Grande parte do sucesso do Google provêm do algoritmo Page Rank, que avalia quantitativamente a importância de cada página na web. Esta ordenação é obtida através do vetor estacionário de uma matriz estocástica específica, utilizando o Método das Potências. A velocidade de convergência deste método será avaliada em detalhe, já que se trata de uma resposta imediata da pesquisa do usuário. Afim de entender as diferentes situações que o modelo pode enfrentar, diversas simulações são apresentadas neste trabalho. Em particular, estamos interessados nos fatores que influenciam a velocidade de convergência. Para tanto, o número de páginas total e de cada conjunto fechado, bem como o número de conjuntos fechados e de nós pendentes foram estudados. / Great part of Google\'s success comes from the Page Rank algorithm, wich quantitatively evaluates the importance of each page on the web. This sort is achieved through a specific stochastic matrix stationary vector, using the Power Method. The convergency speed of this method will be evaluated in details, since this is a imediate response for the user search. In order to understand the diferent situations the model can confront, several simulations are shown in this work. In particular, we are interested in the factors which influences the convergency speed. For that, the total and inside each closed set number of pages and also the closed sets and dangling nodes numbers were studied.

Cette thèse porte sur la localisation de sources acoustiques sous-marines avec application à une expérience en mer. Nous proposons une nouvelle méthode d'appariement basée sur une métrique appelée distance de Hausdorff (HD) en tant que fonction de coût à minimiser, afin d'effectuer l'inversion de localisation. La localisation 2D, en distance et en profondeur, est réalisée en faisant correspondre les schémas de différence de temps d'arrivée (TDOA) en utilisant un seul hydrophone à la réception et en faisant correspondre le TDOA et l'Angle d'arrivée (AOA) lors de l'utilisation d'un tableau des hydrophones à la réception, entre des séquences respectivement mesurées et modélisées. Le TDOA modélisé a été obtenu sur la base du modèle de propagation acoustique Ray-path. Les ensembles de données analysés ici ont été collectés dans un contexte de localisation passive en considérant une cible immobile et dans deux expériences : la cuve acoustique de GIPSA-LAB utilisant des systèmes coopératifs et non coopératifs vérifiés par des simulations du rapport signal sur bruit et sur la campagne ALMA 2015, collectée par la Direction générale de l'armement (DGA) en utilisant un système coopératif qui s'est déroulé dans un environnement en eaux peu profondes de la côte sud de la France. Au cours de l’expérience ALMA, les données acoustiques ont été mesurées sur un réseau linéaire vertical (VLA) de 10 m de haut, composé de 64 hydrophones, ce qui permet non seulement d’adapter le TDOA mais également l’angle d’arrivée (AOA). Plusieurs variantes de la distance de Hausdorff sont appliquées dans deux processus différents: premièrement, séparément dans chaque hydrophone, puis combinées pour améliorer la précision de la localisation (diversité spatiale), et la seconde où les informations des différents hydrophones sont combinées (formation de faisceaux), pour trouver l'emplacement cible. Les résultats des deux processus sont comparés et prouvés pour réduire l'ambiguïté soit la profondeur et la portée, améliorant ainsi la précision finale. Le Cramer Rao Bound montrant la variance minimale effectuée sur la base d’équations déterministes est présenté avec le meilleur résultat de chaque processus. Une performance et une précision très satisfaisantes sont obtenues. Les conclusions et les perspectives de ce travail sont discutées à la fin. / This thesis addresses an acoustic underwater source localization with application to an at-sea experiment. We propose a new matching method based on a fit-metric called as Hausdorff distance (HD) as a cost-function to be minimized, in order to perform the localization inversion. The 2-D localization, in range and depth, is performed by matching the patterns of time difference of arrival (TDOA) when using only one hydrophone at the reception and by matching the TDOA and the Angle of Arrival (AOA) when using an array of hydrophones at the reception, between respectively measured and modeled sequences. The modelled TDOA was obtained based on the Ray-path acoustic propagation model. The data sets analyzed here were collected during two experiments in a context of passive localization considering a motionless target: The tank of GIPSA-LAB using cooperative and non-cooperative systems which were verified by simulations with respect to the signal-to-noise ratio and the ALMA 2015, collected by the Direction générale de l’armement (DGA) using a cooperative system which took place in a shallow water environment of the southern coast of France. During the ALMA experiment the acoustic data were measured over a 10m-high vertical linear array (VLA), composed of 64 hydrophones, allowing not only matching the TDOA but also the Angle of Arrival (AOA). Several variants of the Hausdorff Distance are applied in two different processes: First, separately in each single hydrophone, and then combined in order to improve the localization accuracy (spatial diversity), and the second, the information from the different hydrophones are combined (beamforming) and the HD variants are applied to find the target location. The results of both processes are compared and proved to reduce the ambiguity either is depth and in range, thus improving the final accuracy. The Cramer Rao Bound showing the minimal variance performed based on deterministic equations is presented with the best result of each process. Very satisfactory performance and accuracy are obtained. The conclusions and perspectives of this work are discussed at the end.

