随着受限制的量子计算机逐渐成为现实,寻找有意义的第一应用程序会加剧。在该领域中,较为研究的方法之一是使用一种特殊类型的量子电路(一种所谓的量子神经网络)作为机器学习模型的基础。顾名思义,粗略地说,量子神经网络可以与神经网络发挥相似的作用。但是,专门针对机器学习环境中的应用,对合适的电路体系结构或模型超参数的了解知之甚少。在这项工作中,我们将功能性方差分析框架应用于量子神经网络,以分析哪些超参数对其预测性能最大。我们分析了最常用的量子神经网络架构之一。然后,我们将其应用于OpenML-CC18分类基准中的$ 7 $开源数据集,其功能的数量足够小,足以适合量子硬件,少于$ 20 $ QUBITS。从功能方差分析获得的超参数的排名中检测到了三个主要重要性。我们的实验都证实了预期的模式,并揭示了新的见解。例如,在所有数据集上的边际贡献方面,设定学习率是最关键的超级参数,而所使用的纠缠门的特定选择被认为是最不重要的选择。这项工作介绍了研究量子机学习模型的新方法,并为量子模型选择提供了新的见解。
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尽管深度神经网络能够在各种任务上实现优于人类的表现,但他们臭名昭著,因为他们需要大量的数据和计算资源,将其成功限制在可用的这些资源的领域。金属学习方法可以通过从相关任务中转移知识来解决此问题,从而减少学习新任务所需的数据和计算资源的数量。我们组织了元数据竞赛系列,该系列为世界各地的研究小组提供了创建和实验评估实际问题的新元学习解决方案的机会。在本文中,我们在竞争组织者和排名最高的参与者之间进行了合作,我们描述了竞争的设计,数据集,最佳实验结果以及Neurips 2021挑战中最高的方法,这些方法吸引了15进入最后阶段的活跃团队(通过表现优于基线),在反馈阶段进行了100多次代码提交。顶级参与者的解决方案是开源的。汲取的经验教训包括学习良好的表示对于有效的转移学习至关重要。
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普通交叉验证(CV)等方法,如k倍交叉验证或Monte-Carlo交叉验证估计学习者的预测性能,通过重复在给定数据的大部分数据和对剩余数据上测试的大部分中进行训练。这些技术有两个主要缺点。首先,它们可以在大型数据集上不必要地慢。其次,除了估计最终性能之外,它们几乎没有进入验证算法的学习过程中的见解。在本文中,我们提出了一种基于学习曲线(LCCV)的验证的新方法。 LCCV迭代地增加用于训练的实例数量而不是创建火车测试分裂。在模型选择的背景下,它丢弃了不太可能成为竞争的模型。我们在从自动化基准测试的67个数据集上运行大规模的实验,并经验显示使用LCCV超过90%的案例,导致使用5/10倍的CV相似的性能(最多1.5%)。然而,它平均产生超过20%的大量运行时间减少。此外,它提供了重要的见解,例如允许评估获取更多数据的益处。这些结果与Automl领域的其他进步正交。
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机器学习研究取决于客观解释,可比和可重复的算法基准。我们倡导使用策划,全面套房的机器学习任务,以标准化基准的设置,执行和报告。我们通过帮助创建和利用这些基准套件的软件工具来实现这一目标。这些无缝集成到OpenML平台中,并通过Python,Java和R. OpenML基准套件(A)的接口访问,易于使用标准化的数据格式,API和客户端库; (b)附带的数据集具有广泛的元信息; (c)允许在未来的研究中共享和重复使用基准。然后,我们为分类提供了一个仔细的策划和实用的基准测试套件:OpenML策划分类基准测试套件2018(OpenML-CC18)。最后,我们讨论了使用案例和应用程序,这些案例和应用程序尤其展示了OpenML基准套件和OpenML-CC18的有用性。
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Many sciences have made significant breakthroughs by adopting online tools that help organize, structure and mine information that is too detailed to be printed in journals. In this paper, we introduce OpenML, a place for machine learning researchers to share and organize data in fine detail, so that they can work more effectively, be more visible, and collaborate with others to tackle harder problems. We discuss how OpenML relates to other examples of networked science and what benefits it brings for machine learning research, individual scientists, as well as students and practitioners.
