A ternary semigroup is a nonempty set together with a ternary multiplication which is associative. Any semigroup can be reduced to a ternary semigroup but a ternary semigroup does not necessarily reduce to a semigroup. The notion of fuzzy sets was introduced by Zadeh in 1965 and that of rough sets by Pawlak in 1982. Applications of the fuzzy set theory and rough set theory have been found in va...

In this article we discuss the connection of Rough Set methods and submodular functions. We show that discernibility measure used in reduct calculation is submodular and provides a bridge between certain methods from Rough Set theory and Submodular Function theory.

This model for fuzzy rough sets is one of the most important parts in rough set theory. Moreover, it is based on an equivalence relation (indiscernibility relation). However, many systems are not only concerned with fuzzy sets, but also based on a dominance relation because of various factors in practice. To acquire knowledge from the systems, construction of model for fuzzy rough sets based on...

Web ontologies can contain vague concepts, which means the knowledge about them is imprecise and then query answering will not possible due to open world assumption. A concept description be very exact (crisp concept) or (fuzzy if its complete, otherwise it inexact (vague incomplete. In this paper, we propose a method based on rough set theory for reasoning ontologies. With method, detection of...