全文获取类型
收费全文 | 64篇 |
免费 | 1篇 |
专业分类
公路运输 | 4篇 |
综合类 | 3篇 |
水路运输 | 31篇 |
铁路运输 | 1篇 |
综合运输 | 26篇 |
出版年
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 17篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有65条查询结果,搜索用时 15 毫秒
51.
The number of vehicles on the road (worldwide) is constantly increasing, causing traffic jams and congestion especially in city traffic. Anticipatory vehicle routing techniques have thus far been applied to fairly small networked traffic scenarios and uniform traffic. We note here a number of limitations of these techniques and present a routing strategy on the assumption of a city map that has a large number of nodes and connectivity and where the vehicles possess highly varying speed capabilities. A scenario of operation with such characteristics has not previously been sufficiently studied in the literature. Frequent short‐term planning is preferred as compared with infrequent planning of the complete map. Experimental results show an efficiency boost when single‐lane overtaking is allowed, traffic signals are accounted for and every vehicle prefers to avoid high traffic density on a road by taking an alternative route. Comparisons with optimistic routing, pessimistic routing and time message channel routing are given. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
52.
The main objective of this study is to determine the level of mispricing of transportation IPOs in the Chinese mainland and Hong Kong. A subsidiary objective is to test the hypothesis that there is a strong positive correlation between the initial day returns that are required for new equity issues and the level of ex ante uncertainty associated with the IPO. By applying a standard methodology in finance for assessing the existence and scale of mispricing, the study finds significant underpricing for transportation IPOs in the Chinese mainland and Hong Kong. There is also evidence that freight-related IPOs are subject to more severe underpricing than non-freight related IPOs, and that water-transport IPOs are underpriced more than IPOs of other types of transport business. It is concluded that there does exist support for the hypothesis that the level of ex ante uncertainty is strongly associated with the level of mispricing and that this explains cross-sectional differences in the degree of underpricing of IPOs. In this respect, the results from the Chinese mainland and Hong Kong are consistent with the results of similar studies conducted elsewhere. 相似文献
53.
ABSTRACTThe pursuit of better performance by the local government can influence the investment decision-making related to port expansion. This paper compares the ceilings at which the port enterprise and the local government would stop making investments. To achieve this, the benefits to the port enterprise and the local government are measured over a given time period. An empirical study investigating how a port would respond if a rival port uses a type of capacity investment strategy is conducted for two major ports in Liaoning. The time at which the local government and the port enterprise would stop making investments and the final equilibrium are developed using the data from 2010. From the empirical results, it was found that investment in port capacity contributes greatly to the local government’s performance. Meanwhile, different investment ceilings are discovered for the port enterprise and the local government. This research is meaningful for discussing the institutional relationship between the local government and the port enterprise in China’s current decentralized port governance system.This paper is a revised and expanded version of a paper entitled ‘Port expansion mechanism in the context of political achievement of local government: a special phenomenon in China’ presented at International Association of Maritime Economists 2012 Taipei Conference during 5th September –8th September. 相似文献
54.
Sheldon H. Jacobson Douglas M. King Kevin C. Ryan Matthew J. Robbins 《Transportation Research Part A: Policy and Practice》2012,46(10):1586-1593
An increasing number of legislative efforts have been undertaken to prohibit the use of hand-held wireless devices while driving. As of July 2012, ten states and the District of Columbia enforce laws banning the use of hand-held cell phones while driving. Thirty-nine states and the District of Columbia have banned text messaging while driving. Recent studies of driver behavior suggest that hand-held wireless device usage negatively impacts driver performance. However few studies at the aggregate level address the plausible link between the use of hand-held wireless devices while driving, increased risk of automobile accidents, and government legislative efforts to reduce such risk. This paper analyzes data at the aggregate level and builds a regression model to estimate the long term accident rate reduction due to a hand-held ban. This model differs from previous studies, which consider short term accident rate reduction, by considering time trends in the accident rate due to the ban. Additionally, counties considered in this analysis are placed into groups based on driver density, defined by the number of licensed drivers per centerline mile of roadway, and a separate analysis is performed within these groups. This approach allows one to better quantify the effect of hand-held bans in counties of different driver densities. Results from this paper suggest that bans on hand-held wireless device use while driving reduce the rate of personal injury accidents in counties with high levels of driver density, but may increase accident rates in counties with low driver density levels. These results can inform transportation policymakers interested in reducing automobile-accident-risk attributable to the use of hand-held wireless devices while driving. 相似文献
55.
