Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-03-23T12:12:30Z No. of bitstreams: 1 paulamoraeslupatini.pdf: 2954241 bytes, checksum: 79130d300f2b4037e5c633836842bf06 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-03-23T12:20:52Z (GMT) No. of bitstreams: 1 paulamoraeslupatini.pdf: 2954241 bytes, checksum: 79130d300f2b4037e5c633836842bf06 (MD5) / Made available in DSpace on 2018-03-23T12:20:52Z (GMT). No. of bitstreams: 1 paulamoraeslupatini.pdf: 2954241 bytes, checksum: 79130d300f2b4037e5c633836842bf06 (MD5) Previous issue date: 2017-12-13 / Introdução: A reabsorção radicular apical (RRA) é uma conseqüência comum do tratamento ortodôntico. Sua etiologia é multifatorial, mas ainda não foi totalmente esclarecida. A análise da dimensão fractal é um método quantitativo que descreve e caracteriza a complexidade das imagens ou, mais precisamente, sua composição textural. Objetivo: O objetivo deste estudo transversal observacional foi avaliar a qualidade do tecido dentário e do osso adjacente ao terço apical radicular dos incisivos maxilares com RRA em pacientes sob tratamento ortodôntico, determinando a dimensão fractal nas imagens de tomografia computadorizada de feixe cônico e compará-las com as imagens dos dentes contralaterais correspondentes, sem RRA, no mesmo indivíduo. Metodologia: A amostra consistiu em 20 pacientes sob tratamento ortodôntico com aparelho edgewise, que apresentaram RRA em um incisivo maxilar (grupo experimental) e ausência de reabsorção no incisivo contralateral correspondente (grupo controle), identificado através de radiografias periapicais de rotina . A dimensão fractal de duas regiões no terço apical da raiz e de quatro no osso alveolar adjacente aos incisivos com RRA e seus dentes contralaterais sem RRA foi determinada e comparada. Resultados: Em todas as regiões ósseas e dentárias avaliadas, exceto no terço apical da raiz no corte coronal, os incisivos sem RRA apresentaram valores de DF maiores do que os incisivos com RRA, mas não houve diferença significativa. Conclusão: Não foi encontrada diferença estatística entre a qualidade dos tecidos radiculares e ósseos da região apical dos incisivos maxilares com e sem reabsorção apical radicular do mesmo paciente ortodôntico. / Introduction: Apical root resorption (ARR) is a common consequence of the orthodontic treatment. Its etiology is multifactorial but has not yet been entirely clarified. The fractal dimension analysis is a quantitative method that describes and caracterizes the complexity of images or, more precisely, their textural composition. Objective: The aim of this observational cross-sectional study was to assess the quality of the dental tissue and the adjacent bone of the root apical third of maxillary incisors with ARR in patients under orthodontic treatment by determining the fractal dimension in cone beam computed tomography images and compare them with the images of the corresponding contralateral teeth without ARR in the same individual. Methodology: The study sample consisted of 20 patients under orthodontic treatment with edgewise appliance, who presented apical root resorption in a maxillary incisor (experimental group) and absence of root resorption in the corresponding contralateral incisor (control group), identified through routine periapical dental radiographs. The fractal dimension of two regions in the apical third of the root and four in the adjacent alveolar bone of incisors with ARR and their contralateral teeth without ARR was determined and compared. Results: In all bone and dental regions evaluated, except the coronal slice of the apical third of the root, the incisors without ARR had higher FD values than incisors with ARR, but there was no significant difference. Conclusion: No statistical difference was found between the quality of the radicular and bone tissues of the apical region of the maxillary incisors with and without apical root resorption of the same orthodontic patient.

