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Salas, Donoso Ignacio Antonio. "Packing curved objects with interval methods." Thesis, Nantes, Ecole des Mines, 2016. http://www.theses.fr/2016EMNA0277/document.
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Un problème courant en logistique, gestion d’entrepôt, industrie manufacturière ou gestion d’énergie dans les centres de données est de placer des objets dans un espace limité, ou conteneur. Ce problème est appelé problème de placement. De nombreux travaux dans la littérature gèrent le problème de placement en considérant des objets de formes particulières ou en effectuant des approximations polygonales. L’objectif de cette thèse est d’autoriser toute forme qui admet une définition mathématique (que ce soit avec des inégalités algébriques ou des fonctions paramétrées). Les objets peuvent notamment être courbes et non-convexes. C’est ce que nous appelons le problème de placement générique. Nous proposons un cadre de résolution pour résoudre ce problème de placement générique, basé sur les techniques d’intervalles. Ce cadre possède trois ingrédients essentiels : un algorithme évolutionnaire plaçant les objets, une fonction de chevauchement minimisée par cet algorithme évolutionnaire (coût de violation), et une région de chevauchement qui représente un ensemble pré-calculé des configurations relatives d’un objet (par rapport à un autre) qui créent un chevauchement. Cette région de chevauchement est calculée de façon numérique et distinctement pour chaque paire d’objets. L’algorithme sous-jacent dépend également du fait qu’un objet soit représenté par des inégalités ou des fonctions paramétrées. Des expérimentations préliminaires permettent de valider l’approche et d’en montrer le potentielA common problem in logistic, warehousing, industrial manufacture, newspaper paging or energy management in data centers is to allocate items in a given enclosing space or container. This is called a packing problem. Many works in the literature handle the packing problem by considering specific shapes or using polygonal approximations. The goal of this thesis is to allow arbitrary shapes, as long as they can be described mathematically (by an algebraic equation or a parametric function). In particular, the shapes can be curved and non-convex. This is what we call the generic packing problem. We propose a framework for solving this generic packing problem, based on interval techniques. The main ingredients of this framework are: An evolutionary algorithm to place the objects, an over lapping function to be minimized by the evolutionary algorithm (violation cost), and an overlapping region that represents a pre-calculated set of all the relative configurations of one object (with respect to the other one) that creates an overlapping. This overlapping region is calculated numerically and distinctly for each pair of objects. The underlying algorithm also depends whether objects are described by inequalities or parametric curves. Preliminary experiments validate the approach and show the potential of this framework
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Prokaj, Jan. "DETECTING CURVED OBJECTS AGAINST CLUTTERED BACKGROUNDS." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2847.
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Detecting curved objects against cluttered backgrounds is a hard problem in computer vision. We present new low-level and mid-level features to function in these environments. The low-level features are fast to compute, because they employ an integral image approach, which makes them especially useful in real-time applications. The mid-level features are built from low-level features, and are optimized for curved object detection. The usefulness of these features is tested by designing an object detection algorithm using these features. Object detection is accomplished by transforming the mid-level features into weak classifiers, which then produce a strong classifier using AdaBoost. The resulting strong classifier is then tested on the problem of detecting heads with shoulders. On a database of over 500 images of people, cropped to contain head and shoulders, and with a diverse set of backgrounds, the detection rate is 90% while the false positive rate on a database of 500 negative images is less than 2%.M.S.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science MS
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Hu, Chun-Yi. "Towards robust interval solid modeling of curved objects." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11447.
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Luckock, H. C. "Strings, p-branes and Skyrmions in curved space." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384005.
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Charlebois, Mark A. "Exploring the shape of objects with curved surfaces using tactile sensing." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24105.pdf.
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Lin, Eugene S. (Eguene Seichi). "Recovery of 3-D shape of curved objects from multiple views." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/41372.
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Blanco, Fausto Richetti. "A technique for interactive shape deformation on non-structured objects." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/11176.
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Este trabalho apresenta uma técnica para deformação interativa de objetos 3D não estruturados que combina o uso de sketches em 2D e manipulação interativa de curvas. Através de sketches no plano de imagem, o usuário cria curvas paramétricas a serem usadas como manipulares para modificar a malha do objeto. Um conjunto de linhas desenhadas sobre a projeção do modelo pode ser combinado para criar um esqueleto composto de curvas paramétricas, as quais podem ser interativamente manipuladas, deformando assim a superfície associada a elas. Deformações livres são feitas movendo-se interativamente os pontos de controle das curvas. Alguns outros efeitos interessantes, como torção e escalamento, são obtidos operando-se diretamente sobre o campo de sistemas de coordenadas criado ao longo da curva. Um algoritmo para evitar inter-penetrações na malha durante uma sessão de modelagem com a técnica proposta também é apresentado. Esse algoritmo é executado a taxas interativas assim como toda a técnica apresentada neste trabalho. A técnica proposta lida naturalmente com translações e grandes rotações, assim como superfícies não orientáveis, não variedades e malhas compostas de múltiplos componentes. Em todos os casos, a deformação preserva os detalhes locais consistentemente. O uso de curvas esqueleto permite implementar a técnica utilizando uma interface bem intuitiva, e provê ao usuário um controle preciso sobre a deformação. Restrições sobre o esqueleto e deformações sem inter-penetrações são facilmente conseguidos. É demonstrada grande qualidade em torções e dobras nas malhas e os resultados mostram que a técnica apresentada é consideravelmente mais rápida que as abordagens anteriores, obtendo resultados similares. Dado seu relativo baixo custo computacional, esta abordagem pode lidar com malhas compostas por centenas de milhares de vértices a taxas interativas.This work presents a technique for interactive shape deformation of unstructured 3D models, based on 2D sketches and interactive curve manipulation in 3D. A set of lines sketched on the image plane over the projection of the model can be combined to create a skeleton composed by parametric curves, which can be interactively manipulated, thus deforming the associated surfaces. Free-form deformations are performed by interactively moving around the curves’ control points. Some other interesting effects, such as twisting and scaling, are obtained by operating directly over a frame field defined on the curve. An algorithm for mesh local self-intersection avoidance during model deformation is also presented. This algorithm is executed at interactive rates as is the whole technique presented in this work. The presented technique naturally handles both translations and large rotations, as well as non-orientable and non-manifold surfaces, and meshes comprised of multiple components. In all cases, the deformation preserves local features. The use of skeleton curves allows the technique to be implemented using a very intuitive interface, and giving the user fine control over the deformation. Skeleton constraints and local self-intersection avoidance are easily achieved. High-quality results on twisting and bending meshes are also demonstrated, and the results show that the presented technique is considerably faster than previous approaches for achieving similar results. Given its relatively low computational cost, this approach can handle meshes composed by hundreds of thousand vertices at interactive rates.
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Mason, Lionel J. "Twistors in curved space time." Thesis, University of Oxford, 1985. http://ora.ox.ac.uk/objects/uuid:29de7cd1-84c9-4374-8f7d-9a402dd9e0ed.
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This thesis is concerned with an investigation of twistorial structures present in curved Lorentzian space-times. Chapter 1 introduces the basic definitions and some theorems that will be used later in the text. Chapter 2 investigates generalised connections that arise in twister theory. First the Cartan con-formal connection is studied, and some of the geometry underlying it is shown to be that used by Fefferman and Graham C133. Also a condition that a space-time is conformal to vacuum is given. Secondly the theory of the Chern connection associated to a C.R. manifold is developed in such a way as to make the calculation of the connection associated to a twistor C.R. manifold straight forward. A new proof of the Chern theorem of existence and uniqueness is given. The Chern connection of a twistor C.R. manifold is then calculated, and discussed. In particular S-dimensionai C.R. manifolds arising as twistor C.R. manifolds are characterised. Canonical structures peculiar to the twister case are discussed. Applications of C.R. manifold theory to algebraically special space-times are suggested. Chapter three analyses how various twistorial structures behave in linearised general relativity. First, deformations of the space of complex null geodesies corresponding to variations of the conformal structure of space-time are shown to be generated by hami1tonians. Those that correspond to variations in the metric satisfying the field equations are given, along with hamiltonians corresponding to different fields and field equations. Beneralisations to nonlinear equations are discussed. These ideas are applied to hypersurface twisters in linearised theory, using fiat hypersurfaces and Cech cohoeology. Expressions are obtained for the deformation of the complex structure of the spaces and their evolution. The results are generalised to non flat hypersurfaces using Dolbeault cohomolcgy. It is shown that certain canonically defined forms on the spin bundle are preferred Dolbeault representatives for derivatives of the twister cohomology classes corresponding to the linearised field. In chapter four I generalise the results of chapter three to curved space using the Chern connection. In particular twistorial formulations of the constraint equations are given, and a formula for the evolution that satisfies the the vacuum evolution equations is given in terms of an "infinity" twistor and a "time" twister. This is then discussed. In chapter five I make some comments on the interpretation of a three form on the spin bundle discovered by B.A.J. Sparling as the gravitational hami1tonian. I then use this to show that one can give an interpretation of Penrose's quasi-local angular momentum twistor in terms of the canonical formalism.
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Chutsagulprom, Nawinda. "Thin film flows in curved tubes." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:35071002-e487-4cd3-b85f-3aca6dcb0c93.
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The main motivation of this thesis comes from a desire to understand the behaviours of blood flow in the vicinity of atheroma. The initiation and development of atherosclerosis in arteries are normally observed in the areas of low or oscillating wall shear stress, such as on the outer wall of a bifurcation and the inside of the bends. We start by building on the background to the areas related to our models. We focus on the models of fluid flow travelling through a curved tube of uniform curvature because most arteries are tapered and curved. The flow of an incompressible Newtonian fluid in a curved tube is modelled. The derivation of the corresponding equations of the motion is presented. The equations are then solved for a steady and oscillatory driving axial pressure gradient. In each case, the flow is governed by different dimensionless parameters. The problem is solved for a variety of parameter regimes by using asymptotic technique as well as numerical method. Some aspects of thin-film flows are studied. The well-known thin film equation is derived using lubrication theory. The stability of a thin film in a straight tube and the effects of a surfactant droplet on a liquid film are presented. The moving contact line problem, one of the controversial topics in fluid dynamics, is also discussed. The leading-order equations governing thin-film flow over a stationary curved substrate is derived. Various approaches and the application of flow on particular substrates are shown. Finally, we model two-layer viscous fluids using lubrication approximation. By assuming the thickness of a lower liquid layer is much thinner than that of the upper liquid layer, the equation governing the liquid-liquid interface is derived. The steady-state and trasient solutions of the evolution equation is computed both analytically and computationally.
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Richardson, Ross Monet. "Designing Smooth Motions of Rigid Objects: Computing Curves in Lie Groups." Scholarship @ Claremont, 2003. https://scholarship.claremont.edu/hmc_theses/153.
