最近,未经训练的神经网络(UNNS)显示了在随机采样轨迹上对MR图像重建的令人满意的性能,而无需使用其他全面采样训练数据。但是,现有的基于UNN的方法并未完全使用MR图像物理先验,导致某些常见情况(例如部分傅立叶,常规采样等)的性能差,并且缺乏重建准确性的理论保证。为了弥合这一差距,我们使用特殊设计的UNN提出了一种保障的K空间插值方法,该方法使用特殊设计的UNN,该方法由MR图像的三个物理先验(或K空间数据)驱动,包括稀疏,线圈灵敏度平稳性和相位平滑度。我们还证明,所提出的方法保证了插值K空间数据准确性的紧密界限。最后,消融实验表明,所提出的方法比现有传统方法更准确地表征了MR图像的物理先验。此外,在一系列常用的采样轨迹下,实验还表明,所提出的方法始终优于传统的平行成像方法和现有的UNN,甚至超过了最先进的监督训练的K空间深度学习方法案例。
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最近,对深度学习进行了广泛的研究,以加速动态磁共振(MR)成像,并取得了令人鼓舞的进步。但是,如果没有完全采样的参考数据进行培训,当前方法可能在恢复细节或结构方面具有有限的能力。为了应对这一挑战,本文提出了一个自我监督的协作学习框架(SelfCollearn),以从无效的K-Space数据中进行准确的动态MR图像重建。拟议的框架配备了三个重要组成部分,即双网络协作学习,重新启动数据增强和专门设计的共同培训损失。该框架可以灵活地与数据驱动的网络和基于模型的迭代未滚动网络集成。我们的方法已在体内数据集上进行了评估,并将其与四种最新方法进行了比较。结果表明,我们的方法具有很强的能力,可以从无效的K空间数据捕获直接重建的基本和固有表示形式,因此可以实现高质量且快速的动态MR成像。
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冠状动脉血管造影(CCTA)易受各种扭曲(例如伪影和噪声)的敏感,这严重损害了心血管疾病的确切诊断。适当的CCTA血管级图像质量评估(CCTA VIQA)算法可用于降低错误诊断的风险。 CCTA VIQA的首要挑战是,冠状动脉的本地部分确定最终质量是很难找到的。为了应对挑战,我们将CCTA VIQA作为多种现实学习(MIL)问题,并利用基于变压器的MIL主链(称为T-MIL),以将沿冠状动脉中心线的多个实例汇总为最终质量。但是,并非所有实例都提供最终质量的信息。有一些质量 - 欧元/负面实例介入确切的质量评估(例如,在实例中仅涵盖背景或冠状动脉的实例是无法识别的)。因此,我们提出了一个基于渐进的增强学习的实例丢弃模块(称为PRID),以逐步删除CCTA VIQA的质量 - 欧尔特尔/否定实例。基于上述两个模块,我们根据端到端优化提出了一个加强的变压器网络(RTN),用于自动CCTA VIQA。广泛的实验结果表明,我们提出的方法实现了现实世界中CCTA数据集的最新性能,超过了以前的MIL方法。
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最近,模型驱动的深度学习通过用网络模块替换符号器的一阶信息(即(子)梯度或近端运算符)来拓展到级联网络中的一定迭代算法,该算法呈现出更可说明的与常见的数据驱动网络相比,可以预测。相反,理论上,不一定存在这样的功能常规程序,其一级信息与替换的网络模块匹配,这意味着网络输出可能不被原始正则化模型覆盖。此外,到目前为止,在现实假设下,也没有保证展开网络的全球收敛性和鲁棒性(规律性)。为了弥合这一差距,本文建议在展开网络上提出保障方法。具体而言,专注于加速MRI,我们展开了一个零阶算法,网络模块代表常规器本身,使得网络输出可以仍然被正则化模型覆盖。此外,受到深度均衡模型的理想的启发,在反向化之前,我们执行了展开的迭代网络,以收敛到一个固定点,以确保收敛。如果测量数据包含噪声,我们证明了所提出的网络对嘈杂干扰具有强大。最后,数值实验表明,所提出的网络始终如一地优于最先进的MRI重建方法,包括传统的正规化方法和其他深度学习方法。
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随着深度学习技术的快速发展和计算能力的提高,深度学习已广泛应用于高光谱图像(HSI)分类领域。通常,深度学习模型通常包含许多可训练参数,并且需要大量标记的样品来实现最佳性能。然而,关于HSI分类,由于手动标记的难度和耗时的性质,大量标记的样本通常难以获取。因此,许多研究工作侧重于建立一个少数标记样本的HSI分类的深层学习模型。在本文中,我们专注于这一主题,并对相关文献提供系统审查。具体而言,本文的贡献是双重的。首先,相关方法的研究进展根据学习范式分类,包括转移学习,积极学习和少量学习。其次,已经进行了许多具有各种最先进的方法的实验,总结了结果以揭示潜在的研究方向。更重要的是,虽然深度学习模型(通常需要足够的标记样本)和具有少量标记样本的HSI场景之间存在巨大差距,但是通过深度学习融合,可以很好地表征小样本集的问题方法和相关技术,如转移学习和轻量级模型。为了再现性,可以在HTTPS://github.com/shuguoj/hsi-classification中找到纸张中评估的方法的源代码.git。
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In this paper, we propose a robust 3D detector, named Cross Modal Transformer (CMT), for end-to-end 3D multi-modal detection. Without explicit view transformation, CMT takes the image and point clouds tokens as inputs and directly outputs accurate 3D bounding boxes. The spatial alignment of multi-modal tokens is performed implicitly, by encoding the 3D points into multi-modal features. The core design of CMT is quite simple while its performance is impressive. CMT obtains 73.0% NDS on nuScenes benchmark. Moreover, CMT has a strong robustness even if the LiDAR is missing. Code will be released at https://github.com/junjie18/CMT.
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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.
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Witnessing the impressive achievements of pre-training techniques on large-scale data in the field of computer vision and natural language processing, we wonder whether this idea could be adapted in a grab-and-go spirit, and mitigate the sample inefficiency problem for visuomotor driving. Given the highly dynamic and variant nature of the input, the visuomotor driving task inherently lacks view and translation invariance, and the visual input contains massive irrelevant information for decision making, resulting in predominant pre-training approaches from general