Qi Liu
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Unverified author pages with similar names: Qi Liu
2026
Entropy-KL Divergence-based Token Masking: A Novel Approach for Selective Fine-tuning of Large Language Models
Qi Liu | Mingdi Sun | Yongyi He | Zhi Zheng | Tong Xu | Yi Zheng | Zhefeng Wang | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Qi Liu | Mingdi Sun | Yongyi He | Zhi Zheng | Tong Xu | Yi Zheng | Zhefeng Wang | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Supervised fine-tuning (SFT) followed by reinforcement learning (RL) has become a standard post-training paradigm for large language models. This paradigm provides a cold-start for RL exploration, avoiding the inefficiency of pure RL where on-policy sampling yields insufficient positive samples. However, in practice, existing approaches often use a small amount of data for SFT initialization compared to the RL phase, which can cause the model to fit the limited samples and shift away from its pre-trained distribution. This distribution shift impedes the model’s ability to effectively explore during subsequent RL training. To address this challenge, we propose that in low-data regimes, SFT should prioritize activating task-relevant capabilities rather than memorizing specific content. Along this line, we propose EKSFT (Entropy-KL Selective Fine-Tuning), which selectively masks tokens that exhibit either high entropy or high KL divergence from a reference model. By excluding these high-uncertainty, distribution-shifting tokens from imitation, EKSFT injects task-specific knowledge while preserving the integrity of the model’s pre-trained distribution. Empirical evaluations on mathematical reasoning benchmarks demonstrate that EKSFT consistently outperforms standard SFT. Further RL fine-tuning from the EKSFT model yields consistently better post-RL performance, indicating improved exploration for the RL stage. Our codes and datasets are available at https://github.com/MINE-USTC/EKSFT.
AtomMem: Building Simple and Effective Memory System for LLM Agents via Atomic Facts
Yanyu Yao | Shangze Li | Zhi Zheng | Hui Zheng | Qi Liu | Tong Xu | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Yanyu Yao | Shangze Li | Zhi Zheng | Hui Zheng | Qi Liu | Tong Xu | Enhong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) demonstrate strong reasoning and generation abilities, but their fixed context windows limit long-term information accumulation and reuse across multi-session interactions. Existing memory-augmented systems often construct memory in a coarse and unstable manner, relying on inefficient memory representations or unstable unconstrained updates. To address these challenges, we propose **AtomMem**, a long-term memory system designed for value-dense storage and stable memory evolution. AtomMem introduces a Fact Executor, which selectively extracts high value atomic facts from long form interactions to serve as highly efficient memory representations. Subsequently, AtomMem organizes these facts into hierarchical event structures and temporal profiles, capturing coherent episodic contexts and tracking dynamically evolving user attributes over time. During retrieval, the system activates an associative memory graph to connect fragmented memories. Experiments on the LoCoMo benchmark confirm that AtomMem achieves state-of-the-art performance across various reasoning tasks, offering a scalable and economically viable solution for deploying intelligent personalized agents. The implementation code is publicly available at [https://github.com/MINE-USTC/AtomMem](https://github.com/MINE-USTC/AtomMem).
