王麗麗,聶 飛
(空軍工程大學(xué)裝備管理與安全工程學(xué)院,西安 710051)
基于前景理論的多階段直覺模糊數(shù)決策方法*
王麗麗,聶 飛
(空軍工程大學(xué)裝備管理與安全工程學(xué)院,西安 710051)
針對(duì)航空部隊(duì)事故預(yù)警方案選擇中指標(biāo)權(quán)重未知、指標(biāo)值為直覺模糊數(shù)的多階段直覺模糊數(shù)決策問題,考慮決策者風(fēng)險(xiǎn)偏好引起的指標(biāo)值的動(dòng)態(tài)變化,提出了一種基于前景理論的多階段決策方法。該方法根據(jù)各階段期望均值可能度的比較確定階段變化特征,參考直覺模糊數(shù)距離公式設(shè)置動(dòng)態(tài)參考點(diǎn),然后集結(jié)收益和損失以整體前景值最大化為目標(biāo)建立規(guī)劃模型得到指標(biāo)的動(dòng)態(tài)權(quán)重,計(jì)算方案綜合前景值并排序。最后通過MATLAB仿真實(shí)例驗(yàn)證了該方法的有效性。
前景理論,多階段決策,動(dòng)態(tài)參考點(diǎn),直覺模糊數(shù)
航空部隊(duì)事故預(yù)警中存在著大量的多階段決策問題,隨著信息化的發(fā)展,該類決策問題的重要性日益突出,相對(duì)于單一階段決策,多階段決策問題更加復(fù)雜,決策者面臨更多的不確定性,如多階段決策信息的有效集成、決策者風(fēng)險(xiǎn)態(tài)度的變化、群體意見的沖突和協(xié)調(diào)等。多階段決策方法得到了大量學(xué)者的廣泛關(guān)注,如基于多階段權(quán)重的分析方法[1]和動(dòng)態(tài)綜合評(píng)價(jià)方法[2]等。此外,在實(shí)際決策過程中,除了決策階段的不確定性外,決策信息也往往不能準(zhǔn)確給出,使決策問題呈現(xiàn)出一定的模糊性,于是大量學(xué)者采用直覺模糊集來反映決策信息[3-5]。因此,多階段直覺模糊數(shù)決策問題有著廣闊的研究前景和重要的研究?jī)r(jià)值。徐晨光[6]通過I-IFHA算子解決動(dòng)態(tài)直覺模糊多屬性群決策問題。趙妍[7]等結(jié)合灰色關(guān)聯(lián)分析法研究了動(dòng)態(tài)直覺模糊數(shù)決策問題。需要指出的是,當(dāng)前研究并未考慮多階段決策過程中決策者的風(fēng)險(xiǎn)偏好,存在一定的局限性。
Tversky和Kahneman于1979年提出了前景理論,該理論在進(jìn)行決策時(shí)能夠同時(shí)考慮指標(biāo)值的損失和收益,反映出決策者追求風(fēng)險(xiǎn)與規(guī)避損失的態(tài)度。已有相關(guān)學(xué)者將其用于解決單一階段模糊決策[8-10]和多階段隨機(jī)決策[11-12]。然而根據(jù)文獻(xiàn)檢索結(jié)果,運(yùn)用前景理論解決多階段直覺模糊數(shù)決策問題的研究還未見報(bào)道,因此,本文首先將前景理論的概念引入到多階段直覺模糊數(shù)決策領(lǐng)域,綜合考慮決策者的風(fēng)險(xiǎn)偏好,提出基于前景理論的多階段決策方法,設(shè)置動(dòng)態(tài)參考點(diǎn),計(jì)算指標(biāo)動(dòng)態(tài)權(quán)重,以滿足航空部隊(duì)事故預(yù)警中的多階段決策問題的需要。
1.1 直覺模糊數(shù)
直覺模糊數(shù)中的真隸屬度u、假隸屬度v及猶豫度π,分別表示某對(duì)象屬于直覺模糊數(shù)的支持、反對(duì)和中立的3種證據(jù),它有效地?cái)U(kuò)展了經(jīng)典模糊數(shù)的表示能力,記為a=(u,v),其中π=1-u-v。
定義1[13]設(shè)直覺模糊數(shù)a1=(u1,v1),a2=(u2,v2),稱
為a1≥a2的可能度。
定義2兩直覺模糊數(shù)a1=(u1,v1)和a2=(u2,v2)間的距離[14]為:
1.2 前景理論
前景價(jià)值是由價(jià)值函數(shù)和決策權(quán)重函數(shù)共同決定的[15],即
其中,V為前景值,pi表示第i個(gè)狀態(tài)的概率;π(pi)是決策權(quán)重,它是概率評(píng)價(jià)性的單調(diào)增函數(shù),用對(duì)數(shù)形式表示:
