出行距离分布模型及参数研究

为研究城市交通规划中出行距离的分布特征,在一定假设条件下,运用概率统计理论推导出行距离的概率分布函数形式,用10座城市的居民出行资料对其进行拟合,验证了该假设条件的合理性,分析了函数参数的相关影响因素,如城市规模、城市形状和交通结构等,对其进行量化与非线性回归,得到出行距离的概率分布函数的一般形式,最后,就不同规模城市分析了分布函数参数的取值范围。研究结果表明:出行距离的分布符合瑞利分布,特大城市和大中城市分布函数参数的取值范围分别为0.035～0.076和0.042～0.100。     

带时间窗的动态车辆路径问题的局部搜索算法

为有效求解带时间窗的动态车辆路径问题,建立了该问题的数学模型,通过计划周期分片,将动态问题转换为一系列的静态子问题,采用插入法构造初始解,并将重定位法、节点交换法和2-opt*法3种线路间局部搜索方法,以及2-opt法和Or-opt法2种线路内局部搜索方法的不同组合应用于初始解的改进,分析了客户出现时间、地理位置分布与不同客户时间窗范围对线路选择的影响,比较了标准算例的求解结果。结果表明:在线路间进行局部搜索时,重定位法的效果最好,2-opt*法次之,节点交换法的最差;在线路内进行局部搜索时,2-opt法优于Or-opt法;当客户请求出现时间越早,客户比较集中,客户时间窗较宽的情况下,使用的车辆数量较少,整个线路的行驶距离较短,客户延迟时间也较短。     

大型围填海工程前期一体化策划

大型围填海工程前期策划是集市场需求、工程立项审批、项目建设、环境保护、运营管理和效益评估等众多专业学科为一体的系统分析论证工作。以东莞长安新区围填海大型工程前期工作为例,从项目运作实际需求出发,梳理海洋部门管理政策和审批流程,提出在产业策划、城市规划、项目申报、立项报批、管理模式和生态化海岸规划等项目前期工作全流程运作层面的策划思路和推进路线,总结长安新区围填海工程前期工作的实操经验,探讨提升水运设计咨询单位一体化解决大型围填海工程前期工作问题能力的路径和方法。     

中国救助打捞通信及信息化发展

围绕人命救助、环境救助、财产救助和抢险打捞、特殊政治军事保障任务等救助打捞核心业务,面向我国管辖海域内的救助、打捞、飞行三大业务领域,以支撑国际一流现代化专业救助打捞体系的加快构建为最终目的,从运行监测、应急指挥、通信保障、数据资源、信息安全、标准体系、管理机制等方面,对中国救助打捞2015—2020年通信及信息化能力建设进行规划研究,提出规划水平年内发展目标、主要任务和保障措施,并对远期发展进行展望。     

美国军船入级策略及其带来的积极影响

通过对军船入级的起源、美国军船入级历程和经验的研究,可以更好地了解军船入级的目的、程序和方法。本文首先对美国军船入级组织机构、运作方式及管理模式进行分析。在此基础上,对美国《海军高速舰艇指南》和《海军舰船规范》2个军船入级标准的架构及应用情况进行研究。剖析军船入级在小型高速巡逻艇、鱼雷回收艇及新一代大型水面舰船DDG1000入级过程中的实际应用效果。指出美国船级社及美国海军技术委员会在军船入级过程中所发挥的核心作用。通过研究认为军船入级是一项战略性决策,将在舰船建造管理及全寿命保障中收到事半功倍的良好效果。     

