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Publications

2025

Analysis of a D-Shaped Photonic Crystal Fiber Sensor with Multiple Conducting Layers

Authors
Romeiro, F; Cardoso, P; Miranda, C; Silva, O; Costa, CWA; Giraldi, MR; Santos, L; Baptista, M; Guerreiro, A;

Publication
Journal of Microwaves, Optoelectronics and Electromagnetic Applications

Abstract
In our study, we conducted a thorough analysis of the spectral characteristics of a D-shaped surface plasmon resonance (SPR) photonic crystal fiber (PCF) refractive index sensor, incorporating a full width at half maximum (FWHM) analysis. We explored four distinct plasmonic materials—silver (Ag), gold (Au), Ga-doped zinc oxide (GZO), and an Ag-nanowire metamaterial—to understand their impact on sensor performance. Our investigation encompassed a comprehensive theoretical modeling and analysis, aiming to unravel the intricate relationship between material composition, sensor geometry, and spectral response. By scrutinizing the sensing properties offered by each material, we laid the groundwork for designing multiplasmonic resonance sensors. Our findings provide valuable insights into how different materials can be harnessed to tailor SPR sensing platforms for diverse applications and environmental conditions, fostering the development of advanced and adaptable detection systems. This research not only advances our understanding of the fundamental principles governing SPR sensor performance but also underscores the potential for leveraging varied plasmonic materials to engineer bespoke sensing solutions optimized for specific requirements and performance metrics. © 2025 SBMO/SBMag.

2025

Competitive and Cooperative Player-Oriented GWAPs for Enhancing Crowdsourcing Campaigns - An Evidence-Based Synthesis

Authors
Guimaraes, D; Correia, A; Paulino, D; Paredes, H;

Publication
INTERNATIONAL JOURNAL OF HUMAN-COMPUTER INTERACTION

Abstract
The use of gamified crowdsourcing mechanisms through serious games and games with a purpose (GWAPs) has emerged as an effective motivational strategy for enhancing performance in human intelligence tasks (HITs). In this systematic literature review, we examine the underlying characteristics of competitive and cooperative player-oriented GWAPs and how they can be leveraged to optimize crowdsourcing performance in completing batches of HITs. By exploring gamified crowdsourcing elements in GWAPs, we can evaluate the impact of these two types of player behaviors (i.e., competition and cooperation) on motivation and performance. We reviewed 27 publications and grouped them into five categories: player orientation, game elements and motivation, crowd work optimization, gamified knowledge collection, and comparative studies and best practices. Our research pinpoints the significance of intuitive task instructions, alignment of game elements with player motivations, and the role of competitive and cooperative dynamics in enhancing engagement and performance.

2025

An Educational Robotics Competition - The Robotics@ISEP Open Experience

Authors
Silva, MF; Dias, A; Guedes, P; Barbosa, R; Estrela, J; Moura, A; Cerqueira, V;

Publication
2025 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS, ICARSC

Abstract
There is a strong need to motivate students to learn science, technology, engineering, and mathematics (STEM) subjects. This is a problem not only at lower educational levels, but also at college institutions. With this idea in mind, the School of Engineering of the Porto Polytechnic (ISEP) Electrical Engineering Department decided, in 2021, to launch a robotics competition in order to foster students' interest in the areas of robotics and automation. This event, named Robotics@ISEP Open, aims to raise awareness of the area of electronics, computing, and robotics among students, involving them in the use of techniques and tools in this area, and encompasses three distinct robotics competitions covering both manipulator arms and mobile robots. It is based on two main points of interest: (i) robotic competitions and (ii) outside class training in robotics, aimed at students who want support to participate in competitions. Since its first edition, the event has grown and internationalized and has already become a milestone in the academic life of ISEP. This paper presents the motivations that led to the creation of this event, its main organizational aspects, and the competitions that are part of it, as well as some results gathered from the experience accumulated in organizing it.

