Regularising the parameter matrices of neural networks is ubiquitous in training deep models. Typical regularisation approaches suggest initialising weights using small random values, and to penalise weights to promote sparsity. However, these widely used techniques may be less effective in certain scenarios. Here, we study the Koopman autoencoder model which includes an encoder, a Koopman operator layer, and a decoder. These models have been designed and dedicated to tackle physics-related problems with interpretable dynamics and an ability to incorporate physics-related constraints. However, the majority of existing work employs standard regularisation practices. In our work, we take a step toward augmenting Koopman autoencoders with initialisation and penalty schemes tailored for physics-related settings. Specifically, we propose the "eigeninit" initialisation scheme that samples initial Koopman operators from specific eigenvalue distributions. In addition, we suggest the "eigenloss" penalty scheme that penalises the eigenvalues of the Koopman operator during training. We demonstrate the utility of these schemes on two synthetic data sets: a driven pendulum and flow past a cylinder; and two real-world problems: ocean surface temperatures and cyclone wind fields. We find on these datasets that eigenloss and eigeninit improves the convergence rate by up to a factor of 5, and that they reduce the cumulative long-term prediction error by up to a factor of 3. Such a finding points to the utility of incorporating similar schemes as an inductive bias in other physics-related deep learning approaches.
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对黑暗时代和系外行星(Farside)进行无线电科学调查的遥远阵列是对Lunar Far Side的拟议任务概念,试图在100正方形的区域内部署和操作128双极化的阵列,偶极天线公里。所得的干涉射电望远镜将提供遥远恒星系统的前所未有的无线电图像,从而可以研究冠状质量弹出和能量颗粒事件的微弱无线电特征,还可以导致在其母星的居住区内检测到磁层周围的磁层。同时,Farside还将在一系列红移(z大约50-100)中以全球21厘米信号的全局信号来测量早期宇宙的“黑暗年龄”。阵列中的每个离散天线节点都通过通信和电源系绳连接到中央集线器(位于降落器)。节点是由Cold =可操作的电子设备驱动的,该电子设备连续监测极宽的频率(200 kHz至40 MHz),该频率超过了基于地球的望远镜的能力,该望远镜的功能由两个数量级。实现这种开创性的能力需要在月球表面上制定强大的部署策略,这对于现有高的TRL技术(演示或正在积极发展)是可行的,并且能够在下一代商业地面上传递到地​​表,例如蓝色Origin的蓝月亮着陆器。本文介绍了一种天线包装,放置和表面部署贸易研究,该研究利用了NASA的Jet Propuls实验室开发的束缚移动机器人的最新进展,该机器人用于部署平坦的,天线隔离的,带有光学通信和电源传输的磁带。功能。
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语言模型既展示了定量的改进,又展示了新的定性功能,随着规模的增加。尽管它们具有潜在的变革性影响,但这些新能力的特征却很差。为了为未来的研究提供信息,为破坏性的新模型能力做准备,并改善社会有害的效果,至关重要的是,我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战,我们介绍了超越模仿游戏基准(Big Bench)。 Big Bench目前由204个任务组成,由132家机构的442位作者贡献。任务主题是多样的,从语言学,儿童发展,数学,常识性推理,生物学,物理学,社会偏见,软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号,Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为,跨越了数百万到数十亿个参数。此外,一个人类专家评估者团队执行了所有任务,以提供强大的基准。研究结果包括:模型性能和校准都随规模改善,但绝对的术语(以及与评估者的性能相比);在模型类中的性能非常相似,尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分,而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标;社交偏见通常会随着含糊不清的环境而随着规模而增加,但这可以通过提示来改善。
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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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Cryo Focused Ion-Beam Scanning Electron Microscopy (cryo FIB-SEM) enables three-dimensional and nanoscale imaging of biological specimens via a slice and view mechanism. The FIB-SEM experiments are, however, limited by a slow (typically, several hours) acquisition process and the high electron doses imposed on the beam sensitive specimen can cause damage. In this work, we present a compressive sensing variant of cryo FIB-SEM capable of reducing the operational electron dose and increasing speed. We propose two Targeted Sampling (TS) strategies that leverage the reconstructed image of the previous sample layer as a prior for designing the next subsampling mask. Our image recovery is based on a blind Bayesian dictionary learning approach, i.e., Beta Process Factor Analysis (BPFA). This method is experimentally viable due to our ultra-fast GPU-based implementation of BPFA. Simulations on artificial compressive FIB-SEM measurements validate the success of proposed methods: the operational electron dose can be reduced by up to 20 times. These methods have large implications for the cryo FIB-SEM community, in which the imaging of beam sensitive biological materials without beam damage is crucial.
