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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

Charakterizace elektrických vlastností solárních článků pomocí CCD kamery / Characterisation solar cell electric properties by CCD camera

Steiner, Patrik January 2008 (has links)
The aim of this thesis is the characterization of electrical properties of solar cell using CCD camera. Diagnostic methods are based on electroluminescence and microplasma emitted from the surface of the solar cell. The results are then compared with the method LBIC (Light Beam Induced Current) and described the various defects in industrial production.
22

An EPROM based waveform generator for a CCD test station

Hsieh, Long-Bing January 1988 (has links)
No description available.
23

"Validação das ferramentas de calibragem de medidas em três sistemas de radiografia digital" / Assessment of calibration tools of three digital radiography systems

Girondi, José Raul 30 March 2006 (has links)
O desenvolvimento tecnológico busca fatores que possibilitem uma menor exposição do paciente e profissional aos raios ionizantes, maior agilidade no atendimento ao paciente e maior auxilio no desenvolvimento do diagnóstico final. Assim a associação entre informática e radiologia básica, traduzidas como radiologia digital, fez-se conseguir os fatores buscados. Uma ferramenta dos sistema digitais é a calibração prévia às medidas. Com essas observações avaliamos tais ferramentas de três sistemas de radiografias digitais, objetivando validar e comprovar sua eficácia nas metodologias dos trabalhos presentes e futuros. Para tanto utilizamos 20 dentes humanos secos provindos do Banco de Dentes Permanentes da FOUSP, os quais foram radiografados com o auxílio de três sistemas de radiografia digital, direto e semidireto (Digora, RVG Trophy e Visualix). O padrão ouro das medidas dos dentes foi a verificação das dimensões dos dentes por meio de um paquímetro digital e posteriormente comparados os seus padrões de medidas com os softwares dos respectivos sistema. Os resultados foram analisados estatisticamente pelo ANOVA (métodos de Tukey e Dunnett), chegando às seguintes conclusões: existe diferença significante entre os aparelhos p<0,001; a média das medidas obtidas houve diferença significante (p<0,001) com o aparelho Digora foi menor que as médias obtidas com os aparelhos das marcas Visualix e RVG; considerando-se o padrão A e o padrão B de calibragem, não existe diferença estatística significante entre os avaliadores; considerando-se a calibragem sem padrão, um dos avaliadores obteve média mais elevada que os demais avaliadores no caso das medidas realizadas com o aparelho Digora, porém este fato não se repetiu quando da utilização dos outros aparelhos; comparando-se as medidas de referência (paquímetro) observa-se que mais uma vez o aparelho Digora (padrão A, padrão B e sem padrão) apresentou diferença significativa; os aparelhos das marcas Visualix e RVG não mostraram diferenças significativas quando comparados com o valor de referência. / Technological development aims at reducing exposure of both the professional and the patient to ionizing radiation, improving patient treatment and aiding final diagnosis. The combination of computer technology and radiology, i.e. digital radiography, has made this possible. One of the tools of digital radiography systems is calibration prior to measurement. The purpose of this study was to assess the calibration tools of three digital radiography systems to verify their efficacy. Twenty human teeth obtained from the Human Teeth Bank of the School of Dentistry, University of São Paulo, were used. The dry teeth were radiographed using three different direct digital radiography systems Digora, RVG Trophy and Visualix. The measurements of the teeth obtained with a digital caliper were considered the gold standard. These measurements were later compared with those obtained using the digital systems. The results were submitted to ANOVA (methods of Tukey and Dunnett), and the following conclusions were drawn: there was a significant difference between the systems used (p < 0.001); the averages of the measurements obtained with the three systems were significantly different (p<0,001). Visualix and RVG were more accurate than Digora considering A and B calibration standards, no significant difference was observed between the examiners; when there was no calibration standard and the Digora system was used, one examiner obtained more high averages measurements than the others; when there was no calibration standard and Visualix or RVG systems were used, no differences were observed between the examiners; the measurements obtained with Digora system (standards A, B or no standard) were statistically different from the gold standard the measurements obtained with Visualix and RVG systems presented no significant difference when compared with the gold standard.
24

"Validação das ferramentas de calibragem de medidas em três sistemas de radiografia digital" / Assessment of calibration tools of three digital radiography systems

