Emotion Detection for Social Robots Based on NLP Transformers and an Emotion Ontology. - Graterol, Wilfredo; Diaz-Amado, Jose; Cardinale, Yudith; Dongo, Irvin; Lopes-Silva, Edmundo; Santos-Libarino, Cleia; González-González, Carina Soledad (Sensors (14248220), 2021)