[1] Chonnam Natl Univ, Sch Mech Engn, Gwangju 61186, South Korea
[2] Chosun Coll Sci & Technol, Dept Automat Syst, Gwangju 61453, South Korea
[3] Kyungpook Natl Univ, Dept Precis Mech Engn, Sangju 37224, Gyeongsangbuk D, South Korea
[4] Korea Adv Inst Sci & Technol, Sch Elect Engn, Daejeon 34141, South Korea
[5] Chonnam Natl Univ, Dept Intelligent Elect & Comp Engn, Gwangju 61186, South Korea
[6] Korea Inst Ind Technol KITECH, Energy & Nano Technol Grp, Gwangju 61012, South Korea