1. Graduate School, Akita Prefectural University, 84-4 Aza Ebinokuchi Tsuchiya, Yurihonjo, Akita 015-0055, Japan e-mail:
2. Machine Intelligence and Systems Engineering, Akita Prefectural University, Yurihonjo, Akita 015-0051, Japan e-mail:
3. Department of Mechanical Engineering, Aoyama Gakuin University, Fuchinobe 5-10-1, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258, Japan e-mail:
4. Department of Machine Intelligence and Systems Engineering, Akita Prefectural University, 84-4 Aza Ebinokuchi Tsuchiya, Yurihonjo, Akita 015-0055, Japan e-mail: