Affiliation: | 1. Liberal Arts Division , Tokuyama College of Technology, Gakuendai , Shunan , Yamaguchi , Japan araya@tokuyama.ac.jp;3. Department of Liberal Studies , Nara National College of Technology , Yamatokoriyama , Nara , Japan;4. Department of Mathematical Sciences, Faculty of Science , Shinshu University , Matsumoto , Nagano , Japan |