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Publicações

2025

GASTeNv2: Generative Adversarial Stress Testing Networks with Gaussian Loss

Autores
Teixeira, C; Gomes, I; Cunha, L; Soares, C; van Rijn, JN;

Publicação
PROGRESS IN ARTIFICIAL INTELLIGENCE, EPIA 2024, PT II

Abstract
As machine learning technologies are increasingly adopted, the demand for responsible AI practices to ensure transparency and accountability grows. To better understand the decision-making processes of machine learning models, GASTeN was developed to generate realistic yet ambiguous synthetic data near a classifier's decision boundary. However, the results were inconsistent, with few images in the low-confidence region and noise. Therefore, we propose a new GASTeN version with a modified architecture and a novel loss function. This new loss function incorporates a multi-objective measure with a Gaussian loss centered on the classifier probability, targeting the decision boundary. Our study found that while the original GASTeN architecture yields the highest Frechet Inception Distance (FID) scores, the updated version achieves lower Average Confusion Distance (ACD) values and consistent performance across low-confidence regions. Both architectures produce realistic and ambiguous images, but the updated one is more reliable, with no instances of GAN mode collapse. Additionally, the introduction of the Gaussian loss enhanced this architecture by allowing for adjustable tolerance in image generation around the decision boundary.

2025

Beyond the Hands: Evaluating the Usability of Hands-Free Methods and Controllers for Menu Selection During an Immersive VR Experience

Autores
Monteiro, P; Peixoto, B; Gonçalves, G; Coelho, H; Barbosa, L; Melo, M; Bessa, M;

Publicação
INTERNATIONAL JOURNAL OF HUMAN-COMPUTER INTERACTION

Abstract
Handheld controllers are standard in immersive virtual reality (iVR), but the rise of natural hand-based interactions exposes the limitations of hand gestures, especially for point-and-click tasks with graphical user interfaces (GUI). This shows the need to explore alternative hands-free selection methods. Unlike most studies focusing on the selection task itself, this work evaluates the impact of such methods on multiple dimensions when selections occur alongside another primary task. The tested methods were: head gaze + dwell, leaning, and voice; eye gaze + dwell, leaning, blinking, and voice; and voice-only. Controllers served as the baseline. Methods were further analyzed by pointing and confirming mechanisms. Four dimensions were analyzed: (1) iVR experience, (2) user satisfaction, (3) usability, and (4) efficiency and effectiveness. With 72 participants, results show hands-free methods provide comparable experiences to controllers, suggesting selection methods have a lower impact on the user experience when users focus on a primary task.

2025

Motivating Safe Street Crossings – An EPS@ISEP 2024 Project

Autores
Högkvist, C; Haack, F; de Vries, J; Durnwalder, M; Geirnaert, M; Cordier, S; Duarte, J; Malheiro, B; Ribeiro, C; Justo, J; Silva, F; Ferreira, P; Guedes, P;

Publicação
Lecture Notes in Educational Technology

Abstract
Pedestrian safety is a pressing subject in urban areas. The disorderly sharing of streets and roads between pedestrians and vehicles leads to potentially serious accidents for pedestrians. This student project aims to tackle the issue by placing an interactive gaming device at traffic lights. SMASHY by Stempe Safety offers pedestrians an amusing and active way to discourage jaywalking. The multipurpose solution features a smashing game with buttons on one side and a screen displaying useful information on the other side. While the traffic light remains red for pedestrians, the module buttons light up and the players can start smashing the buttons as fast as possible, until the light turns green and consequently, the game ends. Ultimately, the modules are connected to an app where, if desired by the player, scores can be tracked and difficulty can vary based on user performance. Multiple modules can be placed around the city and the app will track player scores by location. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

2025

Implementation of an Internet of Things Architecture to Monitor Indoor Air Quality: A Case Study During Sleep Periods

Autores
Mota, A; Serôdio, C; Briga-Sá, A; Valente, A;

Publicação
SENSORS

Abstract
Most human time is spent indoors, and due to the pandemic, monitoring indoor air quality (IAQ) has become more crucial. In this study, an IoT (Internet of Things) architecture is implemented to monitor IAQ parameters, including CO2 and particulate matter (PM). An ESP32-C6-based device is developed to measure sensor data and send them, using the MQTT protocol, to a remote InfluxDBv2 database instance, where the data are stored and visualized. The Python 3.11 scripting programming language is used to automate Flux queries to the database, allowing a more in-depth data interpretation. The implemented system allows to analyze two measured scenarios during sleep: one with the door slightly open and one with the door closed. Results indicate that sleeping with the door slightly open causes CO2 levels to ascend slowly and maintain lower concentrations compared to sleeping with the door closed, where CO2 levels ascend faster and the maximum recommended values are exceeded. This demonstrates the benefits of ventilation in maintaining IAQ. The developed system can be used for sensing in different environments, such as schools or offices, so an IAQ assessment can be made. Based on the generated data, predictive models can be designed to support decisions on intelligent natural ventilation systems, achieving an optimized, efficient, and ubiquitous solution to moderate the IAQ.

2025

Function-Oriented Programming Attacks on ARM Cortex-M Processors

Autores
Cirne, A; Sousa, PR; Antunes, L; Resende, JS;

Publicação
IEEE ACCESS

Abstract
In recent years, code-reuse attacks have been used to exploit software vulnerabilities and gain control of numerous software programs and embedded devices. Several measures have been put in place to prevent this type of attack, such as Control-Flow Integrity (CFI) systems, and some of these systems have already been integrated into hardware. Nevertheless, Function-Oriented Programming (FOP) attacks, a form of code-reuse that chains functions to carry out malicious actions, continue to persist. In this work, we present the first analysis of the implications and feasibility of FOP attacks on microcontrollers, focusing on ARM Cortex-M processors that support PACBTI, that is, a hardware feature designed for CFI system implementation. During this process, we identified multiple dispatch gadgets in two common Real-time Operating System (RTOS). Since these gadgets reside within core OS functionalities, they are inherently included in a broad range of embedded operating systems. Furthermore, we also present CortexMFopper - a tool specially built to identify FOP gadgets in embedded devices and to raise awareness of this technique.

2025

Growing Mushrooms on Coffee Grounds - An EPS@ISEP 2024 Project

Autores
Stapel, N; Lupu, R; Kötting, N; Heller, M; Sorribas, V; Boulay, H; Duarte, J; Malheiro, B; Ribeiro, C; Justo, J; Silva, F; Ferreira, P; Guedes, P;

Publicação
Lecture Notes in Educational Technology

Abstract
CoffeeMush is an innovative and sustainable project developed as part of the European Project Semester (EPS) at ISEP in 2024. This student project aims to tackle waste management environmental problems by turning coffee waste into mushrooms, a valuable food source. CoffeeMush consists of a smart device providing optimal conditions for mushroom cultivation, complemented by a user-friendly Android application for remote monitoring and control. The design was guided by ethical, sustainability, market and technical considerations. The paper describes the theoretical background of the project, the technical design, and the prototype development and testing. The results show the feasibility of CoffeeMush as a practical and environmentally friendly solution for urban mushroom cultivation, and its impact on sustainable food production and waste reduction. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

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