动态状态表示学习是机器人学习中的重要任务。可以捕获动力学信息的潜在空间在加速模型的自由强化学习,缩小模拟到现实差距以及降低运动计划的复杂性等领域中具有广泛的应用。但是,当前的动态状态表示方法在复杂的动态系统(例如可变形对象)上的扩展很差,并且不能将良好定义的仿真函数直接嵌入到训练管道中。我们提出了DIFFSRL,这是一种动态状态表示学习管道,利用可区分的模拟可以将复杂的动力学模型嵌入到端到端训练的一部分。我们还将可区分的动态约束作为管道的一部分集成,这为潜在状态提供了意识到动态约束的激励措施。我们进一步建立了在软体体模拟系统PlastonElab上学习基准的国家表示基准,我们的模型在捕获长期动态和奖励预测方面表现出了卓越的性能。
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Knowledge graph embedding (KGE), which maps entities and relations in a knowledge graph into continuous vector spaces, has achieved great success in predicting missing links in knowledge graphs. However, knowledge graphs often contain incomplete triples that are difficult to inductively infer by KGEs. To address this challenge, we resort to analogical inference and propose a novel and general self-supervised framework AnKGE to enhance KGE models with analogical inference capability. We propose an analogical object retriever that retrieves appropriate analogical objects from entity-level, relation-level, and triple-level. And in AnKGE, we train an analogy function for each level of analogical inference with the original element embedding from a well-trained KGE model as input, which outputs the analogical object embedding. In order to combine inductive inference capability from the original KGE model and analogical inference capability enhanced by AnKGE, we interpolate the analogy score with the base model score and introduce the adaptive weights in the score function for prediction. Through extensive experiments on FB15k-237 and WN18RR datasets, we show that AnKGE achieves competitive results on link prediction task and well performs analogical inference.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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Physics-informed neural networks (PINNs) have lately received significant attention as a representative deep learning-based technique for solving partial differential equations (PDEs). Most fully connected network-based PINNs use automatic differentiation to construct loss functions that suffer from slow convergence and difficult boundary enforcement. In addition, although convolutional neural network (CNN)-based PINNs can significantly improve training efficiency, CNNs have difficulty in dealing with irregular geometries with unstructured meshes. Therefore, we propose a novel framework based on graph neural networks (GNNs) and radial basis function finite difference (RBF-FD). We introduce GNNs into physics-informed learning to better handle irregular domains with unstructured meshes. RBF-FD is used to construct a high-precision difference format of the differential equations to guide model training. Finally, we perform numerical experiments on Poisson and wave equations on irregular domains. We illustrate the generalizability, accuracy, and efficiency of the proposed algorithms on different PDE parameters, numbers of collection points, and several types of RBFs.
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Multi-view representation learning has developed rapidly over the past decades and has been applied in many fields. However, most previous works assumed that each view is complete and aligned. This leads to an inevitable deterioration in their performance when encountering practical problems such as missing or unaligned views. To address the challenge of representation learning on partially aligned multi-view data, we propose a new cross-view graph contrastive learning framework, which integrates multi-view information to align data and learn latent representations. Compared with current approaches, the proposed method has the following merits: (1) our model is an end-to-end framework that simultaneously performs view-specific representation learning via view-specific autoencoders and cluster-level data aligning by combining multi-view information with the cross-view graph contrastive learning; (2) it is easy to apply our model to explore information from three or more modalities/sources as the cross-view graph contrastive learning is devised. Extensive experiments conducted on several real datasets demonstrate the effectiveness of the proposed method on the clustering and classification tasks.
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Recent studies reveal that deep neural network (DNN) based object detectors are vulnerable to adversarial attacks in the form of adding the perturbation to the images, leading to the wrong output of object detectors. Most current existing works focus on generating perturbed images, also called adversarial examples, to fool object detectors. Though the generated adversarial examples themselves can remain a certain naturalness, most of them can still be easily observed by human eyes, which limits their further application in the real world. To alleviate this problem, we propose a differential evolution based dual adversarial camouflage (DE_DAC) method, composed of two stages to fool human eyes and object detectors simultaneously. Specifically, we try to obtain the camouflage texture, which can be rendered over the surface of the object. In the first stage, we optimize the global texture to minimize the discrepancy between the rendered object and the scene images, making human eyes difficult to distinguish. In the second stage, we design three loss functions to optimize the local texture, making object detectors ineffective. In addition, we introduce the differential evolution algorithm to search for the near-optimal areas of the object to attack, improving the adversarial performance under certain attack area limitations. Besides, we also study the performance of adaptive DE_DAC, which can be adapted to the environment. Experiments show that our proposed method could obtain a good trade-off between the fooling human eyes and object detectors under multiple specific scenes and objects.
