Abstract This paper describes the application of the Firefly Algorithm for the optimization of linear and planar antenna arrays. In order to demonstrate the potential of this technique, three applications are reported. The first one is the synthesis of a radiation pattern with isoflux distribution with a non-uniformly spaced linear array composed of isotropic antennas. The second application is the optimization of a non-uniformly spaced planar array composed of isotropic radiators installed on an 8-U nanosatellite. Finally, the optimization of a 3×3 planar antenna array for beam steering with simultaneous side lobe level control is described, whereby the beamforming coefficients were allowed to assume only discrete values. In the three cases considered, good agreement between the desired (mask) and the optimized patterns has been obtained.

Abstract Damper optimization is a new area which has been investigated in recent years. There are various methods employed in optimization, among which are highlighted the classic and the most recent that are functioning with reliability, efficiency and speed for optimum results. This paper proposes a method for simultaneous optimization of placement and forces of friction dampers using the Firefly Algorithm, which is a recent meta-heuristic algorithm inspired in the behavior of fireflies. Herein, three different optimization objective are presented: i) minimize the maximum displacement at the top of the structure; ii) minimize the maximum inter-story drift; iii) minimize the maximum acceleration at the top of the structure. The three objective functions were evaluated in two civil structures (a nine-story building and a sixteen-story building) subjected to two real seismic records. The first seismic record is El Centro, which took place in the southeastern California on the boarder of the United States and Mexico in 1940. The second one is the earthquake that occurred in Caucete, province of San Juan, Argentina, in 1977. The results showed that the proposed method was able to optimize the friction dampers, reducing considerably the response of the structures.