arXiv Computer Vision

Activation Boundary Matching: Task-Informed Initialization for Low-Rank Adaptation

The paper introduces Activation Boundary Matching for Low‑Rank Adaptation (ABM‑LoRA), a task‑informed initialization strategy that uses the signs of layer‑wise pre‑activations from a brief probe adapter as targets for a fresh adapter. By training with a margin‑based hinge objective on these activation boundaries, ABM‑LoRA captures useful adaptation directions that standard LoRA initializers miss, while requiring only a few forward passes. Experiments show that ABM‑LoRA outperforms or matches existing LoRA, SVD, and gradient‑based initializers across multiple models and benchmarks, including T5‑base/GLUE, ConvNeXt‑T, Swin‑T, Qwen2.5‑1.5B, and LLaMA2‑7B.

arXiv AI
Sep 3

TaRA: Training-Aware Low-Rank Adaptation Initialization

TaRA: Training-Aware Low-Rank Adaptation Initialization proposes a new way to initialize LoRA by aligning the gradients of low‑rank factors with those of the full‑rank weight matrix. This approach directly incorporates training dynamics, improving gradient fidelity at the start of fine‑tuning while adding negligible computational cost. Experiments on a variety of challenging fine‑tuning tasks show that TaRA consistently outperforms existing state‑of‑the‑art initialization methods, offering a simple, robust, and scalable solution for effective LoRA initialization.

By Taehyeon Kim, Eunhyeok Park
arXiv Machine Learning
Sep 1

Normalized Low-Rank Adaptation

Normalized Low-Rank Adaptation (NoRA) is a lightweight enhancement to the widely used LoRA technique that normalizes the down‑projection matrices during training. By doing so, NoRA stabilizes early optimization dynamics, accelerates convergence, and improves performance across pretraining, supervised fine‑tuning, and reinforcement learning. The method adds no extra trainable parameters or inference‑time cost, making it broadly applicable.

By Jiale Kang, Ziyin Yue, Zheng Zhan, Yangyi Huang, Weiyang Liu
arXiv Machine Learning
4d ago

Rank-Efficient LoRA via Joint Tangent-Space Optimization under Isotropic Curvature

The paper introduces ISO-LoRA, an optimizer that improves rank utilization in Low‑Rank Adaptation (LoRA) by coupling factor updates through spectral descent on the induced tangent perturbation in weight space. Experiments on GPT‑2 adaptation show that standard optimizers like AdamW concentrate updates in a few singular directions, whereas ISO-LoRA distributes energy more evenly, leading to higher effective rank and better downstream performance across 0.1B‑7B models. The authors provide theoretical guarantees under a stylized spiked‑gradient model and demonstrate that ISO-LoRA consistently outperforms factor‑wise optimizers, especially at moderate‑to‑large LoRA ranks.

By Zihan Zhu, Zhehang Du, Xuyang Chen, Tim Tsz-Kit Lau, Jiayuan Wu, X. Y. Han, Qi Long, Weijie Su