6 research outputs found

    Using a variation of empirical mode decomposition to remove noise from signals

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    The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure

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    A Joint Time-Frequency and Matrix Decomposition Feature Extraction Methodology for Pathological Voice Classification

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    The number of people affected by speech problems is increasing as the modern world places increasing demands on the human voice via mobile telephones, voice recognition software, and interpersonal verbal communications. In this paper, we propose a novel methodology for automatic pattern classification of pathological voices. The main contribution of this paper is extraction of meaningful and unique features using Adaptive time-frequency distribution (TFD) and nonnegative matrix factorization (NMF). We construct Adaptive TFD as an effective signal analysis domain to dynamically track the nonstationarity in the speech and utilize NMF as a matrix decomposition (MD) technique to quantify the constructed TFD. The proposed method extracts meaningful and unique features from the joint TFD of the speech, and automatically identifies and measures the abnormality of the signal. Depending on the abnormality measure of each signal, we classify the signal into normal or pathological. The proposed method is applied on the Massachusetts Eye and Ear Infirmary (MEEI) voice disorders database which consists of 161 pathological and 51 normal speakers, and an overall classification accuracy of 98.6% was achieved

    Audio Signal Processing Using Time-Frequency Approaches: Coding, Classification, Fingerprinting, and Watermarking

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    Audio signals are information rich nonstationary signals that play an important role in our day-to-day communication, perception of environment, and entertainment. Due to its non-stationary nature, time- or frequency-only approaches are inadequate in analyzing these signals. A joint time-frequency (TF) approach would be a better choice to efficiently process these signals. In this digital era, compression, intelligent indexing for content-based retrieval, classification, and protection of digital audio content are few of the areas that encapsulate a majority of the audio signal processing applications. In this paper, we present a comprehensive array of TF methodologies that successfully address applications in all of the above mentioned areas. A TF-based audio coding scheme with novel psychoacoustics model, music classification, audio classification of environmental sounds, audio fingerprinting, and audio watermarking will be presented to demonstrate the advantages of using time-frequency approaches in analyzing and extracting information from audio signals.</p

    An谩lisis de m茅todos de parametrizaci贸n y clasificaci贸n para la simulaci贸n de un sistema de evaluaci贸n perceptual del grado de afecci贸n en voces patol贸gicas

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    Los procedimientos de evaluaci贸n de la calidad de la voz basados en la valoraci贸n subjetiva a trav茅s de la percepci贸n ac煤stica por parte de un experto est谩n bastante extendidos. Entre ellos,el protocolo GRBAS es el m谩s com煤nmente utilizado en la rutina cl铆nica. Sin embargo existen varios problemas derivados de este tipo de estimaciones, el primero de los cuales es que se precisa de profesionales debidamente entrenados para su realizaci贸n. Otro inconveniente reside en el hecho de que,al tratarse de una valoraci贸n subjetiva, m煤ltiples circunstancias significativas influyen en la decisi贸n final del evaluador, existiendo en muchos casos una variabilidad inter-evaluador e intra-evaluador en los juicios. Por estas razones se hace necesario el uso de par谩metros objetivos que permitan realizar una valoraci贸n de la calidad de la voz y la detecci贸n de diversas patolog铆as. Este trabajo tiene como objetivo comparar la efectividad de diversas t茅cnicas de c谩lculo de par谩metros representativos de la voz para su uso en la clasificaci贸n autom谩tica de escalas perceptuales. Algunos par谩metros analizados ser谩n los coeficientes Mel-Frequency Cepstral Coefficients(MFCC),las medidas de complejidad y las de ruido.As铆 mismo se introducir谩 un nuevo conjunto de caracter铆sticas extra铆das del Espectro de Modulaci贸n (EM) denominadas Centroides del Espectro de Modulaci贸n (CEM).En concreto se analizar谩 el proceso de detecci贸n autom谩tica de dos de los cinco rasgos que componen la escala GRBAS: G y R. A lo largo de este documento se muestra c贸mo las caracter铆sticas CEM proporcionan resultados similares a los de otras t茅cnicas anteriormente utilizadas y propician en alg煤n caso un incremento en la efectividad de la clasificaci贸n cuando son combinados con otros par谩metros
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