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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

Foundations for Multi-level Ontology-based Conceptual Modeling

CARVALHO, V. A. 16 December 2016 (has links)
Made available in DSpace on 2018-08-02T00:04:06Z (GMT). No. of bitstreams: 1 tese_10529_foundations_for_ontology_based_multi_level_conceptual_modeling_2012 - victorio.pdf: 6142526 bytes, checksum: 3e3483b04f4e9b86ab648e66104ac1e2 (MD5) Previous issue date: 2016-12-16 / Considerando que modelos conceituais são produzidos com o objetivo de representar certos aspectos do mundo físico e social de acordo com uma conceituação específica e que ontologias buscam descrever conceituações, tem havido crescente interesse no uso de ontologias para fornecer uma base teórica sólida para a disciplina de modelagem conceitual. Esse interesse deu origem a uma área de pesquisa denominada modelagem conceitual baseada em ontologias, com avanços significativos na modelagem conceitual nas últimas décadas. Apesar desses avanços, a modelagem baseada em ontologias não provê suporte adequado à modelagem de domínios que exigem a representação de categorias de indivíduos e de categorias de categorias (ou tipos de tipos). A representação de entidades de vários "níveis" de classificação tem sido o foco de uma área de pesquisa distinta denominada modelagem multi-nível. As iniciativas em modelagem multi-nível visam a contornar as limitações impostas pelo paradigma convencional de modelagem em dois níveis. Apesar das contribuições relevantes das áreas de modelagem multi-nível e de modelagem conceitual baseada em ontologias, a combinação dessas duas áreas ainda não recebeu a devida atenção. Este trabalho explora essa lacuna propondo o uso combinado de teorias formais para a modelagem multi-nível e de ontologias de fundamentação para apoiar o que chamamos de modelagem conceitual multi-nível baseada em ontologias. Para fornecer uma abordagem bem fundamentada à modelagem conceitual multi-nível, desenvolvemos uma teoria chamada MLT. MLT caracteriza formalmente a natureza dos níveis de classificação e define precisamente as relações que podem ocorrer entre elementos de diferentes níveis de classificação. A fim de aproveitar os benefícios do uso de ontologias de fundamentação na modelagem de domínios que abrangem vários níveis de classificação, combinamos MLT com uma ontologia de fundamentação. Essa combinação resulta em uma abordagem de modelagem que apoia a construção de modelos conceituais multi-níveis em um espectro de níveis de especificidade, desde ontologias de fundamentação até modelos conceituas de domínios específicos. Para demonstrar a aplicabilidade da nossa abordagem de modelagem conceitual multi-nível baseada em ontologias, a empregamos para desenvolver uma ontologia núcleo para estruturas organizacionais, um domínio que abrange vários níveis de classificação. Além disso, mostramos como MLT pode ser usada como uma teoria de referência para esclarecer a semântica e aumentar a expressividade de UML no que diz respeito à representação de modelos de multi-níveis. O perfil UML produzido viabiliza a aplicação prática de MLT pela comunidade de modelagem conceitual.
532

Perfil de sensibilidade da Pseudomonas aeruginosa estudo retrospectivo em dois hospitais do Recife PE

