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841.
The rapid and continuing changes in travel and mobility needs in India over the last decade necessitates the development and
use of dynamic models for travel demand forecasting rather than cross-sectional models. In this context, this paper investigates
mode choice dynamics among workers in Chennai city, India over a period of five years (1999–2004). Dynamics in mode choice
is captured at four levels: exogenous variable change, state-dependence, changes in users’ sensitivity to attributes, and
unobserved error terms. The results show that the dynamic models provide a substantial improvement (of over 500 log-likelihood
points and ρ2 increases from 44% to 68%) over the cross-sectional model. The performance was compared using two illustrative policy scenarios
with important methodological and practical implications. The results indicate that cross-sectional models tend to provide
inflated estimates of potential improvement measures. Improving the Level of Service (LOS) alone will not produce the anticipated
benefits to transit agencies, as it fails to overcome the persistent inertia captured in the state-dependence factors. The
results and models have important applications in the context of growing motorization and congestion management in developing
countries.
相似文献
P. BhargaviEmail: |
842.
Annual electric bike (e-bike) sales in China grew from 40,000 in 1998 to 10 million in 2005. This rapid transition from human-powered
bicycles, buses and gasoline-powered scooters to an all-electric vehicle/fuel technology system is special in the evolution
of transportation technology and, thus far, unique to China. We examine how and why e-bikes developed so quickly in China
with particular focus on the key technical, economic, and political factors involved. This case study provides important insights
to policy makers in China and abroad on how timely regulatory policy can change the purchase choice of millions and create
a new mode of transportation. These lessons are especially important to China as it embarks on a large-scale transition to
personal vehicles, but also to other countries seeking more sustainable forms of transportation.
相似文献
Christopher CherryEmail: |
843.
Stated choice experiments have proven to be a powerful tool in eliciting preferences across a broad range of choice settings.
This paper outlines the elements of a group-based experiment designed for interdependent urban freight stakeholders, along
with the procedure to administer the questionnaire sequentially. The focus is on the design of a computer-assisted personal
survey instrument and the value in disseminating the details of a new approach to design and collect stated choice data for
interacting agents. The paper also discusses how to specify a reference alternative, and then how to recruit appropriate real-market
or representative decision-making group members to participate in a subsequent phase of the survey, which incorporates the
reference alternative and contextual information from an initial phase. The empirical strategy, set out in some detail, provides
a new framework within which to understand more fully the role that specific attributes, such as variable user charges, influencing
freight distribution chains might play, and who in the supply chain is affected by specific attributes in terms of willingness
to pay for the gains in distribution efficiency.
相似文献
Andrew CollinsEmail: |
844.
Aldo Chircop 《WMU Journal of Maritime Affairs》2007,6(2):193-205
There is wide recognition that the process of climate change may be affecting the Arctic region at a faster pace than other
regions. What is uncertain is the full impact of climate change on ice cover, and in particular whether there will be a significant
decrease of summer ice from the current three months to a longer period and accompanied by navigation conditions suitable
and safe for commercial shipping. New international navigation routes through the Canadian and Russian Arctic sectors could
significantly reduce the length of sea voyages from Asia to North America and Europe. However, on the basis of what is known
to date, there are significant differences of view as to the feasibility of international commercial navigation in the Northwest
Passage. 相似文献
845.
Proshanto K. Mukherjee 《WMU Journal of Maritime Affairs》2007,6(1):21-36
This article provides a synoptic overview of the concept of general average which is one of the saving acts in maritime law.
Its principles were entrenched in the Roman law which acknowledged its origins being rooted in the Sea Law of Rhodes. Its
evolution as customary law through the medieval maritime codes of the Mediterranean region is also traced in the article.
The reader is then brought into the modern era of the international regime of general average through the advent of the York-Antwerp
Rules. The basic principles of general average loss, including expenditures and sacrifices, and general average contributions
are introduced through references to a number of leading cases. The current status of this ancient law and practice and debates
over its future are briefly addressed in conclusion. 相似文献
846.
