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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.
11

Algorithmes de vision pour la pluie et les feux tricolores pour les systèmes d'aide à la conduite / Vision Algorithms for Rain and Traffic Lights in Driver Assistance Systems

De Charette, Raoul 17 September 2012 (has links)
L'utilisation d'algorithmes de vision permettrait d'élargir le domaine d'application des systèmes d'aide à la conduite à d'autres situations telles que : les scènes urbaines ou les conditions météorologiques dégradées. À cette fin, trois nouvelles applications sont étudiées dans cette thèse pour la pluie et les feux tricolores. La pluie est la condition météorologique dégradée la plus fréquente. Nous comparons les modèles physiques et photométriques existants pour la pluie et les gouttes de pluie. Lors d'une conduite en temps de pluie de jour, les gouttes sur le pare-brise diminuent considérablement la visibilité du conducteur. Lorsqu'elles sont vue par une camera embarquée standard celles-ci apparaissent défocalisées. Ainsi, nous proposons de détecter ces gouttes hors-focus en utilisant soit une approche par manque de gradients soit par l'évaluation locale du flou. Lors d'une conduite de nuit sous la pluie, ce sont les phares qui paradoxalement diminuent la visibilité car leur lumière est réfléchie par les gouttes vers le conducteur. Nous appuyant sur la conception d'un simulateur physique, nous proposons un éclairage adaptatif qui illuminerait la scène sans éclairer les gouttes qui tombent. Les résultats de notre simulateur et le premier prototype construit montre que l'idée avancée pourrait efficacement améliorer la visibilité générale d'une scène. D'autre part, nous étudions la détection et le suivi de gouttes de pluie à grande vitesse. Les feux tricolores ont un rôle crucial dans la compréhension des scènes urbaines. Bien qu'il existe déjà des systèmes de détection de feux tricolores, les algorithmes actuels ne fonctionnent que dans des conditions simples. Ainsi, nous avons développé un algorithme de détection de feux tricolores qui utilise une détection en niveau de gris des spots lumineux et une classification par reconnaissance de modèle. L'approche ainsi conçue est assez flexible pour détecter différents types de feux tricolores même avec une camera à faible dynamique. Notre proposition a été évaluée sur des séquences acquises en France, Chine et Suisse. / Vision algorithms can be used to expand the working range of the assistance systems so as to deal with urban scenes or degraded weathers. To this end, three novel applications are investigated in this thesis for both rain and traffic lights. Rain is the most frequent degraded weather condition. We review the various physics and photometry models for rain and raindrops, and highlight some of the misuses. When driving in daytime the raindrops on the windscreen lower the driver visibility. For standard on-board camera these drops appear as unfocused. Hence, we investigate the detection of unfocused raindrops using blur maps or lack of gradients with photometry. For nightime driving in rain, the headlights paradoxically reduce the visibility due to light reflected off of raindrops back toward the driver. Relying on a physic-based simulator, we propose to build an illumination device that would illuminate the scene without shining the falling particles. The performance of the simulator and a proof-of-concept prototype sustain that our idea can efficiently improve the overall scene visibility. Fast reactive drops detection and tracking is also investigated.To deal with urban scenes, traffic lights play a key role. Though traffic light recognition was attempted in the past, the existing algorithms can't handle complex scenarios. Hence, we have developed a traffic light recognition algorithm that uses a grayscale spot light detection and a template matching classification. Our approach is modular and capable of detecting various kind of traffic lights even when using a low-dynamic camera. We have evaluated our algorithm on sequences from France, China and Switzerland.
12

Dopravně-inženýrské řešení křižovatky ulic Přímá-Nábřeží ve Zlíně / Traffic engineering design of Přímá-Nábřeží intersection in Zlin

Hájková, Barbora January 2014 (has links)
The master’s thesis deals with a solution of a complicated traffic situation on the Přímá – Nábřeží intersection in Zlin. The first part of the thesis focuses on the diagnostic of the current state of the junction. In the second part, the author compares possible solutions, traffic light control is chosen as the best. Traffic light plans are designed and coordinated with a nearby traffic light controlled intersection Tomáše Bati – Přímá. It the last part, the solution is verified and represented by a microsimulation.
13

