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Lindgren, David. "Projection techniques for classification and identification /." Linköping : Univ, 2004. http://www.bibl.liu.se/liupubl/disp/disp2005/tek915s.pdf.
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Scott, Michael Andrew. "Interior node projection techniques in sweeping algorithms /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1121.pdf.
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Simoglou, Alexandros. "Modelling and monitoring using subspace projection techniques." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247897.
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Scott, Michael Andrew. "Interior Node Projection Techniques in Sweeping Algorithms." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/335.
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The enhancement of node projection techniques in sweeping is the subject of this thesis. Sweeping is a method used to produce all-hexahedral finite element meshes on certain classes of geometry. The placement of nodes in the interior of the geometry during the sweeping process remains a difficult problem. This thesis presents advancements in this area which improve the speed of the algorithm and the resulting element quality. A comparison of existing projection methods was performed. The existing Faceted projection sweeping method was extended to be applicable to more general classes of sweepable geometry. This comparison and extension of node projection algorithms led to the development of a new node projection technique: the SmartAffine method. This method builds on previous techniques and is characterized by its speed. Finally, a technique for coupling node projection techniques is presented. This technique characterizes the complexity of the sweepable geometry and applies the most appropriate node projection scheme. This is accomplished without user interaction and improves the speed of the sweeping algorithm and the quality of swept meshes.
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Campbell, Sydney. "Experiences of analogue-trained radiographers utilising digital imaging in projection radiography." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/14796.
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The professional work of a radiographer encompasses both patient care and the use of technology. The technology employed could either be analogue or digital technology. Since 1973, the analogue imaging system has slowly been replaced by digital radiography imaging systems. Despite the many advantages of digital imaging it does present the radiographer with added responsibilities. Furthermore, analogue-trained radiographers have found adjusting to digital imaging especially challenging. The aim of the study was to explore and describe the experiences of analogue-trained radiographers utilising digital imaging in projection radiography with the intention of developing guidelines to equip radiography managers to assist analogue-trained radiographers to better utilise digital imaging. The researcher used Schlossberg’s Transition Theory as a lens to look at the experiences of analogue-trained radiographers using digital imaging to produce radiographs. The research study used a qualitative design which was explorative, descriptive and contextual in nature. The target population included all diagnostic radiographers (public and private) in the local municipality who were registered with the Health Professions Council of South Africa. Purposive sampling was employed to select the radiographers that represented all radiographers in the Nelson Mandela Bay Health District. The sample included all radiographers who fulfilled the identified selection criteria. The selected participants were recruited to take part in in-depth, semi-structured individual interviews. The data was analysed using a computer-aided qualitative data analysis software package, ATLAS.ti. The trustworthiness of this study was ensured by applying Guba’s model of trustworthiness that includes credibility, transferability, dependability and confirmability. The ethical principles of respect for persons, beneficence and justice, as espoused by the Belmont Report, were adhered to in order to ensure that the study was conducted in an ethical manner. Two themes emanated from the data, namely the evolution of the radiographer when faced with the advances in technology as well the role that the work environment played in the manner that the participants experienced the change. The experiences of the participants were described using direct quotations from the interviews and a literature control was used to verify the participants’ experiences. Evidence was found of radiographer indifference towards exposure selection, dose optimisation and placement of anatomical side markers when utilising digital imaging. Finally, guidelines were developed to equip radiography managers to assist analogue-trained radiographers to better utilise digital imaging. In addition, the guidelines will assist all other radiographers to better utilise digital imaging.
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Antici, Francesco. "Advanced techniques for cross-language annotation projection in legal texts." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23884/.
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Nowadays, the majority of the services we benefit from, are provided online and their use is regulated by the acceptance to the terms of service by the users. All our data are handled accordingly with the clauses of such document and all our behaviours must comply with it. Given so, it would be very useful to find automated techniques to ensure fairness of the document or inform the users about possible threats.
The focus of this work, is to create resources aimed to the development of such tools in languages other than English, which may lack in linguistic resources and annotated corpus.
The enormous breakthroughs of the last years in Natural Language Processing techniques made it possible the creation of such tools through automated and unsupervised process. One of the means to achieve that is through the annotation projection between two parallel corpora.
The difficulties and costs of creating ad hoc resource for every language has brought the need to find another way for achieving the goal.\\
This work investigates the cross language annotation projection technique based on sentence embedding and similarity metrics to find matches between sentences. Several combination of methods and algorithms are compared, among which there are monolingual and multilingual embedding neural models. The experiments are conducted on two datasets, where the reference language is always English and the projection are evaluated on Italian, German and Polish.
The results obtained provide a robust and reliable technique for the task and a good starting point to build multilingual tools.
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Guisser, Latifa. "Perception surfacique tridimensionnelle par projection de grille." Toulouse 3, 1994. http://www.theses.fr/1994TOU30081.
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Nous proposons un systeme de vision tridimensionnelle utilisant la projection d'une lumiere structuree sous forme d'une grille et permettant de calculer les coordonnees tridimensionnelles ainsi que les parametres de forme des surfaces analysees. La precision du calcul des parametres de forme depend de la methode du calibrage des appareils optiques (camera-projecteur) et du critere utilise dans la mise en correspondance entre la grille image et la grille origine. Le probleme delicat de correspondance est resolu par une methode robuste utilisant des contraintes globales. La correspondance pour une composante connexe de la grille image est faite independamment des autres composantes ; ce qui a permis de detecter les discontinuites et les parties cachees. Le calibrage, qui est a la base de la mise en correspondance, est effectue par une methode originale et precise qui calcule les parametres de la camera et du projecteur directement par relaxation. Par triangulation, on calcule deux familles de courbes 3d permettant de definir directement une parametrisation de surfaces et d'effectuer une etude geometrique de celles-ci. La procedure de calibrage des appareils optiques doit etre repetee a chaque changement des parametres des appareils optiques, ce qui rend les systemes de calibrage standard impraticables pour les taches visuelles. Nous proposons un systeme de reconstruction des informations 3d d'une scene a partir de la projection d'une grille et de deux cameras non calibrees. Contrairement aux autres approches dans ce domaine, basees sur les concepts de la geometrie projective, notre approche travaille directement dans l'espace euclidien en utilisant les equations parametriques fournies par la projection de la grille. La precision des informations tridimensionnelles a ete validee sur un objet dont les dimensions sont connues avec une precision de 0. 1 millimetres. La precision obtenue est de 0. 7 millimetres (la distance entre l'objet et le capteur est de 3. 5 metres)
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Herrmann, Carmen. "Projection techniques for complexity reduction and information extraction in correlated quantum systems /." Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16952.
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Lu, Weizhi. "Contribution to dimension reduction techniques : application to object tracking." Thesis, Rennes, INSA, 2014. http://www.theses.fr/2014ISAR0010/document.
