Hang Lv
Author directory2026
Calibrating Hierarchical Memory Utilization for Long-Term Memory QA
Hang Lv | Xuyang Zhi | Hongchao Gu | Hao Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Hang Lv | Xuyang Zhi | Hongchao Gu | Hao Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Long-term memory systems increasingly organize interaction histories into hierarchical contexts, where coarse summaries, mid-level events, and fine-grained evidence provide complementary signals for future queries. Yet after retrieval, these signals are often collapsed into a single generation context and used implicitly. We ask how retrieved hierarchical memory should shape generation after access, framing it as a post-retrieval calibration problem. We propose HiR, a training-free inference-time framework that contrasts full-hierarchy decoding with a coarse-only reference view, preserving the complete hierarchy while tempering over-reliance on broad abstractions. Extensive experiments and analyses show that HiR enables more effective and robust use of hierarchical memory without changing memory construction or retrieval; more broadly, our results suggest that memory research should consider not only what to store or retrieve, but also how retrieved information shapes generation.
CoSteer: Collaborative Decoding-Time Personalization via Local Delta Steering
Hang Lv | Sheng Liang | Hao Wang | Hongchao Gu | Yaxiong Wu | Wei Guo | Defu Lian | Yong Liu | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Hang Lv | Sheng Liang | Hao Wang | Hongchao Gu | Yaxiong Wu | Wei Guo | Defu Lian | Yong Liu | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Personalization has become crucial for adapting models to the diverse and evolving needs of users across cultural, temporal, and contextual dimensions. While existing methods often rely on centralized fine-tuning or static preference alignment within a single model, they struggle to achieve both real-time and high-quality personalization under the resource and privacy constraints of personal devices. To address this challenge, we propose CoSteer, a collaborative framework that enables tuning-free, real-time personalization via decoding-time adaptation. By leveraging logit differences between context-aware and -agnostic local small models, CoSteer steers cloud-based large models, ensuring effective personalization while preserving the large model’s capabilities. Personalization is handled locally, with only final tokens sent to the cloud, maintaining both user context and system efficiency. Through extensive experiments across a wide range of tasks, we demonstrate that CoSteer generates high-quality personalized content, ensuring both effectiveness and computational efficiency. Our results highlight its robustness across models and environments, confirming its practical applicability in real-world scenarios. Our code and data are available at https://anonymous.4open.science/r/Costeer-4977.
SpecSteer: Synergizing Local Context and Global Reasoning for Efficient Personalized Generation
Hang Lv | Sheng Liang | Hao Wang | Yongyue Zhang | Hongchao Gu | Wei Guo | Defu Lian | Yong Liu | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Hang Lv | Sheng Liang | Hao Wang | Yongyue Zhang | Hongchao Gu | Wei Guo | Defu Lian | Yong Liu | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Realizing personalized intelligence faces a core dilemma: sending user history to centralized large language models raises privacy concerns, while on-device small language models lack the reasoning capacity required for high-quality generation. Our pilot study shows that purely local enhancements remain insufficient to reliably bridge this gap. We therefore propose SpecSteer, an asymmetric collaborative inference framework that synergizes private on-device context with cloud-scale reasoning. SpecSteer casts collaboration as Bayesian knowledge fusion and repurposes speculative decoding as a distributed alignment protocol, yielding a Draft–Verify–Recover pipeline: the on-device model drafts personalized sequences; the cloud validates via a ratio-based mechanism that decouples reasoning verification from private context, filtering logical flaws without accessing raw user context; upon rejection, a steering recovery injects local intent during correction. Experiments demonstrate that SpecSteer successfully closes the reasoning gap and achieves superior personalized generation performance, while delivering a 2.36 X speedup over standard baselines.
Why Thinking Hurts: Diagnosing and Rectifying Linguistic Inertia in Large Language Models for Recommendation
Luankang Zhang | Yonghao Huang | Hang Lv | Xuyang Zhi | Mingjia Yin | Yuyang Ye | Wei Guo | Hao Wang | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Luankang Zhang | Yonghao Huang | Hang Lv | Xuyang Zhi | Mingjia Yin | Yuyang Ye | Wei Guo | Hao Wang | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Chain-of-Thought (CoT) reasoning is widely used to improve LLM performance, and recent foundation recommender models adopt it by generating textual reasoning before predicting target items represented by Semantic IDs (SIDs). However, we observe that enabling thinking mode in models such as OpenOneRec can degrade recommendation quality by up to 25%. We investigate this failure and identify Linguistic Inertia: when a textual CoT segment is inserted before SID generation, the model relies more on natural-language context and less on historical SID evidence. Further analyses show that this effect is amplified by reduced access to historical information and longer CoT lengths. To mitigate it, we propose Linguistic-Inertia-Calibrated Decoding (LICD), a training-free framework that combines Reasoning-Chain Compression and Bias-Subtracted Contrastive Inference. Experiments on three large-scale benchmarks show that LICD consistently outperforms both no-thinking and original-thinking baselines. Our code is available at https://github.com/USTC-StarTeam/LICD.