Le travail présenté constitue une contribution méthodologique dans la séparation des anthraquinoïdes par chromatographie en phase liquide à haute performance à polarité inversée de phases. Cette amélioration a pour but ultime une meilleure détectabilité et caractérisation des composés constituant les colorants anthraquinoniques présents dans les objets du patrimoine culturel.Une série de 40 composés témoins, représentant un large éventail des structures possibles d’anthraquinoïdes a été utilisée pour la modélisation du comportement chromatographique de cette famille de composés.La première partie de cette recherche présente une étude comparative des performances des phases stationnaires greffées alkyle (C18). Ces performances sont décrites par le nombre de paires critiques ainsi que la symétrie de pics. Tenant compte de la dispersion des symétries de pic des différents composés sur différentes phases stationnaires nous avons proposé un nouvel indice global, le paramètre de symétrie d(TF;1) qui nous a permis de classer la totalité de phases selon leurs performances, et trouver celles se montrant les plus satisfaisantes.Face à des faibles différences de sélectivités des phases greffées octadécyle. Nous avons décidé de mettre en jeu d’autres mécanismes de rétention des anthraquinoïdes offerts par les phases fonctionnalisées.Le potentiel séparatif de phases fonctionnalisées a été évalué comme pour les précédentes et les phases les plus performantes ont été désignées.La comparaison globale des différentes phases stationnaires, aussi bien celles greffées octadécyle que celles fonctionnalisées, a été faite avec le coefficient de pertinence de colonnes (CSc), paramètre permettant d’englober le nombre de paires critiques et la symétrie de pics d’une manière univoque. Les diagrammes obtenus par projection des points correspondant aux coordonnées : coefficient de symétrie (Sc) et coefficient de paires critiques (CPc) – ont permis de choisir les phases aux propriétés désirées.Les différences de sélectivités des phases stationnaires étudiées, nous ont conduit à examiner leur orthogonalité en vue de la construction de systèmes séparatifs bi-dimensionnels. En se basant sur le critère de la qualité de séparation, nous avons employé une méthode de calcul de distances minimales et les moyennes arithmétique et harmonique de ces distances permettant de décrire l’étendue et l’homogénéité de la dispersion des pics sur une surface 2D. Cette méthode à été comparée avec les méthodes, classiques ou récentes, d’évaluation de la dispersion. Cette nouvelle approche a démontré son applicabilité à l’évaluation de pouvoir séparatif des systèmes 2D.Le travail expérimental mené principalement sur les standards est enrichi par quelques applications concrètes aux échantillons de colorants trouves dans des textiles historiques.Les résultats de cette recherche sont directement transférables dans des laboratoires impliqués dans l’analyse des anthraquinoïdes dans le but de l’identification des sources des colorants utilisées dans les objets du patrimoine culturel, mais aussi dans la caractérisation de ces composés dans le cadre de la recherche phytochimique, phytopharmacologique et autres. / This work contributes to the improvement in the separation of anthraquinoids by reversed phase high performance chromatography, the final target being setting down the detection limits and improving the characterisation of separated components of anthraquinoid dyes from the cultural heritage artefacts.A series of 40 standards representing large range of existing anthrquinoid structures was used for the modelling of chromatographic behaviour of that family of compounds.First part of that research show the comparative study of the performances of alkyl (C18) bonded stationary phases. These performances are expressed by number of critical pairs as well as by symmetry of peaks. Considering the dispersion of values of symmetry of various peaks on different stationary phases, we introduced a novel symmetry parameter d(TF;1), which allowed to range all stationary phases according to their “global” symmetry and to determine the most satisfactory ones.The selectivity of octadecyl bonded phases was little different each other, so it was decided to test the functionalised phases which could offer complementary retention mechanisms in the separation of anthraquinoid dyes in reversed phase systems.The separation efficiency of these phases was evaluated as before, and the most efficient phases were selected.The general comparison of all studied stationary phases, bonded with octadecyl and functionalised, was done with the column suitability coefficient (CSc), an univocal ranking parameter containing both descriptors: number of critical pairs and peaks’ symmetry. The diagrams obtained by projection of co-ordinates corresponding to the critical pairs’ coefficient (CPc) and symmetry coefficient (Sc) gives a choice of particular properties of phases.The different selectivity of several studied phases driven us to check out their orthogonality in the aim to built bi-dimensional separation systems. Using the separation efficiency criterion, we employed a minimal distances computation method as well as the arithmetic and harmonic means describing the extension and homogeneity of dispersion of peaks on 2D separation surface. This approach was compared with several other classical or recent methods of the evaluation of peak dispersion. It was demonstrated that our method is particularly useful in the comparison of separation power of 2D systems.The experimental work, mainly done with standards of anthraquinone derivatives, was illustrated by some applications to the real samples of dyestuffs found in historical textiles.The results of this research are directly transferable to the application laboratories involved in the analysis of anthraquinoids for the identification of sources of dyestuffs presents in cultural heritage artefacts, but also for their characterisation in phytochemistry, phytopharmacology and other research.

