ISEP – CIDEM – Comunicações em eventos científicos
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- Simulation and Control of a Cyber-Physical System under IEC 61499 StandardPublication . Santos, Adriano A; Silva, A. Ferreira daIEC 61499 standard provides an architecture for control systems using function blocks (FB), languages, and semantics. These devices can be interconnected and communicate with each other. Each device contains several resources and algorithms with a communication FB at the end, which can be created, configured, and deleted without affecting other resources. Physical element can be represented by a FB that encapsulates the functionality (data/events, process, return data/events) in a single module that can be reused and combined. This work presents a simplified implementation of a modular control system using a low-cost device. In the prototyping of the application, we use 4diac to control, model and validate the implementation of the system on a programmable logic controller. It is proved that this approach can be used to model and simulate a cyber-physical system as a single element or in a networked combination. The control models provide a reusable FB design.
- Symbolic Manipulation for Optimization of Boolean Functions for Control of Pneumatic and Electropneumatic CircuitsPublication . Silva, A. Ferreira da; Santos, Adriano ANeste artigo é descrito um programa desenvolvido em PROLOG, que realiza uma manipulação simbólica computacional dos Mapas de Karnaugh (MK), para obter o conjunto de equações lógicas otimizadas que possibilite o controlo de circuitos pneumáticos ou electropneumáticos. A manipulação simbólica de um MK é governada por um conjunto de regras genéricas que permitem obter a minimização/otimização de equações lógicas para controlo do circuito. Essa complexidade advém da explosão combinatória que resulta do aumento do número de cilindros que constituem o ciclo a automatizar. As abordagens de aprendizagem simbólica foram implementadas realizando uma busca no espaço de padrões simbólicos do MK. Esta busca permite com o uso de regras, reduzir o universo de procura no espaço de padrões simbólicos e, obter a solução ideal para controlar o circuito pneumático ou electropneumático desejado
- New conceptual model of Reverse Logistics of a worldwide Fashion CompanyPublication . Janeiro, Ricardo; Pereira, Maria Teresa; Ferreira, Luís Pinto; Sá, José Carlos; Silva, Francisco J. G.This paper focuses on the logistics activity of the Outlet Retail industry of accessories and clothing items produced by a Portuguese fashion company, operated by an also Portuguese Third-Party Logistics providers (3PL). The main goal of this study is to address and analyze the current business and process model used by the Portuguese 3PL, to compare it with other existing models within the state-of-art, and to design a new conceptual model for 3PL’s reverse logistics activities in the Clothing and Fashion Industry. The second main goal is to identify improvement opportunities, while observing and mapping logistic activities, in order to increase productivity, reduce costs, and improve the quality of the service. The analysis was supported by Lean and Supply Chain methodologies and by appropriate tools like the Value Stream Mapping (VSM). VSM contributed to map the business processes in a structured and systematic way and provided a wide perception of the value chain to identify the waste that could be reduced. The data used to feed the VSM was collected by cycle time measurements and also data analytics. After the analysis, a new Value Stream Proposal was presented for that business model, as well as the gains achieved by the execution of technologic and lean-based improvement actions. Finally, this paper presents a Conceptual Business Model for 3PL’s Reverse Logistics in the Clothing and Fashion Industry.
- Analysis and Improvement of the Packaging Sector of an Industrial CompanyPublication . Alves, Diogo; Ferreira, Luís Pinto; Pereira, Maria Teresa; Sá, José Carlos; Silva, Francisco J. G.; Fernandes, N.O.Manual operations in manufacturing companies are still a common practice. This often results in high costs, high cycle times and therefore in lower productivity, particularly for companies operating in western countries. This is why many manufacturing companies relocated their production facilities in low age countries. This study was developed at a leading Portuguese material construction manufacturing company. The objective was to improve the packaging and labeling processes, that were identified as main bottlenecks in the factory. Lean was used to streamline these processes before being automated. This allowed for annual savings of 12432 €, with human operators being reallocated to other departments where they are more useful. Furthermore, cycle times were reduced by 42,9%, non-value-added activities were minimized, and operations with potentially high ergonomic risks were eliminated. In addition, a reduction of 84,3% in lithographed packaging was achieved, with a cost reduction of around 36 000 €/year, which is expected to continue in the forthcoming years.
- Development of a suitable project management approach for projects with parallel planning and executionPublication . Freitas, F.; Silva, Francisco J. G; Campilho, R.D.S.G.; Pimentel, C.; Godina, R.In a big company, project management (PM) is always present. Traditional predictive PM approach is concerned with planning everything in advance and then controlling and adjusting if necessary, throughout the project timeline. This may work well when the requirements are well established, but for maintenance projects brings inherent uncertainty. When the subject is aircraft maintenance, it is almost impossible to plan everything at the beginning and expect that it will occur as planned because however a scheduled maintenance plan exists, according to statistics 60% of the aircraft total failure can only be found with ground inspection which means, that even if a plan is established before receiving the aircraft, it will most certainly need to be significantly changed. This requires a big effort from the planning team to plan everything right and ensure that all tools and resources are available to perform the required tasks. To solve this issue, in this paper we propose a hybrid project management approach developed to a case study company from the aircraft repair sector, to enable a faster planning while taking into account the priorities and dependencies of the inherent project tasks with the available resources.
