机车长交路条件下的技术站列车编组计划无调作业参数模型

基于对传统车流组织优化模式的分析，发现无改编节省参数的局域性。本文在取消直达列车途经支点站均进行无改编技术作业的假设条件，把编组去向和无改编技术作业消耗相关联，通过设置改编作业时间参数和无调作业成本参数取代了无改编节省参数，建立了机车长交路条件下的技术站列车编组计划无调作业参数模型（ＮＴＦＰ），从而实现了支点站〈编组去向〉无改编技术作业站三者之间不规则关联的数学体现。ＮＴＦＰ模型更真实地反映了车流     

客运专线选线主要设计原则和特点

从满足旅客乘坐舒适度,力求使线路短直,做到系统最优,与城市规划结合,节约用地,环境保护,合理处理与军方关系、文物保护等几个方面,阐述客运专线选线设计原则和特点。     

船舶气象导航最省燃料航线研究

船舶气象导航是保证船舶航行安全和节能的重要手段。本文应用最佳控制理论研究和建立船舶最省燃料航线数学模型。在分析比较船舶最短时间航线和最省燃料航线数学模型的基础上，讨论了最省燃料航线算法实现。并针对冬季北太平洋进行了最省燃料航线模拟试验。     

考虑不确定性因素的路径优化(英文)

A route optimization methodology in the frame of an onboard decision support/guidance system for the ship’s master has been developed and is presented in this paper.The method aims at the minimization of the fuel voyage cost and the risks related to the ship’s seakeeping performance expected to be within acceptable limits of voyage duration.Parts of this methodology were implemented by interfacing alternative probability assessment methods,such as Monte Carlo,first order reliability method(FORM) and second order reliability method(SORM),and a 3-D seakeeping code,including a software tool for the calculation of the added resistance in waves of NTUA-SDL.The entire system was integrated within the probabilistic analysis software PROBAN.Two of the main modules for the calculation of added resistance and the probabilistic assessment for the considered seakeeping hazards with respect to exceedance levels of predefined threshold values are herein elaborated and validation studies proved their efficiency in view of their implementation into an on-board optimization system.     

基于遗传算法的道路车辆自组织网络源路由机制

在当前基于交叉路口的城市车辆自组织网络(VANETs)路由协议中，道路上数据包传输大多采用基于地理位置的贪婪转发策略，当数据量较大时，个别节点负载较重，极易引起传输延迟增大乃至丢包的情况.本文提出了一种基于遗传算法的源路由机制，通过记录单体车辆的驾驶信息而非传统方法中的车流均值数据，来预测道路上车辆网络的连通情况，并借助遗传算法，首次基于道路连通性、节点负载和连接跳数这3 点综合考虑，计算得出道路上最佳的源路由节点序列.仿真实验结果表明，在传输率与延迟时间上，性能均优于传统的贪婪路由机制，尤其在车流量为250 veh· lane-1· h-1时，传输率提升约13%.该研究可为智能交通信息通讯提供可靠助力.     

考虑均衡性的城市轨道交通线路负荷水平评估研究

线路负荷水平的评价工作是优化运输组织方案的重要前提。首先，本文分析了采用单一均值性指标表征负荷水平不能体现线路内负荷分布偏差的问题。为此，从城市轨道交通线路客流与运输能力匹配的角度出发，以列车负荷为评价单元，建立包括负荷均值和标准差率二维指标的线路负荷水平评估模型。负荷均值指标考虑了各评价单元加权计算，以反映每个评价单元对线路负荷水平的贡献程度，标准差率指标表征负荷均衡性。模型分析得出，线路所有区间的运力同等规模变化不影响标准差率指标，相对提高大客流区间或大客流方向上的输送能力能够改善线路负荷的均衡性。算例分析表明：客流方向不均衡系数超过 1.4 时，应考虑运力优化措施以提高运输能力利用的均衡；组织列车大小交路方案和不成对行车模式，能够提高线路负荷的均衡程度。     

Stability of transportation networks under adaptive routing policies

Growing concerns regarding urban congestion, and the recent explosion of mobile devices able to provide real-time information to traffic users have motivated increasing reliance on real-time route guidance for the online management of traffic networks. However, while the theory of traffic equilibria is very well-known, fewer results exist on the stability of such equilibria, especially in the context of adaptive routing policy. In this work, we consider the problem of characterizing the stability properties of traffic equilibria in the context of online adaptive route choice induced by GPS-based decision making. We first extend the recent framework of “Markovian Traffic Equilibria” (MTE), in which users update their route choice at each intersection of the road network based on traffic conditions, to the case of non-equilibrium conditions, while preserving consistency with known existence and uniqueness results on MTE. We then exhibit sufficient conditions on the network topology and the latency functions for those MTEs to be stable in the sense of Lyapunov for a single destination problem. For various more restricted classes of network topologies motivated by the observed properties of travel patterns in the Singapore network, under certain assumptions we prove local exponential stability of the MTE, and derive analytical results on the sensitivity of the characteristic time of convergence to network and traffic parameters. The results proposed in this work are illustrated and validated on synthetic toy problems as well as on the Singapore road network with real demand and traffic data.     

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针对城市建设发展中道路交通阻塞问题，研究了两种类型的车辆路径与调度问题，给出了相应的求解框架，并构建了一个具有可变行驶时间的动态车辆路径与调度模型，涉及了车辆的固定费用、运营成本和早到或者延期的惩罚费用等多种费用。该问题是一个NP-hard问题，采用遗传算法确定最优解，并给出了车辆路径与调度方案的表示方式。最后设计了一个交通网络，通过动态交通仿真更新行驶时间，研究了多个不同时间段道路阻塞情况下算法的性能。结果显示比不考虑实时行驶时间信息的模型，该模型能够得到更低的总成本。     

海运集装箱运输路径选择

基于海运集装箱运输问题特性的分析，建立了需求不确定的海运集装箱路径随机规划模型．该模型以集装箱运输过程中利润最大为目标函数，主要约束包括航段容量和装载质量限制、重箱和空箱需求（重箱需求为随机变量）．应用机会约束规划方法求解模型．通过数值仿真，证明了模型的可行性．仿真结果表明，运力以及各起讫对运价是影响集装箱的路径选择的关键因素，而某一单一起讫对运价的变化对集装箱路径选择的影响不大．     

基于帧投递率的无线Mesh网络DSR路由协议

为实现网络负载均衡，提出一种适用于无线Mesh网络的基于帧投递率（frame delivery ratio，FDR）的动态源路由（dynamic source routing，DSR）协议．该协议通过对网络的帧投递率的感知，优化路由发现与路由决策机制．仿真结果表明，该方法在准静态的网络拓扑环境下，使网络吞吐率提升1倍左右．