台湾海峡主航道船舶定线的研究

在对台湾海峡主航道船舶交通的调查与分析的基础上,应用海上交通工程的理论和方法,对海峡通航环境进行定性和定量分析,揭示海峡中主要交通流模式和交通环境特征,结合IMO《关于船舶定线的一般规定》,规划和设计台湾海峡主航道船舶定线制,并对该定线制方案设计中的技术问题进行了探讨。     

铁路沿线线性无线传感器网络路由协议研究

针对铁路沿线环境监测对象种类繁多、位置分散的特点,设计一种无线传感器网络用于将传感器采集信息传输至监测中心,该无线传感器网络由传感器节点、轨边汇聚节点、机房汇聚节点及中继节点组成,重点研究提出轨边汇聚节点与机房汇聚节点之间线性无线传感器网络路由协议。鉴于铁路沿线传感器节点采集信息的重要程度不同,该路由协议根据信息重要程度对数据包进行优先级排序。综合考虑网络寿命和信息重要程度,以网络生命周期内传输数据包数量最大化为目标,建立数据包转发模型和数据包排队模型。在网络能耗均衡的前提下,采用减少优先级高的数据包的转发次数和减少优先级高的数据包在轨边汇聚节点的排队时延两种方式,减少优先级高的数据包的总传输时延。仿真结果表明,该路由协议可以显著减少高优先级数据包的传输时延,均衡使用网络能量,最大化网络寿命。     

旅客列车过站径路优化模型与算法

在给定铁路客运站站形布局和列车运行图的前提下,研究旅客列车过站径路优化问题。过站径路由列车的接车作业进路、占用的到发线和发车作业进路拼接而成。以旅客列车的接发车作业进路为决策,以道岔和到发线占用相容性为约束,以最大化接发车作业进路效用和到发线运用效用为优化目标,建立旅客列车过站径路优化的0-1规划模型。设计基于极大列车过站径路方案k剔除邻域系的模拟退火算法。以某客运站为例验证该模型和算法的合理性。结果表明:模型对实际问题的描述准确,算法效率较高,适用于求解大规模铁路客运站旅客列车过站径路优化问题。     

长江上海段圆圆沙警戒区航行规则的思考

通过对长江上海段圆圆沙警戒区通航现状和船舶流向的分析,结合定线制规则、海员通常航行习惯和船舶操纵等相关知识,给航经此水域船舶的安全航行和船舶间的避碰提出一些可行性的建议,这些建议对保障船舶在该水域安全航行具有重要意义。     

Innovative systems for the transportation disadvantaged: Toward more efficient and operationally usable planning tools

When considering innovative forms of public transport for specific groups, such as demand responsive services, the challenge is to find a good balance between operational efficiency and 'user friendliness' of the scheduling algorithm even when specialized skills are not available. Regret insertion-based processes have shown their effectiveness in addressing this specific concern. We introduce a new class of hybrid regret measures to understand better why the behaviour of this kind of heuristic is superior to that of other insertion rules. Our analyses show the importance of keeping a good balance between short- and long-term strategies during the solution process. We also use this methodology to investigate the relationship between the number of vehicles needed and total distance covered - the key point of any cost analysis striving for greater efficiency. Against expectations, in most cases decreasing fleet size leads to savings in vehicle mileage, since the heuristic solution is still far from optimality.     

铁路行包运输径路算法

针对铁路行包运输网络和运输组织的特征,遵循长短途分工、始发直达、区域中转等铁路行包运输组织基本原则,以营业站和列车运行模式对铁路行包运输网络进行描述;综合考虑运输成本、时间、能力和现场作业等方面因素,给出铁路行包运输径路的基本形式和选择策略,并设计基于选择策略的铁路行包运输径路搜索算法,实现对装车站以及中转站列车的合理选取,有效减少选用列车的数量,提高搜索的效率和有效性。通过限定最大搜索次数对铁路行包运输径路算法的搜索深度进行有效控制;搜索广度主要由可选用的列车数决定。该算法可以完成给定装车站到所有营业站的径路计算,应用于中铁快运公司1 000多个行包营业站、1 600多列列车的大规模铁路行包运输网络的运输径路计算,效果良好。     

船舶定线制在长江尹公洲航段的深化实施

长江江苏段船舶定线制的实施对打造长江成为“水上高速公路”作出了重大贡献，但在位置险要的长江尹公洲段，由于其特殊性，水上安全形势持续稳定仍存在瓶颈。在分析现状的基础上，针对如何在该航段深化实施船舶定线制作了进一步探索，以利于改善长江尹公洲段的通航环境。     

三峡水库主要通航支流船舶定线制的设计原则和基本方法

本文参照国际海事组织关于船舶定线制的设计规范和标准,依据《中华人民共和国内河交通安全管理条例》、《中华人民共和国内河避碰规则》等法律、法规,对三峡水库通航支流船舶定线制的设计原则和基本方法,进行了探索和研究。     

To save money or to save time: Intelligent routing design for plug-in hybrid electric vehicle

Electric vehicles (EVs) are promising alternative to conventional vehicles, due to their low fuel cost and low emissions. As a subset of EVs, plug-in hybrid electric vehicles (PHEVs) backup batteries with combustion engines, and thus have a longer traveling range than battery electric vehicles (BEVs). However, the energy cost of a PHEV is higher than a BEV because the gasoline price is higher than the electricity price. Hence, choosing a route with more charging opportunities may result in less fuel cost than the shortest route. Different with the traditional shortest-path and shortest-time routing methods, we propose a new routing choice with the lowest fuel cost for PHEV drivers. Existing algorithms for gasoline vehicles cannot be applied because they never considered the regenerative braking which may result in negative energy consumption on some road segments. Existing algorithms for BEVs are not competent too because PHEVs have two power sources. Thus, even if along the same route, different options of power source will lead to different energy consumption. This paper proposes a cost-optimal algorithm (COA) to deal with the challenges. The proposed algorithm is evaluated using real-world maps and data. The results show that there is a trade-off between traveling cost and time consumed when driving PHEVs. It is also observed that the average detour rate caused by COA is less than 14%. Significantly, the algorithm averagely saves more than 48% energy cost compared to the shortest-time routing.