从2D图像中估算3D人的姿势和形状是一项至关重要但具有挑战性的任务。虽然先前具有基于模型表示的方法可以在全身图像上表现出色，但当身体的一部分被遮住或框架外面时，它们通常会失败。此外，这些结果通常不会忠实地捕获人类的轮廓，因为它们的可变形模型有限（例如，仅代表裸体）。另一种方法是估计图像空间中预定义模板主体的密集顶点。这样的表示有效地将顶点定位在图像中，但无法处理框架外的身体部位。在这项工作中，我们学习了对部分观察的强大人体估计。我们明确地对X，Y和Z轴中人类关节和顶点的可见性进行了建模。 X和Y轴中的可见性有助于区分框架外情况，深度轴的可见性对应于闭塞（其他对象的自我闭合或遮挡）。我们从密集的紫外线对应关系中获得可见性标签的伪基，并训练神经网络以预测可见性以及3D坐标。我们表明，可见性可以用作1）额外的信号，以解决自锁定顶点的歧义深度的歧义，以及2）将人体模型拟合到预测时的正则化项。对多个3D人类数据集进行的广泛实验表明，可见性建模显着提高了人体估计的准确性，尤其是对于部分体型病例。我们的带代码的项目页面at：https：//github.com/chhankyao/visdb。

人的言语通常伴随着包括手臂和手势在内的身体手势。我们提出了一种方法，该方法将与目标语音音频相匹配的手势重新效果。我们方法的关键思想是通过编码剪辑之间的有效过渡的新型视频运动图从参考视频中拆分和重新组装剪辑。为了在重演中无缝连接不同的剪辑，我们提出了一个姿势感知的视频混合网络，该网络综合了两个剪辑之间的缝线框架周围的视频帧。此外，我们开发了一种基于音频的手势搜索算法，以找到重新成型帧的最佳顺序。我们的系统生成的重演与音频节奏和语音内容一致。我们定量，用户研究对综合视频质量进行评估，并证明我们的方法与以前的工作和基线相比，我们的方法与目标音频的质量和一致性更高。

In neural networks, it is often desirable to work with various representations of the same space. For example, 3D rotations can be represented with quaternions or Euler angles. In this paper, we advance a definition of a continuous representation, which can be helpful for training deep neural networks. We relate this to topological concepts such as homeomorphism and embedding. We then investigate what are continuous and discontinuous representations for 2D, 3D, and n-dimensional rotations. We demonstrate that for 3D rotations, all representations are discontinuous in the real Euclidean spaces of four or fewer dimensions. Thus, widely used representations such as quaternions and Euler angles are discontinuous and difficult for neural networks to learn. We show that the 3D rotations have continuous representations in 5D and 6D, which are more suitable for learning. We also present continuous representations for the general case of the n dimensional rotation group SO(n). While our main focus is on rotations, we also show that our constructions apply to other groups such as the orthogonal group and similarity transforms. We finally present empirical results, which show that our continuous rotation representations outperform discontinuous ones for several practical problems in graphics and vision, including a simple autoencoder sanity test, a rotation estimator for 3D point clouds, and an inverse kinematics solver for 3D human poses.

In this paper, we address referring expression comprehension: localizing an image region described by a natural language expression. While most recent work treats expressions as a single unit, we propose to decompose them into three modular components related to subject appearance, location, and relationship to other objects. This allows us to flexibly adapt to expressions containing different types of information in an end-to-end framework. In our model, which we call the Modular Attention Network (MAttNet), two types of attention are utilized: languagebased attention that learns the module weights as well as the word/phrase attention that each module should focus on; and visual attention that allows the subject and relationship modules to focus on relevant image components. Module weights combine scores from all three modules dynamically to output an overall score. Experiments show that MAttNet outperforms previous state-of-the-art methods by a large margin on both bounding-box-level and pixel-level comprehension tasks. Demo 1 and code 2 are provided.

Figure 1: Example inpainting results of our method on images of natural scene, face and texture. Missing regions are shown in white. In each pair, the left is input image and right is the direct output of our trained generative neural networks without any post-processing.

如何快速自动自动挖掘有效的信息并提供投资决策，吸引了学术界和行业的更多关注。全球大流行已经提出了新的挑战。本文提出了一个两阶段的alphamldigger，可有效地发现高度波动的市场回报。在第1阶段，提出了一个深层的NLP模型，以将Sina Microblog上的博客转移到市场情绪。在第2阶段，预测的市场情绪与社交网络指标功能和股票市场历史记录功能相结合，以使用不同的机器学习模型和优化器来预测股票移动。结果表明，我们的alphamldigger在测试集中的准确性比以前的作品更高，并且在某种程度上对Covid-19的负面影响是牢固的。

Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.

Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.

The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.

Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.