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

Risk, Rail and the Region : A spatial analysis of regional differences of infrastructural safety and the risk of accidents at Swedish level-crossings

Grauers, Henning January 2019 (has links)
Level-crossings, i.e. intersections where railways and road meet in the same vertical level, constitute risk for the users of respective infrastructure system. The aim of this thesis is to examine possible regional differences between the infrastructural safety standard of level-crossings in Sweden. With the use of spatial analyses tools in a Geographical Information System, the differences between Swedish counties are outlined and mapped. By the use of a logistic regression model, the variables that increase the risk of an accident in a level-crossings are analysed. The results show that the variables concerning the level of protection, together with the location on a highway, show statistical significance of being associated with an increased accidental risk. The results of the regression model factors have been returned to the GIS in order to find the most hazardous level-crossings. Considering the train flows and amount of people living in the proximity of the crossings, the hotpots of hazards have been spatially identified. 38 level-crossings with passive or semi-active warning system meet the criteria and should be the targets for practitioners’ work towards an increased level of safety and reduced risk.
2

Conical Intersections and Avoided Crossings of Electronic Energy Levels

Gamble, Stephanie Nicole 14 January 2021 (has links)
We study the unique phenomena which occur in certain systems characterized by the crossing or avoided crossing of two electronic eigenvalues. First, an example problem will be investigated for a given Hamiltonian resulting in a codimension 1 crossing by implementing results by Hagedorn from 1994. Then we perturb the Hamiltonian to study the system for the corresponding avoided crossing by implementing results by Hagedorn and Joye from 1998. The results from these demonstrate the behavior which occurs at a codimension 1 crossing and avoided crossing and illustrates the differences. These solutions may also be used in further studies with Herman-Kluk propagation and more. Secondly, we study codimension 2 crossings by considering a more general type of wave packet. We focus on the case of Schrödinger equation but our methods are general enough to be adapted to other systems with the geometric conditions therein. The motivation comes from the construction of surface hopping algorithms giving an approximation of the solution of a system of Schrödinger equations coupled by a potential admitting a conical intersection, in the spirit of Herman-Kluk approximation (in close relation with frozen/thawed approximations). Our main Theorem gives explicit transition formulas for the profiles when passing through a conical crossing point, including precise computation of the transformation of the phase and its proof is based on a normal form approach. / Doctor of Philosophy / We study energies of molecular systems in which special circumstances occur. In particular, when these energies intersect, or come close to intersecting. These phenomena give rise to unique physics which allows special reactions to occur and are thus of interest to study. We study one example of a more specific type of energy level crossing and avoided crossing, and then consider another type of crossing in a more general setting. We find solutions for these systems to draw our results from.
3

Konverze brněnského úseku I/52 na D52 / Conversion of the road I/52 to motorway D52

Sejkora, Jan January 2018 (has links)
The aim of the diploma thesis is to propose a modification of the road I / 52 between the junction with the D1 motorway and Rajhrad on the D52 motorway in a way that a continuous highway can be created without the need to create an alternative route over the southern tangent in route Wien-Prague and D2 and also to design routes for transport which cannot enter the highway. The other aim is to define the problem elements and create a variant solution.
4

