1. Assistant Professor, School of Management, Shandong Univ., Jinan 250100, People’s Republic of China.
2. Associate Professor, School of Management, Shandong Univ., Jinan 250100, People’s Republic of China.
3. Associate Professor, Faculty of Civil Engineering and Mechanics, Kunming Univ. of Science and Technology, Kunming 650500, People’s Republic of China (corresponding author).