全文获取类型
收费全文 | 198篇 |
免费 | 1篇 |
专业分类
公路运输 | 34篇 |
综合类 | 3篇 |
水路运输 | 100篇 |
铁路运输 | 1篇 |
综合运输 | 61篇 |
出版年
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 47篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 6篇 |
2009年 | 17篇 |
2008年 | 9篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 8篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1988年 | 7篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 4篇 |
排序方式: 共有199条查询结果,搜索用时 140 毫秒
191.
《港口科技动态》编辑部 《港口科技》2005,(1)
<正>在喜迎新春佳节的前夕,全新改版后的第一期《港口科技动态》面世了。新版的《港口科技动态》扩大了版面,由正十六开改为大十六开,增加三分之一的信息量;增设了英文目次,以便于更多的人阅读查询;增设了人物专访,以深入报道各港口科技工作的规划和科技进步的全景。此外,对一些栏目作了调整,在编排形式上也作了改进。希望能得到读者的喜爱。 相似文献
192.
193.
Authors Index
Authors index 相似文献194.
195.
James H. Banks 《先进运输杂志》1991,25(2):161-186
The issue considered is whether the biases that result from assuming a single value of waiting time in variable-demand headway optimizations (and the demand models on which they are based) can have a significant impact on the results of the optimization. Marginal benefit functions based on binary probit demand models, and incorporating the alternative assumptions of either a single value of time, a discrete distribution of time values, or a continuous distribution of time values, are derived and compared for several cases. These comparisons indicate the possibility of significant errors in several cases, the most realistic of which is that of a highly heterogeneous market composed of a large segment of “choice riders” and a smaller segment of “transit captives”. 相似文献
196.
James A. Dunn Jr. 《Transportation》1980,9(1):33-43
In Germany, the need for coordination and integration of transport services has been seen as a pre-condition to improving public transportation. A major step in this direction,which attracted world-wide attention, has been the institution of the Transport Federation (Verkehrs verbund). The paper discusses the operation of the Hamburg Transit Federation and considers a number of factors which have created a favorable climate for the development of public transportation in Germany. 相似文献
197.
In this paper we present a route-level patronage model that incorporates transit demand, supply and inter-route effects in a simultaneous system. The model is estimated at the route-segment level by time of day and direction. The results show strong simultaneity among transit demand, supply and competing routes. Transit ridership is affected by the level of service, which in turn is determined by current demand and ridership in the previous year. The model demonstrates that a service improvement has a twofold impact on ridership; it increases ridership on the route with service changes, but it also reduces the ridership on competing routes so that the net ridership change is small. The model is thus useful for both system-level analysis and route-level service planning. 相似文献
198.
James Odeck 《Transportation》1996,23(2):123-140
This paper explores the priorities for road investments in Norway, with particular emphasis on the use of benefit-cost calculus. The author tests whether the observed rankings of the Ranking Road Agencies are explained and/or influenced positively by the benefit-cost ratio. Second, based on a questionnaire survey, the tradeoff made by Regional Road Authorities between an economic welfare maximizing strategy and the observed strategy in analysed. Benefit-cost ratio is found to be a significant explanatory variable in only four out of fifteen regions. In only one region does benefit cost ratio explain more than 30 percent of the observed variation. The trade-off analysis demonstrates that ranking by benefit-cost ratio if adopted gives formidable return as compared to the observed rankings. The reasons given by the Regional Road Agencies for not ranking investment projects according to benefit cost ratio is that several important impacts are not valued monetarily and therefore are not included in the benefit-cost-ratio. The results of the questionnaire survey give reasons to doubt the Regional Road Agencies understanding of the welfare maximizing principles of benefit cost calculus. Concluding remarks on the observed behaviour of the Regional Road Agencies are also offered. 相似文献
199.
Zeyu Ma James Yang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(2):137-167
A precise estimation of vehicle velocities can be valuable for improving the performance of the vehicle dynamics control (VDC) system and this estimation relies heavily upon the accuracy of longitudinal and lateral tyre force calculation governed by the prediction of normal tyre forces. This paper presents a computational method based on the unscented Kalman filter (UKF) method to estimate both longitudinal and lateral velocities and develops a novel quasi-stationary method to predict normal tyre forces of heavy trucks on a sloping road. The vehicle dynamic model is constructed with a planar dynamic model combined with the Pacejka tyre model. The novel quasi-stationary method for predicting normal tyre forces is able to characterise the typical chassis configuration of the heavy trucks. The validation is conducted through comparing the predicted results with those simulated by the TruckSim and it has a good agreement between these results without compromising the convergence speed and stability. 相似文献