2025
Authors
Cardoso, AF; Sousa, P; Oliveira, HP; Pereira, T;
Publication
2025 47TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)
Abstract
Chest CT scans are essential in diagnosing lung abnormalities, including lung cancer, but their utility in training deep learning models is often pushed back by limited data availability, high labeling costs, and privacy concerns. To address these challenges, this study explores the use of score-based diffusion models for the conditional generation of lung CT scans slices. Two generation scenarios are explored: one limited to lung segmentation masks and another incorporating both lung and nodule segmentation mappings to guide the synthesis process. The proposed methods are custom U-Net architecture models trained to predict the scores in Variance Preserving (VP) and Variance Exploding (VE) Stochastic Differential Equations (SDEs), composing the primary ground for comparison in conditional sample generation. The results demonstrate the VP SDEs model's superiority in generating high-fidelity images, as evidenced by high SSIM (0.894) and PSNR (28.6) values, as well as low domain-specific FID (173.4), MMD (0.0133) and ECS (0.78) scores. The generated images consistently followed the conditional mapping guidance during the generation process, effectively producing realistic lung and nodule structures, highlighting their potential for data augmentation in medical imaging tasks. While the models achieved notable success in generating accurate 2D lung CT scan slices given simple conditional image region mappings, future work surrounds the extension of these methods to 3D conditional generation and the use of richer conditional mappings to account for broader anatomical variations. Nevertheless, this study holds promise for improvement in computer-aided systems through the support in deep learning model training for lung disease diagnosis and classification.
2025
Authors
Ribeiro, P; Coelho, A; Campos, R;
Publication
IFIP Wireless Days
Abstract
Unmanned Aerial Vehicles (UAVs) have emerged as key enablers in Non-Terrestrial Networks (NTNs) to provide flexible wireless coverage, particularly in infrastructure-limited scenarios. In our previous work, we proposed the Sustainable multi-UAV Performance-aware Placement (SUPPLY) algorithm, a pioneering solution for the energy-efficient placement of multiple UAVs acting as Flying Access Points (FAPs). SUPPLY ensures continuous Ground User (GU) coverage while minimizing propulsion energy consumption. However, its quadratic time complexity in the GU grouping phase imposes scalability constraints, especially in large-scale and time-sensitive scenarios. In this paper, we propose eSUPPLY, a computationally efficient enhancement to SUPPLY. By increasing the step size between candidate Flying Access Point (FAP) positions during the GU grouping phase, eSUPPLY significantly reduces the size of the optimization problem. Simulation results demonstrate up to a 97% reduction in execution time, with only a marginal increase in the number of FAPs and energy consumption, enabling realtime operation in large-scale, dynamic Flying Networks (FNs). © 2025 IEEE.
2025
Authors
Nascimento, R; Gonzalez, DG; Pires, EJS; Filipe, V; Silva, MF; Rocha, LF;
Publication
IEEE ACCESS
Abstract
The increasing demand for automated quality inspection in modern industry, particularly for transparent and reflective parts, has driven significant interest in vision-based technologies. These components pose unique challenges due to their optical properties, which often hinder conventional inspection techniques. This systematic review analyzes 24 peer-reviewed studies published between 2015 and 2025, aiming to assess the current state of the art in computer vision-based inspection systems tailored to such materials. The review synthesizes recent advancements in imaging setups, illumination strategies, and deep learning-based defect detection methods. It also identifies key limitations in current approaches, particularly regarding robustness under variable industrial conditions and the lack of standardized benchmarks. By highlighting technological trends and research gaps, this work offers valuable insights and directions for future research-emphasizing the need for adaptive, scalable, and industry-ready solutions to enhance the reliability and effectiveness of inspection systems for transparent and reflective parts.
2025
Authors
Fernandes, D; Neves-Moreira, F; Amorim, P;
Publication
TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW
Abstract
Retailers offering Attended Home Delivery (AHD) struggle with thin profit margins due to high delivery costs and constrained routing flexibility. AHD requires retailers and customers to agree on specific time windows, limiting operational efficiency and increasing fleet requirements, particularly when customer preferences tend to cluster around peak times. While retailers have some ability to influence customer choices through pricing and availability strategies, failing to account for fleet costs and delivery constraints can lead to inefficient operations and reduced profitability. This study introduces an integrated approach to fleet sizing and time-window pricing for price-sensitive customers. We propose a Mixed Integer Programming (MIP) model that maximizes profit by balancing revenue and delivery costs, leveraging a nonparametric rank-based choice model to capture customer behavior while explicitly considering routing constraints and fleet ownership expenses over multiple periods. Using computational experiments on small-sized instances inspired by real-world data, we evaluate the impact of explicitly modeling routing costs, compare different pricing strategies, examine the effects of multi-period fleet planning, and assess sensitivity to varying customer and cost conditions. Results show that explicitly modeling routing constraints reduces profit loss by 29% compared to traditional cost approximations but increases computational complexity. To address this, we develop a Fix & Optimize (F&O) matheuristic approximate solution method that enables the application of our model to larger instances. Our findings emphasize the need for retailers to integrate demand management and fleet planning to optimize operational profitability.
2025
Authors
Barbosa, M; Boldyreva, A; Chen, S; Cheng, K; Esquível, L;
Publication
IACR Cryptol. ePrint Arch.
Abstract
2025
Authors
Fernandes T.B.; Sousa B.B.; Garcia J.E.; da Fonseca M.J.S.;
Publication
Evolving Strategies for Organizational Management and Performance Evaluation
Abstract
This chapter aims to understand how Esports organizations can improve digital marketing strategies, considering the unique characteristics of this sector and the importance of maintaining solid relationships with the target audience. The research was carried out using a mixed methodology, which included the application of quantitative research to evaluate the behaviors of Esports fans and a qualitative literature review to explore the trends and challenges of digital marketing in this context. The results show that the esports audience consists predominantly of young males, with a strong interest in video games, technology and pop culture. The personalization of digital strategies, focusing on platforms such as YouTube and Twitch, as well as the use of promotions and sweepstakes, proved essential for audience engagement. Although the use of influencers has a neutral perception, campaigns that offer direct benefits, such as promotions, are more attractive.
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