γ和δ分別表示決策者對(duì)收益和損失的態(tài)度,0<γ<δ<1表明決策者高估小概率事件而低估較大概率事件。v(x)是價(jià)值函數(shù)代表決策者主觀感受形成的價(jià)值,用冪函數(shù)的形式表示:
x為決策方案相對(duì)于參考點(diǎn)的差值,α和β分別為風(fēng)險(xiǎn)厭惡和風(fēng)險(xiǎn)偏好系數(shù),表征價(jià)值函數(shù)在收益和損失區(qū)域的凹凸程度,其值越大,決策者越傾向于冒險(xiǎn);θ為損失規(guī)避系數(shù),θ>1表征價(jià)值函數(shù)曲線在損失區(qū)域比收益區(qū)域更陡峭的特征,表明決策者相比于收益對(duì)損失更加敏感。文獻(xiàn)[16]指出,參數(shù)α=β=0.88,θ=2.25,γ=0.61,δ=0.69時(shí),試驗(yàn)結(jié)果與經(jīng)驗(yàn)數(shù)據(jù)較為一致。
2.1 決策分析框架
圖1 基于前景理論的多階段直覺模糊數(shù)決策分析框架
2.2 決策方法步驟
Step 1:確定初始直覺模糊數(shù)決策矩陣
并計(jì)算各階段方案在k狀態(tài)時(shí)的期望均值矩陣:
Step 2:根據(jù)式(1)確定各階段期望均值的動(dòng)態(tài)變化特征,若,則該階段向著有利方向變化,其前景值應(yīng)有所提升,所以需要降低該階段參考點(diǎn);若,則該階段向著不利方向變化,其前景值應(yīng)有所降低,所以需要提高該階段參考點(diǎn)。上述調(diào)整實(shí)際上起到了階段權(quán)重的效果,在計(jì)算前景值時(shí)可以不必重復(fù)考慮時(shí)間權(quán)重的影響。根據(jù)式(2)確定各階段期望均值的變化程度,得到階段動(dòng)態(tài)參考點(diǎn)計(jì)算公式:
Step 3:根據(jù)式(1)和式(2)分別計(jì)算各階段方案初始直覺模糊數(shù)決策值與階段動(dòng)態(tài)參考點(diǎn)的可能度和距離
其中
Step 4:以整體前景值最大化為目標(biāo)函數(shù)建立規(guī)劃模型:
表1 初始直覺模糊數(shù)矩陣()3×3×3×3
表1 初始直覺模糊數(shù)矩陣()3×3×3×3
Pk好(0.1) 中(0.6) 差(0.3)G G1 G2 G3 G1 G2 G3 G1 G2 G3t1 a1 [0.2,0.4] [0.6,0.3] [0.3,0.5] [0.3,0.6] [0.6,0.3] [0.4,0.5] [0.2,0.4] [0.5,0.3] [0.4,0.5] a2 [0.3,0.7] [0.2,0.5] [0.2,0.4] [0.2,0.7] [0.3,0.5] [0.2,0.5] [0.2,0.5] [0.4,0.5] [0.3,0.4] a3 [0.4,0.5] [0.4,0.3] [0.5,0.4] [0.5,0.4] [0.5,0.3] [0.6,0.2] [0.4,0.4] [0.4,0.3] [0.5,0.3] t2 a1 [0.3,0.4] [0.5,0.2] [0.4,0.5] [0.4,0.5] [0.5,0.3] [0.3,0.5] [0.2,0.5] [0.5,0.4] [0.4,0.3] a2 [0.4,0.5] [0.2,0.6] [0.3,0.4] [0.2,0.5] [0.3,0.6] [0.3,0.5] [0.3,0.5] [0.5,0.3] [0.3,0.4] a3 [0.4,0.5] [0.3,0.3] [0.5,0.3] [0.4,0.4] [0.4,0.3] [0.5,0.2] [0.4,0.5] [0.4,0.3] [0.6,0.3] t3 a1 [0.2,0.5] [0.5,0.2] [0.4,0.5] [0.4,0.6] [0.5,0.4] [0.4,0.4] [0.2,0.5] [0.5,0.2] [0.4,0.2] a2 [0.3,0.6] [0.3,0.5] [0.3,0.5] [0.3,0.5] [0.3,0.6] [0.3,0.5] [0.3,0.6] [0.5,0.3] [0.5,0.5] a3 [0.5,0.3] [0.3,0.4] [0.5,0.3] [0.3,0.4] [0.4,0.5] [0.4,0.2] [0.5,0.2] [0.4,0.2] [0.5,0.3]
使用Matlab仿真工具進(jìn)行計(jì)算,由Step 1~Step 3并使用文獻(xiàn)[16]中的參數(shù)取值,即α=β=0.88,θ=2.25, γ=0.61,δ=0.69分別得到階段動(dòng)態(tài)參考點(diǎn)及階段方案前景值如表2、表3所示。
