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Utilização de visão computacional para a reconstrução automatizada da área de secção transversa muscular a partir de imagens sequenciais obtidas por ultrassonografia
(Universidade Federal de São Carlos, 2022-03-09) Silva, Deivid Gomes da; Libardi, Cleiton Augusto; https://lattes.cnpq.br/8953409094842074; https://lattes.cnpq.br/5086441110418562
The aim of the present study was to propose and validate a tool based on computer vision techniques that allows for the automated reconstruction (AR) of the vastus lateralis (VL) muscular cross-sectional area (MCSA) from sequential images obtained using an ultrasound (US) machine. Methods: Four hundred and eighty-eight VL US image sequences were used for VL MCSA reconstruction. Two different reconstruction techniques were utilized. For the already validated manual reconstruction (MR) technique, the sequential images were manually adjusted until the MCSA of the VL was fully visible for each image sequence. For AR, computer vision techniques were combined in a tool capable of automatically reconstructing the MCSA of the VL based on the steps described for the proper application of MR. After the quantification in cm² of all VL MCSA by both MR (n = 488) and AR (n = 488) techniques, the results were used to investigate the validity of the AR in measuring VL MCSA from of sequential images of the VL obtained by US. Our findings demonstrated good validity with low coefficient of variation values (1.51%) for AR compared to MR. The Bland-Altman plot showed low bias (-0.01 cm²; IC95% = 0.04, -0.06) and close limits of agreement (+1.18 cm², -1.19 cm²) containing 95% of the comparisons. Conclusion: The AR technique is valid compared to MR when measuring VL MCSA in a heterogeneous sample.
Modelagem matemática aplicada ao estudo de células a combustível a etanol direto
(Universidade Federal de São Carlos, 2022-03-09) Oliveira, Deborah Stolte Bezerra Lisbôa de; Sousa Júnior, Ruy de; https://lattes.cnpq.br/1983482879541203; https://lattes.cnpq.br/7068826648265785
The current fuel cell market is dominated by Hydrogen cells. Nevertheless, due to Hydrogen’s high reactivity, the difficulty in storage and the lack of infrastructure to distribute it, Hydrogen cells might not be the most attractive ones for everyday applications. Direct alcohol cells stand as an alternative because volatile alcohols (methanol and ethanol) can be oxidized at low temperatures (90 °C) and are easily stored and transported since they are liquids. Direct methanol fuel cells are already more commercially established than direct ethanol fuel cells (DEFC), but ethanol has advantages over methanol, namely: lower toxicity, higher theoretical energy density, and greater availability. For DEFC to become economically and technically viable, many challenges still need to be overcome, in specific, the electro-oxidation kinetics at the cell anode, which proceeds slowly, forms less-oxidized intermediate products and reduces cell efficiency. The objective of this master’s project is to model and simulate the ethanol oxidation kinetics in a DEFC. Three models were considered and adjusted to previously collected experimental data: 1) a first-principles ideal model based on Tafel kinetics and complete ethanol oxidation for Pt-Sn catalysts; 2) a realistic first-principles model for the incomplete electro-oxidation of ethanol also for several Pt-Sn catalysts; and 3) a fuzzy model to relate the structural and electronic properties of the Pt3Sn catalyst to cell performance (i.e., predicting current density). All models were implemented in MATLAB. The realistic model had a very good fit for all catalysts studied, as seen by small RMSE (Root Mean Squared Error) values, ranging from 0,22 to 4,21 A/cm2, while also predicting the surface coverage distributions in agreement with previous literature works (experimental basis). The fuzzy model structure also exhibited an excellent fit to experimental data. The addition of the integrated intensity as an input variable did not affect the fitted parameters for the other input variables (crystal size, surface area, presence of PtSn phase and cell potential) and, therefore, it was possible to create a broader and more relevant model that includes an electronic property of the catalyst. Response surface analyses, corroborated by particle swarm optimization, indicated that in order to maximize power density the greatest effect comes from decreasing crystal size. Medium potentials and medium integrated intensity are also favorable. In addition, presence of the PtSn phase in moderate amounts is not unfavorable. With these values it was possible to predict the optimization of the power density value to 24,3 mW/cm2, compared to a maximum experimental value of 19,6 mW/cm2.
Classificação de placas de trânsito com redes neurais para automação de veículos
(Universidade Federal de São Carlos, 2022-03-09) Bademian, Gustavo Bulka Bonafé; França, Celso Aparecido de; https://lattes.cnpq.br/4547836128892982; https://lattes.cnpq.br/2164345541570676
This article aims to develop a study on the functioning of Convolutional Neural Networks in the classification of traffic signs for use in autonomous cars, thus being able to be used as a tool to aid the vehicle in the decision process while driving, either through controlling the vehicle's speed, identifying the changes that the vehicle must make or even displaying information to the passenger through an on-board computer. To carry out this project, the German Traffic Sign dataset [1] was used. It is a public dataset used during the International Joint Conference on Neural Networks (IJCNN) in 2011. It has 39209 images for model training and 12630 images for testing, both divided into 43 distinct classes, each one indicating a different type. of traffic sign. At the end of the article, the reader will not only have knowledge about the theory behind neural networks, but also a theoretical background on the practical use of Convolutional Neural Networks for image classification.
O itinerário de Ody Fraga rumo ao cinema
(Universidade Federal de São Carlos, 2022-03-09) Mamigonian, José Rafael Gallotti; Gamo, Alessandro Constantino; https://lattes.cnpq.br/8208629144314123; Sá Neto, Arthur Autran Franco de; https://lattes.cnpq.br/5055550097454248; https://lattes.cnpq.br/4939371917620355
This research aims to investigate the initiation path of screenwriter and film director Ody Fraga (1927–1987). We chose to approach the period that precedes the making of his first feature film "Vidas Nuas" (1967), originated from an unfinished project entitled "Erótica". To retrace his long journey, we go back to his childhood, adolescence, as well as his early work in journalism and theater. We work with different documentary sources, seeking to establish little-known information about the director's life trajectory and “immature work”, reflecting on aspects of his intellectual production throughout this period.