About the Authors

Zhenhui He

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Resources, Software, Validation, Visualization, Writing – original draft, Writing – review & editing

Affiliation School of Mathematics, Renmin University of China, Beijing China

Kangning Dong

Roles Conceptualization, Funding acquisition, Methodology, Project administration, Resources, Supervision, Writing – review & editing

dongkangning@ruc.edu.cn

Affiliation School of Mathematics, Renmin University of China, Beijing China

Competing Interests

The authors have declared that no competing interests exist.