About the Authors

Qing-chun Meng

Affiliation School of Management, Shandong University, Jinan, Shandong, China

Xiao-le Wan

Affiliation School of Management, Shandong University, Jinan, Shandong, China

Xiao-xia Rong

xiaoxia.rong@hotmail.com

Affiliation School of Mathematics, Shandong University, Jinan, Shandong, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: QM XW XR. Performed the experiments: QM XR. Analyzed the data: XW XR. Contributed reagents/materials/analysis tools: QM XW XR. Wrote the paper: QM XW XR.