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Lablack, Adel. "Estimation du regard dans un environnement contrôlé." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2010. http://tel.archives-ouvertes.fr/tel-00841161.
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L'objectif principal de mon travail de thèse est l'extraction de la direction du regard (attention visuelle) d'une personne à partir de la vidéo. Cette analyse est effectuée dans un environnement composé d'une scène cible et d'une zone d'observation. La scène cible est une région d'intérêt définie pour être analysée (e.g. un écran plasma large, une image projetée sur un mur, une affiche publicitaire, un linéaire dans un magasin, ou la vitrine d'un magasin). La zone surveillée quant à elle est l'emplacement d'où les personnes regardent la scène cible (e.g. la rue, un couloir ou bien les allées d'un supermarché). Les connaissances qui sont extraites sont alors utilisées pour comprendre le comportement visuel de personnes ainsi que pour la réorganisation de la scène cible. Pour atteindre cet objectif, nous proposons une approche basée sur l'estimation de l'orientation de la tête et la projection du champ visuel pour localiser la région d'intérêt. Nous avons utilisé une méthode d'estimation de l'orientation de la tête basée sur l'apparence globale et sur un modèle cylindrique, et une méthode de projection géométrique pour extraire les régions d'intérêts basée sur les données physiologiques de la vision humaine. L'analyse du comportement visuel des personnes a été effectuée à l'aide d'un ensemble de métriques. Les méthodes proposées ont été validées sur des données vidéos et images.
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Dahmane, Afifa. "Estimation du regard à partir de la vidéo." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10010/document.
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L'objectif de cette thèse est l'estimation de la pose de la tête humaine à partir d'imagesmonoculaires. Le but est d'avoir un retour d'information de l'utilisateur sur l'orientationde son regard, et ce, de manière non-intrusive. Ce domaine de recherche est très actifcompte tenu de l'évolution des interfaces de communication entre l'homme et la machine,d'autant plus que plusieurs défis sont toujours ouverts. Notamment, la robustesse dusystème, son invariabilité à l'identité des personnes et à l'illumination ainsi que la qualitédu matériel de capture requis.L'approche que nous avons proposée est basée sur la symétrie bilatérale du visage.Nous utilisons des caractéristiques extraites de la symétrie pour estimer la pose de latête par le biais de l'apprentissage. Les caractéristiques utilisées sont géométriques maisextraites de manière globale à partir de toute la texture du visage, sans que des pointsou des contours spécifiques ne soient requis.Ces caractéristiques ont été validées expérimentalement à l'aide de bases d'images etde vidéos publiques dédiées à l'estimation de la pose de la tête. L'apprentissage superviséainsi que la régression sont utilisés pour construire des modèles de poses. Ces modèles ontété testés sur des séquences vidéo indépendantes des bases utilisées pour l'apprentissage.L'erreur d'estimation a été calculée et les résultats sont supérieurs ou équivalents à l'étatde l'artThe aim of this thesis is to estimate the pose of a human head frommonocular images. The goal is to have a feedback from the user on the direction of hisgaze, and this is done in a non-intrusive manner. This area of research is very activegiven the evolution of the communication interfaces between a human and a machine,especially as many challenges are still there. In particular, the robustness of the system,its invariance to the identity of individuals and enlightenment.The approach we propose is based on the bilateral symmetry of the face. We usefeatures extracted from the symmetry to estimate head pose through learning. Thefeatures used are geometric but extracted holistically from the whole texture of the face,without the need for specifc points or contours.These features have been experimentally validated by means of publicly availabledatabases of images and videos dedicated to head pose estimation. Supervised learningand regression have been used to build models of poses. These models have been testedon video sequences different from the bases used for learning. The estimation error hasbeen calculated and the results are superior or equivalent to the state of the art
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Dahmane, Afifa. "Estimation du regard à partir de la vidéo." Electronic Thesis or Diss., Lille 1, 2015. http://www.theses.fr/2015LIL10010.
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L'objectif de cette thèse est l'estimation de la pose de la tête humaine à partir d'imagesmonoculaires. Le but est d'avoir un retour d'information de l'utilisateur sur l'orientationde son regard, et ce, de manière non-intrusive. Ce domaine de recherche est très actifcompte tenu de l'évolution des interfaces de communication entre l'homme et la machine,d'autant plus que plusieurs défis sont toujours ouverts. Notamment, la robustesse dusystème, son invariabilité à l'identité des personnes et à l'illumination ainsi que la qualitédu matériel de capture requis.L'approche que nous avons proposée est basée sur la symétrie bilatérale du visage.Nous utilisons des caractéristiques extraites de la symétrie pour estimer la pose de latête par le biais de l'apprentissage. Les caractéristiques utilisées sont géométriques maisextraites de manière globale à partir de toute la texture du visage, sans que des pointsou des contours spécifiques ne soient requis.Ces caractéristiques ont été validées expérimentalement à l'aide de bases d'images etde vidéos publiques dédiées à l'estimation de la pose de la tête. L'apprentissage superviséainsi que la régression sont utilisés pour construire des modèles de poses. Ces modèles ontété testés sur des séquences vidéo indépendantes des bases utilisées pour l'apprentissage.L'erreur d'estimation a été calculée et les résultats sont supérieurs ou équivalents à l'étatde l'artThe aim of this thesis is to estimate the pose of a human head frommonocular images. The goal is to have a feedback from the user on the direction of hisgaze, and this is done in a non-intrusive manner. This area of research is very activegiven the evolution of the communication interfaces between a human and a machine,especially as many challenges are still there. In particular, the robustness of the system,its invariance to the identity of individuals and enlightenment.The approach we propose is based on the bilateral symmetry of the face. We usefeatures extracted from the symmetry to estimate head pose through learning. Thefeatures used are geometric but extracted holistically from the whole texture of the face,without the need for specifc points or contours.These features have been experimentally validated by means of publicly availabledatabases of images and videos dedicated to head pose estimation. Supervised learningand regression have been used to build models of poses. These models have been testedon video sequences different from the bases used for learning. The estimation error hasbeen calculated and the results are superior or equivalent to the state of the art
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Jin, Nan. "ModSETS : a model-driven stereo eye tracking system : application in the medical field." Electronic Thesis or Diss., Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0339.
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La plupart des systèmes de suivi de l’œil existants ne fournissent que des analyses précises et en temps réel des mouvements oculaires 2D (horizontaux et verticaux) dans des conditions de laboratoire. Ils sont en général insuffisants pour les applications du domaine médical, parce que leur robustesse est souvent mise à l'épreuve dans la pratique et la mesure du mouvement torsionnel de l’œil est ignorée la plupart du temps. Cela augmente la difficulté d'interprétation des données collectées et peut donc affecter la qualité du diagnostic médical. Un système de suivi de l’œil en stéréophotogrammétrie piloté par modèle (ModSETS) est proposé dans cette thèse de doctorat, pour offrir une analyse précise, robuste et en temps réel des mouvements oculaires 3D (horizontaux, verticaux et torsionnels) pour les applications médicales. La performance de ModSETS dans le suivi des mouvements oculaires 2D est démontrée par un ⟪gaze test⟫. Il a montré une bonne précision (i.e., d'environ 1 °) dans l'estimation du regard qui est conforme aux exigences de nombreuses applications médicales. La robustesse de ModSETS dans des conditions normales d’utilisation est également confirmée, traduit par un taux de réussite élevé dans la segmentation de la pupille (i.e., 91,4%). Certains résultats encourageants ont été obtenus dans la mesure des mouvements torsionnels de l’œil, même s'il est difficile d’effectuer une évaluation quantitative avec le matériel actuel. Le principe d’un tel système de suivi de l’œil en stéréophotogrammétrie piloté par modèle (ModSETS) est validé. Il montre un grand potentiel dans le suivi des mouvements oculaires 3D pour les applications du domaine médicalMost current eye tracking systems only provide accurate and real-time analysis of 2D (horizontal and vertical) eye movement in laboratory conditions. It is usually insufficient for medical applications, because their robustness is often challenged in practice and the measurement of eye torsion is almost ignored. This increases the difficulty of data interpretation and may thus affect the quality of medical diagnosis. A Model-driven Stereo Eye Tracking System (ModSETS) is proposed in this Ph.D. thesis, to provide accurate, robust, and real-time analysis of 3D (horizontal, vertical and torsional) eye movement for medical applications. The performance of ModSETS in 2D eye movement tracking is proved through a gaze test. It showed a good accuracy (i.e., of about 1°) in gaze estimation that is compliant with the requirements of many medical applications. The robustness of ModSETS in practical conditions is also confirmed, which is reflected by a high success rate in pupil segmentation (i.e., 91.4%). Some encouraging results of eye torsion measurement were obtained, even though it is difficult to make a quantitative assessment with current hardware. Therefore, the principle of ModSETS (Model-driven Stereo Eye Tracking System) is validated and shows great potential in 3D eye movement tracking for medical applications
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Masson, Clément. "Direction estimation using visual odometry." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169377.
