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Rajbhandari, Bidur. "Modelling intelligent transport systems applications for public transport." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246885.
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An, Jeong-Hwa. "Le choix d'un système de transport durable : analyse comparative des systèmes de transport guidé de surface." Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1133/document.
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Le choix d'un système de transport guidé de surface exploité en site propre (TCSP) est un travail complexe et difficile. Les différents systèmes peuvent sembler offrir des services équivalents pour les utilisateurs tandis que manquent souvent les informations nécessaires pour mieux distinguer les différences entre tel ou tel système. L'objectif de cette recherche vise, au-delà d'une présentation des différents systèmes guidés de surface qui structurent les réseaux de transport public en France, à procéder à une analyse comparative afin de mieux guider les choix des collectivités territoriales, dans le contexte des efforts qu'elles conduisent pour promouvoir des transports urbains répondant aux enjeux du développement durable. Les avantages et points faibles de chaque système est analysé et présenté de manière désagrégée. De manière complémentaire, est proposée et discutée une méthode multicritère ELECTRE III permettant d'agréger les résultats obtenus et de proposer le (ou les) système(s) le(s) mieux adapté(s) à différents contextes d'exploitation. Le résultat principal met en évidence le fait que le tramway moderne sur fer occupe une place privilégiée dans la majorité des scenarii. Cependant, le CIVIS, le Translohr, TVR et même le trolleybus ont leur place selon le contexte d'exploitation, dès lors en particulier que sont pris en compte les coûts d'infrastructure et d'exploitation associés. Les résultats de cette recherche nous encouragent en outre à recommander, chaque fois qu'il y a un projet de système de transport de surface, de passer en revue la gamme des systèmes et d'effectuer l'analyse comparative avec les différentes contraintes du lieu et du moment, en y intégrant une vision de moyen et long terme et les effets prévisibles sur l'aménagement urbainThe choice of a guided surface transit system operated on separated RoW is a complex and difficult task. Even if different transit systems could provide equivalent services to users, we often lack the necessary information to better distinguish among different systems. Beyond giving a presentation of different surface guided systems structuring the public transport networks in France, the aim of this research is to conduct a comparative analysis in order to better guide decisions of local authorities in their efforts to promote urban transport that meets the challenges of sustainable development. The advantages and the drawbacks of each system are analyzed and presented in a disaggregated way. In addition, a multicriteria method ELECTRE III is proposed and discussed for aggregating the results and proposing system(s) best suited for different operating conditions. The main result shows that the modern tramway on rail occupies a privileged place in most scenarios. However, the CIVIS, Translohr, TVR and even trolleybuses have their places with respect to operating conditions, given that the related infrastructure and operating costs are taken into account. The results of this research therefore encourage us to recommend, every time we propose a surface transit system, to review the whole range of systems and to do the comparative analysis with different context and time constraints integrating mid-term and long-term visions and predictable effects on the urban requalification
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Faure-Vincent, Jérôme. "Transport tunnel polarisé en spin dans le système épitaxié Fe/MgO/Fe : interactions magnétiques et symétries électroniques." Vandoeuvre-les-Nancy, INPL, 2004. http://docnum.univ-lorraine.fr/public/INPL_T_2004_FAURE_VINCENT_J.pdf.
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Les jonctions tunnel magnétiques monocristallines Fe(1 00)/MgO(1 00)/Fe(1 00) élaborées par Epitaxie par Jet Moléculaire sont des systèmes modèles pour la va1idation de concepts spécifiques au transport polarisé en ( spin dans les multicouches cristallines. L'analyse de la structure de bande montre que le Fe(100) apparaît comme un demi-métal au regard de la symétrie 01 : cette nouvelle notion de polarisation en terme de symétrie électronique explique les formidables effets magnétorésistifs prédits dans ce système. Nos résultats magnétorésistifs valident les effets de filtrage en symétrie et montrent l'influence de la structure électronique sur le transport dont les mécanismes dépassent le modèle des électrons libres. Parallèlement, la croissance bidimensionnelle du MgO a permis "élaboration de fines couches de MgO pour lesquelles nous avons fourni la première mise en évidence expérimentale d'une interaction antiferromagnétique entre deux couches magnétiques par effet tunnel polarisé en spinMonocrystalline Fe(1 00)/MgO(1 00)/Fe(1 00) magnetic tunnel junctions (MT J), elaborated by Molecular Beam Epitaxy constitute ideal systems for validation of specific concepts related to the spin polarized transport in crystalline multilayers. The analysis of the band structure shows that the Fe(100) behaves as a half-metal with respect to the 01 electronic symmetry; this new concept of spin polarization/filtering in terms of symmetry being at the origin of huge magnetoresistive effects theoretically predicted in these systems. Our magnetotransport results validate the effects of electronic symmetry filtering. Moreover, they illustrate the influence of the electronic structure on tunnel transport, whose complex mechanisms go weil beyond the free- electron framework. The precise control of the bidimensional epitaxial growth of MgO allowed us the elaboration of extremely thin insulating barriers for which we provide a first experimental proof of magnetic coupling by spin polarized tunneling
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Fletterman, Manuel. "Designing multimodal public transport networks using metaheuristics." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01162009-154801/.
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Aho, Yousef, and Jong Johannes de. "Validation of a Public Transport Model." Thesis, KTH, Optimeringslära och systemteori, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277045.
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During 2018, the Public Transport Administration (Trafikförvaltningen) in the Stockholm region spent approximately 2.2 billion SEK on new infrastructure investments related to the public transport system, many of which were based on their public transport models. The previously used method for validating these models has lacked scientific rigour, efficiency and a systematic approach, which has led to uncertainty in decision making. Furthermore, few scientific studies have been conducted to develop validation methodologies for large-scale models, such as public transport models. For these reasons, a scientific validation methodology for public transport models has been developed in this thesis. This validation methodology has been applied on the 2014 route assignment model used by Trafikförvaltningen, for the transport modes bus, commuter train and local tram. In the developed validation methodology, the selected validation metrics called MAPE, %RMSE and R^2 are used to compare link loads from a route assignment model with observed link loads from an Automatic Passenger Counting (APC) system. To obtain an overview of the performance of the route assignment model, eight different scenarios are set, based on whether the validation metrics meet acceptable thresholds or not. In the application of the developed validation methodology, the average link loads for the morning rush have been validated. To adjust the developed validation methodology to system-specific factors and to set acceptable metric thresholds, discussions with model practitioners have taken place. The validation has been performed on both lines and links, and for bus entire line number series have been validated as well. The validation results show that commuter train meets the set threshold values in a higher proportion than bus and local tram do. However, Trafikförvaltningen is recommended to further calibrate the route assignment model in order to achieve a better model performance. The developed validation methodology can be used for validation of public transport models, and can in combination with model calibration be used in an iterative process to fine-tune model parameters for optimising validation results. Finally, a number of recommendations are proposed for Trafikförvaltningen to increase the efficiency and quality of the validation process, such as synchronising model data with the observed data.Under 2018 spenderade Trafikförvaltningen ungefär 2,2 miljarder kronor på nya infrastrukturinvesteringar för kollektivtrafiksystemet i Stockholm, varav många av dessa baserades på deras kollektivtrafikmodeller. Den tidigare metoden för att valideras dessa modeller har saknat gedigen vetenskaplig grund, effektivitet och ett systematiskt tillvägagångssätt, vilket lett till osäkerhet gällande investeringsbeslut. Dessutom har få vetenskapliga studier genomförts för att ta fram valideringsmetodologier för storskaliga modeller, såsom kollektivtrafikmodeller. Av dessa skäl har en vetenskaplig valideringsmetodologi för kollektivtrafikmodeller tagits fram i detta examensarbete. Denna valideringsmetodologi har tillämpats på Trafikförvaltningens 2014 års nätutläggningsmodell, för trafikslagen buss, pendeltåg och spårväg. I den framtagna valideringsmetodologin har de valda valideringsmåtten vid namn MAPE, %RMSE och R^2 använts för att jämföra länkbelastningar från en nätutläggningsmodell med observerade länkbelastningar från ett Automatisk Trafikanträkning-system (ATR). För att ge en översikt över modellens precision har åtta scenarios satts baserat på om valideringsmåtten godkänns eller inte enligt tröskelvärden. I tillämpningen av den framtagna valideringsmetodologin har de genomsnittliga länkbelastningarna för morgonens rusningstrafik validerats. För att justera den framtagna valideringsmetodologin efter systemspecifika faktorer och för att sätta godkända tröskelvärden för valideringsmåtten, har diskussioner med trafikanalytiker hållits. Valideringen har utförts både på linjer och länkar, och för buss har även hela linjeserier validerats. Valideringsresultaten för pendeltåg har en högre andel godkända mätningar än buss och spårväg. Trafikförvaltningen rekommenderas dock att kalibrera nätutläggningsmodellen ytterligare för att uppnå ett bättre resultat. Den framtagna valideringsmetodologin kan användas för valideringar av kollektivtrafikmodeller, och kan i kombination med modellkalibrering användas i en iterativ process för att finjustera modellparametrar och därmed optimera valideringsresultaten. Slutligen föreslås ett antal rekommendationer för Trafikförvaltningen för att öka effektiviteten och kvaliteten på valideringsprocessen, till exempel att synkronisera modelldata med observerad data.
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李嘉皓 and Ka-ho Carol Lee. "Public transport transfer systems: the policies and management of urban transport systems in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4293008X.
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Lee, Ka-ho Carol. "Public transport transfer systems the policies and management of urban transport systems in Hong Kong /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4293008X.
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Yip, Chi-ching Alexis. "Passenger safety of public transport systems in Hong Kong." Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B31945806.
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Yip, Chi-ching Alexis, and 葉智靑. "Passenger safety of public transport systems in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31945806.
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Guo, Zhan 1973. "Transfers and path choice in urban public transport systems." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45401.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2008.Includes bibliographical references (p. 285-294).
Transfers are endemic in public transport systems. Empirical evidence shows that a large portion of public transport journeys involve at least one change of vehicles, and that the transfer experience significantly affects the travelers' satisfaction with the public transport service, and whether they view public transport as an effective option. Despite their importance, however, transfers have long been overlooked by decision-makers, transportation planners, and analysts. Transfer-related research, practice, and investments are rare compared with many other aspects of transportation planning, probably because (1) the underlying transfer behavior is too complex; (2) the analysis methods are too primitive; and (3) the applications are not straightforward. This dissertation focuses on these issues and contributes to current literature in three aspects: methodology development, behavior exploration, and applications in practice. In this research, I adopt a path-choice approach based on travelers' revealed preference to measure the disutility associated with transfer, or the so-called transfer penalty. I am able to quantify transfer experience in a variety of situations in great spatial detail, and reduce the external "noises" that might contaminate the model estimation. I then apply the method to two public transport networks: a relative small and simple rail network (subway and commuter rail) in Boston and a large and complex network (Underground) in London. Both networks offer a large variability of transfer environment and transfer activities. Estimation results show high system-wide transfer penalties in both studies, indicating that transfer experience can have a very negative impact on the performance and competitiveness of public transport. They also suggest that the system-average value has limited applications in planning and operation because the transfer penalty varies greatly across station and movement. Such variation is largely caused by different transfer environments, not by different personal characteristics, attitudes, preferences, or perceptions, at least in the two investigated networks.
The two applications to the London Underground network illustrate that the lack of careful consideration of transfer effect can lead to inaccurate passenger flow estimation as well as less credible project evaluation and investment justification. The results further confirm the potential, as well as the importance, of transfer planning in major multimodal public transport networks.
by Zhan Guo.
Ph.D.
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Delaunay, Teddy. "L’intégration du covoiturage dans le système de mobilité francilien : hybrider le transport collectif et individuel pour asseoir l’hégémonie de l’automobile ?" Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1088/document.
