Gradient-based training and pruning of radial basis function networks with an application in materials physics.

Journal: Neural networks : the official journal of the International Neural Network Society
Published Date:

Abstract

Many applications, especially in physics and other sciences, call for easily interpretable and robust machine learning techniques. We propose a fully gradient-based technique for training radial basis function networks with an efficient and scalable open-source implementation. We derive novel closed-form optimization criteria for pruning the models for continuous as well as binary data which arise in a challenging real-world material physics problem. The pruned models are optimized to provide compact and interpretable versions of larger models based on informed assumptions about the data distribution. Visualizations of the pruned models provide insight into the atomic configurations that determine atom-level migration processes in solid matter; these results may inform future research on designing more suitable descriptors for use with machine learning algorithms.

Authors

  • Jussi Määttä
    Department of Computer Science, University of Helsinki, Finland; Helsinki Institute for Information Technology (HIIT), Helsinki, Finland. Electronic address: jussi.maatta@alumni.helsinki.fi.
  • Viacheslav Bazaliy
    Department of Computer Science, University of Helsinki, Finland; Helsinki Institute for Information Technology (HIIT), Helsinki, Finland. Electronic address: viacheslav.bazaliy@alumni.helsinki.fi.
  • Jyri Kimari
    Helsinki Institute of Physics and Department of Physics, University of Helsinki, Finland. Electronic address: jyri.kimari@helsinki.fi.
  • Flyura Djurabekova
    Helsinki Institute of Physics and Department of Physics, University of Helsinki, Finland. Electronic address: flyura.djurabekova@helsinki.fi.
  • Kai Nordlund
    Helsinki Institute of Physics and Department of Physics, University of Helsinki, Finland. Electronic address: kai.nordlund@helsinki.fi.
  • Teemu Roos
    Department of Computer Science, University of Helsinki, Helsinki, Finland.