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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Simultaneous cooperative exploration and networking

Kim, Jonghoek 30 March 2011 (has links)
This thesis provides strategies for multiple vehicles to explore unknown environments in a cooperative and systematic manner. These strategies are called Simultaneous Cooperative Exploration and Networking (SCENT) strategies. As the basis for development of SCENT strategies, we first tackle the motion control and planning for one vehicle with range sensors. In particular, we develop the curve-tracking controllers for autonomous vehicles with rigidly mounted range sensors, and a provably complete exploration strategy is proposed so that one vehicle with range sensors builds a topological map of an environment. The SCENT algorithms introduced in this thesis extend the exploration strategy for one vehicle to multiple vehicles. The enabling idea of the SCENT algorithms is to construct a topological map of the environment, which is considered completely explored if the map corresponds to a complete Voronoi diagram of the environment. To achieve this, each vehicle explores its local area by incrementally expanding the already visited areas of the environment. At the same time, every vehicle deploys communication devices at selected locations and, as a result, a communication network is created concurrently with a topological map. This additional network allows the vehicles to share information in a distributed manner resulting in an efficient exploration of the workspace. The efficiency of the proposed SCENT algorithms is verified through theoretical investigations as well as experiments using mobile robots. Moreover, the resulting networks and the topological maps are used to solve coordinated multi-robot tasks, such as capturing intruders.
102

Optical Metrology:Techniques For The Measurement Of Optical Parameters

Rao, S Madhusudana 02 1900 (has links)
The work reported in this thesis has been carried out in the following two areas of Optical metrology: 1. Measurement and correction of prism angles 2. Measurement of refractive indices using a spectrograph. The prism angles are conventionally tested by mechanical bevel protractors, autocol-limators (angle dekkors), simple interference techniques and interferometers. All these methods have their own limitations either in accuracy or in terms of cost. Mechanical methods are usually employed to measure the angles of prisms. Interference techniques and interferometers are also used but they need optically polished components. For both mechanical and simple interference methods of testing, it is essential to fabricate more than a single component in number. The process of building interferometers or purchasing interferometers, angle dekkors and standard angle gauges is not cost effective for many research laboratories, and medium scale industries. To overcome these difficulties simple and inexpensive methods without sacrificing the accuracy in the bargain are suggested for the measurement of prism angles, based on the principles of reflection of light. The refractive indices of prism materials for invisible and weaker spectral lines are usually determined from spectrograms using dispersion formulae and numerical interpolation techniques. In these methods, the accuracy of the results depends on the accuracy of determining the constants of the dispersion formulae. A simple experimental technique, using a spectrograph, is devised for the measurement of refractive indices of solids and liquids both for visible and invisible spectral lines (wavelengths). The thesis has been divided into six chapters. The first chapter starts with the general introduction. The second chapter presents the literature review of the existing methods for angle and refractive index measurements. The third chapter describes the proposed new techniques for prism angle measurements. The fourth chapter presents the experimental results of angle measurements, and the discussion of the accuracy of the results. This chapter also gives the scope for further research. The fifth chapter describes a newly proposed technique for measuring refractive indices and the experimental results. This chapter also gives the scope for further research. The summary of the results, conclusions, and suggestions for further work are presented in chapter six.
103

Um estudo exploratório sobre a formação conceitual em geometria de alunos do ensino médio /

