1. Department of Electrical Engineering and Information Technology, University of Napoli Federico II, via Claudio 21, 80125 Napoli, Italy
2. Department of Civil Engineering, University of Salerno, Salerno, Italy
3. Laboratoire d´hydrogéologie – Unité de formation et de recherche en Sciences de la vie et de la terre, University of Ouagadougou, Ouagadougou, Burkina Faso