اﻟﺗﺣﻠﯾل اﻟﺑﯾﯾزى ﻟﻠﺗوزﯾﻊ اﻻﺳﻰ ﺗﺣت اﺧﺗﺑﺎرات اﻟﺣﯾﺎه
١
) (١ﺗﻘدﯾرات ﺑﯾﯾزﯾﺔ ﺗﺣت ﻓرض ﺗوزﯾﻊ ﺟﺎﻣﺎ اﻟﻌﻛﺳﻰ ﻛﺗوزﯾﻊ ﻗﺑﻠﻰ ﻓﻰ ﺣﺎﻟ ﺔ اﻟﻣﻌﺎﯾﻧ ﺔ ﻣ ن اﻟﻧوع اﻟﺛﺎﻧﻰ ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ ) Shalaby (1990وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃ : إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ ﺣﻴﺚ r nو y y1 , y 2 , , y rواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة . داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ : r !n f (yi )[1 F(y r )]n r (n r)! i 1 y
L(y | ) L
y
r !n ) 1 ( i ) ( r [ e ][e ]n r (n r)! i 1 r
1
] yi (n r ) yr n! 1 ( [ i1 e . (n r)! r
ﻟﻴﻜﻦ : r
u [ yi (n r)y r ]. i 1
ﻣﻘﺪر اﻹﻣﻜﺎن اﻷﻛﱪ MLEﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ اﳊﻞ ﻟﻠﻤﻌﺎدﻟﺔ : ln L 0 ˆ
وﻳﺘﻢ ﺑﺎﳋﻄﻮات اﻟﺘﺎﻟﻴﺔ: ln L u r ln , ln L r u 2.
ﺑﻮﺿﻊ : ln L 0 ˆ
r u ˆ ˆ 2
r
(n r)y r ,
i
y i 1
r ٢
u ˆ r
: ﻫﻮ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ اﻟﻌﻜﺴﻲ ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ واذا ﻛﺎن اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ ﻟﻠﻤﻌﻠﻤﺔ ()
g 1 –g / e (g 1)
; g 1 , , 0.
: ﻟﻠﺤﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻧﺘﺒﻊ اﻟﺘﺎﱃ
n! –(rg-1) 1(u) g1 e d 0 ()L(y | )d (g 1) (n r)! 0
n! g1 . (r g 1) (u )(r g-1) . (g 1) (n r)!
( y)
()L(y | )
( u)
()L(y | )d 0
(u )(r g1) (rg) e (r g 1)
(u )
,r g 1 ; , 0.
:ﻫﻲ
اﻟﻌﺰوم ﻏﻴﺮ اﻟﻤﺮﻛﺰﻳﺔ ﻟﻠﻤﻌﻠﻤﺔ
S
E( u) S ( | u) d 0
(u ) (r g 1) (r g 1)
(r g s 1)
e
(u )
d
0
(u ) (r g 1) (u ) (r g s 1) (r g s 1) (r g 1) (r g s 1) (u )s ; r g 1, s 1, 2,.... (r g 1) ( ﻳﺘﻢ اﻟﺘﻮﺻﻞ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔs=1) ﻓﺒﻮﺿﻊ، ﺑﺎﺳﺘﺨﺪام اﻟﻌﺰوم ﻏﲑ اﳌﺮﻛﺰﻳﺔ ﳝﻜﻦ اﻟﺘﻮﺻﻞ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ وﺗﺒﺎﻳﻨﻪ : ﲢﺖ ﻓﺮض داﻟﺔ ﻣﺮﺑﻊ اﳋﺴﺎرة ﻛﺎﻟﺘﺎﱄ
٣
) (r g 2 ) (u )(r g 1 ) (u rg2
1* E( u)
; r g 2.
وﺑﺎﺳﺘﺨﺪام اﻟﻌﺰم اﻟﺜﺎﱐ ﳝﻜﻦ اﻟﺘﻮﺻﻞ إﱃ ﺗﺒﺎﻳﻦ اﳌﻘﺪر ﻛﻤﺎ ﻳﻠﻲ : 2
Var(1* ) E( 2 u) E( u) (u ) 2 (u ) 2 (r g 3) ) (r g 2 (r g 2) 2 1 1 ( (u ) 2 ) )(r g 2)(r g 3 (r g 2) 2 (u ) 2 . )(r g 2) 2 (r g 3
اﳌﻨﻮال اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ وﻳﺮﻣﺰ ﻟﻪ ﺑﺎﻟﺮﻣﺰ *2وﳝﻜﻦ اﺳﺘﻨﺘﺎﺟﻪ ﺑﺎﺗﺒﺎع اﳋﻄﻮات اﻟﺘﺎﻟﻴﺔ : أوﻻً :إﳚﺎد اﻟﻠﻮﻏﺎرﻳﺘﻢ اﻟﻄﺒﻴﻌﻲ ﻟﺪاﻟﺔ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪي :
(u )(r g1) )(u ln [( u)] ln . (r g)ln (r g 1) ﺛﺎﻧﻴﺎ :ﺑﺎﺷﺘﻘﺎق ﻃﺮﰱ اﳌﻌﺎدﻟﺔ اﻟﺴﺎﺑﻘﺔ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻌﻠﻤﺔ ﻛﻤﺎ ﻳﻠﻲ : ) ln [f( u)] (r g) (u . 2
ﺛﺎﻟﺜﺎً :ﲟﺴﺎواة اﳌﻌﺎدﻟﺔ اﻟﺴﺎﺑﻘﺔ ﺑﺎﻟﺼﻔﺮ وﺣﻞ اﳌﻌﺎدﻟﺔ ﻳﻜﻮن اﳌﻨﻮال اﻟﺒﻴﻴﺰي :
٤
) (u rg
; r g 0.
داﻟﺔ اﻟﻜﺜﺎﻓﺔ ﻟﻠﻤﻨﻮال اﻟﺒﻌﺪى
*2
ﻳﺘﻢ اﺳﺘﻨﺘﺎﺟﻪ ﺑﺎﺳﺘﺨﺪام اﳋﻄﻮات اﻟﺘﺎﻟﻴﺔ :
*2
أوﻻً :ﻳﺼﺎغ اﳌﻨﻮال اﻟﺒﻴﻴﺰي ﺑﺎﺳﺘﺨﺪام اﻟﻮﺳﻂ اﳊﺴﺎﰊ ﻛﻤﺎ ﻳﻠﻲ :
) (u u rg rg rg u , . rg rg
*2
أي أن :
u (r g) ( *2 ). ﺛﺎﻧﻴﺎَ :ﲟﺎ أن اﻹﺣﺼﺎء Uﻳﺘﺒﻊ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ ﺑﺎﳌﻌﻠﻤﺘﲔ ) ( r,θﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ : , u 0.
u
r h (u | ) u r 1 e ) (r
ﺣﻴﺚ :
du (r g) d *2 . ﻓﺈﻧﻪ ﳝﻜﻦ إﳚﺎد داﻟﺔ اﻟﻜﺜﺎﻓﺔ اﻻﺣﺘﻤﺎل ﻟﻠﻤﻨﻮال اﻟﺒﻴﻴﺰي *2ﺑﺎﺳﺘﺨﺪام داﻟﺔ اﻟﻜﺜﺎﻓﺔ ﻟﻺﺣﺼﺎء Uﻛﻤﺎ ﻳﻠﻲ : ) (r g *2 0.
) ( r g ) ( *2
;
اﻟﻘﻴﻤﺔ اﳌﺘﻮﻗﻌﺔ ﻟﻠﻤﻨﻮال اﻟﺒﻌﺪى
) ( r g ) ( *2
r h1 ( ) (r g ) r 1 ( *2 ) r 1 e ) (r * 2
*2
d *2 .
1 * rg r ( ) ( 2 ) r 1 e ) (r
ﻳﺘﻢ إﳚﺎدﻩ ﻛﺎﻟﺘﺎﱄ : ) ( r g ) ( *2
r
e
r 1
* 2
) (
* 2
٥
1 rg E ( ) (r ) * 2
* : ﻳﺘﻢ ﺣﻞ اﻟﺘﻜﺎﻣﻞ اﻟﺴﺎﺑﻖ ﻛﻤﺎ ﻳﻠﻲz ( 2 ) ﺑﺎﺳﺘﺨﺪام اﻟﺘﻌﻮﻳﺾ
r (rg )z 1 rg r 1 E ( ) (z )z e dz (r) 0 * 2
r (rg)z (rg)z 1 rg r r 1 z e dz z e dz 0 (r ) 0 r ( r 1) r 1 rg rg rg (r) (r 1) (r ) r rg r . rg
. ﻣﻘﺪر ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔ*2 وﻳﺘﻀﺢ ﳑﺎ ﺳﺒﻖ ان اﳌﻨﻮال اﻟﺒﻌﺪى : *2 ﻣﺘﻮﺳﻂ ﻣﺮﺑﻊ اﳋﻄﺄ ﻟﻠﻤﻨﻮال اﻟﺒﻌﺪى : ﻓﺈنθ ﻣﻘﺪر ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔ*2 ﲟﺎ أن اﳌﻨﻮال اﻟﺒﻌﺪى M S E ( *2 ) V ar ( *2 ) .
: *2 وﺑﺎﻟﺘﺎﱄ ﻣﺘﻮﺳﻂ ﻣﺮﺑﻊ اﳋﻄﺄ ﻟﻠﻤﻨﻮال اﻟﺒﻌﺪى M S E ( *2 ) E ( *2 ) 2 E ( *2 ) 2 2 E ( *2 ) 2 . : ﻛﻤﺎ ﻳﻠﻲE[ ( *2 ) 2 ] ًوﳊﻞ اﳌﻌﺎدﻟﺔ اﻟﺴﺎﺑﻘﺔ ﻳﺘﻢ إﳚﺎد أوﻻ
1 rg E[( ) ] (r) * 2
2
r
* 2
2
* 2
( )
r 1
e
( r g ) ( *2 )
d *2
: ﻳﺘﻢ ﺣﻞ اﻟﺘﻜﺎﻣﻞ اﻟﺴﺎﺑﻖ ﻛﻤﺎ ﻳﻠﻲz ( *2 ) ﺑﺎﺳﺘﺨﺪام اﻟﺘﻌﻮﻳﺾ ٦
r (r g)z 1 rg 2 r 1 E[ ( ) ] (z ) z e dz (r) 0 r (r g)z (r g)z (r g)z 1 r g r 1 r 2 r 1 dz 2z e dz z e dz z e (r) 0 0 0 r (r 2) (r 1) r 1 rg rg rg rg 2 2 (r 1) (r) (r 2) (r) * 2
2
2
r r(r 1) 2 . 2 rg rg * 2 : ﳓﺼﻞ ﻋﻠﻰ*2 ﰲ ﻣﻌﺎدﻟﺔ ﻣﺘﻮﺳﻂ ﻣﺮﺑﻊ اﳋﻄﺎ ﻟﻠﻤﻨﻮال اﻟﺒﻌﺪىE[ ( 2 ) ] وﺑﺎﻟﺘﻌﻮﻳﺾ ﺑﻘﻴﻤﺔ
M SE ( *2 ) E[ ( *2 ) 2 ] 2 E ( *2 ) 2 2
r r r(r 1) 2 2 2 rg rg rg r 2 ( g ) 2 . 2 r g
2
ﻓﱰات اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰﻳﺔ ﻟﻠﻤﻌﻠﻤﺔ
: ﲝﻞ اﳌﻌﺎدﻟﺘﲔ اﳌﺘﻤﺎﺛﻠﺔ ﻟﻠﻤﻌﻠﻤﺔ100(1- )% ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ ﻓﱰات اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰﻳﺔ t1
0
( u ) d 2
,
( u ) d
t2
. 2
: أي أن، t 2 واﳊﺪ اﻷﻋﻠﻰt1 ﻟﻠﺤﺪ اﻷدﱏ P(t1 t 2 ) 1 .
