接受注释较弱的对象探测器是全面监督者的负担得起的替代方案。但是,它们之间仍然存在显着的性能差距。我们建议通过微调预先训练的弱监督检测器来缩小这一差距,并使用``Box-In-box''(bib'(bib)自动从训练集中自动选择了一些完全注销的样品,这是一种新颖的活跃学习专门针对弱势监督探测器的据可查的失败模式而设计的策略。 VOC07和可可基准的实验表明,围嘴表现优于其他活跃的学习技术,并显着改善了基本的弱监督探测器的性能,而每个类别仅几个完全宣布的图像。围嘴达到了完全监督的快速RCNN的97%,在VOC07上仅10%的全已通量图像。在可可(COCO)上,平均每类使用10张全面通量的图像,或同等的训练集的1%,还减少了弱监督检测器和完全监督的快速RCN之间的性能差距(In AP)以上超过70% ,在性能和数据效率之间表现出良好的权衡。我们的代码可在https://github.com/huyvvo/bib上公开获取。
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对无监督对象发现的现有方法(UOD)不会向大大扩展到大型数据集,而不会损害其性能的近似。我们提出了一种新颖的UOD作为排名问题的制定,适用于可用于特征值问题和链接分析的分布式方法的阿森纳。通过使用自我监督功能,我们还展示了UOD的第一个有效的完全无监督的管道。对Coco和OpenImages的广泛实验表明,在每个图像中寻求单个突出对象的单对象发现设置中,所提出的LOD(大规模对象发现)方法与之相当于或更好地中型数据集的艺术(最多120K图像),比能够缩放到1.7M图像的唯一其他算法超过37%。在每个图像中寻求多个对象的多对象发现设置中,所提出的LOD平均精度(AP)比所有其他用于从20K到1.7M图像的数据的方法更好。使用自我监督功能,我们还表明该方法在OpenImages上获得最先进的UOD性能。我们的代码在HTTPS://github.com/huyvvo/lod上公开提供。
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Air pollution is an emerging problem that needs to be solved especially in developed and developing countries. In Vietnam, air pollution is also a concerning issue in big cities such as Hanoi and Ho Chi Minh cities where air pollution comes mostly from vehicles such as cars and motorbikes. In order to tackle the problem, the paper focuses on developing a solution that can estimate the emitted PM2.5 pollutants by counting the number of vehicles in the traffic. We first investigated among the recent object detection models and developed our own traffic surveillance system. The observed traffic density showed a similar trend to the measured PM2.5 with a certain lagging in time, suggesting a relation between traffic density and PM2.5. We further express this relationship with a mathematical model which can estimate the PM2.5 value based on the observed traffic density. The estimated result showed a great correlation with the measured PM2.5 plots in the urban area context.
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我们提出了一个数据收集和注释管道,该数据从越南放射学报告中提取信息,以提供胸部X射线(CXR)图像的准确标签。这可以通过注释与其特有诊断类别的数据相匹配,这些数据可能因国家而异。为了评估所提出的标签技术的功效,我们构建了一个包含9,752项研究的CXR数据集,并使用该数据集的子集评估了我们的管道。以F1得分为至少0.9923,评估表明,我们的标签工具在所有类别中都精确而始终如一。构建数据集后,我们训练深度学习模型,以利用从大型公共CXR数据集传输的知识。我们采用各种损失功能来克服不平衡的多标签数据集的诅咒,并使用各种模型体系结构进行实验,以选择提供最佳性能的诅咒。我们的最佳模型(CHEXPERT-FRECTER EDIDENENET-B2)的F1得分为0.6989(95%CI 0.6740,0.7240),AUC为0.7912,敏感性为0.7064,特异性为0.8760,普遍诊断为0.8760。最后,我们证明了我们的粗分类(基于五个特定的异常位置)在基准CHEXPERT数据集上获得了可比的结果(十二个病理),以进行一般异常检测,同时在所有类别的平均表现方面提供更好的性能。
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自我监督学习(SSL)利用基础数据结构来生成培训深网络的监督信号。这种方法提供了一种实用的解决方案,可用于学习多重免疫荧光大脑图像,其中数据通常比人类专家注释更丰富。基于对比度学习和图像重建的SSL算法表现出令人印象深刻的性能。不幸的是,这些方法是在自然图像而不是生物医学图像上设计和验证的。最近的一些作品已应用SSL来分析细胞图像。然而,这些作品均未研究SSL对多重免疫荧光脑图像的研究。这些作品还没有为采用特定的SSL方法提供明确的理论理由。在这些局限性的激励下,我们的论文介绍了从信息理论观点开发的一种自我监督的双损坏自适应掩盖自动编码器(DAMA)算法。 Dama的目标函数通过最大程度地降低像素级重建和特征级回归中的条件熵来最大化相互信息。此外,Dama还引入了一种新型的自适应掩码采样策略,以最大程度地提高相互信息并有效地学习脑细胞数据上下文信息。我们首次在多重免疫荧光脑图像上提供了SSL算法的广泛比较。我们的结果表明,Dama优于细胞分类和分割任务的其他SSL方法。 Dama还可以在Imagenet-1k上实现竞争精确度。 Dama的源代​​码可在https://github.com/hula-ai/dama上公开获得
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In this paper we explore the task of modeling (semi) structured object sequences; in particular we focus our attention on the problem of developing a structure-aware input representation for such sequences. In such sequences, we assume that each structured object is represented by a set of key-value pairs which encode the attributes of the structured object. Given a universe of keys, a sequence of structured objects can then be viewed as an evolution of the values for each key, over time. We encode and construct a sequential representation using the values for a particular key (Temporal Value Modeling - TVM) and then self-attend over the set of key-conditioned value sequences to a create a representation of the structured object sequence (Key Aggregation - KA). We pre-train and fine-tune the two components independently and present an innovative training schedule that interleaves the training of both modules with shared attention heads. We find that this iterative two part-training results in better performance than a unified network with hierarchical encoding as well as over, other methods that use a {\em record-view} representation of the sequence \cite{de2021transformers4rec} or a simple {\em flattened} representation of the sequence. We conduct experiments using real-world data to demonstrate the advantage of interleaving TVM-KA on multiple tasks and detailed ablation studies motivating our modeling choices. We find that our approach performs better than flattening sequence objects and also allows us to operate on significantly larger sequences than existing methods.