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This Master thesis tackles the problem of measuring objects’ directions from a motionlessobservation point. A new method based on a single rotating camera requiring the knowledge ofonly two (or more) landmarks’ direction is proposed. In a first phase, multi-view geometry isused to estimate camera rotations and key elements’ direction from a set of overlapping images.Then in a second phase, the direction of any object can be estimated by resectioning the cameraassociated to a picture showing this object. A detailed description of the algorithmic chain isgiven, along with test results on both synthetic data and real images taken with an infraredcamera.Detta masterarbete behandlar problemet med att mäta objekts riktningar från en fastobservationspunkt. En ny metod föreslås, baserad på en enda roterande kamera som kräverendast två (eller flera) landmärkens riktningar. I en första fas används multiperspektivgeometri,för att uppskatta kamerarotationer och nyckelelements riktningar utifrån en uppsättningöverlappande bilder. I en andra fas kan sedan riktningen hos vilket objekt som helst uppskattasgenom att kameran, associerad till en bild visande detta objekt, omsektioneras. En detaljeradbeskrivning av den algoritmiska kedjan ges, tillsammans med testresultat av både syntetisk dataoch verkliga bilder tagen med en infraröd kamera.
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Muhamed, Rias. "Direction of arrival estimation using antenna arrays." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-10022008-063154/.
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Patriksson, Alfred. "Radio signal DOA estimation : Implementing radar signal direction estimation on an FPGA." Thesis, Linköpings universitet, Datorteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157144.
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This master’s thesis covers the design and implementation of a monopulse directionof arrival (DOA) estimation algorithm on an FPGA. The goal is to implement a complete system that is capable of estimating the bearing of an incident signal. In order to determine the estimate quality both a theoretical and practical noise analysis of the signal chain is performed. Special focus is placed on the statistical properties of the transformation from I/Q-demodulated signals with correlated noise to a polar representation. The pros and cons for three different methods of calculating received signal phasors are also covered.The system is limited to two receiving channels which constrains this report to a 2D analysis. In addition the used hardware is limited to C-band signals. We show that an FPGA implementation of monopulse techniques is definitely viable and that an SNR higher than ten dB allows for a gaussian approximation of the polar representationof an I/Q signal.
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Mazeyev, Yuri. "Direction estimation on 3D-tomography images of jawbones." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-1661.
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The present work expose a technique of estimation of optimal direction for placing dental implant. A volumetric computed tomography (CT) scan is used as a help of the following searches. The work offers criteria of the optimal implant placement direction and methods of evaluation on direction’s significance. The technique utilizes structure tensor to find a normal to the jawbone surface. Direction of that normal is then used as initial direction for search of optimal direction.
The technique described in the present work aimed to support doctor’s decisions during dental implantation treatment.
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Rippon, Lee. "Sheet profile estimation and machine direction adaptive control." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61466.
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Sheet and film process control is often structured such that separate controllers and actuators are dedicated to either the temporal (i.e, machine direction) variations or the spatial (i.e., cross direction) variations. The dedicated machine direction (MD) and cross direction (CD) controllers require separate measurements of the MD and CD sheet property profiles, respectively. The current industrial standard involves a traversing sensor that acquires a signal containing both MD and CD property variations. The challenge then becomes how does one extract separate MD and CD profiles from the mixed signal. Numerous techniques have been proposed, but ultimately the traditional exponential filtering method continues to be the industrial standard. A more recent technique, compressive sensing, appears promising but previous developments do not address the industrial constraints. In the first part of this thesis the compressive sensing technique is developed further, specifically with regards to feasibility of implementation. A comparative analysis is performed to determine the benefits and drawbacks of the proposed method.
Model-based control has gained widespread acceptance in a variety of industrial processes. To ensure adequate performance, these model-based controllers require a model that accurately represents the true process. However, the true process is changing over time as a result of the various operating conditions and physical characteristics of the process. In part two of this thesis an integrated adaptive control strategy is introduced for the multi-input multi-output MD process of a paper machine. This integrated framework consists of process monitoring, input design and system identification techniques developed in collaboration with multiple colleagues. The goal of this work is to unify these efforts and exhibit the integrated functionality on an industrial paper machine simulator.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Wirfält, Petter, Guillaume Bouleux, Magnus Jansson, and Petre Stoica. "Optimal prior knowledge-based direction of arrival estimation." KTH, Signalbehandling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109489.
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In certain applications involving direction of arrival (DOA) estimation the operator may have a-priori information on some of the DOAs. This information could refer to a target known to be present at a certain position or to a reflection. In this study, the authors investigate a methodology for array processing that exploits the information on the known DOAs for estimating the unknown DOAs as accurately as possible. Algorithms are presented that can efficiently handle the case of both correlated and uncorrelated sources when the receiver is a uniform linear array. The authors find a major improvement in estimator accuracy in feasible scenarios, and they compare the estimator performance to the corresponding theoretical stochastic Cramer-Rao bounds as well as to the performance of other methods capable of exploiting such prior knowledge. In addition, real data from an ultra-sound array is applied to the investigated estimators.QC 20130107
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SHIKANO, Kiyohiro, Fumitada ITAKURA, Kazuya TAKEDA, Hiroshi SARUWATARI, and Hidekazu KAMIYANAGIDA. "Direction of Arrival Estimation Using Nonlinear Microphone Array." Institute of Electronics, Information and Communication Engineers, 2001. http://hdl.handle.net/2237/15048.
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Dorosh, Anastasiia. "Direction-of-Arrival Estimation in Spherically Isotropic Noise." Thesis, Linnéuniversitetet, Institutionen för fysik och elektroteknik (IFE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-28603.
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Today the multisensor array signal processing of noisy measurements has received much attention. The classical problem in array signal processing is determining the location of an energy-radiating source relative to the location of the array, in other words, direction-of-arrival (DOA) estimation. One is considering the signal estimation problem when together with the signal(s) of interest some noise and interfering signals are present. In this report a direction-of-arrival estimation system is described based on an antenna array for detecting arrival angles in azimuth plane of signals pitched by the antenna array. For this, the Multiple Signal Classication (MUSIC) algorithmis first of all considered. Studies show that in spite of its good reputation and popularity among researches, it has a certain limit of its performance. In this subspace-based method for DOA estimation of signal wavefronts, the term corresponding to additive noise is initially assumed spatially white. In our paper, we address the problem of DOA estimation of multiple target signals in a particular noise situation - in correlated spherically isotropic noise, which, in many practical cases, models a more real context than under the white noise assumption. The purpose of this work is to analyze the behaviour of the MUSIC algorithm and compare its performance with some other algorithms (such as the Capon and the Classical algorithms) and, uppermost, to explore the quality of the detected angles in terms of precision depending on different parameters, e.g. number of samples, noise variance, number of incoming signals. Some modifications of the algorithms are also done is order to increase their performance. Program MATLAB is used to conduct the studies. The simulation results on the considered antenna array system indicate that in complex conditions the algorithms in question (and first of all, the MUSIC algorithm) are unable to automatically detect and localize the DOA signals with high accuracy. Other algorithms andways for simplification the problem (for example, procedure of denoising) exist and may provide more precision but require more computation time.
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Abdelkader, Sherif Gershman Alex B. Wong Max. "Direction-of-arrival estimation in large sensor arrays." *McMaster only, 2007.
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Magnis, Lionel. "Estimation de vitesse de rotation par mesures de direction." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0039/document.
