https://repositorio.unifei.edu.br/jspui/handle/123456789/55 Wed, 29 Jul 2026 01:06:42 GMT 2026-07-29T01:06:42Z https://repositorio.unifei.edu.br/jspui/handle/123456789/3173 Aquisição e validação de sinal de ruído eletroquímico Corrosion is a global problem, which implies costs in industrialized countries of up to 4.5% of GDP, with either economic, but also social and environmental impacts. In the case of Brazil, the waste of water supply networks due to leaks loss is quite significant and much of it is caused by network degradation, indicating that corrosion control should be promoted whenever possible. This study proposes a corrosion monitoring system, in system subject to the use of inhibitor, with the approach of passive technique for monitoring corrosion by electrochemical noise (EN), in which the classification of events in a corrosion sensor by EN is part of methodological study for structural integrity (or “health”) monitoring system (SHM). Due to very dynamic and stochastic nature of the signal, this study and analysis of EN measurements (ENM) considers numerical and graphic characteristics of two corrosion systems both in saline aqueous solution: carbon steel and stainless steel. These experiments are repeated for accumulating data, which allow the generation of several graphs in time and frequency domains, from which at least one characteristic is extracted, which has a good correlation with data from corrosion processes. Then, based on a supervised machine learning system, the training data allows the model to be calibrated. From the test data, the correctness rate of the model above 50% is verified. Dissertação Thu, 17 Feb 2022 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/3173 2022-02-17T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4464 Teletrabalho no contexto brasileiro: fatores socioeconômicos, ambientais e de transporte a partir de uma abordagem de aprendizado de máquina Telework emerges as a potential tool for reducing commuting, lowering external costs, and promoting quality of life. In this context, the main objective of this research is to investigate the adoption of telework in the Brazilian context from a machine learning perspective. Initially, a comprehensive conceptual model was developed to examine the relationships between telework and socioeconomic, transportation, and environmental variables, based on a systematic literature review of studies published up to 2025. The temporal analysis of the literature highlights the growing academic interest in the topic, emphasizing the profile of teleworkers, characterized by factors such as age, educational level, income, and occupation type. Additionally, interactions between telework and urban aspects are explored, including the adoption of sustainable transportation modes, such as walking and cycling, as well as its relationship with urban sprawl. The impacts on quality of life are also discussed, particularly regarding schedule flexibility and work–life balance. The thesis analyzes the evolution of telework in Brazil from 2022 to 2025 through the application of machine learning models to representative microdata from the Continuous National Household Sample Survey, covering approximately 210,000 households per period. A standardized processing workflow was implemented, including data preprocessing, handling of missing values, class balancing through random undersampling, variable encoding and normalization, as well as stratified data splitting with k-fold cross-validation. Nine classification algorithms were evaluated, including Multinomial Logistic Regression, Decision Trees, Random Forest, XGBoost, Support Vector Machines, MARS, and Neural Networks, with hyperparameter tuning performed using the ANOVA racing method. Model performance showed consistently high results (ROC AUC > 0.80) across all analyzed periods. The analysis of variable importance indicates that the main determinants of telework remain relatively stable over time, although their contributions vary, with a notable increase in the influence of gender in more recent periods. The results demonstrate that telework in Brazil is driven by a combination of sociodemographic and occupational factors, reinforcing its selective nature. Overall, this thesis contributes to a deeper understanding of the multiple dimensions of telework by integrating theoretical and empirical evidence. Furthermore, the findings provide relevant insights for policymakers, organizational managers, and urban planners, highlighting how telework shapes urban dynamics and can support efforts to address contemporary urban challenges. Tese Wed, 20 May 2026 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4464 2026-05-20T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4463 Proposta de melhoria da jornada empreendedora de uma incubadora de base tecnológica: um estudo de caso universitário Entrepreneurship plays a strategic role in regional socioeconomic development, particularly in contexts marked by the need for economic diversification. In this scenario, university-based technology business incubators are relevant mechanisms for fostering innovation and supporting the creation of new ventures. In this context, the present study aims to propose the improvement of the entrepreneurial journey of a university-based technology incubator, based on the evaluation of its first operational cycle and on the theoretical foundation of startup development models throughout the entrepreneurial process. To achieve this objective, a basic research approach was adopted, with a descriptive nature and a qualitative methodology, conducted through a single case study. Data collection was carried out through bibliographic research, document analysis, non-participant observation, and semi-structured interviews with the incubator team and the incubated ventures. The data were analyzed using content analysis techniques, allowing for an understanding of the perceptions, experiences, and practices associated with the incubation process. The results showed that the initial entrepreneurial journey, composed of three stages, contributed to the maturation of ideas, market understanding, and the initial structuring of the ventures, with mentoring, advisory support, and networking standing out as the main valuegenerating factors. However, relevant operational limitations were identified, such as the use of a generic entrepreneurial journey model that did not address the specificities of technology-based businesses, as well as the absence of systematized tools for monitoring and tracking the incubated ventures. Based on the analysis of the collected data and the literature on startup development models, a new entrepreneurial journey structured into five stages, focused on technology-based businesses, was proposed. Additionally, a prototype of a digital system was developed to monitor the progress of startups. The evaluation of the perception of the revised journey and the prototype screens was carried out by specialists, confirming its importance for the incubation process and for the management of the incubator. Dissertação Thu, 28 May 2026 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4463 2026-05-28T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4462 A systematic analysis of security and performance in the internet of drones: re-evaluation and enhancement of the PMAP protocol This dissertation investigates authentication protocols applied to the context of the Internet of Drones (IoD), an environment characterized by high mobility, computational constraints, and strict security requirements. The work is divided into two complementary parts. In the rst part, a systematic literature review is conducted, following established methodological guidelines, with the objective of identifying, classifying, and analyzing recent authentication and key agreement protocols for IoD. Aspects such as communication topologies, threat models, employed cryptographic primitives, security properties analyzed both formally and informally, and performance metrics are examined. In the second part, a technical reassessment of the PMAP protocol is carried out, encompassing the Drone-to-ZSP (D2Z) and Drone-to-Drone (D2D) scenarios. The protocol is analyzed from di erent perspectives, including the formal Real-or-Random (RoR) model, automated veri cation using tools such as AVISPA, Scyther, and ProVerif, an informal analysis of resistance to attacks, and an evaluation of communication and computational costs. The results indicate that, under the adopted models, no violations of the speci ed security properties were identi ed in the formal veri cation procedures. However, the analysis also reveals limitations related to the absence of Perfect Forward Secrecy, exposure to privileged insider attacks, the lack of speci c mitigation mechanisms against denial-of-service attacks, and the computational cost of Hénon map based operations on constrained platforms. From a performance perspective, the protocol proved to be executable in an embedded environment, but with signi cant latency, especially in the D2D scenario. Based on the obtained results, it is observed that the advancement of the eld depends not only on the proposal of new cryptographic mechanisms, but also on the adoption of more standardized and robust evaluation methodologies, combining formal models, informal analyses, and compatible metrics that enable comparison across di erent studies. In this way, this dissertation contributes to a more structured understanding of the properties, limitations, and evaluation challenges of authentication protocols applied to the Internet of Drones. Dissertação Tue, 02 Jun 2026 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4462 2026-06-02T00:00:00Z