我们展示了任何具有自由度和局部自由能的系统如何在自由能原理的限制下,都将发展朝着支持层次结构计算的神经形态形态发展,在该计算中,每个层次结构的每个级别都会构成其投入的粗糙度。,并双重地将其输出的细粒度。这种层次结构发生在整个生物学中,从细胞内信号转导途径的体系结构到哺乳动物大脑中的感知和动作周期的大规模组织。正式地,一方面,锥体 - 康基图(CCCD)作为量子参考帧的模型,另一方面是CCCDS和拓扑量子场理论之间的近距离形式连接,允许在全剂量量子中代表此类计算拓扑量子神经网络的计算框架。
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Purpose: The aim of this study was to demonstrate the utility of unsupervised domain adaptation (UDA) in automated knee osteoarthritis (OA) phenotype classification using a small dataset (n=50). Materials and Methods: For this retrospective study, we collected 3,166 three-dimensional (3D) double-echo steady-state magnetic resonance (MR) images from the Osteoarthritis Initiative dataset and 50 3D turbo/fast spin-echo MR images from our institute (in 2020 and 2021) as the source and target datasets, respectively. For each patient, the degree of knee OA was initially graded according to the MRI Osteoarthritis Knee Score (MOAKS) before being converted to binary OA phenotype labels. The proposed UDA pipeline included (a) pre-processing, which involved automatic segmentation and region-of-interest cropping; (b) source classifier training, which involved pre-training phenotype classifiers on the source dataset; (c) target encoder adaptation, which involved unsupervised adaption of the source encoder to the target encoder and (d) target classifier validation, which involved statistical analysis of the target classification performance evaluated by the area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy. Additionally, a classifier was trained without UDA for comparison. Results: The target classifier trained with UDA achieved improved AUROC, sensitivity, specificity and accuracy for both knee OA phenotypes compared with the classifier trained without UDA. Conclusion: The proposed UDA approach improves the performance of automated knee OA phenotype classification for small target datasets by utilising a large, high-quality source dataset for training. The results successfully demonstrated the advantages of the UDA approach in classification on small datasets.
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我们提出了一种新颖的方法,可以将3D人类动画放入3D场景中,同时保持动画中的任何人类场景相互作用。我们使用计算动画中最重要的网格的概念,以与场景进行交互,我们称之为“键框”。这些关键框架使我们能够更好地优化动画在场景中的位置,从而使动画中的互动(站立,铺设,坐着等)与场景的负担相匹配(例如,站在地板上或躺在床上)。我们将我们称为PAAK的方法与先前的方法进行了比较,包括POSA,Prox地面真理和运动合成方法,并通过感知研究突出了我们方法的好处。人类评估者更喜欢我们的PAAK方法,而不是Prox地面真相数据64.6 \%。此外,在直接比较中,与POSA相比,评估者比竞争方法比包括61.5%的竞争方法更喜欢PAAK。
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在不完整的数据集中对样本进行分类是机器学习从业人员的普遍目的,但并非平凡。在大多数现实世界数据集中发现缺失的数据,这些缺失值通常是使用已建立的方法估算的,然后进行分类现在完成,估算的样本。然后,机器学习研究人员的重点是优化下游分类性能。在这项研究中,我们强调必须考虑插补的质量。我们展示了如何评估质量的常用措施有缺陷,并提出了一类新的差异评分,这些分数着重于该方法重新创建数据的整体分布的程度。总而言之,我们强调了使用不良数据训练的分类器模型的可解释性损害。
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深层生成模型已成为检测数据中任意异常的有前途的工具,并分配了手动标记的必要性。最近,自回旋变压器在医学成像中取得了最先进的性能。但是,这些模型仍然具有一些内在的弱点,例如需要将图像建模为1D序列,在采样过程中误差的积累以及与变压器相关的显着推理时间。去核扩散概率模型是一类非自动回旋生成模型,最近显示出可以在计算机视觉中产生出色的样品(超过生成的对抗网络),并实现与变压器具有竞争力同时具有快速推理时间的对数可能性。扩散模型可以应用于自动编码器学到的潜在表示,使其易于扩展,并适用于高维数据(例如医学图像)的出色候选者。在这里,我们提出了一种基于扩散模型的方法,以检测和分段脑成像中的异常。通过在健康数据上训练模型,然后探索其在马尔可夫链上的扩散和反向步骤,我们可以识别潜在空间中的异常区域,因此可以确定像素空间中的异常情况。我们的扩散模型与一系列具有2D CT和MRI数据的实验相比,具有竞争性能,涉及合成和实际病理病变,推理时间大大减少,从而使它们的用法在临床上可行。
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历史流程表现出显着的多样性。尽管如此,学者们长期以来一直试图识别模式,并将历史行动者分类和对一些成功的影响。随机过程框架提供了一种结构化方法,用于分析大型历史数据集,允许检测有时令人惊讶的模式,鉴定内源性和外源对过程的相关因果作用者,以及不同历史案例的比较。随机过程的数据,分析工具和组织理论框架的组合使历史和考古中的传统叙事方法补充了传统的叙事方法。
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通过捕获来自宽频率范围的光谱数据以及空间信息,高光谱成像(HSI)可以检测温度,水分和化学成分方面的微小差异。因此,HSI已成功应用于各种应用,包括遥感安全和防御,植被和作物监测,食品/饮料和药品质量控制的精密农业。然而,对于碳纤维增强聚合物(CFRP)中的病症监测和损伤检测,HSI的使用是一个相对未受破坏的区域,因为现有的非破坏性测试(NDT)技术主要集中在提供有关结构的物理完整性但不对的信息材料组成。为此,HSI可以提供一种独特的方法来解决这一挑战。在本文中,通过使用近红外HSI相机,介绍了HSI对CFRP产品的非破坏性检查的应用,以EU H2020 FibreeUSE项目为背景。详细介绍了三种案例研究的技术挑战和解决方案,包括粘合剂残留检测,表面损伤检测和基于COBOT的自动检查。实验结果充分展示了HSI的巨大潜力和CFRP的NDT的相关视觉技术,特别是满足工业制造环境的潜力。
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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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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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This paper presents a machine learning approach to multidimensional item response theory (MIRT), a class of latent factor models that can be used to model and predict student performance from observed assessment data. Inspired by collaborative filtering, we define a general class of models that includes many MIRT models. We discuss the use of penalized joint maximum likelihood (JML) to estimate individual models and cross-validation to select the best performing model. This model evaluation process can be optimized using batching techniques, such that even sparse large-scale data can be analyzed efficiently. We illustrate our approach with simulated and real data, including an example from a massive open online course (MOOC). The high-dimensional model fit to this large and sparse dataset does not lend itself well to traditional methods of factor interpretation. By analogy to recommender-system applications, we propose an alternative "validation" of the factor model, using auxiliary information about the popularity of items consulted during an open-book exam in the course.
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