Bagging de Detectores por Produto Interno para Detecção de Olhos

Wesley L. Passos, Gabriel M. Araujo, Amaro A. Lima, Felipe M. L. Ribeiro, Eduardo A. B. da Silva

DOI: 10.14209/sbrt.2017.53

Keywords: Computer vision Eye detection Facial features Ensemble methods

Abstract

This article presents a system for eye detection using an ensemble of correlation-based filters known as Inner Product Detector (IPD). This work has three main contributions: i) an ensemble classifier with higher accuracy than the original IPD detector, using the bagging algorithm; ii) new discriminant functions based on the ensemble output; and iii) the study of the influence of bagging on the system performance. The proposed method was evaluated on the BioID dataset, achieving an average accuracy of 98.02% and 95.71% for right and left eyes, respectively, where a deviation of up to 10% of the interocular distance is considered a hit.

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Implementação Eficiente de Filtros Volterra Explorando Abordagens de Posto Reduzido e Caracterı́sticas de Hardware

Felipe Dennis de Resende Oliveira, Eduardo Luiz Ortiz Batista, Rui Seara

DOI: 10.14209/sbrt.2017.49

Keywords: Reduced-rank implementation Volterra filters

Abstract

This paper presents a new approach for obtaining efficient implementations of Volterra filters. Such an approach is based on exploiting the different significance levels of the branches of reduced-rank Volterra structures, aiming to define individual word sizes for the implementation of each branch. In this way, significant reductions of computational cost can be obtained, especially for implementations carried out using field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). Results obtained from a case study are presented, demonstrating the effectiveness of the proposed approach.

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SINTONIA ADAPTATIVA DE ALGORITMOS PID DE CONTROLE DE POTÊNCIA EM REDES NG-PON BASEADO EM PSO

Layhon R. R. dos Santos, Fábio Renan Durand, Taufik Abrão

DOI: 10.14209/sbrt.2017.54

Keywords: Adaptive tuning control algorthm DPCA-FMPID particle swarm optimization (PSO) new generation passive optical networks (NG-PON).

Abstract

In this work the adaptive tuning of a distributed power control algorithm based on the Distributed- Integral-Derivative DPCA-FM-PID (Distributed Power Control Algorithm-Foschini / Miljanic) controller is proposed through optimization by particle swarm (PSO). Power control is applied to a passive optical network of the new generation 40GEOCDMA- PON (Optical Code Division Multiplexing Access - Passive Optical Network). The main results regarding the quality of the responses and convergence speed illustrate the superiority of the algorithm with the adaptive tuning based on PSO with respect to the same algorithm without adaptive tuning, even when considering channel estimation errors.

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Estudo de viabilidade na utilização de RFID para identificação de ovinos e caprinos

Mara Luzia de Araújo Nunes, Edmilson Carneiro Moreira

DOI: 10.14209/sbrt.2017.50

Keywords: RFID ovino caprino.

Abstract

Este trabalho é um estudo sobre a viabilidade da utilização da tecnologia de identificação por rádio frequência – RFID, para identificação de caprinos e ovinos. O intuito é de melhorar a gestão, qualidade e controle, com foco no mercado de ovinocaprinocultura. Para esse estudo um estaleiro foi equipado com RFID, a fim de investigar a possibilidade do uso da tecnologia com esses animais em seu ambiente de confinamento. Os dados levantados são visualizados através de resultados de forma condensada. Os resultados indicam a possibilidade do uso do RFID para identificação de caprinos e ovinos.

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Performance Evaluation of Multicarrier Systems Applied to Underwater Acoustic Communications

Iandra G. Andrade, Marcello L. R. de Campos

DOI: 10.14209/sbrt.2017.55

Keywords: Underwater communication OFDM FSK SC- FDM Doppler

Abstract

In underwater acoustic communications, orthogonal frequency-division multiplexing (OFDM) is an alternative to frequency-shift keying (FSK). The key advantage of OFDM scheme is that it provides a significant increase in transmission rate. In this paper, we simulate and compare the performance in terms of bit-error rate (BER) of the OFDM and FSK in underwater acoustic communications. As an alternative we also analyze the behavior of single-carrier frequency-division multi- plexing (SC-FDM). Lastly, to isolate the consequences of Doppler effect without masking distortions introduced by multi-path and the associated equalization procedures, their performances are also evaluated in the presence of Doppler and additive noise.

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Decodificação Iterativa para Canais com Memória e Decodificação Suave

Igor Moreira, Cecilio Pimentel

DOI: 10.14209/sbrt.2017.260

Keywords: Finite-state Markovian channels LDPC codes sum-product algorithm error probability soft quantization.

