Esta pesquisa analisa fatores que sustentam o uso das metodologias ativas para o aumento do desempenho dos estudantes para a aprendizagem significativa, levando-se em consideração que o ato de aprender é intransferível, só o indivíduo pode fazê-lo e ninguém pode aprender por outro, mas pode-se incentivar o interesse dos estudantes, explorando novas oportunidades de aprendizagem, bem mais centradas na atividade dos estudantes, utilizando a hibridização, que é a mescla de técnicas e ferramentas que auxiliam e dinamizam o aprendizado com a combinação entre ambientes presenciais e virtuais de ensino - usando a ferramenta dos MOOCs pela concepção da sala de aula invertida. Para avaliar a interferência da metodologia ativa de aprendizagem no desempenho, participaram da análise estudantes universitários, de duas instituições particulares, na área de Ciências Sociais Aplicadas, que após um semestre responderam a dois questionários de escalas validadas estatisticamente: Academic Motivation Scale e Escala Estratégica de Aprendizagem para ambientes on-line. Utilizou-se técnicas de análise multivariada, composta pela análise de componentes principais e análise de agrupamento, para avaliar a presença de grupos de motivação. Para a caracterização dos grupos de motivação obtidos foram calculadas as frequências dos grupos formados e médias das componentes principais, bem como as marcações de significância estatística para o teste-t de diferença de médias e técnicas de modelo de regressão para avaliar as médias finais (notas) dos estudantes de acordo com as covariáveis (estudantes que participaram do curso na plataforma MOOC, turma, grupo de motivação e gênero). Os principais resultados demonstram que a escolha de um método ativo de aprendizagem, utilizando a plataforma MOOC interfere em todos os grupos, no aumento da nota final em comparação aos estudantes que não acessaram a plataforma, portanto, não participaram de todo o processo, sendo esse efeito ainda mais expressivo para o grupo de motivação 1 (motivados pela excelência acadêmica), a IES-1 obteve um desempenho superior a IES-2. O êxito da introdução das metodologias ativas está diretamente relacionado a importância do envolvimento de todos os atores desse processo, com destaque as instituições de ensino e professores, para a formação de um indivíduo capaz de transformar a sua vida, o seu meio e a nossa sociedade. / This research analyzes the factors that support the use of active methods to increase the performance of the students towards meaningful learning, taking into account that the act of learning is not transferable, only the individual can do it and no one can learn on the other, but can stimulate the interest of students, exploring new learning opportunities and more focused on the activity of the students, using the hybridization, which is the mixture of techniques and tools to assist and streamline the learning with the combination of classroom and virtual teaching environments - using MOOCs tools for the design of the inverted classroom. In order to evaluate the interference of active learning methodology over performance, students from two private universities in the area of Applied Social Sciences took part in this research and, after one semester answered two statistically validated scales questionnaires: Academic Motivation Scale and Strategic Learning Scale, suitable for online environments. Multivariate analysis techniques, composed by Principal Component Analysis and Cluster Analysis, have been used to assess the presence of motivation groups. In order to characterize obtained motivation groups, frequencies of formed groups and main components averages were calculated as well as markings of statistical significance for the t-test mean difference and regression techniques to assess students final average (grades) according to the covariates (students who took the course in MOOC platform, classroom, motivation group and gender). Main results show that the choice of an active learning method, using MOOC platform interferes in all groups, in the final score increase comparatively to students who had not accessed the platform, thus not participating in the process; this effect was even more significant on motivation of group 1 (motivated by academic excellence), PU-1 achieved a superior performance comparatively to PU-2. The active methods introduction success is directly related to the importance of the involvement of all actors in the process, especially educational institutions and teachers, for the formation of an individual able to transform his life, his environment and our society .

<p>This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). Striations are mainly density depletions of a few percent that are observed when a powerful electromagnetic wave, a pump wave, is launched into the ionosphere. The striations are formed by upper hybrid (UH) oscillations that are localized in the depletion where they are generated by the linear conversion of the pump field on the density gradients. However, the localization is not complete as the UH oscillation can convert to a propagating electromagnetic Z mode wave. This process, termed Z mode leakage, causes damping of the localized UH oscillation. The Z mode leakage is investigated and the theory predicts non-Lorentzian skewed shapes of the resonances for the emitted Z mode radiation. Further, the interaction between individual striations facilitated by the Z mode leakage is investigated. The LHSS are observed by spacecraft in the ionosphere and magnetosphere as localized waves in the lower hybrid (LH) frequency range that coincides with density cavities. The localized waves are immersed in non-localized wave activity. The excitation of localized waves with frequencies below LH frequency is modelled by scattering of electromagnetic magnetosonic (MS) waves off a preexisting density cavity. It is shown analytically that an incident MS wave with frequency less than the minimum LH frequency inside the cavity is focused to localized waves with left-handed rotating wave front. In addition, the theory is shown to be consistent with observations by the Freja satellite. For frequencies between the minimum LH frequency inside the cavity and the ambient LH frequency, the MS wave is instead mode converted and excites pressure driven LH oscillations. This process is studied in a simplified geometry.</p>

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2008.

