activity
20162026
most citedInducing Neural Collapse in Imbalanced Learning: Do We Really Need a Learnable Classifier at the End of Deep Neural Network?

21 citations · 78 across the 16 of their papers we have counts for

collaborators

18 papers

math.OC2026

Polynomial Acceleration of Alternating Projections: Chebyshev Acceleration, Convergence Rates, and Retractions

Dengyu Zheng, Shixiang Chen

Alternating projections (AP) near a clean intersection of smooth manifolds can converge slowly when the Friedrichs angle is small. We develop the \emph{Fixed-Point Manifold Acceler…

math.OC2026

From Manifold Identification to Newton Acceleration on Intersections: Sparse Stiefel Optimization

Shixiang Chen, Wen Huang

We study a Newton acceleration for sparse composite optimization on the Stiefel manifold. The main difficulty is geometric: the active manifold identified by the nonsmooth regulari…

math.OC2026

Retractions by Alternating Projections

Shixiang Chen, Yixiao He, Wen Huang

Alternating projections and their variants are classical tools for computing points in intersections of sets. Existing analyses for smooth manifolds mainly focus on local convergen…

math.OC2025

Distributed Stochastic Proximal Algorithm on Riemannian Submanifolds for Weakly-convex Functions

Jishu Zhao, Xi Wang, Jinlong Lei +1

This paper aims to investigate the distributed stochastic optimization problems on compact embedded submanifolds (in the Euclidean space) where the local cost functions are weakly-…

cs.LG2024

Retraction-Free Decentralized Non-convex Optimization with Orthogonal Constraints

Youbang Sun, Shixiang Chen, Alfredo Garcia +1

In this paper, we investigate decentralized non-convex optimization with orthogonal constraints. Conventional algorithms for this setting require either manifold retractions or oth…

cs.LG2023★ 1 cited

FedLALR: Client-Specific Adaptive Learning Rates Achieve Linear Speedup for Non-IID Data

Hao Sun, Li Shen, Shixiang Chen +4

Federated learning is an emerging distributed machine learning method, enables a large number of clients to train a model without exchanging their local data. The time cost of comm…

cs.LG2023★ 7 cited

Dynamic Regularized Sharpness Aware Minimization in Federated Learning: Approaching Global Consistency and Smooth Landscape

Yan Sun, Li Shen, Shixiang Chen +2

In federated learning (FL), a cluster of local clients are chaired under the coordination of the global server and cooperatively train one model with privacy protection. Due to the…

math.OC2023

Decentralized Weakly Convex Optimization Over the Stiefel Manifold

Jinxin Wang, Jiang Hu, Shixiang Chen +2

We focus on a class of non-smooth optimization problems over the Stiefel manifold in the decentralized setting, where a connected network of agents cooperatively minimize a fin…

cs.LG2023

AdaSAM: Boosting Sharpness-Aware Minimization with Adaptive Learning Rate and Momentum for Training Deep Neural Networks

Hao Sun, Li Shen, Qihuang Zhong +6

Sharpness aware minimization (SAM) optimizer has been extensively explored as it can generalize better for training deep neural networks via introducing extra perturbation steps to…

cs.LG2023★ 1 cited

OmniForce: On Human-Centered, Large Model Empowered and Cloud-Edge Collaborative AutoML System

Chao Xue, Wei Liu, Shuai Xie +25

Automated machine learning (AutoML) seeks to build ML models with minimal human effort. While considerable research has been conducted in the area of AutoML in general, aiming to t…

cs.LG2022★ 6 cited

Penalized Proximal Policy Optimization for Safe Reinforcement Learning

Linrui Zhang, Li Shen, Long Yang +4

Safe reinforcement learning aims to learn the optimal policy while satisfying safety constraints, which is essential in real-world applications. However, current algorithms still s…

cs.LG2022★ 21 cited

Inducing Neural Collapse in Imbalanced Learning: Do We Really Need a Learnable Classifier at the End of Deep Neural Network?

Yibo Yang, Shixiang Chen, Xiangtai Li +3

Modern deep neural networks for classification usually jointly learn a backbone for representation and a linear classifier to output the logit of each class. A recent study has sho…

stat.ML2020★ 3 cited

A Manifold Proximal Linear Method for Sparse Spectral Clustering with Application to Single-Cell RNA Sequencing Data Analysis

Zhongruo Wang, Bingyuan Liu, Shixiang Chen +3

Spectral clustering is one of the fundamental unsupervised learning methods widely used in data analysis. Sparse spectral clustering (SSC) imposes sparsity to the spectral clusteri…

math.OC2020★ 2 cited

Manifold Proximal Point Algorithms for Dual Principal Component Pursuit and Orthogonal Dictionary Learning

Shixiang Chen, Zengde Deng, Shiqian Ma +1

We consider the problem of maximizing the norm of a linear map over the sphere, which arises in various machine learning applications such as orthogonal dictionary learnin…

math.OC2019★ 16 cited

Weakly Convex Optimization over Stiefel Manifold Using Riemannian Subgradient-Type Methods

Xiao Li, Shixiang Chen, Zengde Deng +3

We consider a class of nonsmooth optimization problems over the Stiefel manifold, in which the objective function is weakly convex in the ambient Euclidean space. Such problems are…

stat.ML2019★ 7 cited

An Alternating Manifold Proximal Gradient Method for Sparse PCA and Sparse CCA

Shixiang Chen, Shiqian Ma, Lingzhou Xue +1

Sparse principal component analysis (PCA) and sparse canonical correlation analysis (CCA) are two essential techniques from high-dimensional statistics and machine learning for ana…

math.OC2018★ 6 cited

Proximal Gradient Method for Nonsmooth Optimization over the Stiefel Manifold

Shixiang Chen, Shiqian Ma, Anthony Man-Cho So +1

We consider optimization problems over the Stiefel manifold whose objective function is the summation of a smooth function and a nonsmooth function. Existing methods for solving th…

math.OC2016★ 8 cited

Geometric descent method for convex composite minimization

Shixiang Chen, Shiqian Ma, Wei Liu

In this paper, we extend the geometric descent method recently proposed by Bubeck, Lee and Singh to tackle nonsmooth and strongly convex composite problems. We prove that our propo…