FIGUEIREDO, Eduardo Andrada Pessoa de January 2006 (has links)
Made available in DSpace on 2014-06-12T23:13:25Z (GMT). No. of bitstreams: 2 arquivo8723_1.pdf: 3102671 bytes, checksum: 63033e858f152a6154f2c73715fb9ff6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / O aumento do número de bactérias multi-resistentes aos antibióticos tem crescido significativamente nos últimos anos. Entre as bactérias gram-negativos, a P.aeruginosa tem demonstrado uma maior facilidade de desenvolvimento da resistência aos antibióticos. O objetivo deste estudo foi o de determinar os padrões de susceptibilidade antimicrobiana às diversas classes de antibióticos contra a Pseudomonas aeruginosa e realizar uma análise comparativa entre as unidades de terapia intensiva (UTI) e as enfermarias de dois hospitais terciários do Recife-PE. O estudo foi realizado entre setembro de 2004 e janeiro 2006. Os testes de susceptibilidade antimicrobiana foram realizados em 304 amostras diferentes de P. aeruginosa segundo os padrões do NCCLS (National Commitee for Clinical and Laborastory Standards). Os antibióticos testados foram: polimixina (88,7%) ; piperacilinatazobactam (66,2%) ; aztreonam (59,8%); amicacina (59,4%); meropenem (58,2%); imipenem (57,7%); ciprofloxacina (49,7%); gentamicina e cefepime (48,6%); ceftazidima (30,0%) e cefotaxima (6,8%). Os sitios mais frequentes de infecção foram a urina com 26,7% e a secreção traqueal com 26,1% . O estudo demonstrou ainda uma diferença estatisticamente significativa na susceptibilidade antimicrobiana comparativa entre as UTI e as enfermaria de um dos dois hospitais envolvidos , com menor susceptibilidade aos antibióticos testados nas UTI. Em conclusão, a freqüência de cepas de P.aeruginosa multi-resistente (28,0%) foi maior que a descrita na literatura nacional e mundial, principalmente quando isolamos o grupo de pacientes internados nas UTI(s). Os achados do estudo sugerem que o aparecimento de resistência antibiótica para P.aeruginosa no Recife tem sido mais frequente do que em outros centros Nacionais e Internacionais. Para reduzir a frequência destes clones multi-resistentes , monitorização epidemiológica e otimização da antibioticoterapia deverá ser considerada urgentemente
533

Electron spin resonance studies of food systems

Greenley, Katherine R. January 2001 (has links)
ESR has been used to study multi-phase food systems, including ice cream and chocolate, using both spin probes and spin labels. Chemical and physical methodologies were developed and applied to study the behaviour of 1,1,3,3-tetramethylisoindolin-2-yloxyl (TMIO), the 5-pentyl derivative (PTMIO) and the water-soluble 5-sulphonate (NaTMIOS) spin probes in hydrophilic and hydrophobic phases over a range of temperatures. Linewidths and hyperfine coupling constants (aN) were derived using fitting and simulating computer software, from which rotational correlation times (tauc) and enthalpies of activation of molecular rotation were calculated. These give an indication of the local environment of the probe. In the hydrophilic phase of ice cream there was a sharp reduction in probe mobility at -18°C, which did not occur in the hydrophobic phase. In chocolate, an essentially hydrophobic system, no sudden changes in mobility were detected although at around 60°C there was a change in the enthalpy of activation. Spectral deconvolution techniques enabled the simultaneous study of NaTMIOS and TMIO in the hydrophilic and hydrophobic phases of ice cream and enabled the study of TMIO spectra in the presence of the underlying spectrum of the radical present in chocolate. Guar gum and xanthan gum are used as stabilisers in ice cream and were spin-labelled using 5-carboxy-TMIO (CTMIO) and 5-amino-TEMPO respectively. The ESR spectra showed that the mobilities of the nitroxide moieties were comparable with the free spin probes. The addition of the gums to a sucrose solution, a model hydrophilic system, had no appreciable effect on the mobility of the NaTMIOS spin probe.
534

