1. Research Associate, Dept. of Forest Sciences, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National Univ., Seoul 151-742, Korea.
2. Post Doctoral Fellow, Dept. of Forest Sciences, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National Univ., Seoul 151-742, Korea.
3. Research Scientist, Dept. of Forest Products, Div. of Wood Engineering, Korea Forest Research Institute, Seoul 130-712, Korea.
4. Ph.D. Candidate, Dept. of Forest Sciences, College of Agriculture and Life Sciences, Seoul National Univ., Seoul 151-742, Korea.
5. Professor, Dept. of Forest Sciences, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National Univ., Seoul 151-742, Korea (corresponding author).