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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.
181

O aprendizado da astronomia e das ciências afins com a mediação da observação rudimentar e da imagem astronômica

Debom, Camila Riegel January 2010 (has links)
Apresentamos o planejamento, desenvolvimento e aplicação de uma proposta de curso de extensão em Astronomia, dividido em módulos e oferecido a estudantes de ensino médio visando a aprendizagem da Astronomia e das ciências afins a partir da observação rudimentar e da imagem astronômica. A confecção do material didático destinado ao curso e a elaboração das aulas tiveram por base a teoria da mediação de Lev Vygotsky e a epistemologia de Stephen Toulmin. O projeto incluiu a realização de uma experiência piloto, da qual foram extraídos subsídios para seu aperfeiçoamento. Apresentamos aqui o relato desta experiência e de seus resultados, bem como o desenvolvimento e aplicação de uma segunda versão do curso e dos resultados obtidos. Como instrumentos de avaliação foram utilizados pré e póstestes idênticos. Da análise destes instrumentos, verificamos um aumento no número absoluto de acertos de cerca de 55% na avaliação, com relação à avaliação prévia, na segunda implementação do curso. Esse resultado, conjuntamente com a análise qualitativa dos comentários feitos pelos estudantes concluiu-se que a utilização da imagem astronômica e a observação rudimentar com fins didáticos é viável e frutífera. Como produto educacional desta dissertação confeccionamos um CD com o conteúdo das aulas, que acompanha guias ao professor que queira replicar a experiência. / We present an outreach course in Astronomy and related sciences at high school level, describing its planning, development and application. The course is modulated and uses elementary astronomical observation and images as its basic learning tools. The didatic material for the project and the lecture grid are based on Lev Vygotsky mediation theory and the epistemology be Stephen Toulmin. The project involved an initial test course, from which we extracted subsidies for its improvement. We describe this initial experience and its results. We also describe the application of the second version of the course. Identical pre and post course tests we used to assess the impact of both versions and led to a final 55% improvement in the rate of correct answers, on the second version of the course. This result, along with the qualitative analysis of the comments made by the students, shows the importance of astronomical images and observations as teaching tools. Finally, the course is detailed out in a CD containing not only the material developed for the lectures, but also a guide to other teachers who wish to apply it in their classes.
182

Manipula??o de imagens astron?micas com o uso Aladin para o ensino de astronomia

Lima, Melina Silva de 13 August 2015 (has links)
Submitted by Luis Ricardo Andrade da Silva (lrasilva@uefs.br) on 2016-02-04T21:17:06Z No. of bitstreams: 1 Dissertacao Melina Silva de Lima.pdf: 10052548 bytes, checksum: 73b20a87c9bf7f70b05b1e58665c5b7a (MD5) / Made available in DSpace on 2016-02-04T21:17:07Z (GMT). No. of bitstreams: 1 Dissertacao Melina Silva de Lima.pdf: 10052548 bytes, checksum: 73b20a87c9bf7f70b05b1e58665c5b7a (MD5) Previous issue date: 2015-08-13 / We have used the Aladin software, a sky atlas used to visualize and manipulate astronomical images developed by CDS of Strasbourg. To elaborate teaching activities involving astronomical concepts, such as distance, brightness, image manipulation, colors as well as to explain the nature of different objects showing their images in different filters, among others. In the total, we have elaborated four activities that were applied to students of the 6th year of elementary school, high school and undergraduate ones for the Engineering and Pedagogy courses. All activities and the results of their evaluation with students are detailed discussed and analyzed; a teacher guide is also provided. Our results show that in the four activities, the students have a significant learning supporting the use of such methodology. Also, we elaborated two memory games, based on Java platform, with the images of some astronomical objects. The activities are in The Portuguese language, but they can easily be adapted for any other language. This research also made the translation of Aladin to Portuguese. / Este trabalho contempla a an?lise de um estudo de aplica??es, em sala de aula, de estrat?gias e t?cnicas de facilita??o, que utilizem o software Aladin (http://aladin.u-strasbg.fr/) na forma??o de conceitos de Astronomia e possibilidade de desenvolvimento cognitivo, por meio da aprendizagem, consolidando o aprendizado atrav?s do uso de computadores. Conceitos de dist?ncia, brilho, cor, exist?ncia de diferentes tipos de objetos astron?micos, manipula??o de imagens e dados astron?micos, entre outros aspectos, foram tratados em sala de aula e fizeram parte deste trabalho. A pesquisa foi aplicada em diversas etapas do ciclo de aprendizagem escolar, mais especificamente: 6? ano do ensino fundamental, 2? ano do ensino m?dio, alunos de gradua??o em Engenharia e, por fim, uma turma de alunas de Pedagogia, quase todos professores atuantes e, portanto, divulgadores dos conceitos para eles passados. Todas as atividades utilizaram o software Aladin e uma o aplicativo de Observat?rio Virtual, denominado VO-Stat. Como produto, foi elaborado material did?tico com o conte?do das atividades assim como um roteiro voltado para os professores realizarem a aplica??o da atividade para o ensino fundamental, um jogo da mem?ria virtual que trata de Astronomia. A tradu??o do Aladin para a l?ngua portuguesa tamb?m foi realizada nesse trabalho.
183

Astronomical seeing conditions as determined by turbulence modelling and optical measurement

