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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.
201

Fast Code Exploration for Pipeline Processing in FPGA Accelerators / Exploração Rápida de Códigos para Processamento Pipeline em Aceleradores FPGA

Rosa, Leandro de Souza 31 May 2019 (has links)
The increasing demand for energy efficient computing has endorsed the usage of Field-Programmable Gate Arrays to create hardware accelerators for large and complex codes. However, implementing such accelerators involve two complex decisions. The first one lies in deciding which code snippet is the best to create an accelerator, and the second one lies in how to implement the accelerator. When considering both decisions concomitantly, the problem becomes more complicated since the code snippet implementation affects the code snippet choice, creating a combined design space to be explored. As such, a fast design space exploration for the accelerators implementation is crucial to allow the exploration of different code snippets. However, such design space exploration suffers from several time-consuming tasks during the compilation and evaluation steps, making it not a viable option to the snippets exploration. In this work, we focus on the efficient implementation of pipelined hardware accelerators and present our contributions on speeding up the pipelines creation and their design space exploration. Towards loop pipelining, the proposed approaches achieve up to 100× speed-up when compared to the state-uf-the-art methods, leading to 164 hours saving in a full design space exploration with less than 1% impact in the final results quality. Towards design space exploration, the proposed methods achieve up to 9:5× speed-up, keeping less than 1% impact in the results quality. / A demanda crescente por computação energeticamente eficiente tem endossado o uso de Field- Programmable Gate Arrays para a criação de aceleradores de hardware para códigos grandes e complexos. Entretanto, a implementação de tais aceleradores envolve duas decisões complexas. O primeiro reside em decidir qual trecho de código é o melhor para se criar o acelerador, e o segundo reside em como implementar tal acelerador. Quando ambas decisões são consideradas concomitantemente, o problema se torna ainda mais complicado dado que a implementação do trecho de código afeta a seleção dos trechos de código, criando um espaço de projeto combinatorial a ser explorado. Dessa forma, uma exploração do espaço de projeto rápida para a implementação de aceleradores é crucial para habilitar a exploração de diferentes trechos de código. Contudo, tal exploração do espaço de projeto é impedida por várias tarefas que consumem tempo durante os passos de compilação a análise, o que faz da exploração de trechos de códigos inviável. Neste trabalho, focamos na implementação eficiente de aceleradores pipeline em hardware e apresentamos nossas contribuições para o aceleramento da criações de pipelines e de sua exploração do espaço de projeto. Referente à criação de pipelines, as abordagens propostas alcançam uma aceleração de até 100× quando comparadas às abordagens do estado-da-arte, levando à economia de 164 horas em uma exploração de espaço de projeto completa com menos de 1% de impacto na qualidade dos resultados. Referente à exploração do espaço de projeto, as abordagens propostas alcançam uma aceleração de até 9:5×, mantendo menos de 1% de impacto na qualidade dos resultados.
202

Vers la simulation de perfusion du myocarde à partir d'image tomographique scanner / Toward simulation of myocardial perfusion based on a single CTA scan.

