In this paper, some important issues of granularity are discussed mainly in information systems (ISs) based on binary relation. Firstly, the vector representati
This paper proposes a new model of facility location problem referred to as k-product uncapacitated facility location problem with multi-type clients. The k-pro
Rough set theory is a new mathematical tool to deal with vagueness and uncertainty. The classical rough set theory based on equivalence relation has made a grea