider the NR  NT MIMO system, and H denote a channel matrix with h ij is the channel gain between the ith transmit antenna and the jth receive antenna, j=1,2,...,NR and i=1,2,..,NT. The spatially multiplexed user data and the corresponding received signals are represented by T

MS2

User2

A. Channel Estimation The OFDM technique is capable of satisfying the requirements of supporting a high grade of mobility in diverse propagation environments. This is a benefit of their ability to cope with highly time variant wireless channel characteristics. Also in spite of an immense interest from both the academic and the industrial communities, a practical MIMO transceiver architecture, capable of approaching channel capacity boundaries in realistic channel conditions remains largely an open problem [4]. Thus, the provision of an accurate and robust channel estimation strategy is a crucial factor in achieving a high performance. However, the channel estimation for wireless systems is a challenging problem and the literature treating it is vast, where its simply defined as the process of characterizing the effect of the physical channel on the input sequence. In this work, the channel estimation techniques are assumed to be perfectly done at the BS and it can be used to detect the users data.

Rx1

H1(1)

User1

Figure 1. Illustration of the generic SDMA system.

III.

MS1

...

MS1

(1)

Linear signal detection method treats all transmitted

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y'(1) = y ‫ ــ‬h(1) x'(1)

OSIC signal Detection

= h(1) (x (1) ‫ ــ‬x'(1) ) + h(2) (x (2) ‫ــ‬x'(2) ) + .... + h(N ) (x (N ) ‫ ــ‬x'(N ) )+ z

0 SNR-BASED COLUMN NORM -BASED SINR-BASED

(2) -1

x'(1)

(1)st Stream Estimation

y'(1) = y- h(1) x'(1)

y'(1)

(2)nd Stream Estimation

BER

-2

x'(2)

-3

y'(2) = y'(1) - h(2) x'(2)

y'(2) (3)rd Stream Estimation

x'(3)

-4

10 0

y'(3) = y'(2) - h(3) x'(3)

y'(3)

(4)th Stream Estimation

10 EB/NO (DB)

x'(4) Figure 4. Performance of OSIC methods with different detection ordering.

Figure 3. OSIC signal detection for four transmit antennas.

Among the MUD techniques, is the ML detection scheme achieves the optimal performance as the maximum a posteriori (MAP) detection when all the transmitted vectors are equally likely. The ML method calculates the Euclidean distance between the received signal vectors and the product of all possible transmitted signal vectors with the given channel, and finds the minimum distance [6]. The ML detection determines the estimate of the transmitted signal vector x as x'ML= argmin y ‫ ــ‬Hx ² (3)

If x(1)= x'(1), then the interference is successfully canceled in the course of estimating x(2); however, if x(1) ≠ x'(1), then error propagation is incurred because the MMSE weight that has been designed under the condition of x(1)= x'(1) is used for estimating x(2). Due to the error propagation caused by erroneous decision in the previous stages, the order of detection has significant influence on the overall performance of OSIC detection. There are three different methods of detection ordering. The first method is SINRBased Ordering which start detect the signals with higher post detection signal-to-interference-plus-noise ratio (SINR). In the course of choosing the second detected symbol, the interference due to the first detected symbol is canceled from the received signals. The second method of OSIC detector is the SNR-Based Ordering which use the ZF weight. The same procedure of detection ordering as in the first method but without interference term. The third method is the Column Norm-Based Ordering which is used to reduce the ordering complexity using the norm of the column vectors in a channel matrix. Consider the representation of the received signal in equation(1) which it can be observed that the received signal strength of the ith transmitted signal is proportional to the norm of the ith column in the channel

Where y ‫ ــ‬Hx² corresponds to the ML metric. The number of candidate symbol vectors grows exponentially with NT and the number of bits per constellation point. Thus, with higher order constellations and with multiple transmit antennas (or number of users in SDMA system), ML detection becomes computationally intensive. Simulation results investigate the performance of ML scheme and compare it to OSIC method. ML & OSIC Systems

10 OSIC DETECTOR ML DETECTOR -1

matrix. Therefore, the detect of signal it can be done in the order of the norms h i . In this method, the first is compute NT norms and then, order them only once. Detection is performed in the decreasing order of norms and the complexity is significantly reduced as compared to the previous methods, since ordering is required only once [6].

BER

-2

-3

Fig. 4 compares the error performance of the OSIC detection for the three ordering methods. (SINR-based ordering, SNR-Based ordering, and Column Norm-Based Ordering). The number of users are 4 transmitting at the same time using SDMA technique each one have single transmit antenna (NT) and the number of receive antennas (NR) at the BS is 4 with 16-QAM modulation. It is observed that the detection SINR-based ordering method achieves the best performance among three methods. OSIC receivers reduce the probability of error propagation with the cost of slightly higher computational complexity compared to that of the SIC algorithm.

-4

10 0

6 EB/NO (DB)

Figure 5. Performance comparison: ML vs. OSIC signal detection methods for NT =NR=4.