Jaquet, Clara 18 December 2018 (has links)
De nos jours, les progrès de l’informatisation de l’imagerie médicale assistent au plus près les médecins dans leur soin au patient. Des modèles personnalisés computationnels sont utilisés pour le diagnostique, prognostique et planification du traitement, en diminuant lesrisques pour le patient, et potentiellement les frais médicaux.Heartflow est l’exemple même d’une compagnie qui réussit ce service dans le domaine cardiovasculaire. À partir d’un modèle extrait d’images tomographiques rayons X, les lésions avec impact fonctionnel sont identifiées dans les artères coronaires. Cette analyse qui combine l’anatomie à la fonction est néanmoins limitée par la résolution de l’image. En aval de ces larges vaisseaux, un examen fonctionnel dénommé Imagerie de Perfusion du Myocarde (IPM) met en évidence les régions du myocarde affectées par un déficit de flux sanguin. Cependant, l’IPM n’établie pas de relation fonctionnelle avec les larges vaisseaux coronaires lésés en amont.L’objectif de ce projet est de construire la connexion fonctionnelle entre les coronaires et le myocarde, en extrapolant l’analyse fonctionnelle depuis les larges vaisseaux vers le lit capillaire. À cette fin, il faut étendre le modèle vasculaire jusqu'aux microvaisseaux, et mener une analyse fonctionnelle en direction du comportement myocardique.Nous étendons une méthode de génération d’arbre vasculaire basée sur la satisfaction de principes fonctionnels, nommée Constrained Constructive Optimization (Optimization Constructive sous Contraintes), pour qu’elle s’applique à de multiples arbres vasculaires en compétition. L’algorithme simule l’angiogénèse avec minimisation du volume vasculaire sous contraintes de flux et de géométrie adaptant la croissance simultanée des arbres aux caractéristiques du patient. Cette méthode fournit un modèle hybride composé de coronaires épicardiales extraites d’images et de vaisseaux synthétiques jusqu’aux artérioles, emplissant le ventricule gauche du myocarde.Puis, nous construisons un pipeline d’analyse fonctionnelle multi-échelle pour étendre la simulation de flux depuis les coronaires vers le myocarde. Cela consiste en un modèle de flux coronaire 1D compatible avec la vasculature hybride, et l’analyse de la distribution spatiale des flux provenant des segments terminaux. Cette dernière est réalisée dans une nomenclature similaire à celle de l’IPM pour permettre la comparaison avec des données de vérité terrain fonctionnelles.Nous avons relié l’anatomie du réseau vasculaire à la distribution de flux dans le myocarde pour plusieurs patients. Cette analyse multi-échelle permet d’identifier des pistes pour affiner les méthodes de génération vasculaire et de simulation de flux. Cette extrapolation anatomique et fonctionnelle personnalisée est une première passerelle pour la simulation de perfusion du myocarde à partir d’imagerie tomographique scanner. La construction d’un tel modèle computationnel personnalisé pourrait aider à la compréhension de la physio-pathologie cardiovasculaire complexe et, enfin, à la santé du patient. / Recent advances in medical image computing have allowed automatedsystems to closely assist physicians in patient therapy. Computationaland personalized patient models benefit diagnosis, prognosisand treatment planning, with a decreased risk for the patient,as well as potentially lower cost. HeartFlow Inc. is a successfull exampleof a company providing such a service in the cardiovascularcontext. Based on patient-specific vascular model extracted from XrayCT images, they identify functionally significant disease in largecoronary arteries. Their combined anatomical and functional analysisis nonetheless limited by the image resolution. At the downstreamscale, a functional exam called Myocardium Perfusion Imaging (MPI)highlights myocardium regions with blood flow deficit. However,MPI does not functionally relate perfusion to the upstream coronarydisease.The goal of our project is to build the functional bridge betweencoronary and myocardium, by extrapolating the functional analysisfrom large coronary toward the capillary bed. This objective requiresextension from the coronary model down to the microvasculaturecombined with a functional analysis leading to the myocardium compartment.We expand a tree generation method subjected to functional principles,named Constrained Constructive Optimization, to generate multiplecompeting vascular trees. The algorithm simulates angiogenesisunder vascular volume minimization with flow-related and geometricalconstraints, adapting the simultaneous tree growths to patientpriors. This method provides a hybrid image-based and synthetic geometricmodel, starting from segmented epicardium coronary downto synthetic arterioles, filling the left ventricle myocardium.We then build a multiscale functional analysis pipeline to allowblood flow simulation from the coronaries to the myocardium. Thisis achieved with a 1D coronary model compatible with the hybridvasculature, and a spatial blood flow distribution analysis of the terminalsegments. The latter is performed using a similar nomenclatureto MPI, to enable patient-specific comparison with functional groundtruthdata.We connected the vascular anatomy to blood flow distribution inthe myocardium on several patient datasets. This multiscale frameworkpoints out several leads to refine the vascular network generationand fluid simulation methods. This patient-specific anatomicaland functional extrapolation is a first gateway toward myocardiumperfusion from X-ray CT data. Building such personalized computational model of patient could potentially help investigating cardiovascularcomplex physio-pathology, and, finally, improve the patientcare.
203

Estudo experimental de intermitência severa em um sistema água-ar. / Experimental study of severe slugging in an air-water system.

