潜在位置网络模型是网络科学的多功能工具;应用程序包括集群实体,控制因果混淆,并在未观察的图形上定义前提。估计每个节点的潜在位置通常是贝叶斯推理问题的群体,吉布斯内的大都市是最流行的近似后分布的工具。然而,众所周知,GIBBS内的大都市对于大型网络而言是低效;接受比计算成本昂贵,并且所得到的后绘高度相关。在本文中,我们提出了一个替代的马尔可夫链蒙特卡罗战略 - 使用分裂哈密顿蒙特卡罗和萤火虫蒙特卡罗的组合定义 - 利用后部分布的功能形式进行更有效的后退计算。我们展示了这些战略在吉布斯和综合网络上的其他算法中优于大都市,以及学区的教师和工作人员的真正信息共享网络。
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Kernels are efficient in representing nonlocal dependence and they are widely used to design operators between function spaces. Thus, learning kernels in operators from data is an inverse problem of general interest. Due to the nonlocal dependence, the inverse problem can be severely ill-posed with a data-dependent singular inversion operator. The Bayesian approach overcomes the ill-posedness through a non-degenerate prior. However, a fixed non-degenerate prior leads to a divergent posterior mean when the observation noise becomes small, if the data induces a perturbation in the eigenspace of zero eigenvalues of the inversion operator. We introduce a data-adaptive prior to achieve a stable posterior whose mean always has a small noise limit. The data-adaptive prior's covariance is the inversion operator with a hyper-parameter selected adaptive to data by the L-curve method. Furthermore, we provide a detailed analysis on the computational practice of the data-adaptive prior, and demonstrate it on Toeplitz matrices and integral operators. Numerical tests show that a fixed prior can lead to a divergent posterior mean in the presence of any of the four types of errors: discretization error, model error, partial observation and wrong noise assumption. In contrast, the data-adaptive prior always attains posterior means with small noise limits.
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When testing conditions differ from those represented in training data, so-called out-of-distribution (OOD) inputs can mar the reliability of black-box learned components in the modern robot autonomy stack. Therefore, coping with OOD data is an important challenge on the path towards trustworthy learning-enabled open-world autonomy. In this paper, we aim to demystify the topic of OOD data and its associated challenges in the context of data-driven robotic systems, drawing connections to emerging paradigms in the ML community that study the effect of OOD data on learned models in isolation. We argue that as roboticists, we should reason about the overall system-level competence of a robot as it performs tasks in OOD conditions. We highlight key research questions around this system-level view of OOD problems to guide future research toward safe and reliable learning-enabled autonomy.
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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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Large language models show improved downstream task performance when prompted to generate step-by-step reasoning to justify their final answers. These reasoning steps greatly improve model interpretability and verification, but objectively studying their correctness (independent of the final answer) is difficult without reliable methods for automatic evaluation. We simply do not know how often the stated reasoning steps actually support the final end task predictions. In this work, we present ROSCOE, a suite of interpretable, unsupervised automatic scores that improve and extend previous text generation evaluation metrics. To evaluate ROSCOE against baseline metrics, we design a typology of reasoning errors and collect synthetic and human evaluation scores on commonly used reasoning datasets. In contrast with existing metrics, ROSCOE can measure semantic consistency, logicality, informativeness, fluency, and factuality - among other traits - by leveraging properties of step-by-step rationales. We empirically verify the strength of our metrics on five human annotated and six programmatically perturbed diagnostics datasets - covering a diverse set of tasks that require reasoning skills and show that ROSCOE can consistently outperform baseline metrics.