Nickola, Marisa 12 February 2013 (has links)
Modern space geodetic techniques are required to provide measurements of millimetre-level accuracy. A new fundamental space geodetic observatory for South Africa has been proposed. It will house state-of-the-art equipment in a location that guarantees optimal scientific output. Lunar Laser Ranging (LLR) is one of the space geodetic techniques to be hosted on-site. This technique requires optical (or so-called astronomical) seeing conditions, which allow for the propagation of a laser beam through the atmosphere without excessive beam degradation. The seeing must be at ~ 1 arc second resolution level for LLR to deliver usable ranging data. To establish the LLR system at the most suitable site and most suitable on-site location, site characterisation should include a description of the optical seeing conditions. Atmospheric turbulence in the planetary boundary layer (PBL) contributes significantly to the degradation of optical seeing quality. To evaluate astronomical seeing conditions at a site, a two-sided approach is considered – on the one hand, the use of a turbulence-resolving numerical model, the Large Eddy Simulation NERSC (Nansen Environmental and Remote Sensing Centre) Improved Code (LESNIC) to simulate seeing results, while, on the other hand, obtaining quantitative seeing measurements with a seeing monitor that has been developed in-house. / Dissertation (MSc)--University of Pretoria, 2012. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted
184

Optical Astrometry and Orbit Determination

Patrick Michael Kelly (8817071) 08 May 2020 (has links)
The resident space object population in the near-Earth vicinity has steadily increased since the dawn of the space age. This population is expected to increase drastically in the near future as the realization of proposed mega-constellations is already underway. The resultant congestion in near-Earth space necessitates the availability of more complete and more accurate satellite tracking information to ensure the continued sustainable use of this environment. This work sets out to create an operational system for the delivery of accurate satellite tracking information by means of optical observation. The state estimates resulting from observation series conducted on a GPS satellite and a geostationary satellite are presented and compared to existing catalog information. The satellite state estimate produced by the system is shown to outperform existing two-line element results. Additionally, the statistical information provided by the processing pipeline is evaluated and found to be representative of the best information available for the satellites true state.
185

Phase retrieval in the high-dimensional regime

Bakhshizadeh, Milad January 2021 (has links)
The main focus of this thesis is on the phase retrieval problem. This problem has a broad range of applications in advanced imaging systems, such as X-ray crystallography, coherent diffraction imaging, and astrophotography. Thanks to its broad applications and its mathematical elegance and sophistication, phase retrieval has attracted researchers with diverse backgrounds. Formally, phase retrieval is the problem of recovering a signal 𝔁 ∈ ℂⁿ from its phaseless linear measurements of the form |𝛼ᵢ∗𝔁| + 𝜖ᵢ where sensing vectors 𝛼ᵢ, 𝑖 = 1, 2, ..., 𝓶, are in the same vector space as 𝔁 and 𝜖ᵢ denotes the measurement noise. Finding an effective recovery method in a practical setup, analyzing the required sample complexity and convergence rate of a solution, and discussing the optimality of a proposed solution are some of the major mathematical challenges that researchers have tried to address in the last few years. In this thesis, our aim is to shed some light on some of these challenges and propose new ways to improve the imaging systems that have this problem at their core. Toward this goal, we focus on the high-dimensional setting where the ratio of the number of measurements to the ambient dimension of the signal remains bounded. This regime differs from the classical asymptotic regime in which the signal's dimension is fixed and the number of measurements is increasing. We obtain sharp results regarding the performance of the existing algorithms and the algorithms that are introduced in this thesis. To achieve this goal, we first develop a few sharp concentration inequalities. These inequalities enable us to obtain sharp bounds on the performance of our algorithms. We believe such results can be useful for researchers who work in other research areas as well. Second, we study the spectrum of some of the random matrices that play important roles in the phase retrieval problem, and use our tools to study the performance of some of the popular phase retrieval recovery schemes. Finally, we revisit the problem of structured signal recovery from phaseless measurements. We propose an iterative recovery method that can take advantage of any prior knowledge about the signal that is given as a compression code to efficiently solve the problem. We rigorously analyze the performance of our proposed method and provide extensive simulations to demonstrate its state-of-the-art performance.
186

Introduction to the Development of a Radio Astronomy System at Brigham Young University

Blakley, Daniel Robert 01 July 2014 (has links) (PDF)
The intent of this project was founded upon the need to train students in the techniques of radio astronomy with the purpose of establishing a radio telescope in order to teach the principles and practice of radio astronomy.This document describes the theory, research, to establish the 1st generation radio telescope system within the Department of Physics and Astronomy at Brigham Young University. Included are introductions to: (1) The nature of star forming regions in the spiral arm structure of the galaxy, H I (the hydrogen spin-flip transition) and OH MASERS, (2) The of terminology used with the system components and their measurements, (3) The characteristics of the imaging system and its limitations, and (4) Future work and plans. Within the body of this work, I also present an introduction to the purpose, architectural design, as well as a brief description of some of the system level functions and associated equipment that constitute the development infrastructure for the 2nd generation radio astronomy system.The major work accomplished includes history, some of the fundamental theory behind radio astronomy, significant aspects of the theory behind the system, building of the system, its calibration and characteristics as well as next steps
187

The Frequency of Binary Companions Around KELT Planet Host Stars

Coker, Carl 27 October 2017 (has links)
No description available.
188

Mapping the Local Galactic Halo and An Image Motion Compensation System for the Multi-Object Double Spectrograph

Marshall, Jennifer L. 13 September 2006 (has links)
No description available.
189

KELT: The Kilodegree Extremely Little Telescope

Pepper, Joshua Aaron 22 June 2007 (has links)
No description available.
190

Dynamical and physical conditions of stellar formation : a study of H2O masers associated with galactic H [subscript II] regions

Reisz, Albert Colbert January 1976 (has links)
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Science. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 129-133. / by A. Colbert Reisz. / Ph.D.

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