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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.
51

Documentos da morte‟ : a certidão de óbito e a regulamentação da morte e da vida no sertão Pernambucano

NASCIMENTO, Rebeca Ramany Santos 19 May 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-22T18:36:07Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Documentos da morte_Rebeca_Versão para biblioteca central.pdf: 865557 bytes, checksum: 90dcaaf9ded772c1197fc71795ff11c9 (MD5) / Made available in DSpace on 2016-08-22T18:36:07Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Documentos da morte_Rebeca_Versão para biblioteca central.pdf: 865557 bytes, checksum: 90dcaaf9ded772c1197fc71795ff11c9 (MD5) Previous issue date: 2016-05-19 / FACEPE / Esta dissertação tem como objetivo analisar como as práticas judiciárias de assentamento e retificação do registro de óbito regulamentam a morte e a vida, em uma região do Sertão Central de Pernambuco. Buscou-se mapear os procedimentos acionados pelos familiares dos mortos frente à ausência ou erro da certidão de óbito; analisar os discursos jurídicos sobre os homens e as mulheres rurais requerentes de processos judiciais para assentamento e retificação do registro de óbito; examinar os motivos apresentados pelos familiares dos mortos para requerer a retificação ou a certidão de óbito tardia. Embasamo-nos teoricamente nas noções de Michel Foucault sobre biopoder, governamentalidade e produção de verdade. Como estratégia metodológica, utilizamos a pesquisa em documentos de domínio público (processos judiciais para assentamento ou retificação da certidão de óbito), entrevistas e observação. A partir dos processos judiciais e das entrevistas, observamos que se o óbito não for realizado dentro do prazo legal dos cartórios ou o documento apresente alguma informação errada, é necessário que a família reúna uma série de provas documentais e testemunhais. As análises indicam que o assento tardio da certidão de óbito e sua retificação parecem uma das formas pelas quais as práticas judiciárias definem tipos de subjetividade, formas de saber e relações entre a população e a verdade. Entre as principais motivações da requisição do assento de óbito ou sua retificação, configura-se a necessidade de a família em obter benefícios previdenciários, principalmente o benefício de pensão por morte. Concluímos que a certidão de óbito seguindo os percursos da biopolítica regulamenta a morte e vida. Ao mesmo em tempo que esse documento atua como uma tecnologia de governo de população, ele permite que os familiares dos mortos alcancem direitos garantidos constitucionalmente / This essay aims to analyze how the judicial practices of registration and rectification of death record regulate life and death, in a region of Central Backlands of Pernambuco. It was sought to map the procedures driven by the family of the dead opposite the absence or error of the death certificate; analyze the legal discourses about rural men and women applicants of lawsuits for registration and rectification of the death record; examine the reasons given by the relatives of the dead to request the rectification or late death certificate. We theoretically supported on the concepts of Michel Foucault on biopower, governmentality and production of truth. As a methodological strategy, we used research in the public domain documents (lawsuits for registration or rectification of the death certificate), interviews and observation. From lawsuits and interviews, we observed that if the death is not made within the legal period of the register offices or the document presents some wrong information, it is necessary that the family to gathers a wide range of documentary and testimonial evidence. The analysis indicate that late register of the death certificate seems one of the ways in which judicial practices define types of subjectivity, forms of knowledge and relations between the population and the truth. Among the main reasons of requesting the register of death or its rectification configures the need of the family in obtaining social welfare benefits, especially pension benefit due to death. We conclude that the death certificate following the paths of biopolitics regulates life and death. At the same time that document acts as a technology of population control, it allows the relatives of the dead reach constitutionally guaranteed rights.
52

Object detection and pose estimation from natural features for augmented reality in complex scenes

