Embedding Principle in Depth for the Loss Landscape Analysis of Deep Neural Networks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bai, Zhiwei, Luo, Tao, Xu, Zhi-Qin John, Zhang, Yaoyu
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915238418317312
author Bai, Zhiwei
Luo, Tao
Xu, Zhi-Qin John
Zhang, Yaoyu
author_facet Bai, Zhiwei
Luo, Tao
Xu, Zhi-Qin John
Zhang, Yaoyu
contents Understanding the relation between deep and shallow neural networks is extremely important for the theoretical study of deep learning. In this work, we discover an embedding principle in depth that loss landscape of an NN "contains" all critical points of the loss landscapes for shallower NNs. The key tool for our discovery is the critical lifting operator proposed in this work that maps any critical point of a network to critical manifolds of any deeper network while preserving the outputs. This principle provides new insights to many widely observed behaviors of DNNs. Regarding the easy training of deep networks, we show that local minimum of an NN can be lifted to strict saddle points of a deeper NN. Regarding the acceleration effect of batch normalization, we demonstrate that batch normalization helps avoid the critical manifolds lifted from shallower NNs by suppressing layer linearization. We also prove that increasing training data shrinks the lifted critical manifolds, which can result in acceleration of training as demonstrated in experiments. Overall, our discovery of the embedding principle in depth uncovers the depth-wise hierarchical structure of deep learning loss landscape, which serves as a solid foundation for the further study about the role of depth for DNNs.
format Preprint
id arxiv_https___arxiv_org_abs_2205_13283
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Embedding Principle in Depth for the Loss Landscape Analysis of Deep Neural Networks
Bai, Zhiwei
Luo, Tao
Xu, Zhi-Qin John
Zhang, Yaoyu
Machine Learning
Understanding the relation between deep and shallow neural networks is extremely important for the theoretical study of deep learning. In this work, we discover an embedding principle in depth that loss landscape of an NN "contains" all critical points of the loss landscapes for shallower NNs. The key tool for our discovery is the critical lifting operator proposed in this work that maps any critical point of a network to critical manifolds of any deeper network while preserving the outputs. This principle provides new insights to many widely observed behaviors of DNNs. Regarding the easy training of deep networks, we show that local minimum of an NN can be lifted to strict saddle points of a deeper NN. Regarding the acceleration effect of batch normalization, we demonstrate that batch normalization helps avoid the critical manifolds lifted from shallower NNs by suppressing layer linearization. We also prove that increasing training data shrinks the lifted critical manifolds, which can result in acceleration of training as demonstrated in experiments. Overall, our discovery of the embedding principle in depth uncovers the depth-wise hierarchical structure of deep learning loss landscape, which serves as a solid foundation for the further study about the role of depth for DNNs.
title Embedding Principle in Depth for the Loss Landscape Analysis of Deep Neural Networks
topic Machine Learning
url https://arxiv.org/abs/2205.13283