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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Applications of Deep Learning to Visual Content Processing and Analysis

Liu, Xiaohong January 2021 (has links)
The advancement of computer architecture and chip design has set the stage for the deep learning revolution by supplying enormous computational power. In general, deep learning is built upon neural networks that can be regarded as a universal approximator of any mathematical function. In contrast to model-based machine learning where the representative features are designed by human engineers, deep learning enables the automatic discovery of desirable feature representations based on a data-driven manner. In this thesis, the applications of deep learning to visual content processing and analysis are discussed. For visual content processing, two novel approaches, named LCVSR and RawVSR, are proposed to address the common issues in the filed of Video Super-Resolution (VSR). In LCVSR, a new mechanism based on local dynamic filters via Locally Connected (LC) layers is proposed to implicitly estimate and compensate motions. It avoids the errors caused by the inaccurate explicit estimation of flow maps. Moreover, a global refinement network is proposed to exploit non-local correlations and enhance the spatial consistency of super-resolved frames. In RawVSR, the superiority of camera raw data (where the primitive radiance information is recorded) is harnessed to benefit the reconstruction of High-Resolution (HR) frames. The developed network is in line with the real imaging pipeline, where the super-resolution process serves as a pre-processing unit of ISP. Moreover, a Successive Deep Inference (SDI) module is designed in accordance with the architectural principle suggested by a canonical decomposition result for Hidden Markov Model (HMM) inference, and a reconstruction module is built with elaborately designed Attention based Residual Dense Blocks (ARDBs). For visual content analysis, a new approach, named PSCC-Net, is proposed to detect and localize image manipulations. It consists of two paths: a top-down path that extracts the local and global features from an input image, and a bottom-up path that first distinguishes manipulated images from pristine ones via a detection head, and then localizes forged regions via a progressive mechanism, where manipulation masks are estimated from small scales to large ones, each serving as a prior of the next-scale estimation. Moreover, a Spatio-Channel Correlation Module (SCCM) is proposed to capture both spatial and channel-wise correlations among extracted features, enabling the network to cope with a wide range of manipulation attacks. Extensive experiments validate that the proposed methods in this thesis have achieved the SOTA results and partially addressed the existing issues in previous works. / Dissertation / Doctor of Philosophy (PhD)
72

Studying cellulose nanostructure through fluorescence labeling and advanced microscopy techniques

Babi, Mouhanad January 2022 (has links)
As the major component of the plant cell wall, cellulose is produced by all plant species at an annual rate of over a hundred billion tonnes, making it the most abundant biopolymer on Earth. The hierarchical assembly of cellulose glucan chains into crystalline fibrils, bundles and higher-order networks endows cellulose with its high mechanical strength, but makes it challenging to breakdown and produce cellulose-based nanomaterials and renewable biofuels. In order to fully leverage the potential of cellulose as a sustainable resource, it is important to study the supramolecular structure and hydrolysis of this biomaterial from the nano- to the microscale. In this thesis, we develop new chemical strategies for fluorescently labeling cellulose and employ advanced imaging techniques to study its supramolecular structure at the singlefibril level. The developed labeling method provides a simple and efficient route for fluorescently tagging cellulose nanomaterials with commercially available dyes, yielding high degrees of labeling without altering the native properties of the nanocelluloses. This allowed the preparation of samples that were optimal for super-resolution fluorescence microscopy (SRFM), which was used to provide for the first time, a direct visualization of periodic disorder along the crystalline structure of individual cellulose fibrils. The alternating disordered and crystalline structure observed in SFRM was corroborated with time-lapsed acid hydrolysis experiments to propose a mechanism for the acid hydrolysis of cellulose fibrils. To gain insight on the ultrastructural origin of these regions, we applied a correlative super-resolution light and electron microscopy (SR-CLEM) workflow and observed that the disordered regions were associated nanostructural defects present along cellulose fibrils. Overall, the findings presented in this work provide significant advancements in our understanding of the hierarchical structure and depolymerization of cellulose, which will be useful for the development of new and efficient ways of breaking down this polymer for the production of renewable nanomaterials and bio-based products like biofuels and bioplastics. / Thesis / Doctor of Philosophy (PhD) / In this dissertation, we have studied in unprecedented detail the structure of cellulose – a polymer that is found in every plant. As the main structural component of the plant cell wall, cellulose endows trees with their strength and resilience while storing sunlight energy in its chemical bonds. Since plant biomass represents eighty percent of all living matter on Earth, cellulose is an abundant resource that can be used to produce sustainable and environmentally benign nanomaterials and bioproducts, like biofuels and bioplastics. Our ability to use cellulose as a renewable source of structural materials and energy is intimately linked to our capacity to break apart its tight structural packing. Deconstructing cellulose into various forms demands that we understand the multi-level organization of its structure and the susceptible regions within it. To gain this information, in this thesis we develop new labeling methods and apply state-of-the-art microscopy tools to directly visualize the arrangement of cellulose fibrils at the nanoscale (comparable to 1/10,000 the width of a human hair) and study their breakdown by acid treatment. The findings presented in this work furthers our fundamental understanding of the natural structure of cellulose, which has important implications on the development of industrial strategies to break down this abundant and renewable biomaterial.
73

