关键词: 程度粗糙模糊集, 逻辑且, 序信息系统, 粗糙集理论, 变精度粗糙模糊集

Abstract: By integrating variable precision rough fuzzy set and graded rough fuzzy set based on dominance relation, this paper proposes a rough fuzzy set model based on logical and operator of variable precision and grade in ordered information system, and gives the exact definitions of approximations operators and boundary. This model overcomes the shortcoming that the traditional logical and operator rough model cannot solve the problem of fuzzy concept, so the rough set of variable precision and degree has a wider application field. More, some important properties are discussed carefully. Finally, the solving method and significance of the model are shown by the employee case. The new model has extended variable precision rough set model, graded rough set model and classical rough set model, which provides some new theories about knowledge discovery in ordered information system.

Key words: graded rough fuzzy set, logical and operation, ordered information system, rough set theory, variable precision rough fuzzy set