1. Institute of Applied Sciences and Intelligent Systems, National Research Council of Italy, 80131 Naples, Italy
2. Institute of Applied Calculus, National Research Council of Italy, 80131 Naples, Italy
3. STMicroelectronics, Catania Wafer Fab Operations, 95121 Catania, Italy
4. Department of Mathematics, Katholieke Universiteit Leuven, 3001 Leuven, Belgium
5. Institute of Applied Calculus, National Research Council of Italy, 00185 Rome, Italy
6. Institute of Microelectronics and Microsystems, National Research Council of Italy, 95121 Catania, Italy