A Bioeconomic Model of Recirculating Shrimp Production Systems

Zhou, Xia Vivian 11 August 2007 (has links)
To prevent disease outbreaks and increase competitiveness of U.S. shrimp products, U.S. aquaculture researchers have developed super-intensive, bio-secure, recirculating shrimp production systems since the early 1990s. The general objective of this research is to determine an optimal production strategy to maximize the net revenue for the system. An inventory optimization model was built to determine the optimal harvesting week, shrimp size, and number of crops per year for experimental trials conducted at the Gulf Coast Research Laboratory (Ocean Springs, MS), the Waddell Maricultural Center (Bluffton, SC), and the Oceanic Institute (Oahu, HI). Survival rate and selling price sensitivity analyses were conducted to see their impact on the system¡¯s net revenue. The optimal harvesting week solved by this model is determined by shrimp growth and feed functions. Producer selling price and survival rate can affect the value of net revenue, but do not impact the optimal harvesting week. Shrimp producers can use the developed inventory optimization model and results to efficiently manage their operations.
74

Emergent Phenomena in Classical and Quantum Systems: Cellular Dynamics in <i>E. coli</i> and Spin-Polarization in Fermi Superfluids

Ellis, Jason Keith 02 November 2009 (has links)
No description available.
75

"So aggressive!" : En semiotisk analys av stereotyper i reklamfilmer under Super Bowl 2016

Ekman, Albin, Norlin, Simon January 2016 (has links)
No description available.
76

Les drains dolomitiques super-K : géométries, hétérogénéités-réservoirs, origines : La Formation Khuff en subsurface (Permo-Trias, Qatar-Iran) et un analogue à l'affleurement (Jurassique supérieur, Provence - France)

