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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.
11

Descritores de textura local para reconhecimento biométrico da íris humana / Local texture descriptors applied in human iris biometric recognition

Travaini, Job Nicolau 02 October 2015 (has links)
Técnicas biométricas procuraram identificar usuários pela textura da íris, impressão digital, traços faciais, entre outros. A íris humana apresenta características de textura que a classificam como uma peculiaridade biométrica de grande poder de discriminação no reconhecimento de pessoas. O objetivo deste trabalho é avaliar a eficiência de uma nova metodologia de análise de texturas em desenvolvimento no LAVI (Laboratório de Visão Computacional da EESC-USP) na identificação de indivíduos por meio da textura de sua íris. A metodologia denomina-se Local Fuzzy Pattern e tem sido utilizada com excelente desempenho com texturas gerais, naturais e artificiais. Este documento detalha as técnicas utilizadas para extração e normalização da textura da íris, a utilização e os resultados obtidos com o método Local Fuzzy Pattern aplicado à classificação biométrica da íris humana. Os resultados obtidos apresentam sensibilidade de até 99,7516% com a aplicação da metodologia proposta em bancos de imagens de íris humana disponíveis na internet demonstram a viabilidade da técnica proposta. / Biometric techniques sought to identify users by the texture of the iris, fingerprint, facial features, among others. The human iris have texture characteristics that rank it as a powerful biometric peculiarity on human recognition. The objective of this masters proposal is to investigate the efficiency of a new methodology of iris texture analysis currently in development in LAVI (Laboratório de Visão Computacional da EESC-USP). The methodology is called LFP (Local Fuzzy Pattern) and has been used with excellent overall performance on artificial and natural textures. This document details the techniques used for the extraction and normalization of the iris texture, the use and results of the local fuzzy pattern method applied to biometric classification of the human eye. The results show a sensibility of value up to 99.7516%, obtained by applying the proposed methodology on human iris photos from image database available on the internet does showing the viability of the technique.
12

Metodologia de inspeção visual utilizando limiar(\"Threshold\") entrópico com aplicações na classificação de placas de madeira / Methodology for visual inspection using entropic threshold with aplications in wooden board classification

Rodrigues, Evandro Luis Linhari 11 May 1998 (has links)
O objetivo deste trabalho é o desenvolvimento de um método dedicado de classificação para placas de madeira utilizadas na fabricação de lápis, utilizando procedimentos de visão computacional. O processo aqui proposto, foi idealizado buscando uma metodologia que pudesse ser realizada com baixa complexidade computacional, ou seja, os cálculos dos algoritmos utilizando apenas operações simples - do tipo soma, subtração, multiplicação e divisão - em imagens em níveis de cinza. A intenção em utilizar apenas as operações básicas citadas, tem o objetivo de tornar o método implementável em arquiteturas com tecnologia VLSI, notadamente em Arquiteturas Sistólicas. O trabalho descreve o ciclo de produção do lápis localizando a etapa onde é proposta a metodologia de classificação das placas de madeira. Nesta etapa, há uma seqüência de procedimentos, descritos ao longo do trabalho, que compreendem a aquisição da imagem das placas, a extração de características das imagens, o processamento dessas características e por fim os algoritmos de classificação. Na etapa de extração de características, buscou-se com a aplicação de um método de Limiar automático que utiliza a entropia de Shannon, extrair informações suficientes para classificar adequadamente as placas de madeiras em diferentes classes, fornecendo dessa forma, um sistema ágil, repetitivo e de baixo custo para aproveitamento da madeira em diferentes produtos finais. / The objective of this work was to develop a dedicated computer vision method for the classification of wooden plates used in pencil manufacturing. The process here proposed was idealized looking for a low computational complexity methodology that could be accomplished in VLSI, as for instance using Systolic Computer Architectures made of logic arrays. The pencil cycle of production is described, locating the stage where the proposed classification methodology should be used. There is a sequence of procedures, along the work, that describe the acquisition, extraction of the characteristics and the processing of the images, and finally the classification algorithms. For the extraction of characteristics of the images, it was used an automatic method for the threshold determination, based on Shannon\'s entropy. The information supplied by the threshold determination method allows classifying the plates in different classes. The analysis of the results showed that the method performs well is repetitive and efficient on the classification and its use can be extended to classifying other final products.
13

Descritores de textura local para reconhecimento biométrico da íris humana / Local texture descriptors applied in human iris biometric recognition

