Classification of voice aging based on the glottal signal

Leonardo Forero, Marco Silva, Edson Cataldo, Jose Apolinário Jr., Marley Vellasco

DOI: 10.14209/sbrt.2010.112

Keywords: Speech processing voice aging glottal source neural network classifier

Abstract

Classification of voice aging has many applications in health care and geriatrics. This work focuses on finding the most relevant parameters to classify voice aging. The most significant parameters extracted from the glottal signal are chosen to identify the voice aging process of men and women. After analyzing their statistics, the chosen parameters are used as entries to a neural network and to a support vector machine set to classify male and female Brazilian speakers in three different age groups: young (from 15 to 30 years old), adult (from 31 to 60 years old), and senior (from 61 to 90 years old). The corpus used for this work was composed by one hundred and twenty Brazilian speakers (both males and females) of different ages. As compared to similar works, we employ a larger corpus and obtain a superior classification rate.

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Single shift-register for RFID tag secrecy

Bruno B. Albert, F. M. de Assis, Marcus V. C. Rodrigues

DOI: 10.14209/sbrt.2010.46

Keywords: RFID privacy/security random modulation PRG

Abstract

In this paper we present a new privacy scheme against passive adversaries based on the message modulation instead of classical cryptographic models for low cost wireless devices, such as an RFID tag. The idea is to become the adversary in disadvantage related to the reader-tag communication channel, for example, by reducing her signal-to-noise ratio.

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Logical Operations by Pulse Modulation in Nonlinear Directional Coupler

Alisson da Conceição Ferreira, Cícero Saraiva Sobrinho, José Wally Mendonça Menezes, Guilherme Francisco de Morais Pires Júnior, Antônio Sérgio Bezerra Sombra, Jose Luiz Sousa Lima, Hélio Henrique Barbosa Rocha, Herbert de Oliveira Rodrigues

DOI: 10.14209/sbrt.2010.113

Keywords: Pulse-position modulation nonlinear directional coupler soliton logical gates

Abstract

Implementation of logical gates by pulse modulation in nonlinear fiber directional coupler is investigated numerically. We consider pulses from an optical time-division multiplex system operating with pulse-position modulation (PPM). Such a system is simulated by a PPM modulator. The study shows that with a proper phase control it is possible to accomplish logical operations.

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A First Glance Comparison of Next and New Generation Network Approaches

Antonio Marcos Alberti, Tania Regina Tronco, Christian Esteve Rothenberg

DOI: 10.14209/sbrt.2010.114

Keywords: G wG Future Internet IP networks

Abstract

ext Generation etworks ( xG ), as pursued by international standards development organizations, represent the telecommunication operator approach to provide convergent multimedia experience for their users with improved support for mobility and unfettered service access. In contrast, research efforts in so-called ew Generation etworks ( wG ), such as the Japanese project Akari and the European Future Internet initiatives, are part of an exciting trend towards re-architecting the Internet. Despite the enormous interest regarding both lines of work, few comparisons between their design approaches have been discussed in the literature. This paper provides a first glance comparison between key aspects of both proposals.

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ASSESSING THE OCR DEGRADATION IN THE GENERATION OF JPEG, PNG, AND TIFF FILES FROM ADOBE PDF

Gabriel de França Pereira e Silva, Rafael Dueire Lins

DOI: 10.14209/sbrt.2010.48

Keywords: JPEG PNG TIFF OCR quality

Abstract

Adobe Portable Document Format is de facto standard today due to its widespread use. One of the features of Adobe pdf is that it allows exporting documents as images that may be saved in JPEG, PNG, and TIFF formats. This paper uses an OCR platform to quantitatively assess the quality of these image file formats.

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An Approach for Solving the Base Station Placement Problem using Particle Swarm Intelligence

Marcos Talau, Emilio C. G. Wille, Heitor S. Lopes

DOI: 10.14209/sbrt.2010.49

Keywords: Binary PSO BSP CDMA

Abstract

A large amount of studies deals with the base station placement problem (BSP), but few studies involve the selection of base stations to meet a set of users. This paper presents an approach for solving BSP problems in an indoor environment, aiming at meeting a set of users, with a minimum number of base stations, using a binary particle swarm optimization (PSO). A benchmark of four maps of increasing complexity was created for testing the system. Results of the binary PSO were compared with optimal solutions found by an exhaustive search algorithm. The computational results suggest that the PSO algorithm provides a quite efficient approach to obtain (near) optimal solutions with small computational effort.