Gisquet, Franck 28 June 2012 (has links)
La partie supérieure de la Formation Khuff est un réservoir représentant le plus grand champ gazier mondial, d'âge Permien supérieur à Trias inférieur. Il est formé de la succession de calcaires, de dolomies et de sulfates. Sa production est principalement contrôlée par des intervalles d'épaisseur généralement inférieure à 10 m, totalement dolomitisés, appelés super-drains ou super-K, connectés sur plusieurs dizaines de kilomètres.Les objectifs de l'étude sont (1) de définir la mise en place et l'extension des super-drains dans un cadre stratigraphique, (2) de comprendre la diagenèse contrôlant leurs propriétés réservoirs et (3) de comparer la mise en place des corps dolomitiques stratiformes précoces ou tardifs liés aux failles à ceux d'un analogue à l'affleurement, à savoir les formations calcaréo-dolomitiques d'âge Jurassique supérieur en Provence.Pour les atteindre, des analyses sédimento-diagénétiques (sédimentologiques, pétrographiques et géochimiques) ont été entreprises sur les deux objets d'études du réservoir de subsurface et de l'analogue réservoir d'affleurement. Pour ce dernier, une modélisation en 3D de corps diagénétiques liés aux failles a été réalisée. Les principaux résultats sont que :- les localisations des super-drains ont été contrôlées par la dynamique sédimentaire de séquences à basse fréquences (SBF) et à haute fréquence (SHF) ;- des super-drains sont localisés au sommet des SBF sous les discontinuités d'émersions et à la limite des fronts de dolomitisation de reflux différé. / The upper part of the Khuff Formation includes the biggest gas reserves in the world, from Upper Permian to Lower Triassic age. It is composed by the succession of limestone, dolomite and sulfate. The gas production is mainly driven by layers typically thinner than 10 m, fully dolomitised, and called super-drains or super-K and connected over several dozen kilometers.The goals of this study are (1) to define the formation and the extension of super-K layers in a stratigraphic framework, (2) to understand the diagenesis controlling their reservoir properties and (3) to compare the creation of early stratabound and late fault-related dolomite bodies with an outcrop analogue, from the limestone and dolomite formations from Provence from Upper Jurassic age.To reach this goal, sedimento-diagenetic analyses (sedimentological, petrographical and geochemical) have been carried out on studied objects, the subsurface reservoir and the outcrop analogue reservoir. For the latter, 3D modelling of fault-related dolomite bodies have been realised. The main results are:- the locations of super-K have been controlled by the sedimentary dynamics of low frequency sequences (SBF) and high frequency sequences (SHF) ;- some super-K are located at the top of SBF under emersion unconformities and at the rim of dolomitisation fronts associated to postponed reflux. The reflux was made of brines, coming from synsedimentary dolomite bodies associated with marine transgressions that followed the emersions. This model is corroborated by an outcrop analogue, which is a dolomite reservoir underlying a long lasting emersion unconformity;
77

Imaging beyond the diffraction limit STED and SAF microscopy / Imager au-delà de la limite de diffraction grâce à la microscopie STED et SAF

