粗函数依赖是粗关系数据库理论体系中的重要环节,粗数据分析方法是计算包括数据库在内的各类信,急不确定性的重要方法.本文从粗集理论出发研究了粗关系模型及其数据库实例的粗函数依赖问题.根据粗关系数据库中数据的语义联系构造了粗关系数据库实例元组之间的二元关系,研究了其性质.在此基础上,从信息熵的角度定义了粗函数依赖概念,并研究了它的性质及其满足的推理规则.
The rough functional dependency theory play an important role in the theory set of rough relational database, and the rough sets data analysis is an important method for calculating several kinds of information uncertainty including rough databases. In this paper, the rough functional dependency of RRDM and its examples are studied by use of the rough sets theory. The binary relation between database tuples is firstly constructed according to the semantic connection between dates of RRDB, and its properties are also researched. Based on these, the paper propose a new definition of the concept of rough functional dependency of RRDM from the viewpoint of information entropy, its properties and some inference rules based on rough functional dependency are discussed finally.