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Consider the problem of designing the path of a camera in 3D. As we may identify each camera position with a member of the Euclidean motions, SE(3), the problem may be recast mathematically as constructing interpolating curves on the (non-Euclidean) space SE(3). There exist many ways to formulate this problem, and indeed many solutions. In this thesis we shall examine solutions based on simple geometric constructions, with the goal of discovering well behaved and computable solutions. In affine spaces there exist elegant solutions to the problem of curve design, which are collectively known as the techniques of Computer Aided Geometric Design (CAGD). The approach of this thesis will be the generalization of these methods and an examination of computation on matrix Lie groups. In particular, the Lie groups SO(3) and SE(3) will be examined in some detail.
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Genolini, Pietro Benetti. "Precision holography and supersymmetric theories on curved spaces." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:8526cac1-07a1-4ebc-bde0-f75debf58eda.
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The formulation of rigid supersymmetric field theories on curved space leads to a number of results on their strongly-interacting regime, crucial from both the mathematical and physical point of view, starting from Witten's topological twist of four-dimensional Yang-Mills theory. At the same time, strongly-coupled field theories may also be studied holographically via the AdS/CFT correspondence. The aim of this thesis is to study aspects of the holographic dictionary for supersymmetric theories on curved manifolds. A key aspect of the correspondence is the renormalization of gravity observables, which is realized via holographic renormalization. If the dual boundary field theory is supersymmetric, it is natural to ask whether this scheme is compatible with the rigid supersymmetry at the curved boundary. The latter requires specific geometric structures, and general arguments imply that BPS observables, such as the partition function, are invariant under certain deformations of these structures. We may then formulate a precise check of the holographic dictionary by asking whether the dual holographic observables are similarly invariant, as the free energy of the gauge theory is identified with the holographically renormalized supergravity action. In the first part of the thesis, we consider this question in N = 4 gauged supergravity in four and five dimensions for the holographic dual to the topological twists of N = 4 gauge theories on Riemannian three-manifolds and N = 2 gauge theories on Riemannian four-manifolds. We show that the renormalized on-shell action is independent of the metric on the boundary four-manifold, as required for a topological theory. We then go further, analyzing the geometry of supersymmetric bulk solutions. This allows us to show that the gravitational free energy of any smooth filling vanishes in both AdS4/CFT3 and AdS5/CFT4. In the second part of the thesis, we study the same question in minimal N = 2 gauged supergravity in four and five dimensions. In four dimensions we show that holographic renormalization precisely reproduces the expected field theory results for the dependence of the partition function on the background. Surprisingly, in five dimensions we find that no choice of standard holographic counterterms is compatible with supersymmetry, which leads us to introduce novel finite boundary terms. For a class of solutions satisfying certain topological assumptions we provide some independent tests of these new boundary terms, in particular showing that they reproduce the expected VEVs of conserved charges. We also briefly comment on the relation between these terms and boundary supercurrent anomalies.
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Vasconcelos, Janilse Fernandes Nunes. "O uso de objetos de aprendizagem nas práticas pedagógicas nos cursos de licenciatura em letras e licenciatura em matemática do Centro Universitário Franciscano - UNIFRA." Universidade do Vale do Rio do Sinos, 2009. http://www.repositorio.jesuita.org.br/handle/UNISINOS/1971.
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Essa pesquisa está vinculada à Linha “Práticas Pedagógicas e Formação do Educador” do Programa de Pós-Graduação em Educação da Universidade do Vale do Rio dos Sinos – UNISINOS. O tema está relacionado aos usos de objetos de aprendizagem (OAs) nas práticas pedagógicas nos cursos de Licenciatura em Letras e Licenciatura em Matemática do Centro Universitário Franciscano - UNIFRA. Os autores que embasaram a investigação são: Becker (1992, 1993, 2001, 2003), Dias (1998, 2005, 2008), Figueiredo (2002, 2005), Freire ( 1986, 1987, 1996), Kenski (2003, 2006, 2007), Moraes (2002, 2003, 2006), Ramal (2000), Schlemmer (2001, 2003, 2005, 2006), Tarouco (2003, 2006, 2007). O problema de pesquisa desta dissertação consiste em investigar, a fim de compreender, como são desenvolvidas as práticas pedagógicas com o uso de OAs no contexto dos cursos de Matemática e de Letras na UNIFRA. Do problema derivaram as seguintes questões: Qual é a compreensão que os professores tem sobre OAs? Quais são as práticas pedagógicas desenvolvid
This research is linked to the Line “Pedagogical Practices and Formation of Educators”, of the Valley of Sino’s River University (UNISINOS) Post Graduation Program in Education. The theme is related to the use of Learning Objects in pedagogical practices of Language and Mathematics courses offered in the Franciscan University Center - UNIFRA. The main authors referred to: Becker (1992, 1993, 2001, 2003), Dias (1998, 2005, 2008), Figueiredo (2002, 2005), Freire ( 1986, 1987, 1996), Kenski (2003, 2006, 2007), Moraes (2002, 2003, 2006), Ramal (2000), Schlemmer (2001, 2003, 2005, 2006), Tarouco (2003, 2006, 2007). The research problem of this dissertation consists in to investigate, with the purpose of comprehension, the way pedagogical practices using Learning Objects are developed in the context of the Language and Mathematics courses of UNIFRA. Based on the problem, the following questions arose: What is the comprehension of the teachers about Learning Objects? What are the pedagogical practices developed usin
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Gounelas, Frank. "Free curves on varieties." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:3a7f6dba-fad2-4517-994e-0b51ea311df8.
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In this thesis we study various ways in which every two general points on a variety can be connected by curves of a fixed genus, thus mimicking the notion of a rationally connected variety but for arbitrary genus. We assume the existence of a covering family of curves which dominates the product of a variety with itself either by allowing the curves in the family to vary in moduli, or by assuming the family is trivial for some fixed curve of genus g. A suitably free curve will be one with a large unobstructed deformation space, the images of whose deformations can join any number of points on a variety. We prove that, at least in characteristic zero, the existence of such a free curve of higher genus is equivalent to the variety being rationally connected. If one restricts to the case of genus one, similar results can be obtained even allowing the curves in the family to vary in moduli. In later chapters we study algebraic properties of such varieties and discuss attempts to prove the same rational connectedness result in positive characteristic.
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Coe, Edward Olin. "Printing on Objects: Curved Layer Fused Filament Fabrication on Scanned Surfaces with a Parallel Deposition Machine." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/101096.
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Consumer additive manufacturing (3D printing) has rapidly grown over the last decade. While the technology for the most common type, Fused Filament Fabrication (FFF), has systematically improved and sales have increased, fundamentally, the capabilities of the machines have remained the same. FFF printers are still limited to depositing layers onto a flat build plate. This makes it difficult to combine consumer AM with other objects. While consumer AM promises to allow us to customize our world, the reality has fallen short.
The ability to directly modify existing objects presents numerous possibilities to the consumer: personalization, adding functionality, improving functionality, repair, and novel multi-material manufacturing processes. Indeed, similar goals for industrial manufacturing drove the research and development of technologies like direct write and directed energy deposition which can deposit layers onto uneven surfaces.
Replicating these capabilities on consumer 3-axis FFF machines is difficult mainly due to issues with reliability, repeatability, and quality. This thesis proposes, demonstrates, and tests a method for scanning and printing dimensionally-accurate (unwarped) digital forms onto physical objects using a modified consumer-grade 3D printer. It then provides an analysis of the machine design considerations and critical process parameters.Master of Science
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Lemos, Edith dos Santos. "Acessibilidade para pessoas com deficiência visual em cursos no Moodle: guia para professores." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/10674.
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This dissertation was developed by the Graduate Program in Educational
Technology Network, in line Educational Technology Management Research
Network and its final product one set of Visually Impaired to Accessibility Guidelines
in Moodle, as well as a Learning object to disclosure of the same. It is considered
that education must be democratic must meet all kinds of students, including the
visually impaired. To support the process of inclusion, considering the use of Virtual
Environments for Teaching and Learning (AVEA), different accessibility guidelines
have been designed to be observed in the creation of virtual educational resources.
However, what is observed is a shortage in relation to a closer relationship between
the policies and their applicability in such an environment. Considering the AVEA
Moodle, this dissertation aimed to create an accessibility guidelines guide to support
teachers in developing their disciplines or courses when they require assistance to
make available materials for students with disabilities and present them in an Object
Learning. This was developed as a resource of type Book Moodle, in order to
approach the teacher's guidelines when creating a course. After development, the
guidelines and the book were evaluated by teachers who used the book to create
courses in Moodle, assessing the guidelines itself, as well as the usability of the
feature. Also participated in the evaluation visually impaired students, and they held a
course developed by the author of this research in order to assess whether the
guidelines allow the creation of a more accessible way. In conclusion, after the
evaluations, this research may contribute to teachers who have students with visual
impairments because the way the guidelines were presented can facilitate the
organization and preparation of content and visually impaired students can learn and
participate equally.Esta dissertação de mestrado foi desenvolvida junto ao Programa de Pós- Graduação em Tecnologias Educacionais em Rede, na linha de pesquisa de Gestão de Tecnologias Educacionais em Rede e tem como produto final um Conjunto de Diretrizes de Acessibilidade para Deficientes Visuais no Moodle, bem como um Objeto de Aprendizagem para divulgação das mesmas. Considera-se que a educação tem que ser democrática precisa atender todos os tipos de educandos, incluindo os deficientes visuais. Para apoiar o processo de inclusão, considerando a utilização de Ambientes Virtuais de Ensino e Aprendizagem (AVEA), diferentes diretrizes de acessibilidade vêm sendo criadas para serem observadas na criação de recursos educacionais virtuais. No entanto, o que se percebe é uma carência no que se refere a uma relação mais próxima entre as diretrizes e sua aplicabilidade em tais ambientes. Considerando o AVEA Moodle, esta dissertação teve como objetivo criação de um guia de diretrizes de acessibilidade para apoiar os professores na elaboração de suas disciplinas ou cursos, quando estes necessitarem de auxilio para disponibilizarem materiais para alunos com deficiência e apresentá-las em um Objeto de Aprendizagem. Este foi desenvolvido na forma de um recurso do tipo Livro do Moodle, de forma a aproximar as diretrizes do professor no momento da criação de um curso. Após o desenvolvimento, as diretrizes e o livro foram avaliados por professores, que utilizaram o livro para criarem cursos no Moodle, avaliando as diretrizes em si, bem como a usabilidade do recurso. Também participaram da avaliação alunos deficientes visuais, sendo que estes realizaram um curso desenvolvido pela autora desta pesquisa, no intuito de avaliar se as diretrizes possibilitam a criação de um curso mais acessível. Como conclusão, após as avaliações, esta pesquisa pode contribuir com docentes que tenham alunos com deficiência visual, pois a forma com que as diretrizes foram apresentadas pode facilitar a organização e a elaboração dos conteúdos e os alunos deficientes visuais poderão aprender e participar de forma igualitária.