Proença, Marcelo Carlos de. January 2008 (has links)
Orientador: Nelson Antonio Pirola / Banca: Odalea aparecida Viana / Banca: Regina Maria Pavanello / Resumo: O objetivo da pesquisa foi analisar o conhecimento declarativo de alunos do ensino médio sobre polígnos e poliedros em termos de seus atributos difinidores, das relações subordinadas e supra-ordenadas e de seus exemplos e não-exemplos. A concepção teórica utilizada foi o modelo de formação de conceitos de Klausmeier e Goodwin (1977). Os participantes foram 253 alunos do ensino de uma escola de rede oficial pública de ensino de Bauru, que responderam, na primeira fase, um questionário, uma prova matemática, um testes de atributos definidores, um teste de exemplos e não-exemplos e um teste de relações subordinadas e supra-ordenadas. Na segunda fase, foram selecionados, aleatoriamente, três alunos com média abaixo de cinco pontos e três alunos com média igual ou superior a cinco pontos para participarem de uma entrevista. Os resultados coletados na primeira fase, analisados quantitativamente, mostram que no teste de atributos definidores a nota média foi de 6,03, sendo que não houve diferença significativa entre as séries (p=0,084). No teste de exemplos e não-exemplos a nota média 5,59 refletiu o desempenho dos participantes e não foram encontradas diferenças significativas entre as séries (p=0,057). Em relação ao teste de relações subordinadas e supra-ordenadas a nota média dos participantes foi 5,64, sendo que a nota média obtida pela primeira série diferiu significativamente da nota média obtida pela terceira série (p=0,024). Em relação aos dados da segunda fase, analisados qualitativamente, alguns participantes pensavam, de maneira equivocada, sobre os atributos definidores de polígnos e de poliedros. Os atributos irrelevantes não interferiam na identificação das figuras selecionadas do teste de exemplos e não-exemplos como exemplos polígnos. / Abstract: The objective of this reseach was to analyse the declarative konowledge of students from Elementary School Teaching about polygons and polyhedrons in terms of their defining atributes, the subordinate relations and supraordinate and their examples and no-exemples. The theoretical conception used was the model of formation from Klausmeier and Goodwin (1977)'s concepts. The participants were 253 students from Elementary School Teaching of one school of the Oficial Public Network from Bauru, who answered, in the first phase one questionnaire, one math test, one test of defining attributes, one test of examples and no-examples and one test of subordinate relations and supraordinate. In the second phase, three students were randomly selected with the average below five points and three students with equal average or higher to five points who participated in an interview. The collected results in the first phase, quantitatively analysed, showed that in the test of defining attributes, the average grade was 6,03, so there was no significative difference among the series (p=0,084). In the test of examples and no-examples the average grade 5,59 reflected the performance of the participants and no significative differences were found among the series (p=0,057). In the relation to the test of subordinate relations ans supraordinate the average grade of the participants was 5,64, so the average obtained by the first grade had no significative difference from the average obtained by the third grade (p=0,024). In relation to the data of the second phase, qualitativety analysed, some participants thought wrongly about the defining attributes of polygons and polyhedrons. The irrelevants attributes did not interfere in the identification of the selected pictures of the test of examples and no-examples as polygons examples. / Mestre
104

Aplicação das isometrias na pavimentação do plano com polígonos regulares

Carneiro, Ronaldo Freitas January 2014 (has links)
Orientador: Prof. Dr. Daniel Miranda Machado / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2014. / Este trabalho tem como objetivo de pesquisa fazer um estudo sobre a aplicação da geometria das transformações (em especial das isometrias) e da pavimentação do plano com polgonos regulares em atividades que fazem uso da Geometria Dinâmica como recurso para visualização e manuseio de objetos geometricos. São apresentados inicialmente os pressupostos teoricos dos conceitos envolvidos com algumas de suas principais denic~oes e propriedades. Em seguida, o trabalho de M.C.Escher e exposto para exemplicar o uso da parte teorica nas artes com o intuito de motivar a apreciação do conteudo estudado. Uma situação-problema e colocada como meio para desenvolver a pesquisa atraves do software Geogebra que foi utilizado para auxiliar a execucão das atividades propostas. Atraves do desenvolvimento do presente estudo, foi possvel constatar que ha um interesse muito maior dos alunos e um consenso por parte de todos de que a utilizac~ao de recursos visuais e tecnologicos no ensino de matematica e mais agradavel e estimulante. / This work aims to make a research study on the application of geometry transformations (especially isometries) and paving the plane with regular polygons in activities that make use of Dynamic Geometry as a resource for viewing and handling of geometric objects. The theoretical assumptions of the concepts involved with some of its main denitions and properties are initially presented. Then the work M.C.Escher is exposed to exemplify the use of the theoretical part in the arts in order to motivate the assessment of the content studied. A problem situation is placed as a means to develop the research through the Geogebra software that was used to assist the implementation of the proposed activities. Through the development of this study, it was found that there is a much greater student interest and consensus by all that the use of visual and technological resources in teaching mathematics is more enjoyable and stimulating.
105