ﺗﺘﺒﻊ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ ﲟﻌﻠﻤﺘﲔ وﲟﺎ ان، اﳌﺘﻤﺎﺛﻠﺔ ﻟﻠﻤﻌﻠﻤﺔ100(1- )% ( ﻫﻲ ﻓﱰة اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰﻳﺔt1 , t 2 ) اﻟﻔﱰة : ﻓﺈن
( u, r g 1)
2( u) 22(r g 1) * 2 (r g) 2 22(r g 1)
: ﳓﺼﻞ ﻋﻠﻴﻬﺎ ﻛﺎﻟﺘﺎﱃP(t1 t 2 ) 1 أي أن ٧
2(r g ) *2 P 2 1 2
2 1 2
1 1 P 2 2 * 1 (2 r g ) 2 1 2 2 2(r g ) *2 2( r g ) *2 P 2 2 1 . 1 2 2
اى ان :
2(r g ) *2 2(r g ) *2 , 2 2 1 2 2
ﻳﻤﺜﻼن اﻟﺤﺪﻳﻦ اﻻدﻧﻰ واﻻﻋﻠﻰ ﻟﻔﺘﺮة اﻟﺜﻘﺔ ﻟـ ﺣﻴﺚ
2
2 , 2ﺗﺴﺘﺨﺮﺟﺎن ﻣﻦ ﺟﺪول ﺗﻮزﻳﻊ ﻣﺮﺑﻊ ﻛﺎى ﻣﻦ اﻟﻤﻠﺤﻖ
1
2
) (٥ﻋﻨﺪ درﺟﺎت ﺣﺮ ﻳﺔ ). 2(r g 1 ﳐﺎﻃﺮة ﺑﻴﻴﺰ : أوﻻً :ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﳌﻘﺪر اﳌﻜﺎن اﻻﻛﱪ ˆ) اﳌﻘﺪر ﻏﲑ اﳌﺘﺤﻴﺰ ﺑﺄﻗﻞ ﺗﺒﺎﻳﻦ ﻟﻠﻤﻌﻠﻤﺔ : ( ﲟﺎ أن ˆ ﻣﻘﺪﻳﺮ ﻏﲑ ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔ ﻓﺈن : 2 ˆ ˆ M S E ( ) V ar ( ) . r ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﳌﻘﺪر اﳌﻜﺎن اﻻﻛﱪ ˆ ﻫﻮ :
٨
r ( ˆ )
M SE ( ˆ ) ( ) d 0
0
g 1 (g 3) -(g 3 ) r (g 1)
2 g 1 – g e / d r (g 1)
2 r (g 2)(g 3)
;
g 3 , r 0.
: 1* ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰي: ًﺛﺎﻧﻴﺎ : ﻓﺈن ﻣﻘﺪﻳﺮ ﻏﲑ ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔ1* ﲟﺎ أن M S E ( 1* ) V ar ( 1* ).
1*
: ﻛﺎﻟﺘﺎﱃU ﻓﻴﺠﺐ إﳚﺎد داﻟﺔ اﻟﺘﻮزﻳﻊ ﻟﻺﺣﺼﺎء، U داﻟﺔ ﰲ اﻹﺣﺼﺎء
(u ) وﺣﻴﺚ أن rg2
g (u )
h (u
) ( ) d
0
u r g r 1 g 1 u e e d (r) 0 (g 1)
u r 1 g 1 ( r g 1) (r g 1) (u ) (r) (g 1) u r 1 g 1 ( r g 1) . (u ) (r, g 1)
: ﻛﻤﺎ ﻳﻠﻲ1* وﻣﻨﻪ ﳝﻜﻦ اﺳﺘﻨﺘﺎج ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰي * 1
r ( )
V ar (
* 1
) g (u ) du
0
0
u r 1 g 1 (u ) ( r g 1) (u ) 2 2 (r, g 1) (r g 2 ) (r g 3)
( r g 3) g 1 2 (r g 2) (r g 3) (r, g 1) ٩
0
(1
du
u ( r g 3) ) du.
: ﻛﻤﺎ ﻳﻠﻲ1* ﻳﺘﻢ ﺣﻞ اﻟﺘﻜﺎﻣﻞ اﻟﺴﺎﺑﻖ وإﳚﺎد ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰيz
u , ﺑﺎﺳﺘﺨﺪام اﻟﺘﻌﻮﻳﺾ
(r 2) r (r g 3) r 1 r(1* ) z dz (1 z) 2 (r g 2) (r g 3) (r, g 1) 0 (r, g 3) 2 2 (r g 2) (r g 3) (r, g 1)
2 (r g 2)(g 2)(g 3)
;
rg 3 .
: *2 ﳐﺎﻃﺮة ﺑﻴﻴﺰ ﻟﻠﻤﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻨﻮال: ًﺛﺎﻟﺜﺎ * 2
r( ) MSE(*2 ) () d 0
r2 (g )2 g1 –g / e d 2 (g 1) (r g) 0
g1 r 2–g e / d g22–g e/ d 2g1–g e/ d 2–g e/ d 2 (r g) (g 1) 0 0 0 0 g1 r(g 3)-(g3) g2(g 3)-(g3) 2g(g 2)-(g2) 2(g 1)-(g1) 2 (r g) (g 1) 2 (r g 6) (r g)2 (g 2)(g 3)
;
(r g) 3.
: ﻛﺎﻟﺘﺎﱃ*2 ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻘﺪر1* اﻻن ﻳﺘﻢ ﺣﺴﺎب ﻧﺴﺒﺔ ﳐﺎﻃﺮة ﺑﻴﻴﻴﺰ ﻟﻠﻤﻘﺪر r( 1* , ˆ )
r( 1* ) 2 r(g 2)(g 3) r , * 2 r( 2 ) (g 2)(g 3)(r g 2) (r g 2)
r(*2 ) 2 (r g 6) r(g 2)(g 3) r(r g 6) r( *2 , ˆ ) , 2 2 (r g) 2 r(ˆ ) (r g) (g 3)(g 3)
: اى ان r(1* , ˆ ) r(*2 , ˆ ) r(1* ) r( ˆ ) r( *2 ).
١٠
وﻫﺬا ﻳﻌﲎ ان اﻓﻀﻞ ﻣﻘﺪر ﰱ ﻫﺬﻩ اﳊﺎﻟﺔ ﻫﻮ *. 1 ﻟﻠﻨﺘﺎﺋﺞ اﻟﺴﺎﺑﻘﺔ وﺑﻮﺿﻊ r nﻓﺈﻧﻨﺎ ﳓﺼﻞ ﻋﻠﻰ ﻧﺘﺎﺋﺞ ﲣﺺ اﻟﻌﻴﻨﺔ اﻟﻜﺎﻣﻠﺔ .
) (٢ﺗﻘدﯾرات ﺑﯾﯾزﯾﺔ ﺗﺣت ﻓرض اﻟﺗوزﯾﻊ اﻟﻣﻧﺗظم ﻓﻰ اﻟﻣﻌﺎﯾﻧﺔ ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ
اﻟﻔﺗرة )(,
ﻛﺗوزﯾ ﻊ ﻗﺑﻠ ﻰ ﻓ ﻰ ﺣﺎﻟ ﺔ
ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ ) Bhattacharya (1967وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃ : إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ ﺣﻴﺚ r nو y y1 , y 2 , , y rواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة . داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ : r !n f (yi )[1 F(y r )]n r (n r)! i 1 y
L(y | )
y
r !n ) 1 ( i ) ( r [ e ][e ]n r (n r)! i 1 r
1
] yi (n r ) yr n! 1 ( [ i 1 e . (n r)! r
ﻟﻴﻜﻦ : r
u [ yi (n r)y r ], i 1
وإذاﻛﺎن اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ ﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ اﻟﺘﻮزﻳﻊ اﻟﻤﻨﺘﻈﻢ ﻓﻰ اﻟﻔﺘﺮة ) (, اﻟﺘﺎﻟﻰ : ; 0 .
1 a
ﻟﻠﺤﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻧﺘﺒﻊ اﻟﺘﺎﱃ :
١١
(a 1)() a 1 a 1 a 1
()
( y)
()L(y | )
( u)
()L(y | )d 0 u
(a 1)()a 1 –a n! –r e a1 a 1 (n r)! u (a 1)()a1 –a n! –r e d a 1 a1 (n r)!
u
–(a r) e – r
–(a r)
u
, .
–r
e d
: اﻻن
–(a r )
u
–r
–(a r)
e d 0
let w=
u
–r
e d
–(a r)
0
u
e – r d
u u u = d 2 dz z z
–(a r )
u
u 0
–r
e d
u w
(a r )
e
w
u u u d 2 0 w w
–(a r )
u w e d w2
u u (a r 1) 1 w u e dw w (a r 1) 1e w dw . 0 w 0 u u (r 1, ) (r 1, ) (a r 1)
x
where (n,x)= e-t t (n 1)dt. 0
( u ) u
– ( a r 1)
e
u
, . u u (r 1, ) (r 1, ) : ﲢﺖ ﻓﺮض داﻟﺔ ﻣﺮﺑﻊ اﳋﺴﺎرة ﻛﺎﻟﺘﺎﱄ ﻳﺘﻢ اﳊﺼﻮل ﻋﻠﻰ اﳌﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ
( a r 1)
١٢
*
u
–(a r 2)
E( u)
(a r 1)
–(a r 2)
u
e d
u u (r 1, ) (r 1, )
, .
u
u u e d u (a r 2) (r 1, ) (r 1, )
u u u (r 2, ) (r 2, ) * . u u (r 1, ) (r 1, ) : ﻧﺘﺒﻊ اﻻﺗﻰ* ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﺗﺒﺎﻳﻦ
E(2 u)
u
(a r 1)
u
–(a r 3) e d
u u (r 1, ) (r 1, )
u 2 * (r 3, u) * y y * , (n, y) (n, ) (n, ). (r 1, u)
: اذن * u 2 * (r 3, u) 2 (r 2, u) Var( ) * u * (r 1, u) (r 2, u)
2
*
u 2 * (r 3, u) * (r 2, u) *
2
[ (r 1, u)]
2
.
n
ﲤﺜﻞ زﻣﻦt 0 ﰱ ﺣﺎﻟﺔ اﳌﻌﺎﻳﻨﺔ ﻣﻦ اﻟﻨﻮع اﻻول ﻓﺈن. u x i وr n ﰱ ﺣﺎﻟﺔ اﻟﻌﻴﻨﺔ اﻟﻜﺎﻣﻠﺔ ﳓﺼﻞ ﻋﻠﻰ اﻟﻨﺘﺎﺋﺞ ﺑﻮﺿﻊ i 1
وﻋﻠﻰ ذﻟﻚ داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ. ﺗﺼﺒﺢ ﻣﺘﻐﲑا ﻋﺸﻮاﺋﻴﺎr اﻧﺘﻬﺎء اﻟﺘﺠﺮﺑﺔ واﶈﺪد ﻣﺴﺒﻘﺎ ﻣﻦ ﻗﺒﻞ اﻟﺒﺎﺣﺚ وﰱ ﻫﺬﻩ اﳊﺎﻟﺔ ﻓﺈن : ﻛﺎﻵﰐ r
L(x1 , x 2 ,..., x n | ) f (x i )[1 F(t 0 )]n r i 1
r
1 [ e i 1
x ( i )
t [( 0 )]nr
][e
]
u
1 ( ) e r r
where u
x
i
(n r)t 0 .
i 1
١٣
) (٣ﻣﻘﺎرﻧﺔ ﺑﯾﯾزﯾﺔ ﺗﺣت ﻓرض اﻟﺗوزﯾﻊ اﻻﺳﻰ ﺑﻣﻌﻠﻣﺔ ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ
ﻛﺗوزﯾﻊ ﻗﺑﻠ ﻰ ﻓ ﻰ ﺣﺎﻟ ﺔ اﻟﻣﻌﺎﯾﻧ ﺔ
ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ ) Bhattacharya (1967وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃ : إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ ﺣﻴﺚ r nو y y1 , y 2 , , y rواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة . داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ : r !n f (yi )[1 F(y r )]n r (n r)! i 1
L(y | )
y
r ) ( r !n 1 y [ exp( i )][e ]n r (n r)! i 1 r
1
] yi (n r) yr n! 1 [ i 1 e . (n r)! r
ﻟﻴﻜﻦ :
r
u [ yi (n r)y r ]. i 1
وإذاﻛﺎن اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ ﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ اﻟﺘﻮزﻳﻊ اﻟﺘﺎﱃ :
, 0 ; 0 .
ﻟﻠﺤﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻧﺘﺒﻊ اﻟﺘﺎﱃ :
١٤
1 () e
( y)
()L(y | )
()L(y | )d 0
u
u
1 n! –r e e (n r)!
0
1 e
( u) u
n! –r e d (n r)!
u
– re
0
u – r
e
. d
: اﻻن
١٥
0
b ax x
x e
a dx 2 b
1 2
K 1 2 ab
1 let a= , r
–r
e e
( u)
2 (u)
r 1
u
r 1 2
u
u K r 1 2
u – r
(u) e u 2K r 1 2
.
: ﲢﺖ ﻓﺮض داﻟﺔ ﻣﺮﺑﻊ اﳋﺴﺎرة ﻛﺎﻟﺘﺎﱄ ﻳﺘﻢ اﳊﺼﻮل ﻋﻠﻰ اﳌﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ u
(u) r 1 1–r E( u) e d u 0 2K r 1 2 *
(u) r 1 u 2K r 1 2
1 2 u
K r2 2 u K r 1 2
(r 2) 2
u K r 2 2
u . u : ﻧﺘﺒﻊ اﻻﺗﻰ* ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﺗﺒﺎﻳﻦ
١٦
u
(u) r 1 2–r E( u) e d. u 0 2K r 1 2 1 let a= , r, b u, 2
r 1
E( 2 u)
(u) 1 2 u u 2K r 1 2
K r 3 2 u K r 1 2
(r 3) 2
u K r 3 2
u . u : اذن
u K r 3 2 K r 2 2 u Var(* ) u K r 1 2 u K r 1 2
u u
2
2 u u u K r 3 2 2 K r 1 2 K r 2 2 . u K r 1 2
u
R(t) ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ
اﳌﻘﺪر اﻟﺒﻴﻴﺰى : ﲟﺎ ان
-
t
R(t) e , : وﺑﺈﺳﺘﺨﺪام داﻟﺔ ﺧﺴﺎرة ﻣﺮﺑﻊ اﳋﻄﺎ ﳝﻜﻦ اﳚﺎد اﳌﻘﺪر اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻛﺎﻟﺘﺎﱃ ١٧
*
R (t ) E[R(t)] R(t) ( | u) d 0
u t
(u) r 1 – r e u 0 2K r 1 2 1 let a= , r, b u t, r 1
d.
(u) 1 2 u (u t) 2K r 1 2 ut r 1 K r 1 2 2 u u ut K r 1 2 ut (r 1) K r 1 2 t 2 . 1 u u K r 1 2
R * (t)
(r 2) 2
ut K r 2 2
: اﻳﻀﺎ ﳝﻜﻦ اﳚﺎد ﺗﺒﺎﻳﻦ داﻟﺔ اﻟﺼﻼﺣﻴﺔ ﰱ ﻫﺬﻩ اﳊﺎﻟﺔ ﻛﺎﻟﺘﺎﱃ
١٨
2
Var R * (t) E R 2 (t) u E(R(t ) u) ,
E[R 2 (t )] R 2 (t ) ( | u) d 0
u 2 t
( u) r 1 – r e u 0 2K r 1 2 1 let a= , r, b u 2t,
( u) r 1 E[R (t)] u 2K r 1 2 2
2t 1 u
( r 1) 2
d.
u 2t 2K r 1 2
u 2t K r 1 2 u K r 1 2
( r 1) (u t) 2
.
Var R * (t) E R 2 (t ) u E(R (t) u)
2
2
2t 1 u
1
(r 1) 2
u 2t u t (r 1) K r 1 2 K r 1 2 t 2 1 . u u u K r 1 2 K r 1 2
2t Var R * (t ) 1 2 u u K 2 r 1
( r 1) 2
u 2t K r 1 2
2
u u t K r 1 2 K r 1 2 .
ﻛﺗوزﯾﻊ ﻗﺑﻠﻰ ﻓﻰ ﺣﺎﻟﺔ اﻟﻣﻌﺎﯾﻧﺔprior quasi-density ( ﺗﻘدﯾرات ﺑﯾﯾزﯾﺔ ﺗﺣت ﻓرض٤) ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ : وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃBhattacharya (1967) ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ اﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪاتr ﻫﻰ الy1 y 2 y r إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان واﳌﻄﻠﻮبy y1 , y 2 , , y r وr n ﺣﻴﺚ ﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔn اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ : داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ. ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة ١٩
r n! f (yi )[1 F(yr )]n r (n r)! i 1
L(y | )
y
r ( r ) n! 1 y [ exp( i )][e ]n r (n r)! i 1 r
1
yi (n r ) yr ] n! 1 ( [ i 1 e . (n r)! r
: ﻟﻴﻜﻦ r
u [ yi (n r)y r ] i 1
: ﻫﻮ ﲢﺖ ﻓﺮض ان اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ ل a ,0 . : ﻟﻠﺤﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻧﺘﺒﻊ اﻟﺘﺎﱃ.Bhattacharya (1967 )واﳌﺎﺧﻮذ ﻣﻦ ﻗﺒﻞ
( x)
() L(y | )
( u)
()L(y | )d 0
u
n! –r e (n r)! u n! –r –a 0 (n r)! e d –a
0
–(a r)
e
–( r)
u
e
u
d u
1 u ( )(a r ) e u (a r 1)
: ﲢﺖ ﻓﺮض داﻟﺔ ﻣﺮﺑﻊ اﳋﺴﺎرة ﻛﺎﻟﺘﺎﱄ ﻳﺘﻢ اﳊﺼﻮل ﻋﻠﻰ اﳌﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ
٢٠
u (u) (a r ) –(a r) 1 E( u) e d . 0 (r) (a r 1)) u u u let w= = d 2 dw. w w (a r ) 1 (u) u * u (a r ) 1 w (a r) 1e w 2 dw (a r 1) 0 w *
*
( a r 1)1 u w e w dw 0 (a r 1)
(u) u (a r 2) , r 2. (a r 1) ar2 : ﻧﺘﺒﻊ اﻻﺗﻰ* ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﺗﺒﺎﻳﻦ ( a r 1)1
( a r ) 2 (a r ) 2 u u E( u) u w e w 2 dw (a r 1) 0 w 2
( a r 3)1 u2 w e w dw (a r 1) 0
u2 u2 (a r 3) . (a r 1) (a r 2)(a r 3) : اذن 2
u u2 Var( ) (a r 2)(a r 3) a r 2 u2 u2 . a r 2 a r 3 (r 2)(r 3) (r 2) 2 (r 3) *
( ﺗﻘ دﯾرات ﺑﯾﯾزﯾ ﺔ ﻓ ﻰ ﺣﺎﻟ ﺔ اﻟﻣﻌﺎﯾﻧ ﺔ ﻣ ن اﻟﻧ وع اﻟﺛ ﺎﻧﻰ ﺗﺣ ت ﻓ رض اﻟﺗوزﯾ ﻊ اﻟﻘﺑﻠ ﻰ٥) اﻟﻣراﻓق : وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃBhattacharya (1967 ) ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ
٢١
إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ ﺣﻴﺚ r nو y y1 , y 2 , , y rواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة . داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ : r !n f (yi )[1 F(y r )]n r (n r)! i 1
L(y1 , y 2 ,..., y n | )
r y y !n 1 [ exp( i )][exp( r )]n r (n r)! i 1
n! 1 1 r exp( [ yi (n r)y r ]. (n r)! r i 1
ﻟﻴﻜﻦ : r
] u [ yi (n r)y r i 1
ﻻﺧﺘﻴﺎر اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ اﳌﺮاﻓﻖ ﻣﻦ اﳌﻌﻠﻮم ان داﻟﺔ ﻛﺜﺎﻓﺔ اﻻﺣﺘﻤﺎل ﻻﺑﺪ ان ﻳﻜﺘﺐ ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ : .
a ( ) b( x ) c( )d (x )]
f (x | ) e
وﻋﻠﻰ ذﻟﻚ ﻓﺈن : n
.
d ( x i )] ) na ( )) c( i 1
L(y | ) L e
وﻋﻠﻰ ذﻟﻚ اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ اﳌﺮاﻓﻖ ﻳﻜﺘﺐ ﻋﻠﻰ اﻟﺸﻜﻞ اﻻﺗﻰ : ,
1a ( ) 1c( )]
( ) e
واﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻋﻠﻰ اﻟﺸﻜﻞ اﻻﺗﻰ : n
, 2 1 n, 2 1 d(x i ).
2 a ( ) 2 c( )]
( | x) e
i 1
ﲢﺖ ﻓﺮض اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﻓﺈن Lﳝﻜﻦ ﻛﺘﺎﺑﺘﻬﺎ ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ : n
x i 1
a() ln , c( )
i1
r ln
e
n x i i 1
1 L re
وﻋﻠﻰ ذﻟﻚ اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ اﳌﺮاﻓﻖ ﻫﻮ : ,
1 1 ln ]
( ) e
اى ان :
.
1 ] 1
e
( )
1 1 ln ]
اى ان اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ اﳌﺮاﻓﻖ ﻫﻮ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ اﻟﻌﻜﺴﻰ ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ : ٢٢
( ) e
1 ( ) ( )
1
e
]
,0< , , 0.
: ﻟﻠﺤﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ﻧﺘﺒﻊ اﻟﺘﺎﱃ ()L(y | )
( y)
( | u)
()L(y | )d 0 –r
0
e
–( r 1)
let w=
e
u –r –(1)
0
u –(1)
e
e
–( r 1)
e d
u
e
u
. d
u u u d 2 dw. w w
: اذن
0
–( r 1) e
u w
u
d
u w
0
–( r)
0
w
( r ) 1 w
e
–( r 1)
e
w
u dw w
u dw w2
–( r )
( r).
: اذن ) (u )(r ) –(r1) (u ( u) e (r ) (r 1)
u
(u )
e . (u )(r )
: ﲢﺖ ﻓﺮض داﻟﺔ ﻣﺮﺑﻊ اﳋﺴﺎرة ﻛﺎﻟﺘﺎﱄ ﻳﺘﻢ اﳊﺼﻮل ﻋﻠﻰ اﳌﻘﺪر اﻟﺒﻴﻴﺰي ﻟﻠﻤﻌﻠﻤﺔ
٢٣
(u ) (r ) E( u) (r ) *
(u ) (r ) (r ) *
*
0
0
u w
–(r )
(r )
e
u
d
u e w 2 dw w
(T ) ( r1)1 w w e dw (r ) 0
(u ) (u ) (r 1) , r 1. (r ) (r 1) : ﻧﺘﺒﻊ اﻻﺗﻰ* ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﺗﺒﺎﻳﻦ
(u ) (r ) E( u) (r ) 2
(u ) (r ) (r )
0
0
u w
–(a r ) 1
(r ) 1
e
u
d
u e w 2 dw w
(u ) 2 ( r2 )1 w w e dw (r ) 0
(u ) 2 (u ) 2 (r 2) . (r ) (r 1)(r 2) : اذن 2
(u ) (u )2 (r 1)(r 2) (r 1) (u )2 (u ) 2 . r 1 r 2 (r 1)2 (r 2) (r 1) 2 (r 2) Var(* )
اﻟﻤﻘﺪر اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ :ﲟﺎ ان ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻫﻰ
-
t
R(t ) e , : ﺑﺈﺳﺘﺨﺪام داﻟﺔ ﺧﺴﺎرة ﻣﺮﺑﻊ اﳋﻄﺎ ﳝﻜﻦ اﳚﺎد اﳌﻘﺪر اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻛﺎﻟﺘﺎﱃ
٢٤
*
R (t ) E[R(t)] R(t ) ( | u) d 0
(u )(r ) (r ) (u )(r ) (r )
0
0
–(r 1)
e
( t u )
t u w
(u )(r ) (t u ) (r )
d
(r 1)
t u e w dw 2 w
( r )
w
0
( r ) 1
e w dw
( r )
( r ) (u ) (r )(t u ) (r )
t u u
(r )
t 1 u
(r )
.
