舰船等级修理网络计划优化与管理系统研究

舰船维修是一项对船体结构和机电设备等进行检查、修理和保养的工作。随着海军装备的发展,建立一支强大海军对装备维修管理工作提出了新要求。按照相关要求,根据网络计划图模板编制各项工作。文章对网络计划图进行了收集整理与分析工作,并编制了网络计划图标准模板及对应的网络计划图绘制软件。     

网络信息安全与防范

网络是计算机技术和通信技术的产物,在国防、电信、银行、广播等方面都有广泛的应用。其安全性是不可忽视的,网络安全主要是由于TCP/IP协议的脆弱、网络结构的不安全、易被窃听和缺乏安全意识等原因造成的,网络入侵者主要通过破译口令、IP欺骗和DNS欺骗等途径攻击网络。防范措施主要通过防火墙技术和数据加密技术来完成。     

基于二维数值仿真的集装箱码头规划设计虚拟现实系统

基于二维数值仿真与虚拟现实技术,研究了集装箱码头规划设计的虚拟现实系统.在该系统下可以快速搭建集装箱码头三维动画场景,并通过集装箱码头装卸生产过程的数值分析与三维动画视景,分析码头平面与装卸工艺设计的合理性,揭示码头物流系统的潜在瓶颈,进一步完善和丰富集装箱码头的设计内容.     

计算机病毒武器：“网络中心战”的常规武器

随着美国海军“网络中心战”的提出,计算机病毒武器的研究与应用已成为各国军方关注的重大课题。本文首先讨论了计算机病毒武器的特点,然后分析了计算机病毒武器的现状和攻击样式,最后探讨了计算机病毒武器的发展趋势。     

Workshop 1: Performance measurement and compliance

This workshop discussed challenges of measuring the performance of transport contracts, which is usually achieved by benchmarking the relevant services against a few key performance indicators (KPIs). Such KPIs (the workshop identified cost efficiency, service quality and safety/security as the top three) can be explicitly included in the contracts (with a focus on compliance) or can be rather informal and part of a trusting partnership. Limited availability of good data and appropriate information technology systems appear to be the greatest challenges within developed markets. In the context of creating a formal market (such as the South African taxi market), which encourages public transport measurement and compliance, our findings suggest that it is important to set as a first step minimum standards to address the backlog with respect to establishing performance measurement regimes.     

Ten years after bus deregulation in Japan: An analysis of institutional changes and cost efficiency

The local bus market in Japan was deregulated in 2002. This study examines the impact of this deregulation on the market structure and the operators' cost efficiency over the last ten years. First, we perform a qualitative before-and-after-deregulation analysis of Japan's bus market, finding that there has been little change in the structure of the Japanese bus market so far. Second, we investigate the effectiveness of the deregulation and internal organisational factors by using a dataset of publicly owned (municipal) bus companies. We estimate the total cost frontier functions in order to examine their effects, showing that it is the internal organisational factors (i.e. governance structure) that affect the operator's efficiency, not deregulation. In fact, the coefficient of subsidies to companies is positive, with statistical significance, thereby suggesting that cost efficiency decreases as the subsidy ratio increases. The coefficient of the contracting-out (MCGL) dummy also obtains statistically significant results; thus, we provide an account of how contracting out clearly improves operators' cost efficiency. The deregulation variable did not show significant results.     

Inland transportation system planning by life cycle impact assessment: a case study

The comparison of land and inland water transportation from economical and ecological points of view is discussed. Required freight rates for trucks and ships are calculated and compared to find which has economic superiority. From the environmental impacts of these two transportation types, the comparative environmental destruction indices for two different time-durations are estimated. All these investigations were conducted for the Yokohama–Fukuoka route in Japan. Life cycle impact assessment, a very useful tool for quantitatively evaluating the environmental influence of a product, was used to compare the environmental burden imposed by these types of transportation. Finally, the way that these results can be used for inland transportation system planning is discussed. Received: January 21, 2000 / Accepted: June 27, 2000     

基于面向对象技术的舰船综合电力系统电力网络故障模拟及拓扑跟踪

针对舰船综合电力系统电力网络结构特点,本文实现了基于面向对象技术的对舰船综合电力系统电力网络的拓扑建模。并针对电网故障的随机性特点,在面向对象环境中实现了对随机故障的模拟,同时用深度优先算法进行了快速的拓扑跟踪。算例分析证明了该方法的有效性。     

船舶监控网络中的冗余设计和实现

当前船舶自动化的发展方向是用计算机网络实现船舶机电设备与航海仪器的综合监视、控制和管理，即实现数字化船舶监控。作者结合三年多来在系统设计、软硬件开发和实际工程应用方面的经验，提出了下层使用现场总线、上层使用以大网实现船舶综合网络监控的系统设计方案，给出了其中上层计算机网络的系统组成、软件分布和确保系统高性能运行的一些技术手段，详细论述了系统中所采用的各种软硬件冗余功能和实现原理，给出了部分实现代码。     

Data-driven ferry network design with candidate service arcs: the case of Zhuhai Islands in China

ABSTRACT

We investigate a ferry network design problem with candidate service arcs (FNDP-SA), which is a new variant motivated by areal-world case from Zhuhai Islands. In this research, the design of a ferry schedule must conform to strict constraints including technical feasibility, safety issues, environmental impacts and moreover, avoid conflicting with ferries from neighboring cities (i.e. HongKong, Shenzhen and Macao). Therefore, a set of cautiously approved service arcs are firstly given, based on which the ferry service network is optimized. This study is among the first to formally describe the FNDP-SA and model it as an integer program. A hybrid variable neighborhood descent (VND)-based algorithm is developed. Two sets of instances are generated based on the case of Zhuhai Islands, where the first set is based on historical ticket sales data while the second set is derived by incorporating increased demands in the future according to a questionnaire survey. Numerical studies have shown that 59% cost reduction on the first set can be achieved by the proposed VND algorithm when compared with manual results. Research outcomes of this study have been adopted and implemented to facilitate the sustainable development of the ferry service of Zhuhai Islands.     