Propuesta de implementación de un sistema de semaforización inteligente para mejorar los niveles de servicio de la Av. Javier Prado Oeste, tramo Ca. Las Palmeras y Ca. Las Flores en el distrito de San Isidro

Rivera Saavedra, Gabriel, Velásquez Ochochoque, Luis Alberto 05 March 2020 (has links)
La presente investigación analiza las condiciones de tráfico vehicular actual en dos intersecciones de la avenida Javier Prado Oeste, tramo Calle Las Flores & Calle Las Palmeras, en el distrito de San Isidro. La investigación empieza con la descripción de los problemas existentes en las intersecciones, como la deficiente programación de semáforos, falta de semáforos coordinados e incompatibilidad entre controladores semafóricos. El análisis de la investigación se realizó en base a un modelo microscópico, desarrollado con apoyo del software Vissim. El proceso de construcción de ambos modelos consiste en cuatro fases. La primera fase es el trabajo previo, en la cual se realizó la recolección de datos de campo. En segundo lugar, se encuentra la construcción de los modelos mediante el programa. En tercer lugar, se realizó la calibración y validación de ambos modelos en base a parámetros psicofísicos y estadísticos GEH para certificar que los resultados del modelo se asemejen a las condiciones actuales de las intersecciones. Por último, se incorporaron los nuevos flujos futuros en los modelos cada 15 minutos los cuales se simularon, evaluaron y compararon con los niveles de servicio obtenidos con las intersecciones proyectadas que incorporan la propuesta de mejora. Esencialmente los niveles de servicio de las intersecciones mejoran incorporando la propuesta de semáforos inteligente por medio de la optimización de ciclos semafóricos con el programa Synchro 10.0, esto se deduce a partir de la disminución de longitudes de colas en todos los accesos y la reducción de demoras de viaje en ambas intersecciones. / The present investigation analyzes the current vehicular traffic conditions at two intersections of Javier Prado Oeste Avenue, Las Flores Street and Las Palmeras Street, in the San Isidro district. The investigation begins with the description of the problems existing at the intersections, such as poor traffic light programming, lack of coordinated traffic lights and incompatibility between traffic light controllers. The research analysis was carried out based on a microscopic model, developed with the support of Vissim software. The construction process of both models consists of four phases. The first phase is the previous work, in which the field data collection was carried out. Second, there is the construction of the models through the program. Third, the calibration and validation of both models was performed based on GEH psychophysical and statistical parameters to certify that the results of the model resemble the current conditions of the intersections. Finally, the new future flows were incorporated into the models every 15 minutes, which were simulated, evaluated and compared with the service levels obtained with the projected intersections that incorporate the improvement proposal. Essentially, the service levels of the intersections improve by incorporating the smart traffic lights proposal through the optimization of traffic light cycles with the Synchro 10.0 program, this is deduced from the decrease in queue lengths in all accesses and the reduction of delays of travel at both intersections. / Tesis
14

Evaluación de la precisión para el método de sostenibilidad en el tiempo en intersecciones urbanas / Evaluation of accuracy for the sustainability method in time for urban intersections

