有限的角度X射线断层扫描重建是一个不良反问题一般。特别是当投影角度有限并且在光子限制条件下进行测量时,来自经典算法的重建,例如过滤的反光,可能导致由于缺失的问题而获取伪影。为了获得令人满意的重建结果,通常在重建算法中结合在重建算法中的令人满意的重建结果,例如总变化最小化和非局部图像相似度。在这项工作中,我们介绍了深度神经网络,以确定并应用重建过程的先前分配。我们的神经网络直接从合成训练样本中学习。因此,神经网络获得了对我们对重建感兴趣的对象类的特定的先前分配。特别是,我们使用了具有3D卷积层和3D注意图层的深生成的模型,这些层在来自DubBed电路库的3D合成集成电路(IC)数据上培训。我们证明,当投影角度和光子预算受到限制时,来自我们深度生成模型的前沿可以显着提高合成数据的IC重建质量,而与最大似然估计相比。使用电路库的合成IC数据训练深度生成模型说明了从机器学习之前学到的学习功能。我们预计,如果使用实验数据再现过程,机器学习的优势将持续存在。机器学习在有限角X射线断层扫描的优点可以进一步能够在低光子纳米级成像中实现应用。
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左心室(LV)功能是心脏病患者的患者管理,结局和长期存活方面的重要因素。最近发表的心力衰竭临床指南认识到,仅依赖一种心脏功能(LV射血分数)作为诊断和治疗分层生物标志物的依赖是次优。基于AI的超声心动图分析的最新进展已在LV体积和LV射血分数的自动估计上显示出良好的结果。但是,从随时间变化的2D超声心动图摄取,可以通过从完整的心脏周期中估算功能性生物标志物来获得对心脏功能的更丰富的描述。在这项工作中,我们首次提出了一种基于全心脏周期分割的2D超声心动图的AI方法,用于从2D超声心动图中得出高级生物标志物。这些生物标志物将允许临床医生获得健康和疾病中心脏的丰富图片。 AI模型基于“ NN-UNET”框架,并使用四个不同的数据库进行了训练和测试。结果表明,手动分析和自动分析之间的一致性很高,并展示了晚期收缩期和舒张期生物标志物在患者分层中的潜力。最后,对于50例病例的子集,我们在超声心动图和CMR的临床生物标志物之间进行了相关分析,我们在两种方式之间表现出了极好的一致性。
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与痴呆症相关的认知障碍(CI)在全球范围内影响超过5500万人,并且每3秒钟以一个新病例的速度迅速增长。随着临床试验反复出现的失败,早期诊断至关重要,但是在低水平和中等收入国家中,全球75%的痴呆症病例未被诊断为90%。众所周知,当前的诊断方法是复杂的,涉及对医学笔记,大量认知测试,昂贵的脑部扫描或脊柱液体测试的手动审查。与CI相关的信息经常在电子健康记录(EHR)中找到,并且可以为早期诊断提供重要线索,但是专家的手动审查是繁琐的,并且容易发生。该项目开发了一种新型的最新自动筛选管道,用于可扩展和高速发现EHR中的CI。为了了解EHR中复杂语言结构的语言环境,构建了一个8,656个序列的数据库,以训练基于注意力的深度学习自然语言处理模型以对序列进行分类。使用序列级别分类器开发了基于逻辑回归的患者级别预测模型。深度学习系统的精度达到了93%,AUC = 0.98,以识别其EHR中没有较早诊断,与痴呆有关的诊断代码或与痴呆有关的药物的患者。否则,这些患者将未被发现或检测到太晚。 EHR筛选管道已部署在Neurahealthnlp中,这是一种用于自动化和实时CI筛选的Web应用程序,只需将EHR上传到浏览器中即可。 Neurahealthnlp更便宜,更快,更容易获得,并且胜过当前的临床方法,包括基于文本的分析和机器学习方法。它使得早期诊断可在稀缺的医疗服务中可行,但可访问的互联网或蜂窝服务。
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痴呆症是一种神经退行性疾病,导致认知下降,并影响全世界超过5000万人。痴呆症是由医疗保健专业人士诊断的 - 只有患有痴呆症的四个人中只有一名诊断出来。即使制造诊断,也可能无法作为患者图表中的疾病(ICD)诊断码的结构化国际分类。与认知障碍(CI)有关的信息通常在电子健康记录(EHR)中发现,但专家临床医生票据的手工审查既耗时,往往容易出错。本票据的自动化挖掘为在EHR数据中标记有认知障碍患者的机会。我们开发了自然语言处理(NLP)工具,以识别具有认知障碍的患者,并证明语言背景提高了认知障碍分类任务的性能。我们微调我们的注意力深入学习模型,可以从复杂的语言结构中学习,并且相对于基线NLP模型的精度(0.93)大大提高(0.84)。此外,我们表明深度学习NLP可以成功识别没有痴呆相关的ICD代码或药物的痴呆症患者。
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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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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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The existing methods for video anomaly detection mostly utilize videos containing identifiable facial and appearance-based features. The use of videos with identifiable faces raises privacy concerns, especially when used in a hospital or community-based setting. Appearance-based features can also be sensitive to pixel-based noise, straining the anomaly detection methods to model the changes in the background and making it difficult to focus on the actions of humans in the foreground. Structural information in the form of skeletons describing the human motion in the videos is privacy-protecting and can overcome some of the problems posed by appearance-based features. In this paper, we present a survey of privacy-protecting deep learning anomaly detection methods using skeletons extracted from videos. We present a novel taxonomy of algorithms based on the various learning approaches. We conclude that skeleton-based approaches for anomaly detection can be a plausible privacy-protecting alternative for video anomaly detection. Lastly, we identify major open research questions and provide guidelines to address them.
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The Government of Kerala had increased the frequency of supply of free food kits owing to the pandemic, however, these items were static and not indicative of the personal preferences of the consumers. This paper conducts a comparative analysis of various clustering techniques on a scaled-down version of a real-world dataset obtained through a conjoint analysis-based survey. Clustering carried out by centroid-based methods such as k means is analyzed and the results are plotted along with SVD, and finally, a conclusion is reached as to which among the two is better. Once the clusters have been formulated, commodities are also decided upon for each cluster. Also, clustering is further enhanced by reassignment, based on a specific cluster loss threshold. Thus, the most efficacious clustering technique for designing a food kit tailored to the needs of individuals is finally obtained.
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