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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

O Prob?sica e a forma??o de professores no P?lo de Parnamirim: pol?tica de forma??o profissional no Rio Grande do Norte?

Tavares, Andrezza Maria Batista do Nascimento 28 December 2005 (has links)
Made available in DSpace on 2014-12-17T14:35:58Z (GMT). No. of bitstreams: 1 AndrezzaB.pdf: 817183 bytes, checksum: 3d64e6b7da01de95992cf7047d10fc08 (MD5) Previous issue date: 2005-12-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work studies the thematic of the politics of formation of teachers in the Program of Professional Qualification for Basic Education (PROB?SICA) developed in the City of Parnamirim, Rio Grande do Norte. It has as its main objective to identify and to analyze the contribution of this politics of initial formation for the professional formation of teachers. To install the work, we will use the procedures of bibliographical research, documentary analysis, comment, structuralized interview, questionnaire-script and virtual research. In the analysis of the data, we trace a general view on PROB?SICA while initial formation along with the continued formation, pedagogical research, collaborative research and the exercise of the teaching profession, identifying the possibilities and limits of the Program in the direction to reach the objective considered in this work. From the inquiry, we construct the institutional land scope of the program in question, also focusing, the organizational aspects of its functioning. We have to take care about the results, we evidence that PROB?SICA is making the possible to access of the teachers in the educational service to the University, what the main aspect that consists, trying to prove eminent weak points in its systematic due to give to the organizational structure of this educational politics that does not count with curricular, institutional and financial the necessary conditions for the success of the professional formation of the teachers. The research will try to understand that the operationalization of the politics of formation in Parnamirim will be belong with it the main idea of the Educational Reformation in years of 1990, articulated to the neoliberal interests, that the responsibility for the problems of the public system of education attributed to the teachers, and that are not answered completely through the purpose of the professional formation, and ti seems that it does not define one global national politics that deals with seriousness to the questions the initial formation, permanent formation, pedagogical research, , career and conditions of work for the teachers / Esta disserta??o aborda a tem?tica da pol?tica de forma??o de professores em servi?o, expressa no Programa de Qualifica??o Profissional para Educa??o B?sica (PROB?SICA), desenvolvida no Munic?pio de Parnamirim, Rio Grande do Norte. Tem por objetivo identificar e analisar a contribui??o desta pol?tica de forma??o inicial para a forma??o profissional de professores. Para consubstanciar a investiga??o, utilizamos metodologicamente os procedimentos de pesquisa bibliogr?fica, an?lise documental, observa??o, entrevista semi-estruturada, question?rio-roteiro e pesquisa virtual. Na an?lise dos dados, tra?amos um quadro geral sobre o PROB?SICA enquanto forma??o inicial e sobre suas articula??es com a forma??o continuada, pesquisa pedag?gica, pesquisa colaborativa e o exerc?cio da profiss?o docente, identificando as possibilidades e limites do Programa, no sentido de atingir o objetivo proposto neste trabalho. A partir da investiga??o realizada, constru?mos o desenho institucional do Programa em quest?o, focalizando inclusive, os aspectos organizacionais do seu funcionamento. Quanto aos resultados, constatamos que apesar do PROB?SICA possibilitar o acesso do professor em servi?o ? Universidade, o que se constitui um aspecto forte, evidencia-se eminentes pontos fracos em sua sistem?tica devido ? pr?pria estrutura organizacional dessa pol?tica educacional, que n?o conta com as condi??es curriculares, institucionais e financeiras necess?rias para o ?xito da forma??o profissional. Mediante a pesquisa, entende-se que a operacionaliza??o da pol?tica de forma??o em Parnamirim coaduna-se ao ide?rio da Reforma Educacional difundida nos anos 1990, articulada aos interesses neoliberais, que atribuiu ao professor a responsabilidade pelas mazelas do sistema p?blico de ensino, n?o respondendo completamente a finalidade da forma??o profissional, haja vista que n?o define uma pol?tica nacional global que trate com seriedade das quest?es da forma??o inicial, forma??o permanente, pesquisa pedag?gica, sal?rio, carreira e condi??es de trabalho
2

