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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.
111

Comparação do desempenho de dispositivos de interseções rodoviárias em nível utilizando o simulador Integration / Performance comparison of road intersections at grade using Integration simulator

Giseli Aparecida Ortolani 21 August 2003 (has links)
O trabalho contém uma avaliação do desempenho operacional do tráfego de veículos em três tipos de dispositivos rodoviários em nível, utilizando como critério a capacidade para os diversos níveis de serviço, incluindo uma análise comparativa do entre eles. A avaliação do desempenho é feita com base nos resultados fornecidos pelo simulador INTEGRATION. Os três dispositivos analisados, são: semi-rotatória com prioridade para os veículos da via principal, rotatória com prioridade para os veículos da via principal e rotatória com prioridade para os veículos da via circular. No trabalho também é realizada uma análise de alguns aspectos relevantes da lógica utilizada pelo INTEGRATION e de resultados fornecidos pelo simulador em alguns casos particulares simples, através da comparação de valores obtidos variando-se para alguns parâmetros, bem como da comparação com resultados fornecidos por outros modelos de avaliação de desempenho de interseções com sinal de parada obrigatória ou dê a preferência. / The work contains a performance evaluation of the traffic vehicles in the three types of Road intersections at grade used in Brazil, using as criteria the capacity relatively to the level of service. A comparative analysis of the performance of these intersections is also presented. The performance evaluation is made based on the supplied results by the INTEGRATION simulator. The three analyzed intersections, are: semi roundabout with priority for the vehicles of the main road, roundabout with priority for the vehicles the main road and roundabout with priority for the vehicles in the circular road (modern roundabout).In this research an analysis is also accomplished about some important aspects of the INTEGRATION logic and of the supplied results by the simulator in some specific cases, through the comparison of obtained values being varied some parameters, as well as the comparison with results supplied by other evaluation models of intersections performance with STOP SIGN and GIVE WAY traffic signs.
112

Cyclists' Queue Discharge Characteristics at Signalized Intersections

Paulsen, Kirk Thomas 19 July 2018 (has links)
Wider bike facilities intuitively accommodate a greater number of cyclists in the same amount of time, but specific queue discharge characteristics associated with varying widths and/or types of bike facilities have not been thoroughly documented. The focus of this research analyzed queues of cyclists at four signalized intersections in Portland, OR with varying widths on the approach and downstream intersection legs. A total of 2,820 cyclists within 630 groups of queued cyclists were observed at five different intersection layouts in Portland, Oregon. The layouts consisted of: a standard bike lane six feet wide connecting bicyclists to a standard bike lane six feet wide, a standard bike lane five feet wide connecting bicyclists to two standard bike lanes each five feet wide, a buffered bike lane 12 feet wide connecting bicyclists to a standard bike lane 6.5 feet wide, a bike box 21 feet wide connecting bicyclists to a buffered bike lane 10 feet wide, and a bike box 15 feet wide connecting bicyclists to two standard bike lanes each five feet wide. For each configuration, the following aspects were analyzed: average headway per cyclist within each queue, the time required for queues to enter the intersection, the time required for queues to clear the intersection, the number of cyclists within queues, the width of the bicycle facilities, the approach grade, and the utilization of a bike box at the intersection approach if it was present. The first major focus of the analysis reviewed the average headway values associated with each observed queue of cyclists. The queue size with the lowest mean of the average headway was for groups of seven cyclists with an average headway of approximately 0.8 seconds per cyclist. For queues larger than seven in size, the mean of the average headway remained relatively stable until queues of 12 in size and started to slightly increase toward approximately 1.0 seconds for queues larger than 12 cyclists. In addition, it appears that utilization of a bike box has a potential relationship with a reduced average headway as compared to queues that do not utilize a bike box. The associated reduction in the mean of the average headway was approximately 0.2 to 0.3 seconds per cyclist for queues of three or more in size. The second major focus of the analysis reviewed the queue discharge rate associated with each observed queue of cyclists. The results appear to potentially indicate that wider bike facilities approaching an intersection, wider receiving bike facilities, or utilization of a bike box generally discharge queues of bicyclists into the intersection over a shorter amount of time as compared to facilities that are narrower or underutilized. The installation of a bike box at one of the study intersections increased the approach width from five to 15 feet and resulted in consistently lower average discharge times for all queue sizes, a reduction of greater than one second for queues of two cyclists to as much as about four seconds for queues of nine cyclists. The third major focus of the analysis reviewed the intersection clearance time associated with each observed queue of cyclists. The results appear to potentially indicate that wider bike facilities approaching an intersection, wider receiving bike facilities, or utilization of a bike box generally clear queues of bicyclists through the intersection over a shorter amount of time as compared to facilities that are narrower or underutilized.
113

