非常希望知道模型的预测是多么不确定,特别是对于复杂的模型和难以理解的模型,如深度学习。虽然在扩散加权MRI中使用深度学习方法,但事先作品没有解决模型不确定性的问题。在这里,我们提出了一种深入的学习方法来估计扩散张量并计算估计不确定性。数据相关的不确定性由网络直接计算,并通过损耗衰减学习。使用Monte Carlo辍学来计算模型不确定性。我们还提出了一种评估预测不确定性的质量的新方法。我们将新方法与标准最小二乘张量估计和基于引导的不确定性计算技术进行比较。我们的实验表明,当测量数量小时,深度学习方法更准确,并且其不确定性预测比标准方法更好地校准。我们表明,新方法计算的估计不确定性可以突出显示模型的偏置,检测域移位,并反映测量中的噪声强度。我们的研究表明了基于深度学习的扩散MRI分析中建模预测不确定性的重要性和实际价值。
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胎儿肺扩散加权MRI(DWI)数据的定量分析显示,提供了提供的定量成像生物标志物,这些生物标志物间接反映了胎儿肺的成熟。但是,采集期间的胎儿运动阻碍了对获得的DWI数据的定量分析,因此妨碍了可靠的临床利用。我们介绍了QDWI-Morph,这是一种无监督的深神经网络结构,用于运动补偿定量DWI(QDWI)分析。我们的方法将注册子网络与定量DWI模型拟合子网络融合。我们同时估计QDWI参数和运动模型,通过最大程度地降低整合注册损失和模型拟合质量损失的生物形态信息损失函数。我们证明了QDWI-MORPH的附加值:1)基线QDWI分析没有运动补偿和2)仅包含注册损失的基线深学习模型。 QDWI-morph通过对胎儿肺DWI数据的体内QDWI分析(r-squared = 0.32 vs. 0.13,0.28)实现了与胎龄的相关性。我们的QDWI-MORPH有可能对DWI数据进行运动补偿的定量分析,并为非侵入性胎儿肺成熟度评估提供临床上可行的生物标志物。我们的代码可在以下网址获得:https://github.com/technioncomputationalmrilab/qdwi-morph。
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软机器人技术有可能改变机器人运动,特别是软机器人游泳者提供了一种微创和自适应的解决方案,以探索和保存我们的海洋。不幸的是,当前的软机器人游泳者非常劣于进化的生物游泳者,尤其是在可控性,效率,可操作性和寿命方面。此外,设计软机器人所需的乏味的迭代制造和经验测试阻碍了它们的优化。在这项工作中,我们通过为设计和制造配备静电驱动的软机器人游泳者提供高效且直接的管道来应对这一挑战。我们简化了允许快速增材制造的过程,并显示如何使用可区分的模拟将简化模型与机器人游泳器的真实变形匹配。我们通过改变游泳者的拮抗肌肉的电压和驱动频率来对制造的游泳者进行多个实验。我们展示了在液态油中移动时的电压和频率如何改变游泳者的运动速度,并在前进的游泳速度下观察到明显的最佳选择。我们提出的可区分模拟模型具有各种下游应用,例如游泳者的控制和形状优化;通过我们的SIM到现实匹配,可以将优化结果直接映射回真实机器人。
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对胎儿肺扩散加权MRI(DWI)的数据分析(IVIM)分析显示了提供定量成像的生物标志物的潜力,这些标志物是间接地反映出非侵入性胎儿肺肺部成熟评估的扩散和伪扩散的。然而,由于IVIM分析所需的大量不同的“ B值”图像,较长的获取时间,排除了临床可行性。我们介绍了Super-IVIM-DC一种深神经网络(DNN)方法,该方法将监督损失与数据矛盾项相结合,以实现IVIM分析以有限数量的B值获得的DWI数据。我们通过数值模拟,健康的志愿者研究和IVIM分析了胎儿DWI数据的胎儿肺成熟,从而证明了超级IVIM-DC在经典和最近的DNN方法中的附加价值。 %添加结果我们的数值模拟和健康的志愿者研究表明,与以前的基于DNN的方法相比,来自有限DWI数据的IVIM模型参数的超级IVIM-DC估计值较低。此外,与经典和基于DNN的方法相比,胎儿肺有限的DWI数据的伪扩散分数参数的超级IVIM-DC估计与胎龄相关(0.242 vs. -0.079和0.239)。 Super-IVIM-DC有可能减少与IVIM数据分析DWI数据相关的长期获取时间,并为非侵入性胎儿肺成熟度评估提供临床上可行的生物标志物。
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数据增强是自然语言处理(NLP)模型的鲁棒性评估的重要组成部分,以及增强他们培训的数据的多样性。在本文中,我们呈现NL-Cogmenter,这是一种新的参与式Python的自然语言增强框架,它支持创建两个转换(对数据的修改)和过滤器(根据特定功能的数据拆分)。我们描述了框架和初始的117个变换和23个过滤器,用于各种自然语言任务。我们通过使用其几个转换来分析流行自然语言模型的鲁棒性来证明NL-Upmenter的功效。基础架构,Datacards和稳健性分析结果在NL-Augmenter存储库上公开可用(\ url {https://github.com/gem-benchmark/nl-augmenter})。
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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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Modelling and forecasting real-life human behaviour using online social media is an active endeavour of interest in politics, government, academia, and industry. Since its creation in 2006, Twitter has been proposed as a potential laboratory that could be used to gauge and predict social behaviour. During the last decade, the user base of Twitter has been growing and becoming more representative of the general population. Here we analyse this user base in the context of the 2021 Mexican Legislative Election. To do so, we use a dataset of 15 million election-related tweets in the six months preceding election day. We explore different election models that assign political preference to either the ruling parties or the opposition. We find that models using data with geographical attributes determine the results of the election with better precision and accuracy than conventional polling methods. These results demonstrate that analysis of public online data can outperform conventional polling methods, and that political analysis and general forecasting would likely benefit from incorporating such data in the immediate future. Moreover, the same Twitter dataset with geographical attributes is positively correlated with results from official census data on population and internet usage in Mexico. These findings suggest that we have reached a period in time when online activity, appropriately curated, can provide an accurate representation of offline behaviour.
