In low Earth orbit(LEO)satellite networks,on-board energy resources of each satellite are extremely limited.And with the increase of the node number and the traffic transmis-sion pressure,the energy consumption in the...In low Earth orbit(LEO)satellite networks,on-board energy resources of each satellite are extremely limited.And with the increase of the node number and the traffic transmis-sion pressure,the energy consumption in the networks presents uneven distribution.To achieve energy balance in networks,an energy consumption balancing optimization algorithm of LEO networks based on distance energy factor(DEF)is proposed.The DEF is defined as the function of the inter-satellite link dis-tance and the cumulative network energy consumption ratio.According to the minimum sum of DEF on inter-satellite links,an energy consumption balancing algorithm based on DEF is pro-posed,which can realize dynamic traffic transmission optimiza-tion of multiple traffic services.It can effectively reduce the energy consumption pressure of core nodes with high energy consumption in the network,make full use of idle nodes with low energy consumption,and optimize the energy consumption dis-tribution of the whole network according to the continuous itera-tions of each traffic service flow.Simulation results show that,compared with the traditional shortest path algorithm,the pro-posed method can improve the balancing performance of nodes by 75%under certain traffic pressure,and realize the optimiza-tion of energy consumption balancing of the whole network.展开更多
In today’s datacenter network,the quantity growth and complexity increment of traffic is unprecedented,which brings not only the booming of network development,but also the problem of network performance degradation,...In today’s datacenter network,the quantity growth and complexity increment of traffic is unprecedented,which brings not only the booming of network development,but also the problem of network performance degradation,such as more chance of network congestion and serious load imbalance.Due to the dynamically changing traffic patterns,the state-of the-art approaches that do this all require forklift changes to data center networking gear.The root of problem is lack of distinct strategies for elephant and mice flows.Under this condition,it is essential to enforce accurate elephant flow detection and come up with a novel load balancing solution to alleviate the network congestion and achieve high bandwidth utilization.This paper proposed an OpenFlow-based load balancing strategy for datacenter networks that accurately detect elephant flows and enforce distinct routing schemes with different flow types so as to achieve high usage of network capacity.The prototype implemented in Mininet testbed with POX controller and verify the feasibility of our load-balancing strategy when dealing with flow confliction and network degradation.The results show the proposed strategy can adequately generate flow rules and significantly enhance the performance of the bandwidth usage compared against other solutions from the literature in terms of load balancing.展开更多
The Software Defined Network (SDN) is a concept based on a decoupling between the control plan and the data plan of a network. Thus, the network becomes programmable and can be coupled to the business applications of ...The Software Defined Network (SDN) is a concept based on a decoupling between the control plan and the data plan of a network. Thus, the network becomes programmable and can be coupled to the business applications of the users. The study that is discussed in this article looks at load planning and balancing in distributed controllers. To do this, a model and theoretical methods of performance evaluation related to appropriate software tools, to predict and control the quality of service offered to users is exposed. This paper exposed also a distributed architecture of controllers and then a module based on an adaptive load balancing algorithm that is fault tolerant and fluctuates controller loads. The experiments show a significant gain in efficiency of our solution.展开更多
This paper proposes to use the power system simulation software CYME to plan, model and simulate for an actual distribution network for improving the reliability and efficiency, enhancing the efficiency and capacity, ...This paper proposes to use the power system simulation software CYME to plan, model and simulate for an actual distribution network for improving the reliability and efficiency, enhancing the efficiency and capacity, simulating the abnormal condition of distribution network, and presenting operation program of safe, reliable and having simulation record statements. The modeling simulation results show that the software module has lots of advantages including high accuracy, ideal reliability, powerful practicality in simulation and analysis of distribution network, it only need to create once model, the model can sufficiently satisfy multifarious types of simulation analysis required for the distribution network planning.展开更多
针对无线传感器网络中节点能耗不均造成的能量空洞现象,提出了一种基于密度控制机制的能量空洞避免策略DCDD(Density Control-based Data Delivery algorithm).在对分层成簇网络的各层能耗进行计算和分析的基础上,根据网络各层的能耗比...针对无线传感器网络中节点能耗不均造成的能量空洞现象,提出了一种基于密度控制机制的能量空洞避免策略DCDD(Density Control-based Data Delivery algorithm).在对分层成簇网络的各层能耗进行计算和分析的基础上,根据网络各层的能耗比例在各层网络中配置不同的初始能量,即不同数量的节点.进一步,利用密度控制机制改变节点的工作/休眠状态,使各层网络中的节点能量趋于同时耗尽.同时,为平衡簇头间的负载,引入路由负载平衡分流的思想,让一个簇的数据发送到下一跳的簇头时,不再只发送给一个簇头,而是将数据分流到多个簇头.仿真实验表明,与现有的几种数据传输算法相比,DCDD算法能有效延长网络寿命,平衡网络各层节点的能耗并避免能量空洞现象的出现.展开更多
提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和...提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和变电站AVC站配协调调节方法,并且在调节过程中前者优先于后者。对于前者模型采用免疫遗传算法进行求解,对于后者采用直接法进行计算。所提方法通过对配变低压侧无功补偿柜、分布式电源进行无功补偿分区平衡和变电站AVC的电压协调控制,调节出无功分区平衡、各个节点电压满足合格要求、有功网损较低的潮流可行解。成都某实际10 k V 55节点配电网的仿真结果验证了该方法的有效性。展开更多
基金supported by the National Key Research and Development Program(2021YFB2900604).