Motorist behaviour at railway level crossings : the present context in Australia

Wallace, Angela M. January 2008 (has links)
Railway level crossing collisions in Australia are a major cause of concern for both rail and road authorities. Despite the fact that the number of railway crash fatalities in Australia has fallen in recent years, level crossing collisions constitute a significant proportion of the national rail toll. Although rail transport is presently one of the safest forms of land transport, collisions at level crossings are three times more likely to involve fatalities as compared to all other types of road crashes (Afxentis, 1994). With many level crossing fatalities and injuries resulting in coronial inquests, litigation and negative media publicity, the actions of rail and road infrastructure providers and the behaviour of motorists, pedestrians and rail users, come under close scrutiny. Historically, research in this area has been plagued by the rail/road interface and the separation of responsibilities between rail and road authorities reflecting the social and political context in which they are contained. With the recent rail reform in Australia, safety at level crossings has become a key priority area. Accordingly, there is a need to better understand the scope and nature of motorist behaviour at level crossings, in order to develop and implement more effective countermeasures for unsafe driving behaviour. However, a number of obstacles have hindered research into the area of level crossing safety. As with many road crashes, the contributing causes and factors are often difficult to determine, however a recent investigation of fatal collisions at level crossings supports the notion that human fault is a major contributor (Australian Transport Safety Bureau, 2002a). Additionally, there is a lack of reliable data available relating to the behavioural characteristics and perceptions of drivers at level crossings. Studies that do exist have lacked a strong theoretical base to guide the interpretation of results. Due to the lack of financial viability of continuing to approach risk management from an engineering perspective, the merits of human factor research need to be examined for suitability. In Australia, there has been considerable recognition regarding the importance of human factor approaches to level crossing safety (Australian Transport Council, 2003). However, little attempt has been made by authorities to scientifically develop and measure the effectiveness of road safety educational interventions. Therefore, there exists a significant need for developing targeted road safety educational interventions to improve current risk management solutions at level crossings. This research program is the first of its kind in investigating motorist behaviour at level crossings and the measuring the effectiveness of educational interventions for improving driving safety. Although other ‘educational’ campaigns exist in this field, no campaign or intervention has been guided by empirical research or theory. This thesis adopted a multidisciplinary approach to theory, reviewing perspectives from psychology, sociology and public health to explain driver behaviour at level crossings. This array of perspectives is necessary due to the variety of behaviours involved in collisions and near-misses at level crossings. The motivation underlying motorist behaviour determines to a large extent how successful behaviour change strategies (e.g. educational interventions) may be. Fishbein’s Integrated Model of Behaviour Change (IM) based largely on the health belief model, theory of reasoned action and theory of planned behaviour (Fishbein, 2000), assisted in the planning and development of a ‘oneoff’ targeted educational intervention specific for three different road user groups and in questionnaire development to ascertain the present context of motorist behaviour at level crossings. As no known research has been conducted that utilizes any psychosocial model to explain or predict level crossing behavior within different road user groups, this research program used this model as an exploratory tool rather than a tool to asses the model’s capacity in explaining such behaviour. The difference between this model and others is the inclusion of two important constructs in driving: skills (or abilities) and environmental factors. Fishbein (2003) suggests that the model recognises the lack of skills (or abilities) and/or environmental constraints may prevent a person from acting on their intentions, in light of the fact that intention is viewed as the primary determinant of behaviour. While the majority of behaviour change theories are limited by a range of conceptual and contextual factors (Parker, 2004), the IM was used to assist this research program as it appeared to be the most applicable model to examining level crossing safety. A variety of data collection methods were used in this research program as much of what is currently known about level crossing collisions is derived from coroner’s findings and statistics. The first study (Study One) was designed to extend this knowledge by undertaking a more thorough examination of contributing factors to level crossing crashes and the road user groups at risk. This study used the method of ‘triangulation’ (i.e. combining research methods to give a range of perspectives) whereby both qualitative (focus groups) and quantitative (modified Delphi technique) research designs were utilised (Barbour, 1999, Bryman, 