Burga-Álvarez Llorca, Oswaldo Ayrton, Medina Sánchez, Fabricio Ramiro 23 June 2020 (has links)
Una manera de evaluar si las soluciones para intersecciones urbanizadas son sostenibles en el tiempo, es calculando las demoras para un tránsito futuro y la presente investigación determina la precisión de dicha evaluación. La demora vehicular es uno de los parámetros más importantes utilizado para evaluar el rendimiento de las intersecciones semaforizadas, por tal motivo, profesionales del transporte usan como criterio de optimización del tráfico, la disminución de las demoras. En este artículo, se presenta un enfoque para evaluar la precisión del método de sostenibilidad en el tiempo para intersecciones urbanas, para lo cual se analizarán las demoras en una intersección para diferentes escenarios. Primero, se modelará la intersección de estudio mediante el software Synchro 10. En segundo lugar, el modelo se aplicará para diversos escenarios donde el volumen vehicular incrementará dependiendo del crecimiento vehicular. Se demuestra que, a partir de las demoras obtenidas para cada escenario, se puede estimar la precisión de aplicar la solución que se desee en una intersección, esto en base a la tendencia de la curva de variación porcentual de las demoras en el tiempo. En resumen, la metodología puede ser aplicada en diferentes intersecciones urbanizadas y escenarios donde se pretenda plantear soluciones que sean sostenibles en el tiempo. / A way to evaluate if the solutions for urban intersections are sustainable in time, is about calculating the delays for a future traffic and the present investigation establishes the accuracy of that evaluation. The vehicular delay is one of the most important parameters that is used to evaluate the performance of traffic light intersections, for this reason, professionals of transport use as traffic optimization judgment the decrease of delays. This article presents an approach to evaluate the accuracy for the sustainability method in time for urban intersections, for which this investigation analyzes the delays in one intersection for different stages. This project begins with a model of the intersection of study helped by the software Synchro 10. Then, the model will be applied for many stages where the vehicular volume will be increased depending the vehicular growth. Finally, it is proved that due to the estimated delays for each stage, it will be possible to estimate the accuracy of applying a desired solution in an intersection, that is based on the trend of percentages variation curve on time delays. In brief, the methodology could be applied in different urban intersections and stages where it is pretended to propose solutions that are sustainable over the time. / Trabajo de investigación
15

Potential Impacts of Connected Vehicles in Urban Traffic: A Case Study

Rahimi, Tariq Rahim 21 December 2018 (has links)
No description available.
16

Applying Matsuoka Neuronal Oscillator in traffic light control of intersections : a thesis presented in partial fulfillment of the requirements of the degree of Master of Engineering in Mechatronics at Massey University, Auckland, New Zealand

Lin, Kuo-Chun January 2009 (has links)
The quality of Machine Translation (MT) can often be poor due to it appearing incoherent and lacking in fluency. These problems consist of word ordering, awkward use of words and grammar, and translating text too literally. However we should not consider translations such as these failures until we have done our best to enhance their quality, or more simply, their fluency. In the same way various processes can be applied to touch up a photograph, various processes can also be applied to touch up a translation. This research outlines the improvement of MT quality through the application of Fluency Enhancement (FE), which is a process we have created that reforms and evaluates text to enhance its fluency. We have tested our FE process on our own MT system which operates on what we call the SAM fundamentals, which are as follows: Simplicity - to be simple in design in order to be portable across different languages pairs, Adaptability - to compensate for the evolution of language, and Multiplicity - to determine a final set of translations from as many candidate translations as possible. Based on our research, the SAM fundamentals are the key to developing a successful MT system, and are what have piloted the success of our FE process.
17

Heuristic methods for solving two discrete optimization problems

Cabezas García, José Xavier January 2018 (has links)
In this thesis we study two discrete optimization problems: Traffic Light Synchronization and Location with Customers Orderings. A widely used approach to solve the synchronization of traffic lights on transport networks is the maximization of the time during which cars start at one end of a street and can go to the other without stopping for a red light (bandwidth maximization). The mixed integer linear model found in the literature, named MAXBAND, can be solved by optimization solvers only for small instances. In this manuscript we review in detail all the constraints of the original linear model, including those that describe all the cyclic routes in the graph, and we generalize some bounds for integer variables which so far had been presented only for problems that do not consider cycles. Furthermore, we summarized the first systematic algorithm to solve a simpler version of the problem on a single street. We also propose a solution algorithm that uses Tabu Search and Variable Neighbourhood Search and we carry out a computational study. In addition we propose a linear formulation for the shortest path problem with traffic lights constraints (SPTL). On the other hand, the simple plant location problem with order (SPLPO) is a variant of the simple plant location problem (SPLP) where the customers have preferences on the facilities which will serve them. In particular, customers define their preferences by ranking each of the potential facilities. Even though the SPLP has been widely studied in the literature, the SPLPO has been studied much less and the size of the instances that can be solved is very limited. In this manuscript, we propose a heuristic that uses a Lagrangean relaxation output as a starting point of a semi-Lagrangean relaxation algorithm to find good feasible solutions (often the optimal solution). We also carry out a computational study to illustrate the good performance of our method. Last, we introduce the partial and stochastic versions of SPLPO and apply the Lagrangean algorithm proposed for the deterministic case to then show examples and results.
18