武汉音乐学院校园网的规划与建设

主要是根据网络规划的技术路线介绍了武汉音乐学院校园网工程的网络设计原则、网络系统选型和网络系统的总体设计方案以及VLAN规划策略与实现、校园网的安全管理策略。旨在对加入CERNET的兄弟校园网的建设提供参考。     

Workshop 6: The public agenda: What is working and what is missing

Workshop 6 topics covered social inclusion, the informal transport sector, transport in developing countries and sustainability. The strong connections and complimentary goals were noted, where solutions to social exclusion and greenhouse gas reduction can both be realised with good transport and urban planning. There is an opportunity for developing countries to avoid the transport mistakes in many developed countries, such as car dependence. This will involve the development of infrastructure that offers accessible public transport to the majority of people, providing resources to the informal transport system and integrating this with public transport. The workshop considered specific issues such as rural transport, new technology, car tolls to subsidise public transport, safety issues with informal transport and the failure to evaluate the longer-term impacts of many major transport infrastructure developments. Recommendations were made in relation to research and policy and future Thredbo topics.     

关于海星5舱盖的设计、制造及检验

文章以母型舱盖为蓝本,详细描述了海星5折叠式舱盖的设计、制造及检验过程。舱盖使用液压系统为动力,可实现无级变速,具有更好的操控性。在建造过程中注重精度控制,并论述了调平方法。最后记录了安装、调试过程,最终通过船东、船检的验收。     

大型结构系统可靠性分析方法研究

结构系统的可靠性评估是结构设计的一个重要研究内容,而极限状态函数的建立是进行可靠性评估的基础.但是,大型结构系统的极限状态函数极为复杂,响应面法用简单的多项式进行模拟的精度较低,导致误差较大.文章提出用神经网络替代多项式来拟合复杂的极限状态函数,形成所谓的神经网络响应面.然后,基于塑性极限理论,文中提出了不依赖于失效模式的极限状态函数表达形式及采用ICP对该极限状态函数进行计算的方法.最后,依照拟合得到的神经网络响应面,给出了大型结构系统失效概率的方法.通过两个算例计算并和其它方法进行比较,表明该方法的计算精度较高,而计算时间大大降低.     

Inland transportation system planning by life-cycle impact assessment: a case study. 2nd report: single comparison index

A model to estimate and compare the ecological impact and economic feasibility of a land transportation system (trucks) and a marine transportation system (cargo ships) was developed and presented in a previous report.¹ Three different comparison indices—environmental, economic, and customer service—were used to evaluate and compare their ecological impacts and determine their economic superiority. In this article, a single comparison index is proposed and assessed for the two transportation systems. The estimates were made for nine different routes in Japan. A simple mathematical model of the whole methodology is given. The sensitivity of the weighting factors used in the comparison method was analyzed. The social cost saving in monetary terms through a modal shift is also presented. Received: February 15, 2001 / Accepted: September 19, 2001     

桂梧航道工程GPS控制网的设计与应用

GPS技术在交通水利等行业的勘察设计中已得到广泛应用,用其建立大区域首级控制网已基本取代了传统的布网方式,具有布网方便、精度高、费用省等特点。结合具体的工程实例,系统介绍带状GPS工程控制网的设计、数据采集、基线向量解算及网平差的全过程,并总结一些有益的经验。     

基于角色访问控制的办公自动化系统的研究与实现

介绍了访问控制的几种方法及特点,讨论了基于角色的访问控制方法来实现办公自动化系统中的资源共享、用户角色指派关系,讨论了利用Microsoft．NET中cache等缓存技术和．NET Framework中提供的现有技术,实现办公自动化系统中的角色访问控制。     

CY8800舰船网络自动化系统可靠性设计

本文论述了以多重冗余设计的微机局域网络应用于舰船控制系统中的可靠性,介绍了以此为原则设计的CY8800系统。CY8800系统采用改进的星形网络,即双重树形实时网络,该网络具有节点双重冗余设计,分级树形结构和网络服务器分散到各节点等特点,其可靠性和抗干扰性高。本文还简略介绍了CY8800系统中的控制级、操作级和管理级微机的特点和功能,最后计算分析了CY8800系统的可     

385叶滤机液压系统的分析设计与技术改造

385叶滤机的动力机构是一种自动化程度较高的液压动力直行程自动执行机构,采用叠加阀组控制。本文论述了该产品的液压控制原理、结构设计方案以及应用分析。     

战储器材管理系统设计与开发

战储器材管理是装备管理工作中的一项基础性的工作,但由于战储器材战备完好率要求高的具体特点,使它与常用的器材管理模式有很多不同之处。文章首先介绍了战储器材管理的基本内容,并在此基础上采用Delphi7和SQL Server2000设计开发了满足战储器材特殊管理需求的管理信息系统,充分发挥计算机管理信息系统数据完整全面、分析处理迅速、准确性高的特点,为实现战储器材管理的正规化打下基础。