model can be compared to the previous one except that data required on another
processor are sent asynchronously i.e. without stopping current computations.
This technique allows communications to be partially overlapped by computations
-but unfortunately, the overlapping is only partial and important idle times
-remain. It is clear that, in a grid computing context, where the number of
+but unfortunately, the overlapping is only partial and useless idle times used for synchronization remain.
+It is clear that, in a grid computing context, where the number of
computational nodes is large, heterogeneous and widely distributed, the idle
times generated by synchronizations are very penalizing. One way to overcome
this problem is to use the asynchronous iterations model. Here, local
