← Search

Yihao Feng

26 accepted papers

2026

Adaptive Thinking: Large Language Models Know When to Think in Latent Space

ICLR 2026poster

Recent advances in large language models (LLMs) test-time computing have introduced the capability to perform intermediate chain-of-thought (CoT) reasoning (thinking) before generating answers. While increasing the thinking budget yields smooth performance improvements at inference time, the relatio…

Cited by 0SourceScholar
2026

Learning to Reason as Action Abstractions with Scalable Mid-Training RL

ICLR 2026poster

Large language models excel with reinforcement learning (RL), but fully unlocking this potential requires a mid-training stage. Intuitively, an effective mid-training stage should both learn a strong policy prior and enable fast learning through online interactions. We formalize this intuition by pr…

Cited by 0SourceScholar
2025

Direct Preference Optimization of Video Large Multimodal Models from Language Model Reward

NAACL 2025long

Preference modeling techniques, such as direct preference optimization (DPO), has shown effective in enhancing the generalization abilities of large language model (LLM). However, in tasks involving video instruction-following, providing informative feedback, especially for open-ended conversations,…

2025

Diversity Empowers Intelligence: Integrating Expertise of Software Engineering Agents

ICLR 2025poster

Large language model (LLM) agents have shown great potential in solving real-world software engineering (SWE) problems. The most advanced open-source SWE agent can resolve over 27% of real GitHub issues in SWE-Bench Lite. However, these sophisticated agent frameworks exhibit varying strengths, excel…

Cited by 10SourcePDFScholar
2025

Longhorn: State Space Models are Amortized Online Learners

ICLR 2025poster

The most fundamental capability of modern AI methods such as Large Language Models (LLMs) is the ability to predict the next token in a long sequence of tokens, known as “sequence modeling.” Although the Transformers model is the current dominant approach to sequence modeling, its quadratic computa…

2025

Structured Policy Optimization: Enhance Large Vision-Language Model via Self-referenced Dialogue

ICCV 2025poster

Preference optimization algorithms typically enhance LLM response quality by leveraging human feedback on multiple answers given a fixed instruction. However, these methods often lack capturing the dynamic nature of conversational exchanges. For large vision-language models (LVLMs), direct preferenc…

Cited by 0SourcePDFScholar
2025

Text2Data: Low-Resource Data Generation with Textual Control

AAAI 2025technical

Natural language serves as a common and straightforward control signal for humans to interact seamlessly with machines. Recognizing the importance of this interface, the machine learning community is investing considerable effort in generating data that is semantically coherent with textual instruct…

2025

xLAM: A Family of Large Action Models to Empower AI Agent Systems

NAACL 2025long

Autonomous agents powered by large language models (LLMs) have attracted significant research interest. However, the open-source community faces many challenges in developing specialized models for agent tasks, driven by the scarcity of high-quality agent datasets and the absence of standard protoco…

2024

APIGen: Automated PIpeline for Generating Verifiable and Diverse Function-Calling Datasets

NeurIPS 2024poster

The advancement of function-calling agent models requires diverse, reliable, and high-quality datasets. This paper presents APIGen, an automated data generation pipeline designed to synthesize high-quality datasets for function-calling applications. We leverage APIGen and collect 3,673 executable AP…

2024

FOFO: A Benchmark to Evaluate LLMs’ Format-Following Capability

ACL 2024long

This paper presents FoFo, a pioneering benchmark for evaluating large language models’ (LLMs) ability to follow complex, domain-specific formats, a crucial yet under-examined capability for their application as AI agents. Despite LLMs’ advancements, existing benchmarks fail to assess their format-fo…

2024

HIVE: Harnessing Human Feedback for Instructional Visual Editing

CVPR 2024poster

Incorporating human feedback has been shown to be crucial to align text generated by large language models to human preferences. We hypothesize that state-of-the-art instructional image editing models where outputs are generated based on an input image and an editing instruction could similarly bene…

2024

Retroformer: Retrospective Large Language Agents with Policy Gradient Optimization

ICLR 2024spotlight

Recent months have seen the emergence of a powerful new trend in which large language models (LLMs) are augmented to become autonomous language agents capable of performing objective oriented multi-step tasks on their own, rather than merely responding to queries from human users. Most existing lang…

