金愛(ài)蓮
(延邊大學(xué)理學(xué)院 數(shù)學(xué)系,吉林 延吉133002)
極C-invex條件下多目標(biāo)分式規(guī)劃問(wèn)題的對(duì)稱對(duì)偶性
金愛(ài)蓮
(延邊大學(xué)理學(xué)院 數(shù)學(xué)系,吉林 延吉133002)
給出了多目標(biāo)分式規(guī)劃問(wèn)題,并利用弱有效性和真有效性的概念,證明了在極C-invex條件下與分式規(guī)劃問(wèn)題相關(guān)的弱對(duì)偶定理、強(qiáng)對(duì)偶定理和逆對(duì)偶定理.
極C-invex;多目標(biāo)分式規(guī)劃;對(duì)稱對(duì)偶性;有效性
多目標(biāo)規(guī)劃研究的是一定約束條件下的多個(gè)目標(biāo)函數(shù)的極值問(wèn)題,是近年發(fā)展起來(lái)的數(shù)學(xué)規(guī)劃的新分支,應(yīng)用廣泛.近幾年來(lái),有關(guān)函數(shù)的極C-invex的研究也引起了諸多學(xué)者的興趣.Dantzig[1]等于1965年首先提出了非線性規(guī)劃問(wèn)題的對(duì)稱對(duì)偶性,隨后許多學(xué)者對(duì)此問(wèn)題做過(guò)進(jìn)一步的研究,但其結(jié)果大都是在凸性或廣義凸性上得到的[2-5].楊新民[6]討論并證明了在不變偽凸性條件下兩類非線性規(guī)劃的對(duì)稱對(duì)偶性,陳秀宏[7]討論了錐約束多目標(biāo)規(guī)劃的二階對(duì)稱對(duì)偶性,金愛(ài)蓮[8]討論了極C-invex條件下多目標(biāo)非線性規(guī)劃問(wèn)題的對(duì)稱對(duì)偶性.本文在文獻(xiàn)[8]和[9]的研究基礎(chǔ)上,證明了極C-invex條件下多目標(biāo)分式規(guī)劃問(wèn)題的弱對(duì)偶定理、強(qiáng)對(duì)偶定理和逆對(duì)偶定理.
設(shè)Rp是p 維歐氏空間,記Rp+= {x∈Rp|x≧0},Rp-= {x∈Rp|x≦0}.設(shè)x,y∈Rp,若對(duì)所有的i=1,2,…,p,有xi≤yi,則記為x≦y;若x≦y且x≠y,則記為x≤y;若對(duì)所有的i=1,2,…,p,有xi<yi,則記為x<y;若對(duì)x≤y的否定,則記為xy.
定義1 稱非空集C?Rp是1個(gè)頂點(diǎn)為零的錐,若x∈C,則對(duì)所有λ≥0,有λx∈C.如果C又
其中fi,gi∶C→C1,h∶C→C2,C,C1和C2分別是Rp,Rn和Rm中具有非空的閉凸錐.設(shè)X= {x∈C|h(x)≦0}是所有(MP)的可行解的集合.
定義4 稱1個(gè)錐C+是C的正極錐,若C+={p∈Rp|pTx≧0,?x∈C}.
定義5 設(shè)f=(f1,f2,…,fp)∶C1→C是可微函數(shù),且C1?Rn和C?Rp是非空的閉凸錐,稱f是關(guān)于η∶C1×C1→C1的C1上的極C-invex,如果對(duì)所有λ(≠0)∈C+和所有(x,u)∈C1×C1有(λTf)(x)-(λTf)(u)≧[η(x,u)]T?x(λTf)(u),即對(duì)所有λ∈C+,λ≠0,實(shí)值函數(shù)fλ(x)=λTf(x)是凸的(invex).是凸的,則稱C是1個(gè)凸錐,特別地,當(dāng)C為閉集時(shí),則稱C為閉凸錐.考慮下面的多目標(biāo)分式規(guī)劃問(wèn)題:
設(shè)C,C1和C2為閉凸錐,S1?Rn和S2?Rm是開(kāi)的,且A=S1?Rn,B=S2?Rm.C1?A,C2?B,f∶A→C?Rp,g∶B→C?Rp是2個(gè)可微函數(shù).對(duì)于i=1,2,…,p,假設(shè)f和-g是對(duì)于x的關(guān)于η在C1上的極C-invex,-f和g是對(duì)于y的關(guān)于ξ在C2上的極C-invex.在可行區(qū)域,始終假設(shè)fi>0,i=1,2,…,p,且每個(gè)gi是有界的.注意η∶S1×S1→C1和ξ∶S2×S2→C2.