Simulace dopravy za využití dopravních řadičů / Traffic Simulation Using Traffic Controllers

Dressler, David January 2019 (has links)
The aim of this master's thesis is to design an extension of the existing simulation system for designing traffic intersections. The required extension will allow the use of the Siemens sX traffic controllers. The introduction to the topic of traffic engineering, traffic controllers configuration and the dynamic traffic control is discussed first. The next part is dedicated to describing the implementation of the existing simulation system. The following chapter describes the use of the sX traffic controllers and also describes the design of the required extension of the existing simulation system, for a purpose of enabling the use of sX traffic controllers. This is followed by a chapter describing the implementation of this extension. The last chapter is devoted to testing the whole system in terms of functionality and performance. Finally, other possibilities for the future development are outlined.
19

Optimální nasazení generátorů hypotéz pro detekci semaforů ve snímcích / Optimal Deployment of Multiple Hypotheses Generators for Detecting Traffic Lights in Camera Images

Bajus, Tomáš January 2017 (has links)
Táto práca sa zaoberá detekciou semafórov na snímkoch z kamery. Cieľom je nájsť vhodné nastavenie a kombináciu dostupných detektorov. V prvej časti práce je vysvetlený princíp funkcie použitých detektorov. Nasleduje zhodnotenie vlastností jednotlivých detektorov pred ich optimalizáciou. V ďalšej časti práce je popísaný proces testovania a evaluácie detektorov a predstavený nový systém pre zefektívnenie hľadania optimálneho nastavenia detektorov. V rámci optimizácie je popísaný effekt jednotlivých parametrov na chovanie systému a sú navrhnuté rozpätia vhodných hodnôt pre každý parameter. Taktiež je predstavené nové zapojenie detektorov sú nájdené optimálne pracovné body systému. Posledná časť sa zaoberá použitím vhodných metód na filtorvanie a zhlukovanie hypotéz. Nakoniec je prezentovaná celková funkčnosť systému pred a po optimizácii a výsledky sú zhodnotené.
20

Análise do padrão IEEE 802.11g para a comunicação do sistema de controle distribuído de semáforos. / IEEE 802.11g standart analysis for communication of the distributed control system of traffic lights.

Miguel, Danilo de Souza 16 June 2015 (has links)
Este trabalho propõe a análise da comunicação sem fio para um sistema de controle distribuído de semáforos, a partir da revisão das literaturas, realização de simulações e experimentos, os quais consideram as especificações estabelecidas para o sistema de semáforos. As simulações e os experimentos se baseiam na avaliação do comportamento da comunicação perante a alteração de alguns parâmetros de configuração da rede. O estudo apresentado envolve análises relacionadas ao padrão IEEE 802.11g e às definições da camada física apresentadas nas especificações do padrão. Os métodos utilizados envolvem o estudo e experimentação de parâmetros relacionados à potência de transmissão e recepção, além de análise dos esquemas de modulação utilizados pelo padrão IEEE 802.11g. A metodologia aplicada a este trabalho envolve o conhecimento das características e capacidade dos esquemas de modulação responsáveis pela definição das taxas de transmissão. As análises mostram que a possibilidade de adequação dos parâmetros de configuração de rede, levando em consideração o cenário de aplicação, pode ser um fator essencial para o bom desempenho de todo o sistema. / This work proposes the analysis of wireless communication for a distributed control system of traffic lights, from the review of the literature and conducting simulations and experiments, which consider the specifications established for traffic light system. The simulations and experiments are based on the evaluation of the communication behavior towards changing some network configuration parameters. The study presented involves analysis related to the IEEE 802.11g standard and definitions of the physical layer shown in standard specifications. The methods used involve the study and testing of parameters related to power transmission and reception, and analysis of modulation schemes used by the IEEE 802.11g standard. The methodology applied to this work involves the knowledge of the characteristics and capacity of modulation schemes responsible for setting transmission rates. The analyses show that the possibility of adaptation network configuration parameters considering the application scenario may be an essential factor to the performance of the entire system.

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