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Cette thèse étudie l’estimation de vitesse de rotation d’un corps rigide à partir de mesures de directions (par exemple champ magnétique, direction du soleil) embarquées. L’objectif est de remplacer les gyromètres qui sont chers comparés aux autres capteurs inertiels et sujets à des saturations et à des dysfonctionnements. Dans une première partie de la thèse, on traite les cas spécifiques d’une rotation à axe fixe ou légèrement variable. Dans une seconde partie, on traite le cas d’une rotation quelconque par un observateur asymptotique non-linéaire. On construit l’observateur à partir de mesures de deux vecteurs de référence non colinéaires, ou bien d’un seul vecteur. La connaissance des coordonnées inertielles des vecteurs de référence n’est pas nécessaire. On étend ensuite l’observateur pour estimer en plus le couple et les paramètres d’inertie. Les équations d’Euler jouent un rôle central dans les travaux présentés ici. Il apparaît que, du moins pour les illustrations considérées, les gyromètres peuvent être remplacés par un algorithme d’estimation basé sur des capteurs de direction qui sont bien moins chers et plus robustesThis thesis addresses the general question of estimating the angular rate of a rigid body from on-board direction sensors (e.g. magnetometers, Sun sensors). The objective is to replace rate gyros which are very expensive compared to direction sensors, prone to saturation during high rate rotations and subject to failure. In a first part of the thesis, we address the specific cases of single-axis and slightly perturbed axis rotations.In a second part, we address the general case by an asymptotic non-linear observer. We build the observer from two non-collinear vector measurements or from a single vector measurements. The knowledge of the inertial coordinates of the reference vectors is not necessary. We then extend the observer to further estimate unknown torques and inertia parameters. The Euler’s equations play a central role in all the works developed in this thesis. It appears that, at least for the illustrative cases considered, rate gyros could be replaced with an estimation algorithm employing direction sensors which are much cheaper,more rugged and more resilient sensors
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Yu, Xiaoju, Min Liang, and Rafael Sabory-Garcia. "Novel Broadband Direction of Arrival Estimation Using Luneburg Lens." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581656.
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ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, CaliforniaA broadband passive direction finding system utilizing Luneburg lens has been investigated. With the simulated power level distribution at the detectors mounted on a Luneburg lens, both Cramér-Rao bound (CRB) and the root mean square error (RMS) based on the Correlation Algorithm (CA) for the direction of arrival (DoA) estimation have been derived and calculated. Guidelines on how to design the Luneburg lens detecting system have been studied. Finally, as a proof-of-concept demonstration, the DoA performance of a Luneburg lens fabricated using the polymer jetting technology with five detectors 10° equally spaced to receive the azimuth signal from -20° to 20° is demonstrated.
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Yu, Xiaoju, and Hao Xin. "3-D Direction of Arrival Estimation with Two Antennas." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595622.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaInspired by human auditory system, an improved direction of arrival (DOA) technique using only two antennas with a scatterer in between them to achieve additional magnitude cues is proposed. By exploiting the incident-angle-dependent magnitude and phase differences between the two monopole antennas and applying 2-D / 3-D multiple signal classification algorithms (MUSIC), the DOA of an incident microwave signal can be estimated. Genetic algorithm is applied to optimize the scatterer geometry for the 3-D DOA estimation. The simulated results of both the azimuth and three-dimensional DOA estimation have shown an encouraging accuracy and sensitivity by incorporating a lossy scatterer.
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エディ, タユフェール, and Eddy Taillefer. "Direction of arrival estimation using hexagonal-array signal processing." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB10290094/?lang=0, 2008. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB10290094/?lang=0.
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Shaik, Majid. "Direction of Arrival Estimation using Wideband Spectral Subspace Projection." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1453219825.
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Massé, Benoît. "Etude de la direction du regard dans le cadre d'interactions sociales incluant un robot." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAM055/document.
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Les robots sont de plus en plus utilisés dans un cadre social. Il ne suffit plusde partager l’espace avec des humains, mais aussi d’interagir avec eux. Dansce cadre, il est attendu du robot qu’il comprenne un certain nombre de signauxambiguës, verbaux et visuels, nécessaires à une interaction humaine. En particulier, on peut extraire beaucoup d’information, à la fois sur l’état d’esprit despersonnes et sur la dynamique de groupe à l’œuvre, en connaissant qui ou quoichaque personne regarde. On parle de la Cible d’attention visuelle, désignéepar l’acronyme anglais VFOA. Dans cette thèse, nous nous intéressons auxdonnées perçues par un robot humanoı̈de qui participe activement à une in-teraction sociale, et à leur utilisation pour deviner ce que chaque personneregarde.D’une part, le robot doit “regarder les gens”, à savoir orienter sa tête(et donc la caméra) pour obtenir des images des personnes présentes. Nousprésentons une méthode originale d’apprentissage par renforcement pourcontrôler la direction du regard d’un robot. Cette méthode utilise des réseauxde neurones récurrents. Le robot s’entraı̂ne en autonomie à déplacer sa tête enfonction des données visuelles et auditives. Il atteint une stratégie efficace, quilui permet de cibler des groupes de personnes dans un environnement évolutif.D’autre part, les images du robot peuvent être utilisée pour estimer lesVFOAs au cours du temps. Pour chaque visage visible, nous calculons laposture 3D de la tête (position et orientation dans l’espace) car très fortementcorrélée avec la direction du regard. Nous l’utilisons dans deux applications.Premièrement, nous remarquons que les gens peuvent regarder des objets quine sont pas visible depuis le point de vue du robot. Sous l’hypothèse quelesdits objets soient regardés au moins une partie du temps, nous souhaitonsestimer leurs positions exclusivement à partir de la direction du regard despersonnes visibles. Nous utilisons une représentation sous forme de carte dechaleur. Nous avons élaboré et entraı̂né plusieurs réseaux de convolutions afinde d’estimer la régression entre une séquence de postures des têtes, et les posi-tions des objets. Dans un second temps, les positions des objets d’intérêt, pou-vant être ciblés, sont supposées connues. Nous présentons alors un modèleprobabiliste, suggéré par des résultats en psychophysique, afin de modéliserla relation entre les postures des têtes, les positions des objets, la directiondu regard et les VFOAs. La formulation utilise un modèle markovien à dy-namiques multiples. En appliquant une approches bayésienne, nous obtenonsun algorithme pour calculer les VFOAs au fur et à mesure, et une méthodepour estimer les paramètres du modèle.Nos contributions reposent sur la possibilité d’utiliser des données, afind’exploiter des approches d’apprentissage automatique. Toutes nos méthodessont validées sur des jeu de données disponibles publiquement. De plus, lagénération de scénarios synthétiques permet d’agrandir à volonté la quantitéde données disponibles; les méthodes pour simuler ces données sont explicite-ment détailléeRobots are more and more used in a social context. They are required notonly to share physical space with humans but also to interact with them. Inthis context, the robot is expected to understand some verbal and non-verbalambiguous cues, constantly used in a natural human interaction. In particular,knowing who or what people are looking at is a very valuable information tounderstand each individual mental state as well as the interaction dynamics. Itis called Visual Focus of Attention or VFOA. In this thesis, we are interestedin using the inputs from an active humanoid robot – participating in a socialinteraction – to estimate who is looking at whom or what.On the one hand, we want the robot to look at people, so it can extractmeaningful visual information from its video camera. We propose a novelreinforcement learning method for robotic gaze control. The model is basedon a recurrent neural network architecture. The robot autonomously learns astrategy for moving its head (and camera) using audio-visual inputs. It is ableto focus on groups of people in a changing environment.On the other hand, information from the video camera images are used toinfer the VFOAs of people along time. We estimate the 3D head poses (lo-cation and orientation) for each face, as it is highly correlated with the gazedirection. We use it in two tasks. First, we note that objects may be lookedat while not being visible from the robot point of view. Under the assump-tion that objects of interest are being looked at, we propose to estimate theirlocations relying solely on the gaze direction of visible people. We formulatean ad hoc spatial representation based on probability heat-maps. We designseveral convolutional neural network models and train them to perform a re-gression from the space of head poses to the space of object locations. Thisprovide a set of object locations from a sequence of head poses. Second, wesuppose that the location of objects of interest are known. In this context, weintroduce a Bayesian probabilistic model, inspired from psychophysics, thatdescribes the dependency between head poses, object locations, eye-gaze di-rections, and VFOAs, along time. The formulation is based on a switchingstate-space Markov model. A specific filtering procedure is detailed to inferthe VFOAs, as well as an adapted training algorithm.The proposed contributions use data-driven approaches, and are addressedwithin the context of machine learning. All methods have been tested on pub-licly available datasets. Some training procedures additionally require to sim-ulate synthetic scenarios; the generation process is then explicitly detailed
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Guetat-Calabrese, Narjès. "Diriger une maison d'enfants à caractère social : regard clinique sur la fonction de direction." Thesis, Paris 10, 2018. http://www.theses.fr/2018PA100160.
