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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.
21

氣球載具航空攝影測量之研究 / AERIAL PHOTOGRAMMETRY USING A BALLOON PLATFORM

林士淵, Lin, Shih Yuan Unknown Date (has links)
為有效了解地表資訊,可視研究目的而利用各種遙測方法獲取地面影像,但不論目前常用之飛機、或是以衛星為載具之空中攝影測量等相關研究,在影像獲取方面,常面臨成本費用、機動性、比例尺需求、後續影像處理等問題。因此,本研究選定一小流域面積之河川作為實驗區,並設計以氣球為載具之數值航空攝影方式,裝載CCD攝影機以及數位攝影機,透過CCD攝影機,即時無線傳輸地面影像至監視螢幕,調整氣球至預定之位置後,遙控啟動數位攝影機之快門裝置。   研究設計之攝影方式曾實際應用於偵測河道之變遷,由成果影像中檢核點之精度結果,以及套疊正射糾正並鑲嵌後之河道影像與地形圖之成果,證明氣球載具之數值航空攝影方式,確能有效應用於大比例尺製圖之研究。 / Using a flexible and efficient way to obtain aerial images has been the primary purpose of this study. The balloon platform was used to take aerial images. A video camera and a digital camera were fixed together in a durable plastic box, and hung on the balloon. The video camera was used to monitor the ground view, and its image could be telemetered remotely and displayed on a LCD monitor arranged on the ground. Once monitoring the area of interest shown on the LCD, the shutter button of the digital camera was then pushed remotely and the interested image was taken.   The resultant images were ortho-rectified for analysis and comparison. The accuracy of aerial images was examined by check points. The results showed that the images achieved sub-pixel accuracy and were well-matched with the 1/1000 digital topographic maps. This expressed that it was really a useful and efficient method of taking large-scale images for a small research area.   At last, post-classification comparison method was introduced to detect change of the ortho-rectified images which were taken in three different periods. The classification maps and the from-to change class information clearly indicated the change of river way among various periods.
22

Eddy-covariance carbon balance, photosynthetic capacity and vegetation indices in a harvested boreal jack pine stand

Hawthorne, Iain 05 1900 (has links)
Eddy-covariance (EC) CO₂ flux data were analysed and annual carbon (C) balances estimated for a four-year period (2004-2007) following clearcut harvesting of a boreal jack pine stand in northern Saskatchewan. The site was a source of C to the atmosphere for all years, with annual net ecosystem productivity (NEP) increasing from -153 g C m⁻² yr⁻¹ in 2004 to -63 g C m⁻² yr⁻¹ in 2007. This increase was mainly due to gross primary productivity (GPP) increasing significantly from 78 to 200 g C m⁻² yr⁻¹ , while ecosystem respiration (R) increased only slightly from 231 to 263 g C m⁻² yr⁻¹ over the same period. In the 2006 growing season (GS), a field campaign was conducted to investigate the relationships between monthly destructive measurements of leaf area index (LAI) and daily measurements of the normalized difference vegetation index (NDVI) and photosynthetic capacity (Amax). The latter was derived from 5-day, 16-day, 30-day and annual Michaelis-Menten light response analyses using daytime measurements of NEP and incident photosynthetically active radiation. Digital-camera data were used to evaluate the potential of using the rectilinear-lens vegetation index (RLVI) as a surrogate for NDVI of a young forest stand. Results showed that LAI was linearly related to NDVI and RLVI, which was largely the result of changes in the deciduous vegetation component across the GS. These results indicate that RLVI could be used as a surrogate for NDVI up to a GS maximum LAI of 0.91 m2 m⁻² observed in 2006. Measured mean (± 1 S.D.) GS LAI was 0.67 (± 0.24) m² m⁻² in 2006. LAI accounted for the majority of the variability in Amax at the 30-day time scale, while at shorter time scales air temperature was the dominant control. For 2004 to 2007, mean spring estimates of LAI were 0.25, 0.29, 0.38 (compared to 0.40 m² m⁻² from measurements) and 0.41 m² m⁻², respectively. Results suggest that a steady increase in the jack pine LAI component accounted for the annual increases in GPP and hence NEP over the four years.
23

Communicating Corporate Identity Through Form Attributes And Evaluating Visual Analogy Of Digital Cameras.

