Applied ICT A2
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Index Section 5
Section 7
Expert Systems
Internet Protocols & Hardware
Monitoring and measurement
Network Types
Project Management
Network security
Modelling
Electronic Conferencing
Market Research Research Applications Online Applications Stock Control
Section 6 Digital Divide Disabilities Legal & Political Systems Computer Fraud Antisocial use of ICT Home Entertainment Systems Internet Auctions Booking Systems Information Services Local Regional & government Teaching & Learning
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Section 5 5.1
What is an Expert System?
Keywords: knowledge base, rules base, inference engine, knowledge engineer, user interface, mineral prospecting, investment analysis, financial planning, credit analysis, insurance planning, medical diagnosis, route scheduling, plant & animal identification, advantages & disadvantages. An expert system is computer software that attempts to act like a human expert on a particular subject area. Expert systems are often used to advise non-experts in situations where a human expert in unavailable (for example it may be too expensive to employ a human expert, or it might be a difficult to reach location). How Do Expert Systems Work? An expert system is made up of three parts: 1. A user interface - This is the system that allows a non-expert user to query (question) the expert system, and to receive advice. The user-interface is designed to be a simple to use as possible. 2. A knowledge base - This is a collection of facts and rules. The knowledge base is created from information provided by human experts 3. An inference engine - This acts rather like a search engine, examining the knowledge base for information that matches the user's query. The non-expert user queries the expert system. This is done by asking a question, or by answering questions asked by the expert system. The inference engine uses the query to search the knowledge base and then provides an answer or some advice to the user.
Where Are Expert Systems Used? Medical diagnosis (the knowledge base would contain medical information, the symptoms of the patient would be used as the query, and the advice would be a diagnose of the patient’s illness) Playing strategy games like chess against a computer (the knowledge base would contain strategies and moves, the player's moves would be used as the query, and the output would be the computer's 'expert' moves) Providing financial advice - whether to invest in a business, etc. (the knowledge base 3|Page
would contain data about the performance of financial markets and businesses in the past) Helping to identify items such as plants / animals / rocks / etc. (the knowledge base would contain characteristics of every item, the details of an unknown item would be used as the query, and the advice would be a likely identification) Helping to discover locations to drill for water / oil (the knowledge base would contain characteristics of likely rock formations where oil / water could be found, the details of a particular location would be used as the query, and the advice would be the likelihood of finding oil / water there) Helping to diagnose car engine problems (like medical diagnosis, but for cars!)
Can Expert Systems Make Mistakes? Human experts make mistakes all the time (people forget things, etc.) so you might imagine that a computer-based expert system would be much better to have around. However expert systems can some problems: Can't easily adapt to new circumstances (e.g. if they are presented with totally unexpected data, they are unable to process it) Can be difficult to use (if the non-expert user makes mistakes when using the system, the resulting advice could be very wrong) They have no 'common sense' (a human user tends to notice obvious errors, whereas a computer wouldn't)
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5.2
Monitoring & Measurement
Keywords: sensors, variables, control systems, data logging, medical applications, weather systems, climate, environment, scientific experiments, charts, reports. How Can Computers Measure Things? A sensor, such as a temperature sensor, can be connected to a computer. The computer can then monitor the signal from the sensor, reacting to changes, or it can record the data from the sensor at predefined time intervals. Note: If the sensor is an analogue one then an analogue-to-digital convertor (ADC) will be required. Where is Computer Measurement Used? Anywhere that data needs to be gathered regularly, a computerised data-logging system can be used. Some examples are shown below‌ Scientific experiments Many experiments can be set-up and left to run with a data-logging system measuring things like the temperature of a liquid, etc. Weather stations Often these are placed in very remote areas to collect data about rainfall, temperature, wind-speed, wind-direction, etc. Data needs to be gathered all day, every day. This data can then be used by weather forecasters to help predict the weather over the coming days. Environmental monitoring Scientists are very concerned about the effect that humans are having on the environment. Computer-based data-logging is often used to help gather evidence of these effects: the level of water in a dam, the speed of water flowing down a river, the amount of pollution in the air, etc. Why Use Computers to Measure Things? The main reasons that you would want to use a computer-based data-logging system, instead of a person taking measurements are... Computers do not need to take breaks - they can log data all day, every day, without stopping Computers take much more accurate readings than humans can 5|Page
Computers can take data readings more frequently (1000s of times a second if necessary) Since the logged data is already in a computer, the data can be analysed more quickly and easily (graphs drawn instantly, etc.) Data logging systems can operate in difficult environments (e.g. in the Arctic, or on top of a mountain) People are free to do other more useful tasks (rather than watching a thermometer) Computer system are used in several quite different ways within doctor's surgeries and hospitals...
Monitoring of Patients When a patient is in hospital, they often require close monitoring. It is not possible for a doctor or nurse to monitor patients continuously, 24 hours a day, so computerised monitors are used instead. Sensors are attached to the patient. Sensors are used to monitor:
Pulse rate (heart beats per minute) Temperature Breathing rate (breathes per minute) Blood oxygen levels Blood pressure
The sensors feed information back to a computer which processes the data:
Data is checked for any problems (e.g. pulse rate too low/high) Data is logged so that it can be checked later
Several outputs from the computer system let hospital staff the patient's condition:
A large display / monitor shows graphs of pulse, breathing, etc. A loud buzzer / alarm can be sounded if there is a problem to attract the attention of a nurse/doctor A small printer can produce a hard-copy of the data
The data from several patients can be fed back to a central nursing station so that the nursing staff can see exactly what is happening in the ward.
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Diagnosis of Illness Body Scanners CT scanners and MRI scanners allow doctors to investigate what is happening inside a patient's body without intrusive surgery. The complex signals that come back from these huge machines are picked up by sensors and fed into a computer. The computer processesthe data, then outputs full-colour images, sometimes in 3D, for the doctor, giving views of the patient's body.
Managing Patient Records Doctors and hospitals have to deal with thousands of patients every week. It is essential that the medical details of every patient is recordedaccurately so that the correct diagnosis can be made, and the correct treatment can be given. For this reason, hospitals make use of computerised databases to store patient records. Computerised databases mean that:
Patient data can be easily shared between doctors, pharmaciesand other hospitals It is easy to search for and retrieve patient records Doctors can instruct a pharmacy to issue medication for a patient (no paper note needs to be written)
The patient data that would be typically stored would be:
Patient ID (number or text) - this would be the key field Name (text) Date-of-birth (date) Gender (boolean) Blood group (text) Allergies (text) Medical history (text)
Doctor currently treating (text)
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Current symptoms (text) Current diagnosis (text) Current treatment (text) Current medication (text) X-rays or body scans (links to image/video files)
It used to be the case that patient records were all written on paper, and stored in huge, manual databases. This made accessing the records slow. Sometimes records could get lost, and there was no easy way to make a back-up copy. Doctors can access a patients record whilst they are visiting patients, by using a computer connected wirelessly to the hospital network. Doctors often use tablet computers(which are portable like laptops, but have a touch screen, and no keyboard) as they can be held in one hand, and operated with the other.
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DATA LOGGING
Data logging is a way of using a computer to ___________________ collect data over a period of _________ without the need for_______________ supervision. Data logging is useful when data:
needs to be collected in ______________ or inhospitable conditions
where it would be ________________ for humans to take measurements
in _______________ experiments.
Once the data has been collected it can be transferred anywhere using communication links like ______________ and _________________ lines. Once ‘logged’ the data can be analysed by computers at its final destination. Advantages of using data logging to gather data include:
readings are much more _________________
data can be logged over any period of __________ without the need for human ________________
humans are released from ______________, time consuming and ________________ work.
Data is logged either directly by computer through an input-output port, or remotely by a ‘data logger’ using sensors or probes. Data that is logged is usually about some ______________ quantity e.g. temperature, pressure, which can have many different values and is therefore analogue data. Data loggers transform this into digital data using an analogue-to-digital converter.
Analogue data Sensor
Analogue to digital converter
Digital data
Use each word below just once to complete the worksheet above. boring
satellite
science
time
difficult
human
time
physical
remote
computer
telephone
automatically
accurate
repetitive
intervention
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5.3
Project Management
Keywords: Gantt charts, pert charts, software development,
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Gantt charts - advantages Individual tasks can be shown
The length of time required for each task is shown
Tasks can be viewed against a calendar with their start, end and duration dates listed
Links can be shown between dependent tasks i.e. what must be completed before the next task can begin
They give a very quick visual view to what should be happening at any stage in the project
Shows how long a project should take for completion
Resources required for tasks can be linked to the tasks on the chart
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Critical Path Analysis (CPA) This is a useful Project Management Tool which enables managers to calculate the minimum length of time a project will need to be completed. The idea behind it is that in order to complete a project some activities are dependent on other activities being finished in a certain order. For example, if you are cooking Sunday lunch, you can't carve the meat up until you have cooked it and removed it from the oven. CPA helps to identify every stage of a project and exactly how long each stage will take. The critical path of a project is the longest path from start to finish. Once the critical path is known, the project manager can then plan staff and resources to ensure that the project does not fall behind schedule.