vision less suitable for the autonomous driving task. To this end, we propose PPGeo (Policy Pre-training via Geometric modeling), an intuitive and straightforward fully self-supervised framework curated for the policy pretraining in visuomotor driving. We aim at learning policy representations as a powerful abstraction by modeling 3D geometric scenes on large-scale unlabeled and uncalibrated YouTube driving videos. The proposed PPGeo is performed in two stages to support effective self-supervised training. In the first stage, the geometric modeling framework generates pose and depth predictions simultaneously, with two consecutive frames as input. In the second stage, the visual encoder learns driving policy representation by predicting the future ego-motion and optimizing with the photometric error based on current visual observation only. As such, the pre-trained visual encoder is equipped with rich driving policy related representations and thereby competent for multiple visuomotor driving tasks. Extensive experiments covering a wide span of challenging scenarios have demonstrated the superiority of our proposed approach, where improvements range from 2% to even over 100% with very limited data. Code and models will be available at https://github.com/OpenDriveLab/PPGeo.
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This paper illustrates the technologies of user next intent prediction with a concept knowledge graph. The system has been deployed on the Web at Alipay, serving more than 100 million daily active users. Specifically, we propose AlipayKG to explicitly characterize user intent, which is an offline concept knowledge graph in the Life-Service domain modeling the historical behaviors of users, the rich content interacted by users and the relations between them. We further introduce a Transformer-based model which integrates expert rules from the knowledge graph to infer the online user's next intent. Experimental results demonstrate that the proposed system can effectively enhance the performance of the downstream tasks while retaining explainability.
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Human parsing aims to partition humans in image or video into multiple pixel-level semantic parts. In the last decade, it has gained significantly increased interest in the computer vision community and has been utilized in a broad range of practical applications, from security monitoring, to social media, to visual special effects, just to name a few. Although deep learning-based human parsing solutions have made remarkable achievements, many important concepts, existing challenges, and potential research directions are still confusing. In this survey, we comprehensively review three core sub-tasks: single human parsing, multiple human parsing, and video human parsing, by introducing their respective task settings, background concepts, relevant problems and applications, representative literature, and datasets. We also present quantitative performance comparisons of the reviewed methods on benchmark datasets. Additionally, to promote sustainable development of the community, we put forward a transformer-based human parsing framework, providing a high-performance baseline for follow-up research through universal, concise, and extensible solutions. Finally, we point out a set of under-investigated open issues in this field and suggest new directions for future study. We also provide a regularly updated project page, to continuously track recent developments in this fast-advancing field: https://github.com/soeaver/awesome-human-parsing.
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