Low-field (LF) MRI scanners have the power to revolutionize medical imaging by providing a portable and cheaper alternative to high-field MRI scanners. However, such scanners are usually significantly noisier and lower quality than their high-field counterparts. The aim of this paper is to improve the SNR and overall image quality of low-field MRI scans to improve diagnostic capability. To address this issue, we propose a Nested U-Net neural network architecture super-resolution algorithm that outperforms previously suggested deep learning methods with an average PSNR of 78.83 and SSIM of 0.9551. We tested our network on artificial noisy downsampled synthetic data from a major T1 weighted MRI image dataset called the T1-mix dataset. One board-certified radiologist scored 25 images on the Likert scale (1-5) assessing overall image quality, anatomical structure, and diagnostic confidence across our architecture and other published works (SR DenseNet, Generator Block, SRCNN, etc.). We also introduce a new type of loss function called natural log mean squared error (NLMSE). In conclusion, we present a more accurate deep learning method for single image super-resolution applied to synthetic low-field MRI via a Nested U-Net architecture.

健壮的学习是科学机器学习（SCIML）的重要问题。文献中有几篇关于该主题的作品。但是，对方法的需求不断增加，可以同时考虑SCIML模型识别中涉及的所有不同不确定性组成部分。因此，这项工作提出了一种对SCIML的不确定性评估的综合方法，该方法还考虑了识别过程中涉及的几种不确定性来源。提出的方法中考虑的不确定性是缺乏理论和因果模型，对数据腐败或不完美的敏感性以及计算工作。因此，可以为SCIML领域中的不确定性感知模型提供总体策略。该方法通过案例研究验证，开发了用于聚合反应器的软传感器。结果表明，已识别的软传感器对于不确定性是可靠的，并以所提出的方法的一致性证实。

Delimiting salt inclusions from migrated images is a time-consuming activity that relies on highly human-curated analysis and is subject to interpretation errors or limitations of the methods available. We propose to use migrated images produced from an inaccurate velocity model (with a reasonable approximation of sediment velocity, but without salt inclusions) to predict the correct salt inclusions shape using a Convolutional Neural Network (CNN). Our approach relies on subsurface Common Image Gathers to focus the sediments' reflections around the zero offset and to spread the energy of salt reflections over large offsets. Using synthetic data, we trained a U-Net to use common-offset subsurface images as input channels for the CNN and the correct salt-masks as network output. The network learned to predict the salt inclusions masks with high accuracy; moreover, it also performed well when applied to synthetic benchmark data sets that were not previously introduced. Our training process tuned the U-Net to successfully learn the shape of complex salt bodies from partially focused subsurface offset images.

了解机器人控制器的全球动态，例如识别吸引子及其吸引力区域（ROA），对于安全部署和综合更有效的混合控制器很重要。本文提出了一个拓扑框架，以有效且可解释的方式分析机器人控制器，甚至是数据驱动器的全球动态。它构建了代表基础系统的状态空间和非线性动力学的组合表示形式，该动力学总结在有向的无环图中，即Morse图。该方法仅通过在状态空间离散化上向局部传播短轨迹来探测本地的动力学，这需要是lipschitz的连续函数。对经典机器人基准的数值或数据驱动控制器进行了评估。将其与已建立的分析和最新的机器学习替代方法进行了比较，以估计此类控制器的ROA。证明它在准确性和效率方面表现优于它们。它还提供了更深入的见解，因为它描述了离散化解决方案的全局动态。这允许使用Morse图来识别如何合成控制器以形成改进的混合解决方案或如何识别机器人系统的物理限制。