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Consumer 3D printing is on the rise and has the potential to significantly change the transport and logistics sector. Current literature on 3D printing and transport studies does not provide a systematic model of the impact of 3D printing on transport and related (policy relevant) areas, such as traffic safety, location decisions, accessibility and environmental effects. Based on a literature review and two rounds of expert consultation, we propose and refine a conceptual model as a way to approach this gap in the literature. The expert consultation yields that the conceptual model comprises the relevant and important elements for assessing the impact of 3D printing on transport and transport-related challenges. Location, needs and transport resistance are important: (a) city-level hubs are the most likely locations for 3D printers because they can coordinate material flows and gather expertise; (b) mass-individualisation and personification dictates the needs for 3D printers; (c) distribution networks will be organised more efficiently, less empty vehicles, but raw materials still need shipping. However, experts’ opinions diverged on the impact of 3D printing on transport volumes and environmental impacts.  相似文献   
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The extensive usage of railway infrastructure demands a high level of robustness, which can be achieved partly by considering (and managing) the track and rolling stock as one integral system with due attention to their interface. A growing number of infra managers consider, in this framework, the track-friendliness of vehicles that have access to their tracks as a key control parameter. The aim of this study is to provide further insight into potential contributions to track-friendliness, assessed in relation to track deterioration mechanisms and cost, understanding how potential benefits are best to be utilised. Six proposed freight bogie design measures are evaluated with respect to the improvement in curving behaviour, switch negotiation and related track degradation mechanisms. To this purpose a sensitivity analysis has been carried out by means of track–train simulations in the VAMPIRE® multi body simulation software. Additionally, the impact on track deterioration costs has been calculated for those track-friendly design modifications identified as most promising. Conclusions show that the standard Y25L freight bogie design displays rather a track-friendly behaviour. Tuning the primary yaw stiffness shows a high potential to further improve track-friendliness, significantly reducing track deterioration cost at narrow radius curves and switches (by, respectively, 30% and 60%). When calculating the overall deterioration cost for the travelled route, the calculation model should include a well-balanced representation of switches and narrow radius curves.  相似文献   
3.
Despite ongoing transformations in the maritime transportation industry and the rise of global supply chain systems, most of the world's important container ports remain urban. Ports continue to occupy urban spaces, are embedded in localized knowledge systems, draw on urban labour markets and infrastructure and are subject to local politics and policy concerns. We identify contemporary geographic theories which help us understand the often increasingly urban attachment of core economic activities despite globalization. We explore how these theories may apply to port studies, highlighting both how they have been used by maritime scholars to this point and also why further development and application are warranted. We argue that a central concern of these geographic theories is the articulation of place- and sector-specific processes operating at a variety of spatial scales. This is in contrast to most maritime studies which continue to be dominated by perspectives which emphasize the global logic of the transportation industry and the analysis of space in generalized and abstract terms. We conclude that a re-appreciation in maritime studies of urban economic processes, informed by geographical theory, will provide policy-makers and others with more understanding of why deep connections between ports and urban places still matter.  相似文献   
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Abstract

Transport appraisals in European countries increasingly address three dimensions of sustainability—economic, ecological and social. However, social impacts of transport have been underexposed in (ex‐ante) transport project appraisal, at least in the Netherlands. Firstly, this article presents a theoretical framework describing the relationships between determinants of social impacts of transport; it also provides a definition and categorization of those impacts. Secondly, the article reviews the state of the practice of national transport project appraisal in the Netherlands and the United Kingdom. The article shows that social impacts of transport investments can take on many forms and their levels of importance may vary widely, in project appraisal. The UK transport appraisal guidance includes a spectrum of social impacts through quantitative and qualitative assessments that is broader than the Dutch appraisal guidance. However, it does not cover the full range as identified in the literature. This holds, in particular, for the temporary impacts of transport investments, health impacts, social cohesion, the distribution and accumulation of impacts across population groups and social justice. All in all, it can be concluded that there is a long way to go before social impacts of transport projects are completely included in appraisals, in a way that allows us to compare them to economic and ecological effects.  相似文献   
5.
This article employs an optimized impact pathway approach to marginal external health costs that relies on high-resolution dispersion models calibrated for Belgium and the surrounding areas. Per tonne, the MEHCPM2.5 is found to be many times larger than MEHCNOx, which is currently negative. Further, the impact of Belgian PM2.5 emissions in the immediate area of generation is significantly larger than the impact on more distant areas; the opposite is true for NOx. The MEHCs of both pollutants are predicted to increase in the coming years. Further analysis of the impacts of PM2.5 and NOx reveals that, on average, modern gasoline vehicles outperform their diesel counterparts as far as future emissions are concerned. This contrasts with findings for 2007, which suggested that Euro 5 diesels had fewer associated health costs because of the potential for ozone reduction offered by their NOx emissions.  相似文献   
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