Mensuração automática de copas de Araucaria angustifolia (Bertol.) Kuntze a partir de dados LiDAR para estimativa de variáveis dendrométricas / Automatic measurement of Araucaria angustifolia s crowns (Bertol.) Kuntze from LiDAR data to estimate dendrometric variables

Pereira, João Paulo 25 July 2014 (has links)
Made available in DSpace on 2016-12-12T20:12:29Z (GMT). No. of bitstreams: 1 PGEF14MA008.pdf: 3688775 bytes, checksum: 4a40e070e65e6367243d2ef1f2414666 (MD5) Previous issue date: 2014-07-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper aimed to automatic extract crowns of Araucaria angustifolia using LiDAR data and indirectly obtain dendrometric variables. To conduct the project, a LiDAR point cloud was used with an average density of 7 points/m², located in the city of Painel in Santa Catarina. Four subareas were selected so that only isolated trees would be considered. The laser scanning survey was conducted by the company Aeroimagem S/A from Curitiba, in January 2011 using a Leica ALS-60 system. In the fieldwork, isolated trees of A. angustifolia were measured to give the DBH, total height and 4 crown radius in the direction of the cardinal points. The fieldwork occurred in September and August 2013. To delineate the crowns, it was employed the segmentation methodology of Thiessen polygons. Each segment was measured in order to obtain the canopy diameter for each tree. For the calculation of dendrometric variables, linear regression was used to obtain the DBH as a function of the crown diameter. The total height was obtained directly from LiDAR data. Because of the seasonality between the LiDAR survey and fieldwork, it was necessary to apply a correction in LiDAR data using increment data of the species. Segmentation by Thiessen polygons reached an accuracy ranging between 75.2% and 91.7%. Estimating the 14 DBH the difference between the field was 3,1mm. For total height 0,19m was the difference between the data field and the LiDAR. Using the proposed methodology, it was possible to perform the measurement of the crowns of A. angustifolia and estimate dendrometric variables with satisfactory accuracy / Este trabalho tem como objetivo a medição automática de copas de Araucaria angustifolia utilizando dados LiDAR e indiretamente a obtenção de variáveis dendrométricas. Para a realização da pesquisa utilizou-se uma nuvem de pontos LiDAR com uma densidade média de 7 pontos/m², localizada no município de Painel em Santa Catarina. Quatro subáreas foram selecionadas para que fosse possível trabalhar apenas com árvores isoladas. O levantamento por varredura a LASER foi efetuado pela empresa Aeroimagem S/A de Curitiba, em janeiro de 2011 utilizando um sistema Leica ALS-60. No levantamento a campo, foram medidas árvores isoladas de A. angustifolia obtendo-se o DAP, altura total e 4 raios da copa na direção dos pontos cardeais. O levantamento à campo ocorreu em setembro e agosto de 2013. Para o delineamento das copas foi empregada a metodologia de segmentação de polígonos de Thiessen. Para o cálculo das variáveis dendrométricas, foi utilizado regressão linear para obter o DAP em função do diâmetro da copa. A altura pôde ser obtida diretamente dos dados LiDAR. Devido a sazonalidade entre o levantamento LiDAR e a coleta de dados a campo, foi necessário aplicar uma correção nos dados LiDAR utilizando dados de incremento da espécie. A segmentação por 12 polígonos de Thiessen atingiu uma acurácia que variou entre 75,2% e 91,7%. Na estimativa do DAP chegou-se a uma diferença de 3,1mm em relação ao campo. Para a altura total, 0,19m foi a diferença entre os dados a campo e o LiDAR. Utilizando a metodologia proposta, foi possível realizar a medição das copas de A. angustifolia e estimar as variáveis dendrométricas com precisão satisfatória
106

O ensino de geometria plana pela resolução de problemas do tipo quebra-cabeças com palitos de fósforo

Lacerda, Geraldo Herbetet de 06 May 2011 (has links)
Made available in DSpace on 2015-05-07T15:08:09Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1832682 bytes, checksum: 130715e1d96b5966792eb1ee98ad3518 (MD5) Previous issue date: 2011-05-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This research comprises the result of a process that had beginning as a personal reflection about a specific type of teaching activity that we had developed in the classroom, allowing us to expand our understanding of this topic and work with elements that can be explored in the process of initial and continuing training of teachers of Mathematics. Focusing on the teaching of plane geometry and more specifically exploring relative contents to the study of polygons such as classification, relation between properties, determination of perimeter and area, we take the van Hiele model as the main theoretical reference, which includes establishing different levels of development in student`s geometric thoughts, focusing on the first three (Levels 0, 1 and 2), connecting the action with manipulative materials for teaching geometry and solve problems. As a source of reflection for analysis, we take as the basic proposition a particular type of puzzles with matchsticks in Mathematics textbooks aimed at students from 6 to 9 Years of Elementary Education. We understand that the field of theoretical proposals as highlighted here for the teaching of geometry allows a teacher to do a better plan their actions to the classroom as well as more adequately explore the potential and limitations of various instruments, such textbooks, which are part of everyday school life. We concluded that even activities that may at first seem limited or traditional, can be improved considering references to research in a particular field of research, using them as a starting point for modifying the current reality of our formative student. / O presente trabalho de investigação compreende o resultado de um processo que teve início como uma reflexão pessoal acerca de um tipo específico de atividade didática que desenvolvemos em sala de aula, permitindo-nos ampliar nossa compreensão sobre o tema em tela e colaborar com elementos que podem ser explorados em processos de formação inicial e continuada de professores de Matemática da Educação Básica. Tendo como foco o ensino de Geometria Plana e, mais especificamente, explorando conteúdos relativos ao estudo de polígonos, como a classificação, relação entre propriedades, determinação de perímetro e área, tomamos como principal referencial teórico o Modelo van Hiele, que compreende o estabelecimento de diferentes níveis de desenvolvimento do pensamento geométrico do aluno, centrando-nos nos três primeiros (Níveis 0, 1 e 2), conectando a ação com materiais manipulativos para o ensino de Geometria à Resolução de Problemas. Como fonte de reflexão para análise, tomamos como base a proposição de um tipo particular de quebras-cabeças, com palitos de fósforo, em livros didáticos de Matemática direcionados a alunos do 6º ao 9º Anos do Ensino Fundamental. Compreendemos que o domínio de propostas teóricas como a aqui destacada para o ensino de Geometria, permite ao professor realizar um melhor planejamento de suas ações para a sala de aula, assim como explorar de forma mais adequada as potencialidades e limitações de instrumentos diversos, a exemplo do livro didático, que fazem parte do cotidiano escolar. Concluímos que mesmo atividades que podem, à primeira vista, parecer limitadas ou tradicionais, podem ser melhoradas considerando-se referências de pesquisas realizadas em um determinado campo de investigação, tomando-as como ponto de partida para a modificação da realidade formativa atual de nosso aluno.
107

Evaluating the Effects of Sea Level Rise on Sea Turtle Nesting Sites: A Case Study of the Archie Carr National Wildlife Refuge

Ussa, Melissa 29 March 2013 (has links)
The purpose of this thesis was to determine the extent of sea level rise (SLR) impact on sea turtle nesting beach habitat on Archie Carr National Wildlife Refuge (NWR) as well as impacts on management strategies. The Archie Carr NWR is of exceptional importance due to the high density of Loggerhead, Leatherback, and Green sea turtles that nest there in the summer months. GIS data provided by the Archie Carr NWR and various SLR scenarios, provided by both the Intergovernmental Panel on Climate Change (IPCC) as well as leading scholars, were used to determine inundation area loss across the Refuge as well as nearby parcels targeted for possible acquisition. Inundation losses for the six scenarios were calculated to be in the 20-25% range. Approximately 26% of current lower priority parcels are reclassified as high priority when integrating this information. Therefore, a significant revision to future acquisition strategies is recommended.
108

