Search Results for author: Thinh T. Doan

Found 18 papers, 1 papers with code

Fast Nonlinear Two-Time-Scale Stochastic Approximation: Achieving $O(1/k)$ Finite-Sample Complexity

no code implementations23 Jan 2024 Thinh T. Doan

This paper proposes to develop a new variant of the two-time-scale stochastic approximation to find the roots of two coupled nonlinear operators, assuming only noisy samples of these operators can be observed.

Convergence and Price of Anarchy Guarantees of the Softmax Policy Gradient in Markov Potential Games

no code implementations15 Jun 2022 Dingyang Chen, Qi Zhang, Thinh T. Doan

Our focus in this paper is to study the convergence of the policy gradient method for solving MPGs under softmax policy parameterization, both tabular and parameterized with general function approximators such as neural networks.

Policy Gradient Methods

Convergence Rates of Two-Time-Scale Gradient Descent-Ascent Dynamics for Solving Nonconvex Min-Max Problems

no code implementations17 Dec 2021 Thinh T. Doan

Perhaps, the most popular first-order method in solving min-max optimization is the so-called simultaneous (or single-loop) gradient descent-ascent algorithm due to its simplicity in implementation.

Distributed Optimization

Finite-Time Complexity of Online Primal-Dual Natural Actor-Critic Algorithm for Constrained Markov Decision Processes

no code implementations21 Oct 2021 Sihan Zeng, Thinh T. Doan, Justin Romberg

To solve this constrained optimization program, we study an online actor-critic variant of a classic primal-dual method where the gradients of both the primal and dual functions are estimated using samples from a single trajectory generated by the underlying time-varying Markov processes.

A Two-Time-Scale Stochastic Optimization Framework with Applications in Control and Reinforcement Learning

no code implementations29 Sep 2021 Sihan Zeng, Thinh T. Doan, Justin Romberg

In our two-time-scale approach, one scale is to estimate the true gradient from these samples, which is then used to update the estimate of the optimal solution.

Reinforcement Learning (RL) Stochastic Optimization

Byzantine Fault-Tolerance in Federated Local SGD under 2f-Redundancy

no code implementations26 Aug 2021 Nirupam Gupta, Thinh T. Doan, Nitin Vaidya

However, we do not know of any such techniques for the federated local SGD algorithm - a more commonly used method for federated machine learning.

Improved Convergence Rate for a Distributed Two-Time-Scale Gradient Method under Random Quantization

no code implementations28 May 2021 Marcos M. Vasconcelos, Thinh T. Doan, Urbashi Mitra

In particular, we show that the method converges at a rate $O(log_2 k/\sqrt k)$ to the optimal solution, when the underlying objective function is strongly convex and smooth.

Quantization

Finite Sample Analysis of Two-Time-Scale Natural Actor-Critic Algorithm

no code implementations26 Jan 2021 Sajad Khodadadian, Thinh T. Doan, Justin Romberg, Siva Theja Maguluri

In this paper, we characterize the \emph{global} convergence of an online natural actor-critic algorithm in the tabular setting using a single trajectory of samples.

Vocal Bursts Valence Prediction

Nonlinear Two-Time-Scale Stochastic Approximation: Convergence and Finite-Time Performance

no code implementations3 Nov 2020 Thinh T. Doan

Under some fairly standard assumptions, we provide a formula that characterizes the rate of convergence of the main iterates to the desired solutions.

Vocal Bursts Valence Prediction

Finite-Time Convergence Rates of Decentralized Stochastic Approximation with Applications in Multi-Agent and Multi-Task Learning

no code implementations28 Oct 2020 Sihan Zeng, Thinh T. Doan, Justin Romberg

We study a decentralized variant of stochastic approximation, a data-driven approach for finding the root of an operator under noisy measurements.

Multi-Task Learning Q-Learning +1

Local Stochastic Approximation: A Unified View of Federated Learning and Distributed Multi-Task Reinforcement Learning Algorithms

no code implementations24 Jun 2020 Thinh T. Doan

Motivated by broad applications in reinforcement learning and federated learning, we study local stochastic approximation over a network of agents, where their goal is to find the root of an operator composed of the local operators at the agents.

Federated Learning reinforcement-learning +1

Finite-Time Analysis of Stochastic Gradient Descent under Markov Randomness

no code implementations24 Mar 2020 Thinh T. Doan, Lam M. Nguyen, Nhan H. Pham, Justin Romberg

Motivated by broad applications in reinforcement learning and machine learning, this paper considers the popular stochastic gradient descent (SGD) when the gradients of the underlying objective function are sampled from Markov processes.

reinforcement-learning Reinforcement Learning (RL)

Finite-Time Analysis and Restarting Scheme for Linear Two-Time-Scale Stochastic Approximation

no code implementations23 Dec 2019 Thinh T. Doan

Motivated by their broad applications in reinforcement learning, we study the linear two-time-scale stochastic approximation, an iterative method using two different step sizes for finding the solutions of a system of two equations.

Finite-Time Performance of Distributed Temporal Difference Learning with Linear Function Approximation

no code implementations25 Jul 2019 Thinh T. Doan, Siva Theja Maguluri, Justin Romberg

Our main contribution is to provide a finite-analysis on the performance of this distributed {\sf TD}$(\lambda)$ algorithm for both constant and time-varying step sizes.

Multi-agent Reinforcement Learning

Finite-Sample Analysis of Nonlinear Stochastic Approximation with Applications in Reinforcement Learning

1 code implementation27 May 2019 Zaiwei Chen, Sheng Zhang, Thinh T. Doan, John-Paul Clarke, Siva Theja Maguluri

To demonstrate the generality of our theoretical results on Markovian SA, we use it to derive the finite-sample bounds of the popular $Q$-learning with linear function approximation algorithm, under a condition on the behavior policy.

Q-Learning reinforcement-learning +1

Finite-Time Analysis of Distributed TD(0) with Linear Function Approximation for Multi-Agent Reinforcement Learning

no code implementations20 Feb 2019 Thinh T. Doan, Siva Theja Maguluri, Justin Romberg

In this problem, a group of agents works cooperatively to evaluate the value function for the global discounted accumulative reward problem, which is composed of local rewards observed by the agents.

Optimization and Control

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