: اﻳﻀﺎ ﳝﻜﻦ اﳚﺎد ﺗﺒﺎﻳﻦ داﻟﺔ اﻟﺼﻼﺣﻴﺔ ﰱ ﻫﺬﻩ اﳊﺎﻟﺔ ﻛﺎﻟﺘﺎﱃ 2
Var R * (t) E R 2 (t) u E(R (t) | u) 2
E[R (t)] R 2 (t ) ( | u) d 0
(u )(r ) (r ) (u )(r ) (r )
0
0
–(r 1)
e
(2t u )
2t u w
(u )(r ) (2t u ) (r )
d
(r 1)
2t u e w dw 2 w
( r )
0
w
( r ) 1
( r )
( r ) (u ) (r )(2t u ) (r )
2t u u
(r )
2t 1 u ٢٥
(r )
.
e w dw
2
Var R * (t) E R 2 (t u) E(R (t | u) ) 2(r
.
t 1 u
) (r
2t 1 u
) (٦اﻟﺗﻘدﯾر اﻟﺑﯾﯾزى ﻓﻰ ﺣﺎﻟﺔ ﻧﻘص اﻟﻣﻌﻠوﻣﺎت ﻋن ﻓﻰ ﺣﺎﻟﺔ اﻟﻣﻌﺎﯾﻧﺔ ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ ﺣﻴﺚ r nو y y1 , y 2 , , y rواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻣﺘﻮﺳﻂ زﻣﻦ اﳊﻴﺎة . داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ :
r
yi n r yr
i1
1
r
n! 1 L y1 , y 2 ,..., y r . e n r !
:اﯾﺠﺎد ﻣﻘﺪرات ﺑﯿﯿﺰ ﺗﺤﺖ ﻓﺮض اﻟﺘﻮزﯾﻊ ﻷﺳﻲ ﺑﻤﻌﻠﻤﺘﯿﻦ: r
u yi n r y r .
let
i 1
وﺑﻔﺮض ان : n! r 1 u k e d n r ! 0 !n u r r. ! n r
ﲢﺖ ﻓﺮض ان اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ ل ﻫﻮ : 1 g .
ﻓﺈن اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل ﻫﻮ : u r r
ﲟﺎ ان داﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻟﻠﺘﻮزﻳﻊ اﻻﺳﻰ ﻫﻰ :
u
e
r 1
u
u 1 r u e . r
.
t
R(t) e
ﻓﺈن اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻫﻮ : ٢٦
R * (t) E R(t) x
R(t) x d 0 r
1 u u e d r
t
e 0
u r r 1 1u t e d r 0 u t ut d d 2 ur r * R (t) u t r 1e d r 0 r u r t u r r r t * R (t) 1 . u
ut
let
) (٧اﻟﺗﻘدﯾر اﻟﺑﯾﯾزى ﻟﻣﺗوﺳط اﻟﺣﯾﺎة وداﻟﺔ اﻟﺻﻼﺣﯾﺔ ﻟﻠﺗوزﯾﻊ اﻻﺳ ﻰ ذو اﻟﺑﺗ ر اﻟﻣ زدوج ﻓﻰ ﺣﺎﻟﺔ اﻟﻌﯾﻧﺔ اﻟﻛﺎﻣﻠﺔ ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ ) Shalaby (1994وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃ :
إذا ﻛﺎﻧﺖ Xﳍﺎ اﻟﺘﻮزﻳﻊ اﻵﺳﻲ ﺑﺎﳌﻌﻠﻤﺔ و ﻗﺪ ﰎ ﻋﻠﻴﻬﺎ ﺑﱰ ﻣﺰدوج ﺗﻜﻮن داﻟﺔ ﻛﺜﺎﻓﺔ اﻻﺣﺘﻤﺎل ﳍﺎ ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱄ : t2 1 x t1 f(x| t1 <X< t 2 ) = e (e e ) 1 > 0 , 0 <t1 t 2 ; t1 x t 2 .
داﻟﺔ اﻹﻣﻜﺎن اﻷﻋﻈﻢ ﻟﻌﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﺣﺠﻤﻬﺎ nﻣﻦ اﻟﺘﻮزﻳﻊ اﻵﺳﻲ ذو اﻟﺒﱰ اﳌﺰدوج ﺗﻜﻮن ﻛﺎﻟﺘﺎﱃ:
٢٧
n
L(x1 , x 2 ,..., x n ; , t1 , t 2 ) L f (x i ) i 1
n
xi i 1
n
e 1 = . n t t 1 2 e e t 2 t1 n = e e e
u
n
n
t 2 t1 t1 n = e e 1 e
= n e = n e
u
(T nt1 )
G
n
n
(t t ) 2 1 1 e .
R 1 e
n
n
where G = u-nt1
, R= t 2 t1
,u = x i i=1
: ﻫﻮ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ اﻟﻌﻜﺴﻲ ﻋﻠﻰ اﻟﺸﻜﻞ ﺑﻔﺮض أن اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻲ ﻟﻠﻤﻌﻠﻤﺔ h h 1 () e ( 1)
; h, > 0 .
> 1 ﻫﻲ داﻟﺔ ﺟﺎﻣﺎ و( 1) ﺣﻴﺚ أن . ﺳﻮف ﻧﺴﺘﻔﻴﺪ ﻣﻦ داﻟﺔ ﺟﺎﻣﺎ اﻟﻨﺎﻗﺼﺔ اﻟﺘﺎﻟﻴﺔ ﰱ اﳊﺼﻮل ﻋﻠﻰ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪي ﻟﻠﻤﻌﻠﻤﺔ
(m 1, a) y m e y dy a
aj =(m 1)e , m = 0,1,2, ... j0 j! m
a
٢٨
: ﻳﻜﻮن اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪي ﻟﻠﻤﻌﻠﻤﺔ ( | x)
L(x | )()
.
L(x | )() d 0
f (x) L(x | ) () d 0
(h+G) R h -1 -( +n) = e (1-e ) -n d ( -1) 0
(h+G) jR h -1 n j1 - -( +n) = e j e d ( -1) 0 j=0
(h+G+jR) -1 n j1 h -( +n) = e d. j ( -1) 0 j=0 h+G+jR h+G+jR (h+G+jR) let w = = d = dw, w w2 if =0 w= , if = w=0,
٢٩
0
-1 h+G+jR n j1 h f (x) = w j (-1) j=0
-( +n)
(h+G+jR) e-w dw 2 w
-1 1-( +n) n j1 h n 2 -w = w h+G+jR e dw j ( -1) j=0 0
-1 1-( +n) n j1 h = h+G+jR ( n 1) j ( -1) j=0
1-( +n)
-1 n j1 h ( n 1) ( n )1 h+jR = G 1+ j (-1) h j=0
n 1 h -1 n j1 A j = j n 1 ( n 1) ( -1) j=0 G
h -1 = K 1 , ( -1) -1
where
n 1
h+jR n j1 A j -1 A j = 1+ , K j n 1 ( n 1) h G j=0
G n 1 K n j1 n 1 ( n 1) Aj j j=0 R h -1 -( +n) - (h+G) e (1-e )-n (-1) ( | u) h -1 K 1 , ( -1)
K
-( +n)
e
-
(h+G)
-
R -n
(1-e )
; >0 .
: ﻫﻮU=u ﺑﺸﺮط ﻟﻠﻤﻌﻠﻤﺔm اﻟﻌﺰم اﻟﻼﻣﺮﻛﺰي ذو اﻟﺮﺗﺒﺔ ` m
m
( | u) E( ) m ( | u) d, m 1, 2,... 0
٣٠
=K
-( +n-m)
e
-
(h+G)
-
(h+G)
-
R -n
(1-e ) d
0
=K
-( +n-m)
e
0
Rj
n j1 - j e d j=0
n j1 -( +n-m) =K e j 0 j=0
(h+G+Rj)
d
n j1 =K ( +n-m-1) (G+h+Rj)1-( +n-m) j j=0
h+Rj -( +n-m-1) n j1 1-( +n-m) =K G ( +n-m-1) (1+ ) j G j=0
n j1 1-( +n-m) =K G (+n-m-1) A j +n-m-1 j j=0
G =
n 1
n j1 +n-m-1 1-( +n-m) G ( +n-m-1) j Aj j=0 n j1 +n-1 ( +n-1) Aj j j=0
n j1 +n-m-1 A j G m ( +n-m-1) j=0 j = . n j1 where , m = 1,2,... ( +n-1) +n-1 j Aj j=0 . m و ﳝﻜﻦ إﳚﺎد اﳌﺘﻮﺳﻂ و اﻟﺘﺒﺎﻳﻦ ﻣﻦ اﻟﻌﺰوم اﻟﻼﻣﺮﻛﺰﻳﺔ ذو اﻟﺮﺗﺒﺔ
R(t ) وداﻟﺔ اﻟﺼﻼﺣﻴﺔ اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى ﻟﻜﻞ ﻣﻦ اﳌﻌﻠﻤﺔ : ﲢﺖ ﻓﺮض داﻟﺔ اﳋﺴﺎرة ﳌﺮﺑﻊ اﳋﻄﺄ ﻫﻮ* اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى
٣١
n j1 +n-1-1 j Aj G( +n-1-1) j=0 * E() 1` ( | u) . n j1 ( +n-1) +n-1 j Aj j=0
n j1 +n-2 j Aj G( +n-2) = . j=0 , n j1 ( +n-2)( +n-2) +n-1 j Aj j=0
*
n j1 +n-2 j Aj G = . j=0 . n j1 ( +n-2) +n-1 j Aj j=0
n j1 +n-3 j Aj 2 G ( +n-3) j=0 E(2 ) `2 ( | u) . n j1 ( +n-1) +n-1 j Aj j=0
n j1 +n-3 j Aj G2 j=0 . n j1 . ( +n-2)( +n-3) +n-1 j Aj j=0 : ( و ﻣﻨﻬﺎ ﻳﻜﻮن اﻟﺘﺒﺎﻳﻦ اﻟﺒﻌﺪي ) اﳌﺨﺎﻃﺮة اﻟﺒﻌﺪﻳﻪ
Var(* ) E(2 ) E
2
2 n j1 +n-3 n j1 +n-2 Aj j Aj j G2 ( +n-3) j=0 j=0 . = n j 1 n j 1 ( +n-2)( +n-3) +n-1 ( +n-2) +n-1 A j j j A j j=0 j=0
٣٢
اﳌﻨﻮال اﻟﺒﻌﺪى : ﳝﻜﻦ إﳚﺎدﻩ ﺑﺎﺷﺘﻘﺎق داﻟﺔ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪي ﻛﻤﺎ ﻳﻠﻲ اﳌﻨﻮال اﻟﺒﻌﺪي -( +n)
-
(h+G)
-
R -n
( | u) K e (1-e ) d( | u) d R R - (h+G) -n -( +n)-1 -n -( +n) e (1-e ) -( +n) (1-e ) R K (h+G) (h+G) R (h+G) n( R)e -n-1 2 e -( +n) e (1-e ) 2 (h+G) R R -( +n+1) -n -n -( +n+2) -( +n) e (1-e ) (h+G)(1-e ) K (h+G) (h+G+R) R e nR-( +n-2) e (1-e )-(n+1) R (h+G) R R - (h+G) nR -( +n+1) -n -1 =K(1-e ) e (1-e ) e -( +n)+
d( | u) 0 d R R (h+G) nR -1 -( +n)+ (1-e ) e 0 -
R R -1
-( +n)+(h+G) nR(1-e ) e 0. R R - - 1 -1 (h+G) nR(1-e ) e , ( +n)
R - 1 (h+G) nRe . ( +n)
. و ﻳﺘﻢ إﳚﺎد اﳌﻨﻮال اﻟﺒﻌﺪي ﲝﻞ اﳌﻌﺎدﻟﺔ ﻏﲑ اﳋﻄﻴﺔ اﻟﺴﺎﺑﻘﺔ ٣٣
ˆ ﺗﻘﺪﻳﺮ اﻻﻣﻜﺎن اﻻﻛﱪ
L(x | ) n e
G
n
R 1 e ,
G R n G R n G n n 1e 1 e n 2 e 1 e dL R R n 1 d n G R e n( e ) 1 e 2
n e
G
R 1 e
n
R 1 n G nR R 2 2 e 1 e 1
R dL n G nR R 0 2 2 e 1 e 0 d
n G nRe
R
R 1 e
1
1
R R ˆ 1 (G nRe ˆ 1 e ˆ ) n 1 Rˆ 1 (G nR e 1 ) n R ˆ 1 (G nRe ˆ ) . n وةةة
ااﻻﻟﻠﻜﻤﻢ
٣٤
ﺗﻘﺪﻳﺮ اﻻﻣﻜﺎن اﻻﻛﱪ ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ : ﺣﻴﺚ داﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻫﻰ R(t)
t
t2
t1
t2
e e
.
