关键词: 策信息系统, 知识约简, 核属性, 粗糙集

Abstract: Discernibility matrix is an important method for knowledge reduction in rough set theory, the number of elements in discernibility matrix will directly influence the computation efficiency of knowledge reduction algorithm based on discernibility matrix method, in view of the time complexity and space complexity of these algorithms are not good, the main reason is that computing and storing the discernibility matrix of decision information system consumes a large of time and the discernibility matrix include many empty elements. For this issue, new construction method for discernibility matrix is proposed, which can delete all empty elements in discernibility matrix. On these bases, an algorithm for knowledge reduction in decision information system is presented, the algorithm can effectively consider core attribute in decision information system, which further improve the efficiency of the algorithm. Finally, an example result shows the feasibility of the proposed algorithm.

Key words: decision information system, core attribute, discernibility matrix, rough set