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1、 基于广义Fuzzy偏好关系的决策方法探讨董玉成1,徐寅峰1,2 (1.西安交通大学管理学院; 2.机械制造系统工程国家重点实验室)摘要:本文提出了广义模糊偏好关系的概念。设计了互补化排序和加性一致化排序两种排序方法,讨论了两种排序方法的相关性质。基于这两种排序方法,定义了冗余一致性指标和加性一致性指标,并讨论了采用加权算术平均算子(算子)或有序加权平均算子(算子)对广义模糊偏好关系进行集结,其群体偏好一致性(包括冗余一致性和加性一致性)的相关性质。本文结果对进一步完善基于模糊偏好关系的群决策模型具有理论和现实意义。关键词:广义模糊偏好关系;排序方法;冗余一致;加性一致;信息集成算子 中图分类
2、号:C934 文献标识码:AStudy on decision making using generalized fuzzy preference relations Abstract: This paper first introduces the concept of generalized fuzzy preference relations and designs two methods to obtain the priorities vector from them. Moreover, we discuss desired properties on these two prio
3、rity methods. At last, we give some results on redundancy consistency and additive consistency of the collective preference relation aggregated by weighted averaging operator or ordered weighted averaging operator. These results are very important for GDM with fuzzy preference relations.Keywords: ge
4、neralized fuzzy preference relations; priority method; redundancy consistency; additive consistency; information aggregation operator.1 引言偏好关系又称判断矩阵,在多属性决策中被广泛研究。模糊互补偏好关系是最常见的偏好关系1-8。当决策者在某准则下对个方案进行两两比较构造一个典型的模糊互补偏好关系时,一般需要经过次判断。然而决策者有时可能对某些比较判断缺少把握或不想发表意见,这样就会使偏好关系中的某些项出现空缺,对这类偏好关系一般称为残缺互补偏好关系8-9。另
5、一方面,决策者也可能作出多达次比较判断,这样就出现了冗余判断,使模糊互补偏好关系失去互补性,我们称这种偏好关系为广义模糊偏好关系。这一新概念引入是基于如下理由:1)有些学者10-11在AHP的研究中,认为放弃乘性偏好关系的互反性是合理的,比如在一场球赛中,球队击败了球队,但是球队同样可以击败了球队,这种情形在现实生活中的成对比较判断里很常见。这些研究和分析也完全适合模糊互补偏好关系,它为我们引入广义模糊偏好关系提供了理论支持。2)在采用一些最常见信息集成算子对模糊互补偏好关系进行集成时,无法保证集成的群体偏好关系的互补性。比如采用有序加权平均算子()12对模糊互补偏好关系进行集成后,无法保证集
6、成的群体偏好关系是互补的13。因此,讨论从广义模糊偏好关系中发展权向量就有了必要性,而这些排序方法也能应用于Chiclana等提出的模糊多人决策模型13-16。本文的主要目的是对基于广义模糊偏好关系的决策方法进行探讨。文章给出了广义模糊偏好关系排序的两种方法;定义了广义模糊偏好关系的冗余一致性和加性一致性,并研究采用加权算术平均算子()或有序加权平均算子()对广义模糊偏好关系进行集成,其群体偏好一致性(包括冗余一致性和加性一致性)的相关性质。本文研究对进一步完善基于模糊偏好关系的群决策模型具有理论和现实意义。2 广义模糊偏好关系排序方法2.1 广义模糊偏好关系的互补化排序为了叙述方便先给出几个
7、定义:定义 1 令 是一矩阵,若对任意有,则称为模糊矩阵17。本文定义为广义模糊偏好关系。定义 26,7 令 是一矩阵,若对任意有,则称为模糊互补偏好关系(或称为互补模糊偏好关系)。令是阶广义模糊偏好关系集合,是阶模糊互补偏好关系集合,由定义知。为了通过广义模糊偏好关系对方案进行排序,从中发展权向量,一个直观的方法是采用模糊互补偏好关系去贴近广义模糊偏好关系,然后借助有关模糊互补偏好关系的排序方法6-8,最终获取权向量。本文采用欧氏距离定义两矩阵和的贴近程度,即:。那么这种方法可归纳为寻找一最贴近的模糊互补偏好关系。数学模型如下:设,。令 (1)其中,即为最贴近模糊互补偏好关系。通过模糊互补偏
8、好关系的排序方法6-8(本文采用最小方差法,具体见文献7)对进行排序,其排序向量可以近似作为的排序向量。定理 1 设,为最贴近模糊互补偏好关系,那么。 证明:(1)等价如下优化问题 (2)(2)等价于(3) (3)令得 ,化简得 (4)令,令为采用最小方差法排序公式7对进行排序的权向量,那么 (5)把(4)代入(5)得 (6)把近似作为的排序权向量,我们称该排序方法为广义模糊偏好关系互补化排序。2.2广义模糊偏好关系的加性一致化排序定义 3 令是一模糊互补偏好关系,若对任意有,则称A是加性一致模糊互补偏好关系。令是阶加性一致模糊互补偏好关系集合,由定义知。在这一节,我们考虑通过寻找一个最贴近广
9、义模糊偏好关系的加性一致模糊互补偏好关系,从而直接获取权向量。数学模型如下:设,令 (7)称为的最贴近加性一致模糊互补偏好关系。令,记为对应的权向量。因为是模糊加性一致偏好关系,我们有6-8 (8)由(8)代入(7)有 (9) 称为的排序向量。定理 2设。为的最贴近模糊互补偏好关系,为采用加性一致化排序方法获取的权向量。那么,。证明:(9)等价如下优化问题 (10)构造拉格朗日函数,令,得 (11) (12)联立(11)(12)得 (13)联立(8)(13)得 (14)3进一步讨论3.1 两种排序方法的相关性质一种广义模糊偏好关系的排序方法可以看作由到 的一个映射, 记为。并称是广义模糊偏好关