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Cette thèse étudie et apporte des améliorations significatives sur trois techniques répandues en réduction de dimension : l'acquisition parcimonieuse (ou l'échantillonnage parcimonieux), la projection aléatoire et la représentation parcimonieuse. En acquisition parcimonieuse, la construction d’une matrice de réduction possédant à la fois de bonnes performances et une structure matérielle adéquate reste un défi de taille. Ici, nous proposons explicitement la matrice binaire optimale, avec éléments zéro-Un, en recherchant la meilleure propriété d’isométrie restreinte (RIP). Dans la pratique, un algorithme glouton efficace est successivement développé pour construire la matrice binaire optimale avec une taille arbitraire. Par ailleurs, nous étudions également un autre problème intéressant pour l'acquisition parcimonieuse, c'est celui de la performance des matrices d'acquisition parcimonieuse avec des taux de compression élevés. Pour la première fois, la limite inférieure de la performance des matrices aléatoires de Bernoulli pour des taux de compression croissants est observée et estimée. La projection aléatoire s'utilise principalement en classification mais la construction de la matrice de projection aléatoire s'avère également critique en termes de performance et de complexité. Cette thèse présente la matrice de projection aléatoire, de loin, la plus éparse. Celle-Ci est démontrée présenter la meilleure performance en sélection de caractéristiques, comparativement à d’autres matrices aléatoires plus denses. Ce résultat théorique est confirmé par de nombreuses expériences. Comme nouvelle technique pour la sélection de caractéristiques ou d’échantillons, la représentation parcimonieuse a récemment été largement appliquée dans le domaine du traitement d'image. Dans cette thèse, nous nous concentrons principalement sur ses applications de suivi d'objets dans une séquence d'images. Pour réduire la charge de calcul liée à la représentation parcimonieuse, un système simple mais efficace est proposé pour le suivi d'un objet unique. Par la suite, nous explorons le potentiel de cette représentation pour le suivi d'objets multiplesThis thesis studies three popular dimension reduction techniques: compressed sensing, random projection and sparse representation, and brings significant improvements on these techniques. In compressed sensing, the construction of sensing matrix with both good performance and hardware-Friendly structure has been a significant challenge. In this thesis, we explicitly propose the optimal zero-One binary matrix by searching the best Restricted Isometry Property. In practice, an efficient greedy algorithm is successively developed to construct the optimal binary matrix with arbitrary size. Moreover, we also study another interesting problem for compressed sensing, that is the performance of sensing matrices with high compression rates. For the first time, the performance floor of random Bernoulli matrices over increasing compression rates is observed and effectively estimated. Random projection is mainly used in the task of classification, for which the construction of random projection matrix is also critical in terms of both performance and complexity. This thesis presents so far the most sparse random projection matrix, which is proved holding better feature selection performance than other more dense random matrices. The theoretical result is confirmed with extensive experiments. As a novel technique for feature or sample selection, sparse representation has recently been widely applied in the area of image processing. In this thesis, we mainly focus our attention on its applications to visual object tracking. To reduce the computation load related to sparse representation, a simple but efficient scheme is proposed for the tracking of single object. Subsequently, the potential of sparse representation to multiobject tracking is investigated
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Salhi, Zahir. "Développement des techniques pour le diagnostic des procédés de projection thermique sous pression réduite." Besançon, 2004. http://www.theses.fr/2004BESA2046.
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Le procédé de projection plasma à pression réduite (voire très réduite, inférieur à 10mbar) est en plein essors et connaît actuellement un développement considérable. Cette technique permet d’obtenir des revêtements très denses avec un taux de porosité très faible tout en gardant un bon rendement de projection. Les caractéristiques des dépôts sont directement liées aux paramètres de projection (gaz plasmagène, puissance de la torche, débit de poudre), le réglage de ces paramètres peut être fait en mesurant les caractéristiques du plasma et des particules en vol. Le développement d’un tel procédé nécessite donc des moyens de diagnostics et de contrôles performants. Le but de ce travail est d’explorer les différents moyens de diagnostic optique applicable dans de telles conditions de projection. Notre approche pour cette étude utilise principalement le DPV2000 et la spectrométrie d’émission. Le DPV2000 est utilisé pour les mesures de la température, la vitesse et le diamètre des particules en vol. Dans le cas de fines particules et/ou de basse température les particules sont éclairées par un laser afin de mesurer la vitesse et le flux de particules en vol. La spectrométrie d’émission pour l’étude de la vaporisation des particules en vol et les dimensions de l’écoulement plasmaThere is an increasing interest for thermal plasma spraying at working pressure lower than 10 mbars. By spraying at such low pressure, it is expected that resulting coatings have a very low porosity while keeping a deposition rate higher. Developing such processes requires adjusting operating parameters as gas mixtures, arc current and particle injection quantities, among others, in correlation with coatings to produce. Setting input parameters of this new spray processes can be made by measuring characteristics of the plasma and sprayed particles by using optical diagnose techniques. The aim of this study is to develop the use of different tools for optical diagnostics under such conditions. Particle measurements are performed by using the system DPV2000 with its sensor head located in a cooled tube at atmospheric pressure and measuring the particles through an optical window. When particles are too small or too cold to be detected, they are illuminated by a laser diode. In that case particle temperature measurements are not possible anymore but it is still possible to measure the in-flight particle velocity and flux. In addition to particle diagnostics, optical emission spectroscopy is used to quantify the plasma volume and to study the sprayed particle vaporization. The results allowed defining the characteristics of future process chamber to perform thermal spray technique at 0,1mbar pressure
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Kumar, Sukhbinder. "Modelling and abnormal change detection in multivariate signals and systems using subspace projection techniques." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407636.
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Elsas, Jonathan L. "An Evaluation of Projection Techniques for Document Clustering: Latent Semantic Analysis and Independent Component Analysis." Thesis, School of Information and Library Science, 2005. http://hdl.handle.net/1901/208.
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Dimensionality reduction in the bag-of-words vector space document representation model has been widely studied for the purposes of improving accuracy and reducing computational load of document retrieval tasks. These techniques, however, have not been studied to the same degree with regard to document clustering tasks. This study evaluates the effectiveness of two popular dimensionality reduction techniques for clustering, and their effect on discovering accurate and understandable topical groupings of documents. The two techniques studied are Latent Semantic Analysis and Independent Component Analysis, each of which have been shown to be effective in the past for retrieval purposes.
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Srinivasan, Puri R. "Krylov Subspace Based Direct Projection Techniques for Low Frequency, Fully Coupled, Structural Acoustic Analysis and Optimization." Thesis, Oxford Brookes University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502586.
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Baggu, Gnanesh. "Efficient Approach for Order Selection of Projection-Based Model Order Reduction." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37967.
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The present thrust in the electronics industry towards integrating multiple functions on a single chip while operating at very high frequencies has highlighted the need for efficient Electronic Design Automation (EDA) tools to shorten the design cycle and capture market windows. However, the increasing complexity in modern circuit design has made simulation a computationally cumbersome task. The notion of model order reduction has emerged as an effective tool to address this difficulty. Typically, there are numerous approaches and several issues involved in the implementation of model-order reduction techniques. Among the important ones of those issues is the problem of determining a suitable order (or size) for the reduced system. An optimal order would be the minimal order that enables the reduced system to capture the
behavior of the original (more complex and larger) system up to a user-defined frequency. The contribution presented in this thesis describes a new approach aimed at determining the order of the reduced system. The proposed approach is based on approximating the impulse response of the original system in the time-domain. The core methodology in obtaining that approximation is based on numerically inverting the Laplace-domain of the representation of the impulse response from the complex-domain (s-domain) into the time-domain. The main advantage of the proposed approach is that it allows the order selection algorithm to operate directly on the time-domain form of the impulse response. It is well-known that numerically generating the impulse response in the time-domain is very difficult and its not impossible, since it requires driving the original network with the Dirac-delta function, which is a mathematical abstraction rather than a concrete waveform that can be implemented on a digital computer. However, such a difficulty is avoided in the proposed approach since it uses the Laplace-domain image of the impulse response to obtain its time-domain representation. The numerical simulations presented in the thesis demonstrate that using the time-domain waveform of the impulse response, computed using the proposed approach and properly filtered with a Butterworth filter, guides the order selection algorithm to select a smaller order, i.e., the reduced system becomes more compact in size. The phrase "smaller or more compact" in this context refers to the comparison with existing techniques currently in use, which seek to generate some form of time-domain approximations for the impulse response through driving the original network with pulse-shaped function (e.g., Gaussian pulse).
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Buchholz, Peter, and Tuğrul Dayar. "Block SOR Preconditional Projection Methods for Kronecker Structured Markovian Representations." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-100464.
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Hierarchical Markovian Models (HMMs) are composed of multiple low level models (LLMs) and high level model (HLM) that defines the interaction among LLMs. The essence of the HMM approach is to model the system at hand in the form of interacting components so that its (larger) underlying continous-time Markov chain (CTMC) is not generated but implicitly represented as a sum of Kronecker products of (smaller) component matrices. The Kronecker structure of an HMM induces nested block partitionings in its underlying CTMC. These partitionings may be used in block versions of classical iterative methods based on splittings, such as block SOR (BSOR), to solve the underlying CTMC for its stationary vector. Therein the problem becomes that of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of a particular partitioning. This paper shows that in each HLM state there may be diagonal blocks with identical off-diagonal parts and diagonals differing from each other by a multiple of the identity matrix. Such diagonal blocks are named candidate blocks. The paper explains how candidate blocks can be detected and how the can mutually benefit from a single real Schur factorization. It gives sufficient conditions for the existence of diagonal blocks with real eigenvalues and shows how these conditions can be checked using component matrices. It describes how the sparse real Schur factors of candidate blocks satisfying these conditions can be constructed from component matrices and their real Schur factors. It also demonstrates how fill in- of LU factorized (non-candidate) diagonal blocks can be reduced by using the column approximate minimum degree algorithm (COLAMD). Then it presents a three-level BSOR solver in which the diagonal blocks at the first level are solved using block Gauss-Seidel (BGS) at the second and the methods of real Schur and LU factorizations at the third level. Finally, on a set of numerical experiments it shows how these ideas can be used to reduce the storage required by the factors of the diagonal blocks at the third level and to improve the solution time compared to an all LU factorization implementation of the three-level BSOR solver.
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Buchholz, Peter, and Tuğrul Dayar. "Block SOR Preconditional Projection Methods for Kronecker Structured Markovian Representations." Technische Universität Dresden, 2003. https://tud.qucosa.de/id/qucosa%3A26304.
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Hierarchical Markovian Models (HMMs) are composed of multiple low level models (LLMs) and high level model (HLM) that defines the interaction among LLMs. The essence of the HMM approach is to model the system at hand in the form of interacting components so that its (larger) underlying continous-time Markov chain (CTMC) is not generated but implicitly represented as a sum of Kronecker products of (smaller) component matrices. The Kronecker structure of an HMM induces nested block partitionings in its underlying CTMC. These partitionings may be used in block versions of classical iterative methods based on splittings, such as block SOR (BSOR), to solve the underlying CTMC for its stationary vector. Therein the problem becomes that of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of a particular partitioning. This paper shows that in each HLM state there may be diagonal blocks with identical off-diagonal parts and diagonals differing from each other by a multiple of the identity matrix. Such diagonal blocks are named candidate blocks. The paper explains how candidate blocks can be detected and how the can mutually benefit from a single real Schur factorization. It gives sufficient conditions for the existence of diagonal blocks with real eigenvalues and shows how these conditions can be checked using component matrices. It describes how the sparse real Schur factors of candidate blocks satisfying these conditions can be constructed from component matrices and their real Schur factors. It also demonstrates how fill in- of LU factorized (non-candidate) diagonal blocks can be reduced by using the column approximate minimum degree algorithm (COLAMD). Then it presents a three-level BSOR solver in which the diagonal blocks at the first level are solved using block Gauss-Seidel (BGS) at the second and the methods of real Schur and LU factorizations at the third level. Finally, on a set of numerical experiments it shows how these ideas can be used to reduce the storage required by the factors of the diagonal blocks at the third level and to improve the solution time compared to an all LU factorization implementation of the three-level BSOR solver.
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Rademacher, Eric W. "The path to accurate pre-election forecasts an analysis of the impact of data adjustment techniques on pre-election projection estimates /." Cincinnati, Ohio : University of Cincinnati, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1021921989.
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Blais, Laurent-Bernard. "Analyse objective de deux techniques de projection en judo : seoi͏̈ nage et uchi mata de la réalité mécanique aux applications pédagogiques." Poitiers, 2004. http://www.theses.fr/2004POIT2316.
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Ce travail s'inscrit dans la politique de notre équipe " Mécanique du geste sportif " qui consiste à favoriser les échanges entre le milieu sportif et le milieu de la recherche universitaire, donnant à nos travaux des applications directes en terme de formation et d'entraînement. Au-delà d'une approche intuitive basée sur des connaissances empiriques de l'activité judo, nous avons voulu comprendre objectivement la réalité des gestes techniques de judo, à partir d'une analyse des paramètres mécaniques externes et internes. Dans une première partie, nous expliquons notre démarche de recherche qui tend à aller au-delà d'une approche réductrice pour prendre en compte l'athlète dans sa complexité et mesurer ses paramètres segmentaires, en associant des outils de mesure dynamographiques et cinématographiques. Dans une seconde partie, nous présentons les résultats de l'étude réalisée en collaboration avec des champions Français, qui nous ont permis d'identifier clairement des éléments communs, constituant autant de règles d'action, dont l'acquisition par l'élève s'avère indispensable pour réaliser un geste technique correct. Dans la dernière partie, nous présentons les résultats du calcul des efforts articulaires d'un athlète, réalisant un geste technique de judo sur un ergomètre instrumenté, ainsi que sa dépense énergétique globale, pour chaque phase du mouvement ou encore pour chaque contribution segmentaireThrough this work, we want to support the exchanges between sporting people and university research people, and we want to give to our work direct applications in term of formation and training. Beyond an intuitive approach based on empirical knowledge of the judo activity, we want to objectively understand the reality of the judo throw, from an analysis of the external and internal mechanical parameters. In the first part, we explain our method of research which tends to go beyond a reducing approach of considering the athlete in his complexity and to measure its segmentary parameters, by associating dynamographic and cinematographic measuring tools. In a second part, we present the results of the study carried out in collaboration with French champions, who allowed us to identify clearly common elements, constituting as many rules of action, whose acquisition by the athletes prove to be essential to realize a good movement. In the last part, we present the results of the calculation of the articular efforts of an athlete, carrying out a judo throw on an instrumented ergometer, like its total energy expenditure, for each phase of the movement or for each segmentary contribution
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RADEMACHER, ERIC W. "THE PATH TO ACCURATE PRE-ELECTION FORECASTS: AN ANALYSIS OF THE IMPACT OF DATA ADJUSTMENT TECHNIQUES ON PRE-ELECTION PROJECTION ESTIMATES." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1021921989.
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Zhang, Yu. "Investigating Key Techniques to Leverage the Functionality of Ground/Wall Penetrating Radar." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/799.
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Ground penetrating radar (GPR) has been extensively utilized as a highly efficient and non-destructive testing method for infrastructure evaluation, such as highway rebar detection, bridge decks inspection, asphalt pavement monitoring, underground pipe leakage detection, railroad ballast assessment, etc. The focus of this dissertation is to investigate the key techniques to tackle with GPR signal processing from three perspectives: (1) Removing or suppressing the radar clutter signal; (2) Detecting the underground target or the region of interest (RoI) in the GPR image; (3) Imaging the underground target to eliminate or alleviate the feature distortion and reconstructing the shape of the target with good fidelity.
