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  • 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.
41

ContribuiÃÃo à Tomada de DecisÃo para a IntegraÃÃo dos MunicÃpios Brasileiros ao Sistema Nacional de TrÃnsito / Decision Making Contribution to the Brazilian Cities Integration to the National Traffic System

Regis Rafael Tavares da Silva 06 August 2007 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Os problemas de trÃnsito e transporte vivenciados pelas cidades brasileiras se agravam com o crescente processo de urbanizaÃÃo e a qualidade de vida da populaÃÃo depende de melhorias na sua gestÃo. A ConstituiÃÃo Federal de 1988 instaurou um novo pacto federativo no Brasil, colocando os MunicÃpios e os Estados como partes efetivas da FederaÃÃo e conferindo autonomia aos municÃpios para formular e aplicar polÃticas pÃblicas de desenvolvimento urbano, aà incluÃdas as de trÃnsito, a partir da determinaÃÃo legal de assumir a sua gestÃo, estabelecida pelo CÃdigo de TrÃnsito Brasileiro. PorÃm, essa transiÃÃo de poder nÃo tem se desenvolvido com a rapidez esperada e as suas conseqÃÃncias podem ser muito prejudiciais aos munÃcipes, em virtude do vÃcuo que se verifica. O objetivo geral desta pesquisa foi apresentar um conjunto de recomendaÃÃes que apÃie e motive a tomada de decisÃo dos gestores pela integraÃÃo dos municÃpios brasileiros ao Sistema Nacional de TrÃnsito (SNT). Iniciou-se por uma discussÃo contextualizada do ordenamento jurÃdico da gestÃo do trÃnsito no Brasil, a partir do estudo da sua evoluÃÃo histÃrica. Em seguida, partiu-se para a caracterizaÃÃo da evoluÃÃo temporal do processo de municipalizaÃÃo do trÃnsito, destacando seu estÃgio atual. Apresentou-se, entÃo, uma anÃlise de diagnÃstico institucional da problemÃtica que envolve as dificuldades e os desafios da integraÃÃo dos municÃpios ao SNT, com base na anÃlise da influÃncia de variÃveis relativas ao seu nÃvel de planejamento e desenvolvimento urbano. Concluiu-se a pesquisa com a apresentaÃÃo de um conjunto estruturado de recomendaÃÃes de apoio à tomada de decisÃo pela municipalizaÃÃo do trÃnsito quanto aos aspectos legais e institucionais, financeiros, e de capacitaÃÃo para a gestÃo, visando contribuir para acelerar esse processo no Brasil. / The transportation and traffic problems inherent to Brazilian cities are getting worse because of their growing urbanization process e the people life quality depends on management improvements. The 1988 Brazilian Federal Constitution law restored a new federative pact, placing the Cities and the States as parts of the Federation, and awarded autonomy to the cities to draw up and apply urban development public policies, including the traffic ones, based on the legal obligation of urban management, as established by the Brazilian Traffic Code. However, this power transition is not occurring with the expected speed and its results can be very harmful to the citizens due to the gap that is verified. The main objective of this research was to present a set of recommendations that supports and motivates the managersâ decision making to integrate the Brazilian cities to the National Traffic System (NTS). It was started by a contextualized discussion of the Brazilian traffic management law, based on its historical evolution. And next, it was presented a characterization of the evolution of the traffic management transfer process to the cities in Brazil, with a focus on its current status. Then, it was presented an institutional diagnosis analysis of the problematic involving the difficulties and challenges of the cities integration to the NTS, based on the analysis of the influence of variables related to the urban planning and developing level. The research was concluded with the presentation of a structured set of recommendations related to legal and institutional, financial, and management training aspects, to support the decision making by the cities integration to the NTS, aiming to contribute to accelerate this process in Brazil.
42

Contribution à la régulation coopérative des espaces conflictuels entre véhicules autonomes / Contribution to the cooperative management of conflictual spaces between autonomous vehicles