Génération de tests de vulnérabilité pour la structure des fichiers cap en Java Card

Lassale, Mathieu January 2016 (has links)
Les cartes à puce Java comportent plusieurs mécanismes de sécurité, dont le vérifieur de code intermédiaire (\emph{$ \ll $Java Card bytecode verifier$ \gg $}), qui est composé de deux parties, la vérification de structure et la vérification de type. Ce mémoire porte sur la génération de tests de vulnérabilité pour la vérification de structure. Il s'inspire des travaux sur la vérification de type de l'outil \textsc{VTG} (\emph{$ \ll $Vulnerability Tests Generator$ \gg $}) développé par Aymerick Savary. Notre approche consiste à modéliser formellement la spécification de la structure des fichiers \textsf{CAP} avec le langage \textsf{Event-B}, en utilisant des contextes. Cette modélisation permet de donner une définition formelle d'un fichier \textsf{CAP} valide. Nous utilisons ensuite la mutation de spécification pour insérer des fautes dans cette définition dans le but de générer des fichiers \textsf{CAP} (\emph{$ \ll $Converted APplet$ \gg $}) invalides. Nous utilisons \textsc{ProB}, un explorateur de modèles \textsf{Event-B}, pour générer des tests abstraits de fichiers CAP invalides. La spécification formelle étant d'une taille importante qui entraîne une forte explosion combinatoire (plus de 250 constantes, 450 axiomes, 100 contextes), nous guidons \textsc{ProB} dans sa recherche de modèles en utilisant des valeurs prédéterminées pour un sous-ensemble de symboles de la spécification. Ce mémoire propose un ensemble de patrons de spécification pour représenter les structures des fichiers CAP. Ces patrons limitent aussi l'explosion combinatoire, tout en facilitant la tâche de spécification. Notre spécification \textsf{Event-B} comprend toute la définition des structures des fichiers CAP et une partie des contraintes. Des tests abstraits sont générés pour une partie du modèle, à titre illustratif. Ces tests ont permis de mettre en lumière des imprécisions dans la spécification \textsf{Java Card}. Ces travaux ont permis d'étendre la méthode de génération de test de vulnérabilité aux contextes \textsf{Event-B}. De plus, le modèle proposé permet de tester, à l'aide du \textsc{VTG}, une partie plus importante de la vérification de structure du vérifieur de code intermédiaire.
3

A Study of the Grinding Process for the Optical-Fiber Endface with Double-Variable Curvatures

Chen, Jun-Hong 02 September 2010 (has links)
Mechanical grinding process is the most popular way to fabricate the fiber micro lenses, although there are some other methods, such as chemical etching, laser machining and focused ion beam micro-cutting. Mechanical grinding has its uniqueness in grinding Conical-Wedge-Shaped Fiber Endface, fiber endface with polygon-cone-shape, and fiber endface with double-variable curvatures. The double-variable curvatures fiber endface polisher, designed and manufactured by Mechanism Design Lab of NSYSU, is employed in this study. The normal force of the fiber endface is derived firstly and then the experimental parameters and data are substituted into the material removal rate (M.R.R.) formula to obtain M.R.R. and the Preston¡¦s constant K. The process parameters of the feed rate and polishing time on the fabrication of the fiber endface are analyzed. The polisher is calibrated and adjusted to improve the precision of the optical-fiber endface. A fiber endface with double-variable curvature is successfully fabricated in a single grinding process by properly controlling the fiber rotation angle, inclining angle, and the distant between the endface and the grinding film simultaneously. The grinding process developed in this study can be applied for fabricating optical fiber lenses in fiber optics communication as well as different types of micro probes, and micro spectroscopefors in other applications.
4

Polytopes Arising from Binary Multi-way Contingency Tables and Characteristic Imsets for Bayesian Networks