In the first part of this dissertation, a low-rank and sparse representation based approach is designed to remove the clutter produced by rough ground surface reflection for impulse radar. In the second part, Hilbert Transform and 2-D Renyi entropy based statistical analysis is explored to improve RoI detection efficiency and to reduce the computational cost for more sophisticated data post-processing. In the third part, a back-projection imaging algorithm is designed for both ground-coupled and air-coupled multistatic GPR configurations. Since the refraction phenomenon at the air-ground interface is considered and the spatial offsets between the transceiver antennas are compensated in this algorithm, the data points collected by receiver antennas in time domain can be accurately mapped back to the spatial domain and the targets can be imaged in the scene space under testing. Experimental results validate that the proposed three-stage cascade signal processing methodologies can improve the performance of GPR system.
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Matthews, Elizabetha Johanna Magdalena. "'n Dinamiese assesseringstegniek van invraging by die gebruik van projeksieplate met kinders." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-07242007-122106/.
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Lo, Haw-Jing. "Design of a reusable distributed arithmetic filter and its application to the affine projection algorithm." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28199.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Anderson, Dr. David V.; Committee Member: Hasler, Dr. Paul E.; Committee Member: Mooney, Dr. Vincent J.; Committee Member: Taylor, Dr. David G.; Committee Member: Vuduc, Dr. Richard.
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Brandou, Vincent. "Stéréovision locale et reconstruction 3D/4D." Nice, 2008. http://www.theses.fr/2008NICE4093.
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L’objectif de cette thèse est de proposer une méthodologie complète de reconstruction 3D d’objets sous-marins naturels, améliorée par une nouvelle méthode d’acquisition afin de permettre des mesures quantitatives. Il a d’abord fallu prendre en compte les différents problèmes liés au milieu sous-marin profond ; la contrainte principale est que le système utilisé pour faire l’acquisition des images doit être contrôlé à des profondeurs très importantes, jusqu’à 6000 mètres, à l’aide d’un véhicule positionné sur le fond. Ainsi, une méthode permettant l’acquisition automatique d’images a été développée, adaptée à tout type d’objet sous-marin de faible échelle (environ 1m3). L’acquisition d’image est réalisée avec un système de stéréovision contrÔlé par un bras manipulateur. La méthode que nous proposons permet de connaître les paramètres extrinsèques des caméras du système de vision, par le suivi d’une trajectoire définie par la géométrie de la tête stéréo. Ainsi, la trajectoire est générée par le déplacement d’une caméra sur la position de l’autre caméra par asservissement visuel. Avec cette méthode, nous pouvons enregistrer des images à intervalles réguliers directement liés à la géométrie de la tête stéréo. Ensuite, le modèle 3D de l’objet sous-marin est calculé à partir des images collectées et des paramètres des caméras. Le résultat final est une reconstruction 3D dense avec un plaquage de texture, qui permet de faire des mesures métriques. Mots-clés: métrologie 3D, vision par ordinateur, stéréovision, asservissement visuel, trajectoire d’acquisition, reconstruction 3DThe aim of this study is to propose a complete 3-dimension reconstruction method of natural submarine objects improved by a new acquisition method for quantitative measures, which can be used in operational conditions. First, it was necessary to take into account the various problems connected with the deep sea environment ; the main constraint is that the system used to collect images must be manipulated at very important depths, up to 6000 meters by an underwater vehicle positioned on the sea floor. Thus, a method allowing the automatic acquisition of images was developed, adapted to any type of small-scale submarine object (approximately 1m 3). The image acquisition is performed with a stereovision system operated by a manipulator arm. The method that we propose enables us to know extrinsic camera parameters by following a specific trajectory defined by the geometry of a stereo rig. Indeed, the trajectory is generated by the displacement of one camera onto the position of the other one by visual servoing. With this method, we can register images at regular intervals directly linked to the geometry of the stereo rig. Then, the 3D model of the underwater object is calculated from the collected images and camera parameters. The final result is a dense 3D reconstruction with texture mapping that enables metric measures. Keywords: 3D metrology, computer vision, stereovision system, visual servoing, camera trajectory, 3D reconstruction
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Islam, Md Monowarul, and Muftadi Ullah Arpon. "Image Reconstruction Techniques using Kaiser Window in 2D CT Imaging." Thesis, Linnéuniversitetet, Institutionen för fysik och elektroteknik (IFE), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-94135.
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The traditional Computed Tomography (CT) is based on the Radon Transform and its inversion. The Radon transform uses parallel beam geometry and its inversion is based on the Fourier slice theorem. In practice, it is very efficient to employ a back-projection algorithm in connection with the Fast Fourier Transform, and which can be interpreted as a 1-D filtering across the radial dimension of the 2-D Fourier plane of the transformed image. This approach can easily be adapted to windowing techniques in the frequency domain, giving the capability to reduce image noise. In this work we are investigating the capabilities of the so called Kaiser window (giving an optimal trade-off between the main lobe energy and the sidelobe suppression) to achieve a near optimal trade-off between the noise reduction and the image sharpness in the context of Radon inversion. Finally, we simulate our image reconstruction using MATLAB software and compare and estimate our results based on the normalized Least Square Error (LSE). We conclude that the Kaiser window can be used to achieve an optimal trade-off between noise reduction and sharpness in the image, and hence outperforms all the other classical window function in this regard.
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Vecchione, Rossella. "High-resolution 3D geomatic techniques to assess hazardous spills impacts on road surface performances." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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Constantly growing people’s needs and industrial technologies cause the necessity to increase transport, which simultaneously increases the risk of accidents on the roads and spills of hazardous substances, including leakage of oil, hydraulic fluids, lubricants, and cargo spillage. These substances threaten the safety of road, all the road users and natural environments. Asphalt road surfaces are degraded by fuel or other liquid spillages; they can contribute to increase road surface material damage during vehicles trafficking. The effects of spilled substances on the road surface and consequently on the environment and user safety depend also on the exposure time. Due to the unpredictable of accidental situations and the positioning within the territory, there are situations that are managed at different time. Therefore, the exposure time become a fundamental parameter to be considered in the test to evaluate the different behaviors of road surface and the variation in danger over time. In this scenario, the research aims to evaluate the effects of hazardous liquid spilled from vehicles on the asphalt properties and related safety parameters by means of two combined high-resolution 3D geomatic techniques and over different exposure time. Geomatic techniques employed for the characterization of the asphalt samples belong to two different categories: active triangulation techniques (3D structured light projection scanner) and photogrammetric techniques (digital photogrammetry). These techniques are able to perform a three-dimensional modeling of the detected objects: a process that goes from data acquisition to the creation of a virtual 3D model. Products of these modeling should guarantee the maximum geometry accuracy and photo-realistic nature of the scanned objects. Some indicators have been extracted from high-resolution 3D models to study changes in asphalt performances due to the spillage of five different hazardous substances.
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Zouari, Sahar. "Elaboration et caractérisation mécanique et physico-chimique des revêtements déposés sur des substrats en laiton par les techniques de projection thermique et pulvérisation pneumatique pour application d'industrie sanitaire." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCA019.