Les marchés financiers occupent, depuis des décennies, une place importante dans notre société. Pourtant, ils présentent des risques accrus auxquels font face la majorité des institutions financières. Les crises, les krachs, les bulles et les turbulences financières jalonnent l’histoire de ces marchés et les déstabilisent fréquemment. En effet, l’existence des anomalies et des biais psychologiques, allant à l’encontre de l’hypothèse d’efficience, remettent en question la théorie financière et révèlent de façon rigoureuse les inefficacités des mécanismes de gestion financière et de contrôle du risque du marché. Confrontés à ces évolutions, le comité de Bâle II recommande la Value at Risk comme une nouvelle vision réglementaire des risques. Ce processus d’innovation financière, introduite par la banque JP Morgan dans les années 90, a connu une grande reconnaissance en finance, mais elle est aussi sujette à des controverses continuelles. Pour surmonter les limites de la VaR, nous proposons un nouveau cadre d’analyse de la VaR basé sur des processus fractals. Tenant compte des anomalies et des facteurs de risques du marché financier, qui induisent des rendements par nature non-gaussiens, nous introduisons la VaR en fonction du modèle multifractal à changements de régime markovien de Calvet et Fisher. L’approche VaR-MSM qui modélise la volatilité multifractale à différentes fréquences constitue un aperçu différent d’évaluation du risque du marché. En appliquant ce modèle sur l’indice boursier français le CAC 40, les résultats obtenus révèlent que la VaR-MSM a surpassé assez nettement les autres modèles d’évaluation de la VaR. / Financial markets occupy an important place in our society. However, they present increased risks to financial institutions. Crises, crashes, bubbles and financial turbulence often destabilize these markets. Indeed, the existence of different anomalies and psychological bias, going against the hypothesis of efficiency, put into question financial theory and present an inefficiency of financial and risk management. Faced with these effects, Bale II committee recommended Value at risk as a new financial instrument of risk management. Value at Risk, introduced by JP Morgan Bank in the 90, have a great recognition in finance, but it is also a subject of controversy. To overcome the VaR limits, we propose a new framework based on fractal process. Taking into account abnormalities and risk factors of financial markets, which induce non-Gaussian returns, we introduce the VaR with a Markov-switching multifractal model proposed by Calvet and Fisher. The VaR-MSM approach presents multifractal volatility at different frequencies. We apply this model to the France CAC 40 stock market index. The results clearly show the advantages of VaR-MSM compared with other models of VaR evaluation.

En fait, le concept de texture n’est pas facile à définir, mais il est clair qu’il est fortement lié au Système Visuel Humain. Sachant que le Modèle LIP est compatible avec la vision humaine, il nous a semblé intéressant de créer des outils logarithmiques dédiés à l’évaluation de la texture. Nous nous sommes concentrés sur la notion de covariogramme, qui peut être pilotée par diverses métriques logarithmiques. Ces métriques jouent le rôle d’outils de “corrélation”, avec l’avantage de prendre en compte la vision humaine. De plus, les outils LIP sont peu dépendants des conditions d’éclairement et fournissent donc des résultats robustes si celles-ci varient. Les deux derniers Chapitres proposent une nouvelle approche consistant à considérer les niveaux de gris d’une image comme les phases d’un milieu. Chaque phase permet de simuler la percolation d’un liquide dans le milieu, définissant ainsi des trajectoires de percolation. Chaque propagation d’un pixel à un autre est considérée comme facile ou non, en fonction des niveaux de gris traversés. Une « fonction de coût » est créée, qui modifie le « temps » de propagation d’un point à l’autre. De plus, la fonction de coût peut être calculée dans le contexte LIP, pour prendre en compte la vision humaine / This thesis looks at the evaluation of textures in two different perspectives using logarithmic image processing (LIP) framework. The first case after introducing the concept of textures and giving some classical approaches of textures evaluation, it gives an original approach of textures evaluation called covariogram which is derived from similarity metrics like distances or correlations