The Reaserch On Some Problem Of Intuitionistic Fuzzy Information System

Rough set theory is a mathematical tool for dealing with uncertain,imprecise and in-complete information.One important research of rough set is the rough approximations and attribute reduction.Intuitionistic fuzzy set is an extension of fuzzy set theory,which is more precise to describe the fuzzy phenomena.This thesis aims to study on upper and lower ap-proximation reductions and uncertainty measures of generalized incomplete intuitionistic fuzzy information system,based on ?-dominance relation ext.ension of intuitionistic fuzzy information system.· A similarity dominance relations is introduced in the generalized incomplete intuitionistic fuzzy information system.the definition of upper and lower approximation reductions based on similarity dominance relation is given,the discernibility matrix is constructed the detailed operation method of the upper and lower approximation reductions is obtained.· The definition of rough entropy and conditional entropy is introduced in the generalized incomplete intuitionistic fuzzy information system,heuristic attribute reduction algorithm based on condition entropy is designed,and the example is employed to illustrate the effectiveness of the algorithm.· The degree of ?-dominance ?-dominance relation,?-dominance reductions are intro-duced in intuitionistic fuzzy informatian system,?-dominance-based rough set and a-dominance-based intuitionistic fuzzy rough set are constructed.Moreover,the method of upper and lower approximation reduction based on ?-dominance relation is designed in intuitionistic fuzzy infor-mation system.