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Les alliages de laiton sont utilisés dans de nombreuses applications, plus particulièrement dans le domaine d’industrie sanitaire. Dans ce domaine, le laiton est revêtu d’une couche de chrome par la technique du chromage électrolytique. Cependant, cette technique est réalisée au moyen des solutions dans lesquelles le chrome est à l'état d'oxydation six. À ce degré d'oxydation, le chrome est toxique et a la réputation d'être cancérigène. Dans ce cadre, l’objectif de ce travail est d’élaborer des revêtements fonctionnels sur des substrats en laiton à l’aide de nouvelles techniques à savoir la projection thermique et la pulvérisation pneumatique. Les propriétés mécaniques et physico-chimiques sont étudiées afin d’évaluer les performances de ces revêtements et la possibilité de leurs utilisations dans le domaine d’industrie sanitaireBrass alloys are used in many applications, especially in the sanitary industrial application. In this field, the brass is coated with an electroplated chromium layer. However, the electroplating technique is achieved by means of solutions in which the chromium is in the six oxidation state. At this degree of oxidation, chromium is toxic and has the reputation of being carcinogenic. In this context, the main objective of this work is to develop functional coatings on brass substrates using new techniques namely thermal and pneumatic spraying techniques. The mechanical and physical-chemical properties are studied in order to evaluate the performances of these coatings and the potency of their use in the sanitary industrial field
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Fondard, Jérémie. "Elaboration et test d’une pile à combustible IT-SOFC à support métallique poreux par l’intermédiaire de techniques de dépôt en voie sèche : projection thermique et pulvérisation cathodique magnétron." Thesis, Belfort-Montbéliard, 2015. http://www.theses.fr/2015BELF0254/document.
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L’un des enjeux relatif au déploiement des piles à combustible à oxyde solide comme système de production d’une énergie propre relève de la température de fonctionnement qui est actuellement autour de 1000°C. Abaisser cette température tout en préservant les performances afin de réduire les coûts de fabrication et d’augmenter la durée de vie des systèmes a été l’objectif dece travail de doctorat.Un coeur de pile à combustible (anode-électrolyte-cathode) élaboré avec des procédés physiques de dépôts (projection par plasma atmosphérique et pulvérisation cathodique magnétron) a été développé et optimisé sur un support métallique poreux. Les matériaux étudiés ont été un cermet en Nickel-Zircone stabilisée à l’Ytttrium (Ni-YSZ) pour l’anode, un électrolyte en YSZ avec ou sans couche de cérine gadoliniée (GDC) et les nickelates de terres rares comme cathode. La maitrise des procédés de revêtements a permis de réduire les épaisseurs de chaque couche et d’assurer la cohésion de l’ensemble des 3 couches avec des caractéristiques cristallographiques, microstructurales et de porosité adaptées. . Les performances électrochimiques ont été étudiées pour chaque élément du coeur de pile puis pour l’ensemble du système élaboré sur métal poreux. Même si les performances atteintes ne sont pas encore suffisantes, les procédés de revêtements optimisés pour recouvrir un support métallique poreux ont confirmé leur potentielEnergy production by a clean and environmental processes is a real challenge. Fuel cell technology is good candidate to answer this objective. The major problem of the Solid Oxide Fuel Cell is their high operating temperature (around 1000°C) for a massive industrialisation. Decreasing these temperature at 700°C allows a reduction of cost manufacturing and increase the lifetime, in this case the new challenge is to avoid the performances losses.During this phD work, dry surface treatment processes are employed for produce the fuel cell core. The thickness reduction of each part limit the performances decreasing generate by the modification of the temperature. The materials used is a Ni-Yttria stabilised zirconia cermet (Ni-YSZ) for the anode, YSZ with or without gadolinnia doped ceria (GDC) for electrolyte and rare earth nickelate for the cathode component. All material are a usual employed in the SOFC technology. All coating are synthesized and characterised separately. After a third generation of fuel cell is realized on ITM porous metal support produced by PLANSEE. The anode has been deposit by atmospheric plasma spray, the electrolyte and cathode have been synthesised by reactive magnetron sputtering
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Benmoussat, Mohammed Seghir. "Hyperspectral imagery algorithms for the processing of multimodal data : application for metal surface inspection in an industrial context by means of multispectral imagery, infrared thermography and stripe projection techniques." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4347/document.
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Le travail présenté dans cette thèse porte sur l'inspection de surfaces métalliques industrielles. Nous proposons de généraliser des méthodes de l'imagerie hyperspectrale à des données multimodales comme des images optiques multi-canales, et des images thermographiques multi-temporelles. Dans la première application, les cubes de données sont construits à partir d'images multi-composantes pour détecter des défauts de surface. Les meilleures performances sont obtenues avec les éclairages multi-longueurs d'ondes dans le visible et le proche IR, et la détection du défaut en utilisant l'angle spectral, avec le spectre moyen comme référence. La deuxième application concerne l'utilisation de l'imagerie thermique pour l'inspection de pièces métalliques nucléaires afin de détecter des défauts de surface et sub-surface. Une approche 1D est proposée, basée sur l'utilisation du kurtosis pour sélectionner la composante principale parmi les premières obtenues après réduction des données avec l’ACP. La méthode proposée donne de bonnes performances avec des données non-bruitées et homogènes, cependant la SVD avec les algorithmes de détection d'anomalies est très robuste aux perturbations. Finalement, une approche, basée sur les techniques d'analyse de franges et la lumière structurée est présentée, dans le but d'inspecter des surfaces métalliques à forme libre. Après avoir déterminé les paramètres décrivant les modèles de franges sinusoïdaux, l'approche proposée consiste à projeter une liste de motifs déphasés et à calculer l'image de phase des motifs enregistrés. La localisation des défauts est basée sur la détection et l'analyse des franges dans les images de phaseThe work presented in this thesis deals with the quality control and inspection of industrial metallic surfaces. The purpose is the generalization and application of hyperspectral imagery methods for multimodal data such as multi-channel optical images and multi-temporal thermographic images. In the first application, data cubes are built from multi-component images to detect surface defects within flat metallic parts. The best performances are obtained with multi-wavelength illuminations in the visible and near infrared ranges, and detection using spectral angle mapper with mean spectrum as a reference. The second application turns on the use of thermography imaging for the inspection of nuclear metal components to detect surface and subsurface defects. A 1D approach is proposed based on using the kurtosis to select 1 principal component (PC) from the first PCs obtained after reducing the original data cube with the principal component analysis (PCA) algorithm. The proposed PCA-1PC method gives good performances with non-noisy and homogeneous data, and SVD with anomaly detection algorithms gives the most consistent results and is quite robust to perturbations such as inhomogeneous background. Finally, an approach based on fringe analysis and structured light techniques in case of deflectometric recordings is presented for the inspection of free-form metal surfaces. After determining the parameters describing the sinusoidal stripe patterns, the proposed approach consists in projecting a list of phase-shifted patterns and calculating the corresponding phase-images. Defect location is based on detecting and analyzing the stripes within the phase-images
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Devernay, Frédéric. "Vision stereoscopique et proprietes differentielles de surfaces." Palaiseau, Ecole polytechnique, 1997. http://www.theses.fr/1997EPXX0052.
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Ce document traite de plusieurs aspects de la vision stereoscopique par ordinateur. Cette methode consiste a partir d'une ou de plusieurs paires d'images a reconstruire une scene observee en trois dimensions, c'est-a-dire a produire une description des objets et surfaces observes ainsi que leur position dans l'espace. Le premier probleme aborde est celui du calibrage, dont l'objet est de calculer les parametres des cameras (focale, centre optique, etc. ) ainsi que leur position, soit a partir d'images d'objets de geometrie et de position connue, soit de maniere automatique (on parle alors d'auto-calibrage). Des resultats nouveaux sont presentes sur l'auto-calibrage de la distorsion optique et sur l'auto-calibrage d'une paire de cameras rigidement liees a partir de plusieurs paires d'images. Ensuite sont presentees differentes methodes permettant de rectifier les images de maniere a simplifier la mise en correspondance, puis d'effectuer cette mise en correspondance par une technique de correlation. Outre des ameliorations des resultats classiques, de nouvelles methodes permettant d'obtenir une plus grande precision sont discutees. La derniere phase, dite de reconstruction, permet d'obtenir une description des surfaces observee allant jusqu'aux proprietes differentielles d'ordre un et deux (plan tangent et courbures a la surface), a partir des resultats de stereoscopie par correlation. Ce document se termine par quelques applications realisees au cours de ces recherches telles qu'un systeme d'aide chirurgicale pre-operatoire ou une camera stereo bon marche.
