We consider a class of Riemannian optimization problems where the objective is the sum of a smooth function and a nonsmooth function, considered in the ambient space. This class of problems finds important applications in machine learning and statistics such as the sparse principal component analysis, sparse spectral clustering, and orthogonal dictionary learning. We propose a Riemannian alternating direction method of multipliers (ADMM) to solve this class of problems. Our algorithm adopts easily computable steps in each iteration. The iteration complexity of the proposed algorithm for obtaining an $\epsilon$-stationary point is analyzed under mild assumptions. To the best of our knowledge, this is the first Riemannian ADMM with provable convergence guarantee for solving Riemannian optimization problem with nonsmooth objective. Numerical experiments are conducted to demonstrate the advantage of the proposed method.
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我们考虑了一个联合表示的学习框架,在中央服务器的协助下,一组$ n $分布式客户通过其私人数据协作培训一组实体的表示(或嵌入)(例如,用户在一个中的用户社交网络)。在此框架下,对于以私人方式汇总在客户培训的本地嵌入的关键步骤,我们开发了一个名为SECEA的安全嵌入聚合协议,该协议为一组实体提供信息理论隐私保证,并在每个客户端提供相应的嵌入$同时$ $,对好奇的服务器和最多$ t <n/2 $勾结的客户。作为SECEA的第一步,联合学习系统执行了一个私人实体联盟,让每个客户在不知道哪个实体属于哪个客户的情况下学习系统中的所有实体。在每个聚合回合中,使用Lagrange插值在客户端中秘密共享本地嵌入,然后每个客户端构造编码的查询以检索预期实体的聚合嵌入。我们对各种表示的学习任务进行全面的实验,以评估SECEA的效用和效率,并从经验上证明,与没有(或具有较弱的)隐私保证的嵌入聚合协议相比,SECEA会造成可忽略的绩效损失(5%以内); SECEA的附加计算潜伏期减小,用于培训较大数据集的更深层次模型。
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联邦学习(FL)发现了基于智能手机应用程序的机器学习应用程序中的许多重要应用。尽管已经对FL进行了许多算法,但据我们所知,尚未研究具有非Convex约束的FL算法。本文研究了Riemannian歧管的FL,该歧管发现了重要的应用,例如联合PCA和联合KPCA。我们提出了一种riemannian联合SVRG(RFEDSVRG)方法,以求解对Riemannian歧管的联合优化。我们在不同情况下分析其收敛速率。进行数值实验以将RFEDSVRG与FedAvg和FedProx的Riemannian对应物进行比较。我们从数值实验中观察到RFEDSVRG的优势很重要。
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预先接受的语言模型实现了最先进的导致各种自然语言处理(NLP)任务。 GPT-3表明,缩放预先训练的语言模型可以进一步利用它们的巨大潜力。最近提出了一个名为Ernie 3.0的统一框架,以预先培训大型知识增强型号,并培训了具有10亿参数的模型。 Ernie 3.0在各种NLP任务上表现出最先进的模型。为了探讨缩放的表现,我们培养了百卢比的3.0泰坦参数型号,在PaddlePaddle平台上有高达260亿参数的泰坦。此外,我们设计了一种自我监督的对抗性损失和可控语言建模损失,以使ERNIE 3.0 TITAN产生可信和可控的文本。为了减少计算开销和碳排放,我们向Ernie 3.0泰坦提出了一个在线蒸馏框架,教师模型将同时教授学生和培训。埃塞尼3.0泰坦是迄今为止最大的中国密集预训练模型。经验结果表明,Ernie 3.0泰坦在68个NLP数据集中优于最先进的模型。
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Recognition of facial expression is a challenge when it comes to computer vision. The primary reasons are class imbalance due to data collection and uncertainty due to inherent noise such as fuzzy facial expressions and inconsistent labels. However, current research has focused either on the problem of class imbalance or on the problem of uncertainty, ignoring the intersection of how to address these two problems. Therefore, in this paper, we propose a framework based on Resnet and Attention to solve the above problems. We design weight for each class. Through the penalty mechanism, our model will pay more attention to the learning of small samples during training, and the resulting decrease in model accuracy can be improved by a Convolutional Block Attention Module (CBAM). Meanwhile, our backbone network will also learn an uncertain feature for each sample. By mixing uncertain features between samples, the model can better learn those features that can be used for classification, thus suppressing uncertainty. Experiments show that our method surpasses most basic methods in terms of accuracy on facial expression data sets (e.g., AffectNet, RAF-DB), and it also solves the problem of class imbalance well.
