Learning with noisy-labels has become an important research topic in computer vision where state-of-the-art (SOTA) methods explore: 1) prediction disagreement with co-teaching strategy that updates two models when they disagree on the prediction of training samples; and 2) sample selection to divide the training set into clean and noisy sets based on small training loss. However, the quick convergence of co-teaching models to select the same clean subsets combined with relatively fast overfitting of noisy labels may induce the wrong selection of noisy label samples as clean, leading to an inevitable confirmation bias that damages accuracy. In this paper, we introduce our noisy-label learning approach, called Asymmetric Co-teaching (AsyCo), which introduces novel prediction disagreement that produces more consistent divergent results of the co-teaching models, and a new sample selection approach that does not require small-loss assumption to enable a better robustness to confirmation bias than previous methods. More specifically, the new prediction disagreement is achieved with the use of different training strategies, where one model is trained with multi-class learning and the other with multi-label learning. Also, the new sample selection is based on multi-view consensus, which uses the label views from training labels and model predictions to divide the training set into clean and noisy for training the multi-class model and to re-label the training samples with multiple top-ranked labels for training the multi-label model. Extensive experiments on synthetic and real-world noisy-label datasets show that AsyCo improves over current SOTA methods.
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Exploring dense matching between the current frame and past frames for long-range context modeling, memory-based methods have demonstrated impressive results in video object segmentation (VOS) recently. Nevertheless, due to the lack of instance understanding ability, the above approaches are oftentimes brittle to large appearance variations or viewpoint changes resulted from the movement of objects and cameras. In this paper, we argue that instance understanding matters in VOS, and integrating it with memory-based matching can enjoy the synergy, which is intuitively sensible from the definition of VOS task, \ie, identifying and segmenting object instances within the video. Towards this goal, we present a two-branch network for VOS, where the query-based instance segmentation (IS) branch delves into the instance details of the current frame and the VOS branch performs spatial-temporal matching with the memory bank. We employ the well-learned object queries from IS branch to inject instance-specific information into the query key, with which the instance-augmented matching is further performed. In addition, we introduce a multi-path fusion block to effectively combine the memory readout with multi-scale features from the instance segmentation decoder, which incorporates high-resolution instance-aware features to produce final segmentation results. Our method achieves state-of-the-art performance on DAVIS 2016/2017 val (92.6% and 87.1%), DAVIS 2017 test-dev (82.8%), and YouTube-VOS 2018/2019 val (86.3% and 86.3%), outperforming alternative methods by clear margins.
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Recent deep learning methods have achieved promising results in image shadow removal. However, their restored images still suffer from unsatisfactory boundary artifacts, due to the lack of degradation prior embedding and the deficiency in modeling capacity. Our work addresses these issues by proposing a unified diffusion framework that integrates both the image and degradation priors for highly effective shadow removal. In detail, we first propose a shadow degradation model, which inspires us to build a novel unrolling diffusion model, dubbed ShandowDiffusion. It remarkably improves the model's capacity in shadow removal via progressively refining the desired output with both degradation prior and diffusive generative prior, which by nature can serve as a new strong baseline for image restoration. Furthermore, ShadowDiffusion progressively refines the estimated shadow mask as an auxiliary task of the diffusion generator, which leads to more accurate and robust shadow-free image generation. We conduct extensive experiments on three popular public datasets, including ISTD, ISTD+, and SRD, to validate our method's effectiveness. Compared to the state-of-the-art methods, our model achieves a significant improvement in terms of PSNR, increasing from 31.69dB to 34.73dB over SRD dataset.
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Machine learning has been widely used in healthcare applications to approximate complex models, for clinical diagnosis, prognosis, and treatment. As deep learning has the outstanding ability to extract information from time series, its true capabilities on sparse, irregularly sampled, multivariate, and imbalanced physiological data are not yet fully explored. In this paper, we systematically examine the performance of machine learning models for the clinical prediction task based on the EHR, especially physiological time series. We choose Physionet 2019 challenge public dataset to predict Sepsis outcomes in ICU units. Ten baseline machine learning models are compared, including 3 deep learning methods and 7 non-deep learning methods, commonly used in the clinical prediction domain. Nine evaluation metrics with specific clinical implications are used to assess the performance of models. Besides, we sub-sample training dataset sizes and use learning curve fit to investigate the impact of the training dataset size on the performance of the machine learning models. We also propose the general pre-processing method for the physiology time-series data and use Dice Loss to deal with the dataset imbalanced problem. The results show that deep learning indeed outperforms non-deep learning, but with certain conditions: firstly, evaluating with some particular evaluation metrics (AUROC, AUPRC, Sensitivity, and FNR), but not others; secondly, the training dataset size is large enough (with an estimation of a magnitude of thousands).
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Recent breakthroughs in semi-supervised semantic segmentation have been developed through contrastive learning. In prevalent pixel-wise contrastive learning solutions, the model maps pixels to deterministic representations and regularizes them in the latent space. However, there exist inaccurate pseudo-labels which map the ambiguous representations of pixels to the wrong classes due to the limited cognitive ability of the model. In this paper, we define pixel-wise representations from a new perspective of probability theory and propose a Probabilistic Representation Contrastive Learning (PRCL) framework that improves representation quality by taking its probability into consideration. Through modelling the mapping from pixels to representations as the probability via multivariate Gaussian distributions, we can tune the contribution of the ambiguous representations to tolerate the risk of inaccurate pseudo-labels. Furthermore, we define prototypes in the form of distributions, which indicates the confidence of a class, while the point prototype cannot. Moreover, we propose to regularize the distribution variance to enhance the reliability of representations. Taking advantage of these benefits, high-quality feature representations can be derived in the latent space, thereby the performance of semantic segmentation can be further improved. We conduct sufficient experiment to evaluate PRCL on Pascal VOC and CityScapes to demonstrate its superiority. The code is available at https://github.com/Haoyu-Xie/PRCL.
