基于不完备信息系统的三角模糊数决策粗糙集

在不完备信息系统中,针对用区间值表示一个未知参量时,整个区间内取值机会被认为是均等的,得到的结果可能会产生过大误差的问题,将三角模糊数引入到决策粗糙集中,提出了一种基于不完备信息系统的三角模糊数决策粗糙集。首先,定义了一种描述不完备信息的相似关系;然后,针对不完备信息系统中的缺失值,利用三角模糊数来获取损失函数,构建了三角模糊数决策粗糙集模型;实例表明,本文提出的方法不仅能够弥补用区间数表示的不足,而且可以突出可能性最大的主值,从而减少分类误差。     

基于改进的可能度优势关系的排序方法研究

优势关系是解决多属性决策问题的一种重要方法,也是研究不完备区间值信息系统的一种重要方法。在不完备区间值信息系统排序方法的研究中,针对属性过多从而可能引起排序失效的问题,提出了一种改进的可能度优势关系排序方法。这种新的排序方法把区间值优势关系和可能度相结合来改进经典优势关系定义的不足,并给出了平均综合优势度的定义。最后,通过与 ∝-β优势关系和容差优势关系等排序方法在具体算例中的比较分析,证明了改进的可能度优势关系排序方法不仅能够解决不完备区间值信息系统中的问题,而且能够使排序结果更合理、有效。     

区间值模糊决策序信息系统的分布约简

因信息系统的复杂性和不确定性,对象的属性值难以用精确的数值来表达,而是采用区间形式表示。针对这一问题,对区间值进一步模糊化,并引进优势关系,建立了不协调区间值模糊序决策信息系统。通过分布约简和最大分布约简来简化知识的表达,找出二者之间的关系,得到了分布约简和最大分布约简的判定定理以及可辨识属性集和可辨识矩阵;提供了不协调的区间值模糊序信息系统的分布约简和最大分布约简的具体方法;结合投资风险这一具体案例的求解分析,进一步阐述了对分布约简研究的意义,丰富了区间值模糊序决策信息系统中的粗糙集方法。     

区间值模糊决策序信息系统的部分一致约简

实际问题中,事物的一些属性值介于某个范围之间,常被用来刻画信息系统中的不确定信息。为了表达这种情况,属性值通常用模糊区间来表示,这种信息系统就是区间值模糊信息系统。本文通过在带有决策的区间值模糊信息系统中引入优势关系,建立区间值模糊决策序信息系统。在此基础上构造部分一致函数来简化知识的表达,并获得部分一致约简的判定定理,通过可辨识属性集和可辨识矩阵提供不协调的区间值模糊序信息系统的部分一致约简的具体方法,并结合投资风险这一具体案例的求解分析,进一步阐述了对部分一致约简研究的意义,丰富了区间值模糊序决策信息系统中的粗糙集方法。     

基于改进的优势关系下的不完备区间值信息系统评估模型

优势粗糙集方法是研究不完备区间值信息系统的一种重要方法。针对当前不完备区间值信息系统研究中存在的问题,提出了两种新的优势关系,即上限优势关系和近似优势关系。在此基础上,研究了对象评估和不确定性度量问题,给出了不同优势关系间的区别与联系,最后利用具体算例加以说明。     

区间序信息系统及其属性约简算法

在不含决策属性的区间序信息系统中,区间偏序关系的不完备性造成信息流失。针对该问题,提出一种新的基于区间模糊数的区间序全序关系,以此建立区间序信息系统,并分析其相关上、下近似的单调性和包含性。采用不可区分函数的方法,给出区间序信息系统的属性约简算法,并通过算例验证了该算法的有效性。     

三参数区间灰数信息下系统属性约简方法

针对属性评价值为三参数区间灰数的不完备信息系统,提出了一种基于[θ]-灰色优势关系的信息系统属性约简方法。根据三参数区间灰数的定义,给出两个三参数区间灰数基于可能度的大小关系,在此基础上,构建方案属性值之间的一种[θ]-灰色优势关系,并结合可辨识矩阵,给出了这类不完备信息系统属性约简方法。应用实例表明了方法的合理性和有效性。     

单向S-区间值模糊粗糙集及应用

以Z.Pawlak粗集理论为基础,将动态区间值模糊近似概念引入区间值模糊粗糙集中。由此提出了单向S-区间值模糊粗糙集概念,给出了单向S-区间值模糊粗糙集的结构与性质。定义了单向S-区间值模糊粗糙集的粗相等、截集、粗糙度等概念,并对一些相关性质进行讨论和证明;给出了单向S-区间值模糊粗糙集的应用及存在价值。     

基于不完备区间值信息系统的决策粗糙集

在不完备区间值信息系统中,提出一种基于极大相容类的决策粗糙集模型。首先,针对不完备区间值信息系统中属性相似度存在的缺陷,对属性相似度进行改进。其次,在不完备区间值信息系统中,由于容差关系下建立粗糙集模型存在冗余度高、分类精度低的问题,采用极大相容类代替等价类,结合贝叶斯最小风险决策原则,建立决策粗糙集模型。经证明,基于极大相容类建立粗糙集模型可有效提高分类精度。最后,基于正域分布不变的原则提出基于区分矩阵的属性约简算法并将该算法应用于实例。     

一种基于区间值模糊推理的控制器设计

本文在区间值模糊匹配推理基础上,设计了一种区间值模糊控制器。为了应用区间值模糊匹配推理方法,文中给出了一种清晰量的区间值模糊化方法,最后用实例说明区间值模糊控制器设计过程以及给出Matlab仿真控制效果。     

Incomplete interval-valued intuitionistic fuzzy preference relations

The aim of this paper is to investigate decision making problems with interval-valued intuitionistic fuzzy preference information, in which the preferences provided by the decision maker over alternatives are incomplete or uncertain. We define some new preference relations, including additive consistent incomplete interval-valued intuitionistic fuzzy preference relation, multiplicative consistent incomplete interval-valued intuitionistic fuzzy preference relation and acceptable incomplete interval-valued intuitionistic fuzzy preference relation. Based on the arithmetic average and the geometric mean, respectively, we give two procedures for extending the acceptable incomplete interval-valued intuitionistic fuzzy preference relations to the complete interval-valued intuitionistic fuzzy preference relations. Then, by using the interval-valued intuitionistic fuzzy averaging operator or the interval-valued intuitionistic fuzzy geometric operator, an approach is given to decision making based on the incomplete interval-valued intuitionistic fuzzy preference relation, and the developed approach is applied to a practical problem. It is worth pointing out that if the interval-valued intuitionistic fuzzy preference relation is reduced to the real-valued intuitionistic fuzzy preference relation, then all the above results are also reduced to the counterparts, which can be applied to solve the decision making problems with incomplete intuitionistic fuzzy preference information.     

Generalized interval-valued fuzzy variable precision rough sets determined by fuzzy logical operators

The fuzzy rough set model and interval-valued fuzzy rough set model have been introduced to handle databases with real values and interval values, respectively. Variable precision rough set was advanced by Ziarko to overcome the shortcomings of misclassification and/or perturbation in Pawlak rough sets. By combining fuzzy rough set and variable precision rough set, a variety of fuzzy variable precision rough sets were studied, which cannot only handle numerical data, but are also less sensitive to misclassification. However, fuzzy variable precision rough sets cannot effectively handle interval-valued data-sets. Research into interval-valued fuzzy rough sets for interval-valued fuzzy data-sets has commenced; however, variable precision problems have not been considered in interval-valued fuzzy rough sets and generalized interval-valued fuzzy rough sets based on fuzzy logical operators nor have interval-valued fuzzy sets been considered in variable precision rough sets and fuzzy variable precision rough sets. These current models are incapable of wide application, especially on misclassification and/or perturbation and on interval-valued fuzzy data-sets. In this paper, these models are generalized to a more integrative approach that not only considers interval-valued fuzzy sets, but also variable precision. First, we review generalized interval-valued fuzzy rough sets based on two fuzzy logical operators: interval-valued fuzzy triangular norms and interval-valued fuzzy residual implicators. Second, we propose generalized interval-valued fuzzy variable precision rough sets based on the above two fuzzy logical operators. Finally, we confirm that some existing models, including rough sets, fuzzy variable precision rough sets, interval-valued fuzzy rough sets, generalized fuzzy rough sets and generalized interval-valued fuzzy variable precision rough sets based on fuzzy logical operators, are special cases of the proposed models.     

