In this paper,a novel definition of entropy is introduced. It is used for measuring the uncertainty of roughness of knowledge in tolerant rough sets. In addition ,we prove that the entropy of knowledge decreases monot...In this paper,a novel definition of entropy is introduced. It is used for measuring the uncertainty of roughness of knowledge in tolerant rough sets. In addition ,we prove that the entropy of knowledge decreases monotonously as the granularity of information becomes smaller. Then,a new reduction algorithm based on entropy is developed.Simulation results show that the algorithm can find the minimal reduction in most cases.展开更多
提出CF-WFCM算法,该算法分为属性权重学习算法和聚类算法两部分.属性权重学习算法,从数据自身的相似性出发,通过梯度递减算法极小化属性评价函数CFuzziness(w),为每个属性赋予一个权重.将属性权重应用于Fuzzy C Mean聚类算法,得到CF-WFC...提出CF-WFCM算法,该算法分为属性权重学习算法和聚类算法两部分.属性权重学习算法,从数据自身的相似性出发,通过梯度递减算法极小化属性评价函数CFuzziness(w),为每个属性赋予一个权重.将属性权重应用于Fuzzy C Mean聚类算法,得到CF-WFCM算法的聚类算法.CF-WFCM算法强化重要属性在聚类过程中的作用,消减冗余属性的作用,从而改善聚类的效果.我们选取了部分UCI数据库进行实验,实验结果证明:CF-WFCM算法的聚类结果优于FCM算法的聚类结果.函数CFuzziness(w)不仅可以评价属性的重要性,而且可以评价属性评价函数的优劣.实验说明了这一问题.最后我们对CF-WFCM算法进行了讨论.展开更多
文摘In this paper,a novel definition of entropy is introduced. It is used for measuring the uncertainty of roughness of knowledge in tolerant rough sets. In addition ,we prove that the entropy of knowledge decreases monotonously as the granularity of information becomes smaller. Then,a new reduction algorithm based on entropy is developed.Simulation results show that the algorithm can find the minimal reduction in most cases.
文摘提出CF-WFCM算法,该算法分为属性权重学习算法和聚类算法两部分.属性权重学习算法,从数据自身的相似性出发,通过梯度递减算法极小化属性评价函数CFuzziness(w),为每个属性赋予一个权重.将属性权重应用于Fuzzy C Mean聚类算法,得到CF-WFCM算法的聚类算法.CF-WFCM算法强化重要属性在聚类过程中的作用,消减冗余属性的作用,从而改善聚类的效果.我们选取了部分UCI数据库进行实验,实验结果证明:CF-WFCM算法的聚类结果优于FCM算法的聚类结果.函数CFuzziness(w)不仅可以评价属性的重要性,而且可以评价属性评价函数的优劣.实验说明了这一问题.最后我们对CF-WFCM算法进行了讨论.