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71.
This paper assesses the economic justification for the selection of priority projects defined under the auspices of the Trans-European transport network. Three different transport models are used to analyse the costs and benefits associated with the current list of 30 priority projects. Most of these projects fail the cost-benefit test and few of the economically justifiable projects would need European subsidies to ensure their viability. Two remedies are proposed to minimise the inefficiencies surrounding project selection. The first remedy would oblige each member state or group of states to perform a cost-benefit analysis, followed by peer review and ensure that the results were published publicly prior to the ranking of federally funded priority projects. The second remedy would require federal funding to be made available only for projects with important spillovers to other countries in order to avoid pork barrel political behaviour.  相似文献   
72.
Solving the multi‐objective network design problem (MONDP) resorts to a Pareto optimal set. This set can provide additional information like trade‐offs between objectives for the decision making process, which is not available if the compensation principle would be chosen in advance. However, the Pareto optimal set of solutions can become large, especially if the objectives are mainly opposed. As a consequence, the Pareto optimal set may become difficult to analyze and to comprehend. In this case, pruning and ranking becomes attractive to reduce the Pareto optimal set and to rank the solutions to assist the decision maker. Because the method used, may influence the eventual decisions taken, it is important to choose a method that corresponds best with the underlying decision process and is in accordance with the qualities of the data used. We provided a review of some methods to prune and rank the Pareto optimal set to illustrate the advantages and disadvantages of these methods. The methods are applied using the outcome of solving the dynamic MONDP in which minimizing externalities of traffic are the objectives, and dynamic traffic management measures are the decision variables. For this, we solved the dynamic MONDP for a realistic network of the city Almelo in the Netherlands using the non‐dominated sorting genetic algorithm II. For ranking, we propose to use a fuzzy outranking method that can take uncertainties regarding the data quality and the perception of decision makers into account; and for pruning, a method that explicitly reckons with significant trade‐offs has been identified as the more suitable method to assist the decision making process. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
73.
Abstract

This paper presents an examination of the empirical merits of a set of spatial interaction indices for measuring hierarchical differentiation (i.e. dominance and connectivity) in a spatial network. To allow for the comparison of the degree of hierarchical differentiation in networks with different numbers of nodes/links, we propose to normalize the ratio between the real measures and the corresponding values for a rank size distribution in order to obtain readily interpretable measures of hierarchical differentiation. When applied to data on air passenger flows within Europe, the normalized indices, interpreted together, appear to give a good idea of the tendency toward hierarchical differentiation. The potential usefulness of this analytical framework is discussed in the context of studies on (transnational) inter-city relations and empirical assessments of changes in the spatial configuration of airline networks.  相似文献   
74.
Port authorities generally focus on the development of the local port area and play a minor role in the development of port hinterlands, whereas shippers, forwarders, barge and rail operators have always been involved in the port-hinterland connection. The increasing importance of intermodal hinterland networks for the competitive position of ports has urged port authorities to become active in the hinterland. This new role has already been suggested by different academics. However, limited empirical evidence exists of port authorities taking stakes in inland terminals or developing transport services. Barcelona, as one of the leading port authorities in this respect, is used as a case study in this paper. The case study provides insight in the components and execution of the hinterland strategy of Barcelona. It shows that the strategy of the port authority of Barcelona and the consequent active involvement in the hinterland has had a significant impact on attracting container volumes from distant hinterlands and improving the accessibility of the port.  相似文献   
75.
Summary A stroke dependent damper is designed for the front axle suspension of a truck. The damper supplies extra damping for inward deflections rising above 4 cm. In this way the damper should reduce extreme suspension deflections without deteriorating the comfort of the truck. But the question is which stroke dependent damping curve yields the best compromise between suspension deflection working space and comfort. Therefore an optimization problem is defined to minimize the maximum inward suspension deflection subject to constraints on the chassis acceleration for three typical road undulations. The optimization problem is solved using sequential linear programming (SLP) and multibody dynamics simulation software. Several optimization runs have been carried out for a small two degree of freedom vehicle model and a large full-scale model of the truck semi-trailer combination. The results show that the stroke dependent damping can reduce large deflections at incidental road disturbances, but that the optimum stroke dependent damping curve is related to the acceleration bound. By means of vehicle model simulation and numerical optimization we have been able to quantify this trade-off between suspension deflection working space and truck comfort.  相似文献   
76.
参考CVT装在一辆奔驰A190车辆上,在3个测试循环及两种恒速状态下,通过认可的方法对油耗进行测量。表2所示的是采用绝对安全系数Sfabs=1.3的目前策略与新的控制策略之间的减少量。  相似文献   
77.
This paper considers the market potential for battery electric and plug-in hybrid electric vehicles in Flanders, Belgium. Making use of a large-scale survey conducted in 2011 and applying a choice-based conjoint experiment, it is predicted that by 2020, battery electric vehicles could have a market share of about 5% of new vehicles, and plug-in hybrid electric vehicles could have a share of around 7%. By 2030, these figures could increase to 15% and 29%. The speed of up-take of electric vehicles, however, is sensitive to purchase costs.  相似文献   
78.
Input-output analysis basically provides an estimation of a sector's economic impact by taking into account the indirect effects on all other sectors. For purposes of policy making, however, this may produce rather rigid and inaccurate results. This paper, therefore, introduces some extensions to the basic impact analysis. These extensions secure flexibility, completeness and accurateness of the outcomes. First, an accurate cost structure is determined in a bottom-up approach, i.e. by using data from a sample of representative companies. This allows for reliable outcomes and a flexible definition of sub-sectors. Secondly, the analysis is made in an intercountry context. Thirdly, the expenditure effects of generated income are determined by a macroeconomic module. Fourthly, company-level responses to alternative policy scenarios are investigated and translated into changing model parameters. These four basic elements are applied in a case study concerning the shipping sector of Germany. The scenarios are a continuation of the present policy, a laissez-faire policy, and two framework policies in which the government creates a favourable environment for shipping companies. For each scenario, the effects on value added, employment, tax revenues and expenditures are analysed and evaluated. This paper, thus, shows the relevance of accordingly amplified input-output analysis for policy purposes.  相似文献   
79.
This paper focuses on the response of port authorities to the changing market environment in which they operate. It documents the changes taking place in the relationships between port authorities and terminal management companies and considers the strategic issues faced by these groups and other port interests. In particular, it investigates the potential conflicts of interest for a port authority in matters related to the level of competition amongst terminals within a port and the amount of competition amongst ports.  相似文献   
80.
介绍了目前世界上公路车辆探测方面所进行的一些相关研究及其方法,并对传感器融合检测方法进行了阐述,最后对目前本领域研究所面临的问题进行了简单的概括。  相似文献   
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