集体行为在动物王国范围内普遍存在。然而,迄今为止,集体行为的发展和机械基础尚未正式建立。什么学会机制推动新生动物中集体行为的发展?在这里,我们使用了深度增强学习和好奇心驱动的学习 - 深深植根于心理和神经科学研究的两种学习机制 - 建立开发集体行为的新生人工代理。像新生动物一样,我们的代理商学习来自自然主义环境中的原始感官投入的集体行为。我们的代理商还学习没有外部奖励的集体行为,只使用内在的动机(好奇心)来推动学习。具体而言,当我们在具有组织中的自然视觉环境中提高人工剂时,该代理自发地发展为自我运动,对象识别,以及对组织的偏好,迅速学习集体行为所需的所有核心技能。这项工作桥接了高维感官输入和集体动作之间的划分,导致了集体动物行为的像素与动作模型。更一般地说,我们表明,两个通用学习机制 - 深度加强学习和好奇心驱动的学习 - 足以学习来自无监督的自然体验的集体行为。
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Computational catalysis is playing an increasingly significant role in the design of catalysts across a wide range of applications. A common task for many computational methods is the need to accurately compute the minimum binding energy - the adsorption energy - for an adsorbate and a catalyst surface of interest. Traditionally, the identification of low energy adsorbate-surface configurations relies on heuristic methods and researcher intuition. As the desire to perform high-throughput screening increases, it becomes challenging to use heuristics and intuition alone. In this paper, we demonstrate machine learning potentials can be leveraged to identify low energy adsorbate-surface configurations more accurately and efficiently. Our algorithm provides a spectrum of trade-offs between accuracy and efficiency, with one balanced option finding the lowest energy configuration, within a 0.1 eV threshold, 86.63% of the time, while achieving a 1387x speedup in computation. To standardize benchmarking, we introduce the Open Catalyst Dense dataset containing nearly 1,000 diverse surfaces and 87,045 unique configurations.
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高斯工艺(GPS)是贝叶斯非参数模型,由于其准确性和天然不确定性定量(UQ),因此在各种应用中流行。调整GP超参数对于确保预测准确性和不确定性的有效性至关重要。独特地估计多个超参数,例如Matern内核也可能是一个重大挑战。此外,大规模数据集中的培训GPS是一个高度活跃的研究领域:传统的最大似然超参数训练需要二次记忆以形成协方差矩阵并具有立方训练的复杂性。为了解决可扩展的超参数调整问题,我们提出了一种新型算法,该算法估算了Matern内核中的平滑度和长度尺度参数,以提高所得预测不确定性的鲁棒性。使用与超参数估计算法MUYGPS提供的计算框架中的合并预测算法相似的新型损失函数,我们在数值实验中证明了高度可伸缩性,同时保持了高度可伸缩性。
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While the brain connectivity network can inform the understanding and diagnosis of developmental dyslexia, its cause-effect relationships have not yet enough been examined. Employing electroencephalography signals and band-limited white noise stimulus at 4.8 Hz (prosodic-syllabic frequency), we measure the phase Granger causalities among channels to identify differences between dyslexic learners and controls, thereby proposing a method to calculate directional connectivity. As causal relationships run in both directions, we explore three scenarios, namely channels' activity as sources, as sinks, and in total. Our proposed method can be used for both classification and exploratory analysis. In all scenarios, we find confirmation of the established right-lateralized Theta sampling network anomaly, in line with the temporal sampling framework's assumption of oscillatory differences in the Theta and Gamma bands. Further, we show that this anomaly primarily occurs in the causal relationships of channels acting as sinks, where it is significantly more pronounced than when only total activity is observed. In the sink scenario, our classifier obtains 0.84 and 0.88 accuracy and 0.87 and 0.93 AUC for the Theta and Gamma bands, respectively.
