“…In the 1990s, the first ideas of changing the dynamic characteristics of structures by optimization techniques were based on parameter optimization. In these cases, the design parameter was the thickness of the beam or the plate that composed the structure, and the objective was to move the fundamental frequencies toward higher values [2,3]. Since then, other authors explored the different ways of changing the natural frequencies of a structure by optimizing its parameters, for example, by changing the thickness of wind turbine blade roots [4], by choosing the optimized orientation of fiber reinforcements in composite plates [5,6], by changing the flexibility of the boundary conditions [7], or by choosing the optimum positions of stiffeners (reinforcements) to be placed over plates [8].…”