This author has not been identified. Look up 'Hongtao Xie' in GoogleThis author has not been identified. Look up 'Yongdong Zhang' in GoogleThis author has not been identified. Look up 'Ke Gao' in GoogleThis author has not been identified. Look up 'Sheng Tang' in GoogleThis author has not been identified. Look up 'Kefu Xu' in GoogleThis author has not been identified. Look up 'Li Guo' in GoogleThis author has not been identified. Look up 'Jintao Li' in Google