publications

2024

1. CNMAC 2024

   A Learning-Based Model Predictive Control Framework with an State Observer for Epidemic Mitigation

   Fredson Silva de Souza Aguiar , and Maria Soledad Aronna

   Nov 2024

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   Many applications have shown the use and success of classical compartment models in estimating the states and evolution of disease spreads. Similarly, the study of Optimal Control Theory has shown positive results in those scenarios but, sometimes, lack computational and theoretical tractability, specially in the cases of long-term problems or uncertain scenarios. In that context, Model Predictive Control (MPC) has become apparent, as it provides a more tractable version of a (Stochastic) Optimal Control Problem by approximating the solution through a simplified version of the control problem over a shorter horizon. Nevertheless, the current state or uncertainty can affect the local optimal solution, what provides niche to the introduction of learning methods in the process. We show how this kind of approach could be a reliable option for epidemic disease mitigation. Future works include the discussion of a more complete set of compartments, for vaccine effectiveness estimation, and robust control under uncertain vaccination availability.

   @misc{resumo_poster_cnmac_2024,
     title = {A Learning-Based Model Predictive Control Framework with an State Observer for Epidemic Mitigation},
     language = {en},
     author = {Aguiar, Fredson Silva de Souza and Soledad Aronna, Maria},
     month = nov,
     year = {2024},
     bibtex_show = true,
   }

2021

1. LDK 2021

   On the Utility of Word Embeddings for Enriching OpenWordNet-PT

   Hugo Gonçalo Oliveira , Fredson Silva de Souza Aguiar , and Alexandre Rademaker

   In 3rd Conference on Language, Data and Knowledge (LDK 2021) , Nov 2021

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   The maintenance of wordnets and lexical knwoledge bases typically relies on time-consuming manual effort. In order to minimise this issue, we propose the exploitation of models of distributional semantics, namely word embeddings learned from corpora, in the automatic identification of relation instances missing in a wordnet. Analogy-solving methods are first used for learning a set of relations from analogy tests focused on each relation. Despite their low accuracy, we noted that a portion of the top-given answers are good suggestions of relation instances that could be included in the wordnet. This procedure is applied to the enrichment of OpenWordNet-PT, a public Portuguese wordnet. Relations are learned from data acquired from this resource, and illustrative examples are provided. Results are promising for accelerating the identification of missing relation instances, as we estimate that about 17% of the potential suggestions are good, a proportion that almost doubles if some are automatically invalidated.

   @inproceedings{goncalooliveira_et_al:OASIcs.LDK.2021.21,
     author = {Gon\c{c}alo Oliveira, Hugo and Aguiar, Fredson Silva de Souza and Rademaker, Alexandre},
     title = {{On the Utility of Word Embeddings for Enriching OpenWordNet-PT}},
     booktitle = {3rd Conference on Language, Data and Knowledge (LDK 2021)},
     pages = {21:1--21:13},
     series = {Open Access Series in Informatics (OASIcs)},
     isbn = {978-3-95977-199-3},
     issn = {2190-6807},
     year = {2021},
     volume = {93},
     editor = {Gromann, Dagmar and S\'{e}rasset, Gilles and Declerck, Thierry and McCrae, John P. and Gracia, Jorge and Bosque-Gil, Julia and Bobillo, Fernando and Heinisch, Barbara},
     publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
     address = {Dagstuhl, Germany},
     url = {https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.LDK.2021.21},
     urn = {urn:nbn:de:0030-drops-145578},
     annote = {Keywords: word embeddings, lexical resources, wordnet, analogy tests},
     doi = {10.4230/OASIcs.LDK.2021.21},
     bibtex_show = true,
   }

2. BSc thesis

   Implementação de um Workflow de Atualização e Experimentos Utilizando Word Embeddings e Analogia para o Enriquecimento da OpenWordnet-PT

   Fredson Silva de Souza Aguiar

   Fundação Getulio Vargas , Dec 2021

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   A OpenWordnet-PT é atualmente referência em wordnets para língua portuguesa. No entanto, à medida em que o recurso cresce, a manutenção puramente manual torna-se inviável. Dessa forma, discutimos atualização de infra-estrutura junto a algumas iniciativas em que OWN-PT é empregada, com ênfase no uso de representações vetoriais para o aprendizado de novas relações semânticas.

   @phdthesis{aguiar_fredson_bsc_ownpt,
     address = {Rio de Janeiro, Brazil},
     title = {Implementação de um Workflow de Atualização e Experimentos Utilizando Word Embeddings e Analogia para o Enriquecimento da OpenWordnet-PT},
     language = {pt},
     school = {Fundação Getulio Vargas},
     author = {Aguiar, Fredson Silva de Souza},
     month = dec,
     year = {2021},
     bibtex_show = true,
   }