This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). Striations are mainly density depletions of a few percent that are observed when a powerful electromagnetic wave, a pump wave, is launched into the ionosphere. The striations are formed by upper hybrid (UH) oscillations that are localized in the depletion where they are generated by the linear conversion of the pump field on the density gradients. However, the localization is not complete as the UH oscillation can convert to a propagating electromagnetic Z mode wave. This process, termed Z mode leakage, causes damping of the localized UH oscillation. The Z mode leakage is investigated and the theory predicts non-Lorentzian skewed shapes of the resonances for the emitted Z mode radiation. Further, the interaction between individual striations facilitated by the Z mode leakage is investigated. The LHSS are observed by spacecraft in the ionosphere and magnetosphere as localized waves in the lower hybrid (LH) frequency range that coincides with density cavities. The localized waves are immersed in non-localized wave activity. The excitation of localized waves with frequencies below LH frequency is modelled by scattering of electromagnetic magnetosonic (MS) waves off a preexisting density cavity. It is shown analytically that an incident MS wave with frequency less than the minimum LH frequency inside the cavity is focused to localized waves with left-handed rotating wave front. In addition, the theory is shown to be consistent with observations by the Freja satellite. For frequencies between the minimum LH frequency inside the cavity and the ambient LH frequency, the MS wave is instead mode converted and excites pressure driven LH oscillations. This process is studied in a simplified geometry.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2008.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2008.

Les tapis de nanotubes de carbone verticalement alignés sont des candidats potentiels pour des applications telles que les interconnexions ou les matériaux d'interface thermique. Ce travail de recherche porte sur la synthèse de tapis de nanotubes de carbone alignés selon le procédé de dépôt chimique en phase vapeur (CVD) d'aérosols liquides, sur l'élaboration de nanocomposites constitués de différentes nuances de matrices époxy infiltrées au sein de ces tapis, ainsi que sur l'étude des propriétés mécaniques et thermiques longitudinales et transverses des tapis secs eux-mêmes et des nanocomposites 1D formés. Les conditions de synthèse permettent notamment de faire varier les caractéristiques des tapis telles que leur épaisseur, leur masse volumique, le diamètre externe moyen des nanotubes de carbone (NTC), l'espace intertube et la teneur volumique en NTC, alors que leur structure cristalline peut être modifiée par le biais d'un traitement thermique à haute température. L'objectif principal de ce travail consiste à démontrer et quantifier l'effet de certaines caractéristiques des tapis de nanotubes de carbone sur les propriétés mécaniques et thermiques des différents types de tapis et matériaux composites obtenus. Les deux méthodes d'imprégnation mises en oeuvre, voie liquide et infusion, conduisent à des tapis de NTC alignés denses avec un alignement des NTC conservé et une répartition homogène des NTC au sein du système époxy. La fraction volumique en NTC s'avère être le paramètre-clé permettant d'exacerber, dans la direction longitudinale aux NTC, les propriétés mécaniques et thermiques des nanocomposites. Par ailleurs, les tapis de NTC et les nanocomposites voient leurs propriétés de conduction thermique longitudinale nettement exacerbées lorsque les NTC présentent une amélioration de leur structure cristalline. L'augmentation significative des performances apportées par les tapis de NTC verticalement alignés au sein de ces matériaux nanocomposites anisotropes par rapport aux matrices organiques non chargées est prometteuse et ouvre des pistes de réflexion visant à répondre aux nouvelles exigences de multifonctionnalité des secteurs de l'aéronautique et de l'aérospatial. / Vertically aligned carbon nanotube carpets are potential candidates for applications such as interconnections or thermal interface materials (TIMs). This research work deals with the synthesis of aligned carbon nanotube carpets from the aerosol assisted chemical vapour deposition (CVD) technique, with the elaboration of nanocomposites made of different grades of epoxy matrix infiltrated within these carpets, as well as the study of both longitudinal and transverse mechanical and thermal properties of dry carpets themselves and 1D-nanocomposites separately. The synthesis conditions notably enable to vary characteristics of the differents carpets such as their thickness, their density, the mean external diameter of the carbon nanotubes (CNT), the intertube space and the CNT volume fraction, whereas their crystalline structure can be modified with a high temperature thermal treatment. The main goal of this work is to prove and quantify the effect of some of the characteristics of the carbon nanotubes carpets on both mechanical and thermal properties of the different kinds of CNT carpets and resulting composite materials. The two impregnation methods used, liquid way and infusion, lead to dense CNT carpets with a preserved alignment of the CNT and an homogeneous distribution of these latest within the epoxy system. The CNT volume content is evidenced as the key-parameter exacerbating the mechanical and thermal properties mainly in the longitudinal direction compared with the alignment axis of the CNTs. Moreover the mechanical and thermal conduction properties of the CNT carpets and the 1D-nanocomposites are clearly increased when the crystalline structure of the CNT is improved. The significant increasing of the properties brought by the vertically aligned CNT within these anisotropic 1D-nanocomposites compared with the only organic matrixes is promising and opens new pathways aiming to meet the latest specifications related to multifunctionnality in fields such as aeronautics and aerospace.

