We study the self-organized aggregation of a swarm of robots in a closed arena. We assume that the perceptual range of the robots are smaller than the size of the arena and the robots do not have information on the size of the swarm of the size of the arena. Using a probabilistic generic aggregation behavior model inspired from studies of social insects, we propose a macroscopic model for predi...

An 40Ar/39Ar chronology of in-situ to near insitu volcanic ashfall deposits indicates that the surficial stratigraphy of Arena Valley extends back at least to middleMiocene time. Wet-based glacial ice occupied part of Arena Valley more than 11.3 Ma ago. Thick, northeast-flowing ice subsequently engulfed Arena Valley, again more than 11.3 Ma ago. Only minor glacier expansion occurred during Plio...

For seabird species, the presence of conspecifics in a crowded breeding colony can obstruct locally available orientation cues. Thus, navigation to specific locations can present a challenging problem. We investigated short-range orientation in King Penguin (Aptenodytes patagonicus) chicks that live in a large and densely populated colony. The two main objectives were to determine whether chick...