31 8
2011 8
Systems Engineering — Theory & Practice
Vol.31, No.8
Aug., 2011
: 1000-6788(2011)08-1532-07
: N941.5
: A
1, 1, 1, 2
(1. , 210016; 2. , 321004)
!"#%"#&’*., / 234
78 , : ;<=>23 74@A. BCD, F G B
JKL<=>MN., OPQ, ;FKLJMN R4S, VXY
[\ R4. _‘abde Æ# f ibj .
" 23 ; 78 ; MN; 4
Recursive solution to unbiased grey model and its optimization
SHI Bin1, LIU Si-feng1, DANG Yao-guo1, WANG Zheng-xin2
(1. College of Economics and Management, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. School of Economics and Management, Zhejiang Normal University, Jinhua 321004, China)
Abstract As there are some jumping errors from the differential equation to differential equation in
traditional grey modeling, this paper proposed recursive solution to unbiased grey model based on the
unique expression of such models. It deduced prediction formulas of unbiased grey model under different
initial conditions with the recursive method. On this basis, further study of the optimization problem
under two criteria has been done. The results show that both the optimal models under the same criteria
have the same simulation and prediction values with higher precision than other methods. Finally, the
effectiveness and the practicality of the model are proved by a real project.
Keywords unbiased grey model; recursive solution; optimization; forecast
1 #$
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. 20 80 [1]
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. [4] ’ GM(1,1) ’01,2, * + GM(1,1) , ,’"+0
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Æ*%2, 2/"%/. , :".’ GM(1,1) 1
0 + [5−6], 4 GM(1,1) -SSODMM[7] GM(1,1) -SOB[8]SSODW-GM(1,1)[9] GM
(1, 1) -WELCP[10]5 [11] "%1( GM (1, 1) [12−13], ’+0
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GM(1,1) 1N . . [1] *0*, GM(1,1) 1N O “”,
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BHS2*:. I2, Æ + GM(1,1) A
0 , * +JMM, $ T +JMK , L, M
NN&UT1.
2 <=?@ABCEF
O X (0) N1,
+P1,
k
i=1 x(0)(i).
*, x(1)(k) =
X (0) = {x(0)(1), x(0)(2),··· , x(0)(n)},
X (1) = {x(1)(1), x(1)(2),··· , x(1)(n)},
. [5–6] , )" + GM(1,1) 2T :
x(1)(k) = e−ax(1)(k − 1) +
b
a(1 − e−a), k = 2, 3,··· , n
(1)
*, −a 4W, b ’.
MR β1 = e−a, β2 = b
a(1 − e−a), (1) AP:
(2)
, + (U BGM). *RB, ˆβ = (β1, β2)T K %
x(1)(k) = β1x(1)(k − 1) + β2, k = 2, 3,··· , n
ST6%B.
R ˆβ = (β1, β2)T +X, U +%STB
*,
⎡
⎢⎢⎢⎢⎣
Y =
ˆβ = (BTB)
⎤
⎥⎥⎥⎥⎦ , B =
−1BTY
⎡
⎢⎢⎢⎢⎣
x(1)(1)
x(1)(2)
1
1
...
x(1)(n − 1) 1
...
x(0)(2)
x(0)(3)
...
x(0)(n)
(3)
⎤
⎥⎥⎥⎥⎦ .
I XY-HS2, T L JMKM* +
K .
(U BGM − x(1)(1)) M:
GH 1 O BY ˆβ 4%I, ˆβ = (BTB)−1BTY , ( ˆx(1)(1) = x(1)(1), U +
⎧⎨
⎩ βk−1
x(1)(1) +
1
x(1)(1) + kβ2,
(β1 − 1)βk−2
β2,
1
1 − βk−1
1 − β1
1
· β2,
x(1)(1) + β2βk−2
1
1) ˆx(1)(k) =
2) ˆx(0)(k) =
*, k = 2, 3,··· , n.
