We conduct a systematic study of backdoor vulnerabilities in normally trained Deep Learning models. They are as dangerous as backdoors injected by data poisoning because both can be equally exploited. We leverage 20 different types of injected backdoor attacks in the literature as the guidance and study their correspondences in normally trained models, which we call natural backdoor vulnerabilities. We find that natural backdoors are widely existing, with most injected backdoor attacks having natural correspondences. We categorize these natural backdoors and propose a general detection framework. It finds 315 natural backdoors in the 56 normally trained models downloaded from the Internet, covering all the different categories, while existing scanners designed for injected backdoors can at most detect 65 backdoors. We also study the root causes and defense of natural backdoors.

模型压缩可以显着降低深度神经网络（DNN）模型的大小，以便在资源限制的移动和物联网设备上部署压缩后大型复杂的模型。但是，模型压缩通常将偏离的行为引入压缩模型：原始和压缩模型输出相同输入的不同预测结果。因此，警告开发人员至关重要，并帮助他们全面评估部署前的这种行为的可能后果。为此，我们提出了TriggerFinder，一种新颖，有效和有效的测试方法来自动识别输入以触发压缩模型中的偏离行为。给出一个作为种子的输入I，触发器采用迭代地应用一系列突变操作以改变I，直到得到的输入触发偏离的行为。但是，压缩模型通常隐藏其架构和梯度信息;没有这样的内部信息作为指导，它变得难以有效且有效地触发偏离的行为。为了解决这一挑战，我们提出了一种新颖的健身功能来确定更接近能够触发偏移预测的输入的突变输入。此外，TriggerFinder将该搜索问题模拟作为Markov链过程，并利用了Metropolis-Hasting算法来指导突变运算符的选择。我们在具有两个数据集的18个压缩模型上评估了TriggerFinder。实验结果表明，在某些情况下，基线在基线发生故障时，触发器可以成功找到所有种子输入的触发输入。至于效率，TriggerFinder为5.2x-115.8x，与基线一样快。此外，TriggerFinder要求找到一个触发输入的查询仅为51.8x-535.6x，作为基线。

深度神经网络容易受到来自对抗性投入的攻击，并且最近，特洛伊木马误解或劫持模型的决定。我们通过探索有界抗逆性示例空间和生成的对抗网络内的自然输入空间来揭示有界面的对抗性实例 - 通用自然主义侵害贴片的兴趣类 - 我们呼叫TNT。现在，一个对手可以用一个自然主义的补丁来手臂自己，不太恶意，身体上可实现，高效 - 实现高攻击成功率和普遍性。 TNT是普遍的，因为在场景中的TNT中捕获的任何输入图像都将：i）误导网络（未确定的攻击）;或ii）迫使网络进行恶意决定（有针对性的攻击）。现在，有趣的是，一个对抗性补丁攻击者有可能发挥更大的控制水平 - 选择一个独立，自然的贴片的能力，与被限制为嘈杂的扰动的触发器 - 到目前为止只有可能与特洛伊木马攻击方法有可能干扰模型建设过程，以嵌入风险发现的后门;但是，仍然意识到在物理世界中部署的补丁。通过对大型视觉分类任务的广泛实验，想象成在其整个验证集50,000张图像中进行评估，我们展示了TNT的现实威胁和攻击的稳健性。我们展示了攻击的概括，以创建比现有最先进的方法实现更高攻击成功率的补丁。我们的结果表明，攻击对不同的视觉分类任务（CIFAR-10，GTSRB，PUBFIG）和多个最先进的深神经网络，如WieredEnet50，Inception-V3和VGG-16。

Deep learning based methods have significantly boosted the study of automatic building extraction from remote sensing images. However, delineating vectorized and regular building contours like a human does remains very challenging, due to the difficulty of the methodology, the diversity of building structures, and the imperfect imaging conditions. In this paper, we propose the first end-to-end learnable building contour extraction framework, named BuildMapper, which can directly and efficiently delineate building polygons just as a human does. BuildMapper consists of two main components: 1) a contour initialization module that generates initial building contours; and 2) a contour evolution module that performs both contour vertex deformation and reduction, which removes the need for complex empirical post-processing used in existing methods. In both components, we provide new ideas, including a learnable contour initialization method to replace the empirical methods, dynamic predicted and ground truth vertex pairing for the static vertex correspondence problem, and a lightweight encoder for vertex information extraction and aggregation, which benefit a general contour-based method; and a well-designed vertex classification head for building corner vertices detection, which casts light on direct structured building contour extraction. We also built a suitable large-scale building dataset, the WHU-Mix (vector) building dataset, to benefit the study of contour-based building extraction methods. The extensive experiments conducted on the WHU-Mix (vector) dataset, the WHU dataset, and the CrowdAI dataset verified that BuildMapper can achieve a state-of-the-art performance, with a higher mask average precision (AP) and boundary AP than both segmentation-based and contour-based methods.

