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1

Zahri, Abdellatif. "Développement du modèle PIC-MCC 2D : application aux décharges radiofréquence." Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1344/.

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La méthode particle-In-Cell combinée avec la technique Monte-Carlo est une méthode bien établie pour la modélisation des plasmas, et elle est très utilisée pour simuler les réacteurs de faible pression pour les décharges radiofréquences (RF). Cette technique est une méthode simple et efficace permettant de résoudre une large variété de problèmes complexes impliquant un grand nombre de particules en mouvement sous l'action des forces engendrées par elles-mêmes ainsi que les forces externes appliquées. Le but de notre modèle est de comprendre et de caractériser le comportement du plasma à basse pression pour une géométrie à deux dimensions. Nous voulons comprendre ce qui se passe dans la gaine et en particulier le comportement des ions. Dans ce travail, nous décrivons les modèles PIC-MCC et leurs techniques indispensables à la construction de tels modèles. Nous avons choisi cette technique par sa qualité de description de la physique du plasma. En effet, cette technique fournit plus de précisions et sans aucune hypothèse sur la fonction de distribution des électrons ou des ions, ce qui est loin d'être le cas pour les autres modèles notamment les modèles fluides. Nous montrons certaines fonctions de distribution (densité et énergie des particules chargées, EEDF,. . . ), les caractéristiques électriques de la décharge seront étudiées. Ce travail s'inscrit dans le cadre du projet européen EMDPA: New Elemental and Molecular Depth Analysis of advanced materials by modulated radio frequency glow discharge time of flight mass spectrometry. Ce projet est financé par la commission européenne via le programme de recherche pour le développement technologique
The particle-in-cell method combined with the Monte Carlo techniques is a well established method for plasma modelling, and is widely used to simulate low pressure radiofrequency discharges. This technique is a simple and effective method for solving a wide variety of complex problems involving a large number of particles moving under the action of internal forces and external forces (electromagnetic fields. . . ) The purpose of our model is to understand and characterize the behaviour of low pressure plasmas in a two-dimensional geometry. We want to understand what is happening in the sheath and in particular the behaviour of the ions. In this work, we describe the PIC-MCC models and techniques needed to build such models. We chose this technique by its ability to describe correctly the plasma physics at low pressure. Indeed, this technique provides more details without any assumption on the distribution function of electrons or ions, which is far from being the case for other models including fluid models. We show some distribution functions (density and energy of charged particles, EEDF) ; the electrical characteristics of the discharge are presented. This work is part of the European project EMDPA : New Elemental and Molecular Depth Analysis of advanced materials by modulated radio frequency glow discharge time of flight mass spectrometry. This project is funded by the European Commission through the research program for technological development
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2

Mokrani, Cyril. "Impacts de vagues déferlantes sur un obstacle vertical. Modèle théorique et calcul numérique des pics de pression." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3004/document.

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Cette thèse étudie numériquement l'impact d'une onde déferlante à l'échelle de la vague. Dans un premier temps, le phénomène de percussion présent sur de faibles durées est décrit dans deux cas de lâcher de barrage. Les résultats montrent que la réduction du pas d'espace induit des changements locaux dans le profil d'interface avant l'impact. Ces changements influencent fortement les pics de pression, rendant ainsi leur estimation impossible. L'influence de lagéométrie locale de l'interface est théoriquement étudiée sur le cas d'un jet triangulaire. En développant deux lois semi-empiriques, nous montrons que pour des interfaces fortement inclinées, les pics de pression sont très sensibles aux variations d'angles incidents. L'impact d'une onde déferlante est traité en initialisant le déferlement par la mise en place d'un couplage faible de modèles BEM/VOF afin d'approcher la forme du jet avec une précision optimale. Les efforts critiques sont calculés pour des obstacles situés à différentes altitudes. L'intensité des pics est en accord avec la théorie pour des angles inférieurs à 70°. Deux types d'impacts sont étudiés en appliquant les résultats du jet triangulaire au cas de jets courbes
Numerical simulations are performed to describe different cases of breaking wave impacts at the wave scale. The main purpose is to assess short duration pressure peak involved in impulsive loads. The academical case of a triangular wedge hitting a vertical wall allows to investigate the origin of pressure peak and connect their magnitudes to the local interface inclination. Theoretical results enable us to derive two semi-empirical laws which show that pressure peaks are very sensitive to angle variations for strong interface inclination, making thus theire assessment difficult. This result is illustrated on a breaking dam case for which mesh size has shown to have a great influence on the incident jet shape, revealing that pressure peak assessment requires to know accurately interface profile. The case of a breaking wave is treated by setting up a coupling approach (VOF / BEM). This method allows to accurately approximate the interface profile at the beginning of the breaking stage. Pressure peaks are in good agreement with the theoretical results for angles lower than 70°. Two differents types of impacts are then treated by applying results from triangular case to breaking wave jet and the influence of interface curvature on pressure peak evolution is studied
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3

Liu, Yue. "Two Dimensional PIC/MCC Simulations of RF CCPs with a Dielectric Side Wall." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066338.

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Un code de simulation de plasma à deux dimensions électrostatique à coordonnées cartésiennes Particle-in-cell/ Monte Carlo Collision (PIC/MCC) est présenté, incluant un nouveau traitement de l'équilibre des charges aux limites diélectriques. Il est utilisé pour simuler un plasma dans le gaz Ar dans un réacteur à plaques parallèles à couplage capacitif à radiofréquence a géométrie symétrique avec une paroi latérale diélectrique épaisse. La paroi latérale diélectrique protège efficacement le plasma du champ électrique augmenté au niveau de la jonction entre l'électrode alimentée et l'électrode à la masse, dont on a montré précédemment qu'elle produisait une augmentation localise de la densité de plasma. Néanmoins, un réchauffement accru des électrons est observé dans une région adjacente à la limite diélectrique, conduisant à des maxima de le taux d'ionisation, de la densité du plasma et du flux ionique vers les électrodes dans cette région. Les différents composants du chauffage électronique sont dérivés des simulations PIC/MCC et montrent que cette augmentation du chauffage électronique provient d'un chauffage ohmique accru dans la direction axiale lorsque la densité électronique diminue vers la paroi latérale. Nous avons étudié la validité de différentes formules analytiques pour estimer le chauffage ohmique en les comparant aux résultats PIC. Le chauffage des électrons à composantes x a proximité des coins a été observé aux fréquences d'excitation plus élevées, provenant d'un champ RF oscillant important dans la direction x
A Cartesian-coordinate two-dimensional electrostatic Particle-in-cell/Monte-Carlo Collision (PIC/MCC) plasma simulation code is presented, including a new treatment of charge balance at dielectric boundaries. It is used to simulate an Ar plasma in a symmetric radiofrequency capacitively-coupled parallel-plate reactor with a thick dielectric side-wall. The dielectric side-wall effectively shields the plasma from the enhanced electric field at the powered-grounded electrode junction, which has previously been shown to produce locally enhanced plasma density. Nevertheless, enhanced electron heating is observed in a region adjacent to the dielectric boundary, leading to maxima in ionization rate, plasma density and ion flux to the electrodes in this region. The electron heating components are derived from the PIC/MCC simulations and show that this enhanced electron heating results from increased Ohmic heating in the axial direction as the electron density decreases towards the side-wall. We investigated the validity of different analytical formulas to estimate the Ohmic heating by comparing them to the PIC results. The x component electron heating near the corners was observed at higher driving frequency, which is caused by a significant RF oscillating field in the x direction
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4

Charly, Sigogne. "Contribution à l'analyse de l'évaluation du risque de foudroiement d'un site. Application au pic du midi de Bigorre." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3039/document.

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Le but principal des travaux dont fait l’objet cette thèse, consiste à estimer le risque de foudroiement d’une structure ou d’un site. Un modèle de protection a donc été développé afin d’évaluer les probabilités d’impact sur chaque partie d’une structure complexe. Ce modèle, qui est une évolution du modèle électrogéométrique servant de référence dans les normes de protection, permet notamment d’identifier « très finement » les zones les plus vulnérables de cette structure, quel que soit le type de coup de foudre. À cet effet, une analyse statistique des données du réseau de détection a également été menée et intégrée au modèle pour tenir compte du type de coup de foudre ou encore du contexte géographique. Dans le but de valider ce modèle, celui-ci a été appliqué au site du Pic du Midi de Bigorre, au sommet duquel un ensemble de diagnostics électriques et optiques a été installé. Ce site en altitude présente une structure relativement complexe de par la présence de divers bâtiments et d’une antenne de télédiffusion. Les mesures expérimentales recueillies sur ce site ont mis en évidence le foudroiement quasi systématique de cette antenne, validant ainsi les résultats fournis par le modèle. Par ailleurs, les différents phénomènes physiques mis en jeu lors du foudroiement d’une structure en altitude ont été étudiés grâce à l’instrumentation développée au sommet du Pic du Midi de Bigorre : sondes de courant, capteurs de champ et réseau de caméras. Les différentes phases d’un coup de foudre ont notamment été analysées à partir des mesures des variations rapides du champ électrique. L’analyse de ces variations à l’échelle de la cellule orageuse a également mis en évidence le fait que des décharges apparaissant à plusieurs dizaines de kilomètres du Pic du Midi peuvent initier un coup de foudre ascendant sur le site. Enfin, à partir de l’allure du courant écoulé lors d’un coup de foudre, déduite des enregistrements vidéo d’une caméra rapide, la polarité et le sens de propagation (descendant ou ascendant) de ces coups de foudre ont pu être associés à leurs caractéristiques temporelles et aux quantités de charges consommées au cours de leurs développements
The main purpose of this thesis work is to estimate the risk of a structure or a site being struck by lightning. A lightning protection model was developed with the aim to calculate the impact probability on every part of a complex structure. This model is an evolution of the electrogeometric model used as a reference in the lightning protection standards. In particular it allows identifying the most vulnerable areas of the structure, regardless of the type of lightning. To this end, a statistical analysis of the detection network data was also conducted and integrated in the model to take into account the type of flash or the geographical context. In order to validate this model, it was applied to the site of the Pic du Midi de Bigorre, at the top of which several electrical and optical diagnostics were installed. This site in altitude has a relatively complex structure because of the presence of various buildings and a broadcast antenna. The experimental measurements collected on this site show that the broadcast antenna is struck almost systematically which is in line with the results provided by the model. In addition the different physical phenomena involved during a lightning strike on a structure in altitude were studied using the instrumentation developed at the top of the Pic du Midi de Bigorre: current probes, electric field sensors and video cameras. In particular the different phases of a flash were analyzed from the measurements of the electric field variations. The analysis of the latters at the storm cell scale also highlighted the fact that flashes occurring to tens of kilometers from the Pic du Midi can initiate an upward flash on the site. Finally, the lightning current shape was deduced from video recordings of a high-speed camera. Thus the polarity and the propagation direction (upward or downward) of these flashes were associated with their temporal characteristics and with the charges consumed during their development
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5

Tavant, Antoine. "Study of the plasma/wall interaction and erosion on a plasma thruster of low power." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX085.

