Neural Architecture Search (NAS) is an automatic technique that can search for well-performed architectures for a specific task. Although NAS surpasses human-designed architecture in many fields, the high computational cost of architecture evaluation it requires hinders its development. A feasible solution is to directly evaluate some metrics in the initial stage of the architecture without any training. NAS without training (WOT) score is such a metric, which estimates the final trained accuracy of the architecture through the ability to distinguish different inputs in the activation layer. However, WOT score is not an atomic metric, meaning that it does not represent a fundamental indicator of the architecture. The contributions of this paper are in three folds. First, we decouple WOT into two atomic metrics which represent the distinguishing ability of the network and the number of activation units, and explore better combination rules named (Distinguishing Activation Score) DAS. We prove the correctness of decoupling theoretically and confirmed the effectiveness of the rules experimentally. Second, in order to improve the prediction accuracy of DAS to meet practical search requirements, we propose a fast training strategy. When DAS is used in combination with the fast training strategy, it yields more improvements. Third, we propose a dataset called Darts-training-bench (DTB), which fills the gap that no training states of architecture in existing datasets. Our proposed method has 1.04$\times$ - 1.56$\times$ improvements on NAS-Bench-101, Network Design Spaces, and the proposed DTB.
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Accurate airway extraction from computed tomography (CT) images is a critical step for planning navigation bronchoscopy and quantitative assessment of airway-related chronic obstructive pulmonary disease (COPD). The existing methods are challenging to sufficiently segment the airway, especially the high-generation airway, with the constraint of the limited label and cannot meet the clinical use in COPD. We propose a novel two-stage 3D contextual transformer-based U-Net for airway segmentation using CT images. The method consists of two stages, performing initial and refined airway segmentation. The two-stage model shares the same subnetwork with different airway masks as input. Contextual transformer block is performed both in the encoder and decoder path of the subnetwork to finish high-quality airway segmentation effectively. In the first stage, the total airway mask and CT images are provided to the subnetwork, and the intrapulmonary airway mask and corresponding CT scans to the subnetwork in the second stage. Then the predictions of the two-stage method are merged as the final prediction. Extensive experiments were performed on in-house and multiple public datasets. Quantitative and qualitative analysis demonstrate that our proposed method extracted much more branches and lengths of the tree while accomplishing state-of-the-art airway segmentation performance. The code is available at https://github.com/zhaozsq/airway_segmentation.
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Various depth estimation models are now widely used on many mobile and IoT devices for image segmentation, bokeh effect rendering, object tracking and many other mobile tasks. Thus, it is very crucial to have efficient and accurate depth estimation models that can run fast on low-power mobile chipsets. In this Mobile AI challenge, the target was to develop deep learning-based single image depth estimation solutions that can show a real-time performance on IoT platforms and smartphones. For this, the participants used a large-scale RGB-to-depth dataset that was collected with the ZED stereo camera capable to generated depth maps for objects located at up to 50 meters. The runtime of all models was evaluated on the Raspberry Pi 4 platform, where the developed solutions were able to generate VGA resolution depth maps at up to 27 FPS while achieving high fidelity results. All models developed in the challenge are also compatible with any Android or Linux-based mobile devices, their detailed description is provided in this paper.
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作为一种成功的自我监督学习方法,对比学习旨在学习输入样本扭曲之间共享的不变信息。尽管对比度学习在抽样策略和架构设计方面取得了持续的进步,但仍然存在两个持续的缺陷:任务 - 核定信息的干扰和样本效率低下,这与琐碎的恒定解决方案的反复存在有关。从维度分析的角度来看,我们发现尺寸的冗余和尺寸混杂因素是现象背后的内在问题,并提供了实验证据来支持我们的观点。我们进一步提出了一种简单而有效的方法metamask,这是元学习学到的维度面膜的缩写,以学习反对维度冗余和混杂因素的表示形式。 MetAmask采用冗余技术来解决尺寸的冗余问题,并创新地引入了尺寸掩模,以减少包含混杂因子的特定维度的梯度效应,该效果通过采用元学习范式进行培训,以改善掩盖掩盖性能的目标典型的自我监督任务的表示。与典型的对比方法相比,我们提供了坚实的理论分析以证明元掩体可以获得下游分类的更严格的风险范围。从经验上讲,我们的方法在各种基准上实现了最先进的性能。
