Brain midline shift (MLS) is one of the most critical factors to be considered for clinical diagnosis and treatment decision-making for intracranial hemorrhage. Existing computational methods on MLS quantification not only require intensive labeling in millimeter-level measurement but also suffer from poor performance due to their dependence on specific landmarks or simplified anatomical assumptions. In this paper, we propose a novel semi-supervised framework to accurately measure the scale of MLS from head CT scans. We formulate the MLS measurement task as a deformation estimation problem and solve it using a few MLS slices with sparse labels. Meanwhile, with the help of diffusion models, we are able to use a great number of unlabeled MLS data and 2793 non-MLS cases for representation learning and regularization. The extracted representation reflects how the image is different from a non-MLS image and regularization serves an important role in the sparse-to-dense refinement of the deformation field. Our experiment on a real clinical brain hemorrhage dataset has achieved state-of-the-art performance and can generate interpretable deformation fields.

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

We conduct a systematic study of backdoor vulnerabilities in normally trained Deep Learning models. They are as dangerous as backdoors injected by data poisoning because both can be equally exploited. We leverage 20 different types of injected backdoor attacks in the literature as the guidance and study their correspondences in normally trained models, which we call natural backdoor vulnerabilities. We find that natural backdoors are widely existing, with most injected backdoor attacks having natural correspondences. We categorize these natural backdoors and propose a general detection framework. It finds 315 natural backdoors in the 56 normally trained models downloaded from the Internet, covering all the different categories, while existing scanners designed for injected backdoors can at most detect 65 backdoors. We also study the root causes and defense of natural backdoors.

Federated learning (FL) enables the building of robust and generalizable AI models by leveraging diverse datasets from multiple collaborators without centralizing the data. We created NVIDIA FLARE as an open-source software development kit (SDK) to make it easier for data scientists to use FL in their research and real-world applications. The SDK includes solutions for state-of-the-art FL algorithms and federated machine learning approaches, which facilitate building workflows for distributed learning across enterprises and enable platform developers to create a secure, privacy-preserving offering for multiparty collaboration utilizing homomorphic encryption or differential privacy. The SDK is a lightweight, flexible, and scalable Python package, and allows researchers to bring their data science workflows implemented in any training libraries (PyTorch, TensorFlow, XGBoost, or even NumPy) and apply them in real-world FL settings. This paper introduces the key design principles of FLARE and illustrates some use cases (e.g., COVID analysis) with customizable FL workflows that implement different privacy-preserving algorithms. Code is available at https://github.com/NVIDIA/NVFlare.

当系统中有某些未知术语和隐藏的物理机制时，基于第一原理的复杂物理系统的管理方程可能会非常具有挑战性。在这项工作中，我们采用深度学习体系结构来学习基于从完全动力学模型中获取的数据的等离子体系统的流体部分微分方程（PDE）。证明了学到的多臂流体PDE可以融合诸如Landau阻尼等动力学效应。基于学习的流体闭合，数据驱动的多音阶流体建模可以很好地再现从完全动力学模型中得出的所有物理量。Landau阻尼的计算阻尼率与完全动力学的模拟和线性理论一致。用于复杂物理系统的PDE的数据驱动的流体建模可以应用于改善流体闭合并降低全球系统多规模建模的计算成本。

供应链平台（SCP）为下游行业提供了许多原材料。与传统的电子商务平台相比，由于用户兴趣有限，SCP中的数据更为稀疏。为了解决数据稀疏问题，可以应用跨域建议（CDR），从而通过源域信息提高目标域的建议性能。但是，将CDR应用于SCP，直接忽略了SCP中商品的层次结构，从而降低了建议性能。为了利用此功能，在本文中，我们以餐饮平台为例，并提出了图形跨域推荐模型GRES。该模型首先构造了树状图，以表示菜肴和成分不同节点的层次结构，然后应用我们提出的Tree2Vec方法将GCN和BERT模型组合到嵌入图中以嵌入图表以获取建议。商业数据集上的实验结果表明，GRES在供应链平台的跨域建议中明显优于最先进的方法。

