Individual freight effects,capacity utilization,and Amtrak service quality

This paper offers a new perspective on the post-deregulation rail industry. We hypothesize that a link exists between individual freight effects and Amtrak service quality. Specifically, we investigate the relationship between freight control of the infrastructure on which Amtrak trains operate and Amtrak train delays. Our sample consists of 1117 directional station-pairs for fiscal years 2002 through 2007 on 28 Amtrak non-Northeast Corridor passenger routes. We found that freight effects have a significant impact on Amtrak train delays after controlling for other important delay determinants such as the capacity utilization rate. The impact is higher on long-distance routes. We also observed significant differences between the effects of different freight railroads. For example, Amtrak operations on infrastructure controlled by several Class I railroads experienced significantly larger delays than baseline operations, while Amtrak train delays on Burlington Northern and Santa Fe’s tracks actually fell below baseline levels.     

基于XML和Web Service的异构数据库数据交换

随着Internet上连有越来越多的异构数据库系统,这就导致数据共享比较困难,造成了资源的极大浪费。本文建立了两种异构数据库平台,阐述了使用XML和Web Service实现异构数据库存取数据的原理,最后实现了异构数据库中表之间数据交换,为异构数据库之间数据共享提供了技术支持。     

利用SCE组建安全可控网络

SCE（Service Control Engines）为Cisco服务控制引擎产品，是软硬件结合的服务控制平台，支持互联网IP流量的分类、分析和控制。简单介绍了SCE在网络中的组网方案，并详细阐述该设备在宽带网络中的不同应用。     

服务地方经济建设 促进船检业务发展

《珠江三角洲地区改革发展规划纲要》的颁布实施，对珠三角地区经济社会的发展具有重要战略意义，为珠三角地区船舶工业和航运业的发展提供了历史机遇。本文以珠江三角洲地区相关的船检分支机构[主要以广州海事局（广东省船舶检验局广州分局）为例]如何把握这一历史时期，更好地履行船舶检验职责和体现公共服务职能，发挥专业优势为船舶工业和航运业发展服务，在服务地方经济建设的同时实现自身科学发展为课题进行思考，提出了相应的对策建议。     

50000DWT半潜船总体设计综述

50000DWT半潜船是船院为中远航运开发设计的新一代大型半潜船,具有载货能力强、操作灵活方便、安全环保等显著特点。文章介绍该船的总体设计,首先简要介绍半潜船的基础知识、半潜船运输市场的现状和发展前景,其次介绍该船的设计概况和主要技术特点,然后分析了规则规范的选取和适用情况,最后重点从总体布置设计和总体性能计算两个方面进行展开,对该船总体设计上的特点和难点、与常规货船的差异、所采取的技术措施、运营中的安全保障、操作要点等进行了详细的分析比较和论证。     

Onboard tuning of vessel seakeeping model parameters and sea state characteristics

It is essential for a safe and cost-efficient marine operation to improve the knowledge about the real-time onboard vessel conditions. This paper proposes a novel algorithm for simultaneous tuning of important vessel seakeeping model parameters and sea state characteristics based on onboard vessel motion measurements and available wave data. The proposed algorithm is fundamentally based on the unscented transformation and inspired by the scaled unscented Kalman filter, which is very computationally efficient for large dimensional and nonlinear problems. The algorithm is demonstrated by case studies based on numerical simulations, considering realistic sensor noises and wave data uncertainties. Both long-crested and short-crested wave conditions are considered in the case studies. The system state of the proposed tuning framework consists of a vessel state vector and a sea state vector. The tuning results reasonably approach the true values of the considered uncertain vessel parameters and sea state characteristics, with reduced uncertainties. The quantification of the system state uncertainties helps to close a critical gap towards achieving reliability-based marine operations.     

Rethinking bus punctuality by integrating Automatic Vehicle Location data and passenger patterns

This paper investigates punctuality at bus stops. Although it is typically evaluated from the point of view of bus operators, it must also account for users, as required in recent service quality norms. Therefore, evaluating punctuality at bus stops is highly important, but may also be a complex task, because data on both bus arrivals (or departures) and users must be taken into account and processed. Data on buses can be collected by Automatic Vehicle Location (AVL) systems, but several challenges must be addressed in order to use them effectively. Passengers data at bus stops cannot be derived from AVL, but they can be used to derive passenger patterns and need to be integrated into processed AVL data. This paper proposes a new punctuality measure defined as the fraction of passengers who will be served within an acceptably short interval after they arrive. A method is proposed to determine this measure: it provides (i) several rules to handle AVL collected data, (ii) a procedure integrating processed AVL data and potential passengers’ patterns and (iii) a hierarchical process to perform the punctuality measure on each bus route direction of a transit network, as well as for every bus stop and time period. The paper illustrates the experimentation of this method on more than 4,000,000 data of a real bus operator and represents outcomes by easy-to-read control dashboards.     

Wakes from Large High-Speed Ferries in Confined Coastal Waters: Management Approaches with Examples from New Zealand and Denmark

Large high-speed craft carrying passengers and vehicles produce wake waves that are different from both conventional vessels and smaller fast vessels. Wakes from these high-speed craft can cause environmental problems (such as beach change, ecological disturbance, and damage to structures and archaeological sites) and safety problems (for navigation and for users of the beach and nearshore) in confined waters. As a consequence of the higher speed, the vessel wakes also have a longer period than wakes caused by conventional ships and may lead to substantial wave action in shallow water environments. In both New Zealand and Denmark, issues relating to high-speed craft wakes were not addressed until after the vessels had begun operation, and complex coastal management issues with possibly broader application have had to be addressed. Emerging management strategies have involved regulation using speed and wave height criteria.     

基于R-Lay的硬质管线铺管船发展

R-Lay（Reel-Lay,卷管铺设）是深水、超深水硬质管线铺设主要铺设方式之一,本文对R-Lay发展历程及发展现状进行分析,现役R-Lay铺管船10余艘,集中在Technip、Subsea 7、McDerMott、Emas AMC、HMC等少数海洋工程公司;并结合R-Lay铺设存在不足及R-Lay铺管船发展现状,探讨了未来R-Lay铺管船的发展趋势,为我国R-Lay铺管船发展提供一定的参考。     

海上风电安装技术及装备发展现状分析

我国海上风能资源丰富,发展潜力巨大。文章总结分析了海上风电安装特点及存在问题;探讨了国内外现有风电安装船(或平台)类型、主要机具、关键结构及技术;并进一步提出了海上风电安装技术及设备发展趋势,为我国海上风电安装技术和装备发展提供借鉴和建议。