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Bibliographic Details
Main Authors: Romero, David W., Bekkers, Erik J., Tomczak, Jakub M., Hoogendoorn, Mark
Format: Preprint
Published: 2020
Subjects:
Online Access:https://arxiv.org/abs/2006.05259
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author Romero, David W.
Bekkers, Erik J.
Tomczak, Jakub M.
Hoogendoorn, Mark
author_facet Romero, David W.
Bekkers, Erik J.
Tomczak, Jakub M.
Hoogendoorn, Mark
contents Leveraging the symmetries inherent to specific data domains for the construction of equivariant neural networks has lead to remarkable improvements in terms of data efficiency and generalization. However, most existing research focuses on symmetries arising from planar and volumetric data, leaving a crucial data source largely underexplored: time-series. In this work, we fill this gap by leveraging the symmetries inherent to time-series for the construction of equivariant neural network. We identify two core symmetries: *scale and translation*, and construct scale-translation equivariant neural networks for time-series learning. Intriguingly, we find that scale-translation equivariant mappings share strong resemblance with the wavelet transform. Inspired by this resemblance, we term our networks Wavelet Networks, and show that they perform nested non-linear wavelet-like time-frequency transforms. Empirical results show that Wavelet Networks outperform conventional CNNs on raw waveforms, and match strongly engineered spectrogram techniques across several tasks and time-series types, including audio, environmental sounds, and electrical signals. Our code is publicly available at https://github.com/dwromero/wavelet_networks.
format Preprint
id arxiv_https___arxiv_org_abs_2006_05259
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Wavelet Networks: Scale-Translation Equivariant Learning From Raw Time-Series
Romero, David W.
Bekkers, Erik J.
Tomczak, Jakub M.
Hoogendoorn, Mark
Machine Learning
Leveraging the symmetries inherent to specific data domains for the construction of equivariant neural networks has lead to remarkable improvements in terms of data efficiency and generalization. However, most existing research focuses on symmetries arising from planar and volumetric data, leaving a crucial data source largely underexplored: time-series. In this work, we fill this gap by leveraging the symmetries inherent to time-series for the construction of equivariant neural network. We identify two core symmetries: *scale and translation*, and construct scale-translation equivariant neural networks for time-series learning. Intriguingly, we find that scale-translation equivariant mappings share strong resemblance with the wavelet transform. Inspired by this resemblance, we term our networks Wavelet Networks, and show that they perform nested non-linear wavelet-like time-frequency transforms. Empirical results show that Wavelet Networks outperform conventional CNNs on raw waveforms, and match strongly engineered spectrogram techniques across several tasks and time-series types, including audio, environmental sounds, and electrical signals. Our code is publicly available at https://github.com/dwromero/wavelet_networks.
title Wavelet Networks: Scale-Translation Equivariant Learning From Raw Time-Series
topic Machine Learning
url https://arxiv.org/abs/2006.05259