DC is all you need: describing ReLU from a signal processing standpoint

Fuente: arXiv
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Main Authors: Kechris, Christodoulos, Dan, Jonathan, Miranda, Jose, Atienza, David
Format: Preprint
Published: 2024
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author Kechris, Christodoulos
Dan, Jonathan
Miranda, Jose
Atienza, David
author_facet Kechris, Christodoulos
Dan, Jonathan
Miranda, Jose
Atienza, David
contents Non-linear activation functions are crucial in Convolutional Neural Networks. However, until now they have not been well described in the frequency domain. In this work, we study the spectral behavior of ReLU, a popular activation function. We use the ReLU's Taylor expansion to derive its frequency domain behavior. We demonstrate that ReLU introduces higher frequency oscillations in the signal and a constant DC component. Furthermore, we investigate the importance of this DC component, where we demonstrate that it helps the model extract meaningful features related to the input frequency content. We accompany our theoretical derivations with experiments and real-world examples. First, we numerically validate our frequency response model. Then we observe ReLU's spectral behavior on two example models and a real-world one. Finally, we experimentally investigate the role of the DC component introduced by ReLU in the CNN's representations. Our results indicate that the DC helps to converge to a weight configuration that is close to the initial random weights.
format Preprint
id arxiv_https___arxiv_org_abs_2407_16556
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle DC is all you need: describing ReLU from a signal processing standpoint
Kechris, Christodoulos
Dan, Jonathan
Miranda, Jose
Atienza, David
Machine Learning
Signal Processing
Non-linear activation functions are crucial in Convolutional Neural Networks. However, until now they have not been well described in the frequency domain. In this work, we study the spectral behavior of ReLU, a popular activation function. We use the ReLU's Taylor expansion to derive its frequency domain behavior. We demonstrate that ReLU introduces higher frequency oscillations in the signal and a constant DC component. Furthermore, we investigate the importance of this DC component, where we demonstrate that it helps the model extract meaningful features related to the input frequency content. We accompany our theoretical derivations with experiments and real-world examples. First, we numerically validate our frequency response model. Then we observe ReLU's spectral behavior on two example models and a real-world one. Finally, we experimentally investigate the role of the DC component introduced by ReLU in the CNN's representations. Our results indicate that the DC helps to converge to a weight configuration that is close to the initial random weights.
title DC is all you need: describing ReLU from a signal processing standpoint
topic Machine Learning
Signal Processing
url https://arxiv.org/abs/2407.16556