Department of Information Industrial Engineering, CBITRC, Chungbuk National University, Cheongju Chungbuk 361-763, Korea.|Department of Information Industrial Engineering, CBITRC, Chungbuk National University, Cheongju Chungbuk 361-763, Korea.|Department of Information Industrial Engineering, CBITRC, Chungbuk National University, Cheongju Chungbuk 361-763, Korea.|Department of Information Industrial Engineering, CBITRC, Chungbuk National University, Cheongju Chungbuk 361-763, Korea.|Department of Information Industrial Engineering, CBITRC, Chungbuk National University, Cheongju Chungbuk 361-763, Korea.