e e وﻋﻠﻰ ذﻟﻚ ﻣﻘﺪر اﻻﻣﻜﺎن اﻻﻛﱪ ﻟﺪاﻟﺔ. وان اى داﻟﺔ ﰱ ﻣﻘﺪر اﻻﻣﻜﺎن اﻻﻛﱪ ﻫﻰ ﻣﻘﺪر اﳌﻜﺎن اﻻﻛﱪ ﳍﺬﻩ اﻟﺪاﻟﺔ
: اﻟﺼﻼﺣﻴﺔ ﻫﻮ
t ˆ
t2 ˆ
ˆ ) e e . R(t t1 t2 ˆ e e ˆ
اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ t1 t 0 t 2 ﺣﯾثR(t 0 ) ر اﯾﺎﻟﺔ اﻟﺻﻼﺣﯾﺔ : ﺣﻴﺚR * (t) ﺑﺎﺳﺘﺨﺪام داﻟﺔ اﳋﺴﺎرة ﳌﺮﺑﻊ اﳋﻄﺄ ﳝﻜﻦ إﳚﺎد
R * (t) E R(t )
= R(t ) (|u) d 0
= 0
t
t2
t1
t2
(e e (e
e
=K
-( +n)
e
t t1
)
K
(1 e
e
(t t1 ) -( +n)
e
(1 e
( t 2 t1 )
-( +n)
e
R
`
(h+G)
-
R -n
(1-e ) d
(1 e
(R R ` )
(1 e
)
e
-
(h+G)
R
-
R -n
(1-e ) d
)
(t 2 t1 (t t1 ))
(1 e
0
(t 2 t )
(1 e
0
=K
e
-
)
0
=K
-( +n)
R
)
)
e
-
(h+G)
-
R -n
(1-e ) d
) e
-
(h+G)
)
R t 2 t1 , R ` t t1 ٣٥
-
R -n
(1-e ) d
=K
R` -( +n)
e
(1 e
(R R ` )
) e
-
(h+G)
-
(h+G)
-
R -(n+1)
(1-e )
d
0
=K
R` -( +n)
e
(1 e
(R R ` )
) e
0
=K -( +n) 0
=K 0
j
j=0
-( +n)
n+j
j=0
n+j j
e
e
-
-
(jR+R ` h G)
(jR+R ` h G )
(1 e
jR
n+j - j e d j=0
(R R ` )
) d
d K
-( +n)
0
n+j je j=0
`
((1+j)R h G )
(jR+R h G ) ((1+j)R h G ) n+j -( +n) -( +n) =K e d e d j 0 j=0 0
n+j =K ( n 1) j j=0 (jR+R ` h G) ( n 1) ((1+j)R h G) ( n 1)
n+j =K ( n 1)G ( n 1) j j=0 jR+R ` h (1+j)R h ( n 1) ( n 1) ( 1) ( 1) G G
n+j ( n 1) A j1( n 1) j Bj j=0 = n+j-1 ( n 1) j Aj j=0 jR+R ` h (1+j)R h where B j ( 1) 1 , A j1 ( 1) 1 G G
٣٦
d
ﻓﱰة ﺛﻘﺔ ﻟﻠﻤﻌﻠﻤﺔ
ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ ﻓﱰة ﺛﻘﺔ (t1 , t 2 ) HBDﻟﻠﻤﻌﻠﻤﺔ واﻟﱴ ﳚﺐ ان ﲢﻘﻖ اﻟﺸﺮﻃﲔ اﻟﺘﺎﻟﻴﲔ : : ) (1) ( t 1 u ) ( t 2 u t2
f ( u ) d 1 .
( 2)
t1
وﳓﺼﻞ ﻋﻠﻰ ﻫﺬﻩ اﻟﻔﱰة ﻛﺎﻟﺘﺎﱃ :
) -n
R t2
-
(1 -e
) (h+ G t2
-
e
) -( +n n
n
.
Kt2
-n
)
R t 1 -e 1 R 1-e t 2
R t 1 -e 1 R 1 -e t 2
R t1
-
(1 -e 1
) (h +G t1
-
e
)-( + n
(1) K t 1
1
]) t 1 ( + n) [-(h +G )( t1 - t 2 ) ( e t2 1
]) t 1 ( + n) (h+ G )[ t1 t 2 )(t 2 t 1 ) ( e t2
ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ ﺣﺪود اﻟﺜﻘﺔ وذﻟﻚ ﲝﻞ اﳌﻌﺎدﻟﺘﲔ اﻟﺴﺎﺑﻘﺘﲔ ﺑﺎﺳﺘﺨﺪام اﳊﺎﺳﺐ اﻻﱃ . ﻓﻴﻤﺎ ﻳﻠﻰ اﳊﺎﻻت اﳋﺎﺻﺔ ﻣﻦ اﻟﻨﺘﺎﺋﺞ اﻟﺴﺎﺑﻘﺔ : )ا( ﻋﻨﺪﻣﺎ t 2 ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ اﻟﻨﺘﺎﺋﺞ اﳋﺎﺻﺔ ﺑﺎﻟﺒﱰ ﻣﻦ اﻟﻴﺴﺎر . )ب( ﻋﻨﺪﻣﺎ t1 0ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ اﻟﻨﺘﺎﺋﺞ اﳋﺎﺻﺔ ﺑﺎﻟﺒﱰ ﻣﻦ اﻟﻴﻤﲔ . )ج( ﻋﻨﺪﻣﺎ t1 0, t 2 ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ اﻟﻨﺘﺎﺋﺞ اﳋﺎﺻﺔ ﺑﺎﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺔ واﺣﺪة ﰱ اﻟﻌﻴﻨﺔ اﻟﻜﺎﻣﻠﺔ .
) (٨اﻟﺗﻘدﯾر اﻟﺑﯾﯾ زى ﻟﻣﺗوﺳ ط اﻟﺣﯾ ﺎة وداﻟ ﺔ اﻟﺻ ﻼﺣﯾﺔ ﻟﻠﺗوزﯾ ﻊ اﻻﺳ ﻰ ﻓ ﻰ ﺣﺎﻟ ﺔ اﻟﻌﯾﻧ ﺔ اﻟﻣراﻗﺑﺔ ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ ﻣن ﺟﮭﺗﯾن ٤ﻗﺪم ﻫﺬا اﻟﺒﺤﺚ ﻣﻦ ﻗﺒﻞ ) Shalaby (1990وﻗﺪ ﰎ ﺗﻘﺪﳝﻪ ﺑﺸﻜﻞ ﻣﻔﺼﻞ ﻛﺎﻟﺘﺎﱃ : ٣٧
ﺑﻔﺮض ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nوﺿﻌﺖ ﻟﻼﺧﺘﺒﺎر ﲤﺜﻞ أزﻣﻨﺔ اﻟﻔﺸﻞ وان أزﻣﻨﺔ اﻟﻔﺸﻞ ﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻷﺳﻲ ﲟﻌﻠﻤﺔ وﻛﺎﻧﺖ اﻻﺣﺼﺎءات اﻟﱰﺗﻴﺒﻴﺔ ﻟﻠﻌﻴﻨﻪ اﻟﻌﺸﻮاﺋﻴﺔ ﻫﻰ Yn1 1 ,Yn1 2 ,...,Yn n 2وﺑﺎﻋﺘﺒﺎر أن y n1 1 yn1 2 ... y n n 2ﰎ اﳊﺼﻮل ﻋﻠﻴﻬﺎ ﺣﻴﺚ n1ﰎ ﲢﺪﻳﺪﻫﺎ ﻗﺒﻞ اﻟﺘﺠﺮﺑﺔ وﺑﺎﻟﺘﺎﱃ ﻓﺈن n1ﻣﻦ اﻟﻮﺣﺪات زﻣﻦ ﻓﺸﻠﻬﻤﺎ اﻗﻞ ﻣﻦ . y n1 1اﻳﻀﺎ n 2ﰎ ﲢﺪﻳﺪﻫﺎ ﻗﺒﻞ اﻟﺘﺠﺮﺑﺔ وﺑﺎﻟﺘﺎﱃ ﻓﺈن n 2ﻣﻦ اﻟﻮﺣﺪات ﺻﺎﳊﺔ ﻟﻠﻌﻤﻞ ﺑﻌﺪ اﻟﺰﻣﻦ . y n n 2اى ان ) (n n1 n 2ﺣﺴﺒﺖ
ازﻣﻨﺔ ﻓﺸﻠﻬﺎ .اﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ ﻟﻠﻤﻌﻠﻤﺔ . ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ داﻟﺔ اﻹﻣﻜﺎن ﻛﺎﻟﺘﺎﱄ: n! n n 2 L f (yi ) P(X y n11 ) n1 P(X y n n 2 ) n 2 n1 n 2 in11 n2
y n n2
n2
n1
e
yn1 1
y - i
- 1- e n n2 n y t1* 1 - i -ne in11 1- e
*
- t2 e
n1
n n 2
n! 1 e n1 n 2 in11
!n n1 n 2
- t1 -n -s e 1- e
!n n1 n 2
*
n
=
=
t 2 t1 n = e e e ,
ﺣﻴﺚ n 2 t *2 , n =n-n 1 -n 2 . :
s
=
n n2
i
y
* 2
* 1
t y n1 1 , t y n n 2 ,s
i n1 1
اﻟﻌﻴﻨﺔ اﳌﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱏ ﻣﻦ ﺟﺎﻧﺐ واﺣﺪ ﳓﺼﻞ ﻋﻠﻴﻬﺎ ﺑﻮﺿﻊ n1 0 or n 2 0
ﺑﻔﺮض أن اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻲ ﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ اﻟﻌﻜﺴﻲ :
; h, > 0 .
h h 1 () e )( 1
اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل ﻫﻮ :
٣٨
( | x)
L(x | )()
( | s).