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Les initiatives visant à développer le covoiturage au quotidien et sur de courtes distances font l’objet d’une attention croissante d’acteurs privés et publics depuis l’essor de la pratique sur de longues distances. Cette thèse analyse la manière dont les services de covoiturage intègrent le champ de l’action publique et interroge les transformations qu’ils occasionnent sur le système de mobilité en place. La thèse est structurée en quatre parties. Le cadrage théorique et méthodologique précise la démarche de recherche, qui s’ancre sur trois entrées : les relations entre territoire et système de mobilité, le changement dans l’action publique et le processus de diffusion des innovations dans la société. Ces approches théoriques sont mobilisées pour répondre à la problématique et étudier des expérimentations de services de covoiturage dans les franges de l’Île-de-France (partie 1). La seconde partie retrace la généalogie du covoiturage pour montrer comment il s’affirme comme nouvel élément du système de mobilité et comme un objet d’action publique (partie 2). Nous étudions ensuite le processus de diffusion du covoiturage et l’ampleur de son intégration au sein de l’action publique de transport (partie 3) avant d’analyser les transformations provoquées sur le système de mobilité (partie 4).Cette recherche précise comment les politiques publiques de promotion du covoiturage, initialement mises en œuvre pour limiter les externalités négatives de l’automobile, tendent désormais à concurrencer l’offre de transport publique routière. Ce travail montre ensuite comment s’ouvre une fenêtre d’opportunité pour le développement du covoiturage en France et expose les difficultés que rencontrent les acteurs de l’action publique pour s’approprier cette innovation. La thèse rend également compte de l’émergence de nouvelles formes de services de covoiturage, de nature infrastructurelle, qui favorisent la territorialisation des politiques publiques de covoiturage et l’intégration de ce mode dans le champ du service public de transport. Dans un dernier temps, cette recherche montre qu’en tendant vers une hybridation des modèles de transport collectif-public et individuel-privé, le covoiturage ébranle les principes du service public et promeut une représentation libérale de la notion d’intérêt général. Ce faisant, plus qu’il ne remet en cause les logiques sur lesquelles se fonde notre système de mobilité, il participe au renforcement du système automobile. Ce travail mesure ainsi les limites d’une logique de croissance et d’individualisation des services de mobilités et conclut en proposant des pistes pour optimiser le covoiturage en limitant le risque que les gains de performances promis par ce nouveau modèle ne renforcent trop, à terme, les externalités négatives du système automobileInitiatives aiming to develop carpools on a daily basis have been receiving increasing attention from private and public stakeholders since the rise of long-distance practice. This thesis analyzes how do carpooling services fit the field of public action and the transformations they cause on the mobility system in place. The thesis is structured in four parts. The theoretical and methodological framework specifies the research approach, which is anchored upon three entries: the relationship between the territory and the mobility system, the change in public action and the process of diffusion of innovations in society. These theoretical approaches are mobilized for an-swering to the research question and analyzing experiments of carpool services in the fringes of Ile-de-France (part 1). The second part traces the genealogy of carpooling and demonstrates how it becomes a new element of the public transport system and an object of public policies (part 2). We then study the diffusion process of the innovation and the extent of its integration into the public transport action (part 3), before analyzing the transformations caused on the mobility system (part 4).This research specifies how public policies promoting carpool were originally implemented to limit the negative externalities of the automobile system, and now tends to compete with the public road transport offer. This work then shows how a policy window open for the development of carpooling in France and exposes the difficulties that actors of the public action meets to appropriate this innovation. This research also presents the emergence of new forms of carpool infrastructure-related services, which favors the territorialization of carpool in the public transport policies and the integration of this mode of transport in the public’s utilities. Lastly, this research shows that, by tending towards a hybridization of public-private and individual-private transport models, carpooling un-dermines the principles of public service and promotes a liberal representation of the no-tion of general interest. In doing so, it is more likely that it strengthened the automobile system rather than it modifies it. Finally, this work demonstrate the limits of the growth and the individualization of mobility services and concludes by proposing ways to optimize carpooling by limiting the risk that the performance gains promised by this new model will reinforce, over time, the negative externalities of the automobile system
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Andolfato, Daniele Marques. "Racionalização do transporte público por ônibus da cidade de Jaú." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-29052007-161607/.
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Este trabalho enfoca o transporte público coletivo da cidade de Jaú. Os objetivos precípuos da dissertação são: fazer um diagnóstico do sistema de transporte por ônibus, no tocante à qualidade e à eficiência; e apresentar um projeto de racionalização do sistema (melhoria da qualidade e da eficiência). Os problemas mais graves verificados no diagnóstico foram os seguintes: existência de áreas ocupadas com acessibilidade insatisfatória (situadas além da distância aceitável da rede de linhas), superposições de áreas de influência das linhas, grande intervalo entre atendimentos devido ao excesso de linhas, ausência de integração tarifária, integração física precária, lotações baixas nos períodos fora dos picos, acúmulo de ônibus nos pontos de parada devido à coincidência de horários de diversas linhas, atrasos excessivos na área central, falta de abrigos na maioria dos pontos de parada, etc. No plano de racionalização desenvolvido foram previstas as seguintes principais ações: reestruturação da rede de linhas com a diminuição da quantidade de rotas e eliminação das superposições e faltas de cobertura espacial adequada, redução do intervalo entre atendimentos nas linhas, implantação de estação central fechada para promover integração física e tarifária, pavimentação/recapeamento de alguns trechos de vias, melhoria da sinalização viária nas ruas utilizadas pelos ônibus, melhoria do sistema de informação ao usuário, implementação de programação operacional racional, etc. Em termos de eficiência, os principais benefícios do sistema proposto são: redução da frota de 21%, redução da quilometragem percorrida de 18% e redução do custo de operação de 20%. No tocante à qualidade, os principais ganhos são: melhoria da acessibilidade (cobertura espacial), redução do intervalo entre atendimentos, redução dos tempos de viagem, promoção de integração tarifária, promoção de integração física adequada, aumento do número de abrigos nas paradas, melhoria da superfície de rolamento das vias utilizadas pelos coletivos, etc.This work focuses the urban collective public transportation system by bus of the city of Jaú. The main objectives of this work is to make a diagnostic of the system in terms of quality and efficiency and to present a plan in order to improve the quality and efficiency of the transit system. The main problems faced on the diagnostic were: inadequate space covering, overlapping of bus attendance, long headway between vehicles due to an exaggerate number of bus lines, absence of fare integration, deficient physical integration, low occupation of bus in non peak periods, bus traffic jam at bus stops due to inadequate schedule, huge delays in the central area due to traffic jam, lack of shelters at bus stops, etc. In the developed plan were proposed the following main actions: reorganization of the bus transit netword with reduction of the routes number and the elimination of overlapping of bus routes and the lacks of spatil covering service, reduction of the headway in the routes, implementation of a closed central station to promote physical and fare integration, pavement/rehabilitation of road pavement, improvement of system signs in bus streets, implementation of a rational operational programming, better distribution of the vehicles to the whole city; etc. In terms of efficiency, the main benefits of the proposed system are: fleet reduction 21%, total mileage reduction of 18% and operation cost reduction of 20%. Concerning to the quality, the main gains are: better space covering, small headway in the bus routes, travel time reduction, implementation of physical and fare integration, increase of the number of bus stops shelters, improvement of the rolling surface on bus streets, etc.
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Roux, Yolandi. "A comparative study of public transport systems in developing countries." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/5005.
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Includes abstract.Includes bibliographical references.
The large and mostly impoverished populations of African cities are dependent on public transport to provide them with accessibility and mobility. In most African cities, private vehicle ownership and traffic is increasing rapidly, scheduled or formal public transport systems are declining or have disappeared altogether and the unscheduled or informal Para-transit systems that have replaced them are unsafe and offer a low quality service. The problem with public transport planning in most African cities is that public transport is either poorly planned or not planned at all. This is due to the fact that there is a lack of adequate information and planning framework to guide decision makers and that they either select inappropriate systems based on those used in developed countries or allow private operators to decide. It is the responsibility of government to ensure that public transport systems meet the needs of the communities they serve and political decision-makers urgently need to make the right decisions for the development of public transport. Precise and relevant performance indicators and statistics will give a clear overview of the public transport systems of cities and will help to monitor the benefits of implementing efficient public transport systems. There is therefore a need to develop a methodology to assess public transport systems in African cities. The main aim of this study is to describe, discuss, and compare the public transport systems in developing countries. The methodology will be based on a set of performance indicators and related benchmarks that can be used to evaluate the public transport system of a city against certain goals. This study also describes the current existing public transport systems and their characteristics, as well as findings on the application of the methodology in Cape Town, Dar es Salaam and Nairobi. The literature review aims to identify the characteristics of public transport systems and to develop a methodology that can be used to describe, discuss and compare public systems. It is based on studies that have been done on the characteristics of public transport systems. The first part of the literature review examines various studies and papers on public transport to determine which components of the public transport system are important and is followed by a more detailed discussion on the characteristics of these components.
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Ben, Abdellah Abdellatif. "Contribution à l'étude des propriétés de transport électronique d'alliages liquides à base de manganèse et de transport électronique et atomique du système gallium-plomb présentant une lacune de miscibilité." Metz, 1994. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1994/Ben_Abdellah.Abdellatif.SMZ9441.pdf.
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L'objectif de ce travail est d'étudier les propriétés de transport électronique d'un certain nombre d'alliages dont le comportement structural est en quelque sorte anormal. Ainsi nous avons déterminé la résistivité électrique d'un alliage (Al-Mn) qui, à l'état solide, conduit à des quasicristaux. Nous avons substitué le gallium et le zinc à l'aluminium de façon à examiner l'évolution de la résistivité électrique en fonction de la position du polyvalent dans le tableau périodique. Le système gallium-plomb est typique d'une classe d'alliages à seuil de miscibilité bien marqué. Nous avons voulu examiner si, comme dans le cas du système Cu-Pb, une petite anomalie du coefficient de température de la résistivité indiquait des fluctuations de densité à longue distance susceptibles d'être détectées par la résistivité. Cela a bien été le cas. Nous avons mis en évidence une résistivité anormalement élevée dans le cas de l'alliage Al-Mn par rapport à celle de l'alliage Ga-Mn. Nous avons tenté d'expliquer ce comportement en calculant les déphasages des métaux étudiés en fonction de l'énergie, avec deux types d'échange et avec les deux structures électroniques possible du manganèse. Notre calcul permet d'améliorer considérablement les résultats mais ne permet pas encore de tout expliquer précisément. Dans un deuxième temps, nous avons étudié les propriétés de transport électronique dans la phase homogène. Nous avons, ensuite, étudié les limites du seuil de miscibilité du système Ga-Pb en utilisant un modèle simple. Enfin, nous avons mesuré les résistivités électriques de l'alliage Ga(0. 6)Pb(0. 4) dans différentes zones d'une cellule multi-électrodes. En dessous de Tc, le système se sépare en donnant lieu à deux alliages dont l'un est riche en gallium et l'autre riche en plomb. A l'aide de cette technique, nouvelle et totalement originale à notre connaissance, l'existence du gradient de concentration dans le capillaire permet d'étudier, d'un point de vue phénoménologique, le processus d'interdiffusion dans ce type de systèmeThe aim of this thesis is to study the transport properties of liquid transition metals alloys and the atomic transport properties of the Ga-Pb system which exhibits a miscibility gap. We have measured the electrical resistivity of Al-Mn liquid alloys, which, is quasicristaline, in the solid state. We have also extended this investigation to Ga-Mn and Zn-Mn in order to examine the electrical resistivity evolution as a function of the position of the polyvalent metal in the periodic table. The resistivity has been calculated with the phases shifts m(Ef). Our calculation is based on two possible electronic configurations of manganese and two exchange treatments. We have improved our results in taking into acount the energy dependance of phase shifts and using the Fermi energy obtained by a fit on the experimentals resistivities of pure metals. In addition, we propose a simple method to determine the boundary of a miscibility gap for Ga-Pb system. The optimized phase diagram for Ga-Pb has been obtained by using the square-well potential. The purpose of the last part is the use of a new experimental technique to measure the interdiffusion coefficient in the non dilute binary Ga-Pb, which exhibits a miscibility gap. This technique is based on the use of a finite capillary to measure the resistivity of different section of the capillary enabling us to deduce the concentration profile
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Vasseur, Gabriel. "Transport mésoscopique dans des systèmes d'électrons fortement corrélés." Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/public/theses_doctorat/2006/VASSEUR_Gabriel_2006.pdf.