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Dubourg-Paillous, Michèle. "Caractérisation par microscopie électronique et techniques associées de verres de chalcogénures GeSey obtenus par dépôt en phase vapeur assisté plasma (PECVD)." Toulouse 3, 1992. http://www.theses.fr/1992TOU30193.
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Les verres de chalcogenures gese#3 et gese#5#,#5 deposes par pecvd ont ete etudies par microscopie electronique, avant et apres attaque chimique, et presentent des heterogeneites nodulaires. Le traitement thermique de ces verres amorphes provoque la formation a haute temperature de cristaux de gese#2 et de se. L'irradiation electronique et le vieillissement a l'abri ou non de la lumiere amene la formation de dendrites de se. La gravure aux electrons d'un film mince de gese#3 sensibilise avec une solution de kag(co)#2 donne des motifs bien meilleurs que ceux de gese#5#,#5 sensibilise avec agno#3 et irradie aux uv
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Molinier, Thierry. "Approche coopérative pour l'acquisition et l'observation de formes tridimensionnelles." Phd thesis, Université de Bourgogne, 2009. http://tel.archives-ouvertes.fr/tel-00465787.
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Les progrès technologiques ont permis d'abaisser la frontière entre image réelle et image virtuelle à tel point que les différencier devient difficile. Si la réalité virtuelle évolue au rythme des progrès technologiques, la réalité augmentée, passage du virtuel vers le réel, n'en est qu'à ses débuts. Le but de cette thèse est d'assurer la transition entre le monde virtuel et réel grâce à un système procam (projecteur caméra) pour améliorer l'apparence visuelle d'un objet. La position de l'objet est estimée en projetant une mire codée pour déterminer des points de correspondance entre les caméras et le projecteur sur un objet sans texture (les détecteurs classiques de points d'intérêt sont inefficaces sur de tels objets). Nous combinons l'étalonnage du système et ces points pour estimer la position 3D de l'objet, et ensuite le recalons avec un modèle de points plus fin, issu d'un scanner ou d'un modèle de CAO. La synthèse de vue est réalisée et l'image synthétisée est projetée sur l'objet. De tels outils permettent de générer des textures virtuelles, temporaires (il suffit d'éteindre le projecteur pour enlever la texture de l'objet), qui peuvent décrire l'usure de la texture ou l'objet sous son apparence d'origine.
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Spreyer, Kathrin. "Does it have to be trees? : Data-driven dependency parsing with incomplete and noisy training data." Phd thesis, Universität Potsdam, 2011. http://opus.kobv.de/ubp/volltexte/2012/5749/.
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We present a novel approach to training data-driven dependency parsers on incomplete annotations. Our parsers are simple modifications of two well-known dependency parsers, the transition-based Malt parser and the graph-based MST parser. While previous work on parsing with incomplete data has typically couched the task in frameworks of unsupervised or semi-supervised machine learning, we essentially treat it as a supervised problem. In particular, we propose what we call agnostic parsers which hide all fragmentation in the training data from their supervised components.
We present experimental results with training data that was obtained by means of annotation projection. Annotation projection is a resource-lean technique which allows us to transfer annotations from one language to another within a parallel corpus. However, the output tends to be noisy and incomplete due to cross-lingual non-parallelism and error-prone word alignments. This makes the projected annotations a suitable test bed for our fragment parsers. Our results show that (i) dependency parsers trained on large amounts of projected annotations achieve higher accuracy than the direct projections, and that (ii) our agnostic fragment parsers perform roughly on a par with the original parsers which are trained only on strictly filtered, complete trees. Finally, (iii) when our fragment parsers are trained on artificially fragmented but otherwise gold standard dependencies, the performance loss is moderate even with up to 50% of all edges removed.Wir präsentieren eine neuartige Herangehensweise an das Trainieren von daten-gesteuerten Dependenzparsern auf unvollständigen Annotationen. Unsere Parser sind einfache Varianten von zwei bekannten Dependenzparsern, nämlich des transitions-basierten Malt-Parsers sowie des graph-basierten MST-Parsers. Während frühere Arbeiten zum Parsing mit unvollständigen Daten die Aufgabe meist in Frameworks für unüberwachtes oder schwach überwachtes maschinelles Lernen gebettet haben, behandeln wir sie im Wesentlichen mit überwachten Lernverfahren. Insbesondere schlagen wir "agnostische" Parser vor, die jegliche Fragmentierung der Trainingsdaten vor ihren daten-gesteuerten Lernkomponenten verbergen. Wir stellen Versuchsergebnisse mit Trainingsdaten vor, die mithilfe von Annotationsprojektion gewonnen wurden. Annotationsprojektion ist ein Verfahren, das es uns erlaubt, innerhalb eines Parallelkorpus Annotationen von einer Sprache auf eine andere zu übertragen. Bedingt durch begrenzten crosslingualen Parallelismus und fehleranfällige Wortalinierung ist die Ausgabe des Projektionsschrittes jedoch üblicherweise verrauscht und unvollständig. Gerade dies macht projizierte Annotationen zu einer angemessenen Testumgebung für unsere fragment-fähigen Parser. Unsere Ergebnisse belegen, dass (i) Dependenzparser, die auf großen Mengen von projizierten Annotationen trainiert wurden, größere Genauigkeit erzielen als die zugrundeliegenden direkten Projektionen, und dass (ii) die Genauigkeit unserer agnostischen, fragment-fähigen Parser der Genauigkeit der Originalparser (trainiert auf streng gefilterten, komplett projizierten Bäumen) annähernd gleichgestellt ist. Schließlich zeigen wir mit künstlich fragmentierten Gold-Standard-Daten, dass (iii) der Verlust an Genauigkeit selbst dann bescheiden bleibt, wenn bis zu 50% aller Kanten in den Trainingsdaten fehlen.
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Nord, Christoffer. "The Colours of Diabetes : advances and novel applications of molecular optical techniques for studies of the pancreas." Doctoral thesis, Umeå universitet, Umeå centrum för molekylär medicin (UCMM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-119845.
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Diabetes is a rapidly increasing health problem. In a global perspective,approximately 415 million people suffered from diabetes in 2015 and this number ispredicted to increase to 640 million by 2040. To tackle this pandemic there is a needfor better analytical tools by which we can increase our understanding of the disease.One discipline that has already provided much needed insight to diabetes etiology isoptical molecular imaging. Using various forms of light it is possible to create animage of the analysed sample that can provide information about molecularmechanistic aspects of the disease and to follow spatial and temporal dynamics. The overall aim of this thesis is to improve and adapt existing andnovel optical imaging approaches for their specific use in diabetes research. Hereby,we have focused on three techniques: (I) Optical projection tomography (OPT),which can be described as the optical equivalent of x-ray computed tomography(CT), and two vibrational microspectroscopic (VMS) techniques, which records theunique vibrational signatures of molecules building up the sample: (II) Fouriertransforminfrared vibrational microspectroscopy (FT-IR) and (III) Ramanvibrational microspectroscopy (Raman). The computational tools and hardware applications presented here generallyimprove OPT data quality, processing speed, sample size and channel capacity.Jointly, these developments enable OPT as a routine tool in diabetes research,facilitating aspects of e.g. pancreatic β-cell generation, proliferation,reprogramming, destruction and preservation to be studied throughout the pancreaticvolume and in large cohorts of experimental animals. Further, a novel application ofmultivariate analysis of VMS data derived from pancreatic tissues is introduced.This approach enables detection of novel biochemical alterations in the pancreasduring diabetes disease progression and can be used to confirm previously reportedbiochemical alterations, but at an earlier stage. Finally, our studies indicate thatRaman imaging is applicable to in vivo studies of grafted islets of Langerhans,allowing for longitudinal studies of pancreatic islet biochemistry.viIn summary, presented here are new and improved methods by which opticalimaging techniques can be utilised to study 3D-spatial, quantitative andmolecular/biochemical alterations of the normal and diseased pancreas.