L(x | )() d 0
f (x) L(x | ) () d 0
*
(s+h) t -1 n! h -1 -( +n) n1 = e (1-e ) d n1 n 2 (-1) 0 *
(s+h+jt1 ) n1 n! h -1 j -( +n) = (1) e d n1 n 2 (-1) j=0 j 0 n1 h+jt1* n! h -1 j -(n-1) = (1) (n-1)s (1 ),n = +n . j n1 n 2 (-1) j=0 s
: ﻫﻮ وﻋﻠﻰ ذﻟﻚ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل ( | s) k
-n
e
-
(s+h)
-
t1*
(1-e ) n1
n1 h+jt1* ( n-1 -(n-1) (k ) ( 1) (n -1)s (1 ) ) j s j=0 1
n1
n1
j
n1 ( 1) (n -1)s -(n -1) D (nj -1) , j j=0 j
h+jt1* 1 where D j (1 ) . s
: ﻫﻮs ﺑﺸﺮط ﻟﻠﻤﻌﻠﻤﺔm اﻟﻌﺰم اﻟﻼﻣﺮﻛﺰي ذو اﻟﺮﺗﺒﺔ
٣٩
` m
m
( | s) E( ) m ( | s) d 0
k
-(n-m)
e
-
(s+h)
-
t1* n1
(1-e ) d
0
n1
n1 =k (1) j (n-m-1)s -(n-m-1) D(nj -m-1) j j=0 n1
n1 (n-m-1) (1) j D j (n -m-1) m j=0 s n1 , n1 (n -1) j (n-1) (1) D j j j=0 m 1,2,... . m و ﳝﻜﻦ إﳚﺎد اﳌﺘﻮﺳﻂ و اﻟﺘﺒﺎﻳﻦ ﻣﻦ اﻟﻌﺰوم اﻟﻼﻣﺮﻛﺰﻳﺔ ذو اﻟﺮﺗﺒﺔ R(t ) وداﻟﺔ اﻟﺼﻼﺣﻴﺔ اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى ﻟﻜﻞ ﻣﻦ اﳌﻌﻠﻤﺔ j
: ﲢﺖ ﻓﺮض داﻟﺔ اﳋﺴﺎرة ﳌﺮﺑﻊ اﳋﻄﺄ ﻫﻮ* اﻟﺘﻘﺪﻳﺮ اﻟﺒﻴﻴﺰى n1
n1 (n-2) (1) D j s (n -2) j j=0 * ` E( | s) 1 ( | s) , n1 (n-1) n1 j (n-1) (1) D j j j=0 n1
j
n1 (n-3) (1) D j 2 s (n -3) j j=0 E(2 ) `2 ( | s) . n1 (n -1) n1 (1) j D(nj -1) j j=0
٤٠
j
Var() n1
n1 n1 n1 j (n-3) j (n-2) (1) j D j (1) j D j s 2 (n -3) j=0 s2 j=0 . n1 n1 n1 (n-1) ((n -1))2 n1 j n-1) j (n-1) (1) D j (1) j D j j j=0 j=0
2
2 n1 n1 n1 n1 j (n-3) j (n-2) (1) D j (1) j D j j s2 (n -3) j=0 j=0 . n1 n1 n1 (n -2)(n-3) n1 (n -2) (1) j D(nj -1) (1) j D(nj -1) j=0 j j j=0
اﳌﻨﻮال اﻟﺒﻌﺪى : ﳝﻜﻦ إﳚﺎدﻩ ﺑﺎﺷﺘﻘﺎق داﻟﺔ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪي ﻛﻤﺎ ﻳﻠﻲ اﳌﻨﻮال اﻟﺒﻌﺪي ( | s) k-n e ( | s) k
-n
e
-
(s+h)
-
-
(s+h)
-
t1* n1
(1-e )
t1*
(1-e )n1 .
d( | s) d t* (h+s) -1 - (h+s) -(n+1) -n (h+s) n1 (-n ) e (1-e ) e 2 k (h+s) t1* t1* * t1 -n n1 -1 e (n (1-e ) e ) . 1 2
٤١
*
*
*
(s h ) t t n s h n1 t1* t1 1 1 d( | s) n n1 1 0 e (1 e ) 2 2 e (1 e ) 0 d * 1 1
n s h n t (e
t1*
1) 1 0
*
t 1 1 * 1 s h n t (e 1) 1 1 n *
t 1 1 * s h n 1 t1 e . n
اﳌﻨﻮال اﻟﺒﻌﺪي . ﳝﻜﻦ إﳚﺎدﻩ ﲝﻞ اﳌﻌﺎدﻟﺔ اﻟﺴﺎﺑﻘﺔ ﺑﺎﺳﺘﺨﺪام اﳊﺎﺳﺐ اﻻﱃ R(t) اﳌﻘﺪر اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ
: ﲟﺎ ان
-
t
R(t) e , t1* < t<t *2
: ﺑﺈﺳﺘﺨﺪام داﻟﺔ ﺧﺴﺎرة ﻣﺮﺑﻊ اﳋﻄﺎ ﳝﻜﻦ اﳚﺎد اﳌﻘﺪر اﻟﺒﻴﻴﺰى ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ ﻛﺎﻟﺘﺎﱃ
٤٢
*
R (t 0 ) E[R (t)] R(t )( | s) d 0
k
-n
e
-
(t+s+h)
-
t1* n1
(1-e ) d
0
(t+s+h+jt * )
n1
n1 1 j -n k (1) e d j 0 j=0 n1 n1 k j = (1) (t +s+h+jt1* )-(n-1) (n -1) j=0 j -(n -1)
n1
* 1
k t+h+jt j -(n -1) ( 1) s 1 j (n-1) j=0 s n1
n1
n1 n-1 (1) E j 1 t+h+jt1* j j=0 n1 ,E j 1 . n1 s (1) j D nj -1 j j=0 j
: اﻳﻀﺎ ﳝﻜﻦ اﳚﺎد ﺗﺒﺎﻳﻦ داﻟﺔ اﻟﺼﻼﺣﻴﺔ ﰱ ﻫﺬﻩ اﳊﺎﻟﺔ ﻛﺎﻟﺘﺎﱃ
Var R(t) E(R(t) s) (E(R (t) s)) 2 .
٤٣
2
E[R (t)] R 2 (t)( | s) d 0
k -n e
-
(2t+s+h)
-
t1*
(1-e ) n1 d
0
n1
n1
-n k ( 1) j e j 0 j=0
-
(2t+s+h+jt1* )
-
t1*
(1-e ) n1 d
n1 n1 k (2t+h+jt 1* ) j -(n-1) ( 1) j s 1 s (n -1) j=0
n1
n1 2t+h+jt 1* j -(n -1) ( 1) s 1 s k j j=0 n1 n1 (n -1) j ( 1) D (nj -1) j j=0 n1
-(n -1)
-(n -1)
n1 n-1 ( 1) H j * 1 * 1 j t+h+jt 2t +h+jt j=0 1 1 n1 ,E 1 , H 1 j j . n1 s s j n -1 ( 1) D j j j=0 j
Var R(t ) E(R (t) s) (E(R (t) s)) 2 2
n1
n1 n1 n1 j n-1 j n-1 (1) H j (1) j E j j j=0 . j=0 n1 n n1 n1 1 j n-1 j n-1 ( 1) D ( 1) j j j Dj j=0 j=0
٤٤
ﻟﻠﻣﻌﻠﻣﺗ ﯾن ,
) (٩ﺗﻘ دﯾرات اﻻﻣﻛ ﺎن اﻻﻛﺑ ر اﻟﻛﺎﻣﻠﺔ
ﻟﻠﺗوزﯾ ﻊ اﻻﺳ ﻰ ﺑﻣﻌﻠﻣﺗ ﯾن ﻓ ﻰ ﺣﺎﻟ ﺔ اﻟﻌﯾﻧ ﺔ
ﺑﻔـﺮض ان X X1 ,X 2 ,..., X n ﻋﻴﻨــﺔ ﻋﺸـﻮاﺋﻴﺔ ﻣــﻦ اﳊﺠــﻢ nﻣــﻦ اﻟﻮﺣــﺪات ﳐﺘــﺎرة ﻣــﻦ ﺗﻮزﻳـﻊ ﻟــﻪ داﻟــﺔ ﻛﺜﺎﻓــﺔ اﻻﺣﺘﻤــﺎل اﻻﺳﻰ ﲟﻌﻠﻤﺘﲔ , واﻟﱴ ﺗﺎﺧﺬ اﻟﺸﻜﻞ اﻟﺘﺎﱃ :
, x ,
x
1 e
)f (x; ,
0 , e.w. ﺑﺎﻋﺘﺒﺎر أن y1 y 2 y nﰎ اﳊﺼﻮل ﻋﻠﻴﻬﺎ ﺣﻴﺚ y y1 , y 2 , , y nواﳌﻄﻠﻮب ﺗﻘﺪﻳﺮ اﳌﻌﺎﱂ . , ﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ داﻟﺔ اﻹﻣﻜﺎن ﻛﺎﻟﺘﺎﱄ:
yi ,
1 n ( y i ) i 1
,
1 e n
L
ﺑﻔــﺮض ان اﳌﻌﻠﻤــﺔ ﻣﻌﻠﻮﻣــﺔ ﲝﻴــﺚ ان 0واﳌ ـﺮاد ﺗﻌﻈــﻴﻢ داﻟــﺔ اﻻﻣﻜــﺎن .ﻳــﺘﻢ ذﻟــﻚ ﺑﺘﺼــﻐﲑ )
n i
(y i 1
ﻋﻨﺪﻣﺎ ﻳﻜﻮن ﻟـ أﻛﱪ ﻗﻴﻤﺔ وﺣﻴﺚ إن: y1 , y 2 , , y n .
وﻟﺬﻟﻚ ﻓﺈن اﳌﻘﺪر ﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ: ˆ M in(X1 ,X 2 , ,X n ) Y1 . وﻫﺬا ﻳﻌﲎ ان ˆ ﻣﺴﺘﻘﻞ ﻋﻦ 0وﺑﺎﻟﺘﺎﱃ ﻋﻦ .
اﻻن داﻟﺔ اﻻﻣﻜﺎن ﺗﺼﺒﺢ :
n
1
1 ( yi y1 ) L n e i 1 .
ﻣﻘﺪر اﻹﻣﻜﺎن ﻟﻠﻤﻌﻠﻤﺔ ﻫﻮ اﳊﻞ ﻟﻠﻤﻌﺎدﻟﺔ : ln L 0 ˆ
٤٥
وذﻟ ــﻚ
then : n
) y1
i
(y i 1
.
ln L = - n ln -
n
) (yi y1 ln L n i 1 . 2
ln L ﺑﻮﺿﻊ 0 ˆ
ﻓﺎن : ) n (yi y1 0 ˆ ˆ 2 n
) y1
i
(y i 1
.
ˆ 2
n ˆ n
) y1 .
