Este trabalho apresenta uma associação dos cálculos elástico e plástico, para lajes retangulares com carga uniforme e uma borda livre. O cálculo elástico é usado para pré-dimensionamento, na determinação dos momentos negativos e da razão dos momentos positivos nas duas direções. Esses momentos fletores são obtidos através de funções aproximadoras, determinadas a partir de tabelas. Após compatibilização dos momentos elásticos, são adotados os momentos de plastificação negativos, sendo os positivos obtidos através da teoria das chameiras plásticas, que é utilizada também no cálculo do comprimento das barras sobre os apoios. Conhecidas as armaduras, os momentos elásticos são novamente utilizados na verificação das flechas. Nos exemplos são comparadas as armaduras do cálculo elástico com as obtidas através do cálculo plástico, no qual se pôde constatar a economia deste último em relação ao primeiro. / This work presents an association of elastic and plastic analysis, for rectangular slabs with uniform load and a free edge. The elatic theory is used to estimate the negative moments and the relation between positive moments in the two directions. These bending moments are obtained from approached functions, based on tables. After compatibilization of elastic moments, the negative plastic moments are adopted and the positive moments are obtained from yield line theory, which will be used again in the calculation of the lenght of the bars over the supports. Once the reinforcements are known, the elastic moments are used again for checking the deflexions. In the examples, the results of elastic plate theory are compared with those obtained by plastic analysis, where it is possible to evidence the economy of the later over the former.

Made available in DSpace on 2016-04-25T20:21:19Z (GMT). No. of bitstreams: 1 Walisson Pereira Fernandes.pdf: 3336996 bytes, checksum: 5e0932a05bfd9f262378354964e1b59b (MD5) Previous issue date: 2015-03-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Straight edge is the word used to describe persons who, in their everyday lives, are allied to the punk to not use substances considered addictive as alcohol, tobacco and psychoactive. Its beginnings derive from the late 1970s and early 1980s in the United States. However, the genealogical analysis of their practices through the centuries, going back to abstainers movements of the United States and England between the nineteenth and twentieth centuries and its ballast in the formation of moral, instilling in policy that determine behavior. With the emergence of punk in the 1970s as criticism of moralism, society and the state, the straight edge emerges in this context bringing a punk hygiene and, over the years, has become more violent and reductionist, emancipating itself from protoform and pouring a new ways to build and to solidify. The straight edge approached the environmental movements, looking to list anarchist aspects in their practice, but only reiterated other political forms that are linked more to progressivism that, in fact, to anarchism. In this purpose, several straight edgers who sought anarchism as a way of life, broke with the straight edge to proceed their libertarian path, and kept at the same time, the practical abstainers without the use of the nomenclature that identified previously. In Brazil, similar to what happened in the United States and Europe, the intensification of the straight edge scene brought also the anarchist cells of eruption for the construction of a group of vegan orientation appropriating an anarchist nomenclature for its consolidation among young libertarians causing not only the bedlam among their peers, but catches of anarchism and punk / Straight edge é a palavra utilizada para descrever os sujeitos que, em suas vidas cotidianas, aliam-se ao punk de modo a não utilizarem substâncias consideradas viciantes, como álcool, tabaco e psicoativos. Seus começos derivam do final da década de 1970 e começo da década de 1980 nos Estados Unidos. No entanto, a análise genealógica de suas práticas atravessa os séculos, remontando aos movimentos abstêmios dos Estados Unidos e da Inglaterra entre os séculos XIX e XX e seu lastro na formação da moral, infundindo na elaboração de políticas que determinariam condutas. Com o surgimento do punk na década de 1970 como crítica aos moralismos, à sociedade e ao Estado, o straight edge emerge neste contexto trazendo uma higienização do punk e, com o passar dos anos, se tornou mais violento e reducionista, desvinculando-se de sua protoforma e vertendo novos meios para se construir e se solidificar. O straight edge aproximou-se dos movimentos ambientalistas, procurando elencar aspectos anarquistas em sua prática, mas reiterou apenas outras formas políticas que vinculam-se mais a progressismos que, de fato, aos anarquismos. Neste intento, vários straight edgers que procuraram os anarquismos como forma de vida, romperam com o straight edge para dar prosseguimento a sua trajetória libertária, e mantiveram, ao mesmo tempo, as práticas abstêmias sem o uso da nomenclatura que os identificava anteriormente. No Brasil, semelhantemente ao ocorrido nos Estados Unidos e na Europa, a intensificação da cena straight edge trouxe, ainda, o irrompimento de células anarquistas para a construção de um grupo de orientação vegana apropriando-se de uma nomenclatura anarquista para sua consolidação entre jovens libertários, causando não apenas a balbúrdia entre seus pares, mas capturas dos anarquismos e do punk

