“…However, since GMM is estimated explicitly by expectation maximization (EM) algorithm [19], the computational cost is usually high. Some researchers thus suggested quite a few alternative (and computationally more efficient) approaches, e.g., clustering techniques [15], [20], [21], niching methods [16], and parallel island models [22], [23] to manage multiple Gaussian models. Among them, clustering based EDAs apply clustering techniques to divide a population into several clusters, and form a sub-model for each cluster.…”