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Wong, Tzu Yen. "Image transition techniques using projective geometry." University of Western Australia. School of Computer Science and Software Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0149.
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[Truncated abstract] Image transition effects are commonly used on television and human computer interfaces. The transition between images creates a perception of continuity which has aesthetic value in special effects and practical value in visualisation. The work in this thesis demonstrates that better image transition effects are obtained by incorporating properties of projective geometry into image transition algorithms. Current state-of-the-art techniques can be classified into two main categories namely shape interpolation and warp generation. Many shape interpolation algorithms aim to preserve rigidity but none preserve it with perspective effects. Most warp generation techniques focus on smoothness and lack the rigidity of perspective mapping. The affine transformation, a commonly used mapping between triangular patches, is rigid but not able to model perspective effects. Image transition techniques from the view interpolation community are effective in creating transitions with the correct perspective effect, however, those techniques usually require more feature points and algorithms of higher complexity. The motivation of this thesis is to enable different views of a planar surface to be interpolated with an appropriate perspective effect. The projective geometric relationship which produces the perspective effect can be specified by two quadrilaterals. This problem is equivalent to finding a perspectively appropriate interpolation for projective transformation matrices. I present two algorithms that enable smooth perspective transition between planar surfaces. The algorithms only require four point correspondences on two input images. ...The second algorithm generates transitions between shapes that lie on the same plane which exhibits a strong perspective effect. It recovers the perspective transformation which produces the perspective effect and constrains the transition so that the in-between shapes also lie on the same plane. For general image pairs with multiple quadrilateral patches, I present a novel algorithm that is transitionally symmetrical and exhibits good rigidity. The use of quadrilaterals, rather than triangles, allows an image to be represented by a small number of primitives. This algorithm uses a closed form force equilibrium scheme to correct the misalignment of the multiple transitional quadrilaterals. I also present an application for my quadrilateral interpolation algorithm in Seitz and Dyer's view morphing technique. This application automates and improves the calculation of the reprojection homography in the postwarping stage of their technique. Finally I unify different image transition research areas into a common framework, this enables analysis and comparison of the techniques and the quality of their results. I highlight that quantitative measures can greatly facilitate the comparisons among different techniques and present a quantitative measure based on epipolar geometry. This novel quantitative measure enables the quality of transitions between images of a scene from different viewpoints to be quantified by its estimated camera path.
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Turgut, Canan. "Deposition and adsorption of organic matter in the sub-monolayer range studied by experimental and numerical techniques." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0012/document.
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Les traitements plasma présentent un outil efficace, économique et écologique pour la fonctionnalisation de surfaces. Pour cette technique, l’étude du dépôt et de l’adhésion de molécules et précurseurs dans le régime de la sous-monocouche présente un intérêt majeur, car elle définit les propriétés de la surface et l’adhésion de la couche déposée sur le substrat. L’adhésion des molécules lors de la phase initiale du dépôt est contrôlée par les espèces dans le plasma ainsi que par leurs distributions énergétiques et angulaires. Dans le cadre de ce projet, une approche multidisciplinaire combinant calculs DFT et techniques expérimentales pour la préparation et la caractérisation des dépôts dans la sous-monocouche a été utilisée. Des dépôts de PS et PMMA, préparés par bombardement d’Ar sur une surface d’Ag, ont été caractérisés par XPS et ToF-SIMS. La quantité de matière déposée augmente bien avec le temps de dépôt, ou la dose d’irradiation. Les analyses par TOF-SIMS ont également montré que la proportion des grands fragments augmente au détriment des petits. Ceci est contraire aux résultats attendus et peut seulement être expliqué par la recombinaison de petits fragments sur la surface du collecteur. Cette hypothèse est supporté des calculs DFT qui ont montré que l’énergie d’adsorption des petits fragments est plus grande que celle des grands et, par conséquent, leur probabilité d’adsorption doit être également plus élevée. Les calculs DFT ont été étendus sur d’autres substrats, notamment du Si, Pt et Al2O3 et ont montrés que l’énergie d’adhésion est la plus élevée sur Si et PtPlasma surface treatments present an efficient, economical and ecological tool for surface functionalization. For this technique the deposition and adhesion of molecules and precursors in the sub-monolayer range are of utmost interest, since this layer defines the surface properties and the adhesion between deposit and substrate. The species in the plasma and their energy and angular distributions control the deposition process. To get insights into the latter, a multidisciplinary approach combining DFT calculations with experimental techniques is used for the preparation and characterisation of sub-monolayer deposits of PS and PMMA. The deposits are prepared by sputter deposition using an Ar beam and analysed by ToF-SIMS and XPS. The amount of deposited matter increases well with deposition time or fluence. ToF-SIMS analyses showed also that the proportion of large fragments on the collector surface is increasing with fluence, although the opposite was expected. This can only be explained by the recombination of smaller fragments to form larger ones. This hypothesis is supported by DFT calculations which showed that the adsorption energy, and hence the adsorption probability, is higher for the small fragments than for the large ones. DFT calculations have been extended to Si, Pt and Al2O3 substrates, showing that adsorption energies are highest for Si and Pt
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Appia, Vikram V. "A color filter array interpolation method for digital cameras using alias cancellation." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22542.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Russell Mersereau; Committee Member: Anthony J. Yezzi; Committee Member: Yucel Altunbasak.
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Norton, Eric R., and Jeffrey C. Silvertooth. "Development of a Yield Projection Technique for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/197240.
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A series of boll measurements were taken at numerous locations in cotton producing areas across Arizona in 1998 in an attempt to continue to develop a yield prediction model with a project that began in 1993. Results from 1995 showed the strongest relationship between final open boll counts and yield compared to a number of other measurements. Based on these results, data collection on boll counts began in 1996 and has continued in 1997 and 1998. Boll counts were taken as the number of harvestable bolls meter-1. All boll count measurements were made within one week of harvest. Number of bolls per unit area were then correlated to lint yield and an estimate for the number of bolls per area needed to produce a bale of lint was calculated. Estimates using all three years data combined indicate that approximately 38 bolls meter-1 are needed to produce one bale of lint per acre.
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Norton, E. R., and J. C. Silvertooth. "Development of a Yield Projection Technique for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/197473.
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A series of boll measurements were taken at numerous locations in cotton producing areas across Arizona in 1999 in an attempt to continue to develop a yield prediction model with a project that began in 1993. Results from 1995 showed the strongest relationship between final open boll counts and yield compared to a number of other measurements. Based on these results, data collection on boll counts began in 1996 and has continued in 1997, 1998, and 1999. Boll counts were taken as the number of harvestable bolls per meter. All boll count measurements were made within one week of harvest. Number of bolls per unit area were then correlated to lint yield and an estimate for the number of bolls per area needed to produce a bale of lint was calculated. Estimates using all four years of data combined indicate that approximately 38 bolls per meter are needed to produce one bale of lint per acre.
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Norton, E. R., and J. C. Silvertooth. "Development of a Yield Projection Technique for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210304.
