关键词: 粗糙集, 覆盖, 对偶性, 约简, 上近似

Abstract: Covering-based rough set theory is an extension of the classical rough set theory. In a variety of definitions of approximations operations, duality is always the focus of debate. This paper analyses duality of approximation operations through the definable properties of positive region, negative region and boundary region. With duality, this paper shows how to choose approximation operations for different applications. This paper also investigates the duality of approximation operations in reduct covering. Finally, the paper analyzes two pairs of approximation operations satisfying the duality in covering-based rough sets.

Key words: rough sets, covering, duality, reduct, upper approximation