1,015 research outputs found
The improvement of bus networks based on geographical information systems
No full textThe current regulatory and planning environment means that road-based public transport in UK urban areas (with the exception of London) tends to be planned on a piecemeal basis, and there are often conflicts between the needs and priorities of operators, passengers and planners. In consequence, several local authorities are considering adopting an alternative regulatory environment using quality contracts, with a consequent shift towards centralised service planning. There are though no tools readily available to ensure this centralised service planning will lead to a situation which provides a better balance between the interests of the different stakeholders. This thesis describes the development of a methodology to fill this gap, using Southampton as a case study to diagnose issues with its current bus network, and to explore the corresponding improvement methods which could be applied based on the alternative regulatory environment. Gravity-based accessibility levels from population-weighted centroids of postcodes to key services were calculated as an indicator to measure the performance of the current bus network in Southampton. Based on the accessibility analysis, service improvements, including both route planning and frequency setting, can be developed for the Southampton bus system under the alternative regulatory environment. This service improvement problem is then solved by making use of an optimisation technique, the tabu search algorithm, developed under the environment of ArcObjects for Java. The methodology described above has been shown to work well for the Southampton case study, and the outputs from the optimisation model indicate that the model can deliver a bus network which provides a higher level of accessibility under the alternative regulatory environment. While the methodology is developed in the UK context, the general principles used could be applied more widely to improve transit network planning
Using GIS to assess the potential for centralised planning of bus networks
No full textThe current regulatory and planning environment means that road-based public transport in UK urban areas (with the exception of London) tends to be planned on a piecemeal basis, and there are often conflicts between the needs and priorities of operators, passengers and planners. In consequence, several local authorities are considering adopting an alternative regulatory environment using quality contracts, with a consequent shift towards centralised service planning. There are though no tools readily available to ensure this centralised service planning will lead to a situation which provides a better balance between the interests of the different stakeholders. This paper describes the development of a methodology to fill this gap, using Southampton as a case study to explore the corresponding improvement methods which could be applied based on the alternative regulatory environment. The improvement methods, including both bus route design and frequency setting, are considered in this paper, which demonstrates how this service improvement problem can be solved by making use of an optimisation technique, the tabu search algorithm, developed under the environment of ArcObjects for Java. While the methodology is developed in the UK context, the general principles used could be applied more widely to improve transit network planning
Chun qiu bie dian: [15 juan]. v.1
No full text薛虞畿撰.綫裝, 1函.出版年據伍元薇跋.框18.1 x 14.1公分, 11行22字, 小字雙行同, 黑口, 雙魚尾, 四周單邊. 版心中鐫卷次.Xue Yuji zhuan.Xian zhuang, 1 han.Chu ban nian ju Wu Yuanwei ba.Kuang 18.1 x 14.1 gong fen, 11 xing 22 zi, xiao zi shuang xing tong, hei kou, shuang yu wei, si zhou dan bian. Ban xin zhong juan juan ci
Using accessibility measures in urban bus network improvement: A case study of Southampton, UK
No full textThe current regulatory and planning environment means that road-based publictransport in UK urban areas outside London tends to be planned on a piecemeal basis, and there are often conflicts between the needs and priorities of operators, passengers and planners. In consequence, several local authorities are considering adopting an alternative regulatory environment using quality contracts, with a consequent shift towards centralized service planning. There are though no tools readily available to ensure this centralized service planning will lead to a situation which provides a better balance between the interests of the different stakeholders. This research therefore develops a practical optimization model to fill this gap, using Southampton as a case study to explore the potential improvements, including both route planning andfrequency setting, which could be achieved with centralized planning of bus networks using an adapted tabu search algorithm. The methodology of the improvement approach in this research is defined as a complex multi-objective problem, involves two objective functions: total social cost (which is a combination of operator cost, user cost and external cost) and accessibility levels. The accessibility measures, which integrates the evaluation the transport system with land use patterns, therefore are utilized in the decision-making process of transit network design, alongside the conventional objective function total social cost. The methodology described above has been shown to work well for the Southampton case study. While the methodology described here focuses on the UK context, and potentially could be applied equally well in other contexts around the world.<br/
Exploring the factors affecting mode choice intention of autonomous vehicle based on an extended theory of planned behavior - a case study in China
No full textAutonomous vehicle (AV) is an innovative transport option that has the potential to disrupt all industries tied to transportation systems. The advent of AV technology will bring a novel on-demandmobility pattern such as shared autonomous vehicle (SAV). To promote AV technology, it is important to understand which factors influence travelers' intention to use AVs and SAVs. This paper collected literature from databases such as Scopus, Web of Science and ScienceDirect, and made a systematic review. The study aims to explore the determinants that influence travelers' behavioral intentions towards use AVs and SAVs based on an extended version of the theory of planned behavior, which incorporates knowledge and perceived risk. This study was tested empirically using a valid survey sample collected from 906 respondents in China. Structural equation model was conducted to investigate the predictors of intentions to use AVs and SAVs. Results showed that knowledge about AV technology and perceived risk are the two main potential obstacles for travelers to use AVs and SAVs. Attitude significantly affects AVs and SAV choice intentions. Subjective norm is the most critical factor affecting the travelers' intention to use AVs. Perceived behavioral control potentially stymie the travelers' intention to use SAVs. The findings will enhance the understanding of travelers' choice motivation from psychological and service perspectives, and provide data support for governments and companies in improving travel management strategies and product services.</p
