Weijun Yao
2026
Skill Weaving: Efficient LLM Improvement via Modular Skillpacks
Zhuo Li | Guodong DU | Zesheng Shi | Weiyang Guo | Weijun Yao | Yuan Zhou | Jiabo Zhang | Jing Li
Findings of the Association for Computational Linguistics: ACL 2026
Zhuo Li | Guodong DU | Zesheng Shi | Weiyang Guo | Weijun Yao | Yuan Zhou | Jiabo Zhang | Jing Li
Findings of the Association for Computational Linguistics: ACL 2026
In this work, we introduce SkillWeave, a modular improvement framework that enables large language models to specialize under fixed memory budgets. SkillWeave partitions full capabilities of a general-purpose model into domain-specific skillpacks—lightweight, domain-specific delta modules—that reorganize and refine the model’s internal knowledge. To ensure deployment efficiency, SkillWeave incorporates SkillZip, a compression component that transforms specialized parameters into lightweight, inference-ready skillpacks. Together, these components allow SkillWeave to achieve strong multi-domain performance and inference-efficient execution. On multi-task and agentic benchmarks, a 9B SkillWeave model outperforms task-specific baselines and even surpasses a 32B monolithic LLM, while achieving up to 4× speedup.
Vocabulary Hijacking in LVLMs: Unveiling Critical Attention Heads by Excluding Inert Tokens to Mitigate Hallucination
Yangneng Chen | Junlin Li | Weijun Yao | Xilai Ma | Guodong DU | Wenya Wang | Jing Li
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Yangneng Chen | Junlin Li | Weijun Yao | Xilai Ma | Guodong DU | Wenya Wang | Jing Li
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Large Vision-Language Models (LVLMs) have achieved remarkable progress in multimodal tasks, yet their reliability is persistently undermined by hallucinations—generating text that contradicts visual input. Recent studies often attribute these errors to inadequate visual attention. In this work, we analyze the attention mechanisms via the logit lens, uncovering a distinct anomaly we term **Vocabulary Hijacking**. We discover that specific visual tokens, defined as **Inert Tokens**, disproportionately attract attention. Crucially, when their intermediate hidden states are projected into the vocabulary space, they consistently decode to a fixed set of unrelated words (termed **Hijacking Anchors**) across layers, revealing a rigid semantic collapse. Leveraging this semantic rigidity, we propose **Hijacking Anchor-Based Identification (HABI)**, a robust strategy to accurately localize these Inert Tokens. To quantify the impact of this phenomenon, we introduce the **Non-Hijacked Visual Attention Ratio (NHAR)**, a novel metric designed to identify attention heads that remain resilient to hijacking and are critical for factual accuracy. Building on these insights, we propose **Hijacking-Aware Visual Attention Enhancement (HAVAE)**, a training-free intervention that selectively strengthens the focus of these identified heads on salient visual content. Extensive experiments across multiple benchmarks demonstrate that HAVAE significantly mitigates hallucinations with **no additional computational overhead**, while preserving the model’s general capabilities.
Personalizing LLMs with Binary Feedback: A Preference-Calibrated Optimization Framework
Xilai Ma | Liye Zhao | Weijun Yao | Haibing Di | Wenya Wang | Jing Li
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Xilai Ma | Liye Zhao | Weijun Yao | Haibing Di | Wenya Wang | Jing Li
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Large Language Model (LLM) personalization aims to align model behaviors with individual user preferences.Existing methods often focus on isolated user histories, neglecting the essential role of inter-user differences.We propose C-BPO, a framework that personalizes LLMs via preference-calibrated binary signals.By treating target user data as positive feedback and other users’ data as an auxiliary set of implicit negative signals, C-BPO captures distinct inter-user differences.To mitigate the preference overlap issue, where shared task knowledge is erroneously penalized, we derive an objective grounded in Positive-Unlabeled (PU) learning theory.This approach purifies negative signals by subtracting “positive bias”, ensuring alignment with unique idiosyncrasies without compromising general helpfulness.Empirical experiments across various personalization tasks and backbone LLMs show C-BPO consistently outperforms baselines, demonstrating the efficacy of preference-calibrated binary signals in modeling inter-user differences.