- Y.S. Ryu, "Some Results on Buffer Caching Method for Internet VOD Application," KIFS International Symposium on Advanced Intelligent Systems, Aug. 2001.
- Y.S. Ryu, "On Performance of Buffer Caching Scheme in Video Applications with Looping References," IASTED International Conference on Internet and Multimedia Systems and Applications (IMSA), Hawaii, Aug. 2001.
- K.C. Kang, Y.S. Ryu, "Design of DOIT(Distributed Open Intelligent Telephony) Testbed," Korea Information and Science Society Spring Conference, Apr. 2001.
- Y.S. Ryu, "Web Search Function to Search Information from a Specific Location," US Patent No. 6,321,227, Nov. 2001.
- Y.S. Ryu, "웹 검색 엔진에서 검색된 정보를 지역적으로 근접 순서대로 표시하는 방법," Korea Patent No. 10-0313462, Oct. 2001.