Abstract：Multi-granulation rough set method (MGRS) is one of new directions in rough set theory. It is a data modeling method in the context of multiple granular spaces. Firstly, a concept of distribution reduction is introduced to pessimistic multi-granulation rough model, and a granular space selection under multiple granular spaces is investigated. Then, the important measure of a granular space in this model is defined, and an algorithm is designed to obtain a granular space reduction in the pessimistic multi-granulation rough model. Finally, an example is employed to verify the validity of the proposed algorithm. The obtained results are much closer to the practical decision.
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2012, Vol. 25 