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Les moteurs électriques pour satellites, qui accélèrent les ions d'un plasma, sont primordiaux pour le succès des missions spatiales (GPS, météo, communication, etc.).Le moteur à effet Hall fait partie des technologies les plus performantes et utilisées.Cependant, sa conception et son optimisation sont longs et coûteux, car des processus clefs sont encore mal compris, en particulier, le transport des électrons et l'interaction plasma-paroi.Afin d'étudier ces deux phénomènes, nous utilisons une simulation cinétique bidimensionnelle.Grace aux résultats de simulation 2D, nous avons mis en évidence que les électrons sont non-locaux, car ils sont absorbés plus vite aux parois qu'ils ne sont thermalisés par les collisions.En conséquence, nous avons développé un modèle de gaine avec une loi d'état polytropique pour les électrons, qui décrit plus précisément l'interaction plasma-surface.Ce modèle peut être utilisé en présence, ou non, d'émission électronique secondaire.Lorsque l'émission secondaire est présente, le modèle de gaine présente jusqu'à trois solutions, ce qui explique les oscillations de gaines observées dans les simulations
Electric propulsion systems that accelerate plasma ions are important for the success of spatial missions (GPS, weather forecast, communication, etc.).The Hall effect thruster is one of the most used and efficient technology.However, its conception and optimization is slow and costly, as key processes are still poorly understood, in particular the electron transport and the plasma-wall interaction.In order to study both phenomena, we use a bi-dimensional kinetic simulation.We showed with 2D PIC simulation results that electrons are non-local, as they are absorbed more quickly at the wall compared to the collision frequency.Consequently, we derived a non-isothermal sheath model using a polytropic state law for the electrons that describes more accurately the plasma-wall interaction.The model can be used with and without secondary electron emission.With electron emission, the sheath model can present up to three solutions, explaining the oscillations observed in the simulations.The azimuthal instability observed, responsible for the electron transport, is compared to the dispersion relation of the ion acoustic wave and the electron cyclotron drift instability.We show that, while the first linear stage of the instability is well understood, the saturated quasi-steady-state is affected by particle-wave interactions and non-linear mechanisms that are not included in the dispersion relation
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6

Baraka, Suleiman. "Etude de l'interaction entre le vent solaire et la magnétosphère de la terre : modèle théorique et application sur l'analyse de données de l'événement du Halloween d'octobre 2003." Paris 6, 2007. http://www.theses.fr/2007PA066008.

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Une nouvelle approche, utilisant un code électromagnétique en 3D (PIC), est présentée pour étudier la sensibilité de la magnétosphère de la terre à la variabilité du vent solaire. Avec un vent solaire empiétant sur une terre magnétisée, le temps a été laissé au système pour atteindre une structure magnétosphérique à l'état d'équilibre. Par la suite, afin de simuler une dépression dans la pression dynamique du vent solaire, une perturbation impulsive a été appliquée au système en changeant la vitesse du vent solaire, pour un champ magnétique interplanétaire(IMF) inexistant, orienté nord ou sud respectivement. La perturbation appliquée induit un effet de trou d'air qui pourrait être décrit comme un espace quasi-vide de largeur ~15Re, et qui est formé pour tous les cas de IMF. Dès que le trou d’air atteint le « bow shock » de la magnétosphère régulière, une reconnexion entre le champ magnétique de la terre et le IMF sud a été notée sur le coté jour de la magnétopause(MP). Pendant la phase d'expansion du système, la frontière externe de la MP s’est brisée côté jour lorsque l’IMF=0, mais a conservé sa forme de balle pour un IMF orienté sud ou nord. Le temps de relaxation de la MP a été étudie par la suite pour les trois cas de IMF. Le code est finalement appliqué pour étudier l'événement d’Halloween de l’activité solaire en octobre 2003. Notre simulation a généré dans ce cas un espace raréfié, une sorte de trou d’air, qui a été produit suite un gradient fort dans l’IMF appliqué. Une telle structure est tout à fait semblable à l’anomalie d’écoulement chaud et peut en avoir la même origine
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7

Cherkhani, Rochdi. "Simulations numériques de phénomènes non linéaires dans les systèmes faisceau d'ions-plasmas." Nancy 1, 1993. http://www.theses.fr/1993NAN10297.

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Cette étude concerne la simulation numérique de phénomènes non-linéaires dans les systèmes faisceau d'ions-plasma (F. I. P. ). Dans une première partie, on étudie le régime non-linéaire de l'instabilité acoustique ionique engendrée par l'injection d'un faisceau d'ions dans le plasma. Cette étude a été menée en utilisant successivement un code P. I. C, puis un code eulérien de Vlasov à conditions aux limites périodiques. On observe dans les deux cas la croissance de l'instabilité acoustique ionique, puis la formation de vortex, dans l'espace des phases, associée à la saturation non-linéaire. L'étude détaillée des modes de Fourier et des mécanismes de couplage non-linéaire de ces modes pour des choix de conditions initiales différents permet de montrer l'importance de ce choix pour simuler une instabilité de type faisceau-plasma démarrant naturellement à partir des fluctuations thermiques. Grace à la stabilité du code de la dynamique de coalescence des vortex après la saturation a pu être étudiée sur des temps longs. Dans une deuxième partie, on étudie le système faisceau d'ions plasma perturbé de façon transitoire, à l'aide du code Vlasov adapté à des conditions aux limites non-périodiques. Des expériences avaient montré la formation de structures de type bosse et creux en arrière du choc électrostatique induit par une perturbation de type échelon sur la vitesse du faisceau d'ions. Nous avons pu reproduire ces résultats expérimentaux et interpréter les oscillations de grande amplitude observées dans le puits de potentiel en terme d'instabilité acoustique ionique localisée. Par ailleurs, nous présentons des simulations de propagation de perturbations localisées de type soliton dans les systèmes F. I. P. Les résultats obtenus tendent à confirmer l'hypothèse que le puits de potentiel observé en arrière du choc est bien associé à l'évolution non-linéaire de la réponse portée par le mode lent
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8

Pebernet, Laura. "Etude d'un modèle Particle-In-Cell dans une approximation Galerkin discontinue pour les équations de Maxwell-Vlasov : recherche d'une solution hybride non conforme efficace." Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1080/.

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Cette thèse présente l'étude et le développement d'un outil de simulation numérique efficace pour la modélisation de l'interaction plasma/micro-ondes, à partir d'un solveur électromagnétique basé sur une approximation Galerkin Discontinue (GD). Le travail est organisé en deux parties principales. Tout d'abord, nous développons un modèle Particle-In-Cell (PIC) approprié au schéma GD. Pour cela, d'une part, nous proposons un modèle de correction hyperbolique pour la prise en compte de la loi de conservation de la charge et, d'autre part, nous intégrons des modèles physiques propres au plasma tels que les sources micro-ondes de forte puissance, les surfaces d'émission de particules et les faisceaux d'électrons. Ensuite, nous nous orientons vers la recherche de performances optimales pour le couplage Maxwell-Vlasov afin d'augmenter l'efficacité et la taille des applications à traiter. Cette recherche conduit à l'étude d'une hybridation non conforme de méthodes pour résoudre le problème Maxwell-Vlasov. Dans un premier temps, nous travaillons sur une méthode hybride entre différents schémas numériques pour la résolution d'un problème Maxwell 1D sur des maillages non conformes. Dans un second temps, nous nous intéressons au cas d'un problème 2D en mode TE, dans l'optique d'introduire un modèle PIC. Finalement, nous réalisons une hybridation FDTD/FDTD sur deux maillages non coïncidents pour les équations Maxwell-Vlasov 2D
This thesis presents the study and the development of an efficient numerical simulation's tool for the modeling of plasma/microwave interaction in an electromagnetic software based upon a Discontinuous Galerkin (DG) scheme. This work is organized following two main steps. First, we develop a Particle-In-Cell (PIC) model appropriate for DG scheme. For this, on the one hand, we propose a hyperbolic corrector method to take into account the charge conservation law and, on the other hand, we integrate physical plasma models such as high power microwave sources, emission particles surfaces and electrons beams. Then, we propose also optimal performances for the coupling of Maxwell-Vlasov equations in order to increase the efficiency and the size of the applications to treat. This leads to study a non conformal hybridization of methods to solve the Maxwell-Vlasov problem. In the first time, we work on a hybrid method between different numerical schemes to solve a 1D Maxwell problem on non conformal meshes. In the second time, we interest in a 2D TE Maxwell problem, in order to introduce a PIC model. Finally, we realise a FDTD/FDTD hybridization on two non coincident meshes for the 2D Maxwell-Vlasov system
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9

Lutz, Mathieu. "Etude mathématique et numérique d'un modèle gyrocinétique incluant des effets électromagnétiques pour la simulation d'un plasma de Tokamak." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAD036/document.

