Text and Data Mining valid from 2018-09-27
Received: 30 April 2018
Accepted: 20 September 2018
First Online: 27 September 2018
Compliance with ethical standards
: Drs. Xing Zhang, Dongtao Shi, Zhuwen Yu, Rui Li, Weichang Chen, Feihu Bai, Xudong Wu, Cuie Cheng, Ruihua Shi, and Pengfei Liu have no conflicts of interest or financial ties to disclose.