Cekceoglu, Engin 01 November 2006 (has links) (PDF)
The basic notion of this study is related with visual attributes of products which reflect the identity of the company as well as form and design consistency which is a factor forming corporate identity. The sub-notions of the topic are elaborated in the literature review. The efforts which aimed at finding out the distinguishing characteristics of products focused on certain sample products. Digital camera is selected for the field study. The objective of the study is to put evidence that firms can be distinguished from each other with the help of visual attributes of their products and to determine which factors are effective throughout this process.
24

Eddy-covariance carbon balance, photosynthetic capacity and vegetation indices in a harvested boreal jack pine stand

Hawthorne, Iain 05 1900 (has links)
Eddy-covariance (EC) CO₂ flux data were analysed and annual carbon (C) balances estimated for a four-year period (2004-2007) following clearcut harvesting of a boreal jack pine stand in northern Saskatchewan. The site was a source of C to the atmosphere for all years, with annual net ecosystem productivity (NEP) increasing from -153 g C m⁻² yr⁻¹ in 2004 to -63 g C m⁻² yr⁻¹ in 2007. This increase was mainly due to gross primary productivity (GPP) increasing significantly from 78 to 200 g C m⁻² yr⁻¹ , while ecosystem respiration (R) increased only slightly from 231 to 263 g C m⁻² yr⁻¹ over the same period. In the 2006 growing season (GS), a field campaign was conducted to investigate the relationships between monthly destructive measurements of leaf area index (LAI) and daily measurements of the normalized difference vegetation index (NDVI) and photosynthetic capacity (Amax). The latter was derived from 5-day, 16-day, 30-day and annual Michaelis-Menten light response analyses using daytime measurements of NEP and incident photosynthetically active radiation. Digital-camera data were used to evaluate the potential of using the rectilinear-lens vegetation index (RLVI) as a surrogate for NDVI of a young forest stand. Results showed that LAI was linearly related to NDVI and RLVI, which was largely the result of changes in the deciduous vegetation component across the GS. These results indicate that RLVI could be used as a surrogate for NDVI up to a GS maximum LAI of 0.91 m2 m⁻² observed in 2006. Measured mean (± 1 S.D.) GS LAI was 0.67 (± 0.24) m² m⁻² in 2006. LAI accounted for the majority of the variability in Amax at the 30-day time scale, while at shorter time scales air temperature was the dominant control. For 2004 to 2007, mean spring estimates of LAI were 0.25, 0.29, 0.38 (compared to 0.40 m² m⁻² from measurements) and 0.41 m² m⁻², respectively. Results suggest that a steady increase in the jack pine LAI component accounted for the annual increases in GPP and hence NEP over the four years.
25

Estimativa da altura e produtividade da cana-de-açúcar utilizando imagens obtidas por aeronave remotamente pilotada / Height and productivity estimation of sugarcane using images obtained by remotely piloted aircraft

Maurício Martello 20 June 2017 (has links)
Nos últimos anos, acompanhar o desenvolvimento de uma cultura tem se tornado cada vez mais imprescindível para a tomada de decisões. Sistemas aéreos remotamente pilotados são muito promissores em aplicações de monitoramento. Sua flexibilidade, facilidade de operação e construção relativamente barata os tornam os melhores candidatos para monitorar atividades na agricultura de precisão, onde as reações imediatas de manejo às doenças das plantas, à falta de nutrientes das plantas e às mudanças ambientais são o ponto focal para eficiência e produtividade das plantações. No entanto, no Brasil a utilização desta tecnologia ainda é limitada e o número de publicações científicas sobre o assunto é escasso. No caso específico da cana-de-açúcar, a utilização de aeronave remotamente pilotada (RPA) é bastante promissora e publicações científicas internacionais são limitadas. O objetivo deste trabalho foi avaliar a potencialidade de imagens obtidas a partir de câmeras com diferentes bandas espectrais embarcadas em RPA para obtenção de modelos tridimensionais para estimativa de altura, produtividade e variabilidade espacial. As coletas foram realizadas ao longo da safra 2014/2015, durante o período de um ano. Foi utilizada uma aeronave remotamente pilotada equipada com uma câmera digital com sensibilidade na região espectral do visível (RGB) e outra na região espectral do infravermelho próximo (IVP) sincronizadas com um sistema de navegação global por satélite (GNSS). Este sistema possibilitou a aquisição de imagens com altíssima resolução (3 cm pixel-1) e permitiu a geração de orto-mosaicos e modelos digitais de superfícies (MDS) através de métodos de reconstrução automática em 3D, ajustados por pontos de controle em solo. O RPA seguiu um plano de voo pré-determinado sobre o local do estudo para garantir a aquisição de imagens com cruzamento e sobreposição superior a 90%. O método de validação foi conduzido a partir das medidas de altura obtidas a campo com o auxílio de régua topográfica. Após o processamento das imagens aéreas foi possível a identificação das áreas com ausência de fechamento de dossel, observando também a relação desses locais com o baixo desenvolvimento da altura das plantas ao longo de seu ciclo. A regressão entre os valores da estimativa de altura obtidas com as simulações apresentou erro relativo inferior a 13%, já a estimativa da produtividade apresentou erro na faixa de 6%. A estimativa de altura e produtividade demonstram o alto potencial para o monitoramento e avaliação de talhões de cana-de-açúcar, podendo ser uma ferramenta utilizada no apoio a gestão destas áreas. / In the last few years, monitoring the development of a culture has become increasingly imperative for decision-making. Remotely piloted aircraft systems (RPA) are very promising in monitoring applications. Their flexibility, ease of operation, and relatively inexpensive construction make them the best candidates to monitor precision farming activities where immediate management responses to plant diseases, lack of plant nutrients, and environmental changes are the focal point for efficiency And productivity of plantations. However in Brazil the use of this technology is still limited and the number of scientific publications on the subject is scarce. In the specific case of sugarcane the use of RPA is very promising and international scientific publications are limited. The objective of this work was to evaluate the potentiality of images obtained from cameras with different spectral bands embedded in RPA to obtain three - dimensional models for estimation of height, productivity and spatial variability. The collections were carried out during the 2014/2015 harvest, during a period of one year, using a remotely piloted aircraft equipped with a digital camera with sensitivity in the visible spectral region (RGB) and another in the near infrared spectral region (NIR) Synchronized with a GNSS. This system allowed the acquisition of images with very high resolution (3 cm pixel-1) allowing the generation of ortho-mosaics and digital surface models (DSM), through automatic 3D reconstruction methods adjusted by control points in soil. The RPA followed a pre-determined flight plan on the study site to ensure cross-over and overlapping acquisition of over 90%. The validation method was carried out from the height measurements obtained in the field with the aid of topography. After the aerial images processing, it was possible to identify the areas of crop failure, also observing the relation of these locations with the low development of plant height throughout its cycle. The regression between the values of the height estimation obtained with the simulations resulted in a relative error of less than 13%. The results obtained demonstrate the high potential of this technique for monitoring and evaluation of sugarcane fields, and can be a tool used to support the management of these areas.
26

