我们提出了一种算法,以估计反向和前向kullback-leibler差异的路径梯度,以明显可逆地归一流。与标准的总梯度估计器相比,所得的路径梯度估计器可直接实施,具有较低的差异,不仅可以提高训练的速度更快,而且导致总体近似结果更好。我们还证明,路径梯度训练不太容易受到模式折叠的影响。鉴于我们的结果,我们期望路径梯度估计器将成为训练归一化流量的新标准方法。
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最近的工作已经为简单的高斯分布建立了一个路径梯度估计量,并认为该路径梯度在变化分布接近确切目标分布的状态下尤其有益。但是,在许多应用中,这种制度无法通过简单的高斯分布来达到。在这项工作中,我们通过提出一个途径梯度估计量来克服这一关键限制,以使连续归一化流的表达性变异家族更加表现力。我们概述了一种有效的算法来计算该估计器并通过经验建立其出色的性能。
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State-of-the-art language models are often accurate on many question-answering benchmarks with well-defined questions. Yet, in real settings questions are often unanswerable without asking the user for clarifying information. We show that current SotA models often do not ask the user for clarification when presented with imprecise questions and instead provide incorrect answers or "hallucinate". To address this, we introduce CLAM, a framework that first uses the model to detect ambiguous questions, and if an ambiguous question is detected, prompts the model to ask the user for clarification. Furthermore, we show how to construct a scalable and cost-effective automatic evaluation protocol using an oracle language model with privileged information to provide clarifying information. We show that our method achieves a 20.15 percentage point accuracy improvement over SotA on a novel ambiguous question-answering answering data set derived from TriviaQA.
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Compartmental models are a tool commonly used in epidemiology for the mathematical modelling of the spread of infectious diseases, with their most popular representative being the Susceptible-Infected-Removed (SIR) model and its derivatives. However, current SIR models are bounded in their capabilities to model government policies in the form of non-pharmaceutical interventions (NPIs) and weather effects and offer limited predictive power. More capable alternatives such as agent based models (ABMs) are computationally expensive and require specialized hardware. We introduce a neural network augmented SIR model that can be run on commodity hardware, takes NPIs and weather effects into account and offers improved predictive power as well as counterfactual analysis capabilities. We demonstrate our models improvement of the state-of-the-art modeling COVID-19 in Austria during the 03.2020 to 03.2021 period and provide an outlook for the future up to 01.2024.
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Convolutional neural networks (CNN) define the state-of-the-art solution on many perceptual tasks. However, current CNN approaches largely remain vulnerable against adversarial perturbations of the input that have been crafted specifically to fool the system while being quasi-imperceptible to the human eye. In recent years, various approaches have been proposed to defend CNNs against such attacks, for example by model hardening or by adding explicit defence mechanisms. Thereby, a small "detector" is included in the network and trained on the binary classification task of distinguishing genuine data from data containing adversarial perturbations. In this work, we propose a simple and light-weight detector, which leverages recent findings on the relation between networks' local intrinsic dimensionality (LID) and adversarial attacks. Based on a re-interpretation of the LID measure and several simple adaptations, we surpass the state-of-the-art on adversarial detection by a significant margin and reach almost perfect results in terms of F1-score for several networks and datasets. Sources available at: https://github.com/adverML/multiLID
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在本文中,我们考虑了通过风险最小化监督学习中变异模型的问题。我们的目标是通过双层优化和通过算法展开对学习变异模型的两种方法进行更深入的了解。前者将变分模型视为低于风险最小化问题的较低级别优化问题,而后者将较低级别优化问题替换为解决上述问题的算法。两种方法都在实践中使用,但是从计算的角度来看,展开要简单得多。为了分析和比较两种方法,我们考虑了一个简单的玩具模型,并明确计算所有风险和各自的估计器。我们表明,展开可能比双重优化方法更好,而且展开的性能可以显着取决于进一步的参数,有时会以意外的方式:虽然展开的算法的步骤大小很重要,但展开的迭代数量只有很重要如果数字是偶数或奇数,并且这两种情况截然不同。
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我们提出了一种使用合理的心形和现实外观合成心脏MR图像的方法,目的是生成标记的数据进行深度学习(DL)训练。它将图像合成分解为标签变形和标签到图像翻译任务。前者是通过VAE模型中的潜在空间插值来实现的,而后者是通过条件GAN模型完成的。我们设计了一种在受过训练的VAE模型的潜在空间中的标记操纵方法,即病理合成,旨在合成一系列具有所需心脏病特征的伪病理合成受试者。此外,我们建议通过估计潜在矢量之间的相关系数矩阵来对2D切片之间的关系进行建模,并利用它在解码到图像空间之前将样品随机绘制的元素关联。这种简单而有效的方法导致从2D片段产生3D一致的受试者。这种方法可以提供一种解决方案,以多样化和丰富心脏MR图像的可用数据库,并为开发基于DL的图像分析算法的开发铺平道路。该代码将在https://github.com/sinaamirrajab/cardiacpathologysynthesis中找到。
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收集和注释面向任务的对话框数据很困难,尤其是对于需要专家知识的高度特定领域。同时,非正式的沟通渠道(例如即时使者)在工作中越来越多地使用。这导致了许多与工作相关的信息,这些信息通过这些渠道传播,需要由员工进行后处理。为了减轻这个问题,我们提出了TexPrax,这是一种消息传递系统,以收集和注释与工作有关的聊天中发生的问题,原因和解决方案。 TexPrax使用聊天机器人直接吸引员工,以提供对话的轻量级注释并简化文档工作。为了遵守数据隐私和安全法规,我们使用端到端消息加密,并使用户完全控制其数据,该数据比常规注释工具具有各种优势。我们与德国工厂员工一起在用户研究中评估TexPrax,他们要求同事提供有关日常工作中出现的问题的解决方案。总体而言,我们收集201个面向任务的德语对话,其中包含1,027个句子,并带有句子级专家注释。我们的数据分析还表明,现实世界对话经常包含具有代码转换,对同一实体的缩写的实例,以及NLP系统应该能够处理的方言。
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生成对抗网络(GAN)是图像合成的艺术状态。在这里,我们提出了DAPI2CK,这是一种基于GAN的新型方法,用于合成细胞角蛋白(CK)在非小细胞肺癌(NSCLC)图像中的免疫荧光(IF)DAPI染色中染色。我们使用合成CK来细分上皮区域,与专家注释相比,该区域与染色CK的分割相同的结果相同。考虑到(MIF)面板(MIF)中的标记数量有限,我们的方法允许另一个标记物替换CK,以解决肿瘤微环境(TME)的复杂性,以促进患者选择免疫疗法。与染色的CK相反,DAPI2CK不会遭受诸如非特异性CK染色或肿瘤CK表达丧失之类的问题。
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对于基于MR物理学的模拟,对虚拟心脏MR图像的数据库进行了极大的兴趣,以开发深度学习分析网络。但是,这种数据库的使用受到限制或由于现实差距,缺失纹理以及模拟图像的简化外观而显示出次优性能。在这项工作中,我们1)在虚拟XCAT主题上提供不同的解剖学模拟,以及2)提出SIM2Real翻译网络以改善图像现实主义。我们的可用性实验表明,SIM2REAL数据具有增强训练数据并提高分割算法的性能的良好潜力。
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