In non-smooth stochastic optimization, we establish the non-convergence of the stochastic subgradient descent (SGD) to the critical points recently called active strict saddles by Davis and Drusvyatskiy. Such points lie on a manifold $M$ where the function $f$ has a direction of second-order negative curvature. Off this manifold, the norm of the Clarke subdifferential of $f$ is lower-bounded. We require two conditions on $f$. The first assumption is a Verdier stratification condition, which is a refinement of the popular Whitney stratification. It allows us to establish a reinforced version of the projection formula of Bolte \emph{et.al.} for Whitney stratifiable functions, and which is of independent interest. The second assumption, termed the angle condition, allows to control the distance of the iterates to $M$. When $f$ is weakly convex, our assumptions are generic. Consequently, generically in the class of definable weakly convex functions, the SGD converges to a local minimizer.

Increasingly taking place in online spaces, modern political conversations are typically perceived to be unproductively affirming -- siloed in so called ``echo chambers'' of exclusively like-minded discussants. Yet, to date we lack sufficient means to measure viewpoint diversity in conversations. To this end, in this paper, we operationalize two viewpoint metrics proposed for recommender systems and adapt them to the context of social media conversations. This is the first study to apply these two metrics (Representation and Fragmentation) to real world data and to consider the implications for online conversations specifically. We apply these measures to two topics -- daylight savings time (DST), which serves as a control, and the more politically polarized topic of immigration. We find that the diversity scores for both Fragmentation and Representation are lower for immigration than for DST. Further, we find that while pro-immigrant views receive consistent pushback on the platform, anti-immigrant views largely operate within echo chambers. We observe less severe yet similar patterns for DST. Taken together, Representation and Fragmentation paint a meaningful and important new picture of viewpoint diversity.

Graph Neural Networks (GNNs) are deep learning models designed to process attributed graphs. GNNs can compute cluster assignments accounting both for the vertex features and for the graph topology. Existing GNNs for clustering are trained by optimizing an unsupervised minimum cut objective, which is approximated by a Spectral Clustering (SC) relaxation. SC offers a closed-form solution that, however, is not particularly useful for a GNN trained with gradient descent. Additionally, the SC relaxation is loose and yields overly smooth cluster assignments, which do not separate well the samples. We propose a GNN model that optimizes a tighter relaxation of the minimum cut based on graph total variation (GTV). Our model has two core components: i) a message-passing layer that minimizes the $\ell_1$ distance in the features of adjacent vertices, which is key to achieving sharp cluster transitions; ii) a loss function that minimizes the GTV in the cluster assignments while ensuring balanced partitions. By optimizing the proposed loss, our model can be self-trained to perform clustering. In addition, our clustering procedure can be used to implement graph pooling in deep GNN architectures for graph classification. Experiments show that our model outperforms other GNN-based approaches for clustering and graph pooling.

Pre-trained language models (PLMs) have outperformed other NLP models on a wide range of tasks. Opting for a more thorough understanding of their capabilities and inner workings, researchers have established the extend to which they capture lower-level knowledge like grammaticality, and mid-level semantic knowledge like factual understanding. However, there is still little understanding of their knowledge of higher-level aspects of language. In particular, despite the importance of sociodemographic aspects in shaping our language, the questions of whether, where, and how PLMs encode these aspects, e.g., gender or age, is still unexplored. We address this research gap by probing the sociodemographic knowledge of different single-GPU PLMs on multiple English data sets via traditional classifier probing and information-theoretic minimum description length probing. Our results show that PLMs do encode these sociodemographics, and that this knowledge is sometimes spread across the layers of some of the tested PLMs. We further conduct a multilingual analysis and investigate the effect of supplementary training to further explore to what extent, where, and with what amount of pre-training data the knowledge is encoded. Our overall results indicate that sociodemographic knowledge is still a major challenge for NLP. PLMs require large amounts of pre-training data to acquire the knowledge and models that excel in general language understanding do not seem to own more knowledge about these aspects.

Machine learning models are now able to convert user-written text descriptions into naturalistic images. These models are available to anyone online and are being used to generate millions of images a day. We investigate these models and find that they amplify dangerous and complex stereotypes. Moreover, we find that the amplified stereotypes are difficult to predict and not easily mitigated by users or model owners. The extent to which these image-generation models perpetuate and amplify stereotypes and their mass deployment is cause for serious concern.

