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Dissertations / Theses on the topic 'Focusing techniques'

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Published: 28 June 2021
Last updated: 13 February 2022

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1

Panzner, Berthold [Verfasser]. "Synthetic Aperture Radar Focusing Techniques for Subsurface Radar Imaging / Berthold Panzner." München : Verlag Dr. Hut, 2013. http://d-nb.info/1031844910/34.

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2

Redeby, Theres. "Improved Techniques for Protein Analysis Focusing on Membrane Proteins and Hydrophobic Peptides." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-617.

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3

Coates, Adam Ross. "Methods for ultra-broadband correlator development focusing on high-speed digital sampling techniques." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:8ace9e68-d8e7-4f1d-b6c9-13853eecbd47.

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In radio astronomy, a key limiting factor to observations made is the available bandwidth of the system. This thesis looks at two different approaches to building ultra-broadband correlators for use in radio astronomy. The first was a 2-20GHz double-sideband complex analogue correlator that was constructed before the work of this thesis. Characterisation tests are performed and a basic calibration is attempted. Both these sets of experiments show good results, with the basic calibration successfully being able to compensate for gain difference between the lags over a reduced bandwidth range used in the testing. The second approach was the investigation into different techniques for high-speed digital sampling, capable of providing equivalent bandwidths to the analogue system. The use of FPGA high-speed serial interfaces as direct 1-bit 3.125 GS/s samplers was investigated. Single-frequency sampling showed that a signal-to-noise ratio close to the theoretical maximum across the band was achieved (≈ 0.8 effective bits). Techniques were also identified to use multiple transceivers to generate a single interleaved stream at higher effective sampling rate. Two different methods were also explored for producing greater-than 1-bit sampling. A hysteresis approach was shown not to produce the desired results and a reference based sampler in the end was adopted. Finally, the interleaving and multi-bit techniques were combined to generate a single 1.5-bit 6.25 GS/s sampler. This was seen to have reduced signal-to-noise compared to the expected values. This was believed to be caused by the poor method of RF signal injection causing cross-talk between the channels and large amounts of loss. As a comparison to the direct sampling method, an external 1-bit high-speed Hittite comparator was also examined. The single-frequency experiment was repeated with a slightly higher signal-to-noise ratio found compared to the direct sampling method. This was again believed to be due to the RF environments used. From the sampling setups a four-input, six-baseline lag correlator was constructed using the direct sampling method. The entire correlator, as well as the sampling transceivers, was incorporated into a single Xilinx Virtex 5 FPGA. This was shown to have the expected response to single-frequency, broadband and noise signals. The thesis concludes with a characterisation of the RF devices used throughout the testing procedures. Several new devices were developed through the course of the experiments with the designs being documented. All the necessary components to construct IF chains for both the analogue and digital correlators described are present. This leads to simulations being made of complete IF chains, with the expected responses shown.
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4

Farooque, Mahfuza. "Automated Reasoning Techniques as Proof-search in Sequent Calculus." Palaiseau, Ecole polytechnique, 2013. http://pastel.archives-ouvertes.fr/docs/00/96/13/44/PDF/Farooque.pdf.

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Le raisonnement assisté par ordinateur joue un rôle crucial en informatique et en logique mathématique, de la programmation logique à la déduction automatique, en passant par les assistants à la démonstration. Le but de cette thèse est la conception d'un cadre général où différentes techniques de raisonnement assisté par ordinateur peuvent être implémentées, pour que ces dernières puissent collaborer, être généralisées, et être implémentées de manière plus sûre. Le cadre que je propose est un calcul des séquents appelé LKp(T), qui généralise un système de la littérature à la présence d'une théorie pour laquelle nous avons une procédure de décision, comme l'arithmétique linéaire. Cette thèse développe la méta-théorie de LKp(T), avec par exemple la propriété de complétude logique. Nous montrons ensuite comment le système spécifie une procédure de recherche de preuve qui émule une technique connue du domaine de la Satisfiabilité-modulo-théories appelée DPLL(T). Enfin, les tableaux de clauses et les tableaux de connexions sont d'autres techniques populaires en déduction automatique, d'une nature relativement différente de DPLL. Cette thèse décrit donc également comment ces techniques de tableaux peuvent être décrites en termes de recherche de preuve dans LKp(T). La simulation est donnée à la fois pour la logique propositionnelle et la logique du premier ordre, ce qui ouvre de nouvelles perspectives de généralisation et de collaboration entre les techniques de tableaux et DPLL, même en présence d'une théorie
Computer-aided reasoning plays a great role in computer science and mathematical logic, from logic programing to automated reasoning, via interactive proof assistants, etc. The general aim of this thesis is to design a general framework where various techniques of Computer-aided reasoning can be implemented, so that they can collaborate, be generalised, and implemented in a safe and trusted way. The framework I propose is a sequent calculus called LKp(T), which generalises an older calculus of the literature to the presence of an arbitrary background theory for which we have a decision procedure, like linear arithmetic. The thesis develops the meta-theory of LKp(T), such as its logical completeness. We then show how it specifies a proof-search procedure that can emulate a well-known technique from the field of Satisfiability-modulo-Theories, namely DPLL(T). Finally, clause and connection tableaux are other widely used techniques of automated reasoning, of a rather different nature from that of DPLL. This thesis also described how such tableaux techniques can be described as bottom-up proof-search in LKp(T). The simulation is given for both propositional and first-order logic, opening up new perspectives of generalisation and collaboration between tableaux techniques and DPLL, even in presence of a background theory
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5

Nilavalan, Rajagopal. "FDTD modelling, measurements and analyses of post reception synthetic focusing techniques in ground penetrating radars." Thesis, University of Bristol, 2000. http://hdl.handle.net/1983/84cded96-2d07-4f7d-887d-1fc4854b75e3.

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6

Brath, Alexander J. "Advanced techniques for ultrasonic imaging in the presence of material and geometrical complexity." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1510053440115292.

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7

Liu, Yansheng. "Investigation of Novel Microseparation Techniques." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1816.pdf.

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8

Mathai, Pramod P. "Application of reduced order modeling techniques to problems in heat conduction, isoelectric focusing and differential algebraic equations." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8997.

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Thesis (Ph.D.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Aerospace Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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9

Craps, Davina Denise. "Exploring new research avenues for osteoarthritis and rheumatoid arthritis in palaeopathology : interdisciplinary approaches focusing on methodological techniques." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11115/.

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This project sought to examine and critically evaluate current methodologies for the analysis and interpretation of osteoarthritis and rheumatoid arthritis within palaeopathology, with reference to clinical research. A compartmental recording method was developed for osteoarthritis and a distinction between degenerative joint changes and osteoarthritis was maintained. This method was applied to the analysis of five Post-Medieval skeletal populations from both rural and urban sites from northern England. An analysis of the pattern and distribution of osteoarthritis and DJC between the sites, including rural versus urban differences, age and sex-specific comparisons, and, where possible, a comparison with contemporaneous sites from southern England was undertaken. A set of diagnostic criteria for rheumatoid arthritis was developed, applied, and tested on potential cases of rheumatoid arthritis within the archaeological record. Given this condition’s scarcity within the palaeopathological context, a wider geographical and temporal analysis was conducted. Results, based on clinical research and differential prevalence rates, indicated that DJC and osteoarthritis should be assessed separately. General rural-urban patterns were similar for DJC, even when compared with age or sex, which was not the case for osteoarthritis. The compartmental approach indicated differential distributions between mobile and stable elements of ball-and-socket and between skeletal elements in hinge joints respectively, which was explained through osteophyte-development and biomechanical analysis. The results were compared with clinical research to explore the impact of degeneration on the daily lives of past individuals, while not relying on activity reconstruction. A foundation for future research on rheumatoid arthritis was created by the development of the set of diagnostic criteria and a visual comparative study of the erosive lesions between palaeopathological cases. Remarkable similarities were found in the expression of erosions in several skeletal elements (ulna, radius and cervical vertebrae). By analysing clinical, palaeopathological and historical information this project concluded that the disease is not of recent origin.
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10

Farooque, Mahfuza. "Techniques de déduction automatique vues comme recherche de preuve en calcul des séquents." Phd thesis, Ecole Polytechnique X, 2013. http://pastel.archives-ouvertes.fr/pastel-00961344.

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Le raisonnement assisté par ordinateur joue un rôle crucial en informatique et en logique mathématique, de la programmation logique à la déduction automatique, en passant par les assistants à la démonstration. Le but de cette thèse est la conception d'un cadre général où différentes techniques de raisonnement assisté par ordinateur peuvent être implémentées, pour que ces dernières puissent collaborer, être généralisées, et être implémentées de manière plus sûre. Le cadre que je propose est un calcul des séquents appelé LKp(T), qui généralise un système de la littérature à la présence d'une théorie pour laquelle nous avons une procédure de décision, comme l'arithmétique linéaire. Cette thèse développe la méta-théorie de LKp(T), avec par exemple la propriété de complétude logique. Nous montrons ensuite comment le système spécifie une procédure de recherche de preuve qui émule une technique connue du domaine de la Satisfiabilité-modulo-théories appelée DPLL(T). Enfin, les tableaux de clauses et les tableaux de connexions sont d'autres techniques populaires en déduction automatique, d'une nature relativement différente de DPLL. Cette thèse décrit donc également comment ces techniques de tableaux peuvent être décrites en termes de recherche de preuve dans LKp(T). La simulation est donnée à la fois pour la logique propositionnelle et la logique du premier ordre, ce qui ouvre de nouvelles perspectives de généralisation et de collaboration entre les techniques de tableaux et DPLL, même en présence d'une théorie.
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11

Sherry, Marion Mattis 1945. "AUTOMATED AND ROBOTIC TECHNIQUES FOR LABORATORY FLUID HANDLING IN MICROGRAVITY ON THE SPACE STATION (ISOELECTRIC FOCUSING, NASA, ELECTROPHORESIS, HUMAN/MACHINE INTERFACE, AUTOANALYZER)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276415.

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12

McAllister, Lawrence Brett. "The Use of Risk Analysis Techniques to Determine the Probability of Producing Non-Compliant Drinking Water: Focusing on Dual Media Rapid Gravity Filtration." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/2862.

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The main goal of a drinking water treatment plant is to provide safe drinking water for its consumers. Historically, this was accomplished through monitoring the influent and effluent water quality to ensure that the water quality met a set of guidelines and regulations. However, as the limitations of relying on compliance monitoring become more evident, water utilities and drinking water treatment plants are beginning to utilize risk management frameworks to help provide safe drinking water and to mitigate potential risks. Applying a risk management framework requires an evaluation of potential risks. This systematic evaluation can be performed through using risk analysis methods.

