关键词: 粗糙集, 差别矩阵, 核, 修改

Abstract: The computation of a core of a decision table is one of important parts researched in rough set theory, which mostly is also a key step of many existing algorithms of attributes reduction. At present, many algorithms were proposed for the computation of a core. However, very little work has been done in case of updating.Thus,Ref[9] introduces an incremental updating algorithm of the computation of a core, but only considers the case of inserting. Therefore, in this paper, we introduce an updating algorithm of the computation of a core based on discernibility matrix in the case of updating, which only inserts, deletes or adjusts corresponding rows and columns when updating the discernibility matrix, so the updating efficiency of a core is remarkably improved. Experimental results show that the algorithm of this paper is efficient and effective.

Key words: rough set, discernibility matrix, core, updating