Thiago Barcelos
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Thiago Barcelos has a total of 28 co-authors. Here are the top co-authors by number of shared publications:
- Roberto Munoz
Universidad de Valparaíso
9 shared publications - Rodolfo Villarroel
Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
5 shared publications - Alexandra A. de Souza
Laboratory of Applied Computing - LABCOM3, Federal Institute of Education, Science and Technology of São Paulo, São Paulo, Brazil
4 shared publications - Leandro Augusto Silva
Mackenzie Presbyterian University
4 shared publications - Danilo Candido de Almeida
Nephrology Division - Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
3 shared publications - Ismar Frango Silveira
Universidade Presbiteriana Mackenzie
3 shared publications
Latest Publications
- RetractionOpen Access
- 8 August 2024
- Published by Springer Nature in Soft Computing
- Vol. 28 (S1) , 99
Retraction Note: Simple hemogram to support the decision-making of COVID-19 diagnosis using clusters analysis with self-organizing maps neural network
[This retracts the article DOI: 10.1007/s00500-021-05810-5.].
- 8 August 2024
- Published by Springer Nature in Soft Computing
- Vol. 28 (S1) , 99
RetractionOpen AccessRetraction Note: Simple hemogram to support the decision-making of COVID-19 diagnosis using clusters analysis with self-organizing maps neural network
[This retracts the article DOI: 10.1007/s00500-021-05810-5.].
- Open Access
- 24 April 2023
- Published by Sociedade Brasileira de Computação
- p. 247-253
Computação Criativa Online: relato de experiência da adaptação de uma oficina de desenvolvimento do Pensamento Computacional para crianças
Iniciativas voltadas ao desenvolvimento do Pensamento Computacional (PC) em crianças e adolescentes em idade escolar têm sido organizadas em torno do conceito de Computação Criativa, que busca contextualizar o desenvolvimento do PC em torno da criação de produtos que tenham conexão pessoal com o aprendiz, utilizando a criatividade e imaginação, além dos conceitos computacionais. Este relato descreve a experiência da reformulação de um curso de Computação Criativa, previamente oferecido como uma ação de Extensão presencial, para a modalidade online devido ao isolamento social provocado pela pandemia da COVID-19 durante o ano de 2020. Apesar dos objetivos da oficina terem sido mantidos, o seu conteúdo passou a ser organizado em uma estratégia de curadoria de conteúdos online, principalmente relacionados ao site code.org, associada à produção de videoaulas próprias. O artigo descreve a experiência do oferecimento do curso reformulado a duas turmas entre os meses de maio e agosto de 2020. São discutidos os resultados obtidos a partir de um questionário aplicado às duas turmas e da análise do código produzido pelos participantes. Dificuldades iniciais relacionadas à comunicação remota com as crianças foram contornadas com a inclusão de momentos de interação com as monitoras do projeto. Ainda, os projetos finais cumpriram satisfatoriamente o objetivo do curso, tendo em vista a complexidade do código produzido pelos participantes.
- 24 April 2023
- Published by Sociedade Brasileira de Computação
- p. 247-253
Open AccessComputação Criativa Online: relato de experiência da adaptação de uma oficina de desenvolvimento do Pensamento Computacional para crianças
Iniciativas voltadas ao desenvolvimento do Pensamento Computacional (PC) em crianças e adolescentes em idade escolar têm sido organizadas em torno do conceito de Computação Criativa, que busca contextualizar o desenvolvimento do PC em torno da criação de produtos que tenham conexão pessoal com o aprendiz, utilizando a criatividade e imaginação, além dos conceitos computacionais. Este relato descreve a experiência da reformulação de um curso de Computação Criativa, previamente oferecido como uma ação de Extensão presencial, para a modalidade online devido ao isolamento social provocado pela pandemia da COVID-19 durante o ano de 2020. Apesar dos objetivos da oficina terem sido mantidos, o seu conteúdo passou a ser organizado em uma estratégia de curadoria de conteúdos online, principalmente relacionados ao site code.org, associada à produção de videoaulas próprias. O artigo descreve a experiência do oferecimento do curso reformulado a duas turmas entre os meses de maio e agosto de 2020. São discutidos os resultados obtidos a partir de um questionário aplicado às duas turmas e da análise do código produzido pelos participantes. Dificuldades iniciais relacionadas à comunicação remota com as crianças foram contornadas com a inclusão de momentos de interação com as monitoras do projeto. Ainda, os projetos finais cumpriram satisfatoriamente o objetivo do curso, tendo em vista a complexidade do código produzido pelos participantes.
