Dissertations / Theses on the topic 'Traffic'
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Lenkei, Zsolt. "Crowdsourced traffic information in traffic management : Evaluation of traffic information from Waze." Thesis, KTH, Transportplanering, ekonomi och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239178.
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The early observation and elimination of non-recurring incidents is a crucial task in trafficmanagement. The performance of the conventional incident detection methods (trafficcameras and other sensory technologies) is limited and there are still challenges inobtaining an accurate picture of the traffic conditions in real time. During the last decade,the technical development of mobile platforms and the growing online connectivity made itpossible to obtain traffic information from social media and applications based on spatialcrowdsourcing. Utilizing the benefits of crowdsourcing, traffic authorities can receiveinformation about a more comprehensive number of incidents and can monitor areaswhich are not covered by the conventional incident detection systems. The crowdsourcedtraffic data can provide supplementary information for incidents already reported throughother sources and it can contribute to earlier detection of incidents, which can lead tofaster response and clearance time. Furthermore, spatial crowdsourcing can help to detectincident types, which are not collected systematically yet (e.g. potholes, traffic light faults,missing road signs). However, before exploiting crowdsourced traffic data in trafficmanagement, numerous challenges need to be resolved, such as verification of the incidentreports, predicting the severity of the crowdsourced incidents and integration with trafficdata obtained from other sources.During this thesis, the possibilities and challenges of utilizing spatial crowdsourcingtechnologies to detect non-recurring incidents were examined in form of a case study.Traffic incident alerts obtained from Waze, a navigation application using the concept ofcrowdsourcing, were analyzed and compared with officially verified incident reports inStockholm. The thesis provides insight into the spatial and temporal characteristics of theWaze data. Moreover, a method to identify related Waze alerts and to determine matchingincident reports from different sources is presented. The results showed that the number ofreported incidents in Waze is 4,5 times higher than the number of registered incidents bythe Swedish authorities. Furthermore, 27,5 % of the incidents could have been detectedfaster by using the traffic alerts from Waze. In addition, the severity of Waze alerts isexamined depending on the attributes of the alerts.
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De, Nunzio Giovanni. "Traffic eco-management in urban traffic networks." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT064/document.
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Le problème de la gestion éco-responsable du trafic urbain est adressé. Ce type de gestion du trafic vise à réduire les arrêts des véhicules, les accélérations, la consommation énergétique, ainsi que la congestion. L'éco-management du trafic dans les réseaux urbains peut être catégorisé dans deux classes principales : contrôle du véhicule et contrôle de l'infrastructure. Les deux domaines de contrôle peuvent présenter caractéristiques soit isolées soit coordonnées, en dépendant du type d'information utilisée dans l'optimisation.La gestion du trafic côté véhicule influe sur chaque véhicule en fonction de ses propres caractéristiques et position. Le contrôle isolé du véhicule vise principalement à optimiser la transmission et/ou le profil de conduite des véhicules, en utilisant éventuellement des informations sur les caractéristiques de la route, mais sans communiquer avec les autres agents du réseau. Le contrôle coordonné du véhicule, d'autre part, fait usage de la communication entre les véhicules et avec l'infrastructure pour obtenir des bénéfices plus importants en termes de consommation d'énergie et de fluidité de la circulation.En revanche, la gestion du côté infrastructure influe sur les feux et les panneaux de signalisation, afin d'améliorer les performances de l'ensemble du trafic. Le contrôle isolé de l'infrastructure régule essentiellement les feux de signalisation pour une seule intersection, ou bien les limites de vitesse dans un seul tronçon de route, sans prendre en compte les interactions avec les jonctions et/ou les sections voisines. Le contrôle coordonné de l'infrastructure surmonte cette limitation en utilisant des informations sur les conditions de circulation dans d'autres sections de la route, afin de réduire la congestion.Les contributions de ce travail peuvent être résumées comme suit.Tout d'abord, une solution pour le contrôle coordonné du véhicule a été proposée, dans laquelle la communication avec l'infrastructure est exploitée pour réduire la consommation d'énergie. En particulier, les plans des feux de signalisation sont supposés être communiqués au véhicule et connus, et une vitesse optimale est suggérée au véhicule afin de traverser une séquence de carrefours à feux sans s'arrêter, tout en suivant une trajectoire d'énergie minimale. La stratégie proposée, appliquée indépendamment à chaque véhicule, a été testée dans un simulateur de trafic microscopique afin d'évaluer l'impact sur les performances du trafic. L'analyse a montré que la consommation d'énergie et le nombre d'arrêts peuvent être considérablement réduits sans affecter le temps de parcours.Ensuite, une solution pour le contrôle isolé de l'infrastructure a été proposée. Un modèle macroscopique du trafic urbain a été introduit, et les limites de vitesse variables ont été utilisées pour améliorer les performances de la circulation. L'optimisation vise à trouver un compromis entre la réduction de consommation énergétique et le temps de parcours moyen des véhicules dans le tronçon de route considéré. Des expériences ont démontré qu'il existe une limite de vitesse optimale qui améliore les performances du trafic, et qui réduit la longueur de la file d'attente au feu de signalisation.Enfin, une solution pour le contrôle coordonné de l'infrastructure a été proposée. La synchronisation des feux de signalisation sur les grands axes de circulation a été prouvée efficace pour réduire le temps de parcours. Notre analyse a démontré qu'un problème d'optimisation peut être formalisé pour prendre en compte également les aspects énergétiques. Des expériences approfondies dans un simulateur de trafic microscopique ont montré qu'il existe une corrélation entre la progression du trafic et ses performances. La stratégie de contrôle proposée a montré qu'une réduction significative de la consommation d'énergie peut être atteinte, en éliminant presque complètement les arrêts et le temps d'arrêt, sans affecter le temps de parcoursThe problem of energy-aware traffic management in urban environment is addressed. Such traffic management aims at reducing vehicle stops, accelerations, energy consumption, and ultimately congestion. The eco-management in urban traffic networks may be divided in two broad categories: vehicle-side control and infrastructure-side control. Both control domains can feature isolated or coordinated characteristics, depending on the type of information used in the optimization.The vehicle-side traffic management influences each single vehicle according to its own characteristics and position. Isolated vehicle control aims primarily at optimizing the powertrain and/or the driving profile of the vehicles, possibly using information about the road characteristics, but without communicating with the other agents of the traffic network. Coordinated vehicle control makes use of communication among vehicles and with the infrastructure in order to achieve larger benefits in terms of energy consumption and traffic fluidity.The infrastructure-side management, on the other hand, influences traffic lights and road side panels in order to improve the performance of the traffic as a whole. Isolated infrastructure control regulates essentially the traffic lights at a single signalized intersection, or the speed limits in a single stretch of road, without taking into account the interactions with the neighboring junctions and/or road sections. Coordinated infrastructure control overcomes this limitation by using information about traffic conditions in other road sections to alleviate congestion.The contributions of this work to the energy-aware traffic management may be summarized as follows.Firstly, a solution for the coordinated vehicle control has been proposed, in which communication with the infrastructure is exploited to reduce energy consumption. In particular, the traffic lights timings are assumed to be communicated to the vehicle and known, and the vehicle is suggested an optimal speed to drive through a sequence of signalized intersections without stopping, while following a minimum-energy trajectory. The proposed strategy, independently applied to each vehicle, has been tested in a microscopic traffic simulator in order to assess the impact on the traffic performance. The analysis has demonstrated that the energy consumption and the number of stops can be drastically reduced without affecting the travel time.Then, a solution for the isolated infrastructure control has been proposed. A macroscopic urban traffic model has been introduced, and the variable speed limits have been used as actuation to improve traffic performance. In particular, the analysis has been carried out at saturated traffic conditions, with given and fixed traffic lights scheduling. The optimization aims at reducing the energy consumption in trade-off with the average travel time of the vehicles in the considered road section. Experiments have demonstrated that there exists an optimal speed limit that improves traffic performance and reduces the length of the queue at the traffic light.Lastly, a solution for the coordinated infrastructure control has been proposed. Traffic lights coordination on arterials has been proved to be effective in terms of traffic delay reduction. Our analysis has demonstrated that an optimization problem can be cast to take into account also energetic aspects. Extensive experiments in a microscopic traffic simulator have showed that a correlation exists between traffic progression and traffic performance indexes, such as energy consumption, travel time, idling time, and number of stops. The proposed control strategy has showed that a significant reduction of energy consumption can be achieved, almost completely eliminating number of stops and idling time, without affecting the travel time
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Caldwell, Sean W. "On Traffic Analysis of 4G/LTE Traffic." Cleveland State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=csu1632179249187618.
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Linares, Herreros Mª Paz. "A mesoscopic traffic simulation based dynamic traffic assignment." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/144939.
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In terms of sustainability, traffic is currently a significant challenge for urban areas, where the pollution, congestion and accidents are negative externalities which have strongly impacted the health and economy of cities. The increasing use of private vehicles has further exacerbated these problems.
In this context, the development of new strategies and policies for sustainable urban transport has made transport planning more relevant than ever before. Mathematical models have helped greatly in identifying solutions, as well as in enriching the process of making decisions and planning. In particular, dynamic network models provide a means for representing dynamic traffic behavior; in other words, they provide a temporally coherent means for measuring the interactions between travel decisions, traffic flows, travel time and travel cost. This thesis focuses on dynamic traffic assignment (DTA) models.
DTA has been studied extensively for decades, but much more so in the last twenty years since the emergence of Intelligent Transport Systems (ITS). The objective of this research is to study and analyze the prospects for improving this problem.