Eddy-covariance carbon balance, photosynthetic capacity and vegetation indices in a harvested boreal jack pine stand

Hawthorne, Iain 05 1900 (has links)
Eddy-covariance (EC) CO₂ flux data were analysed and annual carbon (C) balances estimated for a four-year period (2004-2007) following clearcut harvesting of a boreal jack pine stand in northern Saskatchewan. The site was a source of C to the atmosphere for all years, with annual net ecosystem productivity (NEP) increasing from -153 g C m⁻² yr⁻¹ in 2004 to -63 g C m⁻² yr⁻¹ in 2007. This increase was mainly due to gross primary productivity (GPP) increasing significantly from 78 to 200 g C m⁻² yr⁻¹ , while ecosystem respiration (R) increased only slightly from 231 to 263 g C m⁻² yr⁻¹ over the same period. In the 2006 growing season (GS), a field campaign was conducted to investigate the relationships between monthly destructive measurements of leaf area index (LAI) and daily measurements of the normalized difference vegetation index (NDVI) and photosynthetic capacity (Amax). The latter was derived from 5-day, 16-day, 30-day and annual Michaelis-Menten light response analyses using daytime measurements of NEP and incident photosynthetically active radiation. Digital-camera data were used to evaluate the potential of using the rectilinear-lens vegetation index (RLVI) as a surrogate for NDVI of a young forest stand. Results showed that LAI was linearly related to NDVI and RLVI, which was largely the result of changes in the deciduous vegetation component across the GS. These results indicate that RLVI could be used as a surrogate for NDVI up to a GS maximum LAI of 0.91 m2 m⁻² observed in 2006. Measured mean (± 1 S.D.) GS LAI was 0.67 (± 0.24) m² m⁻² in 2006. LAI accounted for the majority of the variability in Amax at the 30-day time scale, while at shorter time scales air temperature was the dominant control. For 2004 to 2007, mean spring estimates of LAI were 0.25, 0.29, 0.38 (compared to 0.40 m² m⁻² from measurements) and 0.41 m² m⁻², respectively. Results suggest that a steady increase in the jack pine LAI component accounted for the annual increases in GPP and hence NEP over the four years. / Land and Food Systems, Faculty of / Graduate
27

Spatial measurement with consumer grade digital cameras

Wackrow, Rene January 2008 (has links)
No description available.
28

Analýza tvorby třísky pomocí digitální vysokorychlostní kamery / Analysis of chip forming mechanism with a high-speed digital camera

Kubela, Petr January 2009 (has links)
In live we often involve monitoring of very fast actions, that are not observable by the human eye. The thesis focuses on possibilities of high speed digital cameras, their application in industry, and the mechanism of chip formation. The experiment part aims to record the chosen process of chip machining and the problems of necessary illumination during the process of object imaging.
29

Analýza tvorby třísky pomocí digitální vysokorychlostní kamery / Analysis of chip forming mechanism with a high-speed digital camera

Frňka, Václav January 2010 (has links)
This thesis is focused on possibilities of high-speed digital cameras and their use in different fields of industry. It describes the mechanism of chip forming in orthogonal turning. Subsequently experiments focused on comparison and select the right lens and method of illumination are implemented. These findings are then used in obtaining the record of chip forming by using high-speed digital camera. Key words
30

Návrh a výroba kamerového modulu / Design and implementation of camera module

Vokoun, Ondřej January 2012 (has links)
Cílem diplomové práce je navrhnout levný, avšak dostatečně výkonný a univerzální systém, schopný snímání a zpracování obrazu z digitální kamery. Další částí je návrh a implementace funkcí pro zpracování obrazu a komunikace s nadřazeným systémem.

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