2018
Autores
Avelar, HH; Ferreira, JC;
Publicação
21st Euromicro Conference on Digital System Design, DSD 2018, Prague, Czech Republic, August 29-31, 2018
Abstract
This work presents the design and analysis of a biological signal processing accelerator, including an interface controller and memory subsystem for a low-power CGRA. The controller design supports several operation modes, which can perform several applications when paired with the CGRA reconfiguration capabilities. Physical synthesis shows that the controller introduces only a 6 percent area and power overhead compared to the CGRA core, while allowing independent processing of inner loops at high frequencies and the exploitation of pipelining and parallelism. In-depth power analysis based on layout information was performed, including an evaluation of the use of power gating techniques. A practical case study (ECG signal processing) was also evaluated. © 2018 IEEE.
2018
Autores
Miyandoab, FD; Canas Ferreira, JC; Grade Tavares, VM;
Publicação
Journal of Mobile Multimedia
Abstract
Source routing (SR) minimum cost forwarding (MCF) – SRMCF – is a reactive, energy-efficient routing protocol proposed to improve the existent MCF methods utilized in heterogeneous wireless sensor networks (WSN). This paper presents an analytical analysis with experimental support that demonstrates the effectiveness of the proposed protocol. SRMCF stems from SR concepts and MCF methods exploited in ad hoc WSNs, where all unicast communications (between sensor nodes and the base station, or vice versa) use minimum cost paths. The protocol utilized in the present work was updated and now also handles link and node failures. Theoretical analysis and simulations show that the final protocol exhibits better throughput and energy consumption than MCF. Memory requirements for the routing table in the base station are also analyzed. Experimental results in a real scenario were obtained for implementations of both protocols, MCF and SRMCF, deployed in a small network of TelosB motes. Results show that SRMCF presents a 33% higher throughput and 24% less energy consumption than MCF. Extensive © 2019 River Publishers
2018
Autores
Derogarian, F; Ferreira, JC; Grade Tavares, VM;
Publicação
J. Mobile Multimedia
Abstract
2018
Autores
Santos, PV; Alves, JC; Ferreira, JC;
Publicação
U.Porto Journal of Engineering
Abstract
2018
Autores
Vaz Freitas, S; Pestana, PM; Almeida, V; Ferreira, A;
Publicação
BIOMEDICAL SIGNAL PROCESSING AND CONTROL
Abstract
Objectives: To describe the results of the acoustic analysis of a database of 90 voice samples with distinct dysphonia levels, using four different - commercial and open source - software programs. Study design: Exploratory, transversal. Methods: The samples were analyzed by four different types of software programs that perform acoustical evaluation - one open source software (Praat) and three commercial ones (Multi Dimensional Voice Program - MDVP by Kay Elemetrics; VoiceStudio by Seegnal; and Dr. Speech by Tiger Electronics) - for comparison among the most commonly used acoustic measures (frequency, perturbation and noise measures). Results: There is a moderate to strong,correlation, positive and statistically significant among the software programs. The mean FO is not statistically different among the used applications. The other acoustic measures revealed statistically significant differences. Conclusion: Even though it is easier to access software programs and there are numerous proposals for acoustic measures, not all of them are statistically representative nor have numeric semblance among the different applications.
2018
Autores
Ferreira, AJ;
Publicação
145th Audio Engineering Society International Convention, AES 2018
Abstract
Magnitude-oriented approaches dominate the voice analysis front-ends of most current technologies addressing e.g. speaker identification, speech coding/compression, voice reconstruction and re-synthesis. A popular technique is all-pole vocal tract modeling. The phase response of all-pole models is known to be non-linear and highly dependent on the magnitude frequency response. In this paper, we use a shift-invariant phase-related feature that is estimated from signal harmonics in order to study the impact of all-pole models on the phase structure of voiced sounds. We relate that impact to the phase structure that is found in natural voiced sounds to conclude on the physiological validity of the group delay of all-pole vocal tract modeling. Our findings emphasize that harmonic phase models are idiosyncratic, and this is important in speaker identification, and in fostering the quality and naturalness of synthetic and reconstructed speech. © 2018 KASHYAP.
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