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Cette thèse porte sur la fonction de direction d’une maison d’enfants à caractère social (MECS). Le travail réalisé s’inscrit dans une approche clinique d’orientation psychanalytique. À partir de quatre entretiens cliniques de recherche auprès de deux directrices et deux directeurs de MECS, la chercheuse, occupant elle-même des fonctions de direction de MECS, propose de poser un regard clinique sur les différentes postures sous-jacentes à l’exercice de cette fonction. La thèse est organisée en trois parties : la première partie analyse l’itinéraire professionnel de la chercheuse et témoigne de l’évolution de son positionnement dans une démarche clinique d’abord en tant que professionnelle puis en tant que chercheuse. La deuxième partie présente le champ de la Protection de l’Enfance, la spécificité des MECS comme institutions de la mésinscription et des adolescents qui y sont accueillis, la fonction de direction à travers plusieurs ouvrages consacrés à cette question mis en écho avec l’expérience de fonction de direction occupée par la chercheuse. Un dernier chapitre propose quelques éclairages théoriques à propos de la pulsion et la pulsion de mort. La troisième et dernière partie est dédiée à l’analyse des entretiens et à la mise en perspective de ces analyses dans laquelle sont avancées des hypothèses de compréhension des enjeux conscients et inconscients dans l’exercice de la fonction de direction de MECSThis thesis focusses on the role of leadership in Children’s Social Care Homes (MECS) and on the analysis of the psychological sources which underlie this role. The work is done as part of a clinical approach from a psychoanalytical position. Based on clinical interviews conducted with directors of MECS, the researcher proposes to take a clinical look at the different aspects of this function. The thesis is organised in three parts : the first part traces the professional journey of the researcher and shows the evolution of her position in a clinical approach to psychoanalytical orientation, first as a professional and then as a researcher. The second part presents an overview of child protection as well as the specificities of the “MECS” as institutions of care (mesinscription) linked to the characteristics of the adolescents they welcome. Based on the reading of several works on the function of leadership in this type of institutions and using her own experience as a director of a MECS countertransferentially, the researcher analyses the outlines of the definition of this function. The third and final part is dedicated to the analysis of the interviews and putting into the perspective of these analyses in which are advanced hypotheses for understanding of the conscious and unconscious stakes process of “déliaison” in such an institution and to the dualism of the impulse to life/impulse to death
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Tayem, Nizar Abdel-Hafeeth Mohammad Kwan Hyuck M. "Direction of arrival angle estimation schemes for wireless communication systems." Diss., Access through your commercial service, 2005. http://il.proquest.com/products_umi/dissertations/.
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Thesis (Ph.D.)--Wichita State University, College of Engineering."May 2005." Title from PDF title page (viewed on August 30, 2006). UMI number: AAT3189244 Thesis adviser: Hyuck M. Kwan. Includes bibliographic references (leaves 141-149).
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Yoon, Yeo-Sun. "Direction-of-arrival Estimation of Wideband Sources Using Sensor Arrays." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5110.
Full textAbstract:
Sensor arrays are used in many applications where their ability to localize signal sources is essential. For many applications, it is necessary to estimate the direction-of-arrival (DOA) of target sources. Although there are many DOA estimation methods available, most of them are valid only for narrowband signals where time delay can be approximated as a phase shift. This thesis focuses on DOA estimation algorithms for wideband sources. Specifically, this thesis proposes the pruned fast beamformer which can reduce the number of computations of Delay-and-Sum (DS) beamforming by using a multi-resolution structure. For high resolution methods, signal
subspace methods are required. Most of the subspace techniques for wideband signals decompose the received wideband signals into several bands of narrowband signals through bandpass filtering. Then, there are two different ways of processing decomposed signals. The incoherent methods process each band independently by a given narrowband method and average the results. The coherent methods attempt to modulate the signals in each band so that they
can be combined coherently. In this thesis, a new DOA estimator, which is called TOPS, is developed to avoid disadvantages of both the incoherent and the coherent methods. The new method which can be categorized as a non-coherent method is tested and compared with other methods. It exhibits many desirable features for a number of applications where the sources are wideband such as acoustic direction finding.
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Filik, Tansu. "Planar Array Structures For Two-dimensional Direction-of-arrival Estimation." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611841/index.pdf.
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In this thesis, two-dimensional (2-D) direction-of-arrival (DOA) estimation problem is considered. Usually, DOA estimation is considered in one dimension assuming a fixed elevation angle. While this assumption simplifies the problem, both the azimuth and elevation angles, namely, the 2-D DOA estimates are required in practical scenarios. In this thesis, planar array structures are considered for 2-D DOA estimation. In this context, V-shaped arrays are discussed and some of the important features of these arrays are outlined. A new method for the design of V-shaped arrays is presented for both isotropic and directional beam patterns. The design procedure is simple and can be applied for both uniform and nonuniform V-shaped sensor arrays. Closed form expressions are presented for the V-angle in order to obtain isotropic angle performance. While circular arrays have the isotropic characteristics, V-shaped arrays present certain advantages due to their large aperture for the same number of sensors and inter-sensor distance. The comparison of circular and V-shaped arrays is done by considering the azimuth and elevation Cramer-Rao Bounds (CRB). It is shown that V-shaped and circular arrays have similar characteristics for the sensor position errors while the uniform isotropic (UI) V-array performs better when there is mutual coupling and the sources are correlated.
In the literature, there are several techniques for 2-D DOA estimation. Usually, fast algorithms are desired for this purpose since a search in two dimensions is a costly process. These algorithms have a major problem, namely, the pairing of the azimuth-elevation couples for multiple sources. In this thesis, a new fast and effective technique for this purpose is proposed. In this technique, a virtual array output is generated such that when the ESPRIT algorithm is used, the eigenvalues of the rotational transformation matrix have the 2-D angle information in both magnitude and phase. This idea is applied in different scenarios and three methods are presented for these cases. In one case, given an arbitrary array structure, array interpolation is used to generate the appropriate virtual arrays. When the antenna mutual coupling is taken into account, a special type of array structure, such as circular, should be used in order to apply the array interpolation. In general, the array mutual coupling matrix (MCM) should have a symmetric Toeplitz form. It is shown that the 2-D DOA performance of the proposed method approaches to the CRB by using minimum number of antennas in case of mutual coupling. This method does not require the estimation of the mutual coupling coefficients. While this technique is effective, it has problems especially when the number of sources increases. In order to improve the performance, MCM is estimated in the third approach. This new approach performs better, but it cannot be used satisfactorily in case of multipath signals. In this thesis, the proposed idea for fast 2-D DOA estimation is further developed in order to solve the problem when mutual coupling and multipath signals jointly exist. In this case, real arrays with some auxiliary sensors are used to generate a structured mutual coupling matrix. It is shown that the problem can be effectively solved when the array structure has a special form. Specifically, parallel uniform linear arrays (PULA) are employed for this purpose. When auxiliary sensors are used, a symmetric banded Toeplitz MCM is obtained for the PULA. This allows the application of spatial smoothing and ESPRIT algorithm for 2-D DOA estimation. The proposed algorithm uses triplets and presents closed form paired 2-D DOA estimates in case of unknown mutual coupling and multipath signals. Several simulations are done and it is shown that the proposed array structure and the method effectively solve the problem.
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Proukakis, Christos. "Modelling, identification and estimation of ambiguities in direction-finding systems." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266479.
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Yu, Xiaoju. "Direction of Arrival Estimation of Broadband Signal Using Single Antenna." International Foundation for Telemetering, 2014. http://hdl.handle.net/10150/577496.
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ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CAIn this paper, we propose a novel technique using a single antenna for direction of arrival (DOA) estimation of broadband microwave signals. We designed and fabricated a microstrip-leaky-wave receiving antenna, which has good matching and reasonable radiation efficiency in the frequency range of interest: 2 - 3.5 GHz. Because the frequency response of the antenna is strongly incident-angle dependent, by using the spectral information at the antenna, we are able to estimate the DOA of a broadband microwave signal with a high degree of accuracy. Simulations and experiments show that the proposed technique enables good DOA estimation performance within a 90˚ range.
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Karimzadeh, Soroush. "Online detection of picketing and estimation of cross direction and machine direction variations using the discrete cosine transform." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/7565.
Full textAbstract:
A scanning sensor at the dry end of a paper machine samples a noisy mix
ture of both cross direction and machine direction variations. Although
many techniques have been developed to separate these two variations and
estimate a filtered profile, industrial practice has changed little over the
years.
In this work, a novel online Cross Direction (CD) /Machine Direction (MD)
separation approach is developed. The method uses a fundamental prop
erty of the CD variations to separate them from the MD variations. It is
shown that the scanned CD variations build an even periodic function in
the time domain and appear only as integer multiples of twice the scanning
frequency in the frequency domain. Based on this property, the Discrete
Cosine Transform (DCT) is utilized to separate the CD profile from noise
and the MD variations. The performance of this method is verified through
comprehensive simulation tests and is compared with existing wavelet and
exponential filters. It is shown that the suggested method has better per
formance in simulation scenarios. This is further validated by applying the
method to industrial data.