The overall goal of this research is to analyze and evaluate risk analysis methodologies that are used in a variety of engineering fields, select two risk analysis methods, and use them to evaluate the probability of producing non-compliant drinking water from a rapid gravity filtration unit with respect to turbidity.

The risk analysis methodologies that were used in this research were the consequence frequency assessment and computer modelling combined with probabilistic risk analysis. Both of the risk analysis methodologies were able to determine the probability of producing non-compliant water from a rapid gravity filtration unit with respect to turbidity. However, these methodologies were found to provide different numerical results with respect to each other. The consequence frequency assessment methodology was found to be easier to implement; however, the consequence frequency assessment was only able to be performed on one parameter at a time. Computer modelling and probabilistic risk analysis enabled the inclusion of multiple parameters which provided a more comprehensive understanding of the filtration unit.

The primary conclusion from this research is that the risk analysis methods, as they are described in this thesis, are not sufficient to use directly on a rapid gravity filtration unit without further modification. Furthermore, although the risk analysis methods provided some guidance, these methods should only be used as a part of a complete risk management process.
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13

Chaigne, Thomas. "Control of scattered coherent light and photoacoustic imaging : toward light focusing in deep tissue and enhanced, sub-acoustic resolution photoacoustic imaging." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066162/document.

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En microscopie, savoir focaliser la lumière à l’échelle micrométrique est déterminant. Dans les tissus biologiques néanmoins, les inhomogénéités du milieu diffusent la lumière, empêchant toute focalisation au-delà d’une profondeur de l’ordre du millimètre. Des techniques de façonnage de front d’onde ont été développées afin de pré-compenser la distorsion du faisceau lumineux induite par la propagation à travers un milieu diffusant. Pour parvenir à focaliser la lumière à l’intérieur même du milieu diffusant, l’enjeu est de mesurer l’intensité lumineuse en profondeur de manière non invasive. Nous proposons d’utiliser l’effet photoacoustique pour sonder cette intensité. Une structure optiquement absorbante éclairée par une impulsion lumineuse émet en effet un signal ultrasonore, dont l’amplitude est proportionnelle à l’intensité lumineuse. Ces ultrasons se propagent de façon quasi-balistique dans les tissus mous et peuvent donc être détectés à l’aide d’un transducteur acoustique externe. Cette mesure permet donc de déterminer l’intensité lumineuse éclairant l’absorbeur. Nous avons montré qu’il était possible d’utiliser l'imagerie photoacoustique pour mesurer la matrice de transmission d’un échantillon diffusant. Cette caractérisation nous permet de focaliser la lumière sur des structures absorbantes et de sonder des propriétés mésoscopiques du milieu diffusant. Nous avons montré que la large bande spectrale des signaux photoacoustiques permet d’améliorer la focalisation. Enfin, nous avons montré que l’utilisation d’une source de lumière cohérente permet de pallier certains artefacts de l’imagerie photoacoustique, ainsi que de franchir la limite de résolution acoustique
Light focusing is a crucial requirement for high resolution optical imaging. In biological tissue though, refractive index inhomogeneities scatter light, preventing any focusing beyond one millimeter. Wavefront shaping techniques have been recently developed to partially compensate for light scattering after propagation through a scattering medium. These techniques require a measurement of the light intensity at the target point. These techniques hold much promise for performing wavefront correction in order to focus light deep inside scattering media. This would require a non-invasive measure of the light intensity at depth. In this PhD study, we propose to use the photoacoustic effect for such task. An optically absorbing structure under pulsed illumination indeed generates ultrasonic waves, whose amplitude is proportional to the absorbed light intensity. These ultrasounds mostly propagate in a ballistic way, and can therefore be detected with an external transducer. We have shown that photoacoustic imaging could be used to measure the transmission matrix of a scattering sample, enabling to focus light on absorbing structures as well as to retrieve mesoscopic properties of the medium. We have shown that the broadband spectral content of the photoacoustic signals can be harnessed to improve the focusing performances. Finally, we demonstrated that coherent illumination could be used to remove fundamentals artefacts, as well as to break the acoustic resolution limit of conventional deep tissue photoacoustic imaging
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14

Jouadé, Antoine. "Millimeter-wave radar imaging systems : focusing antennas, passive compressive devicefor MIMO configurations and high resolution signal processing." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S154/document.

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Les travaux présentés dans cette thèse sont une contribution à l’étude des systèmes d’imagerie active en bande millimétrique et plus spécifiquement sur les parties antennaires et le traitement de signal. Ces travaux ont été menés dans le cadre d’une collaboration entre Canon Research Center France et l’ETR. Une première étude a porté sur les antennes focalisantes et plus spécifiquement sur la lentille de Fresnel avec un procédé de fabrication de matériau à gradient d’indice qui a permis d’améliorer l’efficacité (59%) et la largeur bande de fréquence (75-110 GHz). Cette antenne a été utilisée sur un système rotatif pour imager une scène réelle extérieure. L’étude s’est ensuite focalisée sur la conception d’une configuration Multiple-Input Multiple-Output ou MIMO (entrées multiples, sorties multiples) grâce notamment à l’utilisation d’un dispositif compressif passif 4×1 permettant de réduire, par compression, le nombre de chaînes RF. Ces chaînes sont décompressées par post-traitement. Le dispositif, placé à l’émission, a été associé avec un scanner qui permet de synthétiser un réseau d’antennes à la réception. Cette configuration a permis de générer virtuellement un réseau de plus grande taille, permettant d’améliorer la résolution azimutale du système tout en limitant le nombre de chaînes RF. Cette configuration est utilisée pour imager une scène en chambre anéchoique afin de valider le concept. Pour améliorer encore plus la résolution du système avec un nombre limité de chaînes RF, l’étude d’algorithmes de haute-résolution, ou méthodes d’estimation spectrales, sont utilisés dans des configurations à large bande de fréquences pour imager des cibles en champs proche. L’association de la configuration MIMO, du dispositif compressif passif et des méthodes d’estimation spectrales permet d’améliorer la résolution du système tout en limitant le nombre de chaînes RF nécessaire
The broad topic of the presented Ph.D. thesis consists in the contribution to the study of Radar imaging systems at millimeter-wave and more specifically to the antennas and signal processing. These works have been carried out during a partnership between Canon Research Center France and IETR. A first study on focusing antennas, particularly on Fresnel lens antennas, thanks to a technological process to manufacture inhomogeneous materials, has allowed to improve the efficiency and the frequency bandwidth. The antenna has been mounted on a rotary system to image a real outdoor scene. Then, the study has been focused on the realization of a Multiple-Input Multiple-Output (MIMO) configuration notably using a 4 × 1 passive compressive device allowing to reduce, by compression, the number of radiofrequency (RF) chains. The chains are decompressed by post-processing. The device, used at the transmitting part, is associated with a scanner that synthetizes a receiving array of antennas. This configuration allows to generate a large virtual array, to improve the azimutal resolution of the system while maintaining acceptable the number of RF chains. This configuration has been used to image a scene in an anechoid chamber to validate the concept. To further improve the spatial resolution of the system for a given number of RF chains, the study of high resolution algorithms, or spectral estimation methods, are used to image scenes in near field and wide-band configurations. The combination of MIMO configurations, the passive compressive device and the spectral estimation methods have allowed to drastically improve the spatial resolution of the radar imaging system while limiting the number of RF chains
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15

Espina, Benitez Maria Betzabeth. "Développement et mise en oeuvre de colonnes monolithiques d’affinité boronate pour des techniques séparatives miniaturisées." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1178/document.

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Une partie des recherches actuelles dans le domaine de l’analyse chimique concerne la miniaturisation et l’intégration d’étapes analytiques afin de répondre, entre autres, à des besoins de portabilité, d’automatisation mais aussi d’apporter des solutions pour analyser des échantillons de plus en plus petits. Le développement et la mise en œuvre de colonnes monolithiques d’affinité boronate (µBAMC) couplées « in-line » à des techniques séparatives miniaturisées s’inscrit dans cette démarche. Ce travail de thèse s’est focalisé sur (1) une compréhension des mécanismes de rétention en chromatographie d’affinité boronate (interactions spécifiques avec les composés cis-diols, conditions de reconnaissance, interactions secondaires), (2) le développement de supports monolithiques d’affinité boronate miniaturisés et (3) leur couplage «in-line» avec une séparation électrocinétique et détection conventionnelle dans un format capillaire. Différentes voies d’élaboration de colonnes monolithiques ont été comparées (en termes d’affinité, de nombre de sites boronate actifs et de stabilité). La faisabilité du couplage en ligne de ces supports µBAMC avec une étape de séparation électrophorétique (par CZE et CIEF) a été démontrée vis-à-vis de la purification/préconcentration et séparation de 3 catécholamines contenant des groupements cis-diols (Adrénaline, Noradrénaline et Dopamine) dans l’urine. Les couplages ont été optimisés avec succès permettant l’analyse automatisée et miniaturisée de ces neurotransmetteurs dans l’urine (volume échantillon < 10 µL) avec des limites de détection de l’ordre de la dizaine de ppb et des taux de récupération proches de 100 %
Part of the current research in the field of chemical analysis concerns the miniaturization and the integration of analytical steps in order to meet, among other things, the need of portability and automation but also to provide solutions for analyzing small samples. The development and implementation of monolithic boronate affinity columns (µBAMC) in-line coupled to miniaturized separation techniques is part of this approach. This thesis work focused on (1) an understanding of the retention mechanisms in boronate affinity chromatography (specific interactions with cis-diol compounds, recognition conditions and secondary interactions), (2) the development of miniaturized boronate affinity monolithic supports and (3) their in-line coupling with electrokinetic separation and conventional detection in a capillary format. Different ways of elaboration of monolithic columns were compared (in terms of affinity, number of actives sites and stability). The feasibility of in-line coupling of these µBAMC supports with an electrophoretic separation step (by CZE and CIEF) has been demonstrated in terms of purification / preconcentration and separation of 3 catecholamines containing cis-diol groups (adrenaline, noradrenaline and dopamine) in urine. The couplings have been successfully optimized allowing the automated and miniaturized analysis of these neurotransmitters in urine (sample volume <10 µl) with limits of detection of about the tens of ppb and recovery yields close to 100 %
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16

Fall, Bouna. "Evaluation des performances d'un système de localisation de véhicules de transports guidés fondé sur l'association d'une technique radio ULB et d'une technique de retournement temporel." Thesis, Valenciennes, 2013. http://www.theses.fr/2013VALE0028/document.

