rough sets theory is a mathematical approach for analysis of a vague description of objects presented by a well-known mathematician, pawlak (1982, 1991). this paper explores the use of rough sets theory in site location investigation of buried concrete water reservoirs. making an appropriate decision in site location can always avoid unnecessary expensive costs which is very important in constr...

Virtual communities are not only used to share information among their members with common interests, but also an avenue of entertainments, networking with friends, and shopping. Recently, the main research topics on them include social networking, success factors, reasons for participating, and consequences from joining in virtual communities. Relative few works to discuss what important quali...