Search Results for author: Lexing Ying

Found 64 papers, 11 papers with code

A Mean Field Analysis Of Deep ResNet And Beyond: Towards Provably Optimization Via Overparameterization From Depth

no code implementations ICML 2020 Yiping Lu, Chao Ma, Yulong Lu, Jianfeng Lu, Lexing Ying

Specifically, we propose a \textbf{new continuum limit} of deep residual networks, which enjoys a good landscape in the sense that \textbf{every local minimizer is global}.

A Sinkhorn-type Algorithm for Constrained Optimal Transport

no code implementations8 Mar 2024 Xun Tang, Holakou Rahmanian, Michael Shavlovsky, Kiran Koshy Thekumparampil, Tesi Xiao, Lexing Ying

We derive the corresponding entropy regularization formulation and introduce a Sinkhorn-type algorithm for such constrained OT problems supported by theoretical guarantees.

Scheduling

Multidimensional unstructured sparse recovery via eigenmatrix

no code implementations27 Feb 2024 Lexing Ying

This note considers the multidimensional unstructured sparse recovery problems.

Convergence Analysis of Discrete Diffusion Model: Exact Implementation through Uniformization

no code implementations12 Feb 2024 Hongrui Chen, Lexing Ying

Diffusion models have achieved huge empirical success in data generation tasks.

Ensemble-Based Annealed Importance Sampling

no code implementations28 Jan 2024 Haoxuan Chen, Lexing Ying

We discuss how the proposed algorithm can be implemented and derive a partial differential equation governing the evolution of the ensemble under the continuous time and mean-field limit.

Understanding the Generalization Benefits of Late Learning Rate Decay

no code implementations21 Jan 2024 Yinuo Ren, Chao Ma, Lexing Ying

Why do neural networks trained with large learning rates for a longer time often lead to better generalization?

Accelerating Sinkhorn Algorithm with Sparse Newton Iterations

no code implementations20 Jan 2024 Xun Tang, Michael Shavlovsky, Holakou Rahmanian, Elisa Tardini, Kiran Koshy Thekumparampil, Tesi Xiao, Lexing Ying

To achieve possibly super-exponential convergence, we present Sinkhorn-Newton-Sparse (SNS), an extension to the Sinkhorn algorithm, by introducing early stopping for the matrix scaling steps and a second stage featuring a Newton-type subroutine.

Statistical Spatially Inhomogeneous Diffusion Inference

no code implementations10 Dec 2023 Yinuo Ren, Yiping Lu, Lexing Ying, Grant M. Rotskoff

Inferring a diffusion equation from discretely-observed measurements is a statistical challenge of significant importance in a variety of fields, from single-molecule tracking in biophysical systems to modeling financial instruments.

Generalization Bounds

Eigenmatrix for unstructured sparse recovery

no code implementations28 Nov 2023 Lexing Ying

This note considers the unstructured sparse recovery problems in a general form.

Multi-Objective Optimization via Wasserstein-Fisher-Rao Gradient Flow

no code implementations22 Nov 2023 Yinuo Ren, Tesi Xiao, Tanmay Gangwani, Anshuka Rangi, Holakou Rahmanian, Lexing Ying, Subhajit Sanyal

Multi-objective optimization (MOO) aims to optimize multiple, possibly conflicting objectives with widespread applications.

When can Regression-Adjusted Control Variates Help? Rare Events, Sobolev Embedding and Minimax Optimality

no code implementations25 May 2023 Jose Blanchet, Haoxuan Chen, Yiping Lu, Lexing Ying

We demonstrate that this kind of quadrature rule can improve the Monte Carlo rate and achieve the minimax optimal rate under a sufficient smoothness assumption.

regression

High-dimensional density estimation with tensorizing flow

no code implementations1 Dec 2022 Yinuo Ren, Hongli Zhao, Yuehaw Khoo, Lexing Ying

We propose the tensorizing flow method for estimating high-dimensional probability density functions from the observed data.

