While object reconstruction has made great strides in recent years, current methods typically require densely captured images and/or known camera poses, and generalize poorly to novel object categories. To step toward object reconstruction in the wild, this work explores reconstructing general real-world objects from a few images without known camera poses or object categories. The crux of our work is solving two fundamental 3D vision problems -- shape reconstruction and pose estimation -- in a unified approach. Our approach captures the synergies of these two problems: reliable camera pose estimation gives rise to accurate shape reconstruction, and the accurate reconstruction, in turn, induces robust correspondence between different views and facilitates pose estimation. Our method FORGE predicts 3D features from each view and leverages them in conjunction with the input images to establish cross-view correspondence for estimating relative camera poses. The 3D features are then transformed by the estimated poses into a shared space and are fused into a neural radiance field. The reconstruction results are rendered by volume rendering techniques, enabling us to train the model without 3D shape ground-truth. Our experiments show that FORGE reliably reconstructs objects from five views. Our pose estimation method outperforms existing ones by a large margin. The reconstruction results under predicted poses are comparable to the ones using ground-truth poses. The performance on novel testing categories matches the results on categories seen during training. Project page: https://ut-austin-rpl.github.io/FORGE/
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神经切线内核(NTK)是分析神经网络及其泛化界限的训练动力学的强大工具。关于NTK的研究已致力于典型的神经网络体系结构,但对于Hadamard产品(NNS-HP)的神经网络不完整,例如StyleGAN和多项式神经网络。在这项工作中,我们为特殊类别的NNS-HP(即多项式神经网络)得出了有限宽度的NTK公式。我们证明了它们与关联的NTK与内核回归预测变量的等效性,该预测扩大了NTK的应用范围。根据我们的结果,我们阐明了针对外推和光谱偏置,PNN在标准神经网络上的分离。我们的两个关键见解是,与标准神经网络相比,PNN能够在外推方案中拟合更复杂的功能,并承认相应NTK的特征值衰减较慢。此外,我们的理论结果可以扩展到其他类型的NNS-HP,从而扩大了我们工作的范围。我们的经验结果验证了更广泛的NNS-HP类别的分离,这为对神经体系结构有了更深入的理解提供了良好的理由。
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我们研究(选定的)宽,狭窄,深而浅,较浅,懒惰和非懒惰的训练环境中(选定的)深度神经网络中的平均鲁棒性概念。我们证明,在参数不足的环境中,宽度具有负面影响,而在过度参数化的环境中提高了鲁棒性。深度的影响紧密取决于初始化和训练模式。特别是,当用LeCun初始化初始化时,深度有助于通过懒惰训练制度进行稳健性。相反,当用神经切线核(NTK)初始化并进行初始化时,深度会损害稳健性。此外,在非懒惰培训制度下,我们演示了两层relu网络的宽度如何使鲁棒性受益。我们的理论发展改善了Huang等人的结果。[2021],Wu等。[2021]与Bubeck and Sellke [2021],Bubeck等人一致。[2021]。
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神经体系结构搜索(NAS)促进了神经体系结构的自动发现,从而实现了图像识别的最新精度。尽管NAS取得了进展,但到目前为止,NAS对理论保证几乎没有关注。在这项工作中,我们研究了NAS在统一框架下的概括属性,从而实现(深)层跳过连接搜索和激活功能搜索。为此,我们从搜索空间(包括混合的激活功能,完全连接和残留的神经网络)的(包括)有限宽度方向上得出了神经切线核的最小特征值的下(和上)边界。由于在统一框架下的各种体系结构和激活功能的耦合,我们的分析是不平凡的。然后,我们利用特征值边界在随机梯度下降训练中建立NAS的概括误差界。重要的是,我们从理论上和实验上展示了衍生结果如何指导NAS,即使在没有培训的情况下,即使在没有培训的情况下,也可以根据我们的理论进行无训练的算法。因此,我们的数值验证阐明了NAS计算有效方法的设计。
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基于图像的虚拟试验是以人为中心的现实潜力,是以人为中心的图像生成的最有希望的应用之一。在这项工作中,我们迈出了一步,探索多功能的虚拟尝试解决方案,我们认为这应该具有三个主要属性,即,它们应支持无监督的培训,任意服装类别和可控的服装编辑。为此,我们提出了一个特征性的端到端网络,即用空间自适应的斑点适应性GAN ++(Pasta-gan ++),以实现用于高分辨率不合规的虚拟试验的多功能系统。具体而言,我们的意大利面++由一个创新的贴布贴片的拆卸模块组成,可以将完整的服装切换为归一化贴剂,该贴片能够保留服装样式信息,同时消除服装空间信息,从而减轻在未受监督训练期间过度适应的问题。此外,面食++引入了基于贴片的服装表示和一个贴片引导的解析合成块,使其可以处理任意服装类别并支持本地服装编辑。最后,为了获得具有逼真的纹理细节的尝试结果,面食gan ++结合了一种新型的空间自适应残留模块,以将粗翘曲的服装功能注入发电机。对我们新收集的未配对的虚拟试验(UPT)数据集进行了广泛的实验,证明了面食gan ++比现有SOTA的优越性及其可控服装编辑的能力。
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在现实世界中操纵体积变形物体,例如毛绒玩具和披萨面团,由于无限形状的变化,非刚性运动和部分可观察性带来了重大挑战。我们引入酸,这是一种基于结构性隐式神经表示的容量变形物体的动作条件视觉动力学模型。酸整合了两种新技术:动作条件动力学和基于大地测量的对比度学习的隐式表示。为了代表部分RGB-D观测值的变形动力学,我们学习了占用和基于流动的正向动态的隐式表示。为了准确识别在大型非刚性变形下的状态变化,我们通过新的基于大地测量的对比损失来学习一个对应嵌入场。为了评估我们的方法,我们开发了一个模拟框架,用于在逼真的场景中操纵复杂的可变形形状和一个基准测试,其中包含17,000多种动作轨迹,这些轨迹具有六种类型的毛绒玩具和78种变体。我们的模型在现有方法上实现了几何,对应和动态预测的最佳性能。酸动力学模型已成功地用于目标条件可变形的操纵任务,从而使任务成功率比最强的基线提高了30%。此外,我们将模拟训练的酸模型直接应用于现实世界对象,并在将它们操纵为目标配置中显示成功。有关更多结果和信息,请访问https://b0ku1.github.io/acid/。
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安全已成为对现实世界系统应用深度加固学习的主要挑战之一。目前,诸如人类监督等外部知识的纳入唯一可以防止代理人访问灾难性状态的手段。在本文中,我们提出了一种基于安全模型的强化学习的新框架MBHI,可确保状态级安全,可以有效地避免“本地”和“非本地”灾难。监督学习者的合并在MBHI培训,以模仿人类阻止决策。类似于人类决策过程,MBHI将在执行对环境的动作之前在动态模型中推出一个想象的轨迹,并估算其安全性。当想象力遇到灾难时,MBHI将阻止当前的动作并使用高效的MPC方法来输出安全策略。我们在几个安全任务中评估了我们的方法,结果表明,与基线相比,MBHI在样品效率和灾难数方面取得了更好的性能。
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最近在图像染色的作品表明,结构信息在恢复视觉上令人愉悦的结果方面发挥着重要作用。在本文中,我们提出了由基于两个并行发射机的流组成的端到端架构:主流(MS)和结构流(SS)。在SS的帮助下,MS可以产生具有合理结构和现实细节的合理结果。具体地,MS通过同时推断丢失的结构和纹理来重建详细图像,并且SS仅通过从MS的编码器处理分层信息来恢复丢失的结构。通过在培训过程中与SS进行互动,可以暗示MS可以暗示利用结构性提示。为了帮助SS专注于结构并防止MS中的纹理受到影响,提出了一种门控单元来抑制MS和SS之间的信息流中的结构无关激活。此外,SS中的多尺度结构特征映射用于明确指导通过融合块的MS的解码器中的结构合理的图像重建。在Celeba,Paris Streetview和Parume2数据集上进行了广泛的实验表明我们所提出的方法优于最先进的方法。
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Structured tabular data exist across nearly all fields. Reasoning task over these data aims to answer questions or determine the truthiness of hypothesis sentences by understanding the semantic meaning of a table. While previous works have devoted significant efforts to the tabular reasoning task, they always assume there are sufficient labeled data. However, constructing reasoning samples over tables (and related text) is labor-intensive, especially when the reasoning process is complex. When labeled data is insufficient, the performance of models will suffer an unendurable decline. In this paper, we propose a unified framework for unsupervised complex tabular reasoning (UCTR), which generates sufficient and diverse synthetic data with complex logic for tabular reasoning tasks, assuming no human-annotated data at all. We first utilize a random sampling strategy to collect diverse programs of different types and execute them on tables based on a "Program-Executor" module. To bridge the gap between the programs and natural language sentences, we design a powerful "NL-Generator" module to generate natural language sentences with complex logic from these programs. Since a table often occurs with its surrounding texts, we further propose novel "Table-to-Text" and "Text-to-Table" operators to handle joint table-text reasoning scenarios. This way, we can adequately exploit the unlabeled table resources to obtain a well-performed reasoning model under an unsupervised setting. Our experiments cover different tasks (question answering and fact verification) and different domains (general and specific), showing that our unsupervised methods can achieve at most 93% performance compared to supervised models. We also find that it can substantially boost the supervised performance in low-resourced domains as a data augmentation technique. Our code is available at https://github.com/leezythu/UCTR.
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In recent years, graph representation learning has achieved remarkable success while suffering from low-quality data problems. As a mature technology to improve data quality in computer vision, data augmentation has also attracted increasing attention in graph domain. For promoting the development of this emerging research direction, in this survey, we comprehensively review and summarize the existing graph data augmentation (GDAug) techniques. Specifically, we first summarize a variety of feasible taxonomies, and then classify existing GDAug studies based on fine-grained graph elements. Furthermore, for each type of GDAug technique, we formalize the general definition, discuss the technical details, and give schematic illustration. In addition, we also summarize common performance metrics and specific design metrics for constructing a GDAug evaluation system. Finally, we summarize the applications of GDAug from both data and model levels, as well as future directions.
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