模糊关系数据库的几点注记

Notes of fuzzy relational database

在讨论了模糊关系及其特征之后，给出了在元组隶属函数约束下的模糊关系λ－截集数据库和模糊关系模式的概念，引入并讨论了用模糊集包含度刻划的模糊属性值及元组的语义包含相似度及其性质．在此基础上，导出了经典函数依赖（ＦＤ）的４种相互等价的形式化定义，并由此扩展得到模糊函数依赖（ＦＦＤ）的相应形式化定义和相应于Ａｒｍｓｔｒｏｎｇ公理的有效且完备的推导规则．

The fuzzy relational and its character are discussed,it gives the concept of fuzzy relational λ section set database that is bound by function of membership,and the concept of fuzzy relational model.It introduces and discusses the semantic inclusion similar degree represented by inclusion degree of fuzzy set and its property.On the basis of these,the four equiralent each other,formal definitions of classical function dependency (FD) are derived,and so the similar formal definitions of fuzzy function dependency (FFD) are also derived,and it is shown that the inference rules of FFD,which are similar to classical case for Armstrong′s Axioms,are effective and complete.FFD in paper is special case.