随着物联网，AI和ML/DL算法的出现，数据驱动的医疗应用已成为一种有前途的工具，用于从医学数据设计可靠且可扩展的诊断和预后模型。近年来，这引起了从学术界到工业的广泛关注。这无疑改善了医疗保健提供的质量。但是，由于这些基于AI的医疗应用程序在满足严格的安全性，隐私和服务标准（例如低延迟）方面的困难，因此仍然采用较差。此外，医疗数据通常是分散的和私人的，这使得在人群之间产生强大的结果具有挑战性。联邦学习（FL）的最新发展使得以分布式方式训练复杂的机器学习模型成为可能。因此，FL已成为一个积极的研究领域，尤其是以分散的方式处理网络边缘的医疗数据，以保护隐私和安全问题。为此，本次调查论文重点介绍了数据共享是重大负担的医疗应用中FL技术的当前和未来。它还审查并讨论了当前的研究趋势及其设计可靠和可扩展模型的结果。我们概述了FL将军的统计问题，设备挑战，安全性，隐私问题及其在医疗领域的潜力。此外，我们的研究还集中在医疗应用上，我们重点介绍了全球癌症的负担以及有效利用FL来开发计算机辅助诊断工具来解决这些诊断工具。我们希望这篇评论是一个检查站，以彻底的方式阐明现有的最新最新作品，并为该领域提供开放的问题和未来的研究指示。

音频的高时间分辨率和波形中小不规则性的感知敏感性使得在高采样率中合成复杂和计算密集的任务，禁止在许多方法中的实时，可控合成。在这项工作中，我们的目标是在有条件隐含的神经表示（CINR）的潜力上阐明作为音频合成的生成框架中的轻质骨干。隐式神经表示（INR）是用于近似低维功能的神经网络，训练以通过将输入坐标映射到输入位置处的结构信息来表示单个几何对象。与用于代表几何对象的其他神经方法相比，参数化对象所需的内存与分辨率无关，并且仅具有其复杂性的尺度。这是一个必论是INRS具有无限分辨率，因为它们可以在任意分辨率下进行取样。在生成域中应用INR的概念，我们框架生成建模作为学习连续功能的分布。这可以通过将调节方法引入INRS来实现。我们的实验表明，定期的条件INRS（PCINR）学习更快，并且通常比具有相等参数计数的转换卷积神经网络的定量更好的音频重建。但是，它们的性能对激活缩放超参数非常敏感。当学习代表更均匀的组时，PCINR倾向于在重建中引入人造高频分量。我们通过在训练期间应用标准重量正则化来验证这种噪音，可以减少PCINR的组成深度，并建议未来研究的方向。

加固学习算法可以解决动态决策和最优控制问题。通过连续值的状态和输入变量，强化学习算法必须依赖函数近似器来表示值函数和策略映射。常用的数值近似器，如神经网络或基础函数扩展，具有两个主要缺点：它们是黑匣子型号，可以对学习的映射有很小的洞察力，并且他们需要广泛的试验和错误调整它们的超参数。在本文中，我们通过使用符号回归提出了一种以分析表达式的形式构建平滑值函数的新方法。我们介绍了三种离线方法，用于基于状态转换模型查找值函数：符号值迭代，符号策略迭代，以及Bellman方程的直接解决方案。该方法在四个非线性控制问题上说明：速度控制摩擦力控制，单键和双连杆摆动，和磁操作。结果表明，该价值函数产生良好的策略，并紧凑，数学上易行，易于插入其他算法。这使得它们可能适用于进一步分析闭环系统。使用神经网络的替代方法的比较表明，我们的方法优于基于神经网络的方法。

Given two consecutive frames, video interpolation aims at generating intermediate frame(s) to form both spatially and temporally coherent video sequences. While most existing methods focus on single-frame interpolation, we propose an end-to-end convolutional neural network for variable-length multi-frame video interpolation, where the motion interpretation and occlusion reasoning are jointly modeled. We start by computing bi-directional optical flow between the input images using a U-Net architecture. These flows are then linearly combined at each time step to approximate the intermediate bi-directional optical flows. These approximate flows, however, only work well in locally smooth regions and produce artifacts around motion boundaries. To address this shortcoming, we employ another U-Net to refine the approximated flow and also predict soft visibility maps. Finally, the two input images are warped and linearly fused to form each intermediate frame. By applying the visibility maps to the warped images before fusion, we exclude the contribution of occluded pixels to the interpolated intermediate frame to avoid artifacts. Since none of our learned network parameters are time-dependent, our approach is able to produce as many intermediate frames as needed. To train our network, we use 1,132 240-fps video clips, containing 300K individual video frames. Experimental results on several datasets, predicting different numbers of interpolated frames, demonstrate that our approach performs consistently better than existing methods.

