Pablo Calleja


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RGCL-WLV at SemEval-2019 Task 12: Toponym Detection
Alistair Plum | Tharindu Ranasinghe | Pablo Calleja | Constantin Orăsan | Ruslan Mitkov
Proceedings of the 13th International Workshop on Semantic Evaluation

This article describes the system submitted by the RGCL-WLV team to the SemEval 2019 Task 12: Toponym resolution in scientific papers. The system detects toponyms using a bootstrapped machine learning (ML) approach which classifies names identified using gazetteers extracted from the GeoNames geographical database. The paper evaluates the performance of several ML classifiers, as well as how the gazetteers influence the accuracy of the system. Several runs were submitted. The highest precision achieved for one of the submissions was 89%, albeit it at a relatively low recall of 49%.


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Role-based model for Named Entity Recognition
Pablo Calleja | Raúl García-Castro | Guadalupe Aguado-de-Cea | Asunción Gómez-Pérez
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

Named Entity Recognition (NER) poses new challenges in real-world documents in which there are entities with different roles according to their purpose or meaning. Retrieving all the possible entities in scenarios in which only a subset of them based on their role is needed, produces noise on the overall precision. This work proposes a NER model that relies on role classification models that support recognizing entities with a specific role. The proposed model has been implemented in two use cases using Spanish drug Summary of Product Characteristics: identification of therapeutic indications and identification of adverse reactions. The results show how precision is increased using a NER model that is oriented towards a specific role and discards entities out of scope.