In an operational context, the objective of DTA models is to represent the evolution of traffic on a road network as conditions change. They seek to describe the assignment of the demand on different paths which connect every OD pair in a state of equilibrium.
The behaviour following each individual decision during a trip is a time-dependent generalization of Wardrop's First Principle, the Dynamic User Equilibrium (DUE). This hypothesis is based on the following idea: When current travel times are equal and minimal for vehicles that depart within the same time interval , the dynamic traffic flow through the network is in a DUE state based on travel times for each OD pair at each instant of time ([ran-1996]).
This work begins with the time-continuous variational inequalities model proposed by [friesz-1993] for solving the DUE problem. Different solutions can be used on the proposed DUE formulation. On the one hand, there are the so-called analytical approaches which use known mathematical optimization techniques for solving the problem directly. On the other hand, there are simulation-based formulations that approximate heuristic solutions at a reasonable computational cost. While analytical models concentrate mainly on deriving theoretical insights, simulation-based models focus on trying to build practical models for deployment in real networks. Thus, because the simulation-based formulation holds the most promise, we work on that approach in this thesis.
In the field of simulation-based DTA models, significant progress has been made by many researchers in recent decades. Our simulation-based formulation separates the proposed iterative process into two main components:
- A method for determining the new time dependent path flows by using the travel times on these paths experienced in the previous iteration.
- A dynamic network loading (DNL) method, which determines how these paths flow propagate along the corresponding paths.
However, it is important to note that not all computer implementations based on this algorithmic framework provide solutions that obtain DUE. Therefore, while we analyze both proposals in this thesis we focus on the preventive methods of flow reassignment because only those can guarantee DUE solutions.
Our proposed simulation-based DTA method requires a DNL component that can reproduce different vehicle classes, traffic light controls and lane changes. Therefore, this thesis develops a new multilane multiclass mesoscopic simulation model with these characteristics, which is embedded into the proposed DUE framework.
Finally, the developed mesoscopic simulation-based DTA approach is validated accordingly. The results obtained from the computational experiments demonstrate that the developed methods perform well.En los últimos tiempos, el problema del tráfi co urbano ha situado a las áreas metropolitanas en una difícil situación en cuanto a sostenibilidad se refi ere (en términos de la congestión, los accidentes y la contaminación). Este problema se ha visto acentuado por la creciente movilidad promovida por el aumento del uso del vehículo privado. Además, debido a que la mayor parte del trá fico es canalizada a través de los modos de carretera, el tiempo perdido por los usuarios al realizar sus viajes tiene un importante efecto económico sobre las ciudades. En este contexto, la plani cación de transporte se vuelve relevante a través del desarrollo de nuevas estrategias y políticas para conseguir un transporte urbano sostenible. Los modelos matemáticos son de gran ayuda ya que enriquecen las decisiones de los gestores de trá fico en el proceso de plani ficación. En particular podemos considerar los modelos de trá fico para la predicción, como por ejemplo los modelos de asignación dinámica de tráfi co (ADT), los cuales proveen de una representación temporal coherente de las interacciones entre elecciones de trá fico, fl ujos de trá fico y medidas de tiempo y coste. Esta tesis se centra en los modelos ADT. Durante las últimas décadas, los modelos ADT han sido intensamente estudiados. Este proceso se ha acelerado particularmente en los últimos veinte años debido a la aparición de los Sistemas Inteligentes de Transporte. El objetivo de esta investigación es estudiar y analizar diferentes posibilidades de mejorar la resolución del problema. En un contexto operacional, el objetivo de los modelos ADT es representar la evolución de la red urbana cuando las condiciones de trá fico cambian. Estos modelos tratan de describir la asignación de la demanda en los diferentes caminos que conectan los pares OD siguiendo un estado de equilibrio. En este caso se ha considerado que el comportamiento de los conductores en cada una de sus decisiones individuales tomadas durante el viaje es una generalización dependiente del tiempo del Primer Principio de Wardrop, denominada Equilibrio Dinámico de Usuario (EDU). Esta hipótesis se basa en la siguiente idea: para cada par OD para cada instante de tiempo, si los tiempos de viaje de todos los usuarios que han partido en ese intervalo de tiempo son iguales y mínimos, entonces el ujo dinámico de trá fico en la red se encuentra en un estado de EDU basado en los tiempos de viaje (Ran and Boyce (1996)). El presente trabajo toma como punto de partida el modelo de inecuaciones variacionales continuo en el tiempo propuesto por Friesz et al. (1993) para resolver el problema de equilibrio dinámico de usuario. Por un lado, se encuentran los denominados enfoques analíticos que utilizan técnicas matemáticas de optimización para resolver el problema directamente. Por otro lado, están los modelos cuyas formulaciones están basadas en simulación que aproximan soluciones heurísticas con un coste computacional razonable. Mientras que modelos analíticos se concentran principalmente en demostrar las propiedades teóricas, los modelos basados en simulación se centran en intentar construir modelos que sean prácticos para su utilización en redes reales. Así pues, debido a que las formulaciones basadas en simulación son las que se muestran más prometedoras a la práctica, en esta tesis se ha elegido este enfoque para tratar el problema ADT. En los últimos tiempos, el campo de los modelos ADT basados en simulación ha sido de especial interés. Nuestra formulación basada en simulación consiste en un proceso iterativo que consta de dos componentes principales, sistematizadas por Florian et al. (2001) como sigue: Un método para determinar los nuevos ujos (dependientes del tiempo) en los caminos utilizando los tiempos de viaje experimentados en esos caminos en la iteración previa. Un procedimiento de carga dinámica de la red (CDR) que determine cómo esos fl ujos se propagan a través de sus correspondientes caminos. Los algoritmos de reasignación de flujo pueden ser agrupados en dos categorías: preventivos y reactivos. Es importante notar aquí que no todas las implementaciones computacionales basadas en el marco algorítmico propuesto proporcionan una solución EDU. Por lo tanto, aunque en esta tesis analizamos ambas propuestas, nos centraremos en los métodos preventivos de reasignación de flujo porque son los que nos garantizan alcanzar la hipótesis considerada (EDU). Además, nuestro modelo ADT basado en simulación requiere de una componente de CDR que pueda reproducir diferentes clases de vehículos, controles semafóricos y cambios de carril. Así, uno de los objetivos de esta tesis es desarrollar un nuevo modelo de simulación de trá fico con dichas características (multiclase y multicarril), teniendo en cuenta que será una de las componentes principales del marco ADT propuesto.
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Fehr, Alan. "Traffic 3.1 enhancing performance and functionality of traffic /." Zürich : ETH, Eidgenössische Technische Hochschule Zürich, Department of Computer Science, 2003. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=330.
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Manaka, Maakomele R. "Oncoming traffic." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/1021220.
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The poems in my collection Oncoming Traffic mainly look at the silence in my personal conflicts. Fusing different styles and tones of writing from the lyrical to the surreal, these poems grapple with issues I struggle with on a daily basis. First as a man, second as a man with a physical disability, and lastly as a black man dealing with the reality of living in a dysfunctional/disabled society. The silence in my personal conflicts means, writing what I cannot say, stripping myself bare and vulnerable. My inspiration has come from poets who articulate such silences.
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Wen, Keyao. "Traffic Accident Prediction Model Implementation in Traffic Safety Management." Thesis, Linköping University, Communications and Transport Systems, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52203.
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As one of the highest fatalities causes, traffic accidents and collisions always requires a large amounteffort to be reduced or prevented from occur. Traffic safety management routines therefore always needefficient and effective implementation due to the variations of traffic, especially from trafficengineering point of view apart from driver education.Traffic Accident Prediction Model, considered as one of the handy tool of traffic safety management,has become of well followed with interested. Although it is believed that traffic accidents are mostlycaused by human factors, these accident prediction models would help from traffic engineering point ofview to enlarge the traffic safety level of road segments. This thesis is aiming for providing a guidelineof the accident prediction model implementation in traffic safety management, regarding to trafficengineering field. Discussion about how this prediction models should merge into the existing routinesand how well these models would perform would be given. As well, cost benefit analysis of theimplementation would be at the end of this thesis. Meanwhile, a practical field study would bepresented in order to show the procedures of the implementation of traffic accident prediction model.The field study is about this commercial model set SafeNET, from TRL Limited UK, implemented inRoad Safety Audit procedures combined with microscopic simulation tool. Detailed processing andinput and output data will be given accompany with the countermeasures for accident frequencyreduction finalization.
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Hine, Julian Paul. "Traffic barriers : the impact of traffic on pedestrian behaviour." Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1310.
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Su, Ching-fong. "Efficient traffic management based on deterministically constrained traffic flows /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Warsama, Ahmed. "Traffic Engineering with SDN : Optimising traffic Load-Balancing with OpenFlow." Thesis, Mittuniversitetet, Institutionen för informationssystem och –teknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39385.
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The advent of trends such as virtualization, cloud computing, IoT and BYOD has increased the traffic loads on modern enterprise and data-center networks. As the requirements on today’s networks increase, newer designs and solutions have sprout forth. Software-Defined Networking was developed to cater to the needs of modern networks and to improve traffic handling among other things. This study focuses on the ways SDN, specifically the OpenFlow standard, can be used to load-balance and increase the network throughput, in comparison to traditional methods such as Equal-Cost Load-Balancing. This was done by creating a test environment with the network emulator Mininet, and by creating load-balancing programs. The load-balancers were created using the OpenFlow protocol. These programs were used together with the Floodlight controller and were compared in the same environment. The results showed that the bandwidth load-balancer outperformed the Equal-Cost Load-Balancer.
