ESTiG - Artigos em Proceedings Não Indexados à WoS/Scopus
URI permanente para esta coleção:
Navegar
Entradas recentes
- Do Spanish and Portuguese listed companies converge in their choice of capital structure?Publication . Rogão, Márcia; Serrasqueiro, Zélia; .In order to study the behaviour of capital structure decisions of Spanish and Portuguese listed firms, we using as methodology the dynamic estimators to analyse the influence of firm- specific and country-specific determinants. The sample in this study is composed with 67 Spanish listed non-financial Spanish listed firms and 35 Portuguese listed non-financial firms, for the period of analysis between 2008 and 2016. The results obtained indicate that capital structure decisions of Portuguese and Spanish listed companies converge in terms of transaction costs, however, in greater magnitude for Portuguese companies, since th coefficient of adjustment of current debt towards the optimal level of leverage varies between 0.662 and 0.695 for Spanish firms and between 0.674 and 0.834 for Portuguese firms. The results also indicate a convergence in the behaviour of Spanish and Portuguese firms' financing decisions in the context of agency costs, as the results indicate the existence of a significant positive relationship between the tangibility of firms' assets. Similarly, this convergence is also evident for the determinants of information asymmetry problems, with profitability and liquidity variables negatively influencing Spanish and Portuguese firms' leverage. However, only the financing decisions of Spanish firms are influenced by market conditions and stock market development.
- Extraction of natural fibers for the manufacture of 3D filaments by FDM material extrusionPublication . Stein, Felipe Y.M.; Rocha, João; Santos, Jorge; Ribeiro, J.E.; Deusdado, Leonel; Rocha, CatarinaThe study aimed to extract hemp fibers for the NaturFab project, in order to mechanically strengthen PLA in filaments for 3D printing. In order to find the best extraction method, several chemical treatments were carried out to separate the fibers from the plant, using solutions of 2 g/l of sodium hydroxide (NaOH) + 2 g/l of sodium carbonate (NaCO₃) and another solution of 6% NaOH, both at 80 ºC. After obtaining the first fiber sample, tensile tests were carried out to compare the strength of the hemp fibers with those of commercial flax. Hemp showed inferior performance compared to flax fibers, with a more fragile behavior after treatment with 6% NaOH. However, a solution of NaOH and NaCO₃ with polyglycolic detergent facilitated extraction and improved fiber strength, but further tests should be carried out to verify its effectiveness.
- R&D in Portuguese companiesPublication . Praça, Lídia GalvãoThe purpose of this study is to charactetize and evaluate the Research and Development (R&D) activities of Portuguese companies, from 2016 to 2022. This is a descriptive statistical analysis of R&D activities, from an internal and external perspective of the companies and by sector of activity, based on the Community Innovation Survey. It was possible to observe an increase in R&D activities, especially intramural activities, as well as in activities carried out internally, on a continuous basis.
- Defining industrial tourism in the cross-border region of Portugal and SpainPublication . Scalabrini, Elaine C.B.; Alves, Francisco; Neto, Reginaldo; Teixeira, F.; García, Joaquin; Velasco, M.; Teixeira, João Paulo; Vaz, Roberto; Fernandes, Paula OdeteThis paper deals with the definition and valorisation of industrial and pre-industrial tourism in the cross-border region of Terras de Trás-os-Montes (Portugal) and Castilla y León (Spain). Industrial and pre-industrial heritage is crucial to collective memory and has significant cultural, historical and tourist value. Industrial tourism is emerging as an initiative that enhances historic landscapes and contributes to urban development, the revitalisation of communities and the preservation of heritage. It is considered an innovative strategy for rehabilitating territories, transforming old facilities into attractions, exploring historic sites or operating companies. The “IN_GENIOS_DUERO_DOURO” project focused on promoting this heritage in the Douro-Duero Euroregion. The methodology included detailed mapping and characterisation, creating a database with 1,079 sites identified in 22 Portuguese and 80 Spanish municipalities. The results show that most sites are in Spain (77.1 %). The municipalities with the most identified sites are Valladolid (250) in Spain and Mirandela (32) in Portugal. The main heritage categories include transport infrastructure (335), wineries (255) and the food industry (221). Around 47.27 per cent of the sites identified are accessible to tourists. The database created is fundamental for valuing, safeguarding and designing tourist routes.
- Explorando transformações lineares com recurso ao GeogebraPublication . Cordeiro, Edite; Barros, Paula MariaA compreensão de grande parte dos conceitos de álgebra linear exige um nível de abstração que quase sempre os estudantes do primeiro ano das licenciaturas de engenharia têm dificuldade em atingir. É consensual que se a sala de aula corresponder a um espaço dinâmico, onde os estudantes têm a oportunidade de interagir e de manipular os objetos em estudo, tal favorece o desenvolvimento de raciocínios que levam à identificação de relações/propriedades desses objetos. Vários estudos apontam para o facto de o software Geogebra facilitar a aprendizagem, muito por via da concretização de conceitos mais abstratos. Neste contexto, propomos uma abordagem para a compreensão da noção de transformação linear através das suas possíveis representações. Trata-se de uma experiência baseada na resolução de tarefas que incluem a construção em Geogebra de algumas aplicações, que se realizou em sala de aula no âmbito da unidade curricular de Álgebra Linear e Geometria Analítica de um curso de licenciatura em engenharia. Tais aplicações, ao permitir a exploração de múltiplas transformações lineares através das suas representações, contribuíram para uma melhor apreensão dos conceitos envolvidos.
- Acceptance and familiarization with wearable devices in Portugal and BrazilPublication . Lopes, Isabel Maria; Rocha, João; Oliveira, PedroThis research sought to understand the acceptance of wearable devices in Portugal and Brazil, analyzing aspects such as demographic profiles, experiences with technology and personal perceptions. An adaptation of the UTAUT2 model was made, obtaining responses from university students and frequent internet users through a questionnaire that used the Likert scale. The evaluation of the data indicated a predominance of participants from Portugal, a tendency for acceptance to be more pronounced among younger people, those with a higher level of education and a greater technological proficiency among men and more qualified individuals. The relationship between users and non-users of wearable devices proved to be balanced, with a more marked acceptance by people aged 35 to 59, women and those who have a positive view of technology. The Smartwatch stood out among the devices, followed by the Fitness Bracelet and the Smart Ring. A variation in social influence was observed according to the type of device, being more striking in the case of Smartwatches. Surprisingly, social influence did not prove to be as crucial in the acceptance of wearable devices as initially thought. The findings show a trend towards the adoption of these devices, while also warning of challenges linked to the perceived value and price of products, signaling an area with great potential for future research and innovation.
- A review of best methods for 3D scanning and modeling of terrain and buildings using drones and photogrammetryPublication . Deusdado, Leonel; Rocha, João; .Recent advancements in drone technology and photogrammetry have revolutionized the field of 3D terrain and building modelling. Drones equipped with photogrammetric software provide efficient, accurate, and cost-effective solutions for capturing high-resolution 3D models of both natural and urban environments. This literature review consolidates research on best practices for terrain and building scanning using drones and photogrammetry, focusing on methodologies, integration of technologies, challenges, and future directions. Additionally, the review explores applications in urban planning, environmental monitoring, disaster management, and heritage preservation.
- AI-driven solutions for enhancing digital accessibility in higher educationPublication . Costa, José Paulo; Nacheva, Radka; Coelho, Ana Sofia; Martins, Oliva M.D.Digital accessibility is essential for ensuring that students with disabilities have equal access to educational materials in higher education. Despite the existence of standards like the Web Content Accessibility Guidelines (WCAG) and PDF Universal Access (PDF/UA), many institutions still face challenges in providing accessible digital content. Existing tools can identify accessibility issues but often fall short in automating the remediation process or offering personalized adjustments for individual learners. This paper presents an AI-driven framework designed to automate the detection, remediation, and personalization of digital content to meet accessibility requirements. The proposed framework integrates AI and machine learning to enhance the accessibility of PDFs, HTML content, and multimedia resources, ensuring compliance with WCAG 2.1 and PDF/UA standards. The study demonstrates that the AI system detects accessibility issues with 92% accuracy and successfully remediates 85% of identified issues. Additionally, the framework offers real-time personalized adjustments, improving user satisfaction for 94% of students with disabilities. The AI system also reduces the time and cost of ensuring accessibility, making it an efficient tool for educational institutions. The paper concludes with recommendations for further research to expand the framework’s capabilities and offers insights for developing inclusive education policies that leverage AI technology.
- Manuais escolares do 2.º ciclo do ensino básico: o contexto das tarefas no tema Dados e ProbabilidadesPublication . Barros, Paula Maria; Fernandes, José António; .No texto estudam-se os contextos das tarefas propostas em manuais escolares de matemática do 5.º e 6.º ano de escolaridade no âmbito do tema Dados e Probabilidades. Para tal, selecionaram-se os três manuais escolares adotados por mais escolas em cada um dos anos escolares e analisaram-se as tarefas neles propostas numa perspetiva quantitativa e descritiva. A análise efetuada às tarefas dos manuais revelou o recurso a uma considerável diversidade de contextos, salientando-se: o contexto de pessoas/alunos, que é positivo ao incluir características e interesses dos alunos; a ausência de contexto, que deve ser evitado por dificultar a atribuição de significado; clima, natureza e ambiente, que vai ao encontro de preocupações da atualidade; e referência ao telemóvel e redes sociais, que, apesar da sua grande presença social, apenas é mencionado por um manual.
- Uma experiência colaborativa entre estudantes de diferentes cursos do ensino superiorPublication . Silva, Flora; Ribeiro, J.E.; Barros, Paula MariaO recurso a tarefas com ligação ao contexto laboral pode contribuir para promover uma aprendizagem significativa no ensino superior, tanto em termos de construção de conhecimentos como de desenvolvimento de competências transversais. Neste contexto, implementou-se uma experiência de ensino cujo foco foi a realização de trabalhos colaborativos entre estudantes que se encontravam em etapas diferentes do seu percurso académico. Um grupo frequentava a unidade curricular de Tecnologia Mecânica I, do curso de Licenciatura em Engenharia Mecânica, e o outro a de Segurança e Ambiente, do Curso Superior Técnico Profissional em Tecnologias Sustentáveis em Mecânica e Veículos. Os estudantes tinham o papel de “especialistas” na sua área, contribuindo para os trabalhos colaborativos com os conhecimentos adquiridos nas respetivas unidades curriculares e gerando conhecimento em conjunto. Concluiu-se que esta abordagem de ensino, para além promover uma maior autonomia no estudo dos conteúdos das unidades curriculares, contribuiu para a partilha de conhecimentos entre estudantes e para que estes experienciassem as dificuldades do trabalho em equipas diferenciadas.