In the second part of this thesis, a novel picketing detection method is devel
oped. The picketing pattern is associated with growing components in the
spectrum of actuator profiles. A conventional change detection algorithm,
CUSUM, is applied to detect these growing components. The method is
verified in two simulation scenarios. It is shown that this method can detect
and predict a picketing pattern before any picketing pattern is visible on the
raw profile.
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Papin, Jean-Paul. "Utilisation des enregistrements de la direction du regard dans l'apprentissage de la prise d'information visuelle." Paris 5, 1987. http://www.theses.fr/1987PA05H093.
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En premier lieu, il est fait un rappel des recherches anterieures interessant d'une part les moyens d'enregistrement de la direction du regard et d'autre part les resultats obtenus concernant la prise d'information visuelle. Ceci permet de montrer: - l'existence, chez les sujets realisant une tache donnee, de traits du comportement visuel communs et specifiques, d'un niveau de competence particulier, - que ces traits s'acquierent de maniere partiellement inconsciente au cours de la formation, - que pour des taches differentes il existe des strategies presentants des points communs et permettant d'obtenir une reussite optimale. Ensuite sont rapportees les recherches qui testent l'hypothese suivante : "la presentation, l'explication et ou l'imposition a des eleves du comportement et des strategies d'exploration visuelle d'experts doit ameliorer la qualite de la formation". Ces recherches portent sur : -l'utilisation pedagogique de documents audiovisuels incluant des enregistrements de la direction du regard recueillis dans deux taches ; le pilotage en helicoptere et le diagnostic en radiophotographie, l'imposition, a des eleves, d'un comportement exploratoire juge comme optimal au cours de l'apprentissage du dessin en miroir. Les resultats montrent que, dans tous les cas, la vitesse de realisation de la tache est nettement amelioree mais que la precision reste identique voire devient moins bonne que celle d'eleves sur lesquels il n'y a pas eu intervention. En conclusion, il est propose, afin de remedier a cette absence d'effet positif sur la precision, de continuer ce type d'approche en presentant ou en imposant a des eleves des comportements visuels correspondant a des "passages obliges" identifies au cours des formations "habituelles"First, we relate previous researches dealing with means of gaze recording, and results about pick up of visual information. This shows : - for subjects performing a specific task, the existence of common visual behaviour, related to particular competence level, - that these features are partly unconscious acquisitions during training, - that for different tasks, strategies with common points and optimal performance are evidenced. Then, are presented the researches that test following assumption : "presentation, explanation and or laying down to students of experts "behaviour and strategies for visual pick up information must improve quality of training". These researches deal with : - educational use of audiovisual documents, including gaze recordings collected in two tasks : piloting helicopter, and radiophotograph diagnosis, - laying down, to students, of exploratory behaviour estimated as optimal for learning by means of mirror drawing. The results evidence that, in all cases, task performing speed is increased, but accuracy does not change, or becomes worse than for students who have note performed this training. In conclusion, we propose, to cure this absence of positive effect on accuracy, to continue this way of research by presenting or laying down to students visual behaviour, corresponding to "necessary ways" evidenced during usual training
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Caylar, Selcuk. "A Novel Neural Network Based Approach For Direction Of Arrival Estimation." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608838/index.pdf.
Full textAbstract:
In this study, a neural network(NN) based algorithm is proposed for real time
multiple source tracking problem based on a previously reported work. The proposed
algorithm namely modified neural network based multiple source tracking algorithm
(MN-MUST) performs direction of arrival(DoA) estimation in three stages which are
the detection, filtering and DoA estimation stages. The main contributions of this
proposed system are: reducing the input size for the uncorrelated source case
(reducing the training time) of NN system without degradation of accuracy and
insertion of a nonlinear spatial filter to isolate each one of the sectors where sources
are present, from the others.
MN-MUST algorithm finds the targets correctly no matter whether the targets are
located within the same angular sector or not. In addition as the number of targets
exceeds the number of antenna elements the algorithm can still perform sufficiently
well. Mutual coupling in array does not influence MN-MUST algorithm
performance.
iv
MN-MUST algorithm is further improved for a cylindrical microstrip patch antenna
array by using the advantages of directive antenna pattern properties. The new
algorithm is called cylindrical patch array MN-MUST(CMN-MUST). CMN-MUST
algorithm consists of three stages as MN-MUST does. Detection stage is exactly the
same as in MN-MUST. However spatial filtering and DoA estimation stage are
reduced order by using the advantages of directive antenna pattern of cylindirical
microstrip patch array.
The performance of the algorithm is investigated via computer simulations, for
uniform linear arrays, a six element uniform dipole array and a twelve element
uniform cylindrical microstrip patch array. The simulation results are compared to
the previously reported works and the literature. It is observed that the proposed
algorithm improves the previously reported works. The algorithm accuracy does not
degrade in the presence of the mutual coupling. A uniform cylindrical patch array is
successfully implemented to the MN-MUST algorithm. The implementation does not
only cover full azimuth, but also improv the accuracy and speed. It is observed that
the MN-MUST algorithm provides an accurate and efficient solution to the targettracking
problem in real time.
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Aksoy, Taylan. "Mutual Coupling Calibration Of Antenna Arrays For Direction-of-arrival Estimation." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614065/index.pdf.
Full textAbstract:
An antenna array is an indispensable portion of a direction-of-arrival (DOA) estimation operation. A number of error sources in the arrays degrade the DOA estimation accuracy. Mutual coupling effect is one of the main error sources and should be corrected for any antenna array. In this thesis, a system theoretic approach is presented for mutual coupling characterization of antenna arrays. In this approach, the idea is to model the mutual coupling effect through a simple linear transformation between the measured and the ideal array data. In this context, a measurement reduction method (MRM) is proposed to decrease the number of calibration measurements. This new method dramatically reduces the number of calibration measurements for omnidirectional antennas. It is shown that a single calibration measurement is sufficient for uniform circular arrays when MRM is used. The method is extended for the arrays composed of non-omnidirectional (NOD) antennas. It is shown that a single calibration matrix can not properly model the mutual coupling effect in an NOD antenna array. Therefore, a sectorized calibration approach is proposed for NOD antenna arrays where the mutual coupling calibration is done in angular sectors. Furthermore, mutual coupling problem is also investigated for antenna arrays over a perfect electric conductor plate. In this case, reflections from the plate lead to gain/phase mismatches in the antenna elements. In this context, a composite matrix approach is proposed where mutual coupling and gain/phase mismatch are jointly modelled by using a single composite calibration matrix. The proposed methods are evaluated over DOA estimation accuracies using Multiple Signal Classification (MUSIC) algorithm. The calibration measurements are obtained using the numerical electromagnetic simulation tool FEKO. The evaluation results show that the proposed methods effectively realize the mutual coupling calibration of antenna arrays.
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Chotikakamthorn, Nopporn. "A pre-filtering maximum likelihood approach to multiple source direction estimation." Thesis, Imperial College London, 1996. http://hdl.handle.net/10044/1/8634.
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Bigel, Marla G. "The estimation of distance, direction and self-position through nonvisual locomotion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0018/NQ38223.pdf.
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Howell, Randy Keith. "d-MUSIC : an algorithm for single snapshot direction-of-arrival estimation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37346.pdf.
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O?Keefe, Stephen A. "Autonomous Sun-Direction Estimation Using Partially Underdetermined Coarse Sun Sensor Configurations." Thesis, University of Colorado at Boulder, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3704787.