1992). With the discipline of road safety research requiring methodological strategies that will enhance efforts to conceptualise the multi-faceted nature of motorist behaviour at level crossings, this application provided the robustness required. Results from the Delphi technique indicated that older, younger and heavy vehicle drivers are considered to be three of the highest risk road user groups by experts in the field. For the older driver group, experts agreed that errors in judgment were the most important issue for this group when driving at level crossings. Risk taking by younger drivers, such as trying to beat the train across the crossing, was viewed as the central issue for the younger driver group. Like the younger driver group, a concern by experts with the heavy vehicle group was intentional risk taking at level crossings. However, experts also rated the length of heavy vehicles a major concern due to the possibility of a truck over-hanging a crossing. Results from focus groups with train drivers in Study One indicated that there are unique problems associated with crossings in rural/regional areas compared to urban areas. The metropolitan train drivers generally experienced motorist behaviour at active crossings with flashing lights and boom gates while the regional train drivers experienced behaviours at active crossings with boom gates, crossings with lights only and passive crossings with stationary signs. In the metropolitan train driver group, experiences of motorist behaviour at level crossings included: motorists driving around boom gates, getting stuck under boom gates, queuing over congested crossings and driving through the crossing after the red lights commence flashing. The behaviour of motorists driving around boom gates was noted to occur quite regularly. The majority of metropolitan train drivers reported that it was a common occurrence for motorists to drive through a crossing when the lights are flashing both before and after the booms were activated and some crossings were named as ‘black spots’ (locations where motorists repeatedly violate the road rules). Vehicles protruding into the path of the train and motorists entering congested crossings and then panicking and driving backwards into the boom gates were also mentioned. Regional train drivers indicated that motorists not stopping or giving way to trains is a continual problem at passively controlled crossings (i.e. no boom gates or flashing lights). Regional train drivers generally agreed that the majority of motorists obey protection systems; however some motorists drive through flashing lights or drive around boom gates. Other high risk behaviours included motorists attempting to beat the train across the crossing, speeding up to go through flashing lights, and general risk taking by younger drivers in particular. Motorists not allowing enough time to cross in front of the train or hesitating (stopstarting) at crossings were also noted to be at high risk. There was a general perception by regional train drivers that motorists are unable to judge the speed and distance of an approaching train to determine a safe gap during which to cross. Local motorists were also reported to be a problem at level crossings for regional train drivers. A theme common to regional and metropolitan train drivers was the risk of catastrophic consequence associated with level crossing collisions. The reasons given for this were the threat of derailment, serious property damage, the high risk of a fatality, personal injury and, most earnestly, the potential for enduring psychological consequences. Drivers uniformly spoke about the continual fear they had of being involved in a collision with a heavy vehicle, and many spoke of the effects that such collisions had on train drivers involved. For this reason, train drivers were said to consider any near-miss incident involving trucks particularly serious. The second study undertaken as part of this research program (Study Two), involved formative research as part of the planning, development and delivery of behavioural interventions for each of the three road user groups identified in Study One. This study also used both qualitative and quantitative data collection methods to provide methodological triangulation and ensure reliability of the data. The overall objective of the qualitative data collection was to obtain rich data using a qualitative mode of inquiry, based on the key variables of attitudes, norms, self-efficacy (perceived behavioural control), perceived risk, environmental constraints and the skills/abilities of drivers. The overall objective of the quantitative data collection was to prioritise the issues identified in order to direct and allocate project resources for intervention planning, development and delivery. This combined recruitment strategy was adopted as it was an appropriate and practical data collection strategy within the qualitative and exploration methodology. Information obtained from each of the groups was critical in assisting, guiding, and identifying priority areas for message and material development. The use of focus groups and one-on-one interviews provided insights into why drivers think or do what they do at level crossings. The qualitative component of this study found that for the older driver group, regional drivers hold a greater perception of risk at level crossings than urban older drivers, with many recalling near-misses. Participants from the urban older driver group indicated that level