Density Estimation Vocal Bursts Intensity Prediction

Continuous-in-time Limit for Bayesian Bandits

no code implementations14 Oct 2022 Yuhua Zhu, Zachary Izzo, Lexing Ying

The optimal policy for the limiting HJB equation can be explicitly obtained for several common bandit problems, and we give numerical methods to solve the HJB equation when an explicit solution is not available.

Why self-attention is Natural for Sequence-to-Sequence Problems? A Perspective from Symmetries

no code implementations13 Oct 2022 Chao Ma, Lexing Ying

The knowledge consists of a set of vectors in the same embedding space as the input sequence, containing the information of the language used to process the input sequence.

Minimax Optimal Kernel Operator Learning via Multilevel Training

no code implementations28 Sep 2022 Jikai Jin, Yiping Lu, Jose Blanchet, Lexing Ying

Learning mappings between infinite-dimensional function spaces has achieved empirical success in many disciplines of machine learning, including generative modeling, functional data analysis, causal inference, and multi-agent reinforcement learning.

Causal Inference Multi-agent Reinforcement Learning +1

Importance Tempering: Group Robustness for Overparameterized Models

no code implementations19 Sep 2022 Yiping Lu, Wenlong Ji, Zachary Izzo, Lexing Ying

In this paper, we propose importance tempering to improve the decision boundary and achieve consistently better results for overparameterized models.

imbalanced classification

Generative Modeling via Tree Tensor Network States

no code implementations3 Sep 2022 Xun Tang, YoonHaeng Hur, Yuehaw Khoo, Lexing Ying

In this paper, we present a density estimation framework based on tree tensor-network states.

Density Estimation

Bayesian regularization of empirical MDPs

no code implementations3 Aug 2022 Samarth Gupta, Daniel N. Hill, Lexing Ying, Inderjit Dhillon

Due to noise, the policy learnedfrom the estimated model is often far from the optimal policy of the underlying model.

Sobolev Acceleration and Statistical Optimality for Learning Elliptic Equations via Gradient Descent

no code implementations15 May 2022 Yiping Lu, Jose Blanchet, Lexing Ying

In this paper, we study the statistical limits in terms of Sobolev norms of gradient descent for solving inverse problem from randomly sampled noisy observations using a general class of objective functions.

Beyond the Quadratic Approximation: the Multiscale Structure of Neural Network Loss Landscapes

no code implementations24 Apr 2022 Chao Ma, Daniel Kunin, Lei Wu, Lexing Ying

Numerically, we observe that neural network loss functions possesses a multiscale structure, manifested in two ways: (1) in a neighborhood of minima, the loss mixes a continuum of scales and grows subquadratically, and (2) in a larger region, the loss shows several separate scales clearly.

Monte Carlo Tree Search based Hybrid Optimization of Variational Quantum Circuits

no code implementations30 Mar 2022 Jiahao Yao, Haoya Li, Marin Bukov, Lin Lin, Lexing Ying

Variational quantum algorithms stand at the forefront of simulations on near-term and future fault-tolerant quantum devices.

Provably convergent quasistatic dynamics for mean-field two-player zero-sum games

no code implementations ICLR 2022 Chao Ma, Lexing Ying

In this paper, we study the problem of finding mixed Nash equilibrium for mean-field two-player zero-sum games.

How to Learn when Data Gradually Reacts to Your Model

no code implementations13 Dec 2021 Zachary Izzo, James Zou, Lexing Ying

A recent line of work has focused on training machine learning (ML) models in the performative setting, i. e. when the data distribution reacts to the deployed model.

Operator Shifting for Model-based Policy Evaluation

no code implementations25 Oct 2021 Xun Tang, Lexing Ying, Yuhua Zhu

When the error is in the residual norm, we prove that the shifting factor is always positive and upper bounded by $1+O\left(1/n\right)$, where $n$ is the number of samples used in learning each row of the transition matrix.

Model-based Reinforcement Learning reinforcement-learning +1

A Riemannian Mean Field Formulation for Two-layer Neural Networks with Batch Normalization

no code implementations17 Oct 2021 Chao Ma, Lexing Ying

Later, the infinite-width limit of the two-layer neural networks with BN is considered, and a mean-field formulation is derived for the training dynamics.