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Li, Bo. "Interest Curves : Concept, Evaluation, Implementation and Applications." Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-111175.
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Image features play important roles in a wide range of computer vision applications, such as image registration, 3D reconstruction, object detection and video understanding. These image features include edges, contours, corners, regions, lines, curves, interest points, etc. However, the research is fragmented in these areas, especially when it comes to line and curve detection. In this thesis, we aim to discover, integrate, evaluate and summarize past research as well as our contributions in the area of image features. This thesis provides a comprehensive framework of concept, evaluation, implementation, and applications for image features. Firstly, this thesis proposes a novel concept of interest curves. Interest curves is a concept derived and extended from interest points. Interest curves are significant lines and arcs in an image that are repeatable under various image transformations. Interest curves bring clear guidelines and structures for future curve and line detection algorithms and related applications. Secondly, this thesis presents an evaluation framework for detecting and describing interest curves. The evaluation framework provides a new paradigm for comparing the performance of state-of-the-art line and curve detectors under image perturbations and transformations. Thirdly, this thesis proposes an interest curve detector (Distinctive Curves, DICU), which unifies the detection of edges, corners, lines and curves. DICU represents our state-of-the-art contribution in the areas concerning the detection of edges, corners, curves and lines. Our research efforts cover the most important attributes required by these features with respect to robustness and efficiency. Interest curves preserve richer geometric information than interest points. This advantage gives new ways of solving computer vision problems. We propose a simple description method for curve matching applications. We have found that our proposed interest curve descriptor outperforms all state-of-the-art interest point descriptors (SIFT, SURF, BRISK, ORB, FREAK). Furthermore, in our research we design a novel object detection algorithm that only utilizes DICU geometries without using local feature appearance. We organize image objects as curve chains and to detect an object, we search this curve chain in the target image using dynamic programming. The curve chain matching is scale and rotation-invariant as well as robust to image deformations. These properties have given us the possibility of resolving the rotation-variance problem in object detection applications. In our face detection experiments, the curve chain matching method proves to be scale and rotation-invariant and very computational efficient.Bilddetaljer har en viktig roll i ett stort antal applikationer för datorseende, t.ex., bildregistrering, 3D-rekonstruktion, objektdetektering och videoförståelse. Dessa bilddetaljer inkluderar kanter, konturer, hörn, regioner, linjer, kurvor, intressepunkter, etc. Forskningen inom dessa områden är splittrad, särskilt för detektering av linjer och kurvor. I denna avhandling, strävar vi efter att hitta, integrera, utvärdera och sammanfatta tidigare forskning tillsammans med vår egen forskning inom området för bildegenskaper. Denna avhandling presenterar ett ramverk för begrepp, utvärdering, utförande och applikationer för bilddetaljer. För det första föreslår denna avhandling ett nytt koncept för intressekurvor. Intressekurvor är ett begrepp som härrör från intressepunkter och det är viktiga linjer och bågar i bilden som är repeterbara oberoende av olika bildtransformationer. Intressekurvor ger en tydlig vägledning och struktur för framtida algoritmer och relaterade tillämpningar för kurv- och linjedetektering. För det andra, presenterar denna avhandling en utvärderingsram för detektorer och beskrivningar av intressekurvor. Utvärderingsramverket utgör en ny paradigm för att jämföra resultatet för de bästa möjliga teknikerna för linje- och kurvdetektorer vid bildstörningar och bildtransformationer. För det tredje presenterar denna avhandling en detektor för intressekurvor (Distinctive curves, DICU), som förenar detektering av kanter, hörn, linjer och kurvor. DICU representerar vårt främsta bidrag inom området detektering av kanter, hörn, kurvor och linjer. Våra forskningsinsatser täcker de viktigaste attribut som krävs av dessa funktioner med avseende på robusthet och effektivitet. Intressekurvor innehåller en rikare geometrisk information än intressepunkter. Denna fördel öppnar för nya sätt att lösa problem för datorseende. Vi föreslår en enkel beskrivningsmetod för kurvmatchningsapplikationer och den föreslagna deskriptorn för intressekurvor överträffar de bästa tillgängliga deskriptorerna för intressepunkter (SIFT, SURF, BRISK, ORB, och FREAK). Dessutom utformar vi en ny objektdetekteringsalgoritm som bara använder geometri för DICU utan att använda det lokala utseendet. Vi organiserar bildobjekt som kurvkedjor och för att upptäcka ett objekt behöver vi endast söka efter denna kurvkedja i målbilden med hjälp av dynamisk programmering. Kurvkedjematchningen är oberoende av skala och rotationer samt robust vid bilddeformationer. Dessa egenskaper ger möjlighet att lösa problemet med rotationsberoende inom objektdetektering. Vårt ansiktsigenkänningsexperiment visar att kurvkedjematchning är oberoende av skala och rotationer och att den är mycket beräkningseffektiv.
INTRO – INteractive RObotics research network
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Boedihardjo, Horatio S. "Signatures of Gaussian processes and SLE curves." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:5f835640-d3f5-4b03-b600-10d897644ced.
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This thesis contains three main results. The first result states that, outside a slim set associated with a Gaussian process with long time memory, paths can be canonically enhanced to geometric rough paths. This allows us to apply the powerful Universal Limit Theorem in rough path theory to study the quasi-sure properties of the solutions of stochastic differential equations driven by Gaussian processes. The key idea is to use a norm, invented by B. Hambly and T.Lyons, which dominates the p-variation distance and the fact that the roughness of a Gaussian sample path is evenly distributed over time. The second result is the almost-sure uniqueness of the signatures of SLE kappa curves for kappa less than or equal to 4. We prove this by first expressing the Fourier transform of the winding angle of the SLE curve in terms of its signature. This formula also gives us a relation between the expected signature and the n-point functions studied in the SLE and Statistical Physics literature. It is important that the Chordal SLE measure in D is supported on simple curves from -1 to 1 for kappa between 0 and 4, and hence the image of the curve determines the curve up to reparametrisation. The third result is a formula for the expected signature of Gaussian processes generated by strictly regular kernels. The idea is to approximate the expected signature of this class of processes by the expected signature of their piecewise linear approximations. This reduces the problem to computing the moments of Gaussian random variables, which can be done using Wick’s formula.
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Tavares, Arice Cardoso. "O PAPEL DOS OBJETOS DE APRENDIZAGEM NO ENSINO DE LÍNGUAS: UMA ANÁLISE EM CURSOS ON-LINE DE ESPANHOL COMO LÍNGUA ESTRANGEIRA." Universidade Catolica de Pelotas, 2007. http://tede.ucpel.edu.br:8080/jspui/handle/tede/434.
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Previous issue date: 2007-05-10The use of interactive technologies mediated by computers and Internet is becoming more and more frequent in the teaching of foreign languages, demanding new skills from language teachers so that they can use these technologies more appropriately and evaluate the new methodologies that are introduced almost everyday. A technology that has received a lot of attention lately is the use of learning objects, seen as cultural artifacts capable of promoting language learning. The objective of this study is to describe, analyze, and evaluate the pedagogical content of these objects and detect their presence in courses that propose to teach Spanish on the Web. We start from the social-cultural perspective as advanced by Vygotsky and his followers, constructing an evaluation instrument to measure the educational value of these objects, highlighting the following aspects: (1) content quality; (2) usability; (3) reusability; (4) interactivity; and (5) scaffolding. The methodology used included a survey of Spanish courses offered on the WWW, three of which were selected for analysis. The results showed that the courses varied a lot in terms of the learning objects that they used: the best courses offer objects based on interactive activities, with good content distribution and clear objectives; the other course, poorly evaluated considering the instrument that was used, does not present these features. The conclusion is that the use of the learning objects perspective, with its well-defined criteria, seems to facilitate the preparation of instruments to evaluate courses mediated by the new technologies
O uso de tecnologias interativas mediadas pelo computador e pela Internet está se tornando cada vez mais freqüente no ensino de línguas estrangeiras, exigindo dos professores novas competências, não só para usar essas tecnologias adequadamente, mas também para avaliar criticamente as propostas que surgem a cada dia. Uma proposta que tem recebido destaque recentemente é o uso de objetos de aprendizagem, vistos como artefatos culturais capazes de promover a aprendizagem. O objetivo deste trabalho é descrever, analisar e avaliar o conteúdo pedagógico desses objetos e detectar sua presença nos cursos que propõem o ensino da língua espanhola na rede mundial de computadores. Parte-se da perspectiva sócio-cultural de Vygotsky e seus seguidores, construindo-se a partir daí uma proposta de instrumento de avaliação que possa aferir o valor educacional desses objetos, com destaque para cinco aspectos: (1) qualidade do conteúdo; (2) usabilidade; (3) reusabilidade; (4) interatividade e (5) uso de andaimes. A metodologia constou de um levantamento de cursos de espanhol oferecidos pela Internet, dos quais três foram selecionados para a análise. Os resultados mostram que os cursos variam bastante em termos dos objetos de aprendizagem usados: os cursos mais bem avaliados oferecem objetos baseados em atividades interativas, com conteúdo balanceado e objetivos claros; já o curso com avaliação inferior, de acordo com o instrumento usado, deixa de apresentar essas características. A conclusão é de que o uso da perspectiva dos objetos de aprendizagem, com seus critérios já estabelecidos, parece facilitar a elaboração de instrumentos para a avaliação dos cursos mediados pelas novas tecnologias
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Gattas, Joseph M. "Quasi-static impact of foldcore sandwich panels." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:d6cca0fd-f5e4-4df4-88e3-8f05af5e6db1.
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This thesis considered the design of new and improved foldcore sandwich panels suitable for high-performance energy absorption applications. This was achieved by utilising origami geometry design techniques to alter foldcore structures such that they possessed different mechanical behaviours and failure modes. The major findings of this thesis were in three areas as follows. First, a modified planar foldcore geometry was developed by introducing sub-folds into a standard foldcore pattern. The new geometry, deemed the indented foldcore, successfully triggered a high-order failure mode known as a travelling hinge line failure mode. This was found to have a much higher energy absorption than the plate buckling failure mode seen in an unmodified foldcore structure. A comprehensive numerical, theoretical, and experimental analysis was conducted on the indented core, which included the development of a new foldcore prototyping method that utilised 3D printed moulds. It was shown that compared to available commercial honeycomb cores, the indented foldcore had an improved uniformity of energy absorption, but weaker overall peak and crushing stresses. Second, rigid origami design principles were used to develop extended foldcore geometries. New parametrisations were presented for three patterns, to complete a set of Miura-derivative geometries termed first-level derivatives. The first-level derivative parametrisations were then combined to create complex, piecewise geometries, with compatible faceted sandwich face geometry also developed. Finally, a method to generate rigid-foldable, curved-crease geometry from Miura-derivative straight-crease geometry was presented. All geometry was validated with physical prototypes and was compiled into a MATLAB Toolbox. Third, the performance of these extended foldcore geometries under impact loadings was investigated. An investigation of curved-crease foldcores showed that they were stronger than straight-crease foldcores, and at certain configurations can potentially match the strength, energy-absorption under quasi-static impact loads, and out-of-plane stiffness of a honeycomb core. A brief investigation of foldcores under low-velocity impact loadings showed that curved-crease foldcores, unlike straight-crease foldcores, strengthened under dynamic loadings, however not to the same extent as honeycomb. Finally, an investigation of single-curved foldcore sandwich shells was conducted. It was seen that foldcore shells could not match the energy-absorption capability of an over-expanded honeycomb shell, but certain core types did exhibit other attributes that might be exploitable with future research, including superior initial strength and superior uniformity of response.
