Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.|Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.|Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.|Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.|Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.|Department of Statistics and Information Science, Dongguk University, Gyeongju 780-714, Korea.