Teses de Mestrado ESTiG
Permanent URI for this community
Browse
Browsing Teses de Mestrado ESTiG by Sustainable Development Goals (SDG) "12:Produção e Consumo Sustentáveis"
Now showing 1 - 10 of 16
Results Per Page
Sort Options
- A deep learning system for daily activity recognition in smart home environmentsPublication . Dessanti, Augusto Luvisa; Lima , JoséThis work presents the implementation of a system for daily activity classification using 3D Convolutional Neural Networks (3D CNN) and the Toyota Smarthome Dataset. The system aims to generalize and correctly classify activities, even in the face of data limitations such as high class imbalance, ambient occlusions, and similarities between classes. To overcome these challenges, preprocessing techniques and data augmentation were applied, including spatio-temporal resizing and image enhancement, with the objective of optimizing learning and generalization capabilities of the model. The proposed approach proved to be effective compared to other models on the same dataset, achieving 85.7% accuracy, 0.8568 precision, and 0.8570 recall.
- Analysis of failure in sheet metal stampingPublication . Kawakami, Thiago Fernando; Mesquita, L.M.R.; Morais, Osmano; Souza, Janaína Fracaro deIn the past, forming dies were developed through a trial-and-error process, where failures were identified and the die shape was subsequently adjusted. With the advent of the Finite Element Method (FEM), this process became more efficient, as FEM could be used to simulate and analyze forming results. Meanwhile, the tightening of automotive emission standards has increased the demand for more suitable materials, leading to stricter safety margins to achieve the desired weight reduction. In this work, the FEM will be employed to assess whether the failures observed in the industrial cold stamping process could have been predicted. To achieve this, several tensile tests will be conducted to characterize the material properties of two Ferritic Stainless Steel (FSS), EN 1.4509 and EN 1.4512. Using Digital Image Correlation (DIC), the anisotropy coefficients will be obtained and used to model the Barlat (1989) and Hill (1948) yield criteria. The Forming Limit Diagram (FLD) will be predicted through Abspoel and Keeler and Brazier methods. Finally, FEM simulations will be carried out using Ansys Forming software on two different stamped parts. The first part involves seven forming operations, while the second is limited to only the initial operation. In the first part, an increased tendency for wrinkling is observed near the notches, resulting in a local increase in thickness. In the second part, two of three failures observed in industrial production are successfully reproduced with the default parameters. Subsequently, the Lankford Ratio is varied by ±10%, which leads to the occurrence of the final failure. This highlights a strong dependency on the Lankford Ratio.
- Change management in agile software development projectsPublication . Neves, Kamila Antunes de Souza; Fernandes, José Eduardo; Dalpra , Gabriella Castro Barbosa Costa; Souza, Alinne Cristinne CorrêaThis study proposes a structured approach to change management in software development projects using agile methodologies. Based on a Systematic Literature Review and an empirical survey with industry professionals, the main causes, impacts, and practices related to changes in agile projects were identified. As a result, a practical guide was developed consisting of three checklists - scope definition, requirements gathering, and change management - and two change request templates (complete and simplified). These artifacts were integrated into the Scrum lifecycle, considering agile roles and appropriate application moments to ensure traceability, collaboration, and informed decision-making. The study provides practical tools to support development teams in mitigation risks, improving communication, and increasing the effectiveness of change adoption in agile environments.
- Comparação de soluções digitais para análise da eficiência energética em edifícios residenciaisPublication . Batista, Larissa Aparecida Rogerio; Vaz, António Jorge Ferreira; Guimarães, Mag Geisielly Alves; Fernandes, SílviaImpulsionado pelo crescimento populacional, urbanização acelerada e o aumento do acesso à tecnologia, o consumo mundial de energia aumentou de forma considerável nas últimas décadas. Em Portugal, no ano de 2023 os setores industrial, comercial e habitacional foram responsáveis por 80,4% do consumo total de energia. Esse dado reforça que o setor Arquitetura, Engenharia e Construção (AEC), responsável pelo projeto, pela construção e pela manutenção das edificações destinadas aos fins supracitados, possui grande potencial de atuação na aplicação de medidas que promovam a eficiência energética e a otimização do uso de recursos. A adoção de práticas mais eficientes no uso da energia não depende apenas do bom uso e ocupação, mas também de planejamento técnico adequado, idealmente na concepção do projeto. No entanto, ao considerar um país com elevados índices de envelhecimento no parque edificado, como Portugal, é fundamental direcionar os esforços de minimização do consumo de energia para as reabilitações energéticas das edificações existentes. Sob essa ótica, as ferramentas digitais de simulação energética viabilizam decisões mais conscientes e ajustadas, uma vez que permitem simular o comportamento de uma edificação e antecipar os efeitos das medidas aplicadas e, consequentemente, há um maior rigor na tomada de decisão já que esta é baseada em dados concretos retirados das simulações efetuadas. Diante desse contexto, a presente pesquisa adota uma abordagem descritiva e comparativa, na qual duas ferramentas de simulação energética, nomeadamente Cypetherm SCE-HAB e DesignBuilder, serão utilizadas para simular variadas propostas de reabilitação relativamente a uma habitação existente em diferentes contextos geográficos, com o objetivo final de avaliar semelhanças, limitações, metodologia e potencial de aplicação de cada ferramenta. Os resultados obtidos permitiram avaliar o desempenho, usabilidade e aplicação das ferramentas, das quais uma opera com base em análises dinâmicas e a outra, em análises estáticas, o que revelou a adequação de cada abordagem aos diferentes contextos e objetivos presentes em projetos de reabilitação energética.
