在本文中,提出了一种原始数据驱动方法,用于使用仅输出响应来检测结构中的线性和非线性损坏。该方法部署变分模式分解(VMD)和用于信号处理和特征提取的广义自回归条件异染性(GARCH)模型。为此,VMD将响应信号分解为内在模式功能(IMF)。之后,使用GARCH模型来表示IMF的统计数据。 IMFS的模型系数构造主要特征向量。基于内核的主成分分析(PCA)和线性判别分析(LDA)用于通过将它们映射到新特征空间来降低主要特征的冗余。然后将信息性分别送入三个监督分类器,即支持向量机(SVM),K最近邻(KNN)和细树。在线性和非线性损伤评估方面,在两种实验缩放模型中评估了所提出的方法的性能。 Kurtosis和Arch测试证明了GARCH模型的兼容性。
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本文提出了一种新的劣化和损坏识别程序(DIP)并应用于建筑模型。与这些类型的结构的应用相关的挑战与响应的强相关性有关,这在应对具有高噪声水平的真实环境振动时进一步复杂化。因此,利用低成本环境振动设计了DIP,以分析使用股票变换(ST)来产生谱图的加速响应。随后,ST输出成为建立的两系列卷积神经网络(CNNS)的输入,用于识别建筑模型的恶化和损坏。据我们所知,这是第一次通过高精度的ST和CNN组合在建筑模型中评估损坏和恶化。
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异常检测是要识别在某些方面与训练观察结果不同的样本。这些不符合正常数据分布的样本称为异常值或异常。在现实世界的异常检测问题中,离群值不存在,定义不当或实例非常有限。最近的最新基于深度学习的异常检测方法遭受了高计算成本,复杂性,不稳定的培训程序和非平凡的实施,因此它们很难在现实世界应用中部署。为了解决这个问题,我们利用一个简单的学习程序来训练轻量级的卷积神经网络,在异常检测中达到最先进的表现。在本文中,我们建议将异常检测作为监督回归问题。我们使用连续值的两个可分离分布标记正常和异常数据。为了补偿训练时间中异常样品的不可用,我们利用直接图像增强技术来创建一组不同的样本作为异常。增强集的分布相似,但与正常数据略有偏差,而实际异常将具有进一步的分布。因此,对这些增强样品的训练回归器将导致标签的分布更加可分离,以适应正常和真实的异常数据点。图像和视频数据集的异常检测实验显示了所提出的方法比最新方法的优越性。
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异常检测是确定不符合正常数据分布的样品。由于异常数据的无法获得,培训监督的深神经网络是一项繁琐的任务。因此,无监督的方法是解决此任务的常见方法。深度自动编码器已被广泛用作许多无监督的异常检测方法的基础。但是,深层自动编码器的一个显着缺点是,它们通过概括重建异常值来提供不足的表示异常检测的表示。在这项工作中,我们设计了一个对抗性框架,该框架由两个竞争组件组成,一个对抗性变形者和一个自动编码器。对抗性变形器是一种卷积编码器,学会产生有效的扰动,而自动编码器是一个深层卷积神经网络,旨在重建来自扰动潜在特征空间的图像。这些网络经过相反的目标训练,在这种目标中,对抗性变形者会产生用于编码器潜在特征空间的扰动,以最大化重建误差,并且自动编码器试图中和这些扰动的效果以最大程度地减少它。当应用于异常检测时,该提出的方法会由于对特征空间的扰动应用而学习语义上的富裕表示。所提出的方法在图像和视频数据集上的异常检测中优于现有的最新方法。
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新奇检测是识别不属于目标类分布的样本的任务。在培训期间,缺乏新颖的课程,防止使用传统分类方法。深度自动化器已被广泛用作许多无监督的新奇检测方法的基础。特别地,上下文自动码器在新颖的检测任务中已经成功了,因为他们通过从随机屏蔽的图像重建原始图像来学习的更有效的陈述。然而,上下文AutoEncoders的显着缺点是随机屏蔽不能一致地涵盖输入图像的重要结构,导致次优表示 - 特别是对于新颖性检测任务。在本文中,为了优化输入掩蔽,我们设计了由两个竞争网络,掩模模块和重建器组成的框架。掩码模块是一个卷积的AutoEncoder,用于生成涵盖最重要的图像的最佳掩码。或者,重建器是卷积编码器解码器,其旨在从屏蔽图像重建未受带的图像。网络训练以侵略的方式训练,其中掩模模块生成应用于给予重构的图像的掩码。以这种方式,掩码模块寻求最大化重建错误的重建错误最小化。当应用于新颖性检测时,与上下文自动置换器相比,所提出的方法学习语义上更丰富的表示,并通过更新的屏蔽增强了在测试时间的新颖性检测。 MNIST和CIFAR-10图像数据集上的新奇检测实验证明了所提出的方法对尖端方法的优越性。在用于新颖性检测的UCSD视频数据集的进一步实验中,所提出的方法实现了最先进的结果。
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最新的深度神经网络模型已在受控的高分辨率面部图像上达到了几乎完美的面部识别精度。但是,当他们使用非常低分辨率的面部图像测试时,它们的性能会大大降低。这在监视系统中尤其重要,在监视系统中,低分辨率探测图像应与高分辨率图库图像匹配。超分辨率技术旨在从低分辨率对应物中产生高分辨率的面部图像。尽管它们能够重建视觉上吸引人的图像,但与身份相关的信息尚未保留。在这里,我们提出了一个具有身份的端到端图像到图像翻译的深度神经网络,该网络能够使其高分辨率的高分辨率面孔超级解决方案,同时保留与身份相关的信息。我们通过训练一个非常深的卷积编码器网络来实现这一目标,并在相应层之间具有对称收缩路径。该网络在多尺度的低分辨率条件下训练了重建和具有身份损失的结合。对我们提出的模型的广泛定量评估表明,它在自然和人工低分辨率的面部数据集甚至看不见的身份方面优于竞争超分辨率和低分辨率的面部识别方法。
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Compared to regular cameras, Dynamic Vision Sensors or Event Cameras can output compact visual data based on a change in the intensity in each pixel location asynchronously. In this paper, we study the application of current image-based SLAM techniques to these novel sensors. To this end, the information in adaptively selected event windows is processed to form motion-compensated images. These images are then used to reconstruct the scene and estimate the 6-DOF pose of the camera. We also propose an inertial version of the event-only pipeline to assess its capabilities. We compare the results of different configurations of the proposed algorithm against the ground truth for sequences of two publicly available event datasets. We also compare the results of the proposed event-inertial pipeline with the state-of-the-art and show it can produce comparable or more accurate results provided the map estimate is reliable.
