2025
Autores
Ghorvei, M; Karhu, T; Hietakoste, S; Ferreira Santos, D; Hrubos Strom, H; Islind, AS; Biedebach, L; Nikkonen, S; Leppaenen, T; Rusanen, M;
Publicação
JOURNAL OF SLEEP RESEARCH
Abstract
Obstructive sleep apnea is a heterogeneous sleep disorder with varying phenotypes. Several studies have already performed cluster analyses to discover various obstructive sleep apnea phenotypic clusters. However, the selection of the clustering method might affect the outputs. Consequently, it is unclear whether similar obstructive sleep apnea clusters can be reproduced using different clustering methods. In this study, we applied four well-known clustering methods: Agglomerative Hierarchical Clustering; K-means; Fuzzy C-means; and Gaussian Mixture Model to a population of 865 suspected obstructive sleep apnea patients. By creating five clusters with each method, we examined the effect of clustering methods on forming obstructive sleep apnea clusters and the differences in their physiological characteristics. We utilized a visualization technique to indicate the cluster formations, Cohen's kappa statistics to find the similarity and agreement between clustering methods, and performance evaluation to compare the clustering performance. As a result, two out of five clusters were distinctly different with all four methods, while three other clusters exhibited overlapping features across all methods. In terms of agreement, Fuzzy C-means and K-means had the strongest (kappa = 0.87), and Agglomerative hierarchical clustering and Gaussian Mixture Model had the weakest agreement (kappa = 0.51) between each other. The K-means showed the best clustering performance, followed by the Fuzzy C-means in most evaluation criteria. Moreover, Fuzzy C-means showed the greatest potential in handling overlapping clusters compared with other methods. In conclusion, we revealed a direct impact of clustering method selection on the formation and physiological characteristics of obstructive sleep apnea clusters. In addition, we highlighted the capability of soft clustering methods, particularly Fuzzy C-means, in the application of obstructive sleep apnea phenotyping.
2025
Autores
Aline dos Santos Silva; Miguel Velhote Correia; Andreia Gonçalves da Costa; Hugo Plácido da Silva;
Publicação
2025 IEEE 8th Portuguese Meeting on Bioengineering (ENBENG)
Abstract
2025
Autores
Teixeira, FB; Ricardo, M; Coelho, A; Oliveira, HP; Viana, P; Paulino, N; Fontes, H; Marques, P; Campos, R; Pessoa, L;
Publicação
EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING
Abstract
Telecommunications and computer vision solutions have evolved significantly in recent years, allowing a huge advance in the functionalities and applications offered. However, these two fields have been making their way as separate areas, not exploring the potential benefits of merging the innovations brought from each of them. In challenging environments, for example, combining radio sensing and computer vision can strongly contribute to solving problems such as those introduced by obstructions or limited lighting. Machine learning algorithms, able to fuse heterogeneous and multi-modal data, are also a key element for understanding and inferring additional knowledge from raw and low-level data, able to create a new abstracting level that can significantly enhance many applications. This paper introduces the CONVERGE vision-radio concept, a new paradigm that explores the benefits of integrating two fields of knowledge towards the vision of View-to-Communicate, Communicate-to-View. The main concepts behind this vision, including supporting use cases and the proposed architecture, are presented. CONVERGE introduces a set of tools integrating wireless communications and computer vision to create a novel experimental infrastructure that will provide open datasets to the scientific community of both experimental and simulated data, enabling new research addressing various 6 G verticals, including telecommunications, automotive, manufacturing, media, and health.
2025
Autores
Dias, JT; Santos, A; Mamede, HS;
Publicação
AI and Learning Analytics in Distance Learning
Abstract
This chapter examines how Artificial Intelligence (AI) and Learning Analytics (LA) are transformingdistanceeducation, accelerated by the COVID-19 shift toe-learning. By using data from Learning Management Systems (LMS), these technologies can personalize learning, improve student retention, and automate tasks. AI, particularly machine learning, enables dynamic adaptation to student needs, while LA provides valuable insights for informed instructional decisions. However, ethical concerns, including data privacy and algorithmic bias, must be addressed to ensure equitable access and fair learning outcomes. The future of distance learning lies in responsible integration of AI and LA, creating immersive and inclusive educational experiences. © 2025 by IGI Global Scientific Publishing. All rights reserved.
2025
Autores
Madeira, A; Oliveira, JN; Proença, J; Neves, R;
Publicação
JOURNAL OF LOGICAL AND ALGEBRAIC METHODS IN PROGRAMMING
Abstract
[No abstract available]
2025
Autores
Aline dos Santos Silva; Miguel Velhote Correia; Andreia Gonçalves da Costa; Hugo Plácido da Silva;
Publicação
2025 IEEE 8th Portuguese Meeting on Bioengineering (ENBENG)
Abstract
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.