We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurement...We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurements and the Kalman filter updates with partial packet, the statistical properties of estimator error covariance matrix iteration and stability of the estimator are studied. It is shown that to guarantee the stability of the Kalman filter, the communication network is required to provide for each of the sensor measurements an associated throughput, which captures all the rates of the successive sensor measurements losses. We first investigate a general discrete-time linear system with the observation partitioned into two parts and give sufficient conditions of the stable estimator. Furthermore, we extend the results to a more general case where the observation is partitioned into n parts. The results are illustrated with some simple numerical examples.展开更多
We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scatteri...We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.展开更多
特高频内置传感器布置在气体绝缘金属封闭开关设备(gas insulated switchgear,GIS)内部,可以实时监测局部放电产生的特高频(ultra high frequency,UHF)电磁波信号,然而长期运行过程中受到设备振动、环境温度等因素的影响,内置传感器自...特高频内置传感器布置在气体绝缘金属封闭开关设备(gas insulated switchgear,GIS)内部,可以实时监测局部放电产生的特高频(ultra high frequency,UHF)电磁波信号,然而长期运行过程中受到设备振动、环境温度等因素的影响,内置传感器自身性能可能会发生劣化,从而导致无法准确监测到局部放电信号,因此有必要研究内置传感器的现场校验方法,便于定期对运行中的内置传感器的性能开展评估。文中根据GIS特高频内置传感器的结构原理和多端口网络理论,分析了内置传感器回波损耗的物理意义,确认回波损耗可有效反映内置传感器的运行状态。根据GIS典型气室的结构尺寸,建立了特高频内置传感器等比例的三维仿真模型,并通过回波损耗曲线的仿真结果与现场实测数据对比,验证了仿真模型的正确性。进一步仿真研究了内置传感器介质层绝缘劣化、馈电杆接触不良两种典型缺陷时的回波损耗曲线特征,为运行中的内置传感器现场校验与缺陷诊断提供了参考。展开更多
基金supported by National Natural Science Foundation of China (No. 60504017)Fok Ying Tong Education Foundation(No. 111066)Program for New Century Excellent Talents in University (No. NCET-04-0982)
文摘We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurements and the Kalman filter updates with partial packet, the statistical properties of estimator error covariance matrix iteration and stability of the estimator are studied. It is shown that to guarantee the stability of the Kalman filter, the communication network is required to provide for each of the sensor measurements an associated throughput, which captures all the rates of the successive sensor measurements losses. We first investigate a general discrete-time linear system with the observation partitioned into two parts and give sufficient conditions of the stable estimator. Furthermore, we extend the results to a more general case where the observation is partitioned into n parts. The results are illustrated with some simple numerical examples.
基金supported by the 973 Program (Grant No. 2006CB921603)the 863 Program (Grant No. 2009AA01Z319)+3 种基金the National Natural Science Foundation of China (Grant Nos. 61008012, 11074154, 10934004, 60978018, 60978001, and 60808009)the National Natural Science Foundation of China for Excellent Research Team (Grant No. 60821004)the Natural Science Foundation of Shanxi Province of China (Grant No. 2009011059-2)the New Teacher Fund of the Ministry of Education of China (Grant No. 20101401120004)
文摘We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.
文摘特高频内置传感器布置在气体绝缘金属封闭开关设备(gas insulated switchgear,GIS)内部,可以实时监测局部放电产生的特高频(ultra high frequency,UHF)电磁波信号,然而长期运行过程中受到设备振动、环境温度等因素的影响,内置传感器自身性能可能会发生劣化,从而导致无法准确监测到局部放电信号,因此有必要研究内置传感器的现场校验方法,便于定期对运行中的内置传感器的性能开展评估。文中根据GIS特高频内置传感器的结构原理和多端口网络理论,分析了内置传感器回波损耗的物理意义,确认回波损耗可有效反映内置传感器的运行状态。根据GIS典型气室的结构尺寸,建立了特高频内置传感器等比例的三维仿真模型,并通过回波损耗曲线的仿真结果与现场实测数据对比,验证了仿真模型的正确性。进一步仿真研究了内置传感器介质层绝缘劣化、馈电杆接触不良两种典型缺陷时的回波损耗曲线特征,为运行中的内置传感器现场校验与缺陷诊断提供了参考。
