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Performance on Novel Data

In order to evaluate the generalization capabilities of each of the inverse modeling techniques we constructed a novel data set comprising target sounds that required parameter values that were not in the original training set but that were generalized as a result of the learning. We produced a new set of waveforms using the D string on the violin with stop positions that were in quarter-tones with the training set. The frequencies available at a quarter-tone resolution we were limited by:

  equation287

which gave n = 69. Therefore ( tex2html_wrap_inline526 ). So we had to limit the testing set to 14 waveforms computed in the range D4 - tex2html_wrap_inline526 .

   figure296
Figure: Mean Performance of the Inverse Models: Novel Data

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Figures gif and gif show the distribution of errors in the output of each of the inverse models. The inverse model with the best overall performance on the novel data was the model trained using the predicted performance error. The mean-squared performance error for this model was tex2html_wrap_inline616 giving an error of bits. The accuracy is better than for the original training data because we were testing the model in a small range of the problem space, due to the limited frequency resolution of the physical model. The results show that the generalization capabilities of distal inverse models are good for the given problem domain.

   figure306
Figure: Performance Outcomes of the Inverse Models: Novel Data

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Michael Casey
Mon Mar 4 18:10:46 EST 1996