尽管电子健康记录是生物医学研究的丰富数据来源,但这些系统并未在医疗环境中统一地实施,并且由于医疗保健碎片化和孤立的电子健康记录之间缺乏互操作性,可能缺少大量数据。考虑到缺少数据的案例的删除可能会在随后的分析中引起严重的偏见,因此,一些作者更喜欢采用多重插补策略来恢复缺失的信息。不幸的是,尽管几项文献作品已经通过使用现在可以自由研究的任何不同的多个归档算法记录了有希望的结果,但尚无共识,MI算法效果最好。除了选择MI策略之外,归纳算法及其应用程序设置的选择也至关重要且具有挑战性。在本文中,受鲁宾和范布伦的开创性作品的启发,我们提出了一个方法学框架,可以应用于评估和比较多种多个插补技术,旨在选择用于计算临床研究工作中最有效的推断。我们的框架已被应用于验证和扩展较大的队列,这是我们在先前的文献研究中提出的结果,我们在其中评估了关键患者的描述符和Covid-19的影响在2型糖尿病患者中的影响,其数据为2型糖尿病,其数据为2型糖尿病由国家共同队列合作飞地提供。
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我们展示了一个“物理增强的深替代(”PEDS“)方法朝着部分微分方程(PDE)和类似型号描述的复杂物理系统开发快速替代模型:我们展示了如何结合低保真”粗“求解器对于产生“赋予促进”输入的神经网络,培训端到端以全局匹配昂贵的高保真数值求解器的输出。通过这种方式,通过在低保真模型的形式中纳入有限的物理知识,我们发现可以使用比“黑匣子”神经网络的数据至少为$ \ SIM 10 \倍。出于相同的准确性。渐近的,PED似乎与黑匣子代理人一起学习,并且在与主动学习结合时,甚至进一步利益。我们通过使用电磁散射中的示例问题展示了所提出的方法的可行性和益处出现在光学超材料的设计中。
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Since early in the coronavirus disease 2019 (COVID-19) pandemic, there has been interest in using artificial intelligence methods to predict COVID-19 infection status based on vocal audio signals, for example cough recordings. However, existing studies have limitations in terms of data collection and of the assessment of the performances of the proposed predictive models. This paper rigorously assesses state-of-the-art machine learning techniques used to predict COVID-19 infection status based on vocal audio signals, using a dataset collected by the UK Health Security Agency. This dataset includes acoustic recordings and extensive study participant meta-data. We provide guidelines on testing the performance of methods to classify COVID-19 infection status based on acoustic features and we discuss how these can be extended more generally to the development and assessment of predictive methods based on public health datasets.
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This white paper lays out a vision of research and development in the field of artificial intelligence for the next decade (and beyond). Its denouement is a cyber-physical ecosystem of natural and synthetic sense-making, in which humans are integral participants$\unicode{x2014}$what we call ''shared intelligence''. This vision is premised on active inference, a formulation of adaptive behavior that can be read as a physics of intelligence, and which inherits from the physics of self-organization. In this context, we understand intelligence as the capacity to accumulate evidence for a generative model of one's sensed world$\unicode{x2014}$also known as self-evidencing. Formally, this corresponds to maximizing (Bayesian) model evidence, via belief updating over several scales: i.e., inference, learning, and model selection. Operationally, this self-evidencing can be realized via (variational) message passing or belief propagation on a factor graph. Crucially, active inference foregrounds an existential imperative of intelligent systems; namely, curiosity or the resolution of uncertainty. This same imperative underwrites belief sharing in ensembles of agents, in which certain aspects (i.e., factors) of each agent's generative world model provide a common ground or frame of reference. Active inference plays a foundational role in this ecology of belief sharing$\unicode{x2014}$leading to a formal account of collective intelligence that rests on shared narratives and goals. We also consider the kinds of communication protocols that must be developed to enable such an ecosystem of intelligences and motivate the development of a shared hyper-spatial modeling language and transaction protocol, as a first$\unicode{x2014}$and key$\unicode{x2014}$step towards such an ecology.