Working out the critical path In order to calculate the critical path the following must be done:
Identify all of the activities for the whole project Prioritise the activities in order of importance Identify which activities must be completed before another one can begin Identify the Earliest Start Time (EST) for activities Identify the Latest Finish Time (LFT) for activities Identify the FLOAT - those tasks which can be completed outside the critical path Identify the critical path
CPA - a worked example Let's look at an example of how a CPA is constructed over the next few pages.
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CPA advantages Helps to increase the efficiency of how time and resources are used
It enables time scales for the project to be planned
It enables scheduling of tasks to take place in a logical order
It means that one task isn't held up because its predecessor wasn't started on time
It helps cash flow to be monitored and extra funds to be released when required
It reduces waste
CPA disadvantages It needs skilled people to compile it in the first place
Usefulness may be limited in very large scale or complex projects
Accurate estimates of time are required
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5.4
Modelling Things
Keywords: mainframe, off-the-shelf, bespoke, CAD, scenarios, supercomputers, simulations, weather forecasting, profit, architecture, nuclear research, geology. A computer model is a computer program that attempts to simulate a real-life system. In other words, it is a ‘virtual’ version of something in the realworld. The computer model is designed to behave just like the real-life system. The more accurate the model, the closer it matches real-life. There are several reasons that computer models are used…
To test a system without having to create the system for real (Building real-life systems can be expensive, and take a long time) To predict what might happen to a system in the future (An accurate model allows us to go forward in virtual time to see what the system will be doing in the future) To train people to use a system without putting them at risk (Learning to fly an airplane is very difficult and mistake will be made. In a real plane mistakes could be fatal!) To investigate a system in great detail (A model of a system can be zoomed in/out or rotated. Time can be stopped, rewound, etc.)
Examples of Computer Modelling Designing Safer Cars A computer model of a car can be used to test how safe the design of the car is in a crash. The virtual car can be crashed over and over again, the effects investigated and the design easily changed until it is as safe as possible. This is much quicker and cheaper than building and crashing real cars! Weather Forecasting A computer model of a weather system can be used to predict storms. The wind patterns, temperatures, etc. for the whole planet are simulated using very 20 | P a g e
powerful computers. If the computer model is accurate (it is very difficult to make an accurate model since our planet is rather big) then weather forecasters can use it to ‘fast-forward’ into the future to see a prediction of what the weather will be tomorrow, next week, next month. (Since weather is so complex, and the models are not (yet) accurate enough, often the weather forecast is wrong!) Building Better Bridges
A computer model of a bridge can be used to test the design.
Bridges have to be able to survive extreme weather conditions. It is obvious not practical to build a real bridge and then wait to see if it falls down in a storm. Instead, a computer model of the bridge is created and tested in virtual storms. If the model breaks, it can be quickly and cheaply re-designed and re-tested. If it doesn’t break, the real bridge can be built, confident that it will survive real storms. Bridges can also be tested to see if they can cope with heavy traffic. The virtual bridge can be loaded with a traffic jam of virtual trucks to check that it won’t collapse. A similar system is used by building designers, especially for very large or tall buildings, such as skyscrapers. Running a Business A computer model of a business can be used to help predict future profits. If the workings of a business can be modelled accurately, in particular the financial systems, then these models can be used to make predictions. The models are used to help answer ‘what if …?’ type questions, e.g. “What if we decrease the workforce by 15%? Will our profits increase or decrease?” Based on the answers that the model gives, the managers of the business can make decisions. 21 | P a g e
Training Pilots to Fly an Airplane Trainee pilots have many hours of lessons in flight simulators before being allowed to fly a real airplane. Flight simulators behave almost exactly like real airplanes since they are controlled by a computer with a very accurate and realistic model of the airplane. The main difference is that the simulator can’t actually crash! Pilots can make mistakes without putting anyone’s life at risk. Flight simulators can provide a pilot with any number of highly realistic flying situations: storms, engine failures, low cloud hiding the runway, etc. The experience that pilots gain whilst using the simulator means that when they eventually start flying real airplanes, they already have many of the required skills. There are also car simulators that are used to help train learner drivers, and also ship simulators to help ship captains learn how to navigate and manoeuvre large ships such as oil tankers.
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Scenarios in Excel 2007 Scenarios come under the heading of "What-If Analysis" in Excel 2007. They are similar to tables in that you are changing values to get new results. For example, What if I reduce the amount I'm spending on food? How much will I have left then? Scenarios can be saved, so that you can apply them with a quick click of the mouse. An example of a scenario you might want to create is a family budget. You can then make changes to individual amounts, like food, clothes, or fuel, and see how these changes effect your overall budget. We'll see how they work now, as we tackle a family budget. So, create the spreadsheet below:
The figure in B12 above is just a SUM function, and is your total debts. The figure in D3 is how much you have to spend each month (not a lot!). The figure in D13 is how much you have left after you deduct all your debts. With only 46 pounds spending money left each month, clearly some changes have to be made. We'll create a scenario to see what effect the various budgets cuts have.
From the top of Excel click the Data menu On the Data menu, locate the Data Tools panel Click on the What if Analysis item, and select Scenario Manager from the menu:
When you click Scenario Manager, you should the following dialogue box:
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We want to create a new scenario. So click the Add button. You'll then get another dialogue box popping up:
The J22 in the image is just whatever cell you had selected when you brought up the dialogue boxes. We'll change this. First, type a Name for your Scenario in the Scenario Name box. Call it Original Budget. Excel now needs you to enter which cells in your spreadsheet will be changing. In this first scenario, nothing will be changing (because it's our original). But we still need to specify which cells will be changing. Let's try to reduce the Food bill, the Clothes Bill, and the Phone bill. These are in cells B7 to B9 in our spreadsheet. So in the Changing Cells box, enter B7:B9 Don't forget to include the colon in the middle! But your Add Scenario box should look like this:
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Click OK and Excel 2007 will ask you for some values:
We don't want any values to change in this first scenario, so just click OK. You will be taken back to the Scenario Manager box. It should now look like this:
Now that we have one scenario set up, we can add a second one. This is where we'll enter some new values - our savings. 25 | P a g e
Click the Add button again. You'll get the Add Scenario dialogue box back up. Type a new Name, something like Budget Two. The Changing Cells area should already say B7:B9. So just click OK. You will be taken to the Scenario Values dialogue box again. This time, we do want to change the values. Enter the same ones as in the image below:
These are the new values for our Budget. Click OK and you'll be taken back to the Scenario Manager. This time, you'll have two scenarios to view:
As you can see, we have our Original Budget, and Budget Two. With Budget Two selected, click the Show button at the bottom. The values in your spreadsheet will change, and the new budget will be calculated. The image below shows what it looks like in the spreadsheet:
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Click on the Original Budget to highlight it. Then click the Show button. The first values will be displayed! Click the Close button on the dialogue box when you're done.
So a Scenario offers you different ways to view a set of figures, and allows you to switch between them quite easily.
How to Create a Report from a Scenario Another thing you can do with a scenario is create a report. To create a report from your scenarios, do the following:
Click on Data from the Excel menu bar Locate the Data Tools panel On the Data Tools panel, click What if Analysis From the What if Analysis menu, click Scenario Manager From the Scenario Manager dialogue box, click the Summary button to see the following dialogue box:
What you're doing here is selecting cells to go in your report. To change the cells, click on your spreadsheet. Click individual cells by holding down 27 | P a g e
the CTRL key on your keyboard, and clicking a cell with your left mouse button. Select the cells D3, B12 and D13. If you want to get rid of a highlighted cell, just click inside it again with the CTRL key held down. Click OK when you've selected the cells. Excel will then create your Scenario Summary:
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5.5
Market Research
Keywords: Primary, secondary, advertising, cookies, data capture, pop-ups, CAPI, CATI, CAWI. survey interview Pop -ups
Primary interviewee Public opinion
secondary CATI cookie
online CAPI Data capture
blocking prototype CAWI
Primary research is when prospective or existing customers are interviewed by the organisation themselves. Before an advertising campaign, a prototype version is shown to a selected audience and their reactions recorded. The individual who is asked questions regarding the product is the interviewee Is a method of interviewing by computer where it comes from a call centre, computer dials the number, asks questions and answers recorded online Special blocking Software prevents adverts from appearing. CAWI , where customers or volunteers log on to a site and answer a series of questions online through a questionnaire or web form. Governments use market research in the form of CATI to gather public opinion Secondary research is using existing data to determine attitudes and preferences. A cookie is a little program that informs web sites that the person has accessed this site before. CAPI is the use of computers in a room where an interview takes place, either through questioning or recording the information. survey is the generic name for recording information, either through computers or Data capture on web forms such as pop ups.