i
(y i 1
n
ˆ
وﺑﺎﻟﺘﺎﱃ ﻓﺈن ﻣﻘﺪرات اﻻﻣﻜﺎن ﻟﻠﻤﻌﻠﻤﺘﲔ , ﳘﺎ : 1 n ˆ Y1 , ˆ (Yi Y1 ) X Y1. n i 1
اﳌﻘﺪرﻳﻦ ˆ ˆ , ﻣﺴﺘﻘﻠﲔ ﻻن ˆ , ﻣﺴﺘﻘﻠﲔ اى ان اﻟﺘﻐﺎﻳﺮ ﺑﻴﻨﻬﻤﺎ ﻳﺴﺎوى ﺻﻔﺮ اى ان . Cov(ˆ , ˆ ) 0 اﻻن ﻳﺘﻢ دراﺳﺔ اﻟﺘﻮزﻳﻊ اﳌﻀﺒﻮط ﻟﻜﻞ ﻣﻦ اﳌﻘﺪرﻳﻦ. داﻟﺔ اﻟﻜﺜﺎﻓﺔ اﻻﺣﺘﻤﺎﻟﻴﺔ اﳌﺸﱰﻛﺔ ﻟﻺﺣﺼﺎءات اﻟﱰﺗﻴﺒﻴﺔ ﰲ اﻟﻌﻴﻨﺔ ﺗﻌﻄﻰ ﻛﺎﻟﺘﺎﱄ: ) g(y1 , y 2 ,..., y n ) n!f (y1 )f (y 2 )f (y n
n
1
( yi ) n! i 1 ne . ; y1 y 2 y n . ﻧﻌﺘﱪ اﻟﺘﺤﻮﻳﻠﺔ اﻷﺣﺎدﻳﺔ: Z1 n (Y1 Y0 ),Y0 ,
) Z2 (n 1)(Y2 Y1 ) Z3 (n 2)(Y3 Y2 Zi (n i 1)(Yi Yi1 ) , i 1,2,...,n , Y0 0 واﻟﺘﺤﻮﻳﻠﺔ اﻟﻌﻜﺴﻴﺔ ﳍﺎ ﻫﻲ: ٤٦
Yi
Z1 Z Zi 2 ... , i 1,2,,n, n n 1 n i 1 :وﻣﻨﻬﺎ ﻧﻮﺟﺪ ﺟﺎﻛﻮﺑﻴﺎن اﻟﺘﺤﻮﻳﻞ ﻛﺎﻟﺘﺎﱄ
y1 z1
y1 z 2
y1 z n
y 2 J z1
y 2 z 2
y 2 z n
y n z1
y n z 2
1 n 1 n 1 n
y n z n
0
0
1 0 1 . n 1 n! 1 1 n 1 : ﺳﻮف ﻧﺜﺒﺖ ان
n
n
Z (Y ). i
i
i 1
i 1
: ﲟﺎ ان Z1 n(Y1 ) nY1 n
(٣-٥) : اﻻن n
n
(Y ) Y n. i
i
i 1
i 1
: ( ﻓﺈن٣-٥) ﺑﻘﻴﻤﺘﻬﺎ ﰱn وﺑﺎﻟﺘﻌﻮﺋﺾ ﻋﻦ n
n
n
(Y ) Y Z i
i 1
i
1
nY1 Yi nY1 Z1
i 1
i 1
n
n
n
n
(Yi Y1 ) Z1 (Yi Y1 ) Z1 Zi Z1 Zi . i 1
i2
i 2
i 1
:( ﺗﻌﻄﻰ ﻛﺎﻟﺘﺎﱄi 1,2,,n) وZ i وﻋﻠﻰ ذﻟﻚ داﻟﺔ ﻛﺜﺎﻓﺔ اﻻﺣﺘﻤﺎل اﳌﺸﱰﻛﺔ ﻟـ n
zi
1 [ i 1 ] e n n 1 [ zi ] e i 1
h(z1 ,z 2 ,...,z n )
, 0 z i ,
0 , e.w. . ﻣﺘﻐﲑات ﻋﺸﻮاﺋﻴﺔ ﻣﺴﺘﻘﻠﺔ وﻣﺘﻄﺎﺑﻘﺔ وﻛﻞ ﻣﻨﻬﺎ ﻳﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻲ ﺑﺎﳌﻌﻠﻤﺔZ i ﳑﺎ ﻳﻌﲏ إن اﳌﺘﻐﲑات
٤٧
ﲟﺎ إن : n
n
n
Z Y (n 1)Y (Y Y ), 1
1
i
i
i
i 2
i2
i2
اى ان :
1 n 1 n 1 n ˆ (Yi Y1 ) (Yi Y1 ) Zi . n i1 n i2 n i2 اﻟﺪاﻟﺔ اﳌﻮﻟﺪة ﻟﻠﻌﺰوم ﻟﻼﺣﺼﺎء ˆ ﻫﻰ : )t (n 1 ) . n
(t) (1
n
Zi i=2
Mˆ (t) M
n
n
واﻟﱴ ﲤﺜﻞ اﻟﺪاﻟﺔ اﳌﻮﻟﺪة ﻟﻠﻌﺰوم ﳌﺘﻐﲑ ﻋﺸﻮاﺋﻰ ﻳﺘﺒﻊ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ ﲟﻌﺎﱂ ) . ( , n 1وذﻟﻚ ﻻن : اﳌﺘﻐﲑات Zi ,i 1,2,...n 1ﻣﺘﻐﲑات ﻋﺸﻮاﺋﻴﺔ ﻣﺴﺘﻘﻠﺔ وﻣﺘﻄﺎﺑﻘﺔ وﻛﻞ ﻣﻨﻬﺎ ﻳﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻲ ﺑﺎﳌﻌﻠﻤﺔ . n
اﻟﺪاﻟﺔ اﳌﻮﻟﺪة ﻟﻠﻌﺰوم ﻟﻠﻤﻘﺪر Ziﻫﻰ : i2
.
اى ان ﺗﻮزﻳﻊ
n i
Z i2
) (n 1
)M n (t) (1 t Zi i=2
ﻳﺘﺒﻊ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ ﲟﻌﻠﻤﺘﲔ ). ,(n 1
وذﻟﻚ ﻻن اﳌﺘﻐﲑات Zi ,i 1,2,...n 1ﻣﺘﻐﲑات ﻋﺸﻮاﺋﻴﺔ ﻣﺴﺘﻘﻠﺔ وﻣﺘﻄﺎﺑﻘﺔ وﻛﻞ ﻣﻨﻬﺎ ﻳﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻲ ﺑﺎﳌﻌﻠﻤﺔ . اﻻن : ˆ Y1
ﺣﻴﺚ Y1اﻟﱰﺗﻴﺐ اﻻﺣﺼﺎء اﻻﺻﻐﺮوﳝﻜﻦ اﳊﺼﻮل ﻋﻠﻰ ﺗﻮزﻳﻌﺔ ﻣﻦ اﻟﺼﻴﻐﺔ اﻟﺘﺎﻟﻴﺔ :
n f (y1 ) 1 F(y1 )n 1 , 0 y1 , g1 (y1 ) , e.w. 0 n
اى ان Y1ﻳﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺘﲔ . , اﻻن : Z1 1 ) E(Z1 ) . n n n
٤٨
(E(ˆ ) E
: اﻳﻀﺎ. ﻣﻘﺪر ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔˆ اى ان Z1 1 2 ) 2 Var(Z1 ) 2 . n n n n n 1 1 n 1 E(ˆ ) E( Zi ) E(Zi ) . n i 2 n i 2 n
Var(ˆ ) Var(
: اﻳﻀﺎ. ﻣﻘﺪر ﻣﺘﺤﻴﺰ ﻟﻠﻤﻌﻠﻤﺔˆ اى ان Var(ˆ ) Var(
1 n 1 Zi ) 2 n i 2 n
n
Var(Z ) i
i2
n 1 2 . n2
: ﻣﻘﺪرﻳﻦ ﻣﺘﺤﻴﺰﻳﻦ ﻓﻴﻤﻜﻦ اﳊﺼﻮل ﻣﻨﻬﻤﺎ ﻋﻠﻰ ﻣﻘﺪرﻳﻦ ﻏﲑ ﻣﺘﺤﻴﺰﻳﻦ ﻛﺎﻟﺘﺎﱃˆ , ˆ ﲟﺎ ان اﳌﻘﺪران n ˆ n 1 n (Y Y1 ), ˆ Y1 { [ (Y Y1 )]} n 1 n 1 n 1 n n 1 1 nY Y Y1 [ (Y Y1 )] 1 . n 1 n 1
: اى ان
n nY Y (Y Y1 ), 1 . n 1 n 1 E( )
n n n 1 n2 n 1 E( ) . , Var( ) . 2 2 2 n 1 n 1 n (n 1) n
2 , n 1
1 E( ) E(ˆ ) E( ) , n n n 1 2 1 2 2 1 Var( ) Var(ˆ ) 2 Var() 2 2 2 (1 ). n n n n 1 n n 1
: اﻻن ﻻﺛﺒﺎت ﻫﻞ اﳌﻘﺪرﻳﻦ ﻣﺴﺘﻘﻠﲔ ام ﻻ ﻧﺘﺒﻊ اﻻﺗﻰ
ˆ nˆ ˆ nˆ Cov( , ) Cov(ˆ , ) Cov( , ) n 1 n 1 n 1 n 1 n n n (n 1)2 ˆ ˆ ˆ Cov(, ) Var() . (n 1)2 (n 1)2 (n 1) 2 n2 2 . n(n 1)
. ﻏﲑ ﻣﺴﺘﻘﻠﲔˆ , ˆ اى ان اﳌﻘﺪران
٤٩
n
اﻻن ﺳﻮف ﻧﺜﺒﺖ ان } { (Yi Y1 ), Y1اﺣﺼﺎءات ﻛﺎﻓﻴﺔ ﻟﻠﻤﻌﻠﻤﺘﲔ ) ˆ. (ˆ , ﻧﻔﺮض ان : i 2
n
) . U Y1 , V (Yi Y1وﲟﺎ ان ) ˆ (ˆ , ﻣﺴﺘﻘﻠﲔ ﻓﺈن اى دوال ﻓﻴﻬﻤﺎ ﻣﺴﺘﻘﻠﲔ .اى ان ) (U, Vﻣﺴﺘﻘﻠﲔ اﻳﻀﺎ .ﲟﺎ i 2
ان U Y1ﻳﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺘﲔ , n
ﺣﻴﺚ داﻟﺔ ﻛﺜﺎﻓﺘﻪ اﻻﺣﺘﻤﺎﻟﻴﺔ ﺗﺎﺧﺬ اﻟﺸﻜﻞ اﻟﺘﺎﱃ :
n u
, u ,
n e
)g1 (u; , 0
, e.w. وﲟﺎ ان : n
n
V (Yi Y1 ) Zi i 2
i 2
اى ان Vﺗﺘﺒﻊ ﺗﻮزﻳﻊ ﺟﺎﻣﺎ ﲟﻌﻠﻤﺘﲔ ، , n 1ﺣﻴﺚ داﻟﺔ ﻛﺜﺎﻓﺘﻪ اﻻﺣﺘﻤﺎﻟﻴﺔ ﺗﺎﺧﺬ اﻟﺸﻜﻞ اﻟﺘﺎﱃ :
v 1 n 2 g 2 (v ;)= n-1 v e ) (n 1
, v > 0.
اى ان اﻟﺘﻮزﻳﻊ اﳌﺸﱰك ﻟﻠﻤﺘﻐﲑﻳﻦ ) (V, Uﻫﻮ :
, v > 0,u>.
n u
v 1 n2 v e )n-1(n 1
n
g (u,v) e
وﺑﺎﺳﺘﺨﺪام اﻻﺣﺘﻤﺎل اﻟﺸﺮﻃﻲ:
n
1
( yi ) 1 i1 e v
1 v n 2e n-1 ) (n 1
n u
٥٠
e
n
)L(y; )g(u, v
h(y, u, v)
n
e
1 n ( yi ) i 1
v n u
n n v n 2 e (n 1)
(n 1) e n vn2
(
yi v n nu n)
n ( yi v nu) (n 1) exp i 1 n vn2 N ( yi v ny1 ) ( n 2) (n 1)v exp i 1 n
n [ (yi y1 ) v] ( n 2) (n 1)v exp i 2 n n n [ (y y ) (yi y1 )] ( n 2) i 1 (n 1)v i2 exp i 1 n (n 1)v ( n 2) . n n
{ اﺣﺼﺎءات ﻛﺎﻓﻴﺔ ﻣﺸﱰﻛﺔ (Yi Y1 ), Y1} اى ان. ﺑﻞ داﻟﺔ ﻓﻘﻂ ﰱ اﳌﺸﺎﻫﺪات, وﻫﺬﻩ اﻟﻨﺴﺒﺔ ﻻ ﺗﻌﺘﻤﺪ ﻋﻠﻰ i 2
. , ﻟﻠﻤﻌﻠﻤﺘﲔ : ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﻣﻘﺪر ﳌﺘﻮﺳﻂ اﻟﺘﻮزﻳﻊ ﻧﺘﺒﻊ اﻻﺗﻰ : ﲟﺎ ان nˆ ˆ ˆ , ˆ , Y Y1 , ˆ Y1 , n 1 n 1
: وﲟﺎ ان E(X) ,
: وﻋﻠﻰ ذﻟﻚ ﻣﻘﺪر اﻻﻣﻜﺎن اﻻﻋﻈﻢ ﳌﺘﻮﺳﻂ اﻟﺘﻮزﻳﻊ ﻫﻮ ˆ ˆ Y1 Y Y1 Y. ٥١
اﳌﻘﺪر ﳌﺘﻮﺳﻂ اﻟﺘﻮزﻳﻊ اﻟﻐﲑ ﻣﺘﺤﻴﺰ ﻫﻮ : ˆ ˆn ˆ ˆ ˆ ˆ (n 1) ˆ ˆ Y. n 1 n 1 n 1 1 ﻟﺪاﻟﺔ اﻟﺼﻼﺣﻴﺔ R(t) exp (t ) , t ﻓﺈن اﳌﻘﺪر اﻟﺬى ﻳﻌﺘﻤﺪ ﻋﻠﻰ ﻣﻘﺪرات اﳌﻜﺎن اﻻﻋﻈﻢ ﻫﻮ :
t Y1 R(t) exp , t Y1. Y Y1
) (١٠ﺗﻘدﯾرات ﺑﯾﯾزﯾﺔ ﻟﻣﻌﺎﻟم اﻟﺗوزﯾﻊ اﻻﺳﻰ ﺑﻣﻌﻠﻣﺗﯾن وداﻟ ﺔ اﻟﺻ ﻼﺣﯾﺔ ﻓ ﻰ ﺣﺎﻟ ﺔ اﻟﻣﻌﺎﯾﻧ ﺔ ﻣن اﻟﻧوع اﻟﺛﺎﻧﻰ ٤ إذا ﻛﺎن ﻟﺪﻳﻨﺎ اﺧﺘﺒﺎر اﳊﻴﺎة ﻣﻦ ﻋﻴﻨﺔ ﻣﺮاﻗﺒﺔ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﱐ وﺑﻔﺮض ان y1 y 2 y rﻫﻰ ال rاﻻوﱃ ﻣﻦ اﳌﺸﺎﻫﺪات اﳌﺮﺗﺒﺔ واﳌﺎﺧﻮذة ﻣﻦ ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ اﳊﺠﻢ nﺗﺘﺒﻊ اﻟﺘﻮزﻳﻊ اﻻﺳﻰ ﲟﻌﻠﻤﺘﲔ , ﻋﻠﻰ اﻟﺸﻜﻞ اﻟﺘﺎﱃ:
, x ,
x
1 e
)f (x; , 0
, e.w.