Yamaguchi, Alan Junji 27 October 2016 (has links)
O trabalho tem como objetivo realizar um estudo experimental na bancada do Laboratório Multipropósito de Escoamento Multifásico com o intuito de estudar o fenômeno de intermitência severa em um sistema pipeline-riser com os fluidos água e ar. A intermitência severa pode ocorrer em sistemas pipeline-riser onde o pipeline é descendente seguido de um riser vertical, além de ser necessário a presença de baixas vazões de fluidos. Esse fenômeno é caracterizado por ser cíclico em que há acúmulo de líquido na base do riser e por acabar causando perdas na produção de petróleo e gás devido a grandes flutuações de pressão e vazão que podem durar horas a depender do comprimento do sistema. Os picos de pressão e vazão também podem causar o desligamento do sistema de separação na plataforma. O estudo se dividiu em várias etapas onde inicialmente foram definidos os procedimentos experimentais a serem utilizados. A calibração de placas de orifício foi necessária para o controle de vazão mássica de gás. Os resultados experimentais foram divididos em casos estáveis e instáveis onde a instabilidade é caracterizada pela presença de ciclos de pressão que podem ser observados em históricos de pressão na base do riser. Mapas de estabilidade foram criados e a região instável obtida experimentalmente foi comparada com a curva de estabilidade obtida pelo uso da teoria de estabilidade linear. Os históricos de pressão na base do riser para os casos instáveis obtidos foram comparados com dois modelos numéricos. A variação da pressão no separador foi usada para verificar a mitigação da intermitência severa e/ou da condição instável obtida no sistema para alguns casos instáveis. / The objective of this work is to do an experimental study of the severe slugging phenomenon in the pipeline-riser system of the Multipurpose Multiphase Flow Laboratory by using the fluids air and water. Severe slugging may occur for low flow rates in pipeline-riser systems where a downward pipeline is followed by a vertical riser. In this phenomenon there is liquid accumulation at the bottom of the riser resulting in production losses due to the great fluctuations of pressure and flow rate during its cycles which may last for hours depending on the length of the system. The high pressure values can also cause shutdown of the platform separation system. The first stage of this study was to define the experimental procedure to be adopted. It was necessary to perform a calibration of the orifice plates in order to have a precise control of the gas mass flow rate. The experimental results were divided in stable and unstable cases. The instability is defined by the presence of pressure oscillations at the bottom of the riser. Stability maps were created to compare the stabiliy curve obtained by the stability linear theory with the experimental results. The experimental pressure oscillations were compared with two numerical models. The pressure variation at the separator was studied to verify the mitigation effects during unstable and/or severe slugging conditions.
204

Análise computacional da diversidade viral presente na comunidade microbiana do processo de compostagem do Zoológico de São Paulo / Computational analysis of the viral diversity in the Sao Paulo Zoo composting microbial community

