Ricardo Sousa

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— The general purpose of spin-electronics is to take advantage of the spin of the electrons in addition to their electrical charge to conceive innovative electronic components. These components combine magnetic materials which are used as spin-polarizer or analyzer together with semiconductors or insulators. SPINTEC Laboratory works on the development of(More)
Bilateral posterior fracture-dislocation of the shoulder is a very rare injury. Almost 50% of bilateral posterior dislocations are due to a convulsive seizure, rising to 90% if the dislocations are associated with fractures. Electric shock accounts for less than 5% of bilateral posterior dislocations of the shoulder. A systematization of the clinical and(More)
The paper addresses the design, implementation and test of a beacon receiver coherent detector by using a DSP based software controlled phase locked loop. The system is built around a user developed card, with fast sampling ADCpsilas and dedicated signal processing programmable chips, interfaced with a DSP kit. The DSP implements the loop filter by(More)
Bovine astrovirus (BoAstV) is associated with gastroenterical disorders such as diarrhea, particularly in neonates and immunocompromised animals. Its prevalence is >60 % in the first five weeks of the animal’s life. The aim of this study was to detect and perform a phylogenetic analysis of BoAstV in Brazilian cattle. A prevalence of 14.3 % of BoAstV in(More)
The accurate estimation of the frequency of sinusoids is a frequent problem in many signal processing problems including the real-time analysis of the singing voice. In this paper we rely on a single DFT magnitude spectrum in order to perform frequency estimation in a non-iterative way. Two new frequency estimation methods are derived that are matched to(More)
In this paper we address the accurate estimation of the frequency of sinusoids of natural signals such as singing, voice or music. These signals are intrinsicly harmonic and are normally contaminated by noise. Taking the Crame¿r-Rao Lower Bound for unbiased frequency estimators as a reference, we compare the performance of several DFT-based frequency(More)
Vibrato is a frequency modulation effect of the singing voice and is very relevant in musical terms. Its most important characteristics are the vibrato frequency (in Hertz) and the vibrato extension (in semitones). In singing teaching and learning, it is very convenient to provide a visual feedback of those two objective signal characteristics, in(More)