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Zhao, Haibin. "Multisensor integration and discrete geometry processing for coordinate metrology." Cachan, Ecole normale supérieure, 2010. http://tel.archives-ouvertes.fr/tel-00451244/fr/.
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L'intégration de systèmes multi-capteurs est la réponse la plus adaptée aux besoins croissants en matière de complexité et d'exactitude de mesures en métrologie par coordonnées. Des efforts importants sont consacrés à développer des systèmes multi-capteurs qui permettent d'assurer une mesure globale de la géométrie avec une incertitude réduite. Cette thèse a pour objectif l'intégration de systèmes multi-capteurs en métrologie par coordonnées selon deux aspects: la modélisation des fonctions et des données et le traitement de la géométrie discrète. La modélisation des fonctions et des données permet une meilleure compréhension des exigences des fonctions du système et des spécifications des données pour l'intégration de systèmes multi-capteurs. Des modèles hiérarchiques fonctionnels du système sont construits en utilisant la méthodologie IDEF0 et sont décomposés en quatre activités de base. Une démarche à base d'ontologies est utilisée pour modéliser les différentes données et leur représentation structurée. Quatre domaines de données et de leurs relations sont spécifiés pour gérer les données multiples dans l'intégration des systèmes multi-capteurs. Des méthodes efficaces et robustes pour le traitement de la géométrie discrète dans le cadre de l'intégration multi-capteurs sont l'objet principal de cette thèse. Une estimation fiable de la normale et des courbures est essentielle pour le traitement des formes discrètes. Une méthode basée sur le tenseur de courbure est utilisée pour l'estimation des courbures discrètes. Une analyse comparative montre que la méthode proposée fournit de meilleures performances par rapport à d'autres méthodes existantesMultisensor integration systems are used to fulfill the increasing requirements on the complexity and accuracy of coordinate metrology. Significant efforts are being devoted to develop multisensor integration systems that achieve holistic geometrical measurement with reduced uncertainty. This thesis investigates on the achievement of multisensor integration in coordinate metrology from two main parts: system function and data modeling, and discrete geometry processing. System function and data modeling allow obtaining clear understanding of function requirements and data specification of the multisensor integration system. Hierarchical function models of the system are built using IDEF0 methodology, which are decomposed into four basic activities. An ontology based method is employed to model the various data in the system with structured representation. Four data domains and their inter-relationships are specified to manage the multiple data in multisensor integration system clearly. Efficient and robust methods for discrete geometry processing to support multisensor integration are the main focus of this dissertation. This requires efficient methods for discrete differential geometry properties estimation, registration of discrete shapes, shape recognition and segmentation. Reliable estimation of normal and curvatures is essential for discrete shapes processing. Most discrete geometry processing procedures are based on the normal and curvatures’ information. A tensor based method is used for discrete curvature estimation. The proposed method provides better performance according to a comparative analysis. Registration is one of the most important and decisive steps of multisensor integration. Registration algorithms enable to align the different point data captured in the respective sensor’s coordinate system. A registration method is proposed to align different discrete shapes with unknown correspondences. A combination of curvature information and Euclidean distance is used to improve the performances of the classical ICP algorithm. Discrete shape recognition and segmentation are required in many applications. A new method based on shape index and curvedness is developed. The local surface type of a vertex is recognized according to its shape index value. The vertices are then clustered according to their local surfaces. A connected region algorithm is then implemented to generate the segmentation results. Considerable cases are tested and the method provides satisfying results. The above methods have been implemented in a new computerized system called DSP-COMS. A detailed case study of an industrial workpiece digitized by laser scanning and touch probing is presented. The measured point data are then processed using DSP-COMS. The results show the robustness of the above methods
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Tråsdahl, Øystein. "High order methods for partial differential equations: geometry representation and coordinate transformations." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-17077.
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Li, Feng. "Integrated tactile-optical coordinate measurement for the reverse engineering of complex geometry." Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/23725/.
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Complex design specifications and tighter tolerances are increasingly required in modern engineering applications, either for functional or aesthetic demands. Multiple sensors are therefore exploited to achieve both holistic measurement information and improved reliability or reduced uncertainty of measurement data. Multi-sensor integration systems can combine data from several information sources (sensors) into a common representational format in order that the measurement evaluation can benefit from all available sensor information and data. This means a multi-sensor system is able to provide more efficient solutions and better performances than a single sensor based system. This thesis develops a compensation approach for reverse engineering applications based on the hybrid tactile-optical multi-sensor system. In the multi-sensor integration system, each individual sensor should be configured to its optimum for satisfactory measurement results. All the data measured from different equipment have to be precisely integrated into a common coordinate system. To solve this problem, this thesis proposes an accurate and flexible method to unify the coordinates of optical and tactile sensors for reverse engineering. A sphere-plate artefact with nine spheres is created and a set of routines are developed for data integration of a multi-sensor system. Experimental results prove that this novel centroid approach is more accurate than the traditional method. Thus, data sampled by different measuring devices, irrespective of their location can be accurately unified. This thesis describes a competitive integration for reverse engineering applications where the point cloud data scanned by the fast optical sensor is compensated and corrected by the slower, but more accurate tactile probe measurement to improve its overall accuracy. A new competitive approach for rapid and accurate reverse engineering of geometric features from multi-sensor systems based on a geometric algebra approach is proposed and a set of programs based on the MATLAB platform has been generated for the verification of the proposed method. After data fusion, the measurement efficiency is improved 90% in comparison to the tactile method and the accuracy of the reconstructed geometric model is improved from 45 micrometres to 7 micrometres in comparison to the optical method, which are validated by case study.
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Fields, Lisa Ann. "Use of Web-Based Technology to Enhance Instruction of Virginia's Seventh and Eighth Grade Geometry Standards of Learning." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etd/2087.
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The purpose of this thesis is to develop web-based modules for enhancing instruction of the geometry sections of the Virginia Standards of Learning in the seventh and eighth grades. While all of Virginia's seventh and eighth grade Standards of Learning strands are certainly worthy of these types of modules, geometry appeals to me most because of the vast amount of web-based resources that will be valuable when organized into modules. It is my hope that teachers of these grades will find this useful in their instruction of geometry.
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Soares, Júnior Luiz. "Sistemática para Garantia da Qualidade na Medição de Peças com Geometria Complexa e Superfície com Forma Livre Utilizando Máquina de Medir por Coordenadas." Universidade Federal da Paraíba, 2010. http://tede.biblioteca.ufpb.br:8080/handle/tede/5420.
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Parts with complex geometry and with free-form surface are of great interest in many industrial applications, either for functional or aesthetic issue. Its spread is due to advances in CAD / CAM systems and coordinate measuring technology. Despite technological advances, product design remains a major problem in industry. The problems range from design conception to those inherent in the manufacturing process and control, which are often discovered only in the product application phase. The dimensional variations of shape and surface texture are specified in the technical drawing using geometric and dimensional tolerance. To part with complex geometry variations are allowable tolerances specified by line and surface profile. Their control typically consists of a comparison of the coordinate points measured on the surface to the CAD model available. This paper contains a proposal to systematize procedures for quality assurance of measurement of parts with complex geometry and free-form surface by using coordinate measuring machines. The proposal was based on extensive study on the subject, the findings of problems revealed in visits to six companies that use technology to coordinate measurement and the results of case studies from a company in the automotive sector. The system focuses on the major sources of errors of coordinate measuring and proved easy to be applied in the selected company.
