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Bonnyman, J. I. "A neural network mapping of L.P.C. coefficients for quality speech synthesis." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282690.
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Srivastava, Saurabh. "Crop coefficients and water quality for watermelon and bell pepper under drip and seepage irrigation." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010468.
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Larsson, Alm Kevin. "Automatic Speech Quality Assessment in Unified Communication : A Case Study." Thesis, Linköpings universitet, Programvara och system, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-159794.
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Speech as a medium for communication has always been important in its ability to convey our ideas, personality and emotions. It is therefore not strange that Quality of Experience (QoE) becomes central to any business relying on voice communication. Using Unified Communication (UC) systems, users can communicate with each other in several ways using many different devices, making QoE an important aspect for such systems. For this thesis, automatic methods for assessing speech quality of the voice calls in Briteback’s UC application is studied, including a comparison of the researched methods. Three methods all using a Gaussian Mixture Model (GMM) as a regressor, paired with extraction of Human Factor Cepstral Coefficients (HFCC), Gammatone Frequency Cepstral Coefficients (GFCC) and Modified Mel Frequency Cepstrum Coefficients (MMFCC) features respectively is studied. The method based on HFCC feature extraction shows better performance in general compared to the two other methods, but all methods show comparatively low performance compared to literature. This most likely stems from implementation errors, showing the difference between theory and practice in the literature, together with the lack of reference implementations. Further work with practical aspects in mind, such as reference implementations or verification tools can make the field more popular and increase its use in the real world.
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Andrade, Caroline Piffer de. "Remote sensing of chlorophyll-a concentration based on absorption coefficients in Ibitinga reservoir." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153807.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O presente estudo objetivou estimar as concentrações de clorofila-a (Chl-a) no reservatório da usina hidroelétrica de Ibitinga (RHI), localizado no Rio Tietê, estado de São Paulo, Brasil, por meio de coeficientes de absorção obtidos via algoritmos quase-analíticos (QAAs). Para isso, realizou-se uma caracterização bio-ótica e biogeoquímica do RHI, por meio de dados espectrais e de qualidade da água coletados em dois trabalhos de campo, conduzidos em Julho de 2016 e Junho de 2017. Os desempenhos das versões originais QAAV5 e QAAV6 em estimar as propriedades óticas inerentes (POIs) no RHI foram avaliados. Versões re-parametrizadas para dois reservatórios localizados no sistema em cascata do Rio Tietê, QAABBHR e QAAOMW, foram também testadas para a área de estudo. Além disso, foram avaliadas as performances de esquemas compostos pelas versões do QAA já mencionadas, seguidas por quatro modelos para estimativa de Chl-a, os quais utilizam coeficientes de absorção como dados de entrada. A distribuição espacial das concentrações de Chl-a foi analisada por meio da aplicação desses esquemas em uma imagem do sensor Ocean and Land Colour Instrument (OLCI) instalado a bordo do satélite Sentinel-3A, com aquisição coincidente com o segundo trabalho de campo realizado na área de estudo. A caracterização bio-ótica demonstrou variabilidade espacial e temporal dos constituintes oticamente significativos (COSs) no RHI, com predominância da absorção pelo material orgânico colorido dissolvido (CDOM). As versões do QAA testadas para o primeiro conjunto de dados não se mostraram completamente adequadas na obtenção de coeficientes de absorção em todos os comprimentos de onda. Com relação aos esquemas para estimativa de concentração de Chl-a, apenas aqueles baseados no QAAV5 foram capazes de obter resultados razoáveis - Raiz do Erro Médio Quadrático Normalizado (REMQN) < 47.50 % - para os dados da imagem OLCI. Todos os quatro modelos para estimativa de Chl-a testados apresentaram resultados similares para os dados de saída do QAAV5. Esses resultados enfatizam o desafio gerado pela grande variabilidade ótica dos sistemas em cascata, com relação à modelagem bio-óptica. Os resultados obtidos dão suporte a futuros trabalhos, os quais podem resultar em aplicações como o monitoramento do estado trófico na área de estudo a partir de dados de satélite, com maior acurácia proveniente do uso de modelos que possam estimar consistentemente suas POIs.
This research was aimed at retrieving chlorophyll-a (Chl-a) concentrations in Ibitinga Hydroelectric Reservoir (IHR), located at Tietê River, São Paulo State, Brazil, using absorption coefficients obtained via Quasi-analytical algorithms (QAAs). For this purpose, a bio-optical and bio-geochemical characterization of IHR was carried out, through spectral and water quality data collected in two field campaigns conducted in July, 2016 and June, 2017. The suitability of two QAA native forms (QAAV5 and QAAV6) in retrieving inherent optical properties (IOPs) in IHR was assessed. Versions re-parameterized for two reservoirs also located in the Tietê River cascading system, QAABBHR and QAAOMW, were also tested for the study area. Besides that, the performances of schemes composed by the QAA versions already mentioned followed by four models that use absorption coefficients as inputs for estimating Chl-a concentration in Ibitinga Reservoir were evaluated. Spatial distribution of Chl-a in the reservoir was analyzed, since these schemes were applied in an image of the Ocean and Land Colour Instrument (OLCI) sensor onboard Sentinel-3A satellite, with acquisition date coincident with the second field campaign. The bio-optical characterization showed spatial and temporal variability of optically significant constituent (OSC) in IHR and colored dissolved organic matter (CDOM) predominance in its absorption budget. None of the QAA versions tested for the first dataset was completely satisfactory in retrieving absorption coefficients for IHR in all wavelengths. Regarding the schemes for Chl-a concentration estimates, only the ones based on QAAV5 were able to obtain reasonable results - Normalized Root Mean Square Error (nRMSE) < 47.50 % - for the OLCI image data. All four models for Chl-a estimation tested presented similar results for QAAV5 outputs. These results highlight the challenge of copying with high optical variability in cascading systems. The results obtained support further works, which can, prospectively, lead to many practical applications, as monitoring of trophic state in the study area from satellite data, with higher accuracy provided by the use of models that can consistently retrieve the IOPs for this specific water system.
FAPESP: 2012/19821-1 e 2015/21586-9
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Gallina, Rubens. "Caractérisation du matériau quartz en vue de la réalisation des résonateurs : traitement permettant d'améliorer sa qualité." Besançon, 1995. http://www.theses.fr/1995BESA2027.
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Notre premier but est de rechercher les moyens de caractériser le quartz naturel en vue de sa sélection pour des applications piézoélectriques. Une sélection objective impose de recourir à des mesures de quantités qui soient en relation avec la qualité attendue du matériau et qui puissent constituer un bon indicateur. Après un bref rappel sur la structure du quartz, les conventions utilisées pour décrire ses propriétés et les différentes classifications définies. Nous faisons une synthèse des différents défauts et des impuretés que l'on rencontre dans le quartz. Nous examinons ensuite l'ensemble des coefficients, linéaires et non linéaires, qui permettent de décrire ses propriétés et à partir des données existantes nous proposons un choix pour ceux qui peuvent servir d'indicateur de la qualité du matériau. Nous décrivons un ensemble de mesure simple dérivé de celui de Lamb et Richter, permettant la mesure de l'atténuation des ondes élastiques dans le quartz. Et avec lequel nous avons réalisé la mesure de certains coefficients viscoélastiques. La seconde partie est consacrée à l'étude de la réduction de la densité des "canaux d'attaque chimique" du quartz. La formation de ceux-ci est liée aux dislocations et aux impuretés. Nous nous sommes intéressé essentiellement au traitement par recuit des ébauches de résonateurs, avec éventuellement application d'un champ électrique (traitement par électrodiffusion). Nous en avons conclu que la température seule jouait un rôle primordialOur first aim is to investigate the means to characterize the natural quartz for a selection to piezoelectric applications. After a short overview of quartz lattice, the conventions used to describe quartz properties and his different classifications, we make a brief review of different defects and impurities which we find in quartz crystals. We examine the set of the coefficients, linear and nonlinear, which can describe the properties of the quartz and for which datas are available. We propose to choose the coefficients that can be used as indicators of the material quality. We describe an experimental arrangement derived from that of Lamb and Richter, which with we can measure the elastic waves attenuation in the quartz. We realised the measurements of some viscoelastic coefficients. The second part of this memory is devoted to the study of density reduction of etch-channels in quartz. The formation of etch-channels is linked to dislocations and impurities. We are interested essentialy in the treatement of the resonators by heating, with eventualy electric field application (electrodiffusion treatemerit). We found that the temperature is the main parameter
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Le, Floch Jean-Michel. "Modélisation de nouveaux résonateurs diélectriques à fort coefficient de qualité pour des applications de métrologie." Limoges, 2007. https://aurore.unilim.fr/theses/nxfile/default/dce4dfe5-e130-4125-a6e3-283544f6daa0/blobholder:0/2007LIMO4059.pdf.
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Ces travaux de recherche s’inscrivent dans le cadre de l’utilisation des résonateurs diélectriques à fort coefficient de qualité pour des applications de test de physique fondamentale et de métrologie. Les progrès technologiques récents dans la fabrication de nouveaux matériaux diélectriques ont permis l’utilisation de résonateurs diélectriques dans de nouvelles applications. Ainsi, un nouvel outil de simulation électromagnétique, utilisant la méthode des lignes, est décrit dans le premier chapitre, afin de caractériser ces structures résonantes. Dans les chapitres 3 et 4, deux applications de résonateurs diélectriques à effet Bragg dans deux topologies différentes sont présentées. Dans un cinquième chapitre, un logiciel en C++ pour l’acquisition automatique des données par port GPIB est présenté. Le sixième chapitre est consacré au résonateur diélectrique sphérique à mode de galerie pour une application de filtrage et de test de physique fondamentale. Le septième et dernier chapitre est dédié à la mesure de la stabilité d’un oscillateur bi-mode à température ambianteThese research works have been done in order to use high-Q dielectric resonators for tests of fundamental Physics and metrology applications. Recent technical improvements in the manufacturing of new dielectric materials allowed them to be introduced into new applications. Thus, a new electromagnetic simulation tool, using the Method of Lines, is described in the first chapter in order to characterize resonant structures. In the chapters 3 and 4, two applications of dielectric resonators using Bragg effect in two different topologies has been presented. In a fifth chapter, a program in C++ for automatic data acquisition by GPIB has been presented. The sixth chapter is devoted to a spherical dielectric resonator using whispering galerie mode to be used as a filter and to participate for a Michelson-Morley experiment (Test of Fundamental Physics). The seventh chapter is dedicated to a stability measurement of a dual mode oscillator at room temperature
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Si-Ahmed, Chérif. "Contribution à l'étude du coefficient de qualité dans une chambre réverbérante à brassage de modes." Lille 1, 2001. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2001/50376-2001-5.pdf.