etc. The classical covariogram which is derived from the classical similarity metrics and LIP covariogram are then applied over several images and the efficiency of the LIP one is clearly shown for darkened images. The last two chapters offer a new approach by considering the gray levels of an image as the phases of a medium. Each phase simulates like a percolation of a liquid in a medium defining the percolation trajectories. The propagation from one pixel to another is taken as easy or difficult determined by the difference of the gray level intensities. Finally different parameters like fractality from fractal dimensions, mean histogram etc associated to these trajectories are derived, based on which the primary experiment for the classification of random texture is carried out determining the relevance of this idea. Obviously, our study is only first approach and requires additional workout to obtain a reliable method of classification

Ztrátová komprese signálů EKG je užitečná a v současnosti stále se rozvíjející oblast. Stále se vyvíjí nové a nové kompresní algoritmy. V této oblasti ale chybí standardy pro hodnocení kvality signálu po kompresi. Existuje tedy sice mnoho různých kompresních algoritmů, které ale buď nelze objektivně porovnat vůbec, nebo jen zhruba. V oblasti komprese navíc nikde není popsáno, zda mají na výkon kompresních algoritmů vliv patologie, popřípadě jaký. Tato dizertační práce poskytuje přehled všech nalezených metod pro hodnocení kvality signálů EKG po kompresi. Navíc bylo vytvořeno 10 nových metod. V rámci práce byla provedena analýza všech těchto metod a na základě jejích výsledků bylo doporučeno 12 metod vhodných pro hodnocení kvality signálu EKG po kompresi. Také je zde představen nový kompresní algoritmus „Single-Cycle Fractal-Based (SCyF)“. Algoritmus SCyF je inspirován metodou založenou na fraktálech a využívá jednoho cyklu signálu EKG jako domény. Algoritmus SCyF byl testován na čtyřech různých databázích, přičemž kvalita signálů po kompresi byla vyhodnocena 12 doporučenými metodami. Výsledky byly porovnány s velmi populárním kompresním algoritmem založeným na vlnkové transformaci, který využívá metodu „Set Partitioning in Hierarchical Trees (SPIHT)“. Postup testování zároveň slouží jako příklad, jak by měl vypadat standard hodnocení výkonu kompresních algoritmů. Dále bylo statisticky prokázáno, že existuje rozdíl mezi kompresí fyziologických a patologických signálů. Patologické signály byly komprimovány s nižší efektivitou a kvalitou než signály fyziologické.

The dissertation thesis, Ornament in Nature, Science and Art, deals with the theme of ornaments in contemporary art, design and architecture. Individual chapters are dedicated to exploring nature and science as sources of inspiration for contemporary art. The chapter, Body and Ornament, is about ornaments for the human bodies and patterns created from the form of human bodies. Art creations by the author and her students make up an integral part of the main text. An individual chapter is dedicated to the Bodyornament project. Bodyornament is a project involving artistic, educational and research elements. Its primary body of work took place as an art performance in the Veletržní palace in Prague. Through the active participation of the students, patterns and ornaments made from their bodies were created. The process was documented by means of photography. The photographs together with the students' written reflections about the experience comprise the primary research documents. In this dissertation, these documents were analyzed and interpreted by using a combination of specific forms of qualitative research and art-based research. Our research model was based on three degree reflexive analysis according to Donald Schön. Through interpretation of the research results, thoughts of possible...

This master thesis describes deterministic context-free L-systems and its context in procedural modeling, especially in fractal geometry, deals with rewriting technique and its usage for modeling structures similar to plants. Further it describes more complex types of L-systems, especially their context and parametric variations, and shows usage of L-systems in computer graphics and describes its usage for procedural modeling of architecture. At the end of this thesis there are described some other possibilities of usage procedural modeling with L-systems and introduced some extensions of rewriting rules, which will be subject of future research.

