activity
20192024
most citedA New Algorithm for Non-stationary Contextual Bandits: Efficient, Optimal, and Parameter-free

39 citations · 79 across the 20 of their papers we have counts for

collaborators

20 papers

cs.LG2024

Cost-Effective Proxy Reward Model Construction with On-Policy and Active Learning

Yifang Chen, Shuohang Wang, Ziyi Yang +6

Reinforcement learning with human feedback (RLHF), as a widely adopted approach in current large language model pipelines, is \textit{bottlenecked by the size of human preference d…

cs.LG2024★ 1 cited

Decoding-Time Language Model Alignment with Multiple Objectives

Ruizhe Shi, Yifang Chen, Yushi Hu +4

Aligning language models (LMs) to human preferences has emerged as a critical pursuit, enabling these models to better serve diverse user needs. Existing methods primarily focus on…

cs.LG2024

CLIPLoss and Norm-Based Data Selection Methods for Multimodal Contrastive Learning

Yiping Wang, Yifang Chen, Wendan Yan +4

Data selection has emerged as a core issue for large-scale visual-language model pretaining (e.g., CLIP), particularly with noisy web-curated datasets. Three main data selection ap…

cs.LG2024

Variance Alignment Score: A Simple But Tough-to-Beat Data Selection Method for Multimodal Contrastive Learning

Yiping Wang, Yifang Chen, Wendan Yan +2

In recent years, data selection has emerged as a core issue for large-scale visual-language model pretraining, especially on noisy web-curated datasets. One widely adopted strategy…

cs.CL2024

An Experimental Design Framework for Label-Efficient Supervised Finetuning of Large Language Models

Gantavya Bhatt, Yifang Chen, Arnav M. Das +9

Supervised finetuning (SFT) on instruction datasets has played a crucial role in achieving the remarkable zero-shot generalization capabilities observed in modern large language mo…

cs.LG2023

Active Representation Learning for General Task Space with Applications in Robotics

Yifang Chen, Yingbing Huang, Simon S. Du +2

Representation learning based on multi-task pretraining has become a powerful approach in many domains. In particular, task-aware representation learning aims to learn an optimal r…

cs.LG2023

Improved Active Multi-Task Representation Learning via Lasso

Yiping Wang, Yifang Chen, Kevin Jamieson +1

To leverage the copious amount of data from source tasks and overcome the scarcity of the target task samples, representation learning based on multi-task pretraining has become a…

cs.LG2023★ 1 cited

LabelBench: A Comprehensive Framework for Benchmarking Adaptive Label-Efficient Learning

Jifan Zhang, Yifang Chen, Gregory Canal +8

Labeled data are critical to modern machine learning applications, but obtaining labels can be expensive. To mitigate this cost, machine learning methods, such as transfer learning…

cs.LG2022★ 1 cited

Improved Adaptive Algorithm for Scalable Active Learning with Weak Labeler

Yifang Chen, Karthik Sankararaman, Alessandro Lazaric +6

Active learning with strong and weak labelers considers a practical setting where we have access to both costly but accurate strong labelers and inaccurate but cheap predictions pr…

econ.EM2022

Causal Bandits: Online Decision-Making in Endogenous Settings

Jingwen Zhang, Yifang Chen, Amandeep Singh

The deployment of Multi-Armed Bandits (MAB) has become commonplace in many economic applications. However, regret guarantees for even state-of-the-art linear bandit algorithms (suc…

cs.LG2022★ 1 cited

Active Multi-Task Representation Learning

Yifang Chen, Simon S. Du, Kevin Jamieson

To leverage the power of big data from source tasks and overcome the scarcity of the target task samples, representation learning based on multi-task pretraining has become a stand…

cs.LG2022★ 5 cited

Reward-Free RL is No Harder Than Reward-Aware RL in Linear Markov Decision Processes

Andrew Wagenmaker, Yifang Chen, Max Simchowitz +2

Reward-free reinforcement learning (RL) considers the setting where the agent does not have access to a reward function during exploration, but must propose a near-optimal policy f…

cs.LG2021★ 3 cited

First-Order Regret in Reinforcement Learning with Linear Function Approximation: A Robust Estimation Approach

Andrew Wagenmaker, Yifang Chen, Max Simchowitz +2

Obtaining first-order regret bounds -- regret bounds scaling not as the worst-case but with some measure of the performance of the optimal policy on a given instance -- is a core q…

cs.LG2021

Corruption Robust Active Learning

Yifang Chen, Simon S. Du, Kevin Jamieson

We conduct theoretical studies on streaming-based active learning for binary classification under unknown adversarial label corruptions. In this setting, every time before the lear…

cs.LG2021★ 4 cited

Improved Corruption Robust Algorithms for Episodic Reinforcement Learning

Yifang Chen, Simon S. Du, Kevin Jamieson

We study episodic reinforcement learning under unknown adversarial corruptions in both the rewards and the transition probabilities of the underlying system. We propose new algorit…

quant-ph2020★ 1 cited

More Practical and Adaptive Algorithms for Online Quantum State Learning

Yifang Chen, Xin Wang

Online quantum state learning is a recently proposed problem by Aaronson et al. (2018), where the learner sequentially predicts -qubit quantum states based on given measurements…

cs.LG2019★ 9 cited

Fair Contextual Multi-Armed Bandits: Theory and Experiments

Yifang Chen, Alex Cuellar, Haipeng Luo +3

When an AI system interacts with multiple users, it frequently needs to make allocation decisions. For instance, a virtual agent decides whom to pay attention to in a group setting…

math.OC2019★ 10 cited

Online and Bandit Algorithms for Nonstationary Stochastic Saddle-Point Optimization

Abhishek Roy, Yifang Chen, Krishnakumar Balasubramanian +1

Saddle-point optimization problems are an important class of optimization problems with applications to game theory, multi-agent reinforcement learning and machine learning. A majo…

cs.AI2019★ 4 cited

Multi-Armed Bandits with Fairness Constraints for Distributing Resources to Human Teammates

Houston Claure, Yifang Chen, Jignesh Modi +2

How should a robot that collaborates with multiple people decide upon the distribution of resources (e.g. social attention, or parts needed for an assembly)? People are uniquely at…

cs.LG2019★ 39 cited

A New Algorithm for Non-stationary Contextual Bandits: Efficient, Optimal, and Parameter-free

Yifang Chen, Chung-Wei Lee, Haipeng Luo +1

We propose the first contextual bandit algorithm that is parameter-free, efficient, and optimal in terms of dynamic regret. Specifically, our algorithm achieves dynamic regret $\ma…