Computer Engineering and Applications ›› 2008, Vol. 44 ›› Issue (28): 149-151.DOI: 10.3778/j.issn.1002-8331.2008.28.050

• 数据库、信号与信息处理 • Previous Articles     Next Articles

Approaches to knowledge reductions in generalized incomplete systems

ZHOU Jing   

  1. School of Computer,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China
  • Received:2008-02-29 Revised:2008-05-26 Online:2008-10-01 Published:2008-10-01
  • Contact: ZHOU Jing


周 靖   

  1. 中国矿业大学 计算机学院,江苏 徐州 221008

  • 通讯作者: 周 靖

Abstract: The generalized incomplete system is deeply investigated in this paper.In such information system,“do not care” and lost unknown attribute values coexist.Based on the characteristic relation,the approach to knowledge reduction in the generalized information system is discussed.Moreover,the concepts of the lower and upper approximate distribution reductions are introduced into the generalized incomplete objective information system.The judgment theorems and discernibility formulas associated with these approximate distribution reductions are presented.Finally,an illustrative example is used to show the validity of the approaches to the lower and upper distribution reductions in the generalized objective information system.

Key words: incomplete information system, characteristic relation, rough set, knowledge reduction

摘要: 以同时具有丢失型和遗漏型未知属性值的广义不完备系统为研究对象,根据特征关系,讨论了广义不完备信息系统中的知识约简方法。在广义不完备目标信息系统中,引入了下、上近似分布约简的概念,并给出了相应的判定定理与辨识公式,最后用一个实例说明了此方法的有效性。

关键词: 不完备信息系统, 特征关系, 粗糙集, 知识约简