已经开发了各种方法来结合多组结果的推理,以在集合和共识聚类文献中进行无监督的聚类。从几个候选聚类模型中的一个“最佳”模型报告结果的方法通常忽略了由模型选择产生的不确定性,并且导致对所选择的特定模型和参数敏感的推论,以及制作的假设,尤其是在小样本中所做的假设。尺寸或小簇尺寸。贝叶斯模型平均(BMA)是一种在多种模型中结合结果的流行方法,这些模型在这种情况下提供了一些有吸引力的好处,包括对组合集群结构的概率解释和基于模型的不确定性的量化。在这项工作中,我们介绍了ClusterBMA,该方法可以通过多种无监督聚类算法进行加权模型平均。我们将聚类内部验证标准的组合用作后验模型概率的新近似值,以加权每个模型的结果。从代表跨模型的聚类溶液的加权平均值的组合后相似性矩阵,我们应用对称的单纯形矩阵分解来计算最终的概率群集分配。此方法在随附的R软件包中实现。我们通过案例研究探索这种方法的性能,该案例研究旨在根据脑电图(EEG)数据识别个体的概率簇。我们还使用仿真数据集探索所提出的技术识别稳健的集成簇具有不同级别的集成簇,并在子组之间的分离水平变化,并且模型之间的簇数量变化。
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A Digital Twin (DT) is a simulation of a physical system that provides information to make decisions that add economic, social or commercial value. The behaviour of a physical system changes over time, a DT must therefore be continually updated with data from the physical systems to reflect its changing behaviour. For resource-constrained systems, updating a DT is non-trivial because of challenges such as on-board learning and the off-board data transfer. This paper presents a framework for updating data-driven DTs of resource-constrained systems geared towards system health monitoring. The proposed solution consists of: (1) an on-board system running a light-weight DT allowing the prioritisation and parsimonious transfer of data generated by the physical system; and (2) off-board robust updating of the DT and detection of anomalous behaviours. Two case studies are considered using a production gas turbine engine system to demonstrate the digital representation accuracy for real-world, time-varying physical systems.
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Evaluating neural network performance is critical to deep neural network design but a costly procedure. Neural predictors provide an efficient solution by treating architectures as samples and learning to estimate their performance on a given task. However, existing predictors are task-dependent, predominantly estimating neural network performance on image classification benchmarks. They are also search-space dependent; each predictor is designed to make predictions for a specific architecture search space with predefined topologies and set of operations. In this paper, we propose a novel All-in-One Predictor (AIO-P), which aims to pretrain neural predictors on architecture examples from multiple, separate computer vision (CV) task domains and multiple architecture spaces, and then transfer to unseen downstream CV tasks or neural architectures. We describe our proposed techniques for general graph representation, efficient predictor pretraining and knowledge infusion techniques, as well as methods to transfer to downstream tasks/spaces. Extensive experimental results show that AIO-P can achieve Mean Absolute Error (MAE) and Spearman's Rank Correlation (SRCC) below 1% and above 0.5, respectively, on a breadth of target downstream CV tasks with or without fine-tuning, outperforming a number of baselines. Moreover, AIO-P can directly transfer to new architectures not seen during training, accurately rank them and serve as an effective performance estimator when paired with an algorithm designed to preserve performance while reducing FLOPs.
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Predicting neural architecture performance is a challenging task and is crucial to neural architecture design and search. Existing approaches either rely on neural performance predictors which are limited to modeling architectures in a predefined design space involving specific sets of operators and connection rules, and cannot generalize to unseen architectures, or resort to zero-cost proxies which are not always accurate. In this paper, we propose GENNAPE, a Generalized Neural Architecture Performance Estimator, which is pretrained on open neural architecture benchmarks, and aims to generalize to completely unseen architectures through combined innovations in network representation, contrastive pretraining, and fuzzy clustering-based predictor ensemble. Specifically, GENNAPE represents a given neural network as a Computation Graph (CG) of atomic operations which can model an arbitrary architecture. It first learns a graph encoder via Contrastive Learning to encourage network separation by topological features, and then trains multiple predictor heads, which are soft-aggregated according to the fuzzy membership of a neural network. Experiments show that GENNAPE pretrained on NAS-Bench-101 can achieve superior transferability to 5 different public neural network benchmarks, including NAS-Bench-201, NAS-Bench-301, MobileNet and ResNet families under no or minimum fine-tuning. We further introduce 3 challenging newly labelled neural network benchmarks: HiAML, Inception and Two-Path, which can concentrate in narrow accuracy ranges. Extensive experiments show that GENNAPE can correctly discern high-performance architectures in these families. Finally, when paired with a search algorithm, GENNAPE can find architectures that improve accuracy while reducing FLOPs on three families.
