本文考虑了在线配置器通常使用的一组替代方案中学习用户偏好的任务。在许多设置中，学习者在过去的互动过程中只有一组选定的替代方案。Fargier等。[2018]提出了一种在这种环境中学习用户偏好模型的方法，该模型对先前选择的替代方案进行了排名尽可能高；以及在这种情况下学习的算法，是一种特定的偏好模型：词典偏好树（LP-Trees）。在本文中，我们研究了与这种方法相关的复杂性理论问题。我们对学习LP-Tree的样本复杂性给出了上限，这在属性数量上是对数。我们还证明，计算最小化经验风险的LP树当仅限于线性LP-Trees的类别时，可以在多项式时间内完成。

本文报道的研究通过应用计算机视觉技术将普通的垃圾桶转化为更聪明的垃圾箱。在传感器和执行器设备的支持下，垃圾桶可以自动对垃圾进行分类。特别是，垃圾箱上的摄像头拍摄垃圾的照片，然后进行中央处理单元分析，并决定将垃圾桶放入哪个垃圾箱中。我们的垃圾箱系统的准确性达到90％。此外，我们的模型已连接到Internet，以更新垃圾箱状态以进行进一步管理。开发了用于管理垃圾箱的移动应用程序。

Diabetic Retinopathy (DR) is a leading cause of vision loss in the world, and early DR detection is necessary to prevent vision loss and support an appropriate treatment. In this work, we leverage interactive machine learning and introduce a joint learning framework, termed DRG-Net, to effectively learn both disease grading and multi-lesion segmentation. Our DRG-Net consists of two modules: (i) DRG-AI-System to classify DR Grading, localize lesion areas, and provide visual explanations; (ii) DRG-Expert-Interaction to receive feedback from user-expert and improve the DRG-AI-System. To deal with sparse data, we utilize transfer learning mechanisms to extract invariant feature representations by using Wasserstein distance and adversarial learning-based entropy minimization. Besides, we propose a novel attention strategy at both low- and high-level features to automatically select the most significant lesion information and provide explainable properties. In terms of human interaction, we further develop DRG-Net as a tool that enables expert users to correct the system's predictions, which may then be used to update the system as a whole. Moreover, thanks to the attention mechanism and loss functions constraint between lesion features and classification features, our approach can be robust given a certain level of noise in the feedback of users. We have benchmarked DRG-Net on the two largest DR datasets, i.e., IDRID and FGADR, and compared it to various state-of-the-art deep learning networks. In addition to outperforming other SOTA approaches, DRG-Net is effectively updated using user feedback, even in a weakly-supervised manner.

In the era of Internet of Things (IoT), network-wide anomaly detection is a crucial part of monitoring IoT networks due to the inherent security vulnerabilities of most IoT devices. Principal Components Analysis (PCA) has been proposed to separate network traffics into two disjoint subspaces corresponding to normal and malicious behaviors for anomaly detection. However, the privacy concerns and limitations of devices' computing resources compromise the practical effectiveness of PCA. We propose a federated PCA-based Grassmannian optimization framework that coordinates IoT devices to aggregate a joint profile of normal network behaviors for anomaly detection. First, we introduce a privacy-preserving federated PCA framework to simultaneously capture the profile of various IoT devices' traffic. Then, we investigate the alternating direction method of multipliers gradient-based learning on the Grassmann manifold to guarantee fast training and the absence of detecting latency using limited computational resources. Empirical results on the NSL-KDD dataset demonstrate that our method outperforms baseline approaches. Finally, we show that the Grassmann manifold algorithm is highly adapted for IoT anomaly detection, which permits drastically reducing the analysis time of the system. To the best of our knowledge, this is the first federated PCA algorithm for anomaly detection meeting the requirements of IoT networks.

无线传感器网络由随机分布的传感器节点组成，用于监视目标或感兴趣的区域。由于每个传感器的电池容量有限，因此维持连续监视的网络是一个挑战。无线电源传输技术正在作为可靠的解决方案，用于通过部署移动充电器（MC）为传感器充电传感器。但是，由于网络中出现不确定性，为MC设计最佳的充电路径是具有挑战性的。由于网络拓扑的不可预测的变化，例如节点故障，传感器的能耗率可能会显着波动。这些变化也导致每个传感器的重要性变化，在现有作品中通常被认为是相同的。我们在本文中提出了一种使用深度强化学习（DRL）方法提出新颖的自适应充电方案，以解决这些挑战。具体来说，我们赋予MC采用充电策略，该策略确定了下一个在网络当前状态上充电条件的传感器。然后，我们使用深层神经网络来参数这项收费策略，该策略将通过强化学习技术进行培训。我们的模型可以适应网络拓扑的自发变化。经验结果表明，所提出的算法的表现优于现有的按需算法的大幅度边缘。