[pt] O presente trabalho disserta sobre a utilização dos fractais no ensino de conteúdos matemáticos do Ensino Fundamental e do Ensino Médio, com o objetivo de despertar o interesse e a curiosidade dos educandos através da beleza e do dinamismo que eles oferecem para a construção de conceitos matemáticos tais como: semelhança, perímetro, área, volume, progressão aritmética e geométrica. A dissertação inicia-se com um breve histórico do surgimento dos fractais e um resumo dos níveis do desenvolvimento cognitivo segundo o modelo de van- Hiele. Em seguida, exibe-se uma coletânea de atividades envolvendo fractais com nível de dificuldade crescente que propicia aos estudantes uma aprendizagem significativa e com nuances de modernidade. A partir de suas próprias percepções e da troca de ideias entre si, os alunos formularam técnicas recursivas a ponto de preverem uma próxima iteração da figura e meios para obtenção do perímetro e da área das figuras seguintes. Acreditamos que com essa pesquisa conseguimos não só trabalhar e desenvolver conceitos matemáticos básicos, mas também fomentar o estudo do conceito de infinito, além de diminuirmos a distância entre a Álgebra e a Geometria imposta pela maioria dos atuais livros didáticos em circulação. / [en] This dissertation discusses the use of fractals in the teaching of mathematical subjects in the context of elementary, middle and high school, aiming at raising and attracting the interest and curiosity of the students through the beauty and dynamism they offer to the construction of mathematical concepts such as: similarity, perimeter, area, volume, arithmetic and geometric progression. This work begins with a brief history about the emergence of fractals and a summary of levels of cognitive development according to the van-Hiele model. Then, it is shown a collection of activities involving fractals with increasing difficulty levels that provide students with meaningful learning with nuances of modernity. From their own perceptions and the exchange of ideas between them, they formulated recursive techniques to predict a next iteration of the figure and means to obtaining the perimeter and area of the next figures. We believe that with this dissertation we can not only work and develop basic mathematical concepts, but also foster the study of the infinity concept, in addition to reducing the distance between Algebra and Geometry imposed by most current textbooks in use.

No description available.

Autohesion is defined as the resistance to separation of two bonded identical films that have been joined together for a period of time under a given temperature and pressure. Studies on the autohesion phenomenon can provide fundamental insights into the physical processes of adhesive bond and failure, as well as the practical engineering issues such as crack healing, elastomer tack, polymer fusion, self-healing, and polymer welding. In the first part of this dissertation work, four ethylene/1-octene (EO) copolymers were used in the present study consisting of molecules with linear polyethylene backbone to which hexyl groups are attached at random intervals. These copolymers have similar number-average molecular weight (Mn) and polydispersity, but different 1-octene content. These hexyl groups act as the short branches and hinder the crystallization, reduce density to some extent in the solid state, lower the melting temperature, and decrease the stiffness of the bulk materials. A full understanding of the autohesion behavior of the ethylene/1-octene copolymers involves investigations at three different length scales: 1) the molecular scale which controls the interfacial structure; 2) the mesoscopic or microscopic scale which can provide information on the formation of interfaces and on how the energy is dissipated during a fracture process; and 3) the macroscopic scale at which the mechanical properties such as fracture energy can be obtained for a particular test geometry. In the present study, the effects of the branch content on the formation and fracture of the interface of these ethylene/1-octene assemblies were evaluated at the bonding temperatures (Tb) and bonding times (tb). The correlation among these three length scales was also investigated and modeled. The adhesion strength of these symmetric interfaces of EO copolymers was investigated by T-peel fracture tests. The fracture of the interface is an irreversible entropy creating process which involved a substantial amount of energy dissipation. The results of such mechanical tests with respect to the bonding temperature (Tb), bonding time (tb) and peel rate indicated this energy dissipation is the result of a complicated interplay between the ability of the interface to transfer stress and its plastic and viscoelastic deformation properties. When Tb is much higher than the characteristic temperature (Tc), the interfaces were completely healed and cohesive failure was observed in T-peel tests. In this case, the fracture strength decreased with increasing branch content. In contrast, when Tb is very close to Tc, the fracture strength showed an increase with the branch content with either interfacial failure or cohesive failure being observed depending on the branch content and Tb. At higher peel rates, it is observed that higher peel energies are required to fracture the surfaces. Transmission electron microscopy (TEM) showed that