“…Numerical homogenization for problems with multiple scales have attracted increasing attention in recent years. If the coefficient a(x) has structural properties such as scale separation and periodicity, together with some regularity assumptions (e.g., a(x) ∈ W 1,∞ ), classical homogenization [29,26] can be used to construct efficient multiscale computational methods and have been applied to optimal control problems, such as multiscale asymptotic expansions method [6,7,30], multiscale finite element method (MsFEM) [24,12,10,11], and heterogeneous multiscale method (HMM) [42,21].…”