Xi, Jing 01 January 2013 (has links)
The main theme of this dissertation is the study of polytopes arising from binary multi-way contingency tables and characteristic imsets for Bayesian networks. Firstly, we study on three-way tables whose entries are independent Bernoulli ran- dom variables with canonical parameters under no three-way interaction generalized linear models. Here, we use the sequential importance sampling (SIS) method with the conditional Poisson (CP) distribution to sample binary three-way tables with the sufficient statistics, i.e., all two-way marginal sums, fixed. Compared with Monte Carlo Markov Chain (MCMC) approach with a Markov basis (MB), SIS procedure has the advantage that it does not require expensive or prohibitive pre-computations. Note that this problem can also be considered as estimating the number of lattice points inside the polytope defined by the zero-one and two-way marginal constraints. The theorems in Chapter 2 give the parameters for the CP distribution on each column when it is sampled. In this chapter, we also present the algorithms, the simulation results, and the results for Samson’s monks data. Bayesian networks, a part of the family of probabilistic graphical models, are widely applied in many areas and much work has been done in model selections for Bayesian networks. The second part of this dissertation investigates the problem of finding the optimal graph by using characteristic imsets, where characteristic imsets are defined as 0-1 vector representations of Bayesian networks which are unique up to Markov equivalence. Characteristic imset polytopes are defined as the convex hull of all characteristic imsets we consider. It was proven that the problem of finding optimal Bayesian network for a specific dataset can be converted to a linear programming problem over the characteristic imset polytope [51]. In Chapter 3, we first consider characteristic imset polytopes for all diagnosis models and show that these polytopes are direct product of simplices. Then we give the combinatorial description of all edges and all facets of these polytopes. At the end of this chapter, we generalize these results to the characteristic imset polytopes for all Bayesian networks with a fixed underlying ordering of nodes. Chapter 4 includes discussion and future work on these two topics.
5

Génération de tests de vulnérabilité pour vérifieur de byte code Java Card

Savary, Aymerick January 2013 (has links)
Il devient important d'assurer que tout système critique est fiable. Pour cela différentes techniques existent, telles que le test ou l'utilisation de méthodes formelles. S'assurer que le comportement d'un vérifieur de byte code Java Card n'entraînera pas de faille de sécurité est une tâche complexe. L'automatisation totale de cette vérification n'à popr le moment pas été realisee. Des jeux de tests coûteux ont été produits manuellement, mais ils doivent être refaits à chaque nouvelle spécification. Les travaux présentés dans ce mémoire proposent une nouvelle méthode pour la génération automatique de tests de vulnérabilité. Ceux-ci reposent sur l'utilisation et la transformation automatique de modèles formels. Pour valider cette méthode, un outil à été développé puis utilisé sur différentes implémentations du vérifieur de byte code Java Card. Le langage de modelisation que nous avons utilisé est Event-B. Nos modèles représentent le comportement normal du système que l'on souhaite tester. Chaque instruction est modélisée comme un événement. Leur garde représente l'ensemble des conditions que doit satisfaire une instruction pour être acceptable. À partir de ce modèle initial, une succession de dérivations automatiques génère un ensemble de modèles dérivés. Chacun de ces modèles dérivés représente une faute particulière. On extrait de ces nouveaux modèles les tests de vulnérabilité abstraits. Ceux-ci sont ensuite concrétisés puis envoyés à un système à tester. Ce processus est assuré par notre logiciel qui repose sur les API Rodin, ProB, CapMap et OPAL.
6

Détection de vulnérabilités appliquée à la vérification de code intermédiaire de Java Card / Vulnerability detection into Java Card bytecode verifier