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Cette thèse propose différentes méthodes théoriques et numériques pour simuler à coût réduit le comportement des plasmas ou des faisceaux de particules chargées sous l’action d’un champ magnétique fort. Outre le champ magnétique externe, chaque particule est soumise à champ électromagnétique créé par les particules elles-mêmes. Dans les modèles cinétiques, les particules sont représentées par une fonction de distribution f(x,v,t) qui vérifie l’équation de Vlasov. Afin de déterminer le champ électromagnétique, cette équation est couplée aux équations de Maxwell ou de Poisson. L’aspect champ magnétique fort est alors pris en compte par un dimensionnement adéquat qui fait apparaître un paramètre de perturbation singulière 1/ε
This thesis is devoted to the study of charged particle beams under the action of strong magnetic fields. In addition to the external magnetic field, each particle is submitted to an electromagnetic field created by the particles themselves. In kinetic models, the particles are represented by a distribution function f(x,v,t) solution of the Vlasov equation. To determine the electromagnetic field, this equation is coupled with the Maxwell equations or with the Poisson equation. The strong magnetic field assumption is translated by a scaling wich introduces a singular perturbation parameter 1/ε
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10

Michel, Bertrand. "Modélisation de la production d'hydrocarbures dans un bassin pétrolier." Phd thesis, Université Paris Sud - Paris XI, 2008. http://tel.archives-ouvertes.fr/tel-00345753.

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Cette thèse a pour objet la modélisation de la production pétrolière dans un bassin d'hydrocarbures. Le modèle proposé s'appuie sur une description probabiliste des réserves, de l'exploration des hydrocarbures et de la mise en production des gisements découverts. L'utilisation de la loi de Lévy-Pareto pour décrire les tailles des gisements s'appuie d'une part sur une description probabiliste de la formation des réserves au cours de l'évolution du temps géologique et d'autre part sur les propriétés d'invariance de la distribution de Poisson Dirichlet pour des processus de coalescence et de fragmentation, dans le cadre du modèle de Bolthausen Sznitman. Deux principaux problèmes statistiques, relevant tous les deux d'une problématique de choix de modèle en estimation de densité, sont identifiés. Le premier concerne l'estimation d'un modèle d'exploration pétrolière et le second est une étude de courbes de production qui repose sur une classification non supervisée et une sélection de variables pertinentes effectués via la sélection d'un modèle de mélange Gaussien. Dans les deux cas, un critère de maximum de vraisemblance pénalisé est défini pour obtenir une inégalité de type oracle. Le modèle global de production pétrolière d'un bassin ainsi obtenu permet d'une part de préciser la forme des profils de production de bassin et d'autre part de proposer des scénarios de prolongement de la production de bassin en cours d'exploitation.
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11

Borne, Junior José Ayrton de Souza. "RASTREABILIDADE BOVINA UTILIZANDO IDENTIFICAÇÃO POR RADIOFREQUÊNCIA EM PECUÁRIA DE PRECISÃO MODELO TEÓRICO." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/4818.

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This paper presents a theoretical model of electronic technology applied to Precision Farming and becomes a grant to further increase the use of Precision Farming, setting that is transforming the way you get the results from the works in the field. The design of a radio frequency identification system, currently known as RFID, to be used in the identification and traceability of cattle is the goal to be achieved. It seeks initially emphasize the definition and the use of the use of Precision Farming as a routine in the activities of the field in Brazil. How is the cattle industry and the Precision Farming definition are important items to achieve the proposed goal. The SISBOV system and traceability are presented, showing its importance, but not the obligation deployment along to landowners who work with the creation and marketing of cattle and their meat products. Shows the definition of microprocessors and microcontrollers, their internal architectures and all the associated peripherals to them and is also shown as the definition of embedded systems has made a revolution in the design of these. Plot a marketing scenario and use of electronic products in the Brazilian commercial sphere, indicating how the delay in using technology more turns in the electronics consumers than in technology trainers. Emphasizes in the principle of operation of RFID systems and which the communication protocols that are used. The reader RFID design and miniaturization of electronics has enabled the creation of a device with surface mount technology decreasing the dimensions of the printed circuit board and allowing the reduction of cost in the design of this system. We present all the peripherals that make it up and the way they connect with the master processor, including the slave processor which performs the digital input and output functions and the keyboard. Communication protocols and flowcharts show the use of known commercial channels in using software. The use of solar energy is presented as an alternative source of electric power supply in the operation of the reader equipment. The high cost of commercial RFID modules prevented the practical implementation of the system.
Este trabalho apresenta um modelo teórico da tecnologia eletrônica aplicada à Pecuária de Precisão e transforma-se em um subsídio a mais para incrementar o uso da Agricultura de Precisão, definição que está transformando a maneira como se obtém os resultados advindos do trabalho no campo. O projeto de um sistema de identificação por radiofrequência, conhecido atualmente como RFID, a ser utilizado na identificação e rastreabilidade de gado bovino é o objetivo a ser alcançado. Procura-se inicialmente enfatizar a definição e a utilização do uso da Agricultura de Precisão como uma rotina nas atividades do campo no Brasil. Como está à atividade pecuária e a definição de Pecuária de Precisão são itens importantes para alcançar o objetivo proposto. O sistema SISBOV e a rastreabilidade são apresentados, mostrando a sua importância, mas não a sua obrigação de implantação junto aos proprietários rurais que trabalham com a criação e comercialização de gado e seus produtos cárneos. Mostra-se a definição de microprocessadores e microcontroladores, suas arquiteturas internas e todos os periféricos associados a eles e também é mostrado como a definição de sistemas embarcados tem realizado uma revolução no projeto destes. Traça-se um cenário da comercialização e uso de produtos eletrônicos na esfera comercial brasileira, indicando como o atraso no uso da tecnologia nos transforma muito mais em consumidores de produtos eletrônicos do que em formadores de tecnologia. Enfatiza-se o princípio de funcionamento de sistemas RFID e quais os protocolos de comunicação que são utilizados. O projeto do leitor RFID e a miniaturização da eletrônica possibilitou a criação de um equipamento com tecnologia de montagem em superfície diminuindo as dimensões da placa de circuito impresso e possibilitando a diminuição do custo no projeto deste sistema. Apresentam-se todos os periféricos que o compõem e a maneira como se interligam com o processador mestre, inclusive o processador escravo o qual executa as funções de entrada e saída digitais e o teclado. Protocolos de comunicação e fluxogramas evidenciam a utilização de canais conhecidos comercialmente na utilização de software. O uso da energia solar apresenta-se como uma alternativa de fornecimento de alimentação elétrica no funcionamento do equipamento leitor. O alto custo dos módulos RFID comerciais inviabilizou a parte prática do sistema.
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Motta, Neto Cl?vis Coutinho da. "Haemulidae, modelo cariot?pico de estase evolutiva." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12497.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Os perciformes constituem o maior e mais diversificado grupo de peixes. Uma parcela consider?vel de suas esp?cies apresenta um marcante conservadorismo cromoss?mico exibindo um padr?o caracterizado por 2n=48a, NF=48, que tem sido apontado como uma condi??o basal para a Ordem. Blocos heterocrom?ticos reduzidos e RONs simples s?o caracter?sticos para este grupo de peixes. No entanto, n?o se encontra ainda bem estabelecido se este conservadorismo se deve, em parte, a dados provenientes de bandamentos cromoss?micos pouco resolutivos, como os convencionalmente utilizados nas caracteriza??es citogen?ticas das esp?cies marinhas ou a uma condi??o peculiar cariot?pica deste grupo. Visando clarificar os processos envolvidos no peculiar conservadorismo cromoss?mico observado nesta Ordem, cinco esp?cies da fam?lia Haemulidae foram submetidas ? variadas t?cnicas citogen?ticas como colora??o com Giemsa, bandamento C e impregna??o por nitrato de prata, bem como digest?o com enzimas de restri??o (AluI, TaqI, PstI e EcoRI), bandamento de replica??o pela incorpora??o do an?logo de base 5 BrdU, colora??o com os fluorocromos CMA3/MM e DAPI, double FISH com sondas para as subunidades ribossomais 5S e 45S, sendo tamb?m analisadas morfometricamente atrav?s de morfometria geom?trica (MG). Os dados obtidos permitiram identificar um alto grau de similaridade cariot?pica neste grupo independente do n?vel de resolu??o das t?cnicas utilizadas. As esp?cies Conodon nobilis, Pomadasys corvinaeformis, Haemulon aurolineatum, H. plumierii e H. steindachneri apresentaram uma macroestrutura cariot?pica comum composta por 2n=48a (NF=48), com RONs simples localizadas em um mesmo par cromoss?mico (24? par) nas esp?cies C. nobilis, H. aurolineatum H. plumierii e H. steindachneri e em outro par em P. corvinaeformis (18? par), considerando-se estas regi?es caracteres citotaxon?micos pouco importantes. O padr?o heterocrom?tico apresentou-se similar para todas as esp?cies, observando-se reduzidos blocos heterocrom?ticos detectados preferencialmente em regi?o centrom?ricas e em menor n?mero em regi?es pericentrom?ricas e telom?ricas. Contrastando com a reduzida diferencia??o cromoss?mica observada, as an?lises por MG indicaram uma consp?cua diferencia??o morfol?gica entre as esp?cies. Condi??es ambientais com reduzidas barreiras biogeogr?ficas, caracter?sticas biol?gicas, decorrente da presen?a de grandes contingentes populacionais uniformemente distribu?dos em largas ?reas costeiras, que promoveriam a manuten??o do fluxo g?nico dentro das popula??es, associadas ?s caracter?sticas cariot?picas peculiares, poderiam desempenhar uma a??o sin?rgica contribuindo para a evolu??o bradit?lica do cari?tipo nas esp?cies de Haemulidae
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Cornieles, Ernesto. "Développement d'un module de réglage automatique d'un compensateur PID Dual Loop." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0025/NQ37375.pdf.