Peças com geometria complexa e superfície com forma livre são de grande interesse em muitas aplicações industriais, seja por questão funcional ou estética. Sua disseminação deve-se, em parte, aos avanços nos sistemas CAD/CAM e na tecnologia de medição por coordenadas. Apesar dos avanços tecnológicos, o projeto do produto continua sendo um dos maiores problemas da indústria. Os problemas vão desde a concepção do projeto até àqueles inerentes ao processo de fabricação e controle, que muitas vezes são descobertos somente na aplicação do produto. As variações dimensionais, de forma e de textura da superfície são especificadas no desenho técnico através de tolerância dimensional e geométrica. Para peça com geometria complexa as variações admissíveis são especificadas através de tolerâncias de perfil de linha e de superfície. O seu controle tipicamente consiste na comparação dos pontos coordenados medidos sobre a superfície com o modelo CAD disponível. Este trabalho contém uma proposta de sistematização de procedimentos para garantia da qualidade da medição de peças com geometria complexa e superfície com forma livre através de máquina de medir por coordenadas cartesianas. A proposta foi baseada no amplo estudo sobre o tema, nas constatações de problemas evidenciados nas visitas realizadas em seis empresas que utilizam a tecnologia de medição por coordenadas e nos resultados de estudos de casos realizados numa empresa do setor automotivo. A sistemática foca nas principais fontes de erros da medição por coordenadas e demonstrou ser de fácil aplicação na empresa selecionada.
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Turaça, Angélica. "As coordenadas de Fenchel-Nielsen." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/45/45132/tde-27082015-073617/.
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Nesta dissertação, definimos a geometria hiperbólica usando o disco de Poincaré (D2) e o semiplano superior (H2) com as respectivas propriedades. Além disso, apresentamos algumas funções e relações importantes da geometria hiperbólica; conceituamos as superfícies de Riemann, analisando suas propriedades e representações; estudamos o espaço de Teichmüller com a devida decomposição em calças. Esses temas são ferramentas necessárias para atingir o objetivo da dissertação: definir as coordenadas de Fenchel Nielsen como um sistema de coordenadas locais do espaço de Teichmüller Tg.In this dissertation, we defined the hyperbolic geometry using the Poincares disk (D2) and upper half-plane (H2) with its properties. Besides, we presented some functions and important relations of the hyperbolic geometry; we conceptualize the Riemann surfaces, analyzing its properties and representations; we studied the Teichmüller Space with proper decomposition pants. These themes are essential tools to reach the goal of the work: The definition of the Fenchel Nielsen coordenates as local coordinate system of the Teichmüller space Tg.
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Lidberg, Petter. "Barycentric and harmonic coordinates." Thesis, Uppsala universitet, Algebra och geometri, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179487.
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Soares, Vanessa Ribeiro. "Batalha naval e suas aplicações." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/5909.
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This work has the purpose contribute to the improvement in some teaching contents of analytic geometry and trigonometry in high school . The content work was based on the National Curriculum Parameters, highlighting de nitions, theorems and properties necessary for the development of student learning. The theme was chosen after a practical experience involving the Naval Battle game in order to reduce the students' di culties. The playful work, as the game, has a practical application that does the student become familiar with the content. That's an interesting way to propose problems and solutions involving the content. Thus becomes something attractive to the student and encourages creativity in nding problems solutions.
O trabalho tem como objetivo contribuir para o aprimoramento no ensino de alguns conteúdos de Geometria Analítica e Trigonometria no Ensino Médio. Dentro dos Parâmetros Curriculares Nacionais, trabalhamos o conteúdo destacando de nições, teoremas e propriedades necessárias para o desenvolvimento de aprendizagem do aluno. O tema foi escolhido depois de uma experiência prática envolvendo o jogo Batalha Naval a m de diminuir as di culdades dos alunos. O trabalho lúdico, como o jogo, tem uma aplicação prática que faz o aluno se familiarizar com os conceitos. É uma forma interessante de propor problemas e soluções envolvendo o conceitos. Assim se torna algo atrativo para o aluno e favorece a criatividade na busca de soluções para os problemas.
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White, Edward C. Jr. "Polar - legendre duality in convex geometry and geometric flows." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24689.
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Guimarães, Amanda Ribeiro. "Funções de Base Gaussianas Geradas pelo Método da Coordenada Geradora Aplicadas em Cálculos Quânticos Moleculares." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23102018-113531/.
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O conjunto de funções de base gaussianas, o p-GCHF, foi gerado para os átomos Na, Al, Si, P, S e Cl pelo Método da Coordenada Geradora (MCG) através da expansão integral polinomial para discretizar (DIP) as equações de Griffin-Hill-Wheeler-Hartree-Fock (GHW-HF). A base p-GCHF, de qualidade 7Z, foi contraída por meio do programa Contract que opera segundo os preceitos de contração de Davidson. O processo de contração resultou em 9 funções do tipos e 7 funções p para os átomos de Na e Mg e de 9 funções s e 8 funções p para os átomos de Al, Si, P, S e Cl. Expoentes de polarização foram gerados através do programa Polarization em nível CISD para os átomos de H, B, C, N, O, F, Na, Mg, Al, Si, P, S e Cl. Foram necessários não mais do que 2p1d expoentes de polarização para compor a base p-GCHF para o átomo de H, 2d1f para os átomos da primeira fila e 3d2f, para os átomos da segunda fila da tabela periódica. Cálculos moleculares revelaram que a base p-GCHF é competitiva em energia com as bases cc-pVQZ e cc-pV5Z, entretanto apresentando custos computacionais bem menores que as mencionadas bases de Dunning. Análises das frequências vibracionais e das geometrias de otimização dos pontos estacionários, tanto mínimos quanto de estado de transição, também apontam similaridades entre o conjunto de base p-GCHF e a base cc-pVQZ, porém com diferenças de tempos de CPU que apontam a base gerada pelo MCG como computacionalmente vantajosa. Um conjunto de base capaz de descrever um dado sistema de maneira equivalente à célebres conjuntos de base da literatura, mas trazendo consigo o benefício da economia de tempo computacional é absolutamente oportuno principalmente àqueles que têm como objeto de estudo moléculas com um número considerável de átomos.The gaussian basis sets p-GCHF was generated for a set of atoms from Na to Cl through the Generator Coordinate Method (GCM) based on a polynomial integral expansion to discretize the Griffin-Wheeler-Hartree-Fock equations. The p-GCHF is a 7z type basis sets and was contracted through the Contract program which works based on the Davidson\'s contraction model. The contraction process provided a set of 9s7p functions for Na and Mg atoms and 9s8p functions for Al, Si, P, S e Cl atoms. Polarizations exponents were acquired through the Polarization program at CISD level of theory for H, B, C, N, O, F, Na, Mg, Al, Si, P, S e Cl atoms. No more than 2p1d polarization exponents were necessary to compose the p-GCHF basis set for hydrogen atom, 2d1f for the first row of the periodic table and 3d2f for the second row one. Molecular calculations show that p-GCHF works like cc-pVQZ and cc-pV5Z basis sets but with less computational cost than the Dunning\'s ones. Vibrational frequency analysis and optimization geometry to the stationary points minimum as well as transition state, revealed similarities between p-GCHF and cc-pVQZ basis sets, but again with the GCM basis sets being computationally advantageous. A basis sets capable to describe a system like the main gaussian basis sets known in the literature but demanding less computational effort is very helpful above all for those who work with massive molecular systems.
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Suma, Christopher G. "Parallel Coordinates Diagram Implementation in 3D Geometry." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1542590859588961.
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Sloupenský, Zdeněk. "Návrh odstředivého čerpadla metodami diferenciální geometrie." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-233958.
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This thesis deals with a new approach to the design of impeller, blade and spiral of centrifugal pump. The mathematic model of flow inside meridional section of impeller and spiral is based on the instruments of differential geometry applied to Bezier surfaces. This formerly introduced theory is more deeply developed in this thesis and the conclusions are applied to the design of centrifugal pump parts working with fluid. The main thesis output is the mathematic model and on its principles created software determined for the design of impeller, blade and spiral. The received results are exportable into one of the commonly used 3D modeling programs.