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Schlüeter, Dirk Christopher. "Universal moduli of parabolic sheaves on stable marked curves." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:b0260f8e-6654-4bec-b670-5e925fd403dd.
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The topic of this thesis is the moduli theory of (parabolic) sheaves on stable curves. Using geometric invariant theory (GIT), universal moduli spaces of semistable parabolic sheaves on stable marked curves are constructed: `universal' indicates that these are moduli spaces of pairs where the underlying marked curve may vary as well as the parabolic sheaf (as in the Pandharipande moduli space for pairs of stable curves and torsion-free sheaves without augmentations). As an intermediate step in this construction, we construct moduli spaces of semistable parabolic sheaves on flat families of arbitrary projective schemes (of any dimension or singularity type): this is the technical core of this thesis. These moduli spaces are projective, since they are constructed as GIT quotients of projective parameter spaces. The stability condition for parabolic sheaves depends on a choice of polarisation and is derived from the Hilbert-Mumford criterion. It is not quite the same as traditional stability with respect to parabolic Hilbert polynomials, but it is closely related to it, and the resulting moduli spaces are always compactifications of moduli of slope-stable parabolic sheaves. The construction works over algebraically closed fields of arbitrary characteristic.
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Castro, Pedro Miguel Viçoso. "Objectos de aprendizagem Moodle e SCORM, aplicados aos cursos EFA – duas hipóteses diferentes." Master's thesis, Faculdade de Ciências e Tecnologia, 2010. http://hdl.handle.net/10362/8673.
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Dissertação apresentada no âmbito do programa “Para Ser Mestre”, para obtenção do grau de Mestre (2.º ciclo) em Ensino da Biologia e da GeologiaA Internet já tem um lugar fixo no quotidiano de muitas pessoas, empresas e instituições. O ensino não é excepção a esta regra. Deste modo, as tecnologias aplicadas ao ensino e à aprendizagem têm experimentado uma grande evolução nos últimos anos. Uma dessas evoluções foi, sem dúvida, o surgimento de um novo conceito: os objectos de aprendizagem. Outra será a grande aposta do governo português na melhor qualificação da sua população, dando assim uma grande importância ao ensino e à formação de adultos. Destes dois contextos diferentes surge a necessidade de perceber como se podem integrar um no outro e quais os resultados possíveis desta combinação. Assim, neste trabalho, tentou-se juntar estas duas vertentes. Por um lado, as novas tecnologias, sob a forma de objectos de aprendizagem. Por outro, a formação de adultos. Com esse intuito, estudou-se alguns dos trabalhos que já foram realizados até hoje no campo dos objectos de aprendizagem e, simultaneamente, investigou-se umas das principais teorias sobre o ensino de adultos: a andragogia de Malcolm Knowles. Devido à grande diversidade de tecnologias, decidiu-se tentar explorar dois softwares diferentes, um usando as normas SCORM e outro utilizando um dos recursos de um dos LMS mais utilizados em Portugal, e também no mundo, que é a plataforma Moodle. Para testar tal utilização, um pequeno grupo de alunas de um curso EFA de um agrupamento de escolas da zona da Grande Lisboa serviu de grupo de exploração, a fim de testar a eficácia das novas tecnologias neste tipo de cursos. Os resultados obtidos poderão constituir um ponto de partida para novos estudos, pois há que ter em conta o número reduzido de indivíduos que constituíram a amostra. No entanto, os resultados demonstram que existe uma maior motivação e vontade quando as tecnologias estão presentes. No final, as conclusões são positivas. Mas serão necessários mais estudos, de modo a verificar certas conclusões.
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Chen, Imin. "The Jacobian of modular curves associated to Cartan subgroups." Thesis, University of Oxford, 1996. https://ora.ox.ac.uk/objects/uuid:46babaa0-c498-4211-a4ad-8dbabb8f05d9.
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The mod p representation associated to an elliptic curve is called split/non-split dihedral if its image lies in the normaliser of a split/non-split Cartan subgroup of GL2(Fp). Let X+split(p) and X+non-split(p) denote the modular curves which classify elliptic curves with dihedral split and non-split mod p representation, respectively. We call such curves (split/non-split) Cartan modular curves. It is well known that X+split(p) is isomorphic to the curve X+0(p2). On the other hand, the curve X+non-split(p) is distinctly different from any of the classical modular curves. Despite this apparent disparity, it is shown in this thesis that the jacobian of X+non-split(p) is isogenous to the new part of the jacobian of X+0(p2). The method of proof uses the Selberg trace formula. An explicit formula for the trace of Hecke operators is derived for both split and non-split Cartan modular curves. Comparing these two trace formulae, one obtains a trace relation, which in combination with the Eichler-Shimura relations allows us to conclude that the L-series of the two abelian varieties in question are the same, up to finitely many L-factors. The result then follows by Faltings' isogeny theorem.
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Quick, Laura Elizabeth. "Scribal culture and the composition of Deuteronomy 28 : intertextuality, influence and the Aramaic curse tradition." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:46fcfbc4-eec7-41bd-a646-817a6bbde36f.
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It is often noted that Deuteronomy 28 seems to parallel portions of a Neo-Assyrian treaty, 'The Succession Treaty of Esarhaddon', known as EST. However, while there are undeniably points of similarity between Deuteronomy 28 and EST, affinities to Deuteronomy 28 may also be found in curses from Old Aramaic epigraphs of the first-millennium. In this thesis I consider the relationship of Deuteronomy 28 to the curse traditions of the ancient Near East. I argue that the crux of the issue is the linguistic means of the transmission of these ancient Near Eastern curse traditions to Deuteronomy. Consideration of this is then the prerequisite to a study of the cultural means of transmission: treatments of this problem must encompass a far broader range of materials than hitherto considered, including the Old Aramaic inscriptions. My primary aim in this context is to ascertain whether we may characterize the relation of all these texts to Deuteronomy as one of influence or of intertextuality - terminological categories which I introduce in order to clarify the exact nature of the problem with more precision than that of previous studies. Ultimately it will be found that Deuteronomy 28 reflects a complex interplay between Mesopotamian and Levantine traditions, against previous interpreters who had referred Deuteronomy 28 to an exclusively Mesopotamian horizon. Nevertheless, we cannot consider this interplay to have stemmed from the influence of any one Old Aramaic or Mesopotamian text such as EST in terms of a direct literary connection. Rather, as putative Aramaic vectors of mediation must be posited between the Mesopotamian tradition and Deuteronomy due to the linguistic competence of Judaean scribes in the late monarchic period, this must be understood as a relationship of intertextuality. While the specific literary (or ritual) Vorlage is thus unreconstructable in terms of the documentary evidence, we can nevertheless hypothesize what the Northwest Semitic curse tradition from which this Vorlage was a part may have looked like, based upon the textual traditions to which we do have access - and this tradition is reflected in Deuteronomy 28.
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Weszter, Juraj. "Numerické metody analýzy obrazu zaměřené na protínající se objekty." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-445471.
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This theses presents an image processing approach to estimating the length of cynobacteria strands in digitally acquired images. An algorithm utilizing the Hough transform to determine strand continuity at strand intersections is presented. The algorithm is demonstrated on selected images, the examined strands are separated and their lengths are estimated. A Delphi implementation of the algorithm is included.
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Perhalová, Anna. "Víceúčelový objekt v Plzni." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372052.
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The subject of this diploma thesis is design and static assessment of timber load bearing structure of multipurpose building in Plzeň. It is cupola consited of two radial curved ribs above a triangle ground plan with one oval edge. I got this shape by cutting the cupola vertically on these two triangle edges and that created two walls of the construction. The largest ground plan dimension of load bearing structure is 54,4 meters and the maximum height is +18,0 meters. The design is processed in two various drafts.
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Izciler, Fatih. "3d Object Recognition From Range Images." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614915/index.pdf.
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Recognizing generic objects by single or multi view range images is a contemporary popular problem in 3D object recognition area with developing technology of scanning devices such as laser range scanners. This problem is vital to current and future vision systems performing shape based matching and classification of the objects in an arbitrary scene. Despite improvements on scanners, there are still imperfections on range scans such as holes or unconnected parts on images. This studyobjects at proposing and comparing algorithms that match a range image to complete 3D models in a target database.The study started with a baseline algorithm which usesstatistical representation of 3D shapesbased on 4D geometricfeatures, namely SURFLET-Pair relations.The feature describes the geometrical relationof a surface-point pair and reflects local and the global characteristics of the object. With the desire of generating solution to the problem,another algorithmthat interpretsSURFLET-Pairslike in the baseline algorithm, in which histograms of the features are used,isconsidered. Moreover, two other methods are proposed by applying 2D space filing curves on range images and applying 4D space filling curves on histograms of SURFLET-Pairs. Wavelet transforms are used for filtering purposes in these algorithms. These methods are tried to be compact, robust, independent on a global coordinate frame and descriptive enough to be distinguish queries&rsquocategories.Baseline and proposed algorithms are implemented on a database in which range scans of real objects with imperfections are queries while generic 3D objects from various different categories are target dataset.
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Vasdekis, Vassilios G. S. "An investigation of certain methods in the analysis of growth curves." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:65514ec9-9882-4a0f-a928-8dd78cb7f13b.
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In growth curve studies, measurements are made on individuals over a moderately large period of time and the main problem is set as the best possible evaluation of the curve which is believed to underlie the phenomenon. One important meaning of the term 'best possible evaluation' is the efficient estimation of the coefficients which, postulated by the model, characterize this curve. The important key for doing this, is the 'best' (in a certain way) estimation of the covariance matrix of observations which is supposed here to be the same for all individuals. The purpose of this thesis is to investigate certain methods which have been suggested to be appropriate for this problem both theoretically and empirically as well as to prove certain results concerning the problem of efficiency itself when an estimate of the covariance matrix of observations, irrespective of the method which calculated it, is at hand. More specifically, it is shown that REstricted Maximum Likelihood (REML) gives in general estimates of the regression coefficients whose estimated variance lies nearer to their true value quite independently from the form of the covariance matrix, than Maximum Likelihood (ML) and it is proved that the general estimated scatter of the estimated regression coefficients is greater for REML. When we measure more than one characteristics on time and for a special class of covariance models, the property that the REML estimates of the variance of estimated regression coefficients are larger than the corresponding ML, which holds for one characteristic, is lost. Asymptotically however, the two methods give identical results. Another method which is not based on the adoption of a certain parametric form for the covariance matrix is considered. A new method is suggested for its optimal choice and a comparison is made between this and three other already known methods. Empirical results suggest that it retains a very good balance between the variance of the regression coefficients and their real and optimal value for the majority of the covariance models which have been tested as possible population covariance matrices. Finally, upper and lower bounds of different types of efficiency are obtained by assuming that an estimate of the population covariance matrix has already been calculated and is not distant from the true covariance matrix more than a certain constant.
