Brazil

This work proposes a machine learning model trained from scratch to classify and detect the presence of pneumonia from a collection of chest X-ray images. Unlike most works that use deep learning to classify whether the image is of a lung with pneumonia or not, that is, two classes to achieve a remarkable classification performance, this model uses Oriented Gradient Histogram for extra features from a provided chest X-ray image and classify it into three classes, determining whether or not a person is infected with viral or bacterial pneumonia. Despite greater complexity and use of traditional machine learning techniques, the highest accuracy achieved was 91.32% more higher than works that use deep learning approaches and seeking to solve the same degree of complexity.

BRACIS 2021

Classification of chest X-ray images using Machine Learning and Histogram of Oriented Gradients

medical diagnosis

machine learning

computer vision

**BRACIS** originated from the combination of the two most important scientific events in Brazil in Artificial Intelligence (AI) and Computational Intelligence (CI): the Brazilian Symposium on Artificial Intelligence – **SBIA** (22 editions), and the Brazilian Symposium on Neural Networks – **SBRN** (13 editions). **ENIAC** is a national forum for researchers, practitioners, educators and students to present and discuss innovations, trends, experiences, developments and work in progress in the fields of Artificial and Computational Intelligence. **STIL** is the bi-annual Language Technology event.
All events are supported by the Brazilian Computer Society – Special Interest Groups: **CE-IA**, **CE-IC** and **CE-PLN**.

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BRACIS originated from the combination of the two most important scientific events in Brazil in Artificial Intelligence (AI) and Computational Intelligence (CI): the Brazilian Symposium on Artificial Intelligence – SBIA (22 editions), and the Brazilian Symposium on Neural Networks – SBRN (13 editions). 
ENIAC is a national forum for researchers, practitioners, educators and students to present and discuss innovations, trends, experiences, developments and work in progress in the fields of Artificial and Computational Intelligence. 
STIL is the bi-annual Language Technology event.
All events are supported by the Brazilian Computer Society – Special Interest Groups: CE-IA, CE-IC and CE-PLN

technical paper

Electronic Legal Proceedings are worldwide legal phenomena, allowing
the use of computerized systems for the creation and monitoring of procedural
acts in the most diverse legal bodies. On one hand, it allows greater
transparency in the conduct of procedural acts, on the other, it has contributed
to the bottleneck of open but unresolved lawsuits each year. Nowadays, Information
Retrieval to automate the processing of these procedural objects is at the
forefront of computer systems for Law. In this study, we present MISLA2, a system
to retrieve orders and preliminaries from judicial labor sentences through
ontological models built from previous cases. Instead of tied and difficult-to-maintain
domain specification models, we demonstrate how light ontologies, in
conjunction with regular expressions for extracting significant portions of the
text, can achieve the desired results. In addition, empirical experiments carried
out with real labor lawsuits evidence that results are quite promising.

MISLA2: A System to Information Retrieval in Labor Lawsuits using Legal Ontologies and Regular Expressions

In a multi-agent system (MAS), it is very usual that agents delegate tasks to each other. However, due to the subjectivity of the information used by agents during the decision-making process, an agent may end up delegating a task to an untrustworthy partner. In this work, we present a trust computing approach based on quantitative argumentation with votes (\hbox{QuAD-V}), where a trust measure is estimated according with the agents' opinions about the service provided by a partner. Besides, such an approach provides a mechanism to evaluate the credibility of agents that play as information sources. In our results, we demonstrate how our trust computing approach can be employed for detecting lying agents, which are able to slander or promote other agents.

Trust Computing Based on Argumentation Debates with Votes for Detecting Lying Agents

A taxa de perfuração (ROP) de um poço de petróleo é uma métrica muito importante de se controlar, por influenciar na produtividade do poço, no desgaste da broca e na segurança do poço e operação. Este trabalho avalia a utilização do algoritmo de floresta aleatória para previsão da ROP em poços de petroleo offshore como alternativa para modelos tradicionalmente utilizados pela indústria. Modelos de floresta aleatória foram avaliados com diferentes hiper-parametros para 4 poços offshore no pré-sal da Bacia de Santos. Não houve uma única combinação de hiper-parâmetros ótima comum entre os poços.

