Before revision:  According to our model, structure analysis can be formally defined as decomposing a traffic matrix into low-rank, sparse, and noise sub-matrixes , which is equal to the Robust Principal Component Analysis (RPCA) problem defined in [13].
After revision:  According to our model, structure analysis can be formally defined as decomposing a traffic matrix into low-rank, sparse, and noise sub-matrixes , which is equal to the Robust Principal Component Analysis (RPCA) problem previously studied in [13].