Research On Hybrid Multi-granulation Rough Sets Based On Variable Precision Tolerance Relations

The development of information technology, making today’s society will be faced with the information explosion and information overload problem, because the amount of data is huge and complex, relying solely on general query the database retrieval and statistical methods to solve real needs far. Rough set theory to solve the huge amount of complex data provide solution ideas, including hybrid multi-granularity approach is a way of processing data. In this paper, the system is not perfect, the variable precision rough set theory and hybrid multi-granularity rough set theory together, proposed variable precision hybrid multi-granularity incomplete system under rough set model and incomplete mixing system under multi-granularity rough set model.This paper describes some of the rough set knowledge and content, such as rough set theory, variable precision rough set theory, make them have a preliminary understanding, then introduces the incomplete system and a hybrid multi-granularity rough set.Then a hybrid multi-granularity rough set model under incomplete system, gives the relevant definitions, theorems and properties, and the corresponding proof, and comparative analysis of multi-granularity incomplete mixing system under three different relationships rough set. Also on the basis of hybrid multi-granularity rough set model under incomplete system of above, the idea of adding variable precision constructed variable precision incomplete mixing system under multi-granularity rough set model, given the relevant definitions, theorems and properties and shall be proof.Finally, an example of multi-granularity analysis comparing variable precision mixing system under incomplete rough set model and incomplete mixing system under multi-granularity rough set model. Variable Precision incomplete mixing system under multi-granularity due to variable precision rough set model of thinking has resulted in larger and smaller lower approximation and upper approximation improve the approximation accuracy for handling incomplete system proposed a new theory.