Au cours des dernières années, le secteur touristique a été caractérisé par toute une série de changements fondamentaux. L’un de ces changements, certainement le plus important, a été le fait d’être considéré aujourd’hui comme l’activité productive capable de faire tourner l’économie d’un pays entier.Notre mémoire de recherche se situe à l’intersection de la terminologie thématique, de la linguistique de corpus et du traitement automatique des langues.Dans le premier chapitre du travail que nous allons présenter, nous chercherons à introduire aux domaines d’études théoriques sur lesquels notre recherche s’appuie.Premièrement, on traitera de la linguistique de corpus et on examinera les différentes catégories de corpus existantes. On mettra l’accent sur deux notions fondamentales dans la conception de l’outil corpus en général et dans la création de notre corpus en particulier : représentativité et contexte. Au sein du discours touristique, la représentativité, d’un côté, se relie au caractère spécial de notre micro-langue ; le contexte, de l’autre, révèle la pluralité des sous-domaines qui composent ce technolecte à mi-chemin entre la langue générale et la langue spécialisée.Dans le deuxième chapitre, nous présenterons le corpus thématique trilingue (CTT) que nous avons créé préalablement à la rédaction de la thèse proprement dite.Avant tout, on fournira les indications théoriques et pragmatiques nécessaires pour réaliser un corpus trilingue en langue de spécialité : la collecte des textes, l’homogénéisation des échantillons textuels repérés et l’annotation. Au cours de ce chapitre, nous présenterons Alinea, l’instrument qu’on a utilisé pour l’alignement de textes recueillis et pour la consultation simultanée des traductions trilingues. Dans le troisième et dernier chapitre, on passera à l’interrogation du corpus créé. Sur la base d’un terme pris comme exemple, le terme ville, on lancera la recherche dans le CTT. Ensuite, on analysera les collocations les plus usitées contenant le mot ville.En guise de conclusion de notre mémoire, nous présenterons une annexe consacrée à notre glossaire trilingue comme résultat de notre exploration de la chaîne terminologique qu’on aura analysée précédemment. Pour conclure, l’objectif général de notre étude sera d’explorer la chaîne de gestion terminologique à travers la création d’un glossaire trilingue dans le domaine du tourisme. Notre orientation méthodologique de caractère sémasiologique impliquera ainsi au moins quatre objectifs spécifiques :• créer un corpus trilingue du tourisme (CTT), capable d’attester des usages en contexte des termes.• extraire des termes en utilisant des techniques diverses, telle que l’étude fréquentielle des éléments du corpus.• vérifier les données obtenues et les compléter à l’aide de ressources externes.• répertorier et décrire l’ensemble des termes sous forme d’un glossaire trilingue à sujet touristique (GTT). / Our study concerns the language of tourism from a lexicographical perspective.Exploiting the web we realized a corpus ad hoc. This corpus is composed by about 10.000 texts in three languages (French, Italian and English), aligned using “Alinea”.Starting from terminological extraction, we analysed some collocations at the aim to create a trilingual and tri-directional glossary.We chose this subject according to the increasing importance taken from tourism economy in the world.Our study fields are thematic terminology, corpus linguistics and automatic language treatment.The first chapter presents the study field of our research. First of all, we introduced to corpus linguistics presenting the different categories of corpus and pointing out our attention on two main notions: representativeness and context.Therefore, we explained the link between Language for Special Purposes and tourism discourse as a Specialized Discourse.In the second chapter, we showed the trilingual thematic corpus we created during our researches. We described the main steps to create a corpus: collection of texts, cleaning and annotation.In this chapter, we gave a particular attention to the presentation of “Alinea”.Finally, the third chapter is a study of frequent collocations with the term “town” (ville).The annexes present the glossary as well as the methodological principals we followed in the redaction.

