This paper considers ranking inference of $n$ items based on the observed data on the top choice among $M$ randomly selected items at each trial. This is a useful modification of the Plackett-Luce model for $M$-way ranking with only the top choice observed and is an extension of the celebrated Bradley-Terry-Luce model that corresponds to $M=2$. Under a uniform sampling scheme in which any $M$ distinguished items are selected for comparisons with probability $p$ and the selected $M$ items are compared $L$ times with multinomial outcomes, we establish the statistical rates of convergence for underlying $n$ preference scores using both $\ell_2$-norm and $\ell_\infty$-norm, with the minimum sampling complexity. In addition, we establish the asymptotic normality of the maximum likelihood estimator that allows us to construct confidence intervals for the underlying scores. Furthermore, we propose a novel inference framework for ranking items through a sophisticated maximum pairwise difference statistic whose distribution is estimated via a valid Gaussian multiplier bootstrap. The estimated distribution is then used to construct simultaneous confidence intervals for the differences in the preference scores and the ranks of individual items. They also enable us to address various inference questions on the ranks of these items. Extensive simulation studies lend further support to our theoretical results. A real data application illustrates the usefulness of the proposed methods convincingly.
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草图在快速执行的徒手绘图时会形成直观而有力的视觉表达。我们提出了一种从场景草图中综合现实照片的方法。不需要草图和照片对,我们的框架直接以无监督的方式从随时可用的大型照片数据集中学习。为此,我们引入了一个标准化模块,该模块在训练期间通过将照片和草图转换为标准化域,即边缘地图,从而提供伪素描 - 光谱对。草图和照片之间的域间隙减少也使我们可以将它们分为两个组成部分:整体场景结构和低级视觉样式,例如颜色和纹理。利用这一优势,我们通过结合草图的结构和参考照片的视觉样式来合成照片真实的图像。关于感知相似性指标和人类感知研究的广泛实验结果表明,该方法可以从场景草图和跑赢大于最先进的照片合成基准中产生逼真的照片。我们还证明,我们的框架通过编辑相应草图的笔触来促进对照片综合的可控操作,从而比依赖于区域级编辑的以前的方法提供了更多细粒度的细节。
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对比度学习(CL)最近已应用于对抗性学习任务。这种实践将对抗样本视为实例的其他积极观点,并且通过彼此达成最大的协议,可以产生更好的对抗性鲁棒性。但是,由于对抗性扰动可能会导致实例级别的身份混乱,因此这种机制可能存在缺陷,这可能会通过用单独的身份将不同的实例聚集在一起来阻碍CL性能。为了解决这个问题,我们建议在形成鲜明对比时不平等地对待对抗样本,与不对称的Infonce目标($ a-Infonce $)允许区分对抗样本的考虑。具体而言,对手被视为降低的阳性,会引起较弱的学习信号,或者是与其他负面样本形成较高对比的艰难负面因素。以不对称的方式,可以有效地减轻CL和对抗性学习之间相互冲突目标的不利影响。实验表明,我们的方法始终超过不同鉴定方案的现有对抗性CL方法,而无需额外的计算成本。提出的A-INFONCE也是一种通用形式,可以很容易地扩展到其他CL方法。代码可从https://github.com/yqy2001/a-infonce获得。
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人群计数是一项回归任务,它估计场景图像中的人数,在一系列安全至关重要的应用程序中起着至关重要的作用,例如视频监视,交通监控和流量控制。在本文中,我们研究了基于深度学习的人群计数模型对后门攻击的脆弱性,这是对深度学习的主要安全威胁。后门攻击者通过数据中毒将后门触发植入目标模型,以控制测试时间的预测。与已经开发和测试的大多数现有后门攻击的图像分类模型不同,人群计数模型是输出多维密度图的回归模型,因此需要不同的技术来操纵。在本文中,我们提出了两次新颖的密度操纵后门攻击(DMBA $^{ - } $和DMBA $^{+} $),以攻击模型以产生任意的大或小密度估计。实验结果证明了我们对五个经典人群计数模型和四种类型数据集的DMBA攻击的有效性。我们还深入分析了后门人群计数模型的独特挑战,并揭示了有效攻击的两个关键要素:1)完整而密集的触发器以及2)操纵地面真相计数或密度图。我们的工作可以帮助评估人群计数模型对潜在后门攻击的脆弱性。
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随着预训练的语言模型的发展,对话理解(DU)已经看到了杰出的成功。但是,当前的DU方法通常为每个不同的DU任务采用独立模型,而无需考虑跨不同任务的共同知识。在本文中,我们提出了一个名为{\ em unidu}的统一的生成对话理解框架,以实现跨不同DU任务的有效信息交流。在这里,我们将所有DU任务重新制定为基于统一的立即生成模型范式。更重要的是,引入了一种新颖的模型多任务训练策略(MATS),以动态调整各种任务的权重,以根据每个任务的性质和可用数据在培训期间进行最佳知识共享。涵盖五个基本DU任务的十个DU数据集的实验表明,在所有任务上,提出的UNIDU框架在很大程度上优于特定于特定于任务精心设计的方法。 MATS还揭示了这些任务的知识共享结构。最后,Unidu在看不见的对话领域中获得了有希望的表现,显示了概括的巨大潜力。
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脑电图(EEG)录音通常被伪影污染。已经开发了各种方法来消除或削弱伪影的影响。然而,大多数人都依赖于先前的分析经验。在这里,我们提出了一个深入的学习框架,以将神经信号和伪像在嵌入空间中分离并重建被称为DeepSeparator的去噪信号。 DeepSeparator采用编码器来提取和放大原始EEG中的特征,称为分解器的模块以提取趋势,检测和抑制伪像和解码器以重建去噪信号。此外,DeepSeparator可以提取伪像,这在很大程度上增加了模型解释性。通过半合成的EEG数据集和实际任务相关的EEG数据集进行了所提出的方法,建议DeepSepater在EoG和EMG伪像去除中占据了传统模型。 DeepSeparator可以扩展到多通道EEG和任何长度的数据。它可能激励深入学习的EEG去噪的未来发展和应用。 DeepSeparator的代码可在https://github.com/ncclabsustech/deepseparator上获得。