Amgarten, Deyvid Emanuel 18 November 2016 (has links)
O estudo da diversidade viral em amostras ambientais tem se tornado cada vez mais importante devido a funções-chave desempenhadas por esses organismos. Estudos recentes têm fornecido evidências de que vírus de bactérias (bacteriófagos) podem ser os principais determinantes em ciclos biogeoquímicos de grandes ecossistemas, além de atuarem no fluxo de genes entre comunidades ambientais e na plasticidade funcional das mesmas frente a estresses ambientais. Neste trabalho, propomos a investigação e caracterização da diversidade viral presente em amostras de compostagem através de abordagens não dependentes e dependentes de cultivo. Na primeira abordagem, coletamos amostras seriadas de uma unidade de compostagem do zoológico de São Paulo para realização de sequenciamento metagenômico. O conjunto de sequências gerado foi extensivamente minerado (data-mining) para a produção de resultados de diversidade e abundância de táxons virais ao longo do processo de compostagem. Adicionalmente, procedemos com a montagem e recuperação de sequências virais candidatas a genomas completos e/ou parciais de novos vírus ambientais. Os dois protocolos computacionais utilizados para a mineração de dados encontram-se definidos e automatizados, podendo ser aplicados em quaisquer conjuntos de dados de sequenciamento metagenômico ou metatranscritômico obtidos através da plataforma Illumina. A segunda abordagem correspondeu ao isolamento e caracterização de novos fagos de Pseudomonas obtidos de amostras de compostagem. Três novos fagos foram identificados e tiveram os seus genomas sequenciados. A caracterização genômica desses fagos revelou genomas com alto grau de novidade, insights sobre a evolução de Caudovirales e a presença de genes de tRNA, cuja função pode estar relacionada com um mecanismo dos fagos para contornar o viés traducional apresentado pela bactéria hospedeira. A caracterização experimental dos novos fagos isolados demonstrou grande potencial para lise e dissolução de biofilme da cepa Pseudomonas aeruginosa PA14, conhecida como agente causador de infecções hospitalares em pacientes imunodeprimidos. Em suma, os dados reunidos nesta dissertação caracterizam a diversidade presente no viroma da compostagem e contribuem para o entendimento dos perfis taxonômico, funcional e ecológico do processo. / The study of the viral diversity in environmental samples has become increasingly important due to key-roles that are performed by these organisms in our ecosystems. Recent publications provide evidence that viruses of bacteria (bacteriophages) may be key-players in biogeochemical cycles of large ecosystems, as oceans and forests. Besides, they may also be determinant in the genes flux among populations and in the plasticity of the communities face to environmental stresses. In this work, we propose the investigation and characterization of the viral diversity in composting samples through non-culturable and culturable-dependent approaches. In the first approach, we sampled a composting unit from the Sao Paulo Zoo Park in different time points and proceeded with metagenomic sequencing. The dataset generated was extensively mined to provide results of diversity and abundance of viral taxa through the composting process. Additionally, we proceeded with the assembly and retrieval of candidate sequences to partial or/and complete viral genomes. The two computational protocols were automatized as pipelines and can be applied to any metagenomic dataset of illumina reads. The second approach refers to the isolation and characterization of new Pseudomonas phages obtained from composting samples. Three new phages were identified and their genomes were sequenced. A detailed characterization of these genomes revealed high degree of novelty, insights about evolution of tailed-phages and the presence of tRNA genes, which may be related to a mechanism to bypass host translational bias. The experimental characterization of the new phages demonstrated great potential to lyse bacterial cells and to degrade Pseudomonas aeruginosa PA14 biofilms. In short, the data presented in this dissertation shed light to the composting virome diversity, as well as to the functional and ecological profiles of viruses in the composting environment.
205

Identificação de regiões codificantes de proteína através da transformada modificada de Morlet / Identification of Protein Coding Regions through the Modified Morlet Transform