IJ 1) (2) * k = 2, 3,· · ·, n, "
x(1)(2) = β1x(1)(1) + β2
x(1)(3) = β1x(1)(2) + β2
...
x(1)(n) = β1x(1)(n − 1) + β2
β1 = 1
β1 = 1
β1 = 1
β1 = 1
,
(4)
(5)
(6)
1534
D C U V E S
31
L ˆx(1)(j − 1) Z+J ˆx(1)(j), j = 2, 3,··· , k, :
ˆx(1)(k) = β1ˆx(1)(k − 1) + β2
= β1[β1ˆx(1)(k − 2) + β2] + β2
...
= βk−1
ˆx(1)(1) + (βk−2
1 + βk−3
1
1 + ··· + β1 + 1)β2
ˆx(1)(k) = βk−1
1
ˆx(1)(1) +
1 − βk−1
1 − β1
1
· β2
W β1 = 1 ,
W β1 = 1 ,
(7)
(8)
(9)
(10)
(11)
(12)
(14)
(15)
ˆx(1)(k) = ˆx(1)(1) + kβ2
( ˆx(1)(1) = x(1)(1), ˆx(1)(k) K :
1 − βk−1
1 − β1
⎧⎨
⎩ βk−1
2) ’ ˆx(1)(k) ’+TU6:
W β1 = 1 ,
x(1)(1) +
1
x(1)(1) + kβ2,
ˆx(1)(k) =
1
· β2,
β1 = 1,
β1 = 1,
k = 2, 3,··· , n
ˆx(0)(k) = ˆx(1)(k) − ˆx(1)(k − 1)
ˆx(1)(1) − βk−2
1
ˆx(1)(1) +
1
= βk−1
= (β1 − 1)βk−2
= (β1 − 1)βk−2
1
1
β2
ˆx(1)(1) +
1 − β1
ˆx(1)(1) + β2βk−2
1
· β2 − 1 − βk−2
1 − β1
1
· β2
1
1 − βk−1
1 − β1
· (βk−2
1 − βk−1
1
)
W β1 = 1 ,
ˆx(0)(k) = ˆx(1)(k) − ˆx(1)(k − 1) = β2
( ˆx(1)(1) = x(1)(1), +K :
x(1)(1) + β2βk−2
,
ˆx(0)(k) =
(13)
GH 2 O BY ˆβ 4%I, ˆβ = (BTB)−1BTY , : “ L6”, ( ˆx(1)(n) =
1
β1 = 1,
β1 = 1,
k = 2, 3,· · ·, n
(β1 − 1)βk−2
β2,
1
x(1)(n), U + (U BGM − x(1)(n)) M:
1)
ˆx(1)(k) =
1
x(1)(n) +
⎧⎨
⎩ βk−n
x(1)(n) + (k − n)β2,
(β1 − 1)βk−n−1
β2,
1
1 − βk−n
1 − β1
1
· β2, β1 = 1
β1 = 1
x(1)(n) + β2βk−n−1
1
,
β1 = 1
β1 = 1
2)
ˆx(0)(k) =
*, k = 2, 3,··· , n.
IJ X 1 , .
#NY*JMVA0 W*, +K ZX β1, β2 -(
x(1)(1)x(1)(n), [\$ (LKN%0. L, ZT’I
%1.
3 <=?@ABL
RIN U BGM − x(1)(1)U BGM − x(1)(n) ( ˆx(1)(1) = c1, ˆx(1)(n) = cn.
YTN&U R c1, cn.
8
;, : HEDBIÆ?F@H
1535
O[ c1, cn, 61,ZP]1,0(2Z-%ST#^T%,
&UT, :
n
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
c1 =
k=2
n
k−1
1
1−β1
β2(k−1)
[x(1)(k)− 1−β
n
k=2
x(1)(k)
n−1 + ( n
1
k=2
n
t=2
min
c
S2
1 =
·β2]βk−1
1
, β1 = 1,
[x(1)(t) − ˆx(1)(t)]2
(16)
n
k=2
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
cn =
k−n
1
n
[x(1)(k)− 1−β
n
1−β1
β2(k−n)
k=2
x(1)(k)
n−1 + ( n
1
k=2
·β2]βk−n
1
, β1 = 1,
2 + 1)β2, β1 = 1,
2 + 1)β2, β1 = 1.