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In recent years there has been a significant increase in interest in smaller satellites as lower cost alternatives to traditional satellites, particularly with the rise in popularity of the CubeSat. Due to stringent mass, size, and often budget constraints, these small satellites rely on making the most of inexpensive hardware components and sensors, such as coarse sun sensors (CSS) and magnetometers. More expensive high-accuracy sun sensors often combine multiple measurements, and use specialized electronics, to deterministically solve for the direction of the Sun. Alternatively, cosine-type CSS output a voltage relative to the input light and are attractive due to their very low cost, simplicity to manufacture, small size, and minimal power consumption. This research investigates using coarse sun sensors for performing robust attitude estimation in order to point a spacecraft at the Sun after deployment from a launch vehicle, or following a system fault. As an alternative to using a large number of sensors, this thesis explores sun-direction estimation techniques with low computational costs that function well with underdetermined sets of CSS. Single-point estimators are coupled with simultaneous nonlinear control to achieve sun-pointing within a small percentage of a single orbit despite the partially underdetermined nature of the sensor suite. Leveraging an extensive analysis of the sensor models involved, sequential filtering techniques are shown to be capable of estimating the sun-direction to within a few degrees, with no a priori attitude information and using only CSS, despite the significant noise and biases present in the system. Detailed numerical simulations are used to compare and contrast the performance of the five different estimation techniques, with and without rate gyro measurements, their sensitivity to rate gyro accuracy, and their computation time. One of the key concerns with reducing the number of CSS is sensor degradation and failure. In this thesis, a Modified Rodrigues Parameter based CSS calibration filter suitable for autonomous on-board operation is developed. The sensitivity of this method's accuracy to the available Earth albedo data is evaluated and compared to the required computational effort. The calibration filter is expanded to perform sensor fault detection, and promising results are shown for reduced resolution albedo models. All of the methods discussed provide alternative attitude, determination, and control system algorithms for small satellite missions looking to use inexpensive, small sensors due to size, power, or budget limitations.
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Kassem, Wafaa Ibrahim. "Direction of arrival estimation and beamforming for narrowband and wideband signals." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418235.
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Yu, Xiaoju, Rongguo Zhou, Hualiang Zhang, and Hao Xin. "A Microwave Direction of Arrival Estimation Technique Using a Single Antenna." IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2016. http://hdl.handle.net/10150/621549.
Full textAbstract:
A direction of arrival (DoA) estimation technique for broadband microwave signals is proposed using a single ultrawideband antenna. It is inspired by the sound source localization ability of a human auditory system using just one ear (monaural localization). By exploiting the incident angle-dependent frequency response of a wideband antenna, the DoA of a broadband microwave signal can be estimated. The DoA estimation accuracies are evaluated for two antenna configurations and microwave signals with different signal-to-noise ratios. Encouraging the DoA estimation performance of the proposed technique is demonstrated in both simulation and experiment.
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Ho, Michael T. "A Comparision of Wideband Subspace Methods for Direction-of-Arrival Estimation." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1419265813.
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Suleiman, Wassim [Verfasser], Marius [Akademischer Betreuer] Pesavento, and Abdelhak [Akademischer Betreuer] Zoubir. "Decentralized Direction of Arrival Estimation / Wassim Suleiman ; Marius Pesavento, Abdelhak Zoubir." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1140835831/34.
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Seymour, L. P. H. K. "Bearing estimation in the presence of sensor positioning errors." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/14379.
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Guntz, Thomas. "Estimation du niveau d'expertise à partir du regard et des émotions." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALM030.
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Dans cette thèse, nous explorons comment de telles théories issues des sciences cognitives peuvent servir de base à l'informatique pour favoriser l'émergence des technologies d'intelligence artificielle collaborative.En particulier, nous utilisons l'observation d'humains ayant différents niveaux d'expertise engagés dans la résolution de problèmes d'échecs classiques pour explorer l'efficacité des modèles pour l'attention visuelle, la prise de conscience, la compréhension et la résolution de problèmes.Nous avons construit un instrument pour la capture et l'interprétation de signaux multimodaux d'humains engagés dans la résolution de problèmes.Notre instrument permet d'enregistrer la posture du corps, les gestes, les expressions faciales, la dilatation de la pupille et les trajectoires oculaires, ainsi que les interactions du joueur avec le problème des échecs.Combinés aux rapports verbaux des joueurs, ces enregistrements permettent de construire des modèles informatiques pour la prise de conscience et la compréhension de la situation de jeu lors de la résolution de problèmes en utilisant des concepts et des modèles issus de la littérature des sciences cognitives.Dans le cadre d'une première expérience, les joueurs d'échecs ont été enregistrés alors qu'ils étaient engagés dans des problèmes de difficulté croissante.Ces enregistrements ont été utilisés pour estimer la conscience qu'avait un participant de la situation actuelle et pour prédire la capacité à répondre efficacement aux menaces et aux opportunités.L'analyse des enregistrements montre comment le regard, la posture du corps et les caractéristiques émotionnelles peuvent être utilisés pour capturer et modéliser la conscience de la situation.Cette expérience a validé l'utilisation de notre équipement comme outil général et reproductible pour l'étude des participants engagés dans une interaction sur écran impliquant la résolution de problèmes et a suggéré des améliorations possibles pour de futures expériences.Ces premières expériences ont révélé une observation inattendue de changements rapides dans les émotions des joueurs qui tentent de résoudre des problèmes difficiles.Les tentatives d'explication de cette observation nous ont amenés à explorer le rôle de l'émotion dans le raisonnement lors de la résolution de problèmes.Dans la deuxième partie de la thèse, nous passons en revue la littérature sur les émotions et proposons un modèle cognitif qui décrit comment les émotions influencent le processus par lequel les sujets sélectionnent des éléments cognitives (concepts) à utiliser dans l'interprétation d'une situation de jeu.En particulier, il est bien connu que la résolution de problèmes est fortement contrainte par les limites du nombre de phénomènes qui peuvent être considérés à la fois.Pour surmonter cette limite, les experts humains s'appuient sur l'abstraction pour former de nouveaux concepts à partir de phénomènes émotionnellement marqués.Nos expériences indiquent que l'émotion joue un rôle important, non seulement dans la formation des concepts mais aussi dans la sélection de ceux-ci dans le raisonnement.Nous émettons l'hypothèse que les experts conservent les associations de concepts et d'émotions dans la mémoire à long terme et les utilisent pour guider la sélection des concepts pour le raisonnement.Ce point de vue est conforme à l'hypothèse du marqueur somatique de Damasio (de 1991), qui avance que les émotions guident le comportement, en particulier lorsque les processus cognitifs sont surchargés.Nous présentons les premiers résultats d'une expérience conçue pour explorer la fidélité de notre modèle et pour rechercher des preuves du rôle des émotions dans la résolution des problèmes.Notre modèle suggère qu'une association des émotions avec des situations reconnues guide les experts dans leur sélection de configurations de jeu partielles à utiliser pour explorer l'arbre de jeuIn this thesis, we are concerned with enabling technologies for collaborative intelligent systems.Effective collaboration requires that both the human and the computer share an understanding of their respective roles and abilities.In particular, it requires an ability to monitor the intentions and awareness of the partner in order to determine appropriate actions and behaviors.Cognitive science has much to offer in such an effort.In recent decades, researchers in cognitive science have developed theories and models that describe human abilities for attention, awareness, understanding, and problem-solving.In this thesis, we explore how such theories can inform informatics to enable technologies for Collaborative Artificial Intelligence.In particular, we use observations of humans with different levels of expertise engaged in solving classic chess problems to explore the effectiveness of models for visual attention, awareness, understanding, and problem-solving.We have constructed an instrument for capturing and interpreting multimodal signals of humans engaged in solving problems using off-the-shelf commercially available components combined with in-house software.Our instrument makes it possible to record body posture, gestures, facial expressions, pupil dilation, eye-scan, and fixation, as well as player interactions with the chess problem.When combined with self-reports, these recordings make it possible to construct computer models for the awareness and understanding of the game situation during problem-solving using concepts and models from cognitive science literature.As a first experiment, chess players were recorded while engaged in problems of increasing difficulty.These recordings were used to estimate a participant’s awareness of the current situation and to predict the ability to respond effectively to threats and opportunities.Analysis of the recordings demonstrates how eye-gaze, body posture, and emotional features can be used to capture and model situation awareness.This experiment validated the use of our equipment as a general and reproducible tool for the study of participants engaged in screen-based interaction involving problem-solving and suggested improvements that were possible for future experiments.These initial experiments revealed an unexpected observation of rapid changes in emotion as players attempt to solve challenging problems.Attempts to explain this observation have led us to explore the role of emotion in reasoning during problem-solving.In the second part of the thesis, we review the literature on emotion and propose a cognitive model that describes how emotions influence the process by which subjects select chunks (concepts) for use in interpretation of a game situation.In particular, it is well known that problem-solving is strongly constrained by limits on the number of phenomena that can be considered at a time.To overcome this limit, human experts rely on abstraction to form new concepts (chunks) from emotionally salient phenomena.Our experiments indicate that emotion plays an important role, not only in the formation of concepts but also in the selection of concepts to use in reasoning.We hypothesize that expert players retain associations of concept with emotions in long-term memory and use these to guide the selection of concepts for reasoning.This view is in accordance with Damasio's Somatic Marker hypothesis (from 1991), which posits that emotions guide behavior, particularly when cognitive processes are overloaded.We present initial results from a follow-on experiment designed to explore the fidelity of our model and to search for evidence of the role of emotion in solving problems.Our model suggests that an association of emotions with recognized situations guides experts in their selection of partial game configurations for use in exploring the game tree
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Lesne, Laurence. "Inclinaison horizontale du corps en décubitus dorsal et verticale subjective : direction du regard et référence égocentrée." Grenoble 2, 2006. http://www.theses.fr/2006GRE29056.
