Brazil

This paper describes the application of supervised and unsupervised
machine learning in large volumes of open governmental data from INEP.
This work uses the following algorithms: K-Nearest Neighbors, Logistic
Regression, Decision Tree, Random Forest and K-means. The methodology is
based on the CRISP-DM and KDD processes, requiring the use of the
DataBricks cloud platform. In addition, the Hadoop and Apache Spark cluster
Technologies were also used. Such technologies provided high processing
power for the execution of the experiments. This enabled the performance
evaluation of the models and the discovery of knowledge about Brazilian basic
education.

BRACIS 2020

Cloud Computing and Machine Learning for Analysis ofLarge Volumes of Educational Data

educational data mining

big data

machine learning

AIAI 2020 (16th International Conference on Artificial Intelligence Applications and Innovations) should be held in Halkidiki, Greece. Due to current Covid-19 situation the conference will be held virtually. Underline will host a repository of video talks and preserve them for the future. Videos will be released on Underline one day after the conference.

AIAI 2020

technical paper

The 9th Brazilian Conference on Intelligent Systems (BRACIS), the 16h Encontro Nacional de Inteligência Artificial e Computacional (ENIAC), and the 12th Concurso de Teses e Dissertações em Inteligência Artificial e Computacional (CTDIAC) was held from 20 to 23 October, 2020.

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. CTDIAC is a satellite event whose goals are to disseminate and award the best dissertations and theses (MSc and PhDs concluded in Brazilian universities from June 2018 to May 2020) in Artificial and Computational Intelligence areas.

In this year, the Symposium on Knowledge Discovery, Mining and Learning (KDMiLe) will be held in conjunction with BRACIS 2020. This sysposium aims at integrating researchers, practitioners, developers, students and users to present their research results, to discuss ideas, and to exchange techniques, tools, and practical experiences – related to the Data Mining and Machine Learning areas.

This paper presents a parallel strategy with a heuristic approach to
reduce the execution time bottleneck of a routing and wavelength assignment
problem in wavelength-division multiplexing networks of a previous work that
uses a sequential genetic algorithm. As the parallelization solution, the GPU
hardware processing on CUDA architecture and CUDA C programming lan-
guage were adopted. The results achieved were between 35 and 40 times faster
than the sequential version of the genetic algorithm.

A Parallel Strategy for a Genetic Algorithm in Routing Wavelength Assignment Problem Using GPU with CUDA

Multiple coin detection is a Computer Vision problem which aims at finding coins in an image and classifying their respective values. For Brazilian Real, literature typically consider feature extraction techniques followed by Machine Learning classifiers, specially Artificial Neural Networks. However, some recent results on coin detection with Deep Learning motivated us to propose a hybrid approach for the previously mentioned problem considering localization with traditional Computer Vision techniques and classification with Convolutional Neural Networks. Multiple architectures were tested in a realistic dataset and the proposed solution has mean average precision higher than 92%with classifier accuracy greater than 97% surpassing other work for the same dataset by 6%.


Hybrid Approach for Detecting Brazilian Real Coins with Localization Algorithms and Convolutional Neural Networks

Data classification is a major machine learning paradigm, which has been widely applied to solve a large number of real-world problems. Traditional data classification techniques consider only physical features (e.g., distance, similarity, or distribution) of the input data. For this reason, those are called \textit{low-level} classification. On the other hand, the human (animal) brain performs both low and high orders of learning and it has a facility in identifying patterns according to the semantic meaning of the input data. Data classification that considers not only physical attributes but also the pattern formation is referred to as \textit{high-level} classification. Several high-level classification techniques have been developed, which make use of complex networks to characterize data patterns and have obtained promising results.
In this paper, we propose a pure network-based high-level classification technique that uses the betweenness centrality measure.
We test this model in nine different real datasets and compare it with other nine traditional and well-known classification models. The results show us a competent classification performance.

A Network-Based High-Level Data Classification Algorithm Using Betweenness Centrality

Many works that apply Deep Neural Networks (DNNs) to Speech Emotion Recognition (SER) use single datasets or train and evaluate the models separately when using multiple datasets. Those datasets are constructed with specific guidelines and the subjective nature of the labels for SER makes it difficult to obtain robust and general models. We investigate how DNNs learn shared representations for different datasets in both multi-task and unified setups. We also analyse how each dataset benefits from others in different combinations of datasets and popular neural network architectures. We show that the long-standing belief of more data resulting in more general models doesn’t always hold for SER, as different dataset and meta-parameter combinations hold the best result for each of the analysed datasets.