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To analyze this characteristic of vulnerability, we developed an automated deep learning method for detecting microvessels in intravascular optical coherence tomography (IVOCT) images. A total of 8,403 IVOCT image frames from 85 lesions and 37 normal segments were analyzed. Manual annotation was done using a dedicated software (OCTOPUS) previously developed by our group. Data augmentation in the polar (r,{\theta}) domain was applied to raw IVOCT images to ensure that microvessels appear at all possible angles. Pre-processing methods included guidewire/shadow detection, lumen segmentation, pixel shifting, and noise reduction. DeepLab v3+ was used to segment microvessel candidates. A bounding box on each candidate was classified as either microvessel or non-microvessel using a shallow convolutional neural network. For better classification, we used data augmentation (i.e., angle rotation) on bounding boxes with a microvessel during network training. Data augmentation and pre-processing steps improved microvessel segmentation performance significantly, yielding a method with Dice of 0.71+/-0.10 and pixel-wise sensitivity/specificity of 87.7+/-6.6%/99.8+/-0.1%. The network for classifying microvessels from candidates performed exceptionally well, with sensitivity of 99.5+/-0.3%, specificity of 98.8+/-1.0%, and accuracy of 99.1+/-0.5%. The classification step eliminated the majority of residual false positives, and the Dice coefficient increased from 0.71 to 0.73. In addition, our method produced 698 image frames with microvessels present, compared to 730 from manual analysis, representing a 4.4% difference. When compared to the manual method, the automated method improved microvessel continuity, implying improved segmentation performance. The method will be useful for research purposes as well as potential future treatment planning.
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这项工作描述了使用配备有单个向上的鱼眼相机和背光的移动校准机器人,该机器人的自动注册(约40个)固定网络(约40个)的固定,天花板安装的环境相机(约800平方米)的自动注册(约800平方米) Aruco标记以容易检测。 Fisheye摄像头用于进行视觉进程(VO),Aruco标记有助于在环境摄像机中轻松检测校准机器人。此外,鱼眼摄像机还能够检测到环境相机。这个双向双向检测限制了环境摄像机的姿势以解决优化问题。这种方法可用于自动注册用于监视,自动停车或机器人应用的大型多摄像机系统。这种基于VO的多机登记方法是使用现实世界实验进行了广泛验证的,并且还与使用LIDAR的类似方法进行了比较,该方法使用LIDAR(一种昂贵,更重,更重,饥饿的传感器)。
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微分方程用于多种学科,描述了物理世界的复杂行为。这些方程式的分析解决方案通常很难求解,从而限制了我们目前求解复杂微分方程的能力,并需要将复杂的数值方法近似于解决方案。训练有素的神经网络充当通用函数近似器,能够以新颖的方式求解微分方程。在这项工作中,探索了神经网络算法在数值求解微分方程方面的方法和应用,重点是不同的损失函数和生物应用。传统损失函数和训练参数的变化显示出使神经网络辅助解决方案更有效的希望,从而可以调查更复杂的方程式管理生物学原理。
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与人类类似,动物的面部表情与情绪状态紧密相关。但是,与人类领域相反,动物面部表情对情绪状态的自动识别是没有充满反应的,这主要是由于数据收集和建立地面真相的困难,涉及非语言用户的情绪状态。我们将最近的深度学习技术应用于在受控的实验环境中收集的数据集上对狗的挫败进行分类和(负面)的挫败感。我们探索在此任务的不同监督下不同骨干(例如,重新连接,VIT)的适用性,并发现自我监督的预定的VIT(DINO-VIT)的特征优于其他替代方案。据我们所知,这项工作是第一个解决对受控实验中获得的数据自动分类的任务。
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在过去的三十年中,结构性健康监测(SHM)一直是一个活跃的研究领域,并且在此期间积累了许多关键进展,如文献所示。但是,由于损害状态数据,操作和环境波动,可重复性问题以及边界条件的变化,SHM仍然面临挑战。这些问题在被捕获的功能中是不一致的,并且可能会对实际实施产生巨大影响,但更重要的是对技术的概括。基于人群的SHM旨在通过使用从相似结构组收集的数据对缺失信息进行建模和传输信息来解决其中的一些问题。在这项工作中,从四个健康的,名义上相同的全尺度复合直升机叶片收集了振动数据。制造差异(例如,几何形状和/或材料属性的略有差异),在其结构动力学上显示为可变性,这对于基于振动数据的机器学习而对SHM来说可能非常有问题。这项工作旨在通过使用高斯过程的混合物来定义叶片的频率响应函数的通用模型来解决此变异性。
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心房颤动的计算模型已成功地用于预测最佳消融部位。评估消融模式的效果的关键步骤是从不同,潜在的随机的位置加速模型以确定是否可以在ATRIA中诱导心律失常。在这项工作中,我们建议使用黎曼歧管的多保真高斯过程分类,以有效地确定心律失常是诱导性诱导的区域内的区域。我们构建一个直接在心房表面上运行的概率分类器。我们利用较低的分辨率模型来探索心房表面,并与高分辨率模型无缝结合,以识别诱导区域。当用40个样本培训时,我们的多保真性分级器显示了比使用作为基线心房颤动模型的最近邻分类器的均衡精度,并且在心房颤动的情况下具有9%。我们希望这种新技术将允许更快,更精确地对心房颤动的计算模型临床应用。
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