文摘In low Earth orbit(LEO)satellite networks,on-board energy resources of each satellite are extremely limited.And with the increase of the node number and the traffic transmis-sion pressure,the energy consumption in the networks presents uneven distribution.To achieve energy balance in networks,an energy consumption balancing optimization algorithm of LEO networks based on distance energy factor(DEF)is proposed.The DEF is defined as the function of the inter-satellite link dis-tance and the cumulative network energy consumption ratio.According to the minimum sum of DEF on inter-satellite links,an energy consumption balancing algorithm based on DEF is pro-posed,which can realize dynamic traffic transmission optimiza-tion of multiple traffic services.It can effectively reduce the energy consumption pressure of core nodes with high energy consumption in the network,make full use of idle nodes with low energy consumption,and optimize the energy consumption dis-tribution of the whole network according to the continuous itera-tions of each traffic service flow.Simulation results show that,compared with the traditional shortest path algorithm,the pro-posed method can improve the balancing performance of nodes by 75%under certain traffic pressure,and realize the optimiza-tion of energy consumption balancing of the whole network.
基金This work was supported by the CETC Joint Advanced Research Foundation(Grant Nos.6141B08010102,6141B08080101)the National Science and Technology Major Project for IND(investigational new drug)(Project No.2018ZX09201014).
文摘In today’s datacenter network,the quantity growth and complexity increment of traffic is unprecedented,which brings not only the booming of network development,but also the problem of network performance degradation,such as more chance of network congestion and serious load imbalance.Due to the dynamically changing traffic patterns,the state-of the-art approaches that do this all require forklift changes to data center networking gear.The root of problem is lack of distinct strategies for elephant and mice flows.Under this condition,it is essential to enforce accurate elephant flow detection and come up with a novel load balancing solution to alleviate the network congestion and achieve high bandwidth utilization.This paper proposed an OpenFlow-based load balancing strategy for datacenter networks that accurately detect elephant flows and enforce distinct routing schemes with different flow types so as to achieve high usage of network capacity.The prototype implemented in Mininet testbed with POX controller and verify the feasibility of our load-balancing strategy when dealing with flow confliction and network degradation.The results show the proposed strategy can adequately generate flow rules and significantly enhance the performance of the bandwidth usage compared against other solutions from the literature in terms of load balancing.
文摘The Software Defined Network (SDN) is a concept based on a decoupling between the control plan and the data plan of a network. Thus, the network becomes programmable and can be coupled to the business applications of the users. The study that is discussed in this article looks at load planning and balancing in distributed controllers. To do this, a model and theoretical methods of performance evaluation related to appropriate software tools, to predict and control the quality of service offered to users is exposed. This paper exposed also a distributed architecture of controllers and then a module based on an adaptive load balancing algorithm that is fault tolerant and fluctuates controller loads. The experiments show a significant gain in efficiency of our solution.
文摘This paper proposes to use the power system simulation software CYME to plan, model and simulate for an actual distribution network for improving the reliability and efficiency, enhancing the efficiency and capacity, simulating the abnormal condition of distribution network, and presenting operation program of safe, reliable and having simulation record statements. The modeling simulation results show that the software module has lots of advantages including high accuracy, ideal reliability, powerful practicality in simulation and analysis of distribution network, it only need to create once model, the model can sufficiently satisfy multifarious types of simulation analysis required for the distribution network planning.
文摘针对无线传感器网络中节点能耗不均造成的能量空洞现象,提出了一种基于密度控制机制的能量空洞避免策略DCDD(Density Control-based Data Delivery algorithm).在对分层成簇网络的各层能耗进行计算和分析的基础上,根据网络各层的能耗比例在各层网络中配置不同的初始能量,即不同数量的节点.进一步,利用密度控制机制改变节点的工作/休眠状态,使各层网络中的节点能量趋于同时耗尽.同时,为平衡簇头间的负载,引入路由负载平衡分流的思想,让一个簇的数据发送到下一跳的簇头时,不再只发送给一个簇头,而是将数据分流到多个簇头.仿真实验表明,与现有的几种数据传输算法相比,DCDD算法能有效延长网络寿命,平衡网络各层节点的能耗并避免能量空洞现象的出现.
文摘提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和变电站AVC站配协调调节方法,并且在调节过程中前者优先于后者。对于前者模型采用免疫遗传算法进行求解,对于后者采用直接法进行计算。所提方法通过对配变低压侧无功补偿柜、分布式电源进行无功补偿分区平衡和变电站AVC的电压协调控制,调节出无功分区平衡、各个节点电压满足合格要求、有功网损较低的潮流可行解。成都某实际10 k V 55节点配电网的仿真结果验证了该方法的有效性。