Vers des spécifications formelles : Fondements Mathématiques et Informatiques pour la Géométrie Dynamique

Genevès, Bernard 21 December 2004 (has links) (PDF)
Ce travail est une étude algorithmique et mathématique préparant une axiomatisation ou une spécification de la géométrie dynamique. Le comportement dynamique des intersections de courbes, dans le cas où elles sont multiples, et la gestion algorithmique d'objets géométriques sous-déterminés posent problème. Il est connu depuis peu que la continuité des déplacements et le déterminisme des comportements dynamiques ne sont pas entièrement compatibles ; ce travail précise ce point essentiel : par des procédés globaux qui sortent du cadre de la géométrie discrète, il est montré que le comportement dynamique des intersections de cercles présente des singularités inévitables, qui sont énumérées. Une tentative est faite pour étendre ce résultat aux intersections de coniques. Des propositions pour unifier le traitement algorithmique d'objets sous-déterminés, comme les points sur objet, sont présentées, depuis le cadre mathématique jusqu'à l'implémentation effective. Ce travail montre aussi qu'il existe des concepts mathématiques de base, comme la notion d'aire non signée, dont la justification ultime ne supporte pas le mouvement, au contraire de la notion d'aire signée. En permettant la spécification des algorithmes traitant du comportement dynamique des intersections de cercles, ce travail établit un premier niveau de qualité pour les logiciels de géométrie dynamique, permettant de juger leur cohérence mathématique. Plusieurs des implémentations réalisées sont présentes dans Cabri2 Plus, logiciel largement diffusé par l'entreprise Cabrilog. Au niveau théorique, ce travail repose différemment la question de la nature des figures dynamiques, en particulier de la nature mathématique précise des lieux géométriques en géométrie dynamique.
114

Evaluation of Roadside Collisions with Utility Poles and Trees at Intersection Locations

Mattox, Todd Berry 15 November 2007 (has links)
The United States averages 40,000 traffic fatalities annually. The American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide cites run-off-the-road crashes as contributing greatly to this statistic, with about one-third of all traffic deaths [1]. This number has remained relatively constant over the past four decades, and despite a major increase in vehicle miles traveled (VMT), the rate of fatalities per 100 million vehicle miles traveled has declined. However, this relatively large number of run-off-the-road crashes should remain a major concern in all roadway design. The Highway Safety Act of 1966 marks a defining moment in the history of roadside safety [ ]. Before this point, roadways were only designed for motorists who remained on the roadway, with no regard for driver error. As there was no legislation or guidelines concerning roadside design, roadways constructed prior to 1966 are littered with fixed objects directly off of the edge of pavement. Fortunately, many of these roads have reached their thirty year design lives and have become candidates for improvement. The following report examines roadside crashes on nine Atlanta urban arterial roadways. Accident type, severity, and location for all crashes on these were evaluated. It is found roadside collisions with utility poles and trees were more prone to occur at intersection locations than midblock locations. Also for the studied roadway corridors, on average, roadside collisions were more likely to result in serious injury or fatality. Based on these findings initial recommendations are offer for improving clear zone requirements.
115

Correlational Analysis of Drivers Personality Traits and Styles in a Distributed Simulated Driving Environment

Abbas, Muhammad Hassan, Khan, Mati-ur-Rehman January 2007 (has links)
<p>In this thesis report we conducted research study on driver's behavior in T-Intersections using simulated environment. This report describes and discusses correlation analysis of driver's personality traits and style while driving at T-Intersections.</p><p>The experiments were performed on multi user driving simulator under controlled settings, at Linköping University. A total of forty-eight people participated in the study and were divided into groups of four, all driving in the same simulated world.</p><p>During the experiments participants were asked to fill a series of well-known self-report questionnaires. We evaluated questionnaires to get the insight in driver's personality traits and driving style. The self-report questionnaires consist of Schwartz's configural model of 10 values types and NEO-five factor inventory. Also driver's behavior was studied with the help of questionnaires based on driver's behavior, style, conflict avoidance, time horizon and tolerance of uncertainty. Then these 10 Schwartz's values are correlated with the other questionnaires to give the detail insight of the driving habits and personality traits of the drivers.</p>
116

A novel approach to modeling and predicting crash frequency at rural intersections by crash type and injury severity level