José Raul Girondi 30 March 2006 (has links)
O desenvolvimento tecnológico busca fatores que possibilitem uma menor exposição do paciente e profissional aos raios ionizantes, maior agilidade no atendimento ao paciente e maior auxilio no desenvolvimento do diagnóstico final. Assim a associação entre informática e radiologia básica, traduzidas como radiologia digital, fez-se conseguir os fatores buscados. Uma ferramenta dos sistema digitais é a calibração prévia às medidas. Com essas observações avaliamos tais ferramentas de três sistemas de radiografias digitais, objetivando validar e comprovar sua eficácia nas metodologias dos trabalhos presentes e futuros. Para tanto utilizamos 20 dentes humanos secos provindos do Banco de Dentes Permanentes da FOUSP, os quais foram radiografados com o auxílio de três sistemas de radiografia digital, direto e semidireto (Digora, RVG Trophy e Visualix). O padrão ouro das medidas dos dentes foi a verificação das dimensões dos dentes por meio de um paquímetro digital e posteriormente comparados os seus padrões de medidas com os softwares dos respectivos sistema. Os resultados foram analisados estatisticamente pelo ANOVA (métodos de Tukey e Dunnett), chegando às seguintes conclusões: existe diferença significante entre os aparelhos p<0,001; a média das medidas obtidas houve diferença significante (p<0,001) com o aparelho Digora foi menor que as médias obtidas com os aparelhos das marcas Visualix e RVG; considerando-se o padrão A e o padrão B de calibragem, não existe diferença estatística significante entre os avaliadores; considerando-se a calibragem sem padrão, um dos avaliadores obteve média mais elevada que os demais avaliadores no caso das medidas realizadas com o aparelho Digora, porém este fato não se repetiu quando da utilização dos outros aparelhos; comparando-se as medidas de referência (paquímetro) observa-se que mais uma vez o aparelho Digora (padrão A, padrão B e sem padrão) apresentou diferença significativa; os aparelhos das marcas Visualix e RVG não mostraram diferenças significativas quando comparados com o valor de referência. / Technological development aims at reducing exposure of both the professional and the patient to ionizing radiation, improving patient treatment and aiding final diagnosis. The combination of computer technology and radiology, i.e. digital radiography, has made this possible. One of the tools of digital radiography systems is calibration prior to measurement. The purpose of this study was to assess the calibration tools of three digital radiography systems to verify their efficacy. Twenty human teeth obtained from the Human Teeth Bank of the School of Dentistry, University of São Paulo, were used. The dry teeth were radiographed using three different direct digital radiography systems Digora, RVG Trophy and Visualix. The measurements of the teeth obtained with a digital caliper were considered the gold standard. These measurements were later compared with those obtained using the digital systems. The results were submitted to ANOVA (methods of Tukey and Dunnett), and the following conclusions were drawn: there was a significant difference between the systems used (p < 0.001); the averages of the measurements obtained with the three systems were significantly different (p<0,001). Visualix and RVG were more accurate than Digora considering A and B calibration standards, no significant difference was observed between the examiners; when there was no calibration standard and the Digora system was used, one examiner obtained more high averages measurements than the others; when there was no calibration standard and Visualix or RVG systems were used, no differences were observed between the examiners; the measurements obtained with Digora system (standards A, B or no standard) were statistically different from the gold standard the measurements obtained with Visualix and RVG systems presented no significant difference when compared with the gold standard.
25