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Existing federated classification algorithms typically assume the local annotations at every client cover the same set of classes. In this paper, we aim to lift such an assumption and focus on a more general yet practical non-IID setting where every client can work on non-identical and even disjoint sets of classes (i.e., client-exclusive classes), and the clients have a common goal which is to build a global classification model to identify the union of these classes. Such heterogeneity in client class sets poses a new challenge: how to ensure different clients are operating in the same latent space so as to avoid the drift after aggregation? We observe that the classes can be described in natural languages (i.e., class names) and these names are typically safe to share with all parties. Thus, we formulate the classification problem as a matching process between data representations and class representations and break the classification model into a data encoder and a label encoder. We leverage the natural-language class names as the common ground to anchor the class representations in the label encoder. In each iteration, the label encoder updates the class representations and regulates the data representations through matching. We further use the updated class representations at each round to annotate data samples for locally-unaware classes according to similarity and distill knowledge to local models. Extensive experiments on four real-world datasets show that the proposed method can outperform various classical and state-of-the-art federated learning methods designed for learning with non-IID data.
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New architecture GPUs like A100 are now equipped with multi-instance GPU (MIG) technology, which allows the GPU to be partitioned into multiple small, isolated instances. This technology provides more flexibility for users to support both deep learning training and inference workloads, but efficiently utilizing it can still be challenging. The vision of this paper is to provide a more comprehensive and practical benchmark study for MIG in order to eliminate the need for tedious manual benchmarking and tuning efforts. To achieve this vision, the paper presents MIGPerf, an open-source tool that streamlines the benchmark study for MIG. Using MIGPerf, the authors conduct a series of experiments, including deep learning training and inference characterization on MIG, GPU sharing characterization, and framework compatibility with MIG. The results of these experiments provide new insights and guidance for users to effectively employ MIG, and lay the foundation for further research on the orchestration of hybrid training and inference workloads on MIGs. The code and results are released on https://github.com/MLSysOps/MIGProfiler. This work is still in progress and more results will be published soon.
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This is paper for the smooth function approximation by neural networks (NN). Mathematical or physical functions can be replaced by NN models through regression. In this study, we get NNs that generate highly accurate and highly smooth function, which only comprised of a few weight parameters, through discussing a few topics about regression. First, we reinterpret inside of NNs for regression; consequently, we propose a new activation function--integrated sigmoid linear unit (ISLU). Then special charateristics of metadata for regression, which is different from other data like image or sound, is discussed for improving the performance of neural networks. Finally, the one of a simple hierarchical NN that generate models substituting mathematical function is presented, and the new batch concept ``meta-batch" which improves the performance of NN several times more is introduced. The new activation function, meta-batch method, features of numerical data, meta-augmentation with metaparameters, and a structure of NN generating a compact multi-layer perceptron(MLP) are essential in this study.
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