在机器学习中的半监督学习(SSL)方法越来越关注在分类器的训练数据的情况下形成分类器,该分类器包括有限数量的分类观察,而是更大数量的未分类观察。这是因为由于高收购成本和随后的财务,时间和伦理问题,可以出现的经济型资金,而且可以在尝试为已经获得的未经分类数据提供真正的类标签而产生的,所以提供的分类数据的采购。我们在此提供对该问题的统计SSL方法的审查,侧重于最近的结果,即由部分分类的样本形成的分类器实际上可以具有比样本完全分类的更小的预期误差率。
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专家(MOE)模型的混合物是对数据中的异质性建模的流行框架,由于其灵活性以及可用的统计估计和模型选择工具的丰富性,用于统计和机器学习中的回归和分类问题。这种灵活性来自于允许MOE模型中的混合物重量(或门控函数)与专家(或组件密度)一起取决于解释变量。与经典的有限混合物和回归模型的有限混合物相比,这允许由更复杂的数据生成过程产生的数据建模,该过程的混合参数与协变量无关。从计算的角度来看,当解释变量的数量可能大于样本量时,MOE模型在高维度中的使用是挑战的,尤其是从理论的角度来看,文献是对于统计估计和特征选择问题,仍缺乏处理维度诅咒的结果。我们考虑具有软马克斯门控函数和高斯专家的有限MOE模型,用于在异质数据上进行高维回归,并通过Lasso进行$ L_1 $调查的估计。我们专注于拉索估计属性,而不是其特征选择属性。我们在LASSO函数的正规化参数上提供了一个下限,该参数确保了根据Kullback-Leibler损失,Lasso估算器满足了$ L_1 $ -ORACLE不平等。
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Panoptic segmentation assigns semantic and instance ID labels to every pixel of an image. As permutations of instance IDs are also valid solutions, the task requires learning of high-dimensional one-to-many mapping. As a result, state-of-the-art approaches use customized architectures and task-specific loss functions. We formulate panoptic segmentation as a discrete data generation problem, without relying on inductive bias of the task. A diffusion model based on analog bits is used to model panoptic masks, with a simple, generic architecture and loss function. By simply adding past predictions as a conditioning signal, our method is capable of modeling video (in a streaming setting) and thereby learns to track object instances automatically. With extensive experiments, we demonstrate that our generalist approach can perform competitively to state-of-the-art specialist methods in similar settings.
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尽管语言任务自然而然地以单个,统一的建模框架(即生成代币序列)表示,但在计算机视觉中并非如此。结果,对于不同的视力任务,不同的架构和损失功能的扩散。在这项工作中,我们表明,如果根据共享像素到序列界面进行配制,也可以统一一组“核心”计算机视觉任务。我们专注于四个任务,即对象检测,实例分割,关键点检测和图像字幕,所有这些任务都具有各种类型的输出,例如边界框或密集的掩码。尽管如此,通过将每个任务的输出作为具有统一界面的离散令牌的顺序,我们表明可以在所有这些任务上训练具有单个模型体系结构和损失功能的神经网络,而没有特定于任务的自定义。为了解决特定的任务,我们使用一个简短的提示作为任务说明,序列输出适应提示,以便它可以产生特定于任务的输出。我们表明,与成熟的特定任务模型相比,这种模型可以实现竞争性能。
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量子哈密顿学习和量子吉布斯采样的双重任务与物理和化学中的许多重要问题有关。在低温方案中,这些任务的算法通常会遭受施状能力,例如因样本或时间复杂性差而遭受。为了解决此类韧性,我们将量子自然梯度下降的概括引入了参数化的混合状态,并提供了稳健的一阶近似算法,即量子 - 固定镜下降。我们使用信息几何学和量子计量学的工具证明了双重任务的数据样本效率,因此首次将经典Fisher效率的开创性结果推广到变异量子算法。我们的方法扩展了以前样品有效的技术,以允许模型选择的灵活性,包括基于量子汉密尔顿的量子模型,包括基于量子的模型,这些模型可能会规避棘手的时间复杂性。我们的一阶算法是使用经典镜下降二元性的新型量子概括得出的。两种结果都需要特殊的度量选择,即Bogoliubov-Kubo-Mori度量。为了从数值上测试我们提出的算法,我们将它们的性能与现有基准进行了关于横向场ISING模型的量子Gibbs采样任务的现有基准。最后,我们提出了一种初始化策略,利用几何局部性来建模状态的序列(例如量子 - 故事过程)的序列。我们从经验上证明了它在实际和想象的时间演化的经验上,同时定义了更广泛的潜在应用。
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前列腺癌是美国男人的第二致致命癌症。虽然磁共振成像(MRI)越来越多地用于引导前列腺癌诊断的靶向活组织检查,但其效用仍然受到限制,因为假阳性和假否定的高率以及较低的读者协议。机器学习方法在前列腺MRI上检测和定位癌症可以帮助标准化放射科学诠释。然而,现有的机器学习方法不仅在模型架构中不等,而且还可以在用于模型培训的地面真理标签策略中。在这项研究中,我们比较不同的标记策略,即病理证实放射科标签,整个安装组织病理学图像上的病理学家标签,以及病变水平和像素级数字病理学家标签(先前验证了组织病理学图像上的深层学习算法以预测像素 - 整个安装组织病理学图像上的Gleason模式)。我们分析这些标签对训练有素的机器学习模型的性能的影响。我们的实验表明,用它们培训的(1)放射科标签和模型可能会错过癌症,或低估癌症程度,(2)与他们培训的数字病理学家标签和模型与病理学家标签有高度的一致性,而(3)用数字病理学家培训的模型标签在两种不同疾病分布的两种不同群组中达到最佳性能,而不管使用的模型建筑如何。数字病理学家标签可以减少与人类注释相关的挑战,包括劳动力,时间,和读者间变异性,并且可以通过使可靠的机器学习模型进行培训来检测和定位前列腺癌,帮助弥合前列腺放射学和病理学之间的差距在MRI。
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在高赌注域中的机器学习工具的实际应用通常被调节为公平,因此预测目标应该满足相对于受保护属性的奇偶校验的一些定量概念。然而,公平性和准确性之间的确切权衡并不完全清楚,即使是对分类问题的基本范式也是如此。在本文中,我们通过在任何公平分类器的群体误差之和中提供较低的界限,在分类设置中表征统计奇偶校验和准确性之间的固有权衡。我们不可能的定理可以被解释为公平的某种不确定性原则:如果基本率不同,那么符合统计奇偶校验的任何公平分类器都必须在至少一个组中产生很大的错误。我们进一步扩展了这一结果,以便在学习公平陈述的角度下给出任何(大约)公平分类者的联合误差的下限。为了表明我们的下限是紧张的,假设Oracle访问贝叶斯(潜在不公平)分类器,我们还构造了一种返回一个随机分类器的算法,这是最佳和公平的。有趣的是,当受保护的属性可以采用超过两个值时,这个下限的扩展不承认分析解决方案。然而,在这种情况下,我们表明,通过解决线性程序,我们可以通过解决我们作为电视 - 重心问题的术语,电视距离的重心问题来有效地计算下限。在上面,我们证明,如果集团明智的贝叶斯最佳分类器是关闭的,那么学习公平的表示导致公平的替代概念,称为准确性奇偶校验,这使得错误率在组之间关闭。最后,我们还在现实世界数据集上进行实验,以确认我们的理论发现。