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En transports guidés, la localisation précise des trains s’avère vitale pour une exploitation nominale du système de transport. Dans un environnement de propagation tel que celui d’une emprise ferroviaire, un capteur de localisation efficace est complexe à concevoir et à valider lorsqu’il doit opérer en présence de nombreux obstacles fixes et mobiles constitués par l’infrastructure et les trains. Afin de concevoir un tel capteur, nous proposons dans ce travail de thèse l’emploi de techniques innovantes dites de diversité spectrale que l’on retrouve également sous la dénomination de radio Ultra Large Bande (ULB). Dans ce travail, cette dernière est également associée à la technique de Retournement Temporel (RT) afin de tirer partie de cet environnement de propagation complexe. L’objectif visé est d’obtenir une localisation fiable et robuste des véhicules ferroviaires par focalisation de signaux ULB en direction des antennes sol ou trains. Des études théoriques alliées à des simulations ont été effectuées portant sur les propriétés de focalisation d’énergie de la technique de retournement temporel en tenant compte de plusieurs paramètres liés aux configurations antennaires, aux canaux de propagation rencontrés et à l’électronique utilisée. L’apport du retournement temporel sur la précision du système de localisation Ultra Large Bande a été quantifié en comparant le système de localisation ULB conventionnel, sans retournement temporel puis, en associant le RT. Les résultats théoriques et de simulations de la solution proposée ont été validés par des expérimentations menées en chambre anéchoïque ainsi qu’en environnement indoor
In guided transport, the precise location of trains is vital for nominal operation of the transport system. In a propagation environment such as a railway line, an effective location sensor is complex to design and validate since it must operate in the presence of many fixed and mobile obstacles constituted by the infrastructure and the trains. In this thesis, to design such a sensor, we propose the use of so-called spectral diversity techniques also found under the name of Ultra Wideband radio (UWB). In this work, the latter is also associated with the Time Reversal (TR) technique to take advantage of the complex propagation environment. The objective is to obtain a reliable and robust location of rail vehicles by focusing UWB signals to antennas or ground trains. Theoretical studies combined with simulations were performed on the properties of energy focusing of TR technique taking into account several parameters related to antennal configurations, propagation channels and the railway environment. The contribution of TR on the accuracy of the positioning system was quantified by comparing the conventional UWB positioning system alone and then, combining it with TR. The theoretical results and simulations of the proposed solution have been validated by experiments carried out in an anechoic chamber and in indoor environment
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17

Zalamans, Louise. "3D Synthetic Aperture Imaging Using LaserUltrasonics." Thesis, Luleå tekniska universitet, Signaler och system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-85381.

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Synthetic Aperture Focusing Technique (SAFT) is a powerful method to createfocused images of the inside of opaque samples by using delay-and-sum of acquireddata. It gives a high resolution and when using a generation laser and a detectionlaser it is also non-contact. This thesis was made at Swerim, and the aim wasto create an 3D-SAFT algorithm and to visualise the reconstructed image. Twosamples were used, both were 3D-printed with known defects that varied in sizefrom 0.05 mm to 1 mm. The defects were lined up in rows, with 10 in each row.After the algorithm was used on the acquired data from the two samples, six toeight defects were found in each row. Both samples had three rows of defects. Themeasured sizes of the defects were not exactly as the actual size but ranged a fewmillimetre too small or big compared to the real size. Overall the algorithm workswell. The resolution of the 3D images are the same as for the 2D-SAFT algorithmalready made by Swerim. As of now the 3D images may not be worth the time ittakes to process, but if a better way to visualise the data is made in the future, itwill be good to be able to see the defects in 3D.
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18

Macháček, Jan. "Fokusovací techniky optického měření 3D vlastností." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442511.

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This thesis deals with optical distance measurement and 3D scene measurement using focusing techniques with focus on confocal microscopy, depth from focus and depth from defocus. Theoretical part of the thesis is about different approaches to depth map generation and also about micro image defocusing technique for measuring refractive index of transparent materials. Then the camera calibration for focused techniques is described. In the next part of the thesis is described experimentally verification of depth from focus and depth from defocus techniques. For the first technique are shown results of depth map generation and for the second technique is shown comparison between measured distance values and real distance values. Finally, the discussed techniques are compared and evaluated.
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19

Arden, Jeremy. "Focussing the musical imagination : exploring in composition the ideas and techniques of Joseph Schillinger." Thesis, City University London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361853.

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20

Iliopoulos, Ioannis. "Engineering the near field of radiating systems at millimeter waves : from theory to applications." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S165.

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L'objectif général est de développer un nouvel outil numérique dédié à la focalisation en 3D de l'énergie en zone de champ très proche par un système antennaire. Cet outil permettra de définir la distribution spatiale complexe des champs dans l'ouverture rayonnante afin de focaliser l'énergie sur un volume quelconque en zone de champ réactif. L'hybridation de cet outil avec un code de calcul dédié à l'analyse rapide d‘antennes SIW par la méthode des moments permettra de synthétiser une antenne SIW ad-hoc. Les structures antennaires sélectionnées seront planaires comme par exemple les antennes RLSA (Radial Line Slot Array). Les dimensions de l'antenne (positions, dimensions et nombre de fentes) seront définies à l'aide des outils décrits ci-dessus. Les résultats numériques ainsi obtenus seront validés d'abord numériquement par analyse électromagnétique globale à l'aide de simulateurs commerciaux, puis expérimentalement en ondes millimétriques (mesure en zone de champ très proche). Pour atteindre ces objectifs, nous avons défini quatre tâches principales : Développement d'un outil de synthèse de champ dans l'ouverture rayonnante (formulation théorique couplée à une méthode dite des projections alternées) ; développement d'un outil de calcul rapide (sur la base de traitements par FFT) du champ électromagnétique rayonné en zone de champ proche par une ouverture rayonnante, et retro-propagation ; hybridation de ces algorithmes avec un code de calcul (méthode des moments) en cours de développement à l'IETR et dédié à l'analyse très rapide d'antennes en technologie SIW ; conception d'une preuve ou plusieurs preuves de concept, et validations numérique et expérimentale des concepts proposés
With the demand for near-field antennas continuously growing, the antenna engineer is charged with the development of new concepts and design procedures for this regime. From the microwave and up to terahertz frequencies, a vast number of applications, especially in the biomedical domain, are in need for focused or shaped fields in the antenna proximity. This work proposes new theoretical methods for near-field shaping based on different optimization schemes. Continuous radiating planar apertures are optimized to radiate a near field with required characteristics. In particular, a versatile optimization technique based on the alternating projection scheme is proposed. It is demonstrated that, based on this scheme, it is feasible to achieve 3-D control of focal spots generated by planar apertures. Additionally, with the same setup, also the vectorial problem (shaping the norm of the field) is addressed. Convex optimization is additionally introduced for near-field shaping of continuous aperture sources. The capabilities of this scheme are demonstrated in the context of different shaping scenarios. Additionally, the discussion is extended to shaping the field in lossy stratified media, based on a spectral Green's functions approach. Besides, the biomedical applications of wireless power transfer to implants and breast cancer imaging are addressed. For the latter, an extensive study is included here, which delivers an outstanding improvement on the penetration depth at higher frequencies. The thesis is completed by several prototypes used for validation. Four different antennas have been designed, based either on the radial line slot array topology or on metasurfaces. The prototypes have been manufactured and measured, validating the overall approach of the thesis
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21

Alnasser, Suliman Mohammed Nasser. "A new form of peer feedback technique : an investigation into the impact of focusing Saudi ESL learners on macro level writing features." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2244.

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Although many researchers have explored the use of Peer Feedback (PF) in writing (e.g., Hu & Lam, 2010), several have reported concerns with this technique, such as a tendency to shift most of the attention to micro features (e.g., mechanics, vocabulary) while giving little attention to macro features such as organisation and coherence (e.g., Van Steendam et al., 2010), even though macro features can be argued to be a highly important aspect of good writing (Truscott, 1996). This is one of the factors that have led researchers (e.g., Gielen et al., 2010b) to propose forms of this technique in which emphasis is placed on particular aspects of the PF process. This study introduces one such form of PF technique which requires learners to focus on macro features in writing and the teacher to focus on micro features, in order to give learners more time to critique essays at a macro level while receiving micro level FB from a reliable source. The study investigates the impact of the introduced form on: learners’ motivation to use PF and to learn writing; learners’ attitudes towards PF and towards writing; learners’ linguistic progress, and learners’ preference for giving and receiving macro and/or micro level feedback when practising PF technique. The research was conducted on 41 Saudi Arabian undergraduate students in their final year of an English degree course. An action research approach was adopted using a one-group design, with the PF activities divided into two consecutive phases. During the first phase, subjects practised the conventional use (i.e, providing PF on macro and micro features) of this technique (T1), while during the second phase they practised the new form of the technique (T2). The data were gathered over 15 weeks from pre-, mid- and post-tests; pre-, mid- and post-questionnaires; mid- and post-interviews; field notes; documentary evidence, and recording of several verbal protocol sessions. The findings suggest that both treatments can have a significant impact on the overall quality of learners’ writing, with the second treatment resulting in significantly better quality. Despite these findings, the learners showed a strong preference for conventional PF, suggesting they have difficulty in accepting the prohibition from providing PF on micro features owing to a negative transfer effect from their previous experience of approaches to teaching writing, which placed a great emphasis on the importance of micro features. It is likely that this transfer effect may be found in other contexts with a similar approach to teaching writing; further research is needed in order to test this hypothesis. In addition, in this study, the participants did not have the chance to see how much better they performed in their post-test, which raises the question of whether or not their views would have changed if they had.
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22

Chu, Thi-Xuan. "Fabrication et caractérisation de populations de microcapsules avec une technique microfluidique." Compiègne, 2011. http://www.theses.fr/2011COMP1959.

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Nous avons développé une méthode d’analyse inverse qui combine une technique microfluidique et une simulation numérique afin de déterminer le module de cisaillement de populations de microcapsules. Cette méthode est simple et permet de discriminer des populations de microcapsules d’ovalbumine fabriquées à différentes conditions physicochimiques (pH et temps de réticulation). Notre méthode a montré que les propriétés mécaniques de la membrane étaient corrélées au degré de réticulation induit lors de la fabrication. Nous avons également conçu un microsystème permettant de fabriquer et caractériser en ligne les microcapsules. Ce microsystème est composé de trois parties. La première partie est composée de deux jonctions Y successives (flow-focusing) contrôlant la fabrication de goutte puis l’injection de l’agent réticulant. La seconde est un serpentin contrôlant le temps de réticulation des microcapsules. Enfin, la troisième partie est un microcanal cylindrique qui permet la caractérisation en ligne des propriétés mécaniques des microcapsules. Nous avons montré que la taille des gouttes augmentait avec le rapport de débit des phases continue et dispersée, mais qu’elle ne changeait pas avec le débit de la phase de réticulation. La réticulation in situ a pu être mise en évidence par des plissements sur les membranes. Enfin, les propriétés mécaniques ont été extraites avec succès démontrant le potentiel de notre approche
We have developed an inverse analysis method that combines a microfluidic technique with a numerical simulation to determine the shear modulus of microcapsule populations. This method is simple and allows the discrimination between various microcapsule populations made of cross-linked ovalbumin membranes that are fabricated at different physico-chemical conditions (pH and time of reticulation). Our method showed that the mechanical properties of the microcapsule membrane were correlated with the degree of reticulation used during the fabrication. We also designed a microsystem for online fabrication and characterization of microcapsules. The microsystem is divided in three parts. The first part consists of two successive Y junctions (flow-focusing) controlling the droplet fabrication and the injection of the cross-linking agent. The second is a wavy microchannel controlling the reticulation time of the microcapsules. Then, the third part is a cylindrical microchannel that allows online characterization of mechanical properties of the microcapsule membrane. We have shown that the droplet size increased with the flow rate ratio of continuous and dispersed phases, but did not change with the flow rate of the reticulation phase. The online reticulation has been demonstrated by the crinkles on the membranes. Finally, the mechanical properties were extracted successfully demonstrating the potential of our approach
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23

Selim, Hossam. "Hybrid non-destructive technique for volumetric defect analysis and reconstruction by remote laser induced ultrasound." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669481.

