Bioacústica e filogenia de três grupos de Physalaemus Fitzinger (1826)(Anura, Leptodactylidae)

Pós-graduação em Biologia Animal - IBILCE

Regulação de tensão utilizando compensador série controlado a tiristores para sistemas de distribuição

Pós-graduação em Engenharia Elétrica - FEIS

Avaliação experimental de medidas de aceleração

Acceleration is a key parameter for engineering and is becoming increasingly important because of the need for companies to become more competitive in the market. Both applying new technologies to their products and optimizing their process lines with predictive maintenance and robotic automation. This study aims to analyze the quality of the signals obtained from a capacitive accelerometer. To do that a test rig was mounted, which consist of a shaker, fed by a signal generator, a linear potentiometer and a capacitive accelerometer; for the signal acquisition was used a acquisition board and the Labview software, in order to integrate twice the signal from the accelerometer and compare it with the sign of the potentiometer. This work also demonstrates the impact of acquired signal processing as well as techniques of pre and post processing of signal via software GNU/Octave

Desenvolvimento de software para exibição de exames de eletrocardiograma

The main objective is to create a software, using C++ language, for reading and exhibiting in a graphic an Electrocardiogram (ECG) wave. The data is recorded as a FM modulated signal and compressed using Adaptive Differential Pulse Code Modulation (ADPCM). The signal have this characteristics because it was acquired using an experimental equipment, this equipment is the result of research made by the professor who supervised this work. FM demodulation techniques in discrete time, discrete filters and digital signal processing are some of the topics that can be found in this essay. Some concepts about the human heart and about ECG waves are also briefly introduced. These concepts are necessary for understanding the final evaluation of the software performance. The development is partly made using MATLAB. Most of the functions that are used on the software are first tested and designed in MATLAB environment. In the end, an evaluation is done comparing the results that are expected with the ones that MATLAB presents and the ones that the developed software presents

Utilização da instrumentação virtual em Labview para criação da interface gráfica do amplificador lock-in utilizado em estudos fisiológicos a partir da comunicação via porta serial

This work presents the development of a graphical interface to the Lock-in Amplifier, which is used in physiological studies on the motility of the gastrointestinal tract in rats and signal processing. With a simple and low cost instrumentation, the resources offered by the virtual interface of LabVIEW software allows the creation of commands similar to the actual instrument that, through communication via standard serial port, transmits data between a PC and peripheral device performing specific and particular needs in the amplifier. Created for the lock-in amplifier model SR830 Stanford Research Systems, the remote manipulation gives the user greater accessibility in the process of configuration and calibration. And, since the software is installed, there is the advantage of eliminating the need of purchase new devices to upgrade the system. The commands created were made to perform six basic modifications that are used in routine of the Biomagnetism Laboratory. The instrumentation developed has the following controls: Amplitude, Frequency, Time Constant, slope low pass filter, sensitivity and offset

Variação geográfica no canto de anúncio de Dendropsophus Nanus (Anura, Hylidae)

Pós-graduação em Biologia Animal - IBILCE

Biologia reprodutiva de Hypsiboas lundii (Anura, Hylidae) em um fragmento de Cerrado no sudoeste de Minas Gerais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Monitoramento de integridade estrutural e de sistemas utilizando dispositivos de baixo custo

Pós-graduação em Engenharia Mecânica - FEB

Investigação de técnicas para o acompanhamento do desgaste de um par engrenado utilizando tribologia e análise da resposta dinâmica processada via função densidade probabilidade Beta

Pós-graduação em Engenharia Mecânica - FEIS

Conversor analógico digital de 10 bits utilizando arquitetura pipeline e tecnologia CMOS

Pós-graduação em Engenharia Elétrica - FEIS

Localização de descargas parciais em transformadores de potência por meio de sensores piezelétricos de baixo custo e sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Introdução à identificação de sistemas utilizando o System Identification Toolbox do MATLAB em conjunto com o Arduino para o laboratório de controle linear

