深度学习的成功归功于我们能够相对轻松地解决某些大规模的非凸优化问题。尽管非凸优化是NP硬化,但简单的算法(通常是随机梯度下降的变体)在拟合大型神经网络的实践中具有令人惊讶的有效性。我们认为,在考虑了所有可能的隐藏单元对称对称性之后,神经网络损失景观包含(几乎)一个盆地。我们介绍了三种算法以缩小一个模型的单元,以使它们与参考模型的单位保持一致。这种转换产生了一组功能等效的权重,该权重位于参考模型附近的大约凸盆地中。在实验上,我们证明了各种模型架构和数据集中的单个盆地现象,包括在CIFAR-10和CIFAR-100上独立训练的Resnet模型之间的第一个(据我们所知)的(据我们所知)的第一次演示。此外,我们确定了有趣的现象,将模型宽度和训练时间与各种模型和数据集的模式连接性有关。最后,我们讨论了单个盆地理论的缺点,包括对线性模式连接假设的反例。
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Machine Learning models capable of handling the large datasets collected in the financial world can often become black boxes expensive to run. The quantum computing paradigm suggests new optimization techniques, that combined with classical algorithms, may deliver competitive, faster and more interpretable models. In this work we propose a quantum-enhanced machine learning solution for the prediction of credit rating downgrades, also known as fallen-angels forecasting in the financial risk management field. We implement this solution on a neutral atom Quantum Processing Unit with up to 60 qubits on a real-life dataset. We report competitive performances against the state-of-the-art Random Forest benchmark whilst our model achieves better interpretability and comparable training times. We examine how to improve performance in the near-term validating our ideas with Tensor Networks-based numerical simulations.
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最近,手语研究人员已转向手语解释的电视广播,包括(i)连续签名的视频和(ii)与音频内容相对应的字幕,作为易于使用和大规模的培训数据来源。此类数据可用性的一个关键挑战是缺乏标志注释。利用这种弱对准数据的先前工作仅发现字幕中的关键字与单个符号之间的稀疏对应关系。在这项工作中,我们提出了一个简单,可扩展的框架,以极大地增加自动注释的密度。我们的贡献如下:(1)我们通过使用同义词和字幕签名对齐来显着改善先前的注释方法; (2)我们将标志识别模型中的伪标签的价值作为标志发现的方式; (3)我们提出了一种新的方法,以增加基于内域示例的已知和未知类别的注释; (4)在Bobsl BSL手语语料库上,我们将自信自动注释的数量从670K增加到5M。我们将这些注释公开用于支持手语研究社区。
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域适应(DA)最近在医学影像社区提出了强烈的兴趣。虽然已经提出了大量DA技术进行了用于图像分割,但大多数这些技术已经在私有数据集或小公共可用数据集上验证。此外,这些数据集主要解决了单级问题。为了解决这些限制,与第24届医学图像计算和计算机辅助干预(Miccai 2021)结合第24届国际会议组织交叉模态域适应(Crossmoda)挑战。 Crossmoda是无监督跨型号DA的第一个大型和多级基准。挑战的目标是分割参与前庭施瓦新瘤(VS)的后续和治疗规划的两个关键脑结构:VS和Cochleas。目前,使用对比度增强的T1(CET1)MRI进行VS患者的诊断和监测。然而,使用诸如高分辨率T2(HRT2)MRI的非对比度序列越来越感兴趣。因此,我们创建了一个无人监督的跨模型分段基准。训练集提供注释CET1(n = 105)和未配对的非注释的HRT2(n = 105)。目的是在测试集中提供的HRT2上自动对HRT2进行单侧VS和双侧耳蜗分割(n = 137)。共有16支球队提交了评估阶段的算法。顶级履行团队达成的表现水平非常高(最佳中位数骰子 - vs:88.4%; Cochleas:85.7%)并接近完全监督(中位数骰子 - vs:92.5%;耳蜗:87.7%)。所有顶级执行方法都使用图像到图像转换方法将源域图像转换为伪目标域图像。然后使用这些生成的图像和为源图像提供的手动注释进行培训分割网络。
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数据增强是自然语言处理(NLP)模型的鲁棒性评估的重要组成部分,以及增强他们培训的数据的多样性。在本文中,我们呈现NL-Cogmenter,这是一种新的参与式Python的自然语言增强框架,它支持创建两个转换(对数据的修改)和过滤器(根据特定功能的数据拆分)。我们描述了框架和初始的117个变换和23个过滤器,用于各种自然语言任务。我们通过使用其几个转换来分析流行自然语言模型的鲁棒性来证明NL-Upmenter的功效。基础架构,Datacards和稳健性分析结果在NL-Augmenter存储库上公开可用(\ url {https://github.com/gem-benchmark/nl-augmenter})。
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从单目视频重建3D网格的关键元素之一是生成每个帧的深度图。然而,在结肠镜检查视频重建的应用中,产生良好质量的深度估计是具有挑战性的。神经网络可以容易地被光度分散注意力欺骗,或者不能捕获结肠表面的复杂形状,预测导致破碎网格的缺陷形状。旨在从根本上提高结肠镜检查3D重建的深度估计质量,在这项工作中,我们设计了一系列培训损失来应对结肠镜检查数据的特殊挑战。为了更好的培训,使用深度和表面正常信息开发了一组几何一致性目标。而且,经典的光度损耗延伸,具有特征匹配以补偿照明噪声。随着足够强大的培训损失,我们的自我监督框架命名为COLLE,与利用先前的深度知识相比,我们的自我监督框架能够产生更好的结肠镜检查数据地图。用于重建,我们的网络能够实时重建高质量的结肠网格,而无需任何后处理,使其成为第一个在临床上适用。
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多边缘最佳运输使人们能够比较多种概率措施,这些措施越来越多地发现在多任务学习问题中的应用。多边缘运输的一个实际限制是测量,样品和维度数量的计算可扩展性。在这项工作中,我们提出了一种基于随机一维投影的多边缘最佳运输范例,其(广义)距离我们术语切片的多边缘Wasserstein距离。为了构建该距离,我们介绍了一维多边缘Kantorovich问题的表征,并使用它来突出切片的多边缘Wasserstein距离的许多属性。特别是,我们表明(i)切片的多边缘Wasserstein距离是一种(概括的)指标,其诱导与标准的Wasserstein距离相同的拓扑,(ii)它承认无维样本复杂度,(iii)是与切片沃斯斯坦度量标准下的双重Centric的问题紧密连接。我们通过说明切片的多边缘Wasserstein对多任务密度估计和多动力增强学习问题的结论。