Lombard, Alexandre 11 December 2017 (has links)
L'augmentation continue du nombre de véhicules a sans cesse conduit à innover pour mieux réguler le trafic routier. Aujourd'hui, l'automatisation des véhicules et la communication inter-véhiculaire rend possible une nouvelle approche : l'intersection autonome et coopérative (IAC) dans laquelle les véhicules autonomes communiquent pour négocier leur droit de passage à l'intersection. Théoriquement plus efficace, plus sûre et plus économique que les approches traditionnelles, son implémentation et son déploiement constituent néanmoins un défi scientifique et technologique. Dans ce mémoire, nous proposons plusieurs contributions soutenant ce développement : une stratégie de contrôle longitudinal et latéral du véhicule conçues pour fonctionner avec des informations discrètes et présentant une latence (provenant de la communication sans-fil ou du positionnement satellite), une solution de prévention des risques d'inter-blocage spécifique à l'IAC, et enfin, l'implémentation et l'expérimentation d'un prototype réel d'IAC avec trois véhicules autonomes. Un travail exploratoire est ensuite fourni pour généraliser les principes de l'IAC, afin d'automatiser et optimiser les opérations de changement de voie et d'insertion. / The continuous increase in the number of vehicles has constantly led to innovation to improve the regulation of road traffic. Today, vehicle automation and inter-vehicular communication make possible a new approach: the autonomous and cooperative intersection (ACI) in which autonomous vehicles communicate to negotiate their right of way at the intersection. Theoretically more effective, safer and more economical than traditional approaches, its implementation and deployment constitute a scientific and technological challenge. In this paper, we propose several contributions supporting this development: a longitudinal and lateral vehicle control strategy designed to work with information discrete and suffering from latency (coming from wireless communication or satellite positioning), a preventive solution of the risks of deadlock specific to the ACI, and finally the implementation and testing of a real prototype of ACI with three autonomous vehicles. An exploratory work is then provided to generalize the principles of the ACI, in order to automate and optimize the operations of lane change and insertion.
43

Deployment and Strategies for Application of Intelligent Transportation System Elements for Contra Flow Hurricane Evacuation and Emergency Response

Birenbaum, Ingrid Leuchtenmueller 16 July 2003 (has links)
Deployment and Strategies for Application of Intelligent Transportation System Elements for Contra Flow Hurricane Evacuation and Emergency Response Ingrid Leuchtenmueller Birenbaum ABSTRACT This thesis is focused upon the deployment and strategies for the application of Intelligent Transportation System (ITS) elements for contra flow hurricane evacuation and emergency response. A 99-mile segment of the Mainline of Florida's Turnpike, State Road 91, comprises the research corridor. This segment stands as the potential one way evacuation route for major hurricane evacuations and other types of natural and man-made disasters for the Turnpike System. Plans have been developed and modified over time to address and improve various facets of contra flow evacuations; however, none of these plans have considered advanced transportation technologies as a means through which operational improvements may be implemented. This study presents the ways in which this present-day evacuation corridor may be enhanced through the proactive application of technologies. ITS provides for the betterment of operations, communications, and procedures for emergency situations in real-time. Improvements in effectiveness and efficiency of the contra flow corridor are realized through the instrumentation of the evacuation route, and benefits are realized by all involved in the evacuation scenario: transportation agencies and their many partners, law enforcement and emergency managers, and the public. This thesis presents a proposal for a migration plan to full roadway instrumentation and ITS deployment that allows for evolving capabilities and protocols. Specific strategies outline steps to be taken that are not entirely dependent upon technology; these strategies are therefore flexible and usable for a growing ITS program. ITS deployment and strategies for use of the evolving Intelligent Transportation System are of benefit to normal, everyday roadway operations as well. However, the application of these technologies and strategies provide specific, vital benefits during the course of emergency events that utilize contra flow operations, ensuring the promotion of motorist safety and mobility through the combination of people and technologies.
44

Quality of service support in multi-rate wireless networks

Pong, Dennis, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW January 2006 (has links)
Packet switched wireless networks have become increasingly popular due to improvements in transmission speed, ease of deployment and mobility. Wireless technologies such as the IEEE 802.11 Wireless Local Area Networks provide transmission speeds capable of supporting multimedia applications. However, wireless channels suffer from short term effects such as interference and fading, and long term effects such as signal strength changes that are caused by user mobility. In multi-rate networks, stations can adapt to the channel variations by adjusting their physical transmission rates. This introduces resource management problems as resource usage depends on the application's bit rate as well as the physical transmission rate used. Multimedia applications demand consistent Quality of Service (QoS) performance from the network. This does not fit well with the dynamic nature of wireless networks. In this thesis, we propose a link layer resource manager to maintain application QoS requirements in multi-rate wireless networks. It consists of two components - Resource reservation and Medium Access Control (MAC) parameters selection. The resource reservation algorithm determines the current and future amount of channel resources required by a multimedia application and performs the function of admission control. This prevents any new traffic or physical transmission rate changes from degrading the QoS of the admitted traffic. The design of the MAC parameters selection algorithm is based on the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) scheme. The algorithm enables the provision of QoS to individual multimedia applications with the prioritised service of EDCA. Analytical and simulation studies were performed to demonstrate the efficiency and effectiveness of the algorithms. The results highlighted the ability of the algorithms to mitigate the QoS provision problem in multi-rate wireless networks introduced by channel variations.
45

