... 199 6, Rauch, 199 6, Rauch, 199 7, Ko-honen, 199 5, Falkenauer, 199 8, Paterlini and Minerva, 20 03, Xu and Wunsch, 20 05, Rokach and Maimon, 20 05, Mitra et al .20 02) . One of the most popular approaches ... of the particles:vi,d(t)=ω.vi,d(t −1)+ϕ1.rand1i(0,1).(pli,d(t)−xi,d(t −1))+ϕ 2 .rand2i(0,1).(pgd(t)−xi,d(t −1)) (23 .9) Comparing the two variants in 23 .6 and 23 . 12, the ... isolated) and toalign themselves with neighbors (Partridge and Pitcher, 198 0,Partridge, 19 82) .Couzin et al. (20 02) identified four collective dynamical behaviors as illustrated in Figure 2: 1. Swarm:...