定义了两个域上的多数包含关系,借助引入误差参数β(0≤β〈0.5),提出了两个域上的覆盖变精度粗糙集模型,首先给出了该模型的β上近似、β下近似算子,以及边界域和负域的定义,讨论了它们的若干重要性质和定理,并给出了证明;其次将该模型与两个域上的覆盖粗糙集模型进行对比,找出了它们之间的关系,最后通过实例进一步证明该模型的优越性.
The majority inclusion relation over two different universes is defined. A covering variable precision rough set model over two different universes is proposed by means of the error parameter β(0≤β 〈0. 5). Firstly,β upper approximation,β lower approximation,boundary region and negative field are defined,several important properties and theorems of the upper approximation and the lower approximation are discussed and proved. Secondly,the relationship between the covering rough set model over two different universes is found by comparing with the present model. Finally,an example is illustrated to explain the advantages of the present model.