Abstract

This paper presents a new non-binary finite state Markov channel (FSMC) that captures both the soft-decision information and the temporal correlation of a discrete fading channel. An interative decoding scheme, based on the sumproduct algorithm, is also discussed for joint decoding and channel state estimation. The performance of LDPC codes over the proposed non-binary FSMC is then studied and the coding gain obtained by increasing the channel output alphabet is analyzed.

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Sistema OFDM em Canais Acústicos Submarinos com Desvanecimento por Multipercursos

Daniel R. de Luna, Israel A. N. Dantas, Lívio C. Sousa, Vicente A. de Sousa Jr.

DOI: 10.14209/sbrt.2017.51

Keywords: Canal Submarino desvanecimento por multipercursos,OFDM

Abstract

Cerca de 70% da superfície da terra é coberta por água do mar, uma área ainda pouco explorada para fins de comunicação. Desde aplicações comerciais a aplicações militares (envolvendo também a obtenção e preservação de recursos naturais), explorar comunicações submarinas pode ser estratégico e uma vantagem competitiva para países com costa extensa, como o Brasil. Este trabalho tem como objetivo avaliar por meio de protótipos em software o desempenho de uma comunicação através de um canal acústico submarino sujeito a desvanecimento. A modelagem do canal submarino é comparada a um modelo clássico de canal sem fio por onda eletromagnética, apresentando efeitos similares em relação ao espalhamento temporal e em frequência. Assim, a análise se baseia em um sistema OFDM, o qual é capaz de combater os efeitos de desvanecimento em um canal sem fio tradicional. Após apresentar a modelagem do canal submarino e os trabalhos relacionados a proposta deste artigo, é evidenciado a diferença de desempenho da BER do OFDM nos canais analisados, evidenciando a hostilidade do canal submarino em termos de propagação.

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A Study on Different Strategies for Chirp Rate Sampling in the Fan Chirp Transform

Isabela F. Apolinário, Luiz W. P. Biscainho

DOI: 10.14209/sbrt.2017.56

Keywords: Fan Chirp Transform Time-Frequency Domain PDF Kernel Estimation

Abstract

This article is a study on different strategies for sampling the chirp rate parameter used in the Fan Chirp Transform. In particular, sampling based on the estimation of the parameter’s PDF is proposed; some experiments are performed in order to get some insight on its potentialities, and the corresponding analysis is also presented. The main target is to reduce computational complexity while maintaining performance.

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Receivers for the up-link of multiuser MIMO systems with Spatial Modulation

José Luis Calpa Juajinoy, João Alfredo Cal-Braz, Raimundo Sampaio-Neto

DOI: 10.14209/sbrt.2017.57

Keywords: MIMO systems Up-link Spatial Modulation Decoupling signal detection.

Abstract

This paper presents the results obtained from the conjunction of two techniques proposed for use in modern communication systems: Spatial Modulation (SM) and decoupled signal detection. Theoretical fundamentals of Spatial Modulation signal detection are covered, in addition to signal decoupling techniques that enable the separation at the base station of signals transmitted from different users, aiming at the simplification and utilization of detection procedures best suited to each user in the network. Performance analyses, in terms of bit error rate, and computational complexity, in terms of the average number of flops per detected symbol vector are carried out for the different associations of decoupling techniques and SM detectors.

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Estudo do Compromisso entre Eficiência Espectral e Justiça na Alocação de Recursos de Rádio

Thiago Duarte de Paula, Diego Aguiar Sousa, Tarcisio Ferreira Maciel

DOI: 10.14209/sbrt.2017.58

Keywords: Radio resource allocation capacity-fairness trade- off wireless systems optimization

Abstract

This work studies the trade-off between spectral ef- ficiency and fairness considering the alocation of radio resources in a multi-user system which considers quality of experience constraints for each user and service. The focus herein is to reduce the non-uniformity among the throughput values achieved by the users, which originate from the opportunistic resource distribution performed by the resource allocation algorithms. Thus, it is proposed herein the introduction of a penalty term in the objective function of the resource allocation optimization problem as to provide a better trade-off between fairness (in terms of users’ throughput) and the total system capacity. The obtained results were analyzed in terms of Jain’s index of fairness, where different variations of several relevant parameters which impact the users’ satisfaction have been evaluated. The results have shown that the proposed approach provided a better trade-off between fairness and capacity reaching Jain’s index of fairness values of up to 0.9 with rates close to those obtained in the case without the penalty in the objective function.

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