AsymSpec: Context-Asymmetric Speculative Decoding for Agentic LLMs
Sheng Liang | Yongyue Zhang | Nathanael Brian | Hang Lv | Hao Wang | Chen Zhang | Yong Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Sheng Liang | Yongyue Zhang | Nathanael Brian | Hang Lv | Hao Wang | Chen Zhang | Yong Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Agentic LLM pipelines face escalating inference costs as context accumulates across retrieval, tool use, and multi-turn interactions. To control latency, deployments routinely compress inputs, but this degrades task accuracy. Speculative decoding (SD) accelerates generation losslessly, yet it assumes the drafter and verifier share an identical context, preventing SD from resolving the accuracy–overhead trade-off. We propose AsymSpec, an asymmetric speculative decoding framework that breaks this symmetry: a lightweight drafter reads the full input while the large verifier operates on the compressed view. The drafter steers the verifier via a contrastive 𝛿-fusion of logits, modulated by a divergence-aware acceptance gate that preserves verification stability and high draft acceptance rates. Evaluated across four agentic capabilities and two end-to-end agent benchmarks, AsymSpec reaches ≈ 90% of full-context accuracy on average, delivering throughput speedups of 1.3×–1.7× at 0.2×–0.3× the compute cost on isolated text capabilities. These results show that asymmetric context access yields substantial gains precisely when compression discards critical reasoning signals.
Learning from Emptiness: De-biasing Listwise Rerankers with Content-Agnostic Probability Calibration
Hang Lv | Hongchao Gu | Ruiqing Yang | Liangyue Li | Zulong Chen | Defu Lian | Hao Wang | Enhong Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)
Hang Lv | Hongchao Gu | Ruiqing Yang | Liangyue Li | Zulong Chen | Defu Lian | Hao Wang | Enhong Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)
Generative listwise reranking leverages global context for superior retrieval but is plagued by intrinsic position bias, where models exhibit structural sensitivity to input order independent of relevance. Existing mitigations present a dilemma: inference-time aggregation incurs prohibitive latency, while training-based methods often fail to eradicate ingrained priors, particularly in compact models. To resolve this dilemma, we propose CapCal (Content-Agnostic Probability Calibration), a training-free framework that mechanically decouples positional bias from ranking decisions. By estimating the bias distribution via content-free placeholders, CapCal rectifies output logits through an entropy-adaptive contrastive mechanism. Evaluations across 10 benchmarks confirm that CapCal achieves superior performance among training-free methods while preserving single-pass efficiency. Notably, it unlocks the latent potential of lightweight models (e.g., 0.6B), delivering absolute NDCG gains exceeding 10 points and outperforming computationally expensive data augmentation strategies.
SPARD: Self-Paced Curriculum for RL Alignment via Integrating Reward Dynamics and Data Utility
Xuyang Zhi | Peilun Zhou | Chengqiang Lu | Hang Lv | Yiwei Liang | Rongyang Zhang | Yan Gao | Yiwu | Yao Hu | Hongchao Gu | Defu Lian | Hao Wang | Enhong Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Xuyang Zhi | Peilun Zhou | Chengqiang Lu | Hang Lv | Yiwei Liang | Rongyang Zhang | Yan Gao | Yiwu | Yao Hu | Hongchao Gu | Defu Lian | Hao Wang | Enhong Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
The evolution of Large Language Models (LLMs) is shifting the focus from single, verifiable tasks toward complex, open-ended real-world scenarios, imposing significant challenges on the post-training phase. In these settings, the scale and complexity of reward systems have grown significantly, transitioning toward multi-objective formulations that encompass a comprehensive spectrum of model capabilities and application contexts. However, traditional methods typically rely on fixed reward weights, ignoring non-stationary learning dynamics and struggling with data heterogeneity across dimensions. To address these issues, we propose SPARD, a framework that establishes an automated, self-paced curriculum by perceiving learning progress to dynamically adjust multi-objective reward weights and data importance, thereby synchronizing learning intent with data utility for optimal performance. Extensive experiments across multiple benchmarks demonstrate that SPARD significantly enhances model capabilities across all domains. Our code is publicly available at https://github.com/USTC-StarTeam/SPARD.
