Organisation form,scale effects and efficiency in the British bus industry

The British bus industry is examined in light of fundamental reform in ownership and regulation. The industry is divided between privately and publicly owned companies, with the private sector further split between publicly listed owned subsidiaries and private limited companies. The change in ownership structure since privatization is analysed, and Data Envelopment Analysis used to estimate the extent of returns to scale and technical efficiency, as defined by one output and three inputs. Technical efficiency is further divided into managerial and organisational components, and comparisons made of median efficiency levels using a Mann Whitney statistical test.Increasing returns to scale are found for smaller companies, but the size of such returns varies with the company type. A minimum efficiency scale is identified, with constant returns above this point. A high degree of technical inefficiency is found to be present in the industry, which may initially suggest a lack of competition and reflect the oligopolistic structure that has emerged since privatisation. Privately owned companies are identified as more technically efficient, however this is due to significantly less organisational constraints, and considerable managerial inefficiency exists in this group. It is finally concluded that the high level of inefficiency may not reflect ownership, but rather industry characteristics, and rather than a lack of competition may be indicative of wasteful competition. It is suggested therefore there may be a need to make the market contestable rather than openly competitive.     

美国铁路重载运输

介绍了美国铁路重载运输的现状.     

Efficiency Loss of the Multiclass Stochastic Traffic Equilibrium Assignment with Fixed Demand

There exists efficiency loss when introducing a user equilibrium traffic assignment in comparison with the system optimization assignment. Seeking the upper bound of the efficiency loss has attracted many scholars' attentions. The existing researches mainly focus on single user class and deterministic traffic assignment, few on stochastic user equilibrium (SUE) assignment with multiple user classes. In this paper, the authors investigate the upper bound of this SUE's inefficiency. Two decision-making criteria are used in the SUE, namely, time-based and monetary-based. It is shown that the upper bound of efficiency loss caused by the time-based SUE depends on the type of link travel time function, the network complexity, the travel demand, and the degree of users' perception error to travel cost. The upper bound of efficiency loss caused by the monetary-based SUE depends on the value of time of user classes besides the aforementioned factors.     

运输火箭航天技术产品的带有活动中梁的铁道车辆

介绍了俄罗斯首次研制的运输火箭航天技术产品用装有活动中梁的长大平车的开发过程、结构特点,以及计算、试验情况.     

考虑网络外部性航运商与无车承运人竞合研究

构建由 1个海洋航运商和 2个无车承运人组成的上下游的合作与竞争关系，2个无车承运人有不同的市场地位.通过斯坦伯格博弈研究发现，航运商负责货源或处于领导地位的无车承运人负责货源会影响各方的均衡利润及渠道结构.分析比较了海洋航运商的整合策略和利润共享策略.结果表明，在网络外部性和无车承运人提供差异性服务时，纳什均衡是航运商负责货源且上下游整合或利润分享.     

客货混运铁路专线轨道振动分析

研究目的:分析客货混运铁路专线客车及货车引起轨道振动的规律。研究方法:通过建立考虑线路随机不平顺的轨道结构连续3层梁模型,论述了运用傅里叶变换法分析轨道结构振动的方法。首先对轨道结构振动方程进行傅里叶变换,求解傅里叶变换域中的振动位移,再通过快速离散傅里叶逆变换得到轨道结构的振动响应。研究结果:分析了客、货列车以不同速度运行时对轨道结构振动的影响。研究表明,在客货混运的铁路专线上,最不利的工况应是货车。在同样的列车速度条件下,货车引起的轨道位移比客车大45%~50%,货车引起的轨道加速度比客车大40%~50%,货车引起的轨道动压力比客车大50%~60%。研究结论:客货混运铁路专线比客运专线和货运专线更易损坏,建设客、货分离的铁路专线是有效的解决方法。     

货车弹簧减振装置的计算机辅助设计

详细介绍了货车转向架弹簧减振装置的计算机辅助设计程序及其使用方法。     

从快捷、重载和专用化探讨我国铁路货运装备的发展

简述了国外货运装备的现状和发展;从快捷、重载和专用化角度论述了我国铁路货运装备的技术发展,比较了我国与国外发达国家在货运装备方面的差距,并提出了发展建议。     

铁路货车的在线监测

介绍了西门子公司开发的铁路货车在线监测系统.     

HDJ-I型货车运行故障动态检测系统

介绍了HDJ—I型货车运行故障动态检测系统(TFDS)的主要功能、特点、组成及工作原理。