activity
20202026
most citedMulti-player Multi-armed Bandits with Collision-Dependent Reward Distributions

15 citations · 61 across the 28 of their papers we have counts for

collaborators

28 papers

cs.LG2026

LeAct: Learning to Reason from Expert Actions

Ziran Yang, Chengshuai Shi, Raj Ghugare +3

Modern reasoning models depend on reasoning data, today sourced from human annotations or distilled from stronger LLMs. However, a rich and largely untapped source of supervision l…

cs.AI2026

The Past Is Prologue: A Plug-in Controller for Selective Updates in Sequentially Evolving LLM Memory

Zihan Chen, Songwei Dong, Chengshuai Shi +4

Sequentially evolving LLM memory enables agents to reuse past experience, but existing systems usually deploy each locally generated memory update without checking whether it impro…

cs.LG2026

Is One Score Enough? Rethinking the Evaluation of Sequentially Evolving LLM Memory

Songwei Dong, Zihan Chen, Chengshuai Shi +3

Memory plays a central role in enabling large language models (LLMs) to operate over sequential tasks by accumulating and reusing experience over time. However, existing evaluation…

cs.LG2026

Efficient Multi-objective Prompt Optimization via Pure-exploration Bandits

Donghao Li, Chengshuai Shi, Weijuan Ou +2

Prompt engineering has become central to eliciting the capabilities of large language models (LLMs). At its core lies prompt selection -- efficiently identifying the most effective…

cs.LG2026

Continual Harness: Online Adaptation for Self-Improving Foundation Agents

Seth Karten, Joel Zhang, Tersoo Upaa +5

Coding harnesses such as Claude Code and OpenHands wrap foundation models with tools, memory, and planning, but no equivalent exists for embodied agents' long-horizon partial-obser…

cs.LG2026

-Divergence Regularized RLHF: Two Tales of Sampling and Unified Analyses

Di Wu, Chengshuai Shi, Jing Yang +1

Reinforcement Learning from Human Feedback (RLHF) has become a cornerstone technique for post-training large language models. While most existing approaches rely on the reverse KL-…

cs.LG2026

MLS-Bench: A Holistic and Rigorous Assessment of AI Systems on Building Better AI

Bohan Lyu, Yucheng Yang, Siqiao Huang +25

Modern AI progress has been driven by ML methods that are generalizable across settings and scalable to larger regimes. As large language models demonstrate advanced capabilities i…

cs.LG2026

Odysseus: Scaling VLMs to 100+ Turn Decision-Making in Games via Reinforcement Learning

Chengshuai Shi, Wenzhe Li, Xinran Liang +10

Given the rapidly growing capabilities of vision-language models (VLMs), extending them to interactive decision-making tasks such as video games has emerged as a promising frontier…

cs.LG2025

Greedy Sampling Is Provably Efficient for RLHF

Di Wu, Chengshuai Shi, Jing Yang +1

Reinforcement Learning from Human Feedback (RLHF) has emerged as a key technique for post-training large language models. Despite its empirical success, the theoretical understandi…

cs.AI2025

From Cross-Task Examples to In-Task Prompts: A Graph-Based Pseudo-Labeling Framework for In-context Learning

Zihan Chen, Song Wang, Xingbo Fu +4

The capability of in-context learning (ICL) enables large language models (LLMs) to perform novel tasks without parameter updates by conditioning on a few input-output examples. Ho…

cs.LG2025

Augmenting Online RL with Offline Data is All You Need: A Unified Hybrid RL Algorithm Design and Analysis

Ruiquan Huang, Donghao Li, Chengshuai Shi +2

This paper investigates a hybrid learning framework for reinforcement learning (RL) in which the agent can leverage both an offline dataset and online interactions to learn the opt…

stat.ML2025

Cost-Aware Optimal Pairwise Pure Exploration

Di Wu, Chengshuai Shi, Ruida Zhou +1

Pure exploration is one of the fundamental problems in multi-armed bandits (MAB). However, existing works mostly focus on specific pure exploration tasks, without a holistic view o…

stat.ML2024

Transformers as Game Players: Provable In-context Game-playing Capabilities of Pre-trained Models

