The orthogonality constraints, including the hard and soft ones, have been used to normalize the weight matrices of Deep Neural Network (DNN) models, especially the Convolutional Neural Network (CNN) and Vision Transformer (ViT), to reduce model parameter redundancy and improve training stability. However, the robustness to noisy data of these models with constraints is not always satisfactory. In this work, we propose a novel two-stage approximately orthogonal training framework (TAOTF) to find a trade-off between the orthogonal solution space and the main task solution space to solve this problem in noisy data scenarios. In the first stage, we propose a novel algorithm called polar decomposition-based orthogonal initialization (PDOI) to find a good initialization for the orthogonal optimization. In the second stage, unlike other existing methods, we apply soft orthogonal constraints for all layers of DNN model. We evaluate the proposed model-agnostic framework both on the natural image and medical image datasets, which show that our method achieves stable and superior performances to existing methods.
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The rapid development of aspect-based sentiment analysis (ABSA) within recent decades shows great potential for real-world society. The current ABSA works, however, are mostly limited to the scenario of a single text piece, leaving the study in dialogue contexts unexplored. In this work, we introduce a novel task of conversational aspect-based sentiment quadruple analysis, namely DiaASQ, aiming to detect the sentiment quadruple of target-aspect-opinion-sentiment in a dialogue. DiaASQ bridges the gap between fine-grained sentiment analysis and conversational opinion mining. We manually construct a large-scale, high-quality Chinese dataset and also obtain the English version dataset via manual translation. We deliberately propose a neural model to benchmark the task. It advances in effectively performing end-to-end quadruple prediction and manages to incorporate rich dialogue-specific and discourse feature representations for better cross-utterance quadruple extraction. We finally point out several potential future works to facilitate the follow-up research of this new task. The DiaASQ data is open at https://github.com/unikcc/DiaASQ
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实体链接(EL)是将实体提及在文本中及其相应实体中出现在知识库中的过程。通常基于Wikipedia估算实体的EL特征(例如,先前的概率,相关性评分和实体嵌入)。但是,对于刚刚在新闻中发现的新兴实体(EES)而言,它们可能仍未包含在Wikipedia中。结果,它无法获得Wikipedia和EL模型的EES所需的EL功能,将始终无法将歧义提及与这些EES正确链接,因为它没有其EL功能。为了解决这个问题,在本文中,我们专注于以一般方式为新兴实体学习EL功能的新任务。我们提出了一种名为Stamo的新颖方法,可以自动学习EES的高质量EL功能,该功能仅需要从网络中收集的每个EE的少数标记文档,因为它可以进一步利用隐藏在未标记的数据中的知识。 Stamo主要基于自我训练,这使其与任何EL功能或EL模型都灵活地集成在一起,但也使其很容易遭受由错误标签的数据引起的错误加强问题。我们认为自我训练是相对于EES的EL特征,而不是一些试图将错误标签的数据抛弃的常见自我训练策略,而是提出了内部插槽和斜率优化的多重优化过程,以减轻误差加强问题隐含。我们构建了涉及选定的EE的两个EL数据集,以评估EES获得的EL特征的质量,实验结果表明,我们的方法显着优于其他学习EL特征的基线方法。
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现实世界中的应用程序需要在物理世界中运行的机器人,除了完成任务外,还要意识到潜在风险。大部分危险行为是由于与负担无知的物体相互作用而产生的。为了防止代理做出不安全的决定,我们建议通过强化学习来训练机器人代理,以了解对室内环境中质量和摩擦等物理特性的任务。我们通过一种新颖的物理启发奖励功能来实现这一目标,该功能鼓励代理商学习辨别不同质量和摩擦系数的政策。我们介绍了两项新颖且具有挑战性的室内重排任务 - 可变的摩擦推动任务和可变的质量推动任务 - 允许评估学习绩效和物理启发的风险时学到的政策。我们的结果表明,通过配备拟议的奖励,代理商能够学习选择推动目标或目标轨迹的政策,以最低的身体成本,可以进一步利用这一预防措施来限制代理商在安全性批评中的行为环境。
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Twitter机器人检测已成为打击错误信息,促进社交媒体节制并保持在线话语的完整性的越来越重要的任务。最先进的机器人检测方法通常利用Twitter网络的图形结构,在面对传统方法无法检测到的新型Twitter机器人时,它们表现出令人鼓舞的性能。但是,现有的Twitter机器人检测数据集很少是基于图形的,即使这些基于图形的数据集也遭受有限的数据集量表,不完整的图形结构以及低注释质量。实际上,缺乏解决这些问题的大规模基于图的Twitter机器人检测基准,严重阻碍了基于图形的机器人检测方法的开发和评估。在本文中,我们提出了Twibot-22,这是一个综合基于图的Twitter机器人检测基准,它显示了迄今为止最大的数据集,在Twitter网络上提供了多元化的实体和关系,并且与现有数据集相比具有更好的注释质量。此外,我们重新实施35代表性的Twitter机器人检测基线,并在包括Twibot-22在内的9个数据集上进行评估,以促进对模型性能和对研究进度的整体了解的公平比较。为了促进进一步的研究,我们将所有实施的代码和数据集巩固到Twibot-22评估框架中,研究人员可以在其中始终如一地评估新的模型和数据集。 Twibot-22 Twitter机器人检测基准和评估框架可在https://twibot22.github.io/上公开获得。
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Optical coherence tomography angiography (OCTA) is a novel imaging modality that has been widely utilized in ophthalmology and neuroscience studies to observe retinal vessels and microvascular systems. However, publicly available OCTA datasets remain scarce. In this paper, we introduce the largest and most comprehensive OCTA dataset dubbed OCTA-500, which contains OCTA imaging under two fields of view (FOVs) from 500 subjects. The dataset provides rich images and annotations including two modalities (OCT/OCTA volumes), six types of projections, four types of text labels (age / gender / eye / disease) and seven types of segmentation labels (large vessel/capillary/artery/vein/2D FAZ/3D FAZ/retinal layers). Then, we propose a multi-object segmentation task called CAVF, which integrates capillary segmentation, artery segmentation, vein segmentation, and FAZ segmentation under a unified framework. In addition, we optimize the 3D-to-2D image projection network (IPN) to IPN-V2 to serve as one of the segmentation baselines. Experimental results demonstrate that IPN-V2 achieves an ~10% mIoU improvement over IPN on CAVF task. Finally, we further study the impact of several dataset characteristics: the training set size, the model input (OCT/OCTA, 3D volume/2D projection), the baseline networks, and the diseases. The dataset and code are publicly available at: https://ieee-dataport.org/open-access/octa-500.