Machine Learning For Elliptic PDEs: Fast Rate Generalization Bound, Neural Scaling Law and Minimax Optimality

no code implementations ICLR 2022 Yiping Lu, Haoxuan Chen, Jianfeng Lu, Lexing Ying, Jose Blanchet

In this paper, we study the statistical limits of deep learning techniques for solving elliptic partial differential equations (PDEs) from random samples using the Deep Ritz Method (DRM) and Physics-Informed Neural Networks (PINNs).

Approximate Newton policy gradient algorithms

no code implementations5 Oct 2021 Haoya Li, Samarth Gupta, HsiangFu Yu, Lexing Ying, Inderjit Dhillon

This paper proposes an approximate Newton method for the policy gradient algorithm with entropy regularization.

Statistical Numerical PDE : Fast Rate, Neural Scaling Law and When it’s Optimal

no code implementations NeurIPS Workshop DLDE 2021 Yiping Lu, Haoxuan Chen, Jianfeng Lu, Lexing Ying, Jose Blanchet

In this paper, we study the statistical limits of deep learning techniques for solving elliptic partial differential equations (PDEs) from random samples using the Deep Ritz Method (DRM) and Physics-Informed Neural Networks (PINNs).

Variational Actor-Critic Algorithms

no code implementations3 Aug 2021 Yuhua Zhu, Lexing Ying

The objective function of the variational formulation consists of two parts: one for maximizing the value function and the other for minimizing the Bellman residual.

Combining resampling and reweighting for faithful stochastic optimization

no code implementations31 May 2021 Jing An, Lexing Ying

When the loss function is a sum of multiple terms, a popular method is the stochastic gradient descent.

Stochastic Optimization

On Linear Stability of SGD and Input-Smoothness of Neural Networks

1 code implementation NeurIPS 2021 Chao Ma, Lexing Ying

The multiplicative structure of parameters and input data in the first layer of neural networks is explored to build connection between the landscape of the loss function with respect to parameters and the landscape of the model function with respect to input data.

Adversarial Robustness

A semigroup method for high dimensional elliptic PDEs and eigenvalue problems based on neural networks

no code implementations7 May 2021 Haoya Li, Lexing Ying

In this paper, we propose a semigroup method for solving high-dimensional elliptic partial differential equations (PDEs) and the associated eigenvalue problems based on neural networks.

How to Learn when Data Reacts to Your Model: Performative Gradient Descent

1 code implementation15 Feb 2021 Zachary Izzo, Lexing Ying, James Zou

Performative distribution shift captures the setting where the choice of which ML model is deployed changes the data distribution.

Top-$k$ eXtreme Contextual Bandits with Arm Hierarchy

1 code implementation15 Feb 2021 Rajat Sen, Alexander Rakhlin, Lexing Ying, Rahul Kidambi, Dean Foster, Daniel Hill, Inderjit Dhillon

We show that our algorithm has a regret guarantee of $O(k\sqrt{(A-k+1)T \log (|\mathcal{F}|T)})$, where $A$ is the total number of arms and $\mathcal{F}$ is the class containing the regression function, while only requiring $\tilde{O}(A)$ computation per time step.

Computational Efficiency Extreme Multi-Label Classification +2

An efficient dynamical low-rank algorithm for the Boltzmann-BGK equation close to the compressible viscous flow regime

no code implementations18 Jan 2021 Lukas Einkemmer, Jingwei Hu, Lexing Ying

In this paper, we propose an efficient dynamical low-rank integrator that can capture the fluid limit -- the Navier-Stokes equations -- of the Boltzmann-BGK model even in the compressible regime.

Numerical Analysis Numerical Analysis Computational Physics

A Note on Optimization Formulations of Markov Decision Processes

no code implementations17 Dec 2020 Lexing Ying, Yuhua Zhu

This note summarizes the optimization formulations used in the study of Markov decision processes.

Optimization and Control

Achieving Adversarial Robustness Requires An Active Teacher

no code implementations14 Dec 2020 Chao Ma, Lexing Ying

A new understanding of adversarial examples and adversarial robustness is proposed by decoupling the data generator and the label generator (which we call the teacher).