Consensus control for multi-agent sytems with input delay

Wang, Chunyan January 2016 (has links)
This thesis applies predictor-based methods for the distributed consensus control of multi-agent systems with input delay. "Multi-agent systems" is a term used to describe a group of agents which are connected together to achieve specified control tasks over a communication network. In many applications, the subsystems or agents are required to reach an agreement upon certain quantities of interest, which is referred to as "consensus control". This input delay may represent delays in the network communication. The main contribution of this thesis is to provide feasible methods to deal with the consensus control for general multi-agent systems with input delay. The consensus control for general linear multi-agent systems with parameter uncertainties and input delay is first investigated under directed network connection. Artstein reduction method is applied to deal with the input delay. By transforming the Laplacian matrix into the real Jordan form, delay-dependent conditions are derived to guarantee the robust consensus control for uncertain multi-agent systems with input delay. Then, the results are extended to a class of Lipschitz nonlinear multi-agent systems and the impacts of Lipschitz nonlinearity and input delay in consensus control are investigated. By using tools from control theory and graph theory, sufficient conditions based on the Lipschitz constant are identified for proposed protocols to tackle the nonlinear terms in the system dynamics. Other than the time delay, external disturbances are inevitable in various practical systems including the multi-agent systems. The consensus disturbance rejection problems are investigated. For linear multi-agent systems with bounded external disturbances, Truncated Predictor Feedback (TPF) approach is applied to deal with the input delay and the H_infinity consensus analysis is put in the framework of Lyapunov analysis. Sufficient conditions are derived to guarantee the H_infinity consensus in time domain. Some disturbances in real engineering problems have inherent characteristics such as harmonics and unknown constant load. For those kinds of disturbances in Lipschitz nonlinear multi-agent systems with input delay, Disturbance Observer-Based Control (DOBC) technique is applied to design the disturbance observers. A new predictor-based control scheme is constructed for each agent by utilizing the estimate of the disturbance and the prediction of the relative state information. Sufficient delay-dependent conditions are derived to guarantee consensus with disturbance rejection.
535

Analysis and performance enhancement of a series parallel offshore wind farm topology integrated into a HVDC grid / Analyse et amélioration de la performance d'une architecture série-parallèle de ferme éolienne offshore intégrée dans un réseau HVDC

Zhang, Haibo 22 December 2017 (has links)
L'exploitation de l'énergie éolienne loin des côtes, bien qu'abondante, dépend du transport de puissance en Courant Continu Haute Tension (HVDC) qui nécessite une sous-station placée sur une plateforme dédiée. Cette plate-forme offshore étant volumineuse, son cout d'installation est élevé et sa mise en œuvre est compliquée. Cette thèse s'intéresse à une topologie de ferme éolienne offshore DC qui transporte son énergie vers l'onshore sans utiliser de sous-station offshore. Ce type de Ferme Eolienne est appelé Ferme Eolienne Série Parallèle (SPWF). Il est composé de plusieurs grappes d'éoliennes interconnectées en série, de sorte que cette interconnexion engendre directement un niveau de tension adapté à la tension du réseau HVDC. Cependant, la connexion en série implique que la tension de chacune d'entre elle n'est plus constante. Un déséquilibré de production d'énergie conduit à des variations des tensions en sortie des éoliennes. Ces variations de tension peuvent engendrer des surtensions aux bornes d'une éolienne dans la grappe et l’endommagé. Une stratégie permettant de limiter la surtension d'éolienne est proposée et développée. Cette stratégie est d'abord validée dans un contexte de connexion point à point avec la prise en compte de la transmission HVDC basée sur des câbles DC et un Convertisseur Modulaire Multiniveaux (MMC) permettant de la connecté au réseau onshore. Dans un second temps, la ferme SPWF est intégrée dans des systèmes DC multi-terminaux (MTDC). Les résultats de simulation démontrent la faisabilité de la stratégie et montrent qu'aucune réduction de puissance n'est alors nécessaire pour limiter les tensions en sortie des éoliennes. / The massive exploitation of far offshore wind energy relies heavily on the High Voltage Direct Current (HVDC) transmission system, in which dedicated offshore substations for converting power from AC into DC are necessary. However, the bulky offshore platform is costly and its installation is complicated. This thesis aims to contribute to the study of a pure DC offshore wind farm topology which exports its energy to onshore without using an offshore centralized power conversion substation. The examined wind farm topology is called Series Parallel Wind Farm (SPWF), which comprises several clusters of wind turbines connected in series, so that the output converters of the wind turbines step up the voltage to a higher level for direct power transmission. However, due to this distinctive feature, unbalanced power production of wind turbines leads to output voltage variation of wind turbines, which is harmful to the wind turbines. The work carried out in this thesis begins with the identification of the basic elements to constitute the SPWF. Afterwards, the operation of the SPWF is explained and its overvoltage characteristic is described and emphasized. An overvoltage limitation control strategy is developed, which requires an active participation of the onshore converter. Hence, the onshore Multilevel Modular Converter (MMC) as well as the HVDC cables models are examined. The control strategy is applied to both Point-to-Point (P2P) HVDC transmission system and Multi-Terminal DC (MTDC) systems. The results validate the feasibility of the proposed strategy, and demonstrate its advantage of no power curtailment requirement to limit the wind turbines output voltage.
536