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Axholt, Magnus, and Stephen Peterson. "Modelling Traffic Scenarios for Realistic Air Traffic Control Environment Testing." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2672.
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As air traffic is forecasted to increase, air traffic control software subsequently needs to be more sophisticated. To efficiently push development forward, testing is important in order to determine usability. The tests need to be adapted to fit a particular purpose and carried out with methods that preserve the validity of the results.
This thesis describes an implementation project carried out at the EUROCONTROL Experimental Centre, Bretigny-sur-Orge, France. The purpose of the project is to create an application that enables a user to create datasets of air traffic to be used for these tests. The application allows for manual work or bulk imports from external data sources. Furthermore it compiles scenarios as output datasets intended for prototype air traffic control software developed at Linköping University.
The application design rationale and development process is described. Some time is spent on demonstrating the flexibility of the application and how its usage fits in a bigger picture.
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MacDonald, Gary Douglas. "Modelling the effects on traffic of area-wide traffic-calming." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245708.
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De, Albuquerque Filho Emilio Alverne Falcão. "Analysis of airspace traffic structure and air traffic control techniques." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76097.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 157-163).
Air traffic controller cognitive processes are a limiting factor in providing safe and efficient flow of traffic. Therefore, there has been work in understanding the factors that drive controllers decision-making processes. Prior work has identified that the airspace structure, defined by the reference elements, procedural elements and pattern elements of the traffic, is important for abstraction and management of the traffic. This work explores in more detail this relationship between airspace structure and air traffic controller management techniques. This work looks at the current National Airspace System (NAS) and identifies different types of high altitude sectors, based on metrics that are likely to correlate with tasks that controllers have to perform. Variations of structural patterns, such as flows and critical points were also observed. These patterns were then related to groupings by origins and destinations of the traffic. Deeper pilot-controller voice communication analysis indicated that groupings by flight plan received consistent and repeatable sequences of commands, which were identified as techniques. These repeated modifications generated patterns in the traffic, which were naturally associated with the standard flight plan groupings and their techniques. The identified relationship between flight plan groupings and management techniques helps to validate the grouping structure-base abstraction introduced by Histon and Hansman (2008). This motivates the adoption of a grouping-focused analysis of traffic structures on the investigation of how new technologies, procedures and concepts of operations will impact the way controllers manage the traffic. Consideration of such mutual effects between structure and controllers' cognitive processes should provide a better foundation for training and for engineering decisions that include a human-centered perspective.
by Emilio Alverne Falcão de Albuquerque Filho.
S.M.
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Kundé, Kunal Kamlakar 1978. "Calibration of mesoscopic traffic simulation models for dynamic traffic assignment." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/84839.
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Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.Includes bibliographical references (p. 125-129).
by Kunal Kamlakar Kundé.
S.M.in Transportation
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Ayodele, Emmanuel Gbenga. "Using Bluetooth to estimate traffic metrics for traffic management applications." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3988.
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‘Bluetooth’ is a technology that can be integrated into Intelligent Transport Systems (ITS) to facilitate smarter and enhanced traffic monitoring and management to reduce congestion. The current research focus on Bluetooth is principally on journey time management. However, the applicability and viability of Bluetooth potential in problematic urban areas remains unknown. Besides the generic problem of unavailability of processing algorithms, there is gap in knowledge regarding the variability and errors in Bluetooth-derived metrics. These unknown errors usually cause uncertainty about the conclusions drawn from the data. Therefore, a novel Bluetooth-based vehicle detection and Traffic Flow Origin-destination Speed and Travel-time (TRAFOST) model was developed to estimate and analyse key traffic metrics. This research utilised Bluetooth data and other independently measured traffic data collected principally from three study sites in Greater Manchester, UK. The Bluetooth sensors at these locations generated vehicle detection rates (7-16%) that varied temporally and spatially, based on the comparison with flows from ATC (Automatic Traffic Counters) and SCOOT (Split Cycle Offset Optimisation Technique) detectors. Performance evaluation of the estimation showed temporal consistency and accuracy at a high level of confidence (i.e. 95%) based on criteria such as Mean Absolute Deviation (MAD) - (0.031 – 0.147), Root Mean Square Error (RMSE) - (0.041 – 0.195), Mean Absolute Percentage Error (MAPE) - (0.822 – 4.917) and Kullback-Leibler divergence (KL-D) (0.004 – 0.044). This outcome provides evidence of reliability in the results as well as justification for further investigation of Bluetooth applications in ITS. However, the resulting accuracy depends significantly on sample size, network characteristics, and traffic flow regimes. The Bluetooth approach has enabled a deeper understanding of traffic flow regimes and spatio-temporal variations within the Greater Manchester Networks than is possible using conventional traffic data such as from SCOOT. Therefore, the application of Bluetooth technology in ITS to enhance traffic management to reduce congestion is a viable proposition and is recommended.
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Alammari, Ali. "Traffic Forecasting Applications Using Crowdsourced Traffic Reports and Deep Learning." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703305/.
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Intelligent transportation systems (ITS) are essential tools for traffic planning, analysis, and forecasting that can utilize the huge amount of traffic data available nowadays. In this work, we aggregated detailed traffic flow sensor data, Waze reports, OpenStreetMap (OSM) features, and weather data, from California Bay Area for 6 months. Using that data, we studied three novel ITS applications using convolutional neural networks (CNNs) and recurrent neural networks (RNNs). The first experiment is an analysis of the relation between roadway shapes and accident occurrence, where results show that the speed limit and number of lanes are significant predictors for major accidents on highways. The second experiment presents a novel method for forecasting congestion severity using crowdsourced data only (Waze, OSM, and weather), without the need for traffic sensor data. The third experiment studies the improvement of traffic flow forecasting using accidents, number of lanes, weather, and time-related features, where results show significant performance improvements when the additional features where used.
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Alizadeh, Hassan. "Intrusion detection and traffic classification using application-aware traffic profiles." Doctoral thesis, Universidade de Aveiro, 2018. http://hdl.handle.net/10773/23545.
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Doutoramento em Engenharia Eletrotécnica no âmbito do programa doutoral MAP-teleAlong with the ever-growing number of applications and end-users, online network attacks and advanced generations of malware have continuously proliferated. Many studies have addressed the issue of intrusion detection by inspecting aggregated network traffic with no knowledge of the responsible applications/services. Such systems may detect abnormal tra c, but fail to detect intrusions in applications whenever their abnormal traffic ts into the network normality profiles. Moreover, they cannot identify intrusion-infected applications responsible for the abnormal traffic. This work addresses the detection of intrusions in applications when their traffic exhibits anomalies. To do so, we need to: (1) bind traffic to applications; (2) have per-application traffic profiles; and (3) detect deviations from profiles given a set of traffic samples. The first requirement has been addressed in our previous works. Assuming that such binding is available, this thesis' work addresses the last two topics in the detection of abnormal traffic and thereby identify its source (possibly malware-infected) application. Applications' traffic profiles are not a new concept, since researchers in the field of Traffic Identification and Classification (TIC) make use of them as a baseline of their systems to identify and categorize traffic samples by application (types-of-interest). But they do not seem to have received much attention in the scope of intrusion detection systems (IDS). We first provide a survey on TIC strategies, within a taxonomy framework, focusing on how the referred TIC techniques could help us for building application's traffic profiles. As a result of this study, we found that most TIC methodologies are based on some statistical (well-known) assumptions extracted from different traffic sources and make the use of machine learning techniques in order to build models (profiles) for recognition of either application types-of-interest or application-layer protocols. Moreover, the literature of traffic classification observed some traffic sources (e.g. first few packets of ows and multiple sub- ows) that do not seem to have received much attention in the scope of IDS research. An IDS can take advantage of such traffic sources in order to provide timely detection of intrusions before they propagate their infected traffic. First, we utilize conventional Gaussian Mixture Models (GMMs) to build per-application profiles. No prior information on data distribution of each application is available. Despite the improvement in performance, stability in high-dimensional data and calibrating a proper threshold for intrusion detection are still main concern. Therefore, we improve the framework restoring universal background model (UBM) to robustly learn application specific models. The proposed anomaly detection systems are based on class-specific and global thresholding mechanisms, where a threshold is set at Equal Error Rate (EER) operating point to determine whether a ow claimed by an application is genuine. Our proposed modelling approaches can also be used in a traffic classification scenario, where the aim is to assign each specific ow to an application (type-of-interest). We also investigate the suitability of the proposed approaches with just a few, initial packets from a traffic ow, in order to provide a more eficient and timely detection system. Several tests are conducted on multiple public datasets collected from real networks. In the numerous experiments that are reported, the evidence of the efectiveness of the proposed approaches are provided.
