Optimal timetable development for community shuttle network with metro stations

This paper investigates an issue for optimizing synchronized timetable for community shuttles linked with metro service. Considering a passenger arrival distribution, the problem is formulated to optimize timetables for multiple community shuttle routes, with the objective of minimizing passenger’s schedule delay cost and transfer cost. Two constraints, i.e., vehicle capacity and fleet size, are modeled in this paper. The first constraint is treated as soft, and the latter one is handled by a proposed timetable generating method. Two algorithms are employed to solve the problem, i.e., a genetic algorithm (GA) and a Frank–Wolfe algorithm combined with a heuristic algorithm of shifting departure times (FW-SDT). FW-SDT is an algorithm specially designed for this problem. The simulated and real-life examples confirm the feasibility of the two algorithms, and demonstrate that FW-SDT outperforms GA in both accuracy and effectiveness.     

Recursive expected conditional value at risk in the fleet renewal problem with alternative fuel vehicles

We study the fleet portfolio management problem faced by a firm deciding which alternative fuel vehicles (AFVs) to choose for its fleet to minimise the weighted average of cost and risk, in a stochastic multi-period setting. We consider different types of technology and vehicles with heterogeneous capabilities. We propose a new time consistent recursive risk measure, the Recursive Expected Conditional Value at Risk (RECVaR), which we prove to be coherent. We then solve the problem for a large UK based company, reporting how the optimal policies are affected by risk aversion and by the clustering for each type of vehicle.     

“数字海事”集成信息系统探讨

探讨如何利用当今先进技术手段建设一个“数字海事”集成信息系统，以实现各相关单位共享海事信息，实现对航行船舶的动态监控，保障航行安全、保证船岸信息交流，从而保障海运交通安全通畅。     

Fleet F-77在货物链海运环节应用的探讨

在全球化经济日趋一体化的今天，一旦货物链中的某个环节发生故障将产生连锁反应，导致多个国家地区以至全球经济的重创。海运由于其特殊性在当今货物链中扮演着极其重要的角色，而海运系统又是货物链中的脆弱环节，如何保证海运环节的通畅是保证整个货物链不断的关键。本着上述观点，探讨了Inmarsat新近推出的FteetF-77在保障海运通畅、保证全球货物链不断方面的重要应用，希望新技术业务的推出能对全球经济发展起一定的作用。     

浅谈船队如何安全通过汛期京杭运河扬州邵伯湖航段

京杭运河扬州邵伯湖航段为B级航区。每逢汛期,由于淮河洪水流经该航段形成较大横流,对船舶尤其是船队航行构成严重威胁。文章针对该航段现状,侧重从引航、驾驶、监督管理等技术角度,提出如何确保船队在汛期安全过湖的操作方法和具体安全措施。     

船舶航行数据远程采集系统

介绍了一种基于卫星通信的船舶数据远程采集系统,该系统采用嵌入式控制设计,组合船舶C站和自动识别系统(AIS)设备组建系统,利用C站的卫星通信功能接收陆地远程控制指令,通过嵌入式控制系统实现对C站和AIS设备的远程控制。采集C站和AIS设备中的船舶航行信息,通过卫星通信将航行信息传送到陆地船舶管理系统,实现了船舶数据的远程采集,为提高船舶自动化和现代化管理水平提供了技术平台。     

Routing and fleet deployment in liner shipping with spot voyages

The routing, scheduling and fleet deployment is an important integrated planning problem faced by liner shipping companies which also lift load from the spot market. This paper is concerned with coordinating the decisions of the assignment of ships to contractual and spot voyages, and the determination of ship routes and schedules in order to maximize profit. We propose a new model for representing voyages as nodes of a directed graph which is used to build a mixed integer programming formulation. Besides contractual and spot nodes, another type of node is put forward to represent a combination of a contractual voyage with one or more spot voyages. In addition, the concept of dominated nodes is introduced in order to discard them and reduce the effort of the search for an optimal solution. A set of test problems has been generated taking into account real world assumptions. The test problems are solved by an optimization software and computational results are reported. The results show the potential of the approach to solve test problems of moderate size.     

Multiple objective optimization of the fleet sizing problem for road freight transportation

A fleet sizing problem (FSP) in a road freight transportation company with heterogeneous fleet and its own technical back‐up facilities is considered in the paper. The mathematical model of the decision problem is formulated in terms of multiple objective mathematical programming based on queuing theory. Technical and economical criteria as well as interests of different stakeholders are taken into account in the problem formulation. The solution procedure is composed of two steps. In the first one a sample of Pareto‐optimal solutions is generated by an original program called MEGROS. In the second step this set is reviewed and evaluated, according to the Decision Maker's (DM's) model of preferences. The evaluation of solutions is carried out with an application of an interactive multiple criteria analysis method, called Light Beam Search (LBS). Finally, the DM selects the most desirable, compromise solution.     

我国渔业物流船队的发展历程与经验启示

发展海洋渔业可以缓解国家粮食安全压力,拓宽中国海洋渔业发展空间,维护国家海洋权益。专业化渔业物流船队是保障和支撑海洋渔业发展的重要组成部分,文章从不同的服务对象角度对渔业物流船队进行了划分,详细介绍了各类型渔业物流船队的发展历程、主要做法和取得的成效,指出了我国的渔业物流船船龄大,装备陈旧,自动化程度低和信息化水平弱等严重制约我国渔业物流船队发展的问题,提出了全面推进渔业物流船队的专业化建设、推动渔业物流船装备自动化革新、提升渔业物流船的信息化水平等实现渔业现代化的经验启示。     

基于车队离散特性分析的绿波协调控制研究

文章根据混合整数线性规划理论,建立了考虑车队行驶离散特性的干道协调控制模型,并对某一城市交通干道进行了协调控制仿真分析。结果表明,该模型符合车队的实际行驶情况,且控制效果明显。