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。
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Objective: Accurate visual classification of bladder tissue during Trans-Urethral Resection of Bladder Tumor (TURBT) procedures is essential to improve early cancer diagnosis and treatment. During TURBT interventions, White Light Imaging (WLI) and Narrow Band Imaging (NBI) techniques are used for lesion detection. Each imaging technique provides diverse visual information that allows clinicians to identify and classify cancerous lesions. Computer vision methods that use both imaging techniques could improve endoscopic diagnosis. We address the challenge of tissue classification when annotations are available only in one domain, in our case WLI, and the endoscopic images correspond to an unpaired dataset, i.e. there is no exact equivalent for every image in both NBI and WLI domains. Method: We propose a semi-surprised Generative Adversarial Network (GAN)-based method composed of three main components: a teacher network trained on the labeled WLI data; a cycle-consistency GAN to perform unpaired image-to-image translation, and a multi-input student network. To ensure the quality of the synthetic images generated by the proposed GAN we perform a detailed quantitative, and qualitative analysis with the help of specialists. Conclusion: The overall average classification accuracy, precision, and recall obtained with the proposed method for tissue classification are 0.90, 0.88, and 0.89 respectively, while the same metrics obtained in the unlabeled domain (NBI) are 0.92, 0.64, and 0.94 respectively. The quality of the generated images is reliable enough to deceive specialists. Significance: This study shows the potential of using semi-supervised GAN-based classification to improve bladder tissue classification when annotations are limited in multi-domain data.
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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.
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共形预测(CP)是一种多功能的非参数框架,用于量化预测问题中的不确定性。在这项工作中,我们通过首次提出可以应用于时间不断发展的表面,将这种方法扩展到在双变量域上定义的时间序列函数的情况。为了获得有意义有效的预测区域,CP必须与准确的预测算法结合使用,因此,我们扩展了希尔伯特空间中自回旋过程的理论理论,以允许具有双变量域的功能。考虑到该主题的新颖性,我们提出了功能自回旋模型(FAR)的估计技术。实施了仿真研究,以研究不同的点预测因子如何影响所得的预测频段。最后,我们探索了真正数据集中拟议方法的利益和限制,在过去的二十年中,每天都会观察到黑海的海平面异常。
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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.
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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。
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图表学习方法为解决图形所代表的复杂的现实世界问题打开了新的可能性。但是,这些应用程序中使用的许多图包括数百万节点和数十亿个边缘,并且超出了当前方法和软件实现的功能。我们提供葡萄,这是一种用于图形处理和表示学习的软件资源,能够通过使用专业和智能数据结构,算法和快速并行实现来通过大图扩展。与最先进的软件资源相比,葡萄显示出经验空间和时间复杂性的数量级的改善,以及边缘预测和节点标签预测性能的实质和统计学上的显着改善。此外,葡萄提供了来自文献和其他来源的80,000多种图,标准化界面允许直接整合第三方库,61个节点嵌入方法,25个推理模型和3个模块化管道,以允许公平且可重复的方法比较以及用于图形处理和嵌入的库。
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关于参数化量子电路(PQC)的成本景观知之甚少。然而,PQC被用于量子神经网络和变异量子算法中,这可能允许近期量子优势。此类应用需要良好的优化器来培训PQC。最近的作品集中在专门针对PQC量身定制的量子意识优化器上。但是,对成本景观的无知可能会阻碍这种优化者的进步。在这项工作中,我们在分析上证明了PQC的两个结果:(1)我们在PQC中发现了指数较大的对称性,在成本景观中产生了最小值的呈指数较大的变性。或者,这可以作为相关超参数空间体积的指数减少。 (2)我们研究了噪声下对称性的弹性,并表明,尽管它在Unital噪声下是保守的,但非阴道通道可以打破这些对称性并提高最小值的变性,从而导致多个新的局部最小值。基于这些结果,我们引入了一种称为基于对称的最小跳跃(SYMH)的优化方法,该方法利用了PQC中的基础对称性。我们的数值模拟表明,在存在与当前硬件相当的水平上,SYMH在存在非阴性噪声的情况下提高了整体优化器性能。总体而言,这项工作从局部门转换中得出了大规模电路对称性,并使用它们来构建一种噪声吸引的优化方法。
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变形量子算法(VQAS)可以是噪声中间级量子(NISQ)计算机上的量子优势的路径。自然问题是NISQ设备的噪声是否对VQA性能的基本限制。我们严格证明对嘈杂的VQAS进行严重限制,因为噪音导致训练景观具有贫瘠高原(即消失梯度)。具体而言,对于考虑的本地Pauli噪声,我们证明梯度在Qubits $ N $的数量中呈指数呈指数增长,如果Ansatz的深度以$ N $线性增长。这些噪声诱导的贫瘠强韧(NIBPS)在概念上不同于无辐射贫瘠强度,其与随机参数初始化相关联。我们的结果是为通用Ansatz制定的,该通用ansatz包括量子交替运算符ANSATZ和酉耦合簇Ansatz等特殊情况。对于前者来说,我们的数值启发式展示了用于现实硬件噪声模型的NIBP现象。
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在这项工作中,我们对基本思想和新颖的发展进行了综述的综述,这是基于最小的假设的一种无创新的,无分配的,非参数预测的方法 - 能够以非常简单的方式预测集屈服在有限样本案例中,在统计意义上也有效。论文中提供的深入讨论涵盖了共形预测的理论基础,然后继续列出原始想法的更高级的发展和改编。
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