Wenyu Tao


2025

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SAKI-RAG: Mitigating Context Fragmentation in Long-Document RAG via Sentence-level Attention Knowledge Integration
Wenyu Tao | Xiaofen Xing | Zeliang Li | Xiangmin Xu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Traditional Retrieval-Augmented Generation (RAG) frameworks often segment documents into larger chunks to preserve contextual coherence, inadvertently introducing redundant noise. Recent advanced RAG frameworks have shifted toward finer-grained chunking to improve precision. However, in long-document scenarios, such chunking methods lead to fragmented contexts, isolated chunk semantics, and broken inter-chunk relationships, making cross-paragraph retrieval particularly challenging. To address this challenge, maintaining granular chunks while recovering their intrinsic semantic connections, we propose **SAKI-RAG** (Sentence-level Attention Knowledge Integration Retrieval-Augmented Generation). Our framework introduces two core components: (1) the **SentenceAttnLinker**, which constructs a semantically enriched knowledge repository by modeling inter-sentence attention relationships, and (2) the **Dual-Axis Retriever**, which is designed to expand and filter the candidate chunks from the dual dimensions of semantic similarity and contextual relevance. Experimental results across four datasets—Dragonball, SQUAD, NFCORPUS, and SCI-DOCS demonstrate that SAKI-RAG achieves better recall and precision compared to other RAG frameworks in long-document retrieval scenarios, while also exhibiting higher information efficiency.

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TreeRAG: Unleashing the Power of Hierarchical Storage for Enhanced Knowledge Retrieval in Long Documents
Wenyu Tao | Xiaofen Xing | Yirong Chen | Linyi Huang | Xiangmin Xu
Findings of the Association for Computational Linguistics: ACL 2025

When confronting long document information retrieval for Query-Focused Summarization(QFS), Traditional Retrieval-Augmented Generation(RAG) frameworks struggle to retrieve all relevant knowledge points, and the chunking and retrieve strategies of existing frameworks may disrupt the connections between knowledge points and the integrity of the information. To address these issues, we propose TreeRAG, which employs Tree-Chunking for chunking and embedding in a tree-like structure , coupled with "root-to-leaves" and "leaf-to-root" retrieve strategy named Bidirectional Traversal Retrieval. This approach effectively preserves the hierarchical structure among knowledge points and significantly enhances the ability to retrieve while minimizing noise inference. Our experimental results on the Finance, Law, and Medical subsets of the Dragonball dataset demonstrate that TreeRAG achieves significant enhancements in both recall quality and precision compared to traditional and popular existing methods and achieves better performance to corresponding question-answering tasks, marking a new breakthrough in long document knowledge retrieval.