A New Attribute Reduction Recursive Algorithm Based On Granular Computing

Existing representative research achievement of attribute reduction mainly focused on two aspects. One is how to improve the efficiency of attribute reduction algorithms for all attributes including the added properties. Such as the recursive algorithm to change conjunctive normal form into disjunctive normal form based on the Boolean matrix and algorithm based on radix sorting for computing core and reductions of a given information system, etc. On the other hand focus on objects recursive algorithms. The drawback is that these methods have not fully use knowledge gained when some attributes was added to a discussion on domain. Therefore, in this paper, the regularity of core and reduction's changes under adding new attributes into a given information system were discussed. Moreover, the new incremental recursive reduction algorithms from an information system were proposed based on Granular computing. Experiments show that these algorithms can quickly and exactly calculate new core and reduction of new information system by taking advantage of knowledge of previous information system.