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Autoencoder-Based Detection of Anomalous Stokes V Spectra in the Flare-Producing Active Region 13663 Using Hinode/SP Observations
Batmunkh, Jargalmaa, Iida, Yusuke, Oba, Takayoshi
Detecting unusual signals in observational solar spectra is crucial for understanding the features associated with impactful solar events, such as solar flares. However, existing spectral analysis techniques face challenges, particularly when relying on pre-defined, physics-based calculations to process large volumes of noisy and complex observational data. To address these limitations, we applied deep learning to detect anomalies in the Stokes V spectra from the Hinode/SP instrument. Specifically, we developed an autoencoder model for spectral compression, which serves as an anomaly detection method. Our model effectively identifies anomalous spectra within spectro-polarimetric maps captured prior to the onset of the X1.3 flare on May 5, 2024, in NOAA AR 13663. These atypical spectral points exhibit highly complex profiles and spatially align with polarity inversion lines in magnetogram images, indicating their potential as sites of magnetic energy storage and possible triggers for flares. Notably, the detected anomalies are highly localized, making them particularly challenging to identify in magnetogram images using current manual methods.
- North America > United States (0.34)
- Europe > Norway (0.04)
- Asia > Japan > Honshū > Chūbu > Niigata Prefecture > Niigata (0.04)
Punctate White Matter Lesion Segmentation in Preterm Infants Powered by Counterfactually Generative Learning
Ren, Zehua, Sun, Yongheng, Wang, Miaomiao, Feng, Yuying, Li, Xianjun, Jin, Chao, Yang, Jian, Lian, Chunfeng, Wang, Fan
Accurate segmentation of punctate white matter lesions (PWMLs) are fundamental for the timely diagnosis and treatment of related developmental disorders. Automated PWMLs segmentation from infant brain MR images is challenging, considering that the lesions are typically small and low-contrast, and the number of lesions may dramatically change across subjects. Existing learning-based methods directly apply general network architectures to this challenging task, which may fail to capture detailed positional information of PWMLs, potentially leading to severe under-segmentations. In this paper, we propose to leverage the idea of counterfactual reasoning coupled with the auxiliary task of brain tissue segmentation to learn fine-grained positional and morphological representations of PWMLs for accurate localization and segmentation. A simple and easy-to-implement deep-learning framework (i.e., DeepPWML) is accordingly designed. It combines the lesion counterfactual map with the tissue probability map to train a lightweight PWML segmentation network, demonstrating state-of-the-art performance on a real-clinical dataset of infant T1w MR images.
- Asia > China > Shaanxi Province > Xi'an (0.05)
- Europe > France > Grand Est > Bas-Rhin > Strasbourg (0.04)
- Asia > China > Guangdong Province > Shenzhen (0.04)
- Health & Medicine > Therapeutic Area > Neurology (1.00)
- Health & Medicine > Diagnostic Medicine > Imaging (1.00)