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Junkai Zhang

13 accepted papers

2026

Chasing the Tail: Effective Rubric-based Reward Modeling for Large Language Model Post-Training

ICLR 2026poster

Reinforcement fine-tuning (RFT) often suffers from reward over-optimization, where a policy model hacks the reward signals to achieve high scores while producing low-quality outputs. Our theoretical analysis shows that the key lies in reward misspecification at the high-reward tail: the inability to…

Cited by 0SourcecodeScholar
2026

WebShaper: Agentically Data Synthesizing via Information-Seeking Formalization

ICLR 2026poster

The advent of Large Language Model (LLM)-powered agents has revolutionized artificial intelligence by enabling solutions to complex, open-ended tasks through web-based information-seeking (IS) capabilities. The scarcity of high-quality training data has limited the development of IS agents. Existin…

Cited by 0SourcecodeScholar
2025

Bi-Level Knowledge Transfer for Multi-Task Multi-Agent Reinforcement Learning

NeurIPS 2025poster

Multi-Agent Reinforcement Learning (MARL) has achieved remarkable success in various real-world scenarios, but its high cost of online training makes it impractical to learn each task from scratch. To enable effective policy reuse, we consider the problem of zero-shot generalization from offline da…

Cited by 0SourceScholar
2025

MetaScientist: A Human-AI Synergistic Framework for Automated Mechanical Metamaterial Design

NAACL 2025system demonstrations

The discovery of novel mechanical metamaterials, whose properties are dominated by their engineered structures rather than chemical composition, is a knowledge-intensive and resource-demanding process. To accelerate the design of novel metamaterials, we present MetaScientist, a human-in-the-loop sys…

2025

PUO-Bench: A Panel Understanding and Operation Benchmark with A Privacy-Preserving Framework

NeurIPS 2025poster

Recent advancements in Vision-Language Models (VLMs) have enabled GUI agents to leverage visual features for interface understanding and operation in the digital world. However, limited research has addressed the interpretation and interaction with control panels in real-world settings. To bridge th…

Cited by 0SourceScholar
2025

Protein Large Language Models: A Comprehensive Survey

EMNLP 2025

Protein-specific large language models (ProteinLLMs) are revolutionizing protein science by enabling more efficient protein structure prediction, function annotation, and design. While existing surveys focus on specific aspects or applications, this work provides the first comprehensive overview of

2025

Training LLMs for Optimization Modeling via Iterative Data Synthesis and Structured Validation

EMNLP 2025

Large Language Models (LLMs) have revolutionized various domains but encounter substantial challenges in tackling optimization modeling tasks for Operations Research (OR), particularly when dealing with complex problem. In this work, we propose Step-Opt-Instruct, a framework that augments existing d

2024

A 3D Virtual Try-On Method with Global-Local Alignment and Diffusion Model

ICASSP 2024accepted

3D virtual try-on has recently received more attention due to its great practical and commercial value. However, there remains the problems that the garment cannot accurately correspond to a human body by geometric transformation and abnormal textures may be produced in the synthesis result. To addr…

Cited by 0SourceScholar
2024

Fast Sampling via Discrete Non-Markov Diffusion Models with Predetermined Transition Time

NeurIPS 2024poster

Discrete diffusion models have emerged as powerful tools for high-quality data generation. Despite their success in discrete spaces, such as text generation tasks, the acceleration of discrete diffusion models remains under-explored. In this paper, we propose discrete non-Markov diffusion models (DN…

2024

Intrinsic Action Tendency Consistency for Cooperative Multi-Agent Reinforcement Learning

AAAI 2024technical

Efficient collaboration in the centralized training with decentralized execution (CTDE) paradigm remains a challenge in cooperative multi-agent systems. We identify divergent action tendencies among agents as a significant obstacle to CTDE's training efficiency, requiring a large number of training…

Cited by 3SourcePDFScholar
2024

Uncertainty-Aware Reward-Free Exploration with General Function Approximation

ICML 2024poster

Mastering multiple tasks through exploration and learning in an environment poses a significant challenge in reinforcement learning (RL). Unsupervised RL has been introduced to address this challenge by training policies with intrinsic rewards rather than extrinsic rewards. However, current intrinsi…

2023

Why Does Sharpness-Aware Minimization Generalize Better Than SGD?

NeurIPS 2023poster

The challenge of overfitting, in which the model memorizes the training data and fails to generalize to test data, has become increasingly significant in the training of large neural networks. To tackle this challenge, Sharpness-Aware Minimization (SAM) has emerged as a promising training method, wh…

Cited by 19SourcePDFScholar