表2 階段動(dòng)態(tài)參考點(diǎn)()3×3×3×3
表2 階段動(dòng)態(tài)參考點(diǎn)()3×3×3×3
Pk 好(0.1) 中(0.6) 差(0.3)G e1jk* e2jk* e3jk* G1 G2 G3 G1 G2 G3 G1 G2 G3[0.30,0.53] [0.40,0.37] [0.33,0.43] [0.33,0.57] [0.47,0.37] [0.40,0.40] [0.27,0.43] [0.43,0.37] [0.40,0.40] [0.32,0.52] [0.39,0.31] [0.35,0.45] [0.25,0.55] [0.45,0.35] [0.39,0.38] [0.37,0.43] [0.44,0.36] [0.38,0.38] [0.29,0.51] [0.41,0.33] [0.36,0.47] [0.27,0.56] [0.51,0.39] [0.38,0.32] [0.36,0.40] [0.37,0.33] [0.41,0.39]
表3 階段方案前景值
根據(jù)Step 4調(diào)用linprog函數(shù)得到指標(biāo)的動(dòng)態(tài)權(quán)重值,ω1=(0.282 0,0.190 5,0.527 5),ω2=(0.010 4,0.662 4,0.327 2),ω3=(0.030 3,0.800 9,0.168 8)。根據(jù)Step5得到方案綜合前景值V=(-0.0715,-0.8860,-0.604 8),并對(duì)各航空事故預(yù)警方案排序?yàn)閍1>a3>a2,故a1為最優(yōu)方案。
借鑒文獻(xiàn)[7]中灰色關(guān)聯(lián)決策方法,求得屬性權(quán)重ω=(0.473 9,0.248 5,0.277 6),計(jì)算方案相對(duì)關(guān)聯(lián)度r=(0.098 6,0.149 6,0.055 5),得到方案排序a3>a1>a2,最優(yōu)方案為a3。兩種方法對(duì)方案排序結(jié)果并不一致。通過數(shù)據(jù)分析可以發(fā)現(xiàn)文獻(xiàn)[7]中權(quán)重計(jì)算給予指標(biāo)G1較大數(shù)值,而本文方法則在階段給予較大數(shù)值,后續(xù)階段給予較小數(shù)值,體現(xiàn)了指標(biāo)權(quán)重隨著階段變化相應(yīng)動(dòng)態(tài)調(diào)整的特點(diǎn),所以本文方法具有一定的現(xiàn)實(shí)意義。
綜合以上分析表明進(jìn)行多階段決策時(shí)考慮決策者對(duì)風(fēng)險(xiǎn)的偏好及多階段動(dòng)態(tài)變化特征有一定的必要性,而本文正是在此基礎(chǔ)上研究基于前景理論的多階段決策分析方法,該方法運(yùn)算簡(jiǎn)單、易于實(shí)現(xiàn),能夠有效解決航空部隊(duì)事故預(yù)警中存在動(dòng)態(tài)變化特征的多階段直覺模糊數(shù)決策問題。
本文針對(duì)航空部隊(duì)事故預(yù)警中的多階段決策問題,考慮決策者的風(fēng)險(xiǎn)偏好,根據(jù)指標(biāo)值的動(dòng)態(tài)變化特征,研究了基于前景理論的多階段決策方法,該方法在設(shè)置動(dòng)態(tài)參考點(diǎn)的基礎(chǔ)上集結(jié)收益和損失信息得到方案的排序結(jié)果。實(shí)際決策過程中可根據(jù)決策者的風(fēng)險(xiǎn)偏好適當(dāng)調(diào)整參數(shù),為解決多階段直覺模糊數(shù)決策問題提供了一種新的思路,具有實(shí)際應(yīng)用價(jià)值。同時(shí)該方法中動(dòng)態(tài)參考點(diǎn)的設(shè)置也為區(qū)間直覺模糊數(shù)、梯形直覺模糊數(shù)等模糊類決策問題的解決提供了借鑒,具有一定的參考價(jià)值。
[1]XU Z S.Multi-period multi-attribute group decision-making under linguistic assessments[J].International Journal of General System,2009,38(8):823-850.
