An Improved Incremental Updating Algorithm for the Core Computation of Decision Table

A rough set theory is a new mathematical tool to deal with uncertainty and vagueness of decision system, and the Computation of a Core is one of the most important problems of rough set. This paper introduces an improved algorithm based on discernibility matrix by Yang, and proposes an incremental updating algorithm for Core Computation. The space and time complexity of the new algorithm are cut down. The theoretical analysis and experiments shows the proposed reduction methods are an effective technique to deal with complex data sets.