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14

Menand, Stéphane. "Analyse et validation d'un modèle de comportement directionnel des outils de forage monobloc pdc." Phd thesis, École Nationale Supérieure des Mines de Paris, 2001. http://pastel.archives-ouvertes.fr/pastel-00000017.

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La prédiction du comportement directionnel d'un système de forage nécessite d'établir un modèle de comportement directionnel de l'outil de forage. Par une approche cinématique et sur la base d'une simplification de la structure de coupe de l'outil, le modèle élaboré aboutit à une loi reliant les efforts moyens exercés sur l'outil au déplacement de ce dernier. Chaque partie de l'outil, à savoir, la structure de coupe, la garde active et la garde passive, a une influence distincte sur le comportement directionnel en terme d'angle de walk et de forabilité latérale. Les essais effectués au laboratoire valident les prédictions du modèle théorique développé. La tendance de walk de l'outil peut être alors obtenue à partir de simples critères géométriques décrivant le profil de l'outil. Le modèle d'interaction outil-roche développé couplé avec un code de calcul 3D du comportement mécanique de la garniture devrait déboucher sur un outil performant pour la prédiction de l'inclinaison et de l'azimut des trajectoires de forage.
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15

Mouroux, Mireille. "Le PICA induit par rotation chez le rat : modèle de screening de molécules antinaupathiques." Paris 5, 1991. http://www.theses.fr/1991PA05P150.

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Menand, Stéphane. "Analyse et validation d'un modèle de comportement directionnel des outils de forage monoblocs PDC." Paris, ENMP, 2001. http://www.theses.fr/2001ENMP1051.

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La prédiction du comportement directionnel d'un système de forage nécessite d'établir un modèle de comportement directionnel de l'outil de forage. Par une approche cinématique et sur la base d'une simplification de la structure de coupe de l'outil, le modèle élaboré aboutit à une loi reliant les efforts moyens exercés sur l'outil au déplacement de ce dernier. Chaque partie de l'outil, à savoir, la structure de coupe, la garde active et la garde passive, a une influence distincte sur le comportement directionnel en terme d'angle de Walk et de forabilité latérale. Les essais effectués au laboratoire valident les prédictions du modèle théorique développé. La tendance de walk de l'outil peut être alors oBbtenue à partir de simples critères géométriques décrivant le profil de l'outil. Le modèle d'interaction outil-roche développé couplé avec un code de calcul 3D du comportement mécanique de la garniture devrait déboucher sur un outil performant pour la prédiction de l'inclinaison et de l'azimut des trajectoires de forage.
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17

Vinceller, Sonia. "Effets de l'extinction thermique de la luminescence sur les phénomènes thermostimulées présentés par le pic dosimétrique de l'alumine alpha." Toulouse 3, 2002. http://www.theses.fr/2002TOU30140.

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18

Diop, Daouda. "PIB comparés des différents pays d’Europe occidentale depuis le traité de Rome (1957-2007)." Strasbourg, 2011. https://publication-theses.unistra.fr/public/theses_doctorat/2011/DIOP_Daouda_2011.pdf.

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Cette thèse intitulée PIB comparés des différents pays d’Europe occidentale depuis le traité de Rome (1957-2007) est une étude comparative des croissances économiques entre l’Europe des 15 (plus la Suisse) et les Etats-Unis, des débuts de la construction européenne jusqu’à la crise des subprimes. Les recherches se fondent sur les données constituées par l’Université de Groningue, la Banque mondiale et l’Université de Pennsylvanie. L’analyse fait apparaître deux grandes phases : une phase de forte croissance (1949-1973) et une phase de décélération (1986-2007) séparées par une période de crises (1973-1986). Ce sont les pays d’Europe méridionale qui ont connu les croissances les plus rapides durant la première phase, ce qui fait apparaître la prédominance de l’effet de rattrapage comme principal facteur du dynamisme européen avant l’ouverture des frontières. Les recherches montrent aussi durant cette période, le dynamisme économique des pays à fort transfert de population en provenance du secteur agricole (Europe des six, Autriche, Finlande). Le phénomène de la stagflation causé entre 1973 et 1986 par les chocs pétroliers marque la fin de l’embellie des «Trente Glorieuses». La période 1986 et 2007 laisse apparaître la persistance durable de la décélération dans les espaces économiques nationaux européens. L’écart de la croissance se creuse entre les Etats-Unis et les pays d’Europe occidentale et seuls l’Irlande, le Portugal, le Luxembourg et le Royaume-Uni échappent à ce déclin relatif. Après 1986, le levier fondamental de la croissance économique n’est plus le rattrapage ou le transfert de population active en provenance de l’agriculture, mais le commerce extérieur
This thesis on GDP of different countries of Western Europe compared since the treaty of Rome (1957-2007) is a comparative study of economic growth among the EU 15 (and Switzerland) and United States since the beginning of unification of Europe to the subprime crisis. The research is based on the databases of university of Groningen, world bank and university of Pennsylvania. The analysis of the groxth disparities revealed two major trends : a high-growth phase (1949-1973) and a deceleration phase (1986- 2007) interrupted by a period of crisis (1973-1986). The southern European countries have experienced the fastest growth in the first phase, confirming the predominance of catch-up effect as the main factor of European dynamism before the opening of the borders. Research also shows during this period, strong growth in countries with high transfer of agricultural population (Europe of six, Austria, Finland…). The phenomenon of stagflation caused by the oil crises between 1973 and 1986 marked the end of the upturn of the "Thirty Glorious Years". The period between 1986 and 2007 reveals the persistence of the slowdown in european national economic spaces. The growth gap is widening between the U. S. And Western European countries. Only Ireland, Portugal, Luxembourg and the United Kingdom escape this relative decline. After 1986, the main engine of growth is not longer the catch-up effect nor the agricultural population transfer, but the international trade
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19

Woicik, Richard. "A FLEXIBLE MULTIFUNCTION TELEMETRY INPUT/OUTPUT MODULE." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606458.

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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Many high-performance, reconfigurable data functions can now be integrated into a single PCI circuit board, making possible low-cost and complex systems using PCs or UNIX workstations. FPGA and PCI technologies are an excellent match to telemetry applications where commercial off-the-shelf solutions are desired, but customization is common and performance critical. A Multifunction Telemetry I/O (MFT) module was designed to exploit these technologies for both flight test and space telemetry ground systems. The reconfigurability of the module has facilitated evolutionary hardware enhancements as well as custom applications. These enhancements have been used both as building blocks for system integrators and for commercial-off-the-shelf (COTS) graphic setup, processing, archiving, and display software. The MFT module includes a standard set of telemetry functions: up to two bit synchronizers, an IRIG time decoder, and two independent telemetry serial input and output channels. The MFT module is also available on a 6U VME board. This paper describes some of the proven capabilities and applications of this module.
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Moretti, Alex Sandro. "Um modelo de controle de dispositivos através do barramento PCI." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/84703.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.
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Este trabalho é direcionado ao desenvolvimento de um protocolo PCI, o qual foi aqui denominado, Core PCI. O Core PCI é um núcleo que contém os controles básicos de acesso a um dispositivo PCI de 32bits e 33Mhz. Ele foi desenvolvido para uso geral, por isso, somente foram implementados, os acessos a dispositivos de I/O, mapeados como RAM. Neste trabalho são descritos detalhes e características do barramento PCI, tais como: sinais do barramento, funcionamento do protocolo de transação de dados, configuração plug and play e inicialização dos dispositivos PCI no boot do computador. Também se encontram, detalhes de uma aplicação usando o Core PCI e um software de alto nível para controle da aplicação. O Core PCI foi desenvolvido em um chip FPGA, utilizando-se de uma linguagem de descrição de hardware VHDL e utilizando-se também de simuladores para o código VHDL. Ainda neste
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21

Ntayiya, Witness Sakumzi. "Evaluating the quality of care for sexually transmitted infections (STI) in 14 primary health care (PHC) facilities in Umjindi local municipality, Mpumalanga Province." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&amp.

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The overall aim of this study was to evaluate quality of STI services in Umjindi local municipality. A concrete objective was to investigate the health system issues that may have a negative impact in the provision of quality STI service in the local municipality. These include accessibility of the STI services to the community, training of health workers in syndromic management, availability of necessary equipment and supplies for STI management, turn-around time for blood results and infrastructure of the facilities.
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22

Motloung, Setumo Victor. "Intense pulsed neutron generation based on the principle of Plasma Immersion Ion Implantation (PI3) technique." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9599_1182748458.

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The development of a deuterium-deuterium/ tritium-deuterium (D-D/ D-T) pulsed neutron generator based on the principle of the Plasma Immersion Ion Implantation (PI3) technique is presented, in terms of investigating development of a compact system to generate an ultra short burst of mono-energetic neutrons (of order 1010 per second) during a short period of time (<
20&mu
s) at repetition rates up to 1 kHz. The system will facilitate neutron detection techniques, such as neutron back-scattering, neutron radiography and time-of-flight activation analysis.


Aspects addressed in developing the system includes (a) characterizing the neutron spectra generated as a function of the target configuration/ design to ensure a sustained intense neutron flux for long periods of time, (b) the system was also characterised as a function of power supply operating conditions such as voltage, current, gas pressure and plasma density.

