基于电子海图的计划航线自动审批研究

分析舰船计划航线自动审批的基本原理和流程,建立自动审批的相关数学模型,给出实现自动审批的方法与过程,并在Windows平台用VC6.0语言编程实现计划航线自动审批的功能.     

局部扭曲立方体多播容错路由算法

通过对经典最短路算法的研究,提出一种基于最短路权矩阵法的改进算法。实验结果表明,与权矩阵法相比,改进算法能提高计算效率、增强寻路直观性;特别是当网络中大量节点为目的节点时,该算法更为简捷、有效。     

船舶绕避热带气旋安全-经济决策模型

为了同时对多个来源的热带气旋预报进行综合处理,对可供船舶选用的绕避方案从安全和经济效益两方面同时给予定量评价和分析,基于神经网络的多源热带气旋路径集成预报和未来风浪场确定技术、风险分析理论和模糊信息优化处理技术以及气象-经济决策理论等方面的最新研究成果,提出了一种可用于大洋中船舶绕避热带气旋方案选优的安全-经济决策模型。在对“天丽海”轮7个不同绕避热带气旋方案进行的模拟优选计算中,该模型能够根据决策者的具体要求,优选出效益最佳或效用最佳的绕航方案,得到的结论与多位具有丰富绕避热带气旋经验的船长分析的最佳绕航方案基本一致。     

A bi-objective cyclist route choice model

It is widely acknowledged that cyclists choose their route differently to drivers of private vehicles. The route choice decision of commuter drivers is often modelled with one objective, to reduce their generalised travel cost, which is a monetary value representing the combined travel time and vehicle operating cost. Commuter cyclists, on the other hand, usually have multiple incommensurable objectives when choosing their route: the travel time and the suitability of a route. By suitability we mean non-subjective factors that characterise the suitability of a route for cycling, including safety, traffic volumes, traffic speeds, presence of bicycle lanes, whether the terrain is flat or hilly, etc. While these incommensurable objectives are difficult to be combined into a single objective, it is also important to take into account that each individual cyclist may prioritise differently between travel time and suitability when they choose a route.This paper proposes a novel model to determine the route choice set of commuter cyclists by formulating a bi-objective routing problem. The two objectives considered are travel time and suitability of a route for cycling. Rather than determining a single route for a cyclist, we determine a choice set of optimal alternative routes (efficient routes) from which a cyclist may select one according to their personal preference depending on their perception of travel time versus other route choice criteria considered in the suitability index. This method is then implemented in a case study in Auckland, New Zealand.The study provides a starting point for the trip assignment of cyclists, and with further research, the bi-objective routing model developed can be applied to create a complete travel demand forecast model for cycle trips. We also suggest the application of the developed methodology as an algorithm in an interactive route finder to suggest efficient route choices at different levels of suitability to cyclists and potential cyclists.     

Vehicle routing problem and driver behaviour: a review and framework for analysis

Vehicle routing problems (VRPs) whose typical objective is to minimise total travel costs over a tour have evolved over the years with objectives ranging from minimising travel times and distances to minimising pollution and fuel consumption. However, driver behaviour continues to be neglected while planning for vehicle routes. Factors such as traffic congestion levels, monotonous drives and fatigue have an impact on the behaviour of drivers, which in turn might affect their speed-choice and route-choice behaviours. The behaviour of drivers and their subsequent decision-making owing to these factors impact the revenue of transport companies and could lead to huge losses in extreme cases. There have been studies on the behaviour of drivers in isolation, without inclusion of the objectives and constraints of the traditional routing problem. This paper presents a review of existing models of VRP, planner behaviour models in the VRP context and driver behaviour models and provides a motivation to integrate these models in a stochastic traffic environment to produce practical, economic and driver-friendly logistics solutions. The paper provides valuable insights on the relevance of behavioural issues in logistics and highlights the modelling implications of incorporating planner and driver behaviour in the framework of routing problems.     

地理路由算法在Duty-Cycle网络中的研究

文章提出了Duty-Cycle网络中的地理路由算法MMGR（多度量地理路由）。这个算法所考虑的度量因素不仅包括传统地理路由中提到的地理距离,也包括候选节点睡眠延迟的Duty-Cycle。经仿真表明,在Duty-Cycle网络中,这种新的算法在端到端的延迟方面比传统的GR（地理路由）算法有更好的效果。     

Can agents measure up? A comparative study of an agent-based and on-line optimization approach for a drayage problem with uncertainty

Experiments studying the behavior of agent-based methods over varying levels of uncertainty in comparison to traditional optimization methods are generally absent from the literature. In this paper we apply two structurally distinct solution approaches, an on-line optimization and an agent-based approach, to a drayage problem with time windows under two types of uncertainty. Both solution approaches are able to respond to dynamic events. The on-line optimization approach utilizes a mixed integer program to obtain a feasible route at 30-s intervals. The second solution approach deploys agents that engage in auctions to satisfy their own objectives based on the information they perceive and maintain locally. Our results reveal that the agent-based system can outperform the on-line optimization when service time duration is highly uncertain. The on-line optimization approach, on the other hand, performs competitively with the agent-based system under conditions of job-arrival uncertainty. When both moderate service time and job-arrival uncertainties are combined, the agent system outperforms the on-line optimization; however, in the case of extremely high combined uncertainty, the on-line optimization outperforms the agent-based approach.     

基于MFC的机车交路图辅助设计系统研究

为适应机务发展新环境,提高机车交路绘图效率,采用Visual Studio 2010开发工具研究并设计支持Win7环境的机车交路图辅助设计系统(CAD),该系统基于Microsoft Foundation Classes(MFC)类库运用面向对象的C++语言编程实现,兼容性好,操作简单,所绘矢量图缩放不失真,满足铁道机务绘图需求。     

基于流量矩阵估计的路由推断算法

路由信息对网络而言非常重要。现有的路由推断技术很难适用于任意网络。本文提出了一种路由推断算法,在已知网络的拓扑结构和链路流量的情况下,先通过期望最大化算法对一个包含了多种路由可能性的流量矩阵进行估计,然后根据对应的可能需求的估计值的差异来推断实际路由。仿真结果证明了方法的有效性。     

半开放式的多配送中心纯电动车辆路径优化问题

电子商务促使越来越多的物流企业采用多配送中心模式优化车辆的配送路径,纯电动汽车逐渐替代了传统的燃油配送车辆,以改善生态环境. 结合多配送中心联合服务模式的特点和纯电动物流车辆的行驶特征,构建带时间窗的半开放式多配送中心纯电动车辆路径优化模型,设计蚁群算法对其求解. 算例对比分析结果表明：半开放式的多配送中心联合服务,能合理利用相关物流资源,改善车辆路径,降低物流费用,但需要寻找合适数量和位置的配送中心进行联合,才能达到节约成本的最佳效果;相比单配送中心,多配送中心联合服务提供了更多潜在的较低价格的充电点,在配送中心补充电量可在一定程度上节约物流成本.