1. Professor, Regional Infrastructure Engineering, Kangwon National Univ., Chuncheon, Gangwon 24341, Korea.
2. Assistant Professor, Rural Construction Engineering, Kongju National Univ., Gongju, Chungcheongnam 32588, Korea.
3. Researcher, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, Jeollabuk 55365, Korea.
4. Professor, Texas A&M AgriLife Research, Blackland Research and Extension Center, 720 E. Blackland Rd., Temple, TX 76520.
5. Professor, Agricultural Biological Engineering, Purdue Univ., West Lafayette, IN 47907.
6. Professor, Biological Engineering, Univ. of Florida, 287 Frazier Rogers Hall, FL 32611.
7. Researcher, Regional Infrastructure Engineering, Kangwon National Univ., Chuncheon, Gangwon 24341, Korea (corresponding author).