Advanced control of an industrial circulating fluidized bed boiler using fuzzy logic

Karppanen, E. (Erkki) 10 January 2000 (has links)
Abstract Circulating Fluidized Bed (CFB) boilers are widely used for multi-fuel combustion of waste and bio-fuels. When several non-homogeneous fuels, having varying heat values, are burned simultaneously, the boiler control system can be affected by various control challenges, especially since it is not feasible to reliably measure the energy content of the multi-fuel flow. In order to fulfill energy production needs and maintain the ability to burn low grade fuels, co-firing with high heat value fuels such as gas, oil or coal is needed. Fuzzy Logic Control (FLC) has been successfully used for solving control challenges, where operators' process expertise can be transformed into automation. Real life control objects are often non-linear because the dynamics change with the operating point, or there might be other essential non-linearities in the combustion process. The proposed fuzzy control applications were developed to solve control challenges the operators meet in daily operation of a 150 MW(th) CFB at Varenso Oy's (Stora Enso Oyj) K6 boiler in Varkaus Finland. Before implementing the applications in the fullscale boiler, they were tested at a 2 MW(e) pilot plant boiler at Foster Wheeler Energia Oy's Research Center in Karhula, Finland. According to the industrial experiments, the four applications (steam pressure control, compensation of fuel quality fluctuation, fuel-feed optimization and increased bed inventory monitoring) discussed in this thesis, showed satisfactory performance and various improvements to the boiler control were achieved. Fuzzy logic control was shown to be a notable tool to improve the multi-fuel CFB boiler control.
537

Un modèle pour la prise de décision multi-agent sous incertitude stricte / A model for multiagent decision making under strict uncertainty

Ben Larbi, Ramzi 14 December 2009 (has links)
Le contexte informationnel dans lequel évolue un agent possède une importance extrême quandcelui-ci élabore son comportement futur. Un agent rationnel doit en effet baser ses choix sur les informationsqu’il possède pour choisir ses actions. Or, dans les applications réelles, l’information disponible àl’agent est souvent rare et peu précise. De multiples modèles ont été élaborés dans les différents cadresd’application de l’intelligence artificielle afin de caractériser une décision rationnelle dans chacun descontextes informationnels possibles. Les travaux présentés dans cette thèse concernent l’élaboration d’unmodèle permettant à un agent de prendre des décisions rationnelles dans un contexte informationnel trèspauvre. La seule information dont dispose un agent à propos du résultat de ses actions est la donnée del’ensemble de résultats de chacune d’entre elles. En particulier, aucune information sur la conséquence laplus susceptible de se produire n’est disponible. L’agent est supposé égoïste (au sens où seul compte pourlui son propre intérêt) et autonome. Il évolue de plus dans un environnement où il coexiste avec d’autresagents (qui sont aussi égoïstes et autonomes). Les actions d’un agent influent sur les autres agents. Ladémarche entreprise pour élaborer le modèle est la suivante. D’abord, nous caractérisons les critères dedécision rationnels d’un agent seul dans le contexte informatif étudié. Ensuite, nous étendons ces critèresde décision individuelle au cas multi-agent en nous appuyant sur la théorie des jeux qui est le meilleurcadre pour exprimer les interactions entre agents rationnels et en particulier les possibilités de coordinationentre les agents. Enfin, le domaine de la planification est un excellent cadre pour représenter etexprimer les concepts du modèle. / The informative context in which an agent evolves is extremely important when she elaborates her futurebehaviour. A rational agent must base her choices on the available information. In realistic applications,the information is often rare and imprecise. Many models have been introduced to caracterize rationaldecision in each possible informative context. This thesis is about the elaboration of a model that allowsan agent to make rational decisions in an extremely poor informative context. The only informationthat is available to an agent about her actions’ consequences is the result set of each of her actions. Noinformation about which consequence of any action will eventually happen is available. The agent issupposed to be selfish (which means that her own interest is her only concern) and autonomous. Sheevolves in an environment in which she coexists with other agents (that are as selfish and autonomous asher). An agent action may inflence those of other agents. We used the following approach to build ourmodel. First, we caracterized the rational decision criteria for an agent to use in the context of completeignorance. Then we extended these criteria, by using game theory concepts, to a multiagent environment.Finally, the planning framework is an excellent framework to represent the introduced concepts.
538