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5.6
Research Applications
http://www.teach-ict.com/news/news_stories/news_computers.htm
keywords: supercomputers, research, analyse, experiments, medicine, models, simulations, developing new drugs, predictions, genetics, calculations, databases, science, space, education, podcasts, digital imaging. Applications: Online tutorials that help students to develop their ability to perform basic computer operations Interactive whiteboards which are used by teachers instead of the more conventional whiteboards allowing the use of images, video, sound etc‌ Web design its used to promote schools and provide information for staff. Digital imaging: digital imaging photography and video can be used to make teaching and learning productive. Podcasting: audio broadcasts that can be download from the internet. Blogging enables students to have an area that they can log on to and write what they want. Processes:
Areas used: Medicine (developing new drugs) genetic analysis, space research, universities, education
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5.7
Online applications
Keywords: The Point-of-Sale (POS) in a store is the place that you pay for your purchases. It is usually where the till (cash register) is located. A typical POS will have...
A method of inputting the codes of goods purchased - usually a bar-code scanner. The codes are then used to find more information about the goods, such as price, from a database A system to accept electronic payments - EFTPOS (see below) A system to update the stock-level of goods whenever they are sold, and possibly to automatically re-order goods that have low stock-levels (see below) A method of producing a receipt for purchases - usually a small dot-matrix printer
Handling Electronic Payments (EFTPOS) When you use a bank card to pay for a purchase in a store, the payment is made using a system called Electronic Fund Transfer at Point-of-Sale (EFTPOS). 1 Customer gives the bank card to the cashier
2 The cashier runs the card through a card reader (the customer may have to enter a PIN). The cashier enters the value of the purchase 31 | P a g e
3 The store’s system then connects to the bank computer and sends a message
4 The bank computer uses the account number to access the customer’s record and checks the balance
5 The bank computer sends back a confirmation or rejection message to the store’s system
6 The cashier now confirms the purchase and an EFT message is sent to the bank
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7 The bank computer subtracts $100 from the customer’s account and adds $100 to the store’s account
8 The cashier gives the card back to the customer along with a receipt
'Chip & PIN' Payment System Most bankcards no longer rely on a magnetic strip to store customer account details. Instead the cards are smart cards. The cards contain a small amount of computer memory with the account information stored inside. Smart cards are more secure (since the data is encrypted) and more reliable than magnetic strip cards. When a customer wishes to pay for goods in a store, the customer inserts the bankcard into a smart card reader, and then types in a PIN to confirm that they are the true owner of the card. Once the PIN is verified, the customer can remove the card. One of the reasons this system has proven popular is the extra level of security it provides for users: At no time does the bankcard need to be handled by anyone 33 | P a g e
other than the card owner, so with this system there is less chance of the card being stolen or copied. The nickname for the tiny memory device inside the bankcard is a ‘chip’, and the system uses a PIN as identity proof, so the system is nicknamed ‘Chip and PIN’ in the UK.
Internet Shopping (e-Commerce) In the last few years, Internet shopping has become very popular. Stores like Amazon and the iTunes Store are some of the largest retail businesses in the world. Online you can buy anything from air flights to fresh eggs. Customers like Internet shopping because...
The convenience of being able to browse goods from your home Stores are open 24 hours a day, every day of the year The wider range of choice - can access stores all over the world Easy if you have limited mobility (due to a disability, or old age) Goods are often cheaper than in stores Payment is simple using credit cards or services such as PayPal
Businesses like Internet shopping because...
Lower costs since no expensive retail stores and less staff Lower costs = lower selling prices = higher sales = bigger profits Many more potential customers
However there are some problems too...
You cannot try items before purchasing (e.g. clothes) You may have to wait several days before receiving your goods Returning goods or getting help can be difficult There is a security risk using credit cards online. The card details may be stolen and used to commit fraud.
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5.8
Stock Control Systems
What is Stock Control? Every business needs to keep track of the items that it manufactures or sells (the stock). The system that monitors the items in stock is called the stock control system. E.g. in a store, the stock includes all of the items on the shelves and out the back in the storeroom. It is important that a business does not keep too much stock, nor too little.
Too much stock costs money as you have to store it all somewhere Too much perishable stock (e.g. food) means that it may go bad before it is sold Too little stock means that you might run out of stock before the next delivery arrives
Data in a Stock Control System A stock control system is basically a database. Each record (row) of the database is identified by an item code (the primary key). Other fields in each record would include:
Description Item price Stock level (the number of items held in stock) Minimum stock level (when stock falls below this, it needs to be reordered) Reorder quantity (how many items we should order each time)
Receiving New Stock
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When items are added in to stock (because a delivery has arrived) this is recorded in the stock control system. The code of the new items is input to the system (usually using a barcode scanner, or similar technology). The record for the item is found in the stock database, or a new record is created, and the stock level is increased. In many stores, the POS system is directly linked to the stock control system, so that stock levels are adjusted as soon as an item is sold.
Selling / Delivering Stock When items are taken from stock (because they have been sold, or delivered somewhere) this is recorded in the stock control system. The code of the item is being sold/delivered is input to the system (usually using a barcode scanner, or similar technology). The record for the item is found in the stock database, and the stock level is decreased. In many stores, the POS system is directly linked to the stock control system, so that stock levels are adjusted as soon as an item is sold.
Automatic Re-Ordering of Stock Stock control systems make it very easy for stock levels to be monitored, and for stock to be reordered when it is running low. The stock control system regularly goes through all the records in the stock database and checks if the stock level is less than the minimum stock level.
Is Stock Level < Minimum Stock Level ? If the stock is too low, it is reordered from the supplier. The quantity that is ordered is read from the stock database (larger amounts for more popular items)
Automatic Re-Ordering of Stock In many stores, the POS system is linked to the stock control system... 'Stock' means the things that you have in your store / warehouse. 'Stock Control' is the system that keeps track of what you have in stock
1
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When goods are sold, the POS system send the details of the sale to the stockcontrol system
2 The stock-control system updates the stock-levels in the stock database for the purchased goods
3 If the stock-level falls below a pre-set value, the stock-control system sends an order to the suppliers
4 The suppliers send a delivery to the store.
5 The stock-control system updates the stock-levels in the stock database for the delivered goods
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Section 6 Digital divide ICT is constantly changing and advancing as scientists and engineers create new technologies for us to use and enjoy. For example in the last 50 years these technologies have become commonplace
Personal Computers Mobile Phones The Internet Medical scanners Satellites Lasers CD and DVD Television Car electronics Credit cards
And so on. Imagine what our society was like back in the 1950s compared to today. Generation gap ICT technology moves at such a pace that older generations may be 'left behind'. Today, ICT is taught as a core subject in schools, so the technology is very familiar to schoolchildren. Not so for older people, who have less opportunity to use the technology available. Research shows that nearly a third of parents and grandparents had been encouraged to surf the net by a child aged between 13 and 16. 'Silver surfers' Those older people who have embraced the internet and made it part of their life are called 'silver surfers' by the media. For example, some people have a serious illness to cope with, such as cancer. And they have turned to online diaries called 'weblogs' to share their experience with others. Silver surfers, as a group, have a lot of money to spend and so advertisers are making great efforts to attract them to their products.
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Managing family life Online shopping was said to be one of the most popular uses, with 40% of women questioned admitting to feeling more independent by using the internet. We can now do many chores online if we wish. For example food shopping is simple with most of the big supermarkets having an online store. Once an order is placed, it will be delivered by van within an agreed time slot.. Other specialist shops can supply organic food and direct-from-farm produce. Being able to type and use a computer is fast becoming as basic a skill as reading or writing. This is called 'computer literacy'. Many of the benefits of ICT derive from being able to use a computer and so those who can't are at a disadvantage. Some of the reasons for not being able to make use of a computer and the Internet are: • the need for being able to read and write • language issues; People who speak languages other than the main European and Asian languages may also be left behind because most of the Internet makes use of just a small number of languages.In India, efforts have been made to help illiterate citizens with this problem by developing the 'Simputer' http://www.simputer.org/ Quote from the web site above: The Simputer is a low cost portable alternative to PCs It has a special role in the third world because it ensures that illiteracy is no longer a barrier to handling a computer. Many Community projects are underway to help people become computer literate. Another project supported by the United Nations is the 100 dollar computer. Nicknamed the green machine, it can be used as a conventional computer, or an electronic book. A child can control it using a cursor at the back of the machine or a touchpad on the front. It is powered by a wind-up crank so it can be used even where there is no electricity. Computer Literacy and Work. Many types of jobs now expect you to have some level of computer skills. For example
being able to type - if only with two fingers! being able to use basic Office applications,
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ď&#x201A;ˇ
being able to use email.