Em paralelo com o número crescente de aplicações e usuários finais, os ataques em linha na Internet e as gerações avançadas de malware têm proliferado continuadamente. Muitos estudos abordaram a questão da detecção de intrusões através da inspecção do tráfego de rede agregado, sem o conhecimento das aplicações / serviços responsáveis. Esses sistemas podem detectar tráfego anormal, mas não conseguem detectar intrusões em aplicações sempre que seu tráfego anormal encaixa nos perfis de normalidade da rede. Além disso, eles não conseguem identificar as aplicações infectadas por intrusões que são responsáveis pelo tráfego anormal. Este trabalho aborda a detecção de intrusões em aplicações quando seu tráfego exibe anomalias. Para isso, precisamos: (1) vincular o tráfego a aplicações; (2) possuir perfis de tráfego por aplicação; e (3) detectar desvios dos perfis dado um conjunto de amostras de tráfego. O primeiro requisito foi abordado em trabalhos nossos anteriores. Assumindo que essa ligação esteja disponível, o trabalho desta tese aborda os dois últimos tópicos na detecção de tráfego anormal e, assim, identificar a sua aplicação fonte (possivelmente infectada por um malware). Os perfis de tráfego das aplicações não são um conceito novo, uma vez que os investigadores na área da Identificação e Classificação de Tráfego (TIC) utilizam-nos nos seus sistemas para identificar e categorizar amostras de tráfego por tipos de aplicações (ou tipos de interesse). Mas eles não parecem ter recebido muita atenção no âmbito dos sistemas de detecção de intrusões (IDS). Assim, primeiramente fornecemos um levantamento de estratégias de TIC, dentro de uma estrutura taxonómica, tendo como foco a forma como as técnicas de TIC existentes nos poderiam ajudar a lidar com perfis de tráfego de aplicações. Como resultado deste estudo, verificou-se que a maioria das metodologias TIC baseia-se nalguns pressupostos estatísticos (bem conhecidos) extraídos de diferentes fontes de tráfego e usam técnicas de aprendizagem automática para construir os modelos (perfis) para o reconhecimento de quaisquer tipos de interesse ou protocolos aplicacionais. Além disso, a literatura de classificação de tráfego analisou algumas fontes de tráfego (por exemplo, primeiros pacotes de fluxos e subfluxos múltiplos) que não parecem ter recebido muita atenção no âmbito da IDS. Um IDS pode aproveitar essas fontes de tráfego para fornecer detecção atempada de intrusões antes de propagarem o seu tráfego infectado. Primeiro, utilizamos modelos convencionais de mistura gaussiana (GMMs) para construir perfis por aplicação. Nenhuma informação prévia sobre a distribuição de dados de cada aplicação estava disponível. Apesar da melhoria no desempenho, a estabilidade com dados de alta dimensionalidade e a calibração de um limiar adequado para a detecção de intrusões continuaram a ser um problema. Consequentemente, melhoramos a infraestrutura de detecção através da introdução do modelo basal universal (UBM) para robustecer a aprendizagem do modelo especifico de cada aplicação. As abordagens de modelação que propomos também podem ser usadas cenários de classificação de trafego, onde o objectivo e atribuir cada fluxo especifico a uma aplicação (tipo de interesse). Os sistemas de detecção de anomalias propostos baseiam-se em mecanismos de limiar específicos de classes e globais, nos quais um limiar e definido no ponto de operação da Taxa de Erros Igual (EER) para determinar se um fluxo reivindicado por uma aplicação é genuíno. Também investigamos a adequação das abordagens propostas com apenas alguns pacotes iniciais de um fluxo de trafego, a fim de proporcionar um sistema de detecção mais eficiente e oportuno. Para avaliar a eficácia das aproximações tomadas realizamos vários testes com múltiplos conjuntos de dados públicos, colectados em redes reais. Nas numerosas experiências que são relatadas, são fornecidas evidências da eficácia das abordagens propostas.
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Golden, Gaylynn. "Effects of driver characteristics and traffic composition on traffic flow." Master's thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-10242009-020010/.
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Respati, Sara Wibawaning. "Network-scale arterial traffic state prediction: Fusing multisensor traffic data." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/202990/1/Sara%20Wibawaning_Respati_Thesis.pdf.
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Road traffic congestion is an increasing societal problem. Road agencies and users seeks accurate and reliable travel speed information. This thesis developed a network-scale traffic state prediction based on Convolutional Neural Network (CNN). The method can predict the speed over the network accurately by preserving road connectivity and incorporating historical datasets. When dealing with an extensive network, the thesis also developed a clustering method to reduce the complexity of the prediction. By accurately predict the traffic state over a network, traffic operators can manage the network more effectively and travellers can make informed decision on their journeys.
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Floreteng, Nina. "Hur lär vi våra barn hantera trafikmiljön : Del II: En fallstudie om förskolebarns trafikförståelse." Thesis, Uppsala universitet, Institutionen för pedagogik, didaktik och utbildningsstudier, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182194.
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Utgångspunkten i mina arbeten om barn och trafik har varit trafiksäkerheten som ett genomgripande samhällsproblem, med barnens utsatta läge i fokus. Arbetet är uppdelat i två delar, där ett examensarbete på C-nivå, som är en översikt, utgör Del I. Del II utgörs av detta examensarbete på D-nivå och består av en empirisk undersökning om förskolebarns trafikförståelse. Syftet med föreliggande studie har varit att undersöka femåriga förskolebarns trafikförståelse utifrån tre olika aktörers perspektiv: barnens, förskolans och föräldrarnas. De frågeställningar som studerades var: vilka föreställningar som barnen har om trafik; hur barnen har tillägnat sig dessa föreställningar; hur barnen uppträder i trafiken samt hur förskolepersonalen och föräldrar arbetar med barnens trafikfostran. För att få svar på frågeställningarna genomfördes en fallstudie på en förskola där åtta barn, barnens två förskollärare samt tre föräldrar intervjuades. Dessutom observerades barnen under en trafikutflykt och deras trafikteckningar analyserades. Resultatet pekar på att förskolebarnen hade tillägnat sig såväl kunskaper som missförstånd om trafiken. Barnen uppfattade att trafik i första hand är motorfordon och vägar men såg inte sig själva som en del av trafiken. De kände till att trafiken har ett inneboende regelsystem, men förstod inte i samma utsträckning upphovet och orsaken till detsamma. Barnen visade stort intresse för trafiksignaler, men alla barn greppade inte innebörden av den gula färgen. Barnen i denna studie förstod att vägmärken har en symbolisk innebörd, där märkena med abstrakta symboler var svårast att tolka korrekt. Svårigheter med att särskilja höger och vänster framträdde också i studien. Med avseende på cykelhjälmsanvändning ansåg barnen att hjälmen endast hade till uppgift att skydda dem vid osäker cykling. Barnen hade inhämtat sina kunskaper och föreställningar från många olika, och ibland oväntade källor, huvudsakligen hemmet och förskolan. Barnens observerade vistelse i trafiken förflöt smidigt, där förskolans användning av reflexvästar och grupperingarna vid promenader framstod som invanda och användbara rutiner. Förskolans och hemmets trafikfostran genomfördes som praktisk träning i verklig trafikmiljö, företrädesvis genom promenader, bussresor och cykling. På förskolan var den vuxne en större auktoritet i trafiken än som annars är brukligt. Ibland arbetade förskolan med osynliga gränsdragningar som ett pedagogiskt verktyg för att skydda barnen i trafiken.Traffic safety, viewed as a radical community problem, has been the starting-point in this work, with children’s vulnerable position in focus. This work is divided into two parts. Part I is an examination paper on C-level, consisting of a survey within this field. Part II consists of this examination paper on D-level, an empirical study about pre-school children’s understanding of traffic. The aim of the present work has been to study five-year-old pre-school children’s understanding of traffic, as viewed from the perspective of three different groups, the children, the pre-school teachers and the parents. The questions at issue were: the children’s conceptions of traffic and how those conceptions have been acquired, the children’s conduct in traffic, and how pre-school teachers and parents work with children’s traffic training. To answer those questions a case study was accomplished at a pre-school, where eight children, two pre-school teachers and three parents were interviewed. Moreover, I made a field study of the children during their walks in traffic and analyzed their traffic drawings. The results show that the pre-school children had acquired knowledge as well as misunderstandings about traffic. The children understood traffic as consisting of motor vehicles and roads but did not comprehend themselves as a traffic element. They knew that traffic has an inherent system of rules but did not to the same extent understand the origin or cause of those rules. The children were deeply interested in traffic lights but all children did not grasp the meaning of the yellow light. The children in my study understood that road signs have a symbolic message and road signs with abstract symbols were the most difficult to interpret correctly. Difficulties in distinguishing between right and left also appeared in the study. In regards to the use of bicycle helmets the children believed the sole purpose of the helmet was to protect them during unsteady cycling. The children had acquired their knowledge and conceptions from many different sources, mainly from the home and the pre-school. The observed traffic walks of the children passed smoothly, where the use of reflex vests and the groupings during the walks appeared to be ingrained and useful routines. The education of the pre-school and the home was carried through as practical training in the real traffic environment, preferably through walks, bus rides and cycling. In pre-school, the adult was a greater authority in the traffic situation than normally the case. Sometimes the pre-school worked with invisible delimitations as an educational tool with the purpose of protecting the children when in the traffic setting.
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Grandinetti, Pietro. "Control of large scale traffic network." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT102/document.
