2026
Authors
Figueiredo, A; Figueiredo, F;
Publication
JOURNAL OF APPLIED STATISTICS
Abstract
When directional data fall in the positive orthant of the unit hypersphere, a folded directional distribution is preferred over a simple directional distribution for modeling the data. Since directional data, especially axial data, can be modeled using a Watson distribution, this paper considers a folded Watson distribution for such cases. We first address the parameter estimation of this distribution using maximum likelihood, which requires a numerical algorithm to solve the likelihood equations. We use the Expectation-Maximization (EM) algorithm to obtain these estimates and to analyze the properties of the concentration estimator through simulation. Next, we propose the Bayes rule for a folded Watson distribution and evaluate its performance through simulation in various scenarios, comparing it with the Bayes rule for the Watson distribution. Finally, we present examples using both simulated and real data available in the literature.
2026
Authors
Almeida, F; Buzady, Z;
Publication
JOURNAL OF INTERNATIONAL EDUCATION IN BUSINESS
Abstract
PurposeThis study aims to examine the use of the serious game FLIGBY to recognize and enhance conflict management skills in international business education. It explores how the game's realistic scenarios and embedded conflict resolution frameworks (i.e. Thomas-Kilmann Instrument, Interest-Based Relational approach and Harvard Negotiation Principles) support the development of key competencies through experiential, gamified learning.Design/methodology/approachThis study analyzes data from 16,597 FLIGBY players using multiple regression models to examine how the game facilitates the recognition of conflict situations and the application of resolution strategies. The risk-free, simulated environment of FLIGBY provides a controlled setting to assess players' conflict management competencies.FindingsThe findings demonstrate that serious games like FLIGBY not only enhance students' understanding of conflict management theories but also actively support the development of practical skills and self-awareness. Players are challenged to analyze interpersonal dynamics, make strategic decisions and reflect on the outcomes of their actions, fostering the development of conflict management skills.Originality/valueThe inclusion of FLIGBY in a business education program has the potential to facilitate experiential learning in conflict management, which is a key topic in international business. Furthermore, it offers data-driven insights into how individuals and teams approach conflict resolutions which may be relevant to refine theoretical models based on gameplay analytics.
2026
Authors
Rodrigues, L; Terra, F; Rodrigues, P; Moura, P; Santos, FNd; Cunha, M;
Publication
Abstract
2026
Authors
Rocha, B; Figueira, A;
Publication
SOCIAL NETWORKS ANALYSIS AND MINING, ASONAM 2025, PT III
Abstract
In the competitive landscape of higher education, institutions increasingly rely on international rankings to secure funding, attract talent, and enhance their global reputation. Concurrently, these institutions have expanded their presence on social media, utilizing sophisticated posting strategies not only to disseminate information but also to boost recognition and engagement. This study examines the relationship between the rankings of Higher Education Institutions (HEIs) and their social media posting strategies. We collected and analyzed tweets from 22 HEIs featured in a consolidated ranking system, focusing on various features of their social media posts. The analysis identified six distinct clusters of posting strategies. This paper categorizes the HEIs into these clusters and discusses the implications of differing social media strategies on their rankings The findings suggest a nuanced interaction between social media engagement and the perceived prestige of HEIs.
2026
Authors
Almeida, F; Okon, E;
Publication
Sustainable Development
Abstract
2026
Authors
Nogueira, M; Gomes, EF;
Publication
SN Comput. Sci.
Abstract
Data leakage is a critical issue in deep learning inflating performance and compromise validity, especially in sensitive areas like medical imaging. This study systematically evaluates two common leakage types in oral squamous cell carcinoma classification from histopathology images: (1) preprocessing leakage (global normalization before dataset splitting) and (2) a severe sample-related (patient-related) contamination scenario created by mixing closely related original and augmented images across splits. We trained 11 CNN and Transformer-based models on a public oral cancer histopathology dataset, benchmarking results against published leakage-free baselines. The results obtained show that the configuration with random splitting of original and augmented images (Scenario 2) artificially increased accuracy by up to 18% (mean +14.3%) compared to leakage-free conditions, while the preprocessing-based leakage (Scenario 1) showed smaller deviations (+1.8%). These inflated metrics arise from a combination of cross-split contamination between closely related samples and increased dataset redundancy, rather than genuine gains in generalization ability. Transformers improved leak-free accuracy (+3.9%) but degraded performance in Scenario 2 (-1.4%), revealing sensitivity to sample-specific biases. The observed performance gains under data leakage conditions are methodological artifacts that undermine clinical reliability, with a severe sample-related contamination scenario (Scenario 2) with random splitting of original and augmented images being particularly detrimental due to its promotion of non-generalizable feature learning. The quantitative benchmarks established here-including a mean accuracy gap of 12.5% (Scenario 2 vs. Scenario 1) across 11 models and Transformer architectures’ sensitivity to contamination-reveal fundamental tradeoffs between metric inflation and model trustworthiness. These findings establish quantitative benchmarks for leakage impacts in medical imaging and inform future guidelines for trustworthy AI development in pathology. © The Author(s) 2026.
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.