by Axel Pinz, Horst Bischof
Abstract:
We present a novel method to combine the knowledge of several neural networks by replacement of hidden units. Applying neural networks to digital image analysis, the underlying spatial structure of the image can be propagated into the network and used to visualize its weights (WV-diagrams). This visualization tool helps to interpret the behaviour of hidden units. We notice a process of specialization of certain hidden units, while others remain apparently useless. These units are cut out of one network and replaced by units taken from other networks trained for the same task using different parameters. We achieve better prediction accuracies for the new, combined network than for any of the two original ones. This constitutes a special kind of information fusion in image understanding. We give an application example from the field of remote sensing, where neural networks are used to interpret the species of trees in aerial photographs. The interpretation accuracy is raised from 85\% to 90\%.
Reference:
Neural Network `Surgery': Transplantation of Hidden Units (Axel Pinz, Horst Bischof), Technical report, PRIP, TU Wien, 1992.
Bibtex Entry:
@TechReport{TR015,
author = "Axel {Pinz} and Horst {Bischof}",
institution = "PRIP, TU Wien",
number = "PRIP-TR-015",
title = "Neural {N}etwork `{S}urgery': {T}ransplantation of
{H}idden {U}nits",
year = "1992",
url = "https://www.prip.tuwien.ac.at/pripfiles/trs/tr15.pdf",
abstract = "We present a novel method to combine the knowledge
of several neural networks by replacement of hidden
units. Applying neural networks to digital image
analysis, the underlying spatial structure of the
image can be propagated into the network and used to
visualize its weights (WV-diagrams). This
visualization tool helps to interpret the behaviour
of hidden units. We notice a process of
specialization of certain hidden units, while others
remain apparently useless. These units are cut out
of one network and replaced by units taken from
other networks trained for the same task using
different parameters. We achieve better prediction
accuracies for the new, combined network than for
any of the two original ones. This constitutes a
special kind of information fusion in image
understanding. We give an application example from
the field of remote sensing, where neural networks
are used to interpret the species of trees in aerial
photographs. The interpretation accuracy is raised
from 85\% to 90\%.",
}