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This paper deals with the self-organization of simple mobile agents confined in a two-dimension rectangular area. Each agent interacts with its neighbors inside an interaction disk and moves following various types of force-driven couplings (e.g. repulsion or attraction). The agents do not know their absolute position, do not exchange messages, have no memory, and no learning capabilities. We first study the self-organization appearing in systems made-up with one sole type of agents, initially generated at random in the terrain. By changing the agent–agent repulsive interaction, we observe five different population reorganizations, namely, grouping, diffusion (that is classical), but especially interesting, crystallization (i.e., the agents group together on the vertices a regular hexagonal lattice), alignment along straight lines, and vortex dynamics. Then, we consider reorganization in systems made-up from two to five types of agents, where each pair of agent types has specific interaction parameters. The main result of this work is to show that, by only changing the agent–agent repulsion rules, one can generate hexagonal or rectangular multi-agent crystals or on the contrary, induce complete separation in regular hexagonal tiles. [ABSTRACT FROM AUTHOR]

Abstract: We study the efficacy of allelomimesis as an escape strategy of mobile agents (pedestrians) that aim to leave a two-exit room within the shortest possible time. Allelomimesis is the act of copying one’s kindred neighbors. To escape, an agent employs one of the following strategies: (1) It chooses its own route independently (non-copying, ), (2) It imitates the actions of its neighbors at all times (blind copying, ), or (3) It either copies or acts independently according to a certain probability that is set by the copying parameter . Not more than one agent could occupy a given room location. An agent’s knowledge of the two exit locations is set by its information content . When left alone, an agent with complete knowledge of the exit whereabouts () always takes the shortest possible path to an exit. We obtain plots of the (group) evacuation time and exit throughput as functions of and for cases where the two exits are near (on same room side) and far (on opposite sides of room) from each other. For an isolated agent, is inversely proportional to . The chances of escape for an isolated agent with are higher with adjacent exits. However, for an agent with the chance is better with opposite exits. In a highly occupied room (occupancy rate ) with adjacent exits, agents with escape more quickly if they employ a mixed strategy of copying and non-copying (). On the other hand, blind copying () gives agents with a better chance of escaping from the same room. For the same and values, opposite exits allow faster evacuation for agents with due to the likelihood of streaming and the lower probability of exit clogging. Streaming indicates an efficient utilization of an exit and it happens when the arcs that are formed are smaller and arch interference is less likely. Allelomimesis provides a simple yet versatile mechanism for studying the egress behavior of confined crowds in a multi-exit room. [Copyright &y& Elsevier]