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This PhD thesis is devoted to the design, development and implementation of a non-contact hybrid non-destructive testing (NDT) method applied to the analysis of metallic objects that contain embedded defects or fractures. We propose a hybrid opto-acoustic technique that combines laser generated ultrasound as exciter and ultrasound transducers as receivers. This work envisages a detailed study of the detection and one, two or three-dimensional reconstruction of defects, using the proposed hybrid technique and its application as a remotely controlled non-contact NDT. Our device combines several advantages of both photonic and ultrasonic techniques, while reduces some of the drawbacks of both individual methods. Our method relay on the combination of experimental results with high-resolution signal processing procedures based on different mathematical algorithms. Our basic experimental setup uses a nanosecond pulsed laser at 532nm wavelength that impacts onto the surface of the object under study. The laser pulse is rapidly absorbed into a shallow volume of material and creates a localized thermo-elastic expansion inducing a broadband ultrasound pulse that propagate inside the material. The laser beam scans a selected area of the object surface, being remotely controlled by means of a programmable XY scanner. For each excitation point, the ultrasound waves propagate through the object are reflected or scattered by material 3D defects. They are detected by ultrasound transducers and recorded with a PC data-acquisition system for a further process and analysis. As a first step, the time of flight analysis provides enough data for the location and size of the defect in 1D view. The detection capabilities of internal defects in a metallic sample are studied by means of wavelet transform, chosen due to its multi-resolution time-frequency characteristics. A novel algorithm using a density-based spatial clustering is applied to the resulting time frequency maps to estimate the defect’s position. For the 2D visualization and reconstruction of the defects we extended the signal analysis using the synthetic aperture focusing technique (SAFT). We implement a novel 2D apodization window filtering applied along with the SAFT, and we show it removes undesired effects of the side lobes and wide-angle reflections of ultrasound waves, enhancing the reconstructed image of the defect. We move then towards the 3D analysis and reconstruction of defects and in this case we achieve and implement a fully non-contact and automatized experimental configuration allowing the scan areas on different object’s faces. The defect details are recorded from different angles/perspectives and a complete 3D reconstruction is achieved. Finally, we show our results on a complementary topic related to a particular case of the ultrasound propagation in solids. We were concerned on the physical understanding of the propagation and diffraction of ultrasound waves in solid materials from the first moment. The control of the diffraction pattern in solids, using an ultrasonic lens, would help focus/collimate the ultrasound reducing echoes and boundary reflections, resulting in a further improve NDT process. Phononic crystals have been used to regulate the diffraction and frequency response of ultrasonic waves traveling in fluids. However, they were much less studied in solid materials due to the difficulty of building the crystal and to high coupling losses. We perform detailed numerical simulations of the ultrasound propagation in a solid phononic crystal and we show focusing and the self-collimation effects. We further extend our analysis and couple our phononic crystal lens to a solid under study, showing that the diffraction control is preserved inside the target solid object trough the coupling material.
Esta tesis doctoral versa sobre el diseño, estudio e implementación de un método híbrido, sin contacto, de ensayos no destructivos (NDT, non-destructive testing) para el análisis de objetos metálicos que contienen defectos o fracturas internas. Proponemos una técnica híbrida opto-acústica que combina ultrasonidos generados por impacto láser como excitador y transductores de ultrasonidos como receptores. El trabajo plantea un estudio detallado de la detección y reconstrucción en 1D, 2D y 3D de defectos presentes en un objeto metálico, usando la técnica híbrida de NDT sin contacto y controlado remotamente. Nuestro dispositivo presenta varias ventajas de las técnicas fotónicas y de ultrasonidos, reduciendo al mismo tiempo algunos inconvenientes de dichos métodos tomados por separado. Nuestro método combina resultados experimentales con simulaciones numéricas basadas en el procesado de señal de alta resolución. El montaje experimental consiste en un láser pulsado de ns a una longitud de onda de 532 nm, que impacta sobre la superficie del objeto. El pulso láser se absorbe, creando una expansión termoelástica localizada que induce un pulso de ultrasonidos de banda ancha que se propaga en el material. El láser, controlado remotamente, realiza un barrido sobre un área seleccionada de la superficie del objeto. Por cada punto de excitación, el ultrasonido se propaga a través del objeto y se refleja o dispersa en los defectos del material. Dichas ondas se detectan mediante transductores y se registran en un sistema de adquisición de datos para su ulterior procesado. En un primer paso, mediante el análisis del tiempo de vuelo, podemos localizar y determinar el tamaño del defecto en una vista 1D. Las capacidades de detección de defectos internos en una muestra metálica se estudian también mediante transformación wavelet debido a sus características de multi-resolución en tiempo y frecuencia. Se aplica un algoritmo novedoso de agrupamiento (clustering) espacial y se usan los mapas resultantes de tiempo y frecuencia para estimar la posición del defecto. Para la visualización 2D de los defectos ampliamos el análisis de la señal utilizando la técnica de focalización por apertura sintética (SAFT, synthetic aperture focusing technique). Implementamos un novedoso filtro de apodización 2D, juntamente con la técnica SAFT, y demostramos que elimina efectos no deseados, mejorando la resolución de la imagen reconstruida del defecto. El siguiente paso es un análisis y reconstrucción 3D. En este caso conseguimos una configuración experimental totalmente automatizada y sin contacto, permitiendo áreas de barrido sobre diferentes caras de un objeto. Los detalles de los defectos se registran desde diferentes ángulos, consiguiéndose una completa reconstrucción 3D. Finalmente, mostramos nuestros resultados en un tema complementario, relacionado con un caso particular de propagación de ultrasonidos en sólidos. Desde un primer momento, quisimos tener una comprensión física de la propagación y difracción de ondas de ultrasonidos en materiales sólidos. El control de los patrones de difracción en sólidos, mediante el uso de lentes ultrasónicas, ayudaría a la focalización/colimación del ultrasonido, reduciendo ecos y reflexiones en la superficie de contorno, mejorando del proceso de análisis NDT. Los cristales fonónicos se usan para regular la difracción y la respuesta en frecuencia de ondas de ultrasonido que se propagan en fluidos. No obstante, dichas estructuras se han estudiado mucho menos en materiales sólidos. Hemos realizado detalladas simulaciones numéricas de la propagación de ultrasonidos en un cristal fonónico sólido y hemos demostrado efectos de focalización y autocolimación. Finalmente hemos acoplado nuestra lente de cristal fonónico al sólido objeto de estudio, demostrando que el control de la difracción se conserva en el interior de dicho objeto a través del material de acoplamiento. Finalmente, proporcionamos una conclusión general sobre el trabajo declarado en esta tesis y un plan de trabajo futuro donde esta investigación puede extenderse y expandirse aún más a aplicaciones industriales en colaboración con el mercado de producción
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24

Walter, Ute. "Drivers of customers' service experiences : a customer perspective on co-creation of restaurant services, focusing on interactions, processes and activities." Doctoral thesis, Örebro universitet, Restaurang- och hotellhögskolan - Grythytte Akademi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-14826.

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It is essential for service companies to understand how their customer service experiences are formed. This is especially important since service experiences are highly subjective and involve customers cognitively, emotionally and behaviorally. Although customer service experiences are a well recognised research topic in both, culinary arts and service research, dynamic interactions, activities and the customers’ active involvement have so far gained little attention. As a consequence the approach in previous research paints a rather static picture of customer service experiences. By introducing the principles of service dominant logic a first person view and the understanding of drivers of customer service experiences could be facilitated. The overall aim of the thesis is to extend and deepen the understandin of drivers of favourable and unfavourable customer service experiences.The context selected is the restaurant context. The overall aim is reflected in four intermediate aims. Two separate studies were conducted. First a two-stage questionnaire based study, describing the phone reservation encounter compared to dining satisfaction; second a critical incident technique study including 195 short narratives of customers’ favourable and unfavourable service experiences at restaurants. Interview data were analysed according to constant comparative analysis principles.The main empirical contributions of this thesis are the move from static descriptions of service to examining dynamic drivers of favourable and unfavourable customers’ service experiences, and especially the analysis of social interactions as a driver of service experiences and the categorisation of drivers. Theoretically the thesis introduces the experience driver constellation, reflecting the dynamic process of co-creation in specific situations,when favourable and unfavourable customer service experiences are formed. Suggestions are made to develop the Five Aspects Meal Model and the Experience Room Framework through the addition of actors, the exterior environment and organisational routines to the models.
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25

Phan, Huy Dinh-Thuy. "Retournement temporel : application aux réseaux mobiles." Thesis, Rennes, INSA, 2015. http://www.theses.fr/2015ISAR0026/document.

