1. Electronics and Computer Technology Department Science Faculty Granada University Avda. Fuente Nueva s/n 18071 Granada Spain
2. Dept. Enginyeria Electrònica Universitat Autònoma de Barcelona 08193 Cerdanyola del Vallès Spain
3. Laboratory of Stochastic Multistable Systems Lobachevsky University 23 Gagarin prospect Nizhny Novgorod 603022 Russia
4. Institut de Microelectrònica de Barcelona IMB-CNM (CSIC) Carrer dels Til·lers, s/n. Campus UAB 08193 Bellaterra Spain
5. Physical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
6. Industrial Engineering and Construction Department University of Balearic Islands 07122 Balearic Islands Spain
7. School of Science and Technology International Hellenic University 57001 Thessaloniki Greece
8. Statistics and Operations Research Department Science Faculty Granada University Avda. Fuente Nueva s/n 18071 Granada Spain
9. Dipartimento di Fisica e Chimica “Emilio Segré” Group of Interdisciplinary Theoretical Physics Universitá degli Studi di Palermo and CNISM Unitá di Palermo, Viale delle Scienze, Edificio 18 I-90128 Palermo Italy
10. Electrical Engineering and Computer Science Department University of California Berkeley CA 94720-1770 USA