在许多学科中,在大量解释变量中推断反应变量的直接因果父母的问题具有很高的实际意义。但是,建立的方法通常至少会随着解释变量的数量而呈指数级扩展,难以扩展到非线性关系,并且很难扩展到周期性数据。受{\ em Debiased}机器学习方法的启发,我们研究了一种单Vs.-the-Rest特征选择方法,以发现响应的直接因果父母。我们提出了一种用于纯观测数据的算法,同时还提供理论保证,包括可能在周期存在下的部分非线性关系的情况。由于它仅需要对每个变量进行一个估计,因此我们的方法甚至适用于大图。与既定方法相比,我们证明了显着改善。
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In addition to its public health crisis, COVID-19 pandemic has led to the shutdown and closure of workplaces with an estimated total cost of more than $16 trillion. Given the long hours an average person spends in buildings and indoor environments, this research article proposes data-driven control strategies to design optimal indoor airflow to minimize the exposure of occupants to viral pathogens in built environments. A general control framework is put forward for designing an optimal velocity field and proximal policy optimization, a reinforcement learning algorithm is employed to solve the control problem in a data-driven fashion. The same framework is used for optimal placement of disinfectants to neutralize the viral pathogens as an alternative to the airflow design when the latter is practically infeasible or hard to implement. We show, via simulation experiments, that the control agent learns the optimal policy in both scenarios within a reasonable time. The proposed data-driven control framework in this study will have significant societal and economic benefits by setting the foundation for an improved methodology in designing case-specific infection control guidelines that can be realized by affordable ventilation devices and disinfectants.
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Computer vision and machine learning are playing an increasingly important role in computer-assisted diagnosis; however, the application of deep learning to medical imaging has challenges in data availability and data imbalance, and it is especially important that models for medical imaging are built to be trustworthy. Therefore, we propose TRUDLMIA, a trustworthy deep learning framework for medical image analysis, which adopts a modular design, leverages self-supervised pre-training, and utilizes a novel surrogate loss function. Experimental evaluations indicate that models generated from the framework are both trustworthy and high-performing. It is anticipated that the framework will support researchers and clinicians in advancing the use of deep learning for dealing with public health crises including COVID-19.
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Existing statistical methods can be used to estimate a policy, or a mapping from covariates to decisions, which can then instruct decision makers. There is great interest in using such data-driven policies in healthcare. In healthcare, however, it is often important to explain to the healthcare provider, and to the patient, how a new policy differs from the current standard of care. This end is facilitated if one can pinpoint the aspects (i.e., parameters) of the policy that change most when moving from the standard of care to the new, suggested policy. To this end, we adapt ideas from Trust Region Policy Optimization. In our work, however, unlike in Trust Region Policy Optimization, the difference between the suggested policy and standard of care is required to be sparse, aiding with interpretability. In particular, we trade off between maximizing expected reward and minimizing the $L_1$ norm divergence between the parameters of the two policies. This yields "relative sparsity," where, as a function of a tuning parameter, $\lambda$, we can approximately control the number of parameters in our suggested policy that differ from their counterparts in the standard of care. We develop our methodology for the observational data setting. We propose a problem-specific criterion for selecting $\lambda$, perform simulations, and illustrate our method with a real, observational healthcare dataset, deriving a policy that is easy to explain in the context of the current standard of care. Our work promotes the adoption of data-driven decision aids, which have great potential to improve health outcomes.
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Considering the spectral properties of images, we propose a new self-attention mechanism with highly reduced computational complexity, up to a linear rate. To better preserve edges while promoting similarity within objects, we propose individualized processes over different frequency bands. In particular, we study a case where the process is merely over low-frequency components. By ablation study, we show that low frequency self-attention can achieve very close or better performance relative to full frequency even without retraining the network. Accordingly, we design and embed novel plug-and-play modules to the head of a CNN network that we refer to as FsaNet. The frequency self-attention 1) takes low frequency coefficients as input, 2) can be mathematically equivalent to spatial domain self-attention with linear structures, 3) simplifies token mapping ($1\times1$ convolution) stage and token mixing stage simultaneously. We show that the frequency self-attention requires $87.29\% \sim 90.04\%$ less memory, $96.13\% \sim 98.07\%$ less FLOPs, and $97.56\% \sim 98.18\%$ in run time than the regular self-attention. Compared to other ResNet101-based self-attention networks, FsaNet achieves a new state-of-the-art result ($83.0\%$ mIoU) on Cityscape test dataset and competitive results on ADE20k and VOCaug.