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In this paper, we study the problem of knowledge-intensive text-to-SQL, in which domain knowledge is necessary to parse expert questions into SQL queries over domain-specific tables. We formalize this scenario by building a new Chinese benchmark KnowSQL consisting of domain-specific questions covering various domains. We then address this problem by presenting formulaic knowledge, rather than by annotating additional data examples. More concretely, we construct a formulaic knowledge bank as a domain knowledge base and propose a framework (ReGrouP) to leverage this formulaic knowledge during parsing. Experiments using ReGrouP demonstrate a significant 28.2% improvement overall on KnowSQL.
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In this paper, we introduce a novel variation of model-agnostic meta-learning, where an extra multiplicative parameter is introduced in the inner-loop adaptation. Our variation creates a shortcut in the parameter space for the inner-loop adaptation and increases model expressivity in a highly controllable manner. We show both theoretically and numerically that our variation alleviates the problem of conflicting gradients and improves training dynamics. We conduct experiments on 3 distinctive problems, including a toy classification problem for threshold comparison, a regression problem for wavelet transform, and a classification problem on MNIST. We also discuss ways to generalize our method to a broader class of problems.
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Text-to-SQL semantic parsing is an important NLP task, which greatly facilitates the interaction between users and the database and becomes the key component in many human-computer interaction systems. Much recent progress in text-to-SQL has been driven by large-scale datasets, but most of them are centered on English. In this work, we present MultiSpider, the largest multilingual text-to-SQL dataset which covers seven languages (English, German, French, Spanish, Japanese, Chinese, and Vietnamese). Upon MultiSpider, we further identify the lexical and structural challenges of text-to-SQL (caused by specific language properties and dialect sayings) and their intensity across different languages. Experimental results under three typical settings (zero-shot, monolingual and multilingual) reveal a 6.1% absolute drop in accuracy in non-English languages. Qualitative and quantitative analyses are conducted to understand the reason for the performance drop of each language. Besides the dataset, we also propose a simple schema augmentation framework SAVe (Schema-Augmentation-with-Verification), which significantly boosts the overall performance by about 1.8% and closes the 29.5% performance gap across languages.
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Recently deep neural networks, which require a large amount of annotated samples, have been widely applied in nuclei instance segmentation of H\&E stained pathology images. However, it is inefficient and unnecessary to label all pixels for a dataset of nuclei images which usually contain similar and redundant patterns. Although unsupervised and semi-supervised learning methods have been studied for nuclei segmentation, very few works have delved into the selective labeling of samples to reduce the workload of annotation. Thus, in this paper, we propose a novel full nuclei segmentation framework that chooses only a few image patches to be annotated, augments the training set from the selected samples, and achieves nuclei segmentation in a semi-supervised manner. In the proposed framework, we first develop a novel consistency-based patch selection method to determine which image patches are the most beneficial to the training. Then we introduce a conditional single-image GAN with a component-wise discriminator, to synthesize more training samples. Lastly, our proposed framework trains an existing segmentation model with the above augmented samples. The experimental results show that our proposed method could obtain the same-level performance as a fully-supervised baseline by annotating less than 5% pixels on some benchmarks.
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