Sivankutty, Siddharth 11 June 2014 (has links)
La compréhension des processus cellulaires au niveau membranaire est un domaine d’étude important en recherche biomédicale. Contourner la limite de diffraction en microscopie de fluorescence est maintenant devenu possible en exploitant les transitions moléculaires du fluorophore. Ce travail présente le développement instrumental de deux techniques complémentaires permettant d’atteindre une résolution nanométrique, grâce à l'émission stimulée (STimulated Emission Depletion - STED) d’une part, et la microscopie de fluorescence aux angles supercritiques (Supercritical Angle Fluorescence, SAF) d’autre part. La microscopie STED est une méthode permettant de surpasser la barrière de diffraction et d’atteindre des résolutions latérales de l'ordre de 40 nm dans des échantillons biologiques. Ce dispositif de microscopie exploite les transitions moléculaires des marqueurs fluorescents pour surmonter la limite de résolution due à la diffraction. L'amélioration de la résolution est obtenue par déplétion de l'état excité du fluorophores dans les régions périphériques de l'espace du volume focal. Cependant, malgré l'amélioration importante de la résolution latérale avec la technique STED, cette dernière présente une réelle complexité de mise en œuvre qui a par conséquence un impact important sur le cout des instruments STED commerciaux. Dans ce contexte, la réalisation instrumentale et la performance en imagerie d'un dispositif STED sont présentées dans ce manuscrit. Bien que les microscopes STED classiques offrent une meilleure résolution latérale, la résolution axiale est toujours limitée par la diffraction. L’amélioration de la résolution dans cette direction implique une certaine complexité instrumentale. Dans ce cadre, nous démontrons une nouvelle approche utilisant l’imagerie SAF permettant d'obtenir un sectionnement axial de l'ordre de 150 nm. L’approche se base sur la propriété d'une molécule à émettre dans les angles supercritiques uniquement lorsqu’elle se rapproche de l'interface verre-eau. Le sectionnement axial est obtenu dans une configuration simple en détectant uniquement les composantes de l’émission supercritique. La combinaison de ces techniques d'imagerie donne un outil puissant pour étudier les phénomènes moléculaires sur les membranes biologiques. / Understanding cellular processes on membranes has been a key area of biomedical research. Circumventing the diffraction limit in fluorescence microscopy has now become possible by exploiting the molecular transitions of the fluorophore. In this context, this work presents the instrumental development of two complementary techniques for realizing nanometric all-optical resolution and axial sectioning, namely STimulated Emission Depletion (STED) and Supercritical Angle Fluorescence (SAF) microscopy. STED microscopy is an elegant method that has allowed us to break the diffraction barrier with light microscopes and has achieved resolutions of the order of 40 nm (transverse) in biological samples. In this technique, we exploit the molecular transitions of the fluorescent marker to overcome the resolution limit due to diffraction. Resolution enhancement is achieved by efficient depletion of the excited state of the marker in the peripheral spatial regions of the focal volume by using depletion beams in addition to the excitation beam. Despite the major resolution improvement demonstrated, the technique is not well spread out, mainly due to its apparent complexity; and the cost and limited tunability of the commercial system. In this context, the instrumental realization and the imaging performance of a cost-effective home-built STED microscope is presented in this manuscript. While conventional STED microscopes offer improved lateral resolution, an isotropic gain in resolution usually comes at the cost of complex instrumentation. In this regard, we demonstrate SAF microscopy as a powerful tool that achieves an axial sectioning of the order of 150 nm. This is done by exploiting the property of a molecule to emit into the supercritical anglesonly when near the glass-water interface. Axial sectioning is obtained in a simple configuration by detecting solely the supercritical components of radiation. A combination of these imaging techniques offer a powerful tool to study molecular phenomena on the biological membranes.
78

Obtenção de cerveja super concentrada com a utilização de xarope de milho como adjunto de malte / Obtaining super concentrated beer using corn syrup as adjunct of malt

Castro, Orerves Martinez 06 May 2014 (has links)
Este trabalho teve por objetivo a utilização de xarope de milho na elaboração de cerveja super concentrada. Para atingir este propósito foram realizados ensaios em escala de 5 litros, testando três proporções quanto à relação de extrato de malte e de xarope de milho. Para seguir a legislação brasileira de acordo com o Decreto 6.871, de 2009, foram propostos para a realização dos experimentos as proporções de 70/30, 55/45 e 20/80 de malte:xarope de milho. Na proporção 20/80, definida pelo referido Decreto como cerveja de milho foram avaliadas diferentes variantes para obter diferentes concentrações alcoólicas, obtendo resultados inadequados. As fermentações foram conduzidas em regime descontínuo alimentado, com a adição do xarope por cargas, e foi utilizada uma levedura com alta eficiência fermentativa que tem demonstrado alta tolerância a concentrações de álcool, classificada como PPB - 01. Para comparar com os mostos experimentais, foram elaborados mostos padrões nas proporções 70/30 e 55/45. Em escala piloto foi elaborada uma prova de cerveja super concentrada, para as proporções 70/30 e 55/45, malte/milho. Foram avaliados os parâmetros cinéticos dos processos. As eficiências de formação de álcool e de consumo de extrato foram acima dos 90%, o que garantiu um bom processo fermentativo. As cervejas obtidas na escala piloto foram submetidas a análises sensoriais e comparadas com uma cerveja comercial, obtendo ótimos resultados. As duas proporções aprovadas proporcionaram economia de energia térmica e elétrica, quando comparadas com as cervejas padrões. Os resultados obtidos no projeto demonstraram que é possível a aplicação desta tecnologia, aumentando a produtividade utilizando os mesmos equipamentos e obtendo benefícios energéticos, econômicos e meio ambientais. / The aim of this project was the use of corn syrup to develop super concentrated beer. Accomplishing this purpose was made initially two repeat experiments on a scale of 5 liters and testing three variants as regards the relationship of malt extract and corn. Following the Brazilian law in accordance with the Decree 6.871, 2009, was proposed for the realization of experiments the proportions of 70/30, 55/45 and 20/80 from malt and corn. In the proportion 20/80, defined by Decree as corn beer, were evaluated different variants for obtaining different alcohol concentrations, obtaining inadequate results. Fermentations were conducted in fed batch regime with the addition of the syrup in pulses, and was used one yeast with high efficiency of fermentation and tolerating of alcohol high concentrations, classified as PPB - 01. To compare with the experimental worts, were prepared standards worts for proportions 70/30 and 55/45. In pilot scale, were made experiments of super concentrated beer to the proportions 70/30 and 55/45, malt/corn. The kinetic parameters of the processes were evaluated. The efficiencies of formation of alcohol and consumption of extract were above 90%, which ensured a good fermentation. The experimental beers obtained in pilot scale were subjected to sensory analysis compared with a beer sold in trade, getting great results. The two proportions approved had saving thermal and electrical energy, when compared with standards beers. The results obtained in the project demonstrated that it is possible to apply this technology, increasing equipment productivity and getting energy, economic and environmental benefits.
79

