大脑通过其复杂的尖峰网络的网络有效地执行非线性计算,但这是如何难以捉摸的。虽然可以在尖峰神经网络中成功实现非线性计算,但这需要监督培训,并且产生的连接可能很难解释。相反,可以用尖峰编码网络(SCN)框架直接导出和理解线性动力系统形式的任何计算的所需连通性。这些网络还具有生物学上的现实活动模式,对细胞死亡具有高度稳健的。在这里,我们将SCN框架扩展到直接实施任何多项式动态系统,而无需培训。这导致需要混合突触类型(快速,慢,乘法)的网络,我们术语乘以乘法峰值编码网络(MSCN)。使用MSCN,我们演示了如何直接导出几个非线性动态系统所需的连通性。我们还展示了如何执行高阶多项式,其中耦合网络仅使用配对乘法突触,并为每个突触类型提供预期的连接数。总体而言,我们的作品展示了一种新的用于在尖峰神经网络中实现非线性计算的新方法,同时保持标准SCNS(鲁棒性,现实活动模式和可解释连接)的吸引力特征。最后,我们讨论了我们方法的生物合理性,以及这种方法的高准确度和鲁棒性如何对神经形态计算感兴趣。
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A popular approach to creating a zero-shot cross-language retrieval model is to substitute a monolingual pretrained language model in the retrieval model with a multilingual pretrained language model such as Multilingual BERT. This multilingual model is fined-tuned to the retrieval task with monolingual data such as English MS MARCO using the same training recipe as the monolingual retrieval model used. However, such transferred models suffer from mismatches in the languages of the input text during training and inference. In this work, we propose transferring monolingual retrieval models using adapters, a parameter-efficient component for a transformer network. By adding adapters pretrained on language tasks for a specific language with task-specific adapters, prior work has shown that the adapter-enhanced models perform better than fine-tuning the entire model when transferring across languages in various NLP tasks. By constructing dense retrieval models with adapters, we show that models trained with monolingual data are more effective than fine-tuning the entire model when transferring to a Cross Language Information Retrieval (CLIR) setting. However, we found that the prior suggestion of replacing the language adapters to match the target language at inference time is suboptimal for dense retrieval models. We provide an in-depth analysis of this discrepancy between other cross-language NLP tasks and CLIR.
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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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Granular jamming has recently become popular in soft robotics with widespread applications including industrial gripping, surgical robotics and haptics. Previous work has investigated the use of various techniques that exploit the nature of granular physics to improve jamming performance, however this is generally underrepresented in the literature compared to its potential impact. We present the first research that exploits vibration-based fluidisation actively (e.g., during a grip) to elicit bespoke performance from granular jamming grippers. We augment a conventional universal gripper with a computer-controllled audio exciter, which is attached to the gripper via a 3D printed mount, and build an automated test rig to allow large-scale data collection to explore the effects of active vibration. We show that vibration in soft jamming grippers can improve holding strength. In a series of studies, we show that frequency and amplitude of the waveforms are key determinants to performance, and that jamming performance is also dependent on temporal properties of the induced waveform. We hope to encourage further study focused on active vibrational control of jamming in soft robotics to improve performance and increase diversity of potential applications.
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Context-sensitive two-point layer 5 pyramidal cells (L5PCs) were discovered as long ago as 1999. However, the potential of this discovery to provide useful neural computation has yet to be demonstrated. Here we show for the first time how a transformative L5PCs-driven deep neural network (DNN), termed the multisensory cooperative computing (MCC) architecture, can effectively process large amounts of heterogeneous real-world audio-visual (AV) data, using far less energy compared to best available 'point' neuron-driven DNNs. A novel highly-distributed parallel implementation on a Xilinx UltraScale+ MPSoC device estimates energy savings up to 245759 $ \times $ 50000 $\mu$J (i.e., 62% less than the baseline model in a semi-supervised learning setup) where a single synapse consumes $8e^{-5}\mu$J. In a supervised learning setup, the energy-saving can potentially reach up to 1250x less (per feedforward transmission) than the baseline model. The significantly reduced neural activity in MCC leads to inherently fast learning and resilience against sudden neural damage. This remarkable performance in pilot experiments demonstrates the embodied neuromorphic intelligence of our proposed cooperative L5PC that receives input from diverse neighbouring neurons as context to amplify the transmission of most salient and relevant information for onward transmission, from overwhelmingly large multimodal information utilised at the early stages of on-chip training. Our proposed approach opens new cross-disciplinary avenues for future on-chip DNN training implementations and posits a radical shift in current neuromorphic computing paradigms.