SIMOES, Francisco Paulo Magalhaes 07 March 2016 (has links)
Submitted by Alice Araujo (alice.caraujo@ufpe.br) on 2017-11-29T16:49:07Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TeseFinal_fpms.pdf: 108609391 bytes, checksum: c84c50e3c8588d6c85e44f9ac6343200 (MD5) / Made available in DSpace on 2017-11-29T16:49:07Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TeseFinal_fpms.pdf: 108609391 bytes, checksum: c84c50e3c8588d6c85e44f9ac6343200 (MD5) Previous issue date: 2016-03-07 / CNPQ / Alignment of virtual elements to the real world scenes (known as detection and tracking) relying on features that are naturally present on the scene is one of the most important challenges in Augmented Reality. When it goes to complex scenes like industrial scenarios, the problem gets bigger with the lack of features and models, high specularity and others. Based on these problems, this PhD thesis addresses the question “How to improve object detection and pose estimation from natural features for AR when dealing with complex scenes problems?”. In order to answer this question, we need to ask ourselves “What are the challenges that we face when developing a new tracker for real world scenarios?”. We begin to answer these questions by developing a complete tracking system that tackles some characteristics typically found in industrial scenarios. This system was validated in a tracking competition organized by the most important AR conference in the world, called ISMAR. During the contest, two complementary problems to tracking were also discussed: calibration, procedure which puts the virtual information in the same coordinate system of the real world, and 3D reconstruction, which is responsible for creating 3D models of the scene to be used for tracking. Because many trackers need a pre-acquired model of the target objects, the quality of the generated geometric model of the objects influences the tracker, as observed on the tracking contest. Sometimes these models are available but in other cases their acquisition represents a great effort (manually) or cost (laser scanning). Because of this we decided to analyze how difficult it is today to automatically recover 3D geometry from complex 3D scenes by using only video. In our case, we considered an electrical substation as a complex 3D scene. Based on the acquired knowledge from previous experiments, we decided to first tackle the problem of improving the tracking for scenes where we can use recent RGB-D sensors during model generation and tracking. We developed a technique called DARP, Depth Assisted Rectification of Patches, which can improve matching by using rectified features based on patches normals. We analyzed this new technique under different synthetic and real scenes and improved the results over traditional texture based trackers like ORB, DAFT or SIFT. Since model generation is a difficult problem in complex scenes, our second proposed tracking approach does not depend on these geometric models and aims to track texture or textureless objects. We applied a supervised learning technique, called Gradient Boosting Trees (GBTs) to solve the tracking as a linear regression problem. We developed this technique by using image gradients and analyzing their relationship with tracking parameters. We also proposed an improvement over GBTs by using traditional tracking approaches together with them, like intensity or edge based features which turned their piecewise constant function to a more robust piecewise linear function. With the new approach, it was possible to track textureless objects like a black and white map for example. / O alinhamento de elementos virtuais com a cena real (definido como detecção e rastreamento) através de características naturalmente presentes em cena é um dos grandes desafios da Realidade Aumentada. Quando se trata de cenas complexas, como cenários industriais, o problema se torna maior com objetos pouco texturizados, alta especularidade e outros. Com base nesses problemas, esta tese de doutorado aborda a questão "Como melhorar a detecção de objetos e a estimativa da sua pose através de características naturais da cena para RA ao lidar com problemas de cenários complexos?". Para responder a essa pergunta, precisamos também nos perguntar: Quais são os desafios que enfrentamos ao desenvolver um novo rastreador para cenários reais?". Nesta tese, começamos a responder estas questões através da criação de um sistema de rastreamento completo que lida com algumas características tipicamente encontradas em cenários industriais. Este sistema foi validado em uma competição de rastreamento realizada na principal conferência de RA no mundo, chamada ISMAR. Durante a competição também foram discutidos dois problemas complementares ao rastreamento: a calibração, procedimento que coloca a informação virtual no mesmo sistema de coordenadas do mundo real, e a reconstrução 3D, responsável por criar modelos 3D da cena. Muitos rastreadores necessitam de modelos pré-adquiridos dos objetos presentes na cena e sua qualidade influencia o rastreador, como observado na competição de rastreamento. Às vezes, esses modelos estão disponíveis, mas em outros casos a sua aquisição representa um grande esforço (manual) ou custo (por varredura a laser). Devido a isto, decidimos analisar a dificuldade de reconstruir automaticamente a geometria de cenas 3D complexas usando apenas vídeo. No nosso caso, considerou-se uma subestação elétrica como exemplo de uma cena 3D complexa. Com base no conhecimento adquirido a partir das experiências anteriores, decidimos primeiro resolver o problema de melhorar o rastreamento para as cenas em que podemos utilizar sensores RGB-D durante a reconstrução e o rastreamento. Foi desenvolvida a técnica chamada DARP, sigla do inglês para Retificação de Patches Assistida por Informação de Profundidade, para melhorar o casamento de características usando patches retificados a partir das normais. A técnica foi analisada em cenários sintéticos e reais e melhorou resultados de rastreadores baseados em textura como ORB, DAFT ou SIFT. Já que a reconstrução do modelo 3D é um problema difícil em cenas complexas, a segunda abordagem de rastreamento não depende desses modelos geométricos e pretende rastrear objetos texturizados ou não. Nós aplicamos uma técnica de aprendizagem supervisionada, chamada Gradient Boosting Trees (GBTs) para tratar o rastreamento como um problema de regressão linear. A técnica foi desenvolvida utilizando gradientes da imagem e a análise de sua relação com os parâmetros de rastreamento. Foi também proposta uma melhoria em relação às GBTs através do uso de abordagens tradicionais de rastreamento em conjunto com a regressão linear, como rastreamento baseado em intensidade ou em arestas, propondo uma nova função de predição por partes lineares mais robusta que a função de predição por partes constantes. A nova abordagem permitiu o rastreamento de objetos não-texturizados como por exemplo um mapa em preto e branco.
53