Arrival and departure manager cooperation for reducing airborne holding times at destination airports

Rydell, Sofia 08 1900 (has links)
This thesis addresses the possibility of using a delay-on-ground concept in which flights with less than 1 hour flying time (often referred to as pop-up flights) absorb their arrival sequencing delay at the departure gate by being issued their Arrival Manager (AMAN)-scheduled time as a Required Time of Arrival (RTA) that is inserted into the Flight Management System (FMS). Due to their short duration these flights are currently often inserted into the AMAN sequence shortly before Terminal Manoeuvring Area (TMA) entry and thereby often need to absorb their arrival sequencing delay in the inefficient manner of airborne holding or vectoring close to the arrival airport. The literature review examines current operational procedures of AMANs and Departure Managers (DMANs), the current FMS RTA function and live trials in which the delay-on-ground concept was tested in real operations. A case study airport in Europe that has potential to benefit from the concept is identified. The performance of the delay-on-ground concept for the case study airport is then assessed by performing 180 fast-time Monte Carlo simulation runs. For each run the arrival flow to the case study airport and the departure flows from two medium-sized airports from which the pop-up flights originate are simulated. Each run represents an operational day and variations in departure/arrivals time is put into the timetables to simulate the variation in actual departure/arrival times resulting from operational factors normally encountered in day-to-day operations. An algorithm is written in Matlab to simulate an AMAN-DMAN cooperation in which pop-up flights are locked to the required departure times to meet their RTAs. It is shown that a significant reduction in airborne delay time and fuel consumption can be achieved at the case study airport by using the concept. It is also shown that it is possible to ensure that the pop-up flights depart at the required times to meet their RTAs without negatively affecting the departure sequences.
46

A framework for selecting strategies to impact the success of high volume roadway projects

Chabannes, Clayton C. 16 August 2006 (has links)
State Highway Agencies (SHAs) are being forced to focus more on rehabilitation, resurfacing, and reconstruction of existing roadways rather than the construction of new facilities. These activities can create several challenges when they must be conducted on roadways with high traffic volumes. This research identified numerous strategies that can be implemented by SHAs that have the potential to influence the overall success of roadway projects with high traffic volumes. This research also created a framework for when to implement these different strategies. These strategies were identified through an in-depth literature review and through case studies conducted on highway projects that were under construction. Through the case studies the different strategies were documented within the context that warranted their use. Information from the case studies was collected and documented through interviews and site visits. The strategies identified through this research were used to create four matrices that summarize the research findings. A general matrix was created to show the motivating project conditions that warrant the use of each strategy. A public relations matrix was created to display the influence the impacted road user groups have on public relations and information strategies. A traffic management matrix was created to show different types of traffic management strategies and the potential impact they will have on the project. Finally, an interdependency matrix was created to show groups of strategies that are related to each other or require the use of other strategies to be able to influence the success of the project. These matrices could be further developed to create a set of guidelines that could be used by a SHA during the planning phases of a roadway project.
47

User Preferred Trajectories in Commercial Aircraft Operation: Design and Implementation

Vera Anders, Hanyo January 2007 (has links)
<p>This report describes how an aircraft creates and flies its User Preferred Trajectory from take-off to landing, based on the objectives and constraints the aircraft is subjected to from a technological and operational viewpoint.</p><p>A basic description of commercial aircraft operation is given, with an emphasis on identifying the different stakeholders (Air Navigation Service Providers, Airline Operation Center, Pilot/Aircraft, Airport and Civil Aviation Authority). A general description of Instrument Flight Rules operations is also given, together with an explanation of the capabilities of modern flight management systems.</p><p>The objectives and constraints of the trajectory building process from an aircraft and air traffic management viewpoint are described in Chapter 4. Those are instrumental in understanding how the user preferred trajectory is built. The initial and detail route planning process is then described.</p><p>The initial route planning is performed long before the flight and usually by the airline operating center, while detail flight planning, including take-off, runway and departure procedure is performed later by the crew. This process is re-performed minutes before take-off, and usually iterated during the flight when the details of approach and landing are communicated to the aircraft crew.</p><p>The implementation of this user preferred trajectory is explained in terms of the options that the pilots have in the aircraft avionics to perform the mission. The implementation explained in this report is based on the avionics suite of a Boeing 737NG aircraft equipped with the most advanced flight management systems.</p><p>An implementation of a user preferred trajectory, where the aircraft crew is able to best fulfill their objectives is composed of an idle or near idle descent from the cruise altitude. This type of descent, called an advanced continuous descent approach has been implemented by some air navigation service providers, airlines and airports, based on advanced technology that will be further described in this paper. Those procedures are called Green Approaches.</p><p>In the last part of this report, the benefits of flying Green Approach procedures are analyzed by means of aircraft simulations. The analysis describes in detail the lateral and vertical trajectories of the Green Approaches at Stockholm’s Arlanda Airport and Brisbane Airport (Australia), together with the calculated advantages in term of fuel consumption, noise and gas emissions.</p>
48

