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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.
11

Extração semi-automática do eixo de rodovia em imagens de média e alta resolução usando programação dinâmica /

Vale, Giovane Maia do. January 2003 (has links)
Orientador: Aluir Porfírio Dal Poz / Resumo: A aquisição de informações espaciais é uma das tarefas mais dispendiosa e morosa na implantação e na manutenção de Sistemas de informação Geográfica (SIG's). Nos últimos 30 anos, inúmeras pesquisas foram realizadas objetivando o melhoramento do tempo e custo da aquisição de dados espaciais. No que se refere a aquisição de dados espaciais a partir de imagens digitais, é possível notar que os métodos desenvolvidos até então estão mais próximos desta meta quando os respectivos níveis de automação são mais altos. Como as soluções totalmente automáticas não estão ainda no mesmo nível de confiabilidade dos métodos manuais, soluções semi-automáticas combinando a habilidade natural de operadores humanos em tarefas de reconhecimento e a capacidade de algoritmos computacionais em realizar tarefas de medidas precisas e morosas, têm sido propostas. Seguindo esta tendência, este trabalho propõe uma metodologia semi-automática para a extração de rodovias em imagens digitais de média e alta resolução baseada no algoritmo de otimização global de programação dinâmica. É importante enfatizar que os trabalhos relacionados com extração de feições através de programação dinâmica sempre usam imagens de baixa resolução, na qual as rodovias manifestam-se como estruturas lineares. Ao contrário, rodovias em imagens de média e alta resolução se manifestam como faixas alongadas. Assim, como neste caso o objetivo básico é extrair o eixo da rodovia, este trabalho propõe uma modificação na função custo usada numa metodologia preexistente baseada em programação dinâmica, permitindo que o eixo central da rodovia seja precisamente extraído pela metodologia modificada. A diferença básica entre este método modificado e o original é uma função de injunção, proposta com o objetivo de incorporar características de bordas de rodovia...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The acquisition of spatial information is one of most expensive and time consuming tasks in developing and maintaining Geographical Information Systems (GIS's). In the last 30 years, countless researches have been accomplished aiming at improvement of spatial data acquisition time and cost. Related to the spatial data acquisition from digital images, it is possible to notice that the methods developed until now are closer to that goal when the respective levels of automation are higher. As fully automatic solutions are not in same level of reliability of manual procedures, semi-automatic solutions combining the natural skill of humans operators in recognizing tasks and the power of computational algorithm in carrying out precise and time consuming measurement tasks, have been proposed. Following this trend, this work proposes a semi-automatic methodology for road extraction from mediumand high-resolution digital images based on the global optimization algorithm of dynamic programming. It is important to emphasize that related works on feature extraction by dynamic programming always use low-resolution images, in which roads manifest as linear structures. As opposed to this, roads in medium- and high-resolution manifest as elongated regions. Thus, as in this case the basic objective is to extract the road centerline, this work proposes a modification of cost function used in a preexisting dynamic programming approach, allowing the road centerline to be precisely extracted by the modified method. The basic difference between this modified method and the original one is the proposed constraint function embodying some road edge characteristics, as e.g. the anti-parallelism of gradient vectors at two pixels situated on opposite road edges and belonged to the same road crosssection...(Complete abstract click electronic access below) / Mestre
12

數值航攝資料控制之研究-以政治大學校區為例 / A Study on Control Surveying of Digital Aerial Photographic Data -- An Example of Cheng-Chi University Campus

黃琬瑜, Huang, Wan-Yu Unknown Date (has links)
台灣地區地小人稠,土地使用情況複雜,因此,土地管理為一重要課題。航攝資料具高空間解析力及幾何真實性之特性,若能快速取得,則有助於長期環境監測與土地永續利用。有鑑於此,本研究以機動性高之直昇機為載具,配合9cm焦距之攝影機,採用11.5cm ×11.5cm像幅之彩色正片,航空拍攝實驗區,並於拍攝前佈設空照標,且利用全球定位系統測定地面控制點。 本研究目的在探討小像幅數值影像於重建方位過程中,攝影條件之特性及地面控制之成果,此外,利用解析測圖儀與影像工作站不同量測方法對於空中三角精度影響,結果顯示小像幅亦可完成數值空中三角測量。數位法X、Y、Z方向之RMSE為0.097 m、0.090 m、0.161 m,解析法之RMSE為0.132 m、0.120 m、0.144 m。 / The objective of this thesis has been to investigate the feasibility of digital aerotriangulation using small format photos. A focal length of 9mm camera mounted on a helicopter with format of 11.5cm by 11.5cm color positives have been used for taking pictures of the research area. The premarked ground control points were surveyed by GPS. Photo control was executed using a Leica BC3 analytical plotter and an Intergraph ImageStation respectively. The coordinates measurements of photo points using the two instruments have been evaluated. Both of interior and exterior parameters computed from digital triangulation and digitized photos have been used to produce the orthoimage. The resultant orthoimage was then superimposed and compared with the existing 1/1000 digital map. The results have indicated that: 1. The RMSE of digital method were X = 0.097m, Y = 0.090m, Z = 0.161m; the RMSE of analytical method were X = 0.132m, Y = 0.120m, Z = 0.144m; 2. Digital aerotriangulation could be performed using small format photos.
13

