Close encounters in a pediatric ward: measuring face-to-face proximity and mixing patterns with wearable sensors - Lorenzo Isella; Mariateresa Romano; Alain Barrat; Ciro Cattuto; Vittoria Colizza; Wouter Van den Broeck; Francesco Gesualdo; Elisabetta Pandolfi; L. Ravà; Caterina Rizzo; Alberto E. Tozzi (CoRR, 2011)