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À l’heure où la miniaturisation électronique atteint ses limites, une meilleure compréhension du transport quantique à travers des systèmes de dimensionalité réduite, dans lesquels l’interaction entre électrons ne peut plus être ignorée ou même traitée comme une perturbation, devient primordiale. La description théorique du transport électronique dans de tels systèmes est de fait un des problèmes majeurs de la physique mésoscopique actuelle. Le traitement correct des corrélations introduites par l’interaction est un problème extrêmement non-trivial et malgré les nombreux travaux entrepris dans cette thématique et les résultats accumulés, beaucoup reste à faire pour réellement comprendre les effets des corrélations dans les nano-systèmes. L’approche retenue dans cette thèse consiste à simuler sur ordinateur des modèles physiques simplifiés et à se limiter à des tailles suffisamment petites pour pouvoir faire un traitement numérique exact. Le but est de mettre en évidence les mécanismes qui prennent place dans ces modèles et qui peuvent être similaires à ceux qui apparaissent dans les systèmes réels. En calculant numériquement (à l’aide de la technique de diagonalisation exacte de Lanczos) la statistique des niveaux d’énergie multi-particules, nous avons étudié les effets combinés du désordre et de l’interaction dans les systèmes bidimensionnels. Alors que l’interaction diminue les corrélations spectrales et donc augmente la localisation des électrons (caractère isolant) dans le régime de faible désordre, un comportement non-monotone apparaît dans le régime de fort désordre. Dans ce régime, alors que les électrons sont déjà localisés par le désordre, une interaction modérée a un effet délocalisant. Cette conclusion est confirmée par une étude de la structure des fonctions d’onde multiparticules. L’effet de délocalisation peut être compris comme résultant de réorganisations de charge dues à une compétition entre le désordre et l’interaction pour établir la structure de l’état fondamental. Nous nous sommes également intéressé à l’influence des corrélations sur la conductance des boîtes quantiques. Pour calculer numériquement la conductance en prenant en compte toutes les corrélations, nous avons utilisé une méthode récemment développée : la méthode de la boucle, utilisant un code basé sur l’algorithme DMRG. La généralisation de la méthode à des systèmes inhomogènes a permis d’étudier l’effet d’une tension de grille sur la conductance d’une chaîne en interaction. Bien que le couplage entre la chaîne et les fils jouant le rôle de réservoirs soit parfait dans notre modèle, nos résultats numériques, étendus par une étude analytique dans la limite de forte interaction, montrent que le blocage de Coulomb apparaît sous l’effet des corrélations. L’existence de ce blocage de Coulomb en l’absence de barrières de potentiel constitue le résultat le plus important de cette thèse. Enfin, nous avons aussi travaillé au développement de la méthode de la boucle pour des systèmes avec spin. Introduire ce degré de liberté est bien évidemment souhaitable en vue d’améliorer le réalisme des modèles étudiés. Les premiers résultats que nous avons obtenus montrent que la méthode est toujours valable pour ces systèmes.
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Lidström, Olsson Daniel. "Park and ride, effects on public transport ridership." Thesis, KTH, Transportplanering, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302526.
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As urban growth accelerates and the need to address environmental issues regardingtransportation is larger than ever and many policymakers have chosen to adapt park and rideas one of their methods to reduce car traffic. However, the effect from adapting the policy isnot very well understood and since the policy can directly conflict with other policies relatedto land use it is important to know which effects can be expected. By knowing which effectsto expect, policy makers can make more sustainable choices in their policy adaption.This study has been carried out using data from two different counties to find out if theeffects from park and ride differ depending on the type of environment it serves. Further, anadditional analysis has been done using temporal data to measure the effect of adapting orexpanding a park and ride facility at a public transport station or stop.It was found that in a rural setting, the relation between park and ride and the number ofpassengers at a public transport station is strong. Stations with more parking spaces hadhigher ridership. This was not the case for stations located in a suburban environment, someeffect was indicated but the relationship was not as strong. The analysis of the two countiesdata showed unreasonably high passenger increases from P&R, indicating that some otherfactor also influences the result in this analysis.From the analysis of the temporal dataset the result showed that stations which adapted parkand ride did have a higher average passenger increase than the general trend within thetransport system. This indicates that park and ride do in fact increase public transportridership.Den accelererande urbaniseringen har gjort behovet av att hantera miljöpåverkan ifråntransportsystemet större än någonsin och många beslutsfattare har valt att förordapendlarparkering (park and ride) som en metod för att minska biltrafik. Effekterna av attanvända denna planeringsmetod är dock inte fullt kända och eftersom pendlarparkeringar kanhamna i konflikt med andra planeringsmetoder som berör markanvändning så är det viktigtatt veta vilka effekter som kan förväntas av att införa pendlarparkeringar. Genom att vetavilka effekter som kan förväntas så blir möjligheterna bättre för beslutsfattare att tavälgrundade beslut och införa hållbara direktiv kopplade till stads och trafikplaneringen.Den här studien har utförts med data från två olika regioner för att ta reda på om effekterna avpendlarparkeringar skiljer sig beroende på vilken typ av miljö den är implementerad i.Dessutom har ytterligare en analys gjorts baserad på historiska data över resande, detta för attkunna mäta den direkta effekten av att införa eller expandera pendlarparkering på en hållplatsinom kollektivtrafiken.Resultatet visade att i glesbebyggda områden så var sambandet mellan antalet platser påpendlarparkeringar och antalet passagerare starkt. Statiner med fler pendlarparkeringsplatserhade fler resande än de med färre. Sambandet var inte lika starkt för stationer i förortsmiljö,ett visst samband kunde uppmätas men det var inte lika starkt. Analysen av de två regionernavisade dock på orealistiskt höga förhållanden mellan antalet pendlarparkeringsplatser ochantalet passagerare vilket indikerar att någon annan faktor också påverkar resultatet.Från analysen av historiska data över antal resande så visade resultatet att införandet avpendlarparkeringar ökar resandet med kollektivtrafiken i genomsnitt mer på de stationer därde införs jämfört med den generella trenden i kollektivtrafiksystemet. Detta indikerar attpendlarparkeringar har en positiv effekt på antalet resande med kollektivtrafiken.
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Dongkai, Yang, Bai Xin, and Zhang Qishan. "VEHICLE MONITORING SYSTEM FOR PUBLIC TRAFFIC IN BEIJING." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/607294.
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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, NevadaWith the rapid development of urban economy, there are bus increasing, route extending, and shuttle frequency increasing etc. At the same time, road construction is subject to land surface, so traffic jam often occurs. It is a big trouble for life of citizens and problem for economy development. So it needs to be improved as fast as possible. Vehicle monitoring system for public traffic in Beijing can expediently monitor the state of each controlled bus, thereby making perfect management. With the integration of GPS, analog trunked communication and digital map, the old, blinding manage system of public traffic would be changed into advanced, visualized management mode, and several routes are dispatched in one dispatch center at the same time. The system frame and its components are introduced in this paper.
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Yao, W. "Applying public private partnerships to the provision of intelligent transport systems." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1348213/.
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As an integrated transport solution, ITS (Intelligent Transport Systems) produce direct benefits for the traveller and operator and bring indirect benefits for society as a whole. Nevertheless, insufficient ITS funding holds back ITS development. PPP (Public Private Partnerships) offers an alternative financing channel, which can be advantageous for both public and private parties. Due to the characteristics of ITS, it can be difficult to attract the private sector to invest in some ITS projects where there is a fluctuating profit stream or where the profits cannot cover the investment. In addition, due to the existence of asymmetric information, it is possible for the private company to abuse his/her advantage in information over the public authority to seek excessive private gains. The aim of this research is to develop an incentive mechanism for a PPP contract for the provision of ITS, not only to motivate the private company to enter ITS markets but also to reduce the impact of asymmetric information between the two parties. The benefits and risks to both parties of entering into a contract for ITS provision are revealed in the World Bank and USDOT (United States Department of Transport) databases. ITS costs, potential funding sources, and the economic aspects of ITS are examined. The variety and interdependency of ITS cost components imply that it is possible for the private company to reduce costs under an appropriate incentive mechanism. Additional profit streams can diversify ITS funding sources and make it possible for otherwise low profit or non profit ITS systems to be provided without using government subsidy or an increase road user tolls. In this thesis, an investigation is conducted of ITS provision through PPPs in China, to investigate how they are used in the Chinese road sector and the bottlenecks in ITS development. There are two case studies to show how government regulation is used to encourage ITS provision through user payment and through subsidy. These findings provide a useful reference point for other areas of the world and are especially relevant to developing countries. A comprehensive evaluation framework is developed in this thesis to assess the ITS benefits to the travellers and the wider benefits to the community. Two case studies are presented to demonstrate these methods. In case study One, an SP survey of 1,357 motorway users was conducted in 2007, which examines travellers’willingness to pay for three distinct ITS systems on the Shanghai motorway network. In case study Two, using both AHP and REGIME models, an evaluation of the degree of traffic impact of these three ITS systems is presented. Their relative importance in Shanghai ITS motorway management is then established. This research leads to the development of a theoretical model which incorporates suitable incentive mechanisms for ITS provision through PPPs, on the basis that both parties expect value for money. Complexity has been increased in this model by introducing a subsidy and a shadow cost of subsidy variable, which has not been used in the previous literature. The relationship between subsidy and the efficiency level of the private sector is discussed under conditions of information asymmetry and symmetry. The model shows that it is possible for the private company to maximize the benefits of both the public authority and private company under two constraints, namely Individual Rationality (IR) and Incentive Compatibility (IC). Two working examples sourced from the case studies of two different ITS systems are used to calculate the potential profit and risk costs, first under a flexible payment scheme and then how this simplified by the use of an ITS incentive model. These examples strengthen the argument for the use of incentive models and contribute to ITS project profit control, which is the key for a successful ITS project through PPP.
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Zidi, Salah. "SARR : système d'aide à la régulation et la reconfiguration des réseaux de transport multimodal." Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-Zidi.pdf.
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II est bien difficile, en temps réel, de suivre les horaires issus du processus de planification des réseaux de transport réalisée en temps anticipé. En effet, l'apparition de perturbations complexes et aléatoires nécessite un traitement rapide à travers un processus de régulation. Dans ce contexte, nous proposons un système d'Aide à la décision nommé SARR (Système d'Aide à la Régulation et la Reconfiguration), pour assister les exploitants dans ces tâches de gestion d'exploitation. Les premières contributions portent sur l'élaboration d'un module d'apprentissage et de classification utilisant la technique S. V. M (Séparateurs à Vaste Marge) pour le diagnostic et la régulation des cas familiers. Mais dans les cas de perturbations plus complexes, simultanées et difficiles à gérer, nous proposons alors une première approche à colonie de fourmis pour la reconfiguration spatiale nommé ACFRS (Algorithme à Colonie de Fourmis pour la Reconfiguration Spatiale). Un autre algorithme est développé pour la régulation horaire appelé ACFRH (Algorithme à Colonie de Fourmis pour la Régulation Horaire). Ces deux approches disposent de bonnes performances en termes de convergence et qualité de solutions, Ces dernières sont prouvées et montrés à travers des scénarii de simulation.
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Gebhard, Susanne, and n/a. "The Phn and Pst systems of Mycobacterium smegmatis : phosphate transport and gene regulation." University of Otago. Department of Microbiology & Immunology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070502.112113.
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Phosphate is an essential but often growth-limiting nutrient for bacteria. At low concentrations of phosphate in the growth medium, bacteria induce high-affinity uptake systems for phosphate, and this is usually the ABC-type phosphate specific transport system Pst. In the fully sequenced genomes of pathogenic species of mycobacteria, several copies of the genes encoding for the Pst system (pstSCAB) have been identified and some of these genes have been shown to be virulence factors. The reasons for the presence of multiple copies of pst genes in pathogenic mycobacteria are not understood, and phosphate transport by these bacteria, as well as the gene regulation involved, is poorly characterised. The fast-growing M. smegmatis contains only a single copy of the pst operon, but we recently identified a gene locus containing three genes, phnDCE, which encode for a putative ABC-type phosphate/phosphonate transport system, and a gene, phnF, which encodes for a putative transcriptional regulator of the HutC subfamily of GntR like regulators.
