全文获取类型
收费全文 | 161篇 |
免费 | 3篇 |
专业分类
公路运输 | 29篇 |
综合类 | 1篇 |
水路运输 | 51篇 |
铁路运输 | 1篇 |
综合运输 | 82篇 |
出版年
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 40篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
1999年 | 1篇 |
1990年 | 2篇 |
1985年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
131.
It is commonly argued that, in order to meet increasing competition, public transport organizations and systems need to be market oriented. Even though the notion of market orientationhas not been explicitly addressed in public transport research, studies relevant to market orientation have been conducted. The aim of this paper is to introduce the concept of market orientation into the field of public transport, to review previous research into market orientation in public transport research, and to suggest directions for future research. Market orientation is defined as the generation and dissemination of market intelligence by organizations, as well as responses to it. The review suggests that previous academic research has focused on intelligence generation by developing and using models for measuring travel behaviour, stated preferences, perceived customer quality, and satisfaction. Studies of responsiveness have mainly addressed the physical improvements made in public transport organizations, which is also the primary concern of the industry research accounted for. There has been less research into the dissemination of market intelligence, the drivers of market orientation, the relations between the elements, and the overall concept of market orientation in public transport. It is thus concluded that future public transport research needs to address these issues. 相似文献
132.
Abstract Traditional transport infrastructure assessment methodologies rarely include the full range of strategic benefits for the transportation system. One of these benefits is the contribution to cross‐border integration, critical for the European integration process. However, this is a key issue in strategic planning and decision‐making processes, as its inclusion may increase the probability of large‐scale transport infrastructure projects being funded. This paper presents a methodology for the measurement of the contribution of transport infrastructure plans to European integration. The methodology is based on the measurement of the improvement in network efficiency in cross‐border regions of neighbouring countries, via accessibility calculations in a Geographical Information System support. The methodology was tested by applying it to the ambitious road and rail network extensions included in the Spanish Strategic Transport and Infrastructure Plan (PEIT) 2005–2020. The results show significant and important network efficiency improvements of the PEIT outside the Spanish border. For the road mode, while the Spanish average accessibility improvement accounts for 2.6%, average improvements in cross‐border regions of France and Portugal are of 1.8%. And for the rail mode, the corresponding Spanish value is 34.5%, whereas in neighbouring regions it accounts for 20.2%. These results stress the significant importance of this strategic benefit and the consequent need for its inclusion in strategic planning processes. Finally, the paper identifies the potential of the methodology when applied at different administrative levels, such as the local or state levels. 相似文献
133.
Océane Balland Stein Ove Erikstad Kjetil Fagerholt Stein W. Wallace 《Journal of Marine Science and Technology》2013,18(3):349-357
In this paper we consider the reduction of air emissions from vessels when uncertainty is taken into account. Uncertainty in the reduction effects of the different existing air emission controls is currently high and makes their selection for vessel emission regulations compliance a challenging process. We develop a two-stage stochastic optimization model that addresses this uncertainty. The model’s objective is to plan the installation of air emission controls over a specified time horizon for a vessel to comply in the most cost-efficient way with the air emission regulations. The uncertain reduction effects of the controls are modelled by a set of scenarios. The approach is applied to a case study with real data. The solution exposes the important impact of uncertainty on this problem, especially on the SO X reduction, while the CO2 reduction plan seems in this case not affected by uncertainty. 相似文献
134.
Hugues Chollet Michel Sébès Jean Louis Maupu Jean Bernard Ayasse 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2013,51(4):570-580
The railway multi-body software developed for more than 20 years by INRETS (now IFSTTAR), under the name VOCO®, has been dedicated from the origin to highly nonlinear elements, such as the dry friction dampers of freight bogies and the wheel–rail contact based on measured profiles. A second important step has been the discovery of a particular method in order to simulate on sinuous tracks. In the aim of industrial applications, the specification has always been to reach the goal of real time. Although it is not possible in all the cases, the recent non-Hertzian contact development is allowing real-time simulation to be achieved. 相似文献
135.
