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Recent years have shown a rising popularity of the concept of resilience—both theoretically and empirically—in complex systems analysis. There is also a rising literature on resilience in the transport and spatial-economic field. The pluriform interpretation of resilience (e.g., engineering vs. ecological resilience) is related to methodological differences (e.g., stability in dynamics vs. evolutionary adaptivity). But in all cases the fundamental question is whether a complex system that is subjected to an external shock is able to recover, and if so, to which extent. The present paper [Based on presentation from cluster 6 (Accessibility) of the Nectar 2015 conference in Ann Arbour, USA.] aims to add a new dimension to resilience analysis in spatial systems, by addressing in particular the relationship between spatial accessibility at a municipality level and the resilience outcomes of the spatial system concerned. It does so by investigating to which extent accessibility of Swedish and Dutch municipalities has mitigated the local shock absorption from the recent economic recession. In our study the shock absorption capacity of municipal accessibility is estimated by analysing the relevant resilience indicators for the period concerned. In this context, conventional resilience indicators based on either multivariate complex data (in particular, the Foster Resilience Capacity Index) or employment data (in particular, the Martin Resilience-Employment Index) are confronted with spatial connectivity data based on local accessibility measures, so that geographical mobility may be regarded as one of the shock-mitigating factors. The empirical analysis is carried out for two countries which have both proven to be rather shock-resistant during the recent economic crisis, viz. Sweden and The Netherlands. Clearly, the geographical structure of these countries forms a sharp mutual contrast, viz. a spatially dispersed economy with a few distinct urban concentrations versus a spatially dense economy with one major metropolitan centre (the Randstad), respectively. Our experiments are carried out for the 290 municipalities in Sweden and 40 COROPs in The Netherlands. Our research findings show relevant and new insights into differences in the local recovery potential in Sweden and The Netherlands. 相似文献
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The bicycle is often understood as a disjointed ‘feeder’ mode that provides access to public transport. We argue that combined use of the bicycle and public transport should be understood in a broader perspective, especially where bicycles link to higher speed and higher capacity public transport, such as the train. Cycling and public transport can have a symbiotic relationship forming a hybrid, distinct transport mode, which should be reflected in transport planning. The bicycle is as a way to soften the rigid nature of public transport and thus accommodate diverse individual travel needs and situations. Public transport can be seen as a means to dramatically extend cycling’s speed and spatial reach. We combine a system perspective with conceptual analysis to explore how, why and when this reconsideration is important. We use the Netherlands as illustrative case because of the relative maturity of its bicycle–train connections. The case shows that the synergy between rather opposite yet highly complementary aspects, high speed of the train, high accessibility of the bicycle and flexibility in combining both sub-modes, are the fundamental characteristics to understand the functioning of this system in a wider spatial context. In our conclusion we propose a research agenda, to further explore the relevance of this system for land-use and transport planning and distil wider implications for the international debate. 相似文献
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In modern cities, a rapid increase of motorcycles and other types of Powered Two-Wheelers (PTWs) is observed as an answer to long commuting in traffic jams and complex urban navigation. Such increasing penetration rate of PTWs creates mixed traffic flow conditions with unique characteristics that are not well understood at present. Our objective is to develop an analytical traffic flow model that reflects the mutual impacts of PTWs and Cars. Unlike cars, PTWs filter between cars, have unique dynamics, and do not respect lane discipline, therefore requiring a different modeling approach than traditional “Passenger Car Equivalent” or “Follow the Leader”. Instead, this work