Research On Several Problems Of Multi-granularity Variable Precision Soft Rough Set

In this world,due to the arrival of the information age,the information contains a large amount of useful information,but also contains a large number of miscellaneous information,which affect people's correct judgment of things.Under such circumstances,how to remove the miscellaneous information in large quantities of information and pick out information that is truly useful for people has become a hot topic for scholars to study in recent years.In this paper,based on the theory of multi-granularity,soft set theory and variable precision rough set,we have studied a model that combines the three theories is multi-granularity variable precision soft rough set.The advantage of this model is that it can not only make the granular structure of the information space not be destroyed,but also ensure that the decision-making result more objective and discover relevant data from unrelated data.This paper first introduces the development status of multi-granularity theory,variable precision rough set and soft set theory both at home and abroad,and finds out the existing deficiencies to find the theoretical basis for the new model.Secondly,this paper introduces the basic theoretical knowledge of multi-granularity theory,variable precision rough set and soft set theory.Then,a multi-granularity variable soft rough set model and its related definitions and properties are deduced.A weighted probability soft rough set model and generalized multi-granularity probability soft rough set models are given,and corresponding definitions and simple derivation of properties are given.Finally,this paper proposes a multi-granularity soft decision system based on multi-granularity variable precision rough set model,and further studies its reduction algorithm,and apply it to instances.