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Publicações

2024

Quality assessment of Low-cost retinal Videos for Glaucoma screening

Autores
Abay, SG; Lima, F; Geurts, L; Camara, J; Pedrosa, J; Cunha, A;

Publicação
Procedia Computer Science

Abstract
Low-cost smartphone-compatible portable ophthalmoscopes can capture visuals of the patient's retina to screen several ophthalmological diseases like glaucoma. The images captured have lower quality and resolution than standard retinography devices but enough for glaucoma screening. Small videos are captured to improve the chance of inspecting the eye properly; however, those videos may not always have enough quality for screening glaucoma, and the patient needs to repeat the inspection later. In this paper, a method for automatic assessment of the quality of videos captured using the D-Eye lens is proposed and evaluated with a personal dataset with 539 videos. Based on two methods developed for retina localization on the images/frames, the Circle Hough Transform method with a precision of 78,12% and the YOLOv7 method with a precision of 99,78%, the quality assessment method automatically decides on the quality of the video by measuring the number of frames of good-quality in each video, according to the chosen threshold. © 2024 Elsevier B.V.. All rights reserved.

2024

Enhancing robustness to forecast errors in availability control for airline revenue management

Autores
Gonçalves, T; Almada Lobo, B;

Publicação
Journal of Revenue and Pricing Management

Abstract
Traditional revenue management systems are built under the assumption of independent demand per fare. The fare adjustment theory is a methodology to adjust fares that allows for the continued use of optimization algorithms and seat inventory control methods, even with the shift toward dependent demand. Since accurate demand forecasts are a key input to this methodology, it is reasonable to assume that for a scenario with uncertainties it may deliver suboptimal performance. Particularly, during and after COVID-19, airlines faced striking challenges in demand forecasting. This study demonstrates, firstly, the theoretical dominance of the fare adjustment theory under perfect conditions. Secondly, it lacks robustness to forecast errors. A Monte Carlo simulation replicating a revenue management system under mild assumptions indicates that a forecast error of ±20% can potentially prompt a necessity to adjust the margin employed in the fare adjustment theory by -10%. Moreover, a tree-based machine learning model highlights the forecast error as the predominant factor, with bias playing an even more pivotal role than variance. An out-of-sample study indicates that the predictive model steadily outperforms the fare adjustment theory. © The Author(s), under exclusive licence to Springer Nature Limited 2024.

2024

Smart Factories - design and results of a new course in a MSc curriculum of engineering

Autores
Azevedo, A; Almeida, AH;

Publicação
2024 IEEE GLOBAL ENGINEERING EDUCATION CONFERENCE, EDUCON 2024

Abstract
In the Fourth Industrial Revolution era, commonly known as Industry 4.0, the manufacturing industry is undergoing a profound transformation driven by the convergence of technological advancements. Industry 4.0 technologies are revolutionising how products are manufactured, from design to production to delivery. These technologies, such as collaborative robotics, digital twins, IoT, and data analytics, enable manufacturers to improve efficiency, productivity, and quality. As Industry 4.0 continues to evolve, the demand for skilled engineers who can effectively design, implement, and manage these sophisticated systems is growing rapidly. Future mechanical engineers must be prepared to navigate this complex and data-driven manufacturing landscape. To address this need, the Faculty of Engineering at the University of Porto developed a new course titled Smart Factories, specifically designed to equip master's students with the knowledge and skills necessary to thrive in the factories of the future. This course utilises an innovative, active experimental learning methodology with industry collaborations and a comprehensive curriculum to foster the development of the multidisciplinary skills necessary to excel in this rapidly evolving field. Through this comprehensive and innovative approach, the Smart Factories course aims to prepare future mechanical engineers to become leaders in smart manufacturing, driving innovation and shaping future factories.

2024

Traffic and Obstacle-Aware UAV Positioning in Urban Environments Using Reinforcement Learning

Autores
Shafafi, K; Ricardo, M; Campos, R;

Publicação
IEEE ACCESS

Abstract
Unmanned Aerial Vehicles (UAVs) are suited as cost-effective and adaptable platforms for carrying Wi-Fi Access Points (APs) and cellular Base Stations (BSs). Implementing aerial networks in disaster management scenarios and crowded areas can effectively enhance Quality of Service (QoS). Maintaining Line-of-Sight (LoS) in such environments, especially at higher frequencies, is crucial for ensuring reliable communication networks with high capacity, particularly in environments with obstacles. The main contribution of this paper is a traffic- and obstacle-aware UAV positioning algorithm named Reinforcement Learning-based Traffic and Obstacle-aware Positioning Algorithm (RLTOPA), for such environments. RLTOPA determines the optimal position of the UAV by considering the positions of ground users, the coordinates of obstacles, and the traffic demands of users. This positioning aims to maximize QoS in terms of throughput by ensuring optimal LoS between ground users and the UAV. The network performance of the proposed solution, characterized in terms of mean delay and throughput, was evaluated using the ns-3 simulator. The results show up to 95% improvement in aggregate throughput and 71% in delay without compromising fairness.

2024

Utility Function for Assessing the Cost of Recovering from Ransomware Attacks

Autores
Pinto, L; Pinto, P; Pinto, A;

Publicação
OPTIMIZATION, LEARNING ALGORITHMS AND APPLICATIONS, OL2A 2024, PT II

Abstract
Nowadays ransomware attacks have become one of the main problems organizations face. The threat of ransomware attacks, with their capacity to paralyze entire organizations, creates the need to develop a ransomware recovery utility function to help further prepare for the impact of such attacks and enhance the organization's knowledge and perception of risk. This work proposes a ransomware recovery utility function that aims to estimate the impact of a ransomware attack measured in manpower hours till recovery and taking into account different devices and different scenarios.

2024

Inclusivity Play

Autores
Giesteira, B; Peçaibes, V; Cardoso, P; Maior, GV; Quaresma, I;

Publicação
Advances in Educational Marketing, Administration, and Leadership - Exploring Educational Equity at the Intersection of Policy and Practice

Abstract
“Portal for sharing teaching experience in the inclusion of diversity” corresponds to axis 4.2. of the project Skills for the Next Generation of the University of Porto by supporting the development of innovative and inclusive pedagogical resources, sharing information, experience about inclusivity and ludic tools to cope with the individual differences integrated with the university's information system. This project is intended to contribute to the achievement of the inclusive priorities defined at the European level through a web platform capable of deliverable informative content and gamified resources (serious and critical games) to give adequate support for the university academy, not only to cope with the difference but to take advantage of it, dealing with human differences and specificities as an asset to the community, unlike shortcomings.

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