2025
Authors
Sousa, PA; Faria, N; Pereira, J; Alonso, AN;
Publication
2025 20TH EUROPEAN DEPENDABLE COMPUTING CONFERENCE, EDCC
Abstract
Data intensive applications increasingly make use of multiple data stores in the cloud, providing a diversity of data and query models, as well as durability and scale trade-offs. However, this has a severe impact on reliability, as the key fault-tolerance mechanism for database systems, i.e. ACID transactions, is no longer available. Although it is possible to implement transactions without changes to the database servers, this either requires a proxy server, which compromises scale and availability, or a client-side layer that changes the data schema, excludes legacy applications, and adds significant overhead. We address this challenge with a proposal to delegate functionality from a client-side transactional layer to a server-side query engine such that compatibility with legacy applications is restored. We implemented a proof-of-concept and show that it significantly improves performance for analytical applications.
2025
Authors
Swacha, J; Muszynska, K; Font Fernández, JM; Kocadere, SA; Queirós, R; Damasevicius, R; Maskeliunas, R;
Publication
AIED Companion (1)
Abstract
Artificial Intelligence (AI), in particular Generative Artificial Intelligence (GenAI), is a quickly developing field capable of revolutionizing educational digital escape rooms. Traditionally reliant on static content, these immersive environments have faced limitations in adaptability, replayability, and personalization. However, recent advancements in AI and GenAI enable dynamic puzzle generation, adaptive storytelling, and AI-driven non-player characters (NPCs) with agentic AI, allowing for highly responsive and personalized experiences. This paper reviews the state-of-the-art in integrating AI (with the focus on GenAI) into educational digital escape rooms, integrating interdisciplinary insights from cognitive science, game design, and machine learning, and showing how AI can improve engagement, scalability, and content diversity, but also indicates challenges related to ethical AI use, bias in algorithmic decision-making, and the need for robust evaluation frameworks to assess player satisfaction and learning outcomes.
2025
Authors
Pereira, R; Lima, C; Pinto, T; Barroso, J; Reis, A;
Publication
DEVELOPMENTS AND ADVANCES IN DEFENSE AND SECURITY, MICRADS 2024
Abstract
The Industry 4.0 paradigm (I4.0) supports the improvement of industrial processes through Information and Communication Technologies (ICT), with information systems providing real-time information to humans and machines, in order to make the production process more flexible and efficient. In this context, Virtual Assistants (VA) collect and process production data and provide contextualized and real-time information to the workers in the production environment. This paper presents a prototype of a VA developed to collect production data from heterogeneous sources in the factory, process them based on contextual information, and provide workers with useful information to assist them in taking informed decisions. In that context, VA can represent a valuable aid to improve overall productivity and efficiency in the I4.0 factories.
2025
Authors
Da Silva, EM; Schneider, D; Miceli, C; Correia, A;
Publication
Informatics
Abstract
2025
Authors
Vasconcelos, M; Cavique, L;
Publication
EXPERT SYSTEMS WITH APPLICATIONS
Abstract
Imbalanced datasets present a challenge in machine learning, especially in binary classification scenarios where one class significantly outweighs the other. This imbalance often leads to models favoring the majority class, resulting in inadequate predictions for the minority class, specifically in false negatives. In response to this issue, this work introduces the MinFNR ensemble algorithm, designed to minimize False Negative Rates (FNR) in imbalanced datasets. The new approach strategically combines data-level, algorithmic-level, and hybrid-level approaches to enhance overall predictive capabilities while minimizing computational resources using the Set Covering Problem (SCP) formulation. Through a comprehensive evaluation of diverse datasets, MinFNR consistently outperforms individual algorithms, showing its potential for applications where the cost of false negatives is substantial, such as fraud detection and medical diagnosis. This work also contributes to ongoing efforts to improve the reliability and effectiveness of machine learning algorithms in real imbalanced scenarios.
2025
Authors
Imperadeiro, J; Alonso, AN; Pereira, J;
Publication
2025 55TH ANNUAL IEEE/IFIP INTERNATIONAL CONFERENCE ON DEPENDABLE SYSTEMS AND NETWORKS-SUPPLEMENTAL VOLUME, DSN-S
Abstract
Diversity is crucial in systems that tolerate Byzantine faults. Traditionally, system builders have relied on standardized interfaces (e.g., POSIX for operating systems) to obtain off-the-shelf components or on n-version programming for custom functionality. Unfortunately, standardized alternatives are rare, and the independent development of multiple versions of the same software is costly and justified only on the most critical applications. In this paper, we show that a limited and focused use of LLMs for translation opens up the possibility of leveraging the existing diversity in functionally equivalent but non-standardized components. Specifically, we show that LLMs can produce functionally correct database query translations with minimal guidance and adapt to diverse data models and query contexts, enabling the use of radically different database models, both SQL and NoSQL, together in a Byzantine fault-tolerant replicated system. We outline an approach to achieve this in practice and discuss future research directions.
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