On the suitability of minimum and product operators for the intersection of fuzzy sets

In many papers concerning fuzzy set theory it is assumed that the membership or an element in the intersection of two or more fuzzy sets is given by the minimum of product of the corresponding membership values. To use these operators in modelling aspects of the real world, such as decision making, however, it is necessary to prove their appropriateness empirically. The main question of this study is whether people rating the membership of objects in the intersection of two fuzzy sets behave in accordance with one of these models. An important problem in answering this question is how to measure membership which seems to have the characteristics of an absolute scale. No measurement structure is available at present, but a practical method for scaling is suggested. The results of our experiments indicate that neither the product nor the minimum fit the data sufficiently well, but the latter seems to be preferable.     

Production and marketing decisions with multiple objectives in a competitive environment

This paper presents an application of the mathematical program which has been called the Fritz John problem to a situation in applied economics. A model is presented which enables a firm to maximize profit, subject to constraints on maintenance of market share in the face of collusive action by competitors and subject to resource constraints. An example problem is formulated and solved.The authors wish to acknowledge comments and suggestions offered by J. W. Blankenship and R. E. Kuenne.     

An outranking-based general approach to solving group multi-objective optimization problems

This paper presents a general approach to solving multi-objective programming problems with multiple decision makers. The proposal is based on optimizing a bi-objective measure of “collective satisfaction”. Group satisfaction is understood as a reasonable balance between the strengths of an agreeing and an opposing coalition, considering also the number of decision makers not belonging to any of these coalitions. Accepting the vagueness of “collective satisfaction”, even the vagueness of “person satisfaction”, fuzzy outranking relations and other fuzzy logic models are used.     

Reverse channel decisions for a fuzzy closed-loop supply chain

This article reports the results of a study that explores the decisions of reverse channel choice in a fuzzy closed-loop supply chain. Specifically, a manufacturer produces new products by using original components or by remanufacturing used products and wholesales the new products to the retailer who then sells them to the consumers. The used products are collected by the manufacturer or the retailer or a third party. The primary goal of this paper is to investigate the implications of three different used-product collection modes on the decisions of the manufacturer, the retailer, and the third party, and on their own profits in the expected value model. By using game theory and fuzzy theory, the firms optimal strategies are obtained.     

考虑随机扰动的群体决策理性演化模型

在群体决策过程中,随机噪音对个体理性和群体理性的变化具有不可忽视的影响.针对存在随机扰动条件下群体决策理性的演化行为,在假设个体和群体理性之间存在作用叠加效果的基础上,建立了刻画个体和群体理性受随机噪声影响的个体和群体理性演化动力学模型,利用随机微分方程理论,论证了模型解的存在性和唯一性,在给定群体决策的随机扰动为白噪声的假设条件下得到了模型的解析解,讨论了群体决策中两个重要参数:理性作用强度和随机干扰作用强度对于群体理性演化的影响.理论分析结果表明:群体决策理性的演化行为取决于这两个参数的相对大小,存在着三条不同的演化路径,数值算例验证了模型的合理性和有效性,并对群体理性的演化行为进行了直观说明,对于深入认识群体决策规律和提高决策质量具有积极的理论和实际意义.     

Business models for public emission reduction projects

This study investigates two business models for public emission reduction projects that promote low-carbon behavior, issue corresponding carbon credits, and facilitate the trade of carbon credits at the individual level. We construct two dynamic game-theoretical models to investigate the project owner's business model selection strategy, optimal operational decisions, and the effectiveness of the two business models in reducing carbon emissions.