10、系的排序向量。下面讨论两种排序方法的一些性质。定理 3 当是模糊互补偏好关系(即)时,本文两种排序方法(公式(6)和公式(13)等价于模糊互补偏好关系排序的最小方差法。证明:因为,所以 ,把这两式分别代入(6)和(13),都可得,这即为模糊互补偏好关系的最小方差法排序公式。得证。定理3显示本文两种排序方法是广义最小方差排序法。定义 4 一种排序方法称为强条件下保序的,如果对任意,有和,则, 且当前者所有等式成立时, 有。定义4 推广了模糊互补偏好关系强条件保序的概念。定理4将证明两种排序方法是强条件保序的。定理 4 广义模糊偏好关系互补化排序方法(公式(6)和加性一致化排序方法(公式(13)是
11、强条件下保序的。证明:对任意,有和,将其代入(6)或者(13),有, 且当前者所有等式成立时, 有。所以得证。类似模糊互补偏好关系,定义广义模糊偏好关系排序方法的置换不变性。定义 5 设是一种排序方法,是任一个给定的广义模糊偏好关系,记的排序权向量为。 如果对于任一置换不变矩阵,均有,则称这种排序方法是置换不变的。定理 5广义模糊偏好关系互补化排序(公式(6)和加性一致化排序(公式(13)是置换不变的。证明:设,且设是置换不变矩阵,。令,分别是A 和B 在公式(6)下的排序向量, 经置换后, 的第行成了 的第行, 的第列成了的第列, 因此类似若,分别是和在公式(9)下的排序向量,则有所以两种排
12、序方法具有置换不变性。3.2群决策与一致性偏好关系一致性测量一般包括两个问题3:(1)什么时候决策者提供的个体偏好关系是一致的;(2)什么时候,一群人提供的偏好关系是一致的。对于第(2)个问题一般讨论两个方面:(a)群体偏好关系的一致性13, 18-19;(b)群体决策的共识测量 20。基于本文两种排序方法,我们给出广义模糊偏好关系的冗余一致性指标和加性一致性指标()(见定义6)。基于这些一致性指标,集中讨论一致性测量的第(2)个问题的第(a)方面(注:广义模糊偏好关系一致性测量的其它相关问题我们在今后的研究中讨论),即采用算子和算子对广义模糊偏好关系进行群集成后群体偏好关系的一致性问题。关于
13、无冗余判断的乘性偏好关系和模糊互补偏好关系的群体一致性问题,文献13,18-19作过一些讨论,本节研究可以认为是这些讨论的继续。定义 6设。定义为的冗余一致性指标。定义为的加性一致性指标。由互补化排序方法原理(公式(4)可知 (15)由加性一致化排序方法原理(公式(14)可知 (16)显然越大,则中冗余判断越多,当,则认为是冗余一致的(即是模糊互补偏好关系)。同样越大,则加性一致性越差,当,则认为是加性一致的(即是加性一致模糊互补偏好关系)。可以分别为和设定临界值和。当则认为广义模糊偏好关系是冗余一致可接受;当可认为是加性一致可接受。当和同时成立,则认为是一致可接受,此时从中发展的权向量才认为
14、是可靠和有效的。对临界值的设定,AHP的一致性检验可以给我们启示: (1)类似Saaty21在AHP中使用的方法,通过使用平均随机一致性指标对一致性指标标准化,然后经验性的去设定临界值;(2) 也可类似采用P. Jong 22 的统计方法,把临界值设定归结为卡方检验。限于本文篇幅,作者在今后研究中详细讨论该问题。(1) 用算子进行群决策设为决策者给出的个广义模糊偏好关系。采用加权算术平均算子(算子)对进行集成,得到群体模糊偏好关系记为。其中,为专家的权重且。定理 6设。(a)若 ,那么;(b)若 ,那么。证明:我们仅证明(a)。(b)可以完全类似证明,限于篇幅省略。因为,所以 (17)(18)
15、联立(17)和(18)得 (19)从定理6可得:采用算子进行集成,若个体广义模糊偏好关系的一致性水平(包括冗余一致性和加性一致性)都是可接受的,那么群体偏好必然是一致可接受的。(2)用算子进行群决策采用有序加权算术平均算子(算子)对进行集成,得到群体广义模糊偏好关系记为。其中,且为中第大的元素。为 算子相关联的加权向量,其中。定义 7 设是一组广义模糊偏好关系,定义为其第次序广义模糊偏好关系。定理 7设。(a)若 ,那么;(b)若 ,那么。证明:由定理6和定义7可直接得证。从定理7可知:采用算子进行集成,若次序广义模糊偏好关系的一致性水平(包括冗余一致性和加性一致性)都是可接受的,那么群体偏好
16、必然是一致可接受的。4 算例为了叙述方便,记,为采用本文第一种排序方法(公式6)和第二种排序方法(公式13)从广义模糊偏好关系中获取的权向量。记, 为的冗余一致性指标和加性一致性指标的值。现考虑有两个决策者对四个方案进行评估,分别给出自己的广义模糊偏好关系。按照本文方法计算出,的值,具体如下。,,, , , 如按算子对进行集成,加权向量设为,得到群体偏好关系为。并计算出,。可以看出,这与定理6相符合。,如按算子对进行集成,加权向量不妨设为,得到群体偏好关系为。为的次序广义模糊偏好关系。并计算出,的值。可以看出,这与定理7相符合。,5 结论本文主要做了如下工作:(1)提出了广义模糊偏好关系的概念
17、,并设计了互补化排序和加性一致化排序两种排序方法;(2)讨论了两种排序方法的一些相关性质;(3)给出了冗余一致性指标和加性一致性指标的公式,并讨论了采用加权算术平均算子(算子)和有序加权平均算子(算子)对广义模糊偏好关系进行集结,其群体偏好一致性(包括冗余一致性和加性一致性)的一些性质。本文结果对完善基于模糊偏好关系的群决策模型具有理论和现实意义。在今后的研究中,我们将进一步探讨这些问题。参考文献1 Orlorski S A. Decision-making with a fuzzy preference relation J. Fuzzy Sets and Systems, 3(1978)
18、155-167.2 Tanino T. Fuzzy preference orderings in group decision making J, Fuzzy Sets and Systems 12 (1984) 117-131.3 Herrera-Viedma E, Herrera F, Chiclana F et al. Some issues on consistency of fuzzy preference relations J. European Journal of Operational Research 154 (2004):98-109.4樊治平,姜艳萍,肖四汉.模糊判
19、断矩阵的一致性及其性质J.控制与决策.2001, 16(1):69:71.5 Ma Jian, Fan Zhi-Ping, Jiang Yan-Ping et al. A method for repairing the inconsistency of fuzzy preference relations J. Fuzzy Sets and Systems 157 (2006):20-33.6 樊治平,姜艳萍.模糊判断矩阵排序方法研究的综述J.系统工程.2001, 19(5):12-18.待添加的隐藏文字内容17 徐泽水.模糊互补判断矩阵排序的最小方差法J.系统工程理论与实践.2001, 2
