1. a Department of Innovation Systems Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan;, Email: rahok@ir.ics.utsunomiya-u.ac.jp
2. b Department of Innovation Systems Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan