• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Building an integrated transport system in Northeast Asia : a Delphi study

Zhou, Tianlan January 2011 (has links)
In the current international environment characterized by globalization and regionalization, the importance of the transport and logistics system integration which is the basis of regional economic cooperation has been highlighted. Northeast Asian Region which covers 5.7% of the total world’s area and has around 25.8% of the total world’s population has been one of the most active regions of economic and social development in recent two decades largely due to the emergence of China and Russia in the world market. However, different from the EU which provides an excellent example of economic and transport integration, the transport and logistics system in Northeast Asia still has massive room for improvement. The concept of transportation corridor construction has been adopted in the research and the five most important international transportation corridors in Northeast Asia have been fully examined in terms of current situation and major problems and issues. The major issues include inadequate and imbalanced transportation infrastructure, lack of funding as well as insufficient institutional mechanisms. Consequently, the policy and action plans in four sectors are formulated to improve the performance of the transport and logistics system in Northeast Asia. The current research was facilitated by experts mainly from the transport and logistics field in Northeast Asia, through the application of the Delphi Method. The consensus achieved will provide useful guidance for building a well integrated transport and logistics system in Northeast Asia. The political and economic stability of North Korea is a prerequisite for transport and logistics system construction in Northeast Asia. Furthermore, improving basic transport infrastructure, promoting logistics and transport facilities, building a logistics cooperation system and training logistics specialists are the four most important aspects for the development of the transport and logistics system in the region.
2

A Sensitivity Analysis of a Heuristic Model used for the Placement Allocation of Utilities in Transportation Right-of-Way Corridors

Christian, Steve Clarence 08 November 2004 (has links)
The requirements for public utility systems in the United States of America have grown enormously over the years triggering a tremendous shortage for space available to public utilities on and within transportation right-of-ways (ROW). Overcrowding and improper location of utilities has resulted in problems such as, damage to infrastructure, traffic accidents and, interruption of service to customers. The project titled, "Optimal Placement of Utilities within FDOT Right-of-Way", sponsored by the Florida Department of Transportation (FDOT), and currently being investigated at the University of South Florida, presents a decision-making heuristic aimed at developing a better utility placement allocation system (Kranc et. al) [6]. Working in accordance with the guidelines of safety, relocation, and clearance for utility placement set by the American Association of State Highway and Transportation Officials organization (AASHTO), the heuristic finds suitable locations for the utilities in ROW corridors. However, a model being used to advocate a practice having large social and economical impacts is more likely to play the role of generic evidence in a trial, whose weight must ultimately be established by a 'jury'. The question being addressed to the system must be scrutinized carefully, and the formal structure updated iteratively until it proves capable of providing an answer to the given question. A good sensitivity analysis can provide this generic quality assurance to the model and help demonstrate the worthiness of the model itself. This thesis is a quantitative and qualitative sensitivity analysis of the abovementioned heuristic. The analysis is conducted in two parts, 1. The 'Model Factor Sensitivity Analysis', with the objective of assessing the uncertainties associated with the modeling of the heuristic. This analysis focuses primarily on providing an evaluation of the confidence in the heuristic and its predictions by analyzing the influences that variations in the input factors have on the outputs of the utility cost assessment models and the final output of the heuristic itself. Variance based sensitivity indices derived from Sobol' sensitivity indices [42] are used here for this purpose. 2. The 'Model Output Evaluation and Enhancement' study, which initially focuses on understanding / evaluating the complexities of the discrete step, cost optimization procedure used in the heuristic and later, based on certain observed shortcomings and problems develops an enhancement, the Ideal Configuration Selector (ICS) to be implemented with the heuristic. The ICS addresses all the problems of the heuristic with the help of experimental speedup, positional sensitivity and refinement tools and employs a multi criterion evaluation technique for utility configuration assessment to provide substantiation to the outputs determined by the heuristic.
3

Corridors de demande : Modélisation et contributions à l’évaluation du niveau de durabilité / Demand corridors : Modeling approach and contributions in supply sustainability level assessment

