1c , 2 c are acceleration constant and show how the best position of particle or moving group take effect on the velocity of particle or group. 1 r , 2 r are random numbers uniformly distributed in (0, 1). Eq. (5) mainly has three parts: the first part is the inheritance of previous speed particles, which shows that the trust of current movement
state of particles and it will do inertial movement according to own the speed;