联合优化(FedOpt),在大量分布式客户端协作培训学习模型的目标是对联邦学习的重要性。 Fedopt的主要问题可归因于模型分歧和通信效率,这显着影响了性能。在本文中,我们提出了一种新方法,即Losac,更有效地从异构分布式数据中学习。它的关键算法洞察力是在{每个}常规本地模型更新之后本地更新全局全梯度的估计。因此,Losac可以使客户的信息以更紧凑的方式刷新。特别是,我们研究了Losac的收敛结果。此外,Losac的奖金是能够从最近的技术泄漏梯度(DLG)中捍卫信息泄漏。最后,实验已经验证了与最先进的FedOpt算法比较Losac的优越性。具体而言,Losac平均超过100美元的价格提高了通信效率,减轻了模型分歧问题,并配备了对抗DLG的防御能力。
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This paper studies the distribution estimation of contaminated data by the MoM-GAN method, which combines generative adversarial net (GAN) and median-of-mean (MoM) estimation. We use a deep neural network (DNN) with a ReLU activation function to model the generator and discriminator of the GAN. Theoretically, we derive a non-asymptotic error bound for the DNN-based MoM-GAN estimator measured by integral probability metrics with the $b$-smoothness H\"{o}lder class. The error bound decreases essentially as $n^{-b/p}\vee n^{-1/2}$, where $n$ and $p$ are the sample size and the dimension of input data. We give an algorithm for the MoM-GAN method and implement it through two real applications. The numerical results show that the MoM-GAN outperforms other competitive methods when dealing with contaminated data.
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The processing and recognition of geoscience images have wide applications. Most of existing researches focus on understanding the high-quality geoscience images by assuming that all the images are clear. However, in many real-world cases, the geoscience images might contain occlusions during the image acquisition. This problem actually implies the image inpainting problem in computer vision and multimedia. To the best of our knowledge, all the existing image inpainting algorithms learn to repair the occluded regions for a better visualization quality, they are excellent for natural images but not good enough for geoscience images by ignoring the geoscience related tasks. This paper aims to repair the occluded regions for a better geoscience task performance with the advanced visualization quality simultaneously, without changing the current deployed deep learning based geoscience models. Because of the complex context of geoscience images, we propose a coarse-to-fine encoder-decoder network with coarse-to-fine adversarial context discriminators to reconstruct the occluded image regions. Due to the limited data of geoscience images, we use a MaskMix based data augmentation method to exploit more information from limited geoscience image data. The experimental results on three public geoscience datasets for remote sensing scene recognition, cross-view geolocation and semantic segmentation tasks respectively show the effectiveness and accuracy of the proposed method.
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在本文中,我们考虑了使用$ \ ell_1 $ regularized logistic回归的方法来估算与高维iSing模型相关的图形的元学习问题,用于每个节点的邻域选择。我们的目标是在学习新任务中使用从辅助任务中学到的信息来降低其足够的样本复杂性。为此,我们提出了一种新颖的生成模型以及不当的估计方法。在我们的设置中,所有任务均为\ emph {相似}在其\ emph {Random}模型参数和支持中。通过将所有样品从辅助任务汇总到\ emph {不正确}估计一个参数向量,我们可以恢复假定的尺寸很小的真实支持联合,具有很高的概率,具有足够的样品复杂性为$ \ omega(1) $每任务,对于$ k = \ omega(d^3 \ log P)$具有$ p $节点和最大邻域大小$ d $的ISING型号的任务。然后,在对新任务的支持仅限于估计的支持联盟的支持下,我们证明,可以通过降低$ \ omega(d^3 \ log d)$的足够样品复杂性来获得新任务的一致邻居选择。
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在统计和机器学习中具有重尾数据的模型开发强大的估计估计兴趣兴趣。本文提出了一个用于大家庭统计回归的日志截断的M估计,并在数据具有$ \ varepsilon \中的数据(0,1] $。随着相关风险函数的额外假设,我们获得了估计的$ \ ell_2 $ -Error绑定。我们的定理应用于建立具体回归的强大M估计。除了凸面回归等分位数回归之外广义线性模型,许多非凸回归也可以符合我们的定理,我们专注于强大的深度神经网络回归,这可以通过随机梯度下降算法解决。模拟和实际数据分析证明了日志截断估计的优越性超过标准估计。
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在机器学习和高维统计领域的有限样本理论中,恒定指定的浓度不平等至关重要。我们获得了独立亚网络随机变量总和的更清晰和常数的浓度不平等,这导致了两个尾巴的混合物:尺寸的小偏差和较大偏差的小偏差。这些界限是新的,并通过更清晰的常数改善了现有的界限。另外,如果应保留斜体,则新的子韦布尔参数。请检查整个文本。还提出了提出的,它可以为随机变量(向量)恢复紧密浓度不平等。对于统计应用,我们给出了$ \ ell_2 $ - 估计系数在负二项式回归中的估计系数时,当重尾协变量是稀疏结构分布的亚weibull时,这是负二项式回归的新结果。在应用随机矩阵时,我们得出了Bai-Yin定理的非反应版本,用于具有指数尾巴边界的亚weibull条目。最后,通过为没有第二瞬间条件的对数截断的Z-测验器演示一个子静电区域,我们讨论并定义了独立观测值的sub-weibull类型稳健估计器$ \ {x_i \} _ {i = 1 }^{n} $没有指数矩条件。
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Deep learning models can achieve high accuracy when trained on large amounts of labeled data. However, real-world scenarios often involve several challenges: Training data may become available in installments, may originate from multiple different domains, and may not contain labels for training. Certain settings, for instance medical applications, often involve further restrictions that prohibit retention of previously seen data due to privacy regulations. In this work, to address such challenges, we study unsupervised segmentation in continual learning scenarios that involve domain shift. To that end, we introduce GarDA (Generative Appearance Replay for continual Domain Adaptation), a generative-replay based approach that can adapt a segmentation model sequentially to new domains with unlabeled data. In contrast to single-step unsupervised domain adaptation (UDA), continual adaptation to a sequence of domains enables leveraging and consolidation of information from multiple domains. Unlike previous approaches in incremental UDA, our method does not require access to previously seen data, making it applicable in many practical scenarios. We evaluate GarDA on two datasets with different organs and modalities, where it substantially outperforms existing techniques.
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The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.
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As one of the prevalent methods to achieve automation systems, Imitation Learning (IL) presents a promising performance in a wide range of domains. However, despite the considerable improvement in policy performance, the corresponding research on the explainability of IL models is still limited. Inspired by the recent approaches in explainable artificial intelligence methods, we proposed a model-agnostic explaining framework for IL models called R2RISE. R2RISE aims to explain the overall policy performance with respect to the frames in demonstrations. It iteratively retrains the black-box IL model from the randomized masked demonstrations and uses the conventional evaluation outcome environment returns as the coefficient to build an importance map. We also conducted experiments to investigate three major questions concerning frames' importance equality, the effectiveness of the importance map, and connections between importance maps from different IL models. The result shows that R2RISE successfully distinguishes important frames from the demonstrations.
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Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.
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