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A series of boll measurements were taken at numerous locations across the state in 1997 in an attempt to continue to develop a yield prediction model that began in 1993. Results from 1995 showed the strongest relationship between final open boll counts and yield. Based on these results, data was collected in 1997 from several locations around the state. Boll counts were made just prior to harvest and then correlated to yield. Results showed that a good estimate for lint yield could be obtained using the factor of approximately 13 bolls/row-ft./bale of lint for Upland cotton on 38 to 40 inch row spacings.
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Norton, E. R., and J. C. Silvertooth. "Development of a Yield Projection Technique for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210756.
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A series of boll measurements were taken at several locations across the state in 1995 in an attempt to develop a yield prediction model. Measurements were taken out of two strip plot variety trials at the University of Arizona Maricopa Agricultural Center and in the Coolidge area, and also out of two commercial fields in Buckeye and Paloma Ranch over a period of approximately 2 months from peak bloom through cut-out. Data analysis revealed a best fit model that included seedcotton yield as a function of boll count, boll size, boll diameter, and heat units accumulated after planting (HUAP). A series of open boll counts were also taken from over 120 experimental units across the state within one week of harvest. The data revealed strongest relationships between final open boll counts and yield.
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Norton, E. R., and J. C. Silvertooth. "Development of a Yield Projection Technique for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/210934.
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A series of boll measurements were taken at numerous locations across the state in 1995 in an attempt to continue to develop a yield prediction model that began in 1993. Results from 1995 showed the strongest relationship between final open boll counts and yield. Based on these results, data was collected in 1996 from several locations around the state. Boll counts were made just prior to harvest and then correlated to yield. Results showed that a good estimate for lint yield could be obtained using the factor of approximately 13 bolls/row-ft./bale of lint for Upland cotton on a 38 to 40 inch row spacing.
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Silva, Henrique Paulo Rosa Rodrigues da. "O "elemento fachada" em projectos de requalificação-reconversão." Master's thesis, Instituições portuguesas -- UTL-Universidade Técnica de Lisboa -- IST-Instituto Superior Técnico, 2003. http://dited.bn.pt:80/30054.
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Fujinaga, Ichiro. "Optical music recognition using projections." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61870.
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Breutel, Stephan Werner. "Analysing the behaviour of neural networks." Queensland University of Technology, 2004. http://eprints.qut.edu.au/15943/.
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A new method is developed to determine a set of informative and refined interface assertions satisfied by functions that are represented by feed-forward neural networks. Neural networks have often been criticized for their low degree of comprehensibility.It is difficult to have confidence in software components if they have no clear and valid interface description. Precise and understandable interface assertions for a neural network based software component are required for safety critical applications and for theintegration into larger software systems. The interface assertions we are considering are of the form "e if the input x of the neural network is in a region (alpha symbol) of the input space then the output f(x) of the neural network will be in the region (beta symbol) of the output space "e and vice versa. We are interested in computing refined interface assertions, which can be viewed as the computation of the strongest pre- and postconditions a feed-forward neural network fulfills. Unions ofpolyhedra (polyhedra are the generalization of convex polygons in higher dimensional spaces) are well suited for describing arbitrary regions of higher dimensional vector spaces. Additionally, polyhedra are closed under affine transformations. Given a feed-forward neural network, our method produces an annotated neural network, where each layer is annotated with a set of valid linear inequality predicates. The main challenges for the computation of these assertions is to compute the solution of a non-linear optimization problem and the projection of a polyhedron onto a lower-dimensional subspace.
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Walden, Alan Keith. "Signal processing techniques on an underwater acoustic projector." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/17336.
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Oishi, Cássio Machiaveli. "Análise e implementação de métodos implícitos e de projeção para escoamentos com superfície livre." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-06112008-152601/.
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No contexto do método MAC e baseado em esquemas de diferenças finitas, este trabalho apresenta três estudos: i) uma análise de estabilidade, ii) o desenvolvimento de técnicas implícitas e, iii) a construção de métodos de projeção para escoamentos com superfície livre. Na análise de estabilidade, o principal resultado mostra que o método de Crank-Nicolson torna-se condicionalmente estável quando aplicado para uma malha deslocada com a discretiza ção explícita das condições de contorno do tipo Dirichlet. Entretanto, o mesmo método com condições de contorno implícitas é incondicionalmente estável. Para obter métodos mais estáveis, formulações implícitas são desenvolvidas para a equação da pressão na superfície livre, derivada da condição de tensão normal. Esta estratégia resulta no acoplamento dos campos de velocidade e pressão, o que exige a introdução de novos métodos de projeção. Os métodos de projeção assim desenvolvidos resultam em novas metodologias para escoamentos com superfície livre que são apropriados para o tratamento de problemas com baixo número de Reynolds. Além disso, mostra-se que os métodos propostos podem ser aplicados para fluidos viscoelásticos. Novas estratégias são derivadas para obter métodos de projeção de segunda ordem de precisão para escoamentos com superfícies livres. Além dos resultados teóricos sobre a estabilidade de esquemas numéricos, técnicas implícitas e métodos de projeção, testes computacionais são realizados e comparados para consolidação da teoria apresentada. Os resultados numéricos são obtidos no sistema FREEFLOW. A eficiência e robustez das técnicas desenvolvidas neste trabalho são demonstradas na solução de problemas tridimensionais complexos com superfície livre e baixo número de Reynolds, incluindo os problemas do jato oscilante e do inchamento do extrudadoIn the context of the MAC method and based on finite difference schemes, this work presents three studies: i) a stability analysis, ii) the development of implicit techniques, and iii) the construction of projection methods for free surface flows. In the stability analysis, the main result shows a precise stability restriction on the Crank-Nicolson method when one uses a staggered grid with Dirichlet explicit boundary conditions. However, the same method with implicit boundary conditions becomes unconditionally stable. In order to obtain more stable methods, implicit formulations are applied for the pressure equation at the free surface, which is derived from the normal stress condition. This approach results in a coupling of the velocity and pressure fields; hence new projection methods for free surface flows need to be developed. The developed projection methods result in new methodologies for low Reynolds number free surface flows. It is also shown that the proposed methods can be applied for viscoelastic fluids. New strategies are derived for obtaining second-order accurate projection methods for free surface flows. In addition to the theoretical results on the stability of numerical schemes, implicit techniques and projection methods, computational tests are carried out and the results compared to consolidate the theory. The numerical results are obtained by the FREEFLOW system. The eficiency and robustness of the techniques in this work are demonstrated by solving complex tridimensional problems involving free surface and low Reynolds numbers, including the jet buckling and the extrudate swell problems
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Collaer, Marcia Lee. "IMAGE DATA COMPRESSION: DIFFERENTIAL PULSE CODE MODULATION OF TOMOGRAPHIC PROJECTIONS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291412.
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Harvie, Frederick L. "Vibration measurement of large structures using a dual projection moiré technique." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0027/MQ31584.pdf.
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Norton, E. R., J. C. Silvertooth, and B. L. Unruh. "Development of a Yield Projection Technique for Upland and Pima Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210252.
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A series of boll measurements were taken at two locations in 1994 on 5 different varieties in an attempt to develop a yield prediction model. Measurements were taken in strip plot variety trials at Maricopa Agricultural Center and Marana Agricultural Center over a period of approximately 2 months from peak bloom through cut-out. Measurements taken included boll weight, boll diameter, bolls/meter, plants/meter, and final yield from each specific measurement area. Stepwise linear regression resulted in a yield prediction model expressing yield as a function of heat units accumulated after planting, boll diameter or boll weight, and bolls/meter.
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Berger, Miguel Peres Ferreira Gentil. "Modelos, uma interface criativa entre o projecto e as preexistências." Master's thesis, Instituições portuguesas -- UTL-Universidade Técnica de Lisboa -- -Faculdade de Arquitectura, 2002. http://dited.bn.pt:80/30507.
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