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Sequential prediction problems such as imitation learning, where future observations depend on previous predictions (actions), violate the common i.i.d. assumptions made in statistical learning. This leads to poor performance in theory and often in practice. Some recent approaches (Daumé III et al., 2009;Ross and Bagnell, 2010) provide stronger guarantees in this setting, but remain somewhat unsatisfactory as they train either non-stationary or stochastic policies and require a large number of iterations. In this paper, we propose a new iterative algorithm, which trains a stationary deterministic policy, that can be seen as a no regret algorithm in an online learning setting. We show that any such no regret algorithm, combined with additional reduction assumptions, must find a policy with good performance under the distribution of observations it induces in such sequential settings. We demonstrate that this new approach outperforms previous approaches on two challenging imitation learning problems and a benchmark sequence labeling problem.
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We demonstrate a proof-of-concept of a large language model conducting corporate lobbying related activities. We use an autoregressive large language model (OpenAI's text-davinci-003) to determine if proposed U.S. Congressional bills are relevant to specific public companies and provide explanations and confidence levels. For the bills the model deems as relevant, the model drafts a letter to the sponsor of the bill in an attempt to persuade the congressperson to make changes to the proposed legislation. We use hundreds of ground-truth labels of the relevance of a bill to a company to benchmark the performance of the model, which outperforms the baseline of predicting the most common outcome of irrelevance. However, we test the ability to determine the relevance of a bill with the previous OpenAI GPT-3 model (text-davinci-002), which was state-of-the-art on many language tasks until text-davinci-003 was released on November 28, 2022. The performance of text-davinci-002 is worse than simply always predicting that a bill is irrelevant to a company. These results suggest that, as large language models continue to improve core natural language understanding capabilities, performance on corporate lobbying related tasks will continue to improve. We then discuss why this could be problematic for societal-AI alignment.
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In the past years, deep learning has seen an increase of usage in the domain of histopathological applications. However, while these approaches have shown great potential, in high-risk environments deep learning models need to be able to judge their own uncertainty and be able to reject inputs when there is a significant chance of misclassification. In this work, we conduct a rigorous evaluation of the most commonly used uncertainty and robustness methods for the classification of Whole-Slide-Images under domain shift using the H\&E stained Camelyon17 breast cancer dataset. Although it is known that histopathological data can be subject to strong domain shift and label noise, to our knowledge this is the first work that compares the most common methods for uncertainty estimation under these aspects. In our experiments, we compare Stochastic Variational Inference, Monte-Carlo Dropout, Deep Ensembles, Test-Time Data Augmentation as well as combinations thereof. We observe that ensembles of methods generally lead to higher accuracies and better calibration and that Test-Time Data Augmentation can be a promising alternative when choosing an appropriate set of augmentations. Across methods, a rejection of the most uncertain tiles leads to a significant increase in classification accuracy on both in-distribution as well as out-of-distribution data. Furthermore, we conduct experiments comparing these methods under varying conditions of label noise. We observe that the border regions of the Camelyon17 dataset are subject to label noise and evaluate the robustness of the included methods against different noise levels. Lastly, we publish our code framework to facilitate further research on uncertainty estimation on histopathological data.
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