為了簡(jiǎn)化,(FSP)和(FSD)可重新表示如下:
下面給出關(guān)于(FSP)′和(FSD)′的弱、強(qiáng)和逆對(duì)偶定理,這些結(jié)果同樣適用于(FSP)和(FSD)問(wèn)題.
定理1 (弱對(duì)偶性)設(shè)(x,y,λ)是(FSP)′的可行解,(u,v,λ)是(FSD)′的可行解.假設(shè)f和-g是關(guān)于x的極C-invex,-f和g是關(guān)于y的極C-invex,并且η(x,u)+u∈C1,ξ(v,y)+y∈C2,則qp.
證明 由(3)式及(fi-pigi)是極C-invex的假設(shè),有.由η(x,u)+u∈C1和(5)式有.再由(4)式得到
同樣,由-(fi-qigi)是極C-invex的條件,得到,并由ξ(v,y)+y ∈C2和(2)式得到.再由(1)式得到
由(6)和(7)式得到
如果對(duì)某個(gè)i,qi>pi,且對(duì)所有j≠i,qj≦pj,則因?yàn)間i>0,i=1,2,…,p,我們可以得到1個(gè)與(8)式相矛盾的結(jié)論,因此qp.由此定理1得證.
因?yàn)棣恕蔆+,t≧0,由(14)式容易得到t=0.因此由(13)式可得
因?yàn)閤∈C1,∈C1,C1又是閉凸錐,故可知x+∈C1,因此由(18)式得由此推出同樣在(18)式中,令x=0,x=2,得0.因此,,)是(FSD)′的可行解,且(FSP)′和(FSD)′的目標(biāo)值相等.顯然(,,)是(FSD)′的有效解.如果(,,)是非真有效的,則對(duì)某個(gè)可行解(ui,vi,),滿足p1i=fi(ui,vi)/gi(ui,vi),i=1,2,
…,p,且對(duì)某個(gè)i,對(duì)任意M>0,有p1i->M,又因?yàn)間i(i=1,2,…,p)是有界的,因此p1i)gi,vi)<0,這與弱對(duì)偶性的不等式(8)發(fā)生矛盾,因此(,,)是(FSD)′的真有效解.定理2得證.
同樣可以得到逆對(duì)偶定理,其證明過(guò)程類似于定理2,故省略.
[1] Dantzig G B,Eisenberg E,Cottle R W.Symmetric dual nonlinear programs[J].Pacific J Math,1965,15:809-812.
[2] Mond B,Weir T.Symmetric duality for nonlinear multiobjective programming[C]//S Kumar Recent Developments in Mathematical Programming.London:Gordon and Breach,1997:137-153.
[3] Bazaraa MS,Goode J J.On symmetric duality in nonlinear programming[J].Operation Research,1973,21:1-9.
[4] Chandra S,Craven B D,Mond B.Symmetric dual fractional programming[J].Z Oper Res,1984,29:59-64.
[5] 劉三陽(yáng).分式規(guī)劃的對(duì)稱對(duì)偶性[J].西安交通大學(xué)學(xué)報(bào),1990,24:135-138.
[6] 楊新民.兩類非線性規(guī)劃的對(duì)稱對(duì)偶性[J].重慶師范學(xué)院學(xué)報(bào),1993,10:5-8.
[7] 陳秀宏.錐約束多目標(biāo)規(guī)劃的二階對(duì)稱對(duì)偶性質(zhì)[J].應(yīng)用數(shù)學(xué),2006,19:127-133.
[8] 金愛(ài)蓮.極C-invex條件下多目標(biāo)非線性規(guī)劃問(wèn)題的對(duì)稱對(duì)偶性[J].延邊大學(xué)學(xué)報(bào):自然科學(xué)版,2010,36(4):291-295.
[9] Kim D S,Yun Y B,Lee W J.Multiobjective symmetric duality with cone constraints[J].European Journal of Operational Research,1998,107:686-691.
Symmetric duality for multiobjective fractional programming problem with polarlyC-invexity
JIN Ai-lian
(DepartmentofMathematics,CollegeofScience,YanbianUniversity,Yanji133002,China)
A pair of multiobjective fractional programming with come constraints ws formulated and the definitions of a class of polarlyyC-invex fuctions were introduced.Under the polarlyC-invexity condition,we proved weak,strong and converse duality theorems by concept of the efficiency and the proper efficiency.
polarlyC-invex;multiobjective fractional problem;symmetric duality;efficiency
O212.2
A
1004-4353(2012)01-0033-05
2011-09-24
金愛(ài)蓮!(1968—),女,講師,研究方向?yàn)檫\(yùn)籌學(xué).