Chengkai Huang
2026
SceneAlign: Aligning Multimodal Reasoning to Scene Graphs in Complex Visual Scenes
Chuhan Wang | Xintong Li | Jennifer Yuntong Zhang | Junda Wu | Chengkai Huang | Lina Yao | Julian McAuley | Jingbo Shang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Chuhan Wang | Xintong Li | Jennifer Yuntong Zhang | Junda Wu | Chengkai Huang | Lina Yao | Julian McAuley | Jingbo Shang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Multimodal large language models often struggle with faithful reasoning in complex visual scenes, where intricate entities and relations require precise visual grounding at each step. This reasoning unfaithfulness frequently manifests as hallucinated entities, mis-grounded relations, skipped steps, and over-specified reasoning. Existing preference-based approaches, typically relying on textual perturbations or answer-conditioned rationales, fail to address this challenge as they allow models to exploit language priors to bypass visual grounding. To address this, we propose SceneAlign, a framework that leverages scene graphs as structured visual information to perform controllable structural interventions. By identifying reasoning-critical nodes and perturbing them through four targeted strategies that mimic typical grounding failures, SceneAlign constructs hard negative rationales that remain linguistically plausible but are grounded in inaccurate visual facts. These contrastive pairs are used in Direct Preference Optimization to steer models toward fine-grained, structure-faithful reasoning. Across seven visual reasoning benchmarks, SceneAlign consistently improves answer accuracy and reasoning faithfulness, highlighting the effectiveness of grounding-aware alignment for multimodal reasoning.
MemWeaver: Weaving Hybrid Memories for Traceable Long-Horizon Agentic Reasoning
Juexiang Ye | Xue Li | Yang Xinyu | Chengkai Huang | Lanshun Nie | Lina Yao | Dechen Zhan
Findings of the Association for Computational Linguistics: ACL 2026
Juexiang Ye | Xue Li | Yang Xinyu | Chengkai Huang | Lanshun Nie | Lina Yao | Dechen Zhan
Findings of the Association for Computational Linguistics: ACL 2026
Large language model-based agents operating in long-horizon interactions require memory systems that support temporal consistency, multi-hop reasoning, and evidence-grounded reuse across sessions. Existing approaches largely rely on unstructured retrieval or coarse abstractions, which often lead to temporal conflicts, brittle reasoning, and limited traceability. We propose MemWeaver, a unified memory framework that consolidates long-term agent experiences into three interconnected components: a temporally grounded graph memory for structured relational reasoning, an experience memory that abstracts recurring interaction patterns from repeated observations, and a passage memory that preserves original textual evidence. MemWeaver employs a dual-channel retrieval strategy that jointly retrieves structured knowledge and supporting evidence to construct compact yet information-dense contexts for reasoning. Experiments on the LoCoMo benchmark demonstrate that MemWeaver substantially improves multi-hop and temporal reasoning accuracy while reducing input context length by over 95% compared to long-context baselines.
2025
Embedding-Informed Adaptive Retrieval-Augmented Generation of Large Language Models
Chengkai Huang | Yu Xia | Rui Wang | Kaige Xie | Tong Yu | Julian McAuley | Lina Yao
Proceedings of the 31st International Conference on Computational Linguistics
Chengkai Huang | Yu Xia | Rui Wang | Kaige Xie | Tong Yu | Julian McAuley | Lina Yao
Proceedings of the 31st International Conference on Computational Linguistics
Retrieval-augmented large language models (LLMs) have been remarkably competent in various NLP tasks. However, it was observed by previous works that retrieval is not always helpful, especially when the LLM is already knowledgable on the query to answer. Motivated by this, Adaptive Retrieval-Augmented Generation (ARAG) studies retrieving only when the knowledge asked by the query is absent in the LLM. Previous works of ARAG either require accessing the pre-training corpus or prompting with additional model inferences. Aiming to avoid such drawbacks, we propose to determine whether the model is knowledgeable on a query via inspecting the (contextualized) pre-trained token embeddings of LLMs. We hypothesize that such embeddings capture rich information on the model’s intrinsic knowledge base, which enables an efficient way of judging the necessity to retrieve from an external corpus. Extensive experiments demonstrate our ARAG approach’s superior performance across various benchmarks.