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We consider the problem of finding an accurate representation of neuron shapes, extracting sub-cellular features, and classifying neurons based on neuron shapes. In neuroscience research, the skeleton representation is often used as a compact and abstract representation of neuron shapes. However, existing methods are limited to getting and analyzing "curve" skeletons which can only be applied for tubular shapes. This paper presents a 3D neuron morphology analysis method for more general and complex neuron shapes. First, we introduce the concept of skeleton mesh to represent general neuron shapes and propose a novel method for computing mesh representations from 3D surface point clouds. A skeleton graph is then obtained from skeleton mesh and is used to extract sub-cellular features. Finally, an unsupervised learning method is used to embed the skeleton graph for neuron classification. Extensive experiment results are provided and demonstrate the robustness of our method to analyze neuron morphology.
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Most Deep Learning (DL) based Compressed Sensing (DCS) algorithms adopt a single neural network for signal reconstruction, and fail to jointly consider the influences of the sampling operation for reconstruction. In this paper, we propose unified framework, which jointly considers the sampling and reconstruction process for image compressive sensing based on well-designed cascade neural networks. Two sub-networks, which are the sampling sub-network and the reconstruction sub-network, are included in the proposed framework. In the sampling sub-network, an adaptive full connected layer instead of the traditional random matrix is used to mimic the sampling operator. In the reconstruction sub-network, a cascade network combining stacked denoising autoencoder (SDA) and convolutional neural network (CNN) is designed to reconstruct signals. The SDA is used to solve the signal mapping problem and the signals are initially reconstructed. Furthermore, CNN is used to fully recover the structure and texture features of the image to obtain better reconstruction performance. Extensive experiments show that this framework outperforms many other state-of-the-art methods, especially at low sampling rates.
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Indoor scenes typically exhibit complex, spatially-varying appearance from global illumination, making inverse rendering a challenging ill-posed problem. This work presents an end-to-end, learning-based inverse rendering framework incorporating differentiable Monte Carlo raytracing with importance sampling. The framework takes a single image as input to jointly recover the underlying geometry, spatially-varying lighting, and photorealistic materials. Specifically, we introduce a physically-based differentiable rendering layer with screen-space ray tracing, resulting in more realistic specular reflections that match the input photo. In addition, we create a large-scale, photorealistic indoor scene dataset with significantly richer details like complex furniture and dedicated decorations. Further, we design a novel out-of-view lighting network with uncertainty-aware refinement leveraging hypernetwork-based neural radiance fields to predict lighting outside the view of the input photo. Through extensive evaluations on common benchmark datasets, we demonstrate superior inverse rendering quality of our method compared to state-of-the-art baselines, enabling various applications such as complex object insertion and material editing with high fidelity. Code and data will be made available at \url{https://jingsenzhu.github.io/invrend}.
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由于单峰生物识别系统的不稳定性和局限性,多模式系统吸引了研究人员的关注。但是,如何利用不同方式之间的独立和互补信息仍然是一个关键和具有挑战性的问题。在本文中,我们提出了一种基于指纹和手指静脉的多模式融合识别算法(指纹手指静脉 - 通道 - 通道空间注意融合模块,FPV-CSAFM)。具体而言,对于每对指纹和手指静脉图像,我们首先提出一个简单有效的卷积神经网络(CNN)来提取特征。然后,我们构建一个多模式融合模块(通道空间注意融合模块,CSAFM),以完全融合指纹和指纹之间的互补信息。与现有的融合策略不同,我们的融合方法可以根据渠道和空间维度不同模态的重要性动态调整融合权重,以便更好地将信息之间的信息更好地结合在一起,并提高整体识别性能。为了评估我们方法的性能,我们在多个公共数据集上进行了一系列实验。实验结果表明,所提出的FPV-CSAFM基于指纹和手指静脉在三个多模式数据集上实现了出色的识别性能。
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本文提出了一种延时3D细胞分析的方法。具体而言,我们考虑了准确定位和定量分析亚细胞特征的问题,以及从延时3D共聚焦细胞图像堆栈跟踪单个细胞的问题。细胞的异质性和多维图像的体积提出了对细胞形态发生和发育的完全自动化分析的主要挑战。本文是由路面细胞生长过程和构建定量形态发生模型的动机。我们提出了一种基于深度特征的分割方法,以准确检测和标记每个细胞区域。基于邻接图的方法用于提取分段细胞的亚细胞特征。最后,提出了使用多个单元格特征的基于强大的图形跟踪算法在不同的时间实例中关联单元格。提供了广泛的实验结果,并证明了所提出的方法的鲁棒性。该代码可在GitHub上获得,该方法可通过Bisque Portal作为服务可用。
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