We consider a dynamic domination problem for graphs in which an infinite sequence of attacks occur at vertices with guards and the guard at the attacked vertex is required to vacate the vertex by moving to a neighboring vertex with no guard. Other guards are allowed to move at the same time, and before and after each attack and the resulting guard movements, the vertices containing guards form ...

Clark and Chalmers (1998) have argued that mental states can be extended outside an organism’s skin. In response to some worries about the availability, reliability and portability of such extended resources, Clark (2005) offers a set of rough criteria that non-biological objects must fulfil to legitimately ground mental states. One such criterion is that the information retrieved from these no...

This paper presents an algorithm to deploy a team of free guards equipped with omni-directional cameras for tracking a bounded speed intruder inside a simply-connected polygonal environment. The proposed algorithm partitions the environment into smaller polygons, and assigns a guard to each partition so that the intruder is visible to at least one guard at all times. Based on the concept of dyn...

In recognition, discriminators use sensory information to make decisions. For example, honeybee (Apis mellifera) entrance guards discriminate between nest-mates and intruders by comparing their odours with a template of the colony odour. Comb wax plays a major role in honeybee recognition. We measured the rejection rates of nest-mate and non-nest-mate worker bees by entrance guards before and a...

Let bd(P ) denote the boundary of a simple polygon P . Points p and q of P are mutually visible if segment pq lies entirely inside P . This notion of visibility gave birth to an extensive literature on art-gallery problems [3], concerned with guarding the floor of a polygonal art-gallery. Chvatal [2] showed that bn/3c point guards are always sufficient and sometimes necessary. Allowing guards t...