Yifu Huo
Author directory2026
SPS: Steering Probability Squeezing for Better Exploration in Reinforcement Learning for Large Language Models
Yifu Huo | Chenglong Wang | Ziming Zhu | Shunjie Xing | Peinan Feng | Tongran Liu | Qiaozhi He | Tian Hua Zhou | Changxiaojia | JingBo Zhu | Zhengtao Yu | Tong Xiao
Findings of the Association for Computational Linguistics: ACL 2026
Yifu Huo | Chenglong Wang | Ziming Zhu | Shunjie Xing | Peinan Feng | Tongran Liu | Qiaozhi He | Tian Hua Zhou | Changxiaojia | JingBo Zhu | Zhengtao Yu | Tong Xiao
Findings of the Association for Computational Linguistics: ACL 2026
Reinforcement learning (RL) has emerged as a promising paradigm for training reasoning-oriented models by leveraging rule-based reward signals. However, RL training typically tends to improve single-sample success rates (i.e., Pass@1) while offering limited exploration of diverse reasoning trajectories, which is crucial for multi-sample performance (i.e., Pass@k). Our preliminary analysis reveals that this limitation stems from a fundamental squeezing effect, whereby probability mass is excessively concentrated on a narrow subset of high-reward trajectories, restricting genuine exploration and constraining attainable performance under RL training. To address this issue, in this work, we propose Steering Probability Squeezing (SPS), a training paradigm that interleaves conventional RL with inverse reinforcement learning (IRL). SPS treats on-policy rollouts as demonstrations and employs IRL to explicitly reshape the induced trajectory distribution, thereby enhancing exploration without introducing external supervision. Experiments on five commonly used reasoning benchmarks demonstrate that SPS can enable better exploration and improve Pass@k. Beyond algorithmic contributions, we provide an analysis of RL learning dynamics and identify an empirical upper bound on Pass@k, shedding light on intrinsic exploration limits in RL-based reasoning models. Our findings suggest that alternating between RL and IRL offers an effective pathway toward extending the exploration capacity of reasoning-oriented large language models.
SERM: Self-Evolving Relevance Model with Agent-Driven Learning from Massive Query Streams
Chenglong Wang | Canjia Li | Xingzhao Zhu | Yifu Huo | Huiyu Wang | Weixiong Lin | Yun Yang | Qiaozhi He | Tian Hua Zhou | Changxiaojia | JingBo Zhu | Tong Xiao
Findings of the Association for Computational Linguistics: ACL 2026
Chenglong Wang | Canjia Li | Xingzhao Zhu | Yifu Huo | Huiyu Wang | Weixiong Lin | Yun Yang | Qiaozhi He | Tian Hua Zhou | Changxiaojia | JingBo Zhu | Tong Xiao
Findings of the Association for Computational Linguistics: ACL 2026
Due to the dynamically evolving nature of real-world query streams, relevance models struggle to generalize to practical search scenarios. A sophisticated solution is self-evolution techniques. However, in large-scale industrial settings with massive query streams, this technique faces two challenges: (1) informative samples are often sparse and difficult to identify, and (2) pseudo-labels generated by the current model could be unreliable. To address these challenges, in this work, we propose a Self-Evolving Relevance Model approach (SERM), which comprises two complementary multi-agent modules: a multi-agent sample miner, designed to detect distributional shifts and identify informative training samples, and a multi-agent relevance annotator, which provides reliable labels through a two-level agreement framework. We evaluated SERM on a large-scale industrial platform, which serves billions of user requests daily. Experimental results demonstrate that SERM can achieve significant performance gains through iterative self-evolution, as validated by extensive offline multilingual evaluations and online testing.
When Scaling Fails: Mitigating Audio Perception Decay of LALMs via Multi-Step Perception-Aware Reasoning
Ruixiang Mao | Xiangnan Ma | Dan Chen | Ziming Zhu | Yuan Ge | Haishu Zhao | AoKai Hao | Yifu Huo | Qing Yang | Kaiyan Chang | Xiaoqian Liu | Chenglong Wang | Weiqiao Shan | Qiaozhi He | Changliang Li | Zhengtao Yu | Tong Xiao | JingBo Zhu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Ruixiang Mao | Xiangnan Ma | Dan Chen | Ziming Zhu | Yuan Ge | Haishu Zhao | AoKai Hao | Yifu Huo | Qing Yang | Kaiyan Chang | Xiaoqian Liu | Chenglong Wang | Weiqiao Shan | Qiaozhi He | Changliang Li | Zhengtao Yu | Tong Xiao | JingBo Zhu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Test-Time Scaling has shown notable efficacy in addressing complex problems through scaling inference compute. However, within Large Audio-Language Models (LALMs), an unintuitive phenomenon exists: post-training models for structured reasoning trajectories results in marginal or even negative gains compared to training for direct answering. To investigate it, we introduce **CAFE**, an evaluation framework designed to quantify audio reasoning errors. Evaluation results reveal that LALMs encounter a critical bottleneck: **Audio Perception Decay**, which compromises reasoning performance. To address it, we propose **MPAR2**, a strategy that encourages a step-by-step reasoning process with rich perceptual awareness. With reinforcement learning, MPAR2 improves performance on CAFE from 31.74% to 63.51% and effectively mitigates audio perception decay, concurrently enhancing reasoning ability to achieve a strong 74.59% accuracy on the MMAU benchmark. Further analysis shows that MPAR2 optimizes audio attention and enhances reasoning token budget efficiency.
