尽管强化学习（RL）在许多领域都取得了巨大的成功，但是当很难指定奖励并且不允许探索奖励时，将RL应用于医疗保健等现实世界中的挑战。在这项工作中，我们专注于恢复临床医生在治疗患者方面的回报。我们结合了理由，根据其潜在的未来结果来解释临床医生的治疗方法。我们使用通用的添加剂模型（GAM） - 一类准确的，可解释的模型 - 恢复奖励。在模拟和现实世界医院的数据集中，我们显示模型的表现优于基准。最后，在治疗患者时，我们的模型的解释符合几个临床准则，而我们发现常用的线性模型通常与它们相矛盾。

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.

当前的深度学习自适应优化器方法通过改变每个参数使用的有效学习率来调整参数更新的步骤幅度。由批处理大小和更新步骤幅度的学习率之间的已知反向关系激励，我们引入了一个新颖的培训程序，该过程动态地决定了当前更新步骤的维度和组成。我们的过程，动态批次适应（DBA）分析了每个样本的梯度，并选择了最能改善某些指标的子集，例如网络每一层的梯度差异。我们提出的结果显示DBA显着提高了模型收敛的速度。此外，我们发现DBA在数据稀缺条件中使用时，与标准优化器相比会提高改进MNIST数据集的测试准确性达到97.79％。在更加极端的情况下，它设法使用每班只有10个样本达到97.44％的测试精度。与标准优化器，随机梯度下降（SGD）和ADAM相比，这些结果分别代表了81.78％和88.07％的相对错误率降低。

关于自适应梯度方法等自适应梯度方法等训练动力的知之甚少。在本文中，我们阐明了这些算法在全批处理和足够大的批处理设置中的行为。具体而言，我们从经验上证明，在全批训练中，预处理的Hessian的最大特征值通常在某个数值下平衡 - 梯度下降算法的稳定性阈值。对于带有步长$ \ eta $和$ \ beta_1 = 0.9 $的Adam，此稳定性阈值为$ 38/\ eta $。在Minibatch培训期间发生了类似的影响，尤其是随着批处理大小的增长。然而，即使自适应方法在``稳定性的自适应边缘''（AEOS）上训练，但它们在该制度中的行为与EOS的非自适应方法的行为有很大不同。 EOS处的非自适应算法被阻止进入损失景观的高曲率区域，而AEOS的自适应梯度方法可以继续前进到高外观区域，同时适应预先调节器以补偿。我们的发现可以成为社区对深度学习中适应性梯度方法的未来理解的基础。

COVID-19的大流行造成了毁灭性的经济和社会破坏，使全球医疗机构的资源紧张。这导致全国范围内呼吁模型预测Covid-19患者的住院和严重疾病，以告知有限医疗资源的分配。我们回应针对儿科人群的其中一种。为了应对这一挑战，我们使用电子健康记录研究了针对儿科人群的两项预测任务：1）预测哪些儿童更有可能住院，而2）在住院儿童中，哪些孩子更有可能出现严重的症状。我们通过新颖的机器学习模型MEDML应对国家儿科Covid-19数据挑战。 MEDML根据超过600万个医学概念的医学知识和倾向得分提取了最预测的特征，并通过图神经网络（GNN）结合了异质医学特征之间的功能间关系。我们使用来自国家队列协作（N3C）数据集的数据评估了143,605名患者的MEDML，并在143,605名患者的住院预测任务中评估了严重性预测任务的11,465名患者。我们还报告了详细的小组级和个人级特征的重要性分析，以评估模型的解释性。与最佳的基线机器学习模型相比，MEDML的AUROC得分高达7％，AUPRC得分高达14％，并且自大流行以来的所有九个国家地理区域以及所有三个月的跨度都表现良好。我们的跨学科研究团队开发了一种将临床领域知识纳入新型机器学习模型的框架的方法，该框架比当前最新的数据驱动的功能选择方法更具预测性和可解释。

通用形态（UNIMORPH）项目是一项合作的努力，可为数百种世界语言实例化覆盖范围的标准化形态拐角。该项目包括两个主要的推力：一种无独立的特征架构，用于丰富的形态注释，并以各种语言意识到该模式的各种语言的带注释数据的类型级别资源。本文介绍了过去几年对几个方面的扩张和改进（自McCarthy等人（2020年）以来）。众多语言学家的合作努力增加了67种新语言，其中包括30种濒危语言。我们已经对提取管道进行了一些改进，以解决一些问题，例如缺少性别和马克龙信息。我们还修改了模式，使用了形态学现象所需的层次结构，例如多肢体协议和案例堆叠，同时添加了一些缺失的形态特征，以使模式更具包容性。鉴于上一个UniMorph版本，我们还通过16种语言的词素分割增强了数据库。最后，这个新版本通过通过代表来自metphynet的派生过程的实例丰富数据和注释模式来推动将衍生物形态纳入UniMorph中。