2025
Adaptive Schema-aware Event Extraction with Retrieval-Augmented Generation
Sheng Liang | Hang Lv | Zhihao Wen | Yaxiong Wu | Yongyue Zhang | Hao Wang | Yong Liu
Findings of the Association for Computational Linguistics: EMNLP 2025
Sheng Liang | Hang Lv | Zhihao Wen | Yaxiong Wu | Yongyue Zhang | Hao Wang | Yong Liu
Findings of the Association for Computational Linguistics: EMNLP 2025
Event extraction (EE) is a fundamental task in natural language processing (NLP) that involves identifying and extracting event information from unstructured text. Effective EE in real-world scenarios requires two key steps: selecting appropriate schemas from hundreds of candidates and executing the extraction process.Existing research exhibits two critical gaps: (1) the rigid schema fixation in existing pipeline systems, and (2) the absence of benchmarks for evaluating joint schema matching and extraction.Although large language models (LLMs) offer potential solutions, their schema hallucination tendencies and context window limitations pose challenges for practical deployment. In response, we propose Adaptive Schema-aware Event Extraction (ASEE), a novel paradigm combining schema paraphrasing with schema retrieval-augmented generation. ASEE adeptly retrieves paraphrased schemas and accurately generates targeted structures.To facilitate rigorous evaluation, we construct the Multi-Dimensional Schema-aware Event Extraction (MD-SEE) benchmark, which systematically consolidates 12 datasets across diverse domains, complexity levels, and language settings.Extensive evaluations on MD-SEE show that our proposed ASEE demonstrates strong adaptability across various scenarios, significantly improving the accuracy of event extraction. Our codes and datasets are available at https://github.com/USTC-StarTeam/ASEE.git
RAPID: Efficient Retrieval-Augmented Long Text Generation with Writing Planning and Information Discovery
Hongchao Gu | Dexun Li | Kuicai Dong | Hao Zhang | Hang Lv | Hao Wang | Defu Lian | Yong Liu | Enhong Chen
Findings of the Association for Computational Linguistics: ACL 2025
Hongchao Gu | Dexun Li | Kuicai Dong | Hao Zhang | Hang Lv | Hao Wang | Defu Lian | Yong Liu | Enhong Chen
Findings of the Association for Computational Linguistics: ACL 2025
Generating knowledge-intensive and comprehensive long texts, such as encyclopedia articles, remains significant challenges for Large Language Models. It requires not only the precise integration of facts but also the maintenance of thematic coherence throughout the article. Existing methods, such as multi-agent discussion, often struggle with issues like hallucinations, topic incoherence, and significant latency. To address these challenges, we propose RAPID, an efficient Retrieval-Augmented long text generation framework with writing Planning and Information Discovery. RAPID consists of three main modules: (1) Retrieval-augmented preliminary outline generation to reduce hallucinations, (2) Attribute-constrained search for efficient information discovery, (3) Plan-guided article generation for enhanced coherence. Extensive experiments on our newly compiled benchmark dataset, FreshWiki-2024, demonstrate that RAPID significantly outperforms state-of-the-art methods across a wide range of evaluation metrics (long-text generation, outline quality, latency, etc). Our work provides a robust and efficient solution to the challenges of automated long-text generation.
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- Hao Wang 9
- Enhong Chen 6
- Hongchao Gu 6
- Defu Lian 5
- Yong Liu 5
- Sheng Liang 4
- Wei Guo 3
- Yongyue Zhang 3
- Xuyang Zhi 3
- Yaxiong Wu 2
- Nathanael Brian 1
- Zulong Chen 1
- Kuicai Dong 1
- Yan Gao 1
- Yao Hu 1
- Yonghao Huang 1
- Dexun Li 1
- Liangyue Li 1
- Yiwei Liang 1
- Chengqiang Lu 1
- Zhihao Wen 1
- Ruiqing Yang 1
- Yuyang Ye 1
- Mingjia Yin 1
- Yiwu 1
- Chen Zhang 1
- Hao Zhang 1
- Luankang Zhang 1
- Rongyang Zhang 1
- Peilun Zhou 1