基于下近似的粗糙度不等式  

Inequality of roughness measures based on lower approximation

作　　者：卢鹏[1] 吴建乐[2] 

机构地区：[1]西南交通大学峨眉校区基础课部,四川峨眉614212 [2]西南交通大学数学学院,四川成都610031

出　　处：《西南民族大学学报（自然科学版）》2013年第3期357-361,共5页Journal of Southwest Minzu University(Natural Science Edition)

摘　　要：给出一个新的粗糙度定义,并证明在这种定义下,下近似具有与上近似一样的不等式及其充分条件;最后,针对文献[1]中提出的关于粗糙模糊集的粗糙度不等式及等号成立的充分条件,给出了使等号成立且更一般的两个等价的充分条件.A new definition of the rough degree is proposed, and lower approximation has the same inequality and the sufficient condition as upper approximation under the new definition. Based on the sufficient condition about the rough degree inequality of rough fuzzy sets in this literature [ 1 ], the paper proposes two kinds of sufficient condition of inequality of rough degree that can make the inequality into equality. Then it shows that they are equivalent.

关 键 词：粗糙集 模糊集 粗糙度 上近似 下近似 

分 类 号：O189.13[理学—数学]