期刊信息
- 刊名： 河北师范大学学报（自然科学版）Journal of Hebei Normal University (Natural Science)
- 主办： 河北师范大学
- ISSN： 1000-5854
- CN： 13-1061/N
- 中国科技核心期刊
- 中国期刊方阵入选期刊
- 中国高校优秀科技期刊
- 华北优秀期刊
- 河北省优秀科技期刊
The Upper and Lower Approximations of Fuzzy Sets in a Group
摘要/Abstract
粗糙集概念是由Pawlak于1982年提出的,现已从许多方面作了推广.粗糙集与模糊集的结合近年来越来越受到国际学术界的关注.现在研究群中模糊集的上、下近似,并且讨论了近似算子的乘积结构,定义了粗糙模糊子群的概念,证明了群的模糊子群一定是粗糙模糊子群.在同态映射下,子群的像的上下近似也一定是它的上、下近似的同态像
The theory of rough set is proposed by Z. Pawlak in 1982. It is extended from variouspoints of sides. T he combination of rough set and fuzzy set is studied by many authors. T he concepts ofupper and lower approximations of fuzzy sets in a group are given, and the product structure of ap-proximation operators is studied.The concept of rough fuzzy subgroup is also definde.It is proved thata fuzzy subgroup of a group is a rough fuzzy subgroup. Under a homostasis mapping,the upper andlower approximations of the images of a subgroup are just the images of their apper and lower approxi-mations.