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Gong, Shengjun, and 龔勝軍. "Linear coordinates, test elements, retracts and automorphic orbits." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40988065.
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Gong, Shengjun. "Linear coordinates, test elements, retracts and automorphic orbits." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40988065.
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Silva, Francisco Allan Quintela. "Geometric coordinates parametric functions in winplot." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12408.
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nÃo hÃDesde o princÃpio, as sequÃncias e sÃries numÃricas geraram interesse entre os matemÃticos. Sua aplicabilidade atual à extensa e inclui o cÃlculo refinado da Ãrea da superfÃcie e do volume de uma variedade de sÃlidos. Neste trabalho usaremos as diferenÃas entre os elementos de uma sequÃncia finita a fim de encontrar leis que expressem as tendÃncias nela contidas. Veremos tambÃm como um estudo simples sobre progressÃes aritmÃticas de ordens diversas à capaz de fornecer funÃÃes paramÃtricas de curvas passando por pontos prÃ-definidos, de superfÃcies contendo curvas prÃ-definidas ou, atà mesmo, de regiÃes do R situadas entre duas superfÃcies dadas. AlÃm disso, poderemos, com o auxÃlio do programa computacional Winplot, visualizar as curvas, superfÃcies ou regiÃes obtidas em cada exemplo de nosso estudo, alÃm de, eventualmente, verificar pontos de mÃximo e mÃnimo relativos de uma curva ou calcular a Ãrea de uma superfÃcie e o volume de uma regiÃo limitada do RÂ, tudo isto com um devido e prÃvio embasamento teÃrico.
From the beginning, the numeric sequences and series generated interest among mathematicians. Your present applicability is extensive and includes the refined calculation of the surface area and volume of a variety of solids. In this work we will use the differences between the elements of a finite sequence in order to find laws that express the trends contained therein. We will also see how a simple study about arithmetic progressions of various orders is able to provide curves's parametric functions through predefined points, of surfaces containing predefined curves or even regions of the RÂ localized between two given surfaces. Moreover, we will can, with the aid of the computational program Winplot, visualize the curves, surfaces, or regions obtained in each example of our study, in addition to eventually check points of relative maximum and minimum of a curve or calculate the area of a surface and the volume of a limited region of RÂ, all of this with a necessary and previous theoretical background.
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Yan, Zhongcheng. "Geometric tolerance evaluation and uncertainty analysis for coordinate metrology." Connect to resource, 1994. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1243616513.
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Di, Giacomo Benedito. "Computer aided calibration and hybrid compensation of geometric errors in coordinate measuring machines." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306885.
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Harris, John O. Spence Allan D. "Geometric and quasi-static thermal error compensation of a laser digitizer on a coordinate measuring machine." *McMaster only, 2004.
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Sozak, Ahmet. "Uncertainty Analysis Of Coordinate Measuring Machine (cmm) Measurements." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608887/index.pdf.
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In this thesis, the measurement uncertainty of Coordinate Measuring Machine
(CMM) is analysed and software is designed to simulate this. Analysis begins with
the inspection of the measurement process and structure of the CMMs. After that,
error sources are defined with respect to their effects on the measurement and then an
error model is constructed to compensate these effects. In other words, systematic
part of geometric, kinematic and thermal errors are compensated with error
modelling. Kinematic and geometric error model is specific for the structure of
CMM under inspection. Also, a common orthogonal kinematic model is formed and
with using the laser error data of the CMM and error maps of the machine volume is
obtained. Afterwards, the models are compared with each other by taking the
difference and ratio.
The definition and compensation of the systematic errors leave the uncertainty
of measurements for analysing. Measurement uncertainty consists of the
uncompensated systematic errors and random errors. The other aim of the thesis is to
quantify these uncertainties with using the different methods and to inspect the
success of these methods. Uncertainty budgeting, comparison, statistical evaluation
by designing an experiments and simulation methods are examined and applied to
the CMM under inspection. In addition, Virtual CMM software is designed to simulate the task specific measurement uncertainty of circle, sphere and plane
without using the repeated measurements. Finally, the performance of the software, highly depending on the
mathematical modelling of machine volume, is tested by using actual measurements.
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Glenn, Bradley C. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127225590.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 178 p.; also includes graphics (some col.). Includes bibliographical references (p. 153-158). Available online via OhioLINK's ETD Center
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Glenn, Bradley Charles. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1127225590.
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German, Brian Joseph. "A Riemannian Geometric Mapping Technique for Identifying Incompressible Equivalents to Subsonic Potential Flows." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14623.
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This dissertation presents a technique for the solution of incompressible equivalents to planar steady subsonic potential flows. Riemannian geometric formalism is used to develop a gauge transformation of the length measure followed by a curvilinear coordinate transformation to map a subsonic flow into a canonical Laplacian flow with the same boundary conditions. The method represents the generalization of the methods of Prandtl-Glauert and Karman-Tsien and gives exact results in the sense that the inverse mapping produces the subsonic full potential solution over the original airfoil, up to numerical accuracy. The motivation for this research was provided by the analogy between linear potential flow and the special theory of relativity that emerges from the invariance of the wave equation under Lorentz transformations. Whereas elements of the special theory can be invoked for linear and global compressibility effects, the question posed in this work is whether other techniques from relativity theory could be used for effects that are nonlinear and local. This line of thought leads to a transformation leveraging Riemannian geometric methods common to the general theory of relativity. The dissertation presents the theory and a numerical method for practical solutions of equivalent incompressible flows over arbitrary profiles. The numerical method employs an iterative approach involving the solution of the incompressible flow with a panel method and the solution of the coordinate mapping to the canonical flow with a finite difference approach. This method is demonstrated for flow over a circular cylinder and over a NACA 0012 profile. Results are validated with subcritical full potential test cases available in the literature. Two areas of applicability of the method have been identified. The first is airfoil inverse design leveraging incompressible flow knowledge and empirical data for the potential field effects on boundary layer transition and separation. The second is aerodynamic testing using distorted models.
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Silva, Diego Maradona Félix da. "A hipérbole e suas aplicações." Universidade Federal de Goiás, 2013. http://repositorio.bc.ufg.br/tede/handle/tede/3442.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The Hyperbole and its Applications begins with a brief historical background on the origins of the conic sections analysis, followed by a proposition of a new approach to the conic sections studies in High School, due to the large amount of important applications these studies have in everyday life. The rst chapter of the research presents the primary concepts necessary to a good hyperbole study understanding. After presenting this concepts the research focuses in the evidence of the hyperbole concept, its most important elements, the rotary axis and the hyperbole properties. Among these properties, the main object of this study is the re ective hyperbole property, since it can be applied to many elds of study such as Astronomy, in the Telescopes and even Navigations. Some other properties are brie y mentioned during this work and others have a more detailed approach. Finally, a largely used new coordinates system is presented - the Polar Coordinate System. The research purpose is to infer, by the use of this new system, the equations of the ellipse, parable and hyperbole.
A Hipérbole e suas Aplicações inicia-se com um breve contexto histórico sobre o qual se originou o estudo das cônicas e propõe uma abordagem diferenciada para o estudo de cônicas no Ensino Médio devido a grande quantidade de aplicações importantes das propriedades das cônicas no cotidiano. O primeiro capítulo do trabalho trata-se dos conceitos preliminares para um bom estudo da hipérbole. Logo em seguida apresentamos o conceito de hipérbole, seus principais elementos, rotação de eixos e propriedades da hipérbole. Dentre essas propriedades, o principal objeto de estudo será a propriedade re etora da hipérbole, pois é esta que tem aplicações nos mais variados ramos da ciência tal como Astronomia, nos telescópios e na navegação. Algumas aplicações serão citadas brevemente e outras abordadas com mais detalhes. Finalizando, apresentaremos um novo sistema de coordenadas também muito utilizado: o sistema de Coordenadas Polares e adotando esse novo sistema, deduzir as equações da elipse, parábola e hipérbole.
