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。
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.
出处
《计算机工程与应用》
CSCD
北大核心
2008年第28期149-151,共3页
Computer Engineering and Applications
关键词
不完备信息系统
特征关系
粗糙集
知识约简
incomplete information system
characteristic relation
rough set
knowledge reduction
