Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid ...Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid (UTISAG), which is based on the previous version. In this version, a new architecture and more enhanced services are introduced, The. remarkable characteristic of the new system is providing dynamic information services for travelers by grid technology. Therefore, the key research includes integrating large multi-source traffic data, forecasting route status, simulating regional traffic flow parallelly, and implementing optimum dynamic travel scheme based on massive GPS data.展开更多
Many high performance database servers are becoming idle with the tax data being integrated to country tax data centers. We make use of the idle servers to set up a provincial tax Grid based on open Grid service archi...Many high performance database servers are becoming idle with the tax data being integrated to country tax data centers. We make use of the idle servers to set up a provincial tax Grid based on open Grid service architecture （OGSA）. We put forward practical methods to integrate databases, to define and create basic modular Grid services and apply agent to manage Grid services. This technical innovation scheme is of a service-oriented architecture （SOA） and succeeds in averting resources waste. Tests proved that it greatly improves the quality of tax services.展开更多
In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of ne...In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.展开更多
Maximum power point tracking(MPPT)systems are being developed to produce switching pulses with proper duty ratios for power switches to exert photovoltaic(PV)panels under maximum instantaneous generated power,usually ...Maximum power point tracking(MPPT)systems are being developed to produce switching pulses with proper duty ratios for power switches to exert photovoltaic(PV)panels under maximum instantaneous generated power,usually through a traditional DC-DC boost converter.The fundamental issue,particularly for micro-grid and small-scale green DC or AC energy applications,is that the voltage supplied by the MPPT boost converter is insufficient.In order to increase resulting MPP voltage,this research proposes a new high-voltage gain DC-DC boost converter for a cascade connection with an MPPT boost converter.Input side of the proposed converter employs a switched-inductor cell to reduce input current source ripples which is a critical problem in PV systems for high-reliability applications.Additionally,a switched-capacitor cell is used at the converter’s output side to boost voltage gain and reduce voltage stress across converter’s power switches,which is a crucial factor for longer life of PV panel and proposed converter components,particularly semiconductor devices.Performance of the converter is assessed while taking into account variations in irradiation and temperature brought on by changing weather conditions.A prototype converter at a laboratory scale is utilized and examined.Outcomes of hardware tests support the findings of theoretical and simulation studies.展开更多
The increasing significance of text data in power system intelligence has highlighted the out-of-distribution(OOD)problem as a critical challenge,hindering the deployment of artificial intelligence(AI)models.In a clos...The increasing significance of text data in power system intelligence has highlighted the out-of-distribution(OOD)problem as a critical challenge,hindering the deployment of artificial intelligence(AI)models.In a closed-world setting,most AI models cannot detect and reject unexpected data,which exacerbates the harmful impact of the OOD problem.The high similarity between OOD and indistribution(IND)samples in the power system presents challenges for existing OOD detection methods in achieving effective results.This study aims to elucidate and address the OOD problem in power systems through a text classification task.First,the underlying causes of OOD sample generation are analyzed,highlighting the inherent nature of the OOD problem in the power system.Second,a novel method integrating the enhanced Mahalanobis distance with calibration strategies is introduced to improve OOD detection for text data in power system applications.Finally,the case study utilizing the actual text data from power system field operation(PSFO)is conducted,demonstrating the effectiveness of the proposed OOD detection method.Experimental results indicate that the proposed method outperformed existing methods in text OOD detection tasks within the power system,achieving a remarkable 21.03%enhancement of metric in the false positive rate at 95%true positive recall(FPR95)and a 12.97%enhancement in classi-fication accuracy for the mixed IND-OOD scenarios.展开更多
文摘Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid (UTISAG), which is based on the previous version. In this version, a new architecture and more enhanced services are introduced, The. remarkable characteristic of the new system is providing dynamic information services for travelers by grid technology. Therefore, the key research includes integrating large multi-source traffic data, forecasting route status, simulating regional traffic flow parallelly, and implementing optimum dynamic travel scheme based on massive GPS data.
基金Supported by the National Natural Science Foun-dation of China (60425206)
文摘Many high performance database servers are becoming idle with the tax data being integrated to country tax data centers. We make use of the idle servers to set up a provincial tax Grid based on open Grid service architecture （OGSA）. We put forward practical methods to integrate databases, to define and create basic modular Grid services and apply agent to manage Grid services. This technical innovation scheme is of a service-oriented architecture （SOA） and succeeds in averting resources waste. Tests proved that it greatly improves the quality of tax services.
文摘In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.
文摘Maximum power point tracking(MPPT)systems are being developed to produce switching pulses with proper duty ratios for power switches to exert photovoltaic(PV)panels under maximum instantaneous generated power,usually through a traditional DC-DC boost converter.The fundamental issue,particularly for micro-grid and small-scale green DC or AC energy applications,is that the voltage supplied by the MPPT boost converter is insufficient.In order to increase resulting MPP voltage,this research proposes a new high-voltage gain DC-DC boost converter for a cascade connection with an MPPT boost converter.Input side of the proposed converter employs a switched-inductor cell to reduce input current source ripples which is a critical problem in PV systems for high-reliability applications.Additionally,a switched-capacitor cell is used at the converter’s output side to boost voltage gain and reduce voltage stress across converter’s power switches,which is a crucial factor for longer life of PV panel and proposed converter components,particularly semiconductor devices.Performance of the converter is assessed while taking into account variations in irradiation and temperature brought on by changing weather conditions.A prototype converter at a laboratory scale is utilized and examined.Outcomes of hardware tests support the findings of theoretical and simulation studies.
基金supported in part by the Science and Technology Project of the State Grid East China Branch(No.520800230008).
文摘The increasing significance of text data in power system intelligence has highlighted the out-of-distribution(OOD)problem as a critical challenge,hindering the deployment of artificial intelligence(AI)models.In a closed-world setting,most AI models cannot detect and reject unexpected data,which exacerbates the harmful impact of the OOD problem.The high similarity between OOD and indistribution(IND)samples in the power system presents challenges for existing OOD detection methods in achieving effective results.This study aims to elucidate and address the OOD problem in power systems through a text classification task.First,the underlying causes of OOD sample generation are analyzed,highlighting the inherent nature of the OOD problem in the power system.Second,a novel method integrating the enhanced Mahalanobis distance with calibration strategies is introduced to improve OOD detection for text data in power system applications.Finally,the case study utilizing the actual text data from power system field operation(PSFO)is conducted,demonstrating the effectiveness of the proposed OOD detection method.Experimental results indicate that the proposed method outperformed existing methods in text OOD detection tasks within the power system,achieving a remarkable 21.03%enhancement of metric in the false positive rate at 95%true positive recall(FPR95)and a 12.97%enhancement in classi-fication accuracy for the mixed IND-OOD scenarios.