Those people who cannot do these things are immediately at a disadvantage The Digital Divide This term is used to describe the fact that not everyone in Society is able to take advantage of new technologies such as the Internet or mobile phone technology. Another term used to describe the Digital Divide is "Social Exclusion" Poverty It costs money to buy a computer, then it costs more to subscribe to an Internet Service Provider. If you are poor , it becomes a luxury you cannot afford. Efforts are being made to provide homeless people with Internet and Mobile phone access. Homeless people who want to apply for jobs can use a mobile phone number as a contact point. An e-mail address could be the first step to finding a permanent place to live, by enabling people to receive information about long-term living places while moving between hostels. The government has invested heavily in providing public access computers in our libraries, so allowing any citizen to make use of the internet. A quote from a news article: "According to a report carried out by the Welsh Consumer Council in 2005, 56% of the Welsh population has no access to the internet at home or at work." And it is predicted that 90% of all new jobs require some knowledge of technology. Most cities are well served with excellent communication and computer networks, this is because there are plenty of customers living close together to pay for services. But in the countryside there are fewer people and they live in widely scattered communities.
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This makes it difficult for companies to make any profit, as there are relatively few people to cover the cost of setting up networks. Developing countries There is a 'Digital divide' between rich and poor countries. In the UK it is taken for granted that the electricty supply works, that a telephone system is in place. But there are many poorer nations that do not have these things to any extent.. ICT can be very useful in developing countries. For example, farmers are able to check the prices they may get for their harvest before setting out to market. Health messages can be sent by text if a mobile phone system is in place. Many organisations are setting out to help break down the digital divide between nations. This lady in Bangladesh was able to purchase a single mobile phone by borrowing from a bank. She was then able to sell phone calls to the rest of the village, who were able to contact family and friends from afar. She is called the 'telephone lady' by the villagers and one of the first things she bought with her new income was a bicycle for her son so he could get to school. Communication technology has advanced at an incredible rate over the last 40 years. For example these have become commonplace.
Mobile phones Satellite and Undersea cables. Internet Email Instant Messaging Texting Video Conference 24 hours rolling news.
This has changed the way people in our Society talk or communicate with one another. Sometimes for the good and sometimes for the bad. The next two pages describes each these.
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Travel and the Environment: Video conferencing and email have reduced the need for business travel, this has allowed people to have more time at home with their families rather than being stuck in an airport somewhere. Less travel also means less pollution, as fewer cars and aircraft need to be used. Education and Training: Video conferencing and remote control of another computer has allowed teachers and trainers to run lessons from far away. For example, an International corporation located in the UK may want to train their staff located in Thailand on a new computer application. Normally, the Thai staff would have to come to the UK for training. But now, the UK office sets up a video link with the Thailand office, they also set up remote control of the PCs in Thailand and they run the training course directly from the UK. Everybody wins. Working anywhere: Being able to access the company network from anywhere means that people are no longer tied to the office, they could just as easily work from home. Because of this, home working ('Teleworking') is becoming more common. Also, people working for international corporations can travel from country to country on business and yet settle down to a fully networked local office desk and work as it they are in their home office. Social connections: From the story quoted below:- Research has shown that over 60 million American citizens turn to the Internet when they need career advice, helping people through an illness or finding a new house. It shows that the Internet has become a cornerstone when searching for vital information. The thing to be really careful of though, especially on health matters, is how accurate is the information? Just because a 'fact' appears on a web page somewhere, does not mean that it is true. Good judgement is even more vital as you try and sort out the dross from the good information. Laziness: Having all these methods of communicating has a tendency to make people lazy. They may no longer bother to talk face to face, instead they send an email to a work colleague only a few feet away. Some organisations have even introduced 'email free days' to encourage people to actually talk to one another!
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6.2 Catering for disabilities Keywords: web cams, instant messaging, sticky keys, filter keys, concept keyboards, speech recognition software, tracker balls, joysticks,touch screens, head wand, hard coded. Computers Help the Disabled Personal computers are becoming an integrated part of our lives. Both the educational and working environments have been transformed by the computer age. Computers have become the tools that offer the everyday person access to todayâ&#x20AC;&#x2122;s information. The impact of computers on our lives has been tremendous, but no area has experienced a more important or more liberating affect than the disabled and handicapped. Computers have completely changed the quality of life and have become a primary source of assistance for the disabled. Computers Bring Independence Independence is the major benefit the computer has brought to the disabled. Computers free a person with disabilities from relying on others for assistance. New opportunities offered by computers are impressive. With the use of a computer, an individual can learn at his or her own speed. Adaptive aids have either replaced or augmented the standard input and output devices of the computer. They are the key that has opened the computer world to the disabled. Computers Address Hearing, Sight, and Cognitive Disabilities Because of its versatility, the computer can be the tool that overcomes many physical disabilities such as hearing, sight, and cognitive disabilities. With a hearing disability, the computer can easily substitute words and images for sounds. Because the computer is so sight-oriented, you would anticipate fundamental drawbacks. Technology to the rescue. With the introduction of todayâ&#x20AC;&#x2122;s multimedia programs, alternatives to audio information have been developed that offer a display of visual feedback. Yes, the computer is a visual tool, but it can be modified to accommodate the visually impaired. Both software and hardware can be designed for use by the visually impaired. Programs such as screen readers like the popular JAWS program speak what the computer displays. Braille keyboards and screen magnifiers are popular aids. Key guards and other alternative keyboards are also available. The keytops of some special keyboards have text in a size and color that a visually impaired or mentally retarded person can easily see and read. For cognitive disabilities, head mounted pointers and voice input, also known as speech recognition, are available. Users can simply speak commands into a microphone connected to the computer. For persons with limited mobility and dexterity, ultra-sensitive hyperlinks called hovers allow use of alternative mouse equipment to activate a link just by coming within range.
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PC Manufacturers Provide Access A good sign of the times is that computer manufacturers and developers of operating systems are building in access solutions for the disabled; often the solutions are provided free of charge. Many computer companies are committed to providing the disabled an access to the information highway and all the advantages knowledge brings. Both Microsoft and Apple, the developers of two of the most popular operating systems, have corporate policies for accessibility for people with disabilities. This means that current and future releases of their operating systems will, as standard, contain accessibility features and support for third party manufacturers of assistive devices. Already PCs have slots and serial ports that allow connection of both standard peripherals and assistive devices. More and more warnings and alert messages are presented both visually and audibly. Certain features of the keyboard can be adjusted, such as the key repeat rate and the key activation delay time. The arrow keys of the keyboard can be used for cursor movements instead of the mouse. Windows and Mac computers both have accessibility features like screen magnifiers built into the operating system. Many printers can be controlled and monitored from the computer site, which is advantageous for mobility-impaired persons. Access to todayâ&#x20AC;&#x2122;s information and communication systems is required for disabled people to achieve their full productive potential. Technology continues to modify its tools, primarily the computer, to offer accessible hardware, operating systems, and software so that the handicapped and the disabled can take their place in a productive and meaningful world. For some I am sure that these tools are not being developed quickly enough. But none-the-less, technology is providing a steady stream of support for the disabled.
Devices: Puff-suck switch: you simply have to puff or suck the switch in order to activate a switch, which is connected to the computer. Foot mouse: for people who have little or no mobility in their arms. It can be used with the same purposes as conventional mice. It consists of two parts, one to control the cursor and another to click or to select things. Most foot mice include straps to hold the device in place during its use, and it is connected to the computer via USB port just as conventional mice.
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Eye typer: this is used for people who cannot use a hand or foot operated mouse or a conventional keyboard. The camera is set on the computer and focuses on the userâ&#x20AC;&#x2122;s eye. This way the camera determines where the user is looking and monitors movements made by the eye. Mouse clicks are made by very slow blinking of the eye. Braille keyboard and printer: Braille keyboard: it is a special device that allows the user to type and enter text and instructions for the computer in Braille. Braille display: a piece of equipment that connects to the computer and reads the screen text. Then it presents it via a refreshable Braille display. Braille printer: it operates by embossing raised braille dots onto braille paper. This is done by pressing pins on one side of the paper.