荧光镜检查是一种使用X射线来获得3D对象内部的实时2D视频，帮助外科医生观察病理结构和组织功能，尤其是在干预过程中。然而，它主要是由于低剂量X射线的临床使用而产生的，因此需要荧光镜检查技术。这种脱牙受到了成像对象与X射线成像系统之间的相对运动的挑战。我们通过提出一个自制的三阶段框架来应对这一挑战，从而利用荧光镜检查的领域知识。 （i）稳定：我们首先基于光流计算构建动态全景，以稳定X射线检测器的运动引起的非平稳背景。 （ii）分解：然后，我们提出了一种新型的基于掩模的鲁棒原理分析（RPCA）分解方法，以将探测器运动的视频分离为低级别背景和稀疏前景。这样的分解可容纳专家的阅读习惯。 （iii）denoise：我们终于通过自我监督的学习策略分别降低了背景和前景，并通过双侧时空滤波器将deno的部分融合到最终输出中。为了评估我们工作的有效性，我们策划了27个视频（1,568帧）和相应的地面真相的专用荧光镜数据集。我们的实验表明，与标准方法相比，它在降解和增强效果方面取得了重大改进。最后，专家评级确认了这种功效。

随着COVID-19现在普遍存在，对高危个体的识别至关重要。利用来自宾夕法尼亚州西南部主要医疗保健提供者的数据，我们开发了预测严重Covid-19进展的生存模型。在这项工作中，我们在依赖许多功能的更准确模型和依赖一些与临床医生直觉相一致的功能的模型之间面临一个权衡。使事情变得复杂，许多EHR功能往往较低，从而降低了较小模型的准确性。在这项研究中，我们开发了两组高性能风险评分：（i）由所有可用功能构建的无约束模型；（ii）在训练风险预测因子之前，在培训风险预测因子之前就学习一小部分临床概念的管道。学到的概念提高了相应特征（C-Index 0.858 vs. 0.844）的性能，并在评估样本外（随后的时间段）时证明了（i）的改进。我们的模型表现优于先前的工作（C-Index 0.844-0.872 vs. 0.598-0.810）。

高速，高分辨率的立体视频（H2-STEREO）视频使我们能够在细粒度上感知动态3D内容。然而，对商品摄像机的收购H2-STEREO视频仍然具有挑战性。现有的空间超分辨率或时间框架插值方法分别提供了缺乏时间或空间细节的折衷解决方案。为了减轻这个问题，我们提出了一个双摄像头系统，其中一台相机捕获具有丰富空间细节的高空间分辨率低框架速率（HSR-LFR）视频，而另一个摄像头则捕获了低空间分辨率的高架框架-Rate（LSR-HFR）视频带有光滑的时间细节。然后，我们设计了一个学习的信息融合网络（LIFNET），该网络利用跨摄像机冗余，以增强两种相机视图，从而有效地重建H2-STEREO视频。即使在大型差异场景中，我们也利用一个差异网络将时空信息传输到视图上，基于该视图，我们建议使用差异引导的LSR-HFR视图基于差异引导的流量扭曲，并针对HSR-LFR视图进行互补的扭曲。提出了特征域中的多尺度融合方法，以最大程度地减少HSR-LFR视图中闭塞引起的翘曲幽灵和孔。 LIFNET使用YouTube收集的高质量立体视频数据集以端到端的方式进行训练。广泛的实验表明，对于合成数据和摄像头捕获的真实数据，我们的模型均优于现有的最新方法。消融研究探讨了各个方面，包括时空分辨率，摄像头基线，摄像头解理，长/短曝光和应用程序，以充分了解其对潜在应用的能力。

在6G无线通信网络中，按需服务提供是一个至关重要的问题，因为新兴服务的需求大大不同，并且网络资源变得越来越异质和动态。在本文中，我们研究了按需无线资源编排问题，重点是编排决策过程的计算延迟。具体而言，我们将决策延迟延迟到优化问题。然后，提出了一个基于动态的神经网络（DYNN）的方法，可以根据服务要求调整模型复杂性。我们进一步建立一个知识库，代表服务需求之间的关系，可用的计算资源和资源分配绩效。通过利用知识，可以及时选择DYNN的宽度，从而进一步提高编排的性能。仿真结果表明，所提出的方案大大优于传统的静态神经网络，并且在按需服务提供方面也表现出足够的灵活性。