Repositório UFSCar

O Repositório Institucional da UFSCar (RI UFSCar) é um sistema de informação que visa armazenar, preservar, organizar e disseminar amplamente a produção intelectual dos diversos setores e segmentos da comunidade da UFSCar, provendo o acesso aberto à informação produzida na instituição e registrada como científica, tecnológica, didática, artístico-cultural e técnico-administrativa.

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Arquitetura de retrofit eletrônico para telemetria, alertas e controle remoto: estudo de caso em pá-carregadeira Clark Michigan 55C
(Universidade Federal de São Carlos, 2026-07-08) Mattos, Luiz Filipe de Almeida; Kato, Edilson Reis Rodrigues; http://lattes.cnpq.br/8517698122676145; https://orcid.org/0000-0001-8347-7442
Heavy machines built before the widespread adoption of embedded electronics remain in operation, but provide little digital information to operators and maintenance managers. In this context, this work developed and evaluated an electronic retrofit architecture for elemetry, fault alerts and remote control, using a 1990s Clark Michigan 55C wheel loader as a case study. The prototype was organized into four parts: embedded system, remote control, processing core and mobile application. On the machine, a Raspberry Pi 4 with a HAT and an ADS1115 converter read the pressure of the transmission governor pump through an analog transducer; the ESP8266-based remote control sent commands to pneumatic and electric actuators; the core, built with Apache Kafka and Apache Flink, normalized readings and issued alerts after temporal persistence; and the Flutter application displayed readings and alerts. The evaluation combined a single functional trial in a workshop, with the machine stationary, a bench check of the acquisition chain and synthetic resource-consumption tests. In the real trial, telemetry followed machine ignition and shutdown, and low-pressure alerts were received in the application. Boom, bucket-tilt and acceleration commands worked satisfactorily; however, the steering motor failed during the experiment and direction selection did not behave as expected, preventing any claim of complete teleoperation. The bench check indicated an approximately linear response of the 100 psi transducer, but it was not a metrological calibration, and the 500 psi transducer installed on the machine was not calibrated. In the simulated tests, with 1 vCPU, 1 GiB of memory and unitary parallelism, the core sustained about 200,000 samples/s before CPU saturation; at 1,000,000 samples/s, processed coverage fell to 17.9 – 18.7%. The 100% F1 score measures per-machine classification in the synthetic scenario, not the fraction of consumed messages. Thus, the contribution of this work lies in the integration and practical evaluation of the retrofit on the Michigan 55C, with explicit limitations regarding operational safety, link reliability, calibration and repetition of the real trials.
A verdade neoliberal em campanha: o capital humano e a produção do inimigo interno em enunciados sobre a educação pública
(Universidade Federal de São Carlos, 2026-07-30) Rocha , Efraim Igor Santana; https://lattes.cnpq.br/3091840946017150
A ascensão da extrema-direita no cenário político contemporâneo tem se tornado um dos principais temas de preocupação em diferentes áreas das Ciências da Linguagem, que reconhecem o perigo da reprodução do discurso de ódio — amplamente compartilhado de forma organizada e sistemática por muitos porta-vozes desse espectro político ao redor do mundo. No Brasil, esse fenômeno ganhou um novo capítulo de destaque durante as eleições municipais para a prefeitura de São Paulo (SP), realizadas em 2024, quando os debates eleitorais se transformaram em espetáculos midiáticos de violência explícita — tanto física quanto simbólica —, revelando de forma clara o atual cenário polarizado da sociedade brasileira. Diante dessa emergência, a análise do discurso político-eleitoral torna-se fundamental para compreendermos os mecanismos de disputa ideológica em jogo nas diferentes candidaturas, com destaque para Pablo Marçal (PRTB), Marina Helena (Novo), Ricardo Nunes (MDB) e Guilherme Boulos (PSOL). Os debates analisados ocorreram nos eventos promovidos pelo Estadão, Terra e pela Fundação Armando Alvares Penteado (em 14 de agosto de 2024) e pela TV Cultura (em 15 de setembro de 2024). Resultados parciais indicam que esses candidatos priorizaram temas como “trabalho”, “segurança pública” e “educação” para instrumentalizar sensibilidades como o medo, o ódio e o ressentimento, com o objetivo de convencer os eleitores a aderirem a determinadas posições ideológicas. Para essa análise, utilizamos os aportes teóricos dos Estudos Discursivos Foucaultianos (EDF), com ênfase nos conceitos saber/poder (Foucault, [1971] 2019) e formação discursiva (Foucault, [1969] 2008), a fim de problematizar os discursos proferidos durante os referidos debates eleitorais.