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Cette thèse étudie la technique dite de ‘Retournement Temporel’ afin d’améliorer l’efficacité énergétique des futurs réseaux mobiles d’une part, et réduire le coût des futurs terminaux mobiles, d’autre part. Le retournement temporel consiste à utiliser l’inverse temporel de la réponse impulsionnelle du canal de propagation entre un émetteur et un récepteur pour préfiltrer l’émission d’un signal de données. Avantageusement, le signal ainsi préfiltré est reçu avec une puissance renforcée (c’est la focalisation spatiale) et un écho principal qui est renforcé par rapport aux échos secondaires (c’est la compression temporelle). Lors d’une étape préalable d’apprentissage, l’émetteur estime le canal en mesurant un signal pilote provenant du récepteur. La focalisation spatiotemporelle n’est obtenue qu’à condition que la propagation demeure identique entre la phase d’apprentissage et la phase de transmission de données : c’est la condition de ‘réciprocité du canal’. De nombreux travaux montrent que la focalisation spatiale permet de réduire la puissance émise nécessaire pour atteindre une puissance cible au récepteur d’une part, et que la compression temporelle permet de réduire la complexité du récepteur nécessaire pour gérer l’effet des échos multiples, d’autre part. Cependant, les études sur la réduction de la complexité du récepteur se limitent à l’ultra large bande. Des travaux de cette thèse (basés sur des simulations et des mesures expérimentales) montrent que pour des bandes de fréquences plus typiques des futurs réseaux mobiles (fréquence porteuse à 1GHz et spectre de 30 MHz à 100 MHz), grâce au retournement temporel, un récepteur simple et un signal monoporteuse suffisent pour atteindre de hauts débits. En outre, la condition de réciprocité du canal n’est pas vérifiée dans deux scénarios typiques des réseaux mobiles. Tout d’abord, dans la plupart des réseaux mobiles européens, le mode de duplex en fréquence est utilisé. Ce mode implique que l’émetteur et le récepteur communiquent l’un avec l’autre sur des fréquences porteuses distinctes, et donc à travers des canaux de propagations différents. De plus, lorsqu’on considère un récepteur sur un véhicule connecté en mouvement, l’émetteur et le récepteur communiquent l’un avec l’autre à des instants distincts, correspondants à des positions distinctes du véhicule, et donc à travers des canaux de propagations différents. Des travaux de cette thèse proposent des solutions pour obtenir la focalisation spatio-temporelle dans ces deux scenarios. Enfin, des travaux de la thèse explorent la combinaison du retournement temporel avec d’autres techniques de traitement de signal récentes (la modulation spatiale, d’une part, et une nouvelle forme d’onde multiporteuse, d’autre part), ou des scenarios de déploiement nouveaux (ondes millimétriques et très grands réseaux d’antennes pour inter-connecter les noeuds d’un réseau ultra dense) ou de nouvelles applications (guidage et navigation) envisageables pour les futurs réseaux mobiles
This thesis studies the time reversal technique to improve the energy efficiency of future mobile networks and reduce the cost of future mobile devices. Time reversal technique consists in using the time inverse of the propagation channel impulse response (between a transceiver and a receiver) as a prefilter. Such pre-filtered signal is received with a stronger power (this is spatial focusing) and with a strong main echo, relatively to secondary echoes (this is time compression). During a previous learning phase, the transceiver estimates the channel by measuring the pilot signal emitted by the receiver. Space-time focusing is obtained only at the condition that the propagation remains identical between the learning phase and the data transmission phase: this is the ‘channel reciprocity’ condition. Numerous works show that spatial focusing allows for the reduction of the required transmit power for a given target received power, on the one hand, and that time compression allow for the reduction of the required complexity at the receiver side to handle multiple echoes, on the other hand. However, studies on complexity reduction are limited to ultra wideband. Some works of this thesis (based on simulations and experimental measurements) show that, for bands which are more typical for future networks (a carrier frequency of 1GHz and a spectrum of 30 MHz to 100 MHz), thanks to time reversal, a simple receiver and a mono-carrier signal are sufficient to reach high data rates. Moreover, the channel reciprocity condition is not verified in two scenarios which are typical from mobile networks. Firstly, in most European mobile networks, the frequency division duplex mode is used. This mode implies that the transceiver and the receiver communicate on distinct carriers, and therefore through different propagation channels. Secondly, when considering a receiver on a moving connected vehicle, the transceiver and the receiver communicate one with each other at distinct instants, corresponding to distinct positions of the vehicles, and therefore through different propagation channels. Some works of this thesis propose solutions to obtain space-time focusing for these two scenarios. Finally, some works of this thesis explore the combination of time reversal with other recent signal processing techniques (spatial modulation, on the one hand, a new multi-carrier waveform, on the other hand), or new deployment scenarios (millimeter waves and large antenna arrays to interconnect the nodes of an ultra dense network) or new applications (guidance and navigation) which can be envisaged for future mobile networks
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26

Mejía, Morales Julián. "Dispositif interférométrique pour la cytométrie : optomécanique en acousto-fluidique." Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4000.

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Au cours des dernières années, une demande croissante d’analyse cellulaire sans étiquette est apparue. Cette demande répond au besoin d’analyse cellulaire dans ses étapes de développement et, peut-être plus important encore, d’étudier l’état physiologique des cellules d’une manière plus simple que d’utiliser des analyses basées sur la fluorescence. Les propriétés mécaniques et optiques des cellules deviennent de puissants biomarqueurs pour discriminer les cellules. La déformation cellulaire induite par la pressionacoustique est mesurée avec le Dispositif Interférométrique Acoustofluidique, développé dans cette thèse, et permet d’étudier la déformabilité cellulaire d’une manière similaire à ce qui est fait pour l’analyse du module d’Young. La déformabilité est un biomarqueur intégral qui résume l’expression du gène cellulaire, tandis que l’indice de réfraction cellulaire est lié à la densité des protéines dans le cytosquelette. Le dispositif interférométrique acoustofluidique, développé pour la mesure des propriétés optomécaniques des cellules sur une base cytométrique, est décrit et caractérisé en détail dans cette thèse. L’appareil permet d’évaluer la taille, la déformabilité et l’indice de réfraction (ou une combinaison de ceux-ci) de cellules non adhérentes au moyen d’un résonateur Fabry-Perot de faible finesse et d’une manipulation acoustique. Lorsqu’une cellule focalisée par le champ acoustique (ou une autre particule de micro-taille) croise l’axe de la cavité Fabry-Perot, elle perturbe le motif de franges du résonateur, décrites par la fonction de transmission d’Airy. Une telle perturbation peut être caractérisée et analysée au moyen des paramètres ρ (rayons des franges d’interférence circulaires), pleine largeur à mi-maximum de la frange individuelle et distance entre les franges (intervalle spectrale libre). L’analyse de la perturbation permet d’évaluer les propriétés optomécaniques de la cellule. La mesure de la déformabilité des algues et descellules de levure a été réalisée pour tester les performances de l’instrument et comparée à la perturbation équivalente introduite par les billes de microgel et par des sphères de polystyrène comme témoins. L’expérience est basée sur l’analyse des images de perturbation des franges induites par les cellules. Lesimages sont acquises dans deux conditions différentes; 1) focalisation acoustique et 2) déformation induite acoustiquement. 180 profils d’intensité indépendants sont récupérés et analysés pour chaque image, permettant une analyse statistique des paramètres: distance focale cellulaire et Finesse du résonateur perturbé. Les résultats montrent un changement dans les propriétés optomécaniques des algues, de la levure et du microgel tandis que l’échantillon de polystyrène reste pratiquement inchangé, comme prévu, car le polystyrène est beaucoup plus rigide qu’une cellule et ne peut pas être déformé par le champ de pression de l’instrument. Ces résultats montrent que la technique acoustofluidique présentée ici est utile pour détecter et mesurer différentes propriétés optomécaniques qui, potentiellement, peuvent être utilisées comme biomarqueurs sans étiquette dans le diagnostic clinique
In the past years a growing demand for label-free cell analysis has emerged. This demand answers the need for cell analysis in its developing stages and, perhaps more importantly, to study cell physiological state in a simpler way than using fluorescence-based analyses. Mechanical and optical properties of cells are emerging as powerful biomarkers to discriminate cells. The cell deformation induced by acoustic pressure is measured with the Acoustofluidic Interferometric Device, developed in this Thesis, and allows for studying the cells deformability in a way similar to what is done for the analysis of the Young modulus. Deformability is an integral biomarker that summarizes cell gene expression, while the cell refractive index is related to the density of proteins in the cytoskeleton. The Acoustofluidic Interferometric Device, developed for the measurement of optomechanical cell properties on a cytometric basis, is detailed described and characterized in this thesis. The device enables the assessment of size, deformability and refractive index (or a combination of them) of non-adherent cells by means of a low finesse Fabry Perot resonator and acoustic manipulation.When an acoustically focussed cell (or another micro-sized particle) crosses the axis of the Fabry-Perot cavity it will perturb the resonator’s fringe pattern governed by the Airy’s transmission function. Such perturbation can be characterized and analyzed by means of the parameters ρ (radii of the circular interference fringes), Full Width at Half Maximum of the individual fringe and by the distance between fringes (Free Spectral Range). The analysis of the perturbation enables the assessment of the cell’s optomechanical properties. Measurement of the deformability of Algae and Yeast cells has been carried out to test the instrument’s performance and compared to the equivalent perturbation introduced by Microgel beads and Polystyrene spheres as controls. The experiment is based on the cell-induced fringe pattern perturbation images analysis. Images are acquired under two different conditions; 1) acoustic focussing and 2) acoustically induced deformation. 180 independent intensity profiles are retrieved and analyzed for each image, allowing for statistical analysis of the parameters: cell focal length and perturbed resonator Finesse. The results show a change in the optomechanical properties of the Algae, Yeast and Microgel while the Polystyrene sample remains virtually unchanged, as expected since Polystyrene is much stiffer than a cell and cannot be deformed by the pressure field of the instrument. These results show that the acoustofluidic technique presented here is useful to detect and measure different optomechanical properties which, potentially, can be used as label free biomarkers in clinical diagnosis
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27

Zhan, Yanwei. "Development of Isoelectric Focusing Techniques for Protein Analyses." Thesis, 2008. http://hdl.handle.net/10012/4084.

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Isoelectric focusing (IEF) is a powerful approach in separations of zwitterionic substances such as proteins, peptides and amino acids. It is important in proteomic research. Generally, in IEF, carrier ampholytes (CAs) are necessary to establish a stable pH gradient. However, CAs also bring attendant problems such as a decrease in detection sensitivity and suppression of ionization of analytes in mass spectrometry (MS) detection. It is desirable to build a pH gradient without using CAs. A simple slab based design was developed to establish a pH gradient using the electrolysis of water and the strength of free flow electrophoresis (FFE). The simple and robust CA free FFE-IEF design was applied in protein fractionation. In capillary format, capillary isoelectric focusing (CIEF), coupled to MS is a promising hyphenated technique for biomolecular analysis based on the combination of the high separation power of CE and the high specificity of MS. Coupling of the instruments is usually achieved with a coaxial sheath liquid interface, which decreases the detection sensitivity because of the dilution of sample by the sheath liquid. In this project, nano-electrospray, a sheathless interface, was used for coupling. Additionally, another major challenge is the presence of CAs which suppresses the ionization of analytes and contaminates the MS. In order to complete this project, a microcross union was chosen to couple CIEF with MS. A makeup solution was introduced to dilute the concentration of CAs after IEF to assist the ionization for MS detection. The makeup solution could replace the sheath liquid and could be maintained at a low flow rate so that nanoelectrospray could be performed. Monoliths can be described as integrated continuous porous separation media for micro scale separation columns. CAs were immobilized at different positions in the column according to their pIs, generating a monolithic immobilized pH gradient (M-IPG). In this project, carrier ampholytes was immobilized in poly (GMA-co-EDMA) based monolithic capillary and poly (GMA-co-acrylamide) based monolithic capillary to form a pH gradient. Two proteins were separated by IEF, which was implemented in poly (GMA-co-acrylamide) based monolithic capillary without CAs. The interface to MS was performed following the use of a microcross union as described previously. No typical noise of CAs was observed in the MS spectrum.
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Lin, Hsiao-Ling, and 林筱瓴. "Implementation of Text Mining Techniques in Court Decisions: Focusing on Compensation of Copyright Infringement." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/25984260857438170960.

