Lateral dynamics of motorcycles towing single-wheeled trailers

A motorcycle towing a single-wheel trailer may provide useful transport for light cargo on narrow tracks and off-road use, particularly in rural areas of developing countries. Four designs of such trailers are described. Linear models are derived for the lateral dynamics of an off-road motorcycle towing this type of trailer straight ahead at constant speed. The trailers were tested behind an instrumented motorcycle. Linear autoregressive models were fitted to the experimental data using system identification techniques. Analytical and experimentally derived models largely agreed on frequency, damping and shape of the weave, wobble and trailer sway normal modes. The trailers made the motorcycle’s steering heavier but the analytical models did not predict this. The location of the articulation axes between the motorcycle and the trailer were found to be critical for stability. The best trailer design handled well with loads up to 200 kg and speeds up to 70 km/h.     

西方各国建设工程保险比较研究

进行建筑工程保险是有效控制和管理建设工程风险,保证建设工程项目顺利完成的一种重要手段。该文具体分析了美、英、法、德等西方发达国家建设工程保险的特点,并对其特点进行了比较,在此基础上,指出了我国建设工程保险业存在的主要缺陷。     

an analysis of transportation energy conservation projects in developing countries

Industrialized countries have extensive experience with various transportation energy conservation measures and have been making steady progress in improving the efficiency of their transport sector. Less Developed Countries (LDCs) have also been making progress, but their experience in many aspects of transportation energy conservation is very limited. Development organizations have funded many transportation projects in developing countries, but the vast majority of these projects were designed to improve the transportation infrastructure. Very few transportation energy conservation projects have been implemented and decision-makers face a scarcity of information on effective strategies. This paper gives an overview of transportation projects in LDCs in order to identify those transportation energy conservation measures that offer the greatest potential for LDCs. Two case studies, from Tunisia and Costa Rica, are given to illustrate the issues involved in implementing transportation energy conservation measures in LDCs. Conclusions are drawn to suggest actions for developing countries and for development organizations.Acronyms DECAT Driver Energy Conservation Awareness Training - DSE Direccion Sectorial de Energia (Costa Rica) - GDP Gross domestic product - km Kilometer - LDCs Less Developed Countries - TOE Metric tonne of oil equivalent - USAID US Agency for International Development     

国产压路机发展方向与设计创新

针对目前国内压路机行业存在的问题，结合国外企业的发展，提出了国产压路机的发展方向，并从设计思想、市场导向、方案选择、技术创新等方向提出了有价值的建议，为压路机企业的发展提出了方向。     

辽宁省港口群的组合与发展战略研究

从目前港口在建设和经营中存在的问题入手,阐述了组合港产生的必要性和必然性.论述了构建辽宁省港口群组合发展的"差异化协调发展模式",形成以大连、营口、丹东、锦州等港口的层次分明、功能互补的总体构架,提出了适应辽宁省港口群的组合与发展的若干建议.     

Estimation of Probability of Swarming Pedestrians Violation at Signalized Intersections in Developing Cities

We made an on-site investigation about pedestrian violation of traffic violation decision and the impact of the number of pedestrians in colony that the probability of pedestrian violation rose with the waiting time for simulating mixed vehicles and pedestrians and used the on-site investigation data to validate the model.When traffic volume is light,the error between the simulated values and the measured ones is 2.47%.When traffic volume is heavy,the error is 3.38%.     

汽车空气悬架系统综述

文章阐述了汽车空气悬架的结构类型和工作原理,汽车空气悬架的特性（可变刚度、低固有频率、准等频特性）,汽车空气悬架的优缺点以及汽车空气悬架的发展趋势．     

水翼艇及其控制方法综述

作为高速船舶中的一种,水翼艇以其优异的快速性、耐波性、操纵性及经济性等特点得到广泛的发展和应用。本文首先概述了水翼艇的发展历程,对国内外水翼艇的发展及现状进行了分析研究。重点总结了水翼艇的特点,以不同的角度对水翼艇进行了分类,对水翼艇的纵向控制方法研究进行了简要总结。最后,阐述了目前水翼艇研究存在的问题,对未来水翼艇的发展趋势进行了展望。     

Micro-simulation modelling for traffic safety: A review and potential application to heterogeneous traffic environment

This paper critically reviews micro-simulation modelling applications for traffic safety evaluation with respect to the use of different simulation tools, the application of surrogate safety indicators under different aspects of road environments and crash considerations. General input variables used to develop the models; key parameters for crash prediction; and calibration and validation approaches are explored in the paper. The strengths and weaknesses of used simulation packages for traffic safety evaluation are also pointed out. Moreover, recent advancements in the development and application of traffic safety micro-simulation model for safety assessment are also discussed.Despite having a number of studies, there is still a significant void in the development and application of simulation model to evaluate traffic safety of non-lane based heterogeneous traffic environments that predominate in many developing countries. The paper assessed the potential application of traffic safety micro-simulation model in heterogeneous traffic environments. Finally, a number of potentially fruitful future research directions are highlighted.     

交通需求管理与可持续发展

讨论了交通对可持续发展的影响以及交通需求管理如何达到可持续发展的目标。