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Bobby He

10 accepted papers

2025

The Directionality of Optimization Trajectories in Neural Networks

ICLR 2025poster

The regularity or implicit bias in neural network optimization has been typically studied via the parameter norms or the landscape curvature, often overlooking the trajectory leading to these parameters. However, properties of the trajectory --- particularly its directionality --- capture critical a…

Cited by 0SourcePDFScholar
2024

Recurrent Distance Filtering for Graph Representation Learning

ICML 2024poster

Graph neural networks based on iterative one-hop message passing have been shown to struggle in harnessing the information from distant nodes effectively. Conversely, graph transformers allow each node to attend to all other nodes directly, but lack graph inductive bias and have to rely on ad-hoc po…

2024

Understanding and Minimising Outlier Features in Transformer Training

NeurIPS 2024poster

Outlier Features (OFs) are neurons whose activation magnitudes significantly exceed the average over a neural network's (NN) width. They are well known to emerge during standard transformer training and have the undesirable effect of hindering quantisation in afflicted models. Despite their practica…

Cited by 2SourcePDFScholar
2023

Deep Transformers without Shortcuts: Modifying Self-attention for Faithful Signal Propagation

ICLR 2023poster

Skip connections and normalisation layers form two standard architectural components that are ubiquitous for the training of Deep Neural Networks (DNNs), but whose precise roles are poorly understood. Recent approaches such as Deep Kernel Shaping have made progress towards reducing our reliance on t…

Cited by 37SourcePDFScholar
2023

The Shaped Transformer: Attention Models in the Infinite Depth-and-Width Limit

NeurIPS 2023poster

In deep learning theory, the covariance matrix of the representations serves as a proxy to examine the network’s trainability. Motivated by the success of Transform- ers, we study the covariance matrix of a modified Softmax-based attention model with skip connections in the proportional limit of inf…

Cited by 40SourcePDFScholar
2022

Feature Kernel Distillation

ICLR 2022poster

Trained Neural Networks (NNs) can be viewed as data-dependent kernel machines, with predictions determined by the inner product of last-layer representations across inputs, referred to as the feature kernel. We explore the relevance of the feature kernel for Knowledge Distillation (KD), using a mech…

Cited by 28SourcePDFScholar
2021

Stable ResNet

AISTATS 2021poster

Deep ResNet architectures have achieved state of the art performance on many tasks. While they solve the problem of gradient vanishing, they might suffer from gradient exploding as the depth becomes large (Yang et al. 2017). Moreover, recent results have shown that ResNet might lose expressivity as…

2020

Bayesian Deep Ensembles via the Neural Tangent Kernel

NeurIPS 2020poster

We explore the link between deep ensembles and Gaussian processes (GPs) through the lens of the Neural Tangent Kernel (NTK): a recent development in understanding the training dynamics of wide neural networks (NNs). Previous work has shown that even in the infinite width limit, when NNs become GPs,…