- Open Access
- 19 May 2022
- Published by MDPI AG in Applied Sciences
- Vol. 12 (10) , 5137
Supporting Clinical COVID-19 Diagnosis with Routine Blood Tests Using Tree-Based Entropy Structured Self-Organizing Maps
Data classification is an automatic or semi-automatic process that, utilizing artificial intelligence algorithms, learns the variable and class relationships of a dataset for use a posteriori in situations where the class result is unknown. For many years, work on this topic has been aimed at increasing the hit rates of algorithms. However, when the problem is restricted to applications in healthcare, besides the concern with performance, it is also necessary to design algorithms whose results are understandable by the specialists responsible for making the decisions. Among the problems in the field of medicine, a current focus is related to COVID-19: AI algorithms may contribute to early diagnosis. Among the available COVID-19 data, the blood test is a typical procedure performed when the patient seeks the hospital, and its use in the diagnosis allows reducing the need for other diagnostic tests that can impact the detection time and add to costs. In this work, we propose using self-organizing map (SOM) to discover attributes in blood test examinations that are relevant for COVID-19 diagnosis. We applied SOM and an entropy calculation in the definition of a hierarchical, semi-supervised and explainable model named TESSOM (tree-based entropy-structured self-organizing maps), in which the main feature is enhancing the investigation of groups of cases with high levels of class overlap, as far as the diagnostic outcome is concerned. Framing the TESSOM algorithm in the context of explainable artificial intelligence (XAI) makes it possible to explain the results to an expert in a simplified way. It is demonstrated in the paper that the use of the TESSOM algorithm to identify attributes of blood tests can help with the identification of COVID-19 cases. It providing a performance increase in 1.489% in multiple scenarios when analyzing 2207 cases from three hospitals in the state of São Paulo, Brazil. This work is a starting point for researchers to identify relevant attributes of blood tests for COVID-19 and to support the diagnosis of other diseases.
- 19 May 2022
- Published by MDPI AG in Applied Sciences
- Vol. 12 (10) , 5137
Open AccessSupporting Clinical COVID-19 Diagnosis with Routine Blood Tests Using Tree-Based Entropy Structured Self-Organizing Maps
Data classification is an automatic or semi-automatic process that, utilizing artificial intelligence algorithms, learns the variable and class relationships of a dataset for use a posteriori in situations where the class result is unknown. For many years, work on this topic has been aimed at increasing the hit rates of algorithms. However, when the problem is restricted to applications in healthcare, besides the concern with performance, it is also necessary to design algorithms whose results are understandable by the specialists responsible for making the decisions. Among the problems in the field of medicine, a current focus is related to COVID-19: AI algorithms may contribute to early diagnosis. Among the available COVID-19 data, the blood test is a typical procedure performed when the patient seeks the hospital, and its use in the diagnosis allows reducing the need for other diagnostic tests that can impact the detection time and add to costs. In this work, we propose using self-organizing map (SOM) to discover attributes in blood test examinations that are relevant for COVID-19 diagnosis. We applied SOM and an entropy calculation in the definition of a hierarchical, semi-supervised and explainable model named TESSOM (tree-based entropy-structured self-organizing maps), in which the main feature is enhancing the investigation of groups of cases with high levels of class overlap, as far as the diagnostic outcome is concerned. Framing the TESSOM algorithm in the context of explainable artificial intelligence (XAI) makes it possible to explain the results to an expert in a simplified way. It is demonstrated in the paper that the use of the TESSOM algorithm to identify attributes of blood tests can help with the identification of COVID-19 cases. It providing a performance increase in 1.489% in multiple scenarios when analyzing 2207 cases from three hospitals in the state of São Paulo, Brazil. This work is a starting point for researchers to identify relevant attributes of blood tests for COVID-19 and to support the diagnosis of other diseases.
