一种移动Ad Hoc网络路由协议的设计与实现

Ad Hoc网络是一种无需依赖于事先布设的基础通信设施,没有中心控制节点,抗毁性强,复杂的分布式、多跳无线网络。考虑到Ad Hoc网自身的特点,传统的路由协议（如RIP和OSPF）已不再适用。论文提出了一种反映链路质量的混合路由协议即可优化链路状态协议,其寻径时间较短,路由协议开销较小,能对链路状态的变化做出快速反应。     

Application specific instance generator and a memetic algorithm for capacitated arc routing problems

Capacitated arc routing problem (CARP) is a well known combinatorial problem that requires identifying minimum total distance traveled by a fleet of vehicles in order to serve a set of roads without violating the vehicles’ capacity constraints. A number of optimization algorithms have been proposed over the years to solve basic CARPs and their performance have been analyzed using selected benchmark suites available in literature. From an application point of view, there is a need to assess the performance of algorithms on specific class of instances that resemble realistic applications, e.g., inspection of electric power lines, garbage collection, winter gritting etc. In this paper we introduce a benchmark generator that controls the size and complexity of the underlying road network resembling a target application. It allows generation of road networks with multiple lanes, one-way/two-way roads and varying degree of connectedness. Furthermore, an algorithm capable of solving real life CARP instances efficiently within a fixed computational budget of evaluations is introduced. The proposed algorithm, referred to as MA-CARP, is a memetic algorithm embedded with a similarity based parent selection scheme inspired by multiple sequence alignment, hybrid crossovers and a modified neighborhood search to improve its rate of convergence. The mechanism of test instance generation is presented for three typical scenarios, namely, inspection of electric power lines, garbage collection and winter gritting. The code for the generator is available from http://seit.unsw.adfa.edu.au/research/sites/mdo/Research-Data/InstanceGenerator.rar. The performance of the algorithm is compared with a state-of-the-art algorithm for three generated benchmarks. The results obtained using the proposed algorithm are better for all the above instances clearly highlighting its potential for solving CARP problems.     

基于熵值法和TOPSIS方法的地铁列车交路评估研究

由于地铁列车交路对地铁运营效率有着显著影响,针对地铁列车交路评估,提出一种基于熵值法和逼近理想解排序（TOPSIS）法的地铁列车交路方案评估方法.为更好地反映专家评估中的模糊性,评估指标信息值用语言值给出,采用通用二元语义对语言值进行处理以避免语言信息在运算中过程中失真和扭曲,并提出基于二元语义的成本型指标与效益性指标的转换公式,基于熵值法确定评估指标为二元语义信息的指标权重求解方法.最后,提出基于语言值的TOPSIS的评估方法对地铁列车交路方案排进行排序,并给出地铁列车交路评估实例、结果验证方法的有效性和可行性.     

基于TransCAD的物流设施选址与配送路线优化研究

根据物流设施选址与配送路线的特点并结合TransCAD物流模块,构建适合TransCAD软件进行网络分析的LRP数据结构,探讨基于TransCAD的车辆路线调整技术,旨在说明新的信息技术能更高效、直观地对物流系统进行规划。     

多品种燃油海运库存路径问题鲁棒优化模型与算法

针对需求不确定下的多品种燃油海运库存路径问题(Maritime Inventory Routing Problem, MIRP),提出非专用舱室和非固定停靠供应港的船舶配送策略,通过设置供货商保守系数给定条件下的累积航次多品种燃油不确定需求预算阈值,构建以供货商燃油库存与配送总成本最小化为目标的MIRP非线性鲁棒优化模型,并设计了改进混合自适应遗传算法求解模型。算例结果表明,非专用舱室和船舶非固定停靠配送能有效降低供货商燃油库存与配送总成本;供货商在各需求港关于各品种燃油的保守系数均存在某个不同的恰当值,当保守系数超过恰当值时,客户服务水平变化趋于平缓。研究结论可为供货商多品种燃油MIRP提供决策参考。     

Daily newspaper distribution planning with integer programming: an application in Turkey

Abstract

This paper concerns the newspaper distribution problem. It addresses the transportation of newspapers from printing plant to newsagents with distribution vehicles under various particular constraints. The objective is to minimize the distance traveled by the vehicles and/or the number of vehicles. In this study, the routes for vehicles of a leading newspaper distributor company in the Turkish press sector are examined. The problem is defined as determining optimal delivery routes for a fleet of homogeneous vehicles, starting and ending at the printing plant that is required to serve a number of geographically dispersed newsagents with known demands under capacity and time constraints, while minimizing the total distribution cost. An integar linear programming model is proposed as a solution using Cplex. Computational results demonstrate that the proposed model is fast and able to find optimal solutions for problem scenarios with up to 55 newsagents within reasonable computing times. It was found that the proposed model reduced the delivery cost by 21% on average when compared to the current manual method. The results show that this model is adequate for medium-sized distribution problems.     

车辆路径问题的混沌粒子群算法研究

针对车辆路径问题中单仓库非满载这一基本类型的具体特性,设计了一种混沌粒子群算法;利用混沌系统的随机性、规律性和遍历性初始化粒子,大范围覆盖车辆路径问题的解空间,加强算法最优路径的搜索能力;通过在求解过程中的次优路径处施加混沌扰动,使算法放弃当前求解的路径,避免结果为次优解。并通过试验验证了该算法在车辆路径问题中具有很强的寻优能力。     

铁路网最大货运发送量和流量分配综合优化研究

在高速铁路初步成网、既有线运输能力得到不同程度释放的背景下,本文研究了铁路网最大货运发送量和流量分配的综合优化问题.文中以增长后的铁路网货运需求量来描述货运发送量,构建了符合铁路运输车流组织特点的多目标优化模型.模型的目标函数包括货运发送量的最大化和不同货运发送量情形下的流量分配成本最小化.同时考虑了单股货流增长量上限、车流走行具有树形径路特点、非重复径路的数学逻辑表达等约束条件.最后,基于相同算例数据对所构建模型及既有研究文献中的模型进行求解试验,分别得到两种模型下的铁路网最大货物发送量和流量分配方案,通过对比求解结果,验证了本文模型的有效性.     

一致性车辆路径问题下基于模板路径的模拟退火法

根据一致性车辆路径问题的“服务一致性”特征,本文提出了基于模板路径的 模拟退火法（TSA）以更好地求解此问题.该算法求解分为2 个阶段：第1 阶段求解模板路 径,第2 阶段以所得模板路径为参考获得各天车辆具体配送路径方案,2 个阶段均采用模 拟退火法进行优化.借助小、中规模基准数据集,文章对TSA算法进行数值实验,并将实 验结果与ConRTR算法和TTS算法的结果作比较,利用TSA法求解一致性车辆路径问题 得到的配送路径方案和“服务一致性”指标均得到优化.实验结果表明,运用TSA算法规 划车辆配送路径方案,不仅能够降低运营成本,还能提高配送服务质量.