On Tuning the Knobs of Distribution-Based Methods for Detecting VoIP Covert Channels - Chrisil Arackaparambil; Guanhua Yan; Sergey Bratus; Alper Caglayan (45th Hawaii International International Conference on Systems Science (HICSS-45 2012), Proceedings, 4-7 January 2012, Grand Wailea, Maui, HI, USA, 2012)