VHDL电路优化设计及方法

随着集成电路技术和EDA技术的不断发展，VHDL已经成为IEEE标准化的硬件描述语言。分析VHDL语言设计的优点并对设计中的简化电路结构、优化电路设计等问题进行了研究，从设计思想、语句运用以及描述方法等多方面对电路进行优化设计。通过电路优化设计，可以使用规模更小的可编程逻辑芯片，从而降低系统成本。     

浅谈现代企事业单位的设备管理

设备管理在企事业单位中往往不被重视，制约了单位自身的发展，影响了经济效益。介绍了设备管理在企事业管理中的重要性、管理观念以及模式等，并对设备在管理、使用和维护过程中的一些有效方法进行了探讨，提出了改进措施，促使设备管理向更好的方向发展。     

关于铝热焊超声波探伤异常反射的原因探讨

铝热焊接头的探伤常常会有超声波的异常反射发生,这种反射有时并不是由伤损引起的。本文探讨了这种异常反射形成的原因。     

提高信息化整体水平 共享数字交通便利

2006年春夏之交的北京有点燥动不安，因为人们又要面对一场改变。对于在北京生活了几十年的人们，甚至几年的北飘军而言，公交IC卡取代传统纸质月票的规定一出台，将改变他们长期以来形成的适应性生活状态。而在这种改变中，人们所生活城市的脉搏～交通也因这种现代化设备的实施，开始涌动新一轮的轨道经济热潮，大到自动化客票系统的更新换代，小到IC卡的厂家展开的竞争，都将成为未来城市建设工作中轨道交通行业的炙热话题。本刊就目前北京公交IC卡系统的现状及未来做多方位阐述，共同关注我们所生活、工作着的城市轨道交通行业的发展。[编者按]     

Reliable container line supply chains

Container line supply chains, based on a near-frictionless international transport belief, have contributed to economic prosperity and also rendered themselves uniquely vulnerable to various risks. 9/11 terrorists attacks, the lock-out of American West Ports and the global breakout of SARS disease have gradually shown that a) the safety and reliability in the chains are facing an unprecedented challenge and b) traditional engineeringbased risk assessment methods are inadequate to deal with the threats from variational environments, especially in the era of terrorism rampancy. The purpose of this paper is, therefore, to develop a conceptual risk assessment model for container line supply chains based on a modified Formal Safety Assessment (FSA) methodology that takes risks from vulnerability rather than only hazards into account. It gives particular emphasis on the analysis of the threats with a high level of uncertainty from both safety and economic viewpoints. The advantages of the vulnerability-based risk analysis approach to the hazard-based one are clarified and both engineering-based and managerial risk assessments are also discussed.     

Simulation studies of information propagation in a self-organizing distributed traffic information system

This paper investigates the feasibility of a self-organizing, completely distributed traffic information system based upon vehicle-to-vehicle communication technologies. Unlike centralized traffic information systems, the proposed system does not need public infrastructure investment as a prerequisite for implementation. Due to the complexity of the proposed system, simulation is selected as the primary approach in the feasibility studies. A simulation framework is built based on an existing microscopic traffic simulation model for the simulation studies. The critical questions for building the proposed market-driven system are examined both from communication requirements and traffic engineering points of view. Traffic information propagation both in freeway and arterial networks via information exchange among IVC-equipped vehicles is tested within the simulation framework. Results on the probability of successful IVC and traffic information propagation distance obtained from the simulation studies are generated and analyzed under incident-free and incident conditions for various roadway formats and parameter combinations. Comparisons between the speed of the incident information wave and the speed of the corresponding traffic shock wave due to the incident are analyzed for different scenarios as the most crucial aspect of the information propagation as a potential foundation for application in such a decentralized traffic information system.     

努力开创港口轨道衡管理工作新局面

港口计量工作随着港口运输生产的不断发展，其重要性也越来越受到各级管理者的高度重视与关注。秦皇岛港务集团铁运分公司经过多年的严格管理、扎实工作，逐步摸索出了一条科学的管理方法，在加强计量管理，提高服务质量，提升企业形象等方面做了有益的尝试。     

单片机应用系统的软件可靠性技术与措施

提出了可靠性概念，随后探索了单片机应用系统的软件可靠性技术与措施。     

对铁路罐车准装高度的几点看法及建议

对现行准装高度的确定方法进行了分析，并提出了改进建议。     

加强轨距尺检定器的管理维护确保量传准确可靠

随着轨距尺检定器使用时间的延长。因受外界条件影响，如：温度、湿度、辐射、磨损等，其材质、结构、性能逐渐发生变化，送上级计量检定部门检定时，其计量检测准确度逐渐降低（检定器是合格的）。为保证工务维修用铁路轨距尺计量的单位统一、量传准确。笔者对本公司所使用的是TJGC-1型数显轨距尺检定器的传动系统、调节系统进行了多次认真检查、分析、研究，在TJGC-1型数显轨距尺检定器使用中发现：检定器因使用时间较长，各部件结构松旷、磨损，导致性能不稳定；