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Edmonds, Jennifer Echols. "An Investigation of the Effectiveness of the Division of Corporate Finance as a Monitor of Financial Reporting." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/40437.
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This study uses the Securities and Exchange Commissionâ s (SEC) comment letters to investigate the SECâ s role as a monitor of financial reporting. I examine whether the SEC effectively comments on firms with poor disclosure quality. I utilize forward earnings response coefficients (FERC) as a measure of the marketâ s perception of disclosure quality. I expect comment letter firms to have lower disclosure quality and thus lower FERCs. Secondly, within the firms selected for comment, I investigate whether the Division allocates a greater amount of resources towards firms with more severe disclosure deficiencies. Results indicate that comment letter recipients have significantly lower forward earnings response coefficients than non- recipients. Results also document that comment letter recipients have lower contemporaneous earnings response coefficients than non-recipients. These findings are consistent with the DCF being effective in selecting firms that are perceived by the market as having low disclosure and earnings quality. However, within comment letter firms, I am unable to provide any evidence that the DCF allocates more resources to firms with lower forward earnings response coefficients.Ph. D.
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Amdouni, Asma. "Surveillance statistique du coefficient de variation dans un contexte de petites séries." Nantes, 2015. http://archive.bu.univ-nantes.fr/pollux/show.action?id=dcf36868-32b2-41d6-916b-f9533ee12902.
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La maîtrise statistique des procédés (MSP) est une méthode de contrôle de la qualité basée sur les statistiques. La surveillance du coefficient de variation est une approche efficace à la MSP lorsque la moyenne du processus µ et son écart type σ ne sont pas constants mais leur rapport est constant. Jusqu’à présent, les études portant sur la surveillance du coefficient de variation se sont limitées au cas d’une production avec un horizon infini. Cette thèse présente de nouvelles cartes de contrôle pour surveiller le coefficient de variation dans le contexte fini lorsque les paramètres sont connus : des cartes de contrôle séparées de type Shewhart, des cartes avec des règles supplémentaires et des cartes VSI et VSS. Les paramètres optimaux ont été systématiquement calculés et les performances de chacune de ces cartes ont été également évaluées en développant de nouvelles mesures statistique de performance appropriées dans un contexte de production à horizon fini. Une validation empirique des résultats a été élaborée pour des procédés industriels existantsStatistical Process Control (SPC) is a method of quality control based on statistics and used to monitor production. Monitoring the coefficient of variation is an effective approach to SPC when the process mean µ and standard deviation σ are not constant but their ratio is constant. Until now, research has not investigated the monitoring of the coefficient of variation for short production runs. Viewed under this perspective, in this thesis, we will propose new methods to monitor the coefficient of variation for a finite horizon production, we will investigate the properties (in terms of the Truncated Run Length) of some control charts for the coefficient of variation in a Short Run context in the case of known parameters, such as the one-sided Shewhart Chart, the Run Rules Chart, the VSI and VSS Charts. The performance of each control chart has been evaluated by developing statistical measures of performance appropriate in a Short Run context and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes
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Соболевський, Руслан Вадимович. "Управління якістю нерудних будівельних матеріалів на основі геостатистичного моделювання." Thesis, КПІ ім. Ігоря Сікорського, 2017. https://ela.kpi.ua/handle/123456789/19111.
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Дисертація присвячена вирішенню актуальної науково-практичної проблеми управління якістю нерудних будівельних матеріалів на основі геостатистичного моделювання для обґрунтування оптимальних технологічних рішень, яке полягає у встановленні залежностей природних та технологічних параметрів, які оцінюються інтегральними показниками якості реалізованими при геостатистичному моделюванні ефективності технологічних рішень. Доведено, що при селективному способі розробки родовищ нерудної будівельної сировини управління якістю необхідно здійснювати з врахуванням фрактальної природи показників якості, які визначаються за розробленими методиками. Вперше встановлені залежності між кількістю тріщин та азимутом простягання, між орієнтацією окремих систем тріщин, виділених за результатами кластерного аналізу, і оптимальним напрямком відколу для родовищ декоративного каменю, що може бути використано для прогнозування напрямку розвитку гірничих робіт та управління процесами видобування декоративного каменю. Встановлено, що ефективність процесу управління технологічними процесами при розробці декоративного каменю досягається за результатами оцінки геопросторової мінливості узагальнюючого показника фрактальної розмірності, який є функцією орієнтації тріщинуватості, лінійних розмірів тріщин та швидкості буріння тріщинуватого масиву. Вперше виділені групи родовищ нерудних будівельних матеріалів за геоструктурними показниками та фрактальною розмірністю роз тріщинуватості. Встановлено взаємозв’язок між геохімічними та геоструктурними показниками якості родовищ нерудних будівельних матеріалів та оцінено вплив їх просторової мінливості на ефективність селективного видобування нерудних будівельних матеріалів.The dissertation is devoted to solving the actual scientific and practical problem of quality management of nonmetallic building materials based on geostatistical modeling for grounding the optimal technological solutions that become apparent at the ascertainment of natural and technological parameters relationships which are assessed by integral quality coefficients realized at geostatistical modeling of the effectiveness of technological solutions. It is proved that when using the selective method of mining of non-metallic building materials, the quality management should be carried out taking into account the fractal nature of quality coefficients, which are determined by the developed methods. The relationship between the number of fractures and strike azimuth for ornamental stone deposits is first established, that can be used to predict the direction of mining development and management of ornamental stone extraction processes. As a result of the performed research into regularities of formation of fracturing of deposits of labradorite, we identified the main types of the samples describing the elements of occurrence, and formed the reference samples, the analysis of which allowed us to substantiate the optimal methods of cluster analysis for selecting the systems of fracturing. To predict the direction of development of mining and management of the processes of extraction of decorative stone, we obtained analytical expression of dependency of the quantity of cracks on the strike azimuth in the form of polynomial of the second degree. The relationship between the orientation of individual systems of fractures allocated according to the results of cluster analysis and optimal cleavage direction for gabbro rocks deposits is first established, that allow to develop the optimal method of the mining operations planning, taking into account the anisotropy of ornamental stone deposits properties. It is proved that for quality management and assessment of the prospects of deposits or block stone individual sections development, it is advisable to carry out the evaluation according to the number of fractures in the system that are selected by the results of fractures massif clustering and their dimensional orientation. For the estimation of prospects of development of deposits, or separate sections, we proposed the new cluster-geometric technique of determining the blockiness. In addition, the proposed technique makes it possible to estimate the probability of each of the obtained results, which significantly increases efficiency of risk assessment when designing mining works. It also allows increase in the degree of taking account of the genesis of fracturing and mutual angular correlations between the systems of fracturing, which provides for the possibility to increase the accuracy of assessment of quality of both entire deposit and its separate sections. The technique of fractal analysis of regularities in the fracturing formation for various deposits or their sections, which is based on the comparison of values of fractal dimensionality of the roses of fracturing, was developed. The groups of labradorite deposits were distinguished by index of fractal dimensionality, which allows developing standard technological solutions for each group in order to enhance the effectiveness of quality and productivity control over technological complexes. A map of spatial variability in fractal dimensionality of fracturing in the labradorite deposits of Ukraine was produced, the use of which will make it possible to increase efficiency of discovering new labradorite deposits, which will meet certain quality requirements. The construction of this map will allow enhancing efficiency of the interpretation of conditions for the formation of particular deposits. The patterns of change in fractal dimensionality at the different structural levels were established and the methods for their prediction were developed, which will make it possible, by the results of exploring fractal dimensionality at one of the structural level, to predict their values for others to optimize the process of control over geological exploration and extraction operations. As a result of the performed experimental studies, the influence of fractal dimensionality of fracturing in the blast-hole drilling zone on the productivity of the process was proved. We created objective function of optimal process to control technological processes, based on geostructural and technological indices that were evaluated by generalizing index of fractal dimensionality. The objective function of optimal process of drilling the fractured array, which includes indices of fractal dimensionality of the drilling zone, was proposed. For the first time the regularities of change of primary kaolin samples whiteness depending on the results of determination of colour coordinates, the fractal dimension of the sample surface, the size of scanned samples grains and fractal dimension of grains in the massif are established. For the first time the relationship between the geochemical and geostruсtural parameters of nonmetallic building materials deposits is established and the influence of their spatial variability on the effectiveness of selective extraction of nonmetallic building materials is assessed. Based on the first developed technological coefficient of the contact form, the influence of fractal dimension of conditioned areas contours on the productivity of excavation is established when using selective extraction of nonmetallic building materials. Cluster and fractal technique of determining the volumes, operational noncontact evaluation of spatial variability of quality indicators technique and the method of cluster and crigging averaging of raw materials quality are developed.
Диссертация посвящена решению актуальной научно-практической проблемы управления качеством нерудных строительных материалов на основе геостатистического моделирования для обоснования оптимальных технологических решений, которое заключается в установлении зависимостей природных и технологических параметров, которые оцениваются интегральными показателями качества, реализованными при геостатистическом моделировании эффективности технологических решений. Доказано, что при селективном способе разработки месторождений нерудного строительного сырья управление качеством необходимо осуществлять с учетом фрактальной природы показателей качества, которые определяются по разработанным методикам. Впервые установлены зависимости между количеством трещин и азимутом простирания, между ориентацией отдельных систем трещин, выделенных по результатам кластерного анализа, и оптимальным направлением откола для месторождений декоративного камня, что может быть использовано для прогнозирования направления развития горных работ и управления процессами добычи декоративного камня. Установлено, что эффективность процесса управления технологическими процессами при разработке декоративного камня достигается по результатам оценки геопространственной изменчивости обобщающего показателя фрактальной размерности, который является функцией ориентации трещиноватости, линейных размеров трещин и скорости бурения трещиноватого массива. Впервые выделены группы месторождений нерудных строительных материалов по геоструктурным показателям и фрактальной размерности роз трещиноватости. Установлена взаимосвязь между геохимическими и геоструктурными показателями качества месторождений нерудных строительных материалов и оценено влияние их пространственной изменчивости на эффективность селективной добычи нерудных строительных материалов.
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Aggarwal, Kajal. "Impact of preclinical PET scanner characteristics on the overall image quality." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAE028.