, ,JMK ˆx(0)(k)|c1 ˆx(0)(k)|cn, U ˆx(0)(k)|c1 = ˆx(0)(k)|cn.
[.
GH 3 &UT, O U BGM − x(1)(1)U BGM − x(1)(n) ( ˆx(1)(1) = c1, ˆx(1)(n) = cn
IJ W β1 = 1 , ˆx(0)(k)|c1 = ˆx(0)(k)|cn PH].
W β1 = 1 ,
ˆx(0)(k)|c1 = (β1 − 1)βk−2
n
1
· β2] · βk−1
1
+ β2 · βk−2
1
x(1)(k) · βk−1
(1 − βk−1
1
) · βk−1
1 + β2
n
k=2
β2(k−1)
1
(β1 − 1)
=
=
=
(β1 − 1)
(β1 − 1)
k=2
n
k=2
n
k=2
n
k=2
1
1
k=2
n
[x(1)(k) − 1−βk−1
1−β1
β2(k−1)
n
n
β2(k−1)
n
1 + β2
k=2
k=2
1
1 + β2
βk−1
1
x(1)(k) · βk−1
n
β2(k−1)
1
k=2
x(1)(k) · βk
n
n
β2k
1
k=2
1 + β2
k=2
n
k=2
βk
1
· βk−2
1
· βk−1
1
,
· β2] · βk−n
1
1
1
k=2
n
[x(1)(k) − 1−βk−n
1−β1
β2(k−n)
n
(1 − βk−n
n
β2(k−n)
n
1 + β2
k=2
k=2
1
1
1 + β2
βk−n
1
· βk−n−1
1
x(1)(k) · βk−n
n
β2(k−n)
1
k=2
x(1)(k) · βk
n
β2k
1
1 + β2
k=2
n
k=2
βk
1
· βk−1
1
,
x(1)(k) · βk−n
n
k=2
n
k=2
n
k=2
(β1 − 1)
(β1 − 1)
(β1 − 1)
=
=
=
ˆx(0)(k)|cn = (β1 − 1)βk−n−1
1
k=2
1
+ β2 · βk−n−1
n
) · βk−n
1 + β2
β2(k−n)
1
k=2
· βk−n−1
1
% ˆx(0)(k)|c1 = ˆx(0)(k)|cn.
k=2
O[ c1, cn, 61,0(2Z-%ST#^T%,
[x(0)(t) − ˆx(0)(t)]2
(17)
n
t=2
min
c
S2
0 =
1536
D C U V E S
31
n
&UT, :
n
c1 =
k=2
(β1 − 1)2β2(k−2)
1
k=2
n
; cn =
k=2
[x(0)(k) − β2βk−2
1
](β1 − 1)βk−2
1
[x(0)(k) − β2βk−n−1
1
](β1 − 1)βk−n−1
1
n
k=2
(β1 − 1)2β2(k−n−1)
1
.
[.
GH 4 &UT, O U BGM − x(1)(1)U BGM − x(1)(n) ( ˆx(1)(1) = c1, ˆx(1)(n) = cn
, ,JMK ˆx(0)(k)|c1 ˆx(0)(k)|cn, U ˆx(0)(k)|c1 = ˆx(0)(k)|cn.
IJ
n
k=2
[x(0)(k) − β2βk−2
n
k=2
1
1
] · (β1 − 1) · βk−2
(β1 − 1)2 · β2(k−2)
n
x(0)(k) · βk
n
· βk−2
1 =
k=2
1
1
x(0)(k) · βk−2
1
+ β2 · βk−2
1
· βk
1 ,
β2k
1
k=2
ˆx(0)(k)|c1 = (β1 − 1)βk−2
n
1
(β1 − 1)2
n
=
k=2
(β1 − 1)2 · β2(k−2)
1
k=2
n
k=2
ˆx(0)(k)|cn = (β1 − 1)βk−n−1
n
1
(β1 − 1)2
n
% ˆx(0)(k)|c1 = ˆx(0)(k)|cn.
k=2
=
x(0)(k) · βk−n−1
1
k=2
(β1 − 1)2 · β2(k−n−1)
1
[x(0)(k) − β2βk−n−1
n
k=2
1
1
] · (β1 − 1) · βk−n−1
(β1 − 1)2 · β2(k−2)
n
x(0)(k) · βk
n
· βk−n−1
k=2
=
1
1
1
· βk
1 ,
β2k
1
k=2
+ β2 · βk−n−1
1
4 PQS
‘, [NÆ\1, _ +1N M
’‘, T . [13] ‘]][JMM^.
