Wave-net: a multiresolution, hierarchical neural network with localized learning

Authors

  • Bhavik R. Bakshi,

    1. Laboratory for Intelligent Systems in Process Engineering, Dept. of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
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  • George Stephanopoulos

    1. Laboratory for Intelligent Systems in Process Engineering, Dept. of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
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Abstract

A Wave-Net is an artificial neural network with one hidden layer of nodes, whose basis functions are drawn from a family of orthonormal wavelets. The good localization characteristics of the basis functions, both in the input and frequency domains, allow hierarchical, multiresolution learning of input-output maps from experimental data. Furthermore, Wave-Nets allow explicit estimation for global and local prediction error-bounds, and thus lend themselves to a rigorous and explicit design of the network. This article presents the mathematical framework for the development of Wave-Nets and discusses the various aspects of their practical implementation. Computational complexity arguments prove that the training and adaptation efficiency of Wave-Nets is at least an order of magnitude better than other networks. In addition, it presents two examples on the application of Wave-Nets; (a) the prediction of a chaotic time-series, representing population dynamics, and (b) the classification of experimental data for process fault diagnosis.

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