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
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
In this study,we investigate the optimal location of access points(APs) to connect end nodes with a service provider through power-line communication in smartgrid communication networks.APs are the gateways of power-d...In this study,we investigate the optimal location of access points(APs) to connect end nodes with a service provider through power-line communication in smartgrid communication networks.APs are the gateways of power-distribution communication networks,connecting users to control centers.Hence,they are vital for the reliable,safe,and economical operation of a power system.This paper proposes a planning method for AP allocation that takes into consideration economics,reliability,network delay,and(n-1) resilience.First,an optimization model for the AP location is established,which minimizes the cost of installing APs,while satisfying the reliability,network delay,and(n-1) resilience constraints.Then,an improved genetic algorithm is proposed to solve the optimization problem.The simulation results indicate that the proposed planning method can deal with diverse network conditions satisfactorily.Furthermore,it can be applied effectively with high flexibility and scalability.展开更多
Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained poli...Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.展开更多
Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challengin...Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user’s environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid application is also described.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
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。
基金supported by the National High Technology Research and Development Program of China(2012AA050801)
文摘In this study,we investigate the optimal location of access points(APs) to connect end nodes with a service provider through power-line communication in smartgrid communication networks.APs are the gateways of power-distribution communication networks,connecting users to control centers.Hence,they are vital for the reliable,safe,and economical operation of a power system.This paper proposes a planning method for AP allocation that takes into consideration economics,reliability,network delay,and(n-1) resilience.First,an optimization model for the AP location is established,which minimizes the cost of installing APs,while satisfying the reliability,network delay,and(n-1) resilience constraints.Then,an improved genetic algorithm is proposed to solve the optimization problem.The simulation results indicate that the proposed planning method can deal with diverse network conditions satisfactorily.Furthermore,it can be applied effectively with high flexibility and scalability.
基金Funded by the Natural Science Foundation of China under Grant Nos. 60503040 and 60403027.
文摘Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.
基金Supported by the National Natural Science Foundation of China (No.60403027) .
文摘Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user’s environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid application is also described.
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.