<div>The quantum phase transitions and exotic excitations are exciting and important topics of nowadays condensed matter theory. Topologically protected excitations are of great interest for potential applications in quantum computing. This Thesis explores two examples of exotic topologically protected excitations, Majorana fermions and parafermions in hybrid superconductor/semiconductor systems.</div><div><br></div><div>In the first part of the thesis, after a brief review of ideas on Majorana zero modes in solid state systems obtained by researchers over the past decade, I present our study of the emergence of Majorana fermions in charge carrier holes doped quantum wires. Study of Majorana modes in this system requires understanding Luttinger holes in low dimensions, which is also crucial for numerous spin-dependent phenomena, emerging field of spintronics and nanotechnology. We find that hole-doped quantum wires that are proximity coupled to a conventional s-wave superconductor is a promising system for the observation of Majorana fermions. We advanced understanding of Luttinger holes in quantum wells and quantum wires. We have shown that the vast majority of earlier treatments of Luttinger holes ignored an important effect, a mutual transformation of heavy and light holes at the heteroboundaries. We have derived the effective hole Hamiltonians in the ground size-quantized sub-bands of quantum wells and quantum wires. The effect of mutual transformation of holes is crucial for understanding Zeeman and spin-orbit coupling, and results in several spin-orbit terms linear in momentum in hole-doped quantum wires. We discuss the criterion for realizing Majorana modes in charge carrier hole systems and show that GaAs or InSb hole wires shall exhibit stronger topological superconducting pairing, providing additional opportunities for its control compared to intensively studies InSb and InAs electron systems.</div><div><br></div><div>In the second part of the thesis, I first introduce the basic facts of the current theoretical understanding of the fractional quantum Hall effect and a theoretical model of parafermion excitations. Parafermion zero modes are promising for universal quantum computing. However, physical systems that are predicted to host these exotic excitations are rare and difficult to realize in experiments. I present our work on modeling domain walls on the boundary between gate-induced polarized and unpolarized domains of the fractional quantum Hall effect system near the spin transitions, and the emergence of the parafermion zero modes when such domain wall is proximity coupled to an s-wave superconductor. Exact diagonalization of the Hamiltonian in a disk and torus geometries proves formation of the counter-propagating edge states with different spin polarizations at the boundaries between areas of the electron liquid in polarized and unpolarized filling factor $\nu=2/3$ phases. By analytical and numerical methods we find the conditions for emergence of parafermion zero modes in hybrid fractional quantum Hall/s-wave superconductor system. The phase diagram indicates that the parafermionic phase, which is represented by the six-fold ground state degeneracy, is separated from other phases by a topological phase transition. Such parafermion modes are experimentally feasible. They present a vital step toward the realization of Fibonacci anyons that allow a full universal set of quantum operations with topologically protected quasiparticles.</div><div><br></div>

