语义分割是开发医学图像诊断系统的重要任务。但是,构建注释的医疗数据集很昂贵。因此,在这种情况下,半监督方法很重要。在半监督学习中,标签的质量在模型性能中起着至关重要的作用。在这项工作中,我们提出了一种新的伪标签策略,可提高用于培训学生网络的伪标签的质量。我们遵循多阶段的半监督训练方法,该方法在标记的数据集上训练教师模型,然后使用训练有素的老师将伪标签渲染用于学生培训。通过这样做,伪标签将被更新,并且随着培训的进度更加精确。上一个和我们的方法之间的关键区别在于,我们在学生培训过程中更新教师模型。因此,在学生培训过程中,提高了伪标签的质量。我们还提出了一种简单但有效的策略,以使用动量模型来提高伪标签的质量 - 训练过程中原始模型的慢复制版本。通过应用动量模型与学生培训期间的重新渲染伪标签相结合,我们在五个数据集中平均达到了84.1%的骰子分数(即Kvarsir,CVC-ClinicdB,Etis-laribpolypdb,cvc-colondb,cvc-colondb,cvc-colondb和cvc-300)和CVC-300)只有20%的数据集用作标记数据。我们的结果超过了3%的共同实践,甚至在某些数据集中取得了完全监督的结果。我们的源代码和预培训模型可在https://github.com/sun-asterisk-research/online学习SSL上找到
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We present a new algorithm to learn a deep neural network model robust against adversarial attacks. Previous algorithms demonstrate an adversarially trained Bayesian Neural Network (BNN) provides improved robustness. We recognize the adversarial learning approach for approximating the multi-modal posterior distribution of a Bayesian model can lead to mode collapse; consequently, the model's achievements in robustness and performance are sub-optimal. Instead, we first propose preventing mode collapse to better approximate the multi-modal posterior distribution. Second, based on the intuition that a robust model should ignore perturbations and only consider the informative content of the input, we conceptualize and formulate an information gain objective to measure and force the information learned from both benign and adversarial training instances to be similar. Importantly. we prove and demonstrate that minimizing the information gain objective allows the adversarial risk to approach the conventional empirical risk. We believe our efforts provide a step toward a basis for a principled method of adversarially training BNNs. Our model demonstrate significantly improved robustness--up to 20%--compared with adversarial training and Adv-BNN under PGD attacks with 0.035 distortion on both CIFAR-10 and STL-10 datasets.
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在本文中,我们介绍了一个高质量的大规模基准数据集,用于英语 - 越南语音翻译,其中有508音频小时,由331k的三胞胎组成(句子长度的音频,英语源笔录句,越南人目标subtitle句子)。我们还使用强基础进行了经验实验,发现传统的“级联”方法仍然优于现代“端到端”方法。据我们所知,这是第一个大规模的英语 - 越南语音翻译研究。我们希望我们的公开数据集和研究都可以作为未来研究和英语语音翻译应用的起点。我们的数据集可从https://github.com/vinairesearch/phost获得
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图形神经网络(GNNS)在许多图形挖掘任务中取得了巨大的成功,这些任务从消息传递策略中受益,该策略融合了局部结构和节点特征,从而为更好的图表表示学习。尽管GNN成功,并且与其他类型的深神经网络相似,但发现GNN容易受到图形结构和节点特征的不明显扰动。已经提出了许多对抗性攻击,以披露在不同的扰动策略下创建对抗性例子的GNN的脆弱性。但是,GNNS对成功后门攻击的脆弱性直到最近才显示。在本文中,我们披露了陷阱攻击,这是可转移的图形后门攻击。核心攻击原则是用基于扰动的触发器毒化训练数据集,这可以导致有效且可转移的后门攻击。图形的扰动触发是通过通过替代模型的基于梯度的得分矩阵在图形结构上执行扰动动作来生成的。与先前的作品相比,陷阱攻击在几种方面有所不同:i)利用替代图卷积网络(GCN)模型来生成基于黑盒的后门攻击的扰动触发器; ii)它产生了没有固定模式的样品特异性扰动触发器; iii)在使用锻造中毒训练数据集训练时,在GNN的背景下,攻击转移到了不同​​的GNN模型中。通过对四个现实世界数据集进行广泛的评估,我们证明了陷阱攻击使用四个现实世界数据集在四个不同流行的GNN中构建可转移的后门的有效性
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深度神经网络容易受到来自对抗性投入的攻击,并且最近,特洛伊木马误解或劫持模型的决定。我们通过探索有界抗逆性示例空间和生成的对抗网络内的自然输入空间来揭示有界面的对抗性实例 - 通用自然主义侵害贴片的兴趣类 - 我们呼叫TNT。现在,一个对手可以用一个自然主义的补丁来手臂自己,不太恶意,身体上可实现,高效 - 实现高攻击成功率和普遍性。 TNT是普遍的,因为在场景中的TNT中捕获的任何输入图像都将:i)误导网络(未确定的攻击);或ii)迫使网络进行恶意决定(有针对性的攻击)。现在,有趣的是,一个对抗性补丁攻击者有可能发挥更大的控制水平 - 选择一个独立,自然的贴片的能力,与被限制为嘈杂的扰动的触发器 - 到目前为止只有可能与特洛伊木马攻击方法有可能干扰模型建设过程,以嵌入风险发现的后门;但是,仍然意识到在物理世界中部署的补丁。通过对大型视觉分类任务的广泛实验,想象成在其整个验证集50,000张图像中进行评估,我们展示了TNT的现实威胁和攻击的稳健性。我们展示了攻击的概括,以创建比现有最先进的方法实现更高攻击成功率的补丁。我们的结果表明,攻击对不同的视觉分类任务(CIFAR-10,GTSRB,PUBFIG)和多个最先进的深神经网络,如WieredEnet50,Inception-V3和VGG-16。
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Optimal transport (OT) has become a widely used tool in the machine learning field to measure the discrepancy between probability distributions. For instance, OT is a popular loss function that quantifies the discrepancy between an empirical distribution and a parametric model. Recently, an entropic penalty term and the celebrated Sinkhorn algorithm have been commonly used to approximate the original OT in a computationally efficient way. However, since the Sinkhorn algorithm runs a projection associated with the Kullback-Leibler divergence, it is often vulnerable to outliers. To overcome this problem, we propose regularizing OT with the \beta-potential term associated with the so-called $\beta$-divergence, which was developed in robust statistics. Our theoretical analysis reveals that the $\beta$-potential can prevent the mass from being transported to outliers. We experimentally demonstrate that the transport matrix computed with our algorithm helps estimate a probability distribution robustly even in the presence of outliers. In addition, our proposed method can successfully detect outliers from a contaminated dataset
