Rough Set Model based on Union Neighborhood

Abstract

The rough set idea was presented asan approach to deal with the ambiguity or uncertainty of the data in information systems. The neighborhood (nbd) system is an essential tool for reducing the boundary area and increasing the accuracy of the measurement. The main focus of the present paperis to introduce the new type of union nbds (briefly, ????ʝ-nbds) and to establish their properties. These ????ʝ-nbds are applied to obtain the concept of ????ʝ-lower approximation and ????ʝ-upper approximation, and ????ʝ-accuracy measure. Their properties are proposed. Finally, a medical application to demonstrate the significance of ????ʝ-nbds is presented