Fatigue Does Not Affect The Kinematics Of Free Throw Shooting In Basketball

Uygur, Mehmet 01 September 2009 (has links) (PDF)
Kinematic analysis of basketball shooting is evolving, however the effects of fatigue on free throw shooting have not been studied. Therefore the effects of fatigue on the kinematics of free throw shooting among elite male basketball players was assessed. Ten healthy male collegiate basketball players participated in the study. Resting and fatigue heart rates of the participants were measured. After a 15 minute warm-up period, markers were placed on seven locations on the shooting arm&rsquo / s side upper and lower extremities. The free throw shots were recorded with two digital cameras at a speed of 60 frames/s at a stereoscopic position. Data were analyzed with the photogrammetry technique. Each participant performed free throw shots (pre-fatigue condition) until the two successful and two unsuccessful shots were collected. Then participants completed a fatigue protocol, which included sprints and squat jumping, until reaching their volitional exhaustion and free throw shots were repeated (post-fatigue condition). The elbow, trunk, knee and ankle joint angles were measured. Successful and unsuccessful shots were compared for pre- and post-fatigue conditions. The results demonstrated that fatigue did not affect free throw shooting and there was no significant joint angle difference (p&gt / .05) between successful and unsuccessful shots (p&gt / .05). It was concluded that fatigue does not affect the kinematics of free throw shooting of healthy male collegiate basketball players and there were no differences in the kinematics of selected joint angles for successful and unsuccessful free throw shots.
14

Geração automática de estereomodelos a partir de imagens digitais georreferenciadas

Ruy, Roberto da Silva [UNESP] January 2004 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2004Bitstream added on 2014-06-13T19:09:21Z : No. of bitstreams: 1 ruy_rs_me_prud.pdf: 1282803 bytes, checksum: 215286fc5792de43deaba801a4b4da8b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Com a disponibilidade de câmaras digitais, dados de posicionamento por satélites (GPS) e sistemas inerciais (INS), tornaram-se possíveis novas aplicações que envolvem a obtenção de produtos cartográficos em quase tempo real (após o processamento dos dados coletados em vôo), como o monitoramento de desastres ambientais. Tais aplicações necessitam de informações georreferenciadas com características de rapidez e confiabilidade, que podem ser obtidas pela técnica fotogramétrica digital, apoiada pelos sensores que fornecem a orientação direta da câmara. Em geral, os parâmetros fornecidos pelos sensores de orientação utilizados para mapeamento não possuem a acurácia necessária para eliminar totalmente a paralaxe vertical do modelo e, por conseguinte, a visualização estereoscópica da cena fica prejudicada. Para resolver este problema, propôs-se uma metodologia que é baseada na compatibilização dos parâmetros de orientação direta (GPS + INS), mediante um modelo de coplanaridade modificado, num ajustamento pelo método dos Mínimos Quadrados. Os valores observados correspondem a pontos homólogos medidos automaticamente no modelo por técnicas de correlação por área. Após o refinamento dos parâmetros de orientação exterior (OE), as imagens são normalizadas por meio de uma reamostragem epipolar, com intuito de proporcionar uma melhor visualização estereoscópica da cena e auxiliar o processo de geração automática de Modelos Digitais de Terreno. Neste sentido, módulos computacionais foram desenvolvidos em linguagem C++ para a geração totalmente automática de estereomodelos em quase tempo real. Experimentos com dados simulados e reais foram conduzidos, na ordem de verificar a eficácia da metodologia com respeito a eliminação da paralaxe vertical do modelo e a acurácia das coordenadas no espaço objeto calculadas por intersecção... / With the availability of digital cameras, satellite positioning systems (GPS) and inertial navigation systems (INS), new applications such as fast cartography and real time environmental monitoring became feasible. Such applications require georeferenced information with characteristics of speed and reliability that can be obtained by digital photogrammetry, using additional data from sensors of direct orientation. Generally, the parameters supplied by the sensors are under the required accuracy to elimine the vertical parallax in the model. To solve this problem, the methodology proposed in this project is based on the reprocessing of the parameters of orientation supplied by the sensors, using a modified coplanarity model. The observations are the images coordinates automatically measured in each image using an area-based correspondence method. After the EO parameters refinement, using the modified coplanarity model, the images are normalized through an epipolar resampling, in order to provide a confortable stereoscopic visualization of the model, since vertical parallax is eliminated, and to facilitate the process of automatic Digital Terrain Model generation. In order to test the proposed approach, computational programs were developed in C++ language, enabling the full automatic generation of estereomodelos in almost real time. Experiments with simulated and real data were performed, in order to verify the performance of the method with respect to y-parallax elimination and accuracy of reconstructed object space coordinates. These experiments are presented and discussed showing the effectiveness of the proposed approach for automatic generation of stereo models.
15

