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481.
Gordon Wilmsmeier Kevin P.B. Cullinane Theo Notteboom Ricardo J. Sánchez 《Maritime Policy and Management》2013,40(6):549-554
Latin America and the Caribbean have evolved as a region of increased interest for the maritime and port industry as well as for academic research. Maritime transport activity in the region has experienced sustained growth rates over the last decades, resulting in ever-increasing demand for maritime services and port infrastructure. At the 2011 Annual Conference of the International Association of Maritime Economists (IAME), Latin America received significant attention. This editorial responds to growing research by giving a brief overview of the current situation and contemporary issues in maritime transport within the region. It also introduces the six selected papers for this Special Issue. 相似文献
482.
H. T. Sun J. Wang G. Z. Shen P. Hu 《International Journal of Automotive Technology》2013,14(4):605-610
Aluminum alloys are important technological materials for the application on lightweight design and development of vehicle body. The research works for characterizing warm forming behavior of aluminum alloys have generally reported. However, there were few researches focused on the flow behavior of warm forming aluminum alloy parts for the energy absorbing performance during crash. The tensile stress-strain response for warm forming AA5182 specimens tested under the strain rates of 0.0015 s?1, 0.015 s?1, 0.15 s?1 and 1.5 s?1 are presented in this paper. The data were fit to the Johnson-Cook constitutive model for the simulation of frontal impact. The energy absorbing performance of warm forming AA5182 parts were analyzed. The results show the higher flow stresses and lower fractured strain of warm forming aluminum alloy parts with the strain rate increasing. The flow stresses of warm forming aluminum alloy parts are insensitive to strain rate, while the fractured strain and elongation are sensitive to strain rate. The intrusion displacement of the warm forming aluminum alloy parts is appropriate for the satisfaction of vehicle body design avoiding the excessive deformation for the injury of passenger or the failure of frontal door opening. The feasibility of warm forming aluminum alloy parts is verified with the analysis of energy absorbing performance, stiffness and modal of vehicle body. 相似文献
483.
This paper investigates the impact of a variety of travel information types on the quality of travel choices. Choice quality
is measured by comparing observed choices made under conditions of incomplete knowledge with predicted choice probabilities
under complete knowledge. Furthermore, the potential impact of travel information is considered along multiple attribute-dimensions
of alternatives, rather than in terms of travel time reductions only. Data is obtained from a choice experiment in a multimodal
travel simulator in combination with a web-based mode-choice experiment. A Structural Equation Model is estimated to test
a series of hypothesized direct and indirect relations between a traveler’s knowledge levels, information acquisition behavior
and the resulting travel-choice quality. The estimation results support the hypothesized relations, which provides evidence
of validity and applicability of the developed measure of travel-choice quality. Furthermore, found relations in general provide
some careful support for the often expected impact of information on the quality of travel choices. The effects are largest
for information services that generate previously unknown alternatives, and lowest for services that provide warnings in case
of high travel times only.
Caspar Chorus holds a PhD in Technical Sciences (cum laude) from Delft University of Technology, and is currently an Assistant Professor at Eindhoven University of Technology’s Urban Planning Group. His general interests include traveler behavior research / decision making under knowledge limitations / discrete choice analysis. Theo Arentze received a Ph.D. in Decision Support Systems for urban planning from the Eindhoven University of Technology. He is now an Associate Professor at the Urban Planning Group at the same university. His main fields of expertise and current research interests are decision support systems, activity-based modeling, discrete choice modeling, knowledge discovery and learning-based systems with applications in urban and transport planning. Harry Timmermans received a Ph.D. in Spatial Sciences from the University of Nijmegen. He is Chair of the Urban Planning Group and Director of the European Institute of Retailing and Consumer Services. His main fields of expertise concern behavioral modeling, consumer studies and computer systems in a variety of application contexts including transportation. 相似文献
Caspar G. ChorusEmail: |
Caspar Chorus holds a PhD in Technical Sciences (cum laude) from Delft University of Technology, and is currently an Assistant Professor at Eindhoven University of Technology’s Urban Planning Group. His general interests include traveler behavior research / decision making under knowledge limitations / discrete choice analysis. Theo Arentze received a Ph.D. in Decision Support Systems for urban planning from the Eindhoven University of Technology. He is now an Associate Professor at the Urban Planning Group at the same university. His main fields of expertise and current research interests are decision support systems, activity-based modeling, discrete choice modeling, knowledge discovery and learning-based systems with applications in urban and transport planning. Harry Timmermans received a Ph.D. in Spatial Sciences from the University of Nijmegen. He is Chair of the Urban Planning Group and Director of the European Institute of Retailing and Consumer Services. His main fields of expertise concern behavioral modeling, consumer studies and computer systems in a variety of application contexts including transportation. 相似文献
484.
Dimitrios V. Lyridis Nikolaos P. Ventikos Panayotis G. Zacharioudakis Konstantinos Dilzas Harilaos N. Psaraftis 《WMU Journal of Maritime Affairs》2005,4(1):33-55
This paper proposes a tool to estimate crew composition based on safety/operational and financial requirements. As there is
a tendency of ship owners to implement improved technologies on board their vessels, there is no systematic way to predict
their potential effect on crew size and composition (typically determined by flag state authorities on a case-to-case basis)
nor on the type and complexity of on board duties new technologies might dictate. The main aim of this paper is to develop
a tool to assist in determining crew composition, by taking into account both administration’s and the ship owner’s point
of view. Based on data collected from ship owners, a data mining technique is implemented in order to form a generalized framework
that estimates crew composition as a function of ship type, size, and degree of automation. The agreement of model predictions
with records from specific (vessel) cases is very good in terms of safety (for operations such as watchkeeping, mooring/unmooring,
loading/unloading). The specific intended use of this tool is to help a ship owner decide whether it is cost-beneficial to
retrofit a conventional vessel with advanced technologies that would potentially entail a reduced crew (probably dealing with
different and more complex on board duties). Its main benefits are that it can be used to estimate crew composition before
any vessel construction or upgrade has actually taken place and that it allows crew composition to be easily adapted to the
technological evolution of ship systems even at their current rapid pace. 相似文献
485.
