三齿轮联动双曲柄双环板式针摆行星传动受力分析

在论述三齿轮双曲柄双环板针摆行星传动原理及特点的基础上，针对该新型传动受力属于静不定系统，提出了符合实际的变形协调条件，建立了准确的力分析模型，并编制了相应的软件．所研制样机经过实验室承载能力的试验，证明了该受力分析理论的正确性，并显示出本新型传动的明显优越性，为我国研制双曲柄环板式针摆行星减速器提供了理论依据．     

双曲拱桥的结构特点及加固浅析

双曲拱桥是中国独创的一种少筋混凝土拱桥，目前全国干线和县乡公路上正在运营的大、中型双曲拱桥达4000多座，约占地方道路大中型桥梁总数的25％左右。现在相当一部分双曲拱桥都出现了一些病害现象，已经进行加固处理或需要进行分析处理的桥梁很多。本文主要介绍双曲拱桥的构造、病害现象、分析病害产生的原因，并提出适合双曲拱桥加固的处理技术。     

A study on the determinants of private car ownership in China: Findings from the panel data

This study examines the determinants of private car ownership in China. The target cities are 32 provincial capital cities and the target period is from 2001 to 2011. In order to capture the individual effects (heterogeneity), the fixed and random effect models are adopted and compared, in which 8 explanatory variables are selected to include economic characteristics, urban characteristics, and transportation characteristics. Moreover, double natural logarithm model is employed to measure the elastic relationship between the private car ownership and regressors. The estimated results show that the fixed effect model performs better than pooled regression model and the random effect model. In addition, there are variations of private car ownership among cities and regions. Finally, the influence of factors responsible for these variations is also presented and discussed in this paper.     

基于最小浮动车样本数量的道路覆盖率与交通信息更新周期研究

基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系是浮动车信息采集技术应用中亟待解决的关键问题。浮动车的道路覆盖率与交通信息更新周期之间成正比关系,通过对基于经典概率统计理论的传统计算最小浮动车样本数量方法中所存在不足的分析,提出从路段内车辆运行时间角度出发考虑样本量,引入表征运行时间变化的变量,确定满足道路覆盖率的最小浮动车样本数量,进而建立基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系模型,并给出满足道路覆盖率的浮动车最小样本数量计算的改进算法。通过成渝高速公路成都—龙泉段的实际浮动车数据,验证了关系模型的可靠性及改进算法的优越性。     

基于业务的SNCP在寿平铁路的应用

通信系统的建设遵循技术成熟、经济适用、同时满足发展需要的原则,网络结构满足运营维护管理体制的要求,传输系统必须具备较高的网络保护和恢复能力。基于寿平铁路通信传输系统组网及益羊线既有运营维护管理体制,本次工程通信传输系统组网旨在保证业务的高度可靠。通过参照子网连接保护(SNCP)已广泛用于传输系统的组网案例,其适用于各种网络拓扑结构,倒换速度快,可实时切换工作通道和保护通道。为此,选用基于业务的SNCP作为本线传输系统的网络保护方式,以双发选收的原则保证通信传输业务的高度可靠,并在优化网络结构的同时,一定程度上提高益羊线传输系统的通道利用率。     

高铁公网覆盖工程采用设计施工总承包模式的探讨

为了顺利实现高铁公网覆盖工程与铁路同步开通运营,分析公网覆盖工程实施的关键点,指出特别需要解决电信建设方与铁路方沟通不畅的问题。因此可以把熟悉铁路的设计与施工方结合起来,采用设计施工总承包的工程管理模式,赋予工程总承包商相应的权利与职责,充分发挥其主观能动性来推进工程实施,以实现项目的建设目标。进而分析这种工程建设模式的可行性,并以金丽温铁路公网覆盖工程的成功案例加以说明,描述设计施工总承包商的具体管理工作。希望此种建设模式能够在高铁公网覆盖工程中加以推广。     

典型铁路并线区段GSM-R覆盖方案研究

随着我国高速铁路和客运专线的快速建设,应用GSM-R网络的铁路并线区段越来越多,由于中国铁路GSM-R只有4 MHz频率资源,因此如何在保证并线区段无线覆盖的前提下有效地运用有限的频率资源并避免网内干扰是GSM-R网络规划的重点。分析铁路并线的类型,并对郑武客运专线与合武铁路并线区段、盘营客运专线与哈大客运专线联络区段两个典型铁路并线区段的GSM-R覆盖方案进行了研究。     

分布式覆盖技术在WCDMA网络建设中的应用

从分布式覆盖技术概念、组网设备、组网方式等方面对以RRU设备为主体的分布式覆盖技术进行了阐述,从而总结出其技术特点;以山西省临汾市WCDMA试验网为背景,突出了分布式覆盖技术在3G网络建设方案中的应用,并且得出投资、建设周期、安全、扩容性等方面的结论.     

典型交叉区域GSM-R无线覆盖方案设计

对交叉区域按两线交叉相对位置关系、线路的列控等级、基站设置位置与交叉点位置关系、有无联络线等因素进行了详细分类,并针对每种类型给出了具体的无线覆盖方案建议;然后选取了郑徐客专与京九线交越区域和商合杭铁路引入芜湖站二个典型案例,将交叉区域无线覆盖方案设计建议进行了示范应用;最后总结了交越区域GSM-R系统的设计原则,其他铁路交叉区域的GSM-R系统方案设计可直接参考。     

The reciprocal relationship between policy debate and media coverage: The case of road pricing policy in the Netherlands

This study examined the changes in the media coverage of two road pricing schemes proposed in the Netherlands in the period 1998–2010, as well as the link between the media coverage and the policy debate. Both pricing proposals were debated for several years and neither was introduced. Our findings show that space allocation for type of overall tone (e.g. negative or positive towards a pricing proposal) and the range of issues and policy actors in the media coverage were very different for the two proposals, and for each proposal fluctuated greatly over time. Our analysis suggests that such a variation in the media coverage was a reflection of changes in the content of the policy debate (e.g. caused by the specific design features of pricing proposal under discussion, the different policy actors engaged in the debate and their messages about the proposal). This indicates that policymakers can influence the media coverage of road pricing policies to some extent by managing the policy debate. Our findings also show not only that changes in the content of the policy debate were reflected in the media coverage, but also that the media coverage influenced the policy debate: the statements or actions of policy actors received media coverage, which then in turn stimulated the policy debate. However, the influence of media on the policy debate was rather indirect, in that policy actors mostly reacted to the messages from other policy actors reported in the media and to a lesser extent to the media coverage itself.