The curves corresponding to the cost as a function of iterations
number obtained for different optimization techniques are
presented in Fig. 2(a)–(c) for a population size of 30, 90, and
900, respectively. It is obvious that the initial value of elaborated
optimization algorithms is different from one technique
to another, since it is generated arbitrarily. For a given optimization
technique, with the increase of iterations number, the
cost decreases from its initial value and tends toward the minimum
value. Indeed, the developed iterative algorithms operate
by reducing the cost and guarantee finding the minimum cost.
This latter varies with the optimization technique and population
size. However and regardless of the population size, the cost
curves take a ladder-like shape for HPSGAO and GAO techniques
and a steeper shape for the PSO one.