the interfacial/interphase structure changed from amorphous to crystalline with an increase in the Tb. The results from the bonding time effect studies showed that the peel energy is proportional to tb1/2 regardless of Tb. But the branch content and the Tb play an important role on the seal rate. Thus, higher seal rate was found for higher Tb and higher branch content. These results also suggest that the autohesion of ethylene/1-octene copolymers are strongly associated with the interactions of melted chains. The chain compositions of these Zeigler-Natta EO copolymers are highly heterogeneous with the branches concentrated in the lower molecular weight portion. Long linear chain segments could form large, well-ordered crystals that provide strong anchors for the tie molecules and therefore determine the density of inter-crystalline links. Short chains with lots of branches could behave as protrusions along the chain to obstruct chain disentanglement and limit a chain from sliding through a crystal. Due to these reasons, the short chains with branches would contribute much less than the long linear chains to the full peel strength after complete sealing. However, higher peel strengths could be obtained only at the higher temperatures or longer bonding times at which the long linear chains begin to melt and diffuse across the interface. On the other hand, the higher branch content samples have the lower crystallinity and could obtain the higher chain mobility at the lower bonding temperatures and with shorter bonding times. Therefore, higher seal strength was observed for the higher branch content samples at lower Tb. Following T-peel fracture tests of ethylene/1-octene copolymer assemblies which showed interfacial failures, the fractured surfaces were investigated by using Atomic Force Microscopy (AFM) and characterized by fractal analysis together with the original films. The AFM images showed strong dependence on the peel rate and branch content. Quantitatively, the fractal analyses demonstrated fractal characteristics at the different finite scales. Two regimes showing fractal features were identified for each surface. In regime I (low magnifications) the fracture test did not change the fractal dimensions much. But there were significant changes in regime II before welding and after T-peel fracture tests. The length scale that separated these two regimes is very close to the size of lamellar structures. The characteristic sizes at which the fractal characteristics emerge were shown to appear at larger scales for surfaces fractured at higher peel rates. This suggests that the appearance of fractal behavior at larger scales requires higher fracture energies. The characteristic sizes and fractal dimensions were shown to depend on the molecular structure. Because the fractal analysis suggests at least some crystalline lamellae on the surfaces still existed during T-peel fracture tests, a "Stitch-welding" has been therefore proposed as the autohesion mechanism in which only chains in the amorphous portions could inter-diffuse. In the second part of this dissertation work, a multi-layer lap-shear geometry has been designed and proven as a reliable testing method in evaluation of the dynamical mechanical properties of polyacrylic pressure sensitive adhesive (PSA) in paper lamination for postage stamp applications. In-situ testing of four different PSA stamp laminates constructed by laminating water-based polyacrylic PSAs to the stamp face papers were carried out using a dynamic mechanical analyzer (DMA) in the temperature range from -50 to 60 oC at frequencies 0.1, 1, 10, and 100 Hz. This geometry requires the tension mode on the DMA, but the results which were recorded as tensile properties were converted to shearing properties of the PSA layers in the laminate. The effect of the thickness (layers of laminates) on the dynamical mechanical properties has been studied and the results suggested that a multi-layer geometry with 5-10 layers could be an appropriate structure to produce enhanced responses. Therefore, the geometry with 8-layer laminates was used for frequency sweep/isothermal temperature and frequency sweep/temperature step tests. The results showed three relaxation responses that is, glassy, transition, and flow regions with respect to the frequencies and temperatures. These results also implied the viscoelastic characteristics of these PSA products. The tensile properties of the face papers were also tested using the same parameters as those of the multi-layer geometry. Significant differences were found between the shearing behaviors of the multi-layer geometry and the tensile behaviors of the elastic face paper. This suggests that the tensile deformation of the face paper in the multi-layer geometry could be ignored and the elastic paper did not contribute to the shearing properties of the PSA layers. Time-temperature superposition curves have been produced with reference temperature set at 23 oC, which can be used to predict the long term and short term performances of these samples at this temperature. This method can be utilized as a standard testing method on the PSA adhesives in the laminate form. In addition to the dynamic mechanical properties, it can also be developed to be a general standard method on testing the rheological properties of adhesives, polymer melts and other viscous materials. / Ph. D.

