[ 1 ]
[JIANG DU]College of Applied Sciences, Beijing University of Technology Beijing 100124, P. R. China%School of Statistics, Central University of Finance and Economics Beijing 100081, P. R. China
[ 2 ]
[ZHONGZHAN ZHANG]College of Applied Sciences, Beijing University of Technology Beijing 100124, P. R. China%School of Statistics, Central University of Finance and Economics Beijing 100081, P. R. China
[ 3 ]
[ZHIMENG SUN]College of Applied Sciences, Beijing University of Technology Beijing 100124, P. R. China%School of Statistics, Central University of Finance and Economics Beijing 100081, P. R. China