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La thèse concerne le contrôle de feux tricolores dans de larges réseaux urbains. Le point de départ est l’étude d’un modèle macroscopique se basant sur le Cell Transmission model. Nous avons formulé une version du modèle intégrant les feux tricolores à sa dynamique. De plus, nous avons introduit deux simplifications à ce modèle orientées vers la conception des techniques de contrôle ; la première se base sur la théorie de la moyenne et considère le pourcentage de vert des feux tricolores, la seconde décrit les trajectoires des feux tricolores en utilisant les instants d’activation et de désactivation d’un signal binaire. Nous utilisons des simulations numériques pour valider les modèles en les comparant avec le Cell Transmisson model intégrant les feux tricolores, ainsi que des simulations microscopiques (avec le logiciel Aimsun) afin de valider les mêmes modèles en les comparant cette fois-ci à un comportement réaliste des véhicules.Nous proposons deux techniques de contrôle à partir des deux modèles mentionnés ci-dessus. Le premier, qui utilise le modèle moyen de transmission de véhicules, considère les pourcentages de vert des feux tricolores comme variables contrôlées, et il est formulé comme un problème d'optimisation des mesures de trafic standards. Nous analysons un tel problème et nous montrons que cela équivaut à un problème d'optimisation convexe, afin d'assurer son efficacité de calcul. Nous analysons sa performance par rapport à un best-practice control à la fois dans des simulations MatLab, et dans des simulations microscopiques, avec un modèle Aimsun qui reproduit une grande partie de Grenoble, en France. La deuxième approche proposée est un problème d'optimisation dans lequel les variables contrôlées sont les instants d'activation et de désactivation de chaque feu tricolore. Nous utilisons la technique de modélisation Big-M dans le but de formuler un tel problème comme un programme linéaire avec variables entières, et nous montrons par des simulations numériques que l’expressivité de cette optimisation conduit à des améliorations de la dynamique du trafic, au prix de l'efficacité de calcul.Pour poursuivre la scalabilité des techniques de contrôle proposées nous développons deux algorithmes itératifs pour le problème de contrôle des feux de signalisation. Le premier, basé sur l'optimisation convexe mentionnée ci-dessus, utilise la technique dual descent et nous prouvons qu’il est optimal, i.e., il donne la même solution que l'optimisation centralisée. Le second, basé sur le problème d’optimisation entier susmentionné, est un algorithme sous-optimal qui mène à des améliorations substantielles par rapport au problème centralisé connexe, concernant l'efficacité de calcul. Nous analysons par des simulations numériques la vitesse de convergence des algorithmes itératifs, leur charge de calcul et leurs performances en matière de mesure du trafic.La thèse est conclue avec une étude de l'algorithme de contrôle des feux de circulation qui est utilisé dans plusieurs grandes intersections dans Grenoble. Nous présentons le principe de fonctionnement d'un tel algorithme, en détaillant les différences technologiques et méthodologiques par rapport aux approches proposées. Nous créons dans Aimsun le scénario représentant la partie intéressée de la ville, en reproduisant également l'algorithme de contrôle et en comparant ses performances avec celles de l'une de nos approches sur le même scénarioThe thesis focuses on traffic lights control in large scale urban networks. It starts off with a study of macroscopic modeling based on the Cell Transmission model. We formulate a signalized version of such a model in order to include traffic lights’ description into the dynamics. Moreover, we introduce two simplifications of the signalized model towards control design, one that is based on the average theory and considers duty cycles of traffic lights, and a second one that describes traffic lights trajectories with the time instants of the rising and falling edges of a binary signals. We use numerical simulations to validate the models with respect to the signalized Cell Transmission model, and microsimulations (with the software Aimsun), to validate the same model with respect to realistic vehicles’ behavior.We propose two control algorithms based on the two models above mentioned. The first one, that uses the average Cell Transmission model, considers traffic lights’ duty cycles as controlled variables and it is formulated as an optimization problem of standard traffic measures. We analyze such a problem and we show that it is equivalent to a convex optimization problem, so ensuring its computational efficiency. We analyze its performance with respect to a best-practice control scheme both in MatLab simulations and in Aimsun simulations that emulate a large portion of Grenoble, France. The second proposed approach is an optimization problem in which the decision variables are the activation and deactivation time instants of every traffic lights. We employ the Big-M modeling technique to reformulate such a problem as a mixed integer linear program, and we show via numerical simulations that the expressivity of it can lead to improvements of the traffic dynamics, at the price of the computational efficiency of the control scheme.To pursue the scalability of the proposed control techniques we develop two iterative distributed approaches to the traffic lights control problem. The first, based on the convex optimization above mentioned, uses the dual descent technique and its provably optimal, that is, it gives the same solution of the centralized optimization. The second, based on the mixed integer problem aforesaid, is a suboptimal algorithm that leads to substantial improvements by means of the computational efficiency with respect to the related centralized problem. We analyze via numerical simulations the convergence speed of the iterative algorithms, their computational burden and their performance regarding traffic metrics.The thesis is concluded with a study of the traffic lights control algorithm that is employed in several large intersections in Grenoble. We present the working principle of such an algorithm, detailing technological and methodological differences with our proposed approaches. We create into Aimsun the scenario representing the related part of the city, also reproducing the control algorithm and comparing its performance with the ones given by one of our approaches on the same scenario
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Löfås, Peter. "Advanced Traffic Service." Thesis, Linköping University, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-374.
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More and more travellers use navigation-aid software to find the way while driving. Most of todays systems use static maps with little or no information at all about currently yeilding roads conditions and disturbances in the network. It is desirable for such services
in the future to include information about road works, accidents, surface conditions and other types of events that affects what route is currently the best.
It is also desirable to notify users about changes in the prerequisites of the chosen route after they have started their trip.
This thesis investigates methods to include dynamic traffic information in route calculations and notifying users when the characteristics change for their chosen route.
The thesis utilizes dynamic traffic information from The Swedish Road Agencys (Vägverket) central database for traffic information, TRISS and calculates affected clients with help of positioning through the GSM network.
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Aydin, Ufuk Suat. "Traffic Sign Recognition." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610590/index.pdf.
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Designing smarter vehicles, aiming to minimize the number of driverbased wrong decisions or accidents, which can be faced with during the drive, is one of hot topics of today&rsquos automotive technology. In the design of smarter vehicles, several research issues can be addressed
one of which is Traffic Sign Recognition (TSR). In TSR systems, the aim is to remind or warn drivers about the restrictions, dangers or other information imparted by traffic signs, beforehand. Since the existing signs are designed to draw drivers&rsquo
attention by their colors and shapes, processing of these features is one of the crucial parts in these systems. In this thesis, a Traffic Sign Recognition System, having ability of detection and identification of traffic signs even with bad visual artifacts those originate from some weather conditions or other circumstances, is developed. The developed algorithm in this thesis, segments the required color influenced by the illumination of the environment, then reconstructs the shape of partially occluded traffic sign by its remaining segments and finally, identifies it. These three stages are called as &ldquo
Segmentation&rdquo
, &ldquo
Reconstruction&rdquo
and &ldquo
Identification&rdquo
respectively, within this thesis. Due to the difficulty of analyzing partial segments to construct the main frame (a whole sign), the main complexity of the algorithm takes place in the &ldquo
Reconstruction&rdquo
stage.
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Crespo, Ramírez Daniel. "Smartphone traffic patterns." Thesis, KTH, Kommunikationssystem, CoS, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91051.
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The growing popularity of new generation mobile terminals, known as „smartphones‟,has increased the variety and number of such devices. These devices make use of the resources offered by Universal Mobile Telecommunication Services (UMTS) networks toaccess on-line services such as web browsing, e-mail, audio and video streaming, etc. UMTS networks have to deal with an increasing amount of data traffic generated by smartphones. Because of the fact that the smartphone is battery powered and is trying to satisfy the needs ofboth applications and human users there is a need to be smarter about how to manage both network and terminal resources. This thesis explores the possibility of making a better use of the network and terminal resources by exploiting correlations in the events of the smartphone-generated traffic. We propose a mechanism, through which the network can predict if a terminal is going to produce data transmission or reception in a near future, based on past events in its traffic. According to this prediction, the network will be able to decide if it keeps or releases the resources allocated to the terminal. We analyze the benefits from the network and the terminal point ofview. We also describe a method to estimate an upper bound of the time until the next transmission or reception of data in a near future. We show that it is possible a reduction of the time that each terminal wastes in its maximum power consumption state, but this reduction implies a penalty in the transmission/reception throughput of the terminal. The reduction is not uniform for all terminals: terminals whose traffic presents a predictable behavior gain the most. Estimates of upper bounds of time until the next transmission or reception are more accurate if they are made taking as input information about interarrival times of previous packets.Den växande populariteten för nya generationens mobila terminaler, så kallade"smartphones", har ökat både antal och sådana produkter. Dessa enheter utnyttjar de resursersom Universal Mobile Telecommunication Services (UMTS) att få tillgång till on-line tjänster såsom web webbläsning, e-post, ljud och video streaming, osv. UMTS-nät har hantera med en ökande mängd data som genereras trafik bysmartphones. På grund av det faktum attsmartphone är batteridriven och försöker för att tillgodose behoven hos både applikationer och mänskliga användare det finns ett behov att vara smartare om hur man kan hantera både nätverk och terminaler resurser. Den avhandling undersöker möjligheten att göra en bättre användning av nätverk och terminaler resurser genom att utnyttja samband i händelserna smartphone-genererade trafik. Vi föreslår en mekanism genom vilken nätet kan förutsäga om terminalen kommer att ta fram dataöverföring orreception i en nära framtid, baserat på tidigare händelser i trafiken. Enligt denna förutsägelse, kommer nätet att kunna avgöra om den håller eller frigör resurser till terminalen. Vi analyserar nytta nätet och terminalen synvinkel. Vi beskriver också en metod för att uppskatta övre gränsen för tiden till nästa sändning eller mottagning av data inom ens nar framtidd. Vi visar att det är möjligt att minska den tid som varje terminal avfall i sin maximal strömförbrukning staten, men denna minskning innebär en straffavgift överföring /mottagning genomströmning av terminalen. Minskningen är notuniform för alla terminaler där trafiken utgör en förutsägbart beteende vinna mest. Uppskattningar av övre gränserna för tid untilthe nästa sändning eller mottagning är mer exakta om de görs tar som indata information om interarrival gånger tidigare paket.