Speakers and microphones: Speakers: text can be converted into speech and can be output via the speaker in audio format. There are speech software programs which enable any text on the screen to be selected with the keyboard or mouse and then spoken back to the user in a computer generated voice. Unfortunately the computerâ&#x20AC;&#x2122;s voice can sound disjointed and sometimes pronunciation can make the output difficult to understand. Speakers can also provide audity feedback to the user in order to signal when something has been successful or warn when something has gone wrong.
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Microphones: it can be used for people who can find it difficult to use a keyboard or mouse. Users can say their input out loud and specialist software can be used to convert the speech into text, and then displayed on the screen. Screen magnifier and zoom: Zoom tool (software): many software applications allow users to zoom in closer to the work being displayed on the screen. This can be very useful for people with poor eyesight. Screen magnifier (hardware): a specially designed piece of perspex which is held in place in front of the computer screen. Its role is to magnify what is being displayed on the screen. Predictive text and sticky keys: Predictive text (software): it allows words to be entered with a single key press for each letter. Instead of having to write out the whole word the software tries to predict the word you want. As well as allowing you to type faster it reduces the amount of keystrokes and helps people which have difficulties typing. It is most commonly found in mobile phones and PDAs. Sticky keys (software): it allows the user to press a modifier key (i.e. Ctrl, Shift, Alt) and have it remain active until another key is pressed.
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6.3
Legal & Political Systems
Keywords: focus groups, message board, forums, blogs, wikis, administrators/moderators, chat rooms.
6.4
Computer fraud & 6.5 Anti-social use of ICT
Keywords: Hacking: the act of breaking into a computer system and a criminal offence under the computer misuse. To prevent it avoid commenting on blogs, avoid stalling third-party scripts, avoid websites with lots of spam, clear cookies, donâ&#x20AC;&#x2122;t use generic usernames, update security patches, use strong passwords. Virus: pieces of malicious program code which are created to infect computers and move from one to another. They delete or corrupt data (or even erase the whole hard disk of a computer) or infect e-mail software so that it can be passed on to everyone in the contacts list on that computer. To prevent them it is important that individuals have anti-virus software installed on their computers, regularly scan their hard disks and regularly update the anti-virus software. Spyware: software put on a computer with malicious intent that allows people to access the computer and control its functions. To prevent it adjust your browser security settings for internet zone to medium, practice safe web surfing habits and download cautiously, install and use anti-spyware software, use a firewall with outbound protection. Data misuse: copying software without permission that can lead to corruption of data either accidentally or on purpose. To prevent it the Computer Misuse Act (1990), the Data Protection Act, Copyright law, close down chat rooms, reduce email spamming, regular backups and security. Deleting data: deleting peopleâ&#x20AC;&#x2122;s important information. To prevent it change your password over a period of time and make sure nobody knows it. Amending and distributing data: editing and distributing your personal information.
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To prevent it you have to reject the conditions that certain webpages or organisations would be interested in implying on you. Spam: any kind of unwanted online communication. The most common form of spam is unwanted email. Some spam is annoying but harmless. However, some spam is part of an identity theft scam or other kind of fraud. To prevent it Stop them getting your email address, getting a new email address, having a good spam filter, and do not have a generic email address. Cyber bullying: when people use the Internet or cell phones to send messages to other individuals to intimidate them. It can be spreading rumours or personal data about one individual to others with the aim of embarrassing them or alienating them from their friends. To prevent it it is useful to educate children about its consequences, donâ&#x20AC;&#x2122;t respond, donâ&#x20AC;&#x2122;t retaliate, save the evidence, talk to a trusted adult, block the bully, be civil, and be a friend. Identity theft: the copying of details of a person for illegal use by another. Commonly, details of credit cards are copied onto another card. To prevent it be aware of if anybody is watching you introduce your PIN number, require photo ID verification, shred everything, destroy digital data, be careful about checking statements, pay your bills at the post office, limit the information on your cheques, analyse your credit report annually and protect your social security number. Skimming: a type of identity fraud where a card that is swiped legitimately in a retail outlet is swiped again on another machine that reads all the details from the card. This data is then transferred to a blank card for further use. To prevent it make sure your card stays in sight, and never let anyone leave of your presence with the card if you can help it, you need to be aware that your credit card is, monitor credit card receipts and check them carefully against your statements, and shred unwanted financial solicitations and put your mail on hold when you leave town. Phishing: method of fraud where the user or customer is sent an e-mail which supposedly is from the bank asking for their account details and passwords. To prevent it guard against spam, communicate personal information only via phone or secure web sites, do not click on links, download files or open attachments in emails from unknown senders, never email personal or financial information (even if you are close with the recipient), beware of links in emails that ask for personal information, never enter personal information in a pop-up screen, protect your
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computer with a firewall, spam filters, anti-virus and anti-spyware software, and check your online accounts and bank statements regularly. Pharming: a process whereby the user, typically a bank customer using online banking, of what appears to be a genuine website is redirected to a bogus website. To prevent it use a trusted, legitimate Internet Service Provider, Check the Web browser's address bar to make sure the spelling is correct, the http should change to https (the "s" stands for secure), look for a padlock or key on the bottom of your browser or your computer task bar, install an antivirus program, download the latest security updates. Firewalls: an interface between two networks that prevents access to one from the other by unauthorised computers.
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6.6
Home Entertainment systems
Keywords: home theatre, LCD, plasma screens, blu-ray disk, communication satellites, uplink, transponder, terrestrial television, FM tuner, amplifier, USB, SDMC, flash memory card, VOD, projectors. There are many different media formats available for the storage of audio and video files. They include: Audio tape Vinyl records CD Mini disc MP3 WMA Memory stick/flash memory cards/SD memory cards In order to appreciate some of the new technologies, let’s look at how some of the older ones work first. We will start with old-fashioned audio tapes (which you can still buy in some places) Read the article at http://electronics.howstuffworks.com/gadgets/audio-music/cassette.htm.
Notes:
There are some disadvantages with audio tapes. Because each tape cassette holds about 450 metres of tape, the tape is obviously very thin. This means that it can be damaged relatively easily: if a tape gets hot, for example, it will stretch and distort. This obviously affects the sound quality. Tapes are magnetic, too: this means that they can be affected by strong magnets. Of course, audio tapes and vinyl records are examples of analogue sound. CDs and DVDs store digital data – so what’s the difference? Check out http://communication.howstuffworks.com/analog-digital.htm And – no direct access (sequential access only), so it can take a long time to fast-forward or rewind to the precise track you want
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Like audio tapes, records can be quite seriously affected by heat and this can render them unplayable In addition, the surface of a record can be scratched simply by repeatedly taking it out of and putting it back into its paper sleeve. Dust on the record also interferes with the needle, and if a needle “skips” on a record it can obviously damage the delicate groove. It’s also sequential.
New technological developments brought us the MP3 player – but what exactly IS an MP3? MP3 is a file compression system which allows a digital audio file to be compressed into a much smaller file. Why? How? Check out this link: http://computer.howstuffworks.com/mp3.htm Read through the pages and make some notes here:
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What about CODECs, then? Some codec examples are MP3, WMA, RealVideo, RealAudio, DivX and XviD. There are many different CODECs out there, and although you don’t need to know all the details, you do need to be able to talk about them as if you understand a little bit about them. This link (http://netforbeginners.about.com/od/multimedia/f/codec.htm) will help you do just that
Notes:
OK, now it’s time to look at CDs. We all know what they look like, but how do they store all that data? A normal CD can store around 700MB of data; a DVD can store arounf five Gigabytes while a blu-ray disc can store much, much more
http://electronics.howstuffworks.com/cd.htm will help you understand the peaks and troughs of CDs and DVDs.
Notes
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So whatâ&#x20AC;&#x2122;s the difference between a DVD and a Blu-Ray disc? Blu-ray discs can hold and play back even larger quantities of high-quality audio and video files. A duallayer Blu-ray disc can hold ten times as much data as a DVD â&#x20AC;&#x201C; up to 54GB! This diagram shows you the relative storage capacities of the different media:
This link (http://electronics.howstuffworks.com/blu-ray1.htm) will help you to understand the other significant differences between Blu-ray and DVDs.
Notes:
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The disadvantage, of course, is that if you want to be able to take advantage of this new technology, you will have to buy a Blu-ray player.
