CZ2102柴油机连杆装配件有限元分析

采用三维接触有限元分析方法进行非线性求解计算 ,获得了较为符合实际的连杆装配件在螺栓预紧力及工作负荷共同作用下的受力状况和应力分布规律。为连杆装配件中各零件结构的改进及降低危险部位应力提供了定量分析依据     

汽车试验场可靠性试验强化系数的研究

本文按疲劳等损伤寿命原则推导了计算汽车可靠性试验强化系数的数学模型,并在模型中引入损伤因子统计量和频率因子统计量的概念,使影响强化系数的各因素的物理意义更为清晰。本文编制了计算强化系数的软件,对CA141汽车在试验场可靠性试验道路上的载荷谱测试数据进行了处理,计算得到了各种路面组合的综合强化系数。本文提供的方法对各试验场可靠性试验强化系数的分析计算具有普遍参考价值。     

代理签字算法在智能卡认证环境中的应用

智能卡可作为理想的密钥存储介质，但由于资源有限，在其内部做公钥运算效率较低。为解决这个问题，结合智能卡的特点，给出了一个基于代理签字算法的安全解决方案。实验表明，与其它方案相比具有高效的特点，同时又能保证卡内密钥信息的安全。     

论德育主体客体化和客体主体化

现行道德教育与社会发展的诸多不适应，促使德育研究成为热点。本从科学认识系统的矛盾运动中演绎出德育主体客体化和客体主体化理论，并用来指导德育实践，探索德育的现实有效途径，为我国的道德教育改革提出了一个新的发展方向。     

线路声学检测系统现场应用的初步经验

概述了线路声学检测系统(TADS)的组成、操作和安装,并介绍了Spoornet公司和昆士兰铁路部门运用TADS系统的经验。     

Incorporating features of autonomous vehicles in activity-based travel demand model for Columbus,OH

Transportation - Autonomous vehicles (AVs) could change travel patterns of the population significantly and with the rapid improvements in AV technology, transportation planners should address AV...     

Limitation of egg production in Calanus finmarchicus in the field: A stoichiometric analysis

The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5(n−3) (EPA) and 22:6(n−3) (DHA). However, an understanding of which substrates limit egg production in the natural environment has yet to be reached. The quantities of C, N, EPA and DHA ingested, derived from parental biomass, and invested in eggs by female Calanus finmarchicus during a 5-day incubation experiment were examined using stoichiometric theory to determine which substrate was limiting. The majority of each substrate was derived from parental biomass, and therefore the existing stoichiometric theory is developed to include this route of supply. The females were essentially devoid of lipid reserves, as evidenced by the lack of the storage fatty acids 20:1(n−9) and 22:1(n−11), and carbon limitation was predicted under most of the scenarios examined. Nitrogen limitation was only apparent when carbon and nitrogen utilisation efficiencies were assumed to be high (0.5) and low (0.4) respectively. PUFAs were assumed to be utilised with high efficiency (0.9), and were never predicted to limit production. This work highlights the need for a more detailed understanding of the maintenance requirements that marine copepods have for C, N, EPA, and DHA and hence the efficiencies with these substrates can be utilised for growth.     

Safe design of personal rapid transit systems

The safety of personal rapid transit systems involves careful attention to all features of the design such as the use of a hierarchy of fault-tolerant redundant control systems, bi-stable fail-safe switching, back-up power supplies, vehicle and passenger protection, and attention to the interaction of people with the system. Safety, together with reliability and adequate capacity, must be achieved while making the system economically attractive, hence techniques to achieve these goals at minimum life-cycle cost are primary in PRT design. Building on theory of safe, reliable, environmentally acceptable, and cost-effective design of PRT systems developed during the 1970′s, in 1981 the author and his colleagues initiated design of a new PRT system, now called Taxi 2000. The paper describes the relevant features of Taxi 2000 and principles of safe design incorporated into it.     

Evaluating the effectiveness of a smartphone speed limit advisory application: An on-road study in Port-Harcourt,Nigeria

The development of mobile phone applications that provide speed limit advice and warnings offers opportunities for use of the technology in the improvement of driver safety. This paper looks at the effect of an advisory Intelligent Speed Assistance (ISA) application on driver speeding behaviour. Twenty participants (all males within the age range of 35–60 years) completed a within-group experimental design. Participants drove in real traffic on a 46 km test route which incorporated three-speed limits zones (50 km/h, 60 km/h, and 80 km/h speed limits) and aggregated into 10 different segments. Compared with baseline levels, possible impacts of ISA system functionalities on driver behaviour were studied through appropriate metrics including cumulative speed distribution, mean speed, speed deviation, 85th percentile speed, percentage distanced travelled above the speed limit, and safety benefit estimation. Results indicated the use of the ISA application led to significant improvement in speed limit compliance particularly in the 60 km/h and 80 km/h zones where speeding was eliminated. There were no observed negative effects on driver speeding behaviour from the use of the system. In general, the findings suggest the use of the ISA system, resulted in the adoption of vehicle speeds that are likely to improve road safety.     

Longitudinal control of a vehicle

Generally applicable formulae for the gain constants in a proportional plus integral controller required for stable control of the speed of any vehicle in terms of natural frequency, damping ratio, vehicle mass, and thruster time constant are derived. An example, based on a simulation of the controller and vehicle, is given. The theory shows that only speed and position feedback are needed. Acceleration feedback is unnecessary.