The SLD vertex detector upgrade (VXD3) and a study of bbg events

Dervan, Paul John January 1998 (has links)
This thesis presents a variety of work concerning the design, construction and use of the SLD's vertex detector. SLD's pioneering 120 Mpixel vertex detector, VXD2, was replaced by VXD3, a 307Mpixel CCD vertex detector in January 1996. The motivation for the up-grade detector and its subsquent construction and testing are described in some detail. This work represents the collaborative work of a large number of people. My work was mainly carried out at EEV on the testing of the CCDs and subsequent ladders. VXD3 was commissioned during the 1996 SLD run and performed very close to design specifications. Monitoring the position of VXD3 is crucial for reconstructing the data in the detector for physics analysis. This was carried out using a capacitive wire position monitoring system. The system indicated that VXD3 was very stable during the whole of the 1996 run, except for known controlled movements. VXD3 was aligned globally for each period in-between these known movements using the tracks from e+e- → Z° → hadrons. The structure of three-jet bbg events has been studied using hadronic Z° decays from the 1993-1995 SLD data. Three-jet final states were selected and the CCD-based vertex detector was used to identify two of the jets as a ь or ъ. The distributions of the gluon energy and polar angle with respect to the electron beam direction were examined and were compared with perturbative QCD predictions. If was found that the QCD Parton Shower prediction was needed to describe the data well. These distributions are potentially sensitive to an anomalous b chromomagnetic moment к. к was measured to be -0.031±0.038 0.039(Stat.)±0.003 0.004(Syst.), which is consistent with the Standard Model, with 95% confidence level limit, -0.106 < к < 0.044.
26

Využití metody DIC pro měření deformací na malých zkušebních tělesech / Application of DIC method for measurement of deformations on small specimens

Vejchoda, Ondřej January 2020 (has links)
This diploma thesis tries to find the most suitable optical system for measuring deformation displacements on the surfaces of bodies. The first chapter describes the systems and methods that will be used. The second chapter is devoted to the design of the experiment. It describes the preparation of the experiment from the point of view of software and hardware and what are the important preliminary preparations. The last chapter contains the results of experiments and evaluation of the systems.
27

Optimalizace předmontáže planetových koleček / Optimization of pre-assembly of planetary wheels

Krejcar, Pavel January 2010 (has links)
The aim of my thesis is a comperation with Linde Pohony s.r.o. Our aim is to suggest the realization of automatic control of pre-assembly of planetary wheels. The solution with CCD cameras and sensors is interpreted in a detailed way - treir reliability suggestibility by milieu and attendance service.The second part continue of a suggestion of automized workplace with a full detailed drawings. Abstrakt
28

Mise en oeuvre d'un mode d'imagerie par transillumination et détection multi-vue à ultra-faible bruit dans l'imageur QOS[indice supérieur TM] pour imagerie moléculaire optique sur petit animal / Implementation of transillumination mode and ultra-low noise multi-view detection in the QOS[superscript TM] for small animal optical molecular imaging

Zarif Yussefian, Nikta January 2014 (has links)
La tomographie optique diffuse (TOD) est une technique d’imagerie médicale relativement récente qui utilise la lumière dans le proche infrarouge pour acquérir des images in vivo de façon non invasive. Cette technique est en utilisation croissante par de nombreux chercheurs et biologistes et plusieurs équipes dans le monde travaillent sur le développement de scanners par TOD y compris notre groupe de recherche (groupe TomOptUS). Le Centre d’imagerie moléculaire de Sherbrooke dispose d’un appareil pour imagerie optique sur petit animal développé par la compagnie Quidd, soit le QOS (Quidd Optical imaging System). Cet appareil est utilisé par des biologistes et chercheurs pour diverses études précliniques sur modèles animaux (souris) de maladies humaines comme le cancer. Le QOS est entièrement contrôlé par ordinateur à l’aide d’un logiciel sophistiqué (le QOSoft) qui permet d’obtenir des images en fluorescence et en bioluminescence. Il est toutefois limité en ne permettant d’acquérir que des images planaires de la lumière sortant d’un animal ; il ne permet pas la tomographie, à savoir obtenir des images tridimensionnelles (3D) des sources fluorescentes ou bioluminescentes situées en profondeur à l’intérieur de l’animal. Bien que le QOS offre une grande flexibilité en terme d’angle d’acquisition d’images autour de l’animal avec sa caméra montée sur un bras rotatif, il a une sensibilité limitée pour de l’imagerie en profondeur, notamment parce qu’il fonctionne en mode épiillumination (détection de la lumière du même côté que l’injection de la lumière excitatrice dans l’animal) et aussi à cause de la sensibilité limitée de sa caméra. Afin d’augmenter les capacités tomographiques et la sensibilité du QOS, ainsi que le contraste des images qu’il fournit, le présent projet propose des développements logiciels intégrés au QOSoft. Ces ajouts logiciels au niveau du contrôle d’instrumentation et de l’interface graphique permettent d’intégrer une caméra EMCCD à ultra-haute sensibilité et ultra-faible bruit pour remplacer la caméra CCD refroidie existante ainsi qu’un module d’illumination laser rotatif. Ce module d’illumination, développé par le groupe TomOptUS, permet l’imagerie en mode transillumination ainsi que toutes les configurations intermédiaires jusqu’à l’épi-illumination. Ce module permet en outre d’injecter une densité de puissance lumineuse supérieure à celle possible avec la configuration actuelle du QOS. Le QOS et son logiciel mis à jour avec les ajouts faisant l’objet du présent projet sont validés par des expériences de fluorescence et de bioluminescence sur fantômes et animaux vivants.
29