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The purpose of this work was to tackle practical issues which arise when using a tendon-driven robotic manipulator with a long, passive, flexible proximal section in medical applications. A separable robot which overcomes difficulties in actuation and sterilization is introduced, in which the body containing the electronics is reusable and the remainder is disposable. A control input which resolves the redundancy in the kinematics and a physical interpretation of this redundancy are provided. The effect of a static change in the proximal section angle on bending angle error was explored under four testing conditions for a sinusoidal input. Bending angle error increased for increasing proximal section angle for all testing conditions with an average error reduction of 41.48% for retension, 4.28% for hysteresis, and 52.35% for re-tension + hysteresis compensation relative to the baseline case. Two major sources of error in tracking the bending angle were identified: time delay from hysteresis and DC offset from the proximal section angle. Examination of these error sources revealed that the simple hysteresis compensation was most effective for removing time delay and re-tension compensation for removing DC offset, which was the primary source of increasing error. The re-tension compensation was also tested for dynamic changes in the proximal section and reduced error in the final configuration of the tip by 89.14% relative to the baseline case.
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Transformers have recently gained attention in the computer vision domain due to their ability to model long-range dependencies. However, the self-attention mechanism, which is the core part of the Transformer model, usually suffers from quadratic computational complexity with respect to the number of tokens. Many architectures attempt to reduce model complexity by limiting the self-attention mechanism to local regions or by redesigning the tokenization process. In this paper, we propose DAE-Former, a novel method that seeks to provide an alternative perspective by efficiently designing the self-attention mechanism. More specifically, we reformulate the self-attention mechanism to capture both spatial and channel relations across the whole feature dimension while staying computationally efficient. Furthermore, we redesign the skip connection path by including the cross-attention module to ensure the feature reusability and enhance the localization power. Our method outperforms state-of-the-art methods on multi-organ cardiac and skin lesion segmentation datasets without requiring pre-training weights. The code is publicly available at https://github.com/mindflow-institue/DAEFormer.
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A track-before-detect (TBD) particle filter-based method for detection and tracking of low observable objects based on a sequence of image frames in the presence of noise and clutter is studied. At each time instance after receiving a frame of image, first, some preprocessing approaches are applied to the image. Then, it is sent to the detection and tracking algorithm which is based on a particle filter. Performance of the approach is evaluated for detection and tracking of an object in different scenarios including noise and clutter.
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