Xiaofeng Liu
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2026
ActiveMedAgent: Cost-Aware Trajectory Learning for Multimodal Medical Diagnosis
Weiwei Ma | Xiaobing Yu | Peijie Qiu | Jin Yang | Zhaoqi An | Xuanzhao Dong | Xiaoqi Zhao | Xiaofeng Liu
Findings of the Association for Computational Linguistics: EMNLP 2026
Weiwei Ma | Xiaobing Yu | Peijie Qiu | Jin Yang | Zhaoqi An | Xuanzhao Dong | Xiaoqi Zhao | Xiaofeng Liu
Findings of the Association for Computational Linguistics: EMNLP 2026
Clinical diagnosis is inherently sequential: clinicians escalate from cheap to costly tests only when additional evidence is expected to resolve diagnostic uncertainty. We present ActiveMedAgent, a framework that brings this cost-aware sequential logic to multimodal medical AI. Given a frozen, API-accessed vision-language model, ActiveMedAgent probability distributions over candidate diagnoses induced each acquisition by its per-step diagnostic utility minus cost. A lightweight MLP controller is then trained offline on these scored trajectories, learning when to request additional evidence and when to commit. Across three commonly used benchmarks, trajectory-based policy learning consistently outperforms both unguided acquisition and full-modality baselines. Notably, we identify an information overload effect. In 175 cases, the agent produces a correct diagnosis with fewer channels while the full-modality baseline fails, showing that learning what to omit can be as important as learning what to acquire
LadderEdit: Edit-Level Residual Compression for Memory-Efficient Lifelong Editing of LLMs
Xiaobing Yu | Peijie Qiu | Jin Yang | Xuanzhao Dong | Weiwei Ma | Zhaoqi An | Xiaoqi Zhao | Xiaofeng Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Xiaobing Yu | Peijie Qiu | Jin Yang | Xuanzhao Dong | Weiwei Ma | Zhaoqi An | Xiaoqi Zhao | Xiaofeng Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Lifelong editing of LLMs requires storing thousands of edits after acquisition. A widely used family of approaches attaches one LoRA adapter per edit, which preserves behavior but grows linearly in storage. To address this challenge, we propose LadderEdit, a method that compresses each LoRA adapter after it is acquired. Each edit is first stored at low rank as a cheap sketch. We then check whether this sketch still satisfies the rewrite, generalization, and locality contract on probe prompts. Edits that pass keep the sketch; those that fail are promoted to a higher rank along a ladder until the contract is met. Because every edit retains some representation, coverage is maintained, and only hard edits consume more rank. Across ZsRE, CounterFact, and WikiBigEdit benchmarks on LLaMA-3-8B, Mistral-7B, and Qwen2.5-7B, LadderEdit tracks exact LoRA storage at 5.2× less memory and remains effective at 50,000 sequential edits.
2024
Light-weight Fine-tuning Method for Defending Adversarial Noise in Pre-trained Medical Vision-Language Models
Xu Han | Linghao Jin | Xuezhe Ma | Xiaofeng Liu
Findings of the Association for Computational Linguistics: EMNLP 2024
Xu Han | Linghao Jin | Xuezhe Ma | Xiaofeng Liu
Findings of the Association for Computational Linguistics: EMNLP 2024
Fine-tuning pre-trained Vision-Language Models (VLMs) has shown remarkable capabilities in medical image and textual depiction synergy. Nevertheless, many pre-training datasets are restricted by patient privacy concerns, potentially containing noise that can adversely affect downstream performance. Moreover, the growing reliance on multi-modal generation exacerbates this issue because of its susceptibility to adversarial attacks. To investigate how VLMs trained on adversarial noisy data perform on downstream medical tasks, we first craft noisy upstream datasets using multi-modal adversarial attacks. Through our comprehensive analysis, we unveil that moderate noise enhances model robustness and transferability, but increasing noise levels negatively impact downstream task performance. To mitigate this issue, we propose rectify adversarial noise (RAN) framework, a recipe designed to effectively defend adversarial attacks and rectify the influence of upstream noise during fine-tuning.