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Publications

2026

Deep Learning-Based Acoustic Event Detection and Classification Using Cochleogram Images

Authors
Hajihashemi, V; Ferreira, MC; Machado, JJM; Tavares, JMRS;

Publication
PROCEEDINGS OF 20TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES, CISTI 2025, VOL 4

Abstract
Acoustic Event Detection and Classification (AEDC) aims to identify and classify specific audio events within audio signals. AEDC has applications in various fields, including security systems, scene monitoring, smart hospitals, environmental monitoring, and more. The process of AEDC typically involves steps that include audio signal processing to extract relevant features from the input, a machine learning model to recognise patterns in the extracted features and a classifier to detect events. Recent research on AEDC has increasingly focused on features based on the frequency distribution of the Mel-frequency cepstral coefficients (MFCCs). In this study, the feature extraction is performed based on Cochleogram, which involves the analysis of audio signals using Gammatone filters. Cochleogram features are inspired by the human cochlea, part of the inner ear responsible for converting sound vibrations into electrical signals sent to the brain. A two-dimensional (2D) feature is extracted from the Cochleogram using Welchs spectral density estimation and then converted into a frequency spectrum. The frequency distribution of different cochleogram filter banks is then used as a one-dimensional (1D) feature. The proposed classification method uses a 1D Convolutional Neural Network (CNN), which is less complex than traditional 2D CNNs. The proposed method was evaluated using the URBAN-SED dataset, and its performance was compared against the related state-of-the-art methods. The results showed the competitiveness of the cochleogram over Mel-based features such as MFCC in AEDC if the deep learning algorithm is properly designed and trained.

2026

Integrating Local Post-Delivery Energy and Flexibility Markets under the Portuguese Self-Consumption Regulation

Authors
Mello, J; Faria, AS; Rodrigues, L; Soares, TA; Villar, J;

Publication
2026 22nd International Conference on the European Energy Market (EEM)

Abstract

2026

Evidence-Based Activism and Knowledge Co-production: A Case Study of Online Communities on Therapeutic Cannabis

Authors
Teixeira, AR; Lopes, CT;

Publication
EMERGING TRENDS IN INFORMATION SYSTEMS AND TECHNOLOGIES, WORLDCIST 2025, VOL 1

Abstract
This study examines the role of online health communities in Brazil dedicated to cannabis treatments for chronic diseases as platforms for evidence-based activism. Using a mixed-methods approach, the research combines qualitative analysis with computational techniques, including Latent Dirichlet Allocation (LDA) topic modeling, to analyze six online groups from WhatsApp and Facebook. Key themes emerging from the analysis include treatment per pathology, treatment effects, access barriers, peer support, and advocacy efforts. The findings reveal how these communities act as epistemic networks, where patients and caregivers co-produce knowledge by sharing personal experiences and engaging in dialogue with healthcare professionals. This study highlights how online health communities transform experience sharing into structured evidence, enabling collective action to address barriers such as limited access to cannabis-based treatments. It underscores the potential of digital platforms to empower patients, foster collaboration with healthcare professionals, and influence health governance.

2026

Comparative Analysis of Energy Allocation Mechanisms in Energy Communities Participating in Local Flexibility Markets

Authors
Rodrigues, L; Mello, J; Silva, R; Soares, T; Villar, J;

Publication
2026 22nd International Conference on the European Energy Market (EEM)

Abstract

2026

Enhancing Knowledge Access in Online Health Communities: A Chatbot Prototype for Cannabis Treatment Support

Authors
Teixeira, AR; Lopes, CT;

Publication
EMERGING TRENDS IN INFORMATION SYSTEMS AND TECHNOLOGIES, WORLDCIST 2025, VOL 2

Abstract
Online health communities enable patients and caregivers to share experiences, seek advice, and collaboratively generate knowledge about treatments and condition. However, accessing relevant information often proves challenging due to platform limitations like insufficient search functionalities. A previous study identified key topics discussed in Brazilian online health groups centered on cannabis treatments for chronic diseases. Building on these findings, this study introduces a proof-of-concept chatbot designed to enhance access to the collective knowledge within these communities. The chatbot prototype, built using Google Dialogflow, was tailored to provide contextually relevant, accurate, and user-friendly responses. A user study involving 38 participants evaluated its performance, showing high user satisfaction, task completion rates, and trust in the information provided. The results highlight the chatbot's potential enhance knowledge accessibility, promote patient engagement, and support evidence-based activism by organizing and disseminating community-generated content effectively.

2026

Car rental fleet and demand management: An optimization framework

Authors
Oliveira, BB;

Publication
Encyclopedia in Operations Management

Abstract
Car rental provides an essential mobility solution. The operational complexity requires efficient fleet and demand management, with significant challenges and opportunities in Operations Management. This chapter provides an overview of these issues, discussing key definitions, critical issues, recent developments, and future research directions. We focus on the car rental capacity-pricing problem under uncertainty, which integrates fleet and demand management. We explore mathematical models for this problem and discuss a co-evolutionary algorithmic framework to solve it. Current developments emphasize the need for a sustainability outlook in this business and its integration with other transportation modes. Future research should focus on advanced demand modeling, sustainable fleet management, and innovative pricing strategies, addressing the dynamic and competitive nature of the business. © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

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