A Discrete Particle Swarm Ant Colony Optimization for Design of Steel Frames

A discrete version of Particle Swarm Ant Colony Optimization (DPSACO) for design offrame structures is presented. DPSACO, similar to continous PSACO, is based on a particleswarm optimizer, worked as a global search, and ant colony optimization employed as alocal search. In the DPSACO, the nearest permitted discrete value is replaced with any valueselected by agents (Particles or ants). Therefore, the positions of all agents always contain the permitted discrete values. In order to improve the exploration of the proposed method, a new formula for particles'' velocity is defined. Two design examples are tested using the new method and their results are compared with the results of other PSO-based algorithms to demonstrate the effectiveness of the presented method.