Modeling lies at the core of both the financial and the insurance industry for a wide variety of tasks. The rise and development of machine learning and deep learning models have created many opportunities to improve our modeling toolbox. Breakthroughs in these fields often come with the requirement of large amounts of data. Such large datasets are often not publicly available in finance and insurance, mainly due to privacy and ethics concerns. This lack of data is currently one of the main hurdles in developing better models. One possible option to alleviating this issue is generative modeling. Generative models are capable of simulating fake but realistic-looking data, also referred to as synthetic data, that can be shared more freely. Generative Adversarial Networks (GANs) is such a model that increases our capacity to fit very high-dimensional distributions of data. While research on GANs is an active topic in fields like computer vision, they have found limited adoption within the human sciences, like economics and insurance. Reason for this is that in these fields, most questions are inherently about identification of causal effects, while to this day neural networks, which are at the center of the GAN framework, focus mostly on high-dimensional correlations. In this paper we study the causal preservation capabilities of GANs and whether the produced synthetic data can reliably be used to answer causal questions. This is done by performing causal analyses on the synthetic data, produced by a GAN, with increasingly more lenient assumptions. We consider the cross-sectional case, the time series case and the case with a complete structural model. It is shown that in the simple cross-sectional scenario where correlation equals causation the GAN preserves causality, but that challenges arise for more advanced analyses.

Deep learning models are known to put the privacy of their training data at risk, which poses challenges for their safe and ethical release to the public. Differentially private stochastic gradient descent is the de facto standard for training neural networks without leaking sensitive information about the training data. However, applying it to models for graph-structured data poses a novel challenge: unlike with i.i.d. data, sensitive information about a node in a graph cannot only leak through its gradients, but also through the gradients of all nodes within a larger neighborhood. In practice, this limits privacy-preserving deep learning on graphs to very shallow graph neural networks. We propose to solve this issue by training graph neural networks on disjoint subgraphs of a given training graph. We develop three random-walk-based methods for generating such disjoint subgraphs and perform a careful analysis of the data-generating distributions to provide strong privacy guarantees. Through extensive experiments, we show that our method greatly outperforms the state-of-the-art baseline on three large graphs, and matches or outperforms it on four smaller ones.

Data-driven models such as neural networks are being applied more and more to safety-critical applications, such as the modeling and control of cyber-physical systems. Despite the flexibility of the approach, there are still concerns about the safety of these models in this context, as well as the need for large amounts of potentially expensive data. In particular, when long-term predictions are needed or frequent measurements are not available, the open-loop stability of the model becomes important. However, it is difficult to make such guarantees for complex black-box models such as neural networks, and prior work has shown that model stability is indeed an issue. In this work, we consider an aluminum extraction process where measurements of the internal state of the reactor are time-consuming and expensive. We model the process using neural networks and investigate the role of including skip connections in the network architecture as well as using l1 regularization to induce sparse connection weights. We demonstrate that these measures can greatly improve both the accuracy and the stability of the models for datasets of varying sizes.

There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .

Machine learning models are typically evaluated by computing similarity with reference annotations and trained by maximizing similarity with such. Especially in the bio-medical domain, annotations are subjective and suffer from low inter- and intra-rater reliability. Since annotations only reflect the annotation entity's interpretation of the real world, this can lead to sub-optimal predictions even though the model achieves high similarity scores. Here, the theoretical concept of Peak Ground Truth (PGT) is introduced. PGT marks the point beyond which an increase in similarity with the reference annotation stops translating to better Real World Model Performance (RWMP). Additionally, a quantitative technique to approximate PGT by computing inter- and intra-rater reliability is proposed. Finally, three categories of PGT-aware strategies to evaluate and improve model performance are reviewed.

Logic Mill is a scalable and openly accessible software system that identifies semantically similar documents within either one domain-specific corpus or multi-domain corpora. It uses advanced Natural Language Processing (NLP) techniques to generate numerical representations of documents. Currently it leverages a large pre-trained language model to generate these document representations. The system focuses on scientific publications and patent documents and contains more than 200 million documents. It is easily accessible via a simple Application Programming Interface (API) or via a web interface. Moreover, it is continuously being updated and can be extended to text corpora from other domains. We see this system as a general-purpose tool for future research applications in the social sciences and other domains.