Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptio...Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptions of economical distance of delivery and the best routing algorithm were given on the base of the Dijkstra algorithm with consideration of a coefficient of the road hustle degree. Economical distance of delivery is the shortest physical distance between two customers. It is the value of goods delivery in shortest distance when concerning factors such as the road length, the hustle degree, the driveway quantity, and the type of the road. The improved algorithm is being used in the development and application of a distribution path information system in the terminal distribution of logistics center. The simulation and practical case prove that the algorithm is effective and reasonable.展开更多
Layer 2 network technology is extending beyond its traditional local area implementation and finding wider acceptance in provider＇s metropolitan area networks and large-scale cloud data center networks. This is mainl...Layer 2 network technology is extending beyond its traditional local area implementation and finding wider acceptance in provider＇s metropolitan area networks and large-scale cloud data center networks. This is mainly due to its plug-and-play capability and native mobility support. Many efforts have been put to increase the bisection bandwidth in layer 2 network, which has been constrained by the spanning tree protocol （STP） that layer 2 network uses for preventing looping. The recent trend is to incorporate layer 3＇s routing approach into layer 2 network so that multiple paths can be used for forwarding traffic between any source-destination （S-D） node pair. Equal cost multipath （ECMP） is one such example. However, ECMP may still be limited in generating multiple paths due to its shortest path （lowest cost） requirement. In this paper, we consider a non-shortest-path routing approach, called equal preference multipath （EPMP） based on ordered semi group theory, which can generate more paths than ECMP. In EPMP routing, all the paths with different traditionally-defined costs, such as hops, bandwidth, etc., can be determined equally now and thus they become equal candidate paths. By the comparative tests with ECMP, EPMP routing not only generates more paths, provides 15% higher bisection bandwidth, but also identifies bottleneck links in a hierarchical network when different traffic patterns are applied EPMP is more flexible in controlling the number and length of multipath generation. Simulation results indicate the effectiveness of the proposed algorithm. It is a good reference for non-blocking running of big datacenter networks.展开更多
下一代互联网NGI(Next Generation Internet)需要提供服务质量QoS(Quality of Service)路由能力,支持总最佳连接ABC(Always Best Connected).但是,由于链路状态的难以精确测量与用户QoS需求的难以准确表达,因此QoS路由基于的信息实际上...下一代互联网NGI(Next Generation Internet)需要提供服务质量QoS(Quality of Service)路由能力,支持总最佳连接ABC(Always Best Connected).但是,由于链路状态的难以精确测量与用户QoS需求的难以准确表达,因此QoS路由基于的信息实际上是模糊的.同时,在网络运营日益商业化的环境下,支持ABC需要兼顾用户和网络提供方利益,考虑双方效用共赢.为此,文中引入模糊数学、概率论和博弈论知识,设计了一种ABC支持型QoS单播路由机制.该机制采用区间形式描述用户QoS需求和边(链路)参数,引入用户满意度和边评价,通过博弈分析,基于人工鱼群算法,寻找使用户和网络提供方效用达到或接近Nash均衡下Pareto最优的QoS单播路径.仿真结果表明,该机制是可行和有效的.展开更多
基金Social Science Fund of Zhejiang Province(No 06CGGL22YBG)
文摘Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptions of economical distance of delivery and the best routing algorithm were given on the base of the Dijkstra algorithm with consideration of a coefficient of the road hustle degree. Economical distance of delivery is the shortest physical distance between two customers. It is the value of goods delivery in shortest distance when concerning factors such as the road length, the hustle degree, the driveway quantity, and the type of the road. The improved algorithm is being used in the development and application of a distribution path information system in the terminal distribution of logistics center. The simulation and practical case prove that the algorithm is effective and reasonable.
基金supported by the National Natural Science Foundation of China(61363047)the Open Research Fund of Guangdong Key Laboratory of Big Data Analysis and Processing(2017007)the Foshan Science and Technology Innovation Project(2016AG100792)
文摘Layer 2 network technology is extending beyond its traditional local area implementation and finding wider acceptance in provider＇s metropolitan area networks and large-scale cloud data center networks. This is mainly due to its plug-and-play capability and native mobility support. Many efforts have been put to increase the bisection bandwidth in layer 2 network, which has been constrained by the spanning tree protocol （STP） that layer 2 network uses for preventing looping. The recent trend is to incorporate layer 3＇s routing approach into layer 2 network so that multiple paths can be used for forwarding traffic between any source-destination （S-D） node pair. Equal cost multipath （ECMP） is one such example. However, ECMP may still be limited in generating multiple paths due to its shortest path （lowest cost） requirement. In this paper, we consider a non-shortest-path routing approach, called equal preference multipath （EPMP） based on ordered semi group theory, which can generate more paths than ECMP. In EPMP routing, all the paths with different traditionally-defined costs, such as hops, bandwidth, etc., can be determined equally now and thus they become equal candidate paths. By the comparative tests with ECMP, EPMP routing not only generates more paths, provides 15% higher bisection bandwidth, but also identifies bottleneck links in a hierarchical network when different traffic patterns are applied EPMP is more flexible in controlling the number and length of multipath generation. Simulation results indicate the effectiveness of the proposed algorithm. It is a good reference for non-blocking running of big datacenter networks.
文摘下一代互联网NGI(Next Generation Internet)需要提供服务质量QoS(Quality of Service)路由能力,支持总最佳连接ABC(Always Best Connected).但是,由于链路状态的难以精确测量与用户QoS需求的难以准确表达,因此QoS路由基于的信息实际上是模糊的.同时,在网络运营日益商业化的环境下,支持ABC需要兼顾用户和网络提供方利益,考虑双方效用共赢.为此,文中引入模糊数学、概率论和博弈论知识,设计了一种ABC支持型QoS单播路由机制.该机制采用区间形式描述用户QoS需求和边(链路)参数,引入用户满意度和边评价,通过博弈分析,基于人工鱼群算法,寻找使用户和网络提供方效用达到或接近Nash均衡下Pareto最优的QoS单播路径.仿真结果表明,该机制是可行和有效的.