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Mortier, Richard Michael. "Internet traffic engineering." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620378.
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chiluka, srikanthreddy. "Traffic Sign Recognition." Thesis, Blekinge Tekniska Högskola, Institutionen för matematik och naturvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-21343.
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Smart vehicles with capabilities of autonomous driving are a big revolution in automobile industry. The vehicles can sense their environment and react based on it. It replaces the manual driver. Recognition of traffic sign is an important enabler for autonomous driving. Camera installed in the vehicle captures the traffic sign on the road and they must be recognized accurately for triggering the suitable action. In this thesis both image processing and Euclidean distance matching are used to pre-process and classify the traffic signs and thresholding and thinning are applied on image for feature extraction. In this work, a simple, efficient traffic sign recognition system with low computational time and to achieve good accuracy is proposed. Time to classify the traffic sign is achieved in milliseconds and accuracy is maintained using the proposed system. Keywords: Autonomous Driving, Image processing, Thresholding, Thinning, Euclidean distance matching.
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Farzaneh, Mohamadreza. "Modeling Traffic Dispersion." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29757.
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The dissertation studies traffic dispersion modeling in four parts. In the first part, the dissertation focuses on the Robertson platoon dispersion model which is the most widely used platoon dispersion model. The dissertation demonstrates the importance of the Yu and Van Aerde calibration procedure for the commonly accepted Robertson platoon dispersion model, which is implemented in the TRANSYT software. It demonstrates that the formulation results in an estimated downstream cyclic profile with a margin of error that increases as the size of the time step increases. In an attempt to address this shortcoming, the thesis proposes the use of three enhanced geometric distribution formulations that explicitly account for the time-step size within the modeling process. The proposed models are validated against field and simulated data.
The second part focuses on implementation of the Robertson model inside the popular TRANSYT software. The dissertation first shows the importance of calibrating the recurrence platoon dispersion model. It is then demonstrated that the value of the travel time factor β is critical in estimating appropriate signal-timing plans. Alternatively, the dissertation demonstrates that the value of the platoon dispersion factor α does not significantly affect the estimated downstream cyclic flow profile; therefore, a unique value of α provides the necessary precision. Unfortunately, the TRANSYT software only allows the user to calibrate the platoon dispersion factor but does not allow the user to calibrate the travel time factor. In an attempt to address this shortcoming, the document proposes a formulation using the basic properties of the recurrence relationship to enable the user to control the travel time factor indirectly by altering the link average travel time.
In the third part of the dissertation, a more general study of platoon dispersion models is presented. The main objective of this part is to evaluate the effect of the underlying travel time distribution on the accuracy and efficiency of platoon dispersion models, through qualitative and quantitative analyses. Since the data used in this study are generated by the INTEGRATION microsimulator, the document first describes the ability of INTEGRATION in generating realistic traffic dispersion effects. The dissertation then uses the microsimulator generated data to evaluate the prediction precision and performance of seven different platoon dispersion models, as well as the effect of different traffic control characteristics on the important efficiency measures used in traffic engineering. The results demonstrate that in terms of prediction accuracy the resulting flow profiles from all the models are very close, and only the geometric distribution of travel times gives higher fit error than others. It also indicates that for all the models the prediction accuracy declines as the travel distance increases, with the flow profiles approaching normality. In terms of efficiency, the travel time distribution has minimum effect on the offset selection and resulting delay. The study also demonstrates that the efficiency is affected more by the distance of travel than the travel time distribution.
Finally, in the fourth part of the dissertation, platoon dispersion is studied from a microscopic standpoint. From this perspective traffic dispersion is modeled as differences in desired speed selection, or speed variability. The dissertation first investigates the corresponding steady-state behavior of the car-following models used in popular commercially available traffic microsimulation software and classifies them based on their steady-state characteristics in the uncongested regime. It is illustrated that with one exception, INTEGRATION which uses the Van Aerde car-following model, all the software assume that the desired speed in the uncongested regime is insensitive to traffic conditions. The document then addresses the effect of speed variability on the steady-state characteristics of the car-following models. It is shown that speed variability has significant influence on the speed-at-capacity and alters the behavior of the model in the uncongested regime. A method is proposed to effectively consider the influence of speed variability in the calibration process in order to control the steady-state behavior of the model. Finally, the effectiveness and validity of the proposed method is demonstrated through an example application.Ph. D.
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Vishwanath, Kashi Venkatesh. "Demystifying Internet traffic." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3320633.
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Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed September 24, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 133-142).
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Sanchez, Alex M. "Projection of truck traffic volumes at interstate permanent automatic traffic recorders." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4472.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains x, 111 p. : ill. (some col.), map (part col.). Includes abstract. Includes bibliographical references (p. 93-94).
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Liu, Yan. "Highway Capacity and Traffic Behavior under Connected and Automated Traffic Environment." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627667986751621.
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Bylund, Björn, and Nicklas Blomqvist. "Design and Implementation of a Traffic Generator using Unified Traffic Modelling." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119297.
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This thesis describes the design and implementation of a traffic generator that can simulate the traffic of tens of thousands of networking devices from a given traffic model. It is designed to handle traffic models created with Unified Traffic Modelling. The traffic generator is then evaluated and different solutions are compared in an effort to find the best solution for each issue. This thesis is meant to serve as a guideline for future development of traffic generators by providing insight into the problems faced during the development of one.
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Wall, Zach R. "Traffic management and control utilizing a microscopic model of traffic dynamics /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5922.
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Chow, Lee-Fang. "Integrating adaptive queue-responsive traffic signal control with dynamic traffic assignment." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001280.
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Zhou, Xiao Yi. "Statistical analysis of traffic loads and traffic load effects on bridges." Phd thesis, UNIVERSITE PARIS-EST, 2013. http://tel.archives-ouvertes.fr/tel-00949929.
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Une grande majorité (85%) des ponts français a une portée inférieure à 50 m. Pour ce type d’ouvrage d’art, la charge de trafic peut être déterminante pour la conception et le recalcul. Or, en Europe, le fret routier a augmenté de 36.2% entre 1995 et 2010, et la croissance annuelle du volume transporté par la route a été évaluée à 1.7% entre 2005 et 2030. Il est donc essentiel de s’assurer que les infrastructures européennes sont en mesure de répondre à cette demande croissante en capacité structurelle des ouvrages. Pour les ouvrages neufs, les modèles de trafic dans les normes ou les législations pour la conception des ponts incluent une marge de sécurité suffisante pour que la croissance du trafic soit prise en compte sans dommage par ces ouvrages. Mais pour les ouvrages existants, la résistance structurelle aux trafics actuels et futur est à vérifier et une priorisation des mesures doit être faite pour assurer leur intégrité structurelle et leur sécurité. De plus, afin de préserver leur infrastructure tout en ne menaçant pas leur compétitivité nationale, certains pays réfléchissent à l’introduction de poids lourds plus longs, plus lourds, ce qui permet de réduire le nombre de véhicules pour un volume ou un tonnage donné, ainsi que d’autres coûts (d’essence, de travail, ..), ce qui justifie encore plus les calculs effectués. Pour répondre à ce genre de problématique, différentes méthodes d’extrapolation ont déjà été utilisées pour modéliser les effets extrêmes du trafic, afin de déterminer les effets caractéristiques pour de grandes périodes de retour. Parmi celles-ci nous pouvons citer l’adaptation d’une gaussienne ou d’une loi de Gumbel sur la queue de distribution empirique, la formule de Rice appliquée à l’histogramme des dépassements de niveaux, la méthode des maxima par blocs ou celle des dépassements de seuils élevés. Les fondements et les utilisations faites de ces méthodes pour modéliser les effets extrêmes du trafic sur les ouvrages sont donnés dans un premier chapitre. De plus, une comparaison quantitative entre ces méthodes est réalisée. Deux études sont présentées, l’une basée sur un échantillon numérique et l’autre sur un échantillon réaliste d’effets du trafic. L’erreur induite par ces méthodes est évaluée à l’aide d’indicatifs statistiques simples, comme l’écart-type et les moindres carrés, évalués sur les valeurs caractéristiques et les probabilités de rupture. Nos conclusions sont, qu’en général, les méthodes sont moins précises lorsqu’il s’agit de déterminer des probabilités de rupture que lorsqu’elles cherchent des valeurs caractéristiques. Mais la raison peut en être les faibles probabilités recherchées (10-6 par an). De plus, bien qu’aucune méthode n’ait réalisée des extrapolations de manière correcte, les meilleures sont celles qui s’intéressent aux queues de probabilités, et en particulier des dépassements au-dessus d’un seuil élevé. Ainsi une étude de cette dernière méthode est réalisée : en effet, cette méthode, nommé "dépassements d’un seuil élevé", considère que les valeurs au-dessus d’un seuil correctement choisi, assez élevé, suit une distribution de Pareto généralisée (GPD). Cette méthode est utilisée de manière intensive dans les domaines de l’hydrologie et la finance, mais non encore appliquée dans le domaine des effets du trafic sur les ouvrages. Beaucoup de facteurs influencent le résultat lorsqu’on applique cette méthode, comme la quantité et la qualité des