CHEN Lu-yun WANG De-yu 《船舶与海洋工程学报》2007,6(4):55-61
For the structural-acoustic radiation optimization problem under external loading,acoustic radiation power was considered to be an objective function in the optimization method. The finite element method(FEM) and boundary element method(BEM) were adopted in numerical calculations,and structural response and the acoustic response were assumed to be de-coupled in the analysis. A genetic algorithm was used as the strategy in optimization. In order to build the relational expression of the pressure objective function and the power objective function,the enveloping surface model was used to evaluate pressure in the acoustic domain. By taking the stiffened panel structural-acoustic optimization problem as an example,the acoustic power and field pressure after optimized was compared. Optimization results prove that this method is reasonable and effective. 相似文献
847.
Life-style and travel demand 总被引:1,自引:0,他引:1
Ryuichi Kitamura 《Transportation》2009,36(6):679-710
(Added to the original text) A fundamental solution to the issue of congestion cannot be reached without addressing the question of life-style. This paper reviews the definitions of life-style found in the literature, and identifies variables that have been commonly associated with life-style. Using US consumer expenditure data, life-styles are analyzed longitudinally (examining trends during the 1953–1983 time frame) and cross-sectionally (comparing segments of the population stratified by income, life-cycle stage, and age), and likely relationships to travel behavior are noted. The usefulness of existing empirical findings to long-range forecasting is explored by speculating on shifts of behavioral units across life-style segments, and on shifts in the behavioral patterns within each life-style segment. 相似文献
848.
A vector autoregressive model was developed for a sample of container carrier time charter rates.Although the series of time charter rates are themselves found non-stationary, thus precluding the use of manymodeling methodologies, evidence provided by co-integration tests points to the existence of stable long-termrelationships between the series. An assessment of the forecasts derived from the model suggests that the spec-ification of these long-term relationships does not improve the accuracy of long-term forecasts. These resultsare interpreted as a corroboration of the efficient market hypothesis. 相似文献
849.
Akhil K. Vaish Shijie Chen Neeraja S. Sathe Ralph E. Folsom Promod Chandhok Kuo Guo 《Transportation》2010,37(6):825-848
The National Household Transportation Survey (NHTS) was designed at the national level, and for most states it does not have
a large enough sample to produce reliable estimates, especially for subdomains (e.g., age groups) within a state. Using the
2001 NHTS, we produced small area estimates (SAEs) of the percentage of persons among four age groups (17 or younger, 18–39,
40–54, and 55 or older) having high daily person-miles of travel (more than 87.5 miles a day, which is the 90th percentile for daily person-miles traveled) and associated prediction intervals
for all 50 states and the District of Columbia. The survey weighted hierarchical Bayes (Folsom et al., Proc of the Sect on
Surv Res Methods of the Am Stat Assoc 371–375, 1999) small area estimation (SAE) methodology was used to produce state-level SAEs. This paper describes the methodology and shows
that SAE can be an effective technique for producing reliable state-level estimates from large, national surveys like the
NHTS. In particular, the prediction interval relative widths for SAEs were, on average, 31–48% narrower than the corresponding
design-based confidence interval widths, whereas for small states the reduction was around 47–63%. 相似文献
850.
Telecommuting has been proposed by policy makers as a strategy to reduce travel and emissions. In studying the metropolitan size impact of telecommuting on personal travel, this paper addresses two questions: (1) whether telecommuting is consistently a substitute or complement to travel across different MSA sizes; and (2) whether the impact of telecommuting is higher in larger MSAs where telecommuting programs and policies have been more widely adopted. Data from the 2001 and 2009 National Household Travel Surveys are used. Through a series of tests that address two possible empirical biases, we find that telecommuting consistently had a complementary effect on one-way commute trips, daily total work trips and daily total non-work trips across different MSA sizes in both 2001 and 2009. The findings suggest that policies that promote telecommuting may indeed increase, rather than decrease, people’s travel demand, regardless of the size of the MSA. This seems to contradict what telecommuting policies are designed for. In addition, model results show that the complementary impact of telecommuting on daily travel is lower in larger MSAs, in terms of both daily total work trips and daily total non-work trips. 相似文献