Talks and presentations

Understanding Deep Learning through Over-parameterization: from Kernel Regime to Feature Learning.

February 15, 2023

Invited Talk, The Chinese University of Hong Kong, hosted by Dr. Fenglei Fan, Hong Kong, China

Understanding the learning dynamics of neural networks with (stochastic) gradient descent is a long-term goal for deep learning theory research. In this talk, the trend from the neural tangent kernel (NTK) regime to feature learning dynamics will be introduced. The NTK has been a powerful tool for researchers to understand the optimization and generalization of over-parameterized networks. We first introduce the foundation of the NTK in addition to its application to neural architecture search and active learning. Furthermore, more recent works found that the neural networks are performing feature learning during gradient descent training. We will then introduce how feature learning emerges and its application in understanding the role of graph convolution in graph neural networks.

Towards Deepening Graph Neural Networks: A GNTK-based Optimization Perspective.

June 12, 2022

Invited Talk, AI TIME, Sydney, Australia

We formulate the asymptotic behaviors of GNTK in the large depth, which enables us to reveal the dropping trainability of wide and deep GCNs at an exponential rate in the optimization process. Additionally, we extend our theoretical framework to analyze residual connection-based techniques, which are found to be merely able to mitigate the exponential decay of trainability mildly. Inspired by our theoretical insights on trainability, we propose Critical DropEdge, a connectivity-aware and graph-adaptive sampling method, to alleviate the exponential decay problem more fundamentally.

Closing the Gap between Theory and Applications in Deep Learning.

December 01, 2021

Seminar Talk, RIKEN AIP, hosted by A/Prof. Taiji Suzuki, Tokyo, Japan

Deep learning has been responsible for a step-change in performance across machine learning, setting new benchmarks in a large number of applications. During my Ph.D. study, I seek to understand the theoretical properties of deep neural networks and close the gap between the theory and application sides. This presentation will introduce three concrete works with respect to the neural tangent kernel (NTK), one of the seminal advances in deep learning theory recently.

Understanding deep neural networks through over-parameterization.

June 01, 2021

Talk, Monash University, hosted by Prof. Reza Haffari, Melbourne, Australia

The learning dynamics of neural networks trained by gradient descent are captured by the so-called neural tangent kernel (NTK) in the infinite-width limit. The NTK has been a powerful tool for researchers to understand the optimization and generalization of over-parameterized networks. In this talk, the foundation of the NTK in addition to its application to orthogonally-initialized networks and ultra-wide graph networks will be introduced.

An Introduction to the Neural Tangent Kernel.

July 01, 2020

Talk, Renmin University of China, hosted by A/Prof. Yong Liu, Beijing, China

Recently researcher find that the dynamics of infinitely-wide neural networks under gradient desent training are captured by neural tangent kernel. With the help of neural tangent kernel, researcher can prove that over-paramterized neural network can find global minimum, which is a milestone in the area of deep learning theory. This talk will present the basic properties of neural tangent kernel and my research output regarding neural tangent kernel.