F² - New Technique for Recognition of User Emotional States in Spoken Dialogue Systems Ramón López-Cózar author Jan Silovsky author David Griol author 2010-09 text Proceedings of the SIGDIAL 2010 Conference Yasuhiro Katagiri editor Mikio Nakano editor Association for Computational Linguistics Tokyo, Japan conference publication lopez-cozar-etal-2010-f2 https://aclanthology.org/W10-4354/ 2010-09 281 288