Abstract: In this paper, the definition of a simply discernibility matrix and correspondence core are provided. It is proved that this core is the core of the discernibility matrix. On the foundation, a new computing core algorithm is designed, and the time complexity and space complexity of the new algorithm are cut down max{O(|C||U/C||U/C|),O(|C||U|)} and max{O(|C||U/C||U/C|),O(|U|)}respectively.

Key words: Rough set, Dicernibility matrix, Simply discernibility matrix, Core, Complexity

摘要： 给出简化差别矩阵和相应核的定义,并证明该核与差别矩阵的核是等价的.在此基础上设计了一个新的求核算法,使得新算法的时间复杂度和空间复杂度分别被降为 max{O(|C||U/C||U/C|),O(|C||U|)}和max{O(|C||U/C||U/C|),O(|U|)} .

关键词: 粗糙集, 差别矩阵, 简化差别矩阵, 核, 复杂度