Hung Pham Van
2026
MemORAI: Memory Organization and Retrieval via Adaptive Graph Intelligence for LLM Conversational Agents
Hung Pham Van | Nguyen Manh Hieu | Khang Pham Tran Tuan | Nam Le Hai | Linh Ngo Van | Nguyen Thi Ngoc Diep | Trung Le
Findings of the Association for Computational Linguistics: ACL 2026
Hung Pham Van | Nguyen Manh Hieu | Khang Pham Tran Tuan | Nam Le Hai | Linh Ngo Van | Nguyen Thi Ngoc Diep | Trung Le
Findings of the Association for Computational Linguistics: ACL 2026
Large Language Models (LLMs) lack persistent memory for long-term personalized conversations. Existing graph-based memory systems suffer from information dilution, absent provenance tracking, and uniform retrieval that ignores query context. We introduce MemORAI (Memory Organization and Retrieval via Adaptive Graph Intelligence), a framework that integrates three innovations: selective memory filtering with dual-layer compression to retain user-persona-relevant content, a provenance-enriched multi-relational graph tracking factual origins at the turn level, and query-adaptive subgraph retrieval with Dynamic Weighted PageRank that applies query-conditioned edge weighting. Evaluated on LOCOMO and LongMemEval benchmarks, MemORAI achieves state-of-the-art performance in memory retrieval and personalized response generation, demonstrating that selective storage, enriched representation, and adaptive retrieval are essential for coherent, personalized LLM agents.
2025
MaGiX: A Multi-Granular Adaptive Graph Intelligence Framework for Enhancing Cross-Lingual RAG
Nguyen Manh Hieu | Vu Lam Anh | Hung Pham Van | Nam Le Hai | Linh Ngo Van | Nguyen Thi Ngoc Diep | Thien Huu Nguyen
Findings of the Association for Computational Linguistics: EMNLP 2025
Nguyen Manh Hieu | Vu Lam Anh | Hung Pham Van | Nam Le Hai | Linh Ngo Van | Nguyen Thi Ngoc Diep | Thien Huu Nguyen
Findings of the Association for Computational Linguistics: EMNLP 2025
Retrieval-Augmented Generation (RAG) enhances large language models by grounding their outputs in external knowledge. Recent advances in Graph-based RAG (GRAG) frameworks, such as GraphRAG, LightRAG, and HippoRAG2, integrate knowledge graphs into the retrieval process to improve multi-hop reasoning and semantic coherence. While effective in monolingual settings, these methods remain underexplored in cross-lingual scenarios and face limitations in semantic granularity and entity alignment. In this work, we propose MaGiX, the first GRAG framework tailored for English–Vietnamese cross-lingual question answering. MaGiX constructs a multi-granular cross-lingual knowledge graph using fine-grained attribute descriptions and cross-synonym edges, and incorporates a custom multilingual embedding model trained with contrastive learning for semantic alignment. During retrieval, MaGiX leverages graph-based reasoning and a semantic-aware reranking strategy to enhance cross-lingual relevance. Experiments across five benchmarks show that MaGiX substantially outperforms prior GRAG systems in both retrieval accuracy and generation quality, advancing structured retrieval for multilingual QA.