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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水果苍蝇是果实产量最有害的昆虫物种之一。在AlertTrap中,使用不同的最先进的骨干功能提取器(如MobiLenetv1和MobileNetv2)的SSD架构的实现似乎是实时检测问题的潜在解决方案。SSD-MobileNetv1和SSD-MobileNetv2表现良好并导致AP至0.5分别为0.957和1.0。YOLOV4-TINY优于SSD家族,在AP@0.5中为1.0;但是,其吞吐量速度略微慢。
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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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Modern deep neural networks have achieved superhuman performance in tasks from image classification to game play. Surprisingly, these various complex systems with massive amounts of parameters exhibit the same remarkable structural properties in their last-layer features and classifiers across canonical datasets. This phenomenon is known as "Neural Collapse," and it was discovered empirically by Papyan et al. \cite{Papyan20}. Recent papers have theoretically shown the global solutions to the training network problem under a simplified "unconstrained feature model" exhibiting this phenomenon. We take a step further and prove the Neural Collapse occurrence for deep linear network for the popular mean squared error (MSE) and cross entropy (CE) loss. Furthermore, we extend our research to imbalanced data for MSE loss and present the first geometric analysis for Neural Collapse under this setting.
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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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Three main points: 1. Data Science (DS) will be increasingly important to heliophysics; 2. Methods of heliophysics science discovery will continually evolve, requiring the use of learning technologies [e.g., machine learning (ML)] that are applied rigorously and that are capable of supporting discovery; and 3. To grow with the pace of data, technology, and workforce changes, heliophysics requires a new approach to the representation of knowledge.
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Image classification with small datasets has been an active research area in the recent past. However, as research in this scope is still in its infancy, two key ingredients are missing for ensuring reliable and truthful progress: a systematic and extensive overview of the state of the art, and a common benchmark to allow for objective comparisons between published methods. This article addresses both issues. First, we systematically organize and connect past studies to consolidate a community that is currently fragmented and scattered. Second, we propose a common benchmark that allows for an objective comparison of approaches. It consists of five datasets spanning various domains (e.g., natural images, medical imagery, satellite data) and data types (RGB, grayscale, multispectral). We use this benchmark to re-evaluate the standard cross-entropy baseline and ten existing methods published between 2017 and 2021 at renowned venues. Surprisingly, we find that thorough hyper-parameter tuning on held-out validation data results in a highly competitive baseline and highlights a stunted growth of performance over the years. Indeed, only a single specialized method dating back to 2019 clearly wins our benchmark and outperforms the baseline classifier.
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Dataset scaling, also known as normalization, is an essential preprocessing step in a machine learning pipeline. It is aimed at adjusting attributes scales in a way that they all vary within the same range. This transformation is known to improve the performance of classification models, but there are several scaling techniques to choose from, and this choice is not generally done carefully. In this paper, we execute a broad experiment comparing the impact of 5 scaling techniques on the performances of 20 classification algorithms among monolithic and ensemble models, applying them to 82 publicly available datasets with varying imbalance ratios. Results show that the choice of scaling technique matters for classification performance, and the performance difference between the best and the worst scaling technique is relevant and statistically significant in most cases. They also indicate that choosing an inadequate technique can be more detrimental to classification performance than not scaling the data at all. We also show how the performance variation of an ensemble model, considering different scaling techniques, tends to be dictated by that of its base model. Finally, we discuss the relationship between a model's sensitivity to the choice of scaling technique and its performance and provide insights into its applicability on different model deployment scenarios. Full results and source code for the experiments in this paper are available in a GitHub repository.\footnote{https://github.com/amorimlb/scaling\_matters}
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The devastation caused by the coronavirus pandemic makes it imperative to design automated techniques for a fast and accurate detection. We propose a novel non-invasive tool, using deep learning and imaging, for delineating COVID-19 infection in lungs. The Ensembling Attention-based Multi-scaled Convolution network (EAMC), employing Leave-One-Patient-Out (LOPO) training, exhibits high sensitivity and precision in outlining infected regions along with assessment of severity. The Attention module combines contextual with local information, at multiple scales, for accurate segmentation. Ensemble learning integrates heterogeneity of decision through different base classifiers. The superiority of EAMC, even with severe class imbalance, is established through comparison with existing state-of-the-art learning models over four publicly-available COVID-19 datasets. The results are suggestive of the relevance of deep learning in providing assistive intelligence to medical practitioners, when they are overburdened with patients as in pandemics. Its clinical significance lies in its unprecedented scope in providing low-cost decision-making for patients lacking specialized healthcare at remote locations.
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