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Optical coherence tomography (OCT) captures cross-sectional data and is used for the screening, monitoring, and treatment planning of retinal diseases. Technological developments to increase the speed of acquisition often results in systems with a narrower spectral bandwidth, and hence a lower axial resolution. Traditionally, image-processing-based techniques have been utilized to reconstruct subsampled OCT data and more recently, deep-learning-based methods have been explored. In this study, we simulate reduced axial scan (A-scan) resolution by Gaussian windowing in the spectral domain and investigate the use of a learning-based approach for image feature reconstruction. In anticipation of the reduced resolution that accompanies wide-field OCT systems, we build upon super-resolution techniques to explore methods to better aid clinicians in their decision-making to improve patient outcomes, by reconstructing lost features using a pixel-to-pixel approach with an altered super-resolution generative adversarial network (SRGAN) architecture.
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We propose a new causal inference framework to learn causal effects from multiple, decentralized data sources in a federated setting. We introduce an adaptive transfer algorithm that learns the similarities among the data sources by utilizing Random Fourier Features to disentangle the loss function into multiple components, each of which is associated with a data source. The data sources may have different distributions; the causal effects are independently and systematically incorporated. The proposed method estimates the similarities among the sources through transfer coefficients, and hence requiring no prior information about the similarity measures. The heterogeneous causal effects can be estimated with no sharing of the raw training data among the sources, thus minimizing the risk of privacy leak. We also provide minimax lower bounds to assess the quality of the parameters learned from the disparate sources. The proposed method is empirically shown to outperform the baselines on decentralized data sources with dissimilar distributions.
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Real-life tools for decision-making in many critical domains are based on ranking results. With the increasing awareness of algorithmic fairness, recent works have presented measures for fairness in ranking. Many of those definitions consider the representation of different ``protected groups'', in the top-$k$ ranked items, for any reasonable $k$. Given the protected groups, confirming algorithmic fairness is a simple task. However, the groups' definitions may be unknown in advance. In this paper, we study the problem of detecting groups with biased representation in the top-$k$ ranked items, eliminating the need to pre-define protected groups. The number of such groups possible can be exponential, making the problem hard. We propose efficient search algorithms for two different fairness measures: global representation bounds, and proportional representation. Then we propose a method to explain the bias in the representations of groups utilizing the notion of Shapley values. We conclude with an experimental study, showing the scalability of our approach and demonstrating the usefulness of the proposed algorithms.
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The previous fine-grained datasets mainly focus on classification and are often captured in a controlled setup, with the camera focusing on the objects. We introduce the first Fine-Grained Vehicle Detection (FGVD) dataset in the wild, captured from a moving camera mounted on a car. It contains 5502 scene images with 210 unique fine-grained labels of multiple vehicle types organized in a three-level hierarchy. While previous classification datasets also include makes for different kinds of cars, the FGVD dataset introduces new class labels for categorizing two-wheelers, autorickshaws, and trucks. The FGVD dataset is challenging as it has vehicles in complex traffic scenarios with intra-class and inter-class variations in types, scale, pose, occlusion, and lighting conditions. The current object detectors like yolov5 and faster RCNN perform poorly on our dataset due to a lack of hierarchical modeling. Along with providing baseline results for existing object detectors on FGVD Dataset, we also present the results of a combination of an existing detector and the recent Hierarchical Residual Network (HRN) classifier for the FGVD task. Finally, we show that FGVD vehicle images are the most challenging to classify among the fine-grained datasets.
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