To identify a function for the PhnDCE transport system and to characterise high-affinity phosphate transport in M. smegmatis, we created allelic exchange mutants in phnD and pstS, as well as a phnD pstS double deletion mutant. All three mutants failed to grow in minimal medium containing 10 mM phosphate, while the wildtype was able to grow in the presence of micromolar phosphate concentrations. No differences were observed in complex growth medium. Steady-state levels of [��P]-phosphate uptake were approximately 25% lower in all mutant strains as compared to the wildtype. Kinetics of phosphate uptake in the wildtype strain when grown at low phosphate concentrations (50 [mu]M P[i]) were biphasic, suggesting the presence of two inducible transport systems with apparent K[m] values of 16 [mu]M P[i] and 64 [mu]M P[i], respectively. Analysis of the kinetics of phosphate transport in the mutant strains led us to the proposition that the Pst system has an apparent Km value of ca. 16 [mu]M P[i], and the Phn system has an apparent Km of ca. 60 [mu]M P[i]. A third inducible phosphate transport system, which was active in the double mutant strain, had an apparent K[m] of ca. 90 [mu]M P[i]. Uptake of phosphate in all strains was not inhibited by the presence of excess phosphonates or phosphite, suggesting that all three transport systems were specific for phosphate. The study of phosphate transport in the presence of various metabolic inhibitors revealed that uptake by the Phn and Pst systems is driven by ATP-hydrolysis, consistent with ABC-type transport, while the third, unidentified transport system may be driven by the proton motive force.
We showed that phnDCE formed an operon, and that the promoter area of the operon lies within 200 bp of the start of phnD. To investigate the regulation of the phn and pst genes, β-galacosidase activities of strains carrying transcriptional lacZ-fusions of the pstSCAB, phnDCE and phnF promoter areas, and levels of mRNA of the phn and pst genes were studied. All genes were induced when phosphate concentrations fell below a threshold value of 30 [mu]M, which coincided with a shift in the growth characteristics of M. smegmatis. Expression of the pst operon appeared to be controlled directly by the PhoPR two-component regulatory system, while the phn operon may be under direct or indirect control by PhoPR.
To identify a role for PhnF in the regulation of phn gene expression, we created a phnF deletion mutant. PhnF appeared to repress transcription of phnDCE and phnF under phosphate-replete conditions. We identified two putative binding sequences for PhnF in the intergenic region between phnD and phnF with the sequence TGGTATAGACCA, which is similar to the proposed recognition consensus for HutC-like transcriptional regulators. Using site-directed mutagenesis of these sequences, we demonstrated that they are required for the repression of phnDCE and phnF. To prove PhnF binding to these potential binding sites, we attempted to express the M. smegmatis PhnF protein in E. coli, but could not obtain soluble recombinant protein. Electrophoretic mobility shift assays of the phnDCE promoter fragment using cell-free crude extracts of M. smegmatis were not successful.
We propose that Pst and Phn both constitute high-affinity phosphate specific transport systems of M. smegmatis, and that a third inducible phosphate transport system is present in this bacterium. PhnF is required for repression of phnDCE and phnF transcription under phosphate-replete conditions, while induction of the pst operon, and possibly the phn operon, under phosphate-limited conditions involves the PhoPR system.
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Prendiville, Alison. "An investigation into the design and specification of revenue collection systems in urban mass transit." Thesis, University of East London, 2001. http://roar.uel.ac.uk/1226/.
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This thesis describes the nature of the specification and design of revenue collection systems from four urban mass transit systems: Manchester Metrolink, Sheffield Suptertram, Grenoble Tag Light Rail system and the Netherlands National Ticketing system. Previous research in this area has been generated from an industry perspective that has focused on new technologies and types of ticketing systems available. In addition fare collection is frequently discussed, and there is academic research available, in relation to pricing theory and policy. However, as yet there appears to be no theoretical or empirical research examining urban mass transit revenue collection systems and their specification. This research was initiated from a supplier of revenue collection systems expressing dissatisfaction in the design and specification selection procedure. In addition there was a need to conceptualise the important role that a revenue collection system plays in achieving a public transport operator's objectives. The aim of this study was to add to the theoretical base of this research area through the four case studies and to improve the design and selection of revenue collection systems in `real life' situations. Due to the nature of the research area being `real world' and revenue collection systems being bespoke, theoretical propositions were created from the literature review in order to guide the research and test the hypothesis. Through the theoretical proposition the role of the revenue collection system in a service marketing context is also established. This thesis is presented in seven chapters. Chapter 1 provides an introduction and background information to the research area. In Chapter 2 the research methodology is discussed together with the nature of the research. In Chapter 3 the literature review and the generation of the theoretical propositions and hypothesis are presented. In Chapter 4 the case studies describe the nature of the revenue collection systems and their specifications. In chapter 5 the case study analysis is undertaken based upon the theoretical propositions. Chapter 6 presents the overall conclusions and tests the hypothesis; it also presents recommendations for improving revenue collection system specification. Finally Chapter 7 discusses the research and its strengths and weaknesses and suggests areas for further research.
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Gonzva, Michaël. "Résilience des systèmes de transport guidé en milieu urbain : approche quantitative des perturbations et stratégies de gestion." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1088/document.
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Lorsque surviennent des risques naturels, les dommages aux systèmes urbains représentent habituellement des conséquences économiques et sociales importantes. Parmi eux, les systèmes de transport guidé restent aujourd'hui particulièrement vulnérables notamment face au risque inondation. Par ailleurs, le concept de résilience connait d’importants développements dans le domaine de la gestion des risques naturels. La résilience peut se définir comme la capacité d’un système à absorber une perturbation et à récupérer ses fonctions à la suite de celle-ci.L’objectif de la thèse est d’étudier la vulnérabilité et la résilience des systèmes de transport guidé face au risque inondation à partir d’une analyse des mécanismes de défaillance. Ces systèmes sont assimilables à des systèmes hautement compliqués avec de multiples interdépendances entre les éléments. Etudier ces interdépendances, dans le cas d’une inondation, permet une approche comparative des trois configurations traditionnelles d’implantation d’un système de transport guidé~: en souterrain, en surface et en aérien.Cette démarche qualitative est combinée à une modélisation probabiliste, basée sur l’utilisation des réseaux bayésiens, du système soumis à un risque inondation. La thèse présente la démarche construite qui rend possible~: l’élaboration d’une approche globale c’est-à-dire de l’occurrence de l’aléa avec ses caractéristiques données d’intensité~; l’identification des dommages matériels directs~; l’identification des dommages matériels indirects c’est-à-dire ceux occasionnés par des effets domino~; la déduction des conséquences fonctionnelles c’est-à-dire les modes de fonctionnement dégradé du système relatif à son exploitationThe vulnerability of guided transport systems facing natural hazards is a burning issue for the urban risks management. Experience feedbacks on guided transport systems show they are particularly vulnerable to natural risks, especially flood risks. Besides, the resilience concept is used as a systemic approach for making an accurate analysis of the effect of these natural risks on rail guided transport systems.The purpose of this thesis is to provide an analysis of guided transport systems’ resilience in the face of flood risks through a study of the failure mechanisms to which the components of these systems are subjected. Indeed, the urban critical infrastructures such as guided transport systems are complex systems in which the components are strongly interdependent. This interdependency may imply many failures caused by cascade effect within the system.Moreover, the qualitative methodology is linked to a probabilistic framework. Indeed, from the probability of a natural hazard occurring with a given intensity through components failures due to cascade effect, the objective is to assess the probability of degraded modes of operation. This probabilistic framework allows to shift from a qualitative approach based on dependability methods to a quantitative approach based on Bayesian networks
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Steiner, Konrad [Verfasser]. "Integrated Strategic and Tactical Planning for Public Transport Bus Systems / Konrad Steiner." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1196054665/34.
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Ahern, Aoife. "The potential impact of new urban public transport systems on travel behaviour." Thesis, University College London (University of London), 2001. http://discovery.ucl.ac.uk/1317551/.
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Predicting the potential impacts of new urban public transport on people's travel behaviour is very complex. A key aspect of travel behaviour is the choice of mode. It is particularly difficult to estimate the number of people who will use new urban public transport systems. Understanding modal choices related to these systems is especially important in view of concerns about the impact of the car on the environment, on quality of life and on congestion levels in towns and cities. In this thesis, the modal choices of potential users of two new light rail systems, Luas in Dublin and Tramlink in Croydon, are examined. The decision-making processes behind these people's modal choices are explored using a theory that has been borrowed from social psychology called the Theory of Planned Behaviour. In order to apply the Theory of Planned Behaviour it is necessary to identify the attitudes, beliefs and perceptions of behavioural control of potential users. Hence, interviews have been carried out with potential users of Croydon Tramlink in the six months immediately prior to its opening. This thesis will describe those interviews, the analysis of them and the findings. In addition, follow-up studies were conducted six months after the opening of the system in order to examine how many of the interviewees had used the system. In Dublin, questionnaires were distributed to potential users of the new light rail system planned for the city. The questionnaires were distributed 2 years before the planned opening of the system. The thesis concludes that the Theory of Planned Behaviour is an appropriate tool for understanding and explaining modal choices, particularly those modal choices that relate to new urban public transport. It is also concluded that both Luas and Tramlink are likely to be successful systems and will generate new trips.
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Allansson, Jakob, and Elin Kajander. "Equity in public transport planning? : An investigation of the planning and implementation of a new public transport system and its social consequences in Cape Town." Thesis, Malmö universitet, Malmö högskola, Institutionen för Urbana Studier (US), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-36866.
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Since the 1990s sustainability has been a keyword in all kinds of development. Urban planning is not an exception. The three most common aspects of sustainable development are economic, social, and ecological. However, there are many academics that claim that these three aspects are not prioritized equally. Patsy Healey (2007) among others argues that the economical aspect is hegemony and that sustainable social and ecological development is dependent on economic measures. The purpose of this thesis is to study the planning and implementation of a new public transport system in Cape Town, South Africa, and to investigate how it relates to sustainable social development in particular. This since Cape Town has a long history of segregation of different groups, and today there are large income inequalities and geographical distances that increase the social exclusion in the city. The theoretical framework is concentrated into three themes; Social justice and equity in public transport planning, accessibility and mobility, and finally, social exclusion. The empirical data is collected with a qualitative method in the form of a case study. We can conclude that even though the notion of investing in public transport to combat social exclusion is present in the planning documents in Cape Town, the implementation and investments in the new public transport system do not always follow the documents’ principles. This contributes to little or no change regarding social exclusion in Cape Town.
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Cunty, Claire. "Système d'information géographique et sécurité : une application pour la RATP." Phd thesis, Université Panthéon-Sorbonne - Paris I, 2004. http://tel.archives-ouvertes.fr/tel-00008685.
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Les services de sécurité de la RATP ont souhaité se doter d'un outil informatique pour la représentation cartographique et l'analyse des diverses atteintes aux personnes et aux biens répertoriés dans leur base de données. Dans le cadre d'un contrat CIFRE nous avons constitué un système d'information géographique (SIG) qui permet, à partir de cette base, la réalisation automatique de divers types de cartes, et qui contient des procédures pour l'analyse spatiale et la visualisation spatio-temporelle des processus de délinquance dans le réseau de transport parisien. Le phénomène de la délinquance s'inscrit dans des préoccupations de société, fortement médiatisées, c'est pourquoi il nous a paru utile de consacrer une première partie de la thèse à l'analyse scientifique des questions relatives à la transgression des normes et aux réactions sécuritaires, à partir des investigations menées par des sociologues, des statisticiens, des criminologues, voire des économistes. Nous avons ensuite montré quels pouvaient être les apports de la cartographie à ces analyses, déjà bien intégrée dans les pays anglo-saxons mais encore rarement mise en œuvre en France. Les formulations actuelles des politiques de sécurité ont en effet apporté des conditions favorables à cette coopération. L'exploitation des statistiques de la base de données SAFIRS pour l'année 2001 nous a permis d'analyser la répartition des types d'atteintes selon les réseaux et les lieux. L'image globale oppose d'une part Paris, où la délinquance, concentrée sur le réseau ferré, s'exerce principalement à l'encontre des voyageurs, et d'autre part la banlieue, où les atteintes, principalement enregistrées sur le réseau de surface, prennent pour cible le transporteur perçu comme représentant de l'institution. La géographie de la délinquance présente des concentrations, qui ne s'expliquent pas toutes par les inégalités des volumes de trafic dans les stations. Nous avons mis en évidence des effets de regroupement sur certains axes du réseau, grâce à des mesures d'autocorrélation spatiale. Nous avons également réalisé des cartes animées qui montrent des processus de transfert d'un lieu à l'autre et ouvrent des possibilités futures de modélisation de la dynamique spatio-temporelle de la délinquance.
