“…For = 1, 1 = 3.5, 2 = 0.4, the number of particles 50, and = 100, the minimum variance 18.4 could be obtained by adjusting the acceleration coefficient , which was significantly optimized compared with the variance quoted in the literature [27]. For = 0.8, 1 = 2 = 2.05, the number of particles 50, and = 100, the minimum variance 18.93 could be obtained by adjusting the acceleration coefficient , which was significantly optimized compared with the variance quoted in [27]. For = 0.729, 1 = 2 = 1.454, the number of particles 50, and = 100, variance smaller than 17.83 (acceleration coefficient 1) could not be obtained by adjusting the acceleration coefficient .…”