Amorphous indium-gallium-zinc oxide planar nanodiodes

Fryer, Antony Colin January 2014 (has links)
In this thesis work, novel planar nanodiodes (PNDs) using an amorphous indium-gallium-zinc oxide (IGZO) film as the active layer have been electrically characterised for the first time. Simulation techniques and experimental methods, such as e-beam lithography (EBL) and nanoimprint lithography (NIL), have been explored for these devices. In addition, a novel approach was realized that produced self-aligned contacts for the nanostructured devices. A preliminary parameter space for experimentation of the PNDs was ascertained by simulating the devices using a technology computer aided design (TCAD) simulator. In this study Silvaco’s ATLAS default IGZO material system was adopted. These simulations showed device performance to be heavily dependent on the carrier concentration of the film, owing to the high leakage current during the off-state of device operation. Furthermore, device geometry had a significant influence on the device’s electrical response. Channel width, length and trench width were all examined. Experimental characterisation of PNDs were attained by fabricating devices using EBL. These devices are the first to exhbit diode-like DC electrical response from an IGZO-based PND. Full current rectification was obtained with a rectification ratio of 10^4 for devices with a long, narrow channel with a width of 50nm and a length of 4μm. This particular device geometry had a turn-on voltage, Von, of 2.2V and did not breakdown within the −10V bias range tested. An output drive current of 0.1μA at 10V was obtained by the single PND device. It was also demonstrated that by increasing the channel width, Von could be reduced; however, rectification also diminished. It is reasoned that the exposed IGZO surface was subject to contamination from the ambient which changed the device’s electrical response after 17 days. An ultraviolet NIL (UV-NIL) technique was developed to produce the PNDs. This fabrication method offers a suitable route towards high-volume manufacture of these nanodevices, which is critical for them to be incorporated into a low-cost RF energy harvester. A novel NIL process was established in which the contact pads were self-aligned to within ~ 200nm of the channel by patterning both metal and semiconductor layers with a single imprint. DC electrical characterisation of the imprinted PNDs produced high rectifications ratios at a lower Von. The greater number of devices tested allowed a coarse parameter space for channel width and length to determined. PNDs with a channel aspect ratio (length divided by width) of more than 20 exhibited the greatest DC rectification of 10^4. An alumina capping layer was found to eliminate hysteresis in the electrical response; however, the greater permittivity value had no noticeable effect on device performance. Finally, a large-signal RF analysis is carried out on a device which suggest no deterioration in device perfromance up to at least 1GHz.
54

