关键词: 模糊信息系统, 粗糙集, 模糊粗糙集, 相对约简

Abstract: Considering the fuzzy information system, based on incompact approximation operator defined by R. Jensen, a strict approximation operator is constructed that can ensure monotone increasing of lower approximation with the attributes number of information system. The conceptions of relative reduction about fuzzy information system are given, and a heuristic knowledge reduction algorithm is proposed by dependency degree. The effectiveness of the proposed algorithm is illustrated by applying it to the knowledge reduction of an information system for threat level assessment.

Key words: fuzzy information system, rough set, fuzzy rough set, relative reduction