وﺑﺎﻋﺘﺒﺎر ان y y1 , y 2 , , y rﰎ اﳊﺼﻮل ﻋﻠﻴﻬﺎ واﳌﻄﻠﻮب اﳚﺎد ﺗﻘﺪﻳﺮ ﻟﻠﻤﻌﺎﱂ . , داﻟﺔ اﻹﻣﻜﺎن ﺗﻌﻄﻰ ﻛﺎﻵﰐ :
:اﯾﺠﺎد ﻣﻘﺪرات ﺑﯿﯿﺰ ﺗﺤﺖ ﻓﺮض اﻟﺘﻮزﯾﻊ اﻷﺳﻲ ﺑﻤﻌﻠﻤﺘﯿﻦ: r
1
r
n! 1 y n r y L y , e . n r ! i
r
i 1
اﻻن :
٥٢
r
y i 1
r
n r y r y i r n r y r n r i i 1
r
yi n n r y r [ry1 ry1 ny1 i 1
ny1 ] r y i ry1 n r y r n r y1 i 1 ny1 n r
y i y1 n r y r y1 n y1 . i 1
r
let s yi y1 n r y r y1
;k
i 1
n! n r !
k 1s n y L y , r e . : , ﲢﺖ ﻓﺮض اﻟﺘﻮزﻳﻊ اﻟﻘﺒﻠﻰ اﻟﺘﺎﱃ ل
g ,
1 a
1
;a, 0 , y1 .
: ﻫﻮ, وﻋﻠﻰ ذﻟﻚ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل
, y
k y1
k
a r
a r
e
e
1 s n y1
1 s n y1
. dd
0
: ﺣﻴﺚ
٥٣
y1
k
1
1 a r exp 0 s n y1 dd y1
s n y
1
a r 1
a r 1 d
y1
a r 1 s n y1
a r 1
d
y a r 2 a r 1 s n y . 1 n a r 2 1
a r 1 a r 2 a r 2 k
1
a r2 ns a r 2
, x k
ns a r 2 k ar2
a r
e
1 s n y1
.
اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل The marginal posterior of : ﻟـ
1 y , y d 0
k
a r
e
1 s n y1
d
0
k s n y1
a r 1
a r 1
a r 1 ns a r 2 s n y1 a r 2 a r 2 ar2 n a r 2 s a r 2 a r 1 . s n y1
y1
E y d
n a r 2s
a r 2
y1
s n y
٥٤
1
a r 1
d.
let u du d
dv s n y1 v
a r 1
a r 2 1 s n y1 n a r 2
y a r 2 n a r 2 sa r 2 s n y1 n a r 2 y a r 2 1 s n y1 n a r 2 1
1
1 sa r 2 s a r 2 y1 s a r 3 n a r 3 s y1 . n a r 3
The Marginal y1
y , y d
k
a r
y1
e
1 s n y1
d
1
k
a r
s n y e n
y1
1
k a r 1 ns e n s a r 2 a r 1 ns e ar2
s a r 2 a r 2 s e d ar20 s a r 2 a r 3 s a r3 ar2 a r3 s s . ar2 a r 2
٥٥
, 0.
دى ﻟـ اﻟﺘﻮزﻳﻊ اﻟﺒﻌﺪى ل :
s , n a r 3 s . a r3
y1
٥٦
٥٧
اﻟﻤﺮاﺟﻊ
اﻟﻤﺮاﺟﻊ اﻟﻌﺮﺑﯿﺔ :
o
-١أﺣﻣد ﻋودة ، (١٩٩١) ،ﻣﻘدﻣﺔ ﻓﻲ اﻟﻧظرﯾﺔ اﻹﺣﺻﺎﺋﯾﺔ – ﺟﺎﻣﻌﺔ اﻟﻣﻠك ﺳﻌود -ﻋﻣﺎدة ﺷؤون اﻟﻣﻛﺗﺑﺎت .
o o
-٢أﻣﯾر ﺣﻧﺎ ﻫرﻣز ، (١٩٩٠) ،اﻹﺣﺻﺎء اﻟرﯾﺎﺿﻲ – ﻣدﯾرﯾﺔ دار اﻟﻛﺗب ﻟﻠطﺑﺎﻋﺔ واﻟﻧﺷر – اﻟﺟﻣﻬورﯾﺔ اﻟﻌراﻗﯾﺔ – اﻟﻣوﺻل .
o o
-٣ﺛروت ﻣﺣﻣد ﻋﺑد اﻟﻣﻧﻌم ، (٢٠٠٠) ،ﻧظرﯾﺔ اﻻﺣﺗﻣﺎﻻت – اﻟطﺑﻌﺔ اﻟﺛﺎﻧﯾﺔ -ﻣﻛﺗﺑﺔ اﻟﻣﺗﻧﺑﻰ – اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
o o
-٤ﺛروت ﻣﺣﻣد ﻋﺑد اﻟﻣﻧﻌم ، (٢٠٠٨) ،ﻣدﺧل ﺣدﯾث ﻟﻺﺣﺻﺎء واﻻﺣﺗﻣﺎﻻت – اﻟطﺑﻌﺔ اﻟﺛﺎﻟﺛﺔ
o o
-٥ﺛروت ﻣﺣﻣد ﻋﺑد اﻟﻣﻧﻌم ، (٢٠٠٩) ،اﻟﻣدﺧل اﻟﺣدﯾث ﻟﻺﺣﺻﺎء واﻻﺣﺗﻣﺎﻻت ﻣﻊ اﻟﺣﻠول ل
– ﻣﻛﺗﺑﺔ اﻟﻌﺑﯾﻛﺎن – اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
٧٠٨ﻣﺳﺎﻟﺔ -اﻟطﺑﻌﺔ اﻻوﻟﻰ– ﻣﻛﺗﺑﺔ اﻟﻣﺗﻧﺑﻰ -اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
o o
-٦ﺛروت ﻣﺣﻣد ﻋﺑد اﻟﻣﻧﻌم ، (٢٠١٠) ،ﻧظرﯾﺔ اﻻﺣﺗﻣﺎﻻت ﻣﻊ اﻟﺣﻠول ﻟﺣواﻟﻰ ١٠٣٥ ﻣﺳﺎﻟﺔ– اﻟطﺑﻌﺔ اﻻوﻟﻰ -ﻣﻛﺗﺑﺔ اﻟﻣﺗﻧﺑﻲ – اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
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-٦ﺟﻼل اﻟﺻﯾﺎد ، (١٩٨٨) ،ﻧظرﯾﺔ اﻻﺣﺗﻣﺎﻻت – اﻟطﺑﻌﺔ اﻟﺛﺎﻧﯾﺔ – دار اﻟﺷروق – ﺟدة –
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-٧ﺟﻼل اﻟﺻﯾﺎد ، (١٩٩٣) ،اﻻﺳﺗدﻻل اﻻﺣﺻﺎﺋﻰ – اﻟطﺑﻌﺔ اﻻوﻟﻰ -دار اﻟﻣرﯾﺦ ﻟﻠﻧﺷر –
اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
اﻟرﯾﺎض– اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ .
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o
-٨ﺳﻠﯾم ذﯾﺎب اﻟﺳﻌدي ، (١٩٨٣) ،طرق اﻹﺣﺻﺎء – اﻟﺟﻣﻬورﯾﺔ اﻟﻌراﻗﯾﺔ – و ازرة اﻟﺗﻌﻠﯾم اﻟﻌﺎﻟﻲ واﻟﺑﺣث اﻟﻌﻠﻣﻲ .
o o
-٩ﻋﻠﻲ ﻋﺑد اﻟﺳﻼم اﻟﻌﻣﺎوي وﻋﻠﻲ ﺣﺳﯾن اﻟﻌﺟﯾﻠﻲ ، (١٩٩٨) ،أﺳﺎﺳﯾﺎت اﻻﺣﺻﺎء اﻟرﯾﺎﺿﻲ – إدارة اﻟﻣطﺑوﻋﺎت واﻟﻧﺷر – ﺟﺎﻣﻌﺔ اﻟﻔﺎﺗﺢ .
-١٠ oﻋﺒﺪ اﻟﺤﻔﯿﻆ ﻣﺤﻤﺪ ﻓﻮزي ﻣﺼﻄﻔﻰ ‘)٢٠٠٠أ ( ،اﻻﺳﺘﺪﻻل اﻻﺣﺼﺎﺋﻲ ) ( ١ﻧﻈﺮﯾﺔ اﻟﺘﻘﺪﯾﺮ ،ﻣﺠﻤﻮﻋﺔ اﻟﻨﯿﻞ اﻟﻌﺮﺑﯿﺔ -اﻟﻘﺎھﺮة – ﻣﺪﯾﻨﺔ ﻧﺼﺮ . o -١١ oﻋﺒﺪ اﻟﺤﻔﯿﻆ ﻣﺤﻤﺪ ﻓﻮزي ﻣﺼﻄﻔﻰ ٢٠٠٠) ،ب ( ،اﻻﺳﺘﺪﻻل اﻻﺣﺼﺎﺋﻲ ) ( ٢ﻧﻈﺮﯾﺔ اﻟﺘﻘﺪﯾﺮ ،ﻣﺠﻤﻮﻋﺔ اﻟﻨﯿﻞ اﻟﻌﺮﺑﯿﺔ -اﻟﻘﺎھﺮة – ﻣﺪﯾﻨﺔ ﻧﺼﺮ .
o o
-١٢ﻣﺣﻣد إﺑراﻫﯾم ﻋﻘﯾل و ﻋﺑد اﻟرﺣﻣن ﻣﺣﻣد أﺑو ﻋﻣﻪ ، (٢٠٠٠)،ﻧظرﯾﺔ اﻻﺣﺗﻣﺎﻻت و ﺗطﺑﯾﻘﺎﺗﻬﺎ – اﻟﻧﺷر اﻟﻌﻠﻣﻲ و اﻟﻣطﺎﺑﻊ – ﺟﺎﻣﻌﺔ اﻟﻣﻠك ﺳﻌود – اﻟﻣﻣﻠﻛﺔ اﻟﻌرﺑﯾﺔ اﻟﺳﻌودﯾﺔ.
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