Chengshuai Shi, Kun Yang, Jing Yang +1

The in-context learning (ICL) capability of pre-trained models based on the transformer architecture has received growing interest in recent years. While theoretical understanding…

cs.LG2024★ 1 cited

Building Math Agents with Multi-Turn Iterative Preference Learning

Wei Xiong, Chengshuai Shi, Jiaming Shen +10

Recent studies have shown that large language models' (LLMs) mathematical problem-solving capabilities can be enhanced by integrating external tools, such as code interpreters, and…

stat.ML2024★ 1 cited

Efficient Prompt Optimization Through the Lens of Best Arm Identification

Chengshuai Shi, Kun Yang, Zihan Chen +3

The remarkable instruction-following capability of large language models (LLMs) has sparked a growing interest in automatically finding good prompts, i.e., prompt optimization. Mos…

stat.ML2023

Harnessing the Power of Federated Learning in Federated Contextual Bandits

Chengshuai Shi, Ruida Zhou, Kun Yang +1

Federated learning (FL) has demonstrated great potential in revolutionizing distributed machine learning, and tremendous efforts have been made to extend it beyond the original foc…

stat.ML2023

Provably Efficient Offline Reinforcement Learning with Perturbed Data Sources

Chengshuai Shi, Wei Xiong, Cong Shen +1

Existing theoretical studies on offline reinforcement learning (RL) mostly consider a dataset sampled directly from the target task. In practice, however, data often come from seve…

stat.ML2023

On High-dimensional and Low-rank Tensor Bandits

Chengshuai Shi, Cong Shen, Nicholas D. Sidiropoulos

Most existing studies on linear bandits focus on the one-dimensional characterization of the overall system. While being representative, this formulation may fail to model applicat…

stat.ML2023

Reward Teaching for Federated Multi-armed Bandits

Chengshuai Shi, Wei Xiong, Cong Shen +1

Most of the existing federated multi-armed bandits (FMAB) designs are based on the presumption that clients will implement the specified design to collaborate with the server. In r…

cs.LG2022

A Self-Play Posterior Sampling Algorithm for Zero-Sum Markov Games

Wei Xiong, Han Zhong, Chengshuai Shi +2

Existing studies on provably efficient algorithms for Markov games (MGs) almost exclusively build on the "optimism in the face of uncertainty" (OFU) principle. This work focuses on…

cs.LG2022★ 2 cited

Nearly Minimax Optimal Offline Reinforcement Learning with Linear Function Approximation: Single-Agent MDP and Markov Game

Wei Xiong, Han Zhong, Chengshuai Shi +3

Offline reinforcement learning (RL) aims at learning an optimal strategy using a pre-collected dataset without further interactions with the environment. While various algorithms h…

stat.ML2021★ 6 cited

Heterogeneous Multi-player Multi-armed Bandits: Closing the Gap and Generalization

Chengshuai Shi, Wei Xiong, Cong Shen +1

Despite the significant interests and many progresses in decentralized multi-player multi-armed bandits (MP-MAB) problems in recent years, the regret gap to the natural centralized…

stat.ML2021★ 2 cited

(Almost) Free Incentivized Exploration from Decentralized Learning Agents

Chengshuai Shi, Haifeng Xu, Wei Xiong +1

Incentivized exploration in multi-armed bandits (MAB) has witnessed increasing interests and many progresses in recent years, where a principal offers bonuses to agents to do explo…

cs.IT2021★ 15 cited

Multi-player Multi-armed Bandits with Collision-Dependent Reward Distributions

Chengshuai Shi, Cong Shen

We study a new stochastic multi-player multi-armed bandits (MP-MAB) problem, where the reward distribution changes if a collision occurs on the arm. Existing literature always assu…