Extração semi-automática do eixo de rodovia em imagens de média e alta resolução usando programação dinâmica

Vale, Giovane Maia do [UNESP] January 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T19:09:22Z : No. of bitstreams: 1 vale_gm_me_prud.pdf: 5334838 bytes, checksum: f4c575bb08745181de4e5d2261cfe821 (MD5) / A aquisição de informações espaciais é uma das tarefas mais dispendiosa e morosa na implantação e na manutenção de Sistemas de informação Geográfica (SIG’s). Nos últimos 30 anos, inúmeras pesquisas foram realizadas objetivando o melhoramento do tempo e custo da aquisição de dados espaciais. No que se refere a aquisição de dados espaciais a partir de imagens digitais, é possível notar que os métodos desenvolvidos até então estão mais próximos desta meta quando os respectivos níveis de automação são mais altos. Como as soluções totalmente automáticas não estão ainda no mesmo nível de confiabilidade dos métodos manuais, soluções semi-automáticas combinando a habilidade natural de operadores humanos em tarefas de reconhecimento e a capacidade de algoritmos computacionais em realizar tarefas de medidas precisas e morosas, têm sido propostas. Seguindo esta tendência, este trabalho propõe uma metodologia semi-automática para a extração de rodovias em imagens digitais de média e alta resolução baseada no algoritmo de otimização global de programação dinâmica. É importante enfatizar que os trabalhos relacionados com extração de feições através de programação dinâmica sempre usam imagens de baixa resolução, na qual as rodovias manifestam-se como estruturas lineares. Ao contrário, rodovias em imagens de média e alta resolução se manifestam como faixas alongadas. Assim, como neste caso o objetivo básico é extrair o eixo da rodovia, este trabalho propõe uma modificação na função custo usada numa metodologia preexistente baseada em programação dinâmica, permitindo que o eixo central da rodovia seja precisamente extraído pela metodologia modificada. A diferença básica entre este método modificado e o original é uma função de injunção, proposta com o objetivo de incorporar características de bordas de rodovia... / The acquisition of spatial information is one of most expensive and time consuming tasks in developing and maintaining Geographical Information Systems (GIS’s). In the last 30 years, countless researches have been accomplished aiming at improvement of spatial data acquisition time and cost. Related to the spatial data acquisition from digital images, it is possible to notice that the methods developed until now are closer to that goal when the respective levels of automation are higher. As fully automatic solutions are not in same level of reliability of manual procedures, semi-automatic solutions combining the natural skill of humans operators in recognizing tasks and the power of computational algorithm in carrying out precise and time consuming measurement tasks, have been proposed. Following this trend, this work proposes a semi-automatic methodology for road extraction from mediumand high-resolution digital images based on the global optimization algorithm of dynamic programming. It is important to emphasize that related works on feature extraction by dynamic programming always use low-resolution images, in which roads manifest as linear structures. As opposed to this, roads in medium- and high-resolution manifest as elongated regions. Thus, as in this case the basic objective is to extract the road centerline, this work proposes a modification of cost function used in a preexisting dynamic programming approach, allowing the road centerline to be precisely extracted by the modified method. The basic difference between this modified method and the original one is the proposed constraint function embodying some road edge characteristics, as e.g. the anti-parallelism of gradient vectors at two pixels situated on opposite road edges and belonged to the same road crosssection...(Complete abstract click electronic access below)
16

Estudo e implementação de técnicas de sincronismo de dispositivos para o georreferenciamento de imagens digitais

Reis, Thiago Tiedtke dos. January 2009 (has links)
Resumo: Atualmente, sensores de posição e orientação podem ser adquiridos e integrados com um custo relativamente baixo, fornecendo resultados promissores em aplicações como o mapeamento. Neste contexto, câmaras digitais de pequeno e médio formato proporcionam novos horizontes aos processos de mapeamento, devido às diversas vantagens sobre sistemas convencionais, como custo reduzido, pequenas dimensões, menor peso e fácil manejo. Mas, fatores como estabilidade geométrica e resolução dos sensores ainda podem se tornar limitantes para determinadas aplicações, devendo ser observados e corrigidos nos processos de produção. Neste contexto, este trabalho teve como objetivo o estudo e implementação de hardware e software para permitir o sincronismo entre o receptor GPS e câmaras digitais para aplicações de mapeamento. O sincronismo baseou-se no uso do sistema operacional Linux com modificações em seu núcleo, juntamente com o software NTP, responsável por sincronizar o relógio do computador usando uma referência de tempo externa, no caso o PPS de um receptor GPS. A validação foi realizada comparando-se diretamente os instantes registrados pelo sistema comercial SPAN-CPT e a técnica proposta neste trabalho. Além disto, os Centros Perspectivos determinados pelas técnicas implementadas foram usados em experimentos com fototriangulação de um bloco de imagens, possibilitando a análise das discrepâncias da fototriangulação nos pontos de verificação. O resultado do sincronismo apresentou pequenas discrepâncias em relação ao sistema comercial, implicando na determinação das coordenadas dos CPs com boa qualidade, permitindo seu uso em mapeamento e em outras aplicações. / Abstract: Currently, position and orientation sensors can be acquired and integrated with affordable costs, providing valuable results in mapping applications. In this context, small and medium format digital cameras are offering new horizons in mapping processes, due to several advantages when compared to conventional systems, like: low cost, low size, less weight and easy of handling. However, its internal stability and resolutions can limit use in some applications. This work aims at the study and implementation of hardware and software components for synchronization of a GPS receiver and digital cameras for mapping applications. Synchronization was based on Linux operational system with a modified kernel, and NTP software, used to synchronize computer time with the GPS reference time, through the 1 PPS pulse. The validation of the implemented system was done by comparing directly the recorded events from a commercial navigation system (SPAN-CPT) and from the proposed techniques. Furthermore, the PC coordinate determined by these techniques were used in an aerial triangulation, enabling the analysis of discrepancies in the checkpoints. The result of the synchronization showed small discrepancies with the commercial system, resulting in the determination of the PC coordinates with good quality, enabling its use in mapping and several other applications. / Orientador: Antonio Maria Garcia Tommaselli / Coorientador: Paulo de Oliveira Camargo / Banca: Edson Aparecido Mitishita / Banca: Julio Kiyoshi Hasegawa / Mestre
17

Historical aerial photographs and digital photogrammetry for landslide assessment

Walstra, Jan January 2006 (has links)
This study demonstrates the value of historical aerial photographs as a source for monitoring long-term landslide evolution, which can be unlocked by using appropriate photogrammetric methods. The understanding of landslide mechanisms requires extensive data records; a literature review identified quantitative data on surface movements as a key element for their analysis. It is generally acknowledged that, owing to the flexibility and high degree of automation of modern digital photogrammetric techniques, it is possible to derive detailed quantitative data from aerial photographs. In spite of the relative ease of such techniques, there is only scarce research available on data quality that can be achieved using commonly available material, hence the motivation of this study. In two landslide case-studies (the Mam Tor and East Pentwyn landslides) the different types of products were explored, that can be derived from historical aerial photographs. These products comprised geomorphological maps, automatically derived elevation models (DEMs) and displacement vectors. They proved to be useful and sufficiently accurate for monitoring landslide evolution. Comparison with independent survey data showed good consistency, hence validating the techniques used. A wide range of imagery was used in terms of quality, media and format. Analysis of the combined datasets resulted in improvements to the stochastic model and establishment of a relationship between image ground resolution and data accuracy. Undetected systematic effects provided a limiting constraint to the accuracy of the derived data, but the datasets proved insufficient to quantify each factor individually. An important advancement in digital photogrammetry is image matching, which allows automation of various stages of the working chain. However, it appeared that the radiometric quality of historical images may not always assure good results, both for extracting DEMs and vectors using automatic methods. It can be concluded that the photographic archive can provide invaluable data for landslide studies, when modern photogrammetric techniques are being used. As ever, independent and appropriate checks should always be included in any photogrammetric design.
18

