Understanding integration in collective behavior with experiments

Integration (or aggregation) plays pivotal roles in the pattern formation of various systems that demonstrate collective behavior. This work studies with experiments and agent-based models the integration in the panic escape of human being, symmetry breaking of escaping ants and the group chase and escape. We present a social force based genetic algorithm to optimize the architectural design at the gate. Human experiments with 80 participants correspond well with the simulations indicating that appropriately placing two pillars on both sides can maximize the escape efficiency. Symmetry breaking occurs when ants escape from a closed space with two symmetrically located exits while one exit is used more often than the other. We study how density affects symmetry breaking experimentally. The results show an increase then decrease of symmetry breaking versus ant density. This result suggests that a Vicsek-like model may not be a proper model while a simple alarm pheromone model agrees well with our experimental outcomes. We introduce three aggregation strategies for the prey in the recently popular group chase and escape model on a lattice. Simulation results show that aggregation dramatically increases the group survival time, even allowing immortal prey. Sharing Information and alignment in the aggregation process are the vital factors of the increase of survival time.