Abstract:

It is crucial to develop rough set theory under incomplete information systems,which is implemented by extending the classical rough set theory.In this paper,several extensions of rough set under incomplete information systems are analyzed.Then a novel extension of rough set based on the τ limited tolerance relation is proposed and some concepts such as upper approximation,lower approximation,generalized decision,discernibility function are defined.Finally,three examples are showed to demonstrate advantages of the new extension．

摘要：

对经典粗糙集理论进行适当扩充使其适用于不完备信息系统,是把粗糙集理论进一步推向实用的关键。在分析已有的几个不完备信息系统的粗糙集扩充模型的基础上,提出了τ限制容差关系,并将上近似、下近似、广义决策函数、区分矩阵等概念在该关系下进行了定义,最后通过实例说明了新模型相较于已有模型的优越性。