Previous research has shown that fully-connected networks with small initialization and gradient-based training methods exhibit a phenomenon known as condensation during training. This phenomenon refers to the input weights of hidden neurons condensing into isolated orientations during training, revealing an implicit bias towards simple solutions in the parameter space. However, the impact of neural network structure on condensation has not been investigated yet. In this study, we focus on the investigation of convolutional neural networks (CNNs). Our experiments suggest that when subjected to small initialization and gradient-based training methods, kernel weights within the same CNN layer also cluster together during training, demonstrating a significant degree of condensation. Theoretically, we demonstrate that in a finite training period, kernels of a two-layer CNN with small initialization will converge to one or a few directions. This work represents a step towards a better understanding of the non-linear training behavior exhibited by neural networks with specialized structures.

本研究探讨了卷积神经网络在小初始化和梯度训练方法下内核权重的凝聚现象，实验证明该现象在卷积神经网络中同样存在且显著。理论上，本研究证明在有限的训练期间，具有小初始化的两层卷积神经网络内核将收敛至一个或几个方向，为对具有专业结构的神经网络表现出的非线性训练行为的更好理解迈出了一步。

卷积神经网络初步凝结的理解