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51.
<正>英国石油公司(BP)非常关注船舶质量,希望通过审查,降低风险,降低事故率。为此,BP在世界上建立了很多检查网点,如新加坡、上海、墨尔本、伦敦,鹿特丹、休斯顿以及芝加哥等,都设有专门机构。同时,BP还有一支由70名经过认证的检查员组成的检查队伍,他们在全世界范围内进行检查,然后提交相关报告。  相似文献   
52.
The free trade agreement (FTA) implemented in 1988 by the United States and Canada will complete the integration of the economics of the world's two largest trading partners. While the vast bulk of US-Canadian trade is transported overland, the FTA will also affect the volume, commodity composition, and spatial distribution of maritime trade. The spatial structure of US-Canadian water-borne trade is examined followed by an investigation of the short-run (non-investment related) impacts of the FTA on the US port system. Commodity-specific analyses of tariffs and non-tariff barriers and elasticities of demand are employed to estimate the sectoral and spatial changes in water-borne trade volumes since 1988 that are attributable to the FTA.  相似文献   
53.
Over the last decade, a large number of high capital cost transportation projects have been proposed for the New York City Region. Many have resulted from addressing evolving capacity needs, changes in regional demographics and economics, meeting the improvements necessitated by operating century old subway systems and recognizing the impact of moving freight in a dense region. But the catalyst for bringing all of these projects to the attention of the public and all regional agencies was the tragedy of September 11, 2001. While these projects entail massive investments ($50–$60 billion), little analytical work has been carried out to measure the transportation and economic costs and benefits they entail and to categorize them accordingly. Competition among agencies to secure adequate resources to implement any of the desired projects makes such analysis necessary; yet there still remain political, vested economic interests and agency rivalry barriers to achieving this important planning objective. This paper reports the methodological approach taken by these authors for consistent and transparent project evaluation and then presents results from the ranking and prioritizing methodology. The policy underpinnings and implications of the analysis are discussed in a subsequent paper and thus only briefly touched upon here in the concluding section.  相似文献   
54.
This paper presents an analysis of telecommunications and travel costs for typical business meetings. It is contribution to the debate on the substitutability of telecommunications for travel. An underlying assumption which supports the substitution hypothesis is that the cost of traversing distance through the use of telecommunication is lower than the cost of travelling.This paper addresses the relative cost of telecommunications and travel in conducting interactions. Three factors are assumed to determine these costs: distance, duration of interaction and number of participants. The analysis assumes that cost alone affects choice, and ignores other communication qualities.The relationship between telecommunication and travel costs was tested quantitatively through a case study of typical business meetings in the U.S., based on data from 1988. The results show that travel costs are lower than telecommunication costs for shorter distances, and that the relationship between telecommunications and travel costs differs substantially as a function of number of participants and meeting duration. Because of ongoing rapid changes in the costs of both of these interaction modes, the complex competition between them will continue. The implications of the findings for location decisions and policy-making are discussed.  相似文献   
55.
Arrival processes are important inputs to many transportation system functions, such as vehicle prepositioning, taxi dispatch, bus holding strategies, and dynamic pricing. We conduct a comprehensive survey of the literature which shows that many transport systems employ basic homogeneous arrival process models or static nonhomogeneous processes. We conduct an empirical experiment to compare five state of the art arrival process short term prediction models using a common transportation system data set: New York taxi passenger pickups in 2013. Pickup data is split between 672 observations for model estimation and 96 observations for validation. From our experiment, we obtain evidence to support a recent model called FM‐IntGARCH, which is able to combine the benefits of both time series models and discrete count processes. Using a set of seven performance metrics from the literature, FM‐IntGARCH is shown to outperform the offline models—seasonal factor method, piecewise linear model—as well as the online models—ARIMA, Gaussian Cox process. Implications for operating data‐driven “smart” transit systems and urban informatics are discussed. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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