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La tomographie par émission de positrons (TEP) est l’une des techniques d’imagerie nucléaire utilisées dans les domaines de l’oncologie, de la cardiologie et de la neurologie en tant que modalité d’imagerie fonctionnelle. Au cours des trois dernières décennies, les progrès de la modalité PET et le développement de modèles animaux de maladies humaines ont conduit au développement de la technologie PET dédiée aux petits animaux. En raison de la différence de taille entre l’homme et la souris, les scanners pour petits animaux nécessitent une résolution spatiale améliorée. En raison de l’amélioration de la résolution spatiale, la taille du voxel diminue de manière significative, réduisant ainsi le nombre de signaux d’un voxel. Plus le nombre détecté est élevé, plus le rapport signal sur bruit (SNR) est élevé ; l’amélioration de l’efficacité de la détection joue donc également un rôle important. Notre objectif est d’étudier l’impact des caractéristiques du scanner PET sur la qualité globale de l’image. Pour ce faire, nous avons simulé quatre modèles de scanneurs différents. L’idée des conceptions de scanner sélectionnées dans cette thèse est d’ajouter progressivement une dimension supplémentaire dans la position estimée de l’interaction du photon gamma, c’est-à-dire en passant de la détection 2D à la détection 3D. Nous avons démontré qu’il était possible de découpler la résolution spatiale et l’efficacité de la détection, en améliorant les deux simultanément. En outre, nous avons caractérisé le fait que l’amélioration de la résolution spatiale entraîne l’amélioration du coefficient de récupération (RC). L’efficacité de la détection a un impact sur le RSB, ce qui a également un impact sur l’erreur estimée dans les valeurs de RC. Cependant, d’autres facteurs, tels que l’approche de reconstruction d’image et les corrections de normalisation, dégradent ces valeurs d’erreur. Il est donc important non seulement d’améliorer les paramètres de performance des scanners, mais également de mettre en œuvre avec précision le processus de reconstruction d’image, afin de quantifier correctement l’amélioration de la qualité de l’imagePositron Emission Tomography (PET) is one of the nuclear imaging techniques, used in the field of oncology, cardiology and neurology as a functional imaging modality. During the last three decades, advancement of PET modality and the development of animal models of human disease have lead to the development of PET technology dedicated to small animals. Due to the size difference between humans and mice, small animal scanners require improved spatial resolution. Due to the improved spatial resolution, the voxel size decreases significantly thereby, reducing the number of signals from a voxel. Higher the detected counts, higher the signal-to-noise ratio (SNR), thus improvement in the detection efficiency also plays an important role. Our objective is to study the impact of PET scanner characteristics on the overall image quality. To achieve this, we have simulated four different scanner designs. The idea behind the selected scanner designs studied in this thesis is to progressively add an extra dimension in the estimated position of interaction of the gamma photon, i.e., going from 2D detection to 3D detection. We demonstrated that it is possible to decouple the spatial resolution and detection efficiency, improving both simultaneously. Further, we characterized that improving spatial resolution results in improved Recovery Coefficient (RC). Detection efficiency impacts the SNR, which further impacts the estimated error in the RC values. However, there are other factors such as image reconstruction approach and normalization corrections that degrade these error values. Thus, it is important to not only improve the performance parameters of the scanners but also to accurately implement the image reconstruction process, so as to correctly quantify the improvement in the image quality
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Xu, Wei Jiang. "Etude par ondes acoustiques de la qualité des interfaces dans une structure multicouche." Valenciennes, 1995. https://ged.uphf.fr/nuxeo/site/esupversions/5afaca07-6a3e-43e0-af05-880ce3bbfa41.
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Dans l'industrie moderne, les structures multicouches comme les assemblages collés, les revêtements, les matériaux composites sont de plus en plus utilisées. Ces structures exigent de développer des méthodes d'analyse adaptées. Les méthodes ultrasonores conventionnelles permettent de détecter des défauts comme les inclusions, les porosités et les fissures, mais elles s'avèrent inefficaces pour la mesure de l'adhérence. Le but de ce travail a été d'établir une étude générale sur la modélisation de l'interface en introduisant des conditions aux limites variables, paramètres liés directement à l'adhérence. L'étude de la propagation des ondes dans les structures multicouches est menée en tenant compte de l'atténuation et sans restriction sur le nombre de couches ni la fréquence. Cette étude théorique est complétée par une partie expérimentale permettant de mettre en évidence les grandeurs à exploiter pour caractériser efficacement la qualité d'adhérence. Nous donnons les résultats théoriques et expérimentaux (25 a 500mhz) obtenus avec les ondes longitudinales et transversales sur les échantillons présentant différentes qualités de contact. Nous présentons les bases théoriques des v(z) ainsi que la méthode d'inversion de cette fonction pour obtenir l'évolution du coefficient de réflexion sur la structure multicouches. Le modèle écarte toutes les approximations classiques (rayons géométriques, faisceaux paraxiaux). Cette étude fondamentale a été validée expérimentalement sur plusieurs échantillons (substrat, plaques, multicouche).
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Balvay, Daniel. "Qualité de la modélisation en imagerie dynamique de la microcirculation avec injection d'un agent de contraste : nouveaux critères et applications en multimodalité." Paris 11, 2005. http://www.theses.fr/2005PA112147.
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L'imagerie dynamique de microcirculation dispose d'un potentiel important pour l'étude de nombreuses pathologies in vivo, en complément à l'imagerie conventionnelle. Or pour obtenir des cartes de paramètres microcirculatoires à partir des données dynamiques, une modélisation doit être effectuée. Les méthodes actuelles pour vérifier la qualité de cette modélisation n'étant pas satisfaisantes, le potentiel de l'imagerie dynamique en est fortement réduit. Nous montrons ici que pour étudier la modélisation, tant qualitativement que quantitativement, il est nécessaire de traiter séparément les questions de qualité d'ajustement et de robustesse,. Nous avons mis au point une nouvelle méthode, basée sur l'autocorrélation, pour estimer les amplitudes des composantes corrélées et non corrélées des signaux. Cette méthode nous a permis de corriger le coefficient de corrélation R² et la matrice de covariance, et ainsi de définir de nouveaux critères de fiabilité et une matrice de covariance corrigée pour les remplacer. L'amélioration apportée par les nouveaux critères est démontrée sur simulations et sur données IRM dynamiques réelles. La matrice de covariance corrigée estime la robustesse et la redondance locale des paramètres. Elle peut être calculée conjointement pour compléter les nouveaux critères de fiabilité. Les améliorations apportées par les nouveaux indicateurs doivent faciliter le développement de l'imagerie de la microcirculation. L'intérêt des nouveaux indicateurs est illustré sur un grand panel de données d'imagerie. Ils constituent plus généralement de nouveaux outils de traitement du signalThe microcirculation dynamic imaging could be a relevant imaging when used in addition with more conventional medical imaging. The dynamic data are modeled, pixel by pixel, to provide microcirculation parameters maps. However there is no efficient tool to assess the modeling quality. The relevance of the parametric maps provided by the dynamic imaging is then limited. Here, we show that a qualitative and quantitative study of the modeling quality needs first to distinguish two questions : the quality of the data fits and the robusness for the random noise. To separate the questions, we designed a new autocorrelation based method which is able to estimate the amplitude of both the correlated and not correlated component of a signal. This method allowed us to correct the correlation coefficient R² and the covariance matrix estimation. It allowed us to define new reliability criteria and a corrected covariance matrix to replace the more conventional indicators. It was shown, on simulated data and in MR data, that new reliabily criteria are obviously better than the R² to assess fit quality. The corrected covariance matrix which assess the robustness and the redoundancy can be calculated in addition to the reliability criteria unlike conventional one which is limited to good data fits. Thus the modeling quality is obviously improved by the new indicators. It should improve the clinical use of microcirculation dynamic imaging where guaranties are needed against artefact. The interest of the new criteria is showed on many different dynamic data. More generaly the new indicators appear as new efficient tools for signal analysis
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Urbánek, Pavel. "Komprese obrazu pomocí vlnkové transformace." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236385.
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This thesis is focused on subject of image compression using wavelet transform. The first part of this document provides reader with information about image compression, presents well known contemporary algorithms and looks into details of wavelet compression and following encoding schemes. Both JPEG and JPEG 2000 standards are introduced. Second part of this document analyzes and describes implementation of image compression tool including inovations and optimalizations. The third part is dedicated to comparison and evaluation of achievements.
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Akshaya, Devendra Kumar. "IMPACTS OF LAND USE/LAND COVER AND SOIL ON WATER QUALITY IN THE UPPER LITTLE MIAMI RIVER SUB-BASIN THE UPPER LITTLE MIAMI RIVER SUB-BASIN." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1334693369.
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Jedlička, Roman. "Effect of income inequality on quality of tertiary education: Should professors from Cambridge thank to Robin Hood?" Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-194206.
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Many factors influence quality of higher education. Current research mostly works with economic factors (GDP, higher education expenditures etc.). However, there are also publications that examine an impact of sociological aspects on quality of higher education. My research examined the impact of income inequality on quality of tertiary education. In the analysis of socioeconomic data of 76 countries I have proven that there is no linear relationship between income inequality and quality of tertiary education. According to my results the size of population, GDP per capita and being English speaking country are main drivers of quality of tertiary education. Modified model without outliers also shows that there is a positive effect of R&D expenditures on quality of tertiary education.
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Joint, Pierre Wickir. "Détermination des coefficients de dégradation du chlore libre en vue de la modélisation de la qualité de l'eau des réseaux de distribution d'eau potable." Mémoire, Université de Sherbrooke, 2005. http://savoirs.usherbrooke.ca/handle/11143/1309.
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À mesure que l'eau se déplace dans le système de distribution, elle subit des réactions physiques, chimiques et biologiques qui altèrent sa qualité. Ces réactions surviennent non seulement dans la masse liquide, mais encore au niveau de l'interface eau-paroi. Elles dépendent entres autres des conditions d'écoulement, du pH, de la température, de la composition chimique de l'eau et de la nature du matériau de la conduite. Pour contrôler la qualité de l'eau dans le système de distribution, il faut bien comprendre ces phénomènes et pouvoir les modéliser. L'objectif de cette étude est de comprendre la dégradation du chlore dans la masse liquide sur une portion du réseau de distribution de la ville de Sherbrooke, de déterminer des coefficients associés à cette dégradation, et ce en tenant compte qualitativement de la teneur en matières organiques, abstraction étant faite de tout autre paramètre temporaire ou saisonnier comme la température, le pH, etc. Pour chacune des quatre stations de chloration explorées, l'usine de filtration J. M. Jeanson, les postes de chloration J. S. Bourque, 18ème Avenue et Rue Raby, une vingtaine d'essais ont été réalisés à partir de la méthodologie préconisée par Powell et al. (2000) dans l'article Performance of Various Kinetic Models for Chlorine Decay. Les résultats de cette campagne d'investigation ont montré que les coefficients de dégradation du chlore diminuent avec le niveau de chloration et partant avec la teneur en matières organiques de l'eau. Les valeurs moyennes de 0,25 h[indice supérieur -1] ; 0,087 h[indice supérieur -1] ; 0,097 h[indice supérieur -1] ; 0,073 h[indice supérieur -1] ; 0,004 h[indice supérieur -1] obtenues respectivement pour l'usine de filtration J. M. Jeanson, les postes de chloration J. S. Bourque, 18ème Avenue, Rue Raby et l'eau distillée illustrent bien cette conclusion. Notre étude a montré aussi que les installations de stockage contribuent à diminuer les résiduels de chlore, c'est ce qui explique l'augmentation du coefficient de dégradation observé au niveau du poste de 18ème Avenue. Plusieurs modèles mathématiques permettant de prédire les concentrations résiduelles de chlore sont d'abord présentés dans ce travail. Une attention particulière a été accordée à EPANET, un modèle développé par Lewis A. Rossman de l'USEPA (United States Environmental Protection Agency) et largement utilisé à travers le monde. Ainsi, ce modèle est décrit en détails.