Caractérisation de la susceptibilité électromagnétique des étages d'entrée de composants électroniques / Electromagnetic susceptibility characterization of the input stages of electronic devices

Pouant, Clovis 09 December 2015 (has links)
Le travail de recherche présenté dans ce manuscrit contribue à une étude générale de la susceptibilité électromagnétique (EM) d'un transistor MOS (Metal Oxide Semiconductor) dans une gamme de fréquences allant de 10 MHz à 1 GHz. Ce composant est destiné à un usage général pour des applications analogiques et numériques. Le but principal de ce travail est d'apporter une compréhension fine des mécanismes physiques mis en jeu au sein du composant lorsque ce dernier est soumis à une agression EM injectée en mode conduit au niveau de sa grille. Notre étude porte sur l'élaboration d'un modèle physique, essentiellement basé sur les variations de charges au sein du composant électronique. Cette approche permet à la fois de comprendre le fonctionnement nominal du transistor et la modification de son comportement lors d'un dysfonctionnement. En effet, la compréhension des mécanismes physiques mis en jeu est la base de la compréhension de la susceptibilité EM. Pour mettre en œuvre ce type d'approche, nous avons choisi d'étudier un type de susceptibilité correspondant à la modification de son point de fonctionnement sous agression EM. Cette modification du point de fonctionnement peut induire un dysfonctionnement du circuit dans lequel est implanté le transistor. Le phénomène physique à l'origine duquel les signaux parasites EM modifient le point de fonctionnement d'un composant électronique est le phénomène de redressement. Ce phénomène apparaît lorsqu'une distorsion est créée au sein du composant. C'est aussi pourquoi les non-linéarités du dispositif sont directement responsables de son observation. Ainsi, pour comprendre finement et physiquement l'effet induit par une agression EM, il est nécessaire de mettre en place une méthode d'étude. Celle-ci est basée sur une mesure des formes d'onde des courants à tous les accès du transistor. En effet, la visualisation de ces courants renseigne sur l'évolution des charges au sein de la structure. De plus, une telle mesure donne accès à une large palette d'observables (valeurs moyennes des courants, distorsions des courants, valeurs crêtes des courants, etc..). Dans un premier temps, les différentes mesures des formes d'onde des courants ont été réalisées lorsqu'une impulsion de tension était appliquée sur la grille du composant avec des temps de montée variables et choisis par rapport au temps de réponse du transistor. Cela nous a permis d'approfondir la compréhension du fonctionnement transitoire fort signal du MOSFET. Dans un second temps, nous avons mesuré les courants lors de l'application d'un signal EM à la grille du composant. En support à ces mesures nous avons utilisé deux outils de calcul : analytique et numérique. La méthode analytique permet la prédiction et l'identification des grandeurs du composant mises en jeu dans le mécanisme de la modification du comportement du transistor. La méthode numérique par simulation électrique permet, quant à elle, de prédire les effets de l'agression EM. Une étape de caractérisation statique et dynamique du composant a également été nécessaire pour enrichir la compréhension des phénomènes observés et fournir les entrées au modèle. / The research work presented here contributes to an overall study of the electromagnetic (EM) susceptibility of Metal Oxide Semiconductor Field Effect Transistors (MOSFET's), in a frequency range from 10 MHz to 1 GHz. This device is used for general purpose: analog and digital applications. The main aim of this study is to provide a detailed understanding of the physical mechanisms involved in the device when the Radio-Frequency (RF) interference is superimposed on the gate terminal. Our study focuses on the development of a physical model, based essentially on the charge variations within the electronic device. This approach allows to understand its behavior with and without the RF interference. Indeed, the knowledge of the involved physical mechanisms is the basic understanding of EM susceptibility. When RF interference is superimposed on the MOSFET terminals, various susceptibility effects take place depending on RF power level, frequency and the transistor operation region. Due to the nonlinearity of the MOS current-voltage characteristics, RF excitations cause distorted drain current waveform which leads to a bias point shift. This modification of the average drain current is called rectification effect. So we developed a method to clearly understand the effect induced by the EM interference. This method is based on the measurement of the currents waveforms to all of the transistor access. In fact, these currents waveforms measurements give us information on the charge variations within the electronic device. Moreover, such a measurement provides access to a wide range of current information (average values, distortion, peak values, etc.). Initially, the different currents waveforms measurements were made when a voltage ramp was applied to the device gate with variable rise time in respect to the transistor response time. This allowed us to understand the large signal transient response of the MOSFET. Secondly, we measured the currents waveforms when an EM interference was injected to the gate terminal. In support of these measurements we used two computation tools: analytical and numerical. The analytical method allows prediction and identification of the quantities of the device involved in the modification of transistor's behavior. The numerical method allows electrical simulation to predict the effects of EM aggression. A static and dynamic characterization of the component was also necessary to understand the observed phenomenon and provide data to the electrical model.
55