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Density based representations of atomic environments that are invariant under Euclidean symmetries have become a widely used tool in the machine learning of interatomic potentials, broader data-driven atomistic modelling and the visualisation and analysis of materials datasets.The standard mechanism used to incorporate chemical element information is to create separate densities for each element and form tensor products between them. This leads to a steep scaling in the size of the representation as the number of elements increases. Graph neural networks, which do not explicitly use density representations, escape this scaling by mapping the chemical element information into a fixed dimensional space in a learnable way. We recast this approach as tensor factorisation by exploiting the tensor structure of standard neighbour density based descriptors. In doing so, we form compact tensor-reduced representations whose size does not depend on the number of chemical elements, but remain systematically convergeable and are therefore applicable to a wide range of data analysis and regression tasks.
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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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Colbert-X是跨语言信息检索(CLIR)的密集检索模型。在克里尔(Clir)中,文档是用一种自然语言编写的,而查询则以另一种语言表示。相关任务是多语言IR(MLIR),该系统在其中创建了以多种语言编写的单个文档列表。鉴于Colbert-X依赖于预审慎的多语言神经语言模型对文档进行排名,因此,多语言培训程序可以使Colbert-X版本适合MLIR。本文描述了培训程序。良好MLIR排名的一个重要因素是使用混合语言批次进行微调XLM-R,其中相同的查询与同一批次中不同语言的文档匹配。MS MARCO通道的神经机器翻译用于微调模型。
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机器学习,特别是深度学习方法在许多模式识别和数据处理问题,游戏玩法中都优于人类的能力,现在在科学发现中也起着越来越重要的作用。机器学习在分子科学中的关键应用是通过使用密度函数理论,耦合群或其他量子化学方法获得的电子schr \“ odinger方程的Ab-Initio溶液中的势能表面或力场。我们回顾了一种最新和互补的方法:使用机器学习来辅助从第一原理中直接解决量子化学问题。具体来说,我们专注于使用神经网络ANSATZ功能的量子蒙特卡洛(QMC)方法,以解决电子SCHR \ “ Odinger方程在第一和第二量化中,计算场和激发态,并概括多个核构型。与现有的量子化学方法相比,这些新的深QMC方法具有以相对适度的计算成本生成高度准确的Schr \“ Odinger方程的溶液。
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目的:在存在相误差的情况下恢复QSM一直具有挑战性,这可能是由于脑出血和钙化病例的噪声或局部易感性变化引起的。我们为QSM提出了贝叶斯公式,其中使用两个组分的高斯混合分布来对长尾噪声(误差)分布进行建模,并设计具有自动和适应性参数估计的近似消息传递(AMP)算法。理论:敏感性图的小波系数遵循拉普拉斯分布。测量噪声遵循两个组分的高斯混合分布,其中第二高斯组件对噪声异常值进行了建模。分布参数被视为未知变量,并使用AMP共同恢复了易感性。方法:分别将具有参数估计的AMP与最新的非线性L1-QSM和MEDI方法进行比较,分别采用了L1-norm和L2-norm数据输入项。这三种方法对来自QSM挑战2.0的SIM2SNR1数据进行了测试,即健康和出血扫描中的体内数据。结果:在模拟的SIM2SNR1数据集上,AMP-PE达到了最低的NRMSE和SSIM,MEDI达到了最低的HFEN,并且在各种本地评估指标方面,每种方法都具有自己的强大诉讼。在体内数据集上,AMP-PE比L1-QSM和MEDI更好地保存结构细节和删除条纹伪像。结论:通过利用定制的高斯混合噪声,AMP-PE可以在涉及出血和钙化的具有挑战性的QSM病例上取得更好的性能。它配备了内置参数估计,从而避免了体内重建的通常视觉微调步骤的主观偏差。
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