About the Authors

Xionghui Zhou

Affiliation School of computer, Wuhan University, Wuhan, China

Juan Liu

liujuan@whu.edu.cn

Affiliation School of computer, Wuhan University, Wuhan, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JL. Performed the experiments: XZ. Analyzed the data: XZ JL. Contributed reagents/materials/analysis tools: XZ JL. Wrote the paper: XZ JL.