Browsing by Issue Date, starting with "2020"
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- Ferramenta computacional para auxílio na tomada de decisão no processo de fresagemPublication . Martins, Romulo Matheus Emmerick; Pereira, Ana I.; Ribeiro, J.E.; Nuñez, David LiraA crescente procura das indústrias por melhorias da eficiência produtiva tem se tornado, cada vez mais, um incentivador ao aumento investigação com foco na otimização de processos para o aumento da qualidade ao menor tempo e custo possível. Nesse cenário, o setor industrial tem procurado sistemas inteligentes, capazes de auxiliar no suporte à decisão, como parte de seus negócios e planos de crescimento. No presente trabalho, desenvolveu-se um software baseado no método de otimização de superfícies de resposta combinado com o algoritmo genético para apoiar a identificação de parâmetros ótimos para a diminuição dos níveis vibratórios no processo de fresagem numa CNC. O software prevê os parâmetros de fresagem - velocidade de corte, velocidade de avanço, penetração axial e radial - que resultariam nos menores níveis de vibração e, consequentemente resultando no aumento da qualidade superficial da peça produzida. A fim de comprovar a fiabilidade do software de otimização, comparou-se os resultados obtidos com os melhores resultados experimentais, obtidos anteriormente pelo método de Taguchi. Da comparação verificou-se a fiabilidade da solução proposta.
- Sales cervantinas. Cervantes y lo jocoserioPublication . Dotras Bravo, AlexiaReseña del volumen paradigmático sobre Cervantes y Portugal de 2018, coordinado por Aurelio Vargas y José Manuel Lucía Megías. El presente volumen, de edición cuidada y estética, no se presenta como un trabajo más sobre la relación de Cervantes y Portugal, sino como un estudio transdisciplinar en Historia, Arte y Lite ratura, tal y como reza su subtítulo. No podemos olvidar que existen varias vertientes lusocervantistas. Por un lado, la relación biográfica e historiográfica de Cervantes con Portugal (sus relaciones personales portuguesas, la estancia en Tomar, las referencias en sus obras a lugares y personajes portugueses, etc.), y por otro, la recepción de Cervantes en el país vecino a lo largo de la historia: su influencia en obras y autores portugueses, tanto creadores como eruditos.
- Educational data mining for tutoring support in Higher Education: a web-based tool case study in engineering degreesPublication . Prada, Miguel Angel; Dominguez, Manuel; Vicario, Jose Lopez; Alves, Paulo; Barbu, Marian; Podpora, Michal; Spagnolini, Umberto; Pereira, Maria João; Vilanova, RamonThis paper presents a web-based software tool for tutoring support of engineering students without any need of data scientist background for usage. This tool is focused on the analysis of students' performance, in terms of the observable scores and of the completion of their studies. For that purpose, it uses a data set that only contains features typically gathered by university administrations about the students, degrees and subjects. The web-based tool provides access to results from different analyses. Clustering and visualization in a low-dimensional representation of students' data help an analyst to discover patterns. The coordinated visualization of aggregated students' performance into histograms, which are automatically updated subject to custom filters set interactively by an analyst, can be used to facilitate the validation of hypotheses about a set of students. Classification of students already graduated over three performance levels using exploratory variables and early performance information is used to understand the degree of course-dependency of students' behavior at different degrees. The analysis of the impact of the student's explanatory variables and early performance in the graduation probability can lead to a better understanding of the causes of dropout. Preliminary experiments on data of the engineering students from the 6 institutions associated to this project were used to define the final implementation of the web-based tool. Preliminary results for classification and drop-out were acceptable since accuracies were higher than 90% in some cases. The usefulness of the tool is discussed with respect to the stated goals, showing its potential for the support of early profiling of students. Real data from engineering degrees of EU Higher Education institutions show the potential of the tool for managing high education and validate its applicability on real scenarios.
- Using jason framework to develop a multi-agent system to manage users and spaces in an adaptive environment systemPublication . Oliveira, Pedro Filipe; Novais, Paulo; Matos, PauloManage user preferences and local specifications on an IoT adaptive system is a actual problem. This paper uses Jason framework to develop a multi agent system to achieve a Smart Environment System, and supports interaction between persons and physical spaces, that users want to smartly adapt to their preferences in a transparent way. This work proposes a new approach, that has been developed using a multi agent system architecture with different layers to achieve a solution that entails all the proposed objectives. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021.
- Pillared clays from natural resources as catalysts for catalytic wet peroxide oxidation: Characterization and kinetic insightsPublication . Kalmakhanova, Marzhan; Díaz de Tuesta, Jose Luis; Massalimova, Bakytgul Kabykenovna; Gomes, HelderPillared clays with Zr and Fe/Cu/Zr polycations have been prepared from natural clays found in large deposits of Kazakhstan and assessed as catalysts for the catalytic wet peroxide oxidation (CWPO), using 4-nitrophenol (4-NP) as model compound. The performance of the catalysts was followed by measuring the concentration of 4-NP, H2O2 and the total organic carbon (TOC), considering C4-NP = 5 g L-1, CH2O2 = 17.8 g L-1, Ccat = 2.5 g L-1, initial pH = 3.0 and T = 50°C. At those selected conditions, the pillared clays showed higher activity than natural clays in the CWPO of 4-NP. The conversion of the model pollutant was complete when Fe/Cu/Zr-PILCs were used, with the TOC removal reaching 78.4% after 24 h with the best Fe/Cu/Zr-PILC. The H2O2, 4-NP and TOC time-evolution was well described by a kinetic model based on TOC lumps in three blocks, considering the initial TOC (corresponding to 4-NP), the production of oxidizable intermediates and the formation of refractory products.
- A co-creation methodology in heath graduations; perceptions of the graduating actorsPublication . Pinto, Isabel C.; Almeida-de-Souza, Juliana; Veiga-Branco, Augusta; Pereira, Olívia R.The new education policies hold students accountable for their own learning. Also a growing number of study results are finding positive relationships between active methodologies and student learning. In this sense, it is important to understand the perceptions of innovative process experiences in learning. Aims: Assess the perceptions of students during an implementation of co-creation methodology in curricular units of Dietetics Nutrition and Pharmacy graduations. Methods: It is a quantitative and longitudinal study in 3rd year degree students across one semester. A co-creation pedagogical process was performed including a multidisciplinary group of students from 4 different subjects of the undergraduate courses in Dietetics Nutrition and Pharmacy, School of Health, Polytechnic Institute of Bragança, Portugal. Throughout the semester, students had to develop a multidisciplinary research project. Co-creation events, guided by subject teachers, took place at four different times: kick-off, jam1, jam2 and final-pitch. The students' perception of the teaching-learning process was evaluated in the end of each event, through an online questionnaire with eight positive statements about the working day. Each student should indicate their agreement on a scale from 1 (strongly disagree) to 4 (strongly agree). Options 3 and 4 were considered as satisfaction. Results: Most students are satisfied with this process (52,3%-94,4%), considering all questions at all events (Figure 1). In half of the statements (I loved this day, I love this work, Today was a full day of learning, I understood this methodology/learning process), student satisfaction gradually increased over the course of the events. Teamwork was clearly appreciated at Jam1 (94,4%) and Final Pitch was much appreciated (84,1%) and considered a great learning day (86,3%). However, if students could decide, only around half students choose this learning methodology (52,3%-57,9%). Conclusion: Most students enjoyed this co-creation process, valuing teamwork and learning. However, some students hesitate to use this methodology.
- Deep-learning in identification of vocal pathologiesPublication . Teixeira, Felipe; Teixeira, João PauloThe work consists in a classification problem of four classes of vocal pathologies using one Deep Neural Network. Three groups of features extracted from speech of subjects with Dysphonia, Vocal Fold Paralysis, Laryngitis Chronica and controls were experimented. The best group of features are related with the source: relative jitter, relative shimmer, and HNR. A Deep Neural Network architecture with two levels were experimented. The first level consists in 7 estimators and second level a decision maker. In second level of the Deep Neural Network an accuracy of 39,5% is reached for a diagnosis among the 4 classes under analysis.
- Sensory marketing at the destination level: a conceptual approachPublication . Correia, Ricardo; Franco, Ana; Meneses, RaquelMarketing strategies adopted in many destinations do not take into consideration the potential of the senses to generate memorable experiences. By ignoring a driving force of intangibility, such strategies do not value a major source of differentiation. In fact, in a time where the intangible assumes an essential role, the senses emerge as a key for the differentiation of a particular destination when compared to other alternatives. This article puts in evidence the importance of the sensory marketing at the destination level. We develop a conceptual model where sensory contact points emerge as the central element in the 3 different phases of the tourist experience: a priori to capture the attention and provide (or recall) sensations of the destination, in loco for the generation of a multisensory image of the destination, and a posteriori inspiring a new visit to the destination or it’s recommendation to others. The model proves to be particularly useful for practitioners, offering relevant insights for managers and policy makers.
- Improving additive manufacturing performance by build orientation optimizationPublication . Matos, Marina A.; Rocha, Ana Maria A.C.; Pereira, Ana I.Additive manufacturing (AM) is an emerging type of production technology to create three-dimensional objects layer-by-layer directly from a 3D CAD model. AM is being extensively used in several areas by engineers and designers. Build orientation is a critical issue in AM since it is associated with the part accuracy, the number of supports required and the processing time to produce the object. This paper presents an optimization approach to solve the part build orientation problem taking into account some characteristics or measures that can affect the accuracy of the part, namely the volumetric error, the support area, the staircase effect, the build time, the surface roughness and the surface quality. A global optimization method, the Electromagnetism-like algorithm, is used to solve the part build orientation problem.
- Non-destructive imaging and spectroscopic techniques for assessment of carcass and meat quality in sheep and goats: a reviewPublication . Silva, Severiano; Guedes, Cristina M.; Rodrigues, Sandra; Teixeira, AlfredoIn the last decade, there has been a significant development in rapid, non-destructive and non-invasive techniques to evaluate carcass composition and meat quality of meat species. This article aims to review the recent technological advances of non-destructive and non-invasive techniques to provide objective data to evaluate carcass composition and quality traits of sheep and goat meat. We highlight imaging and spectroscopy techniques and practical aspects, such as accuracy, reliability, cost, portability, speed and ease of use. For the imaging techniques, recent improvements in the use of dual-energy X-ray absorptiometry, computed tomography and magnetic resonance imaging to assess sheep and goat carcass and meat quality will be addressed. Optical technologies are gaining importance for monitoring and evaluating the quality and safety of carcasses and meat and, among them, those that deserve more attention are visible and infrared reflectance spectroscopy, hyperspectral imagery and Raman spectroscopy. In this work, advances in research involving these techniques in their application to sheep and goats are presented and discussed. In recent years, there has been substantial investment and research in fast, non-destructive and easy-to-use technology to raise the standards of quality and food safety in all stages of sheep and goat meat production. © 2020 by the authors.