FE - Artigos de Revistas Internacionais com Arbitragem Científica

Permanent URI for this collectionhttp://hdl.handle.net/10437/10765

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Comparing Freshman and doctoral engineering students in design : mapping with a descriptive framework
(Taylor and Francis Ltd., 2017-11-02) Carmona Marques, P.; FE - Faculty of Engineering
This paper reports the results of a study of engineering students’ approaches to an open-ended design problem. To carry out this, sketches and interviews were collected from 9 freshmen (first year) and 10 doctoral engineering students, when they designed solutions for orange squeezers. Sketches and interviews were analysed and mapped with a descriptive ‘ideation framework’ (IF) of the design process, to document and compare their design creativity (Carmona Marques, P., A. Silva, E. Henriques, and C. Magee. 2014. “A Descriptive Framework of the Design Process from a Dual Cognitive Engineering Perspective.” International Journal of Design Creativity and Innovation 2 (3): 142–164). The results show that the designers worked in a manner largely consistent with the IF for generalisation and specialisation loops. Also, doctoral students produced more alternative solutions during the ideation process. In addition, compared to freshman, doctoral used the generalisation loop of the IF, working at higher levels of abstraction. The iterative nature of design is highlighted during this study–a potential contribution to decrease the gap between both groups in engineering education.
Improvement of aglycone content in soy isoflavones extract by free and immobilized β-Glucosidase and their effects in lipid accumulation
(Springer, 2020-11-01) Angelotti, Joelise A.F.; Dias, Fernanda F.G.; Sato, Hélia H.; Fernandes, Pedro; Nakajima, Vânia M.; Macedo, Juliana; FE - Faculty of Engineering
Soybean is one of the most important commodities in the world, being applied in feed crops and food, pharmaceutical industries in different ways. Soy is rich in isoflavones that in aglycone forms have exhibited significant anti-obesity and anti-lipogenic effects. Obesity is a global problem as several diseases have been related to this worldwide epidemic. The aim of this work was to verify the effect of free and immobilized β-glucosidase, testing Lentikats, and sol–gel as carriers. Moreover, we wanted to examine if the different types of hydrolysis would generate extracts with distinct biological activity concerning lipid accumulation, PPAR-α regulation, and TNF-α, IL-6, and IL-10 concentrations using in vitro assays. Our results show that all formulations of β-glucosidase could hydrolyze soy isoflavones. Thus, after 24 h of incubation, daidzein content increased 2.6-, 10.8-, and 12.2-fold; and genistein content increased 11.7, 11.4, and 11.4 times with the use of free enzyme, Lentikats®, and sol–gel immobilized enzyme, respectively. Moreover, both methodologies for enzyme immobilization led to promising forms of biocatalysts for application in the production of soy extracts rich in isoflavones aglycones, which are expected to bring about health benefits. A mild lipogenic effect was observed for some concentrations of extracts, as well as a slight inhibition in PPAR-α expression, although no significant differences were noticeable in the cytokines TNF-α, IL-10, and IL-6 as compared with the control.
Defence industries and open innovation : ways to increase military capabilities of the Portuguese ground forces
(Routledge, 2022) Reis, João; Melão, Nuno; Costa, Joana; Pernica, Bohuslav; RCM2+ - Research Centre in Asset Management and System Engineering
The European Defence Industry is undergoing profound changes. Industrial activity is now operating on a quintuple helix innovation model with the deep involvement of universities and governments in innovation. In addition, military innovations are being transferred to civil society, with increasing attention paid to the environment. In the first stage, we report on the state-of-the-art of existing research using PRISMA protocol. The PRISMA technique is widely accepted by the academic community for its ability to discover concepts, ideas, and debates about the defence industry. In the second stage, we present a case study involving the Portuguese Defence Industry, for which multiple data collection sources were used to ensure triangulation and corroboration. The results show that, in the light of the quintuple helix innovation model, it was possible to bring applications from theoretical discussion to real life. Moreover, within the scope of the triple helix, it was possible to develop, produce and test military products, allowing to improve the military capacity of ground forces. In the future, ecological concerns will likely increase, so we suggest a greater focus on this area of research. KEYWORDS : Defence industry; open innovation; ground military forces; quintuple helix
Generating multidimensional clusters with support lines
(Elsevier B.V., 2023) Fachada, Nuno; de Andrade, Diogo; COPELABS - Cognitive and People-centric Computing
