基于虚拟样机技术的空气悬架客车平顺性仿真研究

针对某中型客车，利用ADAMS软件建立了空气悬架客车动力学仿真模型，并进行了随机路面输入及三角凸台路面输入的平顺性仿真分析。仿真结果与试验数据对比表明，在测量点处的最大加速度、自功率谱密度及其对应的频率点比较接近，说明所建立的仿真模型是准确的。对影响客车平顺性的2个参数在ADAMS中进行了优化。     

客车车身的大修工艺

结合合肥市公交总公司汽车修造厂的生产过程，以该厂制定的ＨＧ６９１３型城市客车的大修工艺规范为实例，简要介绍了客车车身大修的工艺过程及技术要求，提出了具体的操作规范。     

后置发动机客车噪声源的识别

应用相关分析与谱分析理论，建立了后置发动机客车噪声源识别的多输入单输出模型。运用该噪声识别模型及所介绍的测试分析系统，对GZ6921型后置发动机客车噪声源进行了识别。识别及分析结果表明，冷却风扇噪声是GZ6921型客车的主要噪声源。     

智能控制技术在公交车排气式供暖装置中的应用

在分析公交车运行特点的基础上，设计了一种以发动机排气余热为热源的公交车供暖装置。该装置采用智能检测、控制技术，解决了热管安全性与功率稳定性之间的矛盾。介绍了该供暖装置的设计方法及其智能控制系统的控制原理。通过实车运行试验证明了该供暖装置热能利用率高、升温快，基本达到了预期要求。     

公交专用车道效益评价方法探讨

对于设置公交专用车道的城市道路,其核心功能是满足人的出行需求。因此公交专用车道的评价应以人为单位,而并非以车辆为单位。本文提出的公交专用车道效益评价方法主要从单点交叉口的交通效益、通道的综合效益进行。文章的最后,运用该理论对广州市某路段公交专用车道及相关道路进行了评价和分析,验证了该方法的可行性。     

公交专用道设置前后无港湾公交停靠站特性研究

对有无公交专用道的路段上非公交车和公交车以及无港湾停靠站区域的非公交车分别提出车速模型公式,并考虑交叉口间距和车道宽度的影响。其中在无公交专用道的路段上采用美国联邦公路局路阻函数转化成线性模型,定义停靠度指标。根据在南京市和深圳市采集的实测数据回归,标定各模型参数,并通过F检验和t检验。同时研究无港湾停靠站区域的影响范围,从时间和空间上反映影响变化规律,得到一些有价值的结论。     

Seaports and the structural implications of the economic crisis

The 2008 credit crunch and the subsequent economic crisis ended a period that lasted over two decades wherein international seaports around the globe experienced double-digit volume increases. This chapter provides an analysis of the structural effects that the crisis has on seaports, focusing mostly on developments in Europe. It does so via an examination of (a) the crisis implication for each of the four major types of transport flows that account for the vast majority of port throughput worldwide; (b) the prospects for future capacity organisation and development, given the realignment of the involvement strategies that the various stakeholders (i.e., governments, port authorities, service providers, users, investors) endorse in reaction to the financial tsunami; and (c) the adjustment opportunities, that the trade downturn unintentionally provides, allowing for correction of existing misallocations in the sector via the deployment of relevant adjustment strategies by the related actors. Recapping the identified structural consequences, the final section concludes on the changing role and responsibilities of port authorities and the ‘new issues’ that will require further investigation in the post-financial tsunami era.     

Incompleteness and clarity in bus contracts: Identifying the nature of the ex ante and ex post perceptual divide

In the transport sector, many types of contracts exist. Some are very precise, and strive for completeness; others are very ‘light-weight’ and are incomplete. Bus and coach contracts, won through competitive tendering or negotiation, are typically incomplete in the sense of an inability to verify all the relevant obligations, as articulated through a set of deliverables. This paper draws on recent experiences in contract negotiation, and subsequent commitment in the bus sector, to identify what elements of the contracting regime have exposed ambiguity and significant gaps in what the principal expected, and what the agent believed they were obliged to deliver. We develop a series of regression models to investigate the extent of discrepancy between the principal and the agents perceived ‘understanding’ of contract obligations. The empirical evidence, from a sample of bus operators, is used to identify the extent of perceived incompleteness and clarity across a sample of bus contracts. A noteworthy finding is the important role that a trusting partnership plays in reducing the barriers to establishing greater clarity of contract specification and obligations, and in recognition of the degree of contract completeness.     

Contracting regimes for bus services: What have we learnt after 20 years?

This paper reviews a number of themes that have played a crucial role in the debate on alternative contracting regimes for the provision of urban bus services. We have selected four crucial issues to reflect on: (i) contractual regimes (in particular competitive tendering as compared to negotiated performance-based contracts, as means to award the rights to provide service); (ii) contract completeness (focussing on ex ante and ex post elements); (iii) building trust through partnership; and (iv) tactical or system level planning for bus services. Experience in these areas suggests that competitive tendering has frequently not lived up to expectations and that negotiation is likely in many circumstances to deliver better value for money.     

基于CPCI总线的GMSK调制系统研究

介绍一种基于CPCI总线的GMSK调制系统,采用了DSP结合CPLD的方式构建的系统平台,对系统的结构和功能及硬件,软件设计进行了详细的介绍,并对主要器件的一些特点做了简单的描述。