A representação do espaço nas histórias em quadrinhos do gênero super-heróis: a metrópole nas aventuras de Batman / The representation of space in the super-hero comics: the metropolis in Batman\'s adventures

Rama, Maria Angela Gomez 23 October 2006 (has links)
Este trabalho apresenta uma possibilidade de leitura do espaço geográfico por meio das histórias em quadrinhos do gênero super-heróis - com ênfase em Batman - levando em conta a importância destes ícones e da linguagem quadrinhística no mundo moderno. Ao verificarmos como a paisagem é retratada nas aventuras dos super-heróis, buscamos interpretar as representações do espaço - e se possível os espaços de representação - e como elas ratificam e/ou legitimam os valores e idéias da sociedade que, direta ou indiretamente, as geraram: a sociedade americana/capitalista. A contribuição mais evidente da pesquisa consiste no fato de abordar uma temática ainda pouco explorada dentro dos estudos geográficos e ao mesmo tempo, estabelecer uma possível ponte interdisciplinar com a área de conhecimento da Comunicação / This paper provides a way to interpret geographic space trough the use of super-hero comics - mainly Batman - highlighting the importance of cultural icons and the comic book language in the modern world. We attempted to demonstrate that the landscape itself, as well as what this landscape represents, confirms or legitimizes the values and ideas of american/capitalist society which, directly or indirectly, generates them. The most important contribution of this paper lies in its application of the little used theme of super-hero comics in geographic studies. In addition, this study facilitates the establishment of an interdisciplinary bridge to the area of Communication studies
80

Palatabilidade e digestibilidade aparente de dietas com níveis crescentes de inclusão de polpa crítica para equinos / Palatability and apparent digestibility of diets with increasing levels of citrus pulp for horses

