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Publications

Publications by CPES

2025

Deep Learning for Multi-class Diagnosis of Thyroid Disorders Using Selective Features

Authors
Santana, F; Brito, J; Georgieva, P;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract
Data-based approach for diagnosis of thyroid disorders is still at its early stage. Most of the research outcomes deal with binary classification of the disorders, i.e. presence or not of some pathology (cancer, hyperthyroidism, hypothyroidism, etc.). In this paper we explore deep learning (DL) models to improve the multi-class diagnosis of thyroid disorders, namely hypothyroid, hyperthyroid and no pathology thyroid. The proposed DL models, including DNN, CNN, LSTM, and a hybrid CNN-LSTM architecture, are inspired by state-of-the-art work and demonstrate superior performance, largely due to careful feature selection and the application of SMOTE for class balancing prior to model training. Our experiments show that the CNN-LSTM model achieved the highest overall accuracy of 99%, with precision, recall, and F1-scores all exceeding 92% across the three classes. The use of SMOTE for class balancing improved most of the model’s performance. These results indicate that the proposed DL models not only effectively distinguish between different thyroid conditions but also hold promise for practical implementation in clinical settings, potentially supporting healthcare professionals in more accurate and efficient diagnosis. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

2025

The role of interventions in enhancing indoor environmental quality in higher education institutions for student well-being and academic performance

Authors
Andrade, C; Stathopoulos, S; Mourato, S; Yamasaki, N; Paschalidou, A; Bernardo, H; Papaloizou, L; Charalambidou, I; Achilleos, S; Psistaki, K; Sarris, E; Carvalho, F; Chaves, F;

Publication
CURRENT OPINION IN ENVIRONMENTAL SCIENCE & HEALTH

Abstract
Students spend 30 % of their lives indoors; therefore, a healthy indoor air quality (IAQ) is crucial for their well-being and academic performance in Higher Education Institutions. This review highlights the interventions for improving Indoor Enviclassrooms considering climate change by discussing ventilation techniques, phytoremediation, and building features designed to improve noise levels, thermal comfort, lighting and to reduce odor. Awareness and literacy are enhanced through the student's engagement by offering real-time monitoring knowledge of Indoor Environmental Quality using inexpensive smart sensors combined with IoT technology. Eco-friendly strategies are also highlighted to promote sustainability.

2025

Integrating Machine Learning and Digital Twins for Enhanced Smart Building Operation and Energy Management: A Systematic Review

Authors
Palley, B; Martins, JP; Bernardo, H; Rossetti, R;

Publication
URBAN SCIENCE

Abstract
Artificial Intelligence has recently expanded across various applications. Machine Learning, a subset of Artificial Intelligence, is a powerful technique for identifying patterns in data to support decision making and managing the increasing volume of information. Simultaneously, Digital Twins have been applied in several fields. In this context, combining Digital Twins, Machine Learning, and Smart Buildings offers significant potential to improve energy efficiency and operational effectiveness in building management. This review aims to identify and analyze studies that explore the application of Machine Learning and Digital Twins for operation and energy management in Smart Buildings, providing an updated perspective on these rapidly evolving topics. The methodology follows the PRISMA guidelines for systematic reviews, using Scopus and Web of Science databases. This review identifies the main concepts, objectives, and trends emerging from the literature. Furthermore, the findings confirm the recent growth in research combining Machine Learning and Digital Twins for building management, revealing diverse approaches, tools, methods, and challenges. Finally, this paper highlights existing research gaps and outlines opportunities for future investigation.

2025

Pricing Strategies for Local Transactions in Renewable Energy Communities Business Models

Authors
Sousa, J; Lucas, A; Villar, J;

Publication
International Conference on the European Energy Market, EEM

Abstract
The business models (BM) for renewable energy communities (REC) are often based on their promoters being the sole or primary investors in energy assets, such as photovoltaic panels (PV) and battery energy storage systems (BESS), operating these assets centrally, and selling the locally produced energy to the REC members. This research addresses the computation of fixed local energy prices that the REC developer may apply under the optimal operation of the energy assets to maximize its revenues, while guaranteeing that all REC members benefit from belonging to the REC. We do this from two perspectives, depending on who operates the storage systems: i) maximizing the investor's benefits and ii) minimizing the REC cost by maximizing its self-consumption, ensuring maximization of the energy sold by the REC promoter/investor. The optimization framework includes energy production and demand balance constraints, peak load limitations, and constraints coming from the Portuguese regulatory framework. It also considers the opportunity costs of the members for buying the energy deficit from the grid or selling the energy surplus to the grid. © 2025 IEEE.

2025

Smart Hygrothermal Ventilation, an Energy-Efficient Solution for Controlling Relative Humidity in Historical Constructions: A Case Study

Authors
Palley, B; de Freitas, VP; Abreu, P; Restivo, MT; Freitas, TS;

Publication
PROTECTION OF HISTORICAL CONSTRUCTIONS, PROHITECH 2025, VOL 1

Abstract
All over the world, there are several unoccupied spaces without adequate constant control mechanisms to reduce and prevent mold and provide good internal conditions and indoor air quality. A widespread way to reduce building humidity is through heating and dehumidification, which are costly to maintain and have high energy consumption. In addition, there are few studies on adjustable hygro ventilation systems, which do not consider the influence of temperature fluctuations. This work describes the operation of a prototype, which fills existing research gaps by considering not only the control of relative humidity (RH) but also the temperature peaks in indoor air conditions, allowing the maintenance of good air quality. The prototype Smart Hygrothermal Ventilation system uses two pairs of sensors related to RH and temperature, one pair placed inside an unoccupied compartment of the building and the other pair in the external environment, in order to activate a fan and the respective speed. The proposed prototype was applied in a compartment located on the ground floor in an unoccupied old rural building in a village near Porto during the winter period. The results show that the system performed adequately for different configurations of its functionalities. Therefore, the system offers an efficient alternative to minimize mold and the fluctuation of internal RH and temperature. Furthermore, it could be a vital mechanism for the conservation of historic buildings.

2025

Enhancing Reliability of Power Converters in Wind Farms: A Multi-Faceted Analysis of Wake Effects, Thermal Management, and Machine Learning Applications

Authors
Habib Ur Rahman Habib; Mahmoud Shahbazi;

Publication

Abstract
Abstract

This paper presents an integrated analytical approach to assess the reliability of power electronic converters in Permanent Magnet Synchronous Generator (PMSG)-based wind farms under variable wind conditions. The study focuses on analyzing the impact of wake effect turbulences and thermal management on power converter reliability, driven by the thermal stress induced by fluctuating wind speeds on power converters. Through extensive simulations using FLORIS and MATLAB, the thermal behavior of converters in wind farms affected by wake interactions was examined to identify potential reliability issues. The methodology involved modeling an 80-turbine wind farm in FLORIS to simulate wake effects, processing high-resolution wind speed data in MATLAB to refine wind speed profiles, and using Simulink to simulate the thermal profiles of power electronics. The results of FLORIS simulations highlighted the variations in turbulence intensity (TI) and power output, while the MATLAB and Simulink models quantified critical thermal stresses in power converters, correlating the locations of the turbine rows with temperature fluctuations and potential failures. Machine learning models, including Gradient Boosting and Random Forest Regressor, were utilized to refine and predict the multi-objective reliability function. The findings underscore the importance of understanding and managing thermal dynamics to improve the reliability and operational resilience of the power converter, supporting sustainable wind farm operations in dynamically changing wind conditions.

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