1. Department of Architectural Engineering, Hanbat National University, P. O. Box 34158, S8-313 Daejeon, South Korea
2. Department of Architectural Engineering, Hanbat National University, P. O. Box 34158, S8-323 Daejeon, South Korea
3. Department of Architectural Engineering, Hanbat National University, P. O. Box 34158, S8-327 Daejeon, South Korea