Triangular and parametric approximations of fuzzy numbers—inadvertences and corrections

Recent papers were dedicated to approximate fuzzy numbers by triangular, trapezoidal or parametric fuzzy numbers, with or without additional conditions. Unfortunately, the result of approximation is not always a fuzzy number, sometimes it is not a fuzzy set. We point out the wrongs and inadvertences in some recent papers, then we correct the results.     

模糊数的一种新运算方法及其若干应用

首先给出了模糊数的一种新的函数表示定理;基于该表示定理 ,提出了模糊数的一种新运算方法并将其直接应用到模糊数理论中若干问题的讨论,包括:模糊数的差问题,绝对值问题以及模糊数的确界问题 .     

Bell-shaped Fuzzy Soft Sets and Their Application in Medical Diagnosis

A soft set theory is a new general mathematical tool to dealing with imprecision. The theory differs from traditional mathematical tools to dealing with uncertainties in which many mathematical theories failed. In this paper, we proposed the concept of Bell shaped fuzzy soft set and its application in medical diagnosis using arithmetic operations of discrete- Gaussian fuzzy number, triangular-Cauchy fuzzy number and Gaussian-Cauchy fuzzy number. As an integral part of this paper, we discuss the parametric form of Gaussian membership function is discussed with some important properties.     

On the nearest parametric approximation of a fuzzy number

Many nearest parametric approximation methods of fuzzy sets are proposed in the literature. It is clear that the specific approximations may lead to the loss of information about fuzziness. To overcome this problem, most of these methods rely on the minimization of the distance between the original fuzzy set and its approximation. But these approximations mostly are not flexible to the decision maker's choice. Hence, in this paper, we offer a parametric fuzzy approximation method based on the decision maker's strategy as an extension of trapezoidal approximation of a fuzzy number. This method comprises the selection of the form of the parametric membership function and its evaluation.     

On the nearest parametric approximation of a fuzzy number—Revisited

The problem of finding the nearest parametric approximation of a fuzzy number with respect to the average Euclidean distance is completely solved. Properties of translation invariance, scale invariance, additivity, preservation of expected value, value and ambiguity of this new approximation operator are studied and an algorithm for computing it is provided.     

定义在复数上的复模糊值函数

把所有的关于y轴对称的模糊数都定义为零模糊数,则两个相同的模糊数的差为零,利用~ar-+~ar+这样一个数值来描述模糊数的序关系,就可以得到关于纵向对称的模糊数都是等同的.在此基础之上对实模糊数的模糊距离及极限进行了研究.并研究了复模糊数的距离与复模糊数列的极限以及复模糊值函数的极限.将研究的复模糊值函数是定义在复数集C上取值于F(C)(所有的复模糊数的集合)中的复模糊数的函数.在新的序关系意义下讨论复模糊值函数的极限,并讨论复模糊值函数的收敛性质及Cauchy收敛判别法等.     

Approximation of fuzzy numbers by trapezoidal fuzzy numbers preserving the expected interval

The problem to find the nearest trapezoidal approximation of a fuzzy number with respect to a well-known metric, which preserves the expected interval of the fuzzy number, is completely solved. The previously proposed approximation operators are improved so as to always obtain a trapezoidal fuzzy number. Properties of this new trapezoidal approximation operator are studied.     

梯形模糊数直觉模糊Bonferroni平均算子及其应用

本文研究决策信息为梯形模糊数直觉模糊数(TFNIFN)且属性间存在相互关联的多属性群决策(MAGDM)问题,提出一种基于梯形模糊数直觉模糊加权Bonferroni平均(TFNIFWBM)算子的决策方法.首先,介绍了TFNIFN的概念和运算法则,基于这些运算法则和Bonferroni平均(Bonferroni mean,BM)算子,定义了梯形模糊数直觉模糊Bonferroni平均算子和TFNIFWBM算子.然后,研究了这些算子的一些性质,建立基于TFNIFWBM算子的多属性群决策模型,结合排序方法进行决策.最后,将该方法应用在MAGDM中,算例结果表明了该方法的有效性与可行性.     

M-N Fuzzy Number Space and properties

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On Nash Equilibrium Strategy of Two-person Zero-sum Games with Trapezoidal Fuzzy Payoffs

In this paper, we investigate Nash equilibrium strategy of two-person zero-sum games with fuzzy payoffs. Based on fuzzy max order, Maeda and Cunlin constructed several models in symmetric triangular and asymmetric triangular fuzzy environment, respectively. We extended their models in trapezoidal fuzzy environment and proposed the existence of equilibrium strategies for these models. We also established the relation between Pareto Nash equilibrium strategy and parametric bi-matrix game. In addition, numerical examples are presented to find Pareto Nash equilibrium strategy and weak Pareto Nash equilibrium strategy from bi-matrix game.     