Increased near infrared (NIR) reflection, closely resembling the red edge found in leaves, has been known in frogs for many years. Whereas previously thought of as an isolated rarity, we have shown that it is likely far more prevalent than previously believed, occurring in multiple distinct family groups and world regions. To date, there are now 26 anuran species known to demonstrate increased NIR reflectance, from 12 different genera, 4 families, and 3 ecozones. The visible/NIR reflection spectra of each individual measured was found to be characteristic of its species; whether it was wild or captive bred; and its sex. A machine learning based classification system was demonstrated as a viable method of identifying these properties from a frog's reflection spectra alone. How this reflection spectra developed from a pre-metamorphosis froglet through to adult frog was tracked, with the gradual changes to the reflection spectra of both NIR reflective and other frogs identified as being most likely dominated by the reduction in epidermal melanophores, and the increasing number of dermal iridophores. A modified consumer camera was shown to be a viable method for rapid identification of increased NIR reflection in anurans, and was used to identify that salamanders also show variation in NIR reflection between ground dwelling and leaf sitting species. The overnight colour change in Hylomantis lemur was observed, and found to occur pre-emptively of the frog's future location; with the frogs regularly transitioning from pale green ‘daytime' colouration, to the dark brown ‘night time' colouration, while still on the green leaf surface before becoming active, and undertaking the reverse transition while still active, but shortly before returning to the leaf. It seems likely that this change is for protection from silhouetting whilst active. Optical coherence tomography images were taken of several species of frog, and found to be a viable method for non-invasive investigation of anuran skin structure, with structural differences observed between the two colourations of H. lemur. It was found that the most likely cause of the increased NIR reflection in frogs is a reduction in melanin, either by absence or substitution with pterorhodin. Although the true benefit to the frog is difficult to determine, it seems likely that cryptic thermoregulation plays a key role: the maintenance of body temperature for the purpose of camouflage from animals capable of far-infrared vision. This thesis demonstrates the legitimacy of several techniques and approaches for non-invasive study of anurans, but the ultimate scope of the project is fundamentally limited by the range of frogs available. Further insight is likely to arise from increasing this scope, applying these techniques to more frogs, from more species, in more regions, and the author wishes all future researchers the greatest success in this endeavour.

In this thesis we explore several topics with applications to both aero and hydroacoustics. Due to the much larger speed of sound in water compared to in air, several of the approximations used in aeroacoustics are not applicable underwater over the range of frequencies of interest. Specifically, we study the finite-chord effects on two broadband noise mechanisms: the trailing edge noise and the ingested noise problems. We start by investigating the acoustic wave diffraction by a finite rigid plate using three different methods. We compare the behaviour of the different solutions as a function of the reduced acoustic wavenumber. Our results reveal that the Mathieu function expansion is the most appropriate method as long as the reduced acoustic wavenumber is not too large. Finally, we show how the Mathieu functions can be used to build a Green's function tailored to an elliptic cylinder of arbitrary aspect ratio without relying on addition theorems. The results obtained in chapter two motivated the search for an exact solution to the trailing edge noise problem using a Mathieu function expansion. It is shown that the approximate methods used in aeroacoustics are not accurate enough for reduced acoustic wavenumbers less than unity, and for all wavenumbers near cut-off. Furthermore it is shown that, even at low Mach numbers, it is crucial to take into account the effects of convection at low frequency. Finally Lighthill's analogy is used, combined with the tailored Green's function introduced previously, to recover the two asymptotic Mach number scalings of the acoustic power for a flat plate at high frequency and low frequency. In chapter four, we introduce a novel method to solve the ingested noise problem by decomposing the pressure field into a singular part whose functional form can easily be found, and a regular part that we express using a Mathieu function expansion. It was found that finite-chord effects do have a strong impact for reduced acoustic wavenumbers less than unity, and for all wavenumbers near cut-off. The following chapter focuses on the trailing edge noise mechanism and details how the theory for a single stationary aerofoil can be applied to a rotating propeller. Due to the general geometry of a blade, we extended Amiet's model to take into account a mean flow misaligned with the blade chordline. Different semi-analytical models of wall pressure spectra are introduced and compared. We make extensive use of Brooks' data for a NACA 0012 aerofoil to obtain realistic inputs in the semi-analytical models. Finally, we introduce and compare two models of rotating blade trailing edge noise. The effects of both the angle of attack and the number of strips are then investigated. The final chapter is distinct from the rest of the thesis. We propose a model for studying the low Mach number flow noise from a 2D circular cylinder with small roughness. The method is based on using the Green's function tailored to a smooth cylinder in Curle's acoustic analogy. It was found that the main source of noise was the tonal low frequency scattering by the smooth geometry. However, it is suggested that roughness elements might be the dominant source of noise at higher frequency.