Dynamisches Bandbreitenmanagement im Chemnitzer StudentenNetz

Schade, Markus 20 June 2006 (has links) (PDF)
Das Chemnitzer StudentenNetz (CSN) setzt seit mehreren Jahren ein System zur automatischen Regelung der Bandbreite ("DynShaper") basierend auf den Grundlagen der Diplomarbeit von Jan Horbach "Dynamische Bandbreitenbeschränkung mit QoS" ein. Aufgrund der weiterhin bestehenden Notwendigkeit zum Einsatz dieses Systems, ist es nötig die DynShaper-Software zu überarbeiten, um ihre Implementierung an die Standards des CSN anzupassen und die unvollständige Dokumentation zu ergänzen. Hauptaugenmerk liegt dabei auf der Integration des Systems in die bestehende Softwarearchitektur des CSN und der Schaffung einer modularen Implementierung zur Evaluierung anderer Berechnungsverfahren.
49

Using 3D/4D CAD modeling for traffic management : development, review, and communication

Goyat, Jean 18 June 2012 (has links)
Developing a traffic management plan for a transportation infrastructure project is a complex activity which requires input from many different fields. Ideally, design, construction and traffic engineers all work towards devising an integrated traffic management plan that would consider a variety of aspects. Current literature about traffic management modeling mostly focuses either on high-level tools not adequate to perform required phasing and constructability analysis of construction activities, or study pre- and post-construction conditions. On the other hand, computer aided design (CAD) modeling of infrastructure projects mentions potential benefits for traffic management plan reviewing. However, it does not delve into using 3 dimensional (3D) and 4 dimensional (3D and time) CAD to study (1) the impact of construction activities on traffic, (2) during construction, (3) at a level that allows detailed phasing and constructability reviews for traffic management plan elaboration and communication. Using 3D and 4D CAD modeling can alleviate the complexity of devising traffic management plans for transportation projects by providing an integrated framework from which developers can elaborate, review and communicate their strategies. The many visualization benefits of 3D/4D modeling used in conjunction with their advanced analysis capabilities can tremendously aid compared to more traditional 2D methods. The three transportation projects described in this study aim at illustrating the benefits and added value these models provide to more efficiently and rapidly visualize and analyze intended traffic management strategies, at different stages of the construction process. / text
50

Assessment and reduction of the impacts of large freight vehicles on urban traffic corridor performance

Ramsay, Euan Douglas January 2007 (has links)
Increasing demand for road freight has lead to a widespread adoption of more-productive large freight vehicles (LFVs), such as B-Doubles, by Australia's road freight industry. Individual LFVs have a greater potential to impact traffic efficiency through their greater length and poorer longitudinal performance. However, this is offset to an extent as fewer vehicles are required to perform a given freight task on a tonne-km basis. This research has developed a means of characterising the effects that large freight vehicles have on the performance of an urban arterial corridor managed by signalised intersections. A corridor-level microsimulation model was developed from first principles, which modelled the longitudinal performance of individual vehicles to a greater accuracy than most existing traffic simulation software does. The model was calibrated from traffic counts and GPS-equipped chase car surveys conducted on an urban arterial corridor in Brisbane's southern suburbs. The model was applied to various freight policy and traffic management scenarios, including freight vehicle mode choice, lane utilisation and traffic signal settings; as well as the effectiveness of green time extension for approaching heavy vehicles. Benefits were able to be quantified in terms of reduced travel times and stop rates for both heavy and light vehicles in urban arterial corridors.

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