<p align="justify">Plusieurs métaux de notre vie courante sont obtenus industriellement au moyen de procédés électrolytiques. Un des procédés les plus communs est l’électro-obtention de cuivre, dans lequel le métal est déposé à la cathode tandis que l'oxygène se dégage à l'anode. Généralement, en usine, plusieurs anodes et cathodes, ayant une surface de 1 m2 et séparées par plus ou moins 10 cm sont alternées dans une cellule contenant une solution d'acide sulfurique riche en sulfate de cuivre. En fonction des conditions d'utilisation, les cathodes sont remplacées, après un certain temps, par des nouvelles de façon à récupérer le cuivre déposé. De ce fait, les anodes doivent être capables de résister sans se corroder, se déformer ou perdre leurs propriétés électrocatalytiques pendant de longues périodes. Au début, des alliages en Pb (pb-Ag, Pb-Ca-Sn,) ont été utilisés comme anodes. Malheureusement, malgré leur faible prix, ces anodes présentent des surtensions élevées et une faible résistance à la corrosion et au fluage. Par conséquent, une alternative aux anodes traditionnelles en 1 développée. Ce nouveau type d'anode, connu sous le nom d’anode dimensionnellement stable (DSA) est fabriquée à partir d'une tôle en Ti recouverte par un mélange d'oxydes de métaux nobles catalysant la réaction de dégagement d'oxygène. Différentes techniques peuvent être utilisées pour préparer la couche d'oxyde. La technique la plus souvent employée consiste à décomposer thermiquement une solution de chlorures contenant un ou plusieurs nobles. Malheureusement, ce type d'anode est cher et a tendance à perdre son activité électrocatalytique avec le temps.</p><p><p align="justify">Dans le but de produire une DSA à faible prix, pouvant résister de longues périodes sans se passiver, un nouveau type de DSA a été développé dans le présent travail. Cette anode est produite par électrodépôt d'un métal noble dans les pores d'un substrat microporeux en Ti/TiO2.</p><p><p align="justify">Ce travail a permis de démontrer qu'une DSA avec une concentration en métal noble peut être obtenue par la voie proposée. Il a été montré que les propriétés électriques et électrochimiques de ces DSAs sont directement liées aux caractéristiques morphologiques et structurales du en Ti/TiO2. Lorsque la couche barrière existant au fond des pores est suffisamment fine et que le film présente des défauts, la résistance me l'interface Ti/métal noble est faible. Ceci abouti à des DSAs possédant d'excellentes propriétés électrocatalytiques. Les DSAs optimales sont capables de résister à des conditions similaires à celles employées en industrie avec des surtensions de ~ 0.4 V, ce qui représente un gain de 50% par rapport aux surtensions normalement atteintes par les anodes traditionnelles en Pb.</p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

This dissertation thesis attends to problems of electronic registry for VUT. It deals with the principal of electronic registry functioning, electronic signature and it compares offer of the commercial registries. It goes in for the proposal and implementation of the electronic registry for VUT. Since the using of the e- registry on all public service Office was legalized the people can avoid long queues and the employees are avoided from the stress before dead lines. By the communication through the electronic registry is very important the electronical signature. It is almost a full-valued and lawful alternative to the physical signature. For its safety and utility this system employes asymmetric codes and hash algorithm. Presently in many states, where the electronical signature is legalized it is used together with standard X 509 which defines the format of certificates, organization and action of certification authorities. The certification autority ensures safe connection of the person and general key for using of the electronical signature.

Due sono le constatazioni di base che guidano questo elaborato: la complessità che caratterizza le odierne classi richiede agli insegnanti di differenziare la proposta didattica; spetta al docente saper individuare eventuali difficoltà di apprendimento e/o disturbi specifici (DSA) al fine di favorire un percorso scolastico rispettoso delle peculiarità di ciascuno. Cosa succede, però, quando lo studente con DSA è di origine migratoria ed è bilingue? Il disturbo ha reali basi neurobiologiche o è piuttosto correlato alle fatiche di veicolare l’apprendimento attraverso una lingua diversa da quella parlata in ambito familiare? Il dato da cui partire è quello rilevato in letteratura in merito alla scarsità, in ambito nazionale, di test clinici per DSA strutturati e standardizzati su chi parla più di una lingua. Da ciò consegue la necessità di implementare un’azione a monte, al fine di migliorare l’appropriatezza degli invii ai Servizi Sanitari o agli Enti accreditati: un percorso da attuare con il personale docente. A questo scopo l’indagine intende favorire tra gli insegnanti una corretta informazione circa la distinzione tra disturbo specifico dell’apprendimento e difficoltà di letto-scrittura in alunni bilingui figli di migranti. Inoltre, l’insegnante è chiamato ad appropriarsi di una forma mentis capace di cogliere in maniera attenta e rispettosa le peculiarità di ciascun allievo, unico nella sua arricchente diversità: un insegnante flessibile, disposto a sperimentare una didattica di tipo differenziato. / This thesis is based on two fundamental observations: nowadays classes are becoming ever more complex and diverse. Therefore, teachers must diversify the didactic proposal. It’s up to the educator to identify any learning difficulties and / or learning disabilities (LD), in order to favor a scholastic path that respects the peculiarities of each pupil. What happens, however, when the students with LD come from an immigrant family and they are bilingual? Does the disorder really have a neurobiological bases? Or is it rather related to the effort of learning through a language that is not the native language for the children? The starting point is the one found in literature regarding the national scarcity of clinical tests for LD structured and standardized on those who speaks more than one language. For these reasons it is needed an upstream action, in order to make the advice of teachers more specific towards those children with difficulties who have to undertake a diagnostic assessment process. That is why it is important to encourage greater awareness among teachers and correct information about the difference between specific learning disabilities and reading-writing difficulties in bilingual learners with a migrant background. Furthermore, the inclusive teacher must have a mindset aimed at knowing in a careful and respectful way the peculiarities of each student. Every child is unique in its enriching diversity: we need a flexible teacher, motivated to implement the differentiated instruction.

