In ultra-high-dimensional data, it is common for the response variable to be multi-classified. Therefore, this paper proposes a model-free screening method for variables whose response variable is multi-classified fro...In ultra-high-dimensional data, it is common for the response variable to be multi-classified. Therefore, this paper proposes a model-free screening method for variables whose response variable is multi-classified from the point of view of introducing Jensen-Shannon divergence to measure the importance of covariates. The idea of the method is to calculate the Jensen-Shannon divergence between the conditional probability distribution of the covariates on a given response variable and the unconditional probability distribution of the covariates, and then use the probabilities of the response variables as weights to calculate the weighted Jensen-Shannon divergence, where a larger weighted Jensen-Shannon divergence means that the covariates are more important. Additionally, we also investigated an adapted version of the method, which is to measure the relationship between the covariates and the response variable using the weighted Jensen-Shannon divergence adjusted by the logarithmic factor of the number of categories when the number of categories in each covariate varies. Then, through both theoretical and simulation experiments, it was demonstrated that the proposed methods have sure screening and ranking consistency properties. Finally, the results from simulation and real-dataset experiments show that in feature screening, the proposed methods investigated are robust in performance and faster in computational speed compared with an existing method.展开更多
针对同步发电机故障预测与健康管理(Prognostics and Health Management,PHM)系统故障特征提取困难,信号容易受到噪声干扰,诊断结果可靠性低的缺点,本文以故障率较高的轴承故障为例,提出以小波包熵值作为故障特征,提取轴承典型故障的振...针对同步发电机故障预测与健康管理(Prognostics and Health Management,PHM)系统故障特征提取困难,信号容易受到噪声干扰,诊断结果可靠性低的缺点,本文以故障率较高的轴承故障为例,提出以小波包熵值作为故障特征,提取轴承典型故障的振动信号。通过小波包分析,计算出不同故障、不同故障程度的小波包Shannon熵值。与正常轴承对比进行故障程度预测及故障定位。仿真结果表明小波包Shannon熵值能够清楚地反映出轴承故障程度及故障位置,该方法简单可靠,进行故障预测及诊断效果显著,克服了传统故障特征提取方法的不足。展开更多
在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散...在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散度到分布式评价语言距离度量上,用于衡量专家之间的相似度;基于K-临近算法,设计改进的残缺评价信息补全方法;对专家信息进行集结并构建共识度量与反馈调节机制,得到群决策矩阵,并运用改进的EDAS(evaluation based on distance from average solution,离平均方案(平均解)距离)方法对方案进行排序;通过物流服务供应商综合评估算例验证该群决策方法的可行性和有效性。展开更多
文摘In ultra-high-dimensional data, it is common for the response variable to be multi-classified. Therefore, this paper proposes a model-free screening method for variables whose response variable is multi-classified from the point of view of introducing Jensen-Shannon divergence to measure the importance of covariates. The idea of the method is to calculate the Jensen-Shannon divergence between the conditional probability distribution of the covariates on a given response variable and the unconditional probability distribution of the covariates, and then use the probabilities of the response variables as weights to calculate the weighted Jensen-Shannon divergence, where a larger weighted Jensen-Shannon divergence means that the covariates are more important. Additionally, we also investigated an adapted version of the method, which is to measure the relationship between the covariates and the response variable using the weighted Jensen-Shannon divergence adjusted by the logarithmic factor of the number of categories when the number of categories in each covariate varies. Then, through both theoretical and simulation experiments, it was demonstrated that the proposed methods have sure screening and ranking consistency properties. Finally, the results from simulation and real-dataset experiments show that in feature screening, the proposed methods investigated are robust in performance and faster in computational speed compared with an existing method.
文摘针对同步发电机故障预测与健康管理(Prognostics and Health Management,PHM)系统故障特征提取困难,信号容易受到噪声干扰,诊断结果可靠性低的缺点,本文以故障率较高的轴承故障为例,提出以小波包熵值作为故障特征,提取轴承典型故障的振动信号。通过小波包分析,计算出不同故障、不同故障程度的小波包Shannon熵值。与正常轴承对比进行故障程度预测及故障定位。仿真结果表明小波包Shannon熵值能够清楚地反映出轴承故障程度及故障位置,该方法简单可靠,进行故障预测及诊断效果显著,克服了传统故障特征提取方法的不足。
文摘在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散度到分布式评价语言距离度量上,用于衡量专家之间的相似度;基于K-临近算法,设计改进的残缺评价信息补全方法;对专家信息进行集结并构建共识度量与反馈调节机制,得到群决策矩阵,并运用改进的EDAS(evaluation based on distance from average solution,离平均方案(平均解)距离)方法对方案进行排序;通过物流服务供应商综合评估算例验证该群决策方法的可行性和有效性。