crossings are not as dangerous as other aspects of driving, with many participants being doubtful that motorists are killed while driving at level crossings. Both urban and regional younger drivers tended to hold a low perception of risk for driving at level crossings, however many participants reported having great difficulty in judging the distance a train is from a crossing. Impatience for waiting at level crossings was reported to be the major reason for any risk taking at level crossings in the younger driver group. Complacency and distraction were viewed by heavy vehicle participants as two of the major driver factors that put them at risk at level crossings, while short-stacking (when the trailer of the truck extends onto the crossing), angle of approach (acute or obtuse angle) and lack of advance warning systems were seen as the major engineering problems for driving a truck at level crossings. The quantitative component of this study involving research with train drivers found that at the aggregate train driver level, it is apparent that train drivers consider motorists’ deliberate violations of the road rules and negligently lax approach to hazard detection as the predominant causes of dangerous driving at level crossings. Experts were observed to rank risk taking behaviours slightly lower than train drivers, although they agreed with train drivers that ‘trying to beat the train’ is the single most critical risk taking behaviour observed by motorists. The third study (Study Three) involved three parts. The aim of Part One of this study was to develop targeted interventions specific to each of the three road user groups by using Fishbein’s theoretical model (Integrated Model of Behaviour Change) as a guide. The development of interventions was originally seen as being outside of the scope of this project, however it became intertwined in questionnaire development and thus deemed to be within the realms of the current mode of inquiry. The interventions were designed in the format of a pilot radio road safety advertisement, as this medium was found to be one of the most acceptable to each of the road user groups as identified in the formative research undertaken in Study Two. The interventions were used as a ‘one-off’ awareness raising intervention for each road user group. Part Two involved the investigation of the present context of unsafe driving behaviour at level crossings. This second part involved the examination of the present context of motorist behaviour at level crossings using key constructs from Fishbein’s Integrated Model of Behaviour Change (IM). Part Three involved trialing a pilot road safety radio advertisement using an intervention and control methodology. This part investigated the changes in pre and post-test constructs including intentions, self-reported behaviour, attitudes, norms, selfefficacy/ perceived behaviour control, perceived risks, environment constraints and skills/ability. Results from this third study indicated that younger drivers recognise that level crossings are potentially a highly dangerous intersection yet are still likely to engage in risk taking behaviours. Additionally, their low levels of self-efficacy in driving at level crossings pose challenges for developing interventions with this age group. For the older driver sample, this research confirms the high prevalence of functional impairments such as increasing trouble adjusting to glare and night-time driving, restricted range of motion to their neck and substantial declines in their hearing. While factors contributing to the over-representation of older drivers in collisions at level crossings are likely to be complex and multi-faceted, such functional impairments are expected to play a critical role. The majority of heavy vehicle drivers reported driving safely and intending to drive safely in the future, however, there is a sub-set of drivers that indicate they have in the past and will in the future take risks when traversing crossings. Although this sub-set is relatively small, if generalised to the larger trucking industry it could be problematic for the rail sector and greater public alike. Familiarity was a common factor that was found to play a role in driving intention at level crossings for all three road user groups. This finding supports previous research conducted by Wigglesworth during the 1970’s in Australia (Wigglesworth, 1979). Taken together, the results of the three studies in this research program have a number of implications for level crossing safety in Australia. Although the ultimate goal to improve level crossing safety for all motorists would be to have a combination of engineering, education and enforcement countermeasures, the small number of fatalities in comparison to the national road toll limits this. It must be noted though that the likelihood of creating behavioural change would be increased if risk taking at level crossings by all motorists was detected and penalised, or alternatively, if perceptions of such detection were increased. The instilling of fear in drivers with the threat of punishment via some form of sanction can only be achieved through a combination of a mass media campaign and increasing police presence. Ideally, the aim would be to combine fear of punishment with the guilt associated with the social non-acceptability of disobeying road rules at level crossings. Such findings have direct implications for improving the present context of motorist behaviour at level crossings throughout Australia.
5