données à notre disposition, les critères utilisés pour déterminer les pics indépendants, l’estimation des paramètres et le choix du seuil. C’est pour cette raison qu’une étude et une comparaison des différentes méthodes d’estimation des paramètres de la distribution GPD sont effectuées : les conditions, hypothèses, avantages et inconvénients des différentes méthodes sont listés. Différentes méthodes sont ainsi étudiées, telles la méthode des moments (MM), la méthode des moments à poids (PWM), le maximum de vraisemblance (ML), le maximum de vraisemblance pénalisé (PML), le minimum de la densité de la divergence (MDPD), la méthode des fractiles empiriques (EPM), la statistique du maximum d’adaptation et la vraisemblance des moments (LM). Pour comparer ces méthodes, des échantillons numériques, des effets de trafic simulés par Monte Carlo et des effets mesurés sur un ouvrage réel sont utilisés. Comme prévu, les méthodes ont des performances différentes selon l’échantillon considéré. Néanmoins, pour des échantillons purement numériques, MM et PWM sont recommandées pour des distributions à paramètre de forme négatif et des échantillons de petite taille (moins de 200 valeurs). ML est conseillé pour des distributions à paramètre de forme positif. Pour des effets du trafic simulés, ML et PML donne des valeurs de retour plus correctes lorsque le nombre de valeurs au-dessus du seuil est supérieur à 100 ; dans le cas contraire, MM et PWM sont conseillés. De plus, comme c’est prouvé dans l’étude de valeurs réelles mesurées, les valeurs a priori aberrantes ("outliers") ont une influence notable sur le résultat et toutes les méthodes sont moins performantes. Comme cela a été montré dans la littérature, ces "outliers" proviennent souvent du mélange de deux distributions, qui peuvent être deux sous-populations. Dans le cas de l’effet du trafic sur les ouvrages, cela peut être la raison d’une estimation des paramètres non correcte. Les articles existant sur le sujet soulignent le fait que les effets du trafic sont dus à des chargements indépendants, qui correspondant au nombre de véhicules impliqués. Ils ne suivent pas la même distribution, ce qui contredit l’hypothèse classique en théorie des valeurs extrêmes que les événements doivent être indépendants et identiquement distribués. Des méthodes permettant de prendre en compte ce point et utilisant des distributions mélangées (exponentielles ou valeurs extrêmes généralisées) ont été proposées dans la littérature pour modéliser les effets du trafic. Nous proposons une méthode similaire, que nous appelons dépassement de seuils mélangés, afin de tenir des différentes distributions sous-jacentes dans l’échantillon tout en appliquant à chacune d’entre elles la méthode des dépassements de seuil. Pour des ponts ayant des portées supérieures à 50 m, le scénario déterminant est celui de la congestion, qui n’est pas ce qui est étudié ici. De plus, le trafic n’est pas la composante déterminante pour la conception des ponts de longue portée. Mais des problèmes de fatigue peuvent apparaître dans certains ponts, tels les ponts métalliques à dalle orthotrope, où l’étude du trafic peut devenir nécessaire. Ainsi nous avons fait une étude de l’influence de la position des véhicules sur le phénomène de fatigue. Pour cela, quatre fichiers de trafic réels, mesurés en 2010 et 2011 par quatre stations de pesage différentes, ont été utilisés. Ils ont mis à jour des comportements latéraux différents d’une station à l’autre. Si nous les appliquons au viaduc de Millau, qui est un pont métallique à haubans et à dalle orthotrope, nous voyons que l’histogramme des effets et l’effet de fatigue cumulé est beaucoup affecté par le comportement latéral des véhicules. Ainsi, des études approfondies utilisant les éléments finis pour modéliser les ouvrages et des enregistrements de trafic réel, peuvent être utilisées pour pré-déterminer quels éléments, donc quelles soudures, doivent être examinés dans les ponts afin d’estimer leur santé structurelle.
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Wonta, Yonatan. "Performance analysis and modeling of FCIP san traffic in mixed priority IP traffics." Thesis, Wichita State University, 2012. http://hdl.handle.net/10057/5544.
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Fibre Channel (FC) is a high-speed data transfer technology used in communication between storage subsystems and computing devices commonly called Storage Area Networks (SAN). A Fibre Channel over TCP/IP enables the connection of FC-SANs isolated by IP networks. This thesis examines the FCIP protocol which is used as FC SAN extensions for SANs geographically separated by Wide Area IP networks. The performance of synchronous mirroring is examined between two SAN islands when operating though an IP network. A mathematical model is developed based on a series of experiments which denotes the characteristics of the FCIP protocol under the presence of varying load mixed IP traffics such as voice and video. The author also investigates performance improvement mechanisms using Multi-Protocol Label Switching (MPLS) and IP Quality of Service (QoS). The application of IP QoS to classify data based on priority is used to differentiate mission-critical applications and to apply the appropriate priority schemes. The use of MPLS enables core networks to function with a packet exchange speed closer to that offered by layer 2 switching. This thesis presents a comparison of the real time values against the modeled values. The performance boost observed using IP QoS and MPLS is also presented in this study.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science
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Jun, Insung. "A study of effective traffic control and management schemes based on traffic measurement for VBR traffic sources on ATM networks." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368926.
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Hou, Jiaqi. "An Upgrade of Network Traffic Recognition System for SIP/VoIP Traffic Recognition." Thesis, Högskolan Dalarna, Datateknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:du-4205.
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The purpose of this project is to update the tool of Network Traffic Recognition System (NTRS) which is proprietary software of Ericsson AB and Tsinghua University, and to implement the updated tool to finish SIP/VoIP traffic recognition. Basing on the original NTRS, I analyze the traffic recognition principal of NTRS, and redesign the structure and module of the tool according to characteristics of SIP/VoIP traffic, and then finally I program to achieve the upgrade. After the final test with our SIP data trace files in the updated system, a satisfactory result is derived. The result presents that our updated system holds a rate of recognition on a confident level in the SIP session recognition as well as the VoIP call recognition. In the comparison with the software of Wireshark, our updated system has a result which is extremely close to Wireshark’s output, and the working time is much less than Wireshark. In the aspect of practicability, the memory overflow problem is avoided, and the updated system can output the specific information of SIP/VoIP traffic recognition, such as SIP type, SIP state, VoIP state, etc. The upgrade fulfills the demand of this project.
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Nadella, Sunita. "Effect of machine vision based traffic data collection accuracy on traffic noise." Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1174681979.
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Key, Justin. "Real-Time Open Source Traffic Control Software for the Advance Traffic Controller." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5377.
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Under the initiative of Department of Transportation (DOT) a safety-critical, dual redundant, open source traffic signal control application is currently being developed. The system named SCOPE, for Signal Control Program Environment, currently implements standard 8-phase NEMA logic and the National Cooperative Highway Research Program 3-66 preemption logic. SCOPE is designed to be part of the Advanced Traffic Controller (ATC), making use of API standard 2.06b to integrate with the hardware. Safety-critical status is achieved through redundancy of application logic that constantly compares expected signal phase information. From baseline requirements, engineers independently program application code, one using Ada95 and the other using C++. The Traffic EXperimental Analytical Simulation Model, a microscopic single-intersection vehicular simulation, was used for initial validation and testing of the functionality of the system. The second demonstration of the SCOPE, used actuated detector data collected from a recording of a live intersection. Actuator calls were placed on SCOPE at the same times the vehicles triggered the detectors in the video (assuming the vehicles were not in-queue). Using SCOPE the real-world traffic was not only right-of-way safely yielded, but the traffic flow state time average time in-queue reduced. The final phase of testing will occur when the DOT performs Formal Qualification Testing, which is scheduled for 2013. Upon validation and subsequent release to the open source community SCOPE will provide users the ability to replace the proprietary application software residing in ATC cabinets. Transparency will be provided into another aspect of the traffic control signal thus taking the initiative of ATC one step further.Ph.D.
Doctorate
Industrial Engineering and Management Systems
Engineering and Computer Science
Modeling and Simulation; Engineering
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Yulianto, Budi. "Application of fuzzy logic to traffic signal control under mixed traffic conditions." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440572.
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Vaze, Vikrant (Vikrant Suhas). "Calibration of dynamic traffic assignment models with point-to-point traffic surveillance." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39282.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2007.Includes bibliographical references (p. 173-180).
Accurate calibration of demand and supply simulators within a Dynamic Traffic Assignment (DTA) system is critical for the provision of consistent travel information and efficient traffic management. Emerging traffic surveillance devices such as Automatic Vehicle Identification (AVI) technology provide a rich source of disaggregate traffic data. This thesis presents a methodology for calibration of demand and supply model parameters using travel time measurements obtained from these emerging traffic sensing technologies. The calibration problem has been formulated in two different frameworks, viz. in a state-space framework and in a stochastic optimization framework. Three different algorithms are used for solving the calibration problem, a gradient approximation based path search method (SPSA), a random search meta-heuristic (GA) and a Monte-Carlo simulation based technique (Particle Filter). The methodology is first tested using a small synthetic study network to illustrate its effectiveness. Later the methodology is applied to a real traffic network in the Lower Westchester County region in New York to demonstrate its scalability.
(cont.) The estimation results are tested using a calibrated Microscopic Traffic Simulator (MITSIMLab). The results are compared to the base case of calibration using only the conventional point sensor data. The results indicate that the utilization of AVI data significantly improves the calibration accuracy.
by Vikrant Vaze.
S.M.
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Condé, Rocha Murça Mayara. "Data-driven modeling of air traffic flows for advanced Air Traffic Management." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120378.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 209-219).