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Ferreira, Lucas Santos Silva. "Parametrizações e transformações afins planares." Universidade Federal de Sergipe, 2014. https://ri.ufs.br/handle/riufs/6505.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESThis thesis aims to present aspects of parametric equations and planar a ne transformations that can be exploited in basic education. With respect to parameterizations we present a succession of elementary examples and make the comparison between the parametric and Cartesian equations - highlighting the advantages of using one over the other. Furthermore, we discussed the process of obtaining the Cartesian equations from parametric and importance of this type of equations for physics. With respect to a ne transformations our interest is to look at them from the perspective of Felix Klein program, in which a geometry is classi ed as a set of objects on the action of a group set. We emphasize some special transformations and their importance in the generation of the a nity group and the implementation of coordinated of change process. We emphasize that we have not aimed this work to be fully applied as teaching materials for elementary education, what we want is it to be a provocateur to the teacher researcher instinct .
A presente disserta c~ao tem como objetivo apresentar aspectos das equa c~oes param etricas e das transforma c~oes a ns planares que podem ser explorados no ensino b asico. No que diz respeito as parametriza c~oes apresentamos uma sucess~ao de exemplos elementares e fazemos a compara c~ao entre as equa c~oes param etricas e as cartesianas - destacando as vantagens de usar uma em detrimento da outra. Al em disso, discutimos sobre o processo de obter as equa c~oes cartesianas a partir das param etricas e a import^ancia dessa modalidade de equa c~oes para a f sica. No que se refere as transforma c~oes a ns nosso interesse e olhar para elas segundo a perspectiva do programa de Felix Klein, onde uma geometria e classi cada como um conjunto de objetos sobre a a c~ao de um grupo xado. Enfatizamos algumas transforma c~oes especiais e a import^ancia das mesmas na gera c~ao do grupo de a nidades e na implementa c~ao do processo de mudan ca de coordenadas. Ressaltamos que n~ao temos como objetivo que essa material seja totalmente aplicado como material did atico para o ensino b asico, o que desejamos e que ele seja um provocador ao instinto pesquisador do professor.
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SILVA, Patrício José Félix da. "Referenciais não-inerciais no Espaço-Tempo de Minkowski." Universidade Federal de Campina Grande, 2009. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1453.
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Capes
Um sistema de coordenadas tem a função de localizar os eventos do espaço-tempo com respeito a um sistema de referência. A construção do sistema de coordenadas depende crucialmente da noção de simultaneidade associada ao referencial. No entanto, não existe uma maneira natural, ou privilegiada, de definir simultaneidade para referenciais não inerciais, mesmo no espaço-tempo de Minkowski. Cada procedimento conduz a diferentes sistemas de coordenadas. Neste trabalho, discutimos alguns métodos bem conhecidos da literatura especializada. Estudamos as coordenadas de Rindler, de Fermi-Walker, as coordenadas de Radar e as coordenadas de Emissão (ou GPS). O sistema de coordenadas de Rindler é um dos sistemas de grande destaque porque permite simular algumas propriedades da geometria do Buraco Negro num espaço-tempo plano. As coordenadas de Rindler estão associadas a uma família de observadores uniformemente acelerados que obedecem à relação a=1/ρ, onde a é a aceleração própria do observador e ρ a sua posição inicial com respeito a algum sistema de referência inercial. Neste trabalho, propomos um método para construção de sistemas de coordenadas adaptados a observadores cuja a celeração depende da posição inicial segundo a regra a=a0/ρn, onde n ∈ N e a0 é uma constante, usando o princípio da localidade. O caso n = 1 recupera as coordenadas de Rindler. Os outros casos nos permitem discutir a relação entre a geometria não-Euclidiana das secções espaciais e referenciais acelerados,como originariamente proposto por Einstein. Além disso, com a generalização podemos simular o comportamento de observadores estáticos tanto nas proximidades do horizonte de um Buraco Negro (n=1) quanto em regiões afastadas (n=2).
The main role of a coordinate systein is to localize the event-s of spacetime with respect to a frame of reference. The construetion of a coordinate systein depeuds crucially on the notíon of simultaneity associated to the frame of reference. However, there is no natural manner of defining simultaneity adapted to non-inertial frames of reference, even in the case of Minkowski spacetime. Each procedure leads to different coordinate systems. In thls work. we discuss some well-known methods found in the Literatura. We study the Rindler coordinates. Fermi-Walker coordinates. Radar coodinadates and Emission (or GPS) coordinates. The system of Rindler coordinates has great interest because it simulates in a flat spacetime some aspects of a Black Hole's geometry. We can say that Rindler coordinates are adapted to a family of uniformly accelerated observeis which obey the relatiou a = i, where a is the proper acceieration and p is the initial position with respect to some inertial system. In this work, we also propose a method in order to construct coordinate systems adapted to observers whose accelerations depend on the initial position according to the formula a = where n e N and a» is a constant, by using the locality principie. The case TI = 1 reproduces the Rindler coordinates. The other cases allow us to verify a connection between non-Euciideaii geometry of the spatial sections and non-inertial frames of reference, as it was originally suggested by Einstein. With this generalization we can also simulate the behavior of static observers in the vicinity of a Black Hole"s Horizon (TI = 1) and also in distant regions (n - 2)
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Pereira, Flávia de Ávila. "Aprendizagem de tópicos de uma geometria em ambiente logo : uma proposta didática para os anos finais do ensino fundamental." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/86265.
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Este trabalho apresenta uma proposta didática desenvolvida em uma escola da Rede Adventista de Educação no município de Cachoeirinha, que utilizou a linguagem LOGO em aulas de Matemática. O experimento prático, realizado com estudantes do sétimo ano do Ensino Fundamental e respaldado pelas teorias de Seymour Papert e Gèrard Vergnaud, buscou responder à seguinte questão: Como a utilização do ambiente LOGO auxilia na aprendizagem dos conceitos de Ângulos e Coordenadas Cartesianas, estudados durante o Ensino Fundamental? Outras investigações envolvendo a utilização da linguagem LOGO são mencionadas, bem como suas influências para o trabalho. A partir dos dados analisados qualitativamente, observou-se um crescente interesse pelo estudo dos tópicos de Geometria e um avanço nas elaborações de estratégias de soluções de problemas. Ao final deste trabalho, encontra-se a sequência didática elaborada e aplicada, produto desta dissertação.This dissertation presents a didactic proposal developed in a school of Adventist Education in the city of Cachoeirinha, which used the LOGO language in Mathematic classes. The practical experiment was conducted with students in the seventh grade of elementary school and supported by the theories of Seymour Papert and Gerard Vergnaud, and tried to answer the following question: How the use of the LOGO environment can help the learning of the concepts of angles and Cartesian Coordinates, which were studied during elementary school? Further investigations involving the use of LOGO language are mentioned, as well as their influences for this paper. From the qualitatively analyzed data, it was noticed a growing interest in the study of topics of Geometry and an improvement in the elaboration of strategies for problem solving. At the final of this work, we can find the didactic sequence, made and applied, product of this dissertation.
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Polách, Ondřej. "Prostorové rozšíření objektové databáze." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2012. http://www.nusl.cz/ntk/nusl-236607.
