Mestrado em Engenharia Elétrica

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http://repositorio.ufes.br/handle/10/17619

Nível: Mestrado Acadêmico
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Navegando Mestrado em Engenharia Elétrica por Autor "Almeida, Ailson Rosetti de"

Agora exibindo 1 - 3 de 3
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    Comparação das técnicas de modulação multiportadoras aplicadas às comunicações via rede elétrica
    (Universidade Federal do Espírito Santo, 2004-07-09) Dezan, Tadeu Leite; Segatto, Marcelo Eduardo Vieira; Salles, Evandro Ottoni Teatini; Almeida, Ailson Rosetti de; Lima, Antônio César de Castro
    The use of the low voltage energy grid as high speed communication networks, known as Power Line Communication – PLC, opens up the possibility to establish low cost widespread local area networks services such as internet. In this master thesis dissertation, transmission issues on the power line are investigated and modeling aproaches are investigated. Multi-carrier modulation based on orthogonal transmultiplexer is used, because of its fast algoritms capabilities. Three diferent techniques are compared: Orthogonal Frequency Division Multiplexing, Discrete Wavelet Multitone through Extended Lapped Transform and Wavelet Packet Modulation. The main characteristics of each technique, including their computational cost, are described based on the filter banks theory. The system performance is analysed in terms of the bit-error rate versus signal-tonoise rate in a multipath powerline channel.
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    Estudo do sinal eletroencefalográfico (EEG) aplicado a interfaces cérebro computador com uma abordagem de reconhecimento de padrões
    (Universidade Federal do Espírito Santo, 2005-09-06) Azevedo, Anderson Prado; Almeida, Ailson Rosetti de; Salles, Evandro Ottoni Teatini; Bastos Filho, Teodiano Freire; Andreão, Rodrigo Varejão
    The conjunction of signal processing, pattern recognition and brain electrical signal acquisition made possible a new communication modality, until now a subject for science fiction movies: the Brain-Computer Interface (BCI). This complex system can acquire and process the brain signals in order to obtain information to be used as a control signal. This innovation can benefit people who have neuromuscular disorders, which cause damages on the volunteer movement. These people would communicate, or even move, using a BCI to control electronic devices. Looking ahead, these systems can be used in other applications, mainly for multimedia purposes. The purpose of this work is study the EEG characteristics, the signal processing and pattern recognition techniques in order to use in a Brain Computer Interface (BCI) For this, will be used a international data base, in order to compare our results with results of other international groups. In this context, this work describes the human brain and the EEG characteristics relevant to BCI understanding. Moreover, it presents the implementation of a pattern recognition system, which is able to classify the motor imagination laterality with accuracy over 85%.
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    Sistema de visão para robôs móveis: uma aplicação ao reconhecimento de referências geométricas
    (Universidade Federal do Espírito Santo, 1999-02-26) Freitas, Roger Alex de Castro; Sarcinelli Filho, Mário; Bastos Filho, Teodiano Freire; Almeida, Ailson Rosetti de; Rillo, Márcio
    The availability of sensorial data is an important issue for the navigation systemof autonomous mobile robots. The robot needs information about its surroundingenvironment in order to make a decision on what to do when it faces an obstacle. Insome cases, it not only does need to detect the presence of the obstacle but also torecognize it. This way, it is necessary that the onboard sensing system be much morespecialized. For an agent-based controlled autonomous mobile robot, a sensing systemthat combines ultrasonic sensors and artificial vision is here addressed. It makesavailable information about the type of obstacle detected in the trajectory of the robot, aswell as the distance from the detected object to the robot. This external sensing systemis also able to avoid the generation of redundant and unnecessary information, besidesnot demanding too much computational effort to process the acquired images onboardthe robot