The decomposed left matrix of Non-negative Matrix Factorization (NMF) is required to be full columnrank, which limits of its application to Underdetermined Blind Source Separation (UBSS).
非负矩阵分解（NMF）要求分解得到的左矩阵为列满秩，这限制了它在欠定盲分离（UBSS）中的应用。
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If a portlet is undefined, such as 10 in the Rankcolumn (Figure 15), you will not be able to input a mapping to that portlet in the ClearQuest profile mapping.