António Teixeira


2025

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Inductive Learning on Heterogeneous Graphs Enhanced by LLMs for Software Mention Detection
Gabriel Silva | Mário Rodriges | António Teixeira | Marlene Amorim
Proceedings of the Fifth Workshop on Scholarly Document Processing (SDP 2025)

This paper explores the synergy between Knowledge Graphs (KGs), Graph Machine Learning (Graph ML), and Large Language Models (LLMs) for multilingual Named Entity Recognition (NER) and Relation Extraction (RE), specifically targeting software mentions within the SOMD 2025 challenge. We propose a methodology where documents are first transformed into heterogeneous KGs enriched with linguistic features (Universal Dependencies) and external knowledge (entity linking). An inductive GraphSAGE model, operating on PyTorch Geometric’s ‘HeteroData‘ structure with dynamically generated multilingual embeddings, performs node classification tasks. For NER, Graph ML identifies candidate entities and types, with an LLM (DeepSeek v3) acting as a validation layer. For RE, Graph ML predicts dependency path convergence points indicative of relations, while the LLM classifies the relation type and direction based on entity context. Our results demonstrate the potential of this hybrid approach, showing significant performance gains post-competition (NER Phase 2 Macro F1 improved to 0.4364 from 0.2953, RE Phase 1 0.3355 Macro F1), which are already described in this paper, and highlighting the benefits of integrating structured graph learning with LLM reasoning for information extraction.

2024

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Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 1
Pablo Gamallo | Daniela Claro | António Teixeira | Livy Real | Marcos Garcia | Hugo Gonçalo Oliveira | Raquel Amaro
Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 1

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Towards the automatic creation of NER systems for new domains
Emanuel Matos | Mário Rodrigues | António Teixeira
Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 1

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First assessment of Graph Machine Learning approaches to Portuguese Named Entity Recognition
Gabriel Silva | Mário Rodrigues | António Teixeira | Marlene Amorim
Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 1

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Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 2
Pablo Gamallo | Daniela Claro | António Teixeira | Livy Real | Marcos Garcia | Hugo Gonçalo Oliveira | Raquel Amaro
Proceedings of the 16th International Conference on Computational Processing of Portuguese - Vol. 2

2014

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Multimodal Corpora for Silent Speech Interaction
João Freitas | António Teixeira | Miguel Dias
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

A Silent Speech Interface (SSI) allows for speech communication to take place in the absence of an acoustic signal. This type of interface is an alternative to conventional Automatic Speech Recognition which is not adequate for users with some speech impairments or in the presence of environmental noise. The work presented here produces the conditions to explore and analyze complex combinations of input modalities applicable in SSI research. By exploring non-invasive and promising modalities, we have selected the following sensing technologies used in human-computer interaction: Video and Depth input, Ultrasonic Doppler sensing and Surface Electromyography. This paper describes a novel data collection methodology where these independent streams of information are synchronously acquired with the aim of supporting research and development of a multimodal SSI. The reported recordings were divided into two rounds: a first one where the acquired data was silently uttered and a second round where speakers pronounced the scripted prompts in an audible and normal tone. In the first round of recordings, a total of 53.94 minutes were captured where 30.25% was estimated to be silent speech. In the second round of recordings, a total of 30.45 minutes were obtained and 30.05% of the recordings were audible speech.

2004

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An Acoustic Corpus Contemplating Regional Variation for Studies of European Portuguese Nasals
António Teixeira | Liliana Ferreira | Lurdes Moutinho | Rosa Lídia Coimbra | Raquel Lisboa
Proceedings of the Fourth International Conference on Language Resources and Evaluation (LREC’04)