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In the era of Internet of Things (IoT), network-wide anomaly detection is a crucial part of monitoring IoT networks due to the inherent security vulnerabilities of most IoT devices. Principal Components Analysis (PCA) has been proposed to separate network traffics into two disjoint subspaces corresponding to normal and malicious behaviors for anomaly detection. However, the privacy concerns and limitations of devices' computing resources compromise the practical effectiveness of PCA. We propose a federated PCA-based Grassmannian optimization framework that coordinates IoT devices to aggregate a joint profile of normal network behaviors for anomaly detection. First, we introduce a privacy-preserving federated PCA framework to simultaneously capture the profile of various IoT devices' traffic. Then, we investigate the alternating direction method of multipliers gradient-based learning on the Grassmann manifold to guarantee fast training and the absence of detecting latency using limited computational resources. Empirical results on the NSL-KDD dataset demonstrate that our method outperforms baseline approaches. Finally, we show that the Grassmann manifold algorithm is highly adapted for IoT anomaly detection, which permits drastically reducing the analysis time of the system. To the best of our knowledge, this is the first federated PCA algorithm for anomaly detection meeting the requirements of IoT networks.
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In this paper, we propose a novel architecture, the Enhanced Interactive Transformer (EIT), to address the issue of head degradation in self-attention mechanisms. Our approach replaces the traditional multi-head self-attention mechanism with the Enhanced Multi-Head Attention (EMHA) mechanism, which relaxes the one-to-one mapping constraint among queries and keys, allowing each query to attend to multiple keys. Furthermore, we introduce two interaction models, Inner-Subspace Interaction and Cross-Subspace Interaction, to fully utilize the many-to-many mapping capabilities of EMHA. Extensive experiments on a wide range of tasks (e.g. machine translation, abstractive summarization, grammar correction, language modelling and brain disease automatic diagnosis) show its superiority with a very modest increase in model size.
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Task transfer learning is a popular technique in image processing applications that uses pre-trained models to reduce the supervision cost of related tasks. An important question is to determine task transferability, i.e. given a common input domain, estimating to what extent representations learned from a source task can help in learning a target task. Typically, transferability is either measured experimentally or inferred through task relatedness, which is often defined without a clear operational meaning. In this paper, we present a novel metric, H-score, an easily-computable evaluation function that estimates the performance of transferred representations from one task to another in classification problems using statistical and information theoretic principles. Experiments on real image data show that our metric is not only consistent with the empirical transferability measurement, but also useful to practitioners in applications such as source model selection and task transfer curriculum learning.
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Summary quality assessment metrics have two categories: reference-based and reference-free. Reference-based metrics are theoretically more accurate but are limited by the availability and quality of the human-written references, which are both difficulty to ensure. This inspires the development of reference-free metrics, which are independent from human-written references, in the past few years. However, existing reference-free metrics cannot be both zero-shot and accurate. In this paper, we propose a zero-shot but accurate reference-free approach in a sneaky way: feeding documents, based upon which summaries generated, as references into reference-based metrics. Experimental results show that this zero-shot approach can give us the best-performing reference-free metrics on nearly all aspects on several recently-released datasets, even beating reference-free metrics specifically trained for this task sometimes. We further investigate what reference-based metrics can benefit from such repurposing and whether our additional tweaks help.
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