Labelling a large quantity of social media data for the task of supervised machine learning is not only time-consuming but also difficult and expensive. On the other hand, the accuracy of supervised machine learning models is strongly related to the quality of the labelled data on which they train, and automatic sentiment labelling techniques could reduce the time and cost of human labelling. We have compared three automatic sentiment labelling techniques: TextBlob, Vader, and Afinn to assign sentiments to tweets without any human assistance. We compare three scenarios: one uses training and testing datasets with existing ground truth labels; the second experiment uses automatic labels as training and testing datasets; and the third experiment uses three automatic labelling techniques to label the training dataset and uses the ground truth labels for testing. The experiments were evaluated on two Twitter datasets: SemEval-2013 (DS-1) and SemEval-2016 (DS-2). Results show that the Afinn labelling technique obtains the highest accuracy of 80.17% (DS-1) and 80.05% (DS-2) using a BiLSTM deep learning model. These findings imply that automatic text labelling could provide significant benefits, and suggest a feasible alternative to the time and cost of human labelling efforts.

Purpose: The aim of this study was to demonstrate the utility of unsupervised domain adaptation (UDA) in automated knee osteoarthritis (OA) phenotype classification using a small dataset (n=50). Materials and Methods: For this retrospective study, we collected 3,166 three-dimensional (3D) double-echo steady-state magnetic resonance (MR) images from the Osteoarthritis Initiative dataset and 50 3D turbo/fast spin-echo MR images from our institute (in 2020 and 2021) as the source and target datasets, respectively. For each patient, the degree of knee OA was initially graded according to the MRI Osteoarthritis Knee Score (MOAKS) before being converted to binary OA phenotype labels. The proposed UDA pipeline included (a) pre-processing, which involved automatic segmentation and region-of-interest cropping; (b) source classifier training, which involved pre-training phenotype classifiers on the source dataset; (c) target encoder adaptation, which involved unsupervised adaption of the source encoder to the target encoder and (d) target classifier validation, which involved statistical analysis of the target classification performance evaluated by the area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy. Additionally, a classifier was trained without UDA for comparison. Results: The target classifier trained with UDA achieved improved AUROC, sensitivity, specificity and accuracy for both knee OA phenotypes compared with the classifier trained without UDA. Conclusion: The proposed UDA approach improves the performance of automated knee OA phenotype classification for small target datasets by utilising a large, high-quality source dataset for training. The results successfully demonstrated the advantages of the UDA approach in classification on small datasets.

Machine Learning (ML) technologies have been increasingly adopted in Medical Cyber-Physical Systems (MCPS) to enable smart healthcare. Assuring the safety and effectiveness of learning-enabled MCPS is challenging, as such systems must account for diverse patient profiles and physiological dynamics and handle operational uncertainties. In this paper, we develop a safety assurance case for ML controllers in learning-enabled MCPS, with an emphasis on establishing confidence in the ML-based predictions. We present the safety assurance case in detail for Artificial Pancreas Systems (APS) as a representative application of learning-enabled MCPS, and provide a detailed analysis by implementing a deep neural network for the prediction in APS. We check the sufficiency of the ML data and analyze the correctness of the ML-based prediction using formal verification. Finally, we outline open research problems based on our experience in this paper.

自动驾驶汽车必须能够可靠地处理不利的天气条件（例如，雪地）安全运行。在本文中，我们研究了以不利条件捕获的转动传感器输入（即图像）的想法，将其下游任务（例如，语义分割）可以达到高精度。先前的工作主要将其作为未配对的图像到图像翻译问题，因为缺乏在完全相同的相机姿势和语义布局下捕获的配对图像。虽然没有完美对准的图像，但可以轻松获得粗配上的图像。例如，许多人每天在好天气和不利的天气中驾驶相同的路线；因此，在近距离GPS位置捕获的图像可以形成一对。尽管来自重复遍历的数据不太可能捕获相同的前景对象，但我们认为它们提供了丰富的上下文信息来监督图像翻译模型。为此，我们提出了一个新颖的训练目标，利用了粗糙的图像对。我们表明，我们与一致的训练方案可提高更好的图像翻译质量和改进的下游任务，例如语义分割，单眼深度估计和视觉定位。

由于大规模数据集的可用性，通常在特定位置和良好的天气条件下收集的大规模数据集，近年来，自动驾驶汽车的感知进展已加速。然而，为了达到高安全要求，这些感知系统必须在包括雪和雨在内的各种天气条件下进行稳健运行。在本文中，我们提出了一个新数据集，以通过新颖的数据收集过程启用强大的自动驾驶 - 在不同场景（Urban，Highway，乡村，校园），天气，雪，雨，阳光下，沿着15公里的路线反复记录数据），时间（白天/晚上）以及交通状况（行人，骑自行车的人和汽车）。该数据集包括来自摄像机和激光雷达传感器的图像和点云，以及高精度GPS/ins以在跨路线上建立对应关系。该数据集包括使用Amodal掩码捕获部分遮挡和3D边界框的道路和对象注释。我们通过分析基准在道路和对象，深度估计和3D对象检测中的性能来证明该数据集的独特性。重复的路线为对象发现，持续学习和异常检测打开了新的研究方向。链接到ITHACA365：https：//ithaca365.mae.cornell.edu/