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Miralha, Lorrayne. "ACCOUNTING FOR SPATIAL AUTOCORRELATION IN MODELING THE DISTRIBUTION OF WATER QUALITY VARIABLES." UKnowledge, 2018. https://uknowledge.uky.edu/geography_etds/55.
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Several studies in hydrology have reported differences in outcomes between models in which spatial autocorrelation (SAC) is accounted for and those in which SAC is not. However, the capacity to predict the magnitude of such differences is still ambiguous. In this thesis, I hypothesized that SAC, inherently possessed by a response variable, influences spatial modeling outcomes. I selected ten watersheds in the USA and analyzed them to determine whether water quality variables with higher Moran’s I values undergo greater increases in the coefficient of determination (R²) and greater decreases in residual SAC (rSAC) after spatial modeling. I compared non-spatial ordinary least squares to two spatial regression approaches, namely, spatial lag and error models. The predictors were the principal components of topographic, land cover, and soil group variables. The results revealed that water quality variables with higher inherent SAC showed more substantial increases in R² and decreases in rSAC after performing spatial regressions. In this study, I found a generally linear relationship between the spatial model outcomes (R² and rSAC) and the degree of SAC in each water quality variable. I suggest that the inherent level of SAC in response variables can predict improvements in models before spatial regression is performed. The benefits of this study go beyond modeling selection and performance, it has the potential to uncover hydrologic connectivity patterns that can serve as insights to water quality managers and policy makers.
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Joint, Pierre Wickir. "Détermination des coefficients de dégradation du chlore libre en vue de la modélisation de la qualité de l'eau des réseaux de distribution d'eau potable." [S.l. : s.n.], 2005.
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Palandro, David A. "Coral reef habitat change and water clarity assessment (1984-2002) for the Florida Keys national marine sanctuary using landsat satellite data." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001778.
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Kropáčová, Lucie. "Návrh na snížení zákaznických reklamací." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2016. http://www.nusl.cz/ntk/nusl-234826.
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The master’s thesis is focused on evaluation of present process of managment of complaints in particular company in 2014. The evaluation is made by quality managment tools and with using correlation analysis. On the basis of acquired pieces of information there will be suggest corrective measures. These correctives measures will lead to improvement of managment process of complaints and reduce customer complaints.
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Makich, Hamid. "Etude théorique et expérimentale de l'usure des outils de découpe : influence sur la qualité des pièces décooupées." Phd thesis, Université de Franche-Comté, 2011. http://tel.archives-ouvertes.fr/tel-01068646.
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La qualité des pièces découpées pour les industries électroniques et micromécaniques est appréciée via trois critères principaux : le niveau de bavure, l'aspect du bord découpé et la précision dimensionnelle. Or, l'étude de la qualité des pièces découpées ne peut se faire sans une compréhension de l'usure des poinçons. Ainsi, des méthodes de mesure en continu et in situ de l'usure ont été mises au point et validées, soit l'activation superficielle et la mesure par double réplique. Ainsi, il a été possible de suivre l'influence d'un certain nombre de paramètres du procédé sur l'évolution de l'usure lors du découpage. Par ailleurs, nous avons mis au point une méthode de quantification de la bavure sur la totalité du contour découpé. Il a ainsi été possible d'étudier l'évolution de la bavure au cours de la découpe. L'aspect des bords découpés a été examiné grâce à des relevés topographiques permettant le suivi de son évolution. Ainsi, une corrélation entre la cinétique d'usure des poinçons et l'apparition de la bavure a été établi. De plus, une simulation expérimentale de l'usure des poinçons a été entreprise. Un dispositif expérimental de tribométrie a été conçu et installé sur la ligne de presse, simulant les conditions de frottement d'un poinçon sur une tôle. Il a permis d'évaluer l'abrasivité des tôlesminces vis-à-vis des poinçons. Par ailleurs, une modélisation numérique de l'opération de découpage par éléments finis a été entreprise, permettant d'approcher le profil d'usure d'un poinçon de géométrie cylindrique. Et par conséquent la possibilité de prédire son évolution en fonction du nombre de pièces découpées devient accessible en fonction des paramètres du procédé
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Vasiljevas, Artūras. "Eksperimentinio akrobatinio lėktuvo skrydžio analizė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130621_150246-07379.
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Baigiamajame magistro darbe nagrinėjamos būsimo eksperimentinio akrobatinio lėktuvo aerodinaminės savybės. Pristatomos tokio pobūdžio sritys (temos), kaip tinkamo sparno profilio parinkimas orlaiviui, reikalingo sparno formos apibrėžimas, sparno būsimos charakteristikos ir parametrų apskaičiavimas, kitų orlaivio dalių ir jų įtakos visai lėktuvo dinamikai analizavimas. Kadangi analizuojamas dvivietis eksperimentinis akrobatinis lėktuvas, tikintis geresnių rodiklių, pasirinktas palyginimo objektas dvivietis akrobatinis mokomasis lėktuvas SU 29. Remiantis šio lėktuvo esamomis charakteristikomis ir parametrais, pateikiamos išvados ir siūlymai.The thesis examines the aerodynamics of future experimental aerobatic aircraft. Featured in such areas (topics): proper selection of an aircraft wing profile, the required form of the wing, the wing's future performance and parameter estimation, other aircraft parts and their impact on the entire plane dynamics analysis. As analyzed double seated, experimental aerobatic plane in the hope of better indicators selected comparison object double seated acrobatic training plane SU 29. Based on the existing aircraft characteristics and parameters, the conclusions and recommendations will be made.
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Silva, Elcides Rodrigues da. "Uniformidade de distribuição de água em irrigação localizada com sistema de aeração, decantação e filtragem /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/96906.
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Resumo: A pesquisa teve como objetivo avaliar o desempenho de um sistema de aeração, decantação e filtragem, quanto à prevenção de entupimento dos emissores e avaliar uniformidade de distribuição da água no sistema de irrigação por gotejamento na época de sua implantação e após um ano de utilização do sistema de prevenção. O trabalho foi realizado na Fazenda Estância Tropical, no município de Barretos - SP, no período de março de 2008 a fevereiro de 2009, realizando-se determinações físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, que foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Todas as variáveis analisadas diferenciaram a qualidade da água entre os pontos de amostragem do sistema de tratamento, com exceção do Fe+2. Para sólidos em suspensão, turbidez, sólidos dissolvidos e ferro total, os valores reduziram-se pelo uso do sistema proposto, melhorando a qualidade da água. Após um ano de funcionamento do sistema de prevenção, os coeficientes utilizados para determinar a uniformidade de distribuição de água apresentaram valores acima de 80%, sendo classificados como excelente, bom e muito bomAbstract: The research aimed to evaluate the performance of aeration, sedimentation and filtration system for the prevention of emitters clogging and evaluate the water distribution uniformity of one drip irrigation system at the time of its implementation and after a year using the prevention system. The research was conducted in the Estancia Tropical farm, in the municipality of Barretos - SP, Brazil, from March 2008 to February 2009, carrying out physical and chemical determinations of water along the aeration, sedimentation and filtration system, which was efficient for improving water quality by reducing levels of risk of clogging of severe to medium and medium to low. All variables differed water quality between the collection points of the treatment system with the exception of Fe+2. For suspended solids, turbidity, dissolved solids and total iron values were reduced by the use of the proposed system, improving water quality. After a year of prevention, the coefficients used to determine the uniformity of water distribution had values above 80%, being classified as excellent, good and very good
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Mestre
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Mazet, Stéphane. "Conception et réalisation d'oscillateurs contrôlés en tension à faible bruit de phase pour des systèmes de télécommunications spatiales." Limoges, 2003. http://www.theses.fr/2003LIMO0035.
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Bent, Denzil. "A comparison of Brine evaporation rates under controlled conditions in a laboratory." University of the Western Cape, 2018. http://hdl.handle.net/11394/6443.
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Magister Scientiae - MSc (Environ & Water Science)There are growing concerns around the environmental issues related to processed water as the demand for potable water is on the increase in South Africa. Effluents discharged from various sectors such as water treatment facilities pose a constant threat to the environment and natural water resources, including rivers and groundwater due to their poor chemical and physical composition. As a result, the demand for predicting the elevated concentrations of salts in a spatial and temporal dimension is constantly growing. The effluent at the eMalahleni water reclamation plant in Mpumalanga, South Africa, is being processed through a triple reverse osmosis that improves the water quality of the mine water to potable standards. Two water quality streams emerge from this process, i.e. a potable standard and the other a brine concentrate which is stored in ponds. Brine ponds are used for inland brine disposal in the eMalahleni water reclamation plant. The large volumes and limited capacity to store brines has placed great emphasis on enhanced evaporation rates to increase the efficiency of the ponds. In order to improve the rate of brine evaporation in the pond, an understanding of the effect of brine salt content and other parameters affecting the rate of evaporation is required. This study aimed at establishing the physical and chemical behaviour of the brine from the eMalahleni plant in a controlled environment. The investigation incorporated actual brine from the eMalahleni plant as well as synthetic salts typical of the major components of the eMalahleni brine.
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Duchiron, Guillaume. "Analyse et conception de résonateurs saphir à modes de galerie pour des applications de métrologie et de filtrage microondes." Limoges, 2001. http://www.theses.fr/2001LIMO0049.
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Ce mémoire est dédié à l'analyse et la conception de résonateurs saphir à modes de galerie. Ces études concernent deux applications différentes. La première application s'inscrit dans le cadre du programme d'horloge atomique PHARAO. Cette horloge nécessite aujourd'hui la mise au point d'une source d'interrogation à 9,2 GHz présentant des performances de bruit de phase et de stabilité de fréquence exceptionnelles. Les divers résultats publiés à ce jour montrent que de telles performances pourraient être obtenues directement avec des oscillateurs utilisant des résonateurs saphir à modes de galerie caractérisés par des coefficients de qualité à vide largement supérieurs à la normale. Cependant, ces résonateurs présentent quelques inconvénients parmi lesquels une forte densité de modes parasites autour du mode référence et une grande sensibilité à la température de la fréquence de résonance. Ces deux inconvénients majeurs nous ont donc amené à développer de nouvelles topologies de résonateurs saphir à mode de galerie. Dans un premier temps, afin de supprimer les modes parasites, nous avons mis au point une technique de sélection modale qui consiste à insérer des vis métalliques dans la structure. Cette technique, qui fonctionne bien à température ambiante, présente quelques limites à T=77K. En effet, à cette température, le facteur de qualité du résonateur est détérioré par les pertes ohmiques engendrées par les vis d'une part, et par le blindage d'autre part. Aussi, afin de contourner cette limitation, nous avons inséré dans le résonateur cryogénique des films supraconducteurs HTcThis thesis is devoted to the study of whispering gallery mode sapphire resonators and to the optimisation of their performances for two distinct applications. The first application is a metrological application for atomic clock PHARAO project. The second topic presented is the realisation of microwave ilters for industrial space applications
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Arlot, Fabrice. "Modélisation des transistors bipolaires à hétérojonction : Application à la réalisation d'un oscillateur en bande X à faible bruit de phase dans le cadre du projet PHARAO." Limoges, 2002. http://www.theses.fr/2002LIMO0011.