模糊数的正向和反向表述及模糊数运算的拓展

模糊数运算的存在不可逆等问题,主要在于传统(正向)区间数严格限定所致.因此,提出了"反向区间数"的概念,利用该概念,能够给经典模糊分解定理、扩张原理新的表达形式.之后,分别以正(反)向区间为基础,分析模糊数的结构元表达形式,得到正(反)向区间对应结构元理论中单调增(减)函数.定义了反向区间数和反向区间数加、乘运算法则,利用结构元理论,证明了正、反向模糊数的加、乘运算解析表达式,得到了模糊方程解的判断定理.在保持传统运算法则不变的同时,对模糊数概念进行正(反)向的表述,并定义了二者的运算法则,这拓展了传统模糊数解的空间,进而解决模糊方程求解、不可逆等问题.通过算例看出,这两种表述在实际的计算过程中具有明显的意义.     

Extending and relating different approaches for solving fuzzy quadratic problems

Quadratic programming problems are applied in an increasing variety of practical fields. As ambiguity and vagueness are natural and ever-present in real-life situations requiring solutions, it makes perfect sense to attempt to address them using fuzzy quadratic programming problems. This work presents two methods used to solve linear problems with uncertainties in the set of constraints, which are extended in order to solve fuzzy quadratic programming problems. Also, a new quadratic parametric method is proposed and it is shown that this proposal contains all optimal solutions obtained by the extended approaches with their satisfaction levels. A few numerical examples are presented to illustrate the proposed method.     

Solutions to fuzzy integral equations with arbitrary kernels

Using a parametric Riemann integral representation, a numerical algorithm for solving fuzzy Fredholm and Voltera integral equations of the second kind with arbitrary kernel is proposed and illustrated with examples.     

区间灰数直觉模糊集及其G-TOPSIS模糊多属性决策方法

提出以区间灰数为隶属度、非隶属度和犹豫度的区间灰数直觉模糊集概念,定义了两个区间灰数直觉模糊集之间的距离.对于以灰直觉模糊数为属性值的模糊多属性决策,依据经典TOPSIS准则,提出了基于区间灰数直觉模糊集的模糊多属性决策方法G-TOPSIS.其包含两种方法:一是将区间灰数白化后,按直觉模糊集的TOPSIS方法进行;一是基于区间灰数直觉模糊距离的TOPSIS方法.示例分析表明了两种方法的有效性与一致性.     

Robust control for Takagi–Sugeno fuzzy systems with time-varying state and input delays

The paper investigates the robust control for uncertain Takagi–Sugeno (T–S) fuzzy systems with time-varying state and input delays. Delay-dependent stabilization criterion is proposed to guarantee the asymptotic stabilization of fuzzy systems with parametric uncertainties. The result of [Lee HJ, Park JB, Joo YH. Robust control for uncertain Takagi–Sugeno fuzzy systems with time-varying input delay. ASME J Dyn Syst Meas Control 2005;127:302–6] is extended to uncertain fuzzy systems with time-varying state and input delays. Simulations show that significant improvement over the previous results can be obtained.     

Fuzzy幂群的基数定理

文（１）提出了幂群的概念，给出了幂群中各元素是等势的基数定理，文（２）提出了Ｆｕｚｚｙ幂群的概念，但没研究其中各元素的基数问题，本文深入研究这一问题，得到了由Ｄ．Ｄｕｂｏｉｓ等在文（３）中提出的和由李洪兴等在文（４）中提出的两种Ｆｕｚｚｙ集基数形式下的Ｆｕｚｚｙ幂群的基数定理，并给出了Ｆｕｚｚｙ幂群中与基数有关的若干结果。     

幂模糊数方程和二次模糊方程的结构元求解方法

定义了幂模糊数和幂模糊数方程,基于结构元方法研究了幂模糊数运算和幂模糊数方程的求解,给出了隶属函数的表达式.同时,利用区间[-1,1]上的单调函数将二次模糊方程的求解问题转化为经典参数方程组的求解问题,给出了二次模糊方程解存在的充要条件,并辅以数值例子.     

基于一类新的Picture模糊距离的VIKOR多属性决策方法

针对现有Picture模糊距离的不足。本文构建了一种带有参数的Picture模糊距离,该参数能够反映决策者的态度偏好。其次,将新距离拓展到多准则妥协解排序法(VIKOR)中,并利用新距离计算各备选方案的群体效益值和个体遗憾值进而获得决策结果。最后,通过算例验证所提决策方法的有效性和优点,并对参数进行灵敏度分析。     

Bi-matrix Games with Fuzzy Goals and Fuzzy

A bi-matrix game with fuzzy goal is shown to be equivalent to a (crisp) non-linear programming problem in which the objective as well as all constraint functions are linear except two constraint functions, which are quadratic. This equivalence is further extended to bi-matrix games with fuzzy pay-offs, as well as to bi-matrix games with fuzzy goals and fuzzy payoffs, whose equilibrium strategies are conceptualized by employing a suitable ranking (defuzzification) function.     

三角模糊数互补判断矩阵的一种排序方法及其在项目投资决策中的应用

引入Y ager第三指标将模糊数非模糊化,将专家判断矩阵中的三角模糊数转化成精确数,再利用精确数互补判断矩阵的排序方法进行排序.并通过实例说明了方法的可行性和有效性.