Deng, Jun, active 2013 24 March 2014 (has links)
Safety at intersections is of significant interest to transportation professionals due to the large number of possible conflicts that occur at those locations. In particular, rural intersections have been recognized as one of the most hazardous locations on roads. However, most models of crash frequency at rural intersections, and road segments in general, do not differentiate between crash type (such as angle, rear-end or sideswipe) and injury severity (such as fatal injury, non-fatal injury, possible injury or property damage only). Thus, there is a need to be able to identify the differential impacts of intersection-specific and other variables on crash types and severity levels. This thesis builds upon the work of Bhat et al., (2013b) to formulate and apply a novel approach for the joint modeling of crash frequency and combinations of crash type and injury severity. The proposed framework explicitly links a count data model (to model crash frequency) with a discrete choice model (to model combinations of crash type and injury severity), and uses a multinomial probit kernel for the discrete choice model and introduces unobserved heterogeneity in both the crash frequency model and the discrete choice model, while also accommodates excess of zeros. The results show that the type of traffic control and the number of entering roads are the most important determinants of crash counts and crash type/injury severity, and the results from our analysis underscore the value of our proposed model for data fit purposes as well as to accurately estimate variable effects. / text
117

Intersection discharge performance

Savage, Alpha Badamasie January 1980 (has links)
No description available.
118

Grandes déviations pour les temps locaux d'auto-intersections de marches aléatoires

Laurent, Clément 18 November 2011 (has links) (PDF)
Dans cette thèse on s'intéresse au temps local d'auto-intersections de marches aléatoires. Cette quantité est définie comme la norme-$p$ à la puissance $p$ du temps local de la marche. Elle regarde dans quelle mesure la trajectoire de la marche aléatoire s'intersecte. Le temps local d'auto-intersections est lié à différents modèles physiques comme les modèles de polymères ou les problèmes d'écoulements de flux en milieux stratifiés mais aussi au modèle mathématiques des marches aléatoires en paysages aléatoires. Nous nous sommes pour notre part intéressés en particulier aux grandes déviations du temps local d'auto-intersections, c'est à dire que nous regardons la probabilité que la quantité d'intersections de la marche aléatoire soit plus grande que sa moyenne. Cette question qui a été très étudiée au cours des années 2000 fait apparaitre trois cas distincts, le cas sous-critique, le cas critique et le cas sur-critique. Nous améliorons la connaissance sur cette question au travers de deux résultats complets et d'un résultat partiel. D'abord nous prouvons un principe de grandes déviations dans les cas critique et sur-critique des marches $\alpha$-stables, puis nous améliorons les échelles de déviations au cas sous-critique tout entier de la marche simple, enfin nous sommes en train d'étendre ce dernier résultat aux marches $\alpha$-stables. Par ailleurs les trois preuves sont basées sur l'utilisation d'une version due à Eisenbaum d'un théorème d'isomorphisme de Dynkin. Cette méthode d'abord introduite par Castell dans le cas critique est donc ici étendue aux autres cas. Nous avons donc réussi à unifier les différentes méthodes de preuves au travers ce théorème d'isomorphisme.
119

Approximation numérique de l'équation de Vlasov par des méthodes de type remapping conservatif

Glanc, Pierre 20 January 2014 (has links) (PDF)
Cette thèse présente l'étude et le développement de méthodes numériques pour la résolution d'équations de transport, en particulier d'une méthode de remapping bidimensionnel dont un avantage important par rapport aux algorithmes existants est la propriété de conservation de la masse. De nombreux cas-tests permettront de comparer ces approches entre elles ainsi qu'à des méthodes de référence. On s'intéressera en particulier aux équations dites de Vlasov-Poisson et du Centre-Guide, qui apparaissent très classiquement dans le cadre de la physique des plasmas.
120

Signalized fuzzy logic for diamond interchanges incorporating with fuzzy ramp system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Auckland, New Zealand

Pham, Cao Van January 2009 (has links)
New dynamic signal control methods such as fuzzy logic and artificial intelligence developed recently mainly focused on isolated intersection. In this study, a Fuzzy Logic Control for a Diamond Interchange incorporating with Fuzzy Ramp System (FLDI) has been developed. The signalization of two closely spaced intersections in a diamond interchange is a complicated problem that includes both increasing the diamond interchange capacity and reduce delays at the same time. The model comprises of three main modules. The Fuzzy Phase Timing module controls the current phase green time extension, the Phase Selection module select the next phase based on the pre-defined phase sequence or phase logics and the Fuzzy Ramp module determines the cycle time of the ramp meter bases on current traffic volumes and conditions of the interchanges and the motorways. The developed FLDI model has been compared with the traffic actuated simulation with respects to flow rates and the average delays of the vehicles. The model of an actual diamond interchange is described and simulated by using AIMSUN (Advanced Interactive Microscopic Simulator for Urban and Non-Urban Network) software. Simulation results show the FLDI model outperformed the traffic actuated models with lower system total travel time, average delay and improvements in downstream average speed and average delay.

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