Essais virtuels pour l'industrie du meuble / Virtual tests for the furniture industry

Makhlouf, Heba 14 December 2015 (has links)
Le travail s’inscrit dans le cadre d’une collaboration entre le Pôle Ameublement FCBA et le Laboratoire MSME de l’UPEM. L’objectif était de mettre au point un outil de simulation permettant à FCBA de mener une étude de validation (tenue aux tests normalisés) avant la fabrication du meuble. Ce travail était supporté par les fonds collectifs de la profession ameublement. Il a donné lieu à des développements dans le domaine de l’identification du comportement anisotrope du bois par analyse d’images couplée à la méthode des éléments finis, d’une approche multi-échelle pour identifier le comportement des liens entre éléments de meuble et d’un programme éléments finis utilisant l’approche « poutres » pour réaliser une étude statistique du comportement du meuble prenant en compte la dispersion du comportement du bois. Chaque étape a été validée expérimentalement. La simulation par éléments finis s’est focalisée sur une application « lits superposées en bois massif » pour laquelle un code à base de poutres a été développé dans l’environnement Matlab afin de pouvoir y implanter :• une théorie élastique anisotrope via des poutres de Timoshenko pour prendre en compte l’effet des déformations dues aux faibles rigidités transversales du bois en regard de la rigidité longitudinale ;• des éléments de connexion ponctuels représentant la contribution des composants de quincaillerie (vis, écrou noyé, tourillon…) et les effets locaux 3D aux liaisons entre poutres ;• la possibilité de prendre en compte les incertitudes sur les paramètres matériau d’une poutre à l’autre en fonction de l’orientation des planches, de la densité du bois etc… via une simulation de Monte-Carlo / The work joins within the framework of a collaboration between the Pole Furnishing FCBA and the Laboratory MSME of the UPEM. The objective was to finalize(to work out) a tool of simulation allowing FCBA to lead a study of validation (held the normalized(standardized) tests) before the manufacturing of the piece of furniture
539

Evaluation de l'activité antimicrobienne de nouveaux composés aminostéroïdiens dans le contexte de la mucoviscidose / Evaluation of aminosteroid compounds as a new class of antimicrobial agents in the context of cystic fibrosis

