2025
Authors
Nunes, JD; Montezuma, D; Oliveira, D; Pereira, T; Cardoso, JS;
Publication
MEDICAL IMAGE ANALYSIS
Abstract
Nuclear-derived morphological features and biomarkers provide relevant insights regarding the tumour microenvironment, while also allowing diagnosis and prognosis in specific cancer types. However, manually annotating nuclei from the gigapixel Haematoxylin and Eosin (H&E)-stained Whole Slide Images (WSIs) is a laborious and costly task, meaning automated algorithms for cell nuclei instance segmentation and classification could alleviate the workload of pathologists and clinical researchers and at the same time facilitate the automatic extraction of clinically interpretable features for artificial intelligence (AI) tools. But due to high intra- and inter-class variability of nuclei morphological and chromatic features, as well as H&Estains susceptibility to artefacts, state-of-the-art algorithms cannot correctly detect and classify instances with the necessary performance. In this work, we hypothesize context and attention inductive biases in artificial neural networks (ANNs) could increase the performance and generalization of algorithms for cell nuclei instance segmentation and classification. To understand the advantages, use-cases, and limitations of context and attention-based mechanisms in instance segmentation and classification, we start by reviewing works in computer vision and medical imaging. We then conduct a thorough survey on context and attention methods for cell nuclei instance segmentation and classification from H&E-stained microscopy imaging, while providing a comprehensive discussion of the challenges being tackled with context and attention. Besides, we illustrate some limitations of current approaches and present ideas for future research. As a case study, we extend both a general (Mask-RCNN) and a customized (HoVer-Net) instance segmentation and classification methods with context- and attention-based mechanisms and perform a comparative analysis on a multicentre dataset for colon nuclei identification and counting. Although pathologists rely on context at multiple levels while paying attention to specific Regions of Interest (RoIs) when analysing and annotating WSIs, our findings suggest translating that domain knowledge into algorithm design is no trivial task, but to fully exploit these mechanisms in ANNs, the scientific understanding of these methods should first be addressed.
2025
Authors
Leal, F; Veloso, B; Malheiro, B; Burguillo, JC;
Publication
EXPERT SYSTEMS
Abstract
Crowdsourced data streams are popular and extremely valuable in several domains, namely in tourism. Tourism crowdsourcing platforms rely on past tourist and business inputs to provide tailored recommendations to current users in real time. The continuous, open, dynamic and non-curated nature of the crowd-originated data demands specific stream mining techniques to support online profiling, recommendation, change detection and adaptation, explanation and evaluation. The sought techniques must, not only, continuously improve and adapt profiles and models; but must also be transparent, overcome biases, prioritize preferences, master huge data volumes and all in real time. This article surveys the state-of-art of adaptive and explainable stream recommendation, extends the taxonomy of explainable recommendations from the offline to the stream-based scenario, and identifies future research opportunities.
2025
Authors
Penelas, G; Reis, A; Barbosa, L; Pinto, T;
Publication
DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE, SPECIAL SESSIONS I, 21ST INTERNATIONAL CONFERENCE
Abstract
This paper explores the application of machine learning (ML) methods to enhance decision-making and automation in gaming environments. It examines supervised, unsupervised, and reinforcement learning (RL) strategies, emphasizing RL's effectiveness in interactive environments and its combination with deep learning (DL) to form deep reinforcement learning (DRL) approaches. Additionally, Game Theory (GT) is introduced as a framework for optimizing player interactions. By leveraging these concepts, several practical applications are presented across diverse gaming scenarios, from recreational games, such as Dota2 and ATARI, to serious games designed to educate about managing real-world resources and health complications cases, or replicate vehicle behaviour simulations from real-world driving scenarios. Findings show that DRL excels in complex decision-making tasks, while GT optimizes strategic interactions. Additionally, by considering recreational and serious games as case studies, this work aims to demonstrate the versatility of these methods, showing rich and dynamic environments for testing the adaptability and responsiveness, while can also offer a context for applying these advancements to simulate and solve real-world problems.
2025
Authors
Sousa, H; Ward, AR; Alonso, O;
Publication
PROCEEDINGS OF THE EIGHTEENTH ACM INTERNATIONAL CONFERENCE ON WEB SEARCH AND DATA MINING, WSDM 2025
Abstract
Events like Valentine's Day and Christmas can influence user intent when interacting with search engines. For example, a user searching for gift around Valentine's Day is likely to be looking for Valentine's-themed options, whereas the same query close to Christmas would more likely suggest an interest in Holiday-themed gifts. These shifts in user intent, driven by temporal factors, are often implicit but important to determine the relevance of search results. In this demo, we explore how incorporating temporal awareness can enhance search relevance in an e-commerce setting. We constructed a database of 2K events and, using historical purchase data, developed a temporal model that estimates each event's importance on a specific date. The most relevant events on the date the query was issued are then used to enrich search results with event-specific items. Our demo illustrates how this approach enables a search system to better adapt to temporal nuances, ultimately delivering more contextually relevant products.
2025
Authors
Pistono, A; Santos, A; Baptista, R;
Publication
World Journal of Information Systems
Abstract
2025
Authors
Rodrigues, JF; Cardoso, HL; Lopes, CT;
Publication
COMPANION PROCEEDINGS OF THE ACM WEB CONFERENCE 2025, WWW COMPANION 2025
Abstract
Text simplification converts complex text into simpler language, improving readability and comprehension. This study evaluates the effectiveness of open-source large language models for text simplification across various categories. We created a dataset of 66,620 lead section pairs from English and Simple English Wikipedia, spanning nine categories, and tested Llama 3 for text simplification. We assessed its output for readability, simplicity, and meaning preservation. Results show improved readability, with simplification varying by category. Texts on Time were the most shortened, while Leisurerelated texts had the greatest reduction of words/characters and syllables per sentence. Meaning preservation was most effective for the Objects and Education categories.
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