Adversarial Robustness

A semigroup method for high dimensional committor functions based on neural network

no code implementations12 Dec 2020 Haoya Li, Yuehaw Khoo, Yinuo Ren, Lexing Ying

This paper proposes a new method based on neural networks for computing the high-dimensional committor functions that satisfy Fokker-Planck equations.

Vocal Bursts Intensity Prediction

Efficient Long-Range Convolutions for Point Clouds

1 code implementation11 Oct 2020 Yifan Peng, Lin Lin, Lexing Ying, Leonardo Zepeda-Núñez

We showcase this framework by introducing a neural network architecture that combines LRC-layers with short-range convolutional layers to accurately learn the energy and force associated with a $N$-body potential.

Why resampling outperforms reweighting for correcting sampling bias with stochastic gradients

no code implementations ICLR 2021 Jing An, Lexing Ying, Yuhua Zhu

We consider two commonly-used techniques, resampling and reweighting, that rebalance the proportions of the subgroups to maintain the desired objective function.

Distributed-memory $\mathcal{H}$-matrix Algebra I: Data Distribution and Matrix-vector Multiplication

1 code implementation28 Aug 2020 Yingzhou Li, Jack Poulson, Lexing Ying

We introduce a data distribution scheme for $\mathcal{H}$-matrices and a distributed-memory algorithm for $\mathcal{H}$-matrix-vector multiplication.

Numerical Analysis Distributed, Parallel, and Cluster Computing Numerical Analysis 65F99, 65Y05

Natural Gradient for Combined Loss Using Wavelets

no code implementations29 Jun 2020 Lexing Ying

Natural gradients have been widely used in optimization of loss functionals over probability space, with important examples such as Fisher-Rao gradient descent for Kullback-Leibler divergence, Wasserstein gradient descent for transport-related functionals, and Mahalanobis gradient descent for quadratic loss functionals.

Borrowing From the Future: Addressing Double Sampling in Model-free Control

no code implementations11 Jun 2020 Yuhua Zhu, Zach Izzo, Lexing Ying

The main idea is to borrow extra randomness from the future to approximately re-sample the next state when the underlying dynamics of the problem are sufficiently smooth.

Mirror Descent Algorithms for Minimizing Interacting Free Energy

no code implementations8 Apr 2020 Lexing Ying

This note considers the problem of minimizing interacting free energy.

A Mean-field Analysis of Deep ResNet and Beyond: Towards Provable Optimization Via Overparameterization From Depth

no code implementations11 Mar 2020 Yiping Lu, Chao Ma, Yulong Lu, Jianfeng Lu, Lexing Ying

Specifically, we propose a new continuum limit of deep residual networks, which enjoys a good landscape in the sense that every local minimizer is global.

A Mean-field Analysis of Deep ResNet and Beyond:Towards Provable Optimization Via Overparameterization From Depth

no code implementations ICLR Workshop DeepDiffEq 2019 Yiping Lu, Chao Ma, Yulong Lu, Jianfeng Lu, Lexing Ying

Specifically, we propose a \textbf{new continuum limit} of deep residual networks, which enjoys a good landscape in the sense that \textbf{every local minimizer is global}.

Solving Inverse Wave Scattering with Deep Learning

no code implementations27 Nov 2019 Yuwei Fan, Lexing Ying

This paper proposes a neural network approach for solving two classical problems in the two-dimensional inverse wave scattering: far field pattern problem and seismic imaging.

Seismic Imaging

Solving Traveltime Tomography with Deep Learning

no code implementations25 Nov 2019 Yuwei Fan, Lexing Ying

This paper introduces a neural network approach for solving two-dimensional traveltime tomography (TT) problems based on the eikonal equation.

Solving Optical Tomography with Deep Learning

no code implementations10 Oct 2019 Yuwei Fan, Lexing Ying

Both the forward map from the optical properties to the albedo operator and the inverse map are high-dimensional and nonlinear.