- Retracted
- 17 May 2021
- Published by Springer Nature in Soft Computing
- Vol. 27 (6) , 3295-3306
RETRACTED ARTICLE: Simple hemogram to support the decision-making of COVID-19 diagnosis using clusters analysis with self-organizing maps neural network
The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is related to new coronavirus disease (COVID-19) has mobilized several scientifics to explore clinical data using soft-computing approaches. In the context of machine learning, previous studies have explored supervised algorithms to predict and support diagnosis based on several clinical parameters from patients diagnosed with and without COVID-19. However, in most of them the decision is based on a “black-box” method, making it impossible to discover the variable relevance in decision making. Hence, in this study, we introduce a non-supervised clustering analysis with neural network self-organizing maps (SOM) as a strategy of decision-making. We propose to identify potential variables in routine blood tests that can support clinician decision-making during COVID-19 diagnosis at hospital admission, facilitating rapid medical intervention. Based on SOM features (visual relationships between clusters and identification of patterns and behaviors), and using linear discriminant analysis , it was possible to detect a group of units of the map with a discrimination power around 83% to SARS-CoV-2-positive patients. In addition, we identified some variables in admission blood tests (Leukocytes, Basophils, Eosinophils, and Red cell Distribution Width) that, in combination had strong influence in the clustering performance, which could assist a possible clinical decision. Thus, although with limitations, we believe that SOM can be used as a soft-computing approach to support clinician decision-making in the context of COVID-19.
- 17 May 2021
- Published by Springer Nature in Soft Computing
- Vol. 27 (6) , 3295-3306
RetractedRETRACTED ARTICLE: Simple hemogram to support the decision-making of COVID-19 diagnosis using clusters analysis with self-organizing maps neural network
The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is related to new coronavirus disease (COVID-19) has mobilized several scientifics to explore clinical data using soft-computing approaches. In the context of machine learning, previous studies have explored supervised algorithms to predict and support diagnosis based on several clinical parameters from patients diagnosed with and without COVID-19. However, in most of them the decision is based on a “black-box” method, making it impossible to discover the variable relevance in decision making. Hence, in this study, we introduce a non-supervised clustering analysis with neural network self-organizing maps (SOM) as a strategy of decision-making. We propose to identify potential variables in routine blood tests that can support clinician decision-making during COVID-19 diagnosis at hospital admission, facilitating rapid medical intervention. Based on SOM features (visual relationships between clusters and identification of patterns and behaviors), and using linear discriminant analysis , it was possible to detect a group of units of the map with a discrimination power around 83% to SARS-CoV-2-positive patients. In addition, we identified some variables in admission blood tests (Leukocytes, Basophils, Eosinophils, and Red cell Distribution Width) that, in combination had strong influence in the clustering performance, which could assist a possible clinical decision. Thus, although with limitations, we believe that SOM can be used as a soft-computing approach to support clinician decision-making in the context of COVID-19.
- 22 July 2019
- Published by Springer Nature in Universal Access in the Information Society
- Vol. 18 (3) , 633-643
Using multimodal learning analytics to study collaboration on discussion groups
- 22 July 2019
- Published by Springer Nature in Universal Access in the Information Society
- Vol. 18 (3) , 633-643
Using multimodal learning analytics to study collaboration on discussion groups
- Open Access
- 11 June 2018
- Published by Wiley in Computational Intelligence and Neuroscience
- Vol. 2018, 1-21
Using Black Hole Algorithm to Improve EEG-Based Emotion Recognition
Emotions are a critical aspect of human behavior. One widely used technique for research in emotion measurement is based on the use of EEG signals. In general terms, the first step of signal processing is the elimination of noise, which can be done in manual or automatic terms. The next step is determining the feature vector using, for example, entropy calculation and its variations to generate a classification model. It is possible to use this approach to classify theoretical models such as the Circumplex model. This model proposes that emotions are distributed in a two-dimensional circular space. However, methods to determine the feature vector are highly susceptible to noise that may exist in the signal. In this article, a new method to adjust the classifier is proposed using metaheuristics based on the black hole algorithm. The method is aimed at obtaining results similar to those obtained with manual noise elimination methods. In order to evaluate the proposed method, the MAHNOB HCI Tagging Database was used. Results show that using the black hole algorithm to optimize the feature vector of the Support Vector Machine we obtained an accuracy of 92.56% over 30 executions.
