准确地估算主要山区盆地中的积雪对于水资源经理来说至关重要，以便做出影响当地和全球经济，野生动植物和公共政策的决策。目前，此估计需要多个配备LIDAR的飞机飞行或原位测量值，两者均昂贵，稀疏和对可访问区域有偏见。在本文中，我们证明了来自多个，公开可用的卫星和天气数据源的空间和时间信息的融合，可以估算关键山区的积雪。我们的多源模型的表现优于单源估计值5.0英寸RMSE，并且优于稀疏的原位测量值的估计值1.2英寸RMSE。

Memory efficiency is crucial in training deep learning networks on resource-restricted devices. During backpropagation, forward tensors are used to calculate gradients. Despite the option of keeping those dependencies in memory until they are reused in backpropagation, some forward tensors can be discarded and recomputed later from saved tensors, so-called checkpoints. This allows, in particular, for resource-constrained heterogeneous environments to make use of all available compute devices. Unfortunately, the definition of these checkpoints is a non-trivial problem and poses a challenge to the programmer - improper or excessive recomputations negate the benefit of checkpointing. In this article, we present XEngine, an approach that schedules network operators to heterogeneous devices in low memory environments by determining checkpoints and recomputations of tensors. Our approach selects suitable resources per timestep and operator and optimizes the end-to-end time for neural networks taking the memory limitation of each device into account. For this, we formulate a mixed-integer quadratic program (MIQP) to schedule operators of deep learning networks on heterogeneous systems. We compare our MIQP solver XEngine against Checkmate, a mixed-integer linear programming (MILP) approach that solves recomputation on a single device. Our solver finds solutions that are up to 22.5 % faster than the fastest Checkmate schedule in which the network is computed exclusively on a single device. We also find valid schedules for networks making use of both central processing units and graphics processing units if memory limitations do not allow scheduling exclusively to the graphics processing unit.

Hawkes processes have recently risen to the forefront of tools when it comes to modeling and generating sequential events data. Multidimensional Hawkes processes model both the self and cross-excitation between different types of events and have been applied successfully in various domain such as finance, epidemiology and personalized recommendations, among others. In this work we present an adaptation of the Frank-Wolfe algorithm for learning multidimensional Hawkes processes. Experimental results show that our approach has better or on par accuracy in terms of parameter estimation than other first order methods, while enjoying a significantly faster runtime.

Incorporating computed tomography (CT) reconstruction operators into differentiable pipelines has proven beneficial in many applications. Such approaches usually focus on the projection data and keep the acquisition geometry fixed. However, precise knowledge of the acquisition geometry is essential for high quality reconstruction results. In this paper, the differentiable formulation of fan-beam CT reconstruction is extended to the acquisition geometry. This allows to propagate gradient information from a loss function on the reconstructed image into the geometry parameters. As a proof-of-concept experiment, this idea is applied to rigid motion compensation. The cost function is parameterized by a trained neural network which regresses an image quality metric from the motion affected reconstruction alone. Using the proposed method, we are the first to optimize such an autofocus-inspired algorithm based on analytical gradients. The algorithm achieves a reduction in MSE by 35.5 % and an improvement in SSIM by 12.6 % over the motion affected reconstruction. Next to motion compensation, we see further use cases of our differentiable method for scanner calibration or hybrid techniques employing deep models.

The Concept Bottleneck Models (CBMs) of Koh et al. [2020] provide a means to ensure that a neural network based classifier bases its predictions solely on human understandable concepts. The concept labels, or rationales as we refer to them, are learned by the concept labeling component of the CBM. Another component learns to predict the target classification label from these predicted concept labels. Unfortunately, these models are heavily reliant on human provided concept labels for each datapoint. To enable CBMs to behave robustly when these labels are not readily available, we show how to equip them with the ability to abstain from predicting concepts when the concept labeling component is uncertain. In other words, our model learns to provide rationales for its predictions, but only whenever it is sure the rationale is correct.

Concept bottleneck models perform classification by first predicting which of a list of human provided concepts are true about a datapoint. Then a downstream model uses these predicted concept labels to predict the target label. The predicted concepts act as a rationale for the target prediction. Model trust issues emerge in this paradigm when soft concept labels are used: it has previously been observed that extra information about the data distribution leaks into the concept predictions. In this work we show how Monte-Carlo Dropout can be used to attain soft concept predictions that do not contain leaked information.

在过去的几年中，霍克斯流程的在线学习受到了越来越多的关注，尤其是用于建模演员网络。但是，这些作品通常会模拟事件或参与者的潜在群集之间的丰富相互作用，或者是参与者之间的网络结构。我们建议对参与者网络的潜在结构进行建模，以及在现实世界中的医疗和财务应用环境中进行的丰富互动。合成和现实世界数据的实验结果展示了我们方法的功效。

Hawkes流程最近从机器学习社区中引起了人们对建模事件序列数据的多功能性的越来越多的关注。尽管它们具有丰富的历史可以追溯到几十年前，但其某些属性（例如用于学习参数的样本复杂性和释放差异化私有版本的样本复杂性）尚未得到彻底的分析。在这项工作中，我们研究了具有背景强度$ \ mu $和激发功能$ \ alpha e^{ - \ beta t} $的标准霍克斯进程。我们提供$ \ mu $和$ \ alpha $的非私人和差异私人估计器，并在两种设置中获得样本复杂性结果以量化隐私成本。我们的分析利用了霍克斯过程的强大混合特性和经典的中央限制定理的结果，结果较弱的随机变量。我们在合成数据集和真实数据集上验证了我们的理论发现。

用机器人手操纵物体是一项复杂的任务。不仅需要协调手指，而且机器人最终效应器的姿势也需要协调。使用人类的运动演示是指导机器人行为的直观和数据效率的方式。我们提出了一个具有自动实施例映射的模块化框架，以将记录的人体运动转移到机器人系统中。在这项工作中，我们使用运动捕获来记录人类运动。我们在八项具有挑战性的任务上评估了我们的方法，其中机器人手需要掌握和操纵可变形或小且脆弱的物体。我们测试了模拟和实际机器人中的轨迹子集，并且整体成功率是一致的。

原始的“七个图案”阐述了科学计算领域的基本方法的路线图，其中图案是一种捕获计算和数据移动模式的算法方法。我们介绍了“仿真智力的九个主题”，是一种开发和整合的路线图，以合并科学计算，科学模拟和人工智能所必需的基本算法。我们称之为合并模拟智能（SI），短暂。我们认为模拟智能的主题是相互连接的和相互依存的，很像操作系统层中的组件一样。使用这种隐喻，我们探讨了模拟智能操作系统堆栈（Si-Stack）和其中图案的各层的性质：（1）多种物理和多尺度建模; （2）替代建模和仿真; （3）基于仿真的推理; （4）因果建模和推理; （5）基于代理的建模; （6）概率编程; （7）可微分的编程; （8）开放式优化; （9）机器编程。我们相信图案之间的协调努力提供了加速科学发现的巨大机会，从综合生物和气候科学中解决逆问题，指导核能实验，并预测社会经济环境中的紧急行为。我们详细说明了Si-stack的每层，详细说明了最先进的方法，提出了示例以突出挑战和机遇，并倡导具体的方法来推进主题和与其组合的协同作用。推进和整合这些技术可以实现稳健且有效的假设仿真 - 分析类型的科学方法，我们用几种使用案例为人机组合和自动化学介绍。