域的概括(DG)旨在学习一个对源域的模型,以很好地概括看不见的目标域。尽管它取得了巨大的成功,但大多数现有方法都需要用于源域中所有培训样本的标签信息,这在现实世界中既耗时又昂贵。在本文中,我们求助于解决半监督域的概括(SSDG)任务,其中每个源域中都有一些标签信息。为了解决任务,我们首先分析多域学习的理论,该理论强调了1)减轻域间隙的影响和2)利用所有样品训练模型可以有效地减少每个源域中的概括误差,因此提高伪标签的质量。根据分析,我们提出了Multimatch,即将FixMatch扩展到多任务学习框架,从而为SSDG生成高质量的伪标签。具体来说,我们将每个培训域视为一个任务(即本地任务),并将所有培训域(即全球任务)组合在一起,以训练看不见的测试域的额外任务。在多任务框架中,我们为每个任务使用独立的BN和分类器,这可以有效地减轻伪标记期间不同领域的干扰。同样,共享框架中的大多数参数,可以通过所有培训样本进行培训。此外,为了进一步提高伪标签的准确性和模型的概括,我们分别在培训和测试过程中分别融合了全球任务和本地任务的预测。一系列实验验证了所提出的方法的有效性,并且在几个基准DG数据集上优于现有的半监督方法和SSDG方法。
translated by 谷歌翻译
在这项工作中,我们通过利用3D Suite Blender生产具有6D姿势的合成RGBD图像数据集来提出数据生成管道。提出的管道可以有效地生成大量的照片现实的RGBD图像,以了解感兴趣的对象。此外,引入了域随机化技术的集合来弥合真实数据和合成数据之间的差距。此外,我们通过整合对象检测器Yolo-V4微型和6D姿势估计算法PVN3D来开发实时的两阶段6D姿势估计方法,用于时间敏感的机器人应用。借助提出的数据生成管道,我们的姿势估计方法可以仅使用没有任何预训练模型的合成数据从头开始训练。在LineMod数据集评估时,与最先进的方法相比,所得网络显示出竞争性能。我们还证明了在机器人实验中提出的方法,在不同的照明条件下从混乱的背景中抓住家用物体。
translated by 谷歌翻译
深度强化学习(DRL)是一种有前途的方法,可以通过与环境的互动来学习政策来解决复杂的控制任务。但是,对DRL政策的培训需要大量的培训经验,这使得直接了解物理系统的政策是不切实际的。 SIM到运行的方法可以利用模拟来验证DRL政策,然后将其部署在现实世界中。不幸的是,经过验证的政策的直接现实部署通常由于不同的动态(称为现实差距)而遭受性能恶化。最近的SIM到现实方法,例如域随机化和域的适应性,重点是改善预审预告剂的鲁棒性。然而,经过模拟训练的策略通常需要使用现实世界中的数据来调整以达到最佳性能,这是由于现实世界样本的高成本而具有挑战性的。这项工作提出了一个分布式的云边缘建筑,以实时培训现实世界中的DRL代理。在体系结构中,推理和训练被分配到边缘和云,将实时控制循环与计算昂贵的训练回路分开。为了克服现实差距,我们的体系结构利用了SIM到现实的转移策略,以继续在物理系统上训练模拟预言的代理。我们证明了其在物理倒置螺旋控制系统上的适用性,分析了关键参数。现实世界实验表明,我们的体系结构可以使验证的DRL代理能够始终如一,有效地看不见动态。
translated by 谷歌翻译
安装在机器人上的光学扫描仪通常用于质量检查,例如验证片状结构的尺寸规格。覆盖路径规划(CPP)显着影响机器人质量检验的准确性和效率。传统的CPP战略专注于最小化机器人的观点次数或在完全覆盖检查的条件下。在自由形状表面检查中较少考虑收集扫描数据时的测量不确定度。为了解决这个问题,提出了一种具有最佳观点采样策略的新型CPP方法,以将键测量点(MPS)的测量不确定性纳入自由形状表面检查。首先,基于MP的公差规范计算可行的测量不确定性范围。考虑测量不确定度和MPS的可见性,生成初始可行性视点集。然后,构建检查成本函数以评估所选视点的视野(FOV)的选定视点的数量和平均测量不确定性。之后,提出了一种增强的快速探索随机树(RRT *)算法,用于使用检查成本函数和CPP优化的观点采样。已经进行了案例研究,包括模拟试验和检查实验,以评估所提出的方法的有效性。结果表明,与基准法相比,关键MPS的扫描精度显着提高。
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
A recent study has shown a phenomenon called neural collapse in that the within-class means of features and the classifier weight vectors converge to the vertices of a simplex equiangular tight frame at the terminal phase of training for classification. In this paper, we explore the corresponding structures of the last-layer feature centers and classifiers in semantic segmentation. Based on our empirical and theoretical analysis, we point out that semantic segmentation naturally brings contextual correlation and imbalanced distribution among classes, which breaks the equiangular and maximally separated structure of neural collapse for both feature centers and classifiers. However, such a symmetric structure is beneficial to discrimination for the minor classes. To preserve these advantages, we introduce a regularizer on feature centers to encourage the network to learn features closer to the appealing structure in imbalanced semantic segmentation. Experimental results show that our method can bring significant improvements on both 2D and 3D semantic segmentation benchmarks. Moreover, our method ranks 1st and sets a new record (+6.8% mIoU) on the ScanNet200 test leaderboard. Code will be available at https://github.com/dvlab-research/Imbalanced-Learning.
translated by 谷歌翻译
Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.
translated by 谷歌翻译