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Nicolais, Ray, Stephen J. Nicolo, and Ed Snyder. "HARDWARE DOWNLOADABLE MULTI-FUNCTION TELEMETRY INPUT MODULE." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/608271.

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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California
This paper describes a Multi-Function Telemetry Input Module (TIM). The TIM module includes a 30 Mbps PCM frame synchronizer, a time code translator/generator, a PCM simulator and a tunable bit synchronizer all on a single PCI card. The module uses a generic architecture including: high density Field Programmable Gate Arrays (FPGAs), look-up table memory, dual port A/B data buffer memory and a full function PCI interface. The FPGA and the logic function of the card are downloadable via the PCI interface. This allows a single module to support many hardware functions in a telemetry front-end. The TIM is an integral part of a PC-based Advanced Telemetry Processing and Display System. This concept for hardware design ushers in a new generation of flexible downloadable telemetry products.
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24

Gauthier, Thierry. "Etude des mécanismes d'actions de SuperMApo dans un modèle de sclérose en plaques." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCE010/document.

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La sclérose en plaques (SEP) est une maladie auto-immmune notamment marquée par une défaillance de la mise en place des mécanismes de réparation tissulaire, ne permettant pas de rétablir l'homéostasie. L'utilisation de la résolution de l'inflammation, médiée par les. macrophages phagocytant des cellules apoptotiques. a récemment été évoquée afin de proposer une nouvelle famille de médicaments basée 1 sur cette résolution de l'inflammation. Dans ce cadre, nous proposons de résoudre l'inflammation dans un modèle murin de SEP, à l'aide du surnageant de co-culture de macrophages ayant phagocyté des cellules apoptotiques. induisant la production de facteurs pro-résolutifs (SuperMApo). Nous démontrons ici que l'injection de SuperMApo dans un modéle de SEP permet de contrôler la maladie via une reprogrammation des macrophages et des pDC, mais pas des cDC. dans la rate. Ces cellules démontrent en effet une capacité accrue à générer des T régulateurs (Treg) et moins de Th1, et leur présence est nécessaire pour l'effet du SuperMApo. Cette reprogrammation se fait à deux niveaux moléculaires. Premièrement. un contrôle épigénétique de l'expression des gènes induit notamment une modification de la méthylation globale de I' ADN et des promoteurs de miRNA impliqués dans la régulation des réponses immunes. Deuxièmement, une diminution de l'activation des acteurs de la voie de transcription pro-inflammatoire NFκB (nuclear factor kappa 8) a lieu. résultant d'une baisse de l'activation de ces cellules. Ces travaux démontrent donc que cibler la résolution de l'inflammation est une stratégie intéressante afin de contrôler la SEP
Multiple sclerosis (MS) is an autoimmune disease notably delined bv a default of mechanisms of tissue reparation which are insufficient to establish homeostasis. The active resolution of innammation mediated by macrophage effcrocytosis of apoptotic cells has emerged to propose a new branch of pharmacology named "resolution pharmacology". ln this study. we propose to resolve innammation in a murine model of MS. using the supermatanl issued from the culture between apoptotic cells and macrophages. inducing efferocytosis and the production of pro-resolutive factors (SuperMApo). Here. we demonstrate that injection of SupcrMApo in a model of MS allow the control of the disease correlated with a reduction of the inflammatory inliltrate in the central nervous system. The control of the disease is associated with a reprograrnming of macrophages and pDC, but not cDC, in the spleen, demonstrated by a higher capacity to generate Treg and a lower ability to generate Th 1, and their presence is necessary to the anti-innammatory effect of SupcrMApo. Reprogramming of macrophages and pDC occurs at two main levels. First. an epigenetic control of gene expression induces a modulation of global DNA methylation and a modulation of DNA methylation at the promoter of miRNA implicated in the regulation of immune responses. Secondly, a decreased activation of NFκB activation pathway is observed resulting to a decreased activation of these cells. Thus, this work demonstrates that targeting the resolution of inflammation is an interesting strategy to treat MS
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Mazzag, Barbara Cathrine. "Mathematical models in biology /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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Uhl, Juli D. "Hox Specificity: Constrained vs. Flexible Requirements for the PBC and MEIS Cofactors." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397234792.

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27

Choe, Kyung-Il. "Aisle-based order pick systems with batching, zoning, and sorting." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/25429.

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Gramacy, Robert B. "Bayesian treed Gaussian process models /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2005. http://uclibs.org/PID/11984.

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29

Chuenpibal, Tanitpong. "If I pick up non-normality, can robust models make it better?" Thesis, University of Exeter, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434877.

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Gavin, Gérald Zighed Djamel Abdelkader. "Etude du modèle d'apprentissage Probablement Approximativement Correct (PAC) application aux méthodes d'agrégation /." [S.l.] : [s.n.], 2001. http://theses.univ-lyon2.fr/Theses2001/gavin_g/these.pdf.

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31

Seeger, Matthias. "Bayesian Gaussian process models : PAC-Bayesian generalisation error bounds and sparse approximations." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/321.

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Non-parametric models and techniques enjoy a growing popularity in the field of machine learning, and among these Bayesian inference for Gaussian process (GP) models has recently received significant attention. We feel that GP priors should be part of the standard toolbox for constructing models relevant to machine learning in the same way as parametric linear models are, and the results in this thesis help to remove some obstacles on the way towards this goal. In the first main chapter, we provide a distribution-free finite sample bound on the difference between generalisation and empirical (training) error for GP classification methods. While the general theorem (the PAC-Bayesian bound) is not new, we give a much simplified and somewhat generalised derivation and point out the underlying core technique (convex duality) explicitly. Furthermore, the application to GP models is novel (to our knowledge). A central feature of this bound is that its quality depends crucially on task knowledge being encoded faithfully in the model and prior distributions, so there is a mutual benefit between a sharp theoretical guarantee and empirically well-established statistical practices. Extensive simulations on real-world classification tasks indicate an impressive tightness of the bound, in spite of the fact that many previous bounds for related kernel machines fail to give non-trivial guarantees in this practically relevant regime. In the second main chapter, sparse approximations are developed to address the problem of the unfavourable scaling of most GP techniques with large training sets. Due to its high importance in practice, this problem has received a lot of attention recently. We demonstrate the tractability and usefulness of simple greedy forward selection with information-theoretic criteria previously used in active learning (or sequential design) and develop generic schemes for automatic model selection with many (hyper)parameters. We suggest two new generic schemes and evaluate some of their variants on large real-world classification and regression tasks. These schemes and their underlying principles (which are clearly stated and analysed) can be applied to obtain sparse approximations for a wide regime of GP models far beyond the special cases we studied here.
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Ferreira, Roberto Tatiwa. "Forecasting quarterly brazilian GDP growth rate with linear and non linear diffusion inex models." reponame:Repositório Institucional da UFC, 2005. http://www.repositorio.ufc.br/handle/riufc/659.

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FERREIRA, Roberto Tatiwa. Forecasting quarterly brazilian GDP growth rate with linear and nonlinear diffusion index models. Tese (Doutorado). Universidade Federal do Ceará, Programa de Pós Graduação em Economia, CAEN, Fortaleza, 2005.
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The present study uses linear and non-linear diffusion index models to produce one-step-ahead forecast of quarterly Brazilian GDP growth rate. Diffusion index models are like dynamic factors models. These factors are latent variables that represent a common property from the explanatory variables, then allowing a considerably reduction of its number in econometric models elaborated to attend the main objective of this work. The non-linear diffusion index models used in this thesis are not only parsimonious ones, but also they try to capture economic cycles using for this goal a Threshold diffusion index model and a Markov-Switching diffusion index model. The former is used, besides for forecasting purpose, also to test if there is a non-linear pattern in the quarterly Brazilian GDP growth rate.
Esta Tese estuda modelos lineares e não lineares de índices de difusão para prever, em um período à frente, a taxa de crescimento trimestral do PIB brasileiro. Os modelos de índice de difusão assemelham-se aos modelos de fatores dinâmicos. Estes fatores são variáveis não observáveis e representam uma característica em comum às variáveis explicativas, permitindo a redução significativa do número dessas no modelo econométrico proposto para atender o objetivo principal deste trabalho. Além de parcimoniosos, os modelos utilizados nesta Tese se propõem a capitar as fases de recessão e expansão econômica, através de modelos não lineares do tipo Threshold Effect e Markov-Switching, servindo o primeiro destes dois para testar a hipótese de que existe não linearidades na variável sob estudo.
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33

Baklík, Radim. "Analýza měření PID degradace FV modulů na bázi křemíku." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-319634.

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Diploma thesis deals with crystalline solar modules i relation to PID phenomenon. The thesis focuses on methods of investigation of changing electrical parameters, in the course of PID degradation, such as prallel resistance and leakage current. The effect of degradation will be examined by V-A characteristics and by electroluminiscence method.
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34

Lee, Lik Wee. "Critical behaviour of spin glass models /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2006. http://uclibs.org/PID/11984.

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35

Skordis, Constantinos. "The accelerating universe : models and consequences /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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36

Zhang, Chun. "Hidden Markov models for admixture mapping /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.

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37

Rodriguez, Marko A. "Models of computing in semantic networks /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2007. http://uclibs.org/PID/11984.

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38

Santos, Anabela Marques. "Análise dos efeitos do programa de iniciativa comunitária LEADER na região Alentejo, entre 1991 e 2006." Master's thesis, Universidade de Évora, 2012. http://hdl.handle.net/10174/14938.

