智能系统学报2018，Vol.13Issue(2)：327-330,4.DOI:10.11992/tis.201607018
集族等价与基于粒的下近似算子研究
On collections equivalence and the granule based lower approximation operators
摘要
Abstract
Covering based rough set is one of the methods to extend the classical rough set theory. There are three kinds of approaches, the element based definition, the granule based definition, and the subsystem based definition, to define upper and lower approximation. Most of the literature in the past tends to define based on element. In order to study the properties of the granule based approximation operators, especially the lower approximation operator, referring the con-cepts of irreducible element and reducible element from lattice theory, the concept of collections reduct is put forward. Starting from the concept of collections reduct, the concept and properties of collections equivalence are discussed, and collections reduction algorithm is designed. The result that collections equivalence is the necessary and sufficient condi-tion for generating the same lower approximation by collections is given here. The preliminary theoretical preparation is done here to further develop the axiomatization of the granule based approximation operators under general binary rela-tion.关键词
近似算子/约简/粗集/既约元/可约元/覆盖/粒/集族约简Key words
approximation operators/reduct/rough sets/irreducible element/reducible element/covering/granule/col-lections reduct分类
信息技术与安全科学引用本文复制引用
胡霞,费鹏,杜卫锋..集族等价与基于粒的下近似算子研究[J].智能系统学报,2018,13(2):327-330,4.基金项目
国家自然科学基金项目(61202109). （61202109）