Les fichiers qui accompagnent le document incluent une archive .jar du zoom-éditeur (qui peut être lancé via un browser) et des exemples de z-textes réalisés avec ce logiciel. / L’objectif du projet est la construction d’un nouveau type d’éditeur, appelé ici zoom-éditeur, permettant à l’utilisateur d’augmenter ou de diminuer le degré de détail du texte par des opérations de zoom-in et zoom-out. La principale caractéristique de cette nouvelle forme de textualité sera l’organisation du texte sous la forme d’une structure spatiale à trois dimensions (X, Y, Z), c’est-à-dire une disposition intégrant des niveaux de « profondeur » correspondant à différents degrés de détail et de signification. Nous avons appelé ce type de texte, représentable à plusieurs échelles, z-texte et les processus de création et d’exploration impliqués par cette structure, z-écriture et z-lecture. La première partie décrira le cadre et les enjeux théoriques du projet. Les deux premiers chapitres seront dédiés à la dialectique code / texte et aux méthodes d’analyse de l’esthétique du texte électronique, dans une perspective comparatiste par rapport aux formes textuelles imprimées. Le troisième chapitre présentera l’analyse de cinq types d’ouvrages sur support électronique, parmi les plus connus (hypertexte littéraire, cyberpoésie, blog, encyclopédie libre et journal en ligne). La deuxième partie décrira les sources du modèle proposé, le modèle proprement dit, ainsi que les composantes et la fonctionnalité du zoom-éditeur. Ce volet se réfèrera au cadre théorique décrit dans les trois premiers chapitres. La troisième partie proposera quelques hypothèses sur les applications possibles du modèle, à partir de l’idée de z-texte comme espace multidimensionnel. Chaque dimension correspondrait ainsi à un certain type de loupe, i.e. d’analyse ou d’exploration, applicable à un texte donné. Les domaines mis en discussion seront la critique et la création littéraire, la pédagogie, l’écriture de scénarios, la construction de documentation électronique, la conception de dictionnaires et d’encyclopédies. Le projet inclura également la construction des z-textes, selon les principes de la z-écriture et en utilisant le zoom-éditeur. / The project proposes a new type of interface, that we have called zoom-editor, allowing the user to increase and decrease the degree of detail of the text by zooming-in and out. The main feature of this new kind of textuality would be a 3D textual layout on the three axis (X, Y, Z), i.e. an in-depth structure based on several layers of details and meaning. We have called this type of text, z-text, and the corresponding processes of reading and writing, z-reading and z-writing. The first part describes the theoretical framework of the project. The first two chapters deal with the code/text dialectics and the analytic methods of the electronic text aesthetics, as compared with the printed forms. The third chapter analyses five types of digital documents: literary hypertext, cyberpoetry, blog, free encyclopaedia and on line newspaper. The second part describes the sources of the proposed model, the model itself, and the components and functionality of zoom-editor. This section also contains references and discussions related to the theoretical framework portrayed in the first three chapters. The third part proposes some hypotheses on the possible applications of the model, starting from the idea of a z-text as a multidimensional space. Each dimension would metaphorically correspond to a type of magnifying glass, implying a certain kind of analysis or exploration of a text. The domains considered for discussion are literary criticism, creative writing, pedagogy, encyclopaedias and dictionaries, documentation. The project also supposes the construction of a number of z-texts, according to the principles of z-writing, by using the zoom-editor.