Chalco, Jesus Pascual Mena 19 October 2005 (has links)
Um tópico importante na análise de seqüências biológicas é a busca de genes, ou seja, a identificação de regiões codificantes de proteínas. Esta identificação permite a posterior procura de significado, descrição ou categorização biológica do organismo analisado. Atualmente, vários métodos combinam reconhecimento de padrões com conhecimento coletado de conjuntos de treinamento ou de comparações com banco de dados genômicos. Entretanto, a acurácia desses métodos está ainda longe do satisfatório. Novos métodos de processamento de seqüências de DNA e de identificação de genes podem ser criados através da busca por conteúdo (search-by-content). O padrão periódico de DNA em regiões codificantes de proteína, denominada periodicidade de três bases, vem sendo considerado uma propriedade dessas regiões. As técnicas de processamento digital de sinais fornecem uma base robusta para a identificação de regiões com periodicidade de três bases. Nesta dissertação, são apresentados um \\pipeline, os conceitos básicos da identificação genômica, e métodos de processamento digital de sinais utilizados para a identificação de regiões codificantes de proteínas. Introduzimos um novo método para a identificação dessas regiões, baseado na transformada proposta, denominada Transformada Modificada de Morlet. Apresentamos vários resultados experimentais obtidos a partir de seqüências de DNA sintéticas e reais. As principais contribuições do trabalho consistem no desenvolvimento de um pipeline para projetos genoma e na criação de um método de identificação de regiões codificantes onde a periodicidade de três bases seja latente. O método apresenta desempenho superior e vantagens importantes em comparação ao método tradicional baseado na transformada de Fourier de tempo reduzido. / An important topic in biological sequences analysis is gene finding, i.e. the identification of protein coding regions. This identification allows the posterior research for meaning, description or biological categorization of the analyzed organism. Currently, several methods combine pattern recognition with knowledge collected from training datasets or from comparison with genomic databases. Nonetheless, the accuracy of these methods is still far from satisfactory. New methods of DNA sequences processing and genes identification can be created through search-by-content such sequences. The periodic pattern of DNA in protein coding regions, called three-base periodicity, has been considered proper of coding regions. Digital signal processing techniques supply a strong basis for regions identification with three-base periodicity. In this work, we present a bioinformatics pipeline, basic concepts of the genomic identification and digital signal processing methods used for protein coding regions identification. We introduce a new method for identification of these regions, based on a newly proposed transform, called Modified Morlet Transform. We present some obtained experimental results from synthetic and real DNA sequences. The main contributions consist of the bioinformatics pipeline development for genoma projects and the creation of a method for protein coding regions identification where the three-base periodicity is latent. The method presents superior performance and important advantages in comparison to traditional method based on the short time Fourier transform.
206

Corrosion des aciers dans les sols : mécanismes et cinétiques associés aux périodes transitoires d'humidification-séchage / Corrosion of steel in soil : mechanisms and kinetics associated with transient periods (drying-wetting)

Akkouche, Rym 12 December 2017 (has links)
En 2014, le réseau de pipelines à travers le monde est estimé à près de 3 500 000 km. Ces conduites en acier traversent plusieurs continents, régions, climats et donc différents types de sols. Elles sont protégées contre la corrosion externe par des revêtements et une protection cathodique. Néanmoins, il subsiste toujours un risque infime de dégradation de l’acier. Afin d’évaluer le risque de rupture d’une conduite, il est nécessaire d’étudier l’influence du sol sur la corrosion de l’acier nu non protégé composant cette conduite. Les paramètres régissant la corrosion des aciers dans les sols étant nombreux, nous nous sommes focalisés sur l’un des paramètres clés, à savoir « la teneur en eau » qui est directement reliée à d’autres paramètres très influents comme : l’aération ou taux d’oxygène, la résistivité du sol et la surface active. Dans cette thèse, nous nous sommes intéressés aux phénomènes se produisant lors de périodes transitoires de séchage/humidification de plusieurs types de sols : argileux, limoneux argileux et sableux. Une électrode multi-coupons a aussi été utilisée afin d’étudier les phénomènes liés à l’hétérogénéité de surface (formation de piles d’aération différentielle). Pour cela, différents coupons en acier provenant d’une conduite d’Air Liquide ont été enfouis pendant de longues périodes (4, 6 et 12 mois) dans différents types de sols. Les vitesses de corrosion sont estimées par électrochimie via la modélisation des courbes de voltammétrie autour du potentiel d’abandon. La surface active de l’électrode est estimée via la mesure de la résistance d’électrolyte par spectroscopie d’impédance électrochimique. Les échantillons sont ensuite analysés par micro-spectroscopie Raman, diffraction des rayons X et microscopie (optique, confocale et électronique à balayage) afin de déduire les mécanismes de corrosion de l’acier. Les résultats montrent, notamment, qu’en cas d’un fort taux d’humidité et d’une faible aération, les vitesses de corrosion sont très faibles (de l’ordre de 20 à 30 µm.an-1) mais atteignent 200 à 400 µm.an-1 lors des phases de séchage. La mesure de courants de couplage effectuée avec l’électrode multi-coupons ainsi que l’analyse de surface des coupons conventionnels ont confirmé la présence de piles d’aération différentielle et le caractère localisé de la corrosion. / In 2014, the pipelines network extended over 3500000 km worldwide. These pipes are passing through various continents, regions, areas and thus different types of soils. They are protected against external corrosion by coatings and cathodic protection. However, there is always a slight risk of carbon steel degradation. In order to evaluate the pipeline failure threat, it is necessary to study the influence of soil corrosion on the uncoated steel which composes this pipe. There are many parameters governing the steel corrosion in soils. We focused on one of the most important parameter “water content”. It is directly linked to other prominent parameters such as oxygen concentration, soil resistance and active area. In this thesis, we addressed the phenomena occurring at transitory periods of drying and remoistening in different types of soils : clayey, silt-loamy and sandy. A multi-coupon electrode was used as well in order to study the phenomena linked to surface heterogeneity (formation of differential aeration cells). For this aim, several steel coupons were buried in different types of soil for long periods (4, 6 and 12 months). The corrosion rates are estimated via electrochemical methods by fitting with a theoretical law the voltammetric curves acquired around the open circuit potential. The active area of the electrode was estimated via the determination of the soil electrolyte resistance by electrochemical impedance spectroscopy. Afterwards, the coupons were analyzed by micro-spectroscopy Raman, X-rays diffraction and microscopy in order to understand the corrosion mechanisms. Results showed that in case of very high moisture content and deaerated conditions, the corrosion rates were very weak (about 20 to 30 µm.yr-1) but reached 200 to 400 µm.yr-1 in the drying periods. The galvanic current measurements performed with the multi-coupon electrode and the surface analysis of the conventional electrodes both confirmed the presence of differential aeration cells and the localized nature of the corrosion.
207

