the work presented in this paper is based on the execution time model. To verify this model, the predicted
execution time was compared to the real execution time over Simgrid for all the NAS parallel benchmarks
running class B on 8 or 9 nodes. The comparison showed that the proposed execution time model is very precise,
-the maximum normalized difference between the predicted execution time and the real execution time is equal
+the maximum normalized difference between the predicted execution time and the real execution time is equal
to 0.03 for all the NAS benchmarks.
Since the proposed algorithm is not an exact method and do not test all the possible solutions (vectors of scaling factors)
table~(\ref{table:platform}), it takes on average \np[ms]{0.04} for 4 nodes and \np[ms]{0.15} on average for 144 nodes
to compute the best scaling factors vector. The algorithm complexity is $O(F\cdot (N \cdot4) )$, where $F$ is the number
of iterations and $N$ is the number of computing nodes. The algorithm needs from 12 to 20 iterations to select the best
-vector of frequency scaling factors that gives the results of the sections (\ref{sec.res}) and (\ref{sec.compare}) .
+vector of frequency scaling factors that gives the results of the sections (\ref{sec.res}) and (\ref{sec.compare}).
\section{Conclusion}
\label{sec.concl}
In this paper, we have presented a new online heterogeneous scaling algorithm
that selects the best possible vector of frequency scaling factors. This vector
-gives the maximum distance (optimal tradeoff) between the normalized energy and
-the performance curves. In addition, we developed a new energy model for measuring
+gives the maximum distance (optimal tradeoff) between the predicted energy and
+the predicted performance curves. In addition, we developed a new energy model for measuring
and predicting the energy of distributed iterative applications running over heterogeneous
cluster. The proposed method evaluated on Simgrid/SMPI simulator to built a heterogeneous
platform to executes NAS parallel benchmarks. The results of the experiments showed the ability of