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Ce mémoire est consacré à la modélisation non-linéaire du TBH, appliquée à la réalisation d'un oscillateur en bande X à faible bruit de phase dans le cadre du projet PHARAO. Ce travail permet de dégager les paramètres influant sur le bruit de phase et établit une méthode de conception permettant d'obtenir le minimum de bruit de phase dans les oscillateurs. Le premier chapitre donne un descriptif du fonctionnement du transistor bipolaire et identifie les avantages et inconvénients des différentes familles de TBH par rapport aux transistors à effet de champ afin de confirmer les potentialités du TBH pour les applications microondes. Le second chapitre est alors consacré à la présentation d'un modèle non-linéaire, non-quasi-statique et électro-thermique du TBH. Les différentes étapes permettant de l'obtenir, ainsi que sa validation à travers plusieurs mesures sont présentées. Dans le troisième chapitre, nous présentons la méthodologie de conception d'un oscillateur TBH à faible bruit de phase. La réalisation d'une maquette d'oscillateur sur table, fonctionnant à 9. 2 GHz et s'inscrivant dans le cadre du projet PHARAO financé par le CNES constitue l'aboutissement de ce travailThis research work is dedicated to HBT non linear modeling, applied to optimal design mothod for minimal phase noise in X-Band oscillators for PHARAO project
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Morais, James. "Uniformidade de irrigação por gotejamento usando efluente tratado de abatedouro de aves." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3275.
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The processes that take part of poultry slaughter are responsible for a great amount of water consumption and, consequently, a generation of large volumes of wastewater, which are usually disposed on soil without any control of uniformity regarding its distribution. Thus, this study aimed at evaluating a drip irrigation system, applied to dispose treated poultry slaughterhouse effluent on soil, using three effluent application rates of 100, 200 and 300 m³ ha-1 day-1. Besides the irrigation system, the effluent quality was also evaluated according to its physical-chemical characteristics. The evaluation of the results was given by the following coefficients: Christiansen Uniformity (CUC), Uniform Distribution (UDC), the Statistical Uniformity Coefficient (SUC) as well as quality control techniques. This trial was carried out in an eucalyptus reforestation area from the Industrial Poultry Slaughterhouse of Lar Agroindustrial Cooperative, in Matelândia city, PR. According to data obtained in this research, it was concluded that drip irrigation system, using the proposed rates, can be considered adequate, since it has shown uniformity in distribution of flows, pH and electrical conductivity. For pH and electrical conductivity, all the evaluated uniformity coefficients, CUC, UDC and SUC, were estimated in more than 90% and considered excellent. For the flow rates, all the coefficients were estimated as superior to 90% for 100 m³ ha-1 day-1 treatment and above 80% for treatments of 200 and 300 m³ ha-1 day-1. Usually, the distributions showed the highest coefficient of uniformity for the three parameters evaluated in the three studied treatments, for the highest tested rate of application. Regarding the effluent characterization, it was concluded that its main characteristics are the concentrations of nitrogen, phosphorus and carbon. And during the experiment, the industry kept the standards of disposal in the environment, which were determined by the environmental agencies. Finally, it was concluded that the statistical process control is adequate to evaluate the effluents as well as irrigation uniformity in tests area.
Os processos inerentes ao abate de aves respondem por um grande consumo de água e, consequentemente, a geração de grandes volumes de efluentes que, em geral, são dispostos no solo sem qualquer controle de uniformidade sobre a distribuição. Assim, o objetivo deste estudo foi avaliar um sistema de irrigação por gotejamento, aplicado à disposição de efluente tratado de abatedouro de aves no solo, utilizando três taxas de aplicação de efluente: 100, 200 e 300 m³ ha-1 dia-1. Além do sistema de irrigação, a qualidade do efluente também foi avaliada em função das características físico-químicas. A avaliação dos resultados foi dada pelos Coeficientes de Uniformidade de Christiansen (CUC), de Uniformidade de Distribuição (CUD), de Uniformidade Estatístico (CUE), bem como pelas técnicas de controle de qualidade. O experimento foi realizado na área de reflorestamento com eucalipto da Unidade Industrial de Aves da Lar Cooperativa Agroindustrial, em Matelândia, PR. De acordo com os dados obtidos neste trabalho, concluiu-se que o sistema de irrigação por gotejamento, utilizando-se as taxas propostas, pode ser considerado apropriado, pois apresentou uniformidade na distribuição das vazões, do pH e da condutividade elétrica. Para o pH e a condutividade elétrica, todos os coeficientes de uniformidade avaliados, CUC, CUD e CUE, foram estimados em mais de 90%, considerados excelentes. Para as vazões, todos os coeficientes foram estimados acima dos 90% para o tratamento de 100 m³ ha-1 dia-1 e acima dos 80% para os tratamentos de 200 e 300 m³ ha-1 dia-1. Em geral, as distribuições apresentaram maior coeficiente de uniformidade, para os três parâmetros avaliados, nos três tratamentos, para a maior taxa de aplicação testada. Em relação à caracterização do efluente, concluiu-se que suas principais características são as concentrações de nitrogênio, fósforo e carbono. E, durante o experimento, a indústria manteve os padrões de lançamento no ambiente, determinados pelos órgãos ambientais. Por fim, concluiu-se que o controle estatístico de processo é adequado à avaliação, tanto de efluentes quanto de uniformidade na irrigação, em testes a campo.
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Silva, Elcides Rodrigues da [UNESP]. "Uniformidade de distribuição de água em irrigação localizada com sistema de aeração, decantação e filtragem." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/96906.
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silva_er_me_jabo.pdf: 2805002 bytes, checksum: 1edb5322d15c1af6d99d144fbc53004c (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A pesquisa teve como objetivo avaliar o desempenho de um sistema de aeração, decantação e filtragem, quanto à prevenção de entupimento dos emissores e avaliar uniformidade de distribuição da água no sistema de irrigação por gotejamento na época de sua implantação e após um ano de utilização do sistema de prevenção. O trabalho foi realizado na Fazenda Estância Tropical, no município de Barretos – SP, no período de março de 2008 a fevereiro de 2009, realizando-se determinações físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, que foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Todas as variáveis analisadas diferenciaram a qualidade da água entre os pontos de amostragem do sistema de tratamento, com exceção do Fe+2. Para sólidos em suspensão, turbidez, sólidos dissolvidos e ferro total, os valores reduziram-se pelo uso do sistema proposto, melhorando a qualidade da água. Após um ano de funcionamento do sistema de prevenção, os coeficientes utilizados para determinar a uniformidade de distribuição de água apresentaram valores acima de 80%, sendo classificados como excelente, bom e muito bom
The research aimed to evaluate the performance of aeration, sedimentation and filtration system for the prevention of emitters clogging and evaluate the water distribution uniformity of one drip irrigation system at the time of its implementation and after a year using the prevention system. The research was conducted in the Estancia Tropical farm, in the municipality of Barretos – SP, Brazil, from March 2008 to February 2009, carrying out physical and chemical determinations of water along the aeration, sedimentation and filtration system, which was efficient for improving water quality by reducing levels of risk of clogging of severe to medium and medium to low. All variables differed water quality between the collection points of the treatment system with the exception of Fe+2. For suspended solids, turbidity, dissolved solids and total iron values were reduced by the use of the proposed system, improving water quality. After a year of prevention, the coefficients used to determine the uniformity of water distribution had values above 80%, being classified as excellent, good and very good
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Ávila, Lauren Cortezia. "Modelagem da qualidade da água utilizando coeficientes bibliográficos e experimentais - aplicação ao Rio Vacacaí Mirim." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/7852.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe use of the coefficient of reaeration and quantification of atmospheric reaeration templates for use in process water quality and can be determined by various methods or determined experimentally using formulas that describe the behavior of flow through its hydraulic system. The Approximate Delta method is a experimental method of the simple application. Mathematical models of water quality are instruments developed to assist in problem solving, however their use depends on experimental results. This research aimed to evaluate the importance of experimental determination of kinetic parameters, surface reaeration coefficient K2, in modeling of water quality of the river Vacacaí Mirim. To calculate the coefficient of reaeration, Delta Approximate method, used in the experiments, it was shown a technique to obtain easy field data, simple calculations and experimental apparatus with a low cost. However, this method has limitations in the calculation in places with sewage dumps, as was observed in the data obtained from monitoring points 1 and 2. In these places, in urban areas, there is the discharge of untreated wastewater into the river Vacacaí Mirim modifying the values of dissolved oxygen and causing a wobble in her bow. In monitoring point 3, where there is no presence of inflow of sewage into the river, the Delta Approximate method showed very favorable and consistent results. Obtaining the coefficient of reaeration through calculations of equations proposed in the literature and by the model QUAL2E exhibited large variations in their responses, confirming the claim limitation of using them for obtaining K2, being restricted to using these equations where been developed. When comparing data reaeration coefficient between the experimental methodology by Delta Approximate method and the responses of the equations, it was found that the proposed Formentini (2010) resulted in good fits to the observed data. The information collected experimentally were used as input data in QUAL2E model for simulation of dissolved oxygen in the river Vacacaí Mirim. The QUAL2E model has proved to be an effective tool for obtaining OD in rivers.
