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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

A New Design Of Excitation Mechanism To Be Exploited By Modern Rf Excited Co2 Lasers

Kurucu, Salur Riza 01 September 2004 (has links) (PDF)
On this thesis work, design and construction of an up to date complete RF excitation system was intended. This excitation system is mainly based on highly efficient switching power generators and proper coupling of the power to the object plasma. This new excitation system design should answer the demands of today&#039 / s progressed CO2 lasers on various power ranges. Though it could be used by a large variety of applications including RF plasma and RF heating, on the first occasion in order to define design considerations, this system is to be exploited by RF excited fast flow and RF excited slab CO2 laser constructions.
2

Desenvolvimento e validação de sistema de aquisição de imagens na vela / Images acquisition system development and validation for sailing

Schutz, Gustavo Ricardo 25 August 2006 (has links)
Made available in DSpace on 2016-12-06T17:07:11Z (GMT). No. of bitstreams: 1 PPGCMH Gustavo Ricardo Schutz.pdf: 1852152 bytes, checksum: a639167457cde844f824fd8ad28b069f (MD5) Previous issue date: 2006-08-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to develop instrumentation for images acquisition that makes possible movements quantification and kinematics analysis of the sailor s hiking positions in Laser boats. Two waterproof boxes were developed for cameras protection, confectioned with fiberglass and acrylic lens viewfinder. The camera and lens viewfinder components had been tested in a bidimensional kinematics analysis, and between the analyzed cameras, the digital standard cameras presented superior quality. The developed viewfinders haven t seemd to generate distortion for the reference measures reconstruction. The root mean square error and the maximum error for the combined cameras and with the lens viewfinders had been quantified. With the equipment a procedure for the boat equipment positioning was developed, with one camera located to the front and second, located in the mast. The camera located in the mast intervened with the sailor movement, and this way its use was discarded. With the images gotten from the camera located in the front it was observed movements quantification possibility made for the sailor. To make possible a posterior analysis kinematics of the sailor hiking positions was considered a procedure for calibration from the image picture. The procedure if showed efficient for a bidimensional hiking positions analysis. However, beyond the hip and knee joints extension, the sailor also executes the rotation of the trunk, what makes a three-dimensional hiking analysis more adjusted. / Este estudo teve como objetivo desenvolver uma instrumentação para aquisição de imagens que possibilite uma posterior quantificação dos movimentos e análise cinemática das posturas de escora do velejador em barcos da classe Laser. Foram desenvolvidas duas caixas estanque para proteção das câmeras, confeccionadas com fibra de vidro e com o visor da lente de acrílico. Foram testados os componentes câmera e visor da lente em uma análise cinemática bidimensional, tendo entre as câmeras analisadas, as câmeras de padrão digital apresentaram uma qualidade superior. Os visores desenvolvidos aparentaram não gerar distorção para a reconstrução das medidas de referência. Foram quantificados o erro quadrático médio e o erro máximo para as câmeras e combinadas com os visores da lente. Com o equipamento foi desenvolvido um método para o posicionamento do equipamento do barco, sendo uma câmera posicionada à frente e a segunda, posicionada no mastro. A câmera posicionada no mastro interferia na movimentação normal do velejador, e desta forma foi descartada sua utilização. Com as imagens obtidas pela câmera posicionada à frente observou-se a possibilidade da quantificação dos movimentos realizados pelo velejador. Para possibilitar uma posterior análise cinemática das posturas de escora do velejador foi proposto um procedimento para calibração a partir do quadro de imagem. O procedimento se mostrou eficiente para uma análise bidimensional das posturas de escora. Entretanto, além das extensões das articulações de quadril e joelho, o velejador executa também a rotação do tronco, o que torna uma análise tridimensional da escora mais adequada.

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