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Cette étude aborde le rôle du regard et de la référence égocentrée (Z) dans la perception de la verticale subjective (VS) en décubitus dorsal. Ce paradigme consiste à placer un sujet à plat dos, à modifier la direction du corps dans le plan horizontal et à faire estimer la VS en roulis. Des erreurs sur la VS visuelle apparaissent alors dans la direction de la projection verticale de Z. Trois hypothèses expliquent ce résultat : (a) le sujet projette Z subjectif dans le plan vertical afin de l'apparier avec sa VS, (b) il projette sa VS en tangage, résultante d'une combinaison gravito-idiotropique, (c) l'erreur en roulis est due à la déviation du regard crée par le décubitus dorsal. L'étude expérimentale de ces 3 hypothèses conduit à attribuer un rôle fondamental à la direction du regard dans l'estimation de la VS en décubitus dorsal notamment de par l'interdépendance de l'axe Z et de l'axe du regard. Une réinterprétation des effets d'inclinaison en terme de dissociation de l'espace égocentré et oculocentré apporte alors une nouvelle explication de la dichotomie effet-Aubert vs effet-Müller. Enfin, les résultats montrent une procédure d'ajustement égocentré subjectivo-céphalo-dépendant traduisant une déviation égocentrée céphalo-centrée gauche attribuable à une déviation implicite du regard à gauche liée au sens habituel de balayage oculaire de l'espace. Ainsi, les biais spatiaux égocentrés ne seraient que la manifestation de la déviation de l'espace oculocentré liée aux routines oculomotrices, et les effets d'inclinaison corporelle n'auraient pour origine qu'une mauvaise prise en compte de la dissociation de l'espace oculocentré et égocentréThis study approaches the role of the gaze and the egocentric reference (Z) in the subjective vertical perception (VS) in supine position. This paradigm consists in placing a subject fiat back, modifying the body direction in the horizontal plane and making estimate the SV in rolling. Three assumptions explain this result: (a) the subject projects subjective Z in the vertical plane in order to pair it with its VS, (b) he projects its VS in pitching, result of a gravito-idiotropic combination, (c) the error in rolling is caused by the gaze deviation creates by the supine position. The experimental study of these 3 assumptions leads to give a fundamental role at the gaze direction in the SV estimate in supine position especially by the interdependence of Z axis and gaze axis. So, a re-interpretation of body tilt effects like dissociation between egocentric space and oculocentric space brings a new explanation to the dichotomy Aubert-effect vs Müller-effect. To finish, results show a subjectivo-cephalo-dependent egocentric adjustment procedure. This points to a left egocentric cephalo-centered deviation caused by an implicit left deviation of gaze related to the usual direction of space ocular scanning. Thus, egocentric space bias would be only the manifestation of the deviation of oculocentric space related to the oculomotor process, and body tilt effects would originate in only one mis-knowledge of the dissociation of oculocentric and egocentric space
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Charbonnier, Colette. "La commande oculaire : étude et validation expérimentale d'interfaces homme-machine controlées par la direction du regard." Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10120.
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Qui n'a pas imagine un jour de deplacer les objets par la seule force du regard ? la faculte d'utiliser les yeux comme outil de controle n'est plus du domaine du reve. Le developpement des systemes de mesure des mouvements des yeux permet maintenant d'envisager des commandes visuelles. Cette these traite des interfaces homme-ordinateur controlees par la direction du regard. Dans un premier temps, nous avons identifie les possibilites d'interaction il-ecran en fonction: des capacites des systemes visuel et oculomoteur, des systemes de mesure des mouvements des yeux existants, des champs d'application ou l'utilisation de la commande oculaire est pertinente. Dans un second temps, nous avons evalue 3 possibilites d'interfaces controlees par la direction du regard. Pour cela, des demonstrateurs ont ete realises avec l'oculometre developpe au laboratoire. Les resultats experimentaux obtenus montrent que les yeux peuvent fournir un outil de commande efficace lors de differentes strategies visuelles. Ils permettent egalement de specifier davantage l'instrumentation de mesure en fonction du domaine d'application vise
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Dericquebourg, Guy. "Contribution à l'élaboration d'une méthodologie de conception des interfaces opérateur incluant une commande visuelle." Valenciennes, 1991. https://ged.uphf.fr/nuxeo/site/esupversions/9ce4fb47-1fb5-4c7e-9549-bd476a4b84de.
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Le contexte de cette thèse concerne l'analyse des problèmes liés à la conception et à la mise en œuvre d'une commande visuelle. Un dispositif à commande visuelle est constitué de quatre éléments: deux éléments amont qui permettent l'acquisition et le traitement des coordonnées du regard et deux éléments aval qui assurent la gestion de ces coordonnées et leur utilisation. Le recueil de la direction absolue du regard est obtenu par l'intermédiaire de capteurs oculométriques fixes ou portables associés, soit à une chaine parallèle de repérage de la position de la tête, soit à un dispositif de matérialisation du champ visuel de l'opérateur. L’originalité essentielle de ce travail est constituée par l'étude du comportement théorique et pratique du système oculaire humain, en présence d'un retour visuel matérialisant, en temps réel, la position calculée de l'œil de l'opérateur. Cette étude permet, après une analyse des domaines d'application et des moyens d'obtention des coordonnées oculaires, de prescrire les modes d'utilisation d'un retour visuel et d'appliquer tous les résultats à la mise en œuvre d'une commande visuelle sur un prototype de laboratoire. Ce prototype sert de base pour la réalisation de commandes visuelles industrialisables.
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Birinci, Toygar. "Optimization Of Non-uniform Planar Array Geometry For Direction Of Arrival Estimation." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607396/index.pdf.
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In this work, a novel method is proposed to optimize the array geometry for DOA estimation. The method is based on minimization of fine error variances with the constraint that the gross error probability is below a certain threshold. For this purpose, a metric function that reflects the gross and fine error characteristics of the array is offered. Theoretical analyses show that the minimization of this metric function leads to small DOA estimation error variance and small gross error probability. Analyses have been carried out under the assumptions of planar array geometry, isotropic array elements and AWGN. Genetic algorithm is used as an optimization tool and performance simulation is performed by comparing the DOA estimation errors of optimized array to a uniform circular array (UCA). Computer simulations support
the theoretical analyses and show that the method proposed leads to significant improvement in array geometry in terms of DOA estimation performance.
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Balasubramanian, R. K. "Development of novel approaches for high resolution direction of arrival estimation techniques." Thesis, Coventry University, 2016. http://curve.coventry.ac.uk/open/items/576a5aa1-32f8-4c01-99fa-a9023d7a1fc5/1.
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This thesis presents the development of MUSIC algorithm based novel approaches for the estimation of Direction of Arrival (DOA) of electromagnetic sources. For the 2D-DOA estimation, this thesis proposes orthogonally polarized linear array configuration rather than the conventionally invoked two dimensional array. An elegant one dimensional search technique to compute 2D-DOA estimation for a single source scenario has been proposed. To facilitate one dimensional search for 2D-DOA estimation, a closed form relationship between the azimuth and elevation angles of the 2D-DOA is derived using the analytical expressions of radiation patterns of Rectangular Waveguide (RWG) and Circular Waveguide (CWG). The computation time for the proposed one dimensional search technique is reduced by a factor of 50 and 150 for 1 and 0:5 search interval respectively. To improve the accuracy and the resolution of 2D-DOA estimation in case of closely spaced sources, this thesis proposes novel array configurations such as orthogonally polarized planar array, orthogonally mounted linear array and orthogonally polarized linear array. Through numerous simulation studies, a relative performance comparison of 2D-DOA estimation realized through various proposed novel array configurations has been carried out to highlight the accuracy and resolution under wide range of SNR conditions. The thesis presents a discussion on the analysis of effect of spatial de correlation in lieu of the employed orthogonally polarized elements in the array configuration on the improved accuracy and resolution of the 2D-DOA estimation. This thesis also deals with the utility of the proposed orthogonally polarized array configurations for tracking of 2D-DOA angles of non-stationary signal sources. The weighting factor and forgetting factor approaches for smoothing the time-varying covariance matrix of the non-stationary sources are studied. The simulation studies on 2D-DOA tracking by invoking proposed array configurations along with the proposed smoothing techniques prove that orthogonal polarized array configuration track the DOA source angle with minimum estimation errors. The thesis proposes the replacement of computationally intensive numerical schemes in Multiple Signal Classification (MUSIC) algorithm such as eigen decomposition and singular value decomposition with the subspace tracking techniques such as Bi-Iterative Singular Value Decomposition (Bi-SVD) algorithm. Invoking the concept of sub-band processing, the thesis addresses the validity of the extension of the presented 2D-DOA estimation analysis to wide band signal. A two subband filter approach is proposed for the estimation 2D-DOA of single and two wideband sources. The simulation study of the two subband filter approach along with the orthogonal polarized array configurations confirms the better estimation accuracy as well as the lesser computation time.