Alhanout, Kamel 22 June 2010 (has links)
Les dérivés aminostéroïdiens (DASs) comme la squalamine et ses analogues ont démontré une activité antimicrobienne évaluée in vitro contre des bactéries et des champignons de référence et jamais contre des souches cliniques et/ou multi résistantes. Il a été montré que la squalamine agit contre des bactéries à Gram négatif en perturbant l’intégrité de leur membrane externe. Au contraire, son mécanisme contre les bactéries à Gram-positif n’a pas été étudié. Ainsi, l’objectif de ce travail a été d’évaluer d’une part l’activité antimicrobienne in vitro de la squalamine et de dérivés aminostéroïdiens (DAS 1-2, Figure 1) contre un panel de souches cliniques de bactéries et de champignons filamenteux isolés des crachats des patients atteints de mucoviscidose et des levures impliquées dans des fongémies, et d’autre part de mieux comprendre leur mécanisme d’action vis-à-vis des bactéries à Gram-positif et à Gram-négatif. Nous avons trouvé que les DASs possèdent une activité antibactérienne intéressante qui était d’autant plus importante que la bactérie est non mucoïde et/ou sensible à la colistine laissant supposer qu’une corrélation existe entre l’activité des DASs et celle de la colistine vis-à-vis des bactéries à Gram-négatif. Malgré cette corrélation, les DASs ont été plus actifs contre les bactéries à Gram-positif suggérant la présence de deux mécanismes d’action différents à l’égard des deux groupes de bactéries. Alors que les agents antifongiques classiques ont montré des activités hétérogènes vis-à-vis des champignons filamenteux et des levures testés d’une manière dépendante de l’espèce, les DASs ont présenté des activités homogènes indiquant que ces molécules possèdent un mécanisme d’action différent e ceux rapporté avec les antifongiques classiques. Ainsi, nous données préliminaires ont indiqué que la squalamine induit une rupture de la membrane de levures par, probablement, un effet "mécanique". L’analyse du mécanisme d’action antibactérien de la squalamine a montré que cette molécules agit en perturbant l’intégrité de bactéries à Gram-négatif d’un mécanisme comparable à celui d’un détergeant et en dépolarisant la membrane des bactéries à Grampositif conduisant à la rupture totale de cette membrane et au drainage de la matière cytoplasmique. Finalement, la faisabilité d’une forme galénique aérosol contenant un composé aminostéroïdien a été démontrée. / Aminosterol derivatives (ASDs) such as squalamine and its analogs have demonstrated an interesting in vitro antimicrobial activity evaluated against bacterial and fungal reference strains and never against clinical and / or multiresistant pathogens. It was shown that squalamine acts against Gram-negative bacteria by disrupting the integrity of their outer membrane. Instead, its mechanism of action against Gram-positive bacteria has never been studied. Thus, the aim of this study was firstly to evaluate in vitro antimicrobial activity of squalamine and two synthesized ASDs (ASD 1-2, Figure 1) against a panel of clinical strains of bacteria and filamentous fungi isolated from sputum of cystic fibrosis patients and yeasts involved in fungemia, and secondly to better understand their mechanism of action against Gram-positive and Gram-negative bacteria. We found that ASDs possess an interesting in vitro antibacterial activity which was more important against non-mucoid and/or colistin sensitive strains suggesting that a correlation exists between the activity of ASDs and that of colistin against Gram-negative bacteria. Despite this correlation, ASDs were more active against Gram-positive bacteria indicating the presence of two different mechanisms of action against both groups of bacteria. While classical antifungal agents showed heterogeneous activities against tested filamentous fungi and yeasts specie-dependent manner, ASDs presented homogeneous activities indicating that these molecules may possess a mechanism of action different from those reported with conventional antifungals. Thus, our preliminary data indicated that squalamine induced the disruption of yeast membrane, probably via a "mechanical" effect. Analysis of the antibacterial mechanism of action of squalamine has shown that this molecule acts by disrupting the integrity of bacterial membrane of Gram-negative bacteria via a detergent-like mode of action and by depolarizing the membrane of Grampositive leading to a total disruption of this membrane. Finally, the suitability of one of our compounds to be integrated in an aerosol formulation has been demonstrated.
540

Towards 3D reconstruction of outdoor scenes by mmw radar and a vision sensor fusion / Reconstruction 3D des scènes urbaines par fusion de donnée d'un radar hyperfréquence et de vision