有关后门毒物攻击的广泛文献研究了使用“数字触发图案”的后门攻击和防御措施。相比之下，“物理后门”使用物理对象作为触发器，直到最近才被确定，并且在质量上足够不同，可以抵抗针对数字触发后门的所有防御。对物理后门的研究受到了访问大型数据集的限制，该数据集包含包含与分类目标共同位置的物理对象的真实图像。构建这些数据集是时间和劳动力密集的。这项工作旨在应对有关物理后门攻击研究的可访问性挑战。我们假设在流行数据集（例如Imagenet）中可能存在天然存在的物理共同存在的对象。一旦确定，这些数据的仔细重新标记可以将它们转化为训练样本，以进行物理后门攻击。我们提出了一种方法，可以通过在现有数据集中识别这些潜在触发器的这些亚集，以及它们可能毒害的特定类别。我们称这些天然存在的触发级子集自然后门数据集。我们的技术成功地识别了广泛可用的数据集中的自然后门，并在行为上等同于在手动策划数据集中训练的模型。我们发布我们的代码，以使研究社区可以创建自己的数据集，以研究物理后门攻击。

由于许多科学领域的图形，从数学，生物学，社会科学和物理学到计算机科学的图形，动态图神经网络最近变得越来越重要。尽管时间变化（动态）在许多现实世界应用中起着至关重要的作用，但图形神经网络（GNN）过程静态图的文献中的大多数模型。动态图上的少数GNN模型仅考虑特殊的动力学情况，例如Node属性 - 动态图或结构 - 动力学图，仅限于图形边缘的添加或更改等。因此，我们提供了一个新颖的全动态图形神经网络（可以在连续时间处理完全动态图的fdgnn）。提出的方法提供了一个节点和一个边缘嵌入，其中包括其活动以解决添加和删除的节点或边缘以及可能的属性。此外，嵌入式指定每个事件的时间点进程，以编码结构和属性相关的传入图表事件的分布。此外，可以通过考虑用于本地再培训的单个事件来有效地更新我们的模型。

Graphs are ubiquitous in nature and can therefore serve as models for many practical but also theoretical problems. For this purpose, they can be defined as many different types which suitably reflect the individual contexts of the represented problem. To address cutting-edge problems based on graph data, the research field of Graph Neural Networks (GNNs) has emerged. Despite the field's youth and the speed at which new models are developed, many recent surveys have been published to keep track of them. Nevertheless, it has not yet been gathered which GNN can process what kind of graph types. In this survey, we give a detailed overview of already existing GNNs and, unlike previous surveys, categorize them according to their ability to handle different graph types and properties. We consider GNNs operating on static and dynamic graphs of different structural constitutions, with or without node or edge attributes. Moreover, we distinguish between GNN models for discrete-time or continuous-time dynamic graphs and group the models according to their architecture. We find that there are still graph types that are not or only rarely covered by existing GNN models. We point out where models are missing and give potential reasons for their absence.

在本文中，我们描述了一种概率方法，用于使用神经网络估计物体的位置以及其协方差矩阵。我们的方法被设计为强大对异常值，在其他期望的属性中具有相对于网络输出的有界梯度。为了实现这一目标，我们介绍了由Huber损失启发的新概率分布。我们还介绍了一种新的方式来参数化正定矩阵，以确保不对我们回归的坐标系的方向选择。我们评估我们对流行的身体姿势和面部地标数据集的方法，并在PAR或超出非热映射方法的性能上获得性能。我们的代码可在github.com/davmo049/public_prob_regression_with_huber_distributions提供

形状和姿势估计是自动驾驶汽车充分了解其周围环境的关键感知问题。解决此问题的一个基本挑战是不完整的传感器信号（例如Lidar扫描），尤其是对于遥远或遮挡的物体。在本文中，我们提出了一种新的算法来应对这一挑战，该挑战明确利用了连续捕获的传感器信号：连续信号可以提供有关对象的更多信息，包括不同的观点及其运动。通过通过经常性神经网络编码连续的信号，我们的算法不仅可以改善形状和姿势估计，而且还会产生一种标签工具，可以使自主驱动研究中的其他任务受益。具体而言，在我们的算法上，我们提出了一条新型的管道，以自动注释高质量的标签，以进行图像上的Amodal分割，这很难手动注释。我们的代码和数据将公开可用。