20、1(10):93-96:130.8 徐泽水.不确定多属性决策方法及应用M.清华大学出版社.2004.9 徐泽水.基于残缺互补判断矩阵的交互式群决策方法J.控制与决策.2005, 20(8):913-916.10 Koczkodaj W W, Orlowski M. An orthogonal basis for computing a consistent approximation to a pairwise comparisons matrix J, Computers and Mathematics with Applications. 34(1997):41-47. 11 Koczko
21、daj W W, Orlowski M. Computing a consistency approximation to generalized pairwise comparisons matrix J, Computers and Mathematics with Applications. 37(1999):79-85. 12 Yager RR. On ordered weighted averaging aggregation operators in multicriteria decision making J. IEEE Transactions on Systems, Man
22、 and Cybernetics. 18(1988):183190.13 Chiclana F, Herreraa F, Herrera-Viedmaa E. A note on the reciprocity in the aggregation of fuzzy preference relations using OWA operators J. Fuzzy Sets and Systems. 137 (2003):7183.14 Chiclana F, Herrera F, Herrera-Viedma E. Integrating three representation model
23、s in fuzzy multipurpose decision making based on fuzzy preference relations J. Fuzzy Sets and Systems. 97 (1998): 33-48.15 Chiclana F, Herrera F, Herrera-Viedma E. Integrating multiplicative preference relations in a multipurpose decision-making model based on fuzzy preference relations J. Fuzzy Set
24、s and Systems. 122 (2001): 277-291.16 Chiclana F, Herrera F, Herrera-Viedma E. A note on the internal consistency of various preference representations J. Fuzzy Sets and Systems. 131 (2002): 75-78.17杨伦标,高英仪.模糊数学理论及应用.华南理工大学出版社,1992:98-102.18 Xu Z. On consistency of the weighted geometric mean comple
25、x judgement matrix in AHP J. European Journal of Operational Research. 126(2000): 683687.19 Escobar M T, Aguarn J, Moreno-Jimnez J M. A note on AHP group consistency for the row geometric mean priorization procedure J. European Journal of Operational Research. 153 (2004): 318322.20 Herrera-Viedma E,
26、 Herrera F, Chiclana F. A Consensus model for multiperson decision making with different preference structures J. IEEE Transactions on Systems, Man and Cybernetics. 32(2002): 394-402.21 Saaty TL. The analytic hierarchy process M. New York: McGraw-Hill, 1980.22 Jong P. A statistical approach to Saaty
27、s scaling method for priorities J. Journal of Mathematical Psychology 28 (1984): 467-478.Editors note: Judson Jones is a meteorologist, journalist and photographer. He has freelanced with CNN for four years, covering severe weather from tornadoes to typhoons. Follow him on Twitter: jnjonesjr (CNN) -
28、 I will always wonder what it was like to huddle around a shortwave radio and through the crackling static from space hear the faint beeps of the worlds first satellite - Sputnik. I also missed watching Neil Armstrong step foot on the moon and the first space shuttle take off for the stars. Those ev
29、ents were way before my time.As a kid, I was fascinated with what goes on in the sky, and when NASA pulled the plug on the shuttle program I was heartbroken. Yet the privatized space race has renewed my childhood dreams to reach for the stars.As a meteorologist, Ive still seen many important weather