Passenger Perspectives in Railway Timetabling: A Literature Review

When looking at railway planning, a discrepancy exists between planners who focus on the train operations and publish fixed railway schedules, and passengers who look not only at the schedules but also at the entirety of their trip, from access to waiting to on-board travel and egress. Looking into this discrepancy is essential, as assessing railway performances by merely measuring train punctuality would provide an unfair picture of the level of service experienced by passengers. Firstly, passengers’ delays are often significantly larger than the train delays responsible for the passengers to be late. Secondly, trains’ punctuality is often strictly related to too tight schedules that in turn might translate into knock-on delays for longer dwelling times at stations, trip delays for increased risk of missing transfer connections, and uncertain assessment of the level of service experienced, especially with fluctuating passenger demand. A key aspect is the robustness of railway timetables. Empirical evidence indicates that passengers give more importance to travel time certainty than travel time reductions, as passengers associate an inherent disutility with travel time uncertainty. This disutility may be broadly interpreted as an anxiety cost for the need for having contingency plans in case of disruptions, and may be looked at as the motivator for the need for delay-robust railway timetables. Interestingly, passenger-oriented optimisation studies considering robustness in railway planning typically limit their emphasis on passengers to the consideration of transfer maintenance. Clearly, passengers’ travel behaviour is far more complex and multi-faceted and thus several other aspects should be considered, as becoming more and more evident from passenger surveys. The current literature review starts by looking at the parameters that railway optimisation/planning studies are focused on and the key performance indicators that impact railway planning. The attention then turns to the parameters influencing passengers’ perceptions and travel experiences. Finally, the review proposes guidelines on how to reduce the gap between the operators’ railway planning and performance measurement on the one hand and the passengers’ perception of the railway performance on the other hand. Thereby, the conclusions create a foundation for a more passenger-oriented railway timetabling ensuring that passengers are provided with the best service possible with the resources available.     

Development of efficient stop planning optimization process for high‐speed rail systems

The Taiwan High Speed Rail (THSR) has recently added three additional stations to its original network. Although the three additional stations can improve accessibility to the system, these new stations can present difficulties in the transportation planning process, particularly for planning of train stops. The additional stations may benefit some passengers, but may also lengthen the travel time for the other passengers. Therefore, the main challenge faced by THSR is finding an efficient way to design appropriate stopping patterns. Past studies on stop planning usually adopted meta‐heuristics or decomposition methods to solve this complex problem. Although these solution techniques can improve solution efficiency, none of them can guarantee the optimality of the solution and capture the transfer movement of different stopping patterns. In this research, we proposed an innovative network structure to address complex stop planning problems for high‐speed rail systems. Given its special network structure, two binary integer programming models were developed to simultaneously form and determine the optimal stopping patterns for real‐world THSR stop planning problems. An optimization process was also developed to accurately estimate the station transfer time corresponding to the variation in stopping patterns and passenger flow. Results of the case studies suggest that the proposed binary integer programming models exhibit superior solution quality and efficiency over existing exact optimization models. Consequently, using this stop planning optimization process can help high‐speed rail system planners in designing optimal stopping patterns that correspond to passenger demand. Copyright © 2017 John Wiley & Sons, Ltd.     

Conflict‐free time‐based trajectory planning for aircraft taxi automation with refined taxiway modeling

To mitigate airport congestion caused by increasing air traffic demand, the trajectory‐based surface operations concept has been proposed to improve surface movement efficiency while maintaining safety. It utilizes decision support tools to provide optimized time‐based trajectories for each aircraft and uses automation systems to guide surface movements and monitor their conformance with assigned trajectories. Whether the time‐based trajectories can be effectively followed so that the expected benefits can be guaranteed depends firstly on whether these trajectories are realistic. So, this paper first deals with the modeling biases of the network model typically used for taxi trajectory planning via refined taxiway modeling. Then it presents a zone control‐based dynamic routing and timing algorithm upon the refined taxiway model to find the shortest time taxi route and timings for an aircraft. Finally, the presented algorithm is integrated with a sequential planning framework to continuously decide taxi routes and timings. Experimental results demonstrate that the solution time for an aircraft can be steadily around a few milliseconds with timely cleaning of expired time windows, showing potential for real‐time decision support applications. The results also show the advantages of the proposed methodology over existing approaches. Copyright © 2015 John Wiley & Sons, Ltd.     

快速公交（BRT）线路布局优化研究

为探讨现有公共交通线网结构下BRT线路布设优化问题,对快速公交线路布设的内部条件和外部条件进行了分析;在此基础上依据快速公交的发展特点,以乘客总出行时耗最小和车公里成本投入最小为目标,建立了快速公交布局优化的模型,并且给出了优化目标和相应约束条件的函数表达式。通过事例分析对BRT线路布设优化算法进行说明,从而得知优化模型具有较高的应用价值。     

城市新区市政道路交通设施规划探讨

该文通过鄂尔多斯市东胜铁西二期开发片区市政基础设施专项规划实例,从路网布局、道路竖向、静态交通等方面论述了城市新区市政道路交通设施规划应注意的要素,可供道路专业人员参考。