Um Algoritmo Rápido para a Multiplicação de Octônios

Luciano Barboza Silva, Hélder Barbosa, Gilson Jerônimo da Silva Jr., Ricardo M Campello de Souza

DOI: 10.14209/SBRT.2020.1570658261

Keywords: Octonions Fast algorithms Self-similar matrices Hypercomplex numbers

Abstract

This work proposes a fast algorithm for computing a product of two octonions. The direct computation of an octonion product requires 64 multiplications and 56 additions, while the proposed algorithm uses 30 multiplications and 94 additions, reducing the multiplicative complexity necessary to compute this product.

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Modelo Complexo eta-mu Bivariável com Desbalanceamento de Clusters

Alessandro Paulo de Oliveira, Thiago Bairros, Rausley Adriano Amaral de Souza, Michel Daoud Yacoub

DOI: 10.14209/SBRT.2020.1570658277

Keywords: eta-mu distribution fading channels bivariate phase envelope joint distribution.

Abstract

In this paper, a fading model for the complex bivariate eta-mu channel, with an imbalance between the number of clusters of the in phase and quadrature components, is proposed. An exact closed-form expression for the joint probability density function including the two envelopes and their corresponding phases is obtained. It is assumed that the correlation occurs between the respective in phase components with each other and the respective in quadrature components with each other of the eta-mu signals. The proposed model generalizes two models already presented elsewhere in the literature.

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Mapa de Saliência para Nuvem de Pontos usando Projeções

Victor F Figueiredo, Ricardo de Queiroz

DOI: 10.14209/SBRT.2020.1570658395

Keywords: Mapa de saliência Nuvem de pontos

Abstract

Algorithms for creating saliency maps are well established for images, even though there is no literature on such methods for point clouds. We use orthographic projections in 2D planes which are subject to well established saliency detection algorithms to create a 3D saliency map. The results of each saliency map are projected to the 3D voxels and the results of the many projections are used to generate a 3D saliency map. As a future work it is proposed to use the saliency map to assist in the compression of point cloud.

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Digital Nonlinearity Compensation Techniques for Unrepeatered Optical Systems

José Hélio da Cruz Júnior, Tiago Sutili, Lucas Silva Schanner, Sandro M. Rossi, Rafael C. Figueiredo

DOI: 10.14209/SBRT.2020.1570658398

Keywords: Digital back-propagation Maximum likelihood sequence estimation Nonlinear compensation Unrepeatered systems

Abstract

In this paper, we experimentally investigate the performance of unrepeatered optical transmission comparing different nonlinear compensation (NLC) implementations. Specifically, digital back-propagation (DBP) algorithm and maximum likelihood sequence estimation (MLSE) are applied for intra-channel NLC with and without 4x4 multiple-input multiple-output (MIMO) equalization. Both NLC algorithms are evaluated in an unrepeatered WDM transmission of 17x200-Gb/s channels (32 GBd DP-16QAM) over 350 km of large effective area and low loss single-mode fibers. The results indicate a Q^2 factor and optimum launch power improvements of up to 0.4 dB and 2 dB, respectively, compared to the linear compensation (LC), combining MLSE and DBP with MIMO equalization.

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Estudo de Perdas para Codificação de Geometria de Nuvens de Pontos por Decomposição Diádica

Davi R. Freitas, Eduardo Peixoto, Ricardo L de Queiroz, Edil Medeiros

DOI: 10.14209/SBRT.2020.1570658416

Keywords: Nuvens de pontos Codificação com perdas Compressão de geometria

Abstract

This paper proposes a study about the introduction of lossy techniques over an intra-frame coder of the geometry information of voxelized point clouds (PC). Using an alternative representation approach, this method represents the PC as an array of binary images. Moreover, we sought to assess the quality of the decoded PC with different reconstruction techniques for a given bit rate. We observed that the use of the lossy proposed method alone wasn't enough to reach bitrates values below 0.2 bpov, which suggests the combination of this method with other lossy solutions in future studies.

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Detecção de tráfego anômalo de rede utilizando clusterização em Big Data

Mateus Rocha, Daniel G Silva

DOI: 10.14209/SBRT.2020.1570658430

Keywords: Big Data clustering network intrusion detection

Abstract

Nowadays, the sheer amount of information sent through the Internet enables the adoption of Big Data and machine learning frameworks in order to detect network anomalies. However, there are two key challenges: the processing latency due to huge amounts of data and the reduced flexibility that supervised learning paradigm may cause. In this paper, we propose a Big Data framework that uses unsupervised learning for near real time intrusion detection, which is also capable of periodically retrain the generated models in order to track the network dynamics. The framework is succesfully tested with a well-known dataset and with real network traffic from a reverse proxy server.

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Synthesis of sung Spanish vowels in lyrical singing by sopranos using the Fant source-filter theory and the Rosenberg glottal pulse model

Luis E Barrientos Sandoval, Edson Cataldo

DOI: 10.14209/SBRT.2020.1570658444

Keywords: Voice synthesis Singing voice Rosenberg model Glottal signal

Abstract

This paper aims to synthesize the sung Spanish vowels with covering considering the soprano vocal category of lyrical singers, including variation of sustained pitches with vibrato effect. The Fant source-filter theory is used to model the production of the sustained vowels. The source is based on the Rosenberg glottal pulse model and filter (the vocal tract) is composed by an all-pole filter model with formant frequencies and bandwidths from the vowels of Spanish language. All the sounds synthesized are available to be accessed and they were submitted to a group of listeners and they received a very good evaluation with respect to their intelligibility and naturalness.

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Automatic Generation of Error Correcting Systems Based on Convolutional Codes

Lucas Fernandes Muniz, Daniel G Silva, Romis Ribeiro Attux, Denis Fantinato, Carla Lintzmayer

DOI: 10.14209/SBRT.2020.1570658446

Keywords: Convolutional codes Error correction Genetic Algorithms

Abstract

Due to the wide use of digital systems, bit error control is an important task. Convolutional codes are error correcting codes widely used due to their efficiency. However, the large number of parameters involved in their generation results in a problem with high complexity. In this work, we used the metaheuristics GA and BRKGA to search for efficient coding systems, which showed relevant results in our simulations.

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Comparação do Desempenho de Esquemas de Gerenciamento de Localização em Redes 5G

Lidiano Oliveira, Marcelo S. Alencar, Waslon Lopes

DOI: 10.14209/SBRT.2020.1570658447

Keywords: Cellular Mobile System Location Management 5G Networks

Abstract

Unlike predecessors technologies, the fifth generation (5G) of mobile networks represents a technological paradigm shift. A new location management strategy was introduced to fulfill the new requirements of 5G networks. This article presents the signalling cost of the new location management scheme of proposed by 3GPP. The performance of this scheme is analyzed and compared to the predecessor schemes. The results confirm that the new scheme decreases the signalling cost of a 5G network when compared to the traditional schemes (2G, 3G and LTE networks).

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Caracterização de um Filtro Passa-Banda em banda X utilizando Ressoadores de Anel Dividido Retangulares para diferentes Condições de Contorno

Mateus F Belício, Fernanda Silva

DOI: 10.14209/SBRT.2020.1570658453

Keywords:

Abstract

This work presents the effects of different boundary conditions in bandpass filter implemented with a rectangular split ring resonator (SRR). A characterization is performed with three different boundary conditions. The basic characteristics of the bandpass filter are used for different boundary conditions. The filter was simulated to operate in the X. tThe filter were simulated in the CST Studio software.

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