关键词: 覆盖广义粗糙集;上近似;下近似;等价关系;覆盖信息系统

Abstract:

It is a very important issue that one unites the covering generalized rough set and the classical rough set in the theory of covering generalized rough set. The covering rough set can thus be transformed into the classical one, which can extend their applications to the context of  covering information systems. Several significant properties for simplifying the research of  covering rough sets are obtained. The analysis shows that the proposed method is much easier and more intuitive to understand  than the existing method based on an equal domain relation. In addition, an example is employed to show that the covering rough set not only  be transformed into the classical one but can also  improve the approximation accuracy of the target concept.

Key words: covering generalized rough sets; upper approximation; lower approximation; equivalence relation; covering information system