  We introduce a novel variant of the recursive multilevel trust-region (RMTR)
method, called MASTR. The method is designed for solving non-convex
bound-constrained minimization problems, which arise from the finite element
discretization of partial differential equations. MASTR utilizes an active-set
strategy based on the truncated basis approach in order to preserve the
variable bounds defined on the finest level by the coarser levels. Usage of
this approach allows for fast convergence of the MASTR method, especially once
the exact active-set is detected. The efficiency of the method is demonstrated
by means of numerical examples.