Bahbouh, Kinan 02 December 2016 (has links)
L’utilisation du concept de corridor dans le domaine du transport n’est pas nouvelle. En effet, il existe une importante littérature qui étudie le corridor en tant que produit économique et politique issu du développement urbain notamment associé à la présence de services et d’infrastructures de transport. Cependant, l’utilisation de ce concept plurivoque dans la planification et l’évaluation de l’offre au niveau urbain demeure encore limitée, compte tenu de l’absence d’une définition claire et d’une approche de modélisation adaptée à la nature des déplacements, très dispersés, dans l’aire urbaine. Cette thèse contribue à la modélisation des corridors de déplacement en milieu urbain et au diagnostic de l’offre associée. Dans cette optique, la thèse offre une réflexion approfondie sur la définition et les caractéristiques d’un corridor de transport et propose un cadre de modélisation dont l’identification repose sur la demande. Les corridors de demande qui en émergent sont par la suite utilisés en tant qu’unités de référence à l’échelle collective, ce qui permet d’évaluer l’éloignement entre la demande et l’offre d’un corridor. La thèse définie le corridor comme l'enveloppe qui encapsule une forte concentration de trajectoires similaires. Ainsi, elle propose un algorithme, appelé Trajectory Clustering for Desire Line (TraClus-DL), pour identifier les corridors à partir des données origine-destination (OD) désagrégées (lignes de désir). Par la suite, la thèse distingue trois types de corridor de demande et illustre leurs potentiels dans les processus de planification. La thèse propose un cadre d’évaluation du niveau de durabilité de l’offre reposant sur le concept de corridors de demande. De plus, elle évalue les différentes facettes de la structure spatiale de l’offre en utilisant ce cadre. Les résultats obtenus par l’étude des corridors de demande permettent d’avoir une réflexion plus profonde face au concept des corridors et leur rôle dans les processus de planification. Le potentiel de synthétiser une grande matrice OD en illustrant les principaux flux de mobilité offre aux planificateurs un outil « neutre » de visualisation distant de l’offre et des découpages administratifs ou opérationnels. Les mêmes résultats permettent de tracer les axes denses de mobilité ce qui facilite l’identification des potentiels d’amélioration ou la désignation et la planification de l’offre. Enfin, la demande et l’offre sont inséparables. La combinaison entre les deux visions permet de couvrir un angle plus large qu’une étude basée uniquement sur la demande ou sur l’offre. Le but ultime de cette thèse est d’explorer le concept et les limites d’une approche basée sur la demande brute uniquement pour mieux comprendre la mobilité. Cette compréhension amène à identifier les besoins et les potentiels d’amélioration selon une perspective distante de tous les obstacles et les limites préconçues au niveau opérationnel, technique et politique. / Many researchers have benefited from the concept of the transport corridor to cover mobility issues. However, the use of the concept of the transport corridor in the urban transportation assessment and planning process remains limited due to the lack of a clear definition and modeling approach adapted to the very scattered nature of travel in urban areas. This thesis provides a deep reflection on the transport corridor’s definition and characteristics and offers a modeling framework to identify urban transportation corridors using the transport demand, represented by the Origin and Destination (OD), in the absence of supply elements. In addition, the thesis provides new insights into the possible ways that demand corridors can be seen and used to understand mobility patterns so to assess, plan, and improve the transportation supply. Furthermore, it proposes a global framework and constructs some indicators that incorporate demand corridor as a “fair” comparison unit, to assess the adequacy of transportation supply with respect to the demand. The first main chapter proposes define corridor as the envelope that encapsulate a high concentration of similar trajectories. Then, it defines demand corridors using demand elements such as origin destination data. The second chapter proposes an algorithm called Trajectory Clustering for Desire Line (TraClus-DL) to identify demand corridors. The followed chapter defines three types of demand corridors and highlights their potential use in transportation planning. The next chapter proposes a framework to assess the supply sustainability level by benefiting from the demand corridor as a reference unit. Work in the following chapter benefits from the framework and provides new insights into the possible ways of assessing the spatial characteristics of the supply structure. The results obtained by studying the demand corridors allow a deep reflection on the concept of corridors and their role in transportation assessment and planning. In addition, to synthesizing and visualizing OD matrixes, demand corridors trace the shape of dense mobility axes and appear as relevant tools for transportation planning, and in the decision-making processes in which an indicator is needed to evaluate the current or planned supply. The use of the demand corridor as a reference unit reflects the collective demand standpoint and offers the possibility to rank supplies based on each supply's level of compliance to the demand flow. Finally, the demand and the supply are inseparable. The combination of the demand corridor studies and the supply corridor studies covers a wider angle than studying the demand or the supply. The ultimate goal of this thesis is to explore the concept and limits of an approach based on the unprocessed demand to better understand the mobility. This understanding leads to identify the needs of potential improvements in the absence of preconceived operational, technical, or political limitations.

Page generated in 0.1215 seconds