Dominance-based rough set approach to incomplete interval-valued information system

Since preference order is a crucial feature of data concerning decision situations, the classical rough set model has been generalized by replacing the indiscernibility relation with a dominance relation. The purpose of this paper is to further investigate the dominance-based rough set in incomplete interval-valued information system, which contains both incomplete and imprecise evaluations of objects. By considering three types of unknown values in the incomplete interval-valued information system, a data complement method is used to transform the incomplete interval-valued information system into a traditional one. To generate the optimal decision rules from the incomplete interval-valued decision system, six types of relative reducts are proposed. Not only the relationships between these reducts but also the practical approaches to compute these reducts are then investigated. Some numerical examples are employed to substantiate the conceptual arguments.     

区间直觉模糊粗糙集

将模糊粗糙集推广到区间直觉模糊粗糙集,基于区间直觉模糊等价关系和两个论域之间的一般区间直觉模糊关系,给出了区间直觉模糊粗糙集模型的不同形式,并讨论了一些相关性质。     

Rough set theory for the interval-valued fuzzy information systems

The notion of a rough set was originally proposed by Pawlak [Z. Pawlak, Rough sets, International Journal of Computer and Information Sciences 11 (5) (1982) 341-356]. Later on, Dubois and Prade [D. Dubois, H. Prade, Rough fuzzy sets and fuzzy rough sets, International Journal of General System 17 (2-3) (1990) 191-209] introduced rough fuzzy sets and fuzzy rough sets as a generalization of rough sets. This paper deals with an interval-valued fuzzy information system by means of integrating the classical Pawlak rough set theory with the interval-valued fuzzy set theory and discusses the basic rough set theory for the interval-valued fuzzy information systems. In this paper we firstly define the rough approximation of an interval-valued fuzzy set on the universe U in the classical Pawlak approximation space and the generalized approximation space respectively, i.e., the space on which the interval-valued rough fuzzy set model is built. Secondly several interesting properties of the approximation operators are examined, and the interrelationships of the interval-valued rough fuzzy set models in the classical Pawlak approximation space and the generalized approximation space are investigated. Thirdly we discuss the attribute reduction of the interval-valued fuzzy information systems. Finally, the methods of the knowledge discovery for the interval-valued fuzzy information systems are presented with an example.     

区间直觉模糊信息系统中的信息粒度

区间直觉模糊信息系统比一般信息系统更能全面、细致、直观地描述和刻画决策信息,对其进行不确定性研究具有重要的意义。利用信息粒度对区间直觉模糊信息系统的不确定性进行了刻画,给出了区间直觉模糊粒度结构的交、并、差、补等四种运算。提出了区间直觉模糊粒度结构上的三种偏序关系,并建立了它们之间的联系。定义了区间直觉模糊信息粒度和区间直觉模糊信息粒度的公理化,并研究它们的性质。     

Fuzzy rough set theory for the interval-valued fuzzy information systems

The concept of the rough set was originally proposed by Pawlak as a formal tool for modelling and processing incomplete information in information systems, then in 1990, Dubois and Prade first introduced the rough fuzzy sets and fuzzy rough sets as a fuzzy extension of the rough sets. The aim of this paper is to present a new extension of the rough set theory by means of integrating the classical Pawlak rough set theory with the interval-valued fuzzy set theory, i.e., the interval-valued fuzzy rough set model is presented based on the interval-valued fuzzy information systems which is defined in this paper by a binary interval-valued fuzzy relations RF⁽ⁱ⁾(U×U) on the universe U. Several properties of the rough set model are given, and the relationships of this model and the others rough set models are also examined. Furthermore, we also discuss the knowledge reduction of the classical Pawlak information systems and the interval-valued fuzzy information systems respectively. Finally, the knowledge reduction theorems of the interval-valued fuzzy information systems are built.     

区间直觉模糊连续熵及其多属性决策方法

提出了区间直觉模糊连续熵,并且研究了一种新的处理区间直觉模糊多属性决策问题的方法。基于连续有序加权平均（COWA）算子,给出了区间直觉模糊连续熵的概念,并且证明了区间直觉模糊连续熵满足区间直觉模糊熵的公理化定义的四个条件。在此基础上,针对属性权重信息完全未知的决策问题,通过衡量每一属性所含的信息量来确定属性权重。依据备选方案与理想方案间的加权相关系数,给出了一种新的区间直觉模糊多属性决策方法。实验结果验证了新的决策方法的可行性和有效性。     

基于覆盖的区间直觉模糊粗糙集

在经典的覆盖近似空间中,定义了区间直觉模糊概念的粗糙近似。通过区间直觉模糊覆盖概念,给出了一种基于区间直觉模糊覆盖的区间直觉模糊粗糙集模型。讨论了两种模型的一些相关性质。