Abstract:

 The interval-valued  information system is generalized model of single-valued information system. Four dominance relations are introduced to intervalvalued information system, and some important properties and relationships among four dominance relations are analyzed. Furthermore, based on limitations of four dominance relations, a novel dominance relation——α-dominance relation is proposed. And then, an extended Rough set model based on α-dominance relation is defined. Finally, through a teacher evaluation issue, performances of these extended rough set models based on dominance relation are also compared.
 

Key words: interval-valued information system; dominance relation; α-dominance relation; Rough set