关键词: 知识发现, 粗糙集, 多重粗糙集, 变精度粗糙集, 多重集

Abstract: In order to solve the problem that the domain partition of Zaike variable precision rough set can not overlap, an expansion was made on the domain of Zaike variable precision rough set based on multi-set, a multiple variable precision rough set model was put forward, and its corresponding definitions, theorems and properties were fully described, which included definitions of multiple domain and multiple variable precision approximate sets, proofs of their properties, and relations between multiple Zaike variable precision rough set and multiple variable precision rough set. These definitions, theorems and properties have not only differences but also relations between multiple variable precision rough set and Zaike variable precision rough set. Multiple variable precision rough set can fully describe overlap among knowledge particles, difference of significance among objects and polymorphism of objects, and can conveniently find associated knowledge from data saved in a relation database, having one-to-many and many-to-many dependency, and thought to have no relations.

Key words: knowledge discovery, rough set, multiple rough set, variable precision rough set, multi-set