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Fig. 5 shows the performance of ML compared to OSIC method for SDMA system with 4 users each one have single transmit antenna NT and the number of receive antennas NR equal to 4 with 16-QAM modulation, where it's obvious that the ML outperforms the OSIC detection. ML achieves the optimal performance and its performance serves as a reference to other detection methods, however its complexity increases exponentially as number of users increases.

amples are the Standard Gaussian Approximation (SGA) [2]– [15], the Improved Gaussian Approximation (IGA) [2], [6], [9], [10], [12], [13], [15]–[17], the Simplified IGA (SIGA) [2], [6], [9], [11], [13], [15], and the Improved Holtzman Gaussian Approximation (IHGA) [11]. However, the accuracy of the various Gaussian approximation techniques depends on the specific configuration of the system. It is well known that the Gaussian approximation techniques become less accurate, when a low number of users is supported or when there is a dominant interferer [12]. Therefore the accurate BER analysis dispensing with the previous assumptions on the MAI distribution is desirable. Hence a number of accurate techniques have been developed, such as the series expansion [12], [13], [18]–[20], the Fourier [2], [3], [11], [15], [18] and Laplace [21] transform based methods. The latter two lead to the Characteristic Function (CF) and Moment Generating Function (MGF) based approaches and have been prevalent in the accurate BER analysis of communication systems. The BER performance of DS-CDMA systems communicat-ing over Additive White Gaussian Noise (AWGN) channels has been extensively studied [5]–[10], [12], [13], [15], [16], However, to the authors’ best knowledge, the accurate BER analysis of asynchronous Ricean-faded DS-CDMA systems using random spreading [2]–[17], [19], [20] sequences is still an open problem. There are many propagation environ-ments, such as microcellular urban and suburban land mobile, as well as picocellular indoor and factory scenarios, where there exist Line-Of-Sight (LOS) propagation paths between the transmitter and the receiver [27]. In the presence of a LOS component, the Ricean distribution, also known as the Nakagami-n distribution [28], [29], is a better model of the fading channel. The Ricean distribution becomes the Rayleigh distribution, when the energy of the LOS component becomes zero [27], [30]. The novel contribution of this paper is that we provide an accurate BER expression for asynchronous DS-CDMA systems in a Ricean fading environment, which requires only a single numerical integration, when using the hypergeometric functions of two variables [31]–[33].

The SDMA system solve the capacity problem of the wireless system. However, when the number of users is higher than the number of receive antennas at the receiver, the performance of the system will be decreased and the multi-user detection method should have the ability to improve the performance. ML method will improve the performance in contrast to the other methods at the cost of increasing the computational complexity, especially in the context of a high number of users and higher-order modulation schemes. Fig. 6 shows the improvement of using the ML method in comparison to the OSIC detection when the number of users increased to 6 and number of receivers is 4. It shows that ML method has the ability to maintain low bit error rate even if the number of users higher than the number of receive antennas at the BS. In order to reduce the computational complexity of ML algorithm, a QR decomposition associated M-algorithm was proposed, named QRM-ML algorithm. It performs signal detection sequentially in NT stages after QR decomposition. By appropriately choosing the parameter M the QRM-ML algorithm can achieve similar performance as that of the ML algorithm with significantly reduced computational complexity. Assuming that the number of users(or transmit antennas NT) and number of receiver antennas are equal, the QRM-ML detection method can be investigated for different cases. ML & OSIC Systems

OSIC DETECTOR ML D ETECTOR

10-1 BER

The organization of this paper is as follows. In Section II an asynchronous DS-CDMA system using BPSK modulation is considered in the context of a Ricean fading channel. Then in Section III an accurate BER expression based on the characteristic function approach is derived for the BER calculation of the system using random spreading sequences. [18]–[20], [22]–[26], and there are numerous studies also for transmission over both Rayleigh [2], [12] and Nakagami-m [3], [4], [11], [17], [21] channels. Geraniotis and Purs-ley [18] were the first authors, who investigated the accu-rate BER calculation of asynchronous DS-CDMA systems over AWGN channels using the CF approach. Then Cheng and Beaulieu extended the results to both Rayleigh [2] and Nakagami-m [3] channels.

-2

EB/NO (DB)

Figure 6. Performance comparison: ML vs. OSIC detection methods when number of users equal to 6 and N R=4.

In Direct Sequence Code Division Multiple Access (DSCDMA) systems [1], various versions of the so-called Gaussian approximation are widely used for modeling the distribution of the Multiple Access Interference (MAI). A few ex-

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multipath components, Lk, has a significant influence on the BER performance using the SGA approximation. Fig. 4 shows the BER performance over a frequency selective multipath Rayleigh fading channel with perfect power control, as a function of the process gain ( N = 32, 84, and

Figure 7. The performance of QRM-ML signal detection using N T =NR= 4 with 16-QAM modulation.

Consider QR decomposition of the channel matrix, that is H= QR. Then, the ML metric in equation(3) can be equivalently expressed as y ‫ ــ‬Hx = y ‫ ــ‬QRx H

= Q (y-QRx)

Average BER, dB

= y' ‫ ــ‬Rx (4) The performance of QRM-ML depends on the parameter M, where, it equal to the number of users and number of receive antennas NR. As M increases, its performance approaches ML performance at the sacrifice of the complexity [6]. Fig. 7 shows the performance of QRM-ML for M= 4 and 16. The QRM-ML performance degrades when M= 4 at the benefit of the reduced complexity.