在本文中，我们介绍了一个新的建筑数据集，并提出了一种新颖的域泛化方法，以促进从高分辨率遥感图像中提取建筑物的开发。当前建筑数据集的问题涉及它们缺乏多样性，标签的质量不令人满意，并且几乎不用于培训具有良好概括能力的建筑提取模型，以便正确地评估模型在实践中的真实性能场景。为了解决这些问题，我们建立了一个名为WHU-MIX建筑数据集的多样化，大规模和高质量的建筑数据集，该数据集更加面向实践。 WHU-MIX建筑物数据集由一个培训/验证集组成，该培训/验证集包含来自世界各地的43,727个不同图像，以及一个测试集，其中包含来自五大洲其他五个城市的8402张图像。此外，为了进一步提高建筑物提取模型的概括能力，我们提出了一种名为批处理样式混合（BSM）的域概括方法，该方法可以嵌入建筑物的frond-end中，以嵌入为有效的插件模块提取模型，为模型提供逐渐更大的数据分布，以学习数据不变知识。这项研究中进行的实验证实了WHU-MIX建筑数据集的潜力，以提高建筑物提取模型的性能，与其他现有数据集相比，MIOU提高了6-36％。其他数据集中标签不准确的不利影响可能会导致约20％的IOU减少。该实验还证实了所提出的BSM模块在增强模型的概括能力和鲁棒性方面的高性能，超过了13％的基线模型，而MIOU中最新的域概括方法则超过了4-15％。

神经体系结构搜索（NAS）最近在深度学习社区中变得越来越流行，主要是因为它可以提供一个机会，使感兴趣的用户没有丰富的专业知识，从而从深度神经网络（DNNS）的成功中受益。但是，NAS仍然很费力且耗时，因为在NAS的搜索过程中需要进行大量的性能估计，并且训练DNNS在计算上是密集的。为了解决NAS的主要局限性，提高NAS的效率对于NAS的设计至关重要。本文以简要介绍了NAS的一般框架。然后，系统地讨论了根据代理指标评估网络候选者的方法。接下来是对替代辅助NAS的描述，该NAS分为三个不同类别，即NAS的贝叶斯优化，NAS的替代辅助进化算法和NAS的MOP。最后，讨论了剩余的挑战和开放研究问题，并在这个新兴领域提出了有希望的研究主题。

从嘈杂，不均匀和无知点云中的表面重建是计算机视觉和图形中的一个令人迷人但具有挑战性的问题。随着3D扫描技术的创新，强烈希望直接转换原始扫描数据，通常具有严重噪声，进入歧管三角网格。现有的基于学习的方法旨在学习零级曲面对底层形状进行的隐式功能。然而，大多数人都无法获得嘈杂和稀疏点云的理想结果，限制在实践中。在本文中，我们介绍了神经IML，一种新的方法，它直接从未引起的原始点云学习抗噪声符号距离功能（SDF）。通过最大限度地减少由隐式移动最小二乘函数获得的损耗，我们的方法通过最小化了自我监督的方式，从原始点云中从原始点云中的底层SDF，而不是明确地学习前提。 （IML）和我们的神经网络另一个，我们的预测器的梯度定义了便于计算IML的切线束。我们证明，当几个SDFS重合时，我们的神经网络可以预测符号隐式功能，其零电平集用作底层表面的良好近似。我们对各种基准进行广泛的实验，包括合成扫描和现实世界扫描，以表现出从各种投入重建忠实形状的能力，特别是对于具有噪音或间隙的点云。

Knowledge graphs (KG) have served as the key component of various natural language processing applications. Commonsense knowledge graphs (CKG) are a special type of KG, where entities and relations are composed of free-form text. However, previous works in KG completion and CKG completion suffer from long-tail relations and newly-added relations which do not have many know triples for training. In light of this, few-shot KG completion (FKGC), which requires the strengths of graph representation learning and few-shot learning, has been proposed to challenge the problem of limited annotated data. In this paper, we comprehensively survey previous attempts on such tasks in the form of a series of methods and applications. Specifically, we first introduce FKGC challenges, commonly used KGs, and CKGs. Then we systematically categorize and summarize existing works in terms of the type of KGs and the methods. Finally, we present applications of FKGC models on prediction tasks in different areas and share our thoughts on future research directions of FKGC.

Unsupervised domain adaptation (UDA) for semantic segmentation is a promising task freeing people from heavy annotation work. However, domain discrepancies in low-level image statistics and high-level contexts compromise the segmentation performance over the target domain. A key idea to tackle this problem is to perform both image-level and feature-level adaptation jointly. Unfortunately, there is a lack of such unified approaches for UDA tasks in the existing literature. This paper proposes a novel UDA pipeline for semantic segmentation that unifies image-level and feature-level adaptation. Concretely, for image-level domain shifts, we propose a global photometric alignment module and a global texture alignment module that align images in the source and target domains in terms of image-level properties. For feature-level domain shifts, we perform global manifold alignment by projecting pixel features from both domains onto the feature manifold of the source domain; and we further regularize category centers in the source domain through a category-oriented triplet loss and perform target domain consistency regularization over augmented target domain images. Experimental results demonstrate that our pipeline significantly outperforms previous methods. In the commonly tested GTA5$\rightarrow$Cityscapes task, our proposed method using Deeplab V3+ as the backbone surpasses previous SOTA by 8%, achieving 58.2% in mIoU.

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.