A⋆MCTS: SEARCH WITH THEORETICAL GUARANTEE USING POLICY AND VALUE FUNCTIONS

no code implementations25 Sep 2019 Xian Wu, Yuandong Tian, Lexing Ying

We apply our theoretical framework to different models for the noise distribution of the policy and value network as well as the distribution of rewards, and show that for these general models, the sample complexity is polynomial in D, where D is the depth of the search tree.

Board Games

Mean Field Models for Neural Networks in Teacher-student Setting

no code implementations25 Sep 2019 Lexing Ying, Yuandong Tian

For the two-layer networks, we derive the necessary condition of the stationary distributions of the mean field equation and explain an empirical phenomenon concerning training speed differences using the Wasserstein flow description.

Meta-learning Pseudo-differential Operators with Deep Neural Networks

no code implementations16 Jun 2019 Jordi Feliu-Faba, Yuwei Fan, Lexing Ying

This paper introduces a meta-learning approach for parameterized pseudo-differential operators with deep neural networks.

Meta-Learning

Solving Electrical Impedance Tomography with Deep Learning

no code implementations6 Jun 2019 Yuwei Fan, Lexing Ying

Both the forward map from the electrical conductivity to the DtN map and the inverse map are high-dimensional and nonlinear.

BCR-Net: a neural network based on the nonstandard wavelet form

no code implementations20 Oct 2018 Yuwei Fan, Cindy Orozco Bohorquez, Lexing Ying

This paper proposes a novel neural network architecture inspired by the nonstandard form proposed by Beylkin, Coifman, and Rokhlin in [Communications on Pure and Applied Mathematics, 44(2), 141-183].

A multiscale neural network based on hierarchical nested bases

1 code implementation4 Aug 2018 Yuwei Fan, Jordi Feliu-Faba, Lin Lin, Lexing Ying, Leonardo Zepeda-Nunez

In recent years, deep learning has led to impressive results in many fields.

Numerical Analysis

A multiscale neural network based on hierarchical matrices

1 code implementation5 Jul 2018 Yuwei Fan, Lin Lin, Lexing Ying, Leonardo Zepeda-Nunez

This network generalizes the latter to the nonlinear case by introducing a local deep neural network at each spatial scale.

Numerical Analysis

Stochastic modified equations for the asynchronous stochastic gradient descent

no code implementations21 May 2018 Jing An, Jianfeng Lu, Lexing Ying

The resulting SME of Langevin type extracts more information about the ASGD dynamics and elucidates the relationship between different types of stochastic gradient algorithms.

Solving for high dimensional committor functions using artificial neural networks

no code implementations28 Feb 2018 Yuehaw Khoo, Jianfeng Lu, Lexing Ying

In this note we propose a method based on artificial neural network to study the transition between states governed by stochastic processes.

Vocal Bursts Intensity Prediction

Solving parametric PDE problems with artificial neural networks

1 code implementation11 Jul 2017 Yuehaw Khoo, Jianfeng Lu, Lexing Ying

The representability of such quantity using a neural-network can be justified by viewing the neural-network as performing time evolution to find the solutions to the PDE.

Numerical Analysis 65Nxx

Robust and efficient multi-way spectral clustering

1 code implementation27 Sep 2016 Anil Damle, Victor Minden, Lexing Ying

We present a new algorithm for spectral clustering based on a column-pivoted QR factorization that may be directly used for cluster assignment or to provide an initial guess for k-means.

Numerical Analysis Numerical Analysis Social and Information Networks Physics and Society 68W01, 65F99

A recursive skeletonization factorization based on strong admissibility

3 code implementations26 Sep 2016 Victor Minden, Kenneth L. Ho, Anil Damle, Lexing Ying

We introduce the strong recursive skeletonization factorization (RS-S), a new approximate matrix factorization based on recursive skeletonization for solving discretizations of linear integral equations associated with elliptic partial differential equations in two and three dimensions (and other matrices with similar hierarchical rank structure).

Numerical Analysis 65R20 (primary), 65F08, 65F05 (secondary)

Cannot find the paper you are looking for? You can Submit a new open access paper.