Movie ABM simulation - trails;Movie ABM simulation - travelling bands;Movie ABM simulation - honeycomb structures;Movie ABM simulation - moving clusters;Movie ABM simulation - pinned clusters from How environment affects active particle swarms: a case study
Creators: name: Degond, Pierre
name: Manhart, Angelika
name: Merino-Aceituno, Sara
name: peurichard, Diane
name: Sala, Lorenzo
Publisher: name: The Royal Society
Year: 2022
Subjects: subject: 10299 Applied Mathematics not elsewhere classified
subject: FOS: Mathematics
subject: 10599 Mathematical Physics not elsewhere classified
subject: 19999 Mathematical Sciences not elsewhere classified

description: Link: https://doi.org/10.6084/m9.figshare.19615599.v2 In this video, two simulations are shown : The left movie is obtained for weak obstacle spring stiffness κ = 10, agent friction ζ = 2 and agent-agent repulsion μ = 0:02 and the right movie is obtained for mild obstacle spring stiffness κ = 100, agent friction ζ = 1 and agent-agent repulsion μ = 0:04. Both simulations show the spontaneous formation of trails of agents in a more or less deformable field of obstacle. For weak obstacle spring stiffness (left movie), agents easily repulse the obstacles as they move, creating large trails empty of obstacles that can merge or evolve over time. For larger obstacle spring stiffness (right movie), the agents also organize in trails that push the obstacles, creating tunnels with strong walls, more robust over time. It is noteworthy that trail structures are only observed for weak or mild obstacle spring stiffness.;Link: https://doi.org/10.6084/m9.figshare.19615884.v3 Here, both simulations feature strong obstacle spring stiffness κ = 1000 and agent friction ζ = 2. The left movie is obtained for weak agent-agent repulsion μ = 2x10-5 while the right movie is obtained for μ = 10-3. In both situations, agents end up organizing in travelling bands on the long run, but we can observe a first phase when agents try to organize in trails. This suggest that the trail-like formation is only stable when agents have enough strength to push the obstacles as they move. Comparing the left and right movie, we also observe that larger agent-agent repulsion leads to larger clusters of agents.;Link: https://doi.org/10.6084/m9.figshare.19615116.v2 We consider here the case of weak obstacle spring stiffness = 10. The left movie is obtained for agent friction ζ = 0:2 and mild agent-agent repulsion μ = 0:05 while the right movie is obtained for ζ = 1 and larger agent-agent repulsion μ = 0:1. As one can observe, when the agentagent repulsion is large enough in an easily deformable obstacle field, the agent phase wins over the obstacle phase, creating regularly spaced islands of obstacles in the form of honneycomb structures.;Link: https://doi.org/10.6084/m9.figshare.19615878.v2 Here, the left movie features weak obstacles κ = 10, agent friction ζ = 0:2 and agent-agent repulsion μ = 0:002, while the right movie is for κ = 100, ζ = 1 and μ = 0:004. When agentagent repulsion is low enough, agents spontaneously organize into more or less round clusters surrounded by obstacles. This cluster formation happens very fast, and agent clusters then move more or less fast depending on their environment. Large and slow clusters of agents are observed in the left movie, where obstacles are very loose and agent-agent repulsion is a bit larger, while more numerous, smaller and more stable agent clusters are observed in the right movie (where agent-agent repulsion is a bit larger but obstacles are stronger).;In these movies, we consider a small agent friction ζ = 0:2 and agent-agent repulsion μ = 2x10-4, for mild obstacle spring stiffness κ= 100 (left pannel) and for strong obstacles κ = 1000 (right pannel). We classify these clusters as ’pinned’ as the agents organize very fast into small and highly concentrated clusters that do not move (right pannel) or move very slow in the case of mild obstacles. We can also observe merging of clusters in the case of mild obstacles (left video). In these extreme case, the force exerted by the stretched obstacles overcomes the other forces, preventing the agent clusters to move further from their position.