Almost compactness in fuzzy topological spaces

We introduce and study almost compactness for fuzzy topological spaces. We show that the almost continuous image of an almost compact fuzzy topological space is almost compact. Moreover, we show that generally almost compactness for fuzzy topological spaces is not product-invariant, but if X and Y are almost fuzzy topological spaces and X is product related to Y, then their fuzzy topological product is almost compact.     

Solution of fuzzy equations with extended operations

Assuming that 1 is any operation defined on a product set X × Y and taking values on a set Z, it can be extended to fuzzy sets by means of Zadeh's extension principle. Given a fuzzy subset C of Z, it is here shown how to solve the equation $\text{A 1 B = C}$ (or $\text{A 1 B ? C}$) when a fuzzy subset A of X (or a fuzzy subset B of Y) is given. The methodology we provide includes, as a special case, the resolution of fuzzy arithmetical operations, i.e. when 1 stands for +, ?, × or ÷, extended to fuzzy numbers (fuzzy subsets of the real line). The paper is illustrated with several examples in fuzzy arithmetic.     

正规环的Fuzzy双侧理想

本文首先提出正规环的Fuzzy双侧理想的定义,讨论了Fuzzy双侧理想和Fuzzy理想之间的关系,给出对环、Fuzzy对环、左(右)零环等概念,并在正规环中研究了它们的性质。最后在超正规环和完全正规环中研究了Fuzzy双侧理想和Fuzzy理想,得出一些有趣的结果。     

Fuzzy群的半格

引入 Fuzzy群的半格的概念 ,并讨论它们的一些代数性质。同时利用 Fuzzy理想对 Fuzzy群的半格作了一些等价刻画。     

-可分解Fuzy关系及其*-传递性

对［０，１］上一般的算子‘＊’引入＊－紧Ｆｕｚｚｙ关系及其○＊－可分解Ｆｕｚｙ关系的概念，证明了有单位元１的保序算子‘＊’及有单位元０的保序算子‘＊－’所定义的○＊－可分解和○＊－－可分解Ｆｕｚｚｙ关系在某种意义上构成了新的可传递Ｆｕｚｚｙ关系类，并且还给出了这些类在不同类型的传递性之间的一种位置关系，特别地，对二元○∨－可分解Ｆｕｚｚｙ关系，该文还得到了一个关于其传递性的完全刻画．     

A note on chance constrained programming with fuzzy coefficients

This paper deals with nonlinear chance constrained programming as well as multiobjective case and goal programming with fuzzy coefficients occurring in not only constraints but also objectives. We also present a fuzzy simulation technique for handling fuzzy objective constraints and fuzzy goal constraints. Finally, a fuzzy simulation based genetic algorithm is employed to solve a numerical example.     

A fuzzy genetic algorithm with varying population size to solve an inventory model with credit-linked promotional demand in an imprecise planning horizon

A genetic algorithm (GA) with varying population size is developed where crossover probability is a function of parents’ age-type (young, middle-aged, old, etc.) and is obtained using a fuzzy rule base and possibility theory. It is an improved GA where a subset of better children is included with the parent population for next generation and size of this subset is a percentage of the size of its parent set. This GA is used to make managerial decision for an inventory model of a newly launched product. It is assumed that lifetime of the product is finite and imprecise (fuzzy) in nature. Here wholesaler/producer offers a delay period of payment to its retailers to capture the market. Due to this facility retailer also offers a fixed credit-period to its customers for some cycles to boost the demand. During these cycles demand of the item increases with time at a decreasing rate depending upon the duration of customers’ credit-period. Models are formulated for both the crisp and fuzzy inventory parameters to maximize the present value of total possible profit from the whole planning horizon under inflation and time value of money. Fuzzy models are transferred to deterministic ones following possibility/necessity measure on fuzzy goal and necessity measure on imprecise constraints. Finally optimal decision is made using above mentioned GA. Performance of the proposed GA on the model with respect to some other GAs are compared.     

(m,n)模糊超环

介绍(m,n)超环等一些相关概念,之后将(m,n)超环模糊化,给出(m,n)模糊超环的定义,初步探讨(m,n)模糊超环的结构和性质,分析(m,n)模糊超环在同态下的不变性。     

收益模糊合作对策Shapley值的公理化

研究一类收益模糊的合作对策,这类对策联盟的模糊收益值可以用一个闭区间的形式来表示,本文定义了一个拓展的闭区间空间和一些闭区间线性运算算子,证明了这类对策的Shapley值可以用承载性、可替代性和可加性进行了公理化.     

基于直觉模糊规划的多目标投资组合选择模型

将直觉模糊集合的概念引入投资组合模型中,并将多目标投资组合模型中的收益、方差和偏度三个目标模糊化,用隶属函数与非隶属函数作为新的目标函数.针对该模糊多目标投资组合模型,提出了一个动态遗传算法,算例给出了该模型的一个实例的最优解.