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Englund, Gustav, and Martin Westh. "Transition to electric-powered buses in Stockholm inner citys public transport." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-144582.
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Ökad urbaniseringen och ett annalkande klimathot skapar ett behov av miljövänlig kollektivtrafik. El är ett drivmedel som är på frammarsch. Det finns dock frågor ekonomi och hur praktiska lösningar ska vara utformade. Grundfrågeställningen för detta arbete har varit huruvida en övergång är möjlig att genomföra till 2022. Även de generella möjligheterna, förutsättningarna och konsekvenserna för en övergång till helt eldrivna bussar i Stockholms innerstad undersökts. Slutsatsen har dragits att det rent tekniskt är möjligt att genomföra en övergång till år 2022. Fordons- och batteriteknik finns. Det innebär dock att det kommer uppstå vissa frågor. Bland annat är eldrivna bussar mindre flexibla. Övergången kommer innebära stora kostnader som på sikt kan visa sig lönsamt då eldrift är ett billigare drivmedel. De hinder som finns för en övergång är bland annat de nuvarande trafikavtalen och otydlighet kring laddinfrastrukturen. En övergång kommer leda till positiva miljökonsekvenser såsom minskade koldioxidutsläpp och minskat buller.
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Chun, Jae Seung. "Efficiency of the evolution paths for space transportation system (STS) technology : a qualitative analysis." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. https://publication-theses.unistra.fr/public/theses_doctorat/2005/CHUN_Jae_Seung_2005.pdf.
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Cette étude vise à analyser les facteurs à l'origine des problèmes rencontrés par les programmes américains de développement de lanceurs réutilisables (Reusable Launch Vehicles – RLV), en évaluant la plausibilité des sentiers d'évolution technologique. Afin d'arbitrer entre les sentiers, nous construisons dans un premier temps l'ensemble des sentiers évolutionnaires physiquement possibles, tels que déterminés par les facteurs purement endogènes. Nous avons dans un deuxième temps analysé leur plausibilité. Pour mener à bien la première étape nous avons élaboré une nouvelle méthodologie, ' l'Arbre Hiérarchique d'Evolution Hors Facteurs Exogènes ' (AHEHFE). A l'aide de cette méthodologie, nous avons tout d'abord développé un répertoire des options technologiques des lanceurs puis construit l'arbre hiérarchique évolutionnaire à partir des lanceurs répertoriés, en appliquant les règles d'évolution suivantes: le classement d'hérédité des éléments technologiques et le degré de complexification. Pour la deuxième étape, nous avons trié les sentiers évolutionnaires soutenables en appliquant les facteurs exogènes à l'AHEHFE, puis analysé leur plausibilité en fonction de deux critères d'évaluation: le degré de difficulté de l'apprentissage et l'efficience de la création de connaissances et de leur consolidation. Ces deux critères découlent de la nature du domaine des Systèmes de Transport Spatial (STS), domaine intensif en connaissances où la création de connaissances joue un rôle crucial dans le développement de l'industrie tout comme dans la technologie du produit. Notre analyse démontre que l'approche 'bottom up' offre un sentier plus plausible que l'approche 'top down'. Le cas des programmes de développement américains de RLV montre par ailleurs que les programmes orientés mission initiés par le gouvernement sont basés sur l'approche 'top down' alors que deux initiatives privées, le lanceur Pégase et le véhicule suborbital SpaceShipOne relèvent de l'approche ' bottom up'. Cette étude de cas a partiellement confirmé que l'approche 'top down' est moins plausible, au vu de l'échec du développement du X-33 et des coûts d'opération extrêmement élevés de la navette spatiale. En ce qui concerne l'approche 'bottom up', le nombre de programmes de RLV en cours est insuffisant pour fournir les données nécessaires à une analyse satisfaisante permettant de conclure sur la plausibilité de cette approche.
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Ušpalytė, Vitkūnienė Rasa. "Miesto viešojo transporto maršrutinio tinklo modeliavimas ir plėtra (Vilniaus miesto pavyzdžiu)." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20061103_114347-14327.
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The aim of this paper is to guarantee improved quality of life for inhabitants by modelling the network of public transport routes in Vilnius. To achieve the aim of the paper, the following tasks were formulated: • analysis of measures of modelling the public transport passenger flows, as well as analysis their function, • establish the main criteria of the public transport’s modelling in Vilnius, • modelling of the public transport route networks in accordance with the established criteria, • assessment of the influence of speedy trams on the distribution of passenger flows within the public transport of Vilnius, • proposals on the possibilities of application of the public transport modelling criteria for other Lithuanian towns.
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Granet, Mathieu. "Constantes de temps des processus d'érosion et d'altération dans le système himalayen : Approche géochimique élémentaire et isotopique par les séries de l'Uranium." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/GRANET_Mathieu_2007.pdf.
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La détermination des constantes de temps caractéristiques des processus d’érosion mécanique et d’altération chimique est une étape indispensable pour comprendre la réponse des reliefs vis-à-vis des forçages externes tels que la tectonique, le climat et les activités anthropiques. Cette problématique est abordée par l’analyse des nucléides des séries de l’uranium dans les sédiments et les matières en suspension transportés par les rivières himalayennes des bassins du Gange et du Brahmapoutre. Dans le bassin du Gange, les constantes de temps d’altération déterminées dans la haute chaîne à partir de l’étude des sédiments grossiers de la Kali Gandaki varient de quelques milliers d’années, où la surrection est maximale, à 350 ka. Elles traduisent ainsi une durée d’altération très importante des roches en place avant que les produits d’altération ne soient transportés sous forme de sédiments dans les rivières. En sortie de chaîne, ces sédiments sont transportés par les affluents du Gange, la Gandak et la Ghaghara, sur une période de transfert de l’ordre de 100 ka. L’étude des sédiments à l’exutoire des affluents du Brahmapoutre suggère quant à elle des périodes d’altération variant entre 110 et 270 ka. Ces temps longs confirment le rôle des périodes de stockage provisoires en différents endroits du bassin. Dans le Gange et la Brahmapoutre, les constantes de temps déterminées pour le transfert des sédiments sont respectivement de 575 ka et de 160 ka, c’est-à-dire du même ordre de grandeur que les temps de réponse de ces deux fleuves. Ces temps longs étant supérieurs aux temps caractéristiques des oscillations climatiques quaternaires, ils confirment le pouvoir tampon des plaines alluviales asiatiques sur les variations de flux sédimentaire haute-fréquence en réponse aux forçages externes dans la haute chaîne. L’étude des matières en suspension suggère que leurs compositions chimiques reflètent le rôle des processus de mélange entre des sédiments grossiers et du matériel superficiel plus fin, recyclé par la végétation et ayant des origines variées. A la différence des sédiments grossiers, les temps de transfert des matières en suspension seraient rapides ce qui suggère le potentiel des nucléides des séries de l’uranium pour aborder les lois de transport solide des particules en fonction de leurs taillesThe time-scales of erosion and weathering processes are key parameters which need to be determined to understand the response of the reliefs to external forcings like tectonics, climate and human activities. They were recovered by using U-series nuclides analyzed in sediments and suspended materials carried by the Himalayan rivers of the Ganges and Brahmaputra basins. In the Ganges basin, the time-scales of weathering determined from the study of coarse sediments carried by the Kali Gandaki range from several ky, where the surrection is located, to 350 ky. Such values indicate that the bedrocks are in situ weathered for a long period before the weathering residual products get transported in the rivers as coarse sediments. At the outlet of the high range, these sediments are carried by the tributaries of the Ganges, the Gandak and Ghaghara, during a transfer period of about 100 ka. The study of the sediments at the outlet of the Brahmaputra tributaries allows to propose time-scales of weathering ranging from 110 to 270 ky. Such long periods confirm that during their transfer in the plains, the sediments are temporarily trapped at several places in the basins. In the Ganges and Brahmaputra rivers, the time-scales of sedimentary transfer are 575 and 160 ky, respectively. These values, which are of the same order as their response times, are much longer than the time-scales of the Quaternary climate oscillations. It confirms the buffering action of the asiatic alluvial plains for the high-frequency sediment flux variations in response to external forcings in the chain. The study of suspended materials suggests that their chemical compositions result from the mixing of coarse river sediments with fine particles from various locations in the basin which are affected by vegetation recycling. By contrast to coarse sediments, the time-scales of transfer for the suspended materials are fast, e. G. A few ky, pointing the potential of U-series nuclides to assess particle transport laws as a function of their size
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Gudymenko, Ivan. "Privacy-preserving E-ticketing Systems for Public Transport Based on RFID/NFC Technologies." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-168906.
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Pervasive digitization of human environment has dramatically changed our everyday lives. New technologies which have become an integral part of our daily routine have deeply affected our perception of the surrounding world and have opened qualitatively new opportunities. In an urban environment, the influence of such changes is especially tangible and acute. For example, ubiquitous computing (also commonly referred to as UbiComp) is a pure vision no more and has transformed the digital world dramatically. Pervasive use of smartphones, integration of processing power into various artefacts as well as the overall miniaturization of computing devices can already be witnessed on a daily basis even by laypersons. In particular, transport being an integral part of any urban ecosystem have been affected by these changes.
Consequently, public transport systems have undergone transformation as well and are currently dynamically evolving. In many cities around the world, the concept of the so-called electronic ticketing (e-ticketing) is being extensively used for issuing travel permissions which may eventually result in conventional paper-based tickets being completely phased out already in the nearest future. Opal Card in Sydney, Oyster Card in London, Touch & Travel in Germany and many more are all the examples of how well the e-ticketing has been accepted both by customers and public transport companies.
Despite numerous benefits provided by such e-ticketing systems for public transport, serious privacy concern arise. The main reason lies in the fact that using these systems may imply the dramatic multiplication of digital traces left by individuals, also beyond the transport scope. Unfortunately, there has been little effort so far to explicitly tackle this issue. There is still not enough motivation and public pressure imposed on industry to invest into privacy. In academia, the majority of solutions targeted at this problem quite often limit the real-world pertinence of the resultant privacy-preserving concepts due to the fact that inherent advantages of e-ticketing systems for public transport cannot be fully leveraged.
This thesis is aimed at solving the aforementioned problem by providing a privacy-preserving framework which can be used for developing e-ticketing systems for public transport with privacy protection integrated from the outset. At the same time, the advantages of e-ticketing such as fine-grained billing, flexible pricing schemes, and transparent use (which are often the main drivers for public to roll out such systems) can be retained.
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Dunlop, Rachael. "Public art and the contemporary urban environment with an emphasis on transport systems." Thesis, University of Westminster, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296116.
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Karim, Mohamed. "L’appropriation du tachygraphe numérique par les conducteurs d’une société privée de transport public de voyageurs." Thesis, Evry, Institut national des télécommunications, 2012. http://www.theses.fr/2012TELE0047.
