On topological structure of fuzzy rough sets

This thesis essentially consists of seven chapters. In the first chapter, the subject of the thesis is introduced, in the second chapter, basic knowledges on fuzzy sets and fuzzy closure space are given in order to make understandable the reading of the thesis. The third chapter include basic definitions related with fuzzy rough sets and fuzzy approximation spaces. Moreover some theorems and characterizations concerning these topics are investigated. In the fourth chapter, the definition of fuzzy topology induced by fuzzy approximation space is given. Also topologies generated by reflexivity property and being preorder property in approximation space are discussed and the relationship between them is studied. In the fifth chapter, fuzzy approximation spaces induced by fuzzy topologies are handled and their properties are examined. After words, (TC) and (CC) axioms are investigated. In the final chapter, the concept of quasi-discrete fuzzy closure space is defined and relationship between quasi-discrete closure space and reflexive fuzzy aproximation space are examined.