本文介绍了一个基于双基的算法框架，用于求解具有累积的凸奖励，硬资源限制和不可分割的正常化程序的正规在线资源分配问题。在适应性更新资源约束的策略下，所提出的框架仅要求对经验二重性问题的近似解决方案，直到某种准确性，但在本地强烈凸出的假设下给出了最佳的对数遗憾。令人惊讶的是，对双重目标函数的微妙分析使我们能够消除遗憾的臭名昭著的日志因素。灵活的框架呈现出著名的和计算快速算法，例如双梯度下降和随机梯度下降。如果在双重优化过程中没有适应性更新，则建立了最糟糕的平方根遗憾下限，这强调了自适应双重变量更新的关键作用。全面的数值实验和实际数据应用证明了提出的算法框架的优点。

Objective: Imbalances of the electrolyte concentration levels in the body can lead to catastrophic consequences, but accurate and accessible measurements could improve patient outcomes. While blood tests provide accurate measurements, they are invasive and the laboratory analysis can be slow or inaccessible. In contrast, an electrocardiogram (ECG) is a widely adopted tool which is quick and simple to acquire. However, the problem of estimating continuous electrolyte concentrations directly from ECGs is not well-studied. We therefore investigate if regression methods can be used for accurate ECG-based prediction of electrolyte concentrations. Methods: We explore the use of deep neural networks (DNNs) for this task. We analyze the regression performance across four electrolytes, utilizing a novel dataset containing over 290000 ECGs. For improved understanding, we also study the full spectrum from continuous predictions to binary classification of extreme concentration levels. To enhance clinical usefulness, we finally extend to a probabilistic regression approach and evaluate different uncertainty estimates. Results: We find that the performance varies significantly between different electrolytes, which is clinically justified in the interplay of electrolytes and their manifestation in the ECG. We also compare the regression accuracy with that of traditional machine learning models, demonstrating superior performance of DNNs. Conclusion: Discretization can lead to good classification performance, but does not help solve the original problem of predicting continuous concentration levels. While probabilistic regression demonstrates potential practical usefulness, the uncertainty estimates are not particularly well-calibrated. Significance: Our study is a first step towards accurate and reliable ECG-based prediction of electrolyte concentration levels.

Skull Stripping is a requisite preliminary step in most diagnostic neuroimaging applications. Manual Skull Stripping methods define the gold standard for the domain but are time-consuming and challenging to integrate into pro-cessing pipelines with a high number of data samples. Automated methods are an active area of research for head MRI segmentation, especially deep learning methods such as U-Net architecture implementations. This study compares Vanilla, Residual, and Dense 2D U-Net architectures for Skull Stripping. The Dense 2D U-Net architecture outperforms the Vanilla and Residual counterparts by achieving an accuracy of 99.75% on a test dataset. It is observed that dense interconnections in a U-Net encourage feature reuse across layers of the architecture and allow for shallower models with the strengths of a deeper network.

Federated learning allows multiple clients to collaboratively train a model without exchanging their data, thus preserving data privacy. Unfortunately, it suffers significant performance degradation under heterogeneous data at clients. Common solutions in local training involve designing a specific auxiliary loss to regularize weight divergence or feature inconsistency. However, we discover that these approaches fall short of the expected performance because they ignore the existence of a vicious cycle between classifier divergence and feature mapping inconsistency across clients, such that client models are updated in inconsistent feature space with diverged classifiers. We then propose a simple yet effective framework named Federated learning with Feature Anchors (FedFA) to align the feature mappings and calibrate classifier across clients during local training, which allows client models updating in a shared feature space with consistent classifiers. We demonstrate that this modification brings similar classifiers and a virtuous cycle between feature consistency and classifier similarity across clients. Extensive experiments show that FedFA significantly outperforms the state-of-the-art federated learning algorithms on various image classification datasets under label and feature distribution skews.

Predictive simulations of the shock-to-detonation transition (SDT) in heterogeneous energetic materials (EM) are vital to the design and control of their energy release and sensitivity. Due to the complexity of the thermo-mechanics of EM during the SDT, both macro-scale response and sub-grid mesoscale energy localization must be captured accurately. This work proposes an efficient and accurate multiscale framework for SDT simulations of EM. We employ deep learning to model the mesoscale energy localization of shock-initiated EM microstructures upon which prediction results are used to supply reaction progress rate information to the macroscale SDT simulation. The proposed multiscale modeling framework is divided into two stages. First, a physics-aware recurrent convolutional neural network (PARC) is used to model the mesoscale energy localization of shock-initiated heterogeneous EM microstructures. PARC is trained using direct numerical simulations (DNS) of hotspot ignition and growth within microstructures of pressed HMX material subjected to different input shock strengths. After training, PARC is employed to supply hotspot ignition and growth rates for macroscale SDT simulations. We show that PARC can play the role of a surrogate model in a multiscale simulation framework, while drastically reducing the computation cost and providing improved representations of the sub-grid physics. The proposed multiscale modeling approach will provide a new tool for material scientists in designing high-performance and safer energetic materials.

