Affiliation: | 1. Department of Mechanical Engineering, Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan;2. Department of Mathematics and Computer Science, University of Messina, V.le F. D''Alcontres 31, 98166 Messina, Italy;3. Department of Mathematics, University of Bologna, via Saragozza 8, 40123 Bologna, Italy;4. Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan |