1. Division of Environmental Material Engineering Department of Forest Products, Korea Forest Research Institute Hoegi-Ro 57, Dongdaemun-Gu, Seoul 130-712, Korea,
2. Division of Environmental Material Engineering Department of Forest Products, Korea Forest Research Institute Hoegi-Ro 57, Dongdaemun-Gu, Seoul 130-712, Korea
3. Department of Material Science and Engineering Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-701, Korea
4. Department of Forest Products, Kyungpook National University 1370 Sankyuk-Dong, Buk-Gu, Daegu 702-701, Korea
5. School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA