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Publications

Publications by LIAAD

2025

Study the Capacity of Deep Learning Techniques Information Generalization Using Capsule Endoscopic Images

Authors
Macedo, E; Araujo, H; Abreu, PH;

Publication
PATTERN RECOGNITION: ICPR 2024 INTERNATIONAL WORKSHOPS AND CHALLENGES, PT V

Abstract
Capsule endoscopy has emerged as a non-invasive alternative to traditional gastrointestinal inspection procedures, such as endoscopy and colonoscopy. Removing sedation risks, it is a patient-friendly and hospital-free procedure, which allows small bowel assessment, region not easily accessible by traditional methods. Recently, deep learning techniques have been employed to analyse capsule endoscopy images, with a focus on lesion classification and/or capsule location along the gastrointestinal tract. This research work presents a novel approach for testing the generalization capacity of deep learning techniques in the lesion location identification process using capsule endoscopy images. To achieve that, AlexNet, InceptionV3 and ResNet-152 architectures were trained exclusively in normal frames and later tested in lesion frames. Frames were sourced from KID and Kvasir-Capsule open-source datasets. Both RGB and grayscale representations were evaluated, and experiments with complete images and patches were made. Results show that the generalization capacity on lesion location of models is not so strong as their capacity for normal frame location, with colon being the most difficult organ to identify.

2025

Studying the robustness of data imputation methodologies against adversarial attacks

Authors
Mangussi, AD; Pereira, RC; Lorena, AC; Santos, MS; Abreu, PH;

Publication
Comput. Secur.

Abstract
Cybersecurity attacks, such as poisoning and evasion, can intentionally introduce false or misleading information in different forms into data, potentially leading to catastrophic consequences for critical infrastructures, like water supply or energy power plants. While numerous studies have investigated the impact of these attacks on model-based prediction approaches, they often overlook the impurities present in the data used to train these models. One of those forms is missing data, the absence of values in one or more features. This issue is typically addressed by imputing missing values with plausible estimates, which directly impacts the performance of the classifier. The goal of this work is to promote a Data-centric AI approach by investigating how different types of cybersecurity attacks impact the imputation process. To this end, we conducted experiments using four popular evasion and poisoning attacks strategies across 29 real-world datasets, including the NSL-KDD and Edge-IIoT datasets, which were used as case study. For the adversarial attack strategies, we employed the Fast Gradient Sign Method, Carlini & Wagner, Project Gradient Descent, and Poison Attack against Support Vector Machine algorithm. Also, four state-of-the-art imputation strategies were tested under Missing Not At Random, Missing Completely at Random, and Missing At Random mechanisms using three missing rates (5%, 20%, 40%). We assessed imputation quality using MAE, while data distribution shifts were analyzed with the Kolmogorov–Smirnov and Chi-square tests. Furthermore, we measured classification performance by training an XGBoost classifier on the imputed datasets, using F1-score, Accuracy, and AUC. To deepen our analysis, we also incorporated six complexity metrics to characterize how adversarial attacks and imputation strategies impact dataset complexity. Our findings demonstrate that adversarial attacks significantly impact the imputation process. In terms of imputation assessment in what concerns to quality error, the scenario that enrolees imputation with Project Gradient Descent attack proved to be more robust in comparison to other adversarial methods. Regarding data distribution error, results from the Kolmogorov–Smirnov test indicate that in the context of numerical features, all imputation strategies differ from the baseline (without missing data) however for the categorical context Chi-Squared test proved no difference between imputation and the baseline. © 2025

2025

Wine tourism meets the metaverse: A case study

Authors
Barbosa, B; Singh, S; Yetik, T; Carvalho, C;

Publication
Cases on Metaverse and Consumer Experiences

Abstract
Technological developments are presenting new ways for companies to organize their businesses and offer new products, services, and experiences to their customers. The Metaverse allows the participation and interaction of individuals in immersive experiences that merge virtual and real worlds. The adoption of metaverse platforms by companies worldwide is growing steadily, with the potential to change business in various industries, including tourism. However, the literature on the Metaverse applied to tourism is very scarce. This chapter addresses this gap by exploring a case study of the implementation of a Metaverse strategy by a Portuguese wine brand, Sandeman, as part of their wine tourism experience offerings. The case study is built on secondary data, observation, and interviews with tourists. © 2025, IGI Global Scientific Publishing. All rights reserved.

2025

Exploring the role of product attributes in 9-ending pricing strategies: A study on online retailing

Authors
Gonçalves, MG; Barbosa, B; Saura, JR; Mariani, M;

Publication
JOURNAL OF BUSINESS RESEARCH

Abstract
This study investigates the use of 9-ending pricing strategies in e-commerce by analyzing over 50,000 shoe prices. Using web scraping and a logit model from a German online retailer, the research assesses how product attributes influence the adoption of 9-ending prices. Key findings reveal that 9-ending prices are predominantly used for female and newly introduced products, as well as for items with lower and standard prices. The study also explores the effects of exclusivity and sustainability on pricing strategies, showing that their impact varies with different 9-ending price categories. Overall, this research demonstrates the complex nature of 9-ending pricing strategies, with the 9-zero removal model supporting all hypotheses, whereas the 99c and 95c models show differential effects. This extends our understanding of pricing tactics in online retail and highlights the significance of product attributes for marketing and sales strategies.

2025

Metaverse branding: A review and future directions

Authors
Barbosa, B;

Publication
Strategic Brand Management in the Age of AI and Disruption

Abstract
The main aims of this chapter were to explore metaverse branding by identifying the main trends and contributions in extant literature. Through a bibliometry and the critical analysis of the main contributions in the literature, the chapter proposes a metaverse branding conceptualization, which shows how immersive metaverse experiences that provide multi- dimensional value enhance brand engagement, which leads to increased brand awareness, brand love, satisfaction, trust, and brand equity. These factors ultimately drive online and offline purchases and strengthen brand loyalty. Overall, this chapter and the proposed framework provide relevant insights for both managers defining metaverse branding strategies, and researchers interested in these topics. © 2025, IGI Global Scientific Publishing. All rights reserved.

2025

The role of digital touchpoints in the five-star hospitality customer journey

Authors
Zabjesky, C; Barbosa, B; Neves, S;

Publication
Effective Marketing and Consumer Behavior Tactics for High-End Products

Abstract
The main aim of this chapter is to study the digital touchpoints influencing customers' decisions in the five-star hospitality industry. This chapter adopted a qualitative methodology in the form of semi-structured interviews. The findings suggest the preeminent role of online travel agencies and hotel websites as the two most powerful touchpoints influencing the decision-making of the customer and serving as the principal means of making the reservation at the hotel. It also stresses the growing influence of customer-owned touchpoints, particularly user-generated content, in influencing customer perception. This research emphasizes the significance of personalized engagement in influencing customer satisfaction and loyalty. Overall, the study presents practical managerial implications for hoteliers, offering insights on how to effectively interact with customers at each stage of their journey, thereby enhancing both service delivery and overall guest experience. © 2025, IGI Global Scientific Publishing. All rights reserved.

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