首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   222篇
  免费   0篇
公路运输   32篇
综合类   7篇
水路运输   64篇
铁路运输   2篇
综合运输   117篇
  2022年   2篇
  2021年   7篇
  2020年   6篇
  2019年   10篇
  2018年   13篇
  2017年   11篇
  2016年   15篇
  2015年   8篇
  2014年   3篇
  2013年   53篇
  2012年   14篇
  2011年   5篇
  2010年   16篇
  2009年   17篇
  2008年   7篇
  2007年   4篇
  2006年   6篇
  2005年   4篇
  2004年   2篇
  2003年   4篇
  2002年   4篇
  2001年   2篇
  2000年   2篇
  1988年   2篇
  1986年   1篇
  1985年   1篇
  1979年   1篇
  1976年   1篇
  1973年   1篇
排序方式: 共有222条查询结果,搜索用时 15 毫秒
131.
    
ABSTRACT

Academic research on automated vehicles (AVs) has to date been dominated by the fields of engineering and computer science. Questions of how this potentially transformative technology should be governed remain under-researched and tend to concentrate on governing the technology’s early development. We respond in this paper by exploring the possible longer-term effect of government (lack of) intervention.

The paper tests the hypothesis that a “laissez-faire” governance approach is likely to produce less desirable outcomes in a scenario of mass uptake of AVs than would a well-planned set of government interventions. This is done using two prominent themes in transport policy – traffic flow and accessibility – in a scenario of high market penetration of Level-5 automated vehicles in capitalist market economies. The evidence used is drawn from a literature review and from the findings of a set of workshops with stakeholders.

We suggest that a laissez-faire approach will lead to an increase in traffic volume as a result of a growing population of “drivers” and a probable increase in kilometres driven per passenger. At the same time, the hoped-for increases in network efficiency commonly claimed are not guaranteed to come about without appropriate government intervention. The likely consequence is an increase in congestion. And, with respect to accessibility, it is likely that the benefits of AVs will be enjoyed by wealthier individuals and that the wider impacts of AV use (including sprawl) may lead to a deterioration in accessibility for those who depend on walking, cycling or collective transport.

We consider the range of possible government intervention in five categories: Planning/land-use; Regulation/policy; Infrastructure/technology; Service provision; and Economic instruments. For each category, we set out a series of interventions that might be used by governments (at city, region or state level) to manage congestion or protect accessibility in the AV scenario described. Many of these (e.g. road pricing) are already part of the policy mix but some (e.g. ban empty running of AVs) would be new. We find that all interventions applicable to the management of traffic flow would also be expected to contribute to the management of accessibility; we define a small number of additional interventions aimed at protecting the accessibility of priority groups.

Our general finding is that the adoption of a package of these interventions could be expected to lead to better performance against generic traffic-flow and accessibility objectives than would a laissez-faire approach, though questions of extent of application remain.

In our conclusions, we contrast laissez-faire with both anticipatory governance and “precautionary” governance and acknowledge the political difficulty associated with acting in the context of uncertainty. We point out that AVs do not represent the first emerging technology to offer both opportunities and risks and challenge governments at all levels to acknowledge the extent of their potential influence and, in particular, to examine methodically the options available to them and the potential consequences of pursuing them.  相似文献   
132.
    
Travel demand models typically use mainly objective modal attributes as explanatory variables. Nevertheless, it has been well known for many years that attitudes and perceptions also influence users’ behaviour. The use of hybrid discrete choice models constitutes a good alternative to incorporate the effect of subjective factors. We estimated hybrid models in a short-survey panel context for data among many alternatives. The paper analyses the results of applying these models to a real urban case study, and also proposes an approach to forecasting using these models. Our results show that hybrid models are clearly superior to even highly flexible traditional models that ignore the effect of subjective attitudes and perceptions.  相似文献   
133.
BUICK轿跑     
陈亮 《汽车杂志》2010,(2):332-333
编辑老师们好:有几个问题想请教一下。非常感谢!1.大众的发动机的缸体材料大多数都是铁质的。而其它很多厂家的都是铝制的,请问这两种材料对发动机的寿命、燃油效率、输出功率和扭矩、制作成本和后期维护等方面有什么不同。如果是铝的好。那么大众这样做的原因是降低成本吗?  相似文献   
134.
135.
This paper addresses the situation of transport infrastructure in Central America, which poses issues of insufficiency, high-costs and lack of an integrated vision in a geographic region that is exposed to vulnerabilities due to its geological, geomorphologic and climatic conditions. The major efforts for regional integration with joint infrastructure in place seem to meet the criteria of high prioritization on ground transport and non-diversification of risk. This paper features the characteristics of the area and the potentiality of short-sea shipping to cover infrastructure deficits and the need for a more integrated planning of transport infrastructure services with better conditions to improve the regional economy competitiveness and the economic growth.  相似文献   
136.
更换现代燃油喷射汽车的电动燃油泵,并非一件非常简单的事情。本文将提供有关电动燃油泵诊断的基础知识,以便在你怀疑燃油泵存在问题时,帮你提高诊断成功的机会。  相似文献   
137.
As a consequence of variable traffic speeds, vehicles are excited by road profile processes having spectral densities differing from those known from the literature, although stationary in order two. This phenomenon has to be reckoned with primarily in the dynamic design of vehicles operating mostly in cities. A method has been presented for the numerical construction of distorted road profile spectra for variable travel speeds, using integral transformation methods, of use in the dynamic design of vehicles.  相似文献   
138.
This paper presents a detailed overview of CANDY, a catenary–pantograph dynamic interaction software. Authors describe the main key points of the formulation, focusing on its time-integration scheme, the pantograph and contact models as well as the solution of the initial equilibrium problem. Nonetheless one of the most important features of CANDY is its moving finite element mesh, which enables accurate results without excessive computational cost. The validation of the model against the European Standard EN 50318 and some conclusions and comments about the results of the benchmark are also included.  相似文献   
139.
Viewpoint     
  相似文献   
140.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号