2025
AMoPO: Adaptive Multi-objective Preference Optimization without Reward Models and Reference Models
Qi Liu | Jingqing Ruan | Hao Li | Haodong Zhao | Desheng Wang | Jiansong Chen | Wan Guanglu | Xunliang Cai | Zhi Zheng | Tong Xu
Findings of the Association for Computational Linguistics: ACL 2025
Qi Liu | Jingqing Ruan | Hao Li | Haodong Zhao | Desheng Wang | Jiansong Chen | Wan Guanglu | Xunliang Cai | Zhi Zheng | Tong Xu
Findings of the Association for Computational Linguistics: ACL 2025
Existing multi-objective preference alignment methods for large language models (LLMs) face limitations: (1) the inability to effectively balance various preference dimensions, and (2) reliance on auxiliary reward/reference models introduces computational complexity. To address these challenges, we propose Adaptive Multi-objective Preference Optimization (AMoPO), a novel framework that achieves dynamic balance across preference dimensions. By introducing the multi-objective optimization paradigm to use the dimension-aware generation metrics as implicit rewards, AMoPO aligns LLMs with diverse preferences without additional reward models or reference models. We introduce an adaptive weight assignment mechanism that models the generation space as a Gaussian distribution, allowing dynamic prioritization of preference dimensions. Empirical results demonstrate that AMoPO outperforms state-of-the-art baselines by 28.5%, and the experiments on 7B, 14B, and 32B models reveal the scaling ability of AMoPO. Moreover, additional analysis of multiple dimensions verifies its adaptability and effectiveness. These findings validate AMoPO’s capability to achieve dimension-aware preference alignment, highlighting its superiority. Our codes and datasets are available at https://github.com/Javkonline/AMoPO.
Think and Recall: Layer-Level Prompting for Lifelong Model Editing
Jinke Wang | Zenan Ying | Qi Liu | Wei Chen | Tong Xu | Huijun Hou | Zhi Zheng
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Jinke Wang | Zenan Ying | Qi Liu | Wei Chen | Tong Xu | Huijun Hou | Zhi Zheng
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Lifelong model editing aims to dynamically adjust a model’s output with respect to specific facts, knowledge points, or behaviors, enabling the model to adapt to the ever-changing demands of the real world without requiring retraining. While some retrieval-based methods have demonstrated potential in lifelong editing scenarios by storing edited knowledge in external memory, they often suffer from limitations in usability, such as requiring additional training corpora or lacking support for reversible and detachable edits.To address these issues, we propose a plug-and-play method for knowledge retrieval and storage, i.e., Layer-Level Prompting (LLP), which enables seamless and efficient lifelong model editing. In our LLP framework, the reasoning process of LLMs is divided into two stages, respectively knowledge retrieval (Think) and knowledge injection(Recall). Specifically, the knowledge retrieval process is performed in the early layers of the model. Based on the retrieved information, the model is guided to access the updated knowledge stored in the subsequent layer to complete the knowledge editing process. Experimental results demonstrate that our method consistently outperforms existing techniques on lifelong model editing tasks, achieving superior performance on question answering and hallucination benchmarks across different LLMs.
2024
Granular Entity Mapper: Advancing Fine-grained Multimodal Named Entity Recognition and Grounding
Ziqi Wang | Chen Zhu | Zhi Zheng | Xinhang Li | Tong Xu | Yongyi He | Qi Liu | Ying Yu | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2024
Ziqi Wang | Chen Zhu | Zhi Zheng | Xinhang Li | Tong Xu | Yongyi He | Qi Liu | Ying Yu | Enhong Chen
Findings of the Association for Computational Linguistics: EMNLP 2024
Multimodal Named Entity Recognition and Grounding (MNERG) aims to extract paired textual and visual entities from texts and images. It has been well explored through a two-step paradigm: initially identifying potential visual entities using object detection methods and then aligning the extracted textual entities with their corresponding visual entities. However, when it comes to fine-grained MNERG, the long-tailed distribution of textual entity categories and the performance of object detectors limit the effectiveness of traditional methods. Specifically, more detailed classification leads to many low-frequency categories, and existing object detection methods often fail to pinpoint subtle regions within images. To address these challenges, we propose the Granular Entity Mapper (GEM) framework. Firstly, we design a multi-granularity entity recognition module, followed by a reranking module based on the Multimodal Large Language Model (MLLM) to incorporate hierarchical information of entity categories, visual cues, and external textual resources collectively for accurate fine-grained textual entity recognition. Then, we utilize a pre-trained Large Visual Language Model (LVLM) as an implicit visual entity grounder that directly deduces relevant visual entity regions from the entire image without the need for bounding box training. Experimental results on the GMNER and FMNERG datasets demonstrate that our GEM framework achieves state-of-the-art results on the fine-grained content extraction task.