- Reducing scrap and improving an air conditioning pipe production linePublication . Lopes, R.; Silva, Francisco J. G; Godina, R.; Campilho, R.D.S.G.; Dieguez, T.; Pinto Ferreira, Luís; Baptista, Gabriel A GThe automotive industry is considered one of the most demanding and competitive sectors in the global market. This increasingly implies having a stable and optimized production process, always with a view to continuous improvement. Therefore, it is very important to be aware of all the waste that is generated in all production and logistics operations and take action to reduce them. In this regard and considering the process of producing air conditioning pipes for the automotive industry, a high scrap value was detected mainly due to soldering process. Therefore, the entire production process is analyzed in order to identify the main causes behind the high scrap value. Several Lean and quality tools are used to reduce not only the amount of scrap but also to increase the line productivity. In order to face this challenge, after elaborating the action plan and corresponding implementation, the scrap value is reduced by 12% in general, and productivity increased by 29%, 55% and 22.5% in three different references produced by the same machine. Although this solution is a bit expensive, the corresponding payback is reduced, so it can easily be applied transversally to other similar machines allowing extremely interesting gains in the short term.
- Enhancing student learning in Mechanical Engineering Thermodynamics with a two-stage testPublication . Duarte, MarinaFor years, it has been recognized in the literature, the need to change and improve assessment methods. In spite of that, the purpose of most assessment is still grading students, and not the learning enhancement. In the early 1970s, researchers found that what influenced students most was not the teaching but the assessment, which lead to the idea of the hidden curriculum. According to students’ testimony, what and how much they studied were completely dominated by the way they perceived the demands of the assessment. This effect of assessment in students’ learning is what Biggs defined as backwash, which means that students’ learn what they think will be assessed. Backwash is almost seen as negative, but studying for the test is only negative if the test doesn’t assess what we intend students’ to learn. A two-stage test was used in Thermodynamics (Mechanical Engineering, 2nd year), as a way to improve learning of a particular topic (state properties determination). The stages were a week apart. In the first stage, the students answer 20 questions in 30 minutes. Based on what they thought they missed in the first stage (grades were not published at this time), they could try to improve their performance in the second stage, by studying harder in the week between the two stages. The teacher didn't interfere with this process, encouraging self-assessment and self-regulation, in order to promote the autonomy of the learners. In the second stage, the test only included the questions that each student missed and had the duration of 30 minutes. Students’ evaluation of this task was done through a series of questions, in an anonymous questionnaire. Results (143 valid questionnaires) show that this kind of assessment, that uses a more student-centred approach, as required by the Bologna Process, is seen by the students as a helpful tool to promote study (85,3%) and enhance learning (87,6%). Students express the will to have more two-stage tests (89,1%).
- Engineering Students perceptions on Learner Autonomy: a mixed methodology approachPublication . Duarte, M.Student-centered learning requires students taking responsibility for their own learning, and becoming autonomous learners. Using a mixed methodology approach with a sequential explanatory design, this paper reports some results from an ongoing research about learner autonomy of mechanical engineering students (first cycle) in Portugal. For the purpose of this paper, the focus is the relationship between learner autonomy and academic achievement and the way it translates to students’ perceptions of autonomy in learning, its characteristics and importance, and how having students talk about learner autonomy can be useful to improve their learning and build a bridge between research and practice in Engineering Education. The results show that students have positive perceptions about their own learner autonomy and its importance. A positive moderated statistically significant correlation was found between learner autonomy and academic achievement, which is mainly due to the control dimension of learner autonomy. Students lack initiative, with this dimension being the one that least contributes to learner autonomy, and having no statistically significant correlation with academic achievement. Because of this, promoting actions that increase students taking initiative seems to be a way of improving learner autonomy. However, the actions taken have to consider that for some students, learner autonomy requires perseverance and is difficult to maintain. So, even though for most students, having opportunities to improve may be enough, less autonomous students may require that the action of teachers and the curricular activities proposed, promotes an academic environment that encourages and supports autonomy in learning.
- A roadmap for teaching in higher education: taking students and teachers on a journeyPublication . Duarte, MarinaIn this paper, the metaphor of a “journey” is used to reflect on teaching and learning in Higher Education. Learning is seen as a “journey” where the guide is the teacher and the traveller is the student. Some key elements from the research done on the last decades are brought together in order to raise awareness to the complexity of this process, namely those regarding the teacher and the student, in order to help teachers begin to find the appropriate “journey” for themselves and their students. The ideas presented here are the result of a “teaching and learning journey” that the author took with a group of Professors of Higher Education Universities from Central Asia, in 2015.
- Meaning and benefits of the EUR-ACE label: Portuguese Higher Education InstitutionsPublication . Duarte, Marina; Costa, AntónioThe European Higher Education Area was meant to ensure more comparable, compatible and coherent systems of higher education. This is possible however, only if there is a trustful relationship amongst its members and by the creation of quality assurance mechanisms, such as the European Association for Quality Assurance in Higher Education and its agencies. Nevertheless, it seems that in certain professional areas, like engineering, this European accreditation is not sufficient, and other means of quality assurance with worldwide recognition are sought, such as the EUR-ACE label. The aim of this research is to ascertain how the Portuguese Higher Education Institutions, with studies programmes that were awarded the EUR-ACE label, are using it in their promotion and what are its meanings and benefits. Based on the analysis done, it is possible to conclude that in spite of EUR-ACE labels being awarded to studies programmes and not to Institutions, they are being used to promote the Institutions. The stakeholders that are more frequently mentioned by the Institutions as beneficiaries of the EUR-ACE label are graduates, by means of the European and international professional mobility. The EUR-ACE label is seen by Institutions as a proof of the quality of studies programmes, because of its demanding and rigorous criteria, that assures Excellency and European and international high quality assurance standards.