COVID-19大流行已经暴露了全球医疗服务的脆弱性，增加了开发新颖的工具来提供快速且具有成本效益的筛查和诊断的需求。临床报告表明，Covid-19感染可能导致心脏损伤，心电图（ECG）可以作为Covid-19的诊断生物标志物。这项研究旨在利用ECG信号自动检测COVID-19。我们提出了一种从ECG纸记录中提取ECG信号的新方法，然后将其送入一维卷积神经网络（1D-CNN）中，以学习和诊断疾病。为了评估数字信号的质量，标记了基于纸张的ECG图像中的R峰。之后，将从每个图像计算的RR间隔与相应数字化信号的RR间隔进行比较。 COVID-19 ECG图像数据集上的实验表明，提出的数字化方法能够正确捕获原始信号，平均绝对误差为28.11 ms。我们提出的1D-CNN模型在数字化的心电图信号上进行了训练，允许准确识别患有COVID-19和其他受试者的个体，分类精度为98.42％，95.63％和98.50％，用于分类COVID-19 vs.正常，与正常人分类， COVID-19与异常心跳和Covid-19和其他类别分别与其他阶级。此外，提出的方法还为多分类任务实现了高级的性能。我们的发现表明，经过数字化的心电图信号训练的深度学习系统可以作为诊断Covid-19的潜在工具。

在过去的几十年中，由于其在广泛的应用中，现场文本认可从学术界和实际用户获得了全世界的关注。尽管在光学字符识别方面取得了成就，但由于诸如扭曲或不规则布局等固有问题，现场文本识别仍然具有挑战性。大多数现有方法主要利用基于复发或卷积的神经网络。然而，虽然经常性的神经网络（RNN）通常由于顺序计算而遭受慢的训练速度，并且遇到消失的梯度或瓶颈，但CNN在复杂性和性能之间衡量折衷。在本文中，我们介绍了SAFL，一种基于自我关注的神经网络模型，具有场景文本识别的焦点损失，克服现有方法的限制。使用焦损而不是负值对数似然有助于模型更多地关注低频样本训练。此外，为应对扭曲和不规则文本，我们在传递到识别网络之前，我们利用空间变换（STN）来纠正文本。我们执行实验以比较拟议模型的性能与七个基准。数值结果表明，我们的模型实现了最佳性能。

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.

Current work in named entity recognition (NER) uses either cross entropy (CE) or conditional random fields (CRF) as the objective/loss functions to optimize the underlying NER model. Both of these traditional objective functions for the NER problem generally produce adequate performance when the data distribution is balanced and there are sufficient annotated training examples. But since NER is inherently an imbalanced tagging problem, the model performance under the low-resource settings could suffer using these standard objective functions. Based on recent advances in area under the ROC curve (AUC) maximization, we propose to optimize the NER model by maximizing the AUC score. We give evidence that by simply combining two binary-classifiers that maximize the AUC score, significant performance improvement over traditional loss functions is achieved under low-resource NER settings. We also conduct extensive experiments to demonstrate the advantages of our method under the low-resource and highly-imbalanced data distribution settings. To the best of our knowledge, this is the first work that brings AUC maximization to the NER setting. Furthermore, we show that our method is agnostic to different types of NER embeddings, models and domains. The code to replicate this work will be provided upon request.

Out-of-distribution (OOD) generalisation aims to build a model that can well generalise its learnt knowledge from source domains to an unseen target domain. However, current image classification models often perform poorly in the OOD setting due to statistically spurious correlations learning from model training. From causality-based perspective, we formulate the data generation process in OOD image classification using a causal graph. On this graph, we show that prediction P(Y|X) of a label Y given an image X in statistical learning is formed by both causal effect P(Y|do(X)) and spurious effects caused by confounding features (e.g., background). Since the spurious features are domain-variant, the prediction P(Y|X) becomes unstable on unseen domains. In this paper, we propose to mitigate the spurious effect of confounders using front-door adjustment. In our method, the mediator variable is hypothesized as semantic features that are essential to determine a label for an image. Inspired by capability of style transfer in image generation, we interpret the combination of the mediator variable with different generated images in the front-door formula and propose novel algorithms to estimate it. Extensive experimental results on widely used benchmark datasets verify the effectiveness of our method.