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Recent advances in upper limb prostheses have led to significant improvements in the number of movements provided by the robotic limb. However, the method for controlling multiple degrees of freedom via user-generated signals remains challenging. To address this issue, various machine learning controllers have been developed to better predict movement intent. As these controllers become more intelligent and take on more autonomy in the system, the traditional approach of representing the human-machine interface as a human controlling a tool becomes limiting. One possible approach to improve the understanding of these interfaces is to model them as collaborative, multi-agent systems through the lens of joint action. The field of joint action has been commonly applied to two human partners who are trying to work jointly together to achieve a task, such as singing or moving a table together, by effecting coordinated change in their shared environment. In this work, we compare different prosthesis controllers (proportional electromyography with sequential switching, pattern recognition, and adaptive switching) in terms of how they present the hallmarks of joint action. The results of the comparison lead to a new perspective for understanding how existing myoelectric systems relate to each other, along with recommendations for how to improve these systems by increasing the collaborative communication between each partner.
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The promise of Mobile Health (mHealth) is the ability to use wearable sensors to monitor participant physiology at high frequencies during daily life to enable temporally-precise health interventions. However, a major challenge is frequent missing data. Despite a rich imputation literature, existing techniques are ineffective for the pulsative signals which comprise many mHealth applications, and a lack of available datasets has stymied progress. We address this gap with PulseImpute, the first large-scale pulsative signal imputation challenge which includes realistic mHealth missingness models, an extensive set of baselines, and clinically-relevant downstream tasks. Our baseline models include a novel transformer-based architecture designed to exploit the structure of pulsative signals. We hope that PulseImpute will enable the ML community to tackle this significant and challenging task.
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The NASA Astrophysics Data System (ADS) is an essential tool for researchers that allows them to explore the astronomy and astrophysics scientific literature, but it has yet to exploit recent advances in natural language processing. At ADASS 2021, we introduced astroBERT, a machine learning language model tailored to the text used in astronomy papers in ADS. In this work we: - announce the first public release of the astroBERT language model; - show how astroBERT improves over existing public language models on astrophysics specific tasks; - and detail how ADS plans to harness the unique structure of scientific papers, the citation graph and citation context, to further improve astroBERT.
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Community detection is the task of discovering groups of nodes sharing similar patterns within a network. With recent advancements in deep learning, methods utilizing graph representation learning and deep clustering have shown great results in community detection. However, these methods often rely on the topology of networks (i) ignoring important features such as network heterogeneity, temporality, multimodality, and other possibly relevant features. Besides, (ii) the number of communities is not known a priori and is often left to model selection. In addition, (iii) in multimodal networks all nodes are assumed to be symmetrical in their features; while true for homogeneous networks, most of the real-world networks are heterogeneous where feature availability often varies. In this paper, we propose a novel framework (named MGTCOM) that overcomes the above challenges (i)--(iii). MGTCOM identifies communities through multimodal feature learning by leveraging a new sampling technique for unsupervised learning of temporal embeddings. Importantly, MGTCOM is an end-to-end framework optimizing network embeddings, communities, and the number of communities in tandem. In order to assess its performance, we carried out an extensive evaluation on a number of multimodal networks. We found out that our method is competitive against state-of-the-art and performs well in inductive inference.
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我们提供了证据表明,学到的密度功能理论(``dft')的力场已准备好进行基态催化剂发现。我们的关键发现是,尽管预测的力与地面真相有很大差异,但使用从超过50 \%的评估系统中使用RPBE功能的能量与使用RPBE功能相似或较低能量的力量的力量与使用RPBE功能相似或较低的力量放松。这具有令人惊讶的含义,即学习的潜力可能已经准备好在挑战性的催化系统中替换DFT,例如在Open Catalyst 2020数据集中发现的电位。此外,我们表明,在局部谐波能量表面上具有与目标DFT能量相同的局部谐波能量表面训练的力场也能够在50 \%的情况下找到较低或相似的能量结构。与在真实能量和力量训练的标准模型相比,这种``简易电位''的收敛步骤更少,这进一步加速了计算。它的成功说明了一个关键:即使模型具有高力误差,学到的电位也可以定位能量最小值。结构优化的主要要求仅仅是学到的电位具有正确的最小值。由于学到的电位与系统大小的速度快速且尺寸为线性,因此我们的结果开辟了快速找到大型系统基础状态的可能性。
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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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