O uso do coeficiente de reaeração é na quantificação do processo de reaeração atmosférica para utilização em modelos de qualidade da água e pode ser determinado através de diversos métodos de determinação experimental ou através de fórmulas que descrevem o comportamento do escoamento através de seu regime hidráulico. O método Delta Aproximado é um método experimental de simples aplicação. Os modelos matemáticos de qualidade da água são instrumentos desenvolvidos para auxiliar na solução de problemas, no entanto a sua utilização depende de resultados experimentais. Esta pesquisa objetivou-se avaliar a importância da determinação experimental do parâmetro cinético, coeficiente de reaeração superficial K2, na modelagem da qualidade da água do rio Vacacaí Mirim. Para o cálculo do coeficiente de reaeração, o método Delta Aproximado, usado nos experimentos, demonstrou-se uma técnica de fácil obtenção de dados a campo, de cálculos simples e com um aparato experimental de baixo custo. Porém, esse método possui limitação no cálculo em locais com despejos de esgoto, como foi observada nos dados obtidos dos pontos de monitoramento 1 e 2. Nesses locais, em áreas urbanas, nota-se o despejo de esgoto no rio Vacacaí Mirim modificando os valores de oxigênio dissolvido e provocando uma oscilação em sua curva. No ponto de monitoramento 3, onde não há presença de aporte de esgoto no rio, o método Delta Aproximado apresentou resultados bastante favoráveis e uniformes. A obtenção do coeficiente de reaeração através dos cálculos de equações propostas na literatura e pelo próprio modelo QUAL2E, apresentou grandes variações em suas respostas, confirmando a afirmativa de limitação do uso das mesmas para obtenção do K2, sendo essas equações restringidas ao uso onde foram desenvolvidas. Na comparação de dados de coeficiente de reaeração entre a metodologia experimental através do método Delta Aproximado e as respostas das equações, verificou-se que a proposta de Formentini (2010) resultou em bons ajustes com os dados observados. As informações coletadas experimentalmente foram usadas como dados de entrada no modelo QUAL2E para simulação do oxigênio dissolvido no rio Vacacaí Mirim. O modelo QUAL2E demonstrou-se uma ferramenta eficaz para obtenção do OD em rios.
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Tomal, Alessandra. "Estudo semianalítico da qualidade de imagem e dose em mamografia." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-04042011-145820/.
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Neste trabalho, foram desenvolvidos modelos semianalíticos para estudar os parâmetros de qualidade da imagem (contraste objeto, SC, e razão contraste-ruído, CNR) e a dose glandular normalizada (DgN ) em mamografia convencional e digital. As características de 161 amostras de tecidos mamários (coeficiente de atenuação linear e densidade) e os espectros de raios X mamográficos foram determinados experimentalmente, visando construir uma base de dados consistente destas grandezas para serem utilizadas nos modelos. Os coeficientes de atenuação linear foram determinados utilizando um feixe de raios X polienergético e um detector de Si(Li), e as densidades foram medidas utilizando o método da pesagem hidrostática. Os espectros de raios X de um equipamento industrial, que simula as qualidades de radiação de mamografia, foram medidos utilizando detectores de Si(Li), CdTe e SDD. A resposta de cada detector foi determinada por simulação Monte Carlo (MC). Os modelos semianalíticos desenvolvidos neste trabalho permitem calcular a deposição de energia na mama e no receptor de imagem, e foram utilizados para estudar o SC, a CNR e a DgN, para diferentes tipos de mama (espessura e glandularidade) e características do espectro incidente (combinação ânodo/filtro, potencial do tubo e camada semirredutora), bem como permitem avaliar a figura de mérito (FOM) em mamografia convencional e digital. Os resultados de coeficiente de atenuação e densidade para os diferentes grupos de tecidos mamários, mostram que os tecidos normais fibroglandulares e neoplásicos possuem características similares, enquanto tecidos normais adiposos apresentam menores valores destas grandezas. Os espectros medidos com cada detector, e devidamente corrigidos por suas respostas, mostram que os três tipos de detectores podem ser usados para determinar espectros mamográficos. Com base nos resultados de SC e CNR, foram estimados limites de detecção de nódulos em mamografia convencional e digital, que se mostraram similares entre si. Os resultados de SC, CNR e DgN obtidos também destacam a importância da escolha do modelo da mama e da base de dados de coeficiente de atenuação e espectros de raios X utilizados, uma vez que estes são responsáveis por uma grande variação nas grandezas estudadas. Além disso, os resultados de FOM mostram que, para mamas finas, a combinação Mo/Mo, tradicionalmente utilizada, apresenta o melhor desempenho, enquanto as combinações W/Rh e W/Ag são as mais indicadas para mamas espessas. Para mamas de espessuras médias, a melhor combinação depende da técnica utilizada (convencional ou digital). Finalmente, verificou-se que os modelos semianalíticos desenvolvidos permitem a obtenção de resultados de forma prática e rápida, com valores similares aos obtidos por simulação MC. Desta forma, estes modelos permitirão estudos futuros a respeito da otimização da mamografia, para outros tipos de mama e condições de irradiação.In this work, semianalytical models were developed to study the image quality parameters (subject contrast, SC, and contrast-to-noise ratio, CNR) and the normalized average glandular dose (DgN) in conventional and digital mammography. The characteristics of 161 breast tissue samples (linear attenuation coefficient and density), and the mammographic x-ray spectra were determined experimentally, aiming to establish a consistent experimental database of these quantities to be used in the models. The linear attenuation coefficients were determined using a polyenergetic x-ray beam and a Si(Li) detector, and the densities were measured using the buoyancy method. The x-ray spectra from an industrial equipment, which reproduces the mammographic qualities, were measured using Si(Li), CdTe and SDD detectors. The responses of the detectors were determined using Monte Carlo (MC) simulation. The semianalytical models developed in this work allow computing the energy deposited in the breast and in the image receptor, and they were employed to study the SC, CNR and DgN, for different types of breast (thickness and glandularity) and incident x-ray spectra (anode/filter combination, tube potential and half-value layer). These models also allow evaluating the figure of merit (FOM) for conventional and digital mammography. The results of attenuation coefficient and density for the tissues analyzed show similar characteristics for the normal fibroglandular and neoplasic breast tissues, while the adipose tissue presents lower values of these quantities. From the x-ray spectra obtained using each detector, and corrected by their respective responses, it is observed that the three types of detectors can be used to determine mammographic spectra. Detection limits for nodules were estimated from the results of SC and CNR, and they were similar for both cases. The results of SC, CNR and DgN also show the importance of the choice of the breast model, and of the database of attenuation coefficient of breast tissues and x-ray spectra, since they largely influence the studied quantities. Besides, the results for FOM show that, for thin breasts, the Mo/Mo spectrum exhibits the better performance, while the W/Rh and W/Ag spectra are recommended for thicker breasts. For average thickness breasts, the more indicated spectra depend on the employed technique (conventional or digital). Finally, it was verified that the semianalytical models developed in this work provided results in a fast and simple way, with a good agreement with those obtained by using MC simulation. Therefore, these models allow further studies, regarding optimization of mammography, for other breast characteristics and irradiation parameters.
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Філянін, Данило Володимирович. "Методи і засоби інформаційного забезпечення режимів електричних мереж в умовах низької якості електроенергії." Thesis, Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40949.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018.
Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ.
Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній.Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.
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Філянін, Данило Володимирович. "Методи і засоби інформаційного забезпечення режимів електричних мереж в умовах низької якості електроенергії." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40946.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018.
Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ.
Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній.Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.
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Votavová, Helena. "Vývoj nových přístupů v odstraňování okují při kontinuální výrobě oceli s využitím vysokotlakého vodního paprsku." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401607.
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The thesis summarizes general and up-to-date knowledge of descaling during the continuous production of the hot-rolled steel and proposes further streamlining of this process in industrial production. The first chapter of the thesis deals with the origin, structure and physical properties of the scales. The second chapter describes the principles of descaling by using a high pressure flat water jet. The third chapter introduces the principles of the experimental methods and describes the used laboratory equipment. The fourth chapter summarizes the description of the particular experiments and their evaluation, and thus represents the focus of the dissertation. It is divided into six sections which independently solve predefined objectives of the dissertation. The first section focuses on the height and structure development of the scales on 54SiCr6 and HDT580X steels. It has been proven that the height of the formed scales increases with the time and temperature of the oxidation. The layered nature of the scales was verified at the same time. The second section examines the effect of the nozzle stabilizer on the focussing and distribution of the impact pressure of the nozzle. Experiments have shown that increase of 11 % of an average maximum nozzle pressure can be achieved, depending on the type of nozzle and the length of the stabilizer. The third section deals with the analysis of shadowgraphy images of water jet structures of the nozzles. A script was developed for analysis of these shadowgraphy photos by an adaptive thresholding. The findings are correlated using a regression analysis with an average heat transfer coefficient. It has been reported that most of the standard nozzle configurations produced disintegrated stream of little droplets at the height of the rolled surface. The fourth section focuses on the area of water jet overlap, especially the area of the so-called washout, where the impact pressure of one nozzle is reduced by the nozzle stream of the other. The influence of the pressure change and the mutual displacement of the nozzles is investigated. The analysis showed that the change of pressure did not have any effect on the percentage of reduction of the impact pressure in the area of the washout. It has been shown that if the area of the washout is wide the descaling efficiency in this area may be reduced. The fifth section builds on the previous section and focuses directly on the areas of waterjet overlaps. The influence of the change of rotation and pitch of the nozzles is studied. Experiments have shown that small changes in nozzle pitch do not have a significant impact on impact pressure and heat transfer coefficient. The effect of nozzle rotation, on the other hand, was a significant factor for the efficiency and homogeneity of the descaling of the surface. The last section deals with the effect of the rolling speed on the heat transfer coefficient in the descaling process. The regression model has shown that with a higher rolling speed there is a reduction in the average heat transfer coefficient. Conclusion summarizes the results of the dissertation and proposes which findings can be used in the industry to make the descaling process more effective.
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Bushueva, Olga. "Conception, réalisation et caractérisation d'inductances et de transformateurs tridimensionnels pour applications RF et microondes." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30140/document.
