Statistical convergence of sequences of fuzzy number valued functions

This thesis consists of three chapters. The first chapter is the introduction. In this chapter, different types of statistical convergence for sequences of real numbers and for sequences of real valued functions are given. Then, studies on statistical convergence of sequence of fuzzy numbers are summarized. In the second chapter, well known types of statistical convergence are given and the concept of alpha&beta-statistical convergence is introduced. alpha&beta-statistical pointwise convergence, alpha&beta-statistical uniform convergence, and alpha&beta-equi-istatistical convergence of sequences of real valued functions are defined and Korovkin type approximation theorems are proved by means of these concepts. Then basic definitions and concepts of fuzzy number theory are given and the concept of statistical convergence of sequences of fuzzy numbers and sequence of fuzzy number valued functions is presented. Third Chapter consists of contributions to the literature. In this chapter we define the concept of alpha&beta-equistatistical convergence for sequences of fuzzy number valued functions and properties of this type of convergence are investigated. Then a fuzzy Korovkin type approximation theorem is proved by means of alpha&beta-equistatistical convergence.