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   65篇
  免费   0篇
公路运输   26篇
综合类   4篇
水路运输   9篇
铁路运输   4篇
综合运输   22篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2017年   3篇
  2016年   2篇
  2015年   1篇
  2013年   7篇
  2011年   3篇
  2010年   4篇
  2009年   3篇
  2008年   3篇
  2007年   5篇
  2006年   4篇
  2005年   3篇
  2004年   5篇
  2003年   5篇
  2002年   4篇
  2001年   2篇
  1998年   1篇
  1996年   1篇
  1988年   1篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
排序方式: 共有65条查询结果,搜索用时 0 毫秒
11.
J. Piao  M. McDonald 《运输评论》2013,33(5):659-684
Abstract

Advanced Driver Assistance Systems (ADAS) have been one of the most active areas of ITS studies in the last two decades. ADAS aim to support drivers by either providing warning to reduce risk exposures, or automating some of the control tasks to relieve a driver from manual control of a vehicle. ADAS functions can be achieved through an autonomous approach with all instrumentation and intelligence on board the vehicle, or through a cooperative approach, where assistance is provided from roadways and/or from other vehicles. In this article, recent research and developments of longitudinal control assistance systems are reviewed including adaptive cruise control, forward collision warning and avoidance, and platooning assistants. The review focuses on comparing between autonomous systems and cooperative systems in terms of technologies used, system impacts and implementation. The main objective is to achieve common understanding on ADAS functional potentials and limitations and to identify research needs for further studies.  相似文献   
12.
我认为,造船师和轮机师考虑海上环境设计的船舶,它们99.9%的时间在海上渡过。但他们忘了,这些船舶还必须进入河道装卸货物。当某件引起公众高度关注的事故发生,船舶建造者或许会进入公众视线,发现他们犯有疏忽罪,要为建造了动力不足和操纵不良的船舶负责。一位引航员的观点国际  相似文献   
13.
南安普敦市高速公路入口控制方案案例研究   总被引:1,自引:0,他引:1  
高速公路入口控制最早于1996年出现在芝加哥市,现在北美及欧洲等国家广泛采用它来缓解高速公路交通拥挤状况。此论文研究了南安普敦市高速公路入口控制方案的案例(采用ALINEA)控制策略。研究的详细数据表明:高速公路入口控制系统对辅路上的车流、高速公路主干线上的车流、尤其是对高速公路第一车道入口汇合前的区域存在潜在影响。基于此案例研制高速公路的主干道的车流量和速度的轻微减小。  相似文献   
14.
尽管没有人怀疑42V电气系统的合理性,但是在实施这一标准之前仍然有许多问题必须解决。  相似文献   
15.
本文译自美国《MOTOR》杂志,作者深入浅出地全面讲解汽油直接喷射技术,生动地对这一技术产生的背景、结构原理、主要组成部件以及未来发展趋势进行了系统的阐述。  相似文献   
16.
The new UK Government, elected in May 1997, came to power with a commitment to reverse the decline of the UK shipping industry and enhance the employment prospects of UK seafarers. The Government commissioned Lord Alexander of Weedon to investigate the case for a tonnage tax. In this paper, the economic arguments for supporting the UK shipping industry are reviewed. There is some evidence that the UK holds a comparative advantage in world markets in key sectors of the shipping industry and on-shore maritime related activities, but is being undermined by lower foreign taxes. In the absence of government support, the UK shipping industry is likely to continue to decline, and, by further reducing the supply of qualified UK ex-seafarers, put at risk the successful on-shore activities. Various measures that might be used to support a national shipping industry, e.g. a tonnage tax, are considered. The paper concludes by discussing the likely impact of the tonnage tax on the UK's shipping industry.  相似文献   
17.
The greatest source of human-related mortality for endangered Florida manatees is collisions with watercraft. Regulation of boat speeds is the principal management tool to minimize this threat. Demands on law enforcement limit their ability to monitor boater behavior and managers seek alternative strategies to increase compliance. The purposes of this study were to: (1) explore the effectiveness of an on-site sign to enhance boater compliance in a boating speed zone, and (2) examine the environmental and boating characteristics that influence the probability of compliance. Signs designed to increase compliance were posted halfway through the 18-week study period. The signs were not related to compliance level. Logistic regression models showed that only time of day and boat type were significantly related to compliance. Results suggest that passive methods of persuasion may not be an effective means of influencing boater behavior.  相似文献   
18.
一种功率更大、尾气排放更少和燃油经济性更佳的发动机即将问世,而这种发动机与现在的发动机相比不仅在内部结构上进行了改进,尤其在电子技术方面有了更大的提局。  相似文献   
19.
This paper presents an economic model of generalized travel cost and provides an empirical study of the parameters of the cost function. The route-choice model that is estimated combines McFadden's theory of qualitative choice behavior with a function for the value of travel time in which total trip time and the income level are assumed to influence the marginal value of time. The empirical results indicate that, for a sample of commuters in the Chicago metropolitan area in 1972, the value of time is a positive function of total trip time, but is not a function of income.  相似文献   
20.
目的 了解心脏前负荷减低对中心动脉压及主动脉扩增指数的影响.方法 10例健康志愿者,行下肢负压(LBNP)抽吸造成不同程度前负荷减低.采用超声心动图检测心输出量的变化;采用中心动脉压力分析系统(SphymoCor)检测桡动脉压力波形,经平均转换功能形成中心动脉压力波形.结果 ①随着下肢负压的加大,上腔静脉血流进行性减低,在-30mmHg阶段,S波减低22.4%,VTIs+d减低了15.8%,同时SV减少24.7%,CO减少18.7%;②中心动脉收缩压(CSBP)除在-30mmHg阶段轻度下降外,在-10及-20mmHg阶段没有明显改变,中心动脉舒张压(CDBP)在各个负压阶段没有明显改变;③主动脉压力波P1在各个负压阶段均明显下降,在-30mmHg阶段,P1减少了19.6%[(28.2±5.02)mmHg vs.(22.65±3.08)mmHg, P<0.01],而总外周阻力(TPR)在各负压阶段均较基础阶段明显升高,在-30mmHg阶段升高21.3%[(16.0±2.9)(mmHg·min)/L vs.(20.3±3.4)(mmHg·min)/L, P<0.001].主动脉扩增指数(AI)无明显改变.结论 前负荷减低使中心主动脉压及主动脉压力波P1降低,同时使TPR升高,由于TPR的升高抵消了P1 的降低,因而AI保持不变.  相似文献   
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