DeepAngle is a machine learning-based method to determine the contact angles of different phases in the tomography images of porous materials. Measurement of angles in 3--D needs to be done within the surface perpendicular to the angle planes, and it could become inaccurate when dealing with the discretized space of the image voxels. A computationally intensive solution is to correlate and vectorize all surfaces using an adaptable grid, and then measure the angles within the desired planes. On the contrary, the present study provides a rapid and low-cost technique powered by deep learning to estimate the interfacial angles directly from images. DeepAngle is tested on both synthetic and realistic images against the direct measurement technique and found to improve the r-squared by 5 to 16% while lowering the computational cost 20 times. This rapid method is especially applicable for processing large tomography data and time-resolved images, which is computationally intensive. The developed code and the dataset are available at an open repository on GitHub (https://www.github.com/ArashRabbani/DeepAngle).
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X射线微型计算机断层扫描(Micro-CT)已被广泛利用,以在地下多孔岩石中表征孔隙尺度几何形状。使用深度学习的超分辨率(SR)方法的最新进程允许在大型空间尺度上进行数字增强低分辨率(LR)图像,从而创建与高分辨率(HR)地理真理相当的SR图像。这避免了传统的解决方案和视野折衷。出色的问题是使用配对(已注册的)LR和HR数据,这些数据通常需要在此类方法的训练步骤中,但难以获得。在这项工作中,我们严格比较两种不同的最先进的SR深度学习技术,使用两者和未配对数据,具有类似于类似的地面真理数据。第一方法需要配对的图像来训练卷积神经网络(CNN),而第二种方法使用未配对的图像来训练生成的对抗网络(GaN)。使用具有复杂的微孔纹理的微型CT碳酸盐岩样品进行比较两种方法。我们实现了基于图像的各种图像和数值验证和实验验证,以定量评估两种方法的物理精度和敏感性。我们的定量结果表明,未配对GaN方法可以将超分辨率图像重建为精确,如配对的CNN方法,具有可比的训练时间和数据集要求。这将使用未配对的深度学习方法解除微型CT图像增强的新应用;数据处理阶段不再需要图像注册。来自数据存储平台的解耦图像可以更有效地利用用于培训SR数字岩体应用的网络。这为异构多孔介质中的多尺度流模拟各种应用开辟了新的途径。
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X射线微型计算机断层摄影成像中存在固有的视野和分辨率折衷,这限制了多尺寸多孔系统的表征,分析和模型开发。在本文中,我们通过开发3D增强的深层超分辨率(EDSR)卷积神经网络来克服这些权衡来通过来自低分辨率数据的大型空间尺度创建增强的高分辨率数据。配对高分辨率(HR,2 $ \ MU $ M)和低分辨率(LR,6 $ \ MU $ M)来自Bentheimer Rock样本的图像数据用于培训网络。来自训练样本的未见LR和HR数据以及具有不同微结构的另一个样本,用于验证具有各种度量的网络:文本分析,分段行为和孔网络模型(PNM)多相流模拟。经过验证的EDSR网络用于为每个长度为6-7厘米的全核样品生成约1000个高分辨率转速子图像(总图像大小为约6000x6000x32000体素)。每个子培养物都具有从PNMS预测的不同的岩石物理特性,它们组合以创建每个样本的3D连续级模型。在一系列分数流动下模拟低毛细管数不混溶的流动,并直接在1:1的基础上与实验压力和3D饱和度进行比较。 EDSR产生的模型比在存在异质性存在下预测实验行为的基础LR模型更准确,特别是在遇到孔隙尺寸的广泛分布的流动状态下。该模型通常在预测到在实验重复性和三个数量级的实验重复性和相对渗透率内的饱和度准确。所示的工作流程是一个完全预测的,无需校准,并且打开了在真正的多尺度异构系统中的图像,模拟和分析流动的可能性。
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Numerous models have tried to effectively embed knowledge graphs in low dimensions. Among the state-of-the-art methods, Graph Neural Network (GNN) models provide structure-aware representations of knowledge graphs. However, they often utilize the information of relations and their interactions with entities inefficiently. Moreover, most state-of-the-art knowledge graph embedding models suffer from scalability issues because of assigning high-dimensional embeddings to entities and relations. To address the above limitations, we propose a scalable general knowledge graph encoder that adaptively involves a powerful tensor decomposition method in the aggregation function of RGCN, a well-known relational GNN model. Specifically, the parameters of a low-rank core projection tensor, used to transform neighborhood entities in the encoder, are shared across relations to benefit from multi-task learning and incorporate relations information effectively. Besides, we propose a low-rank estimation of the core tensor using CP decomposition to compress the model, which is also applicable, as a regularization method, to other similar linear models. We evaluated our model on knowledge graph completion as a common downstream task. We train our model for using a new loss function based on contrastive learning, which relieves the training limitation of the 1-N method on huge graphs. We improved RGCN performance on FB15-237 by 0.42% with considerably lower dimensionality of embeddings.
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Diffusion Probabilistic Models (DPMs) have recently been employed for image deblurring. DPMs are trained via a stochastic denoising process that maps Gaussian noise to the high-quality image, conditioned on the concatenated blurry input. Despite their high-quality generated samples, image-conditioned Diffusion Probabilistic Models (icDPM) rely on synthetic pairwise training data (in-domain), with potentially unclear robustness towards real-world unseen images (out-of-domain). In this work, we investigate the generalization ability of icDPMs in deblurring, and propose a simple but effective guidance to significantly alleviate artifacts, and improve the out-of-distribution performance. Particularly, we propose to first extract a multiscale domain-generalizable representation from the input image that removes domain-specific information while preserving the underlying image structure. The representation is then added into the feature maps of the conditional diffusion model as an extra guidance that helps improving the generalization. To benchmark, we focus on out-of-distribution performance by applying a single-dataset trained model to three external and diverse test sets. The effectiveness of the proposed formulation is demonstrated by improvements over the standard icDPM, as well as state-of-the-art performance on perceptual quality and competitive distortion metrics compared to existing methods.
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We consider the constrained Linear Inverse Problem (LIP), where a certain atomic norm (like the $\ell_1 $ and the Nuclear norm) is minimized subject to a quadratic constraint. Typically, such cost functions are non-differentiable which makes them not amenable to the fast optimization methods existing in practice. We propose two equivalent reformulations of the constrained LIP with improved convex regularity: (i) a smooth convex minimization problem, and (ii) a strongly convex min-max problem. These problems could be solved by applying existing acceleration based convex optimization methods which provide better \mmode{ O \left( \nicefrac{1}{k^2} \right) } theoretical convergence guarantee. However, to fully exploit the utility of these reformulations, we also provide a novel algorithm, to which we refer as the Fast Linear Inverse Problem Solver (FLIPS), that is tailored to solve the reformulation of the LIP. We demonstrate the performance of FLIPS on the sparse coding problem arising in image processing tasks. In this setting, we observe that FLIPS consistently outperforms the Chambolle-Pock and C-SALSA algorithms--two of the current best methods in the literature.
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Many existing datasets for lidar place recognition are solely representative of structured urban environments, and have recently been saturated in performance by deep learning based approaches. Natural and unstructured environments present many additional challenges for the tasks of long-term localisation but these environments are not represented in currently available datasets. To address this we introduce Wild-Places, a challenging large-scale dataset for lidar place recognition in unstructured, natural environments. Wild-Places contains eight lidar sequences collected with a handheld sensor payload over the course of fourteen months, containing a total of 67K undistorted lidar submaps along with accurate 6DoF ground truth. Our dataset contains multiple revisits both within and between sequences, allowing for both intra-sequence (i.e. loop closure detection) and inter-sequence (i.e. re-localisation) place recognition. We also benchmark several state-of-the-art approaches to demonstrate the challenges that this dataset introduces, particularly the case of long-term place recognition due to natural environments changing over time. Our dataset and code will be available at https://csiro-robotics.github.io/Wild-Places.
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我们考虑了从一个示例轨迹中学习$ dx_t = f(x_t)dt+sigma(x_t)dw_t $的形式的随机微分方程的问题。这个问题比学习确定性动力学系统更具挑战性,因为一个示例轨迹仅提供有关未知功能$ f $,$ \ sigma $的间接信息,而随机过程$ dw_t $代表漂移,扩散和随机强迫术语,强迫术语,,分别。我们为此问题提出了一个简单的基于内核的解决方案,可以分解如下:(1)表示时间添加映射$ x_t \ rightarrow x_ {t+dt} $作为计算图,其中$ f $,$ \ \ Sigma $和$ DW_T $作为未知功能和随机变量出现。 (2)通过在未知函数上使用高斯过程(GP)先验的最大后验估计(给定数据)来完成图(近似未知的函数和随机变量)。 (3)从具有随机交叉验证的数据中学习GP先验的协方差函数(内核)。数值实验说明了我们方法的功效,鲁棒性和范围。
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我们定义了更广泛的腐败过程,该过程概括了先前已知的扩散模型。为了扭转这些一般的扩散,我们提出了一个称为“软得分匹配”的新目标,可以证明可以学习任何线性腐败过程的得分功能,并为Celeba提供最先进的结果。软得分匹配结合了网络中的降解过程,并训练模型以预测腐败与扩散观察相匹配的干净图像。我们表明,我们的目标在适当的规律性条件下为腐败过程的家庭学习了可能性的梯度。我们进一步开发了一种原则性的方法,以选择一般扩散过程的损坏水平和一种我们称为动量采样器的新型抽样方法。我们评估了我们的框架,腐败是高斯模糊和低幅度添加噪声。我们的方法在Celeba-64上获得了最先进的FID得分$ 1.85 $,表现优于所有以前的线性扩散模型。与香草deno的扩散相比,我们还显示出显着的计算益处。
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随着图形数据变得越来越普遍,在这些复杂的数据域中进行可靠的推论图算法的需求至关重要。在许多感兴趣的情况下,存在对抗数据污染的情况更加复杂。对手的效果通常是以负面影响统计和算法性能的方式改变数据分布。我们在顶点提名的背景下研究这种现象,这是网络数据的半监督信息检索任务。在这里,一系列常见的方法依赖于光谱图嵌入,这些嵌入式既可以提供良好的算法性能和灵活的设置,在该设置中可以实现正则化技术以帮助减轻对手的效果。许多当前的正则化方法依赖于直接网络修剪来有效消除对抗性污染,尽管这种直接修剪通常会导致所得图中的复杂依赖性结构。我们提出了一种在模型空间中运行的新修剪方法,该方法可以解决块结构污染和白噪声污染(污染的分布未知)。与直接修剪相比,该模型修剪更适合理论分析,同时也证明了许多模拟的性能。
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