定向的无环图(DAG)模型已在统计和机器学习中广泛研究和应用 - 实际上,它们的简单性促进了有效的学习和推理程序。不幸的是,这些模型在边缘化下并未关闭,使其能够处理具有潜在混杂的系统。无环向混合图(ADMG)模型表征了DAG模型的边缘,使它们更适合处理此类系统。但是,ADMG模型由于其复杂性和用于分析的统计工具的短缺而没有看到广泛使用。在本文中,我们介绍了M连接IMSET,该IMSET为ADMG引起的独立模型提供了替代表示。此外,我们定义了以单个方程为特征的ADMG模型的M连接分数标准,并证明了其与全球Markov属性的等效性。 M-连接IMSET和分解标准提供了两个新的统计工具,用于使用ADMG模型进行学习和推断。我们通过使用封闭形式解决方案制定和评估一致的评分标准来证明这些工具的有用性。
translated by 谷歌翻译
Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.
translated by 谷歌翻译
我们研究了数据驱动的深度学习方法的潜力,即从观察它们的混合物中分离两个通信信号。特别是,我们假设一个信号之一的生成过程(称为感兴趣的信号(SOI)),并且对第二个信号的生成过程不了解,称为干扰。单通道源分离问题的这种形式也称为干扰拒绝。我们表明,捕获高分辨率的时间结构(非平稳性),可以准确地同步与SOI和干扰,从而带来了可观的性能增长。有了这个关键的见解,我们提出了一种域信息神经网络(NN)设计,该设计能够改善“现成” NNS和经典检测和干扰拒绝方法,如我们的模拟中所示。我们的发现突出了特定于交流领域知识的关键作用在开发数据驱动的方法方面发挥了作用,这些方法具有前所未有的收益的希望。
translated by 谷歌翻译
我们研究了单通道源分离(SCSS)的问题,并专注于环化信号,这些信号特别适用于各种应用领域。与经典的SCSS方法不同,我们考虑了一个仅可用源的示例而不是模型的设置,从而激发了数据驱动的方法。对于具有基本环化高斯成分的源模型,我们为任何基于模型或数据驱动的分离方法建立了可达到的均方误差(MSE)的下限。我们的分析进一步揭示了最佳分离和相关实施挑战的操作。作为一种计算吸引力的替代方案,我们建议使用U-NET体系结构进行深度学习方法,该方法与最低MSE估计器具有竞争力。我们在模拟中证明,有了合适的域信息架构选择,我们的U-NET方法可以通过大幅减少的计算负担来达到最佳性能。
translated by 谷歌翻译
宇宙学调查实验中的数据处理和分析管道引入了数据扰动,可以显着降低基于深度学习的模型的性能。鉴于加工和分析宇宙学调查数据的监督深度学习方法的增加,数据扰动效应的评估以及增加模型稳健性的方法的发展越来越重要。在星系形态分类的背景下,我们研究了扰动在成像数据中的影响。特别是,我们在基线数据培训和扰动数据测试时检查使用神经网络的后果。我们考虑与两个主要来源相关的扰动:1)通过泊松噪声和2)诸如图像压缩或望远镜误差的图像压缩或望远粉误差所产生的步骤所产生的数据处理噪声提高了观测噪声。我们还测试了域适应技术在减轻扰动驱动误差时的功效。我们使用分类准确性,潜在空间可视化和潜在空间距离来评估模型稳健性。如果没有域适应,我们发现处理像素级别错误容易将分类翻转成一个不正确的类,并且更高的观察噪声使得模型在低噪声数据上培训无法对Galaxy形态进行分类。另一方面,我们表明,具有域适应的培训改善了模型稳健性并减轻了这些扰动的影响,以更高的观测噪声的数据提高了23%的分类精度。域适应也增加了基线与错误分类的错误分类的潜在空间距离〜2.3的倍数距离,使模型更强大地扰动。
translated by 谷歌翻译
最近已经提出了与紧急磁化动态的互连磁纳环阵列用于储层计算应用,但是对于它们进行计算有用,必须可以优化其动态响应。在这里,我们使用一种现象学模型来证明可以通过调整使用旋转磁场将数据的缩放和输入速率控制到系统中的超级参数来优化这些储存器。我们使用任务独立的指标来评估每组上的这些超参数的戒指的计算能力,并展示这些指标如何直接关联与口头和书面识别任务中的性能相关联。然后,我们通过扩展储库的输出来包括环阵列磁态的多个并发度量,可以进一步改善这些度量。
translated by 谷歌翻译
This paper presents a machine learning approach to multidimensional item response theory (MIRT), a class of latent factor models that can be used to model and predict student performance from observed assessment data. Inspired by collaborative filtering, we define a general class of models that includes many MIRT models. We discuss the use of penalized joint maximum likelihood (JML) to estimate individual models and cross-validation to select the best performing model. This model evaluation process can be optimized using batching techniques, such that even sparse large-scale data can be analyzed efficiently. We illustrate our approach with simulated and real data, including an example from a massive open online course (MOOC). The high-dimensional model fit to this large and sparse dataset does not lend itself well to traditional methods of factor interpretation. By analogy to recommender-system applications, we propose an alternative "validation" of the factor model, using auxiliary information about the popularity of items consulted during an open-book exam in the course.
