Signal Noise Relation
Mostrando 1-12 de 22 artigos, teses e dissertações.
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1. Effect of Vitiligo on Auditory Functions: Is There Any Association?
Abstract Introduction Vitiligo is an acquired pigmentary disorder of unknown etiology, clinically characterized by whitish macules caused by selective loss of melanocytes. There are many melanocytes in the human cochlea. Recent studies have suggested a direct relation between cochlear dysfunction and decreased amounts of melanin. Objective To determine the
Int. Arch. Otorhinolaryngol.. Publicado em: 2021-04
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2. Estimation Uncertainties in the Optical Signal-to-Noise Ratio Network Optimization
In this work, we investigate the effects of estimation uncertainties in the optimization of the optical signal-to-noise ratio (OSNR) at the wavelength division multiplexing (WDM) optical networks. The OSNR optimization increases the network throughput and energy efficiency and it enables to minimize the number of retransmissions by higher layers. The OSNR op
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-03
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3. AnÃlise experimental da degradaÃÃo imposta por sistemas Ãpticos a aplicaÃÃes IP / Experimental analysis of the degradation imposed by optical systems on IP
The objective of this work is to experimentally evaluate how physical impairments on the network can affect the performance of IP applications. Especially This work encompasses the analysis of the cross-layer effect caused by all-optical wavelength converters in the video signal. For this purpose, it was evaluated the packet error rate degradationcaused by p
Publicado em: 2010
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4. Biblioteca espectral: determinação de espectros de referência para a classificação de tipos de água das áreas alagáveis da Amazônia / Spectral library: references for water types classification in Amazon wetlands
The advent of orbital hyperspectral sensors increased the possibility of assessing water properties in complex inland waters, such as that of Amazon wetlands. The current methods for water properties assessment are based upon empirical and semi-analytical models. An alternative to those methods is to build a water spectral library as reference to classify di
Publicado em: 2009
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5. Contribuições teoricas para o estudo de funções de distribuição correlacionadas em um canal sem fio / Theoretical contributions to the study of correlated distributions funcions of wireless channels
In wireless communications, the multipath fading is modeled by several distributions including Hoyt, Rayleigh, Weibull, Nakagami-m, and Rice. In this thesis, new, exact expressions for the bivariate Hoyt (Nakagami-q) processes with arbitrary correlation in a nonstationary environment are derived. More specifically, the following are obtained: joint probabili
Publicado em: 2009
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6. THE SPEECH-RECEPTIONS THRESHOLD IN NOISY AND QUIET CONDITIONS IN INDIVIDUALS WITH HEARING LOSS / RECONHECIMENTO DE FALA NO SILÊNCIO E NO RUÍDO COM FONES EM INDIVÍDUOS COM PERDA AUDITIVA NEUROSSENSORIAL DE DIFERENTES CONFIGURAÇÕES
Hearing is one of the most important senses for establishing a satisfying communication among people. This way, individuals stroked by different kinds of hearing losses show difficulties on speech-reception and in their ability to communicate through different ways for there is a correlation between these difficulties and the types and degrees of hearing los
Publicado em: 2008
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7. VARIAÇÕES ESPACIAIS DE PROPRIEDADES FÍSICAS DO REMANESCENTE DE SUPERNOVA RCW 103
Since the observation of the supernova event SN 1987A, observational research on supernova and supernova remnants, including the ones on the optical spectrum, has been much explored. However, most of these studies have been limited to present integrated or punctual data from extragalactic or galactic supernova remnants. The present work has the objective of
Publicado em: 2008
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8. DETERMINAÇÃO DO PARAQUAT SOBRE ELETRODOS DE CARBONO VÍTREO MODIFICADO COM FTALOCIANINA TETRASSULFONADA DE NIQUEL EM FILME DE POLI-L-LISINA / DETERMINATION OF THE PARAQUAT ON MODIFIED GLASS CARBON ELECTRODES WITH FTALOCIANINA TETRASSULFONADA OF NICKEL IN POLI-L-LISINA FILM
This work present an evaluation of a modified glassy carbon electrode with NiTSPc immobilized with film PLL of the determination of paraquat by differential pulse voltammetry. The film was formed applying 20μL of a solution prepared for the mixture of equal volume of NiTSPc 0,8mM and poly-L-lisine (PLL) 0,12mM. The maximum signal to noice ratio was obta
Publicado em: 2007
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9. Uma proposta para melhoria na eficencia de um sistema de reconhecimento de iris humana / A new proposal for improvement in the iris recognition system
The biometric has been widely used in automated security systems. In this work we propose a biometrics personal identification system based on iris, due to its better biometrics parameters results. The purpose of this study is to improve existing methods aiming to decrease the processing time, the required storage memory and the error rate. Our research show
Publicado em: 2007
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10. LIMIARES E ÍNDICES PERCENTUAIS DE RECONHECIMENTO DE SENTENÇAS NO RUÍDO, EM CAMPO LIVRE, PARA INDIVÍDUOS ADULTOS / TRESHOLDS AND PERCENTUAL INDEXES OF RECOGNITION SENTENCES IN THE NOISE, AT THE SOUND FIELD, FOR GROWN UPS INDIVIDUALS
At the same time that the society has the comfort reached by the evolution in technology, it comes across with something bad that comes from the same evolution: the competitive noise and, consequently, the difficulty with the verbal communication. Moreover, complaints made by individuals who are not being able to comprehend speeches in the presence of noise
Publicado em: 2006
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11. Uma análise espectroscópica de discos de acresção em variáveis cataclísmicas / A Spectroscopic Analysis of Accretion Disks in Cataclysmic Variables
An observational study of accretion disks in Cataclysmic Variables (CVs) is presented in this work. Time-resolved spectrophotometric data of the emission line profiles are analyzed. The line emissivity of the systems is mapped using the Doppler tomography technique. The basic orbital parameters of the systems, like the orbital period, mass, orbital inclinati
Publicado em: 2006
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12. Obtenção de tabela de quantização para compressão de imagens utilizando algoritmos genéticos
The purpose of this work is to generate a better Quantization Table for a group of natural images and medical images using the Genetic Algorithm method in the process of compression JPEG. The fitness function of the population will be analyzed and the probability of selection the better pairs of chromosomes or matrix, and we will also breach means to improve
Publicado em: 2005