“…We study the transition from microscopic models of interacting particles to the macroscopic limit describing their motion as coherent ensembles. Such problems naturally arise in the description of biological swarms such as flocks of birds [4,15,19], schools of fish [3], ant [7] or bacterial colonies [26], the movement of pedestrian crowds [22,24] or transport of material [20,32]. In some production facilities, e.g.…”