Funding for this research was provided by:
National Natural Science Foundation of China (61201381, 61772548, 61401513)
China Postdoctoral Science Foundation (2016M592989)
Self-Topic Foundation of Information Engineering University (2016600701)
Outstanding Youth Foundation of Information Engineering University (2016603201)
Text and Data Mining valid from 2019-08-20
Received: 5 January 2019
Accepted: 28 June 2019
First Online: 20 August 2019
Ethics approval and consent to participate
: All data and procedures performed in paper were in accordance with the ethical standards of research community. This paper does not contain any studies with human participants or animals performed by any of the authors.
: Informed consent was obtained from all authors included in the study.
: The authors declare that they have no competing interests.