磁共振成像是临床诊断的重要工具。但是,它遭受了漫长的收购时间。深度学习的利用,尤其是深层生成模型,在磁共振成像中提供了积极的加速和更好的重建。然而,学习数据分布作为先验知识并从有限数据中重建图像仍然具有挑战性。在这项工作中,我们提出了一种新颖的Hankel-K空间生成模型(HKGM),该模型可以从一个k-空间数据的训练集中生成样品。在先前的学习阶段,我们首先从k空间数据构建一个大的Hankel矩阵,然后从大型Hankel矩阵中提取多个结构化的K空间贴片,以捕获不同斑块之间的内部分布。从Hankel矩阵中提取斑块使生成模型可以从冗余和低级别的数据空间中学习。在迭代重建阶段,可以观察到所需的解决方案遵守学识渊博的先验知识。通过将其作为生成模型的输入来更新中间重建解决方案。然后,通过对测量数据对其Hankel矩阵和数据一致性组合施加低排名的惩罚来替代地进行操作。实验结果证实,单个K空间数据中斑块的内部统计数据具有足够的信息来学习强大的生成模型并提供最新的重建。
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我们调查了无线网络中多个联合学习(FL)服务的数据质量感知动态客户选择问题,每个客户都有动态数据集,用于同时培训多个FL服务,每种FL服务都必须为客户付费。限制货币预算。在训练回合中,这个问题被正式化为不合作的马尔可夫游戏。提出了一种基于多代理的混合增强算法,以优化共同的客户选择和付款操作,同时避免采取行动冲突。仿真结果表明,我们提出的算法可以显着改善训练性能。
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需求估计在动态定价中起着重要的作用,在动态定价中,可以通过基于需求曲线最大化收入来获得最佳价格。在在线酒店预订平台中,房间的需求或占用率随着房间类型而变化,随着时间的推移变化,因此获得准确的占用估算是一项挑战。在本文中,我们提出了一种新颖的酒店需求功能,该功能明确地模拟了对占用预测需求需求的价格弹性,并设计了价格弹性预测模型,以了解各种影响因素的动态价格弹性系数。我们的模型由精心设计的弹性学习模块组成,以减轻内生性问题,并在多任务框架中接受培训以解决数据稀疏性。我们在现实世界数据集上进行了全面的实验,并验证方法优于最先进的基准,以实现占用预测和动态定价。
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LIDC-IDRI数据库是肺癌预测的最流行的基准。但是,通过放射科医生的主观评估,LIDC中的结节可能与病理基础真理具有完全不同的恶性注释,从而引入了标签分配错误,并在培训期间引起了后续的监督偏见。因此,LIDC数据库需要更多的客观标签来基于学习的癌症预测。基于一个额外的小数据集,该数据集包含通过病理检查诊断的180个结节,我们建议重新标记LIDC数据,以减轻对此强大基准测试的原始注释偏差的影响。我们在本文中证明,基于度量学习的类似结节检索提供新标签将是一种有效的重新标记策略。对这些重新标记的LIDC结节进行的培训可改善模型性能,当添加不确定的结节的新标签时,这将增强。我们进一步推断出,重新标记的LIDC是最终的良好肺癌预测的方便方法,同时构建大型病理预处理的结节数据库提供了长期解决方案。
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近年来,基于深度学习的平行成像(PI)取得了巨大进展,以加速磁共振成像(MRI)。然而,现有方法的性能和鲁棒性仍然可以是不受欢迎的。在这项工作中,我们建议通过柔性PI重建,创建的重量K-Space Genera-Tive模型(WKGM)来探索K空间域学习。具体而言,WKGM是一种通用的K空间域模型,在其中有效地纳入了K空间加权技术和高维空间增强设计,用于基于得分的Genererative模型训练,从而实现良好和强大的重建。此外,WKGM具有灵活性,因此可以与各种传统的K空间PI模型协同结合,从而产生基于学习的先验以产生高保真重建。在具有不同采样模式和交流电因子的数据集上进行实验性重新构建表明,WKGM可以通过先验良好的K-Space生成剂获得最新的重建结果。
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在过去几年中,深度卷积神经网络在低光图像增强中取得了令人印象深刻的成功。深度学习方法大多通过堆叠网络结构并加深网络深度来提高特征提取的能力。在单个时导致更多的运行时间成本为了减少推理时间,在完全提取本地特征和全局特征的同时,我们通过SGN定期,我们提出了基于广泛的自我引导网络(Absgn)的现实世界低灯图像增强。策略是一种广泛的策略处理不同曝光的噪音。所提出的网络被许多主流基准验证.Aditional实验结果表明,所提出的网络优于最先进的低光图像增强解决方案。
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在将人重新识别(REID)模型部署在安全关键型应用程序中时,它是关键,以了解模型的鲁棒性,以反对不同的图像损坏阵列。但是,当前对人的评估Reid仅考虑干净数据集的性能,并忽略各种损坏方案中的图像。在这项工作中,我们全面建立了六种Reid基准,用于学习腐败不变的代表。在Reid领域,我们是第一个在单个和跨模式数据集中开展腐败腐败的彻底研究,包括市场-1501,CUHK03,MSMT17,REGDB,SYSU-MM01。在再现和检查最近的REID方法的鲁棒性能后,我们有一些观察结果:1)基于变压器的模型对损坏的图像更加强大,与基于CNN的模型相比,2)增加了随机擦除的概率(常用的增强方法)伤害模型腐败鲁棒性,3)交叉数据集泛化改善腐败鲁棒性增加。通过分析上述观察,我们提出了一个强大的基线,对单一和跨型号的内部数据集,实现了对不同腐败的改善的鲁棒性。我们的代码可在https://github.com/minghuichen43/cil -reid上获得。
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Although recent deep learning methods, especially generative models, have shown good performance in fast magnetic resonance imaging, there is still much room for improvement in high-dimensional generation. Considering that internal dimensions in score-based generative models have a critical impact on estimating the gradient of the data distribution, we present a new idea, low-rank tensor assisted k-space generative model (LR-KGM), for parallel imaging reconstruction. This means that we transform original prior information into high-dimensional prior information for learning. More specifically, the multi-channel data is constructed into a large Hankel matrix and the matrix is subsequently folded into tensor for prior learning. In the testing phase, the low-rank rotation strategy is utilized to impose low-rank constraints on tensor output of the generative network. Furthermore, we alternately use traditional generative iterations and low-rank high-dimensional tensor iterations for reconstruction. Experimental comparisons with the state-of-the-arts demonstrated that the proposed LR-KGM method achieved better performance.