Television satellites Satellites in geosynchronous and geostationary orbit can illuminate entire continents with their antennas. This coverage makes it an ideal platform for broadcasting television (and radio). A television satellite has a large number of 'transponders'. These receive the original television signal from an earth station, amplify it to high power then broadcast it to customers on the ground. These are called 'Direct Broadcast Satellites' or DBS. When a satellite is constructed, it includes a number of spare transponders to allow for failures over the lifetime of the satellite. Although this does put the launch cost. The earth stations are usually owned and operated by the satellite company itself whilst the television companies rent the channels they need. Satellites can broadcast hundreds of channels because each transponder has a very wide bandwidth. Compression is also used to squeeze even more tv channels within the bandwidth available. Satellites signals come in two forms. Namely 'free-to-air' which means anyone with the right set-top box can view the programmes. 'Freesat' is a free-to-air television service run by the BBC and ITV. It offers over 150 channels including HD tv. The other type is an 'encrypted' paid service such as Sky. Subscribers pay a monthly fee to view these channels. For example, on offer are movie channels, children's tv, foreign channels, sports. Another option is 'pay-per-view' where you just pay to see a particular film or programme. In order to view a satellite channel, you need an satellite dish fitted to the outside wall or roof that points to the satellite. This picks up the signal, amplifies it and sends it to a set-top box. The set-top box converts the signal to a standard television signal. The most well known system in the UK are the Astra satellites. But using a recent satellite magazine to count how many others were visible over the horizon - there were 51 other TV satellites in view. If you had the correct antenna, line of sight and decryption cards there are thousands of tv channels available in many languages - Polish, Czech, French, Portuguese, German, Arabic etc.
Pros and Cons of satellite television Offers literally hundreds of channels both
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Awkward to set up the satellite dish
TV and radio from the same box
and set-top box along with the cable run needed
Can be received in remote areas that are not in range of a terrestrial transmitter
The satellite must be in clear line of sight. Often a tree or a building may be in the way
Can be received in 'dead spot' areas. These are areas where the terrestrial
Hardware is expensive as well as
signal is very weak and noisy for some
paying for it to be fitted
reason.
You can choose to just use the free-to-air
Can be dangerous if you choose to try
services or opt for a monthly subscription
and fit a dish yourself on the roof or
service
high up on a wall - use a professional!
Can choose to use 'pay-per-view' for occasional interesting programmes or sport event.
If you are an 'ex-pat' and want to see television in your own language, then satellite is a good option to check out.
Subscription fees are quite expensive typically a ÂŁ100 to ÂŁ500 per year.
Can be affected by severe weather such as a rain storm or snow
Dishes could be unsightly, especially the larger ones needed for more unusual satellites.
Tend to be only used in a single room, unless you pay for a 'multi-room' arrangement
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fill in the following table : Advantages Audio tapes
Vinyl records
MP3/WMA etc
Codecs
CDs & DVDs
Blu-ray
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Disadvantages
6.7
Internet Auctions
www.ebay.co.uk What hardware & software is required? (pc, modem or broadband Internet connection & Internet browser) What do I need to start using the site? (register first & then user ID and password) What features does the site have? (home page, menus, categories, search facility, time remaining, last bid, highest bid, automatic data retrieval) What are the advantages of these sites? (items no longer needed, could be cheaper than buying in a shop, wide market, wide range of products) What are the disadvantages of using these sites? (buying from a person not a company – problems with quality?, problems of security) How can disadvantages be overcome? (make checks on seller, ask questions, pay with credit card) How are payments made? (credit card, cheque, intermediary such as paypal – need to register, bank account details etc) How do we know that the financial services website is secure? (encryption, “padlock”, certification authority)
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6.8
Booking Systems
Keywords: e-tickets, submit button, of-the-shelf, bespoke, travel agents, rail companies, airlines, cinemas, theatres,
Characteristics of online booking systems Many organisations need a method to allocate their resources to customers or members ahead of time. This is called 'making a booking'. 'Resources' can mean anything
Hotels have rooms, Travel agencies have holidays Clubs have equipment Gyms and Colleges have classes Theatres and Cinemas have seats Doctors and hair-dressers have appointments
A 'booking system' handles the task of allocating resources for a set amount of time to customers.
Characteristic of an appointment booking system Characterisitcs of an appointment booking system
Choose the date and time and perhaps duration of the appointment
View available appointment times
Book the appointment
Change or cancel and appointment
Characterisitcs of a ticket booking system Characterisitcs of a ticket booking system
They allow customers or staff to select the event
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Characterisitcs of a ticket booking system
They allow customers or staff to select the date of the performance
Able to select the number of adults/children who need tickets
Check the availability and position of seats
Check the price of the different seats available
Book the seats/tickets and update the seating plan accordingly
They can automatically issue tickets for posting out to customers
They enable the payment for tickets to be verified and processed
They issue confirmation emails to online customers
They enable changes to be made to the booking if required
Advantages of an automatic booking system
Offers both the customer and business a method of arranging a booking automatically Customers can see what it available, the business can see what is sold Booking can be done well ahead of time Booking is fair - it is usually a first-come first-served system. (Block booking tickets for a popular event might not seem so fair) Very flexible in when you can make a booking. If it is an internet based system then it is available all the time. A telephone menu system can also be set up to work at any time You can 'reserve' a seat / item for a period of time e.g. 30 minutes while you make up your mind Provides an easy way to confirm the appointment \ booking either by email or letter.
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Issuing or posting of tickets can be tracked by the customer
Disadvantages of an automatic booking system
Once payment or firm booking is made then it might be hard to cancel, perhaps you would lose your deposit or the entire value of the booking You could make a mistake and book the wrong seats or the wrong night If the server is down or running very slowly, then much business can be lost and annoy a lot of customers There may be payment processing problems after the booking is made Proving purchase if made a long time in advance and finding the receipts might be a problem. Might have to wait for ticket to be sent by post – if booking close to the day of the event, might not arrive
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6.9
Information services
Trading
The Internet allows companies to take less time to search information about trading regulations in other countries, like for example different purchase taxes can be charged in different countries, so a company needs to know how high they are to know if it’s good for them to operate there or not. It also enables businesses to compare a wider range of suppliers. It allows you to look into trading methods abroad if you are an importer. It allows you to be aware of the resource implications, if you are an exporter company. Web pages also show methods of payment available and contact addresses or e-mails. Governments
Governments now offer many services on the Internet: 1) Education and learning 2) Motoring 3) Home and community 4) Employment 5) Money, tax and benefits 6) Health and well-being 7) Travel and transport 8) Environment and greener living 9) Crime, justice and the law
Website of the UK government
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Internet. The web should be relevant, exciting and useful for the student and it needs to be well-organised and have e-mail facilities. Stocks and shares Many websites now, provide up-to-date figures of prices of stocks and shares to enable businesses and individuals to manage their finances. They allow you to make your own ‘virtual portfolio’ to see what would happen if you have really bought certain shares. This is a way to test the market and allow investors to observe any trends in the market. Investors can also buy shares by the Internet; however a fee is charged, the same happens if they try to sell them afterwards. Public interest Websites set up to provide people information about their interests. A good example is the websites of Friends of the Earth. A good method to allow the user ask what they want is to create a ‘right to know’ section, where users can request information from public authorities. These websites have seriously affected the role of the newspapers, television and radio. Moreover, the use of blogs is now more common and issues can be raised and also can be discussed. Educational research There are organisations that provide teachers information about educational research. I.e.: the National Foundation of Educational Research in the UK. It is a no-for-profit organisation so it’s independent of outside factors. It provides information about the results of research done and it offers a link to a free database which includes all recently completed and on-going post-graduated or equivalent educational research in the UK. Also, it manages and updates the International Review of Curriculum and Assessment (INCA) Frameworks Internet Archive. It gives descriptions of government policy on education in 20 countries. Finally, it focuses on the curriculum, assessment and initial teacher training frameworks.
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6.10 Government Keywords: information services, inland revenue (tax), budgets, electoral register, issue of documents, biometric data, driving licenses, SSL, identity cards. Biometrics means to measure and analyse human characteristics in order to correctly identify an individual. Examples of physical characteristics which can be used are:
fingerprints voice patterns retinas or irises facial patterns palm prints
The use of biometrics is becoming more commonplace as the techniques are refined and become more reliable. Many businesses now use biometrics as a method of allowing access to buildings and information held on computer systems. Governments are beginning to use biometric identifiers in passports, driver's licences and in the future, a national ID card. To use biometrics an organisation needs:
a reader or scanning device that takes a biometric reading from a person software that can convert the scanned information into digital format for the computer to use. This computer identifies the 'match points' from the digital information Once the match points have been identified the data is compared to to all of the records held in the company biometric database. If a matching record is found the individual can be positively identified.
Biometric identification is believed to be more secure than many other methods because the physical characteristics are unique to every individual and cannot be lost, stolen or copied. However, biometric systems are far from being fool-proof. Most systems have a significant number of false accept rates and false reject rates. This might be a reason as to why they are not yet as widely available as a physical method of security as many other more conventional methods.