最近，引入了亚图增强图神经网络（SGNN），以增强图形神经网络（GNN）的表达能力，事实证明，该功能不高于一维Weisfeiler-Leman同构测试。新的范式建议使用从输入图中提取的子图提高模型的表现力，但是额外的复杂性加剧了GNNS中本来可以具有挑战性的问题：解释其预测。在这项工作中，我们将PGEXPlainer（GNNS的最新解释者之一）改编为SGNN。拟议的解释器解释了所有不同子图的贡献，并可以产生人类可以解释的有意义的解释。我们在真实和合成数据集上执行的实验表明，我们的框架成功地解释了SGNN在图形分类任务上的决策过程。

时空时间序列的神经预测推动了几个相关应用领域的研究和工业创新。图神经网络（GNN）通常是预测体系结构的核心组成部分。但是，在大多数时空gnns中，计算复杂度比序列时间长度缩放到二次因子，图中链接的数量是图中的链接数，因此阻碍了这些模型在大图和长时间序列中的应用。尽管在静态图的背景下提出了提高可伸缩性的方法，但很少有研究工作专门用于时空情况。为了填补这一空白，我们提出了一个可扩展的体系结构，该体系结构利用了时间和空间动力学的有效编码。特别是，我们使用一个随机的复发神经网络将输入时间序列的历史嵌入到包括多尺度时间动力学的高维状态表示中。然后，使用图形邻接矩阵的不同功率沿空间维度沿空间维度传播，以生成以富含时空特征池的特征的节点嵌入。可以在不监督的方式中有效地预先计算所得的节点嵌入，然后将其馈送到馈送前向解码器，该解码器学会映射多尺度时空表示形式为预测。然后，可以通过对节点的嵌入而无需破坏任何依赖性，从而使训练过程在节点方面并行化，从而可以对大型网络进行可扩展性。相关数据集的经验结果表明，我们的方法可以与最新技术的状态竞争，同时大大减轻了计算负担。

在这项工作中，我们详细描述了深度学习和计算机视觉如何帮助检测AirTender系统的故障事件，AirTender系统是售后摩托车阻尼系统组件。监测飞行员运行的最有效方法之一是在其表面上寻找油污渍。从实时图像开始，首先在摩托车悬架系统中检测到Airtender，然后二进制分类器确定Airtender是否在溢出油。该检测是在YOLO5架构的帮助下进行的，而分类是在适当设计的卷积神经网络油网40的帮助下进行的。为了更清楚地检测油的泄漏，我们用荧光染料稀释了荧光染料，激发波长峰值约为390 nm。然后用合适的紫外线LED照亮飞行员。整个系统是设计低成本检测设置的尝试。船上设备（例如迷你计算机）被放置在悬架系统附近，并连接到全高清摄像头框架架上。板载设备通过我们的神经网络算法，然后能够将AirTender定位并分类为正常功能（非泄漏图像）或异常（泄漏图像）。

光谱群集中使用的目标函数通常由两个术语组成：i）一个术语最小化群集分配的局部二次变化，并且；ii）一个平衡聚类分区并有助于避免退化解决方案的术语。本文表明，配备合适消息传递层的图形神经网络可以通过仅优化平衡项来生成良好的集群分配。归因图数据集的结果显示了拟议方法在聚类性能和计算时间方面的有效性。

反复出现或持续的尴尬身体姿势是与工作相关的肌肉骨骼疾病（MSD）发展最常见的危险因素之一。为了防止工人采用有害配置，也可以指导他们朝着更符合人体工程学的配置，可穿戴触觉设备可能是理想的解决方案。在本文中，在肢体姿势校正环境中评估了一个称为Ergotac的纤维ac式单元，称为袖口和称为袖口的滑动单元。使用定量与任务相关的指标和主观定量评估，比较了在十二个健康受试者中比较了他们提供单关节（肩膀或膝盖）和多关节（肩膀和膝盖）指导的能力。还建立了一个集成的环境，以简化参与传感器和反馈系统之间的沟通和数据共享。结果显示出两种设备的良好可接受性和直觉。 Ergotac似乎是肩膀的合适反馈装置，而袖口可能是膝盖的有效解决方案。这项比较研究虽然是初步的，但却是对两种设备进行有效全身姿势校正的潜在整合的促进，目的是开发反馈和辅助设备，以提高工人对危险工作条件的认识，从而防止MSD。