针对Hilbert-Huang变换方法中由于信号经验模态分解(empirical mode decomposition,简称EMD)过程中所存在的端点效应问题,分析了现有数据延拓方式的利弊,并在基于斜率(slope based method,简称SBM)方法以及改进方法(improved slope base...针对Hilbert-Huang变换方法中由于信号经验模态分解(empirical mode decomposition,简称EMD)过程中所存在的端点效应问题,分析了现有数据延拓方式的利弊,并在基于斜率(slope based method,简称SBM)方法以及改进方法(improved slope based method,简称ISBM)的基础上提出了一种全新的基于斜率再优化(reoptimization slope based method,简称RO-SBM)方法用于信号序列的极值点延拓,然后对延拓后的数据进行EMD分解,得到相应的本征模函数(intrinsic mode function,简称IMF)分量。数值仿真结果表明,采用基于RO-SBM方法进行数据延拓,相比镜像延拓以及ISBM方法,可以更有效地抑制EMD中的端点效应问题,提升HHT方法的信号分析性能。通过基于RO-SBM方法进行数据延拓的HHT方法准确分离出了某转子系统的局部碰摩径向振动信号中所包含的故障特征分量,并将此方法成功应用于旋转机械故障诊断领域。展开更多
为研究营商环境推动共同富裕的机制路径,首先,运用熵权-TOPSIS(technique for order preference by similarity to an ideal solution,优劣解距离法)模型测度2013—2023年长江经济带营商环境和共同富裕指数;其次,运用Super SBM-DEA(supe...为研究营商环境推动共同富裕的机制路径,首先,运用熵权-TOPSIS(technique for order preference by similarity to an ideal solution,优劣解距离法)模型测度2013—2023年长江经济带营商环境和共同富裕指数;其次,运用Super SBM-DEA(super efficiency data envelopment analysis,超效率数据包络分析)模型测算绿色创新效率;最后,运用面板回归模型和中介效应模型,研究营商环境对共同富裕的直接影响,以及通过提高绿色创新效率所产生的间接影响。长江经济带各省绿色创新效率均呈现逐年上升的趋势,但存在显著的区域差异,上游、中游和下游绿色创新效率的均值分别为0.513、0.583、1.078;营商环境对共同富裕的影响在1%水平上显著为正,且能通过提高绿色创新效率促进共同富裕;营商环境对共同富裕的影响在下游地区最为显著,而对中上游地区的影响较弱。本研究结果可为推动共同富裕的实现提供实证依据,对长江经济带制定提高共同富裕水平政策具有重要意义。展开更多
This study takes the panel data of 278 prefecture-level cities in China from 2011 to 2022 as samples,constructs a super-efficiency SBM model to measure urban energy-environment efficiency,uses the entropy method to sy...This study takes the panel data of 278 prefecture-level cities in China from 2011 to 2022 as samples,constructs a super-efficiency SBM model to measure urban energy-environment efficiency,uses the entropy method to synthesize the digital economy composite index,and introduces the green innovation index as a mediating variable.Breaking through the traditional analysis framework in the empirical method:Firstly,through the fixed-effects model and mediating-effect test,it reveals the direct impact of the digital economy on energy-environment efficiency and the transmission path of green innovation.Secondly,it divides the eastern,central,and western regions and low-carbon pilot cities for heterogeneity tests to identify the moderating effect of policy intervention.Thirdly,it strengthens the robustness of the conclusions by replacing the super-efficiency CCR model,shortening the sample period,and performing winsorization.The study finds that the digital economy significantly improves energy-environment efficiency through green technology innovation.These conclusions provide an empirical basis for optimizing the layout of digital infrastructure and improving the regional collaborative emission-reduction mechanism.展开更多
文摘针对Hilbert-Huang变换方法中由于信号经验模态分解(empirical mode decomposition,简称EMD)过程中所存在的端点效应问题,分析了现有数据延拓方式的利弊,并在基于斜率(slope based method,简称SBM)方法以及改进方法(improved slope based method,简称ISBM)的基础上提出了一种全新的基于斜率再优化(reoptimization slope based method,简称RO-SBM)方法用于信号序列的极值点延拓,然后对延拓后的数据进行EMD分解,得到相应的本征模函数(intrinsic mode function,简称IMF)分量。数值仿真结果表明,采用基于RO-SBM方法进行数据延拓,相比镜像延拓以及ISBM方法,可以更有效地抑制EMD中的端点效应问题,提升HHT方法的信号分析性能。通过基于RO-SBM方法进行数据延拓的HHT方法准确分离出了某转子系统的局部碰摩径向振动信号中所包含的故障特征分量,并将此方法成功应用于旋转机械故障诊断领域。
文摘为研究营商环境推动共同富裕的机制路径,首先,运用熵权-TOPSIS(technique for order preference by similarity to an ideal solution,优劣解距离法)模型测度2013—2023年长江经济带营商环境和共同富裕指数;其次,运用Super SBM-DEA(super efficiency data envelopment analysis,超效率数据包络分析)模型测算绿色创新效率;最后,运用面板回归模型和中介效应模型,研究营商环境对共同富裕的直接影响,以及通过提高绿色创新效率所产生的间接影响。长江经济带各省绿色创新效率均呈现逐年上升的趋势,但存在显著的区域差异,上游、中游和下游绿色创新效率的均值分别为0.513、0.583、1.078;营商环境对共同富裕的影响在1%水平上显著为正,且能通过提高绿色创新效率促进共同富裕;营商环境对共同富裕的影响在下游地区最为显著,而对中上游地区的影响较弱。本研究结果可为推动共同富裕的实现提供实证依据,对长江经济带制定提高共同富裕水平政策具有重要意义。
文摘This study takes the panel data of 278 prefecture-level cities in China from 2011 to 2022 as samples,constructs a super-efficiency SBM model to measure urban energy-environment efficiency,uses the entropy method to synthesize the digital economy composite index,and introduces the green innovation index as a mediating variable.Breaking through the traditional analysis framework in the empirical method:Firstly,through the fixed-effects model and mediating-effect test,it reveals the direct impact of the digital economy on energy-environment efficiency and the transmission path of green innovation.Secondly,it divides the eastern,central,and western regions and low-carbon pilot cities for heterogeneity tests to identify the moderating effect of policy intervention.Thirdly,it strengthens the robustness of the conclusions by replacing the super-efficiency CCR model,shortening the sample period,and performing winsorization.The study finds that the digital economy significantly improves energy-environment efficiency through green technology innovation.These conclusions provide an empirical basis for optimizing the layout of digital infrastructure and improving the regional collaborative emission-reduction mechanism.