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在不失去先前学习的情况下学习新任务和技能(即灾难性遗忘)是人为和生物神经网络的计算挑战,但是人工系统努力与其生物学类似物达成平等。哺乳动物的大脑采用众多神经手术来支持睡眠期间的持续学习。这些是人工适应的成熟。在这里,我们研究了建模哺乳动物睡眠的三个不同组成部分如何影响人工神经网络中的持续学习:(1)在非比型眼运动(NREM)睡眠期间观察到的垂直记忆重播过程; (2)链接到REM睡眠的生成记忆重播过程; (3)已提出的突触降压过程,以调整信噪比和支持神经保养。在评估持续学习CIFAR-100图像分类基准上的性能时,我们发现将所有三个睡眠组件的包含在内。在以后的任务期间,训练和灾难性遗忘在训练过程中提高了最高准确性。尽管某些灾难性遗忘在网络培训过程中持续存在,但更高水平的突触缩减水平会导致更好地保留早期任务,并进一步促进随后培训期间早期任务准确性的恢复。一个关键的要点是,在考虑使用突触缩小范围的水平时,手头有一个权衡 - 更具侵略性的缩减更好地保护早期任务,但较少的缩减可以增强学习新任务的能力。中级水平可以在训练过程中与最高的总体精度达到平衡。总体而言,我们的结果都提供了有关如何适应睡眠组件以增强人工连续学习系统的洞察力,并突出了未来神经科学睡眠研究的领域,以进一步进一步进行此类系统。
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医疗AI通过支持基于证据的医学实践,个性化患者治疗,降低成本以及改善提供者和患者体验,推进医疗保健的巨大潜力。我们认为解锁此潜力需要一种系统的方法来衡量在大规模异构数据上的医疗AI模型的性能。为了满足这种需求,我们正在建立Medperf,这是一个开放的框架,用于在医疗领域的基准测试机器学习。 Medperf将使联合评估能够将模型安全地分配给不同的评估设施,从而赋予医疗组织在高效和人类监督过程中评估和验证AI模型的性能,同时优先考虑隐私。我们描述了当前的挑战医疗保健和AI社区面临,需要开放平台,Medperf的设计理念,其目前的实施状态和我们的路线图。我们呼吁研究人员和组织加入我们创建Medperf开放基准平台。
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Reading comprehension of legal text can be a particularly challenging task due to the length and complexity of legal clauses and a shortage of expert-annotated datasets. To address this challenge, we introduce the Merger Agreement Understanding Dataset (MAUD), an expert-annotated reading comprehension dataset based on the American Bar Association's 2021 Public Target Deal Points Study, with over 39,000 examples and over 47,000 total annotations. Our fine-tuned Transformer baselines show promising results, with models performing well above random on most questions. However, on a large subset of questions, there is still room for significant improvement. As the only expert-annotated merger agreement dataset, MAUD is valuable as a benchmark for both the legal profession and the NLP community.
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While the capabilities of autonomous systems have been steadily improving in recent years, these systems still struggle to rapidly explore previously unknown environments without the aid of GPS-assisted navigation. The DARPA Subterranean (SubT) Challenge aimed to fast track the development of autonomous exploration systems by evaluating their performance in real-world underground search-and-rescue scenarios. Subterranean environments present a plethora of challenges for robotic systems, such as limited communications, complex topology, visually-degraded sensing, and harsh terrain. The presented solution enables long-term autonomy with minimal human supervision by combining a powerful and independent single-agent autonomy stack, with higher level mission management operating over a flexible mesh network. The autonomy suite deployed on quadruped and wheeled robots was fully independent, freeing the human supervision to loosely supervise the mission and make high-impact strategic decisions. We also discuss lessons learned from fielding our system at the SubT Final Event, relating to vehicle versatility, system adaptability, and re-configurable communications.
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There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .
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Attention mechanisms form a core component of several successful deep learning architectures, and are based on one key idea: ''The output depends only on a small (but unknown) segment of the input.'' In several practical applications like image captioning and language translation, this is mostly true. In trained models with an attention mechanism, the outputs of an intermediate module that encodes the segment of input responsible for the output is often used as a way to peek into the `reasoning` of the network. We make such a notion more precise for a variant of the classification problem that we term selective dependence classification (SDC) when used with attention model architectures. Under such a setting, we demonstrate various error modes where an attention model can be accurate but fail to be interpretable, and show that such models do occur as a result of training. We illustrate various situations that can accentuate and mitigate this behaviour. Finally, we use our objective definition of interpretability for SDC tasks to evaluate a few attention model learning algorithms designed to encourage sparsity and demonstrate that these algorithms help improve interpretability.
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