Les systèmes de communications sans fil ne cessent de se multiplier pour devenir incontournables de nos jours. Cette croissance cause une augmentation de la demande des ressources spectrales, qui sont devenues de plus en plus rares. Afin de résoudre ce problème de pénurie de fréquences, Joseph Mitola III, en 2000, a introduit l'idée de l'allocation dynamique du spectre. Il définit ainsi le terme « Cognitive Radio » (Radio Intelligente), qui est largement pressenti pour être le prochain Big Bang dans les futures communications sans fil [1]. Dans le cadre de ce travail on s'intéresse à la problématique du spectrum sensing qui est la détection de présence des Utilisateurs Primaires dans un spectre sous licence, dans le contexte de la radio intelligente. L'objectif de ce travail est de proposer des méthodes de détection efficaces à faible complexité et/ou à faible temps d'observation et ceci en utilisant le minimum d'information a priori sur le signal à détecter. Dans la première partie on traite le problème de détection d'un signal aléatoire dans le bruit. Deux grandes méthodes de détection sont utilisées : la détection d'énergie ou radiomètre et la détection cyclostationnaire. Dans notre contexte, ces méthodes sont plus complémentaires que concurrentes. Nous proposons une architecture hybride de détection des bandes libres, qui combine la simplicité du radiomètre et la robustesse des détecteurs cyclostationnaires. Deux méthodes de détection sont proposées qui se basent sur cette même architecture. Grâce au caractère adaptatif de l'architecture, la détection évolue au cours du temps pour tendre vers la complexité du détecteur d'énergie avec des performances proches du détecteur cyclostationnaire ou du radiomètre selon la méthode utilisée et l'environnement de travail. Dans un second temps on exploite la propriété parcimonieuse de la Fonction d'Autocorrelation Cyclique (FAC) pour proposer un nouvel estimateur aveugle qui se base sur le compressed sensing afin d'estimer le Vecteur d'Autocorrelation Cyclique (VAC), qui est un vecteur particulier de la Fonction d'Autocorrelation Cyclique pour un délai fixe. On montre par simulation que ce nouvel estimateur donne de meilleures performances que celles obtenues avec l'estimateur classique, qui est non aveugle et ceci dans les mêmes conditions et en utilisant le même nombre d'échantillons. On utilise l'estimateur proposé, pour proposer deux détecteurs aveugles utilisant moins d'échantillons que nécessite le détecteur temporel de second ordre de [2] qui se base sur l'estimateur classique de la FAC. Le premier détecteur exploite uniquement la propriété de parcimonie du VAC tandis que le second détecteur exploite en plus de la parcimonie la propriété de symétrie du VAC, lui permettant ainsi d'obtenir de meilleures performances. Ces deux détecteurs outre qu'ils sont aveugles sont plus performants que le détecteur non aveugle de [2] dans le cas d'un faible nombre d'échantillons. / The wireless communications systems continue to grow and has become very essential nowadays. This growth causes an increase in the demand of spectrum resources, which have become more and more scarce. To solve this problem of spectrum scarcity, Joseph Mitola III, in the year 2000, introduced the idea of dynamic spectrum allocation. Mitola defines the term “Cognitive Radio”, which is widely expected to be the next Big Bang in wireless communications [1]. In this work we focus on the problem of spectrum sensing which is the detection of the presence of primary users in licensed spectrum, in the context of cognitive radio. The objective of this work is to propose effective detection methods at low-complexity and/or using short observation time, using minimal a priori information about the signal to be detected. In the first part of this work we deal with the problem of detecting a random signal in noise. Two main methods of detection are used: energy detection or radiometer and cyclostationary detection. In our context, these methods are more complementary than competitive. We propose a hybrid architecture for detecting free bands, which combines the simplicity of the radiometer and the robustness of the cyclostationary detection. Two detection methods are proposed that are based on this same hybrid architecture. Thanks to the adaptive nature of the architecture, the complexity of the detector decreases over time to tend to the one of an energy detector with close performance to the cyclostationary detector or to the performance of a radiometer, depending on the used method and on the working environment. In the second part of this work we exploit the sparse property of the Cyclic Autocorrelation Function (CAF) to propose a new blind estimator based on compressed sensing that estimates the Cyclic Autocorrelation Vector (CAV) which is a particular vector of the CAF for a given lag. It is shown by simulation that this new estimator gives better performances than those obtained with the classical estimator, which is non-blind, under the same conditions and using the same number of samples. Using the new estimator, we propose two blind detectors that require fewer samples than the second order time domain detector of [2] which is based on the classical estimator of the CAF. The first detector uses only the sparse property of the CAV while the second detector exploits the symmetry property of the CAV in addition to its sparse property, resulting in better performances. Both detectors, although they are blind, are more efficient than the non-blind detector of [2] in the case of a small number of samples.