Le présent travail de doctorat vise à proposer une méthode de post-traitement de la plasticité, à partir de deux calculs éléments finis en élasticité, afin de déterminer la durée de vie de structures avec concentration de contraintes, comme les disques ou les aubes de turbines. Leur dimensionnement en fatigue avec des calculs éléments finis en plasticité conduit à des temps de calcul longs, voir prohibitifs. Les méthodes de types Neuber et l’analyse par changement d’échelles sont des alternatives beaucoup moins couteuses en temps de calcul. En effet, ces méthodes permettent d’estimer la plasticité localisée uniquement à l’aide de calculs éléments finis en élasticité. Néanmoins, lorsque l’état de contrainte est multiaxial, le post-traitement de la plasticité est très imprécis. Cette imprécision provient d’une mauvaise estimation de la triaxialité des contraintes. Les méthodes de type Neuber ont été d’abord enrichies par une description plus précise de la triaxialité des contraintes. Elles ont ensuite été validées sur des structures soumises à des chargements monotones. Cependant, cette méthodologie n’est pas adaptée pour les chargements multiaxiaux alternés. Pour remédier à ce problème, une approche fondée sur les lois de changement d’échelles a été développée. Les zones de plasticité confinée sont considérées comme des inclusions. Cette approche est également enrichie par une meilleure description de la triaxialité des contraintes. Le post-traitement de la plasticité obtenue sur les bords libres de structures soumises à des chargements alternés est précis. Cette méthode a finalement été appliquée sur les cas d’un disque et d’une aube de turbine. / This work aims to propose a method to estimate plasticity from two structural analyses in elasticity in order to determine the lifetime of structures with stress concentration, such as turbine discs or turbine blades. Fatigue analyses computed by the finite element method in plasticity leads to costly computations not always suitable. Energetic methods such as Neuber’s and the scale transition approach are much less expensive alternatives. Indeed, these methods are able to estimate localized plasticity at free edges only from both computations in elasticity. However, when the stress state is multiaxial, the estimation of the plasticity is inaccurate. This inaccuracy comes from a wrong estimation of the stress triaxiality. Expressions for the stress triaxiality at free edges of elastoplastic structures are established. These expressions are derived thanks to a new heuristic that unify uniaxial tension (plane stress condition) and plane deformation in a single case. The proposed expressions for the stress triaxiality are then used to enhance energetic methods (as Neuber and Glinka rules). Notched specimens subjected to monotonic loadings are studied. However, this methodology is not able to handle alternating loadings. To deal with this problem, a new scale transition approach is developed. Localized plastic areas are considered as inclusions. This approach is enhanced by the new heuristic of multiaxiality. The elastoplastic notch tip strains and stresses of structure subjected to complex alternating loadings are accurately estimated from both elastic analyses. This method is finally applied to the case of a turbine disk and a turbine blade of a jet engine.

Made available in DSpace on 2016-04-26T14:55:10Z (GMT). No. of bitstreams: 1 Walisson Pereira Fernandes.pdf: 3336996 bytes, checksum: 5e0932a05bfd9f262378354964e1b59b (MD5) Previous issue date: 2015-03-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Straight edge is the word used to describe persons who, in their everyday lives, are allied to the punk to not use substances considered addictive as alcohol, tobacco and psychoactive. Its beginnings derive from the late 1970s and early 1980s in the United States. However, the genealogical analysis of their practices through the centuries, going back to abstainers movements of the United States and England between the nineteenth and twentieth centuries and its ballast in the formation of moral, instilling in policy that determine behavior. With the emergence of punk in the 1970s as criticism of moralism, society and the state, the straight edge emerges in this context bringing a punk hygiene and, over the years, has become more violent and reductionist, emancipating itself from protoform and pouring a new ways to build and to solidify. The straight edge approached the environmental movements, looking to list anarchist aspects in their practice, but only reiterated other political forms that are linked more to progressivism that, in fact, to anarchism. In this purpose, several straight edgers who sought anarchism as a way of life, broke with the straight edge to proceed their libertarian path, and kept at the same time, the practical abstainers without the use of the nomenclature that identified previously. In Brazil, similar to what happened in the United States and Europe, the intensification of the straight edge scene brought also the anarchist cells of eruption for the construction of a group of vegan orientation appropriating an anarchist nomenclature for its consolidation among young libertarians causing not only the bedlam among their peers, but catches of anarchism and punk / Straight edge é a palavra utilizada para descrever os sujeitos que, em suas vidas cotidianas, aliam-se ao punk de modo a não utilizarem substâncias consideradas viciantes, como álcool, tabaco e psicoativos. Seus começos derivam do final da década de 1970 e começo da década de 1980 nos Estados Unidos. No entanto, a análise genealógica de suas práticas atravessa os séculos, remontando aos movimentos abstêmios dos Estados Unidos e da Inglaterra entre os séculos XIX e XX e seu lastro na formação da moral, infundindo na elaboração de políticas que determinariam condutas. Com o surgimento do punk na década de 1970 como crítica aos moralismos, à sociedade e ao Estado, o straight edge emerge neste contexto trazendo uma higienização do punk e, com o passar dos anos, se tornou mais violento e reducionista, desvinculando-se de sua protoforma e vertendo novos meios para se construir e se solidificar. O straight edge aproximou-se dos movimentos ambientalistas, procurando elencar aspectos anarquistas em sua prática, mas reiterou apenas outras formas políticas que vinculam-se mais a progressismos que, de fato, aos anarquismos. Neste intento, vários straight edgers que procuraram os anarquismos como forma de vida, romperam com o straight edge para dar prosseguimento a sua trajetória libertária, e mantiveram, ao mesmo tempo, as práticas abstêmias sem o uso da nomenclatura que os identificava anteriormente. No Brasil, semelhantemente ao ocorrido nos Estados Unidos e na Europa, a intensificação da cena straight edge trouxe, ainda, o irrompimento de células anarquistas para a construção de um grupo de orientação vegana apropriando-se de uma nomenclatura anarquista para sua consolidação entre jovens libertários, causando não apenas a balbúrdia entre seus pares, mas capturas dos anarquismos e do punk