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Many current approaches to machine learning in particle physics use generic architectures that require large numbers of parameters and disregard underlying physics principles, limiting their applicability as scientific modeling tools. In this work, we present a machine learning architecture that uses a set of inputs maximally reduced with respect to the full 6-dimensional Lorentz symmetry, and is fully permutation-equivariant throughout. We study the application of this network architecture to the standard task of top quark tagging and show that the resulting network outperforms all existing competitors despite much lower model complexity. In addition, we present a Lorentz-covariant variant of the same network applied to a 4-momentum regression task.
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对于空中机器人来说,以快速而健壮的方式倒置着陆是一项艰巨的壮举,尤其是完全取决于板载感应和计算。尽管如此,这项壮举通常由蝙蝠,苍蝇和蜜蜂等生物传单进行。我们以前的工作已经确定了一系列板载视觉提示与运动学动作之间的直接因果关系,这些关系允许在小型空中机器人中可靠地执行这种具有挑战性的特技操纵。在这项工作中,我们首先利用深入的强化学习和基于物理的模拟来获得从任何任意方法条件开始的一般最佳控制策略,以实现强大的倒置着陆。这项优化的控制策略提供了从系统的观察空间到其电动机命令动作空间的计算效率映射,包括触发和控制旋转操作。这是通过训练系统在大量和方向变化的大量进式飞行速度上进行训练。接下来,我们通过在仿真中改变了机器人的惯性参数,通过域随机化对学习策略进行了模拟策略的传输和实验验证。通过实验试验,我们确定了几个主要因素,这些因素极大地改善了着陆鲁棒性和确定倒置成功的主要机制。我们希望这项研究中开发的学习框架可以推广以解决更具挑战性的任务,例如利用嘈杂的板载感觉数据,降落在各种方向的表面上或降落在动态移动的表面上。
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超越地球轨道的人类空间勘探将涉及大量距离和持续时间的任务。为了有效减轻无数空间健康危害,数据和空间健康系统的范式转移是实现地球独立性的,而不是Earth-Reliance所必需的。有希望在生物学和健康的人工智能和机器学习领域的发展可以解决这些需求。我们提出了一个适当的自主和智能精密空间健康系统,可以监控,汇总和评估生物医学状态;分析和预测个性化不良健康结果;适应并响应新累积的数据;并提供对其船员医务人员的个人深度空间机组人员和迭代决策支持的预防性,可操作和及时的见解。在这里,我们介绍了美国国家航空航天局组织的研讨会的建议摘要,以便在太空生物学和健康中未来的人工智能应用。在未来十年,生物监测技术,生物标志科学,航天器硬件,智能软件和简化的数据管理必须成熟,并编织成精确的空间健康系统,以使人类在深空中茁壮成长。
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空间生物学研究旨在了解太空飞行对生物的根本影响,制定支持深度空间探索的基础知识,最终生物工程航天器和栖息地稳定植物,农作物,微生物,动物和人类的生态系统,为持续的多行星寿命稳定。要提高这些目标,该领域利用了来自星空和地下模拟研究的实验,平台,数据和模型生物。由于研究扩展到低地球轨道之外,实验和平台必须是最大自主,光,敏捷和智能化,以加快知识发现。在这里,我们介绍了由美国国家航空航天局的人工智能,机器学习和建模应用程序组织的研讨会的建议摘要,这些应用程序为这些空间生物学挑战提供了关键解决方案。在未来十年中,将人工智能融入太空生物学领域将深化天空效应的生物学理解,促进预测性建模和分析,支持最大自主和可重复的实验,并有效地管理星载数据和元数据,所有目标使生活能够在深空中茁壮成长。
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像Astrobee机器人一样的空间自由传单,目前正在运营的国际空间站必须与固有的系统不确定性运行。像质量和惯性矩等的参数不确定性对于量化在这些安全关键空间系统中的量化尤为重要,并且可以在轨道货物运动等场景中改变,其中未知的擒讨的有效载荷显着改变了系统动态。谨慎地学习这些不确定性,途径可能会避免时间和燃料消耗的纯系统识别演习。认识到这一点,这项工作提出了一种在线信息感知运动规划算法,该拨浪鼓明确地将参数模型 - 学习与实时重新扫描能力相结合,可以利用改进的系统模型。该方法包括双层(全局和本地)策划仪,一个低级模型预测控制器和在线参数估计器,可以为机器人的惯性属性进行估算,以便在飞行中重新打倒;所有级别的规划和控制都具有在线更新的模型。 Astrobee自由传单争夺不确定有效载荷的频道的仿真结果与硬件演示的结果展示了明确鼓励模型参数学习的能力,同时实现其他有用的运动。
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