Interaffection of Multiple Datasets with Neural Networks in Speech Emotion Recognition

Machine learning algorithms are widely used in credit card fraud detection systems due to their ability to distinguish between legitimate and fraudulent transactions. A known problem in this field is the high imbalance usually found in the classes, which can compromise the performance of the classifiers. The empirical studies found in the literature apply, at most, two sampling techniques. This article presents a comparative study of five classification models under five different methods of balancing the training sets. The best performance was obtained by random forest, which in addition to having the highest average F-score (0.867), proved to be considerably more robust than the other classifiers in relation to the choice of the balancing technique and attribute selection.

Empirical evaluation of classifiers and balancing methods for fraud detection in credit card transactions

Non-traumatic Vertebral Compression Fractures (VCFs) are generally caused by osteoporosis (benign VCFs) or metastatic cancer (malignant VCFs) and the success of the medical treatment strongly depends on a fast and correct classification of VCFs. Recently, methods for computer-aided diagnosis (CAD) based on machine learning have been proposed for classifying VCFs. In this work, we investigate the problem of clustering images of VCFs and the impact of feature selection by genetic algorithms on this task. The analysis of the clusters helps to understand the results of classifiers and difficulties of differentiating images of different classes by an expert. The results indicate that features selection improved the separability of clusters and purity. Feature selection also helps to understand which attributes are more important for analysing the images of vertebral bodies.

Impact of Feature Selection on Clustering Images of Vertebral Compression Fractures

This work presents an investigation on how to define Neural Networks (NN) architectures adopting a data-driven approach using clustering to create sub-labels to facilitate the learning process and to discover the number of neurons needed to compose the layers. We also increase the depth of the model aiming to represent the samples better, the more in-depth it flows into the model. We hypothesize that the clustering process identifies sub-regions in the feature space in which the samples belonging to the same cluster have strong similarities. We used seven benchmark datasets to validate our hypothesis using 10-fold cross validation 3 times. The proposed model increased the performance, while never decreased it, with statistical significance considering the p-value < 0.05 in comparison with a Multi-Layer Perceptron with a single hidden layer with approximately the same number of parameters of the architectures found by our approach.

Clustering for Data-driven Unraveling Artificial Neural Networks

The identification of running patterns, especially those associated to fatigue, can assist in designing more efficient workouts and preventing injuries in high performance sports. However, this task is not trivial due to the complexity of the patterns. An interesting alternative is to use Machine Learning methods, such as Artificial Neural Networks (ANNs), to classify running patterns. In this research, force signals are obtained by sensors coupled to the base of a low-cost open source treadmill. The goal is to indicate to the user the occurrence of fatigue during training based on running patterns. Different attributes are extracted from the time signals generated during training sessions. The examples are then classified by an ANN. The experimental results indicate that the ANN is able to classify running patterns with good accuracy. Experiments considering different scenarios indicate that the efficiency of the classifier was influenced by the day and stage of the training sessions.

Using Artificial Neural Networks to Classify Treadmill Running Patterns in High-Performance Sports

In this paper, we explore the fine-grained opinion identification and polarity classification tasks using twitter data on the COVID-19 pandemic in Brazilian Portuguese. We trained machine learning-based classifiers using a few different methods and tested how well they per-formed different tasks. For polarity classification, we tested a cross-domain strategy in order to measure the performance of the classifiers among different domains. For fine-grained opinion identification, we provide a taxonomy of opinion aspects and employed them in conjunction with machine learning methods. Based on the obtained results, we found that the cross-domain data improved the results of the polarity classification. For fine-grained opinion identification, the use of a domain taxonomy presented competitive results for the Portuguese language.

Identifying Fine-Grained Opinion and Classifying Polarity on Coronavirus Pandemic

Goal Recognition is the task of recognizing the intended goal of autonomous agents or humans by observing their behavior in an environment. Over the past years, most existing approaches to goal and plan recognition have been ignoring the need to deal with imperfections regarding the domain model that formalizes the environment where autonomous agents behave. In this work, we introduce the problem of goal recognition over imperfect domain models, and develop solution approaches that explicitly deal with two distinct types of imperfect domains models: (1) incomplete discrete domain models that have possible, rather than known, preconditions and effects in action descriptions; and (2) approximate continuous domain models, where the transition function is approximated from past observations and not well- defined. We develop novel goal recognition approaches over imperfect domains models by leveraging and adapting existing recognition approaches from the literature. Experiments and evaluation over these two types of imperfect domains models show that our novel goal recognition approaches are accurate in comparison to baseline approaches from the literature, at several levels of observability and imperfections.

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