Yuanfu Wang
Author directory2026
MemPulse: Memory Pulse-Driven Adaptive Long-Context Reasoning with Fact-based Hypergraph
Wenbiao Tao | Yuanfu Wang | Yunshi Lan | Chao Yang
Findings of the Association for Computational Linguistics: EMNLP 2026
Wenbiao Tao | Yuanfu Wang | Yunshi Lan | Chao Yang
Findings of the Association for Computational Linguistics: EMNLP 2026
Memory-augmented long-context reasoning boosts LLMs’ complex task solving via external knowledge, yet current methods suffer from disjointed memory retrieval-induced context drift and aimless iterations causing premature convergence or redundant computation. We present MemPulse, integrating fact-based memory hypergraphs and pulse-driven adaptive iteration. It builds hypergraphs with facts as hyperedges to gather scattered information and sustain coherent context evolution. Its memory pulse engine computes agent confidence and structural novelty to output dynamic control signals, adjusting retrieval range and stopping criteria for logical reasoning with minimal overhead. Evaluated on Locomo, MemPulse surpasses mainstream baselines in reasoning accuracy and efficiency.
Decoupled Contrastive Decoding via Expert-Aligned Drafting
Zhixuan Liu | Zhichen Dong | Yuanfu Wang | Chao Yang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zhixuan Liu | Zhichen Dong | Yuanfu Wang | Chao Yang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Contrastive Decoding (CD) improves generation quality, but its amateur-model pass makes decoding expensive. Accelerating CD with speculative decoding raises a proposal-alignment question: should the contrastive signal shape the drafter, or should it remain only in verification? We study this question in the lightweight feature-level drafter regime. Two controlled diagnostics, matched Cross-α training and an Approximate Dual-Drafter decomposition, give the same diagnosis: contrastive-aware drafting does not consistently improve over expert-aligned drafting because the contrastive correction is usually weaker than drafter error, and reconstruction can amplify that error. We introduce Decoupled Contrastive Decoding (DCD), which drafts with an expert-aligned lightweight proposer and applies the amateur only in unchanged CD verification. Standard speculative verification preserves the vanilla-CD output distribution. Across the main 8B settings, EAGLE3-based DCD achieves average greedy speedups of 1.65 to 1.95× over vanilla CD and reduces MMLU proposal-path latency by about 5 to 12× relative to amateur-coupled proposal paths.
2025
Adversarial Preference Learning for Robust LLM Alignment
Yuanfu Wang | Pengyu Wang | Chenyang Xi | Bo Tang | Junyi Zhu | Wenqiang Wei | Chen Chen | Chao Yang | Jingfeng Zhang | Chaochao Lu | Yijun Niu | Keming Mao | Zhiyu Li | Feiyu Xiong | Jie Hu | Mingchuan Yang
Findings of the Association for Computational Linguistics: ACL 2025
Yuanfu Wang | Pengyu Wang | Chenyang Xi | Bo Tang | Junyi Zhu | Wenqiang Wei | Chen Chen | Chao Yang | Jingfeng Zhang | Chaochao Lu | Yijun Niu | Keming Mao | Zhiyu Li | Feiyu Xiong | Jie Hu | Mingchuan Yang
Findings of the Association for Computational Linguistics: ACL 2025
Modern language models often rely on Reinforcement Learning from Human Feedback (RLHF) to encourage safe behaviors. However, they remain vulnerable to adversarial attacks due to three key limitations: (1) the inefficiency and high cost of human annotation, (2) the vast diversity of potential adversarial attacks, and (3) the risk of feedback bias and reward hacking. To address these challenges, we introduce Adversarial Preference Learning (APL), an iterative adversarial training method incorporating three key innovations. First, a direct harmfulness metric based on the model’s intrinsic preference probabilities, eliminating reliance on external assessment. Second, a conditional generative attacker that synthesizes input-specific adversarial variations. Third, an iterative framework with automated closed-loop feedback, enabling continuous adaptation through vulnerability discovery and mitigation. Experiments on Mistral-7B-Instruct-v0.3 demonstrate that APL significantly enhances robustness, achieving 83.33% harmlessness win rate over the base model (evaluated by GPT-4o), reducing harmful outputs from 5.88% to 0.43% (measured by LLaMA-Guard), and lowering attack success rate by up to 65% according to HarmBench. Notably, APL maintains competitive utility, with an MT-Bench score of 6.59 (comparable to the baseline 6.78) and an LC-WinRate of 46.52% against the base model.
2024
Inference-Time Language Model Alignment via Integrated Value Guidance
Zhixuan Liu | Zhanhui Zhou | Yuanfu Wang | Chao Yang | Yu Qiao
Findings of the Association for Computational Linguistics: EMNLP 2024
Zhixuan Liu | Zhanhui Zhou | Yuanfu Wang | Chao Yang | Yu Qiao
Findings of the Association for Computational Linguistics: EMNLP 2024
Large language models are typically fine-tuned to align with human preferences, but tuning large models is computationally intensive and complex. In this work, we introduce Integrated Value Guidance (IVG), a method that uses implicit and explicit value functions to guide language model decoding at token and chunk-level respectively, efficiently aligning large language models purely at inference time.This approach circumvents the complexities of direct fine-tuning and outperforms traditional methods.Empirically, we demonstrate the versatility of IVG across various tasks. In controlled sentiment generation and summarization tasks, our method significantly improves the alignment of large models using inference-time guidance from gpt2-based value functions. Moreover, in a more challenging instruction-following benchmark AlpacaEval 2.0, we show that both specifically tuned and off-the-shelf value functions greatly improve the length-controlled win rates of large models against gpt-4-turbo (e.g., 19.51 % → 26.51% for Mistral-7B-Instruct-v0.2 and 25.58 % → 33.75 % for Mixtral-8x7B-Instruct-v0.1 with Tulu guidance).