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A presente dissertação assenta no desenvolvimento de um estudo empírico baseado na apreciação dos resultados do Programa de Iniciativa Comunitário LEADER no Alentejo, entre 1991 e 2006, com recurso a modelos de regressão. Esta análise encontra o seu fundamento na análise do comportamento do investimento realizado por projecto no âmbito deste Programa, para a qual foram utilizadas variáveis explicativas que se identificam com os objectivos deste instrumento de Política Desenvolvimento Rural. Para a estimação do modelo recorreu-se o modelo exponencial de Poisson, utilizando o programa STATA e o método da quasi-máxima verossimilhança. O estudo permitiu concluir, entre outros, que ao longo das três fases do PIC LEADER que decorreram entre 1991 e 2006, o programa permitiu fomentar o empreendedorismo na região Alentejo e originou uma especialização do investimento realizado em torno de três sectores de actividade (turismo, agro-indústria e gastronomia), considerados como estratégicos; ABSTRACT: This dissertation is based on the development of an empirical study on assessment of the results of LEADER Community Initiative Programme in Alentejo’s region, in Portugal, between 1991 and 2006, using regression models. This analysis finds its basis on the analysis of the behavior of investment per project under this program, for which have been used explanatory variables that identify with the objectives of this policy instrument of Rural Development. To estimate the model we used the exponential Poisson model, utilizing the STATA and the method of quasi-maximum likelihood. The study concluded, among others, that during the three phases of the CIP LEADER that took place between 1991 and 2006, the program promote entrepreneurship in Alentejo’s region and produced a specialization of the investment around three sectors (tourism, agro-industry and gastronomy), considered as strategic; RÉSUMÉ: La présente dissertation est basée sur le développement d'une étude empirique fondée sur l'appréciation des résultats du Programme Initiative Communautaire LEADER dans la région Alentejo, au Portugal, entre 1991 et 2006, en utilisant des modèles de régression. Cette exposé trouve son fondement dans l'analyse du comportement de l'investissement par projet dans le cadre de ce programme, pour la quelle ont été utilisées des variables explicatives qui s’identifie aux objectifs de cet instrument de Politique de Développement Rural. Pour estimer le modèle, nous avons eu recours au modèle exponentiel de Poisson, en utilisant le software STATA et la méthode de quasi-maximum de vraisemblance. L'étude a conclu, entre autres, que, durant les trois phases du PIC LEADER qui a eu lieu entre 1991 et 2006, le programme a permit d’encourager l'entrepreneuriat dans la région Alentejo et a conduit à une spécialisation de l'investissement autour de trois secteurs (tourisme, agro-industrie et gastronomie), considéré comme stratégique; RESUMEN: Esta disertación está basada en el desarrollo de un estudio empírico fundado en la apreciación de los resultados del Programa de Iniciativa Comunitaria LEADER la región Alentejo, en Portugal, entre 1991 y 2006, utilizando modelos de regresión. Esta investigación encuentra su fundamento en el análisis de comportamiento de la inversión por proyecto bajo este programa, para el cual se utilizaron variables explicativas que se identifican con los objetivos de este instrumento de la Política de Desarrollo Rural. Para estimar el modelo se recurrió al modelo exponencial de Poisson, utilizando el software STATA y el método de cuasi máxima verosimilitud. El estudio concluyó, entre otras, que durante las tres fases del PIC LEADER, que tuvo lugar entre 1991 y 2006, el programa fomento el espíritu empresarial en la región Alentejo y llevó a una especialización de la inversión en torno a tres sectores (turismo, agroindustria y gastronomía), considerado como estratégico.
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39

Awasthi, Pranjal. "Approximation Algorithms and New Models for Clustering and Learning." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/266.

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This thesis is divided into two parts. In part one, we study the k-median and the k-means clustering problems. We take a different approach than the traditional worst case analysis models. We show that by looking at certain well motivated stable instances, one can design much better approximation algorithms for these problems. Our algorithms achieve arbitrarily good approximation factors on stable instances, something which is provably hard on worst case instances. We also study a different model for clustering which introduces limited amount of interaction with the user. Such interactive models are very popular in the context of learning algorithms but their effectiveness for clustering is not well understood. We present promising theoretical and experimental results in this direction. The second part of the thesis studies the design of provably good learning algorithms which work under adversarial noise. One of the fundamental problems in this area is to understand the learnability of the class of disjunctions of Boolean variables. We design a learning algorithm which improves on the guarantees of the previously best known result for this problem. In addition, the techniques used seem fairly general and promising to be applicable to a wider class of problems. We also propose a new model for learning with queries. This model restricts the algorithms ability to only ask certain “local” queries. We motivate the need for the model and show that one can design efficient local query algorithms for a wide class of problems.
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40

Bandeira, Patr?cia Bock. "Motiva??es para a carreira empreendedora segundo o modelo de carreira caleidosc?pica." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/7831.

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This study was conducted within the Group of Studies in Career Development of the field of Social Psychology, in the Psychology Faculty of Pontif?cia Universidade Cat?lica do Rio Grande do Sul. The research?s main objective was to investigate the female entrepreneurial career in order to understand its motivations under a contemporary career model: the Kaleidoscopic Career Model. Brazil is among the top 10 countries with the highest rates of entrepreneurship in the world, with almost equivalent rates between men and women - the difference is less than 2. Although female entrepreneurship growth has been 16% in the last 10 years compared to male?s 7%, this activity is still strongly associated with male careers. In this context, the specificities of female entrepreneurship may be overshadowed, just as there is a difference between the motivations that lead women and men to open their own businesses. Therefore, the general objective of this research was to verify if there are differences between men and women regarding their motivations for entrepreneurship, according to the parameters of the Kaleidoscopic Career, theoretical model developed based on female career trajectories. To achieve this goal, a narrative review of the literature on the model was carried out, which analyzed 16 articles available in national and international scientific databases on the Kaleidoscopic Career Model, and its relation with female career trajectories. Afterwards, the first empirical study that composes this dissertation has adapted this instrument to Brazilian context within a sample of 272 Brazilian professionals. For the validation, confirmatory factorial analysis has been used, with maximum likelihood estimation method. The final version of the scale presented 19 items, distributed in the predicted factors, with precision values of: Balance (?=.78), Challenge (?=.76) and Authenticity (?=.65). Using this adapted scale, the second empirical study aimed to verify if there is difference between women?s and men?s motivation for opening their own businesses. In addition to the Kaleidoscopic Career Parameter Scale adapted to Brazilian context, a sociodemographic survey and entrepreneurial trajectory and business characteristics questionnaire were used with the respondents. The sample was composed by 416 professionals, in which 54.6% were women and 48.6% were entrepreneurs. Although professionals with their own business had significantly higher averages (M = 3.86) compared to non-entrepreneurs in Challenge parameter [M = 3.53; F (416,1) = 15.15; p <0.001, ?? = 0,4], there was no significant difference between the parameters according to respondent?s sex. Corroborating this result, the main reasons for opening a company - identification of business opportunity, desire for autonomy and work according to personal values - were the most frequently answers among male and female entrepreneurs. By contributing to demystify the idea that the motivations for female entrepreneurship are essentially different from the masculine, we expect results to contribute for a greater awareness and promotion of female entrepreneurship.
Este estudo foi realizado junto ao Grupo de Estudos em Desenvolvimento de Carreira da ?rea de concentra??o em Psicologia Social, da Faculdade de Psicologia da Pontif?cia Universidade Cat?lica do Rio Grande do Sul, e teve como principal objetivo investigar a carreira empreendedora feminina no intuito de compreender suas motiva??es ? luz de um dos modelos de carreira contempor?neos: o Modelo de Carreira Caleidosc?pica. O Brasil est? entre os 10 pa?ses com as maiores taxas de empreendedorismo do mundo, com ?ndices quase equivalentes entre homens e mulheres - a diferen?a ? inferior a 2%. Embora o crescimento do empreendedorismo feminino tenha sido de 16% nos ?ltimos 10 anos ante 7% do masculino, essa atividade ainda ? fortemente associada a carreiras masculinas. Nesse contexto, podem-se ofuscar especificidades do empreendedorismo feminino, tais como poss?veis diferen?as entre as motiva??es de mulheres e homens para empreender. Neste sentido, o objetivo geral desta pesquisa foi verificar se h? diferen?as entre homens e mulheres em rela??o ?s motiva??es para o empreendedorismo, segundo os par?metros da Carreira Caleidosc?pica, modelo te?rico desenvolvido com base nas trajet?rias de carreira femininas. Para atingir esse objetivo, realizou-se primeiramente uma revis?o narrativa da literatura sobre o modelo, que analisou 16 artigos dispon?veis em bases de dados nacionais e internacionais a respeito do Modelo de Carreira Caleidosc?pica e sua rela??o com as trajet?rias de carreira femininas. Ap?s, foi conduzido o primeiro estudo emp?rico que comp?e esta disserta??o, que adaptou o instrumento para mensura??o dos par?metros do modelo utilizando uma amostra de 272 profissionais brasileiros. Para a valida??o, realizou-se an?lises fatoriais confirmat?rias, com m?todo de estima??o da m?xima verossimilhan?a. A vers?o final apresentou 19 itens, distribu?dos nos fatores previstos, com os valores do coeficiente de precis?o: Balan?o (?=,78), Crescimento (?=,76) e Autenticidade (?=,65). Utilizando a escala adaptada, realizou-se o segundo estudo emp?rico com o objetivo de averiguar se h? e como se d? a diferen?a entre mulheres e homens ao optarem por abrir seus pr?prios neg?cios. Al?m da Escala de Par?metros da Carreira Caleidosc?pica adaptada para o contexto brasileiro, foi utilizado um question?rio sociodemogr?fico e um acerca da trajet?ria empreendedora e caracter?sticas dos neg?cios dos participantes empres?rios. Participaram desta etapa 416 profissionais maiores de idade, dos quais 54,6% mulheres e 48,6% empreendedores. Embora profissionais que possuam um neg?cio pr?prio tenham apresentado m?dias significativamente mais altas (M=3,86) em rela??o a n?o-empreendedores no par?metro Crescimento [M=3,53; F(416,1)=15,15; p<0,001, ?? = 0,4], n?o foi verificada diferen?a significativa entre os par?metros segundo o sexo. Corroborando este resultado, as principais raz?es para abertura da empresa ? identifica??o de oportunidade de neg?cio, desejo por autonomia e atua??o segundo valores pessoais ? foram as mais frequentemente citadas entre empreendedoras e empreendedores. Ao contribuir para desmistificar a ideia de que as motiva??es para o empreendedorismo feminino sejam essencialmente diferentes do masculino, espera-se ampliar a conscientiza??o sobre e a promo??o desta atividade, especialmente entre mulheres.
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41