- Descentralização: as vantagens e os desafios para a câmara municipal de Bissau na Guiné-BissauPublication . Lopes, Francelino Aleluia; Silva, Natacha Jesus; Cardim, SofiaA presente dissertação analisa as vantagens e os desafios associados ao processo de descentralização na Guiné-Bissau, com destaque para a Câmara Municipal de Bissau (CMB). Trata-se de um processo que inclui a transferência de competências, recursos e responsabilidades do governo central para entidades locais. É, portanto, considerada como um instrumento estratégico no sentido da promoção da eficiência e eficácia da administração pública, no reforço da democracia participativa e no desenvolvimento local. Partindo da questão de investigação: “Quais são as vantagens e os desafios associados ao processo de descentralização para a Câmara Municipal de Bissau, na Guiné-Bissau, e como esse processo pode ajudar a promover a eficiência e a governança local?”, desagregou-se a mesma nos Objetivos Específicos: identificar as principais reformas descentralizadoras no país; analisar a perceção da população e de funcionários públicos sobre a importância da descentralização; analisar a perceção da população e de funcionários públicos relativamente à descentralização na governança local; e identificar os principais benefícios e desafios associados ao processo descentralizador. O estudo recorre a uma abordagem metodológica mista, que combina num primeiro momento a revisão documental e bibliográfica, com um segundo momento no qual é aplicado um inquérito por questionário dirigido a cidadãos e funcionários públicos. Os resultados obtidos revelam uma perceção amplamente positiva quanto ao potencial da descentralização para melhorar a prestação de serviços públicos, aumentar a participação cidadã e reduzir desigualdades regionais. Identificam-se como desafios a instabilidade política, a escassez de recursos financeiros e humanos, a ausência de um quadro jurídico eficaz e a fragilidade institucional das autarquias locais. Conclui-se que embora a descentralização seja uma oportunidade para tornar a governação mais próxima das populações, a sua concretização exige um compromisso político claro, investimentos em capacitação técnica e o fortalecimento dos mecanismos de transparência e responsabilização. Assim, defende-se que a descentralização, se implementada de forma gradual, coordenada e equitativa, poderá constituir um pilar essencial para a reforma do Estado e a consolidação da democracia local na Guiné-Bissau.
- Development of cosmetic functional formulations incorporating hyaluronic acidPublication . Silva, Thaís Rossetto Cordeiro da; Barreiro, Filomena; Echart, Arantzazu Santamaria Echart; Düsman, ElisângelaThe cosmetic industry has been expanding continuously, driven by demand for innovative, sustainable, and high-performance formulations. In this context, this work aimed to develop particles composed of hyaluronic acid (HA) and Collagen type I (Col) to act as Pickering stabilisers in cosmetic emulsions. The particles were prepared using different methods (direct mixing - mix and droping - drop), with the most promising dispersions obtained after high-shear homogenisation: P_17_Mix_Ultra and P_17_Drop_Ultra. These formulations exhibited particle sizes of 12.30 ± 3.73 μm and 2.55 ± 0.08 μm, respectively. Both showed highly negative zeta potentials (–37.73 ± 1.50 mV for the mix and –37.72 ± 0.56 mV for the drop), confirming colloidal stability. Wettability tests demonstrated strong oil affinity, with contact angles of 128.30 ± 1.05° and 137.22 ± 3.20°. The drop method stood out for producing smaller, more homogeneous particles. Pickering emulsions were then prepared using sweet almond oil, Miglyol 812, and olive oil. Olive oil originated the most stable systems, and emulsions with a higher oil fraction (70:30 oil-to-aqueous ratio) presented superior stability compared to those with lower oil content. Analyses of emulsion type, colourimetry, creaming index, droplet size, microscopy, zeta potential, and rheology confirmed the better performance of olive oil-based formulations obtained by the drop method. The formulation E_70_OO_17d (drop method, olive oil, 70:30 ratio) achieved the most promising overall results, with a creaming index of 10% after 30 days, homogeneous droplets, and rheological behaviour exhibiting viscoelastic properties comparable to those of commercial products. In conclusion, HA-Col particles proved to be efficient Pickering stabilisers, enabling the development of stable emulsions. The most promising formulation, E_70_OO_17d, was particularly suitable for moisturising and anti-ageing cosmetic applications, where hyaluronic acid provides hydration and regeneration while Col enhances elasticity and repair.
