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Publicações

2025

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

Autores
Habib Ur Rahman Habib; Mahmoud Shahbazi;

Publicação

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.

2025

Deciphering the Silent Signals: Unveiling Frequency Importance for Wi-Fi-Based Human Pose Estimation with Explainability

Autores
Capozzi, L; Ferreira, L; Gonçalves, T; Rebelo, A; Cardoso, JS; Sequeira, AF;

Publicação
Pattern Recognition and Image Analysis - 12th Iberian Conference, IbPRIA 2025, Coimbra, Portugal, June 30 - July 3, 2025, Proceedings, Part II

Abstract
The rapid advancement of wireless technologies, particularly Wi-Fi, has spurred significant research into indoor human activity detection across various domains (e.g., healthcare, security, and industry). This work explores the non-invasive and cost-effective Wi-Fi paradigm and the application of deep learning for human activity recognition using Wi-Fi signals. Focusing on the challenges in machine interpretability, motivated by the increase in data availability and computational power, this paper uses explainable artificial intelligence to understand the inner workings of transformer-based deep neural networks designed to estimate human pose (i.e., human skeleton key points) from Wi-Fi channel state information. Using different strategies to assess the most relevant sub-carriers (i.e., rollout attention and masking attention) for the model predictions, we evaluate the performance of the model when it uses a given number of sub-carriers as input, selected randomly or by ascending (high-attention) or descending (low-attention) order. We concluded that the models trained with fewer (but relevant) sub-carriers are competitive with the baseline (trained with all sub-carriers) but better in terms of computational efficiency (i.e., processing more data per second). © 2025 Elsevier B.V., All rights reserved.

2025

Unlocking the potential of digital twins to achieve sustainability in seaports: the state of practice and future outlook

Autores
Homayouni, SM; de Sousa, JP; Marques, CM;

Publicação
WMU JOURNAL OF MARITIME AFFAIRS

Abstract
This paper examines the role of digital twins (DTs) in promoting sustainability within seaport operations and logistics. DTs have emerged as promising tools for enhancing seaport performance. Despite the recognized potential of DTs in seaports, there is a paucity of research on their practical implementation and impact on seaport sustainability. Through a systematic literature review, this study seeks to elucidate how DTs contribute to the sustainability of seaports and to identify future research and practical applications. We reviewed and categorized 68 conceptual and practical digital applications into ten core areas that effectively support economic, social, and environmental objectives in seaports. Furthermore, this paper proposes five preliminary potential applications for DTs where practical implementations are currently lacking. The primary findings indicate that DTs can enhance seaport sustainability by facilitating real-time monitoring and decision-making, improving safety and security, optimizing resource utilization, enhancing collaboration and communication, and supporting the development of the seaport ecosystem. Additionally, this study addresses the challenges associated with DT implementation, including high costs, conflicting stakeholder priorities, data quality and availability, and model validation. The paper concludes with a discussion of the implications for seaport managers and policymakers.

2025

Model Predictive Control Based Unified Power Quality Conditioner for Textile Industry Integrated Distribution Grids

Autores
Habib Ur Rahman Habib; uhammad Kashif Shahzad; Asad Waqar; Saeed Mian Qaisar; rooj Mubashara Siddiqui;

Publicação

Abstract
Abstract

Power quality (PQ) issues, including weak grids, voltage transients, harmonics, notches, current imbalance, and voltage sags, are critical challenges in the textile industry. Even a brief power interruption can halt industrial processes, leading to substantial financial losses. This paper proposes a Model Predictive Control (MPC)-based Unified Power Quality Conditioner (UPQC) as a robust solution to mitigate these PQ disturbances in textile industry-integrated distribution grids. The proposed UPQC is designed to enhance voltage stability, suppress harmonics, regulate reactive power, and correct current imbalance, ensuring uninterrupted industrial operation. A key contribution of this work is the realistic modeling of a textile industry’s electrical network, replicating actual industry ratings to evaluate system performance. The proposed MPC-based UPQC is assessed through five case studies, addressing weak vs. strong grids, voltage transients, current imbalance, and voltage sags—the most significant PQ challenges in textile applications. Simulation results demonstrate that the UPQC significantly improves voltage profiles, reduces harmonic distortion, and effectively compensates for current imbalance. Compared to conventional Proportional-Integral (PI) controllers, the MPC-based UPQC exhibits superior performance in dynamic PQ disturbance mitigation and grid stabilization. These findings underscore the proposed system’s suitability for large-scale industrial deployment, offering a cost-effective and robust solution to enhance operational efficiency and grid reliability in the textile sector.

2025

Enhancing Recruitment with LLMs and Chatbots

Autores
Novais, L; Rocio, V; Morais, J;

Publicação
DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE, SPECIAL SESSIONS II, 21ST INTERNATIONAL CONFERENCE

Abstract
Traditional approaches in the competitive recruitment landscape frequently encounter difficulties in effectively identifying exceptional applicants, resulting in delays, increased expenses, and biases. This study proposes the utilisation of contemporary technologies such as Large Language Models (LLMs) and chatbots to automate the process of resume screening, thereby diminishing prejudices and enhancing communication between recruiters and candidates. Algorithms based on LLM can greatly transform the process of screening by improving both its speed and accuracy. By integrating chatbots, it becomes possible to have personalised interactions with candidates and streamline the process of scheduling interviews. This strategy accelerates the hiring process while maintaining principles of justice and ethics. Its objective is to improve algorithms and procedures to meet changing requirements and enhance the competitive advantage of talent acquisition within organisations.

2025

Comparative analysis of EU-based cybersecurity skills frameworks

Autores
Almeida, F;

Publicação
Computers & Security

Abstract

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