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碩士
國立臺灣大學
科際整合法律學研究所
101
Copyright Act formulates remedies for infringement of rights in the sixth chapter. Article no. 85 and 88 prescribe that a person who infringes on moral rights of an author or economic rights of the copyright holder shall be liable for damages. Because copyright has the features of non-physical properties and copyright cases are quite various, it is difficult for the injured party to prove actual damages. Such complicated situation makes the uncertain factors exist and influences the amount of compensation. It will become disadvantages of the trial process and reconciliation established. This dissertation processes legal empirical studies by using statistics the factors that influence the amount of compensation from the copyright civil trial cases and ancillary civil action of Intellectual Property Court for four years since the establishment. We implement the concept of text mining and combine with regular expressions to design the algorithms of our experimental retrieval program to provide help for the legal empirical studies. The average recall of Experimental program is 97.96% and the precision is 95.4%. The Experimental system is verified to improve the efficiency of research works.
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Lemma, Tibebe. "INVESTIGATION OF PROTEIN-DRUG INTERACTION USING CAPILLARY ISOELECTRIC FOCUSING WITH WHOLE COLUMN IMAGING DETECTION AND SPECTROSCOPIC TECHNIQUES." Thesis, 2009. http://hdl.handle.net/10012/4300.

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In this work, the possibilities of understanding protein-drug interactions and the possible modes of action of the drug have been was explored using capillary isoelectric focusing (CIEF) and spectroscopic techniques. The first study involves the implementation and applications of the new high performance Raman spectrometer with volume phase (VPH) based grating system, which is integrated with a short liquid-core optical waveguide for characterization and analysis of a wide ranges of molecules. The high performance Raman spectrometer has allowed us to measure solid samples with minor differences in chemical compositions. In addition, spectral characteristics of the interactions between therapeutic drugs with human serum albumin have been examined in terms of the cleavage of disulfide (S-S) bonds. The relative intensity of the Raman signal decrease as a complex formation progressed, suggesting perturbation around the disulfide bonds of human serum albumin (HSA). This spectrometer is likely to be broadly applicable for simple to moderately complex samples. Furthermore, the future perspective of combining separation and spectroscopy technologies is a novel approach for capitalizing on the strengths of the two technologies. Capillary isoelectric focusing (CIEF) with whole column imaging detection (WCID) was used to investigate the interaction of platinum-based anticancer drugs, cisplatin and oxaliplatin, with human hemoglobin A0 (Hb) and HSA. This technique facilitates the investigation and characterization of the formation of adducts between drugs and proteins. At higher drug to protein molar ratios (for both oxaliplatin and cisplatin), the results exhibit significant changes in the peak shapes and heights, which may indicate the destabilization of the protein. However, the conformational change was less evident at lower molar ratios. In addition, a major pI shift was observed for the oxaliplatin reaction mixtures (for 1:10, 1:50 and 1:100 ratios). In comparison with previously reported findings obtained by other analytical methods, conclusions were drawn about the validity of CIEF as a simple and convenient method for the investigation of protein-drug interactions. These results may provide useful information for further understanding the activity and toxicity of these chemotherapeutic drugs and improving their clinical performance. Spectroscopic evidence also shows that oxaliplatin causes fluorescence quenching of HSA by formation of on HSA-oxaliplatin complex. The Stern-Volmer equation has been used to calculate the quenching constant in the linear range. The quenching rate constants Kq at three different temperatures indicate the presence of a static quenching mechanism in the interactions of oxaliplatin with HSA. The work describes the validity of the CIEF-WCID technique for the study of protein-drug interactions and provides useful information and insight into the interaction of anti-cancer drugs with HSA concerning their further toxicity of these chemotherapeutic drugs and ways of improving their clinical performance. Finally, a novel two-dimensional (2D) protein characterization using a single one dimensional separation followed by a second characterization in the same instrument was developed. The technique combines capillary isoelectric focusing ( CIEF), which separate proteins based on their isoelectric points, with a dynamic imaging focusing and allows estimates of their molecular weights from measurement of their diffusion coefficients. This techniques applies to simple to moderately complex protein samples.
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Hou, Chih-Hao, and 侯智皓. "A Study on the Multimodal Nature of Taiwanese and Japanese Modern Comics - Focusing on the Construction of Expressive Techniques." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8g9vsg.

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碩士
淡江大學
日本語文學系碩士班
104
This study analyzes the construction of expressive techniques in Taiwanese and Japanese Modern Comics to explore their similarity and characteristics. Furthermore, to allow the readers to reflect on the future and development of Taiwanese comic industry, and to encourage comic artists to understand the social recognition and the advantage of Taiwanese comics leading to the reevaluation of Taiwanese comic industry as a whole. The first chapter mainly deals with the history of modern comics from Taiwan and Japan between 1970s to 2000s and through the understanding of their respective histories, the differences on the social recognition and the perceived value of modern comics between the two countries are shown to the readers. Next, through the summarization on the current state of Japanese and Taiwanese comic industry, the readers are given a basic understanding of the societal approval and future prospect of the comic industry. Lastly, the chapter examines the importance and effects of construction and techniques used in comics. The second chapter is an analysis of Japanese comic expressive techniques such as the use of screentone, the style of the storyboard, the control of pacing, information density and the manipulation of dialogue boxes in order to categorize and statisticize Japanese comic’s style and characteristic. The later half of the chapter uses this data to find the similarity and differences between it and Taiwanese construction of expressive techniques. The third chapter is an analysis of Taiwanese comic expressive techniques using similar methods as the ones used in chapter two in order to categorize and statisticize Taiwanese comic’s style and characteristic. The later half of the chapter uses this data to find the similarity and differences between it and Japanese construction of expressive techniques. Through the analysis of the statistics and comparison of the construction of expressive techniques in chapter two and three, very small difference in quality can be discerned between the expressive techniques of Taiwanese and Japanese comics. However, Taiwanese comics still have much rooms for improvement outside the use of these techniques. Finally, this study summarises the possible directions for future developments for the Taiwanese comic industry in order to achieve positive growth.
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Zeng, Sheng-ya, and 曾聖雅. "Application of Artificial Neural Networks and GIS Techniques for Studying on Slope Failure Potential Analysis -Focusing on Southern Cross-Island Highway Slope." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70120330443195305287.

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碩士
正修科技大學
營建工程研究所
99
Taiwan is an island produced by the compression between two tectonic plates. This results in large variances in geological and terrain structures and frequent seismic activity. Combined with concentrated precipitation, damaged sloping regions in mountainous areas contribute to roadway breakage and endanger lives and property. For many years, disaster prevention has long been a subject of government attention. This research selects the regional corridors in Kaohsiung’s Jiasian region as the focus due to the severity of slope damages in recent years. By referencing previous publications, seven elements are chosen to evaluate the local slopes: slope gradient, slope direction, slope height, Normalized Difference Vegetation Index (NDVI), geological structure, distance from fault lines, and distance of the slope from rivers. Through the application of DEM data, satellite photos, aerial photography, and various types of GIS software to archive the data retrieved and obtain potential factors along a corridor alignment to assess the degree of destruction. Information retrieved from the slopes along corridor alignments shall consist of 17889 data points towards the establishment of the analytical model indicating slope failure potential. Slope elements are differentiated into five different categories: Low, low-medium, medium, medium-high, high potential to assist in the construction of a cliff face destruction potential analysis model similar to a neurological network. The results of the analytical model will be used towards the drafting of charts indicating slope destruction potential in efforts to provide reference towards slope destruction prevention as well as early detection systems.
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Fan, yang-chun, and 范揚駿. "Application of dynamic focusing technique to semiconductor lithography." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/88204014320834083359.

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碩士
國立交通大學
工學院碩士在職專班半導體材料與製程設備組
97
This study explores the reason of Equipment Available Time for semiconductor lithography. This approach is beneficial for the reduction of product repair rate, enhancement of tool run time, and increasing the production capability. The maintenance and repair for semiconductor lithography equipment is related to several important parameters such as Average Run Time, Mean Time Between Failure (MTBF), and Product Rework Rate. After careful study, we find that the Dynamic Focus Error Reject Rate is the decisive factor for the Rework Rate. This study carried out various experiments in addition to data comparison and quality control (QC). Hence, we successfully achieve the identification of Dynamic Focus Error Reject Rate in relation to the Pneumatic Shock Air Mount Instability, Cam Disk Damage, Level Actuator Damage, Flat Cable Touch, HP Laser Head Transmitter, HP Laser Receiver, and Dynamic Shortcut.
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33

吳永泉. "GPR Image Processing by Synthetic Aperture Focusing Technique." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/37837684558953399501.

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碩士
大葉大學
電機工程學系碩士班
92
GPR transmits microwaves into the materials to be inspected, and then assuming the target or volume illuminated is composed of point-like scatters, the received signal consists of a sum of scaled and delayed versions of the transmitted signal. This pulse-echo technique gives range information about the location of targets but no azimuth information. In this article, we tried to develop an efficient high-speed Synthetic Aperture Focusing Technique to focus each of the arcs resulting from a point scatter into a single point. Without making sacrifices of image quality, a reduction of 75% computation time has been achieved.
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Hou, Hui-Hsiung, and 侯輝雄. "Development of Three-Dimensional Focusing Technique for Micro-Flow Cytometer." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/77522686461903804504.