2023

Fantastic Rewards and How to Tame Them: A Case Study on Reward Learning for Task-oriented Dialogue Systems

ICLR 2023poster

When learning task-oriented dialogue (ToD) agents, reinforcement learning (RL) techniques can naturally be utilized to train dialogue strategies to achieve user-specific goals. Prior works mainly focus on adopting advanced RL techniques to train the ToD agents, while the design of the reward functio…

2023

LIBERO: Benchmarking Knowledge Transfer for Lifelong Robot Learning

NeurIPS 2023poster

Lifelong learning offers a promising paradigm of building a generalist agent that learns and adapts over its lifespan. Unlike traditional lifelong learning problems in image and text domains, which primarily involve the transfer of declarative knowledge of entities and concepts, lifelong learning i…

Cited by 108SourcePDFScholar
2023

Metric Residual Network for Sample Efficient Goal-Conditioned Reinforcement Learning

AAAI 2023technical

Goal-conditioned reinforcement learning (GCRL) has a wide range of potential real-world applications, including manipulation and navigation problems in robotics. Especially in such robotics tasks, sample efficiency is of the utmost importance for GCRL since, by default, the agent is only rewarded wh…

2023

Preference-grounded Token-level Guidance for Language Model Fine-tuning

NeurIPS 2023poster

Aligning language models (LMs) with preferences is an important problem in natural language generation. A key challenge is that preferences are typically provided at the *sequence level* while LM training and generation both occur at the *token level*. There is, therefore, a *granularity mismatch* b…

2023

UniControl: A Unified Diffusion Model for Controllable Visual Generation In the Wild

NeurIPS 2023poster

Achieving machine autonomy and human control often represent divergent objectives in the design of interactive AI systems. Visual generative foundation models such as Stable Diffusion show promise in navigating these goals, especially when prompted with arbitrary languages. However, they often fall…

2022

A Unified Framework for Alternating Offline Model Training and Policy Learning

NeurIPS 2022accept

In offline model-based reinforcement learning (offline MBRL), we learn a dynamic model from historically collected data, and subsequently utilize the learned model and fixed datasets for policy learning, without further interacting with the environment. Offline MBRL algorithms can improve the effici…

2022

Regularizing a Model-based Policy Stationary Distribution to Stabilize Offline Reinforcement Learning

ICML 2022spotlight

Offline reinforcement learning (RL) extends the paradigm of classical RL algorithms to purely learning from static datasets, without interacting with the underlying environment during the learning process. A key challenge of offline RL is the instability of policy training, caused by the mismatch be…

2021

Incremental Few-shot Text Classification with Multi-round New Classes: Formulation, Dataset and System

NAACL 2021long

Text classification is usually studied by labeling natural language texts with relevant categories from a predefined set. In the real world, new classes might keep challenging the existing system with limited labeled data. The system should be intelligent enough to recognize upcoming new classes wit…

2021

Non-asymptotic Confidence Intervals of Off-policy Evaluation: Primal and Dual Bounds

ICLR 2021poster

Off-policy evaluation (OPE) is the task of estimating the expected reward of a given policy based on offline data previously collected under different policies. Therefore, OPE is a key step in applying reinforcement learning to real-world domains such as medical treatment, where interactive data col…

Cited by 16SourcePDFScholar
2021

Unsupervised Out-of-Domain Detection via Pre-trained Transformers

ACL 2021long

Deployed real-world machine learning applications are often subject to uncontrolled and even potentially malicious inputs. Those out-of-domain inputs can lead to unpredictable outputs and sometimes catastrophic safety issues. Prior studies on out-of-domain detection require in-domain task labels and…

2020

Accountable Off-Policy Evaluation With Kernel Bellman Statistics

ICML 2020poster

We consider off-policy evaluation (OPE), which evaluates the performance of a new policy from observed data collected from previous experiments, without requiring the execution of the new policy. This finds important applications in areas with high execution cost or safety concerns, such as medical…

Cited by 49SourcePDFScholar
2020

Off-Policy Interval Estimation with Lipschitz Value Iteration

NeurIPS 2020poster

Off-policy evaluation provides an essential tool for evaluating the effects of different policies or treatments using only observed data. When applied to high-stakes scenarios such as medical diagnosis or financial decision-making, it is essential to provide provably correct upper and lower bounds o…

Cited by 5SourcePDFScholar