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1.
不确定规划的研究现状及其发展前景   总被引:19,自引:0,他引:19  
本文简要介绍不确定规划理论、算法以及应用研究的现状,描绘了不确定规划理论的基本框架。首先介绍处理各种不确定性的数学工具;接着阐述不确定规划的建模机理与求解方法,然后提出了不确定规划中值得进一步研究的一些问题,最后展望了不确定规划的发展前景。  相似文献   

2.
模糊密度随机变量的数学描述   总被引:8,自引:2,他引:6  
研究了由于概率密度函数的模糊性而引起的模糊概率随机变量问题。给出了区间密度函数、模糊密度函数、模糊密度随机变量及其分布函数和模糊密度随机变量的模糊数学期望、模糊方差等基本概念及定义和计算方法,并证明了有关定理。  相似文献   

3.
Fuzzy random variables   总被引:1,自引:0,他引:1  
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4.
Summary LetX be a random variable from the one-parameter exponential family with the probability element β(θ) exp (θx)dm(x) for which an ambiguous prior information is available to the effect that θ is likely to be larger than or equal to a known constant. The information is represented by a fuzzy set with the membership function χ(θ). Then it is shown that is an admissible estimator for E 0 (X) under the quadratic loss function.  相似文献   

5.
刘长虹  陈虬 《应用数学和力学》2005,26(10):1191-1197
在多层圆筒结构稳态热传导分析中,根据给定固体壁两侧表面温度总传热量公式,首先推导出当边界温度为随机变量情况下总传热量函数统计参数的均值和方差;然后推导出在导热系数为模糊数,边界温度为随机数下的总传热量的区间表达式.通过比较可以知道由区间数算法得到的区间最大,由概率统计算法得到的区间最小.并给出了两者的相对误差公式.最后引进粗糙集中的上、下近似集,提出用一个参数来统一定义模糊和随机区间进行稳态结构的热传导分析.  相似文献   

6.
We prove that every hesitant fuzzy set on a set E can be considered either a soft set over the universe [0,1] or a soft set over the universe E. Concerning converse relationships, for denumerable universes we prove that any soft set can be considered even a fuzzy set. Relatedly, we demonstrate that every hesitant fuzzy soft set can be identified with a soft set, thus a formal coincidence of both notions is brought to light. Coupled with known relationships, our results prove that interval type-2 fuzzy sets and interval-valued fuzzy sets can be considered as soft sets over the universe [0,1]. Altogether we contribute to a more complete understanding of the relationships among various theories that capture vagueness and imprecision.  相似文献   

7.
Atanassov (1986) defined the notion of intuitionistic fuzzy set, which is a generalization of the notion of Zadeh’ fuzzy set. In this paper, we first develop some similarity measures of intuitionistic fuzzy sets. Then, we define the notions of positive ideal intuitionistic fuzzy set and negative ideal intuitionistic fuzzy set. Finally, we apply the similarity measures to multiple attribute decision making under intuitionistic fuzzy environment.  相似文献   

8.
针对模糊随机桁架结构的动力特性分析,提出了一种新的模糊随机有限元方法.当结构的物理参数和几何尺寸同时具有模糊随机性时,利用模糊因子法和随机因子法建立了结构刚度矩阵和质量矩阵;从结构振动的Rayleigh商表达式出发,利用区间运算推导出结构动力特性模糊随机变量的计算表达式;之后利用随机变量的矩法和代数综合法,推导出结构特征值的数字特征的计算式.通过算例分析了模糊随机桁架结构参数的模糊随机性对其动力特性的影响.该方法的优点是能准确反映结构某一参数的模糊随机性对结构特征值及其数字特征的影响.  相似文献   

9.
We consider a Cauchy problem in a random fuzzy setting. Under the condition of Lipschitzean right-hand side the existence and uniqueness of the solution is proven, also the continuous dependence on the right-hand side and initial condition is shown. Some kind of boundedness of the solution is established.  相似文献   

10.
We obtain necessary and sufficient conditions in the Large Deviation Principle for random upper semicontinuous functions on a separable Banach space. The main tool is the recent work of Arcones on the LDP for empirical processes.