Previsão de Taxa de Perfuração em Poços de Petróleo Offshore Utilizando Algoritmos de Aprendizado de Máquina

The core point of the research process are data. They are records fromscientific investigation, which support the results published in journals and con-ferences. Making research data available in open access digital repositories hasmany advantages, such as increasing the visibility of associated publications,reproducing experiments, and validating results. In Brazil, full and unrestrictedsharing of them is not yet accepted by most researchers. This paper presents aninitial study to describe a model analyzing the attitude of Brazilian researchersconcerning open access research data. A clustering algorithm was used to iden-tify different research profiles. The achieved results indicate the main reasonswhy the researchers object to share their data

A clustering algorithm to evaluate the attitude of Brazilian researchers regarding open access research data

Este trabalho propõem uma abordagem para auxiliar pessoas com deficiência visual no reconhecimento de pessoas independente da idade. O objetivo é desenvolver um sistema que utilize uma abordagem de reconhecimento facial, com foco na invariância na idade, que retorne bons resultados comparados aos resultados obtidos na revisão da literatura. A abordagem estudada utiliza Redes Neurais Convolucionais profundas - CCNs, pré-treinadas pelo conjunto de dados VGGFace2, para extrair descritores de características de imagens de faces e classificar com o algoritmo de classificação Linear SVM. Como pode ser visto no decorrer do trabalho, a abordagem retornou 89,9% de acurácia, utilizando o conjunto de dados FG-NET, com 1002 imagens. E utilizando o conjunto de dados CACD, que contém 163.446 imagens divididas em quatro subconjuntos diferentes, três conjuntos para treino e um para teste, a abordagem retornou 85,2%, 82,4% e 88,2% de acurácia para cada modelo treinado com um conjunto de treinamento diferente.

Age-Invariant Face Recognition to Aid Visually Impaired Pleople

The employment of video surveillance cameras by public safety agencies enables incident detection in monitored cities by using object detection for scene description, enhancing the protection to the general public. Object detection has its drawbacks, such as false positives. Our work aims to enhance object detection and image classification by employing IoU (Intersection over Union) to minimize the false positives and identify weapon holders or fire in a frame, adding more information to the scene.

Detection of weapon possession and fire in Public Safety surveillance cameras

Handwritten signature authentication systems are important in many real world scenarios to avoid frauds. 
Thanks to Deep Learning, state-of-art solutions have been proposed to this problem by making use of Convolutional Neural Networks, but other models in this Machine Learning subarea are still to be furtherexplored. 
In this perspective, the present article introduces a Conditional Deep
Convolutional Generative Adversarial Networks (cDCGAN) approach whose experimental results in a realistic dataset with skilled forgeries have Equal Error Rate (EER) of 18.53 % and balanced accuracy of 87.91 %. 
These results validate a writer-dependent cDCGAN-based solution to the signature authentication problem in a real world scenario where no forgeries are available nor required in training time.

Offline Handwritten Signature Authentication with Conditional Deep Convolutional Generative Adversarial Networks

Summarized the main findings of the paper Face Reconstruction with Variational Autoencoder and Face Masks, answering key questions of how the set up of Face Masks and combined loss functions between L1, L2, and SSIM affects the image reconstruction quality.

Face Reconstruction with Variational Autoencoder and Face Masks

Our work analyses a set of semantic segmentation methods applied todetect people on beach images, as part of an automatic track system to monitorbathers to prevent trespassing the boundaries of the safe region for swimming.In our analysis, we compared the semantic segmentation networks U-net, X-net,LinkNet and Unet++ with the pretrained backbones VGG-16 and VGG-19. Webuilt our own dataset, composed of 300 images. The models were evaluatedbound box-wise using F-score metrics. Our findings show that X-Net achievedthe best value for F-score, with 90.89%, while Linknet was faster than the othernetworks, with no significant statistical difference in the F-score values.

Semantic Segmentation for People Detection on Beach Images

Image classification has been applied to several real problems.
However, getting labeled data is a costly task, since it demands time, resources and experts. Furthermore, some domains like disease detection suffer from unbalanced classes. These scenarios are challenging and degrade the performance of machine learning algorithms. In these cases, we can use \textit{Data Augmentation} (DA) approaches to increase the number of labeled examples in a dataset. The objective of this work is to analyze the use of Generative Adversarial Networks (GANs) as DA, which are capable of synthesizing artificial data from the original data, under an adversarial process of two neural networks. The GANs are applied in the classification of unbalanced Covid-19 radiological images. Increasing the number of images led to better accuracy for all the GANs tested, especially in the multi-label dataset, mitigating the bias for unbalanced classes.

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Classification of chest X-ray images using Machine Learning and Histogram of Oriented Gradients

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