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Barker, Kane McKinney. "Adhesion of nano-objects to chemically modified surfaces." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31837.
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Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2010.Committee Chair: Lawrence A. Bottomley; Committee Member: Aldo A. Ferri; Committee Member: Andrew Lyon; Committee Member: Jean-Luc Bredas; Committee Member: Robert L. Whetten. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Maccari, Neto Alfredo. "Análise de ocorrência de metamerismo em revestimentos cerâmicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/28929.
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Um dos problemas técnicos que ocorrem nos revestimentos cerâmicos é a possibilidade de duas peças serem da mesma cor sob a luz do dia, mas de cores diferentes sob outra iluminação. Tal fenômeno é chamado metamerismo. O presente trabalho teve como objetivo realizar um estudo sobre a influência de variáveis do processo de fabricação de revestimentos cerâmicos na ocorrência do fenômeno de metamerismo, tendo como objeto de estudo uma peça monoporosa de esmalte branco-brilhante, e um porcelanato mate. Para tanto, avaliou-se o efeito da variação de iluminante, correlacionado com as seguintes características dos revestimentos cerâmicos investigados: i) tipologia de esmalte; ii) base, engobe esmaltes; iii) variação de camada; iv) utilização de quartzo, caulim e zirconita; v) variação de corantes. Os resultados mostraram que esmaltes, como o branco-brilhante, se destacam no aparecimento da característica metamérica, tanto mais quanto mais espessa a camada. Já, quando se aumenta a camada do mate, este fenômeno ameniza. A zirconita, por ser um opacificante, ameniza a reflexão da luz, gerando uma diminuição do metamerismo. O quartzo promove o metamerismo, já que influencia no aparecimento do brilho. Quanto aos corantes, pigmentos que amenizam o reflexo da luz, como o preto e cinza, possuem um valor metamérico baixo, já pigmentos que tendem ao reflexo maior da luz, promovem o metamerismo. Com base nisso, o suporte do porcelanato esmaltado que se apresenta em uma base cinza, possui um valor metamérico menor que a base da monoporosa, que possui uma cor bege. Ficou evidenciada a influência das curvas espectrais e do reflexo no aparecimento do metamerismo, podendo ser um ponto crucial para que empresas trabalhem em cima deste problema, a fim de ser um diferencial para seus clientes no mercado competitivo como o de hoje.One of several problems that occur in ceramic tiles, is the possibility that two objects are the same color in the light of day, but of different colors in a different light. This phenomenon, in which two colors are similar under a light source but different under another, is called metamerism. Seeking a study on this phenomenon was analyzed the influence of some variables on the metamerism in a white enamel-bright monoporosity, and a matte porcelain. Some of the variables selected for the study of the influence of the media, and enamel on engobe metamerism, the addition of opacifier material, in suspension and bright enamels in different percentages, the analysis with the addition of pure colors and mixtures of the same in glazes; variations in the enamel layer, among other factors. Before, it was noticed that the enamel provide a high spectral curve, ie, materials that reflect the highly light, tend to influence the onset of this phenomenon. Thus, materials that influence the formation of brightness as quartz help this phenomenon to emerge since opacifying materials that have the feature to break it brightness, ie, which have lower spectral curves, decreases the appearance of this phenomenon. In the matter of color is the same as explained above, ie, pigments that mitigate the reflection of light as the black and gray, have a low value metameric because colors tend to reflect more light, raise this value. On this basis, the support of porcelain enamel that comes in on a gray metameric has a value less than the base of monoporosity, which has a beige color. Having knowledge of these factors, it is clear the influence of spectral curves and reflex formed by these variables in the emergence of this phenomenon and may be a crucial point for companies to work upon this problem, in order to be a differentiator for its customers in competitive market which is today.
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Dahlgren, Mikael. "Object Selection by Relative Hand to Cursor Mapping : Design and Evaluation of a 2D-Object Selection Technique for Hand Tracking in Virtual Environments." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292107.
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Hand and tracker jitter negatively affect performance with ray-casting in virtual environments, making it difficult to acquire small objects which require high levels of precision. This study evaluates an alternative target acquisition technique for 2D-interfaces in virtual environments with relative hand-to-cursor mapping. Trade-offs between the relative hand-to-cursor mapping and ray-casting are explored in comparative evaluation, utilizing Fitts's law, SUS-surveys and interviews. The results demonstrate that relative hand-to-cursor mapping performs equal to ray-casting while also allowing higher precision in certain selection tasks.Strålföljning påverkas negativt av darrning i händer och spårteknik i virtuella miljöer vilket gör det svårt att markera objekt som kräver hög precision. Denna studie utvärderar en alternativ teknik till strålföljning for objektmarkering i 2D-granssnitt i virtuella miljöer kallad relativ hand till musmarkör mappning. Avvägning mellan dessa två tekniker utvärderas i en jämförande studie med hjälp av Fitts's lag, SUS-undersökning och intervjuer. Resultaten demonstrerar att relativ hand till murmarkor mappning presterar jämförbart med strålföljning och tillåter samtidigt högre precision i särskilda objektmarkeringsuppgifter.
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Drewett, Anne. "Curses, Ogres and Lesbians : An Examination of the Subversion and Perpetuation of Fairy Tale Norms in Two Adaptations of Beauty and The Beast." Thesis, Umeå universitet, Institutionen för språkstudier, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-117268.
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Fairy tales as a form of social acculturation can subvert and/or perpetuate potentially harmful social norms. In this essay, Chris Anne Wolfe’s lesbian romance novel Bitter Thorns (1994) and the film Shrek (2001) are analysed as adaptations of the fairy tale Beauty and the Beast, with a focus on the extent to which they challenge and/or reinforce three fairy tale norms: women as tradeable objects, heteronormativity and idealised beauty. Both these texts can be seen as subversive, Bitter Thorns in how it challenges heteronormativity and Shrek in how it challenges the norm of idealised beauty. This subversion, however, is limited, as both texts do more to perpetuate fairy tale norms than to challenge them. They both reinforce the idea of women as objects for trade, Bitter Thorns perpetuates the norm of idealised beauty, and Shrek advocates heteronormative relationships and the dominance of heterosexual masculinity.
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Adema, Willem. "The Beveridge curve and institutional arrangements." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:7d973b3d-e75e-4faa-b8d8-0e41cca8f6a3.
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The main objective of our analysis is to investigate the causes of shifts of the Beveridge curve in Great Britain, the Netherlands and Sweden. In chapter 2., we will outline the model which is the basis for our analysis. The cornerstone of our theoretical framework regarding the long-run relationship between unemployment and vacancies otherwise known as the Beveridge curve is the matching process. We will describe how certain features such as structural mismatch, the relative attractiveness of benefit provisions and changes in search intensity and search effectiveness of the unemployed, could theoretically affect the Beveridge curve. In order to analyse a possible shift of the Beveridge curve, time series analysis will be used. In chapter 3., we describe the patterns of the relevant data series. Also, we describe the significance of the long-term unemployment problem in Great Britain and the Netherlands. In the following chapter we describe the characteristics of the disability arrangements in the three relevant countries. We do this in order to explain how the disability arrangements have affected the unemployment patterns in one of our sample countries. The focal point is the existence of a hidden unemployment component in the disability stock. In order to estimate the Beveridge curve for each country, we will use the instrumental variables technique. In chapter 5., after first having tested for the suitability of our econometric practice regarding the data series in the context of the theory of cointegration, we will present and discuss several model specifications regarding the Beveridge curve. We will also test for the sensitivy of our main results to variations in data and estimation method. Also, we present models of the British and Dutch long-term unemployment patterns. In chapter 6., we will discuss the most relevant results and compare the British, Dutch and Swedish labour market experiences. Conclusions are presented in the final chapter.
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Nascimento, Mauricio Garcia Franco do. "iRepositório: repositório interativo de conteúdos digitais para cursos baseados na Internet." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/45/45134/tde-22082014-114848/.
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A crescente demanda por cursos baseados na World Wide Web (Web) tem imposto uma série de desafios para a área da Tecnologia da Informação e da Comunicação (TIC), em particular quando se considera a Educação apoiada pela Web. Uma das necessidades emergentes da Educação via Web está relacionada com o uso de Objetos de Aprendizagem (OA) dentro de Sistemas Gerenciadores de Curso (SGC). Além de considerar a produção de OA com \"qualidade\", deve-se providenciar seu armazenamento e disseminação de modo eficaz. Entretanto, algumas dificuldades tem sido reportadas por professores envolvidos com cursos pela Web, tais como: o \"custo elevado\" para a autoria do OA; a falta de ferramentas para o compartilhamento desses materiais; e experiências práticas negativas no reúso desses conteúdos em um SGC. Uma primeira proposta para mitigar esses problemas tem sido o desenvolvimento de ferramentas de Repositório de Objetos de Aprendizagem (ROA), visando principalmente facilitar a disseminação dos OA. Apesar do progresso já alcançado, ainda existem várias barreiras para a sua adoção pelos professores, como falta de integração simples entre o SGC e o ROA. Em geral as integrações atuais mostram-se difíceis para um usuário típico. Neste cenário, o objetivo deste projeto é apresentar um ROA inovador, o Repositório Interativo de Conteúdo Digital - iRepositório, cujo modelo prevê uma integração simplificada com um particular SGC e ainda oferece vários recursos para melhorar os processos de ensino e de aprendizagem, como o registro da eficácia educacional do OA. Como contribuição prática os fundamentos do iRepositório foram implementados para um SGC específico, o Moodle. Além de compartilhar OA entre cursos e usuários, ele provê recursos a outro componente do Moodle, o Tarefa Interativa - iTarefa, para armazenamento, classificação e busca de OA ou ainda facilidades para a manipulação dos Módulos de Aprendizagem Interativa (iMA).The increasing demand for World Wide Web (Web) based courses has imposed some challenges in Information and Communications Technology (ICT) field, in particular when considering the education supported by the Web. One of the emerging needs of education supported by the Web is related to the Learning Objects (LO) usage inside Learning Management Systems (LMS). Besides production of \"good quality\" LO, it must be provided efficient methods concerning their storage and dissemination. However, some difficulties have been reported by teachers of Web based courses: \"expensive costs\" for LO authoring; lack of tools for sharing these materials; and negative practical experiences for reusing them in an LMS. Some proposals to mitigate these problems have been the development of Learning Object Repository (LOR) tools, mainly in order to facilitate the dissemination of LO. Despite the progress already achieved, there are still several barriers for their adoption by teachers such as lack of easy integration between LMS environment and LOR. In general, current integrations are not simple for typical users. In this context, the target of this project is to presents an innovative LOR, the Interactive Repository of Digital Contents - iRepository. Its model provides seamless integration with a particular LMS and offers several resources to help teaching and learning processes, such as registry of LO educational effectiveness. As a practical contribution, the fundamentals of iRepository model were implemented for an specific LMS, the Moodle system. Besides promoting LO sharing among courses and users, it provides resources to other Moodle component, the Interactive Assignment - iAssign, for storage, classification e searching of LO, or even ease management of Interactive Learning Module (iLM).