A literature review on accessibility using bibliometric analysis techniques
No full textAccessibility is a key concept in the field of transportation, and there is a rich amount of reviews available on this topic which concentrate on certain perspectives. However, none of them presents a comprehensive and quantitative overview on accessibility-related publications. To fill this gap, this study reviewed two decades of publications (during 2000-2019) drawn from Web of Science (WoS), and aims to figure out the evolution pathway of accessibility related studies so that future research directions can be recognized. By employing the bibliometric analysis techniques, this study provides the potential to trace historical and geographic trends at global level, covering leading journals and institutions, keywords characteristics, citation network analysis, and a qualitative review of the most influential papers. The output results show that there is an increasing geographic spread along with the growth spurt of research publications on the topic of accessibility especially since 2010s. Both the keywords’ characteristics and citation network analysis help to identify research hot points, categorized as new indicators development and accessibility-based applications. Finally, this paper highlights the need for further studies for those two hot points respectively. It is hoped the results output here could benefit researchers engaging in this field to sharpen their own future research directions, and provide practitioners with a greater understanding of the various types of accessibility metrics and help them to identify the most appropriate practice for their specific situation
Forest History and the Great Divergence: China, Japan and the West
No full textThis paper surveys changing interrelationships between man and the earth's forest cover over the past several centuries. The focus is on the interplay between population increase, deforestation and afforestation at both ends of Eurasia. By looking at three numerical indicators-percentage forested, per capita forest resources and the population elasticity of deforestation, Japan is compared with Lingnan, south China, and the East Asians with two European countries, England and France. Based on the East-West comparisons and on somewhat more detailed intra-Asian comparisons between China and Japan with respect to market linkages and the role of the state, the paper examines the proposition made by Ken Pomeranz that although both ends of Eurasia were ecologically constrained at the end of the early modern period, East Asia's pressure on forest resources was eprobably not much worsef than in the West.
Author response image 1.
No full textNeurotransmitter is released at synapses by fusion of synaptic vesicles with the plasma membrane. To sustain synaptic transmission, compensatory retrieval of membranes and vesicular proteins is essential. We combined capacitance measurements and pH-imaging via pH-sensitive vesicular protein marker (anti-synaptotagmin2-cypHer5E), and compared the retrieval kinetics of membranes and vesicular proteins at the calyx of Held synapse. Membrane and Syt2 were retrieved with a similar time course when slow endocytosis was elicited. When fast endocytosis was elicited, Syt2 was still retrieved together with the membrane, but endocytosed organelle re-acidification was slowed down, which provides strong evidence for two distinct endocytotic pathways. Strikingly, CaM inhibitors or the inhibition of the Ca2+-calmodulin-Munc13-1 signaling pathway only impaired the uptake of Syt2 while leaving membrane retrieval intact, indicating different recycling mechanisms for membranes and vesicle proteins. Our data identify a novel mechanism of stimulus-and Ca2+-dependent regulation of coordinated endocytosis of synaptic membranes and vesicle proteins
N=2 supersymmetric dynamics for pedestrians
No full textUnderstanding the dynamics of gauge theories is crucial, given the fact that all known interactions are based on the principle of local gauge symmetry. Beyond the perturbative regime, however, this is a notoriously difficult problem. Requiring invariance under supersymmetry turns out to be a suitable tool for analyzing supersymmetric gauge theories over a larger region of the space of parameters. Supersymmetric quantum field theories in four dimensions with extended N=2 supersymmetry are further constrained and have therefore been a fertile field of research in theoretical physics for quite some time. Moreover, there are far-reaching mathematical ramifications that have led to a successful dialogue with differential and algebraic geometry. These lecture notes aim to introduce students of modern theoretical physics to the fascinating developments in the understanding of N=2 supersymmetric gauge theories in a coherent fashion. Starting with a gentle introduction to electric-magnetic duality, the author guides readers through the key milestones in the field, which include the work of Seiberg and Witten, Nekrasov, Gaiotto and many others. As an advanced graduate level text, it assumes that readers have a working knowledge of supersymmetry including the formalism of superfields, as well as of quantum field theory techniques such as regularization, renormalization and anomalies. After his graduation from the University of Tokyo, Yuji Tachikawa worked at the Institute for Advanced Study, Princeton and the Kavli Institute for Physics and Mathematics of the Universe. Presently at the Department of Physics, University of Tokyo, Tachikawa is the author of several important papers in supersymmetric quantum field theories and string theory
Seven connection patterns between the author research areas.
No full textSeven connection patterns between the author research areas.</p
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