1. Professor, Nagoya Institute of Technology Gokiso‐cho, Showa‐ku Nagoya Aichi 466‐8555 Japan
2. Professor, University of Salerno via Giovanni Paolo II 132 Fisciano SA Italy
3. University of Salerno via Giovanni Paolo II 132 Fisciano SA Italy
4. Ph. D., University of Salerno via Giovanni Paolo II 132 Fisciano SA Italy