Job Nicolau Travaini 02 October 2015 (has links)
Técnicas biométricas procuraram identificar usuários pela textura da íris, impressão digital, traços faciais, entre outros. A íris humana apresenta características de textura que a classificam como uma peculiaridade biométrica de grande poder de discriminação no reconhecimento de pessoas. O objetivo deste trabalho é avaliar a eficiência de uma nova metodologia de análise de texturas em desenvolvimento no LAVI (Laboratório de Visão Computacional da EESC-USP) na identificação de indivíduos por meio da textura de sua íris. A metodologia denomina-se Local Fuzzy Pattern e tem sido utilizada com excelente desempenho com texturas gerais, naturais e artificiais. Este documento detalha as técnicas utilizadas para extração e normalização da textura da íris, a utilização e os resultados obtidos com o método Local Fuzzy Pattern aplicado à classificação biométrica da íris humana. Os resultados obtidos apresentam sensibilidade de até 99,7516% com a aplicação da metodologia proposta em bancos de imagens de íris humana disponíveis na internet demonstram a viabilidade da técnica proposta. / Biometric techniques sought to identify users by the texture of the iris, fingerprint, facial features, among others. The human iris have texture characteristics that rank it as a powerful biometric peculiarity on human recognition. The objective of this masters proposal is to investigate the efficiency of a new methodology of iris texture analysis currently in development in LAVI (Laboratório de Visão Computacional da EESC-USP). The methodology is called LFP (Local Fuzzy Pattern) and has been used with excellent overall performance on artificial and natural textures. This document details the techniques used for the extraction and normalization of the iris texture, the use and results of the local fuzzy pattern method applied to biometric classification of the human eye. The results show a sensibility of value up to 99.7516%, obtained by applying the proposed methodology on human iris photos from image database available on the internet does showing the viability of the technique.
14

Processamento de sinais de ressonância magnética nuclear usando classificador neural para reconhecimento de carne bovina / Signal processing of nuclear magnetic resonance using neural classification for bovine meat recognition

Cíntia Beatriz de Souza Silva 28 August 2007 (has links)
Garantir a qualidade da carne bovina produzida no Brasil tem sido uma preocupação dos produtores, pois contribui para aumentar a exportação e o consumo interno do produto. Por isso, tem-se pesquisado novos métodos que analisam e garantam a qualidade da carne, de forma rápida, eficiente e não destrutiva. A ressonância magnética nuclear (RMN) tem se destacado como uma das técnicas de controle de qualidade de carne. Neste trabalho as redes neurais artificiais estão sendo utilizadas para o reconhecimento de padrões dos dados de ressonância magnética nuclear oriundos de carne bovina. Mais especificamente, os respectivos dados têm sido utilizados por uma rede perceptron multicamadas para a extração de características da carne bovina, possibilitando a classificação do grupo genético e do sexo dos animais a partir de uma amostra da referida carne. Os resultados dos experimentos são também apresentados para ilustrar o desempenho da abordagem proposta. / Guaranteeing the quality of the bovine meat produced in Brazil has been a concern of the producers because it contributes to increase the export and the domestic consumption of the product. Therefore, new methods have been researched that analyze and guarantee the quality of the meat in a fast, efficient and non destructive way. Nuclear magnetic resonance (NMR) has been highlighted as one of the techniques of meat quality control. In this work study artificial neural networks are being used for pattern recognition from data obtained by the resonance equipment, originating from bovine meat. More specifically, the respective data have been used by a multilayer perceptron network for extraction of bovine meat characteristics, making possible the classification of both genetic group and animal sex starting from a single meat sample. Several results of experimental tests are also presented to illustrate the performance of the proposed approach.
15

Example Based Learning for View-Based Human Face Detection

Sung, Kah Kay, Poggio, Tomaso 24 January 1995 (has links)
We present an example-based learning approach for locating vertical frontal views of human faces in complex scenes. The technique models the distribution of human face patterns by means of a few view-based "face'' and "non-face'' prototype clusters. At each image location, the local pattern is matched against the distribution-based model, and a trained classifier determines, based on the local difference measurements, whether or not a human face exists at the current image location. We provide an analysis that helps identify the critical components of our system.
16

Decision Fusion for Protein Secondary Structure Prediction

Akkaladevi, Somasheker 03 August 2006 (has links)
Prediction of protein secondary structure from primary sequence of amino acids is a very challenging task, and the problem has been approached from several angles. Proteins have many different biological functions; they may act as enzymes or as building blocks (muscle fibers) or may have transport function (e.g., transport of oxygen). The three-dimensional protein structure determines the functional properties of the protein. A lot of interesting work has been done on this problem, and over the last 10 to 20 years the methods have gradually improved in accuracy. In this dissertation we investigate several techniques for predicting the protein secondary structure. The prediction is carried out mainly using pattern classification techniques such as neural networks, genetic algorithms, simulated annealing. Each individual algorithm may work well in certain situations but fails in others. Capitalizing on the positive decisions can be achieved by forcing the various methods to collaborate to reach a unified consensus based on their previous performances. The process of combining classifiers is called decision fusion. The various decision fusion techniques such as the committee method, correlation method and the Bayesian inference methods to fuse the solutions from various approaches and to get better prediction accuracy are thoroughly explored in this dissertation. The RS126 data set was used for training and testing purposes. The results of applying pattern classification algorithms along with decision fusion techniques showed improvement in the prediction accuracy compared to that of prediction by neural networks or pattern classification algorithms individually or combined with neural networks. This research has shown that decision fusion techniques can be used to obtain better protein secondary structure prediction accuracy.
17

Classification Of Migraineurs Using Functional Near Infrared Spectroscopy Data

Sayita, Yusuf 01 February 2012 (has links) (PDF)
Classification of migraineur and healthy subjects using statistical pattern classifiers on functional Near Infrared Spectroscopy (NIRS) data is the main purpose of this study. Also a statistical comparison between trials that have different type of classifiers, classifier settings and feature sets is done. Features are extracted from raw light measurement data acquired with NIRS device, namely Niroxcope, during two separate previous studies, using Modified Beer-Lambert Law. After feature extraction, Na&iuml / ve Bayes classifier and k Nearest Neighbor classifier are utilized with and with-out Principal Component Analysis in separate trials. Results obtained are compared within each other using statistical hypothesis tests namely Mc Nemar and Cochran Q.
18

Nichtinvasive Erfassung des Hirndrucks mittels des transkraniellen Dopplersignals und der Blutdruckkurve unter Verwendung systemtheoretischer Methoden / Non-invasive assessment of intracranial pressure from transcranial Doppler ultrasonography and arterial blood pressure signals using systems theory methods

Schmidt, Bernhard 14 November 2003 (has links) (PDF)
Developement of a procedure to calculate intracranial pressure by means of arterial blood pressure and blood flow velocity in a big cerebral artery. Methods of systems theory are used. / Entwicklung eines Verfahrens zur Berechnung des Hirndrucks aus dem Bludrucksignal und der Blutströmungsgeschwindigkeit in einer großen Hirnarterie. Es werden Methoden der Systemtheorie verwendet.
19

Netzverluste in Niederspannungsnetzen

Mehlhorn, Klaus 05 April 2006 (has links) (PDF)
Die Berechnung der Netzverluste in Niederspannungsnetzen kann nur über Umwege erfolgen, da viele Netzbetreiber keine digitalisierten Daten ihrer Netze besitzen. Hier wird ein Ansatz zur Ermittlung der technischen Verluste anhand vorhandener Netzdaten beschrieben. / The major part of network operator of low voltage nets do not have digitised data of their nets. That’s why net losses must be calculated indirectly. This article describes an approach for getting results in a direct way.
20

SUPPORT VECTOR MACHINE FOR HIGH THROUGHPUT RODENT SLEEP BEHAVIOR CLASSIFICATION

Shantilal, 01 January 2008 (has links)
This thesis examines the application of a Support Vector Machine (SVM) classifier to automatically detect sleep and quiet wake (rest) behavior in mice from pressure signals on their cage floor. Previous work employed Neural Networks (NN) and Linear Discriminant Analysis (LDA) to successfully detect sleep and wake behaviors in mice. Although the LDA was successful in distinguishing between the sleep and wake behaviors, it has several limitations, which include the need to select a threshold and difficulty separating additional behaviors with subtle differences, such as sleep and rest. The SVM has advantages in that it offers greater degrees of freedom than the LDA for working with complex data sets. In addition, the SVM has direct methods to limit overfitting for the training sets (unlike the NN method). This thesis develops an SVM classifier to characterize the linearly non separable sleep and rest behaviors using a variety of features extracted from the power spectrum, autocorrelation function, and generalized spectrum (autocorrelation of complex spectrum). A genetic algorithm (GA) optimizes the SVM parameters and determines a combination of 5 best features. Experimental results from over 9 hours of data scored by human observation indicate 75% classification accuracy for SVM compared to 68% accuracy for LDA.

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