Spatial pyramid pooling module or encode-decoder structure are used in deep neural networks for semantic segmentation task. The former networks are able to encode multi-scale contextual information by probing the incoming features with filters or pooling operations at multiple rates and multiple effective fields-of-view, while the latter networks can capture sharper object boundaries by gradually recovering the spatial information. In this work, we propose to combine the advantages from both methods. Specifically, our proposed model, DeepLabv3+, extends DeepLabv3 by adding a simple yet effective decoder module to refine the segmentation results especially along object boundaries. We further explore the Xception model and apply the depthwise separable convolution to both Atrous Spatial Pyramid Pooling and decoder modules, resulting in a faster and stronger encoder-decoder network. We demonstrate the effectiveness of the proposed model on PASCAL VOC 2012 and Cityscapes datasets, achieving the test set performance of 89.0% and 82.1% without any post-processing. Our paper is accompanied with a publicly available reference implementation of the proposed models in Tensorflow at https: //github.com/tensorflow/models/tree/master/research/deeplab.

Existing automated techniques for software documentation typically attempt to reason between two main sources of information: code and natural language. However, this reasoning process is often complicated by the lexical gap between more abstract natural language and more structured programming languages. One potential bridge for this gap is the Graphical User Interface (GUI), as GUIs inherently encode salient information about underlying program functionality into rich, pixel-based data representations. This paper offers one of the first comprehensive empirical investigations into the connection between GUIs and functional, natural language descriptions of software. First, we collect, analyze, and open source a large dataset of functional GUI descriptions consisting of 45,998 descriptions for 10,204 screenshots from popular Android applications. The descriptions were obtained from human labelers and underwent several quality control mechanisms. To gain insight into the representational potential of GUIs, we investigate the ability of four Neural Image Captioning models to predict natural language descriptions of varying granularity when provided a screenshot as input. We evaluate these models quantitatively, using common machine translation metrics, and qualitatively through a large-scale user study. Finally, we offer learned lessons and a discussion of the potential shown by multimodal models to enhance future techniques for automated software documentation.

View-dependent effects such as reflections pose a substantial challenge for image-based and neural rendering algorithms. Above all, curved reflectors are particularly hard, as they lead to highly non-linear reflection flows as the camera moves. We introduce a new point-based representation to compute Neural Point Catacaustics allowing novel-view synthesis of scenes with curved reflectors, from a set of casually-captured input photos. At the core of our method is a neural warp field that models catacaustic trajectories of reflections, so complex specular effects can be rendered using efficient point splatting in conjunction with a neural renderer. One of our key contributions is the explicit representation of reflections with a reflection point cloud which is displaced by the neural warp field, and a primary point cloud which is optimized to represent the rest of the scene. After a short manual annotation step, our approach allows interactive high-quality renderings of novel views with accurate reflection flow. Additionally, the explicit representation of reflection flow supports several forms of scene manipulation in captured scenes, such as reflection editing, cloning of specular objects, reflection tracking across views, and comfortable stereo viewing. We provide the source code and other supplemental material on https://repo-sam.inria.fr/ fungraph/neural_catacaustics/

In large-scale machine learning, recent works have studied the effects of compressing gradients in stochastic optimization in order to alleviate the communication bottleneck. These works have collectively revealed that stochastic gradient descent (SGD) is robust to structured perturbations such as quantization, sparsification, and delays. Perhaps surprisingly, despite the surge of interest in large-scale, multi-agent reinforcement learning, almost nothing is known about the analogous question: Are common reinforcement learning (RL) algorithms also robust to similar perturbations? In this paper, we investigate this question by studying a variant of the classical temporal difference (TD) learning algorithm with a perturbed update direction, where a general compression operator is used to model the perturbation. Our main technical contribution is to show that compressed TD algorithms, coupled with an error-feedback mechanism used widely in optimization, exhibit the same non-asymptotic theoretical guarantees as their SGD counterparts. We then extend our results significantly to nonlinear stochastic approximation algorithms and multi-agent settings. In particular, we prove that for multi-agent TD learning, one can achieve linear convergence speedups in the number of agents while communicating just $\tilde{O}(1)$ bits per agent at each time step. Our work is the first to provide finite-time results in RL that account for general compression operators and error-feedback in tandem with linear function approximation and Markovian sampling. Our analysis hinges on studying the drift of a novel Lyapunov function that captures the dynamics of a memory variable introduced by error feedback.