^_ 1997–2004 a_aJaA 1. ’ 1997–2002 a_aJ U BGM −
x(1)(1)U BGM − x(1)(n), ,N&UT1, *, ’ 2003 - 2004 a_
aJ%, b%‘‘].
T 1 1997–2004 UVXYZ[^ (_‘)
1997
d:bc 8.21
17.89
10.51
12.72
14.84
2002
1998
1999
2000
2001
9.52
2003
2004
21.22
26.79
1997–2002 a_aJ* U BGM − x(1)(1) , JMK
* U BGM − x(1)(n) , JMK
&U1 U BGM − x(1)(1) , JMK
&U1 U BGM − x(1)(n) , JMK
&U1 U BGM − x(1)(1) , JMK
ˆx(0)(k) = 9.1619 × 1.1791k−2;
ˆx(0)(k) = 20.8828 × 1.1791k−7;
ˆx(0)(k) = 9.1679 × 1.1791k−2;
ˆx(0)(k) = 20.8853 × 1.1791k−7;
ˆx(0)(k) = 9.1682 × 1.1791k−2;
8
;, : HEDBIÆ?F@H
1537
&U1 U BGM − x(1)(n) , JMK
ˆx(0)(k) = 20.8858 × 1.1791k−7.
3 4 , c &U () TN10(c, dL, e
JMK , \0(, aA 2.
T 2 cdecfghjemn (_‘)
ofHÆ
U BGM − x(1)(n)
U BGM − x(1)(1)
ofHÆ
ÆdIe
ÆdIe
ÆdIe
ÆdIe
9.1619
10.8019
12.7355
15.0151
17.7028
20.8716
24.6076
9.1669
10.8077
12.7423
15.0232
17.7123
20.8828
24.6207
9.1679
10.8090
12.7438
15.0249
17.7144
20.8853
24.6237
9.1682
10.8091
12.7442
15.0254
17.7149
20.8858
24.6244
de
1998
1999
2000
2001
2002
2003
2004
9.52
10.51
12.72
14.84
17.89
21.22
26.79
*, 1998–2002 0(, 20032004 (. Me\022,
aA 3 -A 4.
Æj
fefkÆ (gh)
feikÆ (%)
*, Zgh’2 = 1
5
T 3 cdpYZ[^ecfqr
U BGM − x(1)(1)
U BGM − x(1)(n)
ofHÆ
ofHÆ
ÆdIe
ÆdIe
ÆdIe
ÆdIe
0.2056
0.2068
1.79
6
1.78
ˆx(0)(i) − x(0)(i)
; Zgc’2 = 1
i=2
0.2071
1.79
6
|ˆx(0)(i)−x(0)(i)|
.
5
i=2
x(0)(i)
0.2071
1.79
T 4 cdpYZ[^eghspqr (%)
U BGM − x(1)(1) U BGM − x(1)(n) ofHÆ ofHÆ
2003
2004
1.6418
8.1462
1.5889
8.0968
1.5775
8.0862
1.5748
8.0837
A 3 - 4 W, \ +2 ]Æ0, 02!K, j
,Æ*)7. GM(1,1) "0+. . [13] , ÆJMM +
0j[P GM(1,1) , b0Mj . [13]
1. j6d, JMMI GM(1,1) * XY.
5 uv
Æ JMMNÆ +-\1, ’$ 1A[,
&UTN10(c. I* XYH
S2, 0‘ GM(1,1) - +1N M"%h.
H-, +JMM%K iH0 , [jJMMiHO2
, -’]U]+. dL, #Yk], UkjM"
-nl, o$%4Wkh.
wxz
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