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821.
介绍了道路交通安全环境的涵义,分析了道路交通安全环境中的软环境和硬环境,提出了改善我国道路交通安全环境的相关措施。  相似文献   
822.
Traffic movement conflict points at intersections are the points at which traffic movements intersect (including crossing, merging, and diverging). Numbers and distribution of different types of conflict points are used to evaluate intersection access management designs and safety performance. Traditionally, the determination of the numbers of conflict points for different traffic movements is based on manual methods, which causes the difficulty for computerized procedures to evaluate safety performance of different access management designs. Sometimes, a programmable calculation procedure may provide more effective solutions as compared with manual methods. This paper presents a programmable calculation procedure for the determination of the numbers of conflict points, which could be used as a basis for a computerized procedure. Concepts of virtual movement lanes and intersection quadrants are introduced to specify types of intersections, traffic lane configurations, and traffic movement regulations. Calculation models, based on such concepts, for traffic movement conflict points at signalized and unsignalized intersections can be obtained. In support of the procedure, case studies are presented in the paper. The procedure presented in the paper can be programmed into a computer program for the purpose of a computerized evaluation of intersection safety and design performance of different access management or control approaches. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
823.
Tram vehicles mainly operate on street tracks where sometimes misguidance in switches occurs due to unfavourable conditions. Generally, in this situation, the first running gear of the vehicle follows the bend track while the next running gears continue straight ahead. This leads to a constraint that can only be solved if the vehicle's articulation is damaged or the wheel derails. The last-mentioned situation is less critical in terms of safety and costs. Five different tram types, one of them high floor, the rest low floor, were examined analytically. Numerical simulation was used to determine which wheel would be the first to derail and what level of force is needed in the articulation area between two carbodies to make a tram derail. It was shown that with pure analytical simulation, only an idea of which tram type behaves better or worse in such a situation can be gained, while a three-dimensional computational simulation gives more realistic values for the forces that arise. Three of the four low-floor tram types need much higher articulation forces to make a wheel derail in a switch misguidance situation. One particular three-car type with two single-axle running gears underneath the centre car must be designed to withstand nearly three times higher articulation forces than a conventional high-floor articulated tram. Tram designers must be aware of that and should design the carbody accordingly.  相似文献   
824.
介绍了吴淞口国际邮轮码头工程引桥工程的设计和施工特点。作为在水上码头的引桥设计,不仅仅满足车辆荷载,还受到水位、波浪、船舶撞击、管线、景观、施工条件、耐久性诸多因素的限制,有关经验可供相关专业人员参考。  相似文献   
825.
A fault classification method is proposed which has been applied to an electric vehicle. Potential faults in the different subsystems that can affect the vehicle directional stability were collected in a failure mode and effect analysis. Similar driveline faults were grouped together if they resembled each other with respect to their influence on the vehicle dynamic behaviour. The faults were physically modelled in a simulation environment before they were induced in a detailed vehicle model under normal driving conditions. A special focus was placed on faults in the driveline of electric vehicles employing in-wheel motors of the permanent magnet type. Several failures caused by mechanical and other faults were analysed as well. The fault classification method consists of a controllability ranking developed according to the functional safety standard ISO 26262. The controllability of a fault was determined with three parameters covering the influence of the longitudinal, lateral and yaw motion of the vehicle. The simulation results were analysed and the faults were classified according to their controllability using the proposed method. It was shown that the controllability decreased specifically with increasing lateral acceleration and increasing speed. The results for the electric driveline faults show that this trend cannot be generalised for all the faults, as the controllability deteriorated for some faults during manoeuvres with low lateral acceleration and low speed. The proposed method is generic and can be applied to various other types of road vehicles and faults.  相似文献   
826.
文中介绍了船舶应急电源系统的结构原理、公约要求,并结合工作实践讲述了系统的检查要点、常见缺陷及处理原则。  相似文献   
827.
尽管<公路工程技术标准>(JTG B01-2003)中规定八车道的高速公路应当设置2.5 m的左侧硬路肩,但国内几条刚刚改建完成的八车道高速公路中没有一条设置了左侧硬路肩,甚至没有宽于0.75 m的路缘带.研究运用可接受间隙理论计算了不同流量和车道数条件下车辆从最内侧车道穿插变道停驶到右侧路肩这一过程的概率和所需距离,并通过交通事故数据调研,分析了左侧路肩设置对提高交通安全的影响,从运行效率和交通安全两个方面定性和定量分析了左侧路肩设置的必要性.  相似文献   
828.
大型舰船坐坞强度衡准与计算方法   总被引:1,自引:0,他引:1  
墩木的合理布置对保证大型水面舰船在船坞建造和进出坞过程中的安全至关重要,而国内现有舰船规范不适用于船长大于160m的舰船的坐坞强度校核。为此首先分析了现有的坐坞强度计算规范和校核衡准,然后提出了新的适用于大型水面舰船的坐坞强度衡准与基于船体梁有限元模型的计算方法,最后对一船长接近200m的舰船在坐坞状态下的船体结构强度与墩木强度进行了分析,结果表明提出的强度衡准与计算方法是合理的。  相似文献   
829.
舰船通信安全保密研究   总被引:1,自引:1,他引:0  
分析和探讨了舰船通信安全保密背景、美海军安全保密动态以及舰船通信安全保密特点,提出了舰船通信安全保密使命任务以及舰船通信安全保密的技术框架.  相似文献   
830.
战术数据链技术的发展趋势   总被引:1,自引:0,他引:1  
根据未来信息化战争对战术数据链网络的需求,从多网结构、自适应能力、频段、高阶、宽带调制、一体化、抗电磁干扰、软件无线电结构、应用扩展和安全保密等方面论述了战术数据链技术的发展趋势.  相似文献   
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