1. Office of Strategy Consulting, Consulting Center, Samsung SDS, Gyeonggi-Do, 463-870, Korea
2. System Engineering Team, Memory Division, Samsung Electronics Co., Ltd., Kyung-gi 445-970, Korea
3. School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
4. Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 305-701, Korea