The education designed and planned in a clear and objective manner is of paramount importance for universities to prepare competent professionals for the labor market, and above all can serve the population with an efficient work. Specifically, in relation to engineering, conducting classes in the laboratories it is very important for the application of theory and development of the practical part of the student. The planning and preparation of laboratories, as well as laboratory equipment and activities should be developed in a succinct and clear way, showing to students how to apply in practice what has been learned in theory and often shows them why and where it can be used when they become engineers. This work uses the MATLAB together with the System Identification Toolbox and Arduino for the identification of linear systems in Linear Control Lab. MATLAB is a widely used program in the engineering area for numerical computation, signal processing, graphing, system identification, among other functions. Thus the introduction to MATLAB and consequently the identification of systems using the System Identification Toolbox becomes relevant in the formation of students to thereafter when necessary to identify a system the base and the concept has been seen. For this procedure the open source platform Arduino was used as a data acquisition board being the same also introduced to the student, offering them a range of software and hardware for learning, giving you every day more luggage to their training

Localização de descargas parciais em transformadores de potência por meio de sensores piezelétricos de baixo custo e sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Introdução à identificação de sistemas utilizando o System Identification Toolbox do MATLAB em conjunto com o Arduino para o laboratório de controle linear

The education designed and planned in a clear and objective manner is of paramount importance for universities to prepare competent professionals for the labor market, and above all can serve the population with an efficient work. Specifically, in relation to engineering, conducting classes in the laboratories it is very important for the application of theory and development of the practical part of the student. The planning and preparation of laboratories, as well as laboratory equipment and activities should be developed in a succinct and clear way, showing to students how to apply in practice what has been learned in theory and often shows them why and where it can be used when they become engineers. This work uses the MATLAB together with the System Identification Toolbox and Arduino for the identification of linear systems in Linear Control Lab. MATLAB is a widely used program in the engineering area for numerical computation, signal processing, graphing, system identification, among other functions. Thus the introduction to MATLAB and consequently the identification of systems using the System Identification Toolbox becomes relevant in the formation of students to thereafter when necessary to identify a system the base and the concept has been seen. For this procedure the open source platform Arduino was used as a data acquisition board being the same also introduced to the student, offering them a range of software and hardware for learning, giving you every day more luggage to their training

Impact of artifact correction methods on R-R interbeat signals to quantifying heart rate variability (HRV) according to linear and nonlinear methods.

In the analysis of heart rate variability (HRV) are used temporal series that contains the distances between successive heartbeats in order to assess autonomic regulation of the cardiovascular system. These series are obtained from the electrocardiogram (ECG) signal analysis, which can be affected by different types of artifacts leading to incorrect interpretations in the analysis of the HRV signals. Classic approach to deal with these artifacts implies the use of correction methods, some of them based on interpolation, substitution or statistical techniques. However, there are few studies that shows the accuracy and performance of these correction methods on real HRV signals. This study aims to determine the performance of some linear and non-linear correction methods on HRV signals with induced artefacts by quantification of its linear and nonlinear HRV parameters. As part of the methodology, ECG signals of rats measured using the technique of telemetry were used to generate real heart rate variability signals without any error. In these series were simulated missing points (beats) in different quantities in order to emulate a real experimental situation as accurately as possible. In order to compare recovering efficiency, deletion (DEL), linear interpolation (LI), cubic spline interpolation (CI), moving average window (MAW) and nonlinear predictive interpolation (NPI) were used as correction methods for the series with induced artifacts. The accuracy of each correction method was known through the results obtained after the measurement of the mean value of the series (AVNN), standard deviation (SDNN), root mean square error of the differences between successive heartbeats (RMSSD), Lomb\'s periodogram (LSP), Detrended Fluctuation Analysis (DFA), multiscale entropy (MSE) and symbolic dynamics (SD) on each HRV signal with and without artifacts. The results show that, at low levels of missing points the performance of all correction techniques are very similar with very close values for each HRV parameter. However, at higher levels of losses only the NPI method allows to obtain HRV parameters with low error values and low quantity of significant differences in comparison to the values calculated for the same signals without the presence of missing points.