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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.
1

EVALUATION OF FLATNESS TOLERANCE AND DATUMS IN COMPUTATIONAL METROLOGY

CHEPURI, SHAMBAIAH January 2000 (has links)
No description available.
2

Ensaio para definição de parâmetros de transformação entre o SAD 69 e o NSWC 9Z2

Castaneda Filho, Rafael March January 1986 (has links)
Orientador: José Bittencourt de Andrade / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Ciências Geodésicas / Bibliografia: p. 177-180 / Resumo: Nesse trabalho, realiza-se um estudo crítico-conceitual do problema de conexão entre referencias geodésicas clássicas e o sistema terrestre médico, com o seguinte objetivo em vista: determinar parâmetros de transformação entre o SAD 69 (Datum Sul-Americano de 1969) e o sistema Doppler NSWC 972, implícito a efemérides precisas. O preenchimento desse objetivo induz uma investigação de erros sistemáticos significantes, possivelmente ocorridos no projeto de definição do SAD 69. Os modelos de transformação focalizados lidam com coordenadas cartesianas de pontos comuns a ambos os referenciais,, aplicando-se o método dos mínimos quadrados com ferramentas matemáticas para calculo de respectivos parâmetros. O trabalho se encerra com a proposição de uma técnica ("justaposição Elipsoidal"), que permite estimar parâmetros de translação, sem recorrer ao uso de altitudes geométricas referentes ao SAD 96. / Abstract: In this work, a critical-conceptual study is made about the problem OF conecttIon between some classical geodetic reference system and the Average Tenrestrial, with the following aim: to determine transformation parameters between the SAP 69 (South American Vatum of 1969) and the Doppler system NSWC 911, implicit to precise ephemeris. The fulfilment of) this aim induces the investigation of significant systmatic errors, possibly occurred in the SAP 69 definition project. The focused transfomation models deal with cartesian coordinates of points whose positions axe available in both systems, being the least-Aquares method the mathematical tool applied for estimation of correspondent parameters. finally, a technique {"Ellipsoid Matching") is proposed,which allows to evaluate translation prAameters making no use of SAP 69 geometric heights.
3

Using LiDAR data and geographical information system (GIS) technology to assess municipal street tree inventories

Jones, Wes 12 August 2016 (has links)
Market and nonmarket urban forest resource values can be achieved through many cost reductions (e.g., improved air quality, fossil fuels for heating and cooling, stormwater runoff) and increases in tax bases for communities from improved property values. These benefits need to be measured quantitatively so decision makers can understand economic gains or losses provided by street trees. Resource inventories are often undertaken as part of the planning phase in a tree management program. It is a comprehensive assessment that requires an inventory of a community's tree resources and it acts as a fundamental starting point for most urban and community forestry programs. Whether an inventory is an estimate or a complete count, quantitative benefits and costs for urban forestry programs cannot accurately be represented without one. This study provides a new approach to understanding a city’s street tree structure using data from a Light Detection And Ranging (LiDAR) sensor and other publicly available data (e.g., roads, city boundaries, aerial imagery). This was accomplished through feature (e.g., trees, buildings) extraction from LiDAR data to identify individual trees. Feature extraction procedures were used with basic geographic information system (GIS) techniques and LiDAR Analyst to create street tree inventory maps to be used in determining a community’s benefit/cost ratio (BCR) for its urban forest. Only by explaining an urban forest’s structure can dollar values be assigned to street trees. Research was performed with LiDAR data and a sample of ground control trees in Pass Christian, and Hattiesburg, Mississippi, located in the lower U.S. South where many communities have publicly available geospatial data warehouses (e.g., MARIS in Mississippi, ATLAS in Louisiana). Results from each city’s estimated street trees revealed a BCR 3.23:1 and 6.91:1 for Pass Christian and Hattiesburg, respectively. This study validated a regression model for predicting street tree occurrence in cities using LiDAR Analyst and a street sample. Results demonstrated that using LiDAR Analyst as a street tree inventory tool with publicly available LiDAR data and a sample adequately described 88% of a community’s street trees which was used to calculate both market and nonmarket resource values.
4

Reconfigure Experience

McCoy, Joseph Andrew 26 July 2004 (has links)
With overcrowded schools as a project vehicle, this thesis investigates the expansion and contraction of an existing infrastructure" and the relationship that developed between the two. The proposed intervention, guided by the site, touches on an urban scale by generating a gateway into the city. / Master of Architecture
5

Multibeam Observations of Mine Scour and Burial near Clearwater, Florida, Including a Test of the VIMS 2D Mine Burial Model

