[1
]Laboratory of Geographic Information Systems, School of Architecture, Civil and Environmental
Engineering, Ecole Polytechique Fédérale de Lausanne (EPFL), and Urban Design Studies
Unit, Department of Architecture, University of Strathclyde, Glasgow, Scotland
[2
]Institute of Physics of São Carlos, University of São Paulo, São Paulo, Brazil
[3
]Departamento de Física de Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza,
Spain, and Institute for Biocomputation and Physics of Complex Systems, Universidad
de Zaragoza, E-50018 Zaragoza, Spain, and Dipartimento di Fisica e Astronomia, Università
de Catania and INFN, Via S Sofia, 64, 95123 Catania, Italy
[4
]Urban Design Studies Unit, Department of Architecture, University of Strathclyde,
Glasgow, Scotland
[5
]School of Mathematical Sciences, Queen Mary, University of London, London, England,
and Dipartimento di Fisica e Astronomia, Università di Catania and INFN, Via S Sofia,
64, 95123 Catania, Italy, and Laboratorio sui Sistemi Complessi, Scuola Superiore
de Catania, Via San Nullo 5/I, 95123 Catania, Italy