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Item 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 EngineeringThis 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.Item Microfluidic bioreactors for enzymatic synthesis in packed-bed reactors—Multi-step reactions and upscaling(Elsevier B.V., 2020-11-10) Brás, Eduardo J.S.; Domingues, Cristiana; Chu, Virginia; Fernandes, Pedro; Conde, João Pedro; HEI-LAB - Human Environment Interaction LabEnzymatic synthesis of biochemical commodities is of upmost importance as it represents a greener alternative to traditional chemical synthesis and provides easier downstream processing strategies compared to fermentation-based processes. A microfluidic system used to optimize the enzymatic production of both levodopa (L-DOPA) and dopamine in both single-step and multistep-reaction sequences with yield of approximately 30 % for L-DOPA production and 70 % for dopamine production is presented. The system for L-DOPA production was then up-scaled (780-fold increase) to a milliliter scale system by maintaining similar mass transport properties resulting in the same yield, space-time yield and biocatalyst yield as its microscale counterpart. The results obtained for yield and biocatalyst yield (351.7 mgL-DOPA mg−1Tyr h−1) were similar to what is reported in the literature for similar systems, however the space-time yield (0.806 mgL-DOPA L−1 h−1) was smaller. This work demonstrates a microfluidic bioreactor that can be used for complex optimizations that can be performed rapidly while reducing the consumption of reagents by immobilizing the catalyst on a carrier which can then be used in a packed-bed reactor, thus extending the enzyme life span.Item 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 ComputingUavnoma 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)Item 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 EngineeringThe 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.Item Upgrading end-of-line residues of the red seaweed Gelidium sesquipedale to polyhydroxyalkanoates using Halomonas boliviensis(Elsevier B.V., 2020-09) Tůma, S.; Izaguirre, J. K.; Bondar, M.; Marques, M. M.; Fernandes, P.; da Fonseca, M. M.R.; Cesário, M. T.; FE - Faculty of EngineeringAgar extraction from Gelidium and Gracilaria red seaweed species produces hundred thousand ton of carbohydrate-rich residues annually. Gelidium sesquipedale waste biomass obtained after agar extraction, still contained 44.2 % w/w total carbohydrates (dry-weight basis). These residues were biologically up-graded to poly-3-hydroxybutyrate (P3HB) after saccharification of their carbohydrate fraction to simple sugars. A combined hydrolysis treatment using sulfamic acid followed by enzymatic hydrolysis with cellulases produced a glucose-rich hydrolysate with a negligible content of inhibitors. With this treatment a sugar yield of circa 30 % (g glucose/g biomass) was attained. The algal hydrolysates were assessed as carbon source for the production of P3HB by the halotolerant bacteria Halomonas boliviensis. A cell concentration of 8.3 g L−1 containing 41 % (w/w) of polymer and a yield (YP/S) of 0.16 gpolymer/gglucose were attained in shake flask assays. In this work, cellulose-rich seaweed waste was shown to be an upgradable, sustainable source of carbohydrates.Item TextCL: a Python package for NLP preprocessing tasks(Elsevier B.V., 2022-07-01) Petukhova, Alina; Fachada, Nuno; FE - Faculty of EngineeringPreprocessing 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 detectionItem MN-DS: A Multilabeled News Dataset for News Articles Hierarchical Classification(Multidisciplinary Digital Publishing Institute (MDPI), 2023-04-23) Petukhova, Alina; Fachada, Nuno; FE - Faculty of Engineering; COPELABS - Cognitive and People-centric ComputingThis article presents a dataset of 10,917 news articles with hierarchical news categories collected between 1 January 2019 and 31 December 2019. We manually labeled the articles based on a hierarchical taxonomy with 17 first-level and 109 second-level categories. This dataset can be used to train machine learning models for automatically classifying news articles by topic. This dataset can be helpful for researchers working on news structuring, classification, and predicting future events based on released news. Keywords: news dataset; text classification; NLP; media topic taxonomyItem ParShift: a Python package to study order and differentiation in group conversations(Elsevier B.V., 2023-12-01) Carvalho, João P. Matos; Fachada, Nuno; Pita, Manuel Arturo Marques; Saraiva, Bruno David Ferreira; Matos-Carvalho, João Pedro; COPELABS - Cognitive and People-centric Computing; CICANT - Centre for Research in Applied Communication, Culture, and New Technologies; ECATI - School of Communication, Architecture, Arts and Information TechnologiesCollective organization in multi-party conversations emerges through the exchange of utterances between participants. While most research has focused on content-centred mechanisms that lead to emergent conversational coordination, less attention has been given to explaining conversational order based on who is addressed and who responds, especially when dealing with large conversational datasets. In this paper, we introduce a Python library, ParShift, that implements a state-of-the-art theoretical quantitative framework known as Participation Shifts. This framework enables researchers to study participant-centred order and differentiation in multi-party conversations. With ParShift, researchers can characterize conversations by quantifying the probabilities of events related to how people address each other during conversations. This library is particularly useful for studying conversation threads in social networks, parliamentary debates, team meetings, or student debates on a large scale. Keywords: Small groups Social interaction Participation shifts Interpersonal coordination Turn-taking Emergent social behaviourItem 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.Item Production, characterization, and immobilization of protease from the yeast Rhodotorula oryzicola(Wiley-Blackwell, 2021-10) de Oliveira, Juliana Mota; Fernandes, Pedro; Benevides, Raquel Guimarães; de Assis, Sandra Aparecida; FE - Faculty of EngineeringThe 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.Item 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 EngineeringSoybean 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.Item 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 EngineeringThe 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 helixItem 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 EngineeringThis 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.Item 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 EngineeringThe 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.Item A descriptive framework of the design process from a dual cognitive-engineering perspective(Taylor and Francis, 2014) Marques, Pedro D.B.Carmona; Silva, Arlindo José P.F.; Henriques, Elsa M.P.; Magee, Christopher L.; FE - Faculty of EngineeringThis 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.Item Generating multidimensional clusters with support lines(Elsevier B.V., 2023) Fachada, Nuno; de Andrade, Diogo; COPELABS - Cognitive and People-centric ComputingSynthetic 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 dataItem 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 ComputingTechnology 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.Item Integrating Product-Service Systems with New Business Models Definition for Manufacturing Industries(IGI Global Publishing, 2014) Marques, Pedro C.; Cunha, Pedro F.; FE - Faculty of Engineering; RCM2+ - Research Centre in Asset Management and System EngineeringNowadays, manufacturing companies are pressured to be competitive and innovative. Particularly this concerns the delivery of value to their customers. The assessment of the overall value chain, designed and implemented for a specific product and/or service, should be sustained by new business models (NBM), thus contributing to higher levels of customer satisfaction. Integrated product-services are assuming importance, allowing manufacturing companies to achieve longer and stable relationships with their customers. This requires, among other, organizational changes and novel methodologies for product-service development. In fact, an effective integration allows product-service innovation, which being exploited, contributes significantly to businesses' competitiveness and sustainability. In this paper, a "roadmap" for NBM definition and implementation is presented, along with a new methodology for Product-Service Systems (PSS) development. Two case studies are used to test both the roadmap and the PSS methodology. As such, this work is expected to contribute to a clear understanding of NBM and their integration in a methodology for PSS.Item Retail system scenario modeling using fuzzy cognitive maps(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Petukhova, Alina; Fachada, Nuno; FE - Faculty of EngineeringA 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 planningItem A survey on sustainable product development(Elsevier B.V., 2019) Marques, Pedro Carmona; Charmier, Maria Adília Januário; Santos, José Oliveira; FE - Faculty of EngineeringThe 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.