1 School of Management Science and Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, Nanjing, 210044 Jiangsu China.
2 Department of Mathematics and Computer Science, University of North Carolina at Pembroke, One University Drive, Pembroke, NC 28372 USA.
3 Ingram School of Engineering, Texas State University, 601 University Drive, San Marcos, TX 78666 USA.