Bezerra, Claudionor Gomes. "Modelo de Ashkin-Teller anisotr?pico: uma abordagem por grupo de renormaliza??o." Universidade Federal do Rio Grande do Norte, 1994. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16617.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Estudamos as propriedades cr?ticas (diagrama de fases e classes de universalidade) do modelo de Ashkin-Teller anisotr?pico ferromagn?tico, cujo hamiltoniano ? dado por: H = -∑_()▒〖{J1TiTj+J2σiσj+J4σiσjTiTj}〗 com: J1 + J2 ≥ 0, J1 + J4 ≥ 0 , J2 + J4 ≥ 0, ( σ, r = ? 1 ). Utilizamos o m?todo do Grupo de Renormaliza??o no espa?o real, aplicado a uma rede hier?rquica que serve como aproxima??o para a rede quadrada. Observamos a exist?ncia de 5 fases : (i) Paramagn?tica ( P : < σ > =< Ƭ > =< σƬ >= 0) ; (ii) Intermedi?ria ( I : < σ > =< Ƭ >= 0, < σƬ > ≠ 0) ; (iii) Ferromagn?tica ( F : < σ > ≠ 0, < Ƭ > ≠ 0, < σƬ > ≠ 0) ; (iv) Ferro σ ( Fσ : < σ > ≠ 0, < Ƭ >=< σƬ >= 0 ) ; (v) Ferro σ ( FƬ : < Ƭ > ≠ 0, < σ >=< σƬ >= 0 ). As fronteiras cr?ticas obtidas reproduzem todos os valores exatos conhecidos (em pontos especiais) para a rede quadrada
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42

Mokrani, Nassim. "Modélisation comportementale du système pantographe-caténaire et stratégies de commande." Thesis, Amiens, 2015. http://www.theses.fr/2015AMIE0026.

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Le système pantographe–caténaire (PAC) est un maillon vital de la chaîne de transmission d'énergie électrique aux moteurs de traction électrique ferroviaire. Ce système est complexe à cause de la nature dynamique de ses composants, qui sont en outre, soumis à diverses sollicitations physiques et environnementales. Il est donc important de bien modéliser et d'analyser le PAC afin d'élaborer des méthodologies adéquates d'analyse, de modélisation et de commande. Dans cette thèse, le travail présenté commence par une étude approfondie du modèle du système PAC en tenant compte des paramètres et des phénomènes physiques du PAC. En premier lieu, un modèle mathématique à base de la méthode des Éléments Finis du système PAC est proposé. En second lieu, et pour des raisons de commande et de régulation, nous proposons un modèle simplifié qui représente suffisamment bien le comportement dynamique du système. L'un de nos objectifs est d'améliorer le contact entre l'archet du pantographe et la caténaire dans le but de garantir un minimum d'usure tout en ayant une alimentation électrique permanente et régulière pour les trains à grande vitesse. La problématique est donc de maintenir une force de contact constante et régulière entre le pantographe et la caténaire dans des limites acceptables et en tenant compte des perturbations occurrentes. Dans cet esprit, nous avons développé des commandes robustes pour améliorer le contact entre le pantographe et la caténaire. Par ailleurs, les aspects pratiques de cette thèse se reflètent par la réalisation et la mise en œuvre d'un banc d'essai pantographe actif/caténaire et le développement d’un logiciel de gestion et de simulation du système PAC
The pantograph-catenary system (PAC) is a vital link in the electrical power transmission chain to the railway electric traction motors. This system is complex due to the dynamic nature of its components, which are subject to various physical and environmental stresses. It is therefore important to model and analyze the PAC to develop appropriate methodologies for analysis, modeling and control. In this thesis, the presented work begins with a thorough study of the PAC model, taking into account the parameters and physical phenomena of the PAC. First, a mathematical model based on the Finite Elements method of the PAC system is proposed. Second, for reasons of control and regulation, we propose a simplified model that adequately represents the dynamic behavior of the system. One of our goals is to improve the contact between the pantograph head and overhead contact line in order to ensure minimum wear while having a permanent and regular power supply for high-speed trains. So the problem is to maintain a constant and regular contact force between the pantograph and the catenary, within acceptable limits and taking into account disturbances. With this in mind, we have developed robust controls to improve the contact between the pantograph and the catenary. The practical aspect of this thesis is reflected by the creation and implementation of a test bed for the pantograph-active/catenary and the development of a management and simulation software for PAC system
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43

Levade, Thierry. "Sphingomyelinases humaines et metabolisme de la sphingomyeline : modele cellulaire en culture des maladies de niemann-pick." Toulouse 3, 1986. http://www.theses.fr/1986TOU30167.

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44

Fang, Fang. "Développement et valorisation d'un modèle animal de gale sarcoptique. Evaluation de molécules acaricides." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC0077/document.

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Sarcoptes scabiei est un acarien ectoparasite obligatoire. Sa présence dans la couche cornée de l’épiderme est à l’origine d’une gale dite sarcoptique. Cette ectoparasitose a été décrite chez 104 espèces de mammifères représentant 27 familles distinctes. Les traitements actuels de la gale sarcoptique ne sont pas toujours satisfaisants et il n’existe pas de produits qui permettent d’éliminer S. scabiei dans l’environnement. Par ailleurs, la diversité génétique de S. scabiei n’est pas clairement définie et l’unicité de l’espèce fait toujours l’objet de controverses.L’objectif de cette thèse a été d’évaluer l’efficacité d’acaricides vis-à-vis de S. scabiei en utilisant un modèle animal ou par le biais de tests in vitro. La diversité génétique d’isolats d’origine animale a également été étudiée. La première partie du travail de thèse a concerné un essai thérapeutique L’efficacité d’une administration orale unique d’afoxolaner, une molécule du groupe des isoaxazolines, a été évaluée sur des porcs expérimentalement infestés. Le critère principal d’évaluation a été la réduction du nombre de sarcoptes mis en évidence dans les raclages cutanés. Huit jours après le traitement, aucun sarcopte n’a été détecté sur les 4 porcs ayant reçu l’afoxolaner alors que des sarcoptes étaient toujours présents sur les 3 porcs ayant reçu de l’ivermectine. Tous les porcs traités étaient guéris à la fin de l’essai (J35) alors que les animaux non traités sont demeurés infestés. Les autres critères d’évaluation étaient l’évolution du score clinique et de prurit. Les lésions cutanées ont rapidement régressé dans le groupe traité par l’afoxolaner alors qu’elles étaient encore présentes à J14 dans le groupe traité avec l’ivermectine. La deuxième partie du travail de thèse a porté sur l’évaluation in vitro de différentes molécules ou produits acaricides. Plusieurs concentrations d’une solution d’ivermectin ou de moxidectine ainsi 11 huiles essentielles ont été testées. Après 24h de contact avec l’ivermectine et la moxidectine, la dose létale 50% étaient de 150,2±31,4 µg/mL et 608,3±88,0 µg/mL, respectivement. Une concentration inférieure à 1 ng/mL (pour l’ivermectine) ou à 10 ng/mL (pour la moxidectine) n’a aucune activité acaricide. Pour les huiles essentielles, des tests par fumigation et par immersion ont été réalisés. Parmi Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara et 3 l’huile essentielle identifiée (BOB4, BOB5, BOB9) testés par immersion, l’huile essentielle identifiée BOB4 s’est révélée la plus efficace (une solution à 1% tue tous les acariens en 20 min). Parmi les 10 huiles essentielles énumérées avant, plus Juniperus oxycedrus testés par immersion, l’huile essentielle de Melaleuca altenifolia s’est révélée la plus efficace (tous les acariens sont morts en 4 min). Pour le contrôle de S. scabiei dans l’environnement, différents biocides ou répulsifs ont été examinés. La durée moyenne de survie a été calculée pour les produits comportant de la perméthrine, de l’esdépallethrine et de la bioresmethrine, de la bifenthrine, de la cyperméthrine et de l’imiprothrine, de la cyfluthrine, de la tétramethrine et de la sumithrine, du DEET, de l’icaridine et le produit IR3535. La deuxième partie du travail de thèse a porté sur la diversité génétique d’isolats de S. scabiei provenant d’animaux. Une partie du gène cox1 a été amplifiée. L’analyse des séquences ainsi obtenues semble montrer que les sarcoptes circulant chez le Chien sont issus de population de sarcoptes d’origine humaine
Sarcoptes scabiei is an ectoparasite responsible for the emerging/re-emerging disease called scabies in humans or mange in animals. It was reported in 104 species across 27 families of domestic and wild animals. Current treatments for scabies/mange are limited and there are no efficient products for the environment control of S. scabiei. Moreover, the taxonomic status of S. scabiei is still under controversy and the question remains that whether it represents a single species or several taxa.The objectives of the thesis were to assess the susceptibility to acaricides and analyse the genetic diversity of S. scabiei from animals. In the first part of the thesis, an animal model was used to evaluate the efficacy of afoxolaner, a new acaricide from the isoaxazoline family. The primary outcome of efficacy was based on the reduction in the number of live mites counted in skin scrapings following treatment. At day 8, four afoxolaner-treated pigs (out of four) were mite-free, while mites were still found in three (out of three) ivermectin-treated pigs. All treated pigs were cured at the end of the study (day 35) and all pigs in the control group remained infected. Secondary outcomes included measures on the reduction of skin lesions and pruritus. The clinical lesions of scabies infection were allowed to disappear completely for all the pigs in the afoxolaner group but not in the ivermectin group at 14 days after the treatment. An increase of the pruritus was observed right after treatment, followed by a decrease of the pruritus score in both treated groups. The second part of the thesis was to evaluate the scabicidal effect of molecules or products using an in vitro test. A gradient of concentrations of ivermectin and moxidectin as well as 11 essential oils have been evaluated in vitro against S. scabiei. After 24h of exposure to ivermectin and moxidectin, the median lethal concentrations were 150.2±31.4 µg/mL and 608.3±88.0 µg/mL, respectively. Doses of ivermectin under 1 ng/mL and moxidectin under 10 ng/mL showed no scabicidal effect. Fumigation and contact bioassays were used for the assessment of essential oils efficacy. Among Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara and 3 other unknown oils (BOB4, BOB5, BOB9) tested with the contact bioassay, the essential oil identified as BOB4 demonstrated the best scabicidal effect (1% solution killed all the mites in 20 min). Among the 10 essential oils listed before plus Juniperus oxycedrus with the fumigation bioassay, the oil Melaleuca altenifolia demonstrated the best scabicidal effect (all the mites died in only 4 min). For environmental control of S. scabiei, the efficacy of biocides or repellents was assessed. The median survival time was calculated for permethrin (4% and 0.6%), esdepallethrin and bioresmethrin, bifenthrin, cypermethrin and imiprothrin, cyfluthrin, tetramethrin and sumithrin, DEET (25% and 50%), icaridin and IR3535. The third part of the thesis included the study of the genetic diversity of populations of S. scabiei from animals. A part of cox1 was used for phylogenetic analyses. The results showed that Sarcoptes mites from dogs seem to derive from humans
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45

