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Xiangyi Chen

9 accepted papers

2022

Distributed adversarial training to robustify deep neural networks at scale

UAI 2022poster

Current deep neural networks (DNNs) are vulnerable to adversarial attacks, where adversarial perturbations to the inputs can change or manipulate classification. To defend against such attacks, an effective and popular approach, known as adversarial training (AT), has been shown to mitigate the nega…

2022

Understanding Clipping for Federated Learning: Convergence and Client-Level Differential Privacy

ICML 2022spotlight

Providing privacy protection has been one of the primary motivations of Federated Learning (FL). Recently, there has been a line of work on incorporating the formal privacy notion of differential privacy with FL. To guarantee the client-level differential privacy in FL algorithms, the clients’ trans…

Cited by 133SourcePDFScholar
2020

Distributed Training with Heterogeneous Data: Bridging Median- and Mean-Based Algorithms

NeurIPS 2020poster

Recently, there is a growing interest in the study of median-based algorithms for distributed non-convex optimization. Two prominent examples include signSGD with majority vote, an effective approach for communication reduction via 1-bit compression on the local gradients, and medianSGD, an algorith…

Cited by 83SourcePDFScholar
2020

Min-Max Optimization without Gradients: Convergence and Applications to Black-Box Evasion and Poisoning Attacks

ICML 2020poster

In this paper, we study the problem of constrained min-max optimization in a black-box setting, where the desired optimizer cannot access the gradients of the objective function but may query its values. We present a principled optimization framework, integrating a zeroth-order (ZO) gradient estimat…

Cited by 100SourcePDFScholar
2020

Understanding Gradient Clipping in Private SGD: A Geometric Perspective

NeurIPS 2020spotlight

Deep learning models are increasingly popular in many machine learning applications where the training data may contain sensitive information. To provide formal and rigorous privacy guarantee, many learning systems now incorporate differential privacy by training their models with (differentially) p…

Cited by 246SourcePDFScholar
2019

On the Convergence of A Class of Adam-Type Algorithms for Non-Convex Optimization

ICLR 2019poster

This paper studies a class of adaptive gradient based momentum algorithms that update the search directions and learning rates simultaneously using past gradients. This class, which we refer to as the ''``Adam-type'', includes the popular algorithms such as Adam, AMSGrad, AdaGrad. Despite their pop…

Cited by 406SourcePDFScholar
2019

ZO-AdaMM: Zeroth-Order Adaptive Momentum Method for Black-Box Optimization

NeurIPS 2019poster

The adaptive momentum method (AdaMM), which uses past gradients to update descent directions and learning rates simultaneously, has become one of the most popular first-order optimization methods for solving machine learning problems. However, AdaMM is not suited for solving black-box optimization…