Modelling of Level Crossing Accident Risk

Sleep, Julie January 2008 (has links)
This thesis details the development of a model of driver behaviour at railway level crossings that allows the probability of an accident under different conditions and interventions to be calculated. A method for classifying different crossings according to their individual risk levels is also described.
6

Quantum two-state level-crossing models in terms of the Heun functions / Modèles quantiques à deux états avec croisements de niveaux décrits par les fonctions de Heun

Ishkhanyan, Tigran 18 September 2019 (has links)
La thèse est consacrée au problème fondamental de l'excitation et de la manipulation de systèmes quantiques à spectre d'énergie discret, via des champs lasers externes. Nous examinons le problème semi-classique à deux états quantiques, dépendant du temps, lorsque le champ électromagnétique externe est résonant ou quasi résonant pour deux des nombreux niveaux du système. La thèse est centrée sur la description analytique de l'évolution non adiabatique des systèmes quantiques soumis à une excitation par des configurations de champs avec croisements de niveaux. Dans la présente thèse, nous classifions l’ensemble complet des modèles quantiques à deux états semi-classiques dépendants du temps, qui peuvent être résolus en cinq fonctions de la classe de Heun.Les principaux résultats de la thèse sont :1. Au total, 61 classes infinies de modèles à deux états (i.e. les configurations de champ laser externe) solubles en termes de fonctions de Heun générale et confluentes sont dérivées.2. Dans ces classes infinies, trois sous-modèles originaux avec croisements de niveaux sont identifiés: l'un décrit les croisements infinis de résonance (périodiques), l'autre décrit les croisements de résonance asymétrique avec un temps de processus fini et le dernier décrit les processus de croisements infinis de résonance asymétrique. Le comportement du système quantique à deux états dans ces configurations de champ est analysé de manière exhaustive.3. Les solutions des équations de Heun en termes de fonctions bêta incomplètes, de fonctions hypergéométriques confluentes de Kummer et de fonctions Hermite d'ordre non entier sont construites.4. Des solutions analytiques du problème quantique à deux états sont projetées sur les équations d'onde relativistes et non relativistes : de nouveaux potentiels pour les équations de Schrödinger et de Klein-Gordon sont dérivés et résolus. / The thesis is devoted to the fundamental problem of excitation and manipulation of quantum systems, having discrete energy spectrum, via external laser fields. We examine the semiclassical time- dependent quantum two-state problem, when the external electromagnetic field is resonant or quasi-resonant for some two of many levels of the system. The focus of the thesis is on the analytic description of the non- adiabatic evolution of quantum systems subject to excitation by level-crossing field configurations. In the present thesis we classify the complete set of the semiclassical time-dependent quantum two-state models solvable in terms of the five function of the Heun class.Main results of the thesis are:1. In total 61 infinite classes of two-state models (i.e. external laser field configurations) solvable in terms of general and confluent Heun functions are derived.2. In these infinite classes three original level-crossing submodels are identified: one describes infinite (periodical) crossings of resonance, one describes asymmetric resonance crossing with a finite time of process and the last one describes infinite asymmetric resonance crossing process. The behavior of the two-state quantum system under these field configurations is comprehensively analyzed.3. Solutions of the Heun equations in terms of incomplete Beta functions, Kummer confluent hypergeometric functions and non-integer-order Hermite functions of a shifted and scaled argument are constructed.4. Analytic solutions of the quantum two-state problem are projected on the relativistic and non-relativistic wave-equations: new potentials for the Schrödinger and Klein-Gordon equations are derived and solved.
7

Reconstruction et analyse de trajectoires 2D d'objets mobiles par modélisation Markovienne et la théorie de l'évidence à partir de séquences d'images monoculaires - Application à l'évaluation de situations potentiellement dangereuses aux passages à niveau / Reconstruction and analysis of moving objects trajectoiries from monocular images sequences, using Hidden Markov Model and Dempster-Shafer Theory-Application for evaluating dangerous situations in level crossings