−1

IV. SIMULATION RESULTS

c =1 Mc = 4

In this section, we present and discuss the numerical results of the BER performance of an asynchronous DS-CDMA system over a frequency-selective multipath Rayleigh fading channel. The numerical results are based on the standard Gaussian approximation (SGA) for the multipath and multiple access interference (MAI) (eq. (11)) with perfect power control. Each cell is equipped with a conventional correlation receiver. The received power of the desired signal is normalized to 1.

Mc = 8

Number of Users

Fig. 2. BER performance over a frequency selective multipath

Rayleigh fading channel with perfect power control, as a function of

Fig. 2 shows the BER performance over a frequency selective multipath Rayleigh fading channel with perfect power control, as a function of the number of interfering cells Mc. In this simulation, the number of multipaths is set to Lk = E 5, the signal-to-noise ratio (SNR)

−2

the number of interfering cells with Lk = 5, the process gain N = 84, and SNR = 20.

The number of interfering cells is set to Mc = 4, the SNR = 20, the number of multipath components is set to Lk = 4, and ¾ = 1. From the figures, it is clear that varying the process gain, N, has a significant influence on the BER performance using the SGA approximation. Fig. 4 shows the average BER performance obtained by simulation over a frequency selective multipath Rayleigh fad-ing and AWGN channel. From the simulation, we find that averaging over more experiments and using a larger symbol size will produce results closer to the theoretical results. The symbol size used in this simulation is 10,000.

= 20, the process gain No

N = 84, and ¾ = 1. As illustrated in Fig. 2, we observed that the BER increases when the number of interfering cells is less. It is evident that the performance of the DS-CDMA system depends on the number of interfering cells. Fig. 3 shows the BER performance over a frequency selective multipath Rayleigh fading channel with perfect power control, as a function of the number of the multipath compo-nents ( Lk = 3, 5, and 10). The number of interfering cells is set to Mc = 4, the SNR = 20, the process gain N = 84, and ¾ = 1. From the figures, it is clear that varying the

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IV. CONCLUSION In this paper, we assume an OFDM/SDMA/CDMA approach that couples the capabilities of these techniques. OFDM helps to enhance the system performance, while SDMA increases the spectral efficiency, where CDMA uses high rate signature pulses to enhance the signal bandwidth far beyond what is necessary for a given data rate. Performance of various multi-user detection schemes based on OFDM/SDMA/CDMA are investigated for different scenarios. Results show the importance of robust detection methods in improving the performance of the system, particularly when the SDMA technique is used to achieve the higher spectral efficiency. It is found that CDMA only performs well in a multi-cellular environment where a single frequency is used in all cells. This increases the comparative performance against other systems that require a cellular pattern of frequencies to reduce inter-cellular interference. ML is the optimal multi-user detection scheme where it gives high performance in comparison to the OSIC method even if the number of users is higher than the number of receive antennas. Thus the ML method can support the SDMA technique, however this technique is associated with large computational requirements. Long time is usually needed for running the algorithm which does not allow real time implementation. One major area, which hasn’t been investigated, is the problems that may be encountered when OFDM is used in a multiuser environment. One possible problem is that the receiver may require a very large dynamic range in order to handle the large signal strength variation between users . Hardware implementation of the algorithm can help reduce the running time considerably. Success in real time implementation of optimization technique for SDMA can play a major role in next generation communication systems. REFERENCES [1]

[2] [3] [4]

[5]

[6]

[7] [8]

L. Jie, and W. Yiwen, "Adaptive resource allocation algorithm based on Sequence strategy of modulated MIMO-OFDM for UWB communication system," in IEEE Inter.l Conf. on Measuring Tech. and Mech. Automation, 2010. L. Hanzo and T. Keller, OFDM and MC-CDMA, 2nd ed. West Sussex, United Kingdom: Wiley, 2006. M. L. Honig, Advances in multiuser detection, Northwestern University, United States of America: Wiley, 2009. L. Hanzo, J. Akhtman, M. Jiang, and L. Wang, MIMO-OFDM for LTE,WIFI and WIMAX Coherent versus Non-Coherent and Cooperative Turbo-Transceivers. UK: University of Southampton, 2010. L. R, and Verdú S , "Linear multiuser detectors for synchronous code division multiple-access channels.," IEEE Transactions on Information Theory, vol. 34, no. 1, 1989. Yong Soo, J. Kim, and C. G.Kang, MIMO-OFDM Wireless Communications with Matlab, Jone Wiely & Sons(Asia) Pte Ltd, Ed., 2010. J. Proakis, Digital Communications.: McGraw-Hill, 2008. K. J. Kim and J. Yue, "Joint channel estimation and data detection algorithms for MIMO-OFDM systems, " 36th Asilomar Conference on Signals, Systems and Computers, pp. 1857–1861, Nov. 2002.

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