Productivity change of the Spanish Port System: impact of the economic crisis

ABSTRACT

The main goal of this study was to assess the impact of the economic crisis on the productivity growth of the Spanish Port System (SPS). The Malmquist Productivity Index (MPI) was estimated for the 28 Port Authorities of the SPS, for a ‘non-crisis period’ (2005–2008) and a ‘crisis period’ (2008–2011). From a policy perspective, the MPI is a very useful approach for assessing the productivity change because it can be decomposed into the catching-up index and the frontier productivity index. The results showed that the economic crisis did not impact all of the Spanish Port Authorities equally. Some Port Authorities presented higher productivity growth during the crisis period than in the non-crisis period. Further analysis by the Mann–Whitney test revealed that Port Authority investments and productivity growth were statistically related. Information provided by this study may be very useful for stakeholders and decision-makers, in terms of long-term strategic planning and improving the competitiveness of the SPS. The findings illustrate that the economic crisis should not be seen as an international tragedy, but as an opportunity to adapt port traffics and installations to new needs and market demands.     

System optimal dynamic traffic assignment: Properties and solution procedures in the case of a many-to-one network

Thanks to its high dimensionality and a usually non-convex constraint set, system optimal dynamic traffic assignment remains one of the most challenging problems in transportation research. This paper identifies two fundamental properties of the problem and uses them to design an efficient solution procedure. We first show that the non-convexity of the problem can be circumvented by first solving a relaxed problem and then applying a traffic holding elimination procedure to obtain the solution(s) of the original problem. To efficiently solve the relaxed problem, we explore the relationship between the relaxed problems based on different traffic flow models (PQ, SQ, CTM) and a minimal cost flow (MCF) problem for a special space-expansion network. It is shown that all the four problem formulations produce the same minimal system cost and share one common solution which does not involve inside queues in the network. Efficient solution algorithms such as the network simplex method can be applied to solve the MCF problem and identify such an optimal traffic pattern. Numerical examples are also presented to demonstrate the efficiency of the proposed solution procedure.     

点检定修制在捣固车检修中的应用

在介绍济南工务段实施点检定修制的基础上,分析点检定修制在捣固车检修中的实施过程、效果及其特点,总结点检定修制在大型养路机械维修中存在的问题。指出如果持之以恒在大型养路机械中开展点检定修制,可为提高设备的可靠性和设备运转的可预测性提供保障,最终实现提高设备生产能力、降低企业运营成本的目的。     

A GIS‐based traffic analysis zone design: implementation and evaluation

The purpose of this paper is to implement an efficient method for GIS‐based traffic analysis zone (TAZ) design in order to evaluate and validate such a method. The method was developed by the authors.

Moran's I spatial autocorrelation coefficient and sample variance are used for evaluating the generated TAZs using the Champaign‐Urbana, IL region as a case study. Sensitivity analysis is also conducted to explore the fluctuations in TAZ generation outcomes. The evaluation, the validation as well as the TAZ design have been implemented with ARC/INFO GIS software on a UNIX workstation platform.     

柳州南站货检安全集中监控系统的建立

柳州南站是南宁铁路局路网性贷检站，主要担负着湘桂、黔桂、焦柳线到发列车的贷检工作。柳州南站采用先进的系统集成技术，通过统一的数据接口，利用计算机网络技术、多媒体技术，将柳州南站与贷运安全有关的各个子系统进行整合，做到贷运安全信息与行车实时信息的融合和系统资源共享，形成一套共保贷运安全的监控系统，提高了贷检安全的质量和效率。     

浅谈船舶定线制在长江尹公洲航段的深化实施

文中通过分析尹公洲航段的复杂环境及航路航法，分析造成尹公洲航段事故多发的主要原因并探讨解决的方法。     

汽车制动辅助系统BAS的应用现状

随着人们对汽车驾驶安全、行人安全的不断重视，各种被动安全技术及主动安全技术被应用于车辆上，其中，BAS（制动辅助系统）作为能极大降低事故发生可能性及降低事故严重程度的主动安全技术，受到越来越多的重视，各大汽车公司争相研发和应用此项技术，欧洲从2009年开始，强制要求新车型安装BAS。文章介绍了BAS的发展历史、特性及分类，对当前国内BAS的应用现状进行了调查分析，并阐述了BAS今后的发展趋势。     

解析铁道行业标准《铁道客车及动车组集便装置》

从规范性引用文件,产品使用环境条件,产品防护等级,产品可靠性、可维护性及安全性规定,以及污物箱液位开关等方面,解析TB/T 3338—2013《铁道客车及动车组集便装置》,对标准的实施提出具体建议。     

兰州铁路局探索专业化管理的新途径

铁路生产力布局调整之后,兰州铁路局在新体制、新布局下,围绕铁路跨越式发展战略,突破传统思维模式和管理理念,积极探索专业化管理的新途径及维修新体制。电务系统实施扁平化管理,以生产指挥、微机监测、视频监控三大系统为基础,零距离控制现场;全面整合检修资源,初步实现“作业流程化、检修专业化、管理现代化”。牵引供电系统探索创新符合行车设备检修需要及发展方向的维修体制,形成科学、系统、规范的设备维修体制,不断提高设备检修的质量与效率。     

SMS水动力学软件

简要介绍了水动力学软件SMS的基本功能,并用简单实例对其前后处理功能做了展示。