“Not just a taxi”? For-profit ridesharing,driver strategies,and VMT

The spread of GPS-based location services using smartphone applications has led to the rapid growth of new startups offering smartphone-enabled dispatch service for taxicabs, limousines, and ridesharing vehicles. This change in communicative technology has been accompanied by the creation of new categories of car service, particularly as drivers of limousines and private vehicles use the apps to provide on-demand service of a kind previously reserved for taxicabs. One of the most controversial new models of car service is for-profit ridesharing, which combines the for-profit model of taxi service with the overall traffic reduction goals of ridesharing. A preliminary attempt is here made at understanding how for-profit ridesharing compares to traditional taxicab and ridesharing models. Ethnographic interviews are drawn on to illustrate the range of motivations and strategies used by for-profit ridesharing drivers in San Francisco, California as they make use of the service. A range of driver strategies is identified, ranging from incidental, to part-time, to full-time driving. This makes possible a provisional account of the potential ecological impacts of the spread of this model of car service, based on the concept of taxicab efficiency, conceived as the ratio of shared versus unshared miles driven.     

阿尔斯通开发的PRIMA 3U15型电力机车

阿尔斯通公司运输部开发了PRIMATM机车系列,其类型满足了运营部门提出的模块化和系列化要求.投放欧洲市场的PRIMA型电力机车既满足了通用性要求,又有助于与公路的经济竞争取得成效.为此,阿尔斯通公司继法国双流制机车后又开发了一种三流制机车,该型机车可用于法国、德国和瑞士之间的跨境运输.文章介绍PRIMATM系列的开发过程以及得到法国国家铁路的订单.详细叙述了PRIMA 3U15型三流制机车,重点是PRIMA电力机车的维修、可靠性和可用性.     

用一个模型分析焊轨列车应用的条件

通过对秦皇岛 -沈阳客运专线 B2 7标段情况的分析得出铺轨基地存轨场地的面积是制约焊轨列车应用的一个重要因素。以预存长钢轨的数量为主要参数 ,利用焊轨列车在两个基地间工作的时间约束关系 ,建立起相应的模型 ,通过对其中其它参数的分析 ,得出应用焊轨列车所适宜的条件。在此基础上结合一次铺设跨区间无缝线路的工艺分析了焊轨工序与铺轨、大型机械养路工序的关系 ,提出了设备配套的建议和施工中应注意的一些问题。本文对设备选型、施工组织的编制及新工艺的采用有一定借鉴意义。     

PCR法区别HBVRC－和CCC－DNA

乙型肝炎病毒（ＨＢＶ）的基因组为一松弛环状、部分双链的ＤＮＡ（ＲＣ－ＤＮＡ）。在其负链的５＇与３＇端之间存在一缺口。当ＨＢＶ进入宿主细胞后，基因组转变为共价闭合环状ＤＮＡ（ＣＣＣ－ＤＮＡ）。我们根据ＨＢＶＲＣ－和ＣＣＣ－ＤＮＡ的结构特点，设计了ＰＣＲ区别ＲＣ－和ＣＣＣ－ＤＮＡ。实验表明，该方法可有效地区别两种形式的ＨＢＶＤＮＡ。     

混合动力汽车故障诊断功能的开发

主要介绍了混合动力汽车故障诊断开发的主要内容,结合实际混合动力量产开发项目,基于ISO14229诊断服务的要求,重点论述了故障诊断开发过程中故障监测,诊断数据管理和诊断服务3方面的基本功能及其实现方式。     

基于嵌入式操作系统的新能源汽车整车控制器软件集成

描述了一种基于嵌入式操作系统的新能源汽车整车控制器软件集成方法。通过使用实时嵌入操作系统将软件各模块进行任务划分和调度的方式进行软件集成,从而在实现软件功能的同时保证软件运行的实时性和可靠性。     

轿车用转向节试验方法

为了减少转向节作为安全件在客户使用过程中发生疲劳及冲击断裂的风险,文章对轿车用转向节设计验证方法进行研究,采用台架疲劳试验和台架冲击试验的方法对某轿车用转向节进行了验讧。通过试验,加强了样件薄弱处的设计并对不合格样件进行了整改。经批量市场考验,通过台架疲劳及冲击验证的转向节在客户使用过程中减少了断裂的风险,提高了产品的质量,具有非常高的使用价值。,     

软土地基水下真空预压固结离心模型试验

采用新发明的真空吸水系统应用于离心机中,可以使土体产生向上渗流并模拟软土地基真空预压。为获得理想的水下真空预压固结对比效果,竖井采用2种不同井间距的砂井,密封膜采用完全覆盖的形式。用发明的装置产生水下真空得以模拟软土水下固结行为。介绍了模型制作、试验程序及真空发生系统,并分析了孔隙水压力、变形、不排水剪切强度的改变和不同井间距对固结速率的影响。     

Towards a simplified performance-linked value for money model as a reference point for bus contract payments

The burgeoning commitment to contracting the delivery of bus services through competitive tendering or negotiated performance-based contracts has been accompanied by as many contract payments schemes as there are contracts. We are now well placed to design a simplified performance-linked payment (SPLP) model that can be used as a reference point to ensure value for money, given the accumulation of experiences throughout the world which have revealed substantive common elements in contracts. Whether the payment to the operator is framed as a payment per passenger or as a payment per service kilometre, the SPLP identifies efficient subsidy outcomes that are linked to a proxy indicator of net social benefit per dollar of subsidy. We illustrate how the SPLP model can be applied to obtain the gross (subsidy) cost per passenger (or per passenger km) from measures of gross cost efficiency and network effectiveness. This model can then be used as part of a benchmarking activity to identify reference value of money prospects in respect of passengers per $ subsidy outlay by adjusting for influences not under the control of the service provider. A single framework to identify contract payments to operators, and to assess (i.e., benchmark) operator performance on critical KPIs, is provided by internalising critical key performance indicators (KPIs) in the design of the SPLP. The proposed SPLP model is sufficiently general to be independent of the procurement method (competitive tendered or negotiated, for example) and of the treatment of revenue allocation (net or gross based contracts), with the additional advantage of being able to assess value for money for government.     

Growth of urban transportation: Peoples republic of China

The Peoples Republic of China, with its great urban populations, is finding it necessary to develop a range of strategies to deal with increasing demand for goods and people movement, increasing motorization and the increasing congestion that results from the increasing travel demand. This paper discusses strategies being adopted in two northern cities, Changchun and Shenyang. Both transit and roadway programs are examined for Changchun. Problems and successes of a new toll road are examined for Shenyang. Sustained infrastructure investment is essential to assure the necessary mobility for economic growth.