A generalized definition of rough approximation based on similarity in variable precision rough sets
Shixin Zhao, Zi-Ru Zhang · 2005
Variable precision rough set theory (VPRS) is an important extension of rough set theory; it incorporates the use of indiscernibility relation (equivalence relation) to approximate sets of objects by /spl beta/-lower and /spl beta/-upper approximation. This paper extends the concepts to the case of more general relation - similarity relation. /spl beta/-lower and /spl beta/-upper approximation are proposed, which are extensional definitions of the classical concepts /spl beta/-lower and /spl beta/-upper approximation.