1. ISEL-Polytechnic Institute of Lisbon,Lisbon,Portugal
2. NOVA School of Science and Technology,UNINOVA-CTS and LASI,ISEL-Polytechnic Institute of Lisbon,Lisbon,Portugal
3. ISEL-Polytechnic Institute of Lisbon,UNINOVA-CTS and LASI,Lisbon,Portugal
4. INESC-ID, IST, Un. de Lisboa,ISEL-Polytechnic Institute of Lisbon,Lisbon,Portugal