RCIPL
Institutional Repository of the Lisbon Polytechnic
Recent Submissions
Gait cycle duration analysis in lower limb amputees using an IoT-based photonic wearable sensor: a preliminary proof-of-concept study
Publication . Alves, Bruna; Fantoni, Alessandro; Matos, José; Costa, João; Vieira, Manuela
This study represents a preliminary proof of concept intended to demonstrate the feasibility of using a single-point LiDAR sensor for wearable gait analysis. The study presents a low-cost wearable sensor system that integrates a single-point LiDAR module and IoT connectivity to assess Gait Cycle Duration (GCD) and gait symmetry in real time. The device is positioned on the medial side of the calf to detect the contralateral limb crossing—used as a proxy for mid-stance—enabling the computation of GCD for both limbs and the derivation of the Symmetry Ratio and Symmetry Index. This was conducted under simulated walking at three cadences (slow, normal and fast). GCD estimated by the sensor was compared against the visual annotation with Kinovea®, showing reasonable agreement, with most cycle-wise relative differences below approximately 13% and both methods capturing similar symmetry trends. The wearable system operated reliably across different speeds, with an estimated materials cost of under 100 € and wireless data streaming to a cloud dashboard for real-time visualization. Although the validation is preliminary and limited to a single healthy participant and a video-based reference, the results support the feasibility of a photonic, IoT-based approach for portable and objective gait assessment, motivating future studies with larger and clinical cohorts and gold-standard references to quantify accuracy, repeatability and clinical utility.
PEF priming of seeds for microgreen production: a comparative study
Publication . Aguiar-Macedo, Mafalda; Dulyanska, Yuliya; Guiné, Raquel P. F.; Costa, Daniela V. T. A.; Redondo, Luis
Seed priming with Pulsed Electric Fields (PEF) is a promising strategy to enhance early plant development and crop quality. This study evaluated PEF priming effects on Beetroot (Beta vulgaris L.), Arugula (Eruca vesicaria), and Basil (Ocimum basilicum L.) microgreens by assessing the effects of three distinct monopolar PEF protocols (PEFA: 2 kV/cm; PEFB: 3 kV/cm; PEFC: 4 kV/cm). PEFB and PEFC treatments significantly influenced imbibition. Germination Indexes (DGI, CGI, and SVI) were positively and significantly affected, with radicle length increasing up to 33% and DGI improving from 40 to 66 on the 1st day (Beetroot, PEFC). Chlorophylls and the Total Carotenoid concentration increased in Basil but decreased in Beetroot and Arugula. Fat and Protein increased in Beetroot (Fat: +41%; Protein: +34%) and Arugula (Fat: +91%; Protein: +11%) treated with PEFC. PEFB led to an increase in Starch in all species. Crude Fibre and Neutral Detergent Fibre decreased amongst all species. Methionine rose by 100% in Beetroot treated with PEFC. Sensory analysis showed slight increases in Sweet (Beetroot) and Aroma Intensity (Basil and Arugula), although these changes were not statistically significant. Species-specific responses to different PEF protocols were observed: optimal protocols seem to be PEFC for Beetroot, PEFB for Arugula, and PEFA/B for Basil.
Heat transfer mechanisms in refrigerated spaces: a comparative study of experiments, CFD predictions and heat load software accuracy
Publication . Lança, Miguel; Garcia, João Nuno Pinto Miranda; Gomes, João
A correct cold room heat load calculation ensures that the refrigeration system operates efficiently, reducing operating costs while maintaining a constant temperature to prevent stored goods from spoiling. Refrigeration engineers typically use software to size equipment such as expansion devices and evaporators and to estimate heat loads in cold rooms. These tools are available for free from refrigeration manufacturers or can be purchased from software developers. Although practical and easy to use, most of these programs do not follow the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)-recommended approach for estimating heat loads. This article evaluates heat transfer mechanisms, especially natural convection in a refrigerator, through experimental and CFD simulations. Depending on the expression used, the estimated convection heat flux at the evaporator ranged from 5.3 W to 14.2 W in case 0-N, 7.7 W to 25.1 W in case −10-N, and 5.1 W to 22.4 W in case 0-Y. Compared to convective heat transfer, radiation heat flux estimations are often more consistent across different expressions. The results from validated simulations were used to assess the performance of cold room heat load estimation software. Differences of up to 236% in heat load estimates were reported between the results.
Decentralized multi-agent reinforcement learning with visible light communication for robust urban traffic signal control
Publication . Augusto Vieira, Manuel; Gonçalo Galvão; Vieira, Manuela; Véstias, Mário; Louro, Paula; Vieira, Pedro
The rapid growth of urban vehicle and pedestrian flows has intensified congestion, delays, and safety concerns, underscoring the need for sustainable and intelligent traffic management in modern cities. Traditional centralized traffic signal control systems often face challenges of scalability, heterogeneity of traffic patterns, and limited real-time adaptability. To address these limitations, this study proposes a decentralized Multi-Agent Reinforcement Learning (MARL) framework for adaptive traffic signal control, where Deep Reinforcement Learning (DRL) agents are deployed at each intersection and trained on local conditions to enable real-time decision-making for both vehicles and pedestrians. A key innovation lies in the integration of Visible Light Communication (VLC), which leverages existing LED-based infrastructure in traffic lights, streetlights, and vehicles to provide high-capacity, low-latency, and energy-efficient data exchange, thereby enhancing each agent’s situational awareness while promoting infrastructure sustainability. The framework introduces a queue–request–response mechanism that dynamically adjusts signal phases, resolves conflicts between flows, and prioritizes urgent or emergency movements, ensuring equitable and safer mobility for all users. Validation through microscopic simulations in SUMO and preliminary real-world experiments demonstrates reductions in average waiting time, travel time, and queue lengths, along with improvements in pedestrian safety and energy efficiency. These results highlight the potential of MARL–VLC integration as a sustainable, resilient, and human-centered solution for next-generation urban traffic management.
Assessing the contribution of ERASMUS+ KA2 projects to the SDGs: an exploratory analysis
Publication . Nogueira, João Robert; Dantas, Lucimar; Galego, Carla; Marques, Pedro
This study examines the contribution of ERASMUS+ Key Action 2 (KA2) projects, funded between 2014 and 2020, to the dissemination and promotion of the United Nations Sustainable Development Goals (SDGs). A predominantly quantitative content analysis was conducted based on metadata extracted from the official European Commission database, focusing on the presence of SDG-related keywords within the titles, topics, and abstracts of the projects. In total, 24,838 KA2 projects were examined. The findings reveal a growing alignment between funded projects and certain SDGs, particularly SDG 3 (Good Health and Well-being), SDG 4 (Quality Education), SDG 13 (Climate Action), SDG 7 (Affordable and Clean Energy), and SDG 9 (Industry, Innovation, and Infrastructure). In contrast, goals such as SDG 2 (Zero Hunger), SDG 6 (Clean Water and Sanitation), and SDG 14 (Life Below Water) are scarcely represented. Overall, the results demonstrate an increasing commitment to sustainability themes over time and also highlight notable gaps in the promotion of several SDGs. This analysis offers valuable insights into the strategic alignment of ERASMUS+ funding with the 2030 Agenda and identifies opportunities for strengthening its future contributions to sustainable development.