Towards Multi-Source Retrieval-Augmented Generation via Synergizing Reasoning and Preference-Driven Retrieval

Retrieval-Augmented Generation (RAG) has emerged as a reliable external knowledge augmentation technique to mitigate hallucination issues and parameterized knowledge limitations in Large Language Models (LLMs). Existing Adaptive RAG (ARAG) systems struggle to effectively explore multiple retrieval sources due to their inability to select the right source at the right time. To address this, we propose a multi-source ARAG framework, termed MSPR, which synergizes reasoning and preference-driven retrieval to adaptive decide "when and what to retrieve" and "which retrieval source to use". To better adapt to retrieval sources of differing characteristics, we also employ retrieval action adjustment and answer feedback strategy. They enable our framework to fully explore the high-quality primary source while supplementing it with secondary sources at the right time. Extensive and multi-dimensional experiments conducted on three datasets demonstrate the superiority and effectiveness of MSPR.

Parameter-Efficient Transformer with Hybrid Axial-Attention for Medical Image Segmentation

Transformers have achieved remarkable success in medical image analysis owing to their powerful capability to use flexible self-attention mechanism. However, due to lacking intrinsic inductive bias in modeling visual structural information, they generally require a large-scale pre-training schedule, limiting the clinical applications over expensive small-scale medical data. To this end, we propose a parameter-efficient transformer to explore intrinsic inductive bias via position information for medical image segmentation. Specifically, we empirically investigate how different position encoding strategies affect the prediction quality of the region of interest (ROI), and observe that ROIs are sensitive to the position encoding strategies. Motivated by this, we present a novel Hybrid Axial-Attention (HAA), a form of position self-attention that can be equipped with spatial pixel-wise information and relative position information as inductive bias. Moreover, we introduce a gating mechanism to alleviate the burden of training schedule, resulting in efficient feature selection over small-scale datasets. Experiments on the BraTS and Covid19 datasets prove the superiority of our method over the baseline and previous works. Internal workflow visualization with interpretability is conducted to better validate our success.