Enhancing the trainability and expressivity of deep MLPs with globally orthogonal initialization
Multilayer Perceptrons (MLPs) defines a fundamental model class that forms the backbone of many modern deep learning architectures. Despite their universality guarantees, practical training via stochastic gradient descent often struggles to attain theoretical error bounds due to issues including (but not limited to) frequency bias, vanishing gradients, and stiff gradient flows. In this work we postulate that many of such issues find origins in the initialization of the network's parameters. While the initialization schemes proposed by Glorot {\it et al.} and He {\it et al.} have become the de-facto choices among practitioners, their goal to preserve the variance of forward- and backward-propagated signals is mainly achieved by assumptions on linearity, while the presence of nonlinear activation functions may partially destroy these efforts. Here, we revisit the initialization of MLPs from a dynamical systems viewpoint to explore why and how under these classical scheme, the MLP could still fail even at the beginning. Drawing inspiration from classical numerical methods for differential equations that leverage orthogonal feature representations, we propose a novel initialization scheme that promotes orthogonality in the features of the last hidden layer, ultimately leading to more diverse and localized features. Our results demonstrate that network initialization alone can be sufficient in mitigating frequency bias and yields competitive results for high-frequency function approximation and image regression tasks, without any additional modifications to the network architecture or activation functions.
Code (0)
등록된 구현이 없습니다.
Similar Papers 제목 키워드 기반
Understanding the Expressivity and Trainability of Fourier Neural Operator: A Mean-Field Perspective
In this paper, we explores the expressivity and trainability of the Fourier Neural Operator (FNO). We establish a mean-field theory for the FNO, analyzing the behavior of the random FNO from an edge of chaos perspective.…
Beyond Over-smoothing: Uncovering the Trainability Challenges in Deep Graph Neural Networks
The drastic performance degradation of Graph Neural Networks (GNNs) as the depth of the graph propagation layers exceeds 8-10 is widely attributed to a phenomenon of Over-smoothing. Although recent research suggests that…
Non-normal Recurrent Neural Network (nnRNN): learning long time dependencies while improving expressivity with transient dynamics
A recent strategy to circumvent the exploding and vanishing gradient problem in RNNs, and to allow the stable propagation of signals over long time scales, is to constrain recurrent connectivity matrices to be orthogonal…
Training-efficient density quantum machine learning
Quantum machine learning (QML) requires powerful, flexible and efficiently trainable models to be successful in solving challenging problems. We introduce density quantum neural networks, a model family that prepares mix…
LEMMAMixture-of-ExpertsQuantum Machine LearningConnecting phases of matter to the flatness of the loss landscape in analog variational quantum algorithms
Variational quantum algorithms (VQAs) promise near-term quantum advantage, yet parametrized quantum states commonly built from the digital gate-based approach often suffer from scalability issues such as barren plateaus,…
Visual Question Answering (VQA)