Esta pesquisa analisa fatores que sustentam o uso das metodologias ativas para o aumento do desempenho dos estudantes para a aprendizagem significativa, levando-se em consideração que o ato de aprender é intransferível, só o indivíduo pode fazê-lo e ninguém pode aprender por outro, mas pode-se incentivar o interesse dos estudantes, explorando novas oportunidades de aprendizagem, bem mais centradas na atividade dos estudantes, utilizando a hibridização, que é a mescla de técnicas e ferramentas que auxiliam e dinamizam o aprendizado com a combinação entre ambientes presenciais e virtuais de ensino - usando a ferramenta dos MOOCs pela concepção da sala de aula invertida. Para avaliar a interferência da metodologia ativa de aprendizagem no desempenho, participaram da análise estudantes universitários, de duas instituições particulares, na área de Ciências Sociais Aplicadas, que após um semestre responderam a dois questionários de escalas validadas estatisticamente: Academic Motivation Scale e Escala Estratégica de Aprendizagem para ambientes on-line. Utilizou-se técnicas de análise multivariada, composta pela análise de componentes principais e análise de agrupamento, para avaliar a presença de grupos de motivação. Para a caracterização dos grupos de motivação obtidos foram calculadas as frequências dos grupos formados e médias das componentes principais, bem como as marcações de significância estatística para o teste-t de diferença de médias e técnicas de modelo de regressão para avaliar as médias finais (notas) dos estudantes de acordo com as covariáveis (estudantes que participaram do curso na plataforma MOOC, turma, grupo de motivação e gênero). Os principais resultados demonstram que a escolha de um método ativo de aprendizagem, utilizando a plataforma MOOC interfere em todos os grupos, no aumento da nota final em comparação aos estudantes que não acessaram a plataforma, portanto, não participaram de todo o processo, sendo esse efeito ainda mais expressivo para o grupo de motivação 1 (motivados pela excelência acadêmica), a IES-1 obteve um desempenho superior a IES-2. O êxito da introdução das metodologias ativas está diretamente relacionado a importância do envolvimento de todos os atores desse processo, com destaque as instituições de ensino e professores, para a formação de um indivíduo capaz de transformar a sua vida, o seu meio e a nossa sociedade. / This research analyzes the factors that support the use of active methods to increase the performance of the students towards meaningful learning, taking into account that the act of learning is not transferable, only the individual can do it and no one can learn on the other, but can stimulate the interest of students, exploring new learning opportunities and more focused on the activity of the students, using the hybridization, which is the mixture of techniques and tools to assist and streamline the learning with the combination of classroom and virtual teaching environments - using MOOCs tools for the design of the inverted classroom. In order to evaluate the interference of active learning methodology over performance, students from two private universities in the area of Applied Social Sciences took part in this research and, after one semester answered two statistically validated scales questionnaires: Academic Motivation Scale and Strategic Learning Scale, suitable for online environments. Multivariate analysis techniques, composed by Principal Component Analysis and Cluster Analysis, have been used to assess the presence of motivation groups. In order to characterize obtained motivation groups, frequencies of formed groups and main components averages were calculated as well as markings of statistical significance for the t-test mean difference and regression techniques to assess students final average (grades) according to the covariates (students who took the course in MOOC platform, classroom, motivation group and gender). Main results show that the choice of an active learning method, using MOOC platform interferes in all groups, in the final score increase comparatively to students who had not accessed the platform, thus not participating in the process; this effect was even more significant on motivation of group 1 (motivated by academic excellence), PU-1 achieved a superior performance comparatively to PU-2. The active methods introduction success is directly related to the importance of the involvement of all actors in the process, especially educational institutions and teachers, for the formation of an individual able to transform his life, his environment and our society .

In this report, an object-space solution to occluder fusion of OBB occluders is explored. Two different approaches are considered were the object-space fusion is reduced to a 2D problem. The first approach finds axis-aligned silhouettes within the projection of occluder OBBs which are then fused together creating large axis-aligned silhouettes. The other approach creates concave hulls of the projected OBB silhouettes from which convex inscribed silhouettes are then found. These silhouettes are then converted back to object-space where shadow frusta created around the silhouettes are used for the culling operation. The effectiveness of the two approaches is evaluated considering the amount of culled geometry. It is shown that fused convex silhouettes are needed to produce competitive results.