The Air Traffic Management (ATM) system enables air transportation by ensuring a safe and orderly air traffic flow. As the air transport demand has grown, ATM has become increasingly challenging, resulting in high levels of congestion, flight delays and environmental impacts. To sustain the industry growth foreseen and enable more efficient air travel, it is important to develop mechanisms for better understanding and predicting the air traffic flow behavior and performance in order to assist human decision-makers to deliver improved airspace design and traffic management solutions. This thesis presents a data-driven approach to modeling air traffic flows and analyzes its contribution to supporting system level ATM decision-making. A data analytics framework is proposed for high-fidelity characterization of air traffic flows from large-scale flight tracking data. The framework incorporates a multi-layer clustering analysis to extract spatiotemporal patterns in aircraft movement towards the identification of trajectory patterns and traffic flow patterns. The outcomes and potential impacts of this framework are demonstrated with a detailed characterization of terminal area traffic flows in three representative multi-airport (metroplex) systems of the global air transportation system: New York, Hong Kong and Sao Paulo. As a descriptive tool for systematic analysis of the flow behavior, the framework allows for cross-metroplex comparisons of terminal airspace design, utilization and traffic performance. Novel quantitative metrics are created to summarize metroplex efficiency, capacity and predictability. The results reveal several structural, operational and performance differences between the metroplexes analyzed and highlight varied action areas to improve air traffic operations at these systems. Finally, the knowledge derived from flight trajectory data analytics is leveraged to develop predictive and prescriptive models for metroplex configuration and capacity planning decision support. Supervised learning methods are used to create prediction models capable of translating weather forecasts into probabilistic forecasts of the metroplex traffic flow structure and airport capacity for strategic time horizons. To process these capacity forecasts and assist the design of traffic flow management strategies, a new optimization model for capacity allocation is developed. The proposed models are found to outperform currently used methods in predicting throughput performance at the New York airports. Moreover, when used to prescribe optimal Airport Acceptance Rates in Ground Delay Programs, an overall delay reduction of up to 9.7% is achieved.
by Mayara Condé Rocha Murça.
Ph. D.
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Thajchayapong, Suttipong. "Monitoring of traffic anomalies using microscopic traffic variables in vehicular transportation networks." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6214.
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This thesis proposes methodologies to monitor traffic anomalies using microscopic traffic variables measured by equipped vehicles sharing information with one another and/or localized road-side infrastructure. The proposed methodologies can identify not only traffic anomalies that lead to traffic incidents, but also small transient deviations that are usually difficult to detect. Firstly, the thesis addresses the issue of anomaly detection where novel supervised and unsupervised algorithms are proposed. The unsupervised algorithm uses the change in variability of microscopic traffic variables to detect traffic anomalies, which is also shown to outperform previous algorithms monitoring ideally placed loop detectors. The supervised algorithm can identify anomalies under different traffic regimes with 100% detection rate and low false alarm rate when applied to real-world data, which presents a signi cant improvement over the unsupervised algorithm. It is also shown that the proposed algorithms can detect anomalies even when the microscopic traffic variables are aggregated and missing. Secondly, three classification algorithms are proposed, which can be integrated with the previously proposed detection algorithms. The first algorithm identifies a lane-blocking, which is a well-known type of anomaly that often leads to traffic incidents, and is shown to outperform existing algorithms. The second algorithm identifies real-world cases of transient anomalies as well as incident precursors by assessing spatial-temporal changes of microscopic traffic variables. The third algorithm addresses the problem of misclassifications under different traffic regimes by employing a certainty-based decision function, and it is shown to successfully classify all anomaly cases in the real-world data set. Finally, the study is extended to the inference of traffic anomalies at a location where traffic variables could not be measured directly. The key contributions of the proposed algorithm are the ability to infer both normal and anomalous traffic conditions at a target location by assessing only microscopic traffic variables from adjacent locations, and the ability to estimate lane-level traffic flow, time occupancy and inter-arrival time. Based on real-world data, it is shown that the proposed algorithm outperforms a Kalman filter-based approach.
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Lee, Chungwon. "Combined traffic signal control and traffic assignment : algorithms, implementation and numerical results /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Debernard, Serge. "Contribution à la répartition dynamique de tâches entre opérateur et système automatisé : application au contrôle du trafic aérien." Valenciennes, 1993. https://ged.uphf.fr/nuxeo/site/esupversions/455a1b3c-57c3-4994-98ff-5dec24c35a2d.
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Dans la plupart des cas, les systèmes modernes de production ont été étudiés de façon a être les plus autonomes possibles. Pour faire face aux erreurs éventuelles des automatismes, la présence de l'opérateur humain reste alors indispensable. Néanmoins, la complexite des tâches peut nécessiter l'apport d'une assistance qui peut consister en une répartition dynamique de tâches entre ces opérateurs et le système d'aide. La contribution de notre travail porte, d'une part sur les aspects théoriques de la répartition dynamique de tâches, et d'autre part sur l'application de cette forme de coopération au contrôle de trafic aérien. Cette application a été réalisée en collaboration avec le centre d'étude de la navigation aérienne. Dans une première partie, la problématique des systèmes intégrant une coopération homme-machine est abordée, et une méthodologie de conception et d'évaluation des systèmes homme-machine est présentée. Dans une deuxième partie, les objectifs et les problèmes de la répartition dynamique sont analysés. Pour résoudre ces problèmes, notamment dus à la complexité des procédés réels, la troisième partie propose une démarche pour la mise en œuvre d'une répartition dynamique de tâches. Cette démarche s'appuie tout d'abord sur une structure qui s'inspire des techniques de la commande adaptative. Ensuite, nous proposerons un ensemble de critères permettant la définition du degré d'automatisation d'un système homme-machine. La quatrième partie présente l'application des principes retenus au domaine du contrôle de trafic aérien, et la cinquième les résultats obtenus.
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Lam, Yat-wai. "Traffic safety and exposure." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43785633.
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Cao, Hua. "Real Time Traffic Recognition." Thesis, Uppsala University, Department of Information Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-89414.
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The rapid growth of Internet in size and complexity, and frequent emergence of new network applications have made it necessary to develop techniques that can monitor and control the traffic. Efficient and accurate recognition of traffic is the key to the management in real time. This thesis work accomplishes the performance evaluation and optimization of a traffic recognition tool called Traffic Analyzer Module (TAM) which implements a technique that is based on passively observing and identifying signature patterns of the packet payload at the application layer, says signature-based payload recognition. This technique has two highlighted features. Firstly, in contrast to most of previous works which perform classification with offline trace files; this technique applies in online mode which can identify the traffic in real time. Secondly, instead of packet inspection, this technique adopts flow inspection, i.e. identifying traffic in terms of flows each of which consists of the well-known 5-tuple, which canproduce more accurate and reliable results.
To demonstrate this technique, its throughput is evaluated in online mode within a high bandwidth network. Besides throughput measurement, optimizing the recognition algorithm in order to improve its performance is also a task of this thesis work. The results of performance measurement demonstrate the feasibility and reliability of this technique, as well as indicate some clues for future work.
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Turull, Torrents Daniel. "Open Source Traffic Analyzer." Thesis, KTH, Telekommunikationssystem, TSLab (stängd 2012-01-01), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-38322.
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Proper traffic analysis is crucial for the development of network systems, services and protocols. Traffic analysis equipment is often based on costly dedicated hardware, and uses proprietary software for traffic generation and analysis. The recent advances in open source packet processing, with the potential of generating and receiving packets using a regular Linux computer at 10 Gb/s speed, opens up very interesting possibilities in terms of implementing a traffic analysis system based on open-source Linux. The pktgen software package for Linux is a popular tool in the networking community for generating traffic loads for network experiments. Pktgen is a high-speed packet generator, running in the Linux kernel very close to the hardware, thereby making it possible to generate packets with very little processing overhead. The packet generation can be controlled through a user interface with respect to packet size, IP and MAC addresses, port numbers, inter-packet delay, and so on. Pktgen was originally designed with the main goal of generating packets at very high rate. However, when it comes to support for traffic analysis, pktgen has several limitations. One of the most important characteristics of a packet generator is the ability to generate traffic at a specified rate. Pktgen can only do this indirectly, by inserting delays between packets. Moreover, the timer granularity prevents precise control of the transmission rate, something which severely reduces pktgen’s usefulness as an analysis tool. Furthermore, pktgen lacks support for receives ide analysis and statistics generation. This is a key issue in order to convert pktgen into a useful network analyser tool. In this paper, improvements to pktgen are proposed, designed, implemented and evaluated, with the goal of evolving pktgen into a complete and efficient network analysis tool. The rate control is significantly improved, increasing the resolution and improving the usability by making it possible to specify exactly the sending rate. A receive-side tool is designed and implemented with support for measurement of number of packets, throughput, inter-arrival time, jitter and latency. The design of the receiver takes advantage of SMP systems and new features on modern network cards, in particular support for multiple receive queues and CPU scheduling. This makes it possible to use multiple CPUs to parallelize the work, improving the overall capacity of the traffic analyser. A significant part of the work has been spent on investigating low-level details of Linux networking. From this work we draw some general conclusions related to high speed packet processing in SMP systems. In particular, we study how the packet processing capacity per CPUdepends on the number of CPUs. This work consists of minimal set of kernel patches to pktgen.
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Doerksen, Julie. "Internet traffic model toolkit." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ64949.pdf.
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Törnquist, Johanna. "Railway traffic disturbance management /." Karlskrona : Blekinge Institute of Technology, 2006. http://www.bth.se/fou/forskinfo.nsf/01f1d3898cbbd490c12568160037fb62/4bff7793d57e9155c1257178004d42f9!OpenDocument.
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