“…However, the research on parallelized methods for eigenvalue problems is still active (Hwang and Parsons, 1994;Katagiri and Kanada, 2001;Lang, 1999;Lui, 1998;Watkins et al, 1996). With regard to structural design optimization problems, various parallel processing ideas such as the parallelization of an optimization algorithm (Padula and Stone, 1998), the combination of the parallel finite element analysis with a serial optimization algorithm (El-Sayed and Hsiung, 1991), structural optimization based on the domain decomposition (Wang et al, 1996) have been proposed. Recently, parallel processing techniques have been applied to structural optimization problems using the zeroth-order optimizer such as genetic algorithms and evolutionary strategies (Thierauf and Cai, 1997;Topping and Leite, 1999).…”