The design of telecommunication network with capacity constraints of links, routers and ports of routers is considered in this paper. Specially, we limit each demand flow traversed through a pre-specified maximal numb...The design of telecommunication network with capacity constraints of links, routers and ports of routers is considered in this paper. Specially, we limit each demand flow traversed through a pre-specified maximal number of links (called hops) under node failure scenarios in IP layer network. Such a design must be the most cost-effective and ensure that feasible flows continue to exist even when any relay node of the network fails. We propose a reliable mixed-integer programming (MIP) model with multi-scenario constraints to optimally design a minimum-cost survivable IP network that continues to support a good communication under any node failure scenario. Then we transform the MIP model into many single scenario models, that is, simplified MIPs, nonlinear programming (NLP) models and MIP models under Benders decomposition Then we transform the MIP model into many single scenario models, that is, simplified MIPs, nonlinear programming (NLP) models and MIP models under Benders decomposition. Three heuristic methods are proposed to solve these models including branch-and-bound algorithm, global algorithm for NLP, and heuristic algorithm based on benders decomposition. We mainly study the application of Benders decomposition method, where dual model and bounding procedures are given for each MIP model under Benders decomposition at each scenario. The results of our computational experiments validate the effectiveness of the proposed models and algorithms.展开更多
Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M...Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M)is developed.Three examples are given,showing that the method proposed is especially suitable for the optimized design of complex structures,and that the global approximate optimal solution can be searched with remarkably reduced computational work.展开更多
当前,建筑信息模型技术(Building Information Modeling,BIM)广泛应用于钢结构建筑设计中,有效促进了建筑行业工业化及信息化。但在装配式钢结构节点设计应用中,BIM钢结构设计软件不能快捷有效地对钢结构节点进行参数设定以及全方位建...当前,建筑信息模型技术(Building Information Modeling,BIM)广泛应用于钢结构建筑设计中,有效促进了建筑行业工业化及信息化。但在装配式钢结构节点设计应用中,BIM钢结构设计软件不能快捷有效地对钢结构节点进行参数设定以及全方位建模设计,同时设计精度不足、应用效果不理想等阻碍了BIM技术的应用。为此,本文以大庆西站钢结构深化设计项目为案例,设计适用于装配式钢结构节点的设计流程,并对梁柱节点、柱脚节点及柱柱节点进行了节点的计算和全方位设计,大大提升了基于BIM技术的装配式钢结构节点设计的效率。展开更多
文摘The design of telecommunication network with capacity constraints of links, routers and ports of routers is considered in this paper. Specially, we limit each demand flow traversed through a pre-specified maximal number of links (called hops) under node failure scenarios in IP layer network. Such a design must be the most cost-effective and ensure that feasible flows continue to exist even when any relay node of the network fails. We propose a reliable mixed-integer programming (MIP) model with multi-scenario constraints to optimally design a minimum-cost survivable IP network that continues to support a good communication under any node failure scenario. Then we transform the MIP model into many single scenario models, that is, simplified MIPs, nonlinear programming (NLP) models and MIP models under Benders decomposition Then we transform the MIP model into many single scenario models, that is, simplified MIPs, nonlinear programming (NLP) models and MIP models under Benders decomposition. Three heuristic methods are proposed to solve these models including branch-and-bound algorithm, global algorithm for NLP, and heuristic algorithm based on benders decomposition. We mainly study the application of Benders decomposition method, where dual model and bounding procedures are given for each MIP model under Benders decomposition at each scenario. The results of our computational experiments validate the effectiveness of the proposed models and algorithms.
基金Project supported by the Natural Science Foundation of Henan Province,China(No.0311010400).
文摘Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M)is developed.Three examples are given,showing that the method proposed is especially suitable for the optimized design of complex structures,and that the global approximate optimal solution can be searched with remarkably reduced computational work.
文摘当前,建筑信息模型技术(Building Information Modeling,BIM)广泛应用于钢结构建筑设计中,有效促进了建筑行业工业化及信息化。但在装配式钢结构节点设计应用中,BIM钢结构设计软件不能快捷有效地对钢结构节点进行参数设定以及全方位建模设计,同时设计精度不足、应用效果不理想等阻碍了BIM技术的应用。为此,本文以大庆西站钢结构深化设计项目为案例,设计适用于装配式钢结构节点的设计流程,并对梁柱节点、柱脚节点及柱柱节点进行了节点的计算和全方位设计,大大提升了基于BIM技术的装配式钢结构节点设计的效率。
