1. Indian Statistical Institute; New Delhi India
2. International College of Arts and Sciences; Yokohama City University; Yokohama Japan
3. Laboratoire de Recherche en Informatique, University Paris-Sud; Orsay Cedex France
4. Department of Mathematical Sciences, Faculty of Science; Tokai University; Hiratsuka Japan
5. Systems Science and Information Studies, Faculty of Education, Art and Science; Yamagata University; Yamagata Japan
6. Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences; Budapest Hungary
7. Department of Computer Science and Systems Technology; University of Pannonia; Veszprém Hungary