optimized from a given ground structure which contains a large
set of candidate trusses, and then, the size as well as the shape
are optimized. Nevertheless, such a two-stage optimization
technique may not always provide the globally best design since
these problems are not linearly separable. Genetic algorithms
[3–5], simulated annealing [6], genetic programming [7], charged
system search [8], big bang-big crunch algorithm [9], differential
evolution [10] and ant colony optimization [11] have been employed
for the optimum design of truss structures with respect to
size, shape, and topology design variables simultaneously. Genetic
algorithms,