在分层图模型的基础上,本文提出一种以最小化全网光路总代价为优化目标的 IP over WDM 光网络动态路由优化模型,设计了一种针对该模型的在线综合路由算法—MCTLP(Minimizing the Cost of Total Lightpaths),MCTLP 通过综合考虑 IP 逻辑...在分层图模型的基础上,本文提出一种以最小化全网光路总代价为优化目标的 IP over WDM 光网络动态路由优化模型,设计了一种针对该模型的在线综合路由算法—MCTLP(Minimizing the Cost of Total Lightpaths),MCTLP 通过综合考虑 IP 逻辑层带宽资源分配和 WDM 光物理层波长链路资源的占用以优化网络资源。与两种有代表性的 IP over WDM 光网络路由算法的性能仿真对比表明:MCTLP 能够在 IP 逻辑层和 WDM 光物理层都使用较少的链路以承载 IP 业务流,接纳更多的 IP 业务连接请求,有效地降低网络阻塞率。展开更多
The route optimization problem for road networks was applied to pedestrian flow.Evacuation path networks with nodes and arcs considering the traffic capacities of facilities were built in metro hubs,and a path impedan...The route optimization problem for road networks was applied to pedestrian flow.Evacuation path networks with nodes and arcs considering the traffic capacities of facilities were built in metro hubs,and a path impedance function for metro hubs which used the relationships among circulation speed,density and flow rate for pedestrians was defined.Then,a route optimization model which minimizes the movement time of the last evacuee was constructed to optimize evacuation performance.Solutions to the proposed mathematical model were obtained through an iterative optimization process.The route optimization model was applied to Xidan Station of Beijing Metro Line 4 based on the actual situations,and the calculation results of the model were tested using buildingExodus microscopic evacuation simulation software.The simulation result shows that the proposed model shortens the evacuation time by 16.05%,3.15% and 2.78% compared with all or none method,equally split method and Logit model,respectively.Furthermore,when the population gets larger,evacuation efficiency in the proposed model has a greater advantage.展开更多
To improve the robustness of the Low Earth Orbit(LEO) satellites networks and realise load balancing, a Cross-layer design and Ant-colony optimization based Load-balancing routing algorithm for LEO Satellite Networks(...To improve the robustness of the Low Earth Orbit(LEO) satellites networks and realise load balancing, a Cross-layer design and Ant-colony optimization based Load-balancing routing algorithm for LEO Satellite Networks(CAL-LSN) is proposed in this paper. In CALLSN, mobile agents are used to gather routing information actively. CAL-LSN can utilise the information of the physical layer to make routing decision during the route construction phase. In order to achieve load balancing, CALLSN makes use of a multi-objective optimization model. Meanwhile, how to take the value of some key parameters is discussed while designing the algorithm so as to improve the reliability. The performance is measured by the packet delivery rate, the end-to-end delay, the link utilization and delay jitter. Simulation results show that CAL-LSN performs well in balancing traffic load and increasing the packet delivery rate. Meanwhile, the end-to-end delay and delay jitter performance can meet the requirement of video transmission.展开更多
文摘在分层图模型的基础上,本文提出一种以最小化全网光路总代价为优化目标的 IP over WDM 光网络动态路由优化模型,设计了一种针对该模型的在线综合路由算法—MCTLP(Minimizing the Cost of Total Lightpaths),MCTLP 通过综合考虑 IP 逻辑层带宽资源分配和 WDM 光物理层波长链路资源的占用以优化网络资源。与两种有代表性的 IP over WDM 光网络路由算法的性能仿真对比表明:MCTLP 能够在 IP 逻辑层和 WDM 光物理层都使用较少的链路以承载 IP 业务流,接纳更多的 IP 业务连接请求,有效地降低网络阻塞率。
基金Project(51078086)supported by the National Natural Science Foundation of China
文摘The route optimization problem for road networks was applied to pedestrian flow.Evacuation path networks with nodes and arcs considering the traffic capacities of facilities were built in metro hubs,and a path impedance function for metro hubs which used the relationships among circulation speed,density and flow rate for pedestrians was defined.Then,a route optimization model which minimizes the movement time of the last evacuee was constructed to optimize evacuation performance.Solutions to the proposed mathematical model were obtained through an iterative optimization process.The route optimization model was applied to Xidan Station of Beijing Metro Line 4 based on the actual situations,and the calculation results of the model were tested using buildingExodus microscopic evacuation simulation software.The simulation result shows that the proposed model shortens the evacuation time by 16.05%,3.15% and 2.78% compared with all or none method,equally split method and Logit model,respectively.Furthermore,when the population gets larger,evacuation efficiency in the proposed model has a greater advantage.
基金supported by the National Natural Science Foundation of China under Grant No.61271281the National High Technology Research and Development Program of China (863 Program) under Grant No.SS2013AA010503
文摘To improve the robustness of the Low Earth Orbit(LEO) satellites networks and realise load balancing, a Cross-layer design and Ant-colony optimization based Load-balancing routing algorithm for LEO Satellite Networks(CAL-LSN) is proposed in this paper. In CALLSN, mobile agents are used to gather routing information actively. CAL-LSN can utilise the information of the physical layer to make routing decision during the route construction phase. In order to achieve load balancing, CALLSN makes use of a multi-objective optimization model. Meanwhile, how to take the value of some key parameters is discussed while designing the algorithm so as to improve the reliability. The performance is measured by the packet delivery rate, the end-to-end delay, the link utilization and delay jitter. Simulation results show that CAL-LSN performs well in balancing traffic load and increasing the packet delivery rate. Meanwhile, the end-to-end delay and delay jitter performance can meet the requirement of video transmission.