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La miniaturisation, la fabrication et l'intégration des composants passifs RF constituent des enjeux majeurs actuels, sans oublier le critère du coût de fabrication, très important notamment pour les applications grand public. Les composants passifs tels que les inductances et les transformateurs font l'objet d'un effort de développement permanent pour accroitre leurs performances et réduire la surface occupée. Les travaux décrits dans ce manuscrit s'inscrivent dans ce contexte et visent le développement d'une nouvelle filière technologique permettant la réalisation à faible coût de composants inductifs tridimensionnels à hautes performances. Le travail présenté dans ce mémoire s'articule en quatre chapitres. Le premier chapitre dresse un état de l'art des inductances et des transformateurs intégrés en abordant les principales topologies utilisées, les technologies de fabrication et les applications. Dans le deuxième chapitre, l'étude et l'optimisation des inductances et des transformateurs solénoïdaux est abordée après avoir décrit les origines des pertes limitant les performances. Pour cela, nous avons recours à la simulation électromagnétiques 3D. Dans le troisième chapitre, un problème de caractérisation des composants inductifs à forts coefficients de surtension est soulevé. Après avoir constaté que l'environnement de mesure réduisait artificiellement les performances, quelques solutions sont proposées et vérifiées expérimentalement. Enfin, le dernier chapitre traite de la fabrication et de la caractérisation des composants mis au point. Les meilleures performances mesurées correspondent à un facteur de qualité de 61 à 5,4 GHz pour une inductance de 2,5 nH et un gain maximum disponible de -0,5 dB à -0,39 dB sur la plage 3,8 - 6,5 GHz pour un transformateur 2:2. Ces résultats placent ces composants parmi les meilleures réalisations actuellesThe miniaturization, fabrication and integration of RF passive components are current major challenges, also taking into account the fabrication cost which is very important especially for consumer applications. Passive components such as inductors and transformers are subject to an ongoing development to improve their performance and reduce the area occupied. The work described in this manuscript is part of that context and target the development of a new technological process allowing the production of low-cost three-dimensional high-performance inductive components. The work presented in this paper is divided into four chapters. The first chapter describes the state of the art of integrated inductors and transformers by addressing the main topologies used fabrication technologies and applications. In the second chapter, the study and optimization of solenoid inductors and transformers is discussed after describing the origins of performance limiting losses. For this, we use the 3D electromagnetic simulation. In the third chapter, the problem concerning the characterization of inductive components with high Q factor is raised. After finding that the measurement environment artificially reduces performance, some solutions are proposed and experimentally verified. Finally, the last chapter discusses the fabrication and characterization of developed components. The best measured performance corresponds to a quality factor of 61 to 5.4 GHz for an inductance value of 2.5 nH and a maximum available gain of -0.5 dB to 0.39 dB over the range from 3.8 to 6.5 GHz for a 2:2 transformer. These results place these components among the best current achievements
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Hamade, Firas Nadim. "Sediment removal from urban runoff using seep berms and vegetative filtration." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50271.
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Previous field demonstration projects in metro-Atlanta have shown that seep berms, which are elongated sedimentation basins at the outlet of a disturbed land area, can provide high suspended sediment trap efficiencies with respect to coarse sediments on construction sites having drainage areas greater than five acres. Previous literature has shown that vegetative filter strips are efficient traps for fine suspended sediment in stormwater runoff. A combination of a seep berm and vegetative filter in series was studied in this thesis as an erosion control measure with quantification of its flow resistance and sediment removal efficiency. First, a field demonstration project was implemented to evaluate seep berms as a viable erosion control measure through a side-by-side comparison with the more commonly-used silt fences on construction sites with drainage areas less than five acres in metro Atlanta. High suspended sediment trap efficiencies were recorded for the seep berm on two separate sites, and the seep berm was shown to be superior to silt fences with respect to sediment control in the site runoff. Then a vegetative filter was studied in the laboratory in a specially-built flume for that purpose. The relationship between vegetative drag coefficient and various parameters reflecting flow conditions and vegetation density in steady, uniform open channel flow was studied in the flume. Both rigid, emergent vegetation and submerged, flexible vegetation were studied at two different plant densities. The application of porous media flow concepts to open channel flow through vegetation resulted in a collapse of data for vegetative drag coefficient for the various vegetation types and densities into a single relationship when plotted against vegetative stem Reynolds number. Point velocity and turbulence intensity profiles at different locations in the vegetative filter were recorded with an acoustic Doppler velocimeter to observe the turbulence structure of the flow and its effects on vegetative drag and settling of sediment. A sediment slurry consisting of a suspension of fine sand was fed into the flume, and an automated sampler was used to measure suspended sediment concentrations along the vegetative filter length for a series of discharges from which sediment flux and trap efficiency could be determined. Experimental data for trap efficiency were plotted against a dimensionless settling efficiency for each type of vegetation and density. These relationships, along with the one developed for the coefficient of drag, were applied in a numerical design technique that allows designers to determine the flow depth, velocity and trap efficiency of a vegetative filter of known dimensions for a given flow rate, sediment grain size distribution, slope, and vegetation density. In a typical design example, the combined trap efficiency proved that a seep berm followed by a vegetative filter can be a very effective erosion control measure.
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Majjad, Hicham. "ÉTUDE ET RÉALISATION DE MICRORÉSONATEURS EN TECHNIQUE LIGA-UV." Phd thesis, Université de Franche-Comté, 2001. http://tel.archives-ouvertes.fr/tel-00009998.
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Cette étude a pour but la conception de microrésonateurs basses fréquences réalisés par une technique de microfabrication collective : la LIGA-UV. Il est donc nécessaire dans un premier temps de connaître les propriétés mécaniques du matériau choisi pour la réalisation, à savoir le nickel obtenu par électroformage. On détermine donc le module de Young ainsi que l'amortissement interne du matériau grâce au plus simple des microrésonateurs à savoir une micropoutre encastrée-libre. La démarche suivie lors de la phase de conception de ces microrésonateurs est la suivante : tout d'abord développer un modèle analytique qui permet de déterminer le maximum de paramètres géométriques. Ensuite, l'utilisation d'un modèle éléments finis, qui prend en compte plus de paramètres, permet d'affiner la géométrie grâce à des conditions aux limites proches de la réalité et de simuler le fonctionnement du microsystème. Ainsi, cette démarche a été suivie par la réalisation et la caractérisation de microrésonateurs en nickel à mode de flexion dans le plan qui vibrent à 70 kHz. L'excitation et la détection se font par le biais de peignes interdigités. Les fréquences expérimentales sont confrontées aux résultats des simulations avec une corrélation très satisfaisante. Enfin, un prototype de microrésonateur qui vibre à 6 MHz et dont l'originalité réside dans son mode de contour ou mode de Lamé a été réalisé. La vibration qui a lieu dans le plan a ses nœuds aux quatre coins et au centre de la plaque. L'excitation du microrésonateur se fait de manière électrostatique, quant à la détection elle se fait par l'intermédiaire d'un interféromètre laser hétérodyne. Les résultats ont montré un coefficient de qualité Q d'environ 1200 à l'air. Ce type de microrésonateur est le candidat idéal pour la réalisation d'un oscillateur intégré sous vide qui entraînerait une nette amélioration de ses performances mécaniques.
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Englund, Sofia. "Optimizing the design of two-stage ditches to improve nutrient and sediment retention." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415420.
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Negative effects on water quality are created by eutrophication of the world’s water resources. Mitigation measures have been implemented, but poor improvements in water quality have been observed. Two-stage ditches have the possibility to increase nutrient and sediment retention to reduce eutrophication in receiving water bodies. A two-stage ditch has floodplain terraces on each side of the ordinary main channel. The terraces are available for flooding during high water flows and enables decreases in flow velocities. However, more knowledge is needed about the two-stage ditch and its effect in Swedish landscapes. The aim of the project was to study the two-stage ditch design with focus on water retention. Optimization of the two-stage ditch design was made by modeling and simulating design parameters and vegetation in the software Hydrologic Engineering Center’s River Analysis System (HEC-RAS). An existing two-stage ditch in Sweden was used as base and comparison to the theoretical model. In addition, a climate change scenario was studied to evaluate the impact of increased storm events in a two-stage ditch. Results showed that increased retention time of water, nutrients, and sediments theoretically can be given by designing two-stage ditches with maximum terrace width and minimum terrace height, and with terraces angled away from the main channel. Vegetation should also be kept on both terraces and in the main channel of the two-stage ditch to increase retention time. The study also showed that the two-stage ditch design has the possibility to decrease peak water levels during storm events, which can be expected to increase in the future. The impact on transport of nutrients and sediments from more future extreme hydrological events needs further studies.Negativa effekter i vattenkvalitet skapas av övergödning i världens vattenresurser. Åtgärder för att begränsa övergödningen har genomförts, men svaga förbättringar i vattenkvalitet har noterats. Tvåstegsdiken har möjligheten att öka retentionen av näringsämnen och sediment för att minska övergödning. Ett tvåstegsdike har terrasser på vardera sida om den vanliga mittfåran. Terrasserna är tillgängliga för översvämning vid höga vattenflöden, vilket möjliggör minskning av flödeshastigheter. Dock krävs mer kunskap för tvåstegsdiken och dess effekt i svenska landskap. Syftet med projektet var att studera designen av tvåstegsdiken med fokus på retention av vattenflöde. Optimering av tvåstegsdikens design genomfördes via modellering och simulering av designparametrar och vegetation i programvaran Hydrologic Engineering Center’s River Analysis System (HEC-RAS). Ett befintligt tvåstegsdike i Sverige användes som bas och jämförelse mot den teoretiska modellen. Ett scenario för klimatförändring studerades även för att utvärdera effekten i ett tvåstegsdike då fler stormevent sker. Resultaten visade att ökad retentionstid for vatten, näringsämnen, och sediment teoretiskt kan ges genom att designa tvåstegsdiken med maximal terrassbredd och minimal terrasshöjd, samt med terrasser vinklade bort från mittfåran. Vegetation bör även behållas på terrasser och i mittfåran av tvåstegsdiket för att öka retentionstiden. Studien visade även att tvåstegs- dikets design har möjligheten att minska toppflöden vid stormevent, vilka kan förväntas öka i framtiden. Påverkan på transport av näringsämnen och sediment från fler framtida extrema hydrologiska event kräver ytterligare studier.
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Герасимчук, Галина Андріївна, and Galina Gerasimchuk. "Обґрунтування параметрів комбінованого однодискового копача кормових буряків." Thesis, Тернопільський національний технічний університет ім. Івана Пулюя, 2011. http://elartu.tntu.edu.ua/handle/123456789/877.
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Робота виконана у Луцькому національному технічному університеті Міністерства освіти і науки, молоді та спорту України, м. Луцьк.
Захист відбувся 3 березня 2011 р. о 1200 годині на засіданні спеціалізованої вченої ради Д.58.052.02 при Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Руська, 56.
З дисертацією можна ознайомитись в бібліотеці Тернопільського національного технічного університету імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Руська, 56.Дисертація присвячена вирішенню наукової задачі підвищення показників якості збирання кормових буряків шляхом обґрунтування параметрів комбінованого копача, виконаного у вигляді сферичного диска, встановленого під кутом атаки до напрямку його руху, у робочій зоні якого і над ним змонтовано горизонтальний вал з очисними лопатями, які закріплено на осях, повернутих відносно осі вала на деякий кут. На основі проведених теоретичних і експериментальних досліджень обґрунтовано раціональні параметри копача. Результати досліджень використовуються проектно-конструкторськими організаціями в процесі розробки КМ.