DAISY Producer: An integrated production management system for accessible media

Egli, Christian 15 June 2011 (has links) (PDF)
Large scale production of accessible media above and beyond DAISY Talking Books requires management of the workflow from the initial scan to the output of the media production. DAISY Producer was created to help manage this process. It tracks the transformation of hard copy or electronic content to DTBook XML at any stage of the workflow and interfaces to existing order processing systems. Making use of DAISY Pipeline and Liblouis, DAISY Producer fully automates the generation of on-demand, user-specific DAISY Talking Books, Large Print and Braille. This paper introduces DAISY Producer and shows how creators of accessible media can benefit from this open source tool.
208

Advanced numerical and experimental transient modelling of water and gas pipeline flows incorporating distributed and local effects.

Kim, Young Il January 2008 (has links)
One of the best opportunities to reduce pipeline accidents and subsequent product loss comes from implementing better pipeline condition assessment and fault detection systems. Transient analysis model based condition assessment is the most promising technique because pressure transients propagate entire system interacting with the pipe and any devices in the system. Transient measurements embody a large amount of information about the physical characteristics of the system. The performance of this technique has its difficulties because a highly accurate transient model is required. Real systems have numerous uncertainties and flow system components that presents a major challenge in the development of precise transient analysis models. To improve transient modelling for the performance of condition assessment, this research undertakes a comprehensive investigation into the transient behaviour of distributed and various local energy loss system components in water and gas pipelines. The dynamic behaviours that have been investigated in this research are the effect of unsteady wall resistance, viscoelasticity effects of polymer pipe, and local energy loss elements including leakages, entrapped air pockets, orifices, and blockages during unsteady pipe flow conditions. The dynamic characteristics of these system components are modelled based on the conservative solution scheme using the governing equations in their conservative form. Use of the conservative form of the equations improves the sensitivity and applicability of transient analysis in both liquid and gas pipeline systems. The numerical model results are compared to laboratory experiments in water and gas pipelines to observe the interaction between transient pressure wave and system components and to verify the proposed models. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337145 / Thesis( Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering 2008
209

Contributions à l’observation par commande d’observabilité et à la surveillance de pipelines par observateurs / Contributions to the observation by observabilty control and pipelines monitoring using observers