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Controlling the Peak-to-Average Power Ratio in the Downlink of WiMAX Systems

Guilherme Guimares Mendes, Andr Noll Barreto

DOI: 10.14209/sbrt.2010.115

Keywords: WiMAX PAPR PAPR reduction schemes non linear amplifiers

Abstract

It is well known that one of the main implementation issues in multicarrier modulation schemes, like OFDM, is their high peak-to-average power ratio (PAPR). Power amplifiers that are employed in the transmitters of communications systems are highly non-linear devices, which present a saturation level, and typically show a higher power efficiency close to saturation. Therefore, the high peak amplitudes common in OFDM may cause severe non-linear effects, such as signal clipping, which result in out-of-band radiation and signal constellation distortion. Several techniques are proposed in the literature in order to reduce the PAPR of OFDM signals, such as clipping with additive or multiplicative windowing, use of virtual subcarriers, active constellation extension and partial transmit sequences, among others. In this contribution we demonstrate the use of some of these techniques in a WiMAX wireless system, based on the IEEE 802.16e, focusing on techniques that can be employed with no or little modifications to existing standards. The PAPR effects are investigated in terms of several different performance metrics, namely the adjacent channel power ratio (ACPR), the total degradation and data throughput, and we see that through the proper combination of different techniques significant performance gains can be achieved.

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Facial Landmarks Detection Based on Correlation Filters

Gabriel M. Araujo, Waldir S. S. Júnior, Eduardo A. B. Silva, Siome K. Goldenstein

DOI: 10.14209/sbrt.2010.50

Keywords:

Abstract

The problem of locating facial landmarks is important in many applications such as security, 3D modeling and expression recognition. In this paper, we present a new facial landmarks detection system. The core of the proposed system is a cascade of a new detector based on correlation filters. This detector inherits from the correlation filters the tolerance to small variations of the desirable pattern. This detector is refereed to as IPD (Inner Product Detector) and, different from the correlation filters, is suitable for features with a small number of dimensions. In our experiments we use cross-validation of 503 images from BioID database. We verify that the proposed method provides competitive performance when compared to Support Vector Machines.

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Optimized Blind Algorithms for Widely Linear Beamforming

Adilson Chinatto, Cynthia Junqueira, João M. T. Romano

DOI: 10.14209/sbrt.2010.116

Keywords: widely linear processing blind algorithms CMA NCMA beamforming

Abstract

The use of array beamforming in modern wireless communication systems has been increasingly investigated, due to their potential in rejecting interference and improving the system capacity. The so-called blind algorithms have been considered in such application in order to avoid training procedures and improve the overall transmission throughput. Most works in the field consider circular signals and classical linear signal processing framework. However, the alternative scenario of Widely Linear Processing was shown to be more suitable under other circularity conditions, particularly in rectilinear modulations schemes. This paper deals with blind algorithms for array beamforming in a Widely Linear Processing framework. We consider the well-known CMA and NCMA algorithms and derive corresponding Widely Linear formulations with optimized performance. In addition, we show that their implementation requires less computational cost than the original CMA and NCMA. Simulation results confirm that both proposed algorithms perform better than their strictly linear counterparts.

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Quaternary LDPC Codes on OFDM Systems

Maria Leopoldina M. N. S. Gonçalves, Renato Baldini Filho

DOI: 10.14209/sbrt.2010.51

Keywords: Quaternary LDPC code OFDM frequencyselective fading

Abstract

This paper evaluates the performance of quaternary LDPC codes associated to OFDM systems. The LDPC codes are based on a ring Z4 of integers modulo-4. Each OFDM subcarrier is modulated using a 4-PSK modulation, and each output symbol of the encoder is mapped onto that modulation. The performance is evaluated, in terms of BER versus Eb/N0, for AWGN and frequency-selective fading channels. The results show good performance when compared to the channel encoding process of the Brazilian Digital Television System (SBTVD).

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