Knowledge Reduction in Incomplete Systems Based on γ–Tolerance Relation

  • Da-kuan Wei
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4092)


The traditional rough set theory is a powerful tool to deal with complete information system, and its performance to process incomplete information system is weak, M.Kryszkiewcz has put forward the tolerance relation to handle the problem. however,the method may not be perfect on account of excessively many intersectional elements between classifications. This paper improves the tolerance relation proposed by M.Kryszkiewcz to obtain the γtolerance relation and γtolerance classes, presents rough set model for incomplete information system based on the γtolerance relation. The method of γtolerance relation is proved to be more superior to that of M.Kryszkiewcz’s tolerance relation. Finally, the conception of γattributes reduction is defined, and the algorithm of γattribute reduction is provided.


Rough set Tolerance relation γtolerance relation incomplete information system γattribute reduction 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Da-kuan Wei
    • 1
    • 2
  1. 1.School of Information EngineeringHunan University of, Science and EngineeringYongzhou, HunanP.R. China
  2. 2.School of AutomationNanjing University of Science, and TechnologyNanjing, JiangsuP.R. China

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