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Still increasing requirements are made on database systems, because users need to work with still more complex data. Because of the historical development of database systems, post-relational database systems are mainly used today. As follows from their name, post-relational database systems are built on relational database systems and expand them so that they are able to work with complex data. The vast majority of today's spatial database systems is based on post-relational databases. However, this work is trying to find a connection between object and spatial databases. The obtained knowledge is reflected in the implementation of the object database spatial extension.
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Duong, Nam duong. "Hybrid Machine Learning and Geometric Approaches for Single RGB Camera Relocalization." Thesis, CentraleSupélec, 2019. http://www.theses.fr/2019CSUP0008.
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Au cours des dernières années, la relocalisation de la caméra à base d'images est devenue un enjeu important de la vision par ordinateur appliquée à la réalité augmentée, à la robotique ainsi qu'aux véhicules autonomes. La relocalisation de la caméra fait référence à la problématique de l'estimation de la pose de la caméra incluant à la fois la translation 3D et la rotation 3D. Dans les systèmes de localisation, le composant de relocalisation de la caméra est nécessaire pour récupérer la pose de la caméra après le suivi perdu, plutôt que de redémarrer la localisation à partir de zéro.Cette thèse vise à améliorer les performances de la relocalisation de la caméra en termes de temps d'exécution et de précision ainsi qu'à relever les défis de la relocalisation des caméras dans des environnements dynamiques.Nous présentons l'estimation de la pose de la caméra basée sur la combinaison de la régression de pose multi-patch pour surmonter l'incertitude des méthodes d'apprentissage profond de bout en bout. Afin d'équilibrer la précision et le temps de calcul de la relocalisation de la caméra à partir d'une seule image RVB, nous proposons une méthode hybride à caractéristiques éparses. Une meilleure prédiction dans la partie d’apprentissage automatique de nos méthodes conduit à une inférence rapide de la pose de la caméra dans la partie géométrique. Pour relever le défi des environnements dynamiques, nous proposons une forêt de régression adaptative qui s'adapte en temps réel au modèle prédictif. Il évolue en partie au fil du temps sans qu'il soit nécessaire de ré-entrainer le modèle entier à partir de zéro. En appliquant cet algorithme à notre relocalisation de la caméra en temps réel et précise, nous pouvons faire face à des environnements dynamiques, en particulier des objets en mouvement. Les expériences prouvent l'efficacité des méthodes que nous proposons. Notre méthode permet d'obtenir des résultats aussi précis que les meilleures méthodes d’état de l’art. De plus, nous obtenons également une grande précision même sur des scènes dynamiquesIn the last few years, image-based camera relocalization becomes an important issue of computer vision applied to augmented reality, robotics as well as autonomous vehicles. Camera relocalization refers to the problematic of the camera pose estimation including both 3D translation and 3D rotation. In localization systems, camera relocalization component is necessary to retrieve camera pose after tracking lost, rather than restarting the localization from scratch.This thesis aims at improving the performance of camera relocalization in terms of both runtime and accuracy as well as handling challenges of camera relocalization in dynamic environments. We present camera pose estimation based on combining multi-patch pose regression to overcome the uncertainty of end-to-end deep learning methods. To balance between accuracy and computational time of camera relocalization from a single RGB image, we propose a sparse feature hybrid methods. A better prediction in the machine learning part of our methods leads to a rapid inference of camera pose in the geometric part. To tackle the challenge of dynamic environments, we propose an adaptive regression forest algorithm that adapts itself in real time to predictive model. It evolves by part over time without requirement of re-training the whole model from scratch. When applying this algorithm to our real-time and accurate camera relocalization, we can cope with dynamic environments, especially moving objects. The experiments proves the efficiency of our proposed methods. Our method achieves results as accurate as the best state-of-the-art methods on the rigid scenes dataset. Moreover, we also obtain high accuracy even on the dynamic scenes dataset
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Stålberg, Martin. "Reconstruction of trees from 3D point clouds." Thesis, Uppsala universitet, Avdelningen för systemteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-316833.
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The geometrical structure of a tree can consist of thousands, even millions, of branches, twigs and leaves in complex arrangements. The structure contains a lot of useful information and can be used for example to assess a tree's health or calculate parameters such as total wood volume or branch size distribution. Because of the complexity, capturing the structure of an entire tree used to be nearly impossible, but the increased availability and quality of particularly digital cameras and Light Detection and Ranging (LIDAR) instruments is making it increasingly possible. A set of digital images of a tree, or a point cloud of a tree from a LIDAR scan, contains a lot of data, but the information about the tree structure has to be extracted from this data through analysis. This work presents a method of reconstructing 3D models of trees from point clouds. The model is constructed from cylindrical segments which are added one by one. Bayesian inference is used to determine how to optimize the parameters of model segment candidates and whether or not to accept them as part of the model. A Hough transform for finding cylinders in point clouds is presented, and used as a heuristic to guide the proposals of model segment candidates. Previous related works have mainly focused on high density point clouds of sparse trees, whereas the objective of this work was to analyze low resolution point clouds of dense almond trees. The method is evaluated on artificial and real datasets and works rather well on high quality data, but performs poorly on low resolution data with gaps and occlusions.
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CORREIA, Balbina Raquel de Brito. "Simulação de reservatórios de petróleo com geometria complexa via método dos volumes finitos e coordenadas generalizadas." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/512.
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A simulação numérica é uma ferramenta utilizada para modelar e estudar reservatórios de petróleo de forma a auxiliar na aplicação de métodos de recuperação suplementar. A injeção de água é o método mais utilizado na recuperação de óleo, devido ao baixo custo de processo, a disponibilidade da água e aos mecanismos de manutenção da pressão e deslocamento de óleo. O presente estudo objetivou estudar o escoamento de óleo e água em um reservatório de óleo pesado, homogêneo, com características do Nordeste brasileiro e modelagem do tipo Black oil, de formato irregular, com o intuito de avaliar o comportamento do reservatório e previsão da recuperação de óleo com a aplicação de injeção isotérmica de água. Para tanto, foi utilizado um simulador numérico, em linguagem C++, com solução das equações governantes pelo método dos volumes finitos e uso de coordenadas generalizadas, a partir de 30 anos de injeção de água, para estudar parâmetros de reservatório e operacionais e avaliar sua influência na recuperação de óleo. Foram realizadas simulações para deliberar sobre a malha do reservatório, estudo do passo de tempo mínimo utilizado nas simulações e efeito de diferentes valores de pressão inicial do reservatório. Dessa forma, foi definida uma malha com 100x50 volumes elementares e o modelo five-spot invertido para avaliar a influência de diferentes valores de permeabilidade absoluta da rocha, grau API do óleo e diferentes vazões de injeção de água, na recuperação de óleo. Foram realizadas análises da localização de poços na malha, a partir da distância entre poços injetores e produtores. A partir dos casos estudados e por meio de gráficos de Volume Poroso Injetado (VPI) versus Volume Poroso de Óleo Recuperado (VPOR), gráficos de Corte de água no tempo e mapas de saturação de água e pressão na formação produtora, ao longo tempo, foi identificado que, no processo de injeção de água, o aumento da permeabilidade absoluta influenciou negativamente e o aumento da vazão de injeção influenciou positivamente a recuperação do óleo, enquanto que o grau API não mostrou influência significativa. Em síntese, com o estudo da alocação dos poços na malha, verificou-se que os poços produtores mais distantes dos poços injetores apresentaram melhores resultados de recuperação de óleo e menor produção de água, pois, o aumento da vazão e a proximidade dos poços, aliada a maiores permeabilidades absoluta da rocha reservatório permitem a ocorrência de fingers viscosos e Breakthrough precoce, fenômenos que reduzem a eficiência do processo de injeção de água.
