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Shicong Cen

7 accepted papers

2025

Faster WIND: Accelerating Iterative Best-of-$N$ Distillation for LLM Alignment

AISTATS 2025poster

Recent advances in aligning large language models with human preferences have corroborated the growing importance of best-of-$N$ distillation (BOND). However, the iterative BOND algorithm is prohibitively expensive in practice due to the sample and computation inefficiency. This paper addresses the…

Cited by 0SourceScholar
2025

Value-Incentivized Preference Optimization: A Unified Approach to Online and Offline RLHF

ICLR 2025poster

Reinforcement learning from human feedback (RLHF) has demonstrated great promise in aligning large language models (LLMs) with human preference. Depending on the availability of preference data, both online and offline RLHF are active areas of investigation. A key bottleneck is understanding how to…

Cited by 31SourcePDFScholar
2024

Federated Natural Policy Gradient and Actor Critic Methods for Multi-task Reinforcement Learning

NeurIPS 2024poster

Federated reinforcement learning (RL) enables collaborative decision making of multiple distributed agents without sharing local data trajectories. In this work, we consider a multi-task setting, in which each agent has its own private reward function corresponding to different tasks, while sharing…

Cited by 4SourcePDFScholar
2023

Faster Last-iterate Convergence of Policy Optimization in Zero-Sum Markov Games

ICLR 2023poster

Multi-Agent Reinforcement Learning (MARL)---where multiple agents learn to interact in a shared dynamic environment---permeates across a wide range of critical applications. While there has been substantial progress on understanding the global convergence of policy optimization methods in single-age…

Cited by 45SourcePDFScholar
2021

Fast Policy Extragradient Methods for Competitive Games with Entropy Regularization

NeurIPS 2021poster

This paper investigates the problem of computing the equilibrium of competitive games, which is often modeled as a constrained saddle-point optimization problem with probability simplex constraints. Despite recent efforts in understanding the last-iterate convergence of extragradient methods in the…

Cited by 94SourcePDFScholar
2020

Communication-Efficient Distributed Optimization in Networks with Gradient Tracking and Variance Reduction

AISTATS 2020poster

Due to the imminent need to alleviate the communication burden in multi-agent and federated learning, the investigation of communication-efficient distributed optimization algorithms for empirical risk minimization has flourished recently. A large fraction of existing algorithms are developed for th…