Nositelná rektifikační anténa pro RF sklízení energie / Wearable rectifying antenna for RF energy harvesting

Kokolia, Martin January 2016 (has links)
The aim of this thesis is to design and rectena that would be able to integrate into a cloth thanks to use of textile substrate. The first part deals with the possibilities of using various communication channels and services for maximizing the useable power. Attention is focused mainly on the use of textile materials for implementing microstrip circuits. It is made valorization of all the typical characteristics and problems using different fabrics as a microwave substrate and the possibilities of realization of conductive structures of microwave patch antenna and microstrip circuits. At the second part are identified parameters and constraints used for the design of the overall device with a rectifying antenna, which will be after the verification of the function in real implementation used for the final concept using textile structures. The design is verified by simulations by CST Microwave Studio and Microwave Designer. The initial design is being gradually extended by other concepts, the use of other materials and technologies. Several design are made, their properties evaluated and the best ones are then compared based on real measurements.
56

Reconstruction 3D et production de carte dense de disparité en stéréovision non-alignée pour des applications industrielles de localisation 3D et d'analyse de surface / 3D reconstruction and production of dense disparity map in non-aligned stereo vision for industrial applications of 3D measurement and surface analysis

Pelcat, Jimmy 23 February 2012 (has links)
En vision industrielle, de nombreuses applications de mesure et de contrôle qualité évoluent vers des problématiques tri-dimensionnelles. Les systèmes de stéréovision sont des solutions technologiques qui attirent les industriels par leur simplicité mécanique. Deux caméras statiques disposées à des endroits stratégiques peut s'avérer suffisantes pour répondre à cette problématique bien que les contraintes industrielles imposent de respecter des temps de traitement courts et des mesures précises. La diversité des applications nous amènent à envisager deux approches afin de répondre à deux types d'application. La première technique consiste en la reconstruction 3D à partir de paires de points images qui se correspondent dans les deux images. Elle est destinée à répondre à la problématique de mesure 3D. Les méthodes de calibration monoculaire et de calcul 3D par triangulation sont la base de la reconstruction 3D. Nous étudions la précision de mesure et son évolution selon la pose du système de capture par rapport à la scène observée. La seconde technique consiste à construire des images de disparité afin de répondre à des problématiques de construction de profil et d'analyse de défaut. La contrainte d'alignement des caméras, nécessaire pour accélérer le processus de mise en correspondance, implique d'utiliser des méthodes de calibration stéréoscopique et de rectification des images. Nous étudions l'impact de l'alignement sur la qualité de la rectification. La production de carte dense de disparité se base sur les techniques de stéréo-corrélation. Nous montrons les limites de l'utilisation d'un noyau de corrélation carré et proposons une alternative par production de deux cartes denses de disparité à partir de deux noyaux mono-directionnels, améliorant la mesure de disparité sur les zones de contours et d'occultations. / In industrial vision, many applications for measuring and quality control are moving to three-dimensional problems. Stereovision systems are technological solutions that attract industry by their mechanical simplicity. Two static cameras placed at strategic locations may be sufficient to address this problem although the industrial constraints imposed to respect a short processing time and precise measurements. The diversity of applications lead us to consider two approaches to resolve the two types of application. The first technique consists in the 3D reconstruction from pairs of image points which correspond in both images. It is intended to address the problem of 3D measurement. The methods of monocular calibration and 3D triangulation are the basis of 3D reconstruction. We study the accuracy and its evolution according to the capture system pose compared to the observed scene. The second technique is to construct disparity maps to address problems of building profile and default analysis. The alignment constraint of cameras needed to accelerate the process of matching involves the use of methods of stereoscopic calibration and image rectification. We study the impact of alignment on the quality of the rectification. The production of dense disparity map is based on the stereo-correlation techniques. We show the limits of the use of a squared correlation kernel and propose an alternative production of two dense disparity maps from two mono-directional kernels, improving the measurement of disparity around edges and occlusions.
57