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In the process of projecting the surface of a three-dimensional object onto a two-dimensional surface, due to the perspective distortion, the image on the surface of the object will have different degrees of distortion according to the level of the surface curvature. This paper presents an imprecise method for flattening this type of distortion on the surface of a regularly curved body. The main idea of this method is to roughly estimate the gridded surface subdivision that can be used to describe the surface of the three-dimensional object through the contour curve of the two-dimensional image of the object. Then, take each grid block with different sizes and shapes inversely transformed into a rectangle with exactly the same shape and size. Finally, each of the same rectangles is splicing and recombining in turn to obtain a roughly flat rectangle. This paper will introduce and show the specific process and results of using this method to solve the problem of bending page flattening, then demonstrate the feasibility and limitations of this method.
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Diabetic retinopathy (DR) is a complication of diabetes, and one of the major causes of vision impairment in the global population. As the early-stage manifestation of DR is usually very mild and hard to detect, an accurate diagnosis via eye-screening is clinically important to prevent vision loss at later stages. In this work, we propose an ensemble method to automatically grade DR using ultra-wide optical coherence tomography angiography (UW-OCTA) images available from Diabetic Retinopathy Analysis Challenge (DRAC) 2022. First, we adopt the state-of-the-art classification networks, i.e., ResNet, DenseNet, EfficientNet, and VGG, and train them to grade UW-OCTA images with different splits of the available dataset. Ultimately, we obtain 25 models, of which, the top 16 models are selected and ensembled to generate the final predictions. During the training process, we also investigate the multi-task learning strategy, and add an auxiliary classification task, the Image Quality Assessment, to improve the model performance. Our final ensemble model achieved a quadratic weighted kappa (QWK) of 0.9346 and an Area Under Curve (AUC) of 0.9766 on the internal testing dataset, and the QWK of 0.839 and the AUC of 0.8978 on the DRAC challenge testing dataset.
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Cross-view geo-localization aims to spot images of the same location shot from two platforms, e.g., the drone platform and the satellite platform. Existing methods usually focus on optimizing the distance between one embedding with others in the feature space, while neglecting the redundancy of the embedding itself. In this paper, we argue that the low redundancy is also of importance, which motivates the model to mine more diverse patterns. To verify this point, we introduce a simple yet effective regularization, i.e., Dynamic Weighted Decorrelation Regularization (DWDR), to explicitly encourage networks to learn independent embedding channels. As the name implies, DWDR regresses the embedding correlation coefficient matrix to a sparse matrix, i.e., the identity matrix, with dynamic weights. The dynamic weights are applied to focus on still correlated channels during training. Besides, we propose a cross-view symmetric sampling strategy, which keeps the example balance between different platforms. Albeit simple, the proposed method has achieved competitive results on three large-scale benchmarks, i.e., University-1652, CVUSA and CVACT. Moreover, under the harsh circumstance, e.g., the extremely short feature of 64 dimensions, the proposed method surpasses the baseline model by a clear margin.
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We study discrete distribution estimation under user-level local differential privacy (LDP). In user-level $\varepsilon$-LDP, each user has $m\ge1$ samples and the privacy of all $m$ samples must be preserved simultaneously. We resolve the following dilemma: While on the one hand having more samples per user should provide more information about the underlying distribution, on the other hand, guaranteeing the privacy of all $m$ samples should make the estimation task more difficult. We obtain tight bounds for this problem under almost all parameter regimes. Perhaps surprisingly, we show that in suitable parameter regimes, having $m$ samples per user is equivalent to having $m$ times more users, each with only one sample. Our results demonstrate interesting phase transitions for $m$ and the privacy parameter $\varepsilon$ in the estimation risk. Finally, connecting with recent results on shuffled DP, we show that combined with random shuffling, our algorithm leads to optimal error guarantees (up to logarithmic factors) under the central model of user-level DP in certain parameter regimes. We provide several simulations to verify our theoretical findings.
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