Moreira, Camilla Garcia 21 February 2014 (has links)
O presente estudo teve como objetivo avaliar o efeito de níveis crescentes de inclusão de polpa cítrica na dieta de equinos, através da avaliação da palatabilidade, digestibilidade aparente e características físico-químicas das fezes. As dietas foram compostas por 60% da energia proveniente do volumoso (feno de Coast Cross) e 40% do concentrado, com níveis crescentes de inclusão de polpa cítrica (0, 7, 14, 21 e 28%). Para a realização do experimento, foram realizados dois testes. O primeiro ensaio consistiu na determinação da palatabilidade dos concentrados, através do teste de preferência. Para isso foram utilizados 15 equinos, por um período de 10 dias, totalizando 150 observações, em delineamento inteiramente casualizado. As variáveis observadas foram primeira ação, primeira escolha e razão de ingestão. Para a realização do ensaio de digestibilidade e características físico-químicas das fezes, foram utilizados cinco equinos, em delineamento quadrado latino 5x5. Avaliou-se a digestibilidade aparente dos nutrientes e as características de cor, consistência, pH, concentração e relação entre ácidos graxos de cadeia curta e capacidade tamponante a pH 5 e a pH 6, das fezes. Observou-se efeito da inclusão da polpa cítrica (P&lt;0,001) sobre a primeira ação, sendo que 66,91% dos animais cheiraram os concentrados, enquanto 33,09% comeram, e também para a primeira escolha (P&lt;0,001),onde os tratamentos 0, 7 e 14% apresentaram maior preferência. Para a razão de ingestão, também houve diferença (P&lt;0,001) entre os tratamentos, sendo que o concentrado controle o mais consumido. Não foi observado efeito (P&gt;0,05) dos níveis de inclusão de polpa cítrica sobre a digestibilidade aparente dos nutrientes. Para as características das fe zes não houve efeito de tratamento (P&gt;0,05) na consistência e cor. A coloração se manteve esverdeada, e a consistência foi classificada como normal (escore 3).Não houve efeito de tratamento (P&gt;0,05) para o pH, concentração e relação entre ácidos graxos de cadeia curta e capacidade tamponante das fezes. O valor médio observado de pH foi de 6,62, e a capacidade tamponante a pH 5 e pH 6 foi de 16,53 e 5,13 mmol/L, respectivamente. Os cavalos têm a capacidade de identificar a presença da polpa cítrica nos concentrados, e preferem concentrados sem a inclusão. A adição de polpa cítrica em até 28% não afeta negativamente a digestibilidade dos concentrados e as características físico-químicas das fezes, sendo uma alternativa de ingrediente na formulação de dietas para equinos. / The purpose of this study was to evaluate the citrus pulp inclusion in horses diet, through evaluation of palatability, apparent digestibility and feces physicochemical characteristics. The diets were composed of 60% of the energy from roughage (Coast Cross hay) and 40% from concentrate with increasing levels of citrus pulp (0, 7, 14, 21 and 28%).To perform the experiment, there were two distinct tests. The first experiment consisted in determining the concentrates palatability. Fifteen horses were used, for a 10-day period, totaling 150 observations, in a randomized design. The variables were first action, first choice and intake rate. For the digestibility test and feces physicochemical characteristics, five horses were used in 5x5 Latin square design. Were evaluated the nutrients digestibility and the feces characteristics of color, consistency, pH, concentration and relation between short-chain fatty acids, and buffering capacity at pH 5 and pH 6. There was an effect of the citrus pulp inclusion (P&lt;0.001) on the first action, 66.91% of the animals smelled the concentrates, while 33.09% ate. For the first choice there was also significant difference (P&lt;0.001) and 0, 7 and 14% treatments had a higher preference. For the intake rate there were differences (P&lt;0.001) between treatments, being the control concentrate the most consumed. There was no effect (P&gt;0.05)of the citrus pulp levels on nutrient digestibility. For feces characteristics there were no treatment effect (P&gt;0.05) in consistency and color. The color remained green, and consistency were classified as normal (score 3). There was no treatment effect (P&gt;0.05) for pH, concentration and relation between short-chain fatty acids, and buffering capacity of the feces, the mean pH value observed was 6.62, and the buffering capacity at 5 and 6 was 16.53 and 5.13 mmol / L respectively. Horses have the ability to identify the citrus pulp presence in concentrates, but they prefer the concentrates without citrus pulp inclusion. Addition of citrus pulp does not adversely affect the concentrates digestibility or the feces physicochemical characteristics, being an alternative ingredient in the horses diets formulation.

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