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Oropallo, William Edward Jr. "A Point Cloud Approach to Object Slicing for 3D Printing." Thesis, University of South Florida, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10751757.
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Various industries have embraced 3D printing for manufacturing on-demand, custom printed parts. However, 3D printing requires intelligent data processing and algorithms to go from CAD model to machine instructions. One of the most crucial steps in the process is the slicing of the object. Most 3D printers build parts by accumulating material layers by layer. 3D printing software needs to calculate these layers for manufacturing by slicing a model and calculating the intersections. Finding exact solutions of intersections on the original model is mathematically complicated and computationally demanding. A preprocessing stage of tessellation has become the standard practice for slicing models. Calculating intersections with tessellations of the original model is computationally simple but can introduce inaccuracies and errors that can ruin the final print.
This dissertation shows that a point cloud approach to preprocessing and slicing models is robust and accurate. The point cloud approach to object slicing avoids the complexities of directly slicing models while evading the error-prone tessellation stage. An algorithm developed for this dissertation generates point clouds and slices models within a tolerance. The algorithm uses the original NURBS model and converts the model into a point cloud, based on layer thickness and accuracy requirements. The algorithm then uses a gridding structure to calculate where intersections happen and fit B-spline curves to those intersections.
This algorithm finds accurate intersections and can ignore certain anomalies and error from the modeling process. The primary point evaluation is stable and computationally inexpensive. This algorithm provides an alternative to challenges of both the direct and tessellated slicing methods that have been the focus of the 3D printing industry.
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Toman, Tomáš. "Víceúčelový objekt v Olomouci." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265286.
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This diploma thesis deals with design of timber load-bearing structure of a Multi-functional object in Olomouc. This object has an eliptical ground plan with dimensions 50x30 metres and height of 11 metres. The idea of the shape is an eliptical dome. This dome was designed in two options, those are a Rib dome and a Föppel dome.
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Chase, Joseph D. "A controlled experiment to identify and test a representative primitive set of user object-oriented cursor actions." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/42070.
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see documentA method for decomposing the user cursor action component of human-computer interfaces into individual components based on the four categories: target size, target distance, target direction, and selection mode, was investigated. A primitive task set consisting of the Cartesian product of specific elements of the four categories listed above was proposed based on observation of user tasks and a cursor action benchmark task set was developed to measure a user's performance for each element of the set of primitive elements with a given cursor control device. An experiment was conducted to test the proposed primitive task set and associated benchmark task set as a predictor of performance for a set of representative graphics tasks. The predicted times and actual times were shown to have very strong correlations and the data were also shown to conform to Fitts' Law. A description of the experiment, the data collected, and the analysis of these data are included.
Master of Science
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Turnes, Vivian Cross. "Cursos técnicos binacionales en informática: la utilización de objetos de aprendizaje para la enseñanza de variedades lingüísticas." Universidade Federal do Pampa, 2018. http://dspace.unipampa.edu.br:8080/jspui/handle/riu/2597.
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Este Informe Crítico-Reflexivo es el resultado de una investigación que tuvo como objetivo planificar e implementar un proyecto de intervención que proponía metodologías alternativas para la enseñanza de variedades lingüísticas en la región de frontera, dentro de la asignatura de Español, utilizando, para sistematizar estos conocimientos, los objetos de aprendizaje por medio de las tecnologías digitales, buscando evaluar si el trabajo corroboró con el aprendizaje de los alumnos. La intervención fue realizada en el Instituto Federal-rio-grandense, en la ciudad de Sant´Ana do Livramento (RS), con un Primer Año del curso Técnico en Informática para Internet. El referencial teórico utilizado trajo informaciones referentes al contexto en que se realizó la investigación; a la utilización de objetos de aprendizaje en clase. La metodología de este proyecto fue la intervencionista, utilizando metodologías alternativas, que enfocaran el tema variedades lingüísticas. Los sujetos involucrados en la intervención fueron veinticinco alumnos con edades entre quince y diecisiete años. Los instrumentos de recolecta de datos fueron el diario de campo de la investigadora y el análisis documental. Los resultados de este trabajo fueron presentados en categorías como “Trabajando el tema variedades lingüísticas”; “Reacciones de los alumnos al tema variedades lingüísticas”; “Especificidades de un salón en la frontera”; “Utilización de los OA en clase”; “Dificultades Encontradas” y “Aspectos Valorados de la Intervención”. La investigación indicó que, por lo general, la utilización de los OA como metodologías alternativas para la enseñanza de variedades lingüísticas, en la región de frontera, fueron herramientas que despertaron el interés de los alumnos y los auxiliaron, haciéndolos protagonistas de sus formas de aprendizaje.
Este Relatório Crítico-Reflexivo é o resultado de uma pesquisa que teve como objetivo planejar e implementar um projeto de intervenção que propusesse metodologias alternativas para o ensino de variedades linguísticas na região de fronteira, dentro do componente curricular Espanhol, utilizando, para sistematizar estes conhecimentos, os objetos de aprendizagem por meio das tecnologias digitais, buscando avaliar se o trabalho colaborou com a aprendizagem dos alunos. A intervenção foi realizada no Instituto Federal-rio-grandense, na cidade de Sant´Ana do Livramento (RS), com um Primeiro Ano do curso Técnico em Informática para Internet. O referencial teórico utilizado trouxe informações referentes ao contexto em que foi realizada a pesquisa; à utilização de objetos de aprendizagem em sala de aula. A metodologia deste projeto foi a intervencionista, utilizando metodologias alternativas, com foco no tema variedades linguísticas. Os sujeitos envolvidos na intervenção foram vinte e cinco alunos com idades entre quinze e dezessete anos. Os instrumentos de coleta de dados foram o diário de campo da pesquisadora e a análise documental. Os resultados deste trabalho foram apresentados em categorias como “Trabalhando o tema variedades linguísticas”; “Reações dos alunos ao tema variedades linguísticas”; “Especificidades de uma sala de aula na fronteira”; “Utilização dos OA na aula”; “Dificuldades Encontradas” e “Aspectos Valorizados da Intervenção”. A pesquisa indicou que, no geral, a utilização dos OA como metodologias alternativas para o ensino de variedades linguísticas, na região de fronteira, foram ferramentas que despertaram o interesse dos alunos e os auxiliaram, tornando-os protagonistas das suas formas de aprendizagem.
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Kutálek, David. "Statistická analýza ROC křivek." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229036.
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The ROC (Receiver Operating Characteristic) curve is a projection of two different cumulative distribution functions F0 and F1. On axis are values 1-F0(c) and 1-F1(c). The c-parameter is a real number. This curve is useful to check quality of discriminant rule which classify an object to one of two classes. The criterion is a size of an area under the curve. To solve real problems we use point and interval estimation of ROC curves and statistical hypothesis tests about ROC curves.
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Garfjeld-Roberts, Patrick. "Improving simulation training in orthopaedics." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:c48dcc24-6850-476f-b143-b02cda4e0429.
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The way surgical trainees acquire technical skills is changing in modern surgical training programmes: simulation is proposed as a key part of those changes. Arthroscopy is a surgical technique that is increasing in both incidence and technical complexity; where simulation is becoming common, but evidence is limited. Real-world performance improvements can be measured following simulation training in other fields, but equivalent measures of intra-operative performance are inadequate. Thus, although surgical simulation is popular and improves simulated performance, there is little objective evidence that it improves intra-operative performance. The original contribution of this thesis is to objectively demonstrate the transfer of simulation training into improved intra-operative technical skills. To achieve this, a systematic literature review investigated the quantitative metrics currently used to measure arthroscopic performance, identifying wireless motion analysis as a potential method to assess performance intra-operatively. Motion analysis is a recognised objective method to measure surgical activity which correlates with surgical experience, so wireless motion analysis was validated against a wired motion analysis method commonly used in simulation but not feasible for intra-operative use. Wireless motion analysis metrics were further validated with a simulated arthroscopy list: this environment allowed deliberate practice of arthroscopic sub-skills with proximate feedback for independent practice. This simulated arthroscopy list with wireless motion analysis was used in two randomised studies: the penultimate study of this thesis investigated the impact of simulated practice on the arthroscopic learning curve and showed that performance improved rapidly with independent practice but was not modified by feedback, while the final study investigated additional simulation practice during early surgical training, and objectively demonstrated that additional simulation training improved intra-operative performance compared to traditional training alone. This thesis is the first to objectively show that simulation affects intra-operative behaviour. It sets the groundwork for further investigations into efficient, cost-effective simulation and the impact of simulation training on patient outcomes.
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Mamic, G. J. "Representation and recognition of 3-D free-form objects incorporating statistical techniques." Thesis, Queensland University of Technology, 2002.
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Calabrese, John. "In the hall of the flop king : two applications of perverse coherent sheaves to Donaldson-Thomas invariants." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b96b2bdd-8c79-4910-8795-f147bc8b2d16.
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This thesis contains two main results. The first is a comparison formula for the Donaldson-Thomas invariants of two (complex, smooth and projective) Calabi-Yau threefolds related by a flop; the second is a proof of the projective case of the Crepant Resolution Conjecture for Donaldson-Thomas invariants, as stated by Bryan, Cadman and Young. Both results rely on Bridgeland’s category of perverse coherent sheaves, which is the heart of a t-structure in the derived category of the given Calabi-Yau variety. The first formula is a consequence of various identities in an appropriate motivic Hall algebra followed by an implementation of the integration morphism (using the technology of Joyce and Song). Our proof of the crepant resolution conjecture is a quick and elegant application of the first formula in the context of the derived McKay correspondence of Bridgeland, King and Reid. The first chapter is introductory and is followed by two chapters of background material. The last two chapters are devoted to the proofs of the main results.