Wolfson, Monica L 19 July 2005 (has links)
The ability to detect buried mines on the seafloor remains one of the most important tasks in mine countermeasures. As such, there is a vested interest in the development of predictive models of mine burial. This research was conducted in support of the Office of Naval Research Program in Mine Burial Prediction. Repeat high-resolution multibeam bathymetry data were collected over the Indian Rocks Beach (IRB) mine burial experiment site during January through March of 2003, in order to observe in situ scour and burial of instrumented inert mines and mine-like cylinders. These data were also used to test the validity of the VIMS 2D mine burial model. A set of six high-resolution multibeam surveys were collected over the IRB experiment site. Three study sites within the IRB site were chosen: two fine sand sites, a shallow one located in ~ 13 meters of water depth and a deep site located in ~ 14 meters of water depth; and a coarse sand site in ~ 13 meters. Results from these surveys indicate that mines deployed in fine sand are upwards of 74.5% buried within two months of deployment. Mines deployed in the coarse sand showed a lesser amount of scour, burying until they presented roughly the same hydrodynamic roughness of the surrounding rippled bedforms. In general, scour around the mines formed pits ~ 0.30 meters deep, with the most pronounced scour occurring at the ends of the mine. The multibeam data were also used to test the VIMS 2D mine burial model, which estimates percent burial of cylindrical mines based on predictions of wave-induced scour. The model proved valid for use in areas of fine sand, sufficiently predicting burial over the course of the experiment. In the area of coarse sand, the model greatly overpredicted the amount of burial. This is believed to be due to the presence of ripples around the mines, which affect local bottom morphodynamics and are not accounted for in the model. This issue is currently being addressed by modelers.
6

CYLINDRICAL DATUM EVALUATION METHODS UNDER MAXIMUM AND LEAST MATERIAL CONDITION SPECIFICATION

TUREK, STEVEN January 2006 (has links)
No description available.
7

Runout Evaluation Methods for Cylindrical, Tapered and Flat surfaces

RAJMOHAN, SIDDHARTH 22 April 2008 (has links)
No description available.
8

"O geóide gravimétrico e o nível médio do mar na região do Datum altimétrico brasileiro: um estudo comparativo" / A comparative study on the gravimetric geoid and the brasilian altimetric Datum.

Lopes, Alexandre Bernardino 17 May 2006 (has links)
Um estudo sobre a compatibilidade de um geóide gravimétrico recente com o nível médio do mar no Datum altimétrico do Sistema Geodésico Brasileiro (SGB), foi realizado. A metodologia usada consiste na comparação do geóide gravimétrico com o nível médio do mar, materializado pelo marégrafo de Imbituba (SC), e análise dos desníveis entre os marégrafos da costa brasileira em relação ao de Imbituba, determinados por nivelamento geométrico e dados oceanográficos. A unificação de Data altimétricos, investigada em vários centros de pesquisas geodésicas, visa homogeneizar altitudes ortométricas em escalas regional e global através de técnicas espaciais de posicionamento e modelos geoidais gravimétricos. Entre as propostas para a unificação de Data altimétricos, a utilização de modelos geoidais gravimétricos vem se mostrando adequada tanto do ponto de vista teórico como prático. Assim, foi determinada a componente sistemática no Datum de Imbituba, a partir da comparação de um geóide gravimétrico da América do Sul, obtido através da colocação por mínimos quadrados, e o geóide GPS/nivelamento, determinado através dos dados da Rede GPS do Sul/Sudeste do Brasil (RGSB). Para representar a componente sistemática no Datum altimétrico brasileiro, foram usados três formas: 1) determinação da componente sistemática na RN fundamental da RAFB (RN 4X), 2) cálculo da média ponderada da componente sistemática a partir das RNs mais próximas ao Datum, e 3) modelagem da componente sistemática usando modelo matemático da transformação de similaridade a partir de todos os dados da RGSB. Os resultados, obtidos no cálculo do nível médio do mar a partir de dados oceanográficos, mostram que as diferenças em relação ao marégrafo de Imbituba são, em grande parte, causadas por mudanças das características oceanográficas (salinidade, temperatura, densidade e pressão) ao longo da costa. A remoção da componente sistemática, obtida no Datum, diminuiu significativamente a diferença entre os geóides gravimétrico e GPS/nivelamento nas RNs da RAFB; entretanto o ajuste da componente sistemática, através da transformação de similaridade, utilizando todos os dados da RGSB, apresentou os melhores resultados na compatibilização dos geóides gravimétricos e GPS/nivelamento. ix / A study on the compatibility of a recent gravimetric geoid with the mean sea level in altimetric Datum of the Sistema Geodésico Brasileiro (SGB) was accomplished. The used methodology consists in comparing gravimetric geoid with mean sea level, at the tide gauge of Imbituba (SC), and the analysis of differences among tide gauges of Brazilian coast with respecto Imbituba, obtained by geometric levelling and oceanographic data. The unification of altimetric Data, investigated in several geodetic research centres, aiming the standardization of orthometric heights in regional and global scales by using spatial positioning techniques, and gravimetric geoid models. Among the suggestions for the altimetric Data unification, the use of gravimetric geoid models is adequate in both, theoretical and practical points of view. Thus, a systematic component at Imbituba Datum was determined by comparing a South American gravimetric geoid, obtained by least-squares collocation, and GPS/levelling geoid, determined at stations of the Rede GPS no Sul/Sudeste do Brasil (RGSB). To represent the systematic component in Brazilian altimetric Datum, three aproaches were used: 1) determining the systematic component at the fundamental benchmark of the RAFB (RN 4X); 2) computing the weighted mean from the stations closer to the Datum, and 3) modelling the systematic component by using the similarity transformation model from all stations of the RGSB, The results of mean sea level, computed from oceanographic data, show that differences with respect to Imbituba tide gauge are mostly due to oceanographic characteristics, (salinity, temperature, density, and pressure) along the coast. The removal of systematic component at Datum, has significantly reduced the difference between gravimetric and GPS/levelling geoids; however, the adjustment of systematic component by using the similarity transformation model, has shown the best results in representing the differences between gravimetric and GPS/levelling geoids.
9