Salmane, Houssam 09 July 2013 (has links)
Les travaux présentés dans ce mémoire s’inscrivent dans le cadre duprojet PANsafer (Vers un Passage A Niveau plus sûr), lauréat de l’appel ANR-VTT2008. Ce projet est labellisé par les deux pôles de compétitivité i-Trans et Véhiculedu Futur. Le travail de la thèse est mené conjointement par le laboratoire IRTESSETde l’UTBM et le laboratoire LEOST de l’IFSTTAR.L’objectif de cette thèse est de développer un système de perception permettantl’interprétation de scénarios dans l’environnement d’un passage à niveau. Il s’agitd’évaluer des situations potentiellement dangereuses par l’analyse spatio-temporelledes objets présents autour du passage à niveau.Pour atteindre cet objectif, le travail est décomposé en trois étapes principales. Lapremière étape est consacrée à la mise en place d’une architecture spatiale des capteursvidéo permettant de couvrir de manière optimale l’environnement du passageà niveau. Cette étape est mise en oeuvre dans le cadre du développement d’unsimulateur d’aide à la sécurité aux passages à niveau en utilisant un système deperception multi-vues. Dans ce cadre, nous avons proposé une méthode d’optimisationpermettant de déterminer automatiquement la position et l’orientation descaméras par rapport à l’environnement à percevoir.La deuxième étape consisteà développer une méthode robuste de suivi d’objets enmouvement à partir d’une séquence d’images. Dans un premier temps, nous avonsproposé une technique permettant la détection et la séparation des objets. Le processusde suivi est ensuite mis en oeuvre par le calcul et la rectification du flotoptique grâce respectivement à un modèle gaussien et un modèle de filtre de Kalman.La dernière étape est destinée à l’analyse des trajectoires 2D reconstruites parl’étape précédente pour l’interprétation de scénarios. Cette analyse commence parune modélisation markovienne des trajectoires 2D. Un système de décision à basede théorie de l’évidence est ensuite proposé pour l’évaluation de scénarios, aprèsavoir modélisé les sources de danger.L’approche proposée a été testée et évaluée avec des données issues de campagnesexpérimentales effectuées sur site réel d’un passage à niveau mis à disposition parRFF. / The main objective of this thesis is to develop a system for monitoringthe close environment of a level crossing. It aims to develop a perception systemallowing the detection and the evaluation of dangerous situations around a levelcrossing.To achieve this goal, the overall problem of this work has been broken down intothree main stages. In the first stage, we propose a method for optimizing automaticallythe location of video sensors in order to cover optimally a level crossingenvironment. This stage addresses the problem of cameras positioning and orientationin order to view optimally monitored scenes.The second stage aims to implement a method for objects tracking within a surveillancezone. It consists first on developing robust algorithms for detecting and separatingmoving objects around level crossing. The second part of this stage consistsin performing object tracking using a Gaussian propagation optical flow based modeland Kalman filtering.On the basis of the previous steps, the last stage is concerned to present a newmodel to evaluate and recognize potential dangerous situations in a level crossingenvironment. This danger evaluation method is built using Hidden Markov Modeland credibility model.Finally, synthetics and real data are used to test the effectiveness and the robustnessof the proposed algorithms and the whole approach by considering various scenarioswithin several situations.This work is developed within the framework of PANsafer project (Towards a saferlevel crossing), supported by the ANR-VTT program (2008) of the French NationalAgency of Research. This project is also labelled by Pôles de compétitivité "i-Trans"and "Véhicule du Futur". All the work, presented in this thesis, has been conductedjointly within IRTES-SET laboratory from UTBM and LEOST laboratory fromIFSTTAR.
8

Détection et localisation tridimensionnelle par stéréovision d’objets en mouvement dans des environnements complexes : application aux passages à niveau / Detection and 3D localization of moving and stationary obstacles by stereo vision in complex environments : application at level crossings

Fakhfakh, Nizar 14 June 2011 (has links)
La sécurité des personnes et des équipements est un élément capital dans le domaine des transports routiers et ferroviaires. Depuis quelques années, les Passages à Niveau (PN) ont fait l’objet de davantage d'attention afin d'accroître la sécurité des usagers sur cette portion route/rail considérée comme dangereuse. Nous proposons dans cette thèse un système de vision stéréoscopique pour la détection automatique des situations dangereuses. Un tel système permet la détection et la localisation d'obstacles sur ou autour du PN. Le système de vision proposé est composé de deux caméras supervisant la zone de croisement. Nous avons développé des algorithmes permettant à la fois la détection d'objets, tels que des piétons ou des véhicules, et la localisation 3D de ces derniers. L'algorithme de détection d'obstacles se base sur l'Analyse en Composantes Indépendantes et la propagation de croyance spatio-temporelle. L'algorithme de localisation tridimensionnelle exploite les avantages des méthodes locales et globales, et est composé de trois étapes : la première consiste à estimer une carte de disparité à partir d'une fonction de vraisemblance basée sur les méthodes locales. La deuxième étape permet d'identifier les pixels bien mis en correspondance ayant des mesures de confiances élevées. Ce sous-ensemble de pixels est le point de départ de la troisième étape qui consiste à ré-estimer les disparités du reste des pixels par propagation de croyance sélective. Le mouvement est introduit comme une contrainte dans l'algorithme de localisation 3D permettant l'amélioration de la précision de localisation et l'accélération du temps de traitement. / Within the past years, railways undertakings became interested in the assessment of Level Crossings (LC) safety. We propose in this thesis an Automatic Video-Surveillance system (AVS) at LC for an automatic detection of specific events. The system allows automatically detecting and 3D localizing the presence of one or more obstacles which are motionless at the level crossing. Our research aims at developing an AVS using the passive stereo vision principles. The proposed imaging system uses two cameras to detect and localize any kind of object lying on a railway level crossing. The cameras are placed so that the dangerous zones are well (fully) monitored. The system supervises and estimates automatically the critical situations by detecting objects in the hazardous zone defined as the crossing zone of a railway line by a road or path. The AVS system is used to monitor dynamic scenes where interactions take place among objects of interest (people or vehicles). After a classical image grabbing and digitizing step, the processing is composed of the two following modules: moving and stationary objects detection and 3-D localization. The developed stereo matching algorithm stems from an inference principle based on belief propagation and energy minimization. It takes into account the advantages of local methods for reducing the complexity of the inference step achieved by the belief propagation technique which leads to an improvement in the quality of results. The motion detection module is considered as a constraint which allows improving and speeding up the 3D localization algorithm.
9

