“…These existing methods include the projected gradient method [34,52], the interior point method [37], the projected quasi-Newton method [22,51], the active-set method [3,46,24,31], the activeset-like method [27,28], the alternating nonnegative least squares based on block principal pivoting (ANLS-BPP) method [28]. There also exist many variants of NMF (1.1) that add constraints and/or penalty terms on U and V for better interpretation and representation of the characteristics of the tasks [1,48] including sparse NMF [9,44,23], orthogonal NMF [33], semi-NMF [42], Joint NMF [14], nonnegative tensor factorization [7,9,25,26,43], manifold NMF [49], kernel NMF [53], regularized NMF [44,47], Symmetric NMF [19,45], integer constrained [12], and so on.…”