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在过去的十年中,深度学习急剧改变了传统的手工艺特征方式,具有强大的功能学习能力,从而极大地改善了传统任务。然而,最近已经证明了深层神经网络容易受到对抗性例子的影响,这种恶意样本由小型设计的噪音制作,误导了DNNs做出错误的决定,同时仍然对人类无法察觉。对抗性示例可以分为数字对抗攻击和物理对抗攻击。数字对抗攻击主要是在实验室环境中进行的,重点是改善对抗性攻击算法的性能。相比之下,物理对抗性攻击集中于攻击物理世界部署的DNN系统,这是由于复杂的物理环境(即亮度,遮挡等),这是一项更具挑战性的任务。尽管数字对抗和物理对抗性示例之间的差异很小,但物理对抗示例具有特定的设计,可以克服复杂的物理环境的效果。在本文中,我们回顾了基于DNN的计算机视觉任务任务中的物理对抗攻击的开发,包括图像识别任务,对象检测任务和语义细分。为了完整的算法演化,我们将简要介绍不涉及身体对抗性攻击的作品。我们首先提出一个分类方案,以总结当前的物理对抗攻击。然后讨论现有的物理对抗攻击的优势和缺点,并专注于用于维持对抗性的技术,当应用于物理环境中时。最后,我们指出要解决的当前身体对抗攻击的问题并提供有前途的研究方向。
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开放世界对象检测是一个更具笼统和挑战性的目标,旨在识别和本地化由任意类别名称描述的对象。最近的工作GLIP通过将检测数据集的所有类别名称连接到句子中,从而将此问题作为接地问题,从而导致类别名称之间的效率低下的相互作用。本文介绍了Distclip,这是一种通过诉诸于设计概念词典的知识富集,是一种平行的视觉概念训练预训练方法,用于开放世界检测。为了提高学习效率,我们提出了一种新型的并行概念公式,该公式分别提取概念,以更好地利用异质数据集(即检测,接地和图像文本对)进行培训。我们进一步设计了来自各种在线资源和检测数据集的概念字典〜(带有描述),以提供每个概念的先验知识。通过用描述丰富这些概念,我们明确地建立了各种概念之间的关系,以促进开放域学习。所提出的概念词典进一步用于提供足够的负面概念,用于构建单词区域对齐损失\,并完成图像对文本对数据标题中缺少描述的对象的标签。所提出的框架显示出强烈的零射击性能性能,例如,在LVIS数据集上,我们的DETCLIP-T优于9.9%的地图GLIPT-T优于GLIP-T,并且与完全避免的型号相比,稀有类别的稀有类别提高了13.5%。作为我们的。
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传统的LIDAR射测(LO)系统主要利用从经过的环境获得的几何信息来注册激光扫描并估算Lidar Ego-Motion,而在动态或非结构化环境中可能不可靠。本文提出了Inten-loam,一种低饮用和健壮的激光镜和映射方法,该方法完全利用激光扫描的隐式信息(即几何,强度和时间特征)。扫描点被投影到圆柱形图像上,这些图像有助于促进各种特征的有效和适应性提取,即地面,梁,立面和反射器。我们提出了一种新型基于强度的点登记算法,并将其纳入LIDAR的探光仪,从而使LO系统能够使用几何和强度特征点共同估计LIDAR EGO-MOTION。为了消除动态对象的干扰,我们提出了一种基于时间的动态对象删除方法,以在MAP更新之前过滤它们。此外,使用与时间相关的体素网格滤波器组织并缩减了本地地图,以维持当前扫描和静态局部图之间的相似性。在模拟和实际数据集上进行了广泛的实验。结果表明,所提出的方法在正常驾驶方案中实现了类似或更高的精度W.R.T,在非结构化环境中,最先进的方法优于基于几何的LO。
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热应力和变形的快速分析在热控制措施和卫星结构设计的优化中起着关键作用。为了实现卫星主板的实时热应力和热变形分析,本文提出了一种新型的多任务注意UNET(MTA-UNET)神经网络,将多任务学习(MTL)和U-NET的优势结合在一起注意机制。此外,在训练过程中使用了物理知识的策略,其中部分微分方程(PDE)被整合到损失函数中作为残留项。最后,将基于不确定性的损失平衡方法应用于重量的多个培训任务的不同损失功能。实验结果表明,与单任务学习(STL)模型相比,提出的MTA-UNET有效提高了多个物理任务的预测准确性。此外,物理信息的方法在每个任务的预测中的错误较小,尤其是在小型数据集上。代码可以在:\ url {https://github.com/komorebitso/mta-unet}下载。
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