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Ce travail doctoral porte sur l’appropriation d’un outil de gestion de l’activité temporelle et de contrôle, « le tachygraphe numérique », par les conducteurs d’une société privée de transport de voyageur. Cet outil conçu et imposé par l’Union Européenne pour renforcer la sécurité routière n’a fait, à notre connaissance, l’objet d’aucune recherche antérieure. Une approche théorique plurielle de l’appropriation, ses facteurs et les typologies d’utilisateurs est adoptée. Elle se base sur la multiplicité des recherches conduites sur la thématique de l’appropriation des outils de gestion et des technologies. Soixante-quatorze entretiens avec des salariés et responsables ont été conduits dans un contexte d’immersion durant trois ans au sein de cette société de transport. Un processus inductif a été privilégié. Cette recherche permet d’une part de montrer que : 1. Il y a appropriation du tachygraphe numérique par l’entreprise et ses conducteurs. 2. Plusieurs facteurs influent sur l’appropriation du tachygraphe numérique par les conducteurs : les facteurs liés aux caractéristiques de l’outil (simplicité, complexité, efficacité, compatibilité, nécessité), les facteurs individuels (expérience professionnelle, situation familiale, efficacité personnelle, image de soi) et les facteurs contextuels (autorités de contrôle extérieur, contrôle interne, les collègues). 3. Il existe quatre attitudes des salariés face à l’outil : rejet, application, adaptation / détournement, déplacement. D’autre part, l’introduction d’une technologie de contrôle de l’activité temporelle dans une entreprise n’est pas neutre. Petit à petit ce sont les relations entre les responsables et les conducteurs ainsi que la conception qu’ont les conducteurs de leur métier qui sont bouleversées. L’appropriation d’une telle technologie modifie non seulement les pratiques et les relations mais c’est sans doute la notion même d’appropriation qui apparaît sous un jour plus complexeThis work concentrates on a device that manages and controls working times for the drivers of a private transportation company (Coaches N): the digital tachymeter. To our knowledge, this tool, designed and enforced by the European Union in order to enhance traffic security, has never been investigated so far. A plural theoretical approach of the question of its appropriation, of its factors and of the users’ typologies is adopted. This approach is based on the numerous previous studies on management tools and technology appropriation. Seventy four interviews with employees and managers were conducted during a three year involvement inside the company. An inductive logic was adopted. Our research shows one the one hand that: 1. An effective appropriation of the digital tachymeter from the company and its drivers is evidenced. 2. Several factors impact this appropriation by the drivers: factors related to the device properties (ease of use, complexity, efficiency, compatibility, obligation), individual factors (professional experience, family status, personal efficiency, self-image), and contextual factors (external control authority, internal control processes, colleagues’ attitude). 3. Four attitudes towards the device are shown: rejection, use, adaptation/hijack, displacement. One the other hand, the adoption of a technology that controls working times in a company is nothing but neutral. Step by step, the relationship between managers and drivers, as well as drivers’ conception of their profession, are shaken. The adoption of such a technology not only alters the practices and relations, but the very notion of appropriation appears in an even more complex fashion
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Klar, Robert Günther. "Geographically Weighted Regression based Investigation of Transport Policies for Increased Public Transport Ridership : A Case Study of Stockholm." Thesis, KTH, Transportplanering, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302708.
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Public transport plays a vital role in society as the economy, the degree of sustainability and the qualityof life of a city is directly affected by transportation. A shift in modal share towards public transport isassociated with many benefits such as increased air quality and improved space allocation within thecity. To further promote public transport, an appropriate measure of competitiveness is required toevaluate the impact of past and future transport policies. This study introduces the journeys per capitaratio as a new way of measuring public transport competitiveness. Firstly, the key factors affecting thepublic transportation usage rate expressed as the journeys per capita ratio are identified to evaluatethe impact of public transport provider efforts. For this purpose, data for a total of 32 explanatoryvariables and a scope of 218 regions for seven consecutive time frames are collected. Secondly,geographically weighted regression (GWR) – a local regression-based spatial analysis technique – isperformed to test if the journeys per capita ratio is a suitable target variable to predict the impact ofcertain transport supply changes. A traditional global ordinary least square (OLS) model is conductedas well to compare if a local model could be more beneficial. The GWR and the OLS model are trainedwith the data of previous years and tested with data from the consecutive following years. Thirdly,further temporal and socio-economic based cluster analyses are performed to assess the validity andthe explanatory power of the journeys per capita ratio. The conducted analyses reveal that thejourneys per capita ratio is a superior measure for assessing public transport competitiveness.Goodness of fit statistics and estimation results demonstrate that the GWR model has betterprediction accuracy and is more capable of retrospectively predicting the impact of previous transportpolicies.Kollektivtrafiken har en avgörande roll i samhället då ekonomin, graden av hållbarhet och städerslivskvalité är direkt påverkad av transport. En förändring av transportanvändning från bil motkollektivtrafik är förknippad med flera fördelar, såsom ökad luftkvalitet och förbättrad rumsligallokering inom staden. För att ytterligare främja kollektivtrafik krävs ett lämpligt mått påkonkurrenskraft för att utvärdera effekterna av tidigare och framtida transportpolitik. Den här studienintroducerar resor per capita-förhållanden som ett nytt sätt att mäta kollektivtransportenskonkurrenskraft. För det första identifieras nyckelfaktorerna som påverkar användningsgraden förkollektivtrafik, uttryckt som förhållandet resor per capita för att utvärdera effekten avkollektivtrafikleverantörens insatser. För det här syftet har data för totalt 32 variabler och ett omfångav 218 regioner under sju, på varandra, följande tidsramar har samlats in. För det andra har Geografisktviktad regression (GWR), vilket är en lokal regressionsbaserad rumslig analysteknik, använts för atttesta om resor per capita-förhållanden är en lämplig målvariabel för att förutsäga effekterna av vissatransportförändringar. En traditionell Global ordinary least square model (OLS) har också använts föratt jämföra om en lokal modell är mer fördelaktig. GWR och OLS modellerna har tränats med data fråntidigare år och testats med data från följande år. För det tredje har ytterligare tidsmässigsocioekonomisk baserad klusteranalys utförts för att bedöma validiteten och förklaringsförmågan förresornas förhållande per capita. De genomförda analyserna pekar på att förhållandet resor per capitaär ett fördelaktigt mått för att bedöma kollektivtrafikens konkurrenskraft. Goodness of fit statistics ochde uppskattade resultaten visar att GWR-modellen har en bättre förmåga att göra noggrannaförutsägelser och är mer kapabel att i efterhand förutsäga effekterna av tidigare transportpolitik.
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Sciandra, Vincent. "Toward unifying on-board intelligent transportation systems architecture in public transports." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1097/document.
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Cette thèse s'inscrit dans une démarche Européenne de recherche sous l'égide du projet European Bus System of the Futur (EBSF). Ce projet vise à définir le bus de demain et de préparer son architecture embarquée, aux systèmes de transport intelligents (STI) critiques ou de divertissement, de plus en plus présents dans les véhicules. Les systèmes autrefois hétérogènes et autonomes, devrons à l'avenir communiquer sur une architecture orientée service (SOA) unique. L'objectif est d'optimiser le fonctionnement de l'architecture dans son ensemble grâce à des protocoles de communication ouverts et standards. C'est à partir de cette base, à laquelle nous avons activement apportée notre contribution, que notre thèse s'appuie. Le dimensionnement et la validation de ces architectures sont restés des éléments sans réponse à la suite du projet EBSF. Cette thèse présente premièrement une méthode dimensionnement des architectures STI basée sur les méthodes de décision multi-critères. Nous nous basons sur une étude poussée des besoins opérationnels collectés tout au long de la thèse. Dans un deuxième temps, nous adaptons le modèle de Criticité Mixte, définit dans le domaine du temps réel, aux flux de communication entre le véhicule et l'infrastructure. Enfin nous présentons les travaux réalisés dans le cadre de la standardisation européenne afin de promouvoir ce type d'architecture et les travaux de cette thèseIntelligent Transportation systems (ITS) are massively used in the Public Transport sector since the Two decades. This profusion of systems on-board and off-board vehicles generates inter-operability issues. The growth of urban zones and the increase of public transport attractiveness, brought multi-modal constraints that are today limited due to a lack of architecture vision embracing all ITS. This thesis proposes to unify the architecture vision of on-board ITS. We based our technical architecture on the Service Oriented Architecture (SOA) proposed in the European Bus System of the Future (EBSF) project, in which this thesis actively contributed. We study first the global requirements of different transportation modes operated in Europe. Those requirements are a basis to the definition of technical constraints of a global architecture. Those constraints are ranked in terms of importance using a proposed method based on Multi-Criteria Decision Making (MCDM) techniques. The method that we propose permits to size the technical architecture. We then study the flow management of data, considering the context of operation of vehicles and the criticality of ITS applications. We propose to adapt the Real-time Mixed-Criticality model to communication systems on-board the vehicles. We apply this method on a communication gateway of a bus, through its journey. Finally we present the work done at the standardization level (CEN) in order promote the global architecture vision presented in the thesis
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Ziedén, Therése. "Development of a Logit model of the transition effect to public transport." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141691.
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The importance of traffic planning has, throughout the years, been in- creased, providing sustainable developments of traffic and infrastructural investments. The analysis of the current traffic situation and the evalua- tion of the effects of a future investment are crucial for the socio-economic benefits maintenance. These analyses and evaluations are most commonly done using traffic simulation models. One of the main traffic planning aims, nowadays, is to increase the number of public transport users against the number of private car users. This change in mode choice is called transition effect and could be beneficial both from an environmental and socio-economic perspective. This thesis aims to evaluate and improve the macroscopic traffic demand and transition model, used fot the city of Norrköping. Additionally, the thesis investigates if a general transition Logit model can be developed and which parameters are the most important to be included in a modal choice estimation. For the needs of this study, the traffic planning software Visum is used. The travel mode distribution is calculated by Logit models coded in Python-scripts integrated in Visum. Then, a traffic assignment is performed by Visum, computing new travel times as inputs to the Logit model and this iterative procedure continues until the system reaches an equilibrium. The thesis aims for a more reliable prediction of the transition effect by correcting the Python-scripts and estimating the parameters of the Logit model using data from surveys. The study shows that travel times is the most important factor for realistic results generation. However, the data used for the estimation of the Logit model parameters did not include sufficient information of travel times. The travel times had to be calculated, using two different methods, in order to be included in the estimation of new parameters. Although these methods could not provide any positive effects on the transition, they did prove the importance and significance travel time have when developing a traffic model. The result of the study invokes the importance to further develop the method of calculating travel times, when the input data is not sufficient, and shows that the travel time parameters are case specific.
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Filbet, Francis. "Contribution à l'analyse et la simulation numérique de l'équation de Vlasov." Nancy 1, 2001. http://docnum.univ-lorraine.fr/public/SCD_T_2001_0068_FILBET.pdf.
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Ce travail est consacré à l'étude de quelques problèmes de la physique des plasmas: le transport de particules chargées et l'étude des collisions. Dans un premier temps, plusieurs méthodes eulériennes pour la discrétisation de l'équation de Vlasov, modélisant le transport des particules, sont proposées. L'originalité de ces méthodes est l'utilisation d'un maillage ou d'une grille de l'espace des phases pouvant aller jusqu'à six dimensions. Une démonstration rigoureuse de la convergence et des estimations d'erreurs sont d'abord présentées pour un schéma simplifié. Puis des schémas d'ordre plus élevé sont proposés et appliqués à la physiques des faisceaux. Leur précision permet de mettre en évidence des phénomènes très fins comme la formation de halos. Ensuite, des schémas déterministes appliquées à l'opérateur de Landau, qui décrit les collisions binaires dans un plasma, sont proposés. Des tests numériques permettent de comparer les différentes méthodes et mettent en évidence l'effet des collisions dans l'évolution du plasma. Dans la dernière partie, le problème d'existence de solutions pour le modèle de Vlasov-Darwinen dimension trois est traité. Pour cela, des méthodes classiques sur les équations cinétiques et des résultats surles problèmes elliptiques sont utilisés. Enfin, la convergence du système de Vlasov-Darwin vers Vlasov-Poisson est prouvée.
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Myschik, Julia, and n/a. "Immunostimulatory lipid implants as delivery systems for model antigen." University of Otago. School of Pharmacy, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080806.114447.
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Aim: Subunit vaccines have received increasing attention due to their good safety profile. However, subunit vaccines feature low immunogenicity, and soluble antigen is largely ignored by the immune system due to its lack of danger signals. To stimulate an appropriate immune response, subunit antigen vaccines require the addition of an adjuvant and multiple administrations. This study aimed to formulate biodegradable lipid implants, containing a suitable adjuvant, which delivers antigen in a sustained manner. The physico-chemical characteristics of the implants and their ability to stimulate immune responses towards a model antigen in vivo were investigated.