[2]郭亞軍,姚遠(yuǎn),易平濤.一種動(dòng)態(tài)綜合評(píng)價(jià)方法及應(yīng)用[J].系統(tǒng)工程理論與實(shí)踐,2007,27(10):154-158.
[3]王堅(jiān)強(qiáng),張忠.基于直覺模糊數(shù)的信息不完全的多準(zhǔn)則規(guī)劃方法[J].控制與決策,2008,23(10):1145-1148.
[4]羅承昆,陳云翔,王超,等.基于改進(jìn)證據(jù)理論的區(qū)間直覺模糊群決策方法[J].計(jì)算機(jī)仿真,2015,32(10):282-286.
[5]郭嗣琮,呂金輝.直覺模糊數(shù)的研究[J].模糊系統(tǒng)與數(shù)學(xué),2013,27(5):11-20.
[6]徐晨光.基于I-IFHA算子的動(dòng)態(tài)直覺模糊多屬性群決策方法[J].南昌工程學(xué)院學(xué)報(bào),2014,33(3):40-46.
[7]趙妍,吳濤,錢慶慶,等.論動(dòng)態(tài)直覺模糊數(shù)的灰色關(guān)聯(lián)多屬性決策方法[J].合肥學(xué)院學(xué)報(bào),2014,24(4):10-14.
[8]高建偉,劉慧暉,谷云東.基于前景理論的區(qū)間直覺模糊多準(zhǔn)則決策方法[J].系統(tǒng)工程理論與實(shí)踐,2014,34(12):3175-3181.
[9]王雪青,唐瑭.基于累積前景理論的信息不完全的風(fēng)險(xiǎn)型多準(zhǔn)則決策方法[J].模糊系統(tǒng)與數(shù)學(xué),2015,29(3):137-144.
[10]余德建,吳應(yīng)宇,賀小榮.基于前景理論的信息不完全的區(qū)間型多屬性決策方法[J].軟科學(xué),2011,25(3):140-144.
[11]胡軍華,楊柳,劉詠梅.基于累積前景理論的動(dòng)態(tài)隨機(jī)多準(zhǔn)則決策方法[J].軟科學(xué),2012,26(2):132-135.
[12]郝晶晶,朱建軍,劉思峰.基于前景理論的多階段隨機(jī)多準(zhǔn)則決策方法[J].中國(guó)管理科學(xué),2015,23(1):73-81.
[13]FACCHINETTI G,RICCI R G,MUZZIOLI S.Note on ranking fuzzy triangularnumbers [J].International Journal of Intelligent Systems,1998(13):613-622.
[14]MAHDAVI I.Design a model of fuzzy TOPSIS in multiple criteria decision making[J].Applied Mathematics and Computation,2008,206(2):607-617.
[15]KAHNEMAND,TVERSKYA.Prospecttheory:Ananalysisof decisionunderrisk[J].Economitrica,1979,47(2):263-291.
[16]TVERSKY A,KAHNEMAN D.Advances in prospect theory:Cumulative representation ofuncertainty[J]. Journal of Risk and Uncertainty,1992(10):297-323.
Multi-stage Intuitionistic Fuzzy Number Decision-making Methods Based on Prospect Theory
WANG Li-li,NIE Fei
(School of Equipment Management and Safety Engineering,Air Force Engineering University,Xi’an 710051,China)
For the multi-stage intuitionistic fuzzy number decision-making problem of aviation troops accident early warnings,in which the information on criteria weights are unknown and the criteria value of alternatives are in the form of intuitionistic fuzzy number,considering the dynamic varying by the risk preference of decision makers,a method of multi-stage decision-making based on the prospect theory is proposed.Comparing the multi-stage expected values’possibility degree the dynamic characteristic of every stage is obtained.Installing dynamic reference point according to distance expression,concentrating the lose and get,enacting a programming model the criteria dynamic weights are attained and the order of alternatives can be listed by calculating the integrated prospect values.Finally,a MATLAB simulation example is illustrated to examine the effectiveness of the method.
prospect theory,multi-stage decision-making,dynamic reference point,intuitionistic fuzzy number
TP301.6
A
1002-0640(2017)05-0006-04
2016-03-06
2016-05-08
國(guó)家自然科學(xué)基金資助項(xiàng)目(71401174)
王麗麗(1991- ),女,河南鄭州人,在讀碩士研究生。研究方向:管理信息與決策支持。