← Search

Xun Qian

8 accepted papers

2023

Catalyst Acceleration of Error Compensated Methods Leads to Better Communication Complexity

AISTATS 2023poster

Communication overhead is well known to be a key bottleneck in large scale distributed learning, and a particularly successful class of methods which help to overcome this bottleneck is based on the idea of communication compression. Some of the most practically effective gradient compressors, such…

Cited by 2SourcePDFScholar
2022

Basis Matters: Better Communication-Efficient Second Order Methods for Federated Learning

AISTATS 2022poster

Recent advances in distributed optimization have shown that Newton-type methods with proper communication compression mechanisms can guarantee fast local rates and low communication cost compared to first order methods. We discover that the communication cost of these methods can be further reduced,…

Cited by 28SourcePDFScholar
2022

FedNL: Making Newton-Type Methods Applicable to Federated Learning

ICML 2022spotlight

Inspired by recent work of Islamov et al (2021), we propose a family of Federated Newton Learn (\algname{FedNL}) methods, which we believe is a marked step in the direction of making second-order methods applicable to FL. In contrast to the aforementioned work, \algname{FedNL} employs a different He…

Cited by 96SourcePDFScholar
2021

Distributed Second Order Methods with Fast Rates and Compressed Communication

ICML 2021spotlight

We develop several new communication-efficient second-order methods for distributed optimization. Our first method, NEWTON-STAR, is a variant of Newton’s method from which it inherits its fast local quadratic rate. However, unlike Newton’s method, NEWTON-STAR enjoys the same per iteration communicat…

Cited by 67SourcePDFScholar
2020

Acceleration for Compressed Gradient Descent in Distributed and Federated Optimization

ICML 2020poster

Due to the high communication cost in distributed and federated learning problems, methods relying on compression of communicated messages are becoming increasingly popular. While in other contexts the best performing gradient-type methods invariably rely on some form of acceleration/momentum to red…

Cited by 174SourcePDFScholar
2019

SGD: General Analysis and Improved Rates

ICML 2019oral

We propose a general yet simple theorem describing the convergence of SGD under the arbitrary sampling paradigm. Our theorem describes the convergence of an infinite array of variants of SGD, each of which is associated with a specific probability law governing the data selection rule used to form m…

Cited by 557SourcePDFScholar