Generalized parameterized approximations

  • Authors:
  • Jerzy W. Grzymala-Busse

  • Affiliations:
  • Department of Electrical Engineering and Computer Science, University of Kansas, Lawrence, KS and Institute of Computer Science, Polish Academy of Sciences, Warsaw, Poland

  • Venue:
  • RSKT'11 Proceedings of the 6th international conference on Rough sets and knowledge technology
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study generalized parameterized approximations, defined using both rough set theory and probability theory. The main objective is to study, for a given subset of the universe U, all such parameterized approximations, i.e., for all parameter values. For an approximation space (U,R), where R is an equivalence relation, there is only one type of such parameterized approximations. For an approximation space (U,R), where R is an arbitrary binary relation, three types of parameterized approximations are introduced in this paper: singleton, subset and concept. We show that the number of parameterized approximations of given type is not greater than the cardinality of U. Additionally, we show that singleton parameterized approximations are not useful for data mining, since such approximations, in general, are not even locally definable.