Digital visualisering av skallgångskedjor : Google Maps som spårningsverktyg

Carlsson, Joel, Ejnarsson, Carl January 2020 (has links)
Varje år försvinner tusentals personer. År 2017 anmäldes 7100 personer som försvunna i Sverige. De allra flesta återfinns inom sex månader, men i genomsnitt 30 personer återfinns aldrig. Svensk polis deltar i sökningar efter minst 300 personer varje år. Polisen samarbetar i sina sökinsatser med försvarsmakten och andra organisationer som Missing People. Missing People som har över 60 000 personer anmälda som volontära sökare, hjälper till genom, bland annat, anordna skallgångskedjor. I detta examensarbete, undersöks verktyg och tekniker som skulle kunna komma till användning vid sökinsatser. Examensarbetet undersöker verktyg som finns tillgängliga i Google Maps API1 för att se hur det går att visualisera hur ett område är sökt och hur länge sedan det genomsöktes. Tre visualiseringstekniker från Google Maps API implementeras och testas för ändamålet. Teknikerna är Heatmaps, Polygons och Circles. Varje teknik implementeras och testas mot ett antal identifierade krav i en iteration. Kraven är framtagna genom att analysera frågeställningen mot de relaterade arbeten, webbplatser och artiklar som detta examensarbete byggt sin bakgrund på. Slutsatsen visar att Heatmaps från Google Maps API inte fyller den önskade funktionen. Om heatmaps ska användas kan ett annat kartverktyg än google maps behöva användas eftersom Google Maps Heatmaps-verktyg inte går att ställa så att de passar kraven som satts upp. Polygons misslyckas på ett av testerna, vilket kan gå att lösa med en algoritm för att förstora polygonen. Circles fungerar efter kraven och kan användas på önskvärt vis. Det krävs dock mer forskning för att vidareutveckla hur verktyget hade kunnat användas i ett skarpt läge.
109

Aktiviteter i geometriundervisning-samt vilken förståelse dessa ämnar utveckla.

Wallin, Alice, Busk, Pauline January 2021 (has links)
Syftet med denna systematiska litteraturstudie var att sammanställa aktiviteter som beskrevs i forskning om polygoner i geometriundervisning samt analysera vilken form av förståelse dessa ämnade utveckla. Respektive aktivitet analyserades utefter van Hieles beskrivning av olika nivåer av geometriskt tänkande för att svara på frågan vilken förståelse som aktiviteten ämnade utveckla. Resultatet visade att det fanns fyra huvudkategorier av aktiviteter och att den största kategorin utgjordes av laborativa aktiviteter vilka i huvudsak ämnade utveckla van Hieles nivå två för geometriskt tänkande. De tre resterande kategorierna varierade i vilken nivå de ämnade utveckla mellan van Hieles nivå 1–4. / Polygons are included in mathematics education for grades 4–6. The aim of this study was to compile activities described in previous research on polygons through a systematic literature review and analyze what kind of geometric thinking they intended to develop. The activities were individually analyzed through a comparison with van Hiele’s levels about how geometric thinking is developed. The results showed that the research mainly contained explorative tasks which aimed to develop van Hiele’s level two of geometric thinking. Other activities that were found varied in what level of geometric thinking they developed.
110

[pt] A GEOMETRIA DE ESPAÇOS DE POLÍGONOS GENERALIZADOS / [en] THE GEOMETRY OF GENERALIZED POLYGON SPACES

RAIMUNDO NETO NUNES LEAO 17 June 2021 (has links)
[pt] Espaços de moduli de polígonos em R(3) com comprimento dos lados fixados é um exemplo amplamente estudado de variedade simplética. Esses espaços podem ser descritos como quociente simplético de um número finito de órbitas coadjuntas pelo grupo SU(2). Nesta tese esses espaços de moduli são identificados como folhas simpléticas de uma variedade de Poisson que pode ser construída como quociente. Essa construção é a seguir generalizada ao caso de um produto de um número finito de órbitas coadjuntas pelo grupo SU(n), e o resultado principal desse trabalho de tese descreve como esses espaços de moduli de polígonos generalizados formam uma folheação em folhas simpléticas de uma variedade de Poisson. / [en] Moduli spaces of polygons in R(3)with fixed sides length are a widely studied example of symplectic manifold that can be described as the symplectic quotient of a finite number of SU(2)−coadjoint orbits by the diagonal action of the group SU(2). In this thesis these spaces are identified as the symplectic leaves of a Poisson manifold, that can itself be obtained by a quotient procedure. The construction is then generalized to the case of the quotient of a product of finitely many SU(n)−coadjoint orbits by the diagonal action of SU(n), and the main result of this thesis describes how these moduli spaces of generalized polygons fit together as the symplectic leaves of a quotient Poisson manifold.

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