Peter Clarke Tariq Muneer Kevin Cullinane 《Transportation Research Part D: Transport and Environment》2010,15(3):160-167
This paper presents an analysis of vehicle regenerative braking systems as a quick and relatively easy means of achieving higher overall fuel efficiency and lowering carbon emissions. The system involves the installation of an additional electric motor/generator in parallel to the vehicle’s internal combustion engine and is used in conjunction with a DCDC converter and ultracapacitor. The system is used to recapture the energy lost in vehicle braking, significantly reducing a vehicle’s overall energy consumption and lowering vehicle emissions. Experimentally-based evidence is collected and compared for two sample vehicles to deduce the potential fuel and emissions saving. 相似文献
56.
57.
The goal of this paper is to better understand home-to-work travel distances throughout the Montréal Metropolitan region.
A simultaneous equation modelling analysis is carried out to jointly explain commuter trip length and home–work location as
a function of neighbourhood typologies, commuter socio-demographics and measures of job and worker accessibility. First, a
factor and cluster analysis of urban form is performed over the entire region on a fine-scale grid pattern. The outcome of
this analysis is the classification of typologies at both home and job locations. Different measures of accessibility and
commuter socio-demographics are then incorporated into the analysis. Varied data sources including a detailed Montréal Origin–Destination
Survey on over 30,000 home-to-work automobile trips are analyzed. Among other results, commuters that live and work in a different
sub-region almost double the average trip distance and although socio-economic factors have a statistically significant correlation
with commuter distance, these factors have a marginal effect. Interestingly, our results highlight the importance of urban
form and job accessibility. Deciding on whether to live and work in the same sub-region was modelled as an endogenous binary
random utility model; unobserved heterogeneities seem to be simultaneously influencing both the home–work location choice
and trip-to-work distances. Our results underscore the importance of home–work location with respect to urban form and job
accessibility. Hence, policies that support more dense and mixed land-use in suburban areas would not be enough to reduce
commuter distances. These actions should be accompanied by other policy initiatives to discourage long car trips. 相似文献
58.
59.
在公交占主导地位的香港居民对小汽车的依赖性 总被引:4,自引:0,他引:4
减少城市的小汽车交通量,促进城市交通运输能力的持续稳定发展,已成为人口密集型的大城市制定交通运输政策的一项主要目标,也是香港制定交通运输政策所期望达到的目标。但根据国际标准,香港居民对小汽车的拥有量和使用频率已经非常低了。首先是明确香港人为什么要拥有小汽车,其次是探索小汽车的拥有者对小汽车的依赖程度,第三是识别政策的含意。基于对401位小汽车拥有者的调查,得出了这样的结论:尽管城市里有很好的公共交通,但人们一旦拥有了小汽车后,便会开始变得依桢小汽车进行所有的外出活动。因此,为了促进交通运输持续、稳定发展,小汽车的拥有量和使用频率必须受到控制。 相似文献
60.
Kevin Cullinane 《Maritime Policy and Management》1992,19(2):91-114
There are numerous possible advantages to be gained from the accurate prediction of future movements in the Baltic Freight Index (BFI). Because of the difficulties inherent in long-range forecasting, however, the potential for such predictions to provide insight into the future state of the physical dry bulk market is perhaps limited. The greater accuracy of short-term forecasts, on the other hand, facilitates the development of a forecasting model form is justified by the inevitably continuous nature of futures market speculation. Such a model is developed through the application of the Box—Jenkins approach to time series analysis and forecasting. The methodology is presented and the resulting model is evaluated on the basis of objective measures of predictive power and by comparison with alternative forecasting models. Finally, the applicability of the model to the practice of BIFFEX speculation is assessed by judging its performance within a simulated BIFFEX trading environment. 相似文献