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11.
本文将粗糙集理论与模糊集理论结合起来,给出一种图书馆最优选书算法.该算法首先从已知数据的初始信息系统出发,计算各选书方案之间的相似度,从而构造相似矩阵,然后根据相似矩阵的传递闭包对各方案进行聚类,并根据粗糙集理论求各属性重要性,最后利用加权综合的思想及最小距离方法选择最优买书方案.  相似文献   

12.
运用清晰集合的交、并运算、模糊集的分解定理,本文提出了一个用多个清晰集合构造一个模糊集合的简易方法,并将这个方法应用于模糊综合评判.本方法能将模糊综合评判中取值范围不同的指标的取值范围归一化为区间(0,1).实例表明,本方法在模糊综合评判领域是有效的、且易于操作,可以广泛应用于工程、社科等领域.  相似文献   

13.
The family of Ordered Weighted Averaging (OWA) operators, as introduced by Yager, appears to be very useful in multi-criteria decision-making (MCDM). In this paper, we extend a family of parameterized OWA operators to fuzzy MCDM based on vague set theory, where the characteristics of the alternatives are presented by vague sets. These families are specified by a few parameters to aggregate vague values instead of the intersection and union operators proposed by Chen. The proposed method provides a “soft” and expansive way to help the decision maker to make his decisions. Examples are shown to illustrate the procedure of the proposed method at the end of this paper.  相似文献   

14.
This paper concerns comparisons between attractors for random dynamical systems and their corresponding noiseless systems. It is shown that if a random dynamical system has negative time trajectories that are transient or explode with probability one, then the random attractor cannot contain any open set. The result applies to any Polish space and when applied to autonomous stochastic differential equations with additive noise requires only a mild dissipation of the drift. Additionally, following observations from numerical simulations in a previous paper, analytical results are presented proving that the random global attractors for a class of gradient-like stochastic differential equations consist of a single random point. Comparison with the noiseless system reveals that arbitrarily small non-degenerate additive white noise causes the deterministic global attractor, which may have non-zero dimension, to ‘collapse’. Unlike existing results of this type, no order preserving property is necessary.   相似文献   

15.
闭模糊集构成凸模糊集的充要条件   总被引:4,自引:1,他引:3  
本文通过引入弱拟凸模糊集的概念,针对欧几里空间上的闭模糊集,给出了它构成凸模糊集的一个充要条件,从而丰富了凸模糊集的理论及其应用。  相似文献   

16.
一方面,需要全面了解馆藏文物腐蚀现状,科学分析和评估造成馆藏文物腐蚀损失的原因,为馆藏文物长期保护提供科学依据和对策;另一方面,文物的腐蚀又是具有多样性、复杂性及不间断性的,每一腐蚀程度之间的界限并非十分清晰,而是连续模糊的,这为全面了解馆藏文物腐蚀现状带来了很大困难.因此,建立科学的模型对文物遭受腐蚀侵害的真实情况做出准确的描述迫在眉睫,利用模糊综合评判及其逆问题给出了科学严谨的具体模型.  相似文献   

17.
The natural language computing today demands for the study of ω-languages. Therefore in this respect it is convenient to consider fuzzy ω-languages. In this paper, the concept of fuzzy local ω-language, Büchi fuzzy local ω-language, and some closure properties of fuzzy local ω-languages are presented. We introduce deterministic fuzzy finite automaton with different acceptance mode on fuzzy ω-languages and establish the relationship between these various classes of fuzzy ω-languages. We have defined deterministic fuzzy local automaton and also establish relationships between deterministic fuzzy local automaton, fuzzy local ω-language and Büchi fuzzy local ω-language. Further we show that every fuzzy regular ω-language is a projection of a Büchi fuzzy local ω-language.  相似文献   

18.
离散型区间概率随机变量和模糊概率随机变量的数学期望   总被引:5,自引:0,他引:5  
研究离散型区间概率随机变量和离散型第二类模糊概率随机变量数学期望的性质及求解方法.利用模糊分解定理,把求模糊概率随机变量的数学期望问题化为求一系列区间概率随机变量的数学期望.求区间概率随机变量的数学期望是一个典型的线性规划问题,用单纯形方法推导了求区间概率随机变量数学期望的一个很实用的计算公式.算例表明,用该计算公式得到的结果和用数学规划方法得到的结果完全吻合,但计算过程相对简单.  相似文献   

19.
Szmidt and Kacprzyk (Lecture Notes in Artificial Intelligence 3070:388–393, 2004a) introduced a similarity measure, which takes into account not only a pure distance between intuitionistic fuzzy sets but also examines if the compared values are more similar or more dissimilar to each other. By analyzing this similarity measure, we find it somewhat inconvenient in some cases, and thus we develop a new similarity measure between intuitionistic fuzzy sets. Then we apply the developed similarity measure for consensus analysis in group decision making based on intuitionistic fuzzy preference relations, and finally further extend it to the interval-valued intuitionistic fuzzy set theory.  相似文献   

20.
随机次自相似集的表示   总被引:2,自引:0,他引:2  
胡迪鹤 《数学杂志》2001,21(4):361-367
本文引进了随机次自相似集与随机推移集的概念,讨论了随机次自相似集的结构,并证明了任一随机集是随机次自相似集的充分必要条件是:该随机集可以表为某一个随机推移集的某个像集。  相似文献   

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