Synthetic data is essential for assessing clustering techniques, complementing and extending real data, and allowing for more complete coverage of a given problem’s space. In turn, synthetic data generators have the potential of creating vast amounts of data – a crucial activity when real-world data is at premium – while providing a well-understood generation procedure and an interpretable instrument for methodically investigating cluster analysis algorithms. Here, we present Clugen, a modular procedure for synthetic data generation, capable of creating multidimensional clusters supported by line segments using arbitrary distributions. Clugen is open source, comprehensively unit tested and documented, and is available for the Python, R, Julia, and MATLAB/Octave ecosystems. We demonstrate that our proposal can produce rich and varied results in various dimensions, is fit for use in the assessment of clustering algorithms, and has the potential to be a widely used framework in diverse clustering-related research tasks. Keywords: Synthetic data, Clustering, Data generation, Multidimensional data
TextCL: a Python package for NLP preprocessing tasks
(Elsevier B.V., 2022-07-01) Petukhova, Alina; Fachada, Nuno; FE - Faculty of Engineering
Preprocessing text data sets for use in Natural Language Processing tasks is usually a time-consuming and expensive effort. Text data, normally obtained from sources such as, but not limited to, web scraping, scanned documents or PDF files, is typically unstructured and prone to artifacts and other types of noise. The goal of the TextCL package is to simplify this process by providing multiple methods suited for text data preprocessing. It includes functionality for splitting texts into sentences, filtering sentences by language, perplexity filtering, and removing duplicate sentences. Another functionality offered by the TextCL package is the outlier detection module, which allows to identify and filter out texts that are different from the main topic distribution of the data set. This method allows selecting one of several unsupervised outlier detection algorithms, such as TONMF (block coordinate descent framework), RPCA (robust principal component analysis), or SVD (singular value decomposition) and apply it to the text data. Keywords: Natural language processing ; Text filtering ; Outlier detection
Impact of artificial intelligence research on politics of the European Union member states : The case study of Portugal
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-08) Reis, João; Santo, Paula; Melão, Nuno; FE - Faculty of Engineering
Currently, artificial intelligence (AI) is at the center of academic and public debate. However, its implications on politics remain little understood. To understand the impact of the AI phenomenon on politics of the European Union (EU), we have carried out qualitative multimethod research by performing a systematic literature review and a case study. The first method was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), in order to report the state-of-the-art in the existing literature and explore the most relevant research areas. The second method contained contributions from experts in data science and AI of the Portuguese scientific community. The results showed that solutions such as intelligent decision support systems are improving the political decision-making process and impacting the Portuguese society at local, regional, and national levels. We also found that practitioners and scientists are currently shifting their interests from environmental and biological sciences to healthcare services, which is bringing new challenges in terms of protecting patient/citizen data and growing concerns about handling of critical information. Future research may focus on comparative studies with other EU States to obtain a comprehensive and holistic understanding of the AI phenomenon.
Uavnoma : a UAV-NOMA Network Model under non-ideal conditions
(Ubiquity Press, 2022-10-19) Lima, Brena; Fachada, Nuno; Dinis, Rui; Costa, Daniel B.; Beko, Marko; COPELABS - Cognitive and People-centric Computing
Uavnoma is a set of Python functions and a front-end script for modeling, studying, and analyzing the communication system composed by an unmanned aerial vehicle (UAV) and two ground users. We assume that the UAV acts as an aerial base station to serve the users according to non-orthogonal multiple access (NOMA) principles. For more practical insights, residual hardware impairments (RHI) and imperfect successive interference cancellation (ipSIC) are considered. More specifically, uavnoma allows the modelers to study and visualize the system performance in terms of achievable rate and outage probability. Additionally, the package produces figures and tables showcasing results from the specified performance metrics. KEYWORDS: Non-orthogonal multiple access (NOMA); Non-ideal conditions; Numerical simulation; Performance analysis; Unmanned aerial vehicle (UAV)
Enlarged PLIN5-uncoated lipid droplets in inner regions of skeletal muscle type II fibers associate with type 2 diabetes
(Elsevier GmbH, 2022-04) Fachada, Vasco; Rahkila, Paavo; Fachada, Nuno; Turpeinen, Tuomas; Kujala, Urho M.; Kainulainen, Heikki; COPELABS - Cognitive and People-centric Computing
Skeletal muscle physiology remains of paramount importance in understanding insulin resistance. Due to its high lipid turnover rates, regulation of intramyocellular lipid droplets (LDs) is a key factor. Perilipin 5 (PLIN5) is one of the most critical agents in such regulation, being often referred as a protector against lipotoxicity and consequent skeletal muscle insulin resistance. We examined area fraction, size, subcellular localization and PLIN5 association of LDs in two fiber types of type 2 diabetic (T2D), obese (OB) and healthy (HC) individuals by means of fluorescence microscopy and image analysis. We found that T2D type II fibers have a significant sub-population of large and internalized LDs, uncoated by PLIN5. Based on this novel result, additional hypotheses for the pathophysiology of skeletal muscle insulin resistance are formulated, together with future research directions.
A descriptive framework of the design process from a dual cognitive-engineering perspective
(Taylor and Francis Ltd., 2014) Marques, Pedro D.B.Carmona; Silva, Arlindo José P.F.; Henriques, Elsa M.P.; Magee, Christopher L.; FE - Faculty of Engineering
This article proposes a new descriptive framework, which we label as the “ideation framework” (IF), of the design process from a dual cognitive-engineering perspective, partly based on existing frameworks from both fields and previous work by the author. The framework is for the ideation or front-end phase of the product development process, representing the interface between cognitive psychology and engineering design. Three domains – inspiration, decomposition, and integration – and three spaces – problem-space, idea-space, and concept-space – are the elements of the framework. The iterative flow of the engineering design process passes through the three domains in a semi-controlled way, through a sequence of specialization and generalization process loops in and between the spaces. An empirical descriptive examination of the ideation process is performed using designers with limited design experience. The designers were faced with a design problem that they had to solve in a limited period of time. Their designs were analyzed, and a post-exercise interview was done to uncover each of the participants’ design process. The empirical work indicates these designers worked in a manner largely consistent with the IF.
Inulinase from Rhodotorula mucilaginosa : immobilization and application in the production of fructooligosaccharides
(The Korean Society of Food Science and Technology, 2021-07) de Araujo Ribeiro, Geise Camila; Fernandes, Pedro; Silva, Dayse Alessandra Almeida; Brandão, Hugo Neves; de Assis, Sandra Aparecida; FE - Faculty of Engineering
The crude extract containing inulinase from Rhodotorula mucilaginosa was obtained by submerged fermentation. Inulinase was immobilized on chicken eggshell by physical adsorption and covalent crosslinking, using glutaraldehyde as a crosslinking reagent, and Celite by adsorption. Fructooligosaccharides production was performed using immobilized inulinase (5%, w/v) and inulin substrate solution under experimental conditions evaluated through Doehlert experimental design. The production of inulinase was optimized for concentrations of D-glucose and yeast extract at 12.5 and 0.5 g/L, respectively, resulting in an optimal activity of 0.62 U. The optimal pH and temperature for enzyme activity were 8.0 and 75 °C, respectively, leading to an optimal activity of 3.54 U. The highest immobilization efficiency (46.27%) was obtained upon immobilization on Celite. Immobilization by adsorption to eggshell allowed for specific activity of 4.15 U/g, and adsorption to Celite resulted in specific activity of 3.70 U/g. The highest titer in fructooligosaccharides was obtained with an initial inulin concentration of 250 g/L (25%, w/v), and a reaction time of 16 h. Hence, immobilized inulinase proved to be a promising catalyst for fructooligosaccharides production since the formulation is performed through a simple, low-cost, and large-scale applicable methodology.
Production, characterization, and immobilization of protease from the yeast Rhodotorula oryzicola
(2021-10) de Oliveira, Juliana Mota; Fernandes, Pedro; Benevides, Raquel Guimarães; de Assis, Sandra Aparecida; FE - Faculty of Engineering
The protease was produced extracellularly in submerged fermentation by the yeast Rhodotorula oryzicola using different sources of nitrogen and maximum activity (6.54 × 10−3 U/mg) was obtained in medium containing 2% casein (w/v). Purification of the protease by gel filtration chromatography resulted in a 3.07-fold increase of specific protease activity. The optimal pH and temperature for enzyme activity were 6.51 and 63.04 °C, respectively. Incubation in the presence of some salts enhanced enzyme activity, which peaked under 0.01 M BaCl2. The enzyme retained about 90% of enzymatic activity at temperatures 50–60 °C. The commercially available enzyme carriers evaluated, silica gel, Celite 545, and chitosan effectively immobilized the protease. The enzyme immobilized in Celite 545 retained 73.53% of the initial activity after 15 reuse cycles. These results are quite promising for large-scale production and immobilization of protease from R. oryzicola, as the high operational stability of the immobilized enzyme lowers production costs in biotechnological applications that require high enzymatic activity and stability under high temperatures.
Drop Project : an automatic assessment tool for programming assignments
(Elsevier B.V., 2022-06-01) Cipriano, Bruno Pereira; Fachada, Nuno; Alves, Pedro; COPELABS - Cognitive and People-centric Computing
Automated assessment tools (AATs) are software systems used in teaching environments to automate the evaluation of computer programs implemented by students. These tools can be used to stimulate the interest of computer science students in programming courses by providing quick feedback on their work and highlighting their mistakes. Despite the abundance of such tools, most of them are developed for a specific course and are not production-ready. Others lack advanced features that are required for certain pedagogical goals (e.g. Git integration) and/or are not flexible enough to be used with students having different computer literacy levels, such as first year and second year students. In this paper we present Drop Project (DP), an automated assessment tool built on top of the Maven build automation software. We have been using DP in our teaching activity since 2018, having received more than fifty thousand submissions between projects, classroom exercises, tests and homework assignments. The tool’s automated feedback has allowed us to raise the difficulty level of the course’s projects, while the grading process has become more efficient and consistent between different teachers. DP is an extensively tested, production-ready tool. The software’s code and documentation are available in GitHub under an open-source software license. Keywords: Automated assessment ;Computer science education; Programming education ; Unit testing
Procedural generation of 3D maps with snappable meshes
(Institute of Electrical and Electronics Engineers Inc., 2022-04-20) Silva, Rafael Castro e; Fachada, Nuno; Andrade, Diogo de; Códices, Nélio; COPELABS - Cognitive and People-centric Computing
In this paper we present a technique for procedurally generating 3D maps using a set of premade meshes which snap together based on designer-specified visual constraints. The proposed approach avoids size and layout limitations, offering the designer control over the look and feel of the generated maps, as well as immediate feedback on a given map’s navigability. A prototype implementation of the method, developed in the Unity game engine, is discussed, and a number of case studies are analyzed. These include a multiplayer game where the method was used, together with a number of illustrative examples which highlight various parameterizations and piece selection methods. The technique can be used as a designer-centric map composition method and/or as a prototyping system in 3D level design, opening the door for quality map and level creation in a fraction of the time of a fully human-based approach. INDEX TERMS : 3D maps, computer games, designer-centric methods, layout, procedural content generation (PCG).
A survey on sustainable product development
(Elsevier B.V., 2019) Marques, Pedro Carmona; Charmier, Maria Adília Januário; Santos, José Oliveira; FE - Faculty of Engineering
The emergent field of sustainable product development has been rapidly evolving in several academic publications. Furthermore, sustainable product development is the basis for innovative products (and services). The analysis begins by identifying published studies within the last five years. A systematic mapping of the field evolution overtime is performed by identifying areas of current research interests and potential directions for future research. The findings will provide a roadmap for further investigations in this field.
A rapid review on the use of free and open source technologies and software applied to precision agriculture practices
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-03-24) Santos, Rogério P. dos; Fachada, Nuno; Beko, Marko; Leithardt, Valderi; FE - Faculty of Engineering; COPELABS - Cognitive and People-centric Computing
Technology plays a crucial role in the management of natural resources in agricultural production. Free and open-source software and sensor technology solutions have the potential to promote more sustainable agricultural production. The goal of this rapid review is to find exclusively free and open-source software for precision agriculture, available in different electronic databases, with emphasis on their characteristics and application formats, aiming at promoting sustainable agricultural production. A thorough search of the Google Scholar, GitHub, and GitLab electronic databases was performed for this purpose. Studies reporting and/or repositories containing up-to-date software were considered for this review. The various software packages were evaluated based on their characteristics and application formats. The search identified a total of 21 free and open-source software packages designed specifically for precision agriculture. Most of the identified software was shown to be extensible and customizable, while taking into account factors such as transparency, speed, and security, although some limitations were observed in terms of repository management and source control. This rapid review suggests that free and open-source software and sensor technology solutions play an important role in the management of natural resources in sustainable agricultural production, and highlights the main technological approaches towards this goal. Finally, while this review performs a preliminary assessment of existing free and open source solutions, additional research is needed to evaluate their effectiveness and usability in different scenarios, as well as their relevance in terms of environmental and economic impact on agricultural production.
