activity
20232026
collaborators

13 papers

stat.ML2026

Standard Transformers Achieve the Minimax Rate in Nonparametric Regression with Targets

Yanming Lai, Defeng Sun

The tremendous success of Transformer models in fields such as large language models and computer vision necessitates a rigorous theoretical investigation. To the best of our knowl…

math.OC2025

Progressive Bound Strengthening via Doubly Nonnegative Cutting Planes for Nonconvex Quadratic Programs

Zheng Qu, Defeng Sun, Jintao Xu

We introduce a cutting-plane framework for nonconvex quadratic programs (QPs) that progressively tightens convex relaxations. Our approach leverages the doubly nonnegative (DNN) re…

math.OC2025

On the -order Semismoothness of the Metric Projection onto Slices of the Positive Semidefinite Cone

Ruoning Chen, Jiaming Ma, Defeng Sun

The metric projection onto the positive semidefinite (PSD) cone is strongly semismooth, a property that guarantees local quadratic convergence for many powerful algorithms in semid…

math.OC2025

The Aubin Property for Generalized Equations over -cone Reducible Sets

Jiaming Ma, Defeng Sun

This paper establishes the equivalence between the Aubin property and strong regularity for generalized equations over -cone reducible sets. This result resolves a long-standi…

math.OC2025

Complexity of normalized stochastic first-order methods with momentum under heavy-tailed noise

Chuan He, Zhaosong Lu, Defeng Sun +1

In this paper, we propose practical normalized stochastic first-order methods with Polyak momentum, multi-extrapolated momentum, and recursive momentum for solving unconstrained op…

math.OC2024

Support matrix machine: exploring sample sparsity, low rank, and adaptive sieving in high-performance computing

Can Wu, Dong-Hui Li, Defeng Sun

Support matrix machine (SMM) is a successful supervised classification model for matrix-type samples. Unlike support vector machines, it employs low-rank regularization on the regr…

stat.ME2024

Robust Gradient Descent Estimation for Tensor Models under Heavy-Tailed Distributions

Xiaoyu Zhang, Di Wang, Guodong Li +1

Low-rank tensor models are widely used in statistics. However, most existing methods rely heavily on the assumption that data follows a sub-Gaussian distribution. To address the ch…

math.OC2024

Lipschitz stability of least-squares problems regularized by functions with -cone reducible conjugates

Ying Cui, Tim Hoheisel, Tran T. A. Nghia +1

In this paper, we study Lipschitz continuity of the solution mappings of regularized least-squares problems for which the convex regularizers have (Fenchel) conjugates that are $\m…

math.OC2024

Characterizations of the Aubin Property of the Solution Mapping for Nonlinear Semidefinite Programming

Liang Chen, Ruoning Chen, Defeng Sun +1

In this paper, we study the Aubin property of the Karush-Kuhn-Tucker solution mapping for the nonlinear semidefinite programming (NLSDP) problem at a locally optimal solution. In t…

math.OC2024

Two Typical Implementable Semismooth* Newton Methods for Generalized Equations are G-Semismooth Newton Methods

Liang Chen, Defeng Sun, Wangyongquan Zhang

Semismooth* Newton methods have been proposed in recent years targeting multi-valued inclusion problems and have been successfully implemented to deal with several concrete general…

math.OC2024

Aubin Property and Strong Regularity Are Equivalent for Nonlinear Second-Order Cone Programming

Liang Chen, Ruoning Chen, Defeng Sun +1

This paper solves a fundamental open problem in variational analysis on the equivalence between the Aubin property and the strong regularity for nonlinear second-order cone program…

cs.AI2024

Machine Learning Insides OptVerse AI Solver: Design Principles and Applications

Xijun Li, Fangzhou Zhu, Hui-Ling Zhen +23

In an era of digital ubiquity, efficient resource management and decision-making are paramount across numerous industries. To this end, we present a comprehensive study on the inte…

math.OC2023

Solving polynomial variational inequality problems via Lagrange multiplier expressions and Moment-SOS relaxations

Jiawang Nie, Defeng Sun, Xindong Tang +1

In this paper, we study variational inequality problems (VIPs) with involved mappings and feasible sets characterized by polynomial functions (namely, polynomial VIPs). We propose…