三层粒结构区间集信息系统上变精度粗糙集

Variable Precision Rough Sets on Interval Set Information System with Three-layer Granular Structure

区间集信息系统作为传统信息系统的扩张,对不确定性信息具有更强表现力,区间集信息系统上面的变精度粗糙集理论值得被探讨.挖掘区间集信息系统上的三层粒结构(相似粒向量,相似粒覆盖和相似等价类),基于这三种粒结构研究了区间集信息系统上的变精度粗糙集理论.定义了区间集信息系统上变精度粗糙集上和下近似算子,由上和下近似算子得到变粗糙度和精度.与此同时诱导变精度三支域,最终获得其不确定性度量变精度依赖度,属性内重要度和外重要度.通过实例对模型和不确定性度量进行了验证.

As an extension of traditional information system,interval set information system has more expressive power for uncertain information.Variable precision rough set theory on interval set information system is worth discussing.Three kinds of granular structures(similar granular vector,similar granular covering and similar equivalence class) on interval set information system are mined.Based on these three granular structures,variable precision rough set theory on interval set information system is studied.The upper and lower approximations of variable precision rough sets in interval set information system are defined,and three variable precision domains are induced by the upper and lower approximations.Finally,the uncertainty measurement variable precision dependence degree,attribute inner importance degree and outer importance degree are obtained.The model and uncertainty measurement are verified by an example.