2025

Enhancing explainability in AI-based energy forecasting through clustering and data selection

Authors
Teixeira, B; Valina, L; Pinto, T; Reis, A; Barroso, J; Vale, Z;

Publication
SUSTAINABLE ENERGY GRIDS & NETWORKS

Abstract
Explainable Artificial Intelligence (XAI) seeks to enhance the interpretability of Artificial Intelligence (AI) systems, ensuring that algorithmic decisions and their underlying data are comprehensible to non-technical stakeholders. While advanced Machine Learning (ML) models, such as deep neural networks, have significantly improved AI capabilities, their complexity poses challenges for XAI, particularly in handling large datasets required for training and interpretation. In particular, the application of Shapley Additive Explanations (SHAP), although widely recognized for its effectiveness, often incurs a high computational cost when applied to large-scale data. Addressing this issue, our previous work proposed a novel approach that leverages K-Means clustering to identify representative data instances, applied after the forecasting phase to refine SHAP-based explanations and reduce computational costs while preserving their fidelity. This extended study further optimizes the clustering strategy and evaluates its applicability across broader use cases in sustainable energy systems. We apply our method to forecast photovoltaic (PV) generation in buildings, a critical aspect of energy management in e-mobility and smart grids. The results show that clustering reduces execution time by more than 50 % compared to random sampling while maintaining comparable explanatory stability. These findings highlight the potential of data-driven clustering techniques in enhancing the explainability of ML models in energy forecasting, contributing to more accessible and practical AI solutions for real-world applications.

2025

Let Me Know What Kind of Leader You Are, and I Will Tell You If I Stay: The Role of Well-Being in the Relationship Between Leadership and Turnover Intentions

Authors
Rodrigues, IR; Palma-Moreira, A; Au-Yong-Oliveira, M;

Publication
ADMINISTRATIVE SCIENCES

Abstract
This study aimed to analyze the association of leadership with turnover intentions and whether this relationship is mediated by employee well-being. The sample consists of approximately 306 individuals working in organizations based in Portugal. The results indicate that transformational leadership has a positive and significant association with turnover intentions, while the relationship between transactional leadership and turnover intentions is negative and significant. Both transformational leadership and transactional leadership have a positive and significant association with well-being. Well-being has a negative and significant association with turnover intentions. Well-being only has a mediating effect on the relationship between transactional leadership and turnover intentions. This study contributes to the advancement of academic research and knowledge about the mechanisms through which transformational and transactional leadership styles can influence employees' turnover intentions, as well as providing empirical evidence on the mediating role of psychological well-being. In addition, practical insights are offered to organizational leaders and managers on adopting practices that foster psychological well-being in the workplace, thereby reducing employee turnover intentions.

2025

NETTAG+ - Towards a cleaner fishing practice and reducing the environmental impact of lost fishing gear

Authors
Viegas, D; Martins, A; Neasham, J; Ramos, S; Almeida, M;

Publication

Abstract
Abandoned, Lost, or otherwise Discarded Fishing Gear (ALDFG) has a great impact on marine ecosystems. This is not only due to the direct contribution to marine litter production with particular emphasis on plastics but also to the effects of ghost fishing.The Nettag+ project aims to reduce these impacts by acting on three main lines of action: prevention, avoidance, and mitigation. In the first line, direct action and collaboration with fishers and nature protection organizations around Europe aim to establish the fishermen community as guardians of the ocean. These actions with active fishers' collaboration range from training and dissemination activities related to marine litter and ocean protection to direct measures in day-to-day work to minimize and recover litter from the sea.In the prevention line, an acoustic tag designed explicitly for the location of ALDFG was developed in collaboration with research institutions and fishing gear manufacturers. It can be integrated into the fishing equipment for future tracking and recovery. This tool can reduce lost fishing gear retrieval costs and is complemented with robotic solutions to support retrieving operations.To mitigate the effects of existing untagged ALDFG, multisensorial  detection algorithms are being developed to detect and map ALDFG on the sea and to take advantage of autonomous and robotic systems to perform this task.

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