translated by 谷歌翻译
Real-world robotic grasping can be done robustly if a complete 3D Point Cloud Data (PCD) of an object is available. However, in practice, PCDs are often incomplete when objects are viewed from few and sparse viewpoints before the grasping action, leading to the generation of wrong or inaccurate grasp poses. We propose a novel grasping strategy, named 3DSGrasp, that predicts the missing geometry from the partial PCD to produce reliable grasp poses. Our proposed PCD completion network is a Transformer-based encoder-decoder network with an Offset-Attention layer. Our network is inherently invariant to the object pose and point's permutation, which generates PCDs that are geometrically consistent and completed properly. Experiments on a wide range of partial PCD show that 3DSGrasp outperforms the best state-of-the-art method on PCD completion tasks and largely improves the grasping success rate in real-world scenarios. The code and dataset will be made available upon acceptance.
translated by 谷歌翻译
Optical coherence tomography (OCT) captures cross-sectional data and is used for the screening, monitoring, and treatment planning of retinal diseases. Technological developments to increase the speed of acquisition often results in systems with a narrower spectral bandwidth, and hence a lower axial resolution. Traditionally, image-processing-based techniques have been utilized to reconstruct subsampled OCT data and more recently, deep-learning-based methods have been explored. In this study, we simulate reduced axial scan (A-scan) resolution by Gaussian windowing in the spectral domain and investigate the use of a learning-based approach for image feature reconstruction. In anticipation of the reduced resolution that accompanies wide-field OCT systems, we build upon super-resolution techniques to explore methods to better aid clinicians in their decision-making to improve patient outcomes, by reconstructing lost features using a pixel-to-pixel approach with an altered super-resolution generative adversarial network (SRGAN) architecture.
translated by 谷歌翻译
Using Structural Health Monitoring (SHM) systems with extensive sensing arrangements on every civil structure can be costly and impractical. Various concepts have been introduced to alleviate such difficulties, such as Population-based SHM (PBSHM). Nevertheless, the studies presented in the literature do not adequately address the challenge of accessing the information on different structural states (conditions) of dissimilar civil structures. The study herein introduces a novel framework named Structural State Translation (SST), which aims to estimate the response data of different civil structures based on the information obtained from a dissimilar structure. SST can be defined as Translating a state of one civil structure to another state after discovering and learning the domain-invariant representation in the source domains of a dissimilar civil structure. SST employs a Domain-Generalized Cycle-Generative (DGCG) model to learn the domain-invariant representation in the acceleration datasets obtained from a numeric bridge structure that is in two different structural conditions. In other words, the model is tested on three dissimilar numeric bridge models to translate their structural conditions. The evaluation results of SST via Mean Magnitude-Squared Coherence (MMSC) and modal identifiers showed that the translated bridge states (synthetic states) are significantly similar to the real ones. As such, the minimum and maximum average MMSC values of real and translated bridge states are 91.2% and 97.1%, the minimum and the maximum difference in natural frequencies are 5.71% and 0%, and the minimum and maximum Modal Assurance Criterion (MAC) values are 0.998 and 0.870. This study is critical for data scarcity and PBSHM, as it demonstrates that it is possible to obtain data from structures while the structure is actually in a different condition or state.
translated by 谷歌翻译