LaTeXTrans Structure-Aware Translation of Complex LaTeX Documents
Ziming Zhu | Chenglong Wang | Haosong Xu | Shunjie Xing | Yifu Huo | Fengning Tian | Quan Du | Di Yang | Chunliang Zhang | Tong Xiao | JingBo Zhu
The Proceedings of Workshop on Document Intelligence and Understanding
Ziming Zhu | Chenglong Wang | Haosong Xu | Shunjie Xing | Yifu Huo | Fengning Tian | Quan Du | Di Yang | Chunliang Zhang | Tong Xiao | JingBo Zhu
The Proceedings of Workshop on Document Intelligence and Understanding
Translating LaTeX documents is challenging because natural-language content is tightly interleaved with executable structures such as commands, equations, environments, and cross-references. Direct translation may therefore corrupt document structure and lead to formatting errors or compilation failures. We present LaTeXTrans, a structure-aware framework that separates semantic translation from executable LaTeX structure through four stages: structure-aware parsing, protected translation, structural validation, and document reconstruction. LaTeXTrans isolates non-translatable structures with protected placeholders, validates structural constraints after translation, and reconstructs the translated content into the original multi-file project structure. We evaluate LaTeXTrans on 100 real-world LaTeX projects across multiple domains and translation directions. Experimental results show consistent improvements in translation quality over direct large language model (LLM) translation while maintaining strong structural reliability. On English–Chinese translation, LaTeXTrans achieves a 97% compilation success rate with only 0.43 formatting errors per document on average. Controlled experiments further show that its structural performance remains stable when previously unseen user-defined command and environment identifiers are introduced.
2025
HEAL: A Hypothesis-Based Preference-Aware Analysis Framework
Yifu Huo | Chenglong Wang | Qiren Zhu | Shunjie Xing | Tong Xiao | Chunliang Zhang | Tongran Liu | JingBo Zhu
Findings of the Association for Computational Linguistics: EMNLP 2025
Yifu Huo | Chenglong Wang | Qiren Zhu | Shunjie Xing | Tong Xiao | Chunliang Zhang | Tongran Liu | JingBo Zhu
Findings of the Association for Computational Linguistics: EMNLP 2025
Preference optimization methods like DPO have achieved remarkable performance in LLM alignment. However, the evaluation for these methods relies on a single response and overlooks other potential outputs, which could also be generated in real-world applications within this hypothetical space. To address this issue, this paper presents a Hypothesis-based PrEference-aware AnaLysis Framework (HEAL), a novel evaluation paradigm that formulates preference alignment as a re-ranking process within hypothesis spaces. The framework incorporates two complementary metrics: ranking accuracy for evaluating ordinal consistency and preference strength correlation for assessing continuous alignment. To facilitate this framework, we develop UniHypoBench, a unified hypothesis benchmark constructed from diverse instruction-response pairs. Through extensive experiments based on HEAL, with a particular focus on the intrinsic mechanisms of preference learning, we demonstrate that current preference learning methods can effectively capture preferences provided by proxy models while simultaneously suppressing negative samples. These findings contribute to preference learning research through two significant avenues. Theoretically, we introduce hypothesis space analysis as an innovative paradigm for understanding preference alignment. Practically, HEAL offers researchers robust diagnostic tools for refining preference optimization methods, while our empirical results identify promising directions for developing more advanced alignment algorithms capable of comprehensive preference capture.
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Co-authors
- Chenglong Wang 5
- Tong Xiao 5
- JingBo Zhu (朱靖波) 5
- Qiaozhi He 3
- Shunjie Xing 3
- Ziming Zhu 3
- Changxiaojia 2
- Tongran Liu 2
- Zhengtao Yu (余正涛) 2
- Chunliang Zhang 2
- Tian Hua Zhou 2
- Kaiyan Chang 1
- Dan Chen 1
- Quan Du 1
- Peinan Feng 1
- Yuan Ge 1
- AoKai Hao 1
- Canjia Li 1
- Changliang Li 1
- Weixiong Lin 1
- Xiaoqian Liu 1
- Xiangnan Ma 1
- Ruixiang Mao 1
- Weiqiao Shan 1
- Fengning Tian 1
- Huiyu Wang 1
- Haosong Xu 1
- Di Yang 1
- Qing Yang 1
- Yun Yang 1
- Haishu Zhao 1
- Qiren Zhu 1
- Xingzhao Zhu 1