Savary, Aymerick 30 June 2016 (has links)
La vérification de la résistance aux attaques des implémentations embarquées des vérifieurs de code intermédiaire Java Card est une tâche complexe. Les méthodes actuelles n'étant pas suffisamment efficaces, seule la génération de tests manuelle est possible. Pour automatiser ce processus, nous proposons une méthode appelée VTG (Vulnerability Test Generation, génération de tests de vulnérabilité). En se basant sur une représentation formelle des comportements fonctionnels du système sous test, un ensemble de tests d'intrusions est généré. Cette méthode s'inspire des techniques de mutation et de test à base de modèle. Dans un premier temps, le modèle est muté selon des règles que nous avons définies afin de représenter les potentielles attaques. Les tests sont ensuite extraits à partir des modèles mutants. Deux modèles Event-B ont été proposés. Le premier représente les contraintes structurelles des fichiers d'application Java Card. Le VTG permet en quelques secondes de générer des centaines de tests abstraits. Le second modèle est composé de 66 événements permettant de représenter 61 instructions Java Card. La mutation est effectuée en quelques secondes. L'extraction des tests permet de générer 223 tests en 45 min. Chaque test permet de vérifier une précondition ou une combinaison de préconditions d'une instruction. Cette méthode nous a permis de tester différents mécanismes d'implémentations de vérifieur de code intermédiaire Java Card. Bien que développée pour notre cas d'étude, la méthode proposée est générique et a été appliquée à d'autres cas d'études. / Verification of the resistance of attacks against embedded implementations of the Java Card bytecode verifiers is a complex task. Current methods are not sufficient, only the generation of manual testing is possible. To automate this process, we propose a method called VTG (Vulnerability Test Generation). Based on a formal representation of the functional behavior of the system under test, a set of intrusion test is generated. This method is based on techniques of mutation and model-based testing. Initially, the model is transferred according to rules that we have defined to represent potential attacks. The tests are then extracted from the mutant models. Two Event-B models have been proposed. The first represents the structural constraints of the Java Card application files. The VTG allows in seconds to generate hundreds of abstract tests. The second model is composed of 66 events to represent 61 Java Card instructions. The mutation is effected in a few seconds. Extraction tests to generate 223 test 45 min. Each test checks a precondition or a combination of preconditions of a statement. This method allowed us to test different implementations of mechanisms through Java Card bytecode verifier. Although developed for our case study, the proposed method is generic and has been applied to other case studies.
7

Element-Specific Magnetization Dynamics Using T-MOKE at the HELIOS Laboratory

Stångberg Valgeborg, Fredrik January 2016 (has links)
Magnetism is a familiar phenomenon, and is applied in a variety of devices, from simple ones, like compasses, to the more sophisticated magnetic hard disk drives. It is also known that the magnetization of a material can change, for example by heating or by exposure to an external magnetic field. The dynamics of transitions between different magnetizations, however, is largely unknown, particularly in complex materials. To further the understanding of such dynamics, this thesis presents an observational study of the dynamics of laser induced demagnetization of permalloy (Ni0.8Fe0.2). Dynamics were studied with element-specificity, i.e. Fe and Ni were studied simultaneously, but separately, rather than studying the overall material. The study was conducted at the HELIOS laboratory at Uppsala University, which features equipment for the study of magnetization dynamics. Important concepts like high-order harmonic generation (HHG) and the transverse magneto-optic Kerr effect (T-MOKE) are discussed. HHG is the laser induced generation of high energy photons, and T-MOKE relates the intensity of reflected light to the magnetization of the reflecting material. The study revealed a very short demagnetization time, and maximum demagnetization of both elements was achieved within 1 picosecond. An onset delay in the demagnetizations of Fe and Ni of about 25 femtoseconds was also observed. Both phenomena have been previously reported. The results further imply that the magnetizations diverge over a 10 picosecond time interval after the onset of demagnetization, which has not been previously reported. The apparent divergence may be due to an unknown transient setup-related issue. The short demagnetization times, as well as the onset delay could potentially contribute to the development of a more complete theory of magnetization dynamics. / Magnetism är ett bekant fenomen, som utnyttjas i allt från enkla tillämpningar, som kompasser,till mer sofistikerade sådana, som hårddiskar. Det är också känt att magnetiseringen i ett material kan ändras, t.ex. genom upphettning eller genom att det utsätts för ett yttremagnetiskt fält. Dynamiken vid övergångar mellan olika magnetiseringstillstånd är dock ett relativt okänt ämne, i synnerhet när det kommer till komplexa material. För främjandet av en större förståelse inom ämnet, presenteras här en observationell studie av dynamiken för laserinducerad avmagnetisering av permalloy (Ni0.8Fe0.2). Dynamiken undersöktes med grundämnesspecificitet, d.v.s. Fe och Ni undersöktes samtidigt, men var för sig, snarare än att materialet undersöktes som helhet. Undersökningen gjordes vid HELIOS-laboratoriet vid Uppsala Universitet, som tillhandahåller utrustning för undersökning av magnetiseringsdynamik. Viktiga koncept diskuteras, såsom övertonsgenerering och den transversella magnetooptiska Kerr-effekten (T-MOKE). Övertonsgenerering innebär laserinducerad generering av högenergifotoner, och T-MOKE relaterar reflekterad intensitet till magnetiseringen i det reflekterande materialet. Undersökningen påvisade en mycket kort avmagnetiseringstid, och maximal avmagnetisering nåddes inom en pikosekund. En relativ tidsförskjutning mellan avmagnetiseringsförloppen för Fe och Ni om ungefär 25 femtosekunder observerades också. Båda fenomen har rapporterats tidigare. Resultatet visar även en divergens mellan magnetiseringsförloppen under ett tidsspann på 10 pikosekunder efter avmagnetiseringens början, vilket inte har rapporterats förr. Den skenbara divergensen kan bero på ett okänt, tillfälligt problem i uppställningen. Den korta avmagnetiseringstiden och den relativa tidsförskjutningen skulle kunna bidra till utvecklingen av en mer komplett teori för magnetiseringsdynamik.
8

