Access G rid是计算网格的一个扩展,用于支持在网格上进行组对组的大规模视频会议,也可用于协同工作、远程教学等多个领域。基于任务和角色的访问控制是最新的访问控制模型,它对传统访问控制进行了改进和扩充,能为Access G rid提供更高...Access G rid是计算网格的一个扩展,用于支持在网格上进行组对组的大规模视频会议,也可用于协同工作、远程教学等多个领域。基于任务和角色的访问控制是最新的访问控制模型,它对传统访问控制进行了改进和扩充,能为Access G rid提供更高效的安全和管理服务。因此,Access G rid中基于任务和角色的访问控制是网格研究中的重要方向。展开更多
There are numerous electricians,but only a few of them have obtained certificate. Training and examination agencies provide services relating to training,examination,and certificate application and so on.Thus,training...There are numerous electricians,but only a few of them have obtained certificate. Training and examination agencies provide services relating to training,examination,and certificate application and so on.Thus,training resources are not rationally utilized,and the increased training demand cannot be fully satisfied.Under such circumstances,it is recommended to transform the regulatory agency mode by establishing a scientific management process,and put forward a new mode of electrical grid access training and examination to better meet related demands. Under the coordination of examination center regulatory agency, uniform training program,training materials,charging standard,examination and certificate can be guaranteed. This project is carried out as an effort to improve the quality of electronic- engineering training and examination,so that electricity accident rate can be reduced,and the security of electrical grid operation can be guaranteed to boost the rapidly developing economy.展开更多
The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The curr...The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The current electric grid was established before the 1960’s. It is believed that the electric grid is the most complex and gigantic machine ever made in human history;it consists of wires, cables, towers, transformers and circuit breakers installed together in outdated manner. During the 60’s, computers and sensors were used to monitor and slightly control the grid;however, fifty years later these sensors are considered less than ideal. Presented here is a review of the smart grid communication network in terms of configuration, bandwidth and latency requirements as well as the technology used. We simulate the access layer of the smart grid net-work and show that no single available communication technology can be used for all layers of the smart grid;thus, different technologies for different layers are needed. A new protocol for optimizing the smart grid is recommended.展开更多
This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facil...This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facilities. The article further discusses the proposed and on-going reform and restructure in the electricity price sector, and the trial reforms in regional electricity markets.展开更多
A critical component of the smart grid (SG) infrastructure is the embedded communications network, where an important objective of the latter is the expansion of its throughput, in conjunction with the satisfaction of...A critical component of the smart grid (SG) infrastructure is the embedded communications network, where an important objective of the latter is the expansion of its throughput, in conjunction with the satisfaction of specified latency and accuracy requirements. For the effective design of the communications network, the user and traffic profiles, such as known-user vs. unknown-user populations and bursty vs. non-bursty data traffics, must be carefully considered and subsequently modeled. This paper relates user and traffic models to the deployment of effective multiple access transmission algorithms in the communications network of the SG.展开更多
文摘Access G rid是计算网格的一个扩展,用于支持在网格上进行组对组的大规模视频会议,也可用于协同工作、远程教学等多个领域。基于任务和角色的访问控制是最新的访问控制模型,它对传统访问控制进行了改进和扩充,能为Access G rid提供更高效的安全和管理服务。因此,Access G rid中基于任务和角色的访问控制是网格研究中的重要方向。
文摘There are numerous electricians,but only a few of them have obtained certificate. Training and examination agencies provide services relating to training,examination,and certificate application and so on.Thus,training resources are not rationally utilized,and the increased training demand cannot be fully satisfied.Under such circumstances,it is recommended to transform the regulatory agency mode by establishing a scientific management process,and put forward a new mode of electrical grid access training and examination to better meet related demands. Under the coordination of examination center regulatory agency, uniform training program,training materials,charging standard,examination and certificate can be guaranteed. This project is carried out as an effort to improve the quality of electronic- engineering training and examination,so that electricity accident rate can be reduced,and the security of electrical grid operation can be guaranteed to boost the rapidly developing economy.
文摘The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The current electric grid was established before the 1960’s. It is believed that the electric grid is the most complex and gigantic machine ever made in human history;it consists of wires, cables, towers, transformers and circuit breakers installed together in outdated manner. During the 60’s, computers and sensors were used to monitor and slightly control the grid;however, fifty years later these sensors are considered less than ideal. Presented here is a review of the smart grid communication network in terms of configuration, bandwidth and latency requirements as well as the technology used. We simulate the access layer of the smart grid net-work and show that no single available communication technology can be used for all layers of the smart grid;thus, different technologies for different layers are needed. A new protocol for optimizing the smart grid is recommended.
文摘This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facilities. The article further discusses the proposed and on-going reform and restructure in the electricity price sector, and the trial reforms in regional electricity markets.
基金Acknowledgements： This work is supported by National Natural Science Foundation of China （No. 60773118）, National High Tech. Development Plan （No. 2006AA01A109） and Program for Changjiang Scholars and Innovative Research Team in University.
文摘A critical component of the smart grid (SG) infrastructure is the embedded communications network, where an important objective of the latter is the expansion of its throughput, in conjunction with the satisfaction of specified latency and accuracy requirements. For the effective design of the communications network, the user and traffic profiles, such as known-user vs. unknown-user populations and bursty vs. non-bursty data traffics, must be carefully considered and subsequently modeled. This paper relates user and traffic models to the deployment of effective multiple access transmission algorithms in the communications network of the SG.