Rubio Scola, Ignacio Eduardo 30 January 2015 (has links)
Ce travail se compose de deux parties, dans la première, deux types de méthodologies sont proposées pour garantir l'observabilité sur des systèmes non uniformément observables. Premièrement sont présentées les méthodes basées sur le grammien d'observabilité et, à continuation, les méthodes basées directement sur l'équation de l'observateur. Dans la deuxième partie, diverses techniques sont détaillées pour la détection de défauts (fuites et obstructions) dans les canalisations sous pressions. Pour cela on construit plusieurs modèles en discrétisant les équations du coup de bélier par différences finies, implicites et explicites dans le temps. Sur ces modèles des techniques sont développés en utilisant des observateurs et des algorithmes d'optimisation. Les modèles discrets ainsi que certains observateurs ont été validés par une série d'expériences effectuées dans des canalisations d'essai. Des résultats de convergence, expérimentaux et en simulation sont exposés dans ce mémoire. / This work consists of two parts, in the first one, two types of methods are proposed to ensure the observability of non-uniformly observable systems. Firstly methods based on the observability gramian are presented, and then some methods based directly on the equation of the observer. In the second part, various techniques are detailed for the detection of defaults (leaks and obstructions) in a pipeline under pressure. For that, we built several models by discretizing the water hammer equations using finite differences explicit and implicit in time. Then some techniques are developed using observers and optimization algorithms. Discrete models and some observers were validated by a series of experiments in pipelines. Convergence, experimental and simulation results are presented in this manuscript.
210

Medi??o e modelagem da resposta de um sensor de pig perfilom?trico sob diferentes solicita??es din?micas / Measuring and modeling the response of a feeler pig sensor under different dynamic loads

Medeiros, Jarbas Santos 05 August 2013 (has links)
Made available in DSpace on 2014-12-17T14:58:23Z (GMT). No. of bitstreams: 1 JarbasSM_DISSERT.pdf: 2192547 bytes, checksum: 650bc570adcbb8b8a6b8e1427b27389d (MD5) Previous issue date: 2013-08-05 / Ensure the integrity of the pipeline network is an extremely important factor in the oil and gas industry. The engineering of pipelines uses sophisticated robotic inspection tools in-line known as instrumented pigs. Several relevant factors difficult the inspection of pipelines, especially in offshore field which uses pipelines with multi-diameters, radii of curvature accentuated, wall thickness of the pipe above the conventional, multi-phase flow and so on. Within this context, appeared a new instrumented Pig, called Feeler PIG, for detection and sizing of thickness loss in pipelines with internal damage. This tool was developed to overcome several limitations that other conventional instrumented pigs have during the inspection. Several factors influence the measurement errors of the pig affecting the reliability of the results. This work shows different operating conditions and provides a test rig for feeler sensors of an inspection pig under different dynamic loads. The results of measurements of the damage type of shoulder and holes in a cyclic flat surface are evaluated, as well as a mathematical model for the sensor response and their errors from the actual behavior / Garantir a integridade da rede de dutos ? um fator de extrema import?ncia na ind?stria de petr?leo e g?s. A engenharia de dutos utiliza sofisticadas ferramentas robotizadas de inspe??o in-line (durante opera??o) conhecidas como pigs instrumentados. V?rios fatores relevantes dificultam a inspe??o de dutos, especialmente em campos offshore onde se utiliza dutos com multi-di?metros, raios de curvatura acentuados, espessura de parede do duto acima do convencional, escoamento multif?sico e etc. Dentro deste contexto, surgiu um novo Pig instrumentado, chamado de Pig perfilom?trico, para detec??o e dimensionamento de perda de espessura em dutos com danos interno. Esta ferramenta foi desenvolvida para superar diversas limita??es que outros pigs instrumentados convencionais t?m durante a inspe??o. Diversos fatores influenciam nos erros de medi??o do pig afetando a confiabilidade dos resultados obtidos. O presente trabalho aponta diferentes condi??es de opera??o e apresenta uma bancada para ensaiar sensores perfilometricos de pig de inspe??o sob diferentes solicita??es din?micas. Os resultados das medi??es dos danos do tipo ressaltos e rebaixos em uma superf?cie plana c?clica s?o avaliados, assim como, um modelo matem?tico para a resposta do sensor e seus erros em rela??o ao comportamento real

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