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Modeling lies at the core of both the financial and the insurance industry for a wide variety of tasks. The rise and development of machine learning and deep learning models have created many opportunities to improve our modeling toolbox. Breakthroughs in these fields often come with the requirement of large amounts of data. Such large datasets are often not publicly available in finance and insurance, mainly due to privacy and ethics concerns. This lack of data is currently one of the main hurdles in developing better models. One possible option to alleviating this issue is generative modeling. Generative models are capable of simulating fake but realistic-looking data, also referred to as synthetic data, that can be shared more freely. Generative Adversarial Networks (GANs) is such a model that increases our capacity to fit very high-dimensional distributions of data. While research on GANs is an active topic in fields like computer vision, they have found limited adoption within the human sciences, like economics and insurance. Reason for this is that in these fields, most questions are inherently about identification of causal effects, while to this day neural networks, which are at the center of the GAN framework, focus mostly on high-dimensional correlations. In this paper we study the causal preservation capabilities of GANs and whether the produced synthetic data can reliably be used to answer causal questions. This is done by performing causal analyses on the synthetic data, produced by a GAN, with increasingly more lenient assumptions. We consider the cross-sectional case, the time series case and the case with a complete structural model. It is shown that in the simple cross-sectional scenario where correlation equals causation the GAN preserves causality, but that challenges arise for more advanced analyses.
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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.
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AASM准则是为了有一种常用的方法,旨在标准化睡眠评分程序的数十年努力的结果。该指南涵盖了从技术/数字规格(例如,推荐的EEG推导)到相应的详细睡眠评分规则到年龄的几个方面。在睡眠评分自动化的背景下,与许多其他技术相比,深度学习表现出更好的性能。通常,临床专业知识和官方准则对于支持自动睡眠评分算法在解决任务时至关重要。在本文中,我们表明,基于深度学习的睡眠评分算法可能不需要充分利用临床知识或严格遵循AASM准则。具体而言,我们证明了U-Sleep是一种最先进的睡眠评分算法,即使使用临床非申请或非规定派生,也可以解决得分任务,即使无需利用有关有关的信息,也无需利用有关有关的信息。受试者的年代年龄。我们最终加强了一个众所周知的发现,即使用来自多个数据中心的数据始终导致与单个队列上的培训相比,可以使性能更好。确实,我们表明,即使增加了单个数据队列的大小和异质性,后者仍然有效。在我们的所有实验中,我们使用了来自13个不同临床研究的28528多个多摄影研究研究。
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传统的过程挖掘技术将事件数据作为输入,其中每个事件与一个对象完全关联。对象表示过程的实例化。以对象为中心的事件数据包含与表达多个过程相互作用的多个对象关联的事件。由于传统的过程挖掘技术假设与一个对象相关的事件,因此这些技术不能应用于以对象为中心的事件数据。为了使用传统的过程挖掘技术,通过删除所有对象引用,以一种以对象为中心的事件数据来平坦。扁平过程是有损的,导致从扁平数据中提取的不准确的特征。此外,在变平时丢失了以对象事件数据的图形结构。在本文中,我们介绍了一个通用框架,用于从对象事件数据中提取和编码功能。我们在以对象为中心的事件数据上本地计算功能,从而导致准确的度量。此外,我们为这些功能提供了三个编码:基于表格,顺序和图形。尽管表格和顺序编码已在过程挖掘中大量使用,但基于图的编码是一种保留以对象事件数据结构的新技术。我们提供六种用例:为三个编码中的每个编码中的每一个提供可视化和预测用例。我们在预测用例中使用可解释的AI来显示以对象为中心的特征的实用性以及针对预测模型的基于顺序和基于图的编码的结构。
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城市规划师越来越多地使用基于深度学习的计算机视觉模型来支持塑造城市环境的决策。这样的模型预测人们如何从例如它的安全或美丽。但是,深度学习模型的黑盒本质阻碍了城市规划师,以了解哪些景观对象有助于特别高质量或低质量的城市空间感知。这项研究调查了如何使用计算机视觉模型来提取有关人们对城市空间的看法的相关政策信息。为此,我们训练了两个广泛使用的计算机视觉架构。卷积神经网络和变压器,并应用Gradcam(一种众所周知的可解释的AI技术),以突出图像区域对模型的预测很重要。使用这些GradCAM可视化,我们手动注释与模型的感知预测相关的对象。结果,我们能够发现以前研究中用于注释的当前对象检测模型中未表示的新对象。此外,我们的方法论结果表明,变压器架构更适合与GARGCAM技术结合使用。代码可在GitHub上找到。
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