- 11 June 2018
- Published by Wiley in Computational Intelligence and Neuroscience
- Vol. 2018, 1-21
Open AccessUsing Black Hole Algorithm to Improve EEG-Based Emotion Recognition
Emotions are a critical aspect of human behavior. One widely used technique for research in emotion measurement is based on the use of EEG signals. In general terms, the first step of signal processing is the elimination of noise, which can be done in manual or automatic terms. The next step is determining the feature vector using, for example, entropy calculation and its variations to generate a classification model. It is possible to use this approach to classify theoretical models such as the Circumplex model. This model proposes that emotions are distributed in a two-dimensional circular space. However, methods to determine the feature vector are highly susceptible to noise that may exist in the signal. In this article, a new method to adjust the classifier is proposed using metaheuristics based on the black hole algorithm. The method is aimed at obtaining results similar to those obtained with manual noise elimination methods. In order to evaluate the proposed method, the MAHNOB HCI Tagging Database was used. Results show that using the black hole algorithm to optimize the feature vector of the Support Vector Machine we obtained an accuracy of 92.56% over 30 executions.
- Open Access
- 27 October 2017
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 6 (1) , 932
Mensurando o desenvolvimento do Pensamento Computacional por meio de mapas auto-organizáveis: um estudo preliminar em uma Oficina de Jogos Digitais
A análise automatizada de código desenvolvido por alunos em atividades de desenvolvimento do Pensamento Computacional vem mostrando potencial em identificar práticas e estratégias utilizadas para a resolução dos problemas propostos. No entanto, ainda não tem sido explorada em detalhes a evolução do código produzido por alunos e sua relação com a aquisição de competências do Pensamento Computacional. Neste estudo foram empregados mapas auto-organizáveis na análise de jogos produzidos por alunos em uma Oficina de Produção de Jogos Digitais nos anos de 2013 e 2017. O resultado do processo de treinamento produziu agrupamentos no mapa que apresentaram coerência com características dos jogos vinculadas a estratégias utilizadas pelos alunos que foram previamente observadas em sala de aula. Implicações dos resultados para estudos futuros também são discutidas.
- 27 October 2017
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 6 (1) , 932
Open AccessMensurando o desenvolvimento do Pensamento Computacional por meio de mapas auto-organizáveis: um estudo preliminar em uma Oficina de Jogos Digitais
A análise automatizada de código desenvolvido por alunos em atividades de desenvolvimento do Pensamento Computacional vem mostrando potencial em identificar práticas e estratégias utilizadas para a resolução dos problemas propostos. No entanto, ainda não tem sido explorada em detalhes a evolução do código produzido por alunos e sua relação com a aquisição de competências do Pensamento Computacional. Neste estudo foram empregados mapas auto-organizáveis na análise de jogos produzidos por alunos em uma Oficina de Produção de Jogos Digitais nos anos de 2013 e 2017. O resultado do processo de treinamento produziu agrupamentos no mapa que apresentaram coerência com características dos jogos vinculadas a estratégias utilizadas pelos alunos que foram previamente observadas em sala de aula. Implicações dos resultados para estudos futuros também são discutidas.
- Open Access
- 10 November 2016
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 1249
Proposta de Aplicação e Avaliação de Conceitos do Pensamento Computacional em Crianças Hospitalizadas
Proposta de Aplicação e Avaliação de Conceitos do Pensamento Computacional em Crianças Hospitalizadas
- 10 November 2016
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 1249
Open AccessProposta de Aplicação e Avaliação de Conceitos do Pensamento Computacional em Crianças Hospitalizadas
Proposta de Aplicação e Avaliação de Conceitos do Pensamento Computacional em Crianças Hospitalizadas
- Open Access
- 26 October 2015
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 1369
Relações entre o Pensamento Computacional e a Matemática: uma Revisão Sistemática da Literatura
Relações entre o Pensamento Computacional e a Matemática: uma Revisão Sistemática da Literatura
- 26 October 2015
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 1369
Open AccessRelações entre o Pensamento Computacional e a Matemática: uma Revisão Sistemática da Literatura
Relações entre o Pensamento Computacional e a Matemática: uma Revisão Sistemática da Literatura
- Open Access
- 26 October 2015
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 748
Desarrollo de un Software de Apoyo el Desarrollo de la Función Ejecutiva en Niños con Trastornos del Espectro Autista
Desarrollo de un Software de Apoyo el Desarrollo de la Función Ejecutiva en Niños con Trastornos del Espectro Autista
- 26 October 2015
- Published by Sociedade Brasileira de Computação in Anais dos Workshops do Congresso Brasileiro de Informática na Educação
- Vol. 1 (1) , 748
Open AccessDesarrollo de un Software de Apoyo el Desarrollo de la Función Ejecutiva en Niños con Trastornos del Espectro Autista
Desarrollo de un Software de Apoyo el Desarrollo de la Función Ejecutiva en Niños con Trastornos del Espectro Autista