Some Problems For Multigranulation Variable Precision Rough Sets

The promotion of rough set theory is an important research subject in rough set theory study. In this paper, We introduce multigranulation variable precision rough set model, which is based on the characteristics of variable precision rough set and multigranulation rough set, then we study the characteristics of the model. Firstly, we introduce the concepts of multigranulation variable precision rough set; Secondly, we study the attribute reduction problem based on the multigranulation variable precision rough set; Finally, we get further improvements of the model.The main work is as follows:1, we introduce definition of upper and lower approximation operator on the multigranulation variable precision set, and discuss the structural characteristics of operator space.2, we introduce the concept of attribute reduction of multigranulation variable precision set based on Decision Information Systems, and discuss the properties of attribute reduction and give some equivalent statements of the attribute reduction.3, we improve the multigranulation variable precision set model, giving appropriate concepts.