В диссертации на основании совокупности обобщенных результатов решена актуальная научная задача, которая состоит в повышении показателей качества работы выкапывающих рабочих органов кормовой свеклы путем обоснования параметров работы комбинированного однодискового копателя. В первом разделе проведен анализ литературных источников. В частности, рассмотрены классификация выкапывающих рабочих органов и очистителей головок корнеплодов кормовой свеклы, их конструкции, основные технологии сбора кормовой свеклы, а также обоснован выбор рабочего органа для проведения исследований. Во втором разделе теоретически исследовано секундные подачи примесей вороха корнеплодов и коэффициенты технологической эффективности работы копателя в зависимости от параметров копателя, характеристик корнеплодов и условий работы корнеуборочной машины. На основании анализа процесса взаимодействия очистительной лопати горизонтального вала с головкой корнеплодов получены математические модели, характеризирующие условия невываливания корнеплодов с почвы та их неповреждения, определена критическая угловая скорость вращения лопати. В третьем разделе представлено программу экспериментальных исследований, приведено перечень оборудования, приборов, разработанных опытных установок и методики проведения исследований. С учетом программы экспериментальных исследований изготовлена экспериментальная лабораторно-полевая установка комбинированного копателя кормовых корнеплодов. В четвертом разделе приведены результаты экспериментальных исследований. Установлено влияние конструктивно-кинематических параметров копателя на секундные подачи примесей вороха и основные показатели качества работы – потери, повреждения корнеплодов, остатки ботвы на головках корнеплодов. В пятом разделе определены перспективные направления усовершенствования конструкций рабочих органов копателей и основные показатели экономической эффективности использования копателя. Конструктивная новизна разработок защищена двумя патентами Украины на изобретения.
Dissertation is devoted to the scientific problem of improving indexes of quality of gathering fodder beet by grounding parameters of combined digger, designed as a spherical disc which is set due to an angle of attack to the direction of its movement in the working area of which it is mounted a horizontal shaft with scrubbing blades that are fixed on turned on defined angle axis according to axis of a shaft. It was grounded rational parameters of a digger on the basis of theoretical and experimental studies. Research results are used by design organizations in the development of RDM.
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Sauveplane, Jean-Baptiste. "Caractérisation thermomécanique de films métalliques déposés en couche mince pour la simulation de la fiabilité de composants microélectroniques de puissance." Phd thesis, INSA de Toulouse, 2007. http://tel.archives-ouvertes.fr/tel-00158019.
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La fiabilité de la simulation thermomécanique de composants de puissance est fortement liée à la précision des paramètres mécaniques tels que le module de Young (E) et le coefficient de dilatation thermique (CTE) des matériaux le constituant. La plupart du temps, les valeurs disponibles dans la littérature concernent les matériaux massifs, de plus leurs variations en fonction de la température ainsi que l'évolution de ces propriétés lors de cycles de fatigue sont rarement données. Afin de répondre à ce besoin, une technique a été développée utilisant une micro poutre bicouche (cantilever) qui possède la propriété de se courber lorsqu'elle subit un échauffement. Le module de Young et le cSfficient de dilation thermique de l'aluminium de 4µm et 10µm d'épaisseur, déposé par DC magnétron sputering, ont ainsi été mesurés avec précision. Les structures ont ensuite été soumises à des vibrations harmoniques forcées afin de caractériser l'évolution du module de Young lors de cycles de fatigue répétés. Les propriétés mécaniques des matériaux déterminées de manière expérimentale ont été implémentées dans un modèle éléments finis d'un composant de puissance à très faible résistance à l'état passant (RON) de Freescale semiconducteur. Des simulations électro-thermo-mécaniques ont été effectuées permettant d'évaluer l'impact des connexions entre la puce et le boîtier sur le RON du composant, sur la distribution des températures ainsi que sur les contraintes générées dans les matériaux.
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Svoboda, Lukáš. "Studie snížení energetické náročnosti bytového domu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226693.
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The goal of the thesis is firstly to get all the information about the initial state of solved block of flats, which is located on the street Merhautova 76/954 in Brno – Černá pole, in terms of constructions, energy consumption and initial state of heating system. In the second part of the thesis, where are discussed the possibilities of reduction of energy consumption, variant drafts of reduction of energy consumption and their financial costs and the choice of optimal variant. Third part deals with assement of solved block of flats in terms of sustainable built environment by using tool to rate buildings in terms of sustainable built environment - SBToolCZ, evaluation of possibility to use renewables. In the end are written summaries and recommendations.
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Lin, You-Cheng, and 林宥澄. "The quality evaluation of medical images evaluated by using grey relational coefficients." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/qjq27e.
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碩士中臺科技大學
放射科學研究所
96
PURPOSE: The purpose of this study was to develop Grey Relational Coefficient (GRC) system to evaluate compressed medical images. MATERIALS and METHODS: The researcher used Local Grey Relational Coefficients (LGRC) which developed by Hsia, Wen, Wu and Nagai to examine respectively compressed CT, MRI and DR images from compression ratios from 10:1 to 100:1 at 10 different level. The compressed images were also calculated by Mean Squared Error (MSE), Peak Signal to Noise Ratio (PSNR), Signal to Noise Ratio (SNR), Universal Quality Index (UQI), Mean Structural Similarity (MSSIM), Human Visual System(HVS) and Moran''s Peak Ratio (MPR) algorithms. This was to compare the consequences among GRC and the algorithms. The compression algorithms were JJ2000 and Apollo which are wavelet based algorithm. RESULTS: Four LGRCs were all able to evaluate the compressed image quality changes efficiently. The coefficient of GRC decreased with increasing compression ratios. The Nagai method was superior than others in identification. LGRC had similar tendency comparing with other objective methods, JJ2000 and Apollo had no significant difference at 0.05 between DR and CT images, yet compressed MRI with JJ2000 was superior than that compressed with Apollo (p＜0.05). For the evaluation speed on compressed images, Nagai''s method was faster than UQI and MSSIM. The second for each image was 0.44,1.2 and 1.1 respectively. For the sampling size of 3×3, LGRC was also superior than MSSIM, UQI and MPR with r-values of 0.999,0.994,0.978 and 0.856 respectively. CONCLUSION: LGRC is not affected by choosing sampling size, LGRC is recommended as for evaluating image quality objectively.
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Chen, Yi-Jing, and 陳怡靜. "The Impact of the Implementation of Corporate Social Responsibility on Earnings Quality and Earnings Response Coefficients." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88572634841327792085.
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碩士中國文化大學
會計學系
99
The purpose of this study is to explore the relationship of the implementation of corporate social responsibility with earnings quality, and the impact of implementing corporate social responsibility on investors perceived value of earnings. To conduct this research, I employ a pair-matched sample, comprising companies receiving the CSR contribution award in the period from 2006 to 2009, and their matched companies. My findings show that companies receiving the CSR award suffer less earnings manipula-tions; that is, those companies are of higher quality in terms of accounting earnings. However, this study provides no evidence that investors give a higher price reaction to the earnings of companies receiving the CSR award. Such results may indicate that market participants do not take account of the award information in their decision mak-ing of firm value.
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TANG, LI-FEN, and 湯麗芬. "FAMILY-CONTROLLED FIRMS AND EARNINGS QUALITY: FROM THE PERSPECTIVE OF EARNINGS MANAGEMENT AND EARNINGS RESPONSE COEFFICIENTS." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/12399038221811934326.
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博士國立臺北大學
會計學系
96
In Taiwan, most firms are family-controlled business. And the characteristics of family-controlled firms may lead the corporate governance is unique. However, due to limited data available, there are few study investigate the relation between the family-controlled firms and the earnings quality. For this reason, this study will investigate how the characteristics of family-controlled firms affect the earnings quality. The earnings quality is measured by discretionary accruals and earnings response coefficients. By using the discretionary accruals as a proxy for earnings quality, we find that the most characteristics (such as family ownership, degree of divergence between the ultimate owner’s control and the equity ownership level, the number of oversea subsidiaries in the group, and the founder occupied CEO or chairman) will lower earnings quality. However, when the earnings quality is measured by earnings response coefficients, the most characteristics (such as family ownership, the number of non-listed subsidiaries in the group, and the founder occupied CEO or chairman) are associated with greater earnings informativeness. Furthermore, the study examine whether the relation between family ownership and earnings quality is nonlinear. However, we did not find evidence that the relation between family ownership and earnings quality is nonlinear. The study probes the relation between family-controlled firms and earnings quality, which is not fully investigated in prior literature and the results provide regulators with a guidelines to improve the earnings quality and corporate governance of family-controlled firms.
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Meng-Chieh, Yu. "The Effects of Earnings Growth from Various components of Earnings on Quality of Earnings and on Earnings Response Coefficients." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0307200621150100.
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Yu, Meng-Chieh, and 游孟潔. "The Effects of Earnings Growth from Various components of Earnings on Quality of Earnings and on Earnings Response Coefficients." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/82904504327648701987.
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碩士國立臺灣大學
會計學研究所
94
This study intends to empirically examine the effects of earnings growth from various components of earnings on quality of earnings and earnings response coefficients. In order to measure the quality of earnings, I use both earnings persistence and earnings management. The study explores whether firms with sustained increases in earnings attained by sustained increases in revenues have higher earnings persistence, less possibility of managing earnings, and larger earnings response coefficients. Results indicate that firms with revenue-maintained earnings growth do have higher earnings persistence and less possibility of earnings management and larger earnings response coefficients than those with only earnings growth. In addition, like the results in the previous literature (Ohlson, 1995), the results in this study portrays that the larger the earnings response coefficients firms have, the smaller the book value response coefficients they do.
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Lee, Hsiu-Hsia, and 李秀霞. "Perceived Auditor Quality and the Earnings Response Coefficient." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/69075293620968275165.
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Chen, Yi-Lin, and 陳義麟. "The Relation between Perceived Auditor Quality and Earnings Response Coefficient." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/18323798097868744059.
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李賜寬. "The Effect of Information Transparency on Earnings Quality and Earnings Response Coefficient." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/67674490774238034122.
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碩士國立彰化師範大學
會計學系
94
Abstract Corporate scandals occur continuously from all over the world and the reason is about the opacity of corporations’ information. Consequently, investors suffer severe damages. In order to meet investors’ expectations and needs and propagate the capital market, enhancing information transparency becomes the hottest issue in the world. To improve the transparency of corporate information disclosures, Taiwan Stock Exchange Corporation (TSEC) and Gre Tai Securities Market (GTSM) requested the Securities and Futures Institute (SFI) to implement an information disclosure and evaluation system for all publicly traded and over the counter (OTC) listed in TSEC. This study divides information into two types based on it. The type Ⅰ is elevating earnings quality and the type Ⅱ is substituting for informativeness of earnings announcements. This study investigates whether the more information corporations disclose, the better earnings quality corporations have? Whether investors have different responses facing different types of information in the capital market? Research sample contains publicly traded companies from 2003 to 2004. The empirical results support that the more type Ⅰ information corporations disclose, the better earnings quality corporations have. Secondly, earnings quality and earnings response coefficient (ERC) are significantly positive. Third, the relation between the information environments produced by disclosing typeⅠ information and ERC is significantly positive. Furthermore, the more type Ⅱ information corporations disclose, the lower earnings response coefficients are. Finally, combined with two types of information, information transparency is negatively associated with market reactions to earnings announcements, but not significantly. Keywords：Information transparency、Earnings quality、Earnings response coefficient（ERC）