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有效的缩放和灵活的任务接口使大型语言模型能够在许多任务中表现出色。帕利(Pali)根据视觉和文本输入生成文本,并使用该界面以许多语言执行许多视觉,语言和多模式任务。为了训练帕利,我们利用了大型的编码器语言模型和视觉变压器(VITS)。这使我们能够利用其现有能力,并利用培训它们的大量成本。我们发现,视觉和语言组成部分的联合缩放很重要。由于现有的语言变压器比其视觉对应物要大得多,因此我们训练迄今为止最大的VIT(VIT-E),以量化甚至大容量视觉模型的好处。为了训练Pali,我们基于一个新的图像文本训练集,其中包含10B图像和文本,以100多种语言来创建大型的多语言组合。帕利(Pali)在多个视觉和语言任务(例如字幕,视觉问题,索方式,场景文本理解)中实现了最新的,同时保留了简单,模块化和可扩展的设计。
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单细胞RNA-seq数据集的大小和复杂性正在增长,从而可以研究各种生物/临床环境中的细胞组成变化。可扩展的降低性降低技术需要消除它们的生物学变异,同时考虑技术和生物混杂因素。在这项工作中,我们扩展了一种流行的概率非线性维度降低的方法,即高斯过程潜在变量模型,以扩展到大量的单细胞数据集,同时明确考虑技术和生物混杂因素。关键思想是使用增强的内核,该内核可以保留下限的可分式性,从而允许快速随机变化推断。我们证明了其在Kumasaka等人中重建先天免疫的潜在潜在签名的能力。 (2021)训练时间较低9倍。我们进一步分析了一个共同数据集并在130个人群中证明了该框架,该框架可以在捕获可解释的感染签名的同时进行数据集成。具体而言,我们探讨了互联的严重程度,作为优化患者分层并捕获疾病特异性基因表达的潜在维度。
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我们介绍Audiolm,这是具有长期一致性高质量音频产生的框架。 Audiolm将输入音频映射到一系列离散令牌,并将音频生成作为此表示空间中的语言建模任务。我们展示了现有的音频令牌如何在重建质量和长期结构之间提供不同的权衡,我们提出了一个混合代币化计划来实现这两个目标。也就是说,我们利用在音频中预先训练的蒙版语言模型的离散激活来捕获长期结构和神经音频编解码器产生的离散代码,以实现高质量的合成。通过培训大型原始音频波形,Audiolm学会了在简短的提示下产生自然和连贯的连续性。当接受演讲训练时,没有任何笔录或注释,Audiolm会在句法和语义上产生可行的语音连续性,同时还为看不见的说话者保持说话者身份和韵律。此外,我们演示了我们的方法如何通过产生连贯的钢琴音乐连续性来超越语音,尽管受过训练而没有任何象征性的音乐代表。
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ISO 14971是用于医疗设备风险管理的主要标准。尽管它指定了医疗设备风险管理的要求,但并未指定执行风险管理的特定方法。因此,医疗设备制造商可以自由开发或使用任何适当的方法来管理医疗设备的风险。最常用的方法,例如故障树分析(FTA),无法为计算风险估计有限或没有可用的历史数据或数据对数据存在二阶不确定性时提供合理的依据。在本文中,我们使用混合贝叶斯网络(BNS)提出了一种新颖的医疗设备风险管理方法,该方法解决了经典方法(例如FTA)的局限性,并结合了影响医疗设备风险的相关因素。提出的BN方法是通用的,但可以按系统的基础进行实例化,我们将其应用于除颤器设备,以证明生产和后期生产过程中医疗设备风险管理所涉及的过程。该示例已根据现实世界数据进行验证。
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我们分析了投影随机梯度下降的行为,该梯度下降的重点是最佳的约束集边界,并且梯度不会以最佳限制消失。在这里,迭代可能会在每个步骤中取得反对目标的进展。当这种噪声上的适当力矩条件保持时,我们证明了与约束随机梯度下降最佳的收敛速率将有所不同,并且通常比无约束的随机梯度下降算法更快。我们的结果认为,最佳的浓度是指数分布的,而不是正态分布,这通常确定在不受约束的情况下的限制收敛性。我们开发的方法依赖于几何形状的证明。这将Hajek(1982)的马尔可夫链的结果扩展到了随机近似算法的区域。作为示例,我们显示了结果如何适用于线性编程和表格加固的学习。
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