基于依赖空间的变精度粗糙集属性约简

Attribute Reduction in Variable Precision Rough Set Based on Dependence Space

针对求解变精度粗糙集模型属性约简问题,在对象集上定义一种上下近似二元关系.利用此关系建立属性集上的等价关系,由此构造出依赖空间,从而得到变精度粗糙集的上下近似协调集的判定定理.同时建立一种保持每个决策类的上下近似不变的属性约简方法.最后通过实例验证方法的有效性.

To get the attribute reduction in variable precision rough set model, an upper and lower approximation binary relation is defined on object sets. By applying the binary relation, the equivalence relation is constructed on attribute sets and thus a dependence space is produced. Then, theorems for judging upper and lower approximation consistent sets are obtained. Meanwhile, a new attribute reduction method is proposed to preserve some invariant characters of upper and lower approximation in each decision class. Finally, a practical example illustrates the validity of the proposed method.