Improving the wire boom deployment system used on SPIDER-2 : Increasing reliability, robustness and ease of assembly for a wire boom deployment system / Förbättring av utfällningssystemet för trådbommar som användes i SPIDER-2 : Ökning av tillförlitlighet, robusthet samt monteringssimplicitet av ett utfällningssystem för trådbommar

Sandgren, Jona January 2021 (has links)
This project deals with the improvement of a wire boom deployment system to be used on a proposed Rocket Experiments for University Students (REXUS) mission. The system to be improved was previously used on the Small Payload for Investigation of Disturbances in Electrojet by Rockets (SPIDER-2) mission and the objective was to make that system more robust and reliable as well as easier to assemble. The wire boom system itself consisted of four probes for measuring electric fields as well as four probes to measure space plasma properties. These all needed to be deployed from a free flying unit, while still being attached to it with thin wires. The wires were stored on spools which unwound using a piezoelectric motor and the probes were deployed by releasing a locking mechanism and then pushing them out with springs. Based on that, along with deployment testing of the SPIDER-2 system, the areas to improve were selected. It was chosen to focus on getting the probes out of the hull more reliably and making the spools rotate more evenly while being more constrained. In addition, focus was placed on simplifying assembly and bettering the guiding of the wires wherever possible. To accomplish this, in the end, nearly every part was replaced or altered. This resulted in the system being able to deploy even without any rotation to provide centrifugal force and also made the wire guiding better to decrease the chance of tangling. However, more work remains to be done on the system to finalize the new parts and to make further improvements on parts that were not handled during this project. / Detta projekt hanterar förbättring av ett system för att fälla ut trådbommar från en fritt fallande enhet. Arbetet blir en fortsättning på det som tidigare gjorts för uppdrag kallade SPIDER och SPIDER-2 men är denna gång främst riktad mot ett studentexperiment. De huvudsakliga syftena med arbetet var att förbättre tillförlitligheten och robustheten samt att förenkla ihopsättningen av systemet. Dessa kom från de tidigare uppdragen systemet använts för. System består av fyra prober som mäter elektriska fält samt fyra som mäter egenskaper av plasman kring jorden. Dessa prober måste placeras en bit bort från den fritt fallande enheten för att göra mätningar. De kopplas till enheten med tunna trådar som lagras på spolar innan proberna ska fällas ut. En piezoelektrisk motor roterar sedan spolarna samtidigt som proberna puttas ut ur enheten under utfällning. Egen testning samt tidigare erfarenhet kombinerades sedan för att bestämma att arbetet skulle fokusera på att få ut proberna mer tillförlitligt samt göra spolarnas rotation mer jämn och kontrollerad. Samtidigt skulle även ihopsättningen förenklas där det gick och åtgärder för att minska chans för trassel tas där det gick. Resultatet blev att i stort sett alla delar av systemet byttes ut och det visade sig efter tester att fungera precis som tänkt. Proberna kunde därför lämna enheten utan någon rotation och trådarna kontrollerades bättre, för att minimera risken för trassel. Däremot finns det mer arbete att göra innan systemet är redo för att användas. Detta inkluderar både att färdigställa de delar som hanterats i detta arbete samt att jobba med de delar som inte hanns med.
9

