Poset approaches to covering-based rough sets

Abstract

Rough set theory is a useful and effective tool to cope with granularity and vagueness in information system and has been used in many fields. However, it is hard to get the reduct of a covering in rough sets. This paper attempts to get the reduct of a covering at a high speed in theory. It defines upset and downset based on a poset in a covering, studies the relationship between reducible element and downset, and obtains some good results such as sufficient and necessary condition about the reducible element in a covering. © 2010 Springer-Verlag Berlin Heidelberg.