Stochastic nested variance reduction for nonconvex optimization

D Zhou, P Xu, Q Gu - Journal of machine learning research, 2020 - jmlr.org
We study nonconvex optimization problems, where the objective function is either an
average of n nonconvex functions or the expectation of some stochastic function. We …

Convex optimization algorithms in medical image reconstruction—in the age of AI

J Xu, F Noo - Physics in Medicine & Biology, 2022 - iopscience.iop.org
The past decade has seen the rapid growth of model based image reconstruction (MBIR)
algorithms, which are often applications or adaptations of convex optimization algorithms …

Momentum improves normalized sgd

A Cutkosky, H Mehta - International conference on machine …, 2020 - proceedings.mlr.press
We provide an improved analysis of normalized SGD showing that adding momentum
provably removes the need for large batch sizes on non-convex objectives. Then, we …

A single-timescale method for stochastic bilevel optimization

T Chen, Y Sun, Q Xiao, W Yin - International Conference on …, 2022 - proceedings.mlr.press
Stochastic bilevel optimization generalizes the classic stochastic optimization from the
minimization of a single objective to the minimization of an objective function that depends …

A Single-Timescale Method for Stochastic Bilevel Optimization

T Chen, Y Sun, Q Xiao, W Yin - arXiv preprint arXiv:2102.04671, 2021 - arxiv.org
Stochastic bilevel optimization generalizes the classic stochastic optimization from the
minimization of a single objective to the minimization of an objective function that depends …

A general sample complexity analysis of vanilla policy gradient

R Yuan, RM Gower, A Lazaric - International Conference on …, 2022 - proceedings.mlr.press
We adapt recent tools developed for the analysis of Stochastic Gradient Descent (SGD) in
non-convex optimization to obtain convergence and sample complexity guarantees for the …

A unified convergence analysis for shuffling-type gradient methods

LM Nguyen, Q Tran-Dinh, DT Phan, PH Nguyen… - Journal of Machine …, 2021 - jmlr.org
In this paper, we propose a unified convergence analysis for a class of generic shuffling-type
gradient methods for solving finite-sum optimization problems. Our analysis works with any …

Accelerated zeroth-order and first-order momentum methods from mini to minimax optimization

F Huang, S Gao, J Pei, H Huang - Journal of Machine Learning Research, 2022 - jmlr.org
In the paper, we propose a class of accelerated zeroth-order and first-order momentum
methods for both nonconvex mini-optimization and minimax-optimization. Specifically, we …

On momentum-based gradient methods for bilevel optimization with nonconvex lower-level

F Huang - arXiv preprint arXiv:2303.03944, 2023 - arxiv.org
Bilevel optimization is a popular two-level hierarchical optimization, which has been widely
applied to many machine learning tasks such as hyperparameter learning, meta learning …

Momentum-based policy gradient methods

F Huang, S Gao, J Pei, H Huang - … conference on machine …, 2020 - proceedings.mlr.press
In the paper, we propose a class of efficient momentum-based policy gradient methods for
the model-free reinforcement learning, which use adaptive learning rates and do not require …