Factors shaping pedestrians’ unsafe behaviour at actively protected level crossings / Facteurs influençant le comportement non sécuritaire des piétons aux passages à niveau actifs

Stefanova, Teodora 10 September 2015 (has links)
Le nombre des collisions avec des piétons aux passages à niveau restant stable dans les dernières années, c’est un problème majeur au niveau international. Suite à la revue étendue de la littérature, des lacunes scientifiques importantes liées à l’étude du comportement du piéton ont été identifiées. L’objectif principal de ce programme de recherche était de contribuer à mieux comprendre le comportement du piéton aux passages à niveau actifs en Australie, où malgré la mise en place des protections renforcées pour les piétons, le nombre de collisions reste plus important que sur les autres types de passages à niveau. Trois études ont été réalisées pour répondre aux trois buts de recherche que nous nous proposons d'examiner dans le cadre de ce programme. La première étape de recherche qui est exploratoire a été réalisée dans le cadre des études 1 et 2 dont les conclusions ont permis d'identifier les facteurs influençant la prise de décision aux passages à niveau. A la fin de cette étape un nouveau modèle systémique a été développé pour servir d’instrument à l’analyse du comportement du piéton, influencé par des facteurs de tous les niveaux du système. Dans la deuxième étape empirique de recherche, nous avons mené l’étude 3 pour examiner l’impact de facteurs clés sur les comportements à risque dans différentes situations à risque de traversée des piétons. L’articulation des trois études est une illustration des bénéfices associés avec l’utilisation à la fois des méthodes systémiques et traditionnelles, résultant des contributions théoriques et pratiques importantes. / Level crossing collisions with pedestrians are a major issue worldwide and in Australia, where their number remains stable in recent years. An extended review of the literature highlighted a number of important scientific gaps in current knowledge on the factors shaping specifically pedestrian behaviour. The main objective of this research program was to contribute to the better understanding of pedestrian behaviour at active level crossings in Austalia, where a larger number of collisions are reported despite the reinforced safety measures in place. Three research aims were formulated and supported the development of three studies.Study 1 and 2 were part of the first explorative stage of research and informed on the main factors shaping crossing decisions of pedestrians. At the end of this stage a new systems-based framework was developed as a tool for the analysis of pedestrian behaviour as influenced by factors across all system levels. Study 3, part of the empirical stage of research, examined in depth the influence of key precursors of unsafe behaviour across different crossing situations. The articulation of the three studies demonstrates the benefits of using systems-based and traditional individual-centred methods in a complementary manner resulting in important theoretical and practical contributions.
10

Návrh modernizace žst. Brandýs nad Orlicí / Design of modernization of Brandýs nad Orlicí railway station

Štrumfa, David January 2013 (has links)
Design for modernization of the railway station Brandys nad Orlici. The reconstruction of both the gridiron. The main rails increase the speed to the maximum, in passing tracks increase the speed to 60 km / h The station will eliminate level crossings on the platform. Width arrangement of the platforms will be designed to accommodate persons with reduced mobility options.

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