Covering based approximation - a new type approach

摘要

The rough set theory, proposed by Pawlak is termed as basic (traditional) rough set theory and it has been .extended in many directions. Covering based rough set is one of the extensions of the basic rough set theory. A covering is a generalisation of notion of partitioned rough set (Pawalk rough set) introduced by W. Zakowski. In this article it is introduced a new type of covering-based rough set in which both lower and upper approximation operators are improved.