“…A promising way to make RO approaches efficiently is to adopt metamodel (or surrogate), which can mimic the original system at a considerably reduced computational cost. There are a lot of commonly used metamodels, such as polynomial response surface models (Eddy et al, 2015), Kriging metamodels (Kleijnen, 2009;Zhou et al, 2016), neural networks models (Chang et al, 2016;Wang et al, 2016), radial basis function models (Jiang et al, 2015) and support vector regression models (Zhou et al, 2015b;Xiao et al, 2015). Among these metamodeling techniques, Kriging metamodel is the most intensively On-line Kriging metamodel investigated metamodel for improving the computational efficiency of RO because it presents several interesting difference compared with other metamodels (Kleijnen, 2009;Gao et al, 2016).…”