Methods: Lipid implants were prepared from phospholipid and cholesterol. Different adjuvants were added, and their potential to induce an immune response to the model antigen ovalbumin (OVA) was investigated. The adjuvants and immunomodulators assessed were Quil-A (QA), imiquimod, and an α-Galactosylceramide (α-GalCer) analogue. Liposomal dispersions were prepared using the lipid film hydration method. These were freeze-dried, and the powder compressed into matrices (diameter of 2 mm). Physico-chemical characterisation was undertaken by transmission electron microscopy (TEM) to investigate the release of colloidal structures (liposomes, immunostimulating complexes [ISCOMs]) upon hydration with release media. Surface changes of the implant matrices were analysed using scanning electron microscopy (SEM). The release of the fluorescently-labelled antigen ovalbumin (FITC-OVA) and its entrapment into the colloidal particles was investigated using spectrofluorophotometry. Additionally, incorporation of the cationic cholesterol derivative DC-cholesterol (DCCHOL) into implants to allow for charge-charge interactions with the negatively-charged OVA, and replacement of the phospholipid with a phospholipid having a higher transition temperature to facilitate the manufacturing process, were attempted and assessed. The immune response stimulated towards OVA released from the implants was analysed in vivo using a C57Bl/6 mouse model. Expansion of CD8⁺ T cells and CD8 T cells specific for the CD8 epitope of OVA (SIINFEKL), as well as expansion of CD4⁺ T cells, were assessed. The ability of implants to stimulate T cell proliferation and interferon-γ production after in vitro restimulation with OVA was analysed. Serum samples were analysed for OVA-specific IgG antibodies.
Results: Lipid implants containing Quil-A released colloidal structures upon hydration with buffer. The type of colloids observed by TEM depended on the ratio of QA:cholesterol:phospholipid. Release of OVA was sustained over ten days in implants prepared with egg yolk PC. However, the release kinetics depended strongly on the choice of phospholipid. In vivo, lipid implants containing Quil-A evoked expansion of CD8⁺ T cells. The immune response to one implant was comparable to that obtained by two equivalent injection immunisations. Therefore, the implants obviated the need for multiple immunisations in the vaccination regime tested here. Expansion of CD8⁺ T cells towards the Quil-A-containing implant was greater than that achieved by the immunomodulators imiquimod and the α-GalCer analogue. Quil-A-containing implants produced OVA-specific IgG antibodies to a greater extent than the implants containing imiquimod or α-GalCer. Incorporation of the cationic DCCHOL did not increase the entrapment efficiency of OVA into liposomes. However, the in vivo investigation of DCCHOL-containirig implants showed an adjuvant effect of DCCHOL on antibody responses, but not on cell-mediated immunity.
Conclusion: Lipid implants offer great potential as sustained release vaccine delivery systems. The lipid components in the implant formulation were well-tolerated and biodegradable. Lipid implants combine the advantages of sustained release of antigen and particulate delivery by the formation of colloidal particles.
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Zidi, Kamel. "Système interactif d’aide au déplacement multimodal (SIADM)." Ecole Centrale de Lille, 2006. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2006/50376-2006-Zidi.pdf.
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L’objectif de notre travail est la réalisation d’un système interactif d’aide aux déplacements, en mode normal, et en mode dégradé de fonctionnement du réseau de transport en commun. Ce système vise par ailleurs à minimiser le temps d’attente des voyageurs, en mode dégradé, dans les pôles d’échanges et à leur assurer, dans la mesure du possible, la continuité des déplacements dans les réseaux multimodaux. Il s’agit donc d’améliorer la qualité du service rendu aux voyageurs et les maintenir informés. Une grande partie du travail de cette thèse concerne la conception, le développement et la validation des approches qui permettent de donner des solutions optimales ou quasi optimales, pour un réseau de transport normal et perturbé. Ces approches utilisent une méthode multicritère de recherche d’itinéraire qui s’appuie sur une hybridation entre un algorithme de Dijkstra modifié et un algorithme génétique, pour générer une population de chemins minimums. L’algorithme de Dijkstra modifié nous donne un ensemble de solutions servant de population initiale pour l’algorithme génétique. La modélisation du réseau de transport est représentée par une architecture multi-zones. Cette architecture nous montre l’aspect distribué du système, les interactions et les relations qui peuvent avoir lieu entre les différentes zones. Nous présentons dans ce travail un Système Multi-Agent d’Aide au Déplacement, SMAAD. Les agents de ce système utilisent le module d’optimisation développé dans la première partie. Notre travail est réalisé dans le cadre du projet « VIATIC-MOBILITE », qui est le projet 6 du pôle de compétitivité I-TransThe objective of this work is the realization of a system allowing to assist the travellers, and to facilitate their movement in normal and degraded functioning of the transport network. This system aims to minimize the waiting time of the travellers, in degraded mode, at exchanges stations and to assure them, as well as possible, the continuity of their journey in the multimodal transport networks. So it improves the quality of the service returned to the travellers in order to inform them. A first part of the work in this thesis concerns conception, development and validation of our approach which allows giving optimal or almost optimal solutions for a normal and disrupted transport system. This approach uses a multi-objective method of search for optimal route which leans on a hybridization between a modified Dijkstra algorithm and a genetic algorithm. The modified Dijkstra algorithm gives us a set of solutions serving as initial population for the genetic algorithm. The modelling of the transport system is represented by multi-zones architecture. This architecture shows us the distributed aspect of the system, and the interactions and the relations which can take place among various zones. We present in this work a Multi-agent system of Help to the Movement. These agents use the module of optimization developed in the first part. Our work is realized within the framework of the "VIATIC-MOBILITE" project, which is the project 6 of the I-Trans Competitiveness cluster
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Jovic, Katarina. "Analysis of Customer Personal Data Processing in a Swedish Public Transport Organization." Thesis, Karlstads universitet, Handelshögskolan (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-78037.
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Purpose: The purpose of this research is to analyze the current routine for processing customers’ personal data in a Swedish public transport organization and advise on improvements that might be made to better comply with GDPR. Methodology: A qualitative study of personal data (as defined in the GDPR) based on five telephone interviews. The interviews were held in Swedish, then transcribed and finally translated to English for analysis. Literature perspectives: A research (neutral) perspective of the implementation regarding the General Data Protection Regulation (GDPR) within an organization. It is reported that GDPR tend to increase the tension in an organization. Some organizations expect GDPR will increase the annual budget and believe the business strategy will be changed. Findings: The organization is interested to clearly implement the regulation to their best interest they can. The organization see the centralization of customers’ data as a positive outcome and want to continue with IT-support for the GDPR process to get automated. The organization expresses they want to create a good relationship with their customers and be clear with the purpose of data collection. Conclusions: The research suggests that the organization should invest in IT support, help guiding the employees to understand the purpose of GDPR and produce staff guidelines. The staff guidelines should cover most of the issues that may occur during daily routines. However, if any anomalies occur regarding GDPR, the data processor should act as a guide to the employee.Syfte: Syftet med kandidatuppsatsen är att analysera den nuvarande processen för bearbetning av kunders personuppgifter i en svensk kollektivtrafikorganisation samt ge förbättringsråd angående saker som kan förbättras för att bättre följa GDPR. Metod: En kvalitativ studie som handlar om personuppgifter (enligt definitionen i GDPR); baserat på fem telefonintervjuer. Intervjuerna hölls på svenska, transkriberades och översattes sedan till engelska för en analys. Teoretiska perspektiv: Ett forsknings- (objektivt) perspektiv på implementeringen av den allmänna dataskyddsförordningen (GDPR) inom en organisation. Det rapporteras att GDPR tenderar att öka stressen i en organisation. Vissa organisationer förväntar sig att GDPR kommer öka den årliga utgiften för databehandling samt tror att deras affärsstrategi kommer förändras. Resultat: Region Värmland Kollektivtrafik är intresserade av att genomföra GDPR förordningen i högsta grad. Organisationen ser centraliseringen av kundens personliga data som ett positivt resultat och vill fortsätta med IT-stöd för GDPR- processen för att den ska kunna bli automatiserad. Organisationen uttrycker att de vill skapa en bra relation med sina kunder och vara tydliga med syftet av datainsamlingen. Slutsatser: Studien antyder att organisationen bör investera i IT-stöd, hjälpa anställda att förstå syftet med GDPR samt ta fram personalriktlinjer. Personalriktlinjerna bör täcka de flesta problem som kan uppstå i de dagliga rutinerna. Om det däremot uppstår några avvikelser gällande GDPR, bör personbiträde fungera som en hjälpande hand för de anställda.
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Hasalova, Pavlina. "Microstructural, petrological and geochemical records of pervasive melt transport in the crust." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/HASALOVA_Pavlina_2007.pdf.
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Cette thèse de doctorat présente les résultats d'études détaillées de terrain, microstructures, pétrologie et géochimie, effectuées sur deux large terrane migmatitique d'âge Varisque: l'unité Gföhl de la zone Moldanubienne, du massif de Bohême et Vosges (France). Les données ont été utilisé pour contraindre l'origine des roches migmatitiques, ainsi que permettre une meilleure compréhension du transport de produits fondus dans la croûte. Un nouveau modèle est proposé pour l'infiltration des produits fondus, à partir d'une source externe, pour expliquer (1) les variations dans l'apparence des migmatites et (2) le modèle “reactive porous melt flow” par le mouvement de produits fondus dans la croûte. Ce conception implique une infiltration de matériel à partir d'une source externe pendant l’exhumation, ou ce matériel se déplace le long des limites de grains, à travers l'ensemble du volume des roches, changeant ainsi l'apparence macroscopique et microscopique des rochesThis thesis represents an outcome of detailed field, microstructural, petrological and geochemical studies on two large Variscan migmatitic terranes, Gföhl Unit of the Moldanubian Zone in Bohemian Massif and Vosges Mts. In France. Obtained data are used to constrain the origin of the migmatitic rocks and for better understanding of the melt transport in the crust. We introduce a new possible model of melt infiltration from external source to explain the variations in the migmatite appearance and “reactive porous melt flow” for the melt movement on a crustal scale. In this concept melt passes pervasively along grain boundaries through the whole rock volume and changes macroscopic and microscopic appearance of the rock. We suggest that the individual migmatite types represent different degrees of equilibration between the host rock and migrating melt. It should be emphasized, that all these processes occur along a retrograde path during exhumation of the Gföhl Unit
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Hamnebo, Karl, and Oscar Askfelt. "Information flows in Demand Responsive Public Transport : Interactivity, information, and flexibility in a modern ridesharing service." Thesis, Malmö universitet, Fakulteten för teknik och samhälle (TS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-43270.
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The focus of this thesis is to study what and how information flows can be used to improve Demand responsive transport (DRT) systems by understanding potential users and how they could be willing to participate in DRT to a higher degree. The viewpoint of this thesis tends to lean towards a DRT service of a public transport type. This thesis studies users in relation to what interaction and information they perceive to be needed in dealing with a DRT service and the different pros and cons with various approaches. The study gathers information by performing adapted qualitative interviews with a select number of users between the ages of 20-35. The participants give their views on three DRT scenarios and reflect on DRT in general as a concept presented to them through a tangible mocked-up interactive prototype. The thesis makes several distinct findings. The importance of pricing a DRT service correctly is vital to the users, as several participants in the study relied on pricing for decision-making. It also finds that the usage of zones as nomenclature is confusing to many users. The services must be dependable and punctual to both attract users, keep users, and build trust among the general populace. This study shows that DRT services could be a difficult concept to introduce to users. DRT could be introduced as a complement or as an alternative to conventional public transport. An important factor is a well-designed flow of information in the application to keep the user engaged and involved. It is shown that the usability of the application is a cornerstone for a theoretical DRT service to excel. Context is important where DRT and ridesharing would have a higher success rate. Nighttime in urban areas could be a niche market, due to the irregularity, delay, or interruption of regular public transport services at these hours.
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Pugliesi, Reyes Piero Alexander. "An Expansion of the Current Metrorail System for an Ease Public Transportation and an Increase in Economic Activity." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/656644.
