针对以太网无源光网络的网络规划和算法研究,在IEEE802.3ah标准的基础上,通过扩展开源网络模拟程序Network Simulator Version 2(NS2),完成对以太网无源光网络(EPON)的建模与测试,实现了光网络单元(ONU)注册、测距、带宽分配、服务质量(...针对以太网无源光网络的网络规划和算法研究,在IEEE802.3ah标准的基础上,通过扩展开源网络模拟程序Network Simulator Version 2(NS2),完成对以太网无源光网络(EPON)的建模与测试,实现了光网络单元(ONU)注册、测距、带宽分配、服务质量(QoS)等诸多功能,为EPON网络规划和算法研究提供了一个全面完整的仿真平台(EPONns).注册过程模拟给出成功注册的ONU数目与注册窗口值的关系;光传输线路终端(OLT)负载状况检测反映出EPONns在高负荷下的状态.展开更多
The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matc...The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matching theory are applied to analyzing power flow of incidence and reflection in WPT system,then setting up power flow model. The maximum power transmission efficiency can be obtained when the load and distance between secondary resonator and output coil meets impedance matching at 2-port network's output port. The simulation and experimental results shown the impedance matching method can effectively improve and maintain transmission efficiency by adjusting load and distances between coils or relay resonators.展开更多
Currently,building construction and operation are responsible for 36%of global final energy usage and nearly 40%of energy-related carbon dioxide(CO_(2))emissions.From the sustainable development perspective,it is cruc...Currently,building construction and operation are responsible for 36%of global final energy usage and nearly 40%of energy-related carbon dioxide(CO_(2))emissions.From the sustainable development perspective,it is crucial to consider the impact of construction material on the achievement of life cycle benefits.This study proposed a simulation-based multi-objective optimization method to minimize both life cycle cost and CO_(2) emissions of buildings.We built an energy simulation model with hybrid ventilation and light-dimming control in EnergyPlus based on an operational passive residential building in a severe cold climate.Next,this investigation selected insulation thickness,window type,window-to-wall ratio,overhang depth and building orientation as design variables.The study ran parametric simulations to establish a database and then used artificial neural network models to correlate the design variables and the objective functions.Finally,we used the multi-objective optimization algorithm NSGA-Ⅱ to search for the optimal design solutions.The results showed potential reductions of 10.9%-18.9%in life cycle cost and 13.5%-22.4%in life cycle CO_(2) emissions compared with the initial design.The results indicated that the optimization approach in this study would improve building performance.The optimal values of the design variables obtained in this study can guide designers in meeting economic and environmental targets in passive buildings.展开更多
文摘针对以太网无源光网络的网络规划和算法研究,在IEEE802.3ah标准的基础上,通过扩展开源网络模拟程序Network Simulator Version 2(NS2),完成对以太网无源光网络(EPON)的建模与测试,实现了光网络单元(ONU)注册、测距、带宽分配、服务质量(QoS)等诸多功能,为EPON网络规划和算法研究提供了一个全面完整的仿真平台(EPONns).注册过程模拟给出成功注册的ONU数目与注册窗口值的关系;光传输线路终端(OLT)负载状况检测反映出EPONns在高负荷下的状态.
基金Human Provincial Natural Science Foudation of China(No.2016JJ4043)Youth Foundation of Education Bureau of Hunan Province,China(No.16B137)Science and Technology Projects of Loudi City,China
文摘The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matching theory are applied to analyzing power flow of incidence and reflection in WPT system,then setting up power flow model. The maximum power transmission efficiency can be obtained when the load and distance between secondary resonator and output coil meets impedance matching at 2-port network's output port. The simulation and experimental results shown the impedance matching method can effectively improve and maintain transmission efficiency by adjusting load and distances between coils or relay resonators.
基金supported by the National Natural Science Foundation of China(No.51938003,No.51678179).
文摘Currently,building construction and operation are responsible for 36%of global final energy usage and nearly 40%of energy-related carbon dioxide(CO_(2))emissions.From the sustainable development perspective,it is crucial to consider the impact of construction material on the achievement of life cycle benefits.This study proposed a simulation-based multi-objective optimization method to minimize both life cycle cost and CO_(2) emissions of buildings.We built an energy simulation model with hybrid ventilation and light-dimming control in EnergyPlus based on an operational passive residential building in a severe cold climate.Next,this investigation selected insulation thickness,window type,window-to-wall ratio,overhang depth and building orientation as design variables.The study ran parametric simulations to establish a database and then used artificial neural network models to correlate the design variables and the objective functions.Finally,we used the multi-objective optimization algorithm NSGA-Ⅱ to search for the optimal design solutions.The results showed potential reductions of 10.9%-18.9%in life cycle cost and 13.5%-22.4%in life cycle CO_(2) emissions compared with the initial design.The results indicated that the optimization approach in this study would improve building performance.The optimal values of the design variables obtained in this study can guide designers in meeting economic and environmental targets in passive buildings.