Mark Richard Wilby Juan José Vinagre Díaz Ana Belén Rodríguez Gonz´lez Miguel Ángel Sotelo 《智能交通系统杂志
》2014,18(2):149-163
》2014,18(2):149-163
Advanced traffic management systems rely heavily on technology to perform accurate estimations of the current state of the traffic as well as its short-term evolution. The objectives are improving traffic flow and enhancing road safety. Their success is based on accurate monitoring of two key variables, specifically speed and occupancy. The latter of the two has, to date, received significantly less attention from the scientific community. In this work we present a lightweight method to perform “on-line” occupancy estimation. We first propose three occupancy measurements calculated from data collected by a floating car: vehicle count, percentage of stop time, and headway. We then extend these discrete values to a continuous estimation of occupancy in space and time. The proposed estimators are based on a pairwise linear regression of each of the previously calculated measurements over certain references obtained from other floating cars or magnetic loop detectors. The method has been calibrated and validated under real traffic conditions and data. Despite the ease of implementation, the method is able to reproduce the occupancy values generated by the actual loop detectors, achieving promising results, with estimation errors down to 6.52%, even before multivehicle systems are considered. 相似文献
136.
This article describes the first application of a novel path flow and origin/destination (OD) matrix estimator for iterated dynamic traffic assignment (DTA) microsimulations. The presented approach, which operates on a trip-based demand representation, is derived from an agent-based DTA calibration methodology that relies on an activity-based demand model (Flötteröd, Bierlaire, & Nagel, 2011). The objective of this work is to demonstrate the transferability of the agent-based approach to the more widely used OD matrix-based demand representation. The calibration (i) operates at the same disaggregate level as the microsimulation and (ii) has drastic computational advantages over conventional OD matrix estimators in that the demand adjustments are conducted within the iterative loop of the DTA microsimulation, which results in a running time of the calibration that is in the same order of magnitude as a plain simulation. We describe an application of this methodology to the trip-based DRACULA microsimulation and present an illustrative example that clarifies its capabilities. 相似文献
137.
138.
Sergio?Jara-DíazEmail author Beatriz?Tovar De La Fé Lourdes?Trujillo 《Transportation》2005,32(3):275-291
Cargo handling in ports is a multioutput activity, as freight can arrive in many forms such as containers, bulk, rolling stock, or non-containerised general cargo. In this paper, the operation of cargo handling firms in a Spanish port is analysed through the estimation of a multioutput cost model that uses monthly data on three representative firms located at the Las Palmas port. This permits the calculation of product specific marginal costs, economies of scale (general and by firm) and economies of scope, which help identifying optimal pricing policies and the potential cost advantages of increasing production. 相似文献
139.
Vehicle Handling Improvement by Active Steering 总被引:10,自引:0,他引:10
Saï d Mammar Damien Koenig 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2002,38(3):211-242
Summary This paper first analyses some stability aspects of vehicle lateral motion, then a coprime factors and linear fractional transformations (LFT) based feedforward and feedback H 8 control for vehicle handling improvement is presented. The control synthesis procedure uses a linear vehicle model which includes the yaw motion and disturbance input with speed and road adhesion variations. The synthesis procedure allows the separate processing of the driver reference signal and robust stabilization problem or disturbance rejection. The control action is applied as an additional steering angle, by combination of the driver input and feedback of the yaw rate. The synthesized controller is tested for different speeds and road conditions on a nonlinear model in both disturbance rejection and driver imposed yaw reference tracking maneuvers. 相似文献
140.
Régis Duvigneau Michel Visonneau Gan Bo Deng 《Journal of Marine Science and Technology》2003,8(1):11-25
The practical use of automated computational fluid dynamics (CFD)-based design tools in the ship-building industry requires
powerful flow solvers which are able to take into account realistic geometries as well as complex physical phenomena, such
as turbulence. A shape optimization tool is developed in this framework. A derivative-free optimizer, yielding both flexibility
and robustness, is preferred to the classical gradient-based method, which is more difficult to implement and is still limited
to only moderately complex problems. The flow solver included in the design procedure solves the incompressible Reynolds-averaged
Navier–Stokes equations on unstructured grids using a finite-volume formulation involving several near-wall low-Reynolds-number
turbulence models. The design tool is used to optimize the stern of a modern hull shape at model and full scale, with different
purposes being considered. More precisely, the drag reduction and the homogenization of the flow in the wake are expected
by controlling the longitudinal vortex generated. Our interest is particularly focused on the influence of turbulence modeling
in the design process. The effects of a two-equation model based on the eddy-viscosity assumption and a second-order closure
relying on the Reynolds stress transport equations are compared.
Received: September 24, 2002 / Accepted: April 14, 2003
RID="*"
Acknowledgment. The authors thank the scientific committee of CINES (project dmn2050) for the attribution of CPU time. 相似文献