非侵入式负荷监测(non-intrusive load monitoring,NILM)是研究居民用户负荷信息的常用方法,但存在分解准确度低、算法泛化性能低等系列问题。为此,该文应用图信号处理(graph signal processing,GSP)理论,提出一种基于图信号交替优化的...非侵入式负荷监测(non-intrusive load monitoring,NILM)是研究居民用户负荷信息的常用方法,但存在分解准确度低、算法泛化性能低等系列问题。为此,该文应用图信号处理(graph signal processing,GSP)理论,提出一种基于图信号交替优化的居民用户NILM方法。该方法根据总负荷数据构建图信号模型,并基于图信号模型得到关于功率损耗的约束条件,较好地解决了传统方法缺乏负荷数据相关性研究的问题。相比于传统方法需要对模型参数多次调整,交替优化法可以自动调整参数,提高了实时监测能力,降低了电网运营成本。仿真结果表明,在1min采样率下,基于图信号交替优化法的总负荷分解准确度比NILM-GSP提高了15%,计算时间降低了10%,充分体现了该文算法性能的优越性。展开更多
Fuzzy clustering has been used widely in pattern recognition, image processing, and data analysis An improved fuzzy clustering algorithm was developed based on the conventional fuzzy c-means （FCM） to obtain better q...Fuzzy clustering has been used widely in pattern recognition, image processing, and data analysis An improved fuzzy clustering algorithm was developed based on the conventional fuzzy c-means （FCM） to obtain better quality clustering results. The update equations for the membership and the cluster center are derived from the alternating optimization algorithm. Two fuzzy scattering matrices in the objective function assure the compactness between data points and cluster centers, and also strengthen the separation between cluster centers in terms of a novel separable criterion. The clustering algorithm properties are shown to be an improvement over the FCM method＇s properties. Numerical simulations show that the clustering algorithm gives more accurate clustering results than the FCM method.展开更多
This paper investigates subcarrier and power allocation in a multi-UAV OFDM system.The study considers a practical scenario,where certain subcarriers are unavailable for dynamic subcarrier allocation,on account of pre...This paper investigates subcarrier and power allocation in a multi-UAV OFDM system.The study considers a practical scenario,where certain subcarriers are unavailable for dynamic subcarrier allocation,on account of pre-allocation for burst transmissions.We first propose a novel iterative algorithm to jointly optimize subcarrier and power allocation,so as to maximize the sum rate of the uplink transmission in the multiUAV OFDM system.The key idea behind our solution is converting the nontrivial allocation problem into a weighted mean square error(MSE) problem.By this means,the allocation problem can be solved by the alternating optimization method.Besides,aiming at a lower-complexity solution,we propose a heuristic allocation scheme,where subcarrier allocation and transmit power allocation are separately optimized.In the heuristic scheme,closedform solution can be obtained for power allocation.Simulation results demonstrate that in the presence of stretched subcarrier resource,the proposed iterative joint optimization algorithm can significantly outperform the heuristic scheme,offering a higher sum rate.展开更多
研究了一种透射反射双功能可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)系统。部署STA...研究了一种透射反射双功能可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)系统。部署STAR-RIS以辅助从多天线接入点(Access Point,AP)到多个单天线信息解码接收器(Information Decoding Receiver,IDR)和能量收集接收器(Energy Harvesting Receiver,EHR)的信息或功率传输。目标是通过联合优化其发射预编码矩阵及STAR-RIS的反射和透射系数矩阵,在IDR可实现通信速率和EHRs的能量收集量约束下,使AP的发射功率最小化。然而,这个优化问题是非凸的,变量之间有着复杂的耦合。为了解决这一问题,采用交替优化算法解耦耦合的变量,对发射预编码矩阵及STAR-RIS的反射和透射系数矩阵可以分别使用半正定松弛(Semidefinite Relaxation,SDR)算法和基于惩罚的算法进行优化。仿真结果表明,STAR-RIS系统方案可以获得比传统的仅反射或仅透射RIS更好的性能。展开更多
文摘非侵入式负荷监测(non-intrusive load monitoring,NILM)是研究居民用户负荷信息的常用方法,但存在分解准确度低、算法泛化性能低等系列问题。为此,该文应用图信号处理(graph signal processing,GSP)理论,提出一种基于图信号交替优化的居民用户NILM方法。该方法根据总负荷数据构建图信号模型,并基于图信号模型得到关于功率损耗的约束条件,较好地解决了传统方法缺乏负荷数据相关性研究的问题。相比于传统方法需要对模型参数多次调整,交替优化法可以自动调整参数,提高了实时监测能力,降低了电网运营成本。仿真结果表明,在1min采样率下,基于图信号交替优化法的总负荷分解准确度比NILM-GSP提高了15%,计算时间降低了10%,充分体现了该文算法性能的优越性。
基金Supported by the National Excellent Doctoral Dissertation Foundation(No. 200041) and the National Key Basic Research and Development (973) Program of China (No. G2002cb312205)
文摘Fuzzy clustering has been used widely in pattern recognition, image processing, and data analysis An improved fuzzy clustering algorithm was developed based on the conventional fuzzy c-means （FCM） to obtain better quality clustering results. The update equations for the membership and the cluster center are derived from the alternating optimization algorithm. Two fuzzy scattering matrices in the objective function assure the compactness between data points and cluster centers, and also strengthen the separation between cluster centers in terms of a novel separable criterion. The clustering algorithm properties are shown to be an improvement over the FCM method＇s properties. Numerical simulations show that the clustering algorithm gives more accurate clustering results than the FCM method.
基金supported by China NSF Grants(61631020)the Fundamental Research Funds for the Central Universities(NP2018103,NE2017103,NC2017003)
文摘This paper investigates subcarrier and power allocation in a multi-UAV OFDM system.The study considers a practical scenario,where certain subcarriers are unavailable for dynamic subcarrier allocation,on account of pre-allocation for burst transmissions.We first propose a novel iterative algorithm to jointly optimize subcarrier and power allocation,so as to maximize the sum rate of the uplink transmission in the multiUAV OFDM system.The key idea behind our solution is converting the nontrivial allocation problem into a weighted mean square error(MSE) problem.By this means,the allocation problem can be solved by the alternating optimization method.Besides,aiming at a lower-complexity solution,we propose a heuristic allocation scheme,where subcarrier allocation and transmit power allocation are separately optimized.In the heuristic scheme,closedform solution can be obtained for power allocation.Simulation results demonstrate that in the presence of stretched subcarrier resource,the proposed iterative joint optimization algorithm can significantly outperform the heuristic scheme,offering a higher sum rate.
文摘研究了一种透射反射双功能可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)系统。部署STAR-RIS以辅助从多天线接入点(Access Point,AP)到多个单天线信息解码接收器(Information Decoding Receiver,IDR)和能量收集接收器(Energy Harvesting Receiver,EHR)的信息或功率传输。目标是通过联合优化其发射预编码矩阵及STAR-RIS的反射和透射系数矩阵,在IDR可实现通信速率和EHRs的能量收集量约束下,使AP的发射功率最小化。然而,这个优化问题是非凸的,变量之间有着复杂的耦合。为了解决这一问题,采用交替优化算法解耦耦合的变量,对发射预编码矩阵及STAR-RIS的反射和透射系数矩阵可以分别使用半正定松弛(Semidefinite Relaxation,SDR)算法和基于惩罚的算法进行优化。仿真结果表明,STAR-RIS系统方案可以获得比传统的仅反射或仅透射RIS更好的性能。