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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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Modelling and forecasting real-life human behaviour using online social media is an active endeavour of interest in politics, government, academia, and industry. Since its creation in 2006, Twitter has been proposed as a potential laboratory that could be used to gauge and predict social behaviour. During the last decade, the user base of Twitter has been growing and becoming more representative of the general population. Here we analyse this user base in the context of the 2021 Mexican Legislative Election. To do so, we use a dataset of 15 million election-related tweets in the six months preceding election day. We explore different election models that assign political preference to either the ruling parties or the opposition. We find that models using data with geographical attributes determine the results of the election with better precision and accuracy than conventional polling methods. These results demonstrate that analysis of public online data can outperform conventional polling methods, and that political analysis and general forecasting would likely benefit from incorporating such data in the immediate future. Moreover, the same Twitter dataset with geographical attributes is positively correlated with results from official census data on population and internet usage in Mexico. These findings suggest that we have reached a period in time when online activity, appropriately curated, can provide an accurate representation of offline behaviour.
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Existing federated classification algorithms typically assume the local annotations at every client cover the same set of classes. In this paper, we aim to lift such an assumption and focus on a more general yet practical non-IID setting where every client can work on non-identical and even disjoint sets of classes (i.e., client-exclusive classes), and the clients have a common goal which is to build a global classification model to identify the union of these classes. Such heterogeneity in client class sets poses a new challenge: how to ensure different clients are operating in the same latent space so as to avoid the drift after aggregation? We observe that the classes can be described in natural languages (i.e., class names) and these names are typically safe to share with all parties. Thus, we formulate the classification problem as a matching process between data representations and class representations and break the classification model into a data encoder and a label encoder. We leverage the natural-language class names as the common ground to anchor the class representations in the label encoder. In each iteration, the label encoder updates the class representations and regulates the data representations through matching. We further use the updated class representations at each round to annotate data samples for locally-unaware classes according to similarity and distill knowledge to local models. Extensive experiments on four real-world datasets show that the proposed method can outperform various classical and state-of-the-art federated learning methods designed for learning with non-IID data.
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