Stationary (static) shoulder friction stir welding (SSFSW) is a variant of conventional friction stir welding (FSW) that was originally invented to improve the quality of welds produced with titanium alloys. Its predominant advantage is a reduction of the severe through thickness temperature gradients seen in conventional FSW, when welding low thermal conductivity alloy. However, SSFSW has rarely been utilised as a method to weld aluminium alloys because it is generally thought that in conventional FSW the rotating shoulder plays an essential role in the heat generation and, due to the high thermal conductivity of aluminium alloys, a rotating shoulder is beneficial for the welding process. In the work presented, the advantages of SSFSW have been examined when welding a typical high strength aluminium alloy AA7050-T7651. The process window for each approach has first been determined, and the optimum welding conditions were systematically evaluated, using power-rotation rate curves. Direct comparison of the two processes was subsequently carried out under these optimum conditions. It has been demonstrated that SSFSW can dramatically improve the quality of a weld's surface finish. Under optimum conditions it has also been shown that SSFSW was able to weld with approximately a 30% lower heat input than FSW and the stationary shoulder led to a narrower heat affected zone (HAZ). As a result, the through thickness properties of SSFSW were much better and more homogeneous than that for FSW, in terms of grain sizes, hardness and cross-weld mechanical properties. Uniaxial tensile tests proved that the average tensile strength of SSFSW samples was around 500 MPa, which was about 100 MPa larger than that of the FSW sample. Also, it was shown that during tensile testing the deformation zones, which correspond to minima in the hardness distribution of SSFSW welds, were about half the size of those found in FSW welds under the same traverse speed. The mechanisms that give rise to these advantages have been investigated systematically, focusing on directly comparing the SSFSW and FSW processes, and are discussed aided by finite element modelling (FEM) of the heat distribution in welds produced by each process and microstructural investigations.

Grande parte do sucesso do Google provêm do algoritmo Page Rank, que avalia quantitativamente a importância de cada página na web. Esta ordenação é obtida através do vetor estacionário de uma matriz estocástica específica, utilizando o Método das Potências. A velocidade de convergência deste método será avaliada em detalhe, já que se trata de uma resposta imediata da pesquisa do usuário. Afim de entender as diferentes situações que o modelo pode enfrentar, diversas simulações são apresentadas neste trabalho. Em particular, estamos interessados nos fatores que influenciam a velocidade de convergência. Para tanto, o número de páginas total e de cada conjunto fechado, bem como o número de conjuntos fechados e de nós pendentes foram estudados. / Great part of Google\'s success comes from the Page Rank algorithm, wich quantitatively evaluates the importance of each page on the web. This sort is achieved through a specific stochastic matrix stationary vector, using the Power Method. The convergency speed of this method will be evaluated in details, since this is a imediate response for the user search. In order to understand the diferent situations the model can confront, several simulations are shown in this work. In particular, we are interested in the factors which influences the convergency speed. For that, the total and inside each closed set number of pages and also the closed sets and dangling nodes numbers were studied.

