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11.
This paper examines some key aspects of a charging system for promoting railway transport, including charges reflecting a clear relationship with costs (transparency) and charges reflecting the quality of the infrastructure manager's service. Train running charges recover track-related costs and can help to develop a charging system that meets these requirements. To orient train running charges to the market, a method for processing track maintenance and renewal costs is proposed whereby the quality of the service provided by an infrastructure is measured according to its utility to the railway undertaking. To achieve transparency, a single indicator is used for cost planning and the subsequent levying of costs on railway undertakings. The paper includes an example of how proposed train running charges would be calculated according to data from 14 European countries. The example shows that short-distance trains generate the lowest maintenance and renewal costs, followed by long-distance trains and freight trains.  相似文献   
12.
Historic vehicles (HVs) are the heritage of road transport that have surprisingly received little attention in the academic literature. This study presents an overview of the literature on HVs, focusing on the three topics that dominate the policy debate on transport: environmental, safety and congestion impacts. We observed that polluting emissions of HVs are per kilometre much higher (often a factor 5 or more) than those of moderns vehicles. The annual average mileage per vehicle per year of HVs is much lower than other vehicles. The lower active and passive safety levels of HVs are compensated by the way these vehicles are driven, resulting in the risk factors per kilometre being roughly equal or lower than other vehicles. The contribution of HVs to congestion is negligible. However, the transport policy discourse is divided on the topic of HVs. More comprehensive and effective laws and regulation are needed to protect this aspect of the heritage of road transport whilst concurrently avoiding or limiting the problems caused by them.  相似文献   
13.
BINGO—9000型平台是目前世界上最先进的第五代半潜式钻井平台,能在深海(工作水深3000m),恶劣气候海况(零下20℃、风速41m/s、浪高32m)下开采石油。以BINGO—9000型平台为例,介绍了平台结构和压载状态实时监测系统设计的关键技术问题,以及基于疲劳寿命分析的结构设计思想。展开了该平台波浪载荷的分析计算,在此基础上对主体结构进行了三维有限元强度分析。对平台特殊结构如K型管节点及支撑结构和立柱结构进行了强度分析和疲劳寿命分析。还研究了平台吃水数据采集、压载状态监测等技术。通过以上关键技术的研究,平台结构设计更趋安全可靠合理,既具有必需的强度储备,又可减轻结构重量。  相似文献   
14.
The dynamics of the coastal ocean along the southeastern coast of Africa is dominated by a strong and intense western boundary current, the Agulhas Current. With a near-uniform, narrow continental shelf and a steep shelf slope that stabilizes this current, the trajectory of the Agulhas exhibits great stability. The only substantial perturbation occurs with the irregular passage of a Natal Pulse, a soliton meander. The initiation of this meander at the Natal Bight is due to a barotropic instability when the intensity of the landward border of the current exceeds a certain threshold value. This may come about with natural fluctuations in the current or with the adsorption of deep-sea eddies onto the current. Under a climate change scenario of altered wind stress curl over the South Indian Ocean it is conceivable that the threshold for the triggering of a Natal Pulse will occur more frequently. This will lead to a situation where the current axis on average lies further offshore. The possible consequences of such a situation on the rainfall of the coast, on the ecology of estuaries and the coastal ocean, and on the socio-economics of the region is discussed.  相似文献   
15.
This paper offers an overview of the currently available Ballast Water Treatment systems, their efficacy in reducing the number of organisms in relation with the IMO and other, future standards, and explores potentially new and promising technologies and current gaps.  相似文献   
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17.
Recent advances in the specification of the utility function of mixed logit models allow the analyst, in principle, to consider a vast variety of individual heterogeneity. Nevertheless, when estimating the model it is common practice to experience severe difficulties in discriminating between different specifications to infer the “true” data generating process. We investigate possible sources for this difficulty focusing on the confounding effects inherent in two basic assumptions of discrete choice model utilities: linearity in the parameters and added error terms. We analyse the role of these assumptions in giving rise to confounding effects and why this increases the difficulty of discriminating among different structures. Finally, we investigate how these problems may affect benefit appraisal using these models. Empirical evidence is provided for two different environmental contexts and a more typical transport context using various kinds of data.  相似文献   
18.
The spatial economic effects in integrated land use and transport models are increasingly disaggregate and can benefit from improved knowledge into the effect of accessibility and agglomeration on the spatial behaviour of firms. This article strives to contribute to this knowledge by first analysing the influence of accessibility and agglomeration on firm behaviour with exceptionally detailed firm data for the province of South Holland in The Netherlands. Next the added value of incorporating such effects in urban simulation models is tested with two series of validation runs with a microscopic model for firm dynamics.The presented Spatial Firm-demographic Micro-simulation (SFM) model simulates transitions and events in the firm population, including firm relocations, firm growth, firm dissolution and firm formation. Accessibility is measured with proximity to infrastructure access points and logsums of business and commuting trips from a transport model. Agglomeration measures are based on theories from urban economics and integrate travel time range bands into measures for specialisation and diversification. Estimation results confirm a significant influence of accessibility and agglomeration on the choice behaviour of firms. Application of these measures prove to increase the validity of the firm-demographic simulation model to a significant but modest extend.  相似文献   
19.
According to the mid-term review of the EU White Paper on Transport, Short Sea Shipping (SSS) is expected to grow at a rate of 59% (metric tonnes) between 2000 and 2020. If we consider that the overall expected increase in both freight exchanges and volume is 50%, sea transport is one of the most feasible alternatives to reduce traffic congestion on European roads. Maritime transportation may compete with road transport as far as certain traffics are concerned, but only when assuming external costs. This paper analyzes several intermodal transport chains involving a sea leg by comparing the effect of pollutant emissions from different ship types and road transport in terms of potential external cost savings. The translation of these emissions into environmental costs shows, for certain conditions, savings in the case of sea transport that would justify the use of an environmental bonus to promote the sea option.  相似文献   
20.
Transportation - In recent years, the e-bike has become increasingly popular in many European countries. With higher speeds and less effort needed, the e-bike is a promising mode of transport to...  相似文献   
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