If there exists error between ({{hat {mathbf {a}}}_{S}}) and a S, the following iterative method will reduce this error step by step so as to make (22) reliable.
Since label proportions estimated by human in grid labeling may differ from the true label proportions, there possibly exist errors in label proportion p k.
The quality of the clinical chart is notoriously variable, so there may exist errors and distortions from missing symptoms and falsely rating symptoms as absent when reviewing a chart, because of the failure of the clinician to mention them in the chart, which would have been detected in a structured, face-to-face interview.
However, there still exist errors in several areas (e.g., the red color indicated by arrows) due to signal intensity variations across different diffusion-encoding directions (i.e., Type 3 artifacts).
In practice, there exist channel errors between users, as discussed in [16], where the authors proposed an adaptive DF scheme with BNC.
However, we are well aware that the structure of the model is simplified and there exist modeling errors embedded in the structure of the mathematical model.
Note that there always exists errors in channel estimation by using outdated CSI due to the channel variant characteristics of R→D links, and those errors will consequently deteriorate the relay selection if full CSI is employed.
Case 3. Two errors: when there exist two errors in the column, only if the two errors are both not located at the erasure, the erasure can be recovered.
For the pollutant source identification of multiple point sources in a water pollution incident, there exists certain error even mistake, because this kind of "inverse problem" is a so called "ill-posed problem" mathematically, which does not have a unique solution.