P. A. Caridis 《Marine Structures》1988,1(2)
Results from a series of studies on stiffened plates under axial compression are presented in this paper. The large-deflection elasto-plastic behaviour of each panel component is described by the von Karman equations, thus enabling the lateral-torsional buckling of the stiffener to be modelled in a rigorous manner. Material nonlinearity is represented using the von Mises yield criterion in conjunction with the Prandtl-Reuss flow rule. Results are presented in the form of average stress-strain curves which are used to generate maximum strength curves for the stiffener and plate. 相似文献
486.
The distribution of mesopelagic copepods between 250 and 1000 m depth was studied along a transect off the coast of Villefranche-sur-Mer in June 1991 by means of a BIONESS multiple-net sampler. Among the most abundant species at all stations were Pleuromamma gracilis, Paraeuchaeta acuta and overwintering Calanus helgolandicus CV copepodites, each species inhabiting different depth layers with maximum abundances in the 250–350 m, 450–550 m and the 700–850 m layer, respectively. Cluster analysis of the vertical distribution of all species caught revealed three distinct strata (‘TOP', ‘INTERMEDIATE', ‘BOTTOM') consisting of characteristic species that occurred in the same stratum at all stations. Differences in total abundances of the species assemblage occupying each layer are discussed with regard to predation pressure by mesopelagic macroplanktonic crustaceans and fish. We show that each stratum is characterized by distinct trophic interactions and life strategies, which play an important role in the structuring of mesopelagic zooplankton communities. 相似文献
487.
本文分析了传统二冲发动机的优缺点,全面阐述了对现代二冲程发动机的要求和各方面的改进设想,对今后设计新的二冲程发动机有一定的指导价值。 相似文献
488.
中国城市轨道交通未来十年发展趋势及政策导向 总被引:8,自引:5,他引:8
分析了我国城市轨道交通的发展现状、特点和问题.结合城市轨道交通的发展趋势,探讨了发展过程中的政策缺陷.从综合性、公交优先、国产化、标准化、市场化以及一体化等方面提出了发展我国城市轨道交通的导向政策. 相似文献
489.
C. Vera B. Suarez J. Paulin P. Rodrí guez 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(8):595-614
Overhead rigid conductor arrangements for current collection for railway traction have some advantages compared to other, more conventional, energy supply systems. They are simple, robust and easily maintained, not to mention their flexibility as to the required height for installation, which makes them particularly suitable for use in subway infrastructures. Nevertheless, due to the increasing speeds of new vehicles running on modern subway lines, a more efficient design is required for this kind of system.
In this paper, the authors present a dynamic analysis of overhead conductor rail systems focused on the design of a new conductor profile with a dynamic behaviour superior to that of the system currently in use. This means that either an increase in running speed can be attained, which at present does not exceed 110 km/h, or an increase in the distance between the rigid catenary supports with the ensuing saving in installation costs.
This study has been carried out using simulation techniques. The ANSYS programme has been used for the finite element modelling and the SIMPACK programme for the elastic multibody systems analysis. 相似文献
In this paper, the authors present a dynamic analysis of overhead conductor rail systems focused on the design of a new conductor profile with a dynamic behaviour superior to that of the system currently in use. This means that either an increase in running speed can be attained, which at present does not exceed 110 km/h, or an increase in the distance between the rigid catenary supports with the ensuing saving in installation costs.
This study has been carried out using simulation techniques. The ANSYS programme has been used for the finite element modelling and the SIMPACK programme for the elastic multibody systems analysis. 相似文献
490.
Fionn Rogan Emer Dennehy Hannah Daly Martin HowleyBrian P. Ó Gallachóir 《Transportation Research Part A: Policy and Practice》2011,45(7):583-597
This paper assesses the impacts of a targeted policy designed to influence car purchasing trends towards lower CO2 emitting vehicles. Vehicle registration tax and annual motor tax rates in Ireland changed in July 2008 from being based on engine size to emissions performance of cars. This paper provides a one year ex-post analysis of the first year of the tax change, tracking the change in purchasing trends arising from the measure related to specific CO2 emissions, engine size and fuel, and the implications for car prices, CO2 emissions abatement, and revenue gathered. While engine efficiency improvements had been offset by purchasing trends towards larger and generally less efficient cars in the past, with the average MJ/km remaining constant from 2000 to 2007, this analysis shows that in the first year of the new taxation system the average specific emissions of new cars fell by 13% to 145 g/km. This was brought about, not by a reduction in engine size, but rather through a significant shift to diesel cars. Despite an unexpected reduction in car sales due to a recession in 2008, the policy measure has had a larger than anticipated impact on CO2 emissions, calculated to be 5.9 ktCO2 in the first year of the measure. The strong price signal did however result in a 33% reduction in tax revenue from VRT, in financial terms amounting to a drop of €166 million compared to a baseline situation. 相似文献