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Afonso, Maria da Conceição Lima. "A visão dos docentes dos cursos de graduação em licenciatura brasileiros sobre os Repositórios de Objetos de Aprendizagem (ROA)." reponame:Repositório Institucional da UnB, 2014. http://repositorio.unb.br/handle/10482/16828.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciência da Informação, Programa de Pós-graduação em Ciência da Informação, 2014.Submitted by Ana Cristina Barbosa da Silva (annabds@hotmail.com) on 2014-11-03T17:15:17Z No. of bitstreams: 1 2014_MariadaConceiçaoLimaAfonso.pdf: 1036123 bytes, checksum: 041e0dcad7a88bf52ae4aa88197e98f3 (MD5)
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Busca conhecer a visão dos docentes dos cursos de graduação em licenciatura brasileiros sobre os Repositórios de Objetos de Aprendizagem (ROA), caracterizando os aspectos que favorecem seu uso no desenvolvimento das atividades de ensino-aprendizagem. Para isso, esta pesquisa discorre em sua revisão de literatura sobre: os Repositórios de Objetos de Aprendizagem (ROA), tanto no contexto da Ciência da Informação como no contexto educacional; e sobre as Tecnologias de Informação e Comunicação (TIC) no âmbito da Educação, contextualizando sua importância no âmbito da educação superior no Brasil. A metodologia utilizada foi a pesquisa exploratória qualitativa, tendo como método de levantamento dos dados o uso de questionário e entrevistas em profundidade semiestruturadas. Dentre os resultados obtidos estão a identificação e caracterização dos ROA e dos docentes dos cursos de graduação em licenciatura brasileiros. Além disso, examinou a receptividade dos docentes aos ROA, identificando as razões pelas quais esses docentes utilizam ou não esses ambientes. _________________________________________________________________________________ ABSTRACT
It seeks to understand the vision of Brazilian teachers of undergraduate degree on Learning Object Repositories (LOR), characterizing aspects that favor its use in the development of teaching-learning activities. To this end, this research discusses in its review of literature about: the Learning Object Repositories (LOR), both in the context of Information Science and the educational context; and on Information and Communication Technologies (ICT) in the scope of Education, contextualizing its importance in the scope of higher education in Brazil. The methodology used was a qualitative exploratory research, using as the method of collection of data questionnaires and interviews in semi-structured depth. Among the results are the identification and characterization of LOR used in Brazil and of Brazilian teachers of undergraduate degree. In addition, it examined the responsiveness of teachers to LOR, identifying the reasons why these teachers use or not these environments.
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Gallardo, Mathias. "Contributions to Monocular Deformable 3D Reconstruction : Curvilinear Objects and Multiple Visual Cues." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC021/document.
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La reconstruction 3D monoculaire déformable est le problème général d'estimation de forme 3D d'un objet déformable à partir d'images 2D. Plusieurs scénarios ont émergé : le Shape-from-Template (SfT) et le Non-Rigid Structure-from-Motion (NRSfM) sont deux approches qui ont été grandement étudiées pour leur applicabilité. La première utilise une seule image qui montre un objet se déformant et un patron (une forme 3D texturée de l'objet dans une pose de référence). La seconde n'utilise pas de patron, mais utilise plusieurs images et estime la forme 3D dans chaque image. Les deux approches s'appuient sur le mouvement de points de correspondances entre les images et sur des a priori de déformations, restreignant ainsi leur utilisation à des surfaces texturées qui se déforment de manière lisse. Cette thèse fait avancer l'état de l'art du SfT et du NRSfM dans deux directions. La première est l'étude du SfT dans le cas de patrons 1D (c’est-à-dire des courbes comme des cordes et des câbles). La seconde direction est le développement d'algorithmes de SfT et de NRSfM qui exploitent plusieurs indices visuels et qui résolvent des cas réels et complexes non-résolus précédemment. Nous considérons des déformations isométriques et reconstruisons la partie extérieure de l'objet. Les contributions techniques et scientifiques de cette thèse sont divisées en quatre parties.La première partie de cette thèse étudie le SfT curvilinéaire, qui est le cas du patron curvilinéaire plongé dans un espace 2D ou 3D. Nous proposons une analyse théorique approfondie et des solutions pratiques pour le SfT curvilinéaire. Malgré son apparente simplicité, le SfT curvilinéaire s'est avéré être un problème complexe : il ne peut pas être résolu à l'aide de solutions locales non-holonomes d'une équation différentielle ordinaire et ne possède pas de solution unique, mais un nombre fini de solutions ambiguës. Une contribution technique majeure est un algorithme basé sur notre théorie, qui génère toutes les solutions ambiguës. La deuxième partie de cette thèse traite d'une limitation des méthodes de SfT : la reconstruction de plis. Cette limitation vient de la parcimonie de la contrainte de mouvement et de la régularisation. Nous proposons deux contributions qui s'appuient sur un cadre de minimisation d'énergie non-convexe. Tout d'abord, nous complétons la contrainte de mouvement avec une contrainte robuste de bord. Ensuite, nous modélisons implicitement les plis à l'aide d'une représentation dense de la surface basée maillage et d'une contrainte robuste de lissage qui désactive automatiquement le lissage de la courbure sans connaître a priori la position des plis.La troisième partie de cette thèse est dédiée à une autre limitation du SfT : la reconstruction de surfaces peu texturées. Cette limitation vient de la difficulté d'obtenir des correspondances (parcimonieuses ou denses) sur des surfaces peu texturées. Comme l'ombrage révèle les détails sur des surfaces peu texturées, nous proposons de combiner l'ombrage avec le SfT. Nous présentons deux contributions. La première est une initialisation en cascade qui estime séquentiellement la déformation de la surface, l'illumination de la scène, la réponse de la caméra et enfin les albédos de la surface à partir d'images monoculaires où la surface se déforme. La seconde est l'intégration de l'ombrage à notre précédent cadre de minimisation d'énergie afin de raffiner simultanément les paramètres photométriques et de déformation.La dernière partie de cette thèse relâche la connaissance du patron et aborde deux limitations du NRSfM : la reconstruction de surfaces peu texturées avec des plis. Une contribution majeure est l'extension du second cadre d'optimisation pour la reconstruction conjointe de la forme 3D de la surface sur toutes les images d'entrée et des albédos de la surface sans en connaître un patronMonocular deformable 3D reconstruction is the general problem of recovering the 3D shape of a deformable object from monocular 2D images. Several scenarios have emerged: the Shape-from-Template (SfT) and the Non-Rigid Structure-from-Motion (NRSfM) are two approaches intensively studied for their practicability. The former uses a single image depicting the deforming object and a template (a textured 3D shape of this object in a reference pose). The latter does not use a template, but uses several images and recovers the 3D shape in each image. Both approaches rely on the motion of correspondences between the images and deformation priors, which restrict their use to well-textured surfaces which deform smoothly. This thesis advances the state-of-the-art in SfT and NRSfM in two main directions. The first direction is to study SfT for the case of 1D templates (i.e. curved, thin structures such as ropes and cables). The second direction is to develop algorithms in SfT and NRSfM that exploit multiple visual cues and can solve complex, real-world cases which were previously unsolved. We focus on isometric deformations and reconstruct the outer part of the object. The technical and scientific contributions of this thesis are divided into four parts. The first part of this thesis studies the case of a curvilinear template embedded in 2D or 3D space, referred to Curve SfT. We propose a thorough theoretical analysis and practical solutions for Curve SfT. Despite its apparent simplicity, Curve SfT appears to be a complex problem: it cannot be solved locally using exact non-holonomic partial differential equation and is only solvable up to a finite number of ambiguous solutions. A major technical contribution is a computational solution based on our theory, which generates all the ambiguous solutions.The second part of this thesis deals with a limitation of SfT methods: reconstructing creases. This is due to the sparsity of the motion constraint and regularization. We propose two contributions which rely on a non-convex energy minimization framework. First, we complement the motion constraint with a robust boundary contour constraint. Second, we implicitly model creases with a dense mesh-based surface representation and an associated robust smoothing constraint, which deactivates curvature smoothing automatically where needed, without knowing a priori the crease location. The third part of this thesis is dedicated to another limitation of SfT: reconstructing poorly-textured surfaces. This is due to correspondences which cannot be obtained so easily on poorly-textured surfaces (either sparse or dense). As shading reveals details on poorly-textured surfaces, we propose to combine shading and SfT. We have two contributions. The first is a cascaded initialization which estimates sequentially the surface's deformation, the scene illumination, the camera response and then the surface albedos from deformed monocular images. The second is to integrate shading to our previous energy minimization framework for simultaneously refining deformation and photometric parameters.The last part of this thesis relaxes the knowledge of the template and addresses two limitations of NRSfM: reconstructing poorly-textured surfaces with creases. Our major contribution is an extension of the second framework to recover jointly the 3D shapes of all input images and the surface albedos without any template
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Geng, Xi. "The signature of a rough path : uniqueness." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:f15c0439-2b30-4738-9eab-0dffd86bed69.
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The main contribution of the present thesis is in two aspects. The first one, which is the heart of the thesis, is to explore the fundamental relation between rough paths and their signatures. Our main goal is to give a geometric characterization of the kernel of the signature map in different situations. In Chapter Two, we start by establishing a general fact that a continuous Jordan curve on a Riemannian manifold can be arbitrarily well approximated by piecewise minimizing geodesic interpolations which are again Jordan. This result enables us to prove a generalized version of Green’s theorem for planar Jordan curves with finite p-variation 1 ≤ p < 2, and to prove that two such Jordan curves have the same signature if and only if they are equal up to reparametrization. In Chapter Three, we investigate the problem for general weakly geometric rough paths. In particular, we show that a weakly geometric rough path has trivial signature if and only if it is tree-like in the sense we will define later on. In Chapter Four, we study the problem in the probabilistic setting. In particular, we show that for a class of stochastic processes, with probability one the sample paths are determined by their signatures up to reparametrization. A fundamental example is Gaussian processes including fractional Brownian motion with Hurst parameter H > 1/4, the Ornstein-Uhlenbeck process and the Brownian bridge. The second one is an application of rough path theory to the study of nonlinear diffusions on manifolds under the framework of nonlinear expectations. In Chapter Five, we begin by studying the geometric rough path nature of G-Brownian motion. This enables us to introduce rough differential equations driven by G-Brownian motion from a pathwise point of view. Next we establish the fundamental relation between rough (pathwise theory) and stochastic (L2-theory) differential equations driven by G-Brownian motion. This is a crucial point of understanding nonlinear diffusions and their generating heat flows on manifolds from an intrinsic point of view. Finally, from the pathwise point of view we construct G-Brownian motion on a compact Riemannian manifold and establish its generating heat flow for a class of G-functions under orthogonal invariance. As an independent interest, we also develop the Euler-Maruyama scheme for stochastic differential equations driven by G-Brownian motion.