"O geóide gravimétrico e o nível médio do mar na região do Datum altimétrico brasileiro: um estudo comparativo" / A comparative study on the gravimetric geoid and the brasilian altimetric Datum.

Alexandre Bernardino Lopes 17 May 2006 (has links)
Um estudo sobre a compatibilidade de um geóide gravimétrico recente com o nível médio do mar no Datum altimétrico do Sistema Geodésico Brasileiro (SGB), foi realizado. A metodologia usada consiste na comparação do geóide gravimétrico com o nível médio do mar, materializado pelo marégrafo de Imbituba (SC), e análise dos desníveis entre os marégrafos da costa brasileira em relação ao de Imbituba, determinados por nivelamento geométrico e dados oceanográficos. A unificação de Data altimétricos, investigada em vários centros de pesquisas geodésicas, visa homogeneizar altitudes ortométricas em escalas regional e global através de técnicas espaciais de posicionamento e modelos geoidais gravimétricos. Entre as propostas para a unificação de Data altimétricos, a utilização de modelos geoidais gravimétricos vem se mostrando adequada tanto do ponto de vista teórico como prático. Assim, foi determinada a componente sistemática no Datum de Imbituba, a partir da comparação de um geóide gravimétrico da América do Sul, obtido através da colocação por mínimos quadrados, e o geóide GPS/nivelamento, determinado através dos dados da Rede GPS do Sul/Sudeste do Brasil (RGSB). Para representar a componente sistemática no Datum altimétrico brasileiro, foram usados três formas: 1) determinação da componente sistemática na RN fundamental da RAFB (RN 4X), 2) cálculo da média ponderada da componente sistemática a partir das RNs mais próximas ao Datum, e 3) modelagem da componente sistemática usando modelo matemático da transformação de similaridade a partir de todos os dados da RGSB. Os resultados, obtidos no cálculo do nível médio do mar a partir de dados oceanográficos, mostram que as diferenças em relação ao marégrafo de Imbituba são, em grande parte, causadas por mudanças das características oceanográficas (salinidade, temperatura, densidade e pressão) ao longo da costa. A remoção da componente sistemática, obtida no Datum, diminuiu significativamente a diferença entre os geóides gravimétrico e GPS/nivelamento nas RNs da RAFB; entretanto o ajuste da componente sistemática, através da transformação de similaridade, utilizando todos os dados da RGSB, apresentou os melhores resultados na compatibilização dos geóides gravimétricos e GPS/nivelamento. ix / A study on the compatibility of a recent gravimetric geoid with the mean sea level in altimetric Datum of the Sistema Geodésico Brasileiro (SGB) was accomplished. The used methodology consists in comparing gravimetric geoid with mean sea level, at the tide gauge of Imbituba (SC), and the analysis of differences among tide gauges of Brazilian coast with respecto Imbituba, obtained by geometric levelling and oceanographic data. The unification of altimetric Data, investigated in several geodetic research centres, aiming the standardization of orthometric heights in regional and global scales by using spatial positioning techniques, and gravimetric geoid models. Among the suggestions for the altimetric Data unification, the use of gravimetric geoid models is adequate in both, theoretical and practical points of view. Thus, a systematic component at Imbituba Datum was determined by comparing a South American gravimetric geoid, obtained by least-squares collocation, and GPS/levelling geoid, determined at stations of the Rede GPS no Sul/Sudeste do Brasil (RGSB). To represent the systematic component in Brazilian altimetric Datum, three aproaches were used: 1) determining the systematic component at the fundamental benchmark of the RAFB (RN 4X); 2) computing the weighted mean from the stations closer to the Datum, and 3) modelling the systematic component by using the similarity transformation model from all stations of the RGSB, The results of mean sea level, computed from oceanographic data, show that differences with respect to Imbituba tide gauge are mostly due to oceanographic characteristics, (salinity, temperature, density, and pressure) along the coast. The removal of systematic component at Datum, has significantly reduced the difference between gravimetric and GPS/levelling geoids; however, the adjustment of systematic component by using the similarity transformation model, has shown the best results in representing the differences between gravimetric and GPS/levelling geoids.
10

„Omne Datum Optimum“ (Päpstliches Privileg)

Napp, Anke 08 April 2024 (has links)
No description available.

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