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很少有学习模型学习人类注释有限,而这种学习范式在各种任务中证明了实用性数据使该模型无法充分探索语义信息。为了解决这个问题,我们将知识蒸馏引入了几个弹出的对象检测学习范式。我们进一步进行了激励实验,该实验表明,在知识蒸馏的过程中,教师模型的经验误差将少数拍物对象检测模型的预测性能(作为学生)退化。为了了解这种现象背后的原因,我们从因果理论的角度重新审视了几个对象检测任务上知识蒸馏的学习范式,并因此发展了一个结构性因果模型。遵循理论指导,我们建议使用基于后门调整的知识蒸馏方法,用于少数拍物检测任务,即Disentangle和Remerge(D&R),以对相应的结构性因果模型进行有条件的因果干预。从理论上讲,我们为后门标准提供了扩展的定义,即一般后门路径,可以在特定情况下扩展后门标准的理论应用边界。从经验上讲,多个基准数据集上的实验表明,D&R可以在几个射击对象检测中产生显着的性能提升。
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深度学习在计算机视觉方面取得了巨大的成功,而由于数据注释的稀缺性,医疗图像细分(MIS)仍然是一个挑战。几次分割的元学习技术(meta-fs)已被广泛用于应对这一挑战,而它们忽略了查询图像和支持集之间可能的分配变化。相比之下,经验丰富的临床医生可以通过从查询图像中借用信息,然后相应地对其(她)先前的认知模型进行微调或校准。在此灵感的启发下,我们提出了一种Q-NET,这是一种质疑的Meta-FSS方法,它在精神上模仿了专家临床医生的学习机制。我们基于ADNET构建Q-NET,这是一种最近提出的异常检测启发方法。具体而言,我们将两个查询信息的计算模块添加到ADNET中,即一个查询信息的阈值适应模块和一个查询信息的原型细化模块。将它们与特征提取模块的双路扩展相结合,Q-NET在两个广泛使用的数据集上实现了最先进的性能,分别由腹部MR图像和心脏MR图像组成。我们的作品通过利用查询信息来改善元FSS技术的新颖方法。
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从一个非常少数标记的样品中学习新颖的课程引起了机器学习区域的越来越高。最近关于基于元学习或转移学习的基于范例的研究表明,良好特征空间的获取信息可以是在几次拍摄任务上实现有利性能的有效解决方案。在本文中,我们提出了一种简单但有效的范式,该范式解耦了学习特征表示和分类器的任务,并且只能通过典型的传送学习培训策略从基类嵌入体系结构的特征。为了在每个类别内保持跨基地和新类别和辨别能力的泛化能力,我们提出了一种双路径特征学习方案,其有效地结合了与对比特征结构的结构相似性。以这种方式,内部级别对齐和级别的均匀性可以很好地平衡,并且导致性能提高。三个流行基准测试的实验表明,当与简单的基于原型的分类器结合起来时,我们的方法仍然可以在电感或转换推理设置中的标准和广义的几次射击问题达到有希望的结果。
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知识图形嵌入(KGE)旨在学习实体和关系的陈述。大多数KGE模型取得了巨大的成功,特别是在外推情景中。具体地,考虑到看不见的三倍(H,R,T),培训的模型仍然可以正确地预测(H,R,Δ)或H(Δ,r,t),这种外推能力令人印象深刻。但是,大多数现有的KGE工作侧重于设计精致三重建模功能,主要告诉我们如何衡量观察三元的合理性,但是对为什么可以推断到未看见数据的原因有限的解释,以及什么是重要因素帮助Kge外推。因此,在这项工作中,我们试图研究kge外推两个问题:1。凯格如何推断出看看的数据? 2.如何设计KGE模型,具有更好的外推能力?对于问题1,我们首先分别讨论外推和关系,实体和三级的影响因素,提出了三种语义证据(SES),可以从列车集中观察,并为推断提供重要的语义信息。然后我们通过对几种典型KGE方法的广泛实验验证SES的有效性。对于问题2,为了更好地利用三个级别的SE,我们提出了一种新的基于GNN的KGE模型,称为语义证据意识图形神经网络(SE-GNN)。在SE-GNN中,每个级别的SE由相应的邻居图案明确地建模,并且通过多层聚合充分合并,这有助于获得更多外推知识表示。最后,通过对FB15K-237和WN18RR数据集的广泛实验,我们认为SE-GNN在知识图表完成任务上实现了最先进的性能,并执行更好的外推能力。
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传统的检测网络通常需要丰富的标记训练样本,而人类可以只有几个例子逐步学习新概念。本文侧重于更具挑战性,而是逼真的类渐进的少量对象检测问题(IFSD)。它旨在逐渐逐渐地将新型对象的模型转移到几个注释的样本中,而不会灾难性地忘记先前学识的样本。为了解决这个问题,我们提出了一种新的方法,最小的方法可以减少遗忘,更少的培训资源和更强的转移能力。具体而言,我们首先介绍转移策略,以减少不必要的重量适应并改善IFSD的传输能力。在此基础上,我们使用较少的资源消耗方法整合知识蒸馏技术来缓解遗忘,并提出基于新的基于聚类的示例选择过程,以保持先前学习的更多辨别特征。作为通用且有效的方法,最多可以在很大程度上提高各种基准测试的IFSD性能。
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Deep neural networks (DNNs) are found to be vulnerable to adversarial attacks, and various methods have been proposed for the defense. Among these methods, adversarial training has been drawing increasing attention because of its simplicity and effectiveness. However, the performance of the adversarial training is greatly limited by the architectures of target DNNs, which often makes the resulting DNNs with poor accuracy and unsatisfactory robustness. To address this problem, we propose DSARA to automatically search for the neural architectures that are accurate and robust after adversarial training. In particular, we design a novel cell-based search space specially for adversarial training, which improves the accuracy and the robustness upper bound of the searched architectures by carefully designing the placement of the cells and the proportional relationship of the filter numbers. Then we propose a two-stage search strategy to search for both accurate and robust neural architectures. At the first stage, the architecture parameters are optimized to minimize the adversarial loss, which makes full use of the effectiveness of the adversarial training in enhancing the robustness. At the second stage, the architecture parameters are optimized to minimize both the natural loss and the adversarial loss utilizing the proposed multi-objective adversarial training method, so that the searched neural architectures are both accurate and robust. We evaluate the proposed algorithm under natural data and various adversarial attacks, which reveals the superiority of the proposed method in terms of both accurate and robust architectures. We also conclude that accurate and robust neural architectures tend to deploy very different structures near the input and the output, which has great practical significance on both hand-crafting and automatically designing of accurate and robust neural architectures.
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