“…The shape of Rastrigin benchmark function is shown in Figure 4, which illustrates the large number of its local optima. The results obtained from SSO algorithm for the test case are shown in Table 1 and compared with the results obtained from 32 other metaheuristic optimization approaches including EA [17], GA [37], improved GA (IGA) [37], DE [18], PSO [6], iteration PSO (IPSO) [38], chaotic PSO (CPSO) [32], APSO [32], PSO with time varying acceleration coefficients (PSOTVAC) [6], PSO with improved inertia weight (PSOIIW) [39], hybrid GA-PSO (HGAPSO) [40], dynamic PSO (DPSO) [41], fuzzy PSO (FPSO) [42], harmony search algorithm (HSA) [43], improved HSA (IHSA) [43], ACO [7], chaotic ACO (CACO) [8], bacterial foraging algorithm (BFA) [13], GSA [20], IGSA [21], seeker optimization algorithm (SOA) [44], imperialist competitive algorithm (ICA) [45], ABC [12], improved ABC (IABC) [11], chaotic ABC (CABC) [46], parallel ABC (PABC) [36], discrete ABC (DABC) [47], rosenberg ABC (RABC) [48], modified ABC (MABC) [48], HBMO [9], improved HBMO (IHBMO) [10], and honey bee optimization (HBO) [49]. All of these 32 benchmark methods have frequently been used in engineering applications and, for this reason, have been considered here for comparison with the proposed SSO algorithm.…”