follows an approach that models the flow of PTWs similarly to a fluid in a porous medium, where PTWs “percolate” between cars depending on the gap between them.Our contributions are as follows: (I) a characterization of the distribution of the spacing between vehicles by the densities of PTWs and cars; (II) a definition of the equilibrium speed of each class as a function of the densities of PTWs and cars; (III) a mathematical analysis of the model’s properties (IV) an impact analysis of the gradual penetration of PTWs on cars and on heterogeneous traffic flow characteristics.The proposed model could contribute as an enabler for ‘PTW-aware’ future Cooperative Intelligent Transport Systems technologies and traffic regulations. 相似文献
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为推动公路建设水平,确保公路正常运营和沿线生态环境可持续发展,文章总结了公路绿化的特点和功能,从安全性、经济性、生物多样性、景观性等方面分析了公路绿化设计的原则,并探讨了公路中央分隔带、路基边坡、互通立交、服务区的绿化设计内容,从公路环保的重要性,认知公路环保的内容、功能及意义,并多方角度的加以分析和采取措施,达到预期效果,把建设和环境紧密协调统一。并对公路环保的设计理念、评价指标、评价方法及施工阶段的环保措施进行了论述。 相似文献
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开展水土流失监测是水土保持监管的重要手段。文章以广西沿海高速公路改扩建工程一期工程水土保持监测实践为例,分析了工程建设水土流失特点,介绍了水土保持监测技术和方法,并通过对工程实例监测结果的分析评价,提出了水土保持监测工作中易出现的问题及相应的解决方案。 相似文献
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Demand for commercial air travel has been increasing over the years and recent forecasts indicate similar future trends. New aircraft with enhanced design features are being built and entering the airline service globally. These enhancements aim to ensure continued safety, efficiency, performance and prolonged life serviceability. However, these new enhancements often neglect the impact of the changing anthropometric characteristics of the passenger. Past studies have identified increasing trends in the average weight, height and other anthropometrical and biometrical measures of people at a global scale. However, many are limited to only exploring the ramifications primarily from the perspective of passenger experience. This paper highlights the importance of considering passengers’ anthropometric characteristics from a holistic perspective and identifies gaps for future research. 相似文献
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在我国交通运输行业节能减排的背景下,本文以交通运输行业能耗特点与统计监测方法为基础,建立涵盖了公路客运、公路货运、城市公交、城市出租、水路运输、港口生产等行业的能耗碳排统计监测系统,分析了省级交通运输能耗与排放特点,明确了能耗数据统计对象与内容,并对能耗数据采集的方法进行了研究,建立了省级交通运输能耗统计监测系统,并以辽宁省交通运输为依托,对全省交通运输行业能耗统计监测系统进行了验证与应用,同时也为交通运输行业的节能减排提供了决策支撑和数据支持。 相似文献
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This paper proposes the adoption of an integrated inventory and transportation system (IITS) to minimize the total costs of inventory and transportation. A non-linear programing is developed by analyzing transportation and inventory costs with one supplier and many retailers in the distribution environment. The paper compares the proposed model with the traditional approach in computing total costs with numerical data. The results indicate that the total costs can be optimized by adopting integrated programing rather than the traditional approach, along with achieving improved customer service levels. In particular, sensitivity analysis is applied to determine the performance of the IITS under various transportation costs, holding costs and shortage costs. It shows that the transportation cost per unit is most sensitive in the proposed model. In this situation, the IITS is more effective for cost saving when set-up cost, holding and shortage costs are high, but is less effective for situations involving high per-unit transportation costs. 相似文献
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随着交通运输的迅速发展,超大断面小近距高速公路隧道或城市快速干道的建设将成为发展的重点。福州市机场二期隧道初步设计定为加宽五车道,无论是洞室跨度还是设计施工难度均属全国公路隧道之首。对于超大断面隧道来说,扁平率不但直接影响工程造价,而且对结构设计和施工带来新的问题。文章主要通过结构受力和经济比选内轮廓,并通过有限元计算,分析隧道设计的合理性。 相似文献
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通过探讨项目实施阶段变更索赔的前期策划、施工过程中变更索赔要点以及变更索赔有关技巧,阐述了项目变更索赔管理的思路与方法,最大程度上提高项目经济效益。 相似文献
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在酸性条件下,管道腐蚀相当严重,产生的危害也很大.因此,进行金属防腐分析具有重要意义.文中对国内外天然气管道的使用情况进行了介绍,并对这些管道的材质以及特点进行了说明.针对腐蚀发生的不同原因,介绍了采用涂防腐绝缘层、阴极保护和连接线等有效延缓管道腐蚀的防护措施,并分析了各自的优缺点.实际上,既经济可行又有效的防腐方法是... 相似文献
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推制弯头用芯棒设计和推制过程中断裂问题的分析 总被引:1,自引:1,他引:0
通过推制弯头过程中管坯和芯棒(工装)的应力分析,运用塑性加工和金属(钢管)二次加工理论,建立了芯棒强度计算公式,解决了芯棒尺寸与管坯尺寸的合理匹配问题,同时确定了特种管件的制造工艺。 相似文献
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为促进全球海上安全和防污染相关国际公约的有效执行,国际海事组织于2009年批准了"IMO成员国自愿审核机制"强制化,我国将于2021年接受IMO的强制审核。船检占强制审核政府义务条款大部分内容,其被视为IMO进行强制审核的重点领域。因此,本文拟针对IMO履约规则及相关国际公约中有关船检的管理要求,对我国海事船检履约情况进行评估,分析我国船检海事立法与管理方面存在的问题,提出我国针对船检履约与应对IMO强制审核的要点及改进措施,以满足2021年IMO强制审核的要求。 相似文献