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由于临床实践所需的放射学报告和研究是在自由文本叙述中编写和存储的,因此很难提取相对信息进行进一步分析。在这种情况下,自然语言处理(NLP)技术可以促进自动信息提取和自由文本格式转换为结构化数据。近年来,基于深度学习(DL)的模型已适用于NLP实验,并具有令人鼓舞的结果。尽管基于人工神经网络(ANN)和卷积神经网络(CNN)的DL模型具有显着潜力,但这些模型仍面临临床实践中实施的一些局限性。变形金刚是另一种新的DL体系结构,已越来越多地用于改善流程。因此,在这项研究中,我们提出了一种基于变压器的细粒命名实体识别(NER)架构,以进行临床信息提取。我们以自由文本格式收集了88次腹部超声检查报告,并根据我们开发的信息架构进行了注释。文本到文本传输变压器模型(T5)和covive是T5模型的预训练域特异性适应性,用于微调来提取实体和关系,并将输入转换为结构化的格式。我们在这项研究中基于变压器的模型优于先前应用的方法,例如基于Rouge-1,Rouge-2,Rouge-L和BLEU分别为0.816、0.668、0.528和0.743的ANN和CNN模型,同时提供了一个分数可解释的结构化报告。
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基于深度学习的图生成方法具有显着的图形数据建模能力,从而使它们能够解决广泛的现实世界问题。使这些方法能够在生成过程中考虑不同的条件,甚至通过授权它们生成满足所需标准的新图形样本来提高其有效性。本文提出了一种条件深图生成方法,称为SCGG,该方法考虑了特定类型的结构条件。具体而言,我们提出的SCGG模型采用初始子图,并自动重新收获在给定条件子结构之上生成新节点及其相应的边缘。 SCGG的体系结构由图表表示网络和自动回归生成模型组成,该模型是端到端训练的。使用此模型,我们可以解决图形完成,这是恢复缺失的节点及其相关的部分观察图的猖and固有的困难问题。合成数据集和现实世界数据集的实验结果证明了我们方法的优势与最先进的基准相比。
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尽管大量研究专门用于变形检测,但大多数研究都无法推广其在训练范式之外的变形面。此外,最近的变体检测方法非常容易受到对抗攻击的影响。在本文中,我们打算学习一个具有高概括的变体检测模型,以对各种形态攻击和对不同的对抗攻击的高度鲁棒性。为此,我们开发了卷积神经网络(CNN)和变压器模型的合奏,以同时受益于其能力。为了提高整体模型的鲁棒精度,我们采用多扰动对抗训练,并生成具有高可传递性的对抗性示例。我们详尽的评估表明,提出的强大合奏模型将概括为几个变形攻击和面部数据集。此外,我们验证了我们的稳健集成模型在超过最先进的研究的同时,对几次对抗性攻击获得了更好的鲁棒性。
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在本文中,我们试图在抽象嵌入空间中绘制额叶和轮廓面图像之间的连接。我们使用耦合编码器网络利用此连接将额叶/配置文件的面部图像投影到一个常见的潜在嵌入空间中。提出的模型通过最大化面部两种视图之间的相互信息来迫使嵌入空间中表示的相似性。拟议的耦合编码器从三个贡献中受益于与极端姿势差异的匹配面。首先,我们利用我们的姿势意识到的对比学习来最大程度地提高身份额叶和概况表示之间的相互信息。其次,由在过去的迭代中积累的潜在表示组成的内存缓冲区已集成到模型中,因此它可以比小批量大小相对较多的实例。第三,一种新颖的姿势感知的对抗结构域适应方法迫使模型学习从轮廓到额叶表示的不对称映射。在我们的框架中,耦合编码器学会了扩大真实面孔和冒名顶替面部分布之间的边距,这导致了相同身份的不同观点之间的高度相互信息。通过对四个基准数据集的广泛实验,评估和消融研究来研究拟议模型的有效性,并与引人入胜的最新算法进行比较。
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尽管对抗性和自然训练(AT和NT)之间有基本的区别,但在方法中,通常采用动量SGD(MSGD)进行外部优化。本文旨在通过研究AT中外部优化的忽视作用来分析此选择。我们的探索性评估表明,与NT相比,在诱导较高的梯度规范和方差。由于MSGD的收敛速率高度取决于梯度的方差,因此这种现象阻碍了AT的外部优化。为此,我们提出了一种称为ENGM的优化方法,该方法将每个输入示例对平均微型批次梯度的贡献进行正规化。我们证明ENGM的收敛速率与梯度的方差无关,因此适合AT。我们介绍了一种技巧,可以使用有关梯度范围W.R.T.规范的相关性的经验观察来降低ENGM的计算成本。网络参数和输入示例。我们对CIFAR-10,CIFAR-100和Tinyimagenet的广泛评估和消融研究表明,Engm及其变体一致地改善了广泛的AT方法的性能。此外,Engm减轻了AT的主要缺点,包括强大的过度拟合和对超参数设置的敏感性。
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