Building an automated engagement recognizer based on video analysis. - Minsu Jang; Cheonshu Park; Hyun-Seung Yang; Jaehong Kim 001; Young-Jo Cho; Dong-Wook Lee; Hye-Kyung Cho; Young-Ae Kim; Kyoungwha Chae; Byeong-Kyu Ahn (HRI, 2014)