abstract: Internet of Things (IoT) is emerging as part of the infrastructures for advancing a large variety of applications involving connections of many intelligent devices, leading to smart communities. Due to the severe limitation of the computing resources of IoT devices, it is common to offload tasks of various applications requiring substantial computing resources to computing systems with sufficient computing resources, such as servers, cloud systems, and/or data centers for processing. However, this offloading method suffers from both high latency and network congestion in the IoT infrastructures. Recently edge computing has emerged to reduce the negative impacts of tasks offloading to remote computing systems. As edge computing is in close proximity to IoT devices, it can reduce the latency of task offloading and reduce network congestion. Yet, edge computing has its drawbacks, such as the limited computing resources of some edge computing devices and the unbalanced loads among these devices. In order to effectively explore the potential of edge computing to support IoT applications, it is necessary to have efficient task management and load balancing in edge computing networks. In this dissertation research, an approach is presented to periodically distributing tasks within the edge computing network while satisfying the quality-of-service (QoS) requirements of tasks. The QoS requirements include task completion deadline and security requirement. The approach aims to maximize the number of tasks that can be accommodated in the edge computing network, with consideration of tasks’ priorities. The goal is achieved through the joint optimization of the computing resource allocation and network bandwidth provisioning. Evaluation results show the improvement of the approach in increasing the number of tasks that can be accommodated in the edge computing network and the efficiency in resource utilization. / Dissertation/Thesis / Doctoral Dissertation Computer Engineering 2018

Mixed reality, or augmented reality, where the real and the virtual worlds are combined, has seen an increase in interest in recent years with the release of tools like Google ARCore and Apple ARkit. Edge computing, where the distributed computing resources are located near the end device at the edge of the network, is a paradigm that enables offloading of computing tasks with latency requirements to dedicated servers. This thesis studies how edge computing can be used to bring mixed reality capabilities to mobile end devices that lack native support for that. It presents a working prototype for delivering mixed reality, evaluates the different technologies in it in relation to stability, responsiveness and resource usage, and studies the requirements on the end and edge devices. The experimental evaluation revealed that transmission time is the most significant chunk of end-to-end latency for the developed application. Reducing that delay will have a significant impact on future deployments of such systems. The thesis also presents other bottlenecks and best practices found during the prototype’s development, and how to proceed from here.

Fool’s Gold is a collection of handmade books that illustrate selected Grimms’ fairy tales and offer an unexpected interpretation of the actions of the heroes. Each book displays a unique cover decoration, inspired by medieval European treasure bindings. Treasure bindings incorporate dimensional decorative elements such as gems, gold or other metalwork and often depict Christ's suffering. In a similar way, Fool's Gold beautifies the suffering of the protagonists using gold leaf, glass beads and lush illustrations. A traditional hidden fore-edge painting technique is used to reveal more scenes from each story. When the pages are fanned opened, the fore-edge paintings display the gruesome revenge the perceived heroes take upon the villains.