This thesis addresses three problems related to image registration, prediction and tracking, applied to Angiography and Oncology. For image analysis, various probabilistic models have been employed to characterize the image deformations, target motions and state estimations. (i) In Digital Subtraction Angiography (DSA), having a high quality visualization of the blood motion in the vessels is essential both in diagnostic and interventional applications. In order to reduce the inherent movement artifacts in DSA, non-rigid image registration is used before subtracting the mask from the contrast image. DSA image registration is a challenging problem, as it requires non-rigid matching across spatially non-uniform control points, at high speed. We model the problem of sub-pixel matching, as a labeling problem on a non-uniform Markov Random Field (MRF). We use quad-trees in a novel way to generate the non uniform grid structure and optimize the registration cost using graph-cuts technique. The MRF formulation produces a smooth displacement field which results in better artifact reduction than with the conventional approach of independently registering the control points. The above approach is further improved using two models. First, we introduce the concept of pivotal and non-pivotal control points. `Pivotal control points' are nodes in the Markov network that are close to the edges in the mask image, while 'non-pivotal control points' are identified in soft tissue regions. This model leads to a novel MRF framework and energy formulation. Next, we propose a Gaussian MRF model and solve the energy minimization problem for sub-pixel DSA registration using Random Walker (RW). An incremental registration approach is developed using quad-tree based MRF structure and RW, wherein the density of control points is hierarchically increased at each level M depending of the features to be used and the required accuracy. A novel numbering scheme of the control points allows us to reuse the computations done at level M in M + 1. Both the models result in an accelerated performance without compromising on the artifact reduction. We have also provided a CUDA based design of the algorithm, and shown performance acceleration on a GPU. We have tested the approach using 25 clinical data sets, and have presented the results of quantitative analysis and clinical assessment. (ii) In External Beam Radiation Therapy (EBRT), in order to monitor the intra fraction motion of thoracic and abdominal tumors, the lung diaphragm apex can be used as an internal marker. However, tracking the position of the apex from image based observations is a challenging problem, as it undergoes both position and shape variation. We propose a novel approach for tracking the ipsilateral hemidiaphragm apex (IHDA) position on CBCT projection images. We model the diaphragm state as a spatiotemporal MRF, and obtain the trace of the apex by solving an energy minimization problem through graph-cuts. We have tested the approach using 15 clinical data sets and found that this approach outperforms the conventional full search method in terms of accuracy. We have provided a GPU based heterogeneous implementation of the algorithm using CUDA to increase the viability of the approach for clinical use. (iii) In an adaptive radiotherapy system, irrespective of the methods used for target observations there is an inherent latency in the beam control as they involve mechanical movement and processing delays. Hence predicting the target position during `beam on target' is essential to increase the control precision. We propose a novel prediction model (called o set sine model) for the breathing pattern. We use IHDA positions (from CBCT images) as measurements and an Unscented Kalman Filter (UKF) for state estimation. The results based on 15 clinical datasets show that, o set sine model outperforms the state of the art LCM model in terms of prediction accuracy.

The main goal of this thesis is to summarize and introduce general theoretical concepts of Data Warehousing by using the systems approach. The thesis defines Data Warehousing and its main areas and delimitates Data Warehousing area in terms of higher-level area called Business Intelligence. It also describes the history of Data Warehousing & Business Intelligence, focuses on key principals of Data Warehouse building and explains the practical applications of this solution. The aim of the practical part is to perform the evaluation of theoretical concepts. Based on that, design and build Data Warehouse in environment of an existing company. The final solution shall include Data Warehouse design, hardware and software platform selection, loading with real data by using ETL services and building of end users reports. The objective of the practical part is also to demonstrate the power of this technology and shall contribute to business decision-making process in this company.