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碩士
國立屏東科技大學
材料工程所
96
This study presents a novel three-dimensional hydrodynamic focusing technique for micro-flow cytometers. To employ hydrodynamic focusing phenomenon to press sample stream constrain in the microchannel positioned directly beneath an detection system. The sample stream is initially compressed in the horizontal direction by sheath flows such that it is constrained in the central region of the microchannel. The sample stream is then focused in the vertical direction by a second pair of sheath flows and to produce vertical direction of focusing phenomenon. After that the sample stream subsequently passes over a micro-weir structure and to employ optical detection system to capture cells/particles fluorescent signal. The microchannel configuration and operational parameters are optimized by performing a series of numerical simulations to examine the effects on the sample stream distribution of the vertical and horizontal focusing ratios, the entrance angle of the second set of sheath flow channels, and the width and depth of the second set of sheath flow channels. And to employ numerical simulation parameters via MEMS fabrication technique and isotropic wet etch method to fabricate micro-flow cytometer. The results indicate that the horizontal and vertical sheath flows successfully constrain the sample stream within a narrow,well-defined region of the microchannel. Furthermore, the micro-weir structure results in the separation of the cells/particles in the vertical direction and ensures that they flow in a sequential fashion through the detection region of the microchannel and can therefore be reliably counted.
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35

Chiu, Shao-Chun, and 邱紹鈞. "The real-time image focusing technique via DVD pickup head." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/p6qq2a.

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碩士
國立中山大學
機械與機電工程學系研究所
95
Due to maturity of experimental technology in recent years, automatic optical inspection (AOI) is used in many industrial applications to replace visual inspection with high-speed and reliable characteristics. Because standard industrial AOI instruments are very expensive, this work introduces a low-cost and high performance AOI instrumentation technique for industrial applications. In this study, we develop an image auto focusing system based on the pickup head of DVD player. We alter the optical path of pickup head and integrate the CCD camera in this system. The idea is to use focus error signal in the linear focus region to estimate the distance between pickup head and object surface. In addition, a capacitance gauging instrument is used to measure the displacement. A PC based control law is then developed by using the PZT to drive the auto focusing system. By setting up such a low-cost system, the experimental results show that the time required for focusing performance is within 0.4s in most cases while the longest focusing time is about 1s. It is hoped that the results of this study can be implemented for real industrial AOI applications.
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36

Fortin, Joel. "Enhancement of synthetic aperture focusing technique (SAFT) by advanced signal processing." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370372&T=F.

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37

Chu, De-ming, and 朱得銘. "RADAR IMAGE FOCUSING PROCESS IN AZIMUTH DIRECTION USING SYNTHETIC ARRAY TECHNIQUE." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/10091551763402728186.

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碩士
國立聯合大學
電子工程學系碩士班
94
The Remote Sensing Image Processing Lab cooperated with the Center for Space and Remote Sensing Research at National Central University to design a ground radar system. The aims of this system are to acquire a radar image and to make use of digital signal processing techniques to focus the image for improving image resolution. In the previous studies, which were performed in the Center of Space and Remote Sensing Research, step frequency continuous wave technique was adopted to modulate the transmitted electromagnetic waves so that Inverse Fourier Transform could be applied to the received radar echoes and image focusing in the range direction could be achieved. However, without Doppler frequency, image focusing in the azimuth direction can not be realized by making use of the conventional approach because that this system has no moving mechanism. To overcome this difficulty, this study applies synthetic array technique to transfer time domain Fourier Transform into spatial domain Fourier Transform with a virtual speed so as to attain image focusing in the azimuth direction. A computer simulation of this approach is done in this study. Then, this approach is applied to the real radar image acquired by this system as a verification. experimental result indicates that the parameters designed in the precious studies are over-sampled in the range direction and under-sampled in the azimuth direction.
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Chen, Chih-sheng, and 陳志昇. "Applications of the Optical Flow Technique to Image Tracking of Auto-focusing." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/03624031099437930671.

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碩士
國立中山大學
機械與機電工程學系研究所
92
Optical flow indicates a computing method which utilizes the brightness variation of image motion in further image disposition, without the prior understanding of field, environment, or related object. It also reflects the image variation to compute the variation of optical flow field due to the motion of time and distance. The Essay content follows the optical flow as its basis theory consideration to find the direction of image motion. It utilizes the auto-focus principle to search the corrective focus basis, to proceed the identify analysis through the target object. To obtain the visual tracking result after the auto-focus of image definition, moving direction when achieve the target object. The application method is easily to determine the movement or stationary target in the certain field.
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Heng-JianChang and 張恆健. "Spatial Detection of 1D Double-Row Formation Using Transverse Magnetic Focusing Technique." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/94620364784751042959.

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40

LeBeau, Claire S. "Maternal Guilt: An Existential Phenomenological Study of the Early Experiences of First-Time Mothers." 2013. http://digital.library.duq.edu/u?/etd,162287.

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The present study is an existential phenomenological investigation of the experiences of maternal guilt of five first-time mothers with infant children. Maternal guilt is a powerful, pervasive, and complex phenomenon that effects and is experienced by mothers in different ways. This research explores the experiences of these five mothers in feeling guilt related to being a mother and, using an adapted research methodology utilizing Focusing Technique (Gendlin, 1981), their embodied reflections about a particular memory of feeling maternal guilt. This study utilizes procedures explicated by Colaizzi (1978), Giorgi & Giorgi (2003), Todres (2007), von Eckartsberg (1998), Walsh (1995; 2004) and Wertz (1984). All participants provided data via a written account of a particular memory of feeling a sense of guilt related to being a mother, an individual interview which incorporated a modified Focusing component, and written and verbal feedback related to the write-up of the provisional thematic analysis of the interview. The interpreted analyses of the five interviews indicate seven formulated themes; physical and emotional connection to their babies, intense feelings of responsibility, feelings of being divided, multi-dimensionality of guilt with other emotions, pre-verbal miscommunication, anxiety over the unknown in the beginning, and social expectations and comparisons. The findings suggest that the process of embodied reflection regarding a new mother's emotional experiences of guilt can foster important awareness for how she can care for her own and her child's needs. Relationships between contemporary cultural discourses on motherhood and philosophical interpretations of guilt are discussed. Implications for creating networks of support and community for new parents are also explored.
McAnulty College and Graduate School of Liberal Arts;
Clinical Psychology
PhD;
Dissertation;
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41

Chiu, Chin-Lung, and 邱進隆. "A Synthetic Aperture Focusing Technique for Imaging Defects inside the Reinforced Concrete Element." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24808746724068965750.

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博士
國立中央大學
土木工程學系
101
This study combined with the transient elastic wave propagation theory and the synthetic aperture focusing technique (SAFT) to develop a method for imaging the defects inside the reinforced concrete structure. In the study, the finite deference method was used to simulate the stress wave propagation behavior in the concrete specimen with embedded defects and verified the results by the experiment. For most of the existing elastic-wave-based nondestructive testing methods, it is hard to detect defects inside reinforced concrete elements owing to the complex signals reflected from rebars. Therefore, this study conferred the possibility for using SAFT to scan and image the defects inside the reinforced concrete. In the first, the time-velocity curves were used to get an image by SAFT. The numerical and experimental images also show nice results can be obtained either holes or cracks inside the absolute concrete specimens. Next, the influence of the rebar on quality of SAFT image was quantitatively analyzed by a serious of numerical simulations. The experimental results show good agreements with the quantitative analyzing results. Then, the time-frequency analysis was further used to transform the original time domain signals. After the transform, the instantaneous frequency can occur an obviously hopping in the non-continuous of the signals. According to the property of HT, the reflection signal can be highlighted and get better SAFT image. This study also brought up to a multi-directional many-dimensional inspection technique to improve problem of the defect information missing in the one-directional inspection and used image reconstruct technique to upgrade the integrity of defect image. The image quality (resolution and contrast) of SAFT quality was qualitative analyzed by elastic wave theory and finite deference. From the analysis results, It is shown that this newly developed an inspecting procedure for in situ detection is fairly good. Finally, a hardware system for detecting and imaging the defects inside the reinforced concrete based on the SAFT theory and operation procedure was developed. Due to the integration of the hardware control of graphical interface and the signal and image processing program, the total time for SAFT detection is dramatically reduced. The system can be more suitable for in situ non-destructive testing of the reinforced concrete.
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42

Liu, Wen Yu, and 劉文裕. "the study of methanol cluster and new measuring technique of focusing laser beam waist." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/95368273156576510440.

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43

Chia-CheHo and 何嘉哲. "A Modified Synthetic Aperture Focusing Technique Utilizing Beam Characteristics of Transducer for Ultrasound Image Improvement." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/62145656818565086452.

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碩士
國立成功大學
醫學資訊研究所
102
Synthetic aperture focusing technique (SAFT) has been proposed to improve the lateral resolution of ultrasound image outside the focal region of the transducer. However, SAFT would result an unexpected artifact image at the region near the focal point of transducer; which is due to the use of a virtue source concept associated with limited numbers of scan lines. The artifact image could be eliminated by using an appropriate time gain compensation (TGC). However, TGC is subjective to users’ settings. To further improve this issue, the present study incorporated the transducer’s depth-dependency beam characteristics into SAFT imaging procedure. Ultrasound images were acquired using different frequency of single element transducers. Initially, the beam widths of transducer were estimated from B-mode wire images using from -3 to -20dB width. Due to the erroneous time delay in accompanying with geometric calculation, the time delay was also estimated from those B-mode wire images. The -20dB beam width of transducer as a function of axial depth were measured for better estimating the time delay of each scanning point. The modified SAFT were verified by means of self-made phantoms with wire targets and contrast targets and in-vivo images. With the experiments, the modified SAFT images with the correction of beam width of the transducer may not only retain the advantages of original SAFT but also improve the artifact image near the focal region. The beam widths of transducer estimated from B-mode wire images using from -6 to -20dB width could be incorporated into SAFT imaging procedure and the modified SAFT was adaptive to different frequency of single element transducers. These results show that current modified SAFT-based imaging may greatly enhance ultrasound image quality for further clinical applications.
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Chun-Ching, Lin, and 林浚清. "A High Efficient Auto-Focusing Technique Applied to Depth Measurement of Multi-Layer Ceramic Capacitor." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/58295187500809607148.

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碩士
國立屏東科技大學
機械工程系
95
This study developed a high efficient auto-focusing measurement system for depth measurement of multi-layer ceramic capacitor. This measuring system integrates auto-focusing vision-based technique with a precise moving X-Y stage. Especially, dual video cameras are used to locate sample position and measure sample depth respectively. One CCD with low magnification rate take a wide field for position-searching, while another CCD with high magnification rate take a micro field for depth-measuring. The principle of depth measurement make use of auto-focusing technique by precise optical scale built on the Z axis of stage to find out the optimal focusing position. The system is able to measure 25 numbers of multi-layer ceramic capacitors at one batch. The measuring time costs only 7 seconds per chip. Therefore, it is applied in large quantities of measurement. After the experiment of practical measurement, the measuring reproducibility reaches 0.02mm and its accuracy to 0.033mm, which all measurement ability meet the demands of practical field. Eventually, this developed measuring system can shorten the time of measurement and decrease human resource, as well as bring them more convenience.
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45

Liu, Sung-Lin, and 劉松林. "Numerical and Experimental Study on applying Synthetic Aperture Focusing Technique to Test Cracks and Defects in Reinforced Concrete." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/17512009468205965826.