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The recently developed discrete diffusion models perform extraordinarily well in the text-to-image task, showing significant promise for handling the multi-modality signals. In this work, we harness these traits and present a unified multimodal generation model that can conduct both the "modality translation" and "multi-modality generation" tasks using a single model, performing text-based, image-based, and even vision-language simultaneous generation. Specifically, we unify the discrete diffusion process for multimodal signals by proposing a unified transition matrix. Moreover, we design a mutual attention module with fused embedding layer and a unified objective function to emphasise the inter-modal linkages, which are vital for multi-modality generation. Extensive experiments indicate that our proposed method can perform comparably to the state-of-the-art solutions in various generation tasks.
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Point cloud completion, as the upstream procedure of 3D recognition and segmentation, has become an essential part of many tasks such as navigation and scene understanding. While various point cloud completion models have demonstrated their powerful capabilities, their robustness against adversarial attacks, which have been proven to be fatally malicious towards deep neural networks, remains unknown. In addition, existing attack approaches towards point cloud classifiers cannot be applied to the completion models due to different output forms and attack purposes. In order to evaluate the robustness of the completion models, we propose PointCA, the first adversarial attack against 3D point cloud completion models. PointCA can generate adversarial point clouds that maintain high similarity with the original ones, while being completed as another object with totally different semantic information. Specifically, we minimize the representation discrepancy between the adversarial example and the target point set to jointly explore the adversarial point clouds in the geometry space and the feature space. Furthermore, to launch a stealthier attack, we innovatively employ the neighbourhood density information to tailor the perturbation constraint, leading to geometry-aware and distribution-adaptive modifications for each point. Extensive experiments against different premier point cloud completion networks show that PointCA can cause a performance degradation from 77.9% to 16.7%, with the structure chamfer distance kept below 0.01. We conclude that existing completion models are severely vulnerable to adversarial examples, and state-of-the-art defenses for point cloud classification will be partially invalid when applied to incomplete and uneven point cloud data.
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