A New Approach to Attribute Reduction of Covering Information System

This paper focuses on eliminating data redundancy of covering information system. Firstly, we enumerate several usual covering reduction methods and analysis their contact among them. Secondly, we take the attributes value of explicit and implicit value into consider, and we obtain a network topology(shorthand as NT) of covering information sysytem. Through NT, we turn the covering information system into information system. Thirdly, we obtain the attribute reduction of information system through the "effect rough degree", ( shorthand as NT ERD-RM). Finally, we proved the particle of the methods combined with an example. Our study can enrich the existing attribute reduction theories and methods to a certain extent.