1. Department of Civil Engineering and Environmental Sciences, Korea Military Academy, Seoul 01805, Republic of Korea
2. Department of Geography Education, Korea University, Seoul 02841, Republic of Korea
3. Arizona Geological Survey, 1955 East 6th Street, Tucson, Arizona 85704, USA
4. AMS Laboratory, Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
5. Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, NC 27695, USA