Neste trabalho é desenvolvido um sistema de controle ativo para supressão de flutter de uma asa utilizando-se sensores de pressão em pontos estratégicos de sua superfície. O flutter é um fenômeno aeroelástico que caracteriza um acoplamento instável entre estrutura flexível e escoamento aerodinâmico não estacionário. Quando a modificação da estrutura ou da aerodinâmica da asa não é viável, o uso de sistemas de controle passa a ser uma boa opção. Para o desenvolvimento do sistema de controle proposto, é primeiramente desenvolvido um modelo numérico de asa flexível. Com esse modelo numérico e a pressão na superfície da asa medida em certos pontos e realimentada ao sistema controlador, são determinadas correções no ângulo de uma superfície de controle no bordo de fuga. A tentativa de se utilizar um sistema de controle bem simples, com o uso de um único sensor de pressão, mostra a viabilidade de se implementar um sistema deste tipo em aeronaves reais. Esse sistema pode tornar-se uma alternativa aos desenvolvidos até então com o uso de acelerômetros, além de ser útil em sistemas onde se procura prever o estol e observar o comportamento da distribuição de pressão sobre a asa em vôo. / In this work, a wing flutter suppression active control system using pressure sensors in strategic points is developed. Flutter is an aeroelastic phenomenon characterized by an unstable coupling of a flexible structure and a non-stationary aerodynamic flow. When changes of the wing structure or of the aerodynamics are not viable, the use of automatic control systems becomes a good option. For the developing of the suggested control system, a numeric model of a finite flexible wing is firstly done. With this model and the pressure over the wing surface read in certain points and fedback to the control system, changes of the control surface angle on the trailing edge are determined. The attempt to use a simple control system, with a unique pressure sensor shows the viability of implanting this kind of system in real aircrafts. This system may become an alternative to those developed until now, using accelerometers. Yet, it could be useful, in systems where it is necessary to predict stall and observe the pressure load behavior over the wing in flight.

A bicicleta estacionária articulada é um tipo de equipamento disponibilizado recentemente ao mercado de fitness, consequentemente não explorado em estudos no meio acadêmico científico. Desta forma surgem alguns problemas de pesquisas, desde o fato da instrumentação deste equipamento até a escolha de metodologias e variáveis a serem estudadas para potencializar o seu uso. Este estudo foi realizado com o proposito de descrever as diferenças quanto ao padrão angular da pedalada do ciclista, ou seja, o ângulo do pedal relativo ao pedivela, utilizando-se desta nova bicicleta estacionária de ciclismo indoor, comparando a condição chassi fixo com o articulado. Para a instrumentação, foi acoplado um gerador e um encoder junto a roda de inércia tendo controle das variáveis carga e cadência. Para a medição do ângulo do pedal, os pedais (direito e esquerdo) da bicicleta foram substituídos por pedais instrumentados com potenciômetros, já para o registro do ângulo do pedivela, foi utilizado um sensor eletromagnético, do tipo reed switch. A amostra foi composta por cinco praticantes, todos devidamente adaptados com bicicletas de chassi articulado, submetidas a um protocolo pré-estabelecido, variando condição (fixo e articulado) e posição (pedalando no selim e em pé) com carga e cadência determinada. Embora a amplitude de movimento para ambos os pedais não apresentaram diferenças, em análise, os resultados apontaram que o uso do chassi articulado afeta o padrão angular do pedal durante o ciclo da pedalada, menos acentuado quando utilizou-se a posição sentado no selim, e mais acentuado quando estava-se pedalando em pé. Das posições no pedivela que apresentaram as diferenças no padrão angular durante o uso do chassi articulado, 80% foram na parte produtiva da pedalada (ângulo de 0° a 180°), e o ângulo de 150° concentrou 60% destas ocorrências. Já, tratando-se de forças no pedal, o chassi articulado apresenta evidência de ser mais eficiente do que o chassi fixo. / The stationary articulated bicycle is a type of equipment which is available to the fitness market only recently, and therefore it was not investigated in academic or scientific studies yet. Thus, this fact arises some problems of research, from the fact of instrumentation of this equipment to the choice of methods and variables to be studied to maximize its use. This study was conducted with the purpose to describe the differences in the angular pattern of cyclist pedaling, i.e., the angle on the pedal crank, using this new stationary bicycle of indoor cycling, by comparing the condition of the fixed chassis with the articulated one. For the instrumentation, a generator and an encoder were connected to the wheel of inertia, taking control of the load and cadence variables. To measure the angle of the pedal, the left and right pedals of the bicycle were replaced by pedals which were instrumented with potentiometers. To record the angle of the crank, we used an electromagnetic sensor, the reed switch. The sample consisted of five practitioners, all suitably adapted with articulated frame bicycles, which were subjected to a pre-established protocol, varying the condition (fixed or articulated), and the position (pedaling in the saddle or standing up), with determined load and cadence. The results indicated that the use of articulated frame affects the pattern of the pedal angle during the pedaling cycle, less marked when the sitting position on the saddle was used, and more pronounced when pedaling on the standing up position. About the positions of the crank that showed differences in angle while using the articulated frame: 80% were in the productive part of the pedaling (angle from 0° to 180°), and the angle of 150° concentrated 60% of these incidents. The amplitude of angular movement of the pedal showed no differences between fixed and articulated frame. However, in the case of forces on the pedal, the articulated frame shows evidence of being more efficient than the fixed frame.