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碩士
中華大學
土木工程學系碩士班
102
In this paper the capability of the Synthetic Aperture Focusing Technique (SAFT) in detecting and imaging the cracks in plain concrete and the voids in reinforced concrete were studied. This research first utilized the Finite Element models to simulate the response of the stress wave propagation of a plain concrete with horizontal and tilted cracks and of a reinforced concrete with void subjected to impacting forces. The response signals were analyzed with SAFT and the resultant images were presented so that the feasibility of applying this technique on scanning and revealing the cracks and voids embedded in reinforced concrete can be studied. Two experimental specimens are then constructed in this research to be impacted by steel balls of different sizes and analysis was conducted with SAFT imaging procedure. Finally the results from experiments and from numerical simulation were compared for the purpose of verification. It was revealed from numerical simulation and experimental verification that the resolution of the images would be affected by the wave length of the stress waves introduced by the impacts of different steel balls. If the wave length of the introduced stress waves is short, fine cracks in the specimen can be revealed, whereas if the wave length is long, the interfering of reinforced bars can be reduced so that the defective voids can be scanned and revealed. Finally the feasibility of rotating the surfaces for impacting tests for testing and revealing defects was studied.
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JHANG, YOU-BIN, and 張祐賓. "Use of Synthetic Aperture Focusing Technique to Detect the Defects in Concrete Specimen with Single Void and Single Layer∕ Double Layers Rebars." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48896472840613747925.

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碩士
中華大學
土木工程學系碩士班
100
The testing constraints and the capability of using the Synthetic Aperture Focusing Technique (SAFT) to detect void defects embedded in concrete block subjected to different introduced stress wave lengths and rebars are studied in this paper. This study first used the numerical simulation of finite elements to study the effects of the sizes of the impacting steel balls, the rebars and the layers of rebars on the testing responses. The testing results were processed with the Synthetic Aperture Focusing Technique and presented in images so that the direct effects of various kinds of parameters can be assessed. The study also cast concrete specimen with single void and single layer and double layers of rebars. Impact-response tests were carried out and the results were compared with those from numerical simulation. The results from the numerical simulation and experiments revealed that the sizes of the impacting steel balls would directly affect the resolution of the images from the SAFT. It was also found that the effect of existing rebars on the testing signals can be neglected when the wave length of the introduced stress waves is larger than eight to ten times of the size of the rebars. In this condition, the specimen can be regarded as uniform material and thus the results of evaluating the void defects would not be affected by the size of aggregates. Through this study, it is hoped that the capability of application of the SAFT can be enhanced in scanning and detecting the defects embedded in concrete structures.
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47

James, David. "On two Random Models in Data Analysis." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DBE-D.

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48

Chung-t’ai, Huang, and 黃中泰. "An Examination of the Linear Stroke Technique Used in the Portrayal of Clothing in Chinese Ink-Wash Portraiture, Focusing on the Work of Jen Po-Nien and its Relationship to the Author’s Own Work." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/36399733556789392786.

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碩士
中國文化大學
藝術研究所
93
One of the most important characteristics of Chinese painting is the use of linear stroke techniques. On the surface, Chinese painting utilizes linear stroke techniques in order to construct images, but on a deeper level, these techniques provide the medium through which the artist can express vibrancy and emotion. Indeed, one might say that the use of linear stroke techniques enables the artist to express himself through his art. Jen Po-nien’s paintings have enjoyed an enduring fame, and his techniques and styles have had a profound influence on later generations. Master Jen lived in Shanghai at a time when the city’s prosperity attracted talented artists from around the country. In the midst of this flourishing artistic environment, Master Jen eventually created his own unique style of painting featuring vibrant figures portrayed using innovative techniques. Whether refined and detailed or bold and unrestrained, Master Jen’s brush was able to portray the myriad expressions of commoner and gentry alike in ways that seemed to capture their nature and emotions in a realistic manner. His work also reflected the unique free-style approach of the “xie yi” style, and brought about the emergence of portraiture as a category of “wen ren” or idealist painting. Even today, there is much we can learn from Master Jen’s work. In keeping with the spirit of studying the past to improve the present, this thesis focuses on Jen Po-nien’s techniques for portraying people and their influence on the author’s own style of painting.
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Λιάρος, Νικόλαος. "Μη γραμμική οπτική απόκριση αζοβενζολικών μοριακών συστημάτων." Thesis, 2011. http://hdl.handle.net/10889/5095.

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Abstract:
Ο όρος μη γραμμική οπτική (nonlinear optics) αναφέρεται στον κλάδο της φυσικής που μελετά τις μεταβολές που επέρχονται στις οπτικές ιδιότητες της ύλης, όταν αυτή αλληλεπιδρά με ισχυρά ηλεκτρομαγνητικά πεδία. Οι δέσμες λέιζερ (laser) αποτελούν το κατ’ εξοχήν ηλεκτρομαγνητικό πεδίο που χρησιμοποιείται για να προκαλέσει τη μη γραμμική οπτική απόκριση της ύλης, λόγω της ισχυρής ακτινοβολίας. Με την ανακάλυψη του λέιζερ τη δεκαετία του 1960, παράλληλα αναπτύχθηκαν πολλές τεχνικές μέσω των οποίων καθίσταται εφικτός ο προσδιορισμός της μη γραμμικής οπτικής απόκρισης των υλικών. Κίνητρο για αυτή την εκτεταμένη έρευνα αποτελεί το γεγονός ότι υλικά με σημαντική μη γραμμική απόκριση βρίσκουν πολλές εφαρμογές στη φωτονική και την οπτοηλεκτρονική. Ειδικότερα, τέτοια υλικά μπορούν να χρησιμοποιηθούν ως οπτικοί περιοριστές (optical limiters) για την προστασία από υψηλές δέσμες λέιζερ, ως οπτικοί διακόπτες (optical switches), καθώς και ως οπτικές λογικές πύλες (optical logic gates) κ.α. Τα τελευταία χρόνια υπάρχει ιδιαίτερο ερευνητικό ενδιαφέρον στο πεδίο των μοριακών διακοπτών (molecular switches). Ο όρος μοριακός διακόπτης αναφέρεται στην δυνατότητα ύπαρξης ενός μορίου μεταξύ δύο διαφορετικών καταστάσεων, ικανότητα που θα αποτελέσει την αφετηρία για μια λειτουργία “on/off”, σε μοριακό επίπεδο. Υποψήφια μόρια που μπορούν να υποστηρίξουν μια διακοπτική λειτουργία είναι εκείνα που παρουσιάζουν κάτω από ορισμένες συνθήκες αλλαγή σε μια εγγενή ιδιότητά τους, όπως ο φθορισμός, η αγωγιμότητα, η μαγνήτιση, ο στερεο-ισομερισμός, η μη γραμμικότητα κ.α. Σκοπός της παρούσας ειδικής ερευνητικής εργασίας ήταν ο προσδιορισμός της τρίτης τάξης μη γραμμικής οπτικής απόκρισης μοριακών συστημάτων που περιέχουν αζοβενζόλιο, υπό μορφή διαλυμάτων. Τα μόρια αυτά είναι ενδιαφέροντα γιατί αφ’ ενός εμφανίζουν trans/cis ισομερισμό, αφ’ ετέρου παρουσιάζουν μια αλλαγή στη μη γραμμικότητά τους εξαιτίας του φωτο-ισομερισμού του διπλού δεσμού –N=N-. Η δομή της εργασίας έχει ως εξής : Στο πρώτο κεφάλαιο θα γίνει μια περιγραφή της μη γραμμικής αλληλεπίδρασης ύλης-πεδίου, η εξαγωγή της μη γραμμικής κυματικής εξίσωσης, καθώς επίσης και μερικών φυσικών διαδικασιών που περιγράφονται μέσω αυτής. Στο δεύτερο κεφάλαιο θα περιγραφεί η πειραματική τεχνική που ακολουθήθηκε, θα αναφερθούν οι οπτικές παράμετροι που σχετίζονται με τη τρίτης τάξης μη γραμμικότητα και τέλος θα περιγραφεί η διαδικασία ανάλυσης των πειραματικών αποτελεσμάτων. Στο τρίτο κεφάλαιο θα γίνει μια σύντομη περιγραφή της πειραματικής διάταξης καθώς και των κυριότερων οργάνων που την αποτελούν. Στο τέταρτο κεφάλαιο θα παρουσιασθούν τα πειραματικά αποτελέσματα που προέκυψαν από την εργασία. Αρχικά παρουσιάζεται μια σύντομη περιγραφή των μοριακών συστημάτων που μελετήθηκαν. Ακολουθεί η μη γραμμική οπτική απόκριση των συστημάτων για διέγερση με παλμούς χρονικής διάρκειας 35 ps, στα 532 και 1064 nm,και ακολουθεί ο προσδιορισμός της μη μεταβατικής μη γραμμικής απόκρισης για διέγερση με παλμούς διάρκειας 4 ns. Αναφέρονται τα συμπεράσματα από τη μελέτη των συστημάτων και ακολουθεί μια πρόταση για μελλοντική μελέτη.
Extensive research in the field of molecular switches promises a wide variety of switching mechanisms characterized by an eclectic range of intrinsic properties regarding their luminescence, conductivity, magnetic and optical outputs. Because of their controlled alternating properties and the ease of their preparation and modification, molecular switches hold the promise of becoming pivotal components of organic–integrated photonic devices. Among the many available systems, azobenzene dyes represent a particularly promising class of organic switchable materials. The advantage of azobenzene chromophores as molecular switches is based not only on the large geometrical change accompanying the cis–trans isomerization, but also on their photo–stability, and the ease of their preparation and derivatization. In addition, azobenzene chromophores, exhibiting in general large nonlinear optical response, are characterized by an important change in their third-order nonlinear optical response due to the photo-isomerization of the –N=N- double bond. The purpose of this work is hence to describe how the NLO properties of the azobenzene are influenced when surrounded by an always more electron-donating and conjugated environment. In order to do so, we are studying three azobenzene-centered molecules. In two of them, the switch is bonded to two electron-rich groups such as alkylated anilines via either one or two ethynil spacers. In the latter, a Zn-porphyrin was instead linked to the aza-core. The insertion of a porphyrin core was driven by its high polarizability and optical oscillator strength which gives the material remarkable NLO behavior, making it potentially useful for ultra-fast switching technologies. In that view, the nonlinear optical response of these novel azobenzene based molecules dissolved in dichloromethane are studied by means of Z-scan technique using 35 ps laser pulses at 532 and 1064 nm. From the measurements, the nonlinear absorption and refraction and the corresponding third-order susceptibility χ(3) and second hyperpolarizability are determined.
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