Dissimilar metals laserwelding between DP1000 steel and aluminum alloy 1050
(Multidisciplinary Digital Publishing Institute (MDPI), 2019) Pereira, António B.; Cabrinha, Ana; Rocha, Fábio; Marques, Pedro; Fernandes, Fábio A.O.; Alves de Sousa, Ricardo J.; FE - Faculty of Engineering; RCM2+ - Research Centre in Asset Management and System Engineering
The welding of dissimilar metals was carried out using a pulsed Nd: YAG laser to join DP1000 steel and an aluminum alloy 1050 H111. Two sheets of each metal, with 30 14 1 mm3, were lap welded, since butt welding proved to be nearly impossible due to the huge thermal conductivity differences and melting temperature differences of these materials. The aim of this research was to find the optimal laser welding parameters based on the mechanical and microstructure investigations. Thus, the welded samples were then subjected to tensile testing to evaluate the quality of the joining operation. The best set of welding parameters was replicated, and the welding joint obtained using these proper parameters was carefully analyzed using optical and scanning electron microscopes. Despite the predicted difficulties of welding two distinct metals, good quality welded joints were achieved. Additionally, some samples performed satisfactorily well in the mechanical tests, reaching tensile strengths close to the original 1050 aluminum alloy.
Mycobacterium vaccae adaptation to disinfectants and hand sanitisers, and evaluation of cross-tolerance with antimicrobials
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-09) de Carvalho, Carla C.C.R.; Teixeira, Raquel; Fernandes, Pedro; FE - Faculty of Engineering
Mycobacterium vaccae is being considered as an adjuvant to antituberculosis therapy, tested for the treatment of autoimmune diseases, and as an anti-depressive agent. This bacterium is ubiquitous in the environment and the widespread use of disinfectants and sanitisers may lead to its adaptation to these compounds. In the present study, M. vaccae cells adapted to these compounds mainly by making adjustments in their lipid composition and net surface charge. The modifications in the lipid composition led to changes in membrane permeability which resulted in increased tolerance towards levofloxacin, thioridazine, and omeprazole.
Retail system scenario modeling using fuzzy cognitive maps
(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Petukhova, Alina; Fachada, Nuno; FE - Faculty of Engineering
A retail business is a network of similar-format grocery stores with a sole proprietor and a well-established logistical infrastructure. The retail business is a stable market, with low growth, limited customer revenues, and intense competition. On the system level, the retail industry is a dynamic system that is challenging to represent due to uncertainty, nonlinearity, and imprecision. Due to the heterogeneous character of retail systems, direct scenario modeling is arduous. In this article, we propose a framework for retail system scenario planning that allows managers to analyze the effect of different quantitative and qualitative factors using fuzzy cognitive maps. Previously published fuzzy retail models were extended by adding external factors and combining expert knowledge with domain research results. We determined the most suitable composition of fuzzy operators for the retail system, highlighted the system’s most influential concepts, and how the system responds to changes in external factors. The proposed framework aims to support senior management in conducting flexible long-term planning of a company’s strategic development, and reach its desired business goals. Keywords: retail; complex systems; fuzzy cognitive maps; scenario planning
Where are smart cities heading? A meta-review and guidelines for future research
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-08) Reis, João; Marques, Pedro Alexandre; Marques, Pedro Carmona; RCM2+ - Research Centre in Asset Management and System Engineering
(1) Background: Smart cities have been gaining attention in the community, both among researchers and professionals. Although this field of study is gaining some maturity, no academic manuscript yet offers a unique holistic view of the phenomenon. In fact, the existing systematic reviews make it possible to gather solid and relevant knowledge, but still dispersed; (2) Method: through a meta-review it was possible to provide a set of data, which allows the dissemination of the main theoretical and managerial contributions to enthusiasts and critics of the area; (3) Results: this research identified the most relevant topics for smart cities, namely, smart city dimensions, digital transformation, sustainability and resilience. In addition, this research emphasizes that the natural sciences have dominated scientific production, with greater attention being paid to megacities of developed nations. Recent empirical research also suggests that it is crucial to overcome key cybersecurity and privacy challenges in smart cities; (4) Conclusions: research on smart cities can be performed as multidisciplinary studies of small and medium-sized cities in developed or underdeveloped countries. Furthermore, future research should highlight the role played by cybersecurity in the development of smart cities and analyze the impact of smart city development on the link between the city and its stakeholders.
Economic disposal quantity of leftovers kept in storage : a Monte Carlo simulation method
(Walter de Gruyter GmbH, 2019) Assis, R.; Marques, Pedro Carmona; Santos, J. Oliveira; Vidal, R.; FE - Faculty of Engineering
This article describes how to reach an item's threshold, or in other words, the limit time for it to be retrieved from stock and sold for a different use, as well as the remaining foreseen period for this situation to occur. Once a minimum length, or weight, is reached, left quantities are more difficult to sell, as demand often exceeds the remaining parts or leftovers. The number of unfulfilled orders increases, as time goes by, until it becomes further cost effective to dispose the leftover and sell it for a lower price and alternative use. A Monte Carlo simulation model was built in order to consider the randomness of future transactions and quantifying consequences providing this way a simple and effective decision-making framework.

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