摘要
分析Pawlak粗糙集上下近似具有的性质,结合上下近似的含义和近似精度,讨论覆盖粗糙集上近似的定义方法,提出覆盖粗糙集最小上近似的概念,对其存在性及唯一性进行分析。最后,讨论最小上近似与其他上近似的关系,并对此作了证明。
In this paper,the characteristics of lower and upper approximation based on Pawlak rough set theory are introduced and analyzed. Combined with approximation-degree, the method of defining upper approximation on covering rough set theory is studied. Then,a new concept named minimal upper approximation is proposed,and its existence and uniqueness are analyzed. In the end, this paper presents and proves the relationship between minimal upper approximation and other upper approximations.
出处
《广西师范大学学报（自然科学版）》
CAS
北大核心
2010年第3期93-98,共6页
Journal of Guangxi Normal University:Natural Science Edition
基金
国家自然科学基金资助项目(60873077/F020107)
关键词
粗糙集
覆盖
上近似
最小上近似
rough set
covering
upper approximation
minimal upper approximation