Sistema de controle de qualidade dos processos fotogramétricos digitais para produção de dados espaciais / Quality control system of the digital photogrammetric process for producing spatial data

Sato, Simone Sayuri 28 August 2003 (has links)
Este trabalho propõe um Sistema de Controle de Qualidade (CQP) dos processos fotogramétricos digitais para a produção de dados espaciais baseados nos conceitos de gestão de qualidade ISO 9000 e nas diretrizes normativas suíças e norte-americanas. Procurou-se obter parâmetros de qualidade em cada um dos processos fotogramétricos digitais, de forma a garantir a qualidade final dos produtos e satisfazer às necessidades de precisão e exatidão dos dados espaciais e as suas aplicações. As principais fontes de erros são identificadas e comentadas e algumas das soluções propostas foram testadas com sucesso. / This work is aimed to the development of a Quality Control Process to be applied in the digital photogrametric processes that are part of the spatial data production. It is based on quality managements standards of ISO 9000 and in the Swiss and North American standards guidelines. Each step of the process was investigated to obtain individual parameters of quality that, collectively, were able to assure the quality of the end product, mostly in those aspects regarding the requirements for precision and accuracy. The main sources of errors are identified and discussed and some of the proposed solutions were tested successfully.
19

Sistema de controle de qualidade dos processos fotogramétricos digitais para produção de dados espaciais / Quality control system of the digital photogrammetric process for producing spatial data

Simone Sayuri Sato 28 August 2003 (has links)
Este trabalho propõe um Sistema de Controle de Qualidade (CQP) dos processos fotogramétricos digitais para a produção de dados espaciais baseados nos conceitos de gestão de qualidade ISO 9000 e nas diretrizes normativas suíças e norte-americanas. Procurou-se obter parâmetros de qualidade em cada um dos processos fotogramétricos digitais, de forma a garantir a qualidade final dos produtos e satisfazer às necessidades de precisão e exatidão dos dados espaciais e as suas aplicações. As principais fontes de erros são identificadas e comentadas e algumas das soluções propostas foram testadas com sucesso. / This work is aimed to the development of a Quality Control Process to be applied in the digital photogrametric processes that are part of the spatial data production. It is based on quality managements standards of ISO 9000 and in the Swiss and North American standards guidelines. Each step of the process was investigated to obtain individual parameters of quality that, collectively, were able to assure the quality of the end product, mostly in those aspects regarding the requirements for precision and accuracy. The main sources of errors are identified and discussed and some of the proposed solutions were tested successfully.
20

數值航攝影像應用於土地利用強度之研究 / A Study of Land Intensity Using Digital Aerial Photography Data

謝怡昇, Hsieh, Yi-Sheng Unknown Date (has links)
建蔽率、容積率為都市規劃及控制都市成長所必需之土地利用強度資訊,對這些資訊的狀況瞭解程度會影響整個都市規劃政策的好壞。而現行調查方式為人工現地調查,常需花費大量的人力與時間。實際上,數值航空攝影測量與地理資訊系統等技術的進步,已可應用於輔助建立這些方面的資訊。 本研究目的在結合數值航攝影像與地理資訊系統之技術,以應用於探求土地利用強度之相關資訊。研究主要從數值航攝影像中萃取三維空間資訊,利用地理資訊系統轉換成建蔽率及容積率等土地利用強度資訊。此外,為瞭解成果之精度,本研究亦曾以地面實際測量驗證數值航測成果,結果顯示,利用單像個別量測並利用前方交會計算高程之方式,已可達到精度之要求。除此之外,轉換後之建蔽率、容積率亦較建築物原計畫之建蔽率、容積率數據大約1.1∼1.2倍。研究顯示,在進行現地調查建蔽率、容積率之前,這種方式可為快速輔助判斷之良好工具。 / It needs the information of land use intensity to control the growth of cities, such as building coverage ratio and building bulk ratio. It spends much manpower and time to get the information. The improving technology of digital photogrammetry and geographic information systems can assist investigate and collect the information. The objective of this research has been to analyze the land use intensity with assistance of geographic information systems and digital photogrammetry. Digital aerial photographs have been used to collect 3-D spatial information of research area. This information has been imported into a geographic information system. Building coverage ratio and building bulk ratio of whole research area could be established thereafter. The information collected by digital photogrammetry has also been investigated and checked in situ. The results have indicated that: 1. The ratios of both building coverage ratio and building bulk ratio to the original planned record have been of 1.1~1.2. 2. The most suitable height of each floor is 3.3m when calculating the floor number of building in the research area. 3. Digital aerial photographs could be very useful when the information of land use intensity was required.

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