Jin, Wenlong. "Kinematic wave models of network vehicular traffic /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.

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46

Mainguy, Thomas. "Processus de substitution markoviens : un modèle statistique pour la linguistique." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066354/document.

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Ce travail de thèse propose une nouvelle approche au traitement des langues naturelles. Plutôt qu'essayer d'estimer directement la probabilité d'une phrase quelconque, nous identifions des structures syntaxiques dans le langage, qui peuvent être utilisées pour modifier et créer de nouvelles phrases à partir d'un échantillon initial. L'étude des structures syntaxiques est accomplie avec des ensembles de substitution Markoviens, ensembles de chaînes de caractères qui peuvent être échangées sans affecter la distribution. Ces ensembles définissent des processus de substitution Markoviens qui modélisent l'indépendance conditionnelle de certaines chaînes vis-À-Vis de leur contexte. Ce point de vue décompose l'analyse du langage en deux parties, une phase de sélection de modèle, où les ensembles de substitution sont sélectionnés, et une phase d'estimation des paramètres, où les fréquences pour chaque ensemble sont estimées. Nous montrons que ces processus constituent des familles exponentielles quand la structure du langage est fixée. Lorsque la structure du langage est inconnue, nous proposons des méthodes pour identifier des ensembles de substitution à partir d'un échantillon, et pour estimer les paramètres de la distribution. Les ensembles de substitution ont quelques relations avec les grammaires hors-Contexte, qui peuvent être utilisées pour aider l'analyse. Nous construisons alors des dynamiques invariantes pour les processus de substitution. Elles peuvent être utilisées pour calculer l'estimateur du maximum de vraisemblance. En effet, les processus de substitution peuvent être vus comme la limite thermodynamique de la mesure invariante d'une dynamique de crossing-Over
This thesis proposes a new approach to natural language processing. Rather than trying to estimate directly the probability distribution of a random sentence, we will detect syntactic structures in the language, which can be used to modify and create new sentences from an initial sample.The study of syntactic structures will be done using Markov substitute sets, sets of strings that can be freely substituted in any sentence without affecting the whole distribution. These sets define the notion of Markov substitute processes, modelling conditional independence of certain substrings (given by the sets) with respect to their context. This point of view splits the issue of language analysis into two parts, a model selection stage where Markov substitute sets are selected, and a parameter estimation stage where the actual frequencies for each set are estimated.We show that these substitute processes form exponential families of distributions, when the language structure (the Markov substitute sets) is fixed. On the other hand, when the language structure is unknown, we propose methods to identify Markov substitute sets from a statistical sample, and to estimate the parameters of the distribution. Markov substitute sets show some connections with context-Free grammars, that can be used to help the analysis. We then proceed to build invariant dynamics for Markov substitute processes. They can among other things be used to effectively compute the maximum likelihood estimate. Indeed, Markov substitute models can be seen as the thermodynamical limit of the invariant measure of crossing-Over dynamics
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47

Miranda, Jorge Umberto Ramalho. "Os fundos permanentes na Casa Pia de Lisboa." Master's thesis, Universidade de Évora, 2015. http://hdl.handle.net/10174/16219.

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Pretende-se com este Relatório Profissional fazer uma descrição detalhada do curriculum vitae que comprove a experiência e atividade profissional desenvolvida no âmbito da especialidade do Mestrado, assim como a apresentação de um tema relacionado com o mesmo. O tema escolhido para desenvolvimento e discussão nas provas foi “Os Fundos Permanentes na Casa Pia de Lisboa”, na medida em que o candidato, enquanto técnico superior na UAF (Unidade de Assuntos Financeiros) dos Serviços Centrais (SC) da CPL (Casa Pia de Lisboa, Instituto Público), é corresponsável pela operacionalização do processo de Gestão do Património/subprocesso dos Fundos Permanentes. Deste modo, justifica-se a importância deste trabalho pela apresentação do tema, na medida em que permite avaliar a identificação e descrição da gestão dos Fundos Permanentes na CPL, que estabeleça a uniformidade de procedimentos e modelos/impressos, por forma a garantir uma informação mais rigorosa e fidedigna e uma fácil consolidação pela UAF da CPL e pela descrição detalhada do curriculum vitae, na medida em que permite avaliar as minhas habilitações académicas e profissionais, bem como minhas habilitações sociais. Finalmente pretende-se demonstrar que o mestrando possui competências equivalentes ou superiores às do estudante que obtém o grau de Mestre em Gestão com o plano curricular da mesma edição do curso; The Permanent Funds at Casa Pia de Lisboa ABSTRACT: The aim of this Professional Report is to present a detailed description of the curriculum vitae to make proof that the professional activity and experience acquired within the Master’s degree, as well as the presentation of one of the studied topics. The elected theme for presentation and discussion was "The Permanent Funds at Casa Pia de Lisboa", because the candidate, as a senior technician in the UAF (Financial Affairs Unit) of SC (Central Services) of the CPL (Casa Pia de Lisboa), is co-responsible for the Heritage Management process / subprocess of Permanent Funds. Thus, this is a very important essay because of the theme presentation that allows to evaluate the identification and description of the management of the Permanent Funds in CPL, which must be able to establish regular procedures and templates/ forms, in order to ensure more accurate and reliable data as well as the strong position of the UAF CPL. The detailed description of the curriculum vitae, allows the evaluation of my academic and professional skills as well as my social skills. As a conclusion, it aims to prove that the master candidate have the same or more skills as a student who gets the degree with the regular study plan.
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48

Ismail, Aneesah. "Characterisation of Eight Non-Codis Ministrs in Four South African Populations to Aid The Analysis of Degraded Dna." Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9258_1280766024.

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In many forensic cases, such as mass disasters reconstruction cases, the recovered DNA is highly degraded. In such incidences, typing of STR loci has become one of the most powerful tools for retrieving information from the degraded DNA. However, as DNA degradation proceeds, three phenomena occur consecutively: loci imbalance, allele dropout and no amplification. To solve the problem of degraded DNA, redesigned primer sets have been developed in which the primers were positioned as close as possible to the STR repeat region. These reduced primer sets were called Miniplexes. Unfortunately, a few of the CODIS STR loci cannot be made into smaller amplicons. For this reason non-CODIS miniSTRs have been developed. The present study was undertaken for the population genetic analysis of microsatellite variation in four South African populations
Afrikaner, Xhosa, Mixed Ancestry and Asian Indian using eight non-CODIS miniSTR loci. These miniSTRs loci were characterized within the populations by estimating the levels of diversity of the markers, estimating the population genetic parameters, and studying the inter-population relationships. All of the miniSTRs were amplified successfully and the genetic variability parameters across all loci in Afrikaner, Mixed Ancestry, Asian Indian and Xhosa were estimated to be in the range of 3 (D4S2364) to 12 (D9S2157) alleles, the total number of alleles over all loci ranged from 100 to 204, the allelic richness ranged from 3.612 to 10.307 and the heterozygosity ranged from 0.4360 to 0.8073. Genetic distance was least between Afrikaner and Asian Indian and highest between Xhosa and Mixed Ancestry. Deviations from Hardy-Weinberg equilibrium were not observed for most of the loci. The low mean FIS (-0.027) and FIT (-0.010) and FST (0.017) values across the populations indicated low level of inbreeding within (FIS) and among (FST) the populations. The Asian Indian population showed higher levels of the inbreeding coefficient, indicating less gene exchange between it and other populations. These 8 markers can be used for genetic investigations and assessing population structure. The study contributed to the knowledge and genetic characterization of four South African populations. In addition, these MiniSTRs prove to be useful in cases where more genetic information is needed.

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Schmelzer, Kara Renee. "Oxidized lipids in systemic and lung inflammatory models /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2005. http://uclibs.org/PID/11984.

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50

Sokhansanj, Bahrad Ali. "Mathematical models of human DNA base excision repair /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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