预计下一代(NEVERG)网络将支持苛刻的触觉互联网应用,例如增强现实和连接的自动车辆。虽然最近的创新带来了更大的联系能力的承诺,它们对环境的敏感性以及不稳定的性能无视基于传统的基于模型的控制理由。零触摸数据驱动的方法可以提高网络适应当前操作条件的能力。诸如强化学习(RL)算法等工具可以仅基于观察历史来构建最佳控制策略。具体而言,使用深神经网络(DNN)作为预测器的深RL(DRL)已经被示出,即使在复杂的环境和高维输入中也能够实现良好的性能。但是,DRL模型的培训需要大量数据,这可能会限制其对潜在环境的不断发展统计数据的适应性。此外,无线网络是固有的分布式系统,其中集中式DRL方法需要过多的数据交换,而完全分布的方法可能导致较慢的收敛速率和性能下降。在本文中,为了解决这些挑战,我们向DRL提出了联合学习(FL)方法,我们指的是联邦DRL(F-DRL),其中基站(BS)通过仅共享模型的重量协作培训嵌入式DNN而不是训练数据。我们评估了两个不同版本的F-DRL,价值和策略,并显示出与分布式和集中式DRL相比实现的卓越性能。
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Convolutional Neural Networks (CNN) have shown promising results for displacement estimation in UltraSound Elastography (USE). Many modifications have been proposed to improve the displacement estimation of CNNs for USE in the axial direction. However, the lateral strain, which is essential in several downstream tasks such as the inverse problem of elasticity imaging, remains a challenge. The lateral strain estimation is complicated since the motion and the sampling frequency in this direction are substantially lower than the axial one, and a lack of carrier signal in this direction. In computer vision applications, the axial and the lateral motions are independent. In contrast, the tissue motion pattern in USE is governed by laws of physics which link the axial and lateral displacements. In this paper, inspired by Hooke's law, we first propose Physically Inspired ConsTraint for Unsupervised Regularized Elastography (PICTURE), where we impose a constraint on the Effective Poisson's ratio (EPR) to improve the lateral strain estimation. In the next step, we propose self-supervised PICTURE (sPICTURE) to further enhance the strain image estimation. Extensive experiments on simulation, experimental phantom and in vivo data demonstrate that the proposed methods estimate accurate axial and lateral strain maps.
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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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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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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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