Computational Tools

Vieira, V., Custódio, L.

Numerical analysis is a subject present in the curriculum of several undergraduate courses, especially the STEM ones. Its objectives are the study and application of numerical methods for root approximation, function approximation, interpolation, and integration approximation. Given the importance of these topics for academia and industry, it is necessary that the student masters the concepts studied. Therefore, this work proposes the development of a computational tool that helps students and teachers in teaching and learning numerical analysis. To achieve this, the R programming language and its packages, especially Shiny, were used to develop a web application that can be accessed through a device with internet access or through local installation on a computer. The developed software has functionalities such as user input, plot animation and control over graphic elements. The tool was named “CnVisual” and the result of a group of tests showed that the outlined objectives were achieved.

Criscuolo, B., Zanatta, D., Custódio, L.

The evolution of computational resources enabled a great advance in studies and proposals for the development of Assistive Technologies. It is worth emphasizing as a great ally of assistive solutions the use of techniques related to voice command, which have gained prominence, especially in the last decade, due to the popularization of personal assistants present in most mobile devices today. Another factor that contributed to enabling voice command as a leading tool in the context of accessibility was the evolution of the structures that make up programming languages, making their applicability more flexible in various systems and enabling, for example, the use of algorithms for natural language processing in an abstracted way. In terms of the applicability of Assistive Technologies for teaching, even in the face of a technologically favorable scenario and although the rates studied in this work show a growing increase, the inclusion of people with disabilities in higher education courses in Brazil still has a low representation if compared to the entry of non-disabled people, especially in the technology area. Therefore, this work aims to present a prototype platform, conceived based on the fundamental models of the theory of compilers and language processing, aiming to use voice commands as an accessibility tool that contributes to the inclusion of people with visual impairments and/or motor in the field of computing, more specifically with regard to the introductory teaching of computer programming.

Guimaraẽs, S., Custódio, L.

Given the growth of social networks and e-commerce sites as major sources of public opinion, there was a need to automatically analyze the sentiment of users and consumers. Several methods have been developed to classify the texts in a computational way, however, there are still idiomatic and subject limitations. Therefore, this work proposes the development of an application that performs the analysis of feelings in Portuguese texts and that displays the results in a visual way for a better understanding of the information. For that, it is only necessary that the user stipulate some filters and perform the search in real time for texts that were published in Brazil, on the social network Twitter; After data collection, sentiment analysis is performed on each tweet using the lexicon method, which uses the Portuguese lexicon dictionary, OpLexicon. The classification results are accurate, provide an overview and new perspectives through visualization in the graph, in the word cloud and on the maps.

Marques, M., Custódio, L.

This work writes the development of an app for Android operational system, in which it is used techniques of information visualization and calculations to receive a feedback of the user’s health. It was evaluated statistic data of Brazil and its population’s habits and its indexes of obesity from a research done annualy by VIGITEL. It was performed consultancy with professional of health to implement calculations related to human health and to describe the physical exercises suggested. To have an equality evalution of the app it was done an opinion interview with four people. The app was developed in React Native which is a hybrid technology.

Freitas, L., Custodio, L. 

Nowadays the tourist who wishes to visit small towns finds it very difficult to find informations about tourist attractions. There are a lot of information spread across websites and social media, making it difficult to quickly and objectively obtain relevant information. In this way, the proposed tool aims make easier the way the tourist obtain the informations about the attractions of a city. Using only a table containing the data on the tourist points the tool manages to show them in an intuitive way. With the R language it was possible to build a strong feature that can contribute to the data visualization within specific touristic areas, either showing information of each touristic place, or suggesting roadmap, which is generated through user interaction with the tool.

Custodio, L., Etiene, T., Pesco, S. and Silva, C. T.

For over two decades, topologically correct isosurface extraction algorithms have been studied. In particular, Marching Cubes has received special attention from the scientific community. Chernyaev's Marching Cubes 33 is one of the first algorithms intended to preserve the topology of the trilinear interpolant. In this work, we address three issues with the Marching Cubes 33 algorithm, two of which are related to its original description and one that is related to its variant. In particular, we solve a problem with the core disambiguation procedure of Marching Cubes 33 that prevents the extraction of topologically correct isosurfaces for the ambiguous configuration 13.5. This is an important step towards closing an existing gap in the topological correctness Marching Cubes 33. Furthermore, we make our results reproducible, meaning that examples provided in this work can be easily explored and studied. Finally, as part of the philosophy of reproducibility, we provide a corrected version of the Marching Cubes 33 open-source implementation and access to datasets that can be used to verify the correctness of any available topologically correct isosurface extraction implementation that preserves the topology of the trilinear interpolant.

[Project Page]