Highly rectifying p-ZnCo2O4/n-ZnO heterojunction diodes

Schein, Friedrich-Leonhard, Winter, Markus, Böntgen, Tammo, von Wenckstern, Holger, Grundmann, Marius 10 August 2018 (has links)
We present oxide bipolar heterojunction diodes consisting of p-type ZnCo2O4 and n-type ZnO fabricated by pulsed-laser deposition. Hole conduction of ZnCo2O4 (ZCO) was evaluated by Hall and Seebeck effect as well as scanning capacitance spectroscopy. Both, ZCO/ZnO and ZnO/ZCO type heterostructures, showed diode characteristics. For amorphous ZCO deposited at room temperature on epitaxial ZnO/Al2O3 thin films, we achieved current rectification ratios up to 2x1010, ideality factors around 2, and long-term stability.
58

Reconstruction 3D infrarouge par perception active / 3D infrared reconstruction with active perception

Ducarouge, Benoit 26 September 2011 (has links)
Ces travaux de thèse ont été menés dans le contexte du projet ANR blanc "Real Time and True Temperature measurement" (R3T), dédié à la métrologie thermique à partir de mesures dans l'infrarouge. L'estimation d'une température vraie à partir d'une mesure de température apparente par une caméra infrarouge, exploite un modèle radiométrique dans lequel apparaît des facteurs qui dépendent de la nature et de la forme de l'objet considéré. Ces travaux portent sur la construction d'un modèle géométrique de l'objet à partir de caméras infrarouges déplacées par un robot autour d'un objet.Ces caméras, par rapport à des caméras standards, ont des caractéristiques spécifiques : faible résolution, peu de texture. Afin de faciliter la mise en œuvre et de minimiser la complexité du système final, nous avons choisi une approche de stéréovision non calibrée. Nous avons donc un banc de stéréovision infrarouge embarqué sur un robot cartésien, pour acquérir plusieurs vues de l'objet d'intérêt ; les principales étapes concernent la rectification non calibrée des images acquises par le banc stéréo, puis le calibrage des caméras rectifiées et de la relation main-œil sans utilisation de mire, puis la construction de modèles 3D locaux denses et le recalage de ces modèles partiels pour construire un modèle global de l'objet. Les contributions portent sur les deux premières étapes, rectification et calibrage pour la stéréovision. Pour la rectification non calibrée, il est proposé une approche d'optimisation sous contraintes qui estime les homographies, à appliquer sur ces images pour les rectifier, sans calcul préalable de la matrice Fondamentale, tout en minimisant les déformations projectives entre images d'origine et images rectifiées. La fonction coût est calculée à partir de la distance de Sampson avec une décomposition de la matrice fondamentale. Deux types de contraintes, géométriques et algébriques, sont comparés pour minimiser les déformations projectives. L'approche proposée est comparée aux méthodes proposées par Loop et Zhang, Hartley, Mallon et al... sur des jeux de données classiques de la littérature. Il est montré que les résultats sont au moins équivalents sur des images classiques et meilleurs sur des images de faible qualité comme des images infrarouges.Pour le calibrage sans mire, l'auteur propose de calibrer les caméras ainsi que la transformation main-œil, indispensable dès lors que le banc stéréo est porté par un robot, en une seule étape ; l'une des originalités est que cette méthode permet de calibrer les caméras préalablement rectifiées et ainsi de minimiser le nombre de paramètres à estimer. De même plusieurs critères sont proposés et évalués par de nombreux résultats sur des données de synthèse et sur des données réelles. Finalement, les méthodes de stéréovision testées pour ce contexte applicatif sont rapidement décrites ; des résultats expérimentaux acquis sur des objets sont présentés ainsi que des comparaisons vis-à-vis d'une vérité terrain connue / This dissertation was lead in the context of the R3T project (Real Time and True Temperature measurement), dedicated to metrology from thermal infrared measurements. The estimation of true temperature from apparent temperature measurement by an infrared camera uses a radiometric model which depends on nature and shape of the considered object. This work focuses on the construction of a geometric model from infrared cameras moved by a robot around an object.Those cameras, in comparison with standard ones, have specific characteristics : low resolution, low texture. To minimize the complexity and easily implement the final system, we chose a stereo approach using uncalibrated cameras. So we have an infrared stereoring embeded on a Cartesian robot, to acquire multiple views of the object of interest. First, the main steps implemented concern uncalibrated images rectification and autocalibration of infrared stereoring and hand-eye transformation without use of a calibration pattern. Then, the reconstruction of locals 3D models and the merge of these models was done to reach a global model of the object. The contributions cover the first two stages, rectification and autocalibration, for the other stereo reconstruction steps, different algorithms were tested and the best was chosen for our application.For the uncalibrated images rectification, an optimization approach under constraints is proposed. The estimation of rectification homographies is done, without the Fundamental matrix determination, while minimizing the distortion between original and corrected images. The cost function is based on the Sampson's distance with breakdown of the Fundamental matrix. Two constraints, geometrical and analytical, are compared to minimize distortion. The proposed approach is compared to methods proposed by Loop and Zhang, Hartley, Mallon et al ... on data sets from state of art. It is shown that the results are at least equivalent on conventional images and better on low quality images such as infrared images.For the autocalibration, the author proposes to calibrate cameras and hand-eye transformation, essential whenever the stereoring is embedded on a robot, in one step. One of the originality is that this method allows to calibrate rectified cameras and so minimize the number of parameters to estimate. Similarly, several criteria are proposed and evaluated by numerous results on synthetic and real data.Finally, all methods of stereovision tested for this application context are briefly described, the experimental results obtained on objects are presented and compared to ground truth
59

Application of a direct algorithm for the rectification of uncalibrated images

Ipson, Stanley S., Alzahrani, Ahmed S., Haigh, J.G.B. January 2004 (has links)
No / An algorithm for the rectification of uncalibrated images is presented and applied to a variety of cases. The algorithm generates the rectifying transformations directly from the geometrical relationship between the images, using any three correspondences in the images to define a reference plane. A small set of correspondences is used to calculate an initial rectification. Additional correspondences are introduced semi-automatically, by correlating regions of the rectified images. Since the rectified images of surfaces in the reference plane have no relative distortion, features can be matched very accurately by correlation, allowing small changes in disparity to be detected. In the 3-d reconstruction of an architectural scene, differences in depth are resolved to about 0.001 of the distance from camera to subject.
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KINEMATIC SYNTHESIS AND ANALYSIS TECHNIQUES TO IMPROVE PLANAR RIGID-BODY GUIDANCE

Myszka, David H. 19 August 2009 (has links)
No description available.

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