1. College of General Education, Division of Undeclared Majors, Chosun University, Gwangju 501-759, South Korea
2. Department of Fire Service Administration, Honam University, Gwangju 62399, South Korea
3. Department of Bioenvironmental & Chemical Engineering, Chosun College of Science & Technology, Gwangju 501-744, South Korea
4. Department of Environment and Energy Engineering, Chonnam National University, Gwangju 61186, South Korea
5. Department of Advanced Materials and Chemical Engineering, Catholic University of Daegu, Gyeongbuk 712-702, South Korea
6. Advanced Materials and Devices Lab., Korea Institute of Energy Research, Daejeon 305-343, South Korea