Diagnóstico de influência e validação em modelos não lineares com efeitos mistos
(Universidade Federal de São Carlos, 2026-06-15) Pinheiro, Camila Xavier Sá Peixoto; Russo, Cibele Maria; http://lattes.cnpq.br/1011098065426388; http://lattes.cnpq.br/0093205921769184; Russo, Cibele Maria; Cabral, Celso Romulo Barbosa; Zeller, Camila Borelli; Matos, Larissa Avila; Aoki, Reiko; http://lattes.cnpq.br/1011098065426388; http://lattes.cnpq.br/4430596586607764; http://lattes.cnpq.br/6671405481844657; http://lattes.cnpq.br/6330766834005870; http://lattes.cnpq.br/0621850261580868
Nonlinear mixed-effects (NLME) models are a widely used statistical tool for modeling data with hierarchical structure and nonlinear relationships among variables. Despite their flexibility, the adequacy and robustness of NLME models depend on careful evaluations of the influence of individual observations and the predictive performance of the fitted models. This thesis develops and evaluates methods aimed at influence diagnostics and validation of NLME models. Initially, results are presented for local influence diagnostics in nonlinear mixed-effects models under the Scale Mixture of Skew-Normal (SMSN) family of distributions, where several perturbation schemes are applied to analyze model sensitivity using two pharmacokinetic datasets. Subsequently, a systematic analysis of different validation methods for normally distributed NLME models is developed, comparing error and variability measures across resampling schemes. Finally, new diagnostic approaches are proposed for NLME models under the normal distribution. The results contribute to improving predictive assessment and influence analysis in nonlinear mixed-effects models.
Avaliação ecotoxicológica de nanopartículas de quitosana obtidas de resíduos agroindustriais para aplicação agrícola sustentável
(Universidade Federal de São Carlos, 2026-06-26) Lopes, Gabriela Foguel; Ceccato-Antonini, Sandra Regina; http://lattes.cnpq.br/7600793543184032; Morales , Dânia Elisa Christofoletti Mazzeo; http://lattes.cnpq.br/2378883705248821; https://lattes.cnpq.br/6224994308419278; Matsumoto, Silvia Tamie; http://lattes.cnpq.br/2158304667499789
The growing demand for food has driven the development of more sustainable biotechnologies for agriculture, including the use of agroindustrial waste in the production of bioinputs. In this context, chitosan nanoparticles, obtained through the chemical deacetylation of chitin extracted from shrimp waste by lactic fermentation of molasses, followed by the ionic gelation of chitosan, stand out as a promising alternative. However, their ecotoxicological effects are still poorly understood. Therefore, this study aimed to evaluate the ecotoxicological and toxicogenetic effects of these nanoparticles, at concentrations of 0.05%, 0.10%, 0.15%, 0.20%, and 0.30%, in different biological systems. In Chapter 1, the physicochemical characterization of the chitosan nanoparticles was performed, and their cytotoxic, genotoxic, mutagenic, and biochemical effects were investigated in Allium cepa. In Chapter 2, phytotoxic effects were evaluated in Lactuca sativa, and chronic toxicity was assessed in soil organisms using Folsomia candida as a bioindicator. The nanoparticles showed an average size of 196 ± 75 nm and good colloidal stability. In A. cepa, a reduction in the mitotic index and genotoxic damage were observed at the highest concentrations, without induction of mutagenicity, in addition to increased activity of antioxidant enzymes, such as superoxide dismutase, peroxidase, and phenylalanine ammonia-lyase, indicating oxidative stress and plant resistance. In L. sativa, there was no effect on germination; however, the highest concentrations reduced root growth, with the 0.30% concentration being classified as moderately toxic based on the germination index. In F. candida, survival was less affected than reproduction, with the latter being reduced at all tested concentrations. Overall, the results demonstrate concentration-dependent effects, with impacts at the cellular, physiological, and ecological levels. Although chitosan nanoparticles show potential for agricultural applications, especially at low concentrations such as 0.05%, their use requires careful evaluation regarding potential environmental risks.
Navegação autônoma em ambientes internos baseada em estimativa de profundidade monocular
(Universidade Federal de São Carlos, 2026-07-03) Santos, Antonio Caique dos; Pedrino, Emerson Carlos; http://lattes.cnpq.br/6481363465527189
Autonomous navigation in indoor environments constitutes an important challenge in mobile robotics, especially in applications that require low computational cost, real-time operation, and the use of embedded platforms. In this context, monocular depth estimation emerges as a promising alternative to traditional depth sensors, as it allows spatial information to be inferred from a single RGB image. This work investigates the feasibility of using modern monocular depth models in autonomous navigation systems, focusing on the FastDepth model due to its computational efficiency and suitability for resource-constrained devices. To this end, a comparative evaluation was initially carried out between the FastDepth, MiDaS Small, and Depth Anything Small models, considering metrics such as number of parameters, model size, inference time, and computational cost. Then, FastDepth was integrated into a reactive controller implemented in the Webots simulator, with the aim of evaluating its performance in different indoor scenarios. The system was tested in three distinct environments: a large room, a narrow corridor, and a room with tables, representing increasing levels of spatial complexity. The results demonstrated that FastDepth presents excellent performance in processing time; however, its limitations related to relative depth and frame-to-frame instability hinder its application in denser and less structured environments. It is concluded that reactive monocular navigation is viable in controlled scenarios, but still requires complementary strategies to ensure greater robustness in real and varied environments.