Numerical simulation is a tool used for modeling and studying oil reservoirs in order to aid in applying additional recovery methods. Water injection is the most common method used in oil recovery due to the low cost process, the availability of water and pressure maintenance and oil displacement mechanisms. This study aimed to study the flow of oil and water in a homogeneous heavy oil reservoir, with Brazilian Northeast characteristics and black oil model, of irregularly form, with the purpose of evaluate the reservoir behavior and prediction of oil recovery due to application of the isothermal water injection. Thus, it was used a numerical simulator, in C++ code, with solution of the governing equations by the finite volume method and the use of generalized coordinates, from 30 years of water injection to study reservoir and opertaing parameters to assess into oil recovery influence. Simulations were accomplished to deliberate on the mesh of the reservoir, minimum time step of the study used in simulations and effects of different initial pressure values of the reservoir. A mesh with 100x50 elementary volumes was defined and inverted five-spot model to evaluate the influence of different absolute values of permeability rock, oil API gravity and different flow rates of water injection on the oil recovery. Wells location analyzes were conducted in the mesh, considering the distance between injection and producers wells. Based on the case studies and using graphs Volume Porous Injected (VPI) and Volume Porous Recovered oil (VPOR), water cut graphs, in time, and reservoir pressure and water saturation maps, over time, it was identified that the water injection process, the absolute permeability increasing have influenced negatively and injection flow rate increased have influenced positively on the oil recovery, while the API gravity has not shown significant influence. In conclusion, it was identified, with the study of allocation of wells in the mesh, that most distance form producing wells of injection wells showed better results on the oil recovery and and reduced water production, therefore, with increasing the flow rate and the proximity of the wells, it combined with larger absolute permeabilities of the reservoir rock, has allowed the occurrence of viscous fingers and early Breakthrough, phenomena which reduce the efficiency of the water injection process.
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Alcantara, Priscila Rodrigues de. "Hypersurfaces with prescribed mean curvature in Riemannian manifolds." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5278.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorThis work shows results existence and uniqueness of graphs with prescribed mean curvature. We demonstrate that a natural fixation Dirichlet problem for graphs of average curvature is required to consider those graphs like leaves on a Riemannian submersion Killing transversal cylinder, the cylinder given by flow lines of a Killing vector field. Using this approach, we are able to solve the problem in a way more comprehensive, giving a unified proof and existence results.
O objetivo deste trabalho à exibir resultados de existÃncia e unicidade de grÃficos com curvatura mÃdia prescrita. Demonstraremos que uma fixacÃo natural do problema de Dirichlet para grÃficos de curvatura mÃdia prescrita à considerar esses grÃficos como folhas em uma submersÃo Riemanniana transversal ao cilindro de Killing, isto Ã, ao cilindro dado pelas linhasde fluxo de um campo de vetores de Killing. Usando essa aproximaÃÃo, somos capazes de resolver o problema em um modo mais compreensivo, dando uma prova unificada e resultados de existÃncia para uma ampla gama do ambiente de variedades Riemannianas.
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Dvořáček, Jan. "Analýza silového zatížení řezného nástroje při pětiosém frézování." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228829.
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The diploma thesis is focused on machining using the ball-end shank mill. Content of the preliminary part of the work is a shank mill characteristic and a consequent part shows a splitting of ball-end milling cutters, its application, the cutting tool geometry and a characteristic signs of machining. The cutting force model of the ball-end mill is presented as well. A part of proposed model is the conversion of the resultant force too. Practical part is aimed at cutting force analysis of the ball-end mill and the main purpose of this part is a quantification of the cutting force for different work piece tilt angles while milling is performed.
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Lahsen-Cherif, Iyad. "Spectral and Energy Efficiency in 5G Wireless Networks." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS506/document.
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La pénurie d'énergie et le manque d'infrastructures dans les régions rurales représentent une barrière pour le déploiement et l'extension des réseaux cellulaires. Les approches et techniques pour relier les stations de base (BSs) entre elles à faible coût et d'une manière fiable et efficace énergiquement sont l'une des priorités des opérateurs. Ces réseaux peu denses actuellement, peuvent évoluer rapidement et affronter une croissance exponentielle due principalement à l'utilisation des téléphones mobiles, tablettes et applications gourmandes en bande passante. La densification des réseaux est l'une des solutions efficaces pour répondre à ce besoin en débit élevé. Certes, l'introduction de petites BSs apporte de nombreux avantages tels que l'amélioration du débit et de la qualité du signal, mais entraîne des contraintes opérationnelles telles que le choix de l'emplacement des noeuds dans ces réseaux de plus en plus denses ainsi que leur alimentation. Les problèmes où la contrainte spatiale est prépondérante sont bien appropriés à la modélisation par la géométrie stochastique qui permet une modélisation réaliste de distribution des BSs. Ainsi, l'enjeu est de trouver de nouvelles approches de gestions d'interférence et de réductions de consommation énergétique dans les réseaux sans fil. Le premier axe de cette thèse s'intéresse aux méthodes de gestion d'interférence dans les réseaux cellulaires se basant sur la coordination entre les BSs, plus précisément, la technique Coordinated MultiPoint Joint Transmission (CoMP-JT). En CoMP-JT, les utilisateurs en bordure de cellules qui subissent un niveau très élevé d'interférences reçoivent plusieurs copies du signal utile de la part des BSs qui forment l'ensemble de coordination. Ainsi, nous utilisons le modèle r-l Square Point Process (PP) à fin de modéliser la distribution des BSs dans le plan. Le processus r-l Square PP est le plus adapté pour modéliser le déploiement réel des BSs d'un réseau sans fil, en assurant une distance minimale, (r - l), entre les points du processus. Nous discutons l'impact de la taille de l'ensemble de coordination sur les performances évaluées. Ce travail est étendu pour les réseaux denses WiFi IEEE 802.11, où les contraintes de portées de transmission et de détection de porteuse ont été prises en compte. Dans le deuxième axe du travail, nous nous intéressons à l'efficacité énergétique des réseaux mesh. Nous proposons l'utilisation des antennes directionnelles (DAs) pour réduire la consommation énergétique et améliorer le débit de ces réseaux mesh. Les DAs ont la capacité de focaliser la transmission dans la direction du récepteur, assurant une portée plus importante et moins d'énergie dissipée dans toutes les directions. Pour différentes topologies, nous dérivons le nombre de liens et montrons que ce nombre dépend du nombre de secteurs de l'antenne. Ainsi, en utilisant les simulations, nous montrons que le gain, en énergie et en débit, apporté par les DAs peut atteindre 70% dans certains cas. De plus, on propose un modèle d'optimisation conjointe d'énergie et du débit adapté aux réseaux WMNs équipés de DAs. La résolution numérique de ce modèle conforte les résultats de simulation obtenus dans la première partie de cette étude sur l'impact des DAs sur les performances du réseau en termes de débit et d'énergie consommée. Ces travaux de thèse s'inscrivent dans le cadre du projet collaboratif (FUI16 LCI4D), qui consiste à concevoir et à valider une architecture radio ouverte pour renforcer l'accès aux services broadband dans des lieux ne disposant que d'une couverture minimale assurée par un réseau macro-cellulaire traditionnelToday's networks continue to evolve and grow resulting more dense, complex and heterogeneous networks.This leads to new challenges such as finding new models to characterize the nodes distribution in the wireless network and approaches to mitigate interference. On the other hand, the energy consumption of WMNs is a challenging issue mainly in rural areas lacking of default electrical grids. Finding alternative technologies and approaches to reduce the consumed energy of these networks is a interesting task. This thesis focuses on proposing and evaluating interference management models for next generation wireless networks (5G and Very Dense High WLANs), and providing tools and technologies to reduce energy consumption of Wireless Mesh Networks (WMNs). Two different problems are thus studied; naturally the thesis is divided into two parts along the following chapters.The contribution of the first part of the thesis is threefold. Firstly, we develop our interference management coordination (CoMP-JT) model. The main idea of CoMP-JT is to turn signals generating harmful interference into useful signals. We develop a new model where BSs inside the coordinated set send a copy