30、 and space events, but right now, if you were sitting next to me, youd hear my foot tapping rapidly under my desk. Im anxious for the next one: a space capsule hanging from a crane in the New Mexico desert.Its like the set for a George Lucas movie floating to the edge of space.You and I will have th
31、e chance to watch a man take a leap into an unimaginable free fall from the edge of space - live.The (lack of) air up there Watch man jump from 96,000 feet Tuesday, I sat at work glued to the live stream of the Red Bull Stratos Mission. I watched the balloons positioned at different altitudes in the
32、 sky to test the winds, knowing that if they would just line up in a vertical straight line we would be go for launch.I feel this mission was created for me because I am also a journalist and a photographer, but above all I live for taking a leap of faith - the feeling of pushing the envelope into u
33、ncharted territory.The guy who is going to do this, Felix Baumgartner, must have that same feeling, at a level I will never reach. However, it did not stop me from feeling his pain when a gust of swirling wind kicked up and twisted the partially filled balloon that would take him to the upper end of
34、 our atmosphere. As soon as the 40-acre balloon, with skin no thicker than a dry cleaning bag, scraped the ground I knew it was over.How claustrophobia almost grounded supersonic skydiverWith each twist, you could see the wrinkles of disappointment on the face of the current record holder and capcom
35、 (capsule communications), Col. Joe Kittinger. He hung his head low in mission control as he told Baumgartner the disappointing news: Mission aborted.The supersonic descent could happen as early as Sunday.The weather plays an important role in this mission. Starting at the ground, conditions have to
36、 be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 mile
37、s/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause), he can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000
38、 feet (22.7 miles/36.53 kilometers). Here, Fearless Felix will unclip. He will roll back the door.Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too h
39、ard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seco
40、nds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it
41、s not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he los
42、es consciousness at mach speeds.Even if everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).It might not be the moon, but Kittinger free fell from 102,800 feet in 1960 - at the dawn of an infamous space race that captured the hearts of many. Baumgartner will attempt to break that record, a feat that boggles the mind. This is one of those monumental moments I will always remember, because there is no way Id miss this.