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Se nos ha encomendado la tarea de desarrollar una propuesta innovadora para agregar a la industria del sector público para este informe. Siendo nativos de un condado afectado por el tráfico como Miami Dade, decidimos abordar el desafío de aliviar la red de transporte del área proponiendo una expansión del actual sistema de Metrorail obsoleto en los tramos occidental y sur del condado. Creemos que esta expansión no solo creará puestos de trabajo en el proceso de construcción, sino que en última instancia permitirá un flujo de transporte que conducirá a una economía en auge explosivo. La ciudad está preparada para una innovación de este tipo, ya que los inmigrantes de todo el mundo y los EE. UU. Acuden a ella rápidamente transformando la ciudad día a día en un titán global. Una ciudad de tal magnitud y promesas necesita un sistema de transporte público a la altura.We have been tasked with developing an innovative proposal to add onto the public sector industry for this report. Being natives of a traffic-stricken county such as Miami Dade, we decided to tackle the challenge of alleviating the transportation network of the area by proposing an expansion to the current outdated Metrorail system into the Western and Southern reaches of the county. We believe that this expansion will not only create jobs in the process of construction but will ultimately allow a flow of transportation that will lead to an explosively booming economy. The city is primed for such an innovation as immigrants from all over the world and the US flock into it quickly transforming the city day by day into a Global titan. A city of such magnitude and promise needs a public transportation system to match it.
Trabajo de investigación
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Kšonžek, Miloš. "Dopravná sieť Bratislavy a okolia." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-76051.
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The thesis describes and assesses the current state of the transport network situation in the capital of the Slovak Republic, Bratislava. The core topic is a description of the problem areas, assessing the current status and evolution over time, for the urban public transport system.
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Eriksson, Charlotte, and Olivia Jansson. "Analysis of Automated Vehicle Location Data from Public Transport Systems to Determine Level of Service." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-158176.
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Many cities suffer from problems with high traffic flows in the city centers which leads to a desire to get more people to choose public transport over cars. For many car drivers, the main reason to take the car is the convenience and time efficiency; the price is often of less importance. The public transport providers should, therefore, strive to improve their Level of Service (LOS). A general process that can be used by public transport providers or other stakeholders to evaluate the LOS in a public transport system based on Automated Vehicle Location (AVL) data is developed and presented in this thesis.The process values the quality and suitability of the AVL data, propose which KPIs to use and how to use the results to find possible improvements. Four different types of erroneous data were discovered: outliers in position, outliers in speed, outliers in travel time and general errors. KPIs are developed in three main areas: on-time performance, travel time distribution and speed, where each KPI is divided into several sub-areas.
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Du, Preez Simeon Johannes. "Traffic impacts of shared right-of-way public transport systems: A microsimulation-based case study." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/79572.
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Bus Rapid Transit systems are becoming a more integral part of public transport systems in major African cities. Although BRT systems are more versatile than other public transport alternatives, they do require support from other transport systems. Due to geographic limitations and varying transport demand, a BRT system can only function optimally if it is well integrated with the surrounding transport network. In the case of most African transport networks, the informal modes serve as the foundation of the system. In South African cities the minibus taxi is responsible for over 60% of the daily passenger trips. It is evident that in order for a BRT system to function within the African context, a synergistic relationship between the BRT and minibus taxi must be found.
The interaction between BRT and minibus taxis is diverse and cannot be captured in one individual study. The aim of this study is to look at the traffic flow performance of road networks which operate under varying hybrid scenarios. These hybrid scenarios consist of varying configurations where minibus taxis and BRT buses are expected to use the same infrastructure. Specifically, the question is what the implications would be of using existing BRT infrastructure in a shared operational model. Traffic flow performance is calculated and measured by means of a microsimulation model which simulates various hybrid (between taxis and BRT) conditions.
Currently very limited detailed information is available about the interaction of these public transport modes. Modelling a calibrated microsimulation provides detailed insight into the interaction of minibus taxis and BRT buses and allows the testing of various experimental scenarios which have yet to be examined. The microsimulation and the data extracted from its analysis provides information about the individual performance of buses, minibus taxis and passenger vehicles. This provides decision makers with important data which can be used to optimise the network for the desired transport modes. The microsimulation also indicates a number of physical interactions between buses and taxis which can further assist in decision making and could indicate required physical changes in the network which may be required to optimise the system.
The analysis indicates that there are different scenarios available in order to achieve different objectives such as improving traffic conditions for general traffic, buses or taxis. The findings also indicate that the current operating conditions (BRT buses have exclusive use of the dedicated lanes) yields the worst traffic conditions for general traffic and minibus taxis. The current scenario also yields the highest overall travel time per passenger. This indicates that consideration should be given to implementing an alternative scenario.
The findings (which indicate positive results for shared Right-of-Way) are provisional and require further research. Further research should be focused on expanding on these findings by determining the effects of taxis stopping in BRT lanes as well as safety concerns which are caused by allowing taxis to use BRT lanes. This results in passengers boarding and alighting taxis in BRT lanes (on the moving traffic side of the taxi) and requires specific attention.Dissertation (MEng)--University of Pretoria, 2020.
Civil Engineering
MEng
Unrestricted
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Lachance-Bernard, Nicolas. "Modélisation des coûts généralisés de déplacement en transport privé et public : automatisation des spécifications de paramètres pour la géo-simulation." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25404/25404.pdf.
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Dans un premier temps, cette recherche développe une méthodologie pour la modélisation des coûts généralisés de déplacement en transport privé et public. La méthodologie permet l’automatisation des spécifications de paramètres pour la géo-simulation d’itinéraires individuels multimodaux avec TransCAD. Nous présentons les trois applications SIG-T développées dans le cadre de ce projet : CRADVoyagesTC – pour la définition et la localisation de l’offre du transport en commun, CRADTNetwork – pour la construction de graphes de transport en commun, et CRADRoutes – pour la simulation d’itinéraires individuels multiples.
Dans un second temps, une étude de cas réalise la simulation d’itinéraires ayant pour origine les lieux de résidence et pour destination les principales agglomérations commerciales du territoire de la Communauté Métropolitaine de Québec (CMQ). Cette étude de cas vise à démontrer le bon fonctionnement et l’efficience de la méthodologie développée pour de futures recherches portant sur l’accessibilité et la mobilité. Les résultats sont commentés de manière sommaire.This research develops a methodology for modelling generalized trip costs using private and public transportation modes. The methodology enables computer-assisted specification of parameters for disaggregated multimodal trip geo-simulations using TransCAD. We present three developed GIS-T applications within the current project: CRADVoyagesTC – for public transit supply definition and localization, CRADTNetwork – for public transit graph construction, and CRADRoutes – for multiple disaggregated trip paths simulation. Finally, a proof of concept application based on trip simulation using as origin the residential places and as destination the major shopping places of the Quebec Metropolitan Area (QMA) is presented. The main objective of this study case is to demonstrate the functionality and the efficiency of the developed methodology to be used in future accessibility and mobility researches. Preliminary results are discussed.
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Norman, Joel. "Assessing the potential for improving public transport in rural areas by using driverless vehicles." Thesis, Kungliga tekniska högskolan, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-394107.
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Driverless vehicles might fundamentally change the transport system in multiple ways. Reducing driver costs in mobility services could create opportunities for new mobility concepts. Research on driverless vehicles have previously concentrated on urban areas, though driverless vehicles in rural areas could have greater positive effects. Hence, the aim of the study is to see how driverless vehicles can be used in rural areas to contribute to a more sustainable transport system. Three rural mobility concepts for driverless vehicles are developed and by applying these to different case locations, the feasibility of the concepts is discussed. Interviews with local actors in Sweden were conducted to learn about general and local challenges with specific case locations. What rural mobility concept for driverless vehicles to use depends on access to public transport, distance to main roads and spatial density of travel demand. A modelling approach of a first and last mile feeder service is used to evaluate the feasibility of this mobility concept further. Model results show that driverless shuttles can feed travel demands of 100-150 passengers daily and still perform alternative tasks. Even though rural areas have general challenges, local issues also need consideration to optimize the benefits of the services. Public transport authorities are experts on local challenges and could take more responsibility in questions regarding driverless vehicles. For instance, flexibility, accessibility and equality could be improved by merging routes and shorten travel times for entire bus routes. Furthermore, other societal functions can be developed by reinvesting capital in other areas.
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Vigren, Andreas. "Competition in Public Transport : Essays on competitive tendering and open-access competition in Sweden." Doctoral thesis, KTH, Transportvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217267.
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The results of this work show that the cost efficiency of tendered bus services is similar across all Swedish counties, except for the more high-density counties where efficiency is lower. Considerably lower efficiency is also found for contracts with services run in-house by the Public Transport Authority (PTA), compared to when the same service is run by a private actor. With respect to the competitive environment, it was found that many contract design factors have little or no effect on the number of bids that the PTA sees in their tenders. No measure that could be imposed by a single PTA was found to increase the total number of bidders by more than 0.5 bidders. However, the results suggest that PTAs as a collective could try to avoid tendering too many contracts at the same time because this was shown to reduce participation by up to about two bidders. In addition, these studies show that the local competitive environment is important for the PTAs to consider. The way in which contract areas are defined will also affect the participation rate as operators were found to participate in tenders to a lower extent the farther their workplaces are from the contract area. While larger operators appear to be less sensitive with respect to such distances, the fact that smaller operators are, and that they often bid as one unit as members of cooperation companies, makes the competitive environment important. The results suggest that depots could be included in the contract to stimulate participation, but this is by no means the only nor an easy solution. This thesis has also analyzed the entry made in 2015 by MTR Express (MTR) on the Stockholm-Gothenburg railway line. The overall conclusion is that customers are indeed facing lower prices one and a half years after the entry. MTR's prices are on average 100 SEK lower than the incumbent SJ's prices. Furthermore, the analysis shows that the incumbent’s prices have also gone down, by almost 13 percent, following the entry.QC 20171106
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Giamberini, Laure. "Etude des mécanismes de transport et de détoxication des métaux lourds chez la moule d'eau douce Dreissena polymorpha : rôle des hémocytes et des organes du système excréteur (histologie, ultrastructure, microanalyse)." Metz, 1993. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1993/Giamberini.Laure.SMZ9321_1.pdf.
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La capacité bioindicatrice des mollusques bivalves vis-à-vis des métaux est actuellement reconnue et utilisée dans le cadre du biomonitoring. La compréhension de cette capacité nécessitait une étude plus fondamentale des voies d'intoxication, de transport et d'élimination des métaux. Une étude anatomique, cytologique et microanalytique des hémocytes, de la glande péricardiale et des reins a montré le rôle des granulocytes dans le transport puis le rôle de détoxication de la glande péricardiale et des reins. Le système lysosomal joue un rôle important. La nature du métal modifie la répartition au sein des organes. Le plomb est bioconcentré en association avec P, S, Ca dans les concrétions des cellules du rein distal. La microanalyse de rayons x a été, à ce titre performante. Une adaptation éventuelle à la présence de micropolluants métalliques a été recherchée par numération des hémocytes, suivi de l'activité enzymatique et des capacités de phagocytose. Il y a tendance à l'augmentation du nombre des hémocytes ; augmentation de l'activité phosphatasique acide mais pas de modification significative de l'activité de phagocytose. Les réponses cytochimiques et biochimiques des hémocytes en présence de métaux peuvent être proposées comme méthodes d'évaluation précoce (7 jours) des effets de la contamination des eaux par les métaux ; le niveau de bioaccumulation étant évalué par la méthode des transplantations seulement après trois semainesBioindicator capacity of bivalves molluscs for metal is now well know and use in biomonitoring studies. Understanding of this capacity needed a more fundamental study of metal uptake, transport and excretion pathways. Anatomical, cytological and microanalytical studies of hemocytes, pericardial gland and kidney has shown granulocyte rule in transport and detoxication functions of pericardial gland and kidney. Lysosomal system plays an important function. Metal nature changes its distribution in organs. Lead is accumulated with P, S, Ca in concretion in epithelial cells of kidney distal limb. Microanalysis was performed in this case. Possible adaptation of metallic micropolluants presence was research by hemocytes counts, enzymatic activity and phagocytosis capacities evaluation. Hemocytes number and acid phosphatases activity seem to increase but no significant modifications of phagocytosis capacities was observed. Cytological and biochemical responses of hemocytes in presence of metal can be propose of early test (7 days) of metal contamination effects in aquatics systems ; bioaccumulation levels was evaluated by transplant methods after 3 weeks