of data to border's users experiencing high interference. We consider the r-l Square point process to model the BSs distribution in the network. We derive network performance in terms of coverage probability and throughput. Additionally, we study the impact of the size of coordination set on the network performance. Secondly, we extend these results and provide a new model adopted for Dense Very high throughput WLANs. We take into consideration constraints of WLANs in our model such as carrier sensing range. Thirdly, we tackle resource allocation strategies to limit the interference in LTE networks. We study three cyclic allocation strategies: (i) the independent allocation, (ii) the static allocation and (iii) the load-dependent strategy. We derive tractable analytical expression of the first and second mean of interference. We validate the model using extensive simulations. Reducing the energy consumption and improving the energy efficiency of WMNs is our concern in the second part of the thesis. Indeed, we aim at studying the impact of directional antennas technology on the performance of WMNs, using both analysis and simulations. Fisrt, We derive the Number of Links (NLs) for the chain and grid topologies for different antennas beams. These results are based on the routing tables of nodes in the network. We consider different scenarios such as 1Source-NDestinations to model the downlink communications, NSources-1Destination to model the uplink communications and the 1Source-1Destination as a baseline scenario. Using ns-3 simulator, we simulate network performance in terms of Mean Loss Ratio, throughput, energy consumption and energy efficiency. Then, we study the impact of number of beams, network topology and size, the placement of the gateway on the network performance. Next, we go beyond simulations and propose an optimization framework minimizing the consumed energy while maximizing the network throughput for DAs WMNs. We consider a weighted objective function combining the energy consumption and the throughput. We use power control to adapt transmission power depending on the location of the next hop. This model is a first step to approve the obtained simulation results. We use ILOG Cplex solver to find the optimal solution. Results show that DAs improves the network throughput while reduce the energy consumption and that power control allows saving more energy. In this direction, the LCI4D Project aims at providing low cost infrastructure to connect isolated rural and sub-urban areas to the Internet. In order to reduce the installation and maintenance costs, LCI4D proposes the usage of self-configured Wireless Mesh Networks (WMNs) to connect multimode outdoor femtocells to the remote Marco cell (gateway)
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Flores, Fabricio Jesus. "Medição do tipo passa-não passa em máquina de medir a três coordenadas." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-20032017-103759/.
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A fabricação de produtos cada vez melhores é fator imperativo, pois sob o ponto de vista dos fabricantes, maior fatia do mercado, maiores lucros, e para o consumidor produtos de melhor desempenho, maior vida útil, maior compacticidade, ou seja, qualidade. Por sua vez, garantir esta qualidade exige uma definição adequada das características do produto, obrigando o mundo tecnológico a investir na procura por melhores meios de controle dimensional. A tendência pelo aumento da qualidade dos produtos faz surgir a necessidade de se construir ou aperfeiçoar sistemas de medição que possam avaliar com grande rapidez e acuracidade as mais diversas características dimensionais. O objetivo deste trabalho é implementar um sistema informatizado que permita simular calibradores do tipo Passa-Não Passa em uma Máquina de Medir a Três Coordenadas (MM3C) do tipo Ponte Móvel. Cabe destacar que a grande vantagem do sistema proposto consiste na flexibilidade que se tem nas mudanças das características geométricas de cada calibrador. Com pequenas alterações no programa computacional pode-se modificar tolerâncias, diâmetros e qualidades de inspeção. Para tanto, o sistema deve possuir uma base de dados com informações da peça a ser avaliada. Com o auxílio destas informações, o sistema pode orientar o operador sobre os procedimentos a serem tomados durante o processo de inspeção.The manufacturing of better products is an imperative factor, as it results, from the manufacturers point of view, in larger market share, high profit and, for the consumers, better performance and long life products, which means quality. On the other hand, providing quality demands a suitable definition of the product features, pushing the technology world into a search for better means of dimensional control. The tendency of increasing product quality raises the necessity of constructing or improving measurement systems which are able to evaluate a wide variety of dimensional characteristics with high accuracy and velocity. The aim of this work is to accomplish a computer system that simulates go-not-go gauges on a moving bridge coordinate measuring machine. The great advantage of the proposed system consists in the flexibility available to adapt into each gauge different geometric features. With small modifications in the computational program, tolerances, diameters and ISO tolerance can be altered. In order to perform these modifications, the system must hold a database regarding the article to be evaluated. With this information, the system can guide the operator about the procedure to be followed during the inspection process.
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Katzenbach, Michael. "Individual Approaches in Rich Learning Situations Material-based Learning with Pinboards." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-80328.
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Active Approaches provide chances for individual, comprehension-oriented learning and can facilitate the acquirement of general mathematical competencies. Using the example of pinboards, which were developed for different areas of the secondary level, workshop participants experience, discuss and further develop learning tasks, which can be used for free activities, for material based concept
formation, for coping with heterogeneity, for intelligent exercises, as tool for the presentation of students’ work and as basis for games. The material also allows some continuous movements and can thus prepare an insightful usage of dynamic geometry programs. Central Part of the workshop is a work-sharing group work with learning tasks for grades 5 to 8. The workshop will close with a discussion of general aspects of material-based learning.
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Ferraz, Alexandre Machado. "Procedimento de calibração indireta para máquinas de medir a três coordenadas." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-12022016-143059/.
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A economia mundial, cada vez mais competitiva, impulsiona o acelerado desenvolvimento tecnológico e conseqüentemente promove o crescente uso de Máquinas de Medir a Três Coordenadas (MM3Cs). A preferência por essas máquinas pode ser justificada pela sua grande flexibiÍidade e produtividade e é uma tentativa de melhorar a área de inspeção dimensional do processo produtivo. Um grande esforço no desenvolvimento de novas metodologias se realiza para se obter e modelar os erros de MM3Cs. Padrões para calibração de MM3Cs foram sugeridos e colocados em uso através dos diferentes anos, com a finalidade de utilizá-los em testes de aceitação e verificação periódica da incerteza de medição de MM3Cs. Novos artefatos para a calibração indireta de MM3Cs visam melhorar os procedimentos de calibração para uso em sistemas de compensação de erros. Diante do exposto acima, este trabalho tem como objetivo desenvolver um Procedimento de Calibração Indireta de MM3Cs com o Esquadro Mecânico de Esferas aliado a um Modelo Reduzido de Sintetização de Erros (MRSE) para uso em um Sistema de Compensação de Erros. O procedimento possibilita maior rapidez na obtenção dos valores e comportamentos dos erros quando comparado com outros procedimentos de calibração indireta. Aliado a um MRSE, o procedimento proposto tem como vantagem o uso de um único artefato para medir todos os termos das componentes do erro volumétrico, nas direções X, Y e Z de uma MM3C.The increasingly competitive world economy promotes the technological development and, as a consequence, the growing use of Coordinate Measuring Machines (CMMs). The predilection for CMMs can be justified by their great flexibility and productivity and is also an attempt to improve the dimerisional inspection quality of the productive process. Considerable effort was made on the development of new methodologies to obtain and model CMMs errors. Calibration standards were suggested and employed for years aiming at acceptance tests and periodic verification of measurement uncertainty of CMMs. The development of new artefacts for CMM indirect calibration seeks to enhance calibration procedures for error compensation systems. Therefore, this work aims at the development of an indirect CMM calibration procedure using a mechanical ball square and the Error Synthesization Reduced Model (ESRM) for an error compensation system. The procedure allows faster obtaining of error values and behaviour if compared with other indirect calibration procedures. The proposed procedure, along with the ESRM, is advantageous since only one artefact is employed to measure all the terms of the volumetric error components m directions X, Y and Z of the CMM.