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6.11
teaching & learning
See last year
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Section 7 What is a Network? A network is two or more computers, or other electronic devices, connected together so that they can exchange data. For example a network allows computers to share files, users to message each other, a whole room of computers to share a single printer, etc. Network connections between computers are typically created using cables (wires). However, connections can be created using radio signals (wireless / wi-fi), telephone lines (and modems) or even, for very long distances, via satellite links.
Why Use Networks? Using a computer connected to a network allows us to…
Easily share files and data Share resources such as printers and Internet connections Communicate with other network users (e-mail, instant messaging, videoconferencing, etc.) Store data centrally (using a file server) for ease of access and back-up Keep all of our settings centrally so we can use any workstation
In particular, if we use a computer connected to The Internet, we can…
Make use of on-line services such as shopping (e-commerce) or banking Get access to a huge range of information for research Access different forms of entertainment (games, video, etc.) Join on-line communities (e.g. MySpace, Facebook, etc.)
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Why Not Use Networks? Using a computer connected to a network means that…
The computer is vulnerable to hackers If the network breaks, many tasks become very difficult Your computer can more easily be attacked by a virus
In particular, if we use a computer connected to The Internet…
We have to be careful about revealing personal information We have to be careful to avoid suspect websites that might contain malware We have to be aware that information found on The Internet is not always accurate or reliable
Computers in a Network Computers connected together to create a network fall into two categories: servers and clients (workstations). Clients Client computers, or workstations, are the normal computers that people sit at to get their work done. When you use your Web browser, you are in fact using a Web client. When you type in the URL of a web page, you are actually providing the address of a Web server. e.g. www.bbc.co.uk is the address of the BBC’s web server. Your Web browser/client asks this server for the web page you want, and the server ‘serves’ the page back to the browser/client for you to see.
Servers Servers are special, powerful computers that provide ‘services’ to the client computers on the network. These services might include:
Providing a central, common file storage area Sharing hardware such as printers Controlling who can or can’t have access the network Sharing Internet connections
Servers are built to be very reliable. This means that they are much more expensive that normal computers.
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In a small network one server might provide all of these services. In a larger network there might be many servers sharing the work.
Protocols OSI is a standard or protocol that defines the functions of a network and how data communication takes place across the network. The OSI Model defines seven independent layers:
1. 2. 3. 4. 5. 6. 7.
Application Presentation Session Transport Network Data link Physical
These layers ensure that all hardware and software throughout the world could be compatible, as the OSI ensures all systems are compatible. However, using the OSI model is purely voluntary and many applications do not use it, so there are plenty of applications out there that do not work with one another. Computers on a network must all have a way of being able to 'talk' or 'communicate' with one another and they do this by following a protocol. A protocol is a set of rules which define:
How to establish communication between the machines The format of any data which is to be exchanged between the machines How errors in the data will be detected How errors will be corrected Methods of compressing the data to transmit it faster and more efficiently How the connection between the machines is to be terminated
The protocol that is used on most LANs and the Internet is known as the TCP/IP protocol. If any computers on the Internet are not using this standard then they will not be able to communicate with others that are.
IP is short for Internet Protocol. A 'protocol' is a set of rules for doing something. In this case it is the task of being able to uniquely identify every computer connected to an IP based network. The way this is done is to assign a long number to each computer made up of 4 bytes. This normally takes the form of four, three digit numbers separated by a dot. Like this 255.168.101.004
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Of course behind the scene this is actually a 32 bit binary number (4 bytes). Each number group in the address sub-divides the network to which the computer is connected with the final number (004 above) being the actual computer. The Internet is a vast collection of smaller networks each connected to one another through routers. Interesting fact: The internet is running out of addresses. The current scheme was designed to handle up to 4 billion addresses and everyone thought this would be enough. But with mobiles, gaming machines and even fridges getting connected to the internet this will soon become a problem. A new protocol called IPv6 has been developed, this uses 128 bits for each address rather than 32. This offers a range of 3 followed by 38 zeros unique addresses. Enough to address every grain of sand on Earth - it should be enough!
FTP is a protocol used for sending files between computers and over the internet. The protocol or standard describes how this file transfer should be take place. How does it happen? The server will be running an "FTP server" application that is constantly listening for transfer requests. Your computer will have an 'FTP client' that sets up the connection to the server. Normally an user-name and password is required to access the server. Once the connection is set up, you can either download files from the server or upload file to the server. HTTP stands for Hyper Text Transfer Protocol. HTTP is the set of rules that are used for transmitting files, (text, graphics, sound, video etc) over the World Wide Web. Almost every web page needs to start with http:// This tells the browser that the rules for moving files from the web server will be those defined by the protocol called 'http'
Handshaking A computer protocol term. A 'handshake' is when two computers exchange signals in order to set up a communication link.
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For example a network protocol might have this 'handshake' > Computer A signals "I am ready to receive data" > Computer B receives the signal and sends back "I am ready to send data" > Computer A receives the signal and sends back "OK, send the data" > Computer B receives the signal and sends the data Of course, the "I am ready to receive data" is not a real sentence being sent! it is more likely to be a digital signal on a particular wire within the cable connecting the two computers.
Parity Error To help make digital data more reliable when moving through noisy channels, 'error correction' methods are used. These methods allow one or more errors to be detected and possibly fixed at the receiving end. 'Noisy' means interference. For instance, electrical interference in a data cable or lightning storms affecting radio channels. One such method or error detection is called 'parity checking'. This involves adding an extra bit to each data packet. When an error is detected, a 'parity error' is indicated in some way. For example, hard disks make use of parity checking, as does RAM. So do DVD players, Mobile Phones, Fibre-Optics, Radio broadcasts, Digital Television and many other data communicating technologies. There are two types of parity error checking - Even and Odd Even parity is checking that the number of 1's in the data word adds up to an even number Odd parity is checking that the number of 1's in the data word adds up to an odd number. 'Even Parity' checking can only detect an odd number of bits being corrupted (one, three etc) If the errors have caused an even number of bits to change, then parity checking cannot detect the problem. This is why more complicated error checking schemes have been developed. But parity checks are still very common as it is such a simple way of detecting errors.
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Types of Network Local Area Network (LAN) A Local Area Network is a network confined to one building or site. Often a LAN is a private network belonging to an organisation or business. Because LANs are geographically small, they usually use cables or low-power radio (wireless) for the connections.
Wireless Local Area Network (WLAN) A wireless LAN (WLAN) is a LAN that uses radio signals (WiFi) to connect computers instead of cables. At the centre of the WLAN is a wireless switch or router - a small box with one or two antennas sticking out the back used for sending and receiving data to the computers. (Most laptops have a wireless antenna built into the case.) It is much more convenient to use wireless connections instead of running long wires all over a building. However, WLANs are more difficult to make secure since other people can also try to connect to the wireless network. So, it is very important to have a good, hard-to-guess password for the WLAN connections. Typically, the range of a wireless connection is about 50m, but it depends how many walls, etc. are in the way.
Wide Area Network (WAN) A Wide Area Network is a network that extends over a large area. A WAN is often created by joining several LANs together, such as when a business that has offices in different countries links the office LANs together. Because WANs are often geographically spread over large areas and links between computers are over long distances, they often use quite exotic connections technologies: optical fibre (glass) cables, satellite radio links, microwave radio links, etc.
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The Internet is an example of a global WAN .In fact it is the world’s largest WAN. Computers on the International Space Station are linked to the Internet, so the you could say the the Internet is now the first off-planet WAN!
Bluetooth (Personal Area Network) Bluetooth is a wireless networking technology designed for very short-range connections (typically just a few metres). The idea of Bluetooth is to get rid of the need for all of those cables (e.g. USB cables) that connect our computer to peripheral devices such as printers, mice, keyboards, etc. Bluetooth devices contain small, low-power radio transmitters and receivers. When devices are in range of other Bluetooth devices, they detect each other and can be 'paired' (connected) Typical uses of Bluetooth: Connecting a wireless keyboard to a computer Connecting a wireless mouse to a computer Using a wireless headset with a mobile phone Printing wirelessly from a computer or PDA Transferring data / music from a computer to an MP3 player Transferring photos from a phone / camera to another device Synchronising calendars on a PDA and a computer Because Bluetooth networking only works over very short distances, and with devices belonging to one user, this type of network is sometimes called a 'Personal Area Network'
LAN Topologies The word topology means ‘arrangement’, so when we talk about the topology of a network, we mean how the different parts are arranged and connected together. 71 | P a g e
There are three common network topologies...