Dispositivo de tecnologia assistiva baseado no processamento em tempo real de imagens do globo ocular

Figueiredo Vieira, Tiago 31 January 2009 (has links)
Made available in DSpace on 2014-06-12T17:39:16Z (GMT). No. of bitstreams: 2 arquivo6862_1.pdf: 5607350 bytes, checksum: 3d442f50af98e4c48b6fc2082aa93d2d (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Nesta dissertação são investigadas algumas técnicas de rastreamento ocular para o desenvolvimento de um dispositivo de tecnologia assistiva simples e de baixo custo, para indivíduos com deficiências motoras severas. O dispositivo desenvolvido permite que o usuário controle a posição de um cursor em uma tela gráfica e acione programas de computador com seus movimentos oculares. Dessa forma, os indivíduos vítimas de doenças degenerativas do sistema nervoso ou de acidentes vasculares cerebrais, com pouca ou nenhuma liberdade de movimento dos membros e/ou da cabeça, podem exercer alguma atuação no mundo à sua volta se comunicando com outras pessoas. Os sistemas desenvolvidos utilizam webcams de baixo custo e iluminação do objeto com LEDs infravermelhos. Algumas técnicas de detecção de formas e de calibração de câmeras foram investigadas para localização, em tempo real, da pupila do globo ocular de um indivíduo. Os algoritmos de processamento de imagens desenvolvidos para funcionamento da interface foram implementados inicialmente em Matlab® e posteriormente em C. Este último forneceu um ganho substancial em velocidade de processamento. Foi desenvolvida uma primeira configuração de dispositivo de tecnologia assistiva, em formato de armação de óculos, que funciona sem necessidade de re-calibração, desde que o usuário permaneça com a cabeça imóvel. São também descritos resultados preliminares obtidos no âmbito de desenvolvimento de uma segunda configuração de dispositivo, para uso remoto, que permite rastrear os movimentos oculares independentemente dos movimentos da cabeça do indivíduo
30

Calibration of a CCD Camera and Correction of its Images

Rest, Armin 23 August 1996 (has links)
Charge-Coupled-Device (CCD) cameras have opened a new world in astronomy and other related sciences with their high quantum efficiency, stability, linearity, and easy handling. Nevertheless, there is still noise in raw CCD images and even more noise is added through the image calibration process. This makes it essential to know exactly how the calibration process impacts the noise level in the image. The properties and characteristics of the calibration frames were explored. This was done for bias frames, dark frames and flat-field frames at different temperatures and for different exposure times. At first, it seemed advantageous to scale down a dark frame from a high temperature to the temperature at which the image is taken. However, the different pixel populations have different doubling temperatures. Although the main population could be scaled down accurately, the hot pixel populations could not. A global doubling temperature cannot be used to scale down dark frames taken at one temperature to calibrate the image taken at another temperature. It was discovered that the dark count increased if the chip was exposed to light prior to measurements of the dark count. This increase, denoted as dark offset, is dependent on the time and intensity of the prior exposure of the chip to light. The dark offset decayes with a characteristic time constant of 50 seconds. The cause might be due to storage effects within chip. It was found that the standard procedures for image calibration did not always generate the best and fastest way to process an image with a high signal-to-noise ratio. This was shown for both master dark frames and master flat-field frames. In a real world example, possible night sessions using master frame calibration are explained. Three sessions are discussed in detail concerning the trade-offs in imaging time, memory requirements, calibration time, and noise level. An efficient method for obtaining a noise map of an image was developed, i.e., a method for determining how accurate single pixel values are, by approximating the noise in several different cases.

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