Rough sets and topological spaces

Rough set theory is a powerful mathematical tool for dealing with inexact, uncertain or vague information. The fundamental concepts of rough set theory are information systems, equivalence relations and approximation operators of approximation spaces. The starting point of this theory is data set which consists of objects and attiributes obtained from measurements and human experts. Topology is a branch of mathematics and has many applications. It is a tool to study information systems and rough sets. Approximation operators draw close links between rough set theory and topology. Using topology and neighborhood system is established a model of granular computing. In this thesis, generalized approximation spaces via topological methods and topological properties of rough sets are investigated.