In this study, four different chromatographic column chemistries (octadecylsilane/ C18, pentafluorophenyl/ PFP, octadecylated polystyrene-divinylbenzene/ PRP and underivatized silica/ HILIC) were compared under optimal conditions to evaluate the relative strengths and weaknesses of the phases for use in the determination of pain management drugs by LC-MS. Furthermore, different column scaffoldings, traditional silica, porous shell, and porous polymer, were also compared. The drugs included in this study included buprenorphine, fentanyl, methadone, naloxone, oxycodone, and tramadol. Factors such as peak area, peak resolution, theoretical plates, and reproducibility were compared among the columns and analytes using a 2-way analysis of variance (ANOVA). Because of the lipophilic nature of these drugs, the C18 columns tended to offer the best performance; however, PFP and PRP columns were viable alternatives. Finally, HILIC separation was also suitable for most of the compounds under study; often providing higher peak areas (sensitivity) likely associated with higher organic (% B) conditions, thus favoring mass spectrometric detection. To our knowledge, this is the first study to explore viability of other non-C18 stationary phases such as PRP and HILIC for this drug class.

Choosing a stationary phase is the first step in developing a liquid chromatography (LC) separation method, where the selectivity is governed by the differential interactions of the analytes with the stationary and mobile phases. Introducing a gradient in stationary phase functionality allows for tuning of analyte retention, translating to a possible improvement in selectivity and an increase in resolution versus that offered by uniform stationary phases. In this work, C18-silica, phenylbutyl-silica, and phenylbutyl-ammonium opposed continuous stationary phase gradients were fabricated using controlled rate infusion (CRI) on particle packed LC columns. Characterization of the stationary phase was carried out using spectroscopy and LC analysis to relate the ligand density gradient profile to the observed chromatographic parameters. C18-silica gradients were created with a time-dependent acid hydrolysis infusion and demonstrated an increase in resolution when combined with a mobile phase gradient. Phenylbutyl-silica and phenylbutyl-ammonium gradients were produced using an in-situ silanization CRI method. Phenylbutyl-silica gradients were confirmed to be stable and reproducible; however, produced tailing peak shapes. Phenylbutyl-ammonium gradients were utilized to incorporate an ion exchange model into a simulator built by Jeong et al. The phenylbutyl-ammonium gradient was not reproducible but did exhibit an increase in resolution when combined with a mobile phase gradient. Also, the ion exchange model was successfully added within the simulator, with percent differences for retention prediction all under 5 %. This dissertation serves as a proof-of-concept for gradient stationary phases on particle packed LC columns.

本文的主要目的為比較不同模型或者不同檢定所產生的不同結果。選擇的遞延期數(lag)不同,則所得到的模型與共積數目也不一樣,使得不同遞延期數(lag)、不同模型 所得到的共積關係也不相同。所以本文將驗證在不同遞延期數下,所得到的不同模型共積關係的表現。因此希望利用Johansen Sequential Testing Procedure來同時決定共積關係數目及資料產生過程(DGP),而且也能探討共積關係。但其仍有缺點,例如Johansen Sequential Testing Procedure所取的遞延期數不同則所選定的模型也將不一樣,另一點是共積係數的估計值只是一basis。