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CHI, LIANG WAN, and 梁婉祺. "Geometry Analysis of Coordinate Measuring Machines." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/34047667829339426114.
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碩士大葉大學
機械工程研究所碩士在職專班
94
Coordinate measuring machines have been predominatly used to generate measurement points for a surface .The measurement data are analyzed to yield geometric tolerance information for the surface features. In virtue of utilizing coordinate measuring machines, artificial operation is usually used. Therefore, the operating instructions are determined by personal experience. with different measurement staffs. The measurement results lead to inaccuracy casily. This study utilized average discrepancy rate, specification discrepancy rate and synthetic method to choose measuring points instead of personal experience. Finally, the Response Surface Method is used to optimize measuring systems. With Gage Repeatability and Reproducibility Analysis of the geometry tolerance.
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DeMetsenaere, Anna Lisa. "Geometric representations of quadratic solutions." 2013. http://hdl.handle.net/2152/22668.
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This report explores several geometric representations of quadratic equations and their solutions. Topics discussed include applications of geometry relating to solving quadratic equations using graphs and constructions as well as deriving compatible pairs of equations from Pythagorean triples. A brief discussion on the inclusion of advanced graphing methods and constructions into a secondary mathematics class is also included.text
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Pike, Robert P. "A grade 9 coordinate geometry unit : bridging basic skills and the APEF curriculum /." 2001.
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Herman, David Leigh. "Volume-Preserving Coordinate Gauges in Linear Perturbation Theory." Thesis, 2012. http://hdl.handle.net/10222/21376.
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The main goal of this thesis is to present cosmological perturbation theory (based on the standard Friedmann cosmological model) in volume-preserving coordinates, which then provides a suitable basis for studies in cosmological averaging. We review perturbation theory to second order, allowing for averaging to second order in future research. To solve the averaging problem we need a method of covariantly and gauge invariantly averaging tensorial objects on a background manifold. This is a very difficult problem. However, the definition of an average takes on a particularly simple form when written in a system of volume-preserving coordinates. Therefore, we develop a three dimensional and a four dimensional volume-preserving coordinate gauge in this thesis that can be used for averaging in cosmological perturbation theory.
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Li, Wenjung, and 李文榮. "Study on the Geometry Measurement of Bevel Gear and Its Mold on a Gear Coordinate Measuring Machine." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/31907423019429251816.
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碩士國立中正大學
機械工程學系暨研究所
100
Methods for coordinate measuring bevel gear and its mold are studied in this research. First, the mathematical model of the coordinate measuring machine is established and the shortest paths of measuring bevel gear and its mold are planned. Then, the 3D model of the workpiece is imported into the virtual coordinate measuring system in STL format. The STL file of the workpiece is segmented into different arrays with the database partition processing method to increase the speed of simulation. The measured data points are obtained by the better collision rules between the probe head and the tooth profile. Therefore, the simulation program is able to evaluate the possibility of path planning before actual operation. The simulation program is also used to study the compensation method for measuring machine and fixture errors. Finally, the path planning is performed on the real coordinate measuring machine to verify the tooth surface measurement planning. Machining deviations are accumulated in the bevel gear mold manufacturing process. These corrections can be obtained by analyzing the differences between the measurements of mold and molded gear with Ease-off method. The research can be applied to manufacture high precision molded gear. Study on measuring unknown gears without theoretical measuring data are included in this research, too. The flank coordinates can be obtained by minimizing the topographic error between fitting surface and unknown flank. It also can be applied in measuring gear mold and other kinds of gear without theoretical measuring data.
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楊秋惠. "Bidentate and Unidentate Trifluoroacetato Ligand in Bis(trifluoroacetato)-(N-methyl-meso-tetraphenylrinato) Thallium(III), a New Fluxional 4:3 piano stool seven-Coordinate Geometry." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/89712167635226543197.
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Kreslová, Iva. "Analytický a syntetický přístup k řešení metrických úloh v prostoru." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-404938.
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The diploma thesis deals with metric tasks in space, using synthetic and analytical geometry. In addition to explaining the different approaches, there is a set of examples to practice. The solution of the examples is part of the Portal of High School Mathematics (Portál středoškolské matematiky), where we can and analytical solutions, synthetic numerical solutions and synthetic constructional solutions.
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Irving, Corey 1977. "Wachspress Varieties." Thesis, 2012. http://hdl.handle.net/1969.1/148270.
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Barycentric coordinates are functions on a polygon, one for each vertex, whose values are coefficients that provide an expression of a point of the polygon as a convex combination of the vertices. Wachspress barycentric coordinates are barycentric coordinates that are defined by rational functions of minimal degree. We study the rational map on P2 defined by Wachspress barycentric coordinates, the Wachspress map, and we describe polynomials that set-theoretically cut out the closure of the image, the Wachspress variety. The map has base points at the intersection points of non-adjacent edges.
The Wachspress map embeds the polygon into projective space of dimension one less than the number of vertices. Adjacent edges are mapped to lines meeting at the image of the vertex common to both edges, and base points are blown-up into lines. The deformed image of the polygon is such that its non-adjacent edges no longer intersect but both meet the exceptional line over the blown-up corresponding base point.
We find an ideal that cuts out the Wachspress variety set-theoretically. The ideal is generated by quadratics and cubics with simple expressions along with other polynomials of higher degree. The quadratic generators are scalar products of vectors of linear forms and the cubics are determinants of 3 x 3 matrices of linear forms. Finally, we conjecture that the higher degree generators are not needed, thus the ideal is generated in degrees two and three.
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Chao-Hsin, Luo, and 羅兆鑫. "A Study of Geometric Error Estimating Model for Coordinate Measuring Machines." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/71755440885636636584.
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碩士大同工學院
機械工程研究所
81
This study develops a method for estimating volumetric errors of coordinate measuring machine. By way of measuring reference- part he coordinate measuring machine errors can be modeled. Order 2 to 6 error models based on rigid body kinematics are discussed. The modeling method can be used in machine tools to reduce the rework cost while higher accuracy machining is requested. Also, a backpropagation network learning method is proposed to enhancehe estimating accuracy. Experimental results show that both the mathematical error models and the backpropagation network can estimate the coordinate measuring machine volumetric errors.
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Daněk, Jiří. "Vlastnosti geometrie prostoročasů v blízkosti horizontu." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-321393.
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Nowadays, the near-horizon regions of black holes have enjoyed great attention thanks to their role in the popular AdS/CFT correspondence and their specific geometry suitable for formulations of uniqueness theorems in higher dimensions. A strictly general-relativistic point of view reveals also many interesting phenomena taking place near black-hole horizons. Our aim was to investigate how horizon multiplicity affects near-horizon geometry, geodesical distance, radial motion of photons and massive, charged particles, and also the possibility of collision processes leading to unbound collision energies near the horizon. We chose the Reissner-Nordström-de Sitter metric, which, on the one hand, is simple thanks to being static and spherically symmetric but which, on the other hand, is rich enough to enable the existence of up to a doubly degenerate ultra-extreme horizon. After discussing the physical feasibility of the near-horizon limit, we applied it to single, double, and triple horizons, their near-horizon geometries, and local collision processes. We found continuous coordinate systems covering all types of horizons and analytic solutions for motion of radial photons and special or critical, massive, charged particles in their vicinity. We addressed particle collisions in the immediate vicinity of horizons...
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Wang, Jing. "The influence of coordination geometry on the lanthanide(III) (S)-P-NB-DOTA-tetraamide derivatives /." 2005. http://proquest.umi.com/pqdweb?did=1003853771&sid=1&Fmt=2&clientId=10361&RQT=309&VName=PQD.
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