Spectral Subtraction
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Filtros de Kalman no tempo e freqüência discretos combinados com subtração espectral / Kalman filters of time and frequency discrete combined with spectral subtraction
Este trabalho tem a finalidade de apresentar e comparar técnicas de redução de ruído utilizando como critérios de avaliação a mínima distorção espectral e a redução de ruído, na reconstrução dos sinais de voz degradados por ruído. Para tanto, utilizou-se os filtros de Kalman de tempo discreto e de freqüência discreta em conjunto com a técn
Publicado em: 2007
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2. Sugar cane harvested area monitoring using MODIS images / Monitoramento da área colhida de cana-de-açucar por meio de imagens do sensor MODIS
Brazil is among the world leaders in producing and exporting several agricultural products and is the largest producer and exporter of sugar and alcohol. The State of São Paulo is responsible for approximately 60% of the entire national production of cane, alcohol and sugar and for 70% of the exportations. In the current globalized market there is a great d
Publicado em: 2007
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3. Avaliação da Relação entre Qualidade Perceptual da Fala e Taxa de Acerto de Sistemas de Reconhecimento de Fala em Ambientes Ruidosos
The goal of this work is to evaluate the distortion of the noisy speech signal being after enhanced by noise-reduction algorithms. This is performed by comparison of word accuracy (%) of a standardized Automatic Speech Recognition (ASR) system and objective measures of perceptual speech quality (PESQ-MOS score), obtained after applying noise-reduction method
Publicado em: 2005
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4. RECONOCIMIENTO DE VOZ EN PRESCENCIA DE RUIDO / SPEECH RECOGNITION IN NOISE ENVIRONMENT / RECONHECIMENTO DE VOZ EM PRESENÇA DE RUÍDO
Este trabalho apresenta um estudo comparativo de três técnicas de melhoria das taxas de reconhecimento de voz em ambiente adverso, a saber: Normalização da Média Cepestral (CMN), Subtração Espectral e Regressão Linear no Sentido da Máxima Verossimilhança (MLLR), aplicadas isoladamente e em concomitância, duas a duas. Os testes são realizados usan
Publicado em: 2001
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5. Poli(tereftalato de etileno) : reprocessamento por extrusão e metodologias de caracterização
Pellets of virgin PET were reprocessed by extrusion to evaluate the number of recycles that these materiaIs can suffer without changes their properties. After each reprocessing cycle the thermal, mechanical, optics properties, the carboxylic end groups concentration (CEG), intrinsic viscosity [h] and non-isothermal crystallization kinetics by Ozawa and Avram
Publicado em: 2000
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6. Patency and flow velocity profiles in the internal carotid artery assessed by digital subtraction angiography and Doppler studies three months following endarterectomy.
Pulsed Doppler spectral analysis and intravenous digital subtraction angiography have been carried out in 55 patients, three months after a total of 60 carotid endarterectomies. Five patients were operated on both sides and there were no re-operations. There were no re-stenoses and only one of the 60 internal carotid arteries was occluded. Spectral spreading
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7. Resonance Raman study of the primary photochemistry of bacteriorhodopsin.
Resonance Raman multicomponent spectra of the light-adapted form of bacteriorhodopsin, bRLA568, and its first photoproduct, K628, have been obtained at liquid nitrogen temperatures. The spectra of both bRLA568 and K628 could be obtained with the known sample compositions under our irradiating conditions and computer subtraction techniques. In agreement with
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8. Circular dichroism spectroscopy of heparin-antithrombin interactions
We have utilized circular dichroism spectroscopy to examine the interaction of antithrombin with heparin-derived oligosaccharides and mucopolysaccharides of various sizes. Our studies demonstrate that the various complexes exhibit two major types of chiral absorption spectra. The first of these patterns is seen when octasaccharide, decasaccharide, dodecasacc
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9. Inward rectifier current noise in frog skeletal muscle.
Inwardly rectifying K+ currents were studied in cut muscle fibres from frogs using the Vaseline-gap voltage-clamp method. Both faces of the membrane were exposed to 120 mM-K+ methylsulphate solution. At small negative potentials, -10 and -21 mV, the current noise spectrum, after subtraction of a control spectrum at the zero current potential, could be fitted