Formal Modelling of Cruise Control System Using Event-B and Rodin Platform

Predut, S., Ipate, F., Gheorghe, Marian, Campean, Felician 28 June 2018 (has links)
no / Formal modelling is essential for precisely defining, understanding and reasoning when designing complex systems, such as cyberphysical systems. In this paper we present a formal specification using Event-B and Rodin platform for a case study of a cruise control system for a hybrid propulsion vehicle and electric bicycle (e-Bike). Our work uses the EventB method, a formal approach for reliable systems specification and verification, being supported by the Rodin platform, based on theorem proving, allowing a stepwise specification process based on refinement. We also use, from the same platform, the ProB model checker for the verification of the B-Machine and iUML plug-in to visualize our model. This approach shows the benefits of using a formal modelling platform, in the context of cyberphysical systems, which provides multiple ways of analysing a system. / Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-III-P4-ID-PCE-20160210.
10

Plateforme multifonctionnelle de microscopies à sonde locale sous illumination / Scanning Probe Microscopies platform under Illumination

Roche, Roland 17 October 2014 (has links)
Afin de répondre à des besoins croissants en nano-caractérisation, nous avons développé une plateforme multifonctionnelle combinant des techniques de microscopie optique et de microscopies en champ proche.Au coeur de ce dispositif se trouve l'échantillon. Ceux optiquement semi-transparents en exploiteront au mieux la palette des techniques implémentées. Parmi eux des couches minces (100nm), nanostructurées, de matériaux organiques photovoltaïques.La plateforme permet d'utiliser différentes techniques de microscopies à sonde locale (AFM1, KPFM2, SNOM3, ...) couplées à un microscope optique inversé qui autorise illumination ou imagerie. Versatile, elle peut accueillir des portes-échantillons d'autres techniques développées ou présentes au laboratoire (en particulier les microscopies électroniques à projection, à transmission ou à balayage). Elle est également conçue pour faciliter l'intégration d'autres techniques.Outre le développement de la plateforme, ce manuscrit montre la part importante du travail effectuée pour mettre au point et exploiter une microscopie à sonde de Kelvin (KPFM) à haute résolution sous illumination.Des résultats obtenus sur des matériaux organiques photovoltaïques permettent notamment d'illustrer les excellentes performances de notre plateforme de nano-caractérisation et des techniques associées. / To address the increasing demand on nanomaterials investigation, we developed a cross-characterization platform combining scanning probe microscopies (AFM 1, KPFM 2, SNOM 3, ...) and inverted optical microscopy. The inverted optical microscope, allowing both illumination and imaging, is augmented with near field microscopies such as cited above.The heart of our setup is the sample. Optically semi-transparent samples will best benefit the range of implemented complementary technics, among these samples, nanostructured organic photovoltaic thin (100nm) films. However, the flexible platform is thought to be adaptable to other samples and thus sample-holders used for other characterization techniques existing in the Institute, such as scanning or transmission electron or projection microscopies. The platform is also designed to simplify future extension to other experimental technics.Beyond the platform itself, the manuscript shows the important effort devoted to develop, and take benefit of, a Kelvin probe microscopy under illumination.Results obtained on organic photovoltaic materials demonstrate the possibilities of our original setup and prove its performance to be at state of the art.

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