El Natour, Ghina 14 December 2016 (has links)
L’objectif de cette thèse est de développer des méthodes permettant la cartographie d’un environnement tridimensionnel de grande dimension en combinant radar panoramique MMW et caméras optiques. Contrairement aux méthodes existantes de fusion de données multi-capteurs, telles que le SLAM, nous souhaitons réaliser un capteur de type RGB-D fournissant directement des mesures de profondeur enrichies par l’apparence (couleur, texture...). Après avoir modélisé géométriquement le système radar/caméra, nous proposons une méthode de calibrage originale utilisant des correspondances de points. Pour obtenir ces correspondances, des cibles permettant une mesure ponctuelle aussi bien par le radar que la caméra ont été conçues. L’approche proposée a été élaborée pour pouvoir être mise en oeuvre dans un environnement libre et par un opérateur non expert. Deuxièmement, une méthode de reconstruction de points tridimensionnels sur la base de correspondances de points radar et image a été développée. Nous montrons par une analyse théorique des incertitudes combinées des deux capteurs et par des résultats expérimentaux, que la méthode proposée est plus précise que la triangulation stéréoscopique classique pour des points éloignés comme on en trouve dans le cas de cartographie d’environnements extérieurs. Enfin, nous proposons une stratégie efficace de mise en correspondance automatique des données caméra et radar. Cette stratégie utilise deux caméras calibrées. Prenant en compte l’hétérogénéité des données radar et caméras, l’algorithme développé commence par segmenter les données radar en régions polygonales. Grâce au calibrage, l’enveloppe de chaque région est projetée dans deux images afin de définir des régions d’intérêt plus restreintes. Ces régions sont alors segmentées à leur tour en régions polygonales générant ainsi une liste restreinte d’appariement candidats. Un critère basé sur l’inter corrélation et la contrainte épipolaire est appliqué pour valider ou rejeter des paires de régions. Tant que ce critère n’est pas vérifié, les régions sont, elles même, subdivisées par segmentation. Ce processus, favorise l’appariement de régions de grande dimension en premier. L’objectif de cette approche est d’obtenir une cartographie sous forme de patchs localement denses. Les méthodes proposées, ont été testées aussi bien sur des données de synthèse que sur des données expérimentales réelles. Les résultats sont encourageants et montrent, à notre sens, la faisabilité de l’utilisation de ces deux capteurs pour la cartographie d’environnements extérieurs de grande échelle. / The main goal of this PhD work is to develop 3D mapping methods of large scale environment by combining panoramic radar and cameras. Unlike existing sensor fusion methods, such as SLAM (simultaneous localization and mapping), we want to build a RGB-D sensor which directly provides depth measurement enhanced with texture and color information. After modeling the geometry of the radar/camera system, we propose a novel calibration method using points correspondences. To obtain these points correspondences, we designed special targets allowing accurate point detection by both the radar and the camera. The proposed approach has been developed to be implemented by non-expert operators and in unconstrained environment. Secondly, a 3D reconstruction method is elaborated based on radar data and image point correspondences. A theoretical analysis is done to study the influence of the uncertainty zone of each sensor on the reconstruction method. This theoretical study, together with the experimental results, show that the proposed method outperforms the conventional stereoscopic triangulation for large scale outdoor scenes. Finally, we propose an efficient strategy for automatic data matching. This strategy uses two calibrated cameras. Taking into account the heterogeneity of cameras and radar data, the developed algorithm starts by segmenting the radar data into polygonal regions. The calibration process allows the restriction of the search by defining a region of interest in the pair of images. A similarity criterion based on both cross correlation and epipolar constraint is applied in order to validate or reject region pairs. While the similarity test is not met, the image regions are re-segmented iteratively into polygonal regions, generating thereby a shortlist of candidate matches. This process promotes the matching of large regions first which allows obtaining maps with locally dense patches. The proposed methods were tested on both synthetic and real experimental data. The results are encouraging and prove the feasibility of radar and vision sensor fusion for the 3D mapping of large scale urban environment.

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