核心空间中精确高效的低秩模型融合
Accurate and Efficient Low-Rank Model Merging in Core Space
September 22, 2025
作者: Aniello Panariello, Daniel Marczak, Simone Magistri, Angelo Porrello, Bartłomiej Twardowski, Andrew D. Bagdanov, Simone Calderara, Joost van de Weijer
cs.AI
摘要
本文探讨了在合并大型神经网络低秩适配时面临的挑战。随着参数高效适配技术(如低秩适配LoRA)的兴起,模型微调变得更加便捷。尽管使用LoRA进行模型微调极为高效,现有合并方法往往通过合并全尺寸权重矩阵牺牲了这一效率。我们提出了核心空间合并框架,该框架能够在共同对齐基础上合并LoRA适配模型,从而在保持低秩适配效率的同时,显著提升跨任务准确率。我们进一步提供了形式化证明,表明投影至核心空间可确保信息无损,并通过复杂度分析展示了效率提升。大量实证结果表明,核心空间显著改进了现有合并技术,在视觉与语言任务上均取得了最先进的成果,同时仅消耗少量计算资源。代码库已发布于https://github.com/apanariello4/core-space-merging。
English
In this paper, we address the challenges associated with merging low-rank
adaptations of large neural networks. With the rise of parameter-efficient
adaptation techniques, such as Low-Rank Adaptation (LoRA), model fine-tuning
has become more accessible. While fine-tuning models with LoRA is highly
efficient, existing merging methods often sacrifice this efficiency by merging
fully-sized weight matrices. We propose the Core Space merging framework, which
enables the merging of LoRA-adapted models within a common alignment basis,
thereby preserving the efficiency of low-rank adaptation while substantially
improving accuracy across tasks. We further provide a formal proof that
projection into Core Space ensures no loss of information and provide a
complexity analysis showing the efficiency gains. Extensive empirical results
demonstrate that Core Space significantly improves existing merging techniques
and achieves state-of-the-art results on both vision and language tasks while
utilizing a fraction of the computational resources. Codebase is available at
https://github.com/apanariello4/core-space-merging.