Knocker VideoMay 13, 2020 Knocker Video Paper Knocker: Vibroacoustic-based Object Recognition with Smartphones Taesik Gong, Hyunsung Cho, Bowon Lee, and Sung-Ju Lee Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT), Vol. 3, No. 3, pp. 1–21, September 2019