在图像分类中，在检测分布（OOD）数据时发生了许多发展。但是，大多数OOD检测方法是在一组标准数据集上评估的，该数据集与培训数据任意不同。没有明确的定义``好的''ood数据集。此外，最先进的OOD检测方法已经在这些标准基准上取得了几乎完美的结果。在本文中，我们定义了2类OOD数据使用与分布（ID）数据的感知/视觉和语义相似性的微妙概念。我们将附近的OOD样本定义为感知上相似但语义上与ID样本的不同，并将样本转移为视觉上不同但在语义上与ID相似的点数据。然后，我们提出了一个基于GAN的框架，用于从这两个类别中生成OOD样品，给定一个ID数据集。通过有关MNIST，CIFAR-10/100和Imagenet的广泛实验，我们表明A）在常规基准上表现出色的ART OOD检测方法对我们提出的基准测试的稳健性明显较小。 N基准测试，反之亦然，因此表明甚至可能不需要单独的OOD集来可靠地评估OOD检测中的性能。

在评估临床机器学习模型的性能时，必须考虑部署人群。当观察到的标签患者的人群只是部署人群的一部分（选择标签）时，对观察到的人群的标准模型绩效估计可能会产生误导。在这项研究中，我们描述了三类的标签选择，并模拟了五个有因果关系的场景，以评估特定选择机制如何偏向一套常见的二进制机器学习模型性能指标。 Simulations reveal that when selection is affected by observed features, naive estimates of model discrimination may be misleading. When selection is affected by labels, naive estimates of calibration fail to reflect reality.我们从因果推理文献中借用传统的加权估计器，发现当正确指定选择概率时，它们会恢复全部人口估计。然后，我们解决了监视部署的机器学习模型的性能的现实任务，该模型的相互作用与临床医生相互作用并影响标签的选择机制。我们训练三个机器学习模型来标记低收益实验室的诊断，并模拟它们减少浪费实验室利用的预期结果。我们发现，对观察到的人群的幼稚估计值降低了20％。这样的差异可能足够大，可以导致成功终止成功的临床决策支持工具。我们提出了一个更改的部署程序，该程序将注入随机化的注入随机化与传统加权估计相结合，并发现其恢复了真正的模型性能。

现有的数据驱动和反馈流量控制策略不考虑实时数据测量的异质性。此外，对于缺乏数据效率，传统的加固学习方法（RL）方法通常会缓慢收敛。此外，常规的最佳外围控制方案需要对系统动力学的精确了解，因此对内源性不确定性会很脆弱。为了应对这些挑战，这项工作提出了一种基于不可或缺的增强学习（IRL）的方法来学习宏观交通动态，以进行自适应最佳周边控制。这项工作为运输文献做出了以下主要贡献：（a）开发连续的时间控制，并具有离散增益更新以适应离散时间传感器数据。 （b）为了降低采样复杂性并更有效地使用可用数据，将体验重播（ER）技术引入IRL算法。 （c）所提出的方法以“无模型”方式放松模型校准的要求，该方式可以稳健地进行建模不确定性，并通过数据驱动的RL算法增强实时性能。 （d）通过Lyapunov理论证明了基于IRL的算法和受控交通动力学的稳定性的收敛性。最佳控制定律被参数化，然后通过神经网络（NN）近似，从而缓解计算复杂性。在不需要模型线性化的同时，考虑了状态和输入约束。提出了数值示例和仿真实验，以验证所提出方法的有效性和效率。

ICECUBE是一种用于检测1 GEV和1 PEV之间大气和天体中微子的光学传感器的立方公斤阵列，该阵列已部署1.45 km至2.45 km的南极的冰盖表面以下1.45 km至2.45 km。来自ICE探测器的事件的分类和重建在ICeCube数据分析中起着核心作用。重建和分类事件是一个挑战，这是由于探测器的几何形状，不均匀的散射和冰中光的吸收，并且低于100 GEV的光，每个事件产生的信号光子数量相对较少。为了应对这一挑战，可以将ICECUBE事件表示为点云图形，并将图形神经网络（GNN）作为分类和重建方法。 GNN能够将中微子事件与宇宙射线背景区分开，对不同的中微子事件类型进行分类，并重建沉积的能量，方向和相互作用顶点。基于仿真，我们提供了1-100 GEV能量范围的比较与当前ICECUBE分析中使用的当前最新最大似然技术，包括已知系统不确定性的影响。对于中微子事件分类，与当前的IceCube方法相比，GNN以固定的假阳性速率（FPR）提高了信号效率的18％。另外，GNN在固定信号效率下将FPR的降低超过8（低于半百分比）。对于能源，方向和相互作用顶点的重建，与当前最大似然技术相比，分辨率平均提高了13％-20％。当在GPU上运行时，GNN能够以几乎是2.7 kHz的中位数ICECUBE触发速率的速率处理ICECUBE事件，这打开了在在线搜索瞬态事件中使用低能量中微子的可能性。

我们解决了受控生成小分子的任务，该任务需要在某些约束（例如，与参考分子相似）下找到具有所需特性的新分子。在这里，我们介绍了Molmim，这是一种用于学习信息丰富且聚集的潜在空间的小分子药物发现的概率自动编码器。 Molmim通过共同信息机（MIM）学习训练，并提供可变长度微笑字符串的固定长度表示。由于编码器模型可以通过无效样品的``孔''来学习表示形式，因此我们在这里提出了训练程序的新型扩展，该过程促进了促进密集的潜在空间，并允许模型从潜在代码的随机扰动中采样有效分子。我们提供了Molmim与几个可变大小和固定尺寸的编码器模型的彻底比较，这表明了Molmim的上一代，如有效性，独特性和新颖性而言。然后，我们利用CMA-E，一种天真的黑盒和无梯度的搜索算法，是Molmim的潜在空间来实现属性引导分子优化的任务。我们实现了最新的单个属性优化任务以及多目标优化的具有挑战性的任务，从而提高了先前的成功率SOTA超过5 \％。我们将强有力的结果归因于莫尔米姆的潜在表示，这些表示在潜在空间中聚集了相似的分子，而CMA-ES通常用作基线优化方法。我们还证明了莫尔米姆在计算有限的制度中有利，使其成为这种情况的有吸引力的模型。