Bus Network In this type of network, a long, central cable, the ‘bus’ is used to connect all of the computers together. Each computer has a short cable linking it to the ‘bus’. A bus network…
Is cheap to install (just one long cable) Can be quite slow since all computers share the same cable when communicating Will stop working if there is a break in the central bus cable.
Ring Network In this type of network each computer is connected to a loop of cable, the ‘ring’. (If you took a bus network and connected the ends of the bus cable together, you would have a ring network.) A ring network…
Can cope with a break in the ring cable since all computers are still joined together (it is now a bus network)
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Star Network In this type of network every computer is connected to a central device. The device passes messages between computers. At the centre of a star network you might use a hub (cheap, but slower) or a switch (more expensive, but faster). A star network…
Is quite expensive to install (you have to buy lots of cable and the central device) Is very fast since each computer has its own cable which it doesn’t need to share Can cope with a broken cable (only one computer will be affected) Will stop working if the central device breaks Is the most common network topology
Hybrid Network A hybrid network is simply one that combines two or more of the above basic topologies.
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E.g. A network that has several star networks linked together is a hybrid network
Network Interface Card (NIC) Any computer that is to be connected to a network, needs to have a network interface card (NIC). Most modern computers have these devices built into the motherboard, but in some computers you have to add an extra expansion card (small circuitboard)
Some computers, such as laptops, have two NICs: one for wired connections, and one for wireless connections (which uses radio signals instead of wires)
In a laptop, the wireless radio antenna is usually built in to the side of the screen, so you don't need to have a long bit of plastic sticking out the side of your computer!
Network Cable To connect together different devices to make up a network, you need cables. Cables are still used in most networks, rather than using only wireless, because they can carry much more data per second, and are more secure (less open to hacking). The most common type of network cable cable in use today looks like the one shown above, with plastic plugs on the ends that snap into sockets on the network devices. Inside the cable are several copper wires (some used for sending data in one direction, and some for the other direction). 74 | P a g e
Hub A hub is a device that connects a number of computers together to make a LAN. The typical use of a hub is at the centre of a star network (or as part of a hybrid network) - the hub has cables plugged into it from each computer.
A hub is a ‘dumb’ device: if it receives a message, it sends it to every computer on the network. This means that hub-based networks are not very secure - everyone can listen in to communications.
Hubs are pretty much obsolete now (you can't buy them any more), having been superseded by cheap switches.
Switch A switch, like a hub, is a device that connects a number of computers together to make a LAN. The typical use of a switch is at the centre of a star network (or as part of a hybrid network) the switch has cables plugged into it from each computer. A switch is a more ‘intelligent’ device than a hub: if it receives a message, it checks who it is addressed to, and only sends it to that specific computer. Because of this, networks that use switches are more secure than those that use hubs, but also a little more expensive.
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Router A router is a network device that connects together two or more networks. A common use of a router is to join a home or business network (LAN) to the Internet (WAN). The router will typically have the Internet cable plugged into it, as well as a cable, or cables to computers on the LAN.
Alternatively, the LAN connection might be wireless (WiFi), making the device a wireless router. (A wireless router is actually a router and wireless switch combined) Routers are the devices that join together the various different networks that together make up the Internet. These routers are much more complex than the one you might have in your home
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Proxy Server A proxy server is a computer setup to share a resource, usually an Internet connection. Other computers can request a web page via the proxy server. The proxy server will then get the page using its Internet connection, and pass it back to the computer who asked for it. Proxy servers are often used instead of router since additional software can be easily installed on the computer such as anti-virus, web filtering etc.
Bridge A bridge is a network device that typically links together two different parts of a LAN.
Whereas a router is usually used to link a LAN to a WAN (such as the Internet), a bridge links independent parts of a LAN so that they act as a single LAN.
Firewall A firewall is a device, or a piece of software that is placed between your computer and the rest of the network (where the hackers are!) If you wish to protect your whole LAN from hackers out on the 77 | P a g e
Internet, you would place a firewall between the LAN and the Internet connection.
A firewall blocks unauthorised connections being made to your computer or LAN. Normal data is allowed through the firewall (e.g. e-mails or web pages) but all other data is blocked.
In addition to physical devices, firewalls can also be software. In fact most computer operating systems have a software firewall built in (e.g. Windows, Linux and Mac OS)
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7.3
Network security
Keywords: Physical security; Securing computer rooms, security guards, Software Security; Firewalls, Encryption, Digital certification, Authentication techniques, Anti-virus software, USER Id, Passwords, Chip & Pin, Anti-spam, Anti-pop up, Anti-spyware, WEP, Wifi protected.
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Network Security 1. Locking rooms
Scans disks & removes programs that may have malicious Track all activity on a network
2. Security guards
3. Firewalls
Slotted in keyboard, user enters card & enters number. Physical security where entry points are locked.
4. Encryption
5. Authentication
Free blockers incorporated into web browsers. Scan disks, ports looking to remove files from a host computer.
6. Digital certification
7. Anti-virus
8. Audit controls
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Supersedes WEP
Used to log on to a network system
9. User id
Use of passwords, digital certificates or biometric data.
10. Passwords
11. Chip & pin cards
Used in routers to deter stumbling across a network by accident
12. Anti-spam
13. Anti-pop-up
16. WPA
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Normally provided by security firm wear uniforms and make themselves visible.
software that prevents unauthorised communications into or out of the network Enables user to complete login process.
14. Anti-spyware
15. WEP
Used by a body that users trust and details both sender & receiver are trustworthy.
Installed on e-mail server to reject or filter emails.
Prevents confidential data from being read by unauthorised hackers. Makes it incomprehensible to anyone who does not hold the â&#x20AC;&#x2DC;keyâ&#x20AC;&#x2122; to decode it.
7.4
Electronic conferencing
Keywords: hardware, software, conference software, VOIP, instant messaging, uses. Teleconferencing allows people in different locations to talk to each other as a group. This is also known as an Audio-conference or simply a 'Conference Call' It works by each person 'logging on' to the conference call. When you switch on your conference call device and enter your user ID number, an automatic voice saying something like "Mr Jones has joined the conference" is broadcast. Everyone says hello and carries on with the meeting. Video conferencing is similar to teleconferencing except that people in the meeting can now see one another because video cameras are used to send live images over telephone lines.
Typical uses
Business meetings Remote training sessions - a trainer in one country could run a session for a group in another country avoiding the need for travel Online education. For instance attending an University lecture remotely Family and friends. Basic video conferencing equipment such as a webcam is cheap enough for domestic use. Broadband links make this feasible. Gaming. It is common for an online gaming team / group to join an audio conference server so they can chat whilst playing. Virtual tourism. Many museums and exhibitions offer a virtual tour of their exhibits Remote medical care. There are pilots underway that make it possible for a doctor to consult with patients remotely. A medical assistant at the remote site carries out the doctor's instructions such as taking a pulse or measuring blood pressure
Video conferencing pros and cons
Everyone who is going to 'attend' the There is no need to spend time and money
meeting needs access to suitable
travelling to meetings
hardware and software. This can be expensive and can take a while to set up.
You can have a 'meeting' with people from many different offices /countries without any of them having to travel
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A very reliable, fast data link is needed. Many companies hire a connection specifically to allow video conferences to take place
You can see people as well as hear them. This means you can see their body language which you can't do with a telephone call.
You can all view a document on the screen at the same time. People can work together and add their ideas. The document can be emailed to all of the people at the meeting later on.
Even with a fast connection, there might be a slight delay between responses. Especially from one side of the planet to the other.
If the hardware breaks down for any of the participants, they cannot 'attend' the meeting
Ideas and knowledge can be communicated
People could be in different time zones
between all those at the meeting very quickly
around the world. This might mean that
and responses gathered. Video conferencing is
some people have to stay up through the
good for 'brainstorming'.
night in order to attend the meeting.
One trainer or expert can provide a lecture or training session for hundreds of students at the same time
The video camera might not be able to see all parts of the room at the same time. Some people might not be easy to see at the meeting.
There is no substitute for a face-to-face meeting in getting to know someone.
Audio / Video conferencing facilities Teleconferencing equipment can range from a simple webcam arrangement to a fully fledged multi-media suite. Of course the cost is also very different between the two! Facilities to be considered are
Can it support multiple locations or is it one-on-one only Can everyone in the intended facility be heard i.e. no dead spots or lack of sensitive mikes Can additional resources be shared such as a screen or whiteboard Can applications be run remotely, especially important in training scenarios Is there an effective and simple login system to the conference
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If it includes video is it of sufficient quality for the data link available Is it high resolution, high bandwidth setup or a low-resolution lower bandwidth application What are the bandwidth requirements Can panning and zooming of the remote camera be carried out
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