—Covering-based rough set theory is an extension to classical rough set. The main purpose of this paper is to study covering rough sets from a topological point of view. The relationship among upper approximations based on topological spaces are explored.
One of the most advantages of the Semantic Web is to augment the data with a well-defined meaning and linking between data by using the RDF ontology language. Today most of data are stored in relational databases. In order to reuse and infer this data on the Semantic Web, there is a need for converting the data stored in relational databases to the form of… (More)