2025
Autores
de Castro, R; Araujo, RE; Brembeck, J;
Publicação
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
Abstract
This work focuses on designing nonlinear control algorithms for dual half-bridge converters (DHBs). We propose a two-layer controller to regulate the current and voltage of the DHB. The first layer utilizes a change in the control variable to obtain a quasi-linear representation of the DHB, allowing for the application of simple linear controllers to regulate current and power flow. The second layer employs a nonlinear control allocation algorithm to select control actions that fulfill (pseudo) power setpoints specified by the first control layer; it also minimizes peak-to-peak currents in the DHB and enforces voltage balance constraints. We apply the DHB and this new control strategy to manage power flow in a hybrid energy storage system comprising of a battery and supercapacitors. Numerical simulation results demonstrate that, in comparison with state-of-the-art approaches, our control algorithm is capable of maintaining good transient behavior over a wide operating range, while reducing peak-to-peak current by up to 80%.
2025
Autores
Palumbo, G; Carneiro, D; Alves, V;
Publicação
INTERNATIONAL JOURNAL OF DATA SCIENCE AND ANALYTICS
Abstract
The field of AI Ethics has recently gained considerable attention, yet much of the existing academic research lacks practical and objective contributions for the development of ethical AI systems. This systematic literature review aims to identify and map objective metrics documented in literature between January 2018 and June 2023, specifically focusing on the ethical principles outlined in the Ethics Guidelines for Trustworthy AI. The review was based on 66 articles retrieved from the Scopus and World of Science databases. The articles were categorized based on their alignment with seven ethical principles: Human Agency and Oversight, Technical Robustness and Safety, Privacy and Data Governance, Transparency, Diversity, Non-Discrimination and Fairness, Societal and Environmental Well-being, and Accountability. Of the identified articles, only a minority presented objective metrics to assess AI ethics, with the majority being purely theoretical works. Moreover, existing metrics are primarily concentrating on Diversity, Non-Discrimination and Fairness, with a clear under-representation of the remaining principles. This lack of practical contributions makes it difficult for Data Scientists to devise systems that can be deemed Ethical, or to monitor the alignment of existing systems with current guidelines and legislation. With this work, we lay out the current panorama concerning objective metrics to quantify AI Ethics in Data Science and highlight the areas in which future developments are needed to align Data Science projects with the human values widely posited in the literature.
2025
Autores
Felgueiras, F; Mourao, Z; Moreira, A; Gabriel, MF;
Publicação
BUILDING AND ENVIRONMENT
Abstract
It is widely recognized that the well-being, health, and productivity of office workers can be influenced by indoor environmental quality (IEQ) conditions in the workplace. This study aimed to investigate associations between multi-domain IEQ in offices and workers' well-being, health, productivity, and perceived IEQ in 30 open office spaces (6 buildings) located in the urban area of Porto, Portugal. This cross-sectional study included 277 office workers and used a combination of methods to assess their perceptions and physiological responses. Data were collected through questionnaires (covering self-reported well-being, health, productivity, and IEQ satisfaction), pupillometry (autonomic nervous system activity), and concurrent monitoring of IEQ. Correlation, comparative, and regression methods were used to explore associations and differences between IEQ indicators and participants' outcomes. The findings showed that offices typically met acceptable IEQ standards. However, a higher prevalence of health problems and symptoms was observed in offices with higher levels of carbon dioxide (CO2), ozone (O3), particulate matter (PM10), and ultrafine particles (UFP). Interestingly, offices with higher COQ, PM2.5, and volatile organic compounds concentrations were linked to a reduced likelihood of participants reporting asthma, dry cough, and allergies. Additionally, thermal discomfort due to high temperatures, increased PM2.5, UFP, CO2, and O3, and low illuminance appear to reduce eye response in office workers. Higher CO2 and noise levels, and temperatures outside the comfortable range, were linked to lower productivity. The multi-domain analysis showed that perception of multiple IEQ factors significantly explained both self-reported productivity and overall satisfaction with work environment. Overall, ensuring proper IEQ and enhancing workers' satisfaction are essential for creating healthy and productive workplaces.
2025
Autores
António Correia; Tommi Kärkkäinen; Shoaib Jameel; Daniel Schneider; Pedro Antunes; Benjamim Fonseca; Andrea Grover;
Publicação
Lecture notes in networks and systems
Abstract
2025
Autores
Cunha, LF; Guimarães, N; Mendes, A; Campos, R; Jorge, A;
Publicação
ECIR (5)
Abstract
In healthcare, diagnoses usually rely on physician expertise. However, complex cases may benefit from consulting similar past clinical reports cases. In this paper, we present MedLink (http://medlink.inesctec.pt), a tool that given a free-text medical report, retrieves and ranks relevant clinical case reports published in health conferences and journals, aiming to support clinical decision-making, particularly in challenging or complex diagnoses. To this regard, we trained two BERT models on the sentence similarity task: a bi-encoder for retrieval and a cross-encoder for reranking. To evaluate our approach, we used 10 medical reports and asked a physician to rank the top 10 most relevant published case reports for each one. Our results show that MedLink’s ranking model achieved NDCG@10 of 0.747. Our demo also includes the visualization of clinical entities (using a NER model) and the production of a textual explanation (using a LLM) to ease comparison and contrasting between reports.
2025
Autores
Graca, A; Alves, JC; Ferreira, M;
Publicação
Oceans Conference Record (IEEE)
Abstract
Conventional localization systems typically rely on fixed transmission parameters and signal types, limiting their effectiveness in variable and dynamic underwater environments. The present work investigates the potential of adaptable transmission strategies to enhance signal detection estimation for localization purposes. Two widely used signal types, Linear Frequency Modulated (LFM) chirps and BPSK-modulated Msequences, are selected due to their strong autocorrelation properties and robustness to noise. A matched-filter detection approach based on peak correlation is implemented and evaluated. The analysis examines the impact of varying transmission parameters, namely transmission power and signal duration, on detection performance, which inherently influences time-based localization. Results demonstrate that reconfiguring signal parameters significantly reduces estimation dispersion. Moreover, the optimal signal type is shown to depend on the acoustic scenario, with no single waveform consistently outperforming the other. These findings highlight the value of reconfigurable acoustic systems capable of adapting acoustic systems characteristics based on environmental or system feedback, thereby improving localization performance in navigation tasks and dynamic underwater conditions. © 2025 Marine Technology Society.
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