基于VISSIM的城市非互通式立体交叉口交通拥堵改善研究

文章分析了城市非互通式立体交叉口存在的问题及其成因,并以甘肃省兰州市北滨河路和城关黄河大桥立交为实例,提出了四种改善方案,同时运用VIS-SIM仿真软件对所提出的改善方案进行模拟和对比,得出最优的改善方案,为非互通式立交交通改善提供理论依据。     

深水铺管起重船驾驶模拟系统设计与实现

基于实时仿真软件Vega Prime和仪表仿真软件GL Studio开发深水铺管起重船驾驶模拟系统,通过分析深水铺管起重船驾驶特点,对驾驶模拟系统进行了总体及分系统功能设计,建立了风浪中船舶运动数学模型,逼真模拟深水铺管起重船驾控设备仪表和航行环境,实现了船舶驾驶模拟训练功能,达到了深水铺管起重船驾驶人员的桌面级驾驶培训要求。     

Methods for probabilistic safety assessments of ships

 At the 62nd MSC conference (MSC62) in 1993, the UK proposed a new methodology for the consideration of safety regulations. This method is called formal safety assessment (FSA). FSA is an application of probabilistic safety assessment (PSA). Risk is used as an index of safety. One of the most important parts of FSA is to evaluate the risk to a ship when it is equipped with the safety measures recommended by the proposed safety regulations. The National Maritime Research Institute (NMRI, formerly the Ship Research Institute) has been developing a method which allows the risk to be obtained holistically by utilizing a scientific method. To obtain the risk, the probability and consequences of every accident must be evaluated. This paper examines the following points: (a) a holistic methodology for risk evaluation; (b) a method used in the process of estimating the probability of collision; (c) a method to reduce the numbers of fire escalation scenarios; (d) a trial risk evaluation of cabin fire. Received: January 10, 2002 / Accepted: April 18, 2002     

船舶操纵中各种制动效果的比较

船舶操纵中的制动效果是评价一艘船整体性能的一项重要指标。对于不同船型、不同吨位的船舶采用不同的制动方法,直接涉及到船舶的安全。通过船舶操纵模拟器,设定测试条件,对船舶操纵中倒车制动、Z型操纵制动、满舵旋回制动、拖锚制动、拖轮协助制动效果进行试验,得出各种制动效果的差异,比较说明各种制动效果的适用场合,以利船长、驾驶员选择适合当时环境自身条件状况的制动方法,安全的操纵船舶。     

浅谈CTCS-2级列控中心系统功能人工仿真测试

以下辛店站列控系统试验为例,简要论述了CTCS-2级列控中心系统功能人工仿真测试的内容和方法.     

EPS电动机模型的建立及实现

EPS（电动助力转向系统）应用于众多车型，代表未来动力转向的发展方向。文章通过对EPS的分析，初步设定了用于该EPS的激他式直流电动机方案。通过建立电动机的数学模型，在MATLAB中实现了该模型，并通过仿真分析，进一步验证了该选择方案的正确性。指出所选择建立的电动机模型，对电动助力转向系统仿真分析中电动机模型的建立选择具有一定的借鉴作用。     

Computer Simulation of Mould Filling and Solidification of Castings

InfoructionThCcastingProcsscoInbinOsacomplex,dynandcPrOblemoffluldflowtalhCattransferinorthetoProduCethehighqualitycastings,thefoundryengineesshOuldknOWthCsesfluldflowandheaIransferMmenaPr6viouslyUoftwtaty,theSe~naaretDOdifficulttousethetheOrodcalanalysiswithOutcowtonalteWes'ThedeSignOfthecastingsystem(suchasgatinndeq)usedhaydepeAnunonextwthanonengineeringbo.MnysuccesshodeSigDSarendybasedontalanderrorInrecenW'theinCrodsingN[i]forwtraridPrOtOtyPincashngs~tomakacastingrightatthefu…     

A discrete optimization approach for locating Automatic Vehicle Identification readers for the provision of roadway travel times

This paper develops an algorithm for optimally locating Automatic Vehicle Identification tag readers by maximizing the benefit that would accrue from measuring travel times on a transportation network. The problem is formulated as a quadratic 0–1 optimization problem where the objective function parameters represent benefit factors that capture the relevance of measuring travel times as reflected by the demand and travel time variability along specified trips. An optimization approach based on the Reformulation–Linearization Technique coupled with semidefinite programming concepts is designed to solve the formulated reader location problem. To illustrate the proposed methodology, we consider a transportation network that is comprised of freeway segments that might include merge, diverge, weaving, and bottleneck sections. In order to derive benefit factors for the various origin–destination pairs on this network, we employ a simulation package (INTEGRATION) in combination with a composite function, which estimates the travel time variability along a trip that is comprised of links that include any of the four identified sections. The simulation results are actually recorded as generic look-up tables that can be used for any such section for the purpose of computing the associated benefit factor coefficients. Computational results are presented using data pertaining to a freeway section in San Antonio, Texas, as well as synthetic test cases, to demonstrate the effectiveness of the proposed approach, and to study the sensitivity of the quality of the solution to variations in the number of available readers.     

计算机联锁车站站改过渡方法探讨

针对车站信号计算机联锁过渡改造中联锁机柜接口外电路的试验,给出了驱动和采集模拟试验盘电路、试验方法、注意事项和特点.     

堆积层边坡人工降雨致滑的原位监测试验研究

降雨可引起堆积层边坡失稳。为了研究降雨入渗诱发堆积层滑坡的失稳机理以及边坡性状随时间变化的特性,选取贵州晴隆一个典型堆积层边坡进行人工降雨模拟试验和原位综合监测。结果表明:堆积层边坡在降雨入渗影响下多发浅层松弛型破坏,滑动变形区为坡面以下0~4 m之内,变形量以坡面最大,从坡面到坡体深部逐渐减小;在实施人工降雨2 h,平均入渗率为86%之后,入渗率由于地表径流的增加而随时间逐渐减少,一段时间(6 h)之后,入渗率降到一个相对稳定值(50%);降雨入渗造成土体中孔隙水压力增加,致使边坡土体的抗剪强度由于有效应力的减少及土体吸水软化而降低,降雨入渗的这一双重效应是降雨诱发堆积层边坡失稳的主要原因之一。