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Abusultan, Monther Younis. "Digital implementation of direction-of-arrival estimation techniques for smart antenna systems." Thesis, Montana State University, 2010. http://etd.lib.montana.edu/etd/2010/abusultan/AbusultanM0510.pdf.
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Adaptive antenna arrays use multiple antenna elements to form directional patterns in order to improve the performance of wireless communication systems. The antenna arrays also have the ability to detect the direction of incoming signals. These two capabilities allow a smart antenna system to adaptively beamform to more efficiently communicate between nodes. The direction-of-arrival estimation is a crucial component of the smart antenna system that uses open-loop adaptive approach. Historically this estimation has been accomplished using a personal computer. Implementing the estimation in the digital domain has the potential to provide a low cost and light weight solution due to recent advances in digital integrated circuit fabrication processes. Furthermore, digital circuitry allows for more sophisticated estimation algorithms to be implemented using the computational power of modern digital devices. This thesis presents the design and prototyping of direction-of-arrival (DOA) estimation for a smart antenna system implemented on a reconfigurable digital hardware fabric. Two DOA estimation algorithms are implemented and the performance tradeoffs between a custom hardware approach and a microprocessor-based system are compared. The algorithms were implemented for a 5.8 GHz, 8-element circular antenna array and their functionality was verified using a testbed platform. The implementation and analysis presented in this work will aid system designers to understand the tradeoffs between implementing algorithms in custom hardware versus an embedded system and when a hybrid approach is more advantageous.
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SOUZA, MARCIO ALBUQUERQUE DE. "MAXIMUM LIKELIHOOD ESTIMATION OF THE DIRECTION-OF-ARRIVAL OF PSK MODULATED CARRIERS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5718@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOEm sistemas de comunicações móveis, a modulação digital em fase (PSK)é amplamente utilizada em esquemas de transmissão em rádio-propagação. Trabalhos anteriores consideraram alguns métodos baseados no critério de máxima verossimilhança (MV) para estimação de direção-de-chegada de sinais genéricos que atingem um conjunto (array) de sensores. Esta tese propõe um novo estimador MV para a direção-de-chegada, desenvolvido especificamente para sistemas de comunicação PSK. Dois modelos de transmissão são concebidos para estimação dos parâmetros: um mais idealizado, considerando todas as portadoras alinhadas no tempo com o receptor, e outro que considera este desalinhamento na forma de retardo. O número de parâmetros a serem conjuntamente estimados é significativamente reduzido ao se calcular o valor esperado dos sinais medidos no array de antenas com relação µas fases de modulação (dados de informação). O desempenho do estimador em vários cenários simulados é apresentado e comparado ao desempenho do estimador MV clássico desenvolvido sem considerar uma estrutura específica para o sinal. Limitantes de Cramér-Rao para os cenários de portadora única também são calculados. O método proposto se mostra mais robusto por apresentar melhor desempenho que o estimador MV clássico em todas as simulações.
In mobile communication systems, phase shift keying (PSK) modulation is widely used in digital transmission schemes. Previous works have considered several maximum likelihood (ML) methods for the direction-of-arrival (DOA) estimation of generic signals reaching a phased-array of sensors. This thesis proposes a new ML DOA estimator designed to be used in PSK communication systems. Two transmission models are considered for parameter estimation: a simpler one, considering all carrier clocks time-aligned with the receiver clock, and another that considers this misalignment as a delay for each carrier. The number of parameters to be jointly estimated is significantly reduced when the expected value of the antenna array measured signals with respect to the modulation phases is evaluated. The estimator performance in several simulation scenarios is presented and compared to the performance of a classic ML estimator designed for all sorts of signal models. Cramér-Rao bounds for single carrier scenarios are also evaluated. The proposed method robustly outperforms the classic ML estimator in all simulations.
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Yu, Xiaoju. "Direction of Arrival Estimation Improvement for Closely Spaced Electrically Small Antenna Array." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579580.
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ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NVIn this paper, a new technique utilizing a scatterer of high dielectric constant in between electrically small antennas to achieve good Direction of arrival (DOA) estimation performance is demonstrated. The phase information of the received signal at the antennas is utilized for direction estimation. The impact of the property of the scatterer on the directional sensitivity and the output signal to noise ratio (SNR) level are studied. Finally the DOA estimation accuracy is analyzed with the proposed technique under the consumption of white Gaussian noise environment.
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Tait, Daniel Beale. "Electromagnetic Vector-Sensor Direction-of-Arrival Estimation in the Presence of Interference." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99961.
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This research investigates signal processing involving a single electromagnetic vector-sensor, with an emphasis on the problem regarding signal-selective narrowband direction-of-arrival (DOA) estimation in the presence of interference. The approach in this thesis relies on a high-resolution ESPRIT-based algorithm. Unlike spatially displaced arrays, the sensor cannot estimate the DOA of sources using phase differences between the array elements, as the elements are spatially co-located. However, the sensor measures the full electromagnetic field vectors, so the DOA can be estimated through the Poynting vector. Limited information is available in the open literature regarding signal-selective DOA estimation for a single electromagnetic vector-sensor. In this thesis, it is shown how the Uni-Vector-Sensor-ESPRIT (UVS-ESPRIT) algorithm that relies on a time-series invariance and was originally devised for deterministic harmonic sources can be applied to non-deterministic sources. Additionally, two algorithms, one based on cyclostationarity and the other based on fourth-order cumulants, are formulated based on the UVS-ESPRIT algorithm and are capable of selectively estimating the source DOA in the presence of interference based on the statistical properties of the sources. The cyclostationarity-based UVS-ESPRIT algorithm is capable of selectively estimating the signal-of-interest DOA when the sources have the same carrier frequency, and thus overlap in frequency. The cumulant-based UVS-ESPRIT algorithm devised for this sensor relies on the independent component analysis algorithm JADE and is capable of selectively estimating the signal-of-interest DOA through the fourth-order cumulants only, is robust to spatially colored noise, and is capable of estimating the DOA of more sources than sensor elements.Master of Science
Electromagnetic vector-sensors are specialized sensors capable of capturing the full electromagnetic field vectors at a single point in space. Direction-of-arrival (DOA) estimation is the problem of estimating the spatial-angular parameters of one or more wavefronts impinging on an array. For a single electromagnetic vector-sensor, the array elements are not spatially displaced, but it is still possible to estimate the direction-of-arrival through the Poynting vector, which relates the electric and magnetic field vectors to the direction of propagation of an electromagnetic wave. Although direction-of-arrival estimation is a well-established area of research, there is limited discussion in the open literature regarding signal-selective DOA estimation in the presence of interference for a single electromagnetic vector-sensor. This research investigates this problem and discusses how the high-resolution Uni-Vector-Sensor-ESPRIT (UVS-ESPRIT) algorithm may be applied to non-deterministic sources. ESPRIT based algorithms capable of selectively estimating the source DOA are formulated based on the cyclostationarity and higher-order statistics of the sources, which are approaches known to be robust to interference. The approach based on higher-order statistics is also robust to spatially colored noise and is capable of estimating the DOA of more sources than sensor elements. The formulation of the UVS-ESPRIT for higher-order statistics relies on the application of the independent component analysis algorithm JADE, an unsupervised learning technique. Overall, this research investigates signal-selective direction-of-arrival estimation using an ESPRIT-based algorithm for a single electromagnetic vector-sensor.
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Statzer, Eric L. "Matrix Pencil Method for Direction of Arrival Estimation with Uniform Circular Arrays." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313427307.
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Chaturvedi, Amal. "Wideband Signal Delay and Direction of Arrival Estimation using sub-Nyquist Sampling." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416231079.
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