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Niches, Cláudia Cardoso. "Alfabetização e alfabetizadoras: objeto inconsistente, ofício contingente." Universidade do Vale do Rio dos Sinos, 2014. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3119.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A presente tese analisa a fragilidade que envolve o objeto de estudos alfabetização na formação inicial de professores para o Ensino Fundamental. De forma mais precisa, investe-se em compreender como esse objeto tem se configurado nesses processos formativos e como tal configuração correlaciona-se ao ofício de alfabetizar. Para o desenvolvimento da pesquisa buscou-se sustentação no amplo campo teórico da história da escolarização no Ocidente, assinalando os elementos que estruturaram a emergência da escola obrigatória no Brasil, bem como, o lugar da alfabetização e da formação de alfabetizadores nesse conjunto. O corpus analítico compõe-se de narrativas de alfabetizadoras que atuam, há mais de cinco anos, nos dois primeiros anos do Ensino Fundamental, na rede pública municipal de Montenegro, estado do rio Grande do Sul. A abordagem metodológica empreendida para a produção do corpus empírico valeu-se da entrevista narrativa orientada sobre: 1) os significados que o objeto alfabetização e o ser/estar alfabetizadora assumem para essas professoras, produzindo referências e/ou identificações entre essas profissionais; 2) as bases epistemológicas dominantes que esteiam os saberes práticos e instrumentais dessas alfabetizadoras, dando contornos a esse "lugar profissional"; 3) as implicações de seus processos formativos nas im/possibilidades de sua constituição como alfabetizadoras; e, 4) os elementos que vêm tensionando a experiência cultural de alfabetizar, configurando-a e projetando-a. As análises nutriram-se de elementos da teoria foucaultiana do discurso que, priorizando os procedimentos descritivos, compreende o conhecimento como produção continua e contingente de verdades. Os resultados da pesquisa apontam para a (1) inconsistência da alfabetização na formação de professores, a qual se configura sobre a predominância da abordagem mecânica no ensino-aprendizagem da leitura e da escrita; a frágil inserção do conceito de letramento nesses discursos, os quais não contemplam, minimamente, a amplitude que perfaz a alfabetização na atualidade; e, o apagamento de referências específicas da alfabetização e que são ofertadas pela multidisciplinaridade das ciências que contemplam esse objeto. Compreende-se, assim, que as especificidades da alfabetização são obliteradas por elementos relacionados à docência em sua forma mais ampla e genérica, e (2) o ofício de alfabetizar adquire um status contingente à medida que seu objeto é abordado de forma frágil, tanto na formação quanto na sua prática escolarizada, sustendo-se, predominantemente, nos saberes e crenças sucedidas das experiências dessas profissionais e sob o apagamento de referências associadas às suas especificidades.
The present paper aims at analyzing the weakness that involves the object of studies Literacy in the formative processes of Elementary School teachers. It has been set, in a more precise way, on how Literacy has been configured in the beginning of Elementary School teacher’s formation and how this is correlated to the job of teaching how to read and write. In order to develop the research, one found support in the wide theoretical field of the history of schooling in the West, pointing out the elements that structure the emergency of compulsory school in Brazil, as well, the place of Literacy and the formation of teachers as a whole. The analytical corpus includes Literacy teachers’ narratives, who have worked, for more than five years, in the first two years of Elementary public schools, in the city of Montenegro, Rio Grande do Sul. The methodological approach applied for the development of the empirical corpus made use of oriented narrative interview about: the meanings that the object Literacy and the fact of been literate takes on to those teachers, making references and/or identifications between those professionals; the epistemological dominant basis that support these teachers’ practical and instrumental knowledge, outlining their professional place; the implications of their formative processes in their im/possibilities as literacy teachers and, the elements that have been provoking tension in the cultural experience of Literacy, adjusting and projecting it. The analysis of the content was based in the Foucauldian discourse analysis that concerns to the meanings that the subjects attribute to the objects that surround them and their experiences, prioritizes descriptive proceedings, welcomes subjective interference and understands knowledge as a continuing and occasional production of true. The results of the research point to: 1) the inconsistency of Literacy in the formation of teachers, shaped by the predominance of the mechanical approach in the learning/ teaching reading and writing process, which does not prioritize the reading of the world; 2) the fragile introduction of Literacy concepts in this discourse that do not contemplate, the least, the huge role that literacy currently has; and 3) the fading of specific references related to literacy, offered by the multi discipline in sciences that contemplate this object. The inconsistency of Literacy ends up for being suppressed, in this discourse, by elements related to teaching job in its broader generic way. One can infer that the literacy job acquires a vulnerable status, as its object is invisible, not only in its formation but also in its schooling practice, supporting itself, therefore, in the predominance of knowledge and beliefs coming from the experiences of these professionals and over the fading of references connected to its specificities.
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Marwah, Hanaan. "Investing in ghosts : building and construction in Nigeria's oil boom and bust c.1960-2000." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:44dde983-2993-41c9-9346-9783f3d6e52a.
Full textAbstract:
Nigeria, Africa’s most populous country, has been portrayed in scholarly literature as a prominent case of postcolonial African ‘growth failure’. Between 1960 and 2000 oil reserves were exploited resulting in revenues of more than $300 billion to the Nigerian government, while real per capita income fell over the same period. This thesis, by focusing on building and construction in Nigeria from 1960 to 2000, explains how and why Nigeria failed to invest its oil revenues to create long-term economic growth. Its findings have important implications for investment analyses of other commodity-rich countries in Africa and across the developing world. It draws on a wide range of primary quantitative and qualitative sources including government surveys, construction-related company financial data and project lists, industry publications, newspapers, and the correspondence files of a major Nigerian architecture firm. These are used to present a picture of historical building activity which includes a 40-year dataset of cement price and consumption, and a construction supply curve for both the oil boom and bust periods. By quantifying for the first time the long-observed ‘ghost construction’ of the oil boom, this thesis finds that annually about two thirds of what scholars and national accounts statistics had estimated was being invested in construction was never actually invested, implying that what was invested offered a greater return than has previously been acknowledged. Although investment in construction was overstated during the oil boom, during the oil bust construction was understated as major government projects were funded off-budget and away from public scrutiny. This thesis demonstrates that the most productive area of public investment has been infrastructure, and further that the private sector construction industry was a valuable asset which greatly enhanced the government’s ability to implement investment programmes, when it had the political will to do so.
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Špačková, Eva. "Multifunkční objekt v Českých Budějovicích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240487.
Full textAbstract:
The subject of this thesis is the design and assessment of the supporting structure multifunctional building in the Czech Budejovice . The construction of a sphere with a maximum diameter of 30 m and a height of 19.5 meters the highest point . The supporting structure consists of curved ribs , elevator shaft and ceiling beams . The structure is designed in 4 versions . Two variants are made of steel, the third option is wooden and the latest version solves a combination of wood and steel. In the variant selected is done loading , ultimate limit state, serviceability limit state , fire resistance and compounds selected details.
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Köcher, Paul Tilman. "Nanoscale measurements of the mechanical properties of lipid bilayers." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:0b478b9f-70fc-436f-9803-5d3a203f0d7e.
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Lipid bilayers form the basis of the membranes that serve as a barrier between a cell and its physiological environment. Their physical properties make them ideally suited for this role: they are extremely soft with respect to bending but essentially incompressible under lateral tension, and they are quite permeable to water but essentially impermeable to ions which allows the rapid establishment of the osmotic gradients. The function of membrane proteins, which are vital for tasks ranging from signal transduction to energy conversion, depends on their interactions with the lipid environment. Because of the complexity of natural membranes, model systems consisting of simpler lipid mixtures have become indispensable tools in the study of membrane biophysics. The objective of the work reported here is to develop a deeper understanding of the underlying physics of lipid bilayers through nanoscale measurements of the mechanical properties of mixed lipid systems including cholesterol, a key ingredient of cell membranes. Atomic force microscopy (AFM) has been used extensively to measure the topographical and elastic properties of supported lipid bilayers displaying complex phase behaviour and containing mixtures of important PC, PE lipids and cholesterol. Phase transformations have been investigated varying the membrane temperature, and the effects of cholesterol in controlling membrane fluidity, phase, and energetics have been studied. Elastic modulus measurements were correlated with phase behaviour observations. To aid in the nanoscale probing of lipid bilayers, AFM probes with a high aspect ratio and tip radii of $sim$4~nm were fabricated and characterised. These probes were used to investigate the phase boundary in binary and ternary lipid systems, leading to the discovery of a raised region at the boundary which has implications for the localisation of reconstituted proteins as well as the role of natural domains or lipid rafts. The electrical properties of the probes were examined to assess their potential application for combined structural and electrical measurements in liquid. A novel technique was developed to aid in the study of the physical properties of lipid bilayers. Membrane budding was induced above microfabricated substrates through osmotic pressure. Modification of the adhesion energy of the bilayer through biotin-avidin linking was successful in modulating budding behaviour of liquid disordered bilayers. The free energy of the system was modelled to allow quantitative information to be extracted from the data.
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Engel, Megan Clare. "Exploration of DNA systems under internal and external forcing using coarse-grained modelling." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:019ce971-fead-4afe-8794-c1361a40098c.
Full textAbstract:
The profound simplicity and versatility of the molecule at the heart of all earth- bound life forms, DNA, continues to inspire new frontiers of scientific inquiry. Central to many of these, including the de novo design of novel DNA nanostructures and the use of DNA to probe the principles of biological self-assembly and the operation of cellular nanomachines, is the interaction of DNA with forces, both internal and external. This thesis comprises a survey of three key ways coarse-grained simulations using the oxDNA model can contribute to efforts to characterize these interactions. First, a non-equilibrium data analysis framework based on the Jarzynski equality from statistical physics is validated for use with oxDNA through the reconstruction of free energy landscapes for canonical DNA hairpin systems. We provide a framework for assessing errors in the method and apply it to study a system for which conventional equilibrium simulations would be impractical: DNA origami 'handles' proposed for use in force spectroscopy experiments. Next, we simulate the forcible unravelling of three DNA origami structures, the largest systems yet studied with simulated force spectroscopy. We combine these results with experimental AFM data to probe the mechanical response of origami in unprecedented detail, highlighting the effect of nanostructure design on unfolding behaviour. Lastly, we examine the validity of using widely-employed polymer elastic models to predict internal entropic forces in ssDNA. We develop a framework for measuring internal forces in the oxDNA coarse-grained model and apply it to analyze the pico-Newton range forces exerted by a recently proposed DNA origami force clamp, ultimately concluding that conventional means of estimating internal ssDNA forces are often inaccurate and should be supplemented with coarse-grained simulations. In addition to providing new insights about the DNA systems we present, our results highlight the significant fruits of complementing experimental studies with coarse-grained simulations.
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Rozsypalová, Iva. "Stavebně technický průzkum objektu poškozeného požárem." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227489.
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Diploma thesis summarizes knowlegde related to the behavior of structures and material in the fire, focusing mainly on concrete and reinforced concrete structures. It deals with the design and implementation of diagnostic work of Building no. 103 in complex Svit Zlín affected by a large fire. There are presented evaluation of laboratory experiments of samples and static analysis.