- Development of scheduling and routing systems for multiple autonomous robots in the industryPublication . Silva, João Guilherme Martins; Lima, José; Fabro , João Alberto; Braun, JoãoWith transport logistics representing the majority of logistic expenses in industrial warehouses, task allocation and scheduling strategies must take into account travel times to achieve an effective optimization. This work represents the RobotAtFactory competition as a Hybrid Flow Shop Scheduling Problem with Transportation Resources, evaluates the ideal number of resources for the competition and proposes a joint scheduling and routing algorithm. The impact of the number of available vehicles was simulated while controlling for variations in machine processing time, in the initial setup of parts and in the effectiveness of the scheduling strategy. The results showed that, for the competition layout, the usage of two robots significantly reduced the makespan even when guided by simple strategies, while higher number of robots demanded a higher complexity while offering diminishing returns. The joint scheduling and routing approach did not improve upon the baseline, possibly due to a lack of complexity in the environment.
- Direção de obras na área das instalações elétricas de edificações: desafios e boas práticasPublication . Marinho, Bruno Olavo Pinheiro; Soares, OrlandoAs infraestruturas desempenham um papel essencial no desenvolvimento económico e na qualidade de vida das populações. O crescimento do investimento global neste setor tem conduzido a um aumento significativo do número de projetos e empreendimentos, exigindo técnicos e entidades responsáveis capazes de assegurar a sua conceção, execução e fiscalização. Neste contexto, a direção de obra assume-se como uma função central, garantindo a articulação entre os aspetos técnicos e práticos da construção. O presente relatório resulta do estágio curricular realizado na empresa Bragalux, S.A., no âmbito da obtenção do grau de Mestre em Engenharia Eletrotécnica e de Computadores. O estágio foi desenvolvido no departamento de Edificações, na especialidade de instalações elétricas, acompanhando de forma direta as funções e responsabilidades inerentes à direção de obra. Ao longo do relatório são explorados os regulamentos e legislações que regem tanto as edificações como as instalações elétricas, bem como as principais entidades envolvidas no processo de conceção e execução em Portugal. Para além disso, descrevem-se as diferentes atividades desempenhadas no âmbito da direção de obra, ilustradas com casos práticos e acompanhadas de considerações finais e boas práticas, consolidando o conhecimento adquirido. O trabalho evidencia ainda a relevância do acompanhamento contínuo da obra como ponte entre os aspetos técnicos e a realidade prática da execução, assegurando que os trabalhos decorrem em conformidade com os requisitos regulamentares, contratuais e de planeamento.
- Exploring sustainable consumer behavior among young adults: a comparative study between Georgia and PortugalPublication . Shcherbakova, Sophi; Fernandes, Paula; Mamulaidze, TamtaThis study investigates how different factors influence the decisions of 18- to 35-year-old consumers toward sustainability in Georgia and Portugal. It examines the various elements that shape sustainable consumer behavior, including education, government support, cultural values, and trust in green marketing. Sustainability has become a global priority, and recent research suggests that consumer behavior toward sustainable products is strongly influenced by the effectiveness of green marketing especially when it aligns with consumer values on environmental responsibility. Georgia is promoting green growth through initiatives like the Batumi Initiative on Green Economy (BIGE), which supports sustainable practices in agriculture, tourism, and small businesses. In Portugal, sustainable consumerism continues to grow, supported by public awareness and targeted green marketing strategies. Using a mixed-methods approach combining survey responses from 261 participants and 14 semistructured interviews, the study found that while both Georgian and Portuguese youth show interest in sustainable choices, Portuguese respondents were more likely to trust green marketing, actively seek sustainability information, and perceive government support more positively. In contrast, Georgian participants expressed greater levels of skepticism and obstacles related to price and product accessibility. Education was recognized as an important influence in cultivating favorable attitudes toward sustainability in both contexts. These results offer practical ideas for firms and policymakers looking to encourage more sustainable consumption habits in both nations.
- Greening the grey: application of eco- engineering to coastal and harbour infrastructuresPublication . Monteiro, Maria Luiza Carvalho; Bráz-César, Manuel; Ferreira, Saulo RochaThis research explores the application of nature-based solutions in port infrastructures as a strategy to promote environmental sustainability in traditionally artificialized coastal environments. In a scenario of global warming, rising sea levels and increased frequency of extreme weather events, especially in urbanised coastal areas, the applicability of these solutions in Portugal’s commercial ports was analysed. These approaches are in line with European and global goals for sustainable development and biodiversity conservation, as they help to mitigate the impacts of dredging, restore degraded habitats, favour marine biodiversity and protect coastal areas from overtopping and flooding. The research is based on the concept of greening the grey, derived from eco-engineering, which proposes the incorporation of ecological principles into the hard environment of urban infrastructures. The methodology consisted of selecting six techniques applicable to ports, identified through a review of the Scopus database and the EcoShape website, followed by an analysis of 26 commercial ports in mainland Portugal and the autonomous regions, based on physical, operational and environmental parameters. The results indicate that three of the techniques, including two aimed at promoting biodiversity and one at coastal protection, have demonstrated applicability in at least 19 ports, due to their technical and economic viability. The other techniques, with more specific requirements, were considered viable in a smaller number of ports. Even so, all the ports analysed showed potential for adopting at least two solutions. The research contributes to future studies aimed at the implementation of these techniques by port authorities and encourages the integration of nature-based solutions into rigid port infrastructures.