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Classification on smartphone-captured chest X-ray (CXR) photos to detect pathologies is challenging due to the projective transformation caused by the non-ideal camera position. Recently, various rectification methods have been proposed for different photo rectification tasks such as document photos, license plate photos, etc. Unfortunately, we found that none of them is suitable for CXR photos, due to their specific transformation type, image appearance, annotation type, etc. In this paper, we propose an innovative deep learning-based Projective Transformation Rectification Network (PTRN) to automatically rectify CXR photos by predicting the projective transformation matrix. To the best of our knowledge, it is the first work to predict the projective transformation matrix as the learning goal for photo rectification. Additionally, to avoid the expensive collection of natural data, synthetic CXR photos are generated under the consideration of natural perturbations, extra screens, etc. We evaluate the proposed approach in the CheXphoto smartphone-captured CXR photos classification competition hosted by the Stanford University Machine Learning Group, our approach won first place with a huge performance improvement (ours 0.850, second-best 0.762, in AUC). A deeper study demonstrates that the use of PTRN successfully achieves the classification performance on the spatially transformed CXR photos to the same level as on the high-quality digital CXR images, indicating PTRN can eliminate all negative impacts of projective transformation on the CXR photos.
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Covid-19-Pandemic继续在社交媒体上提出各种讨论或辩论的主题。为了探索大流行对人们生活的影响,了解公众对与大流行有关的实体(例如药物,疫苗)对社交媒体的关注和态度至关重要。但是,对现有命名实体识别(NER)或目标情感分析(TSA)数据集培训的模型具有有限的理解与COVID相关的社交媒体文本的能力有限,因为这些数据集并未从医学角度设计或注释。本文释放了Mets-COV,这是一种包含医疗实体的数据集和与COVID相关的推文中的目标情感。 Mets-COV包含10,000条带有7种实体的推文,包括4种医疗实体类型(疾病,药物,症状和疫苗)和3种通用实体类型(人,位置和组织)。为了进一步调查推文用户对特定实体的态度,选择了4种类型的实体(人,组织,药物和疫苗),并用用户情感注释,从而产生了具有9,101个实体(5,278个推文)的目标情感数据集。据我们所知,METS-COV是第一个收集与COVID相关推文的医疗实体和相应情感的数据集。我们通过广泛的实验对经典机器学习模型和最先进的深度学习模型进行基准测试。结果表明,该数据集在NER和TSA任务方面都有大量改进的空间。 METS-COV是开发更好的医学社交媒体工具并促进计算社会科学研究的重要资源,尤其是在流行病学方面。我们的数据,注释准则,基准模型和源代码公开可用(https://github.com/ylab-open/mets-cov),以确保可重复性。
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最先进的(SOTA)深度学习乳房X线照片分类器接受了弱标记的图像训练,通常依赖于产生有限解释性预测的全球模型,这是他们成功地转化为临床实践的关键障碍。另一方面,基于原型的模型通过将预测与训练图像原型相关联,改善了可解释性,但是它们的准确性不如全球模型,其原型往往具有差的多样性。我们通过BraixProtopnet ++的建议解决了这两个问题,该问题通过将基于原型的模型结合起来,为全局模型增添了解释性。 BraixProtopnet ++在训练基于原型的模型以提高合奏的分类精度时,会提炼全局模型的知识。此外,我们提出了一种方法来通过保证所有原型都与不同的训练图像相关联,以增加原型多样性。对弱标记的私人和公共数据集进行的实验表明,BraixProtopnet ++的分类精度比基于SOTA Global和基于原型的模型具有更高的分类精度。使用病变定位来评估模型可解释性,我们显示BraixProtopnet ++比其他基于原型的模型和全球模型的事后解释更有效。最后,我们表明,BraixProtopnet ++学到的原型的多样性优于基于SOTA原型的方法。
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在分析筛查乳房X线照片时,放射科医生可以自然处理每个乳房的两个同侧视图,即颅底审计(CC)和中外侧 - 粘合剂(MLO)视图。这些多个相关图像提供了互补的诊断信息,并可以提高放射科医生的分类准确性。不幸的是,大多数现有的深度学习系统,受过全球标记的图像培训,缺乏从这些多种观点中共同分析和整合全球和本地信息的能力。通过忽略筛选发作的多个图像中存在的潜在有价值的信息,人们限制了这些系统的潜在准确性。在这里,我们提出了一种新的多视图全球分析方法,该方法基于全球一致性学习和对乳房X线照片中同侧观点的局部同时学习,模仿放射科医生的阅读程序。广泛的实验表明,在大规模的私人数据集和两个公开可用的数据集上,我们的模型在分类准确性和概括方面优于竞争方法,在该数据集和两个公开可用的数据集上,模型仅受到全球标签的培训和测试。
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在推荐系统中,项目可能会接触到各种用户,我们想了解新用户对现有项目的熟悉。这可以作为异常检测(AD)问题进行配置,该问题区分“普通用户”(名义)和“新用户”(异常)。考虑到物品的庞大数量和用户项目配对数据的稀疏性,在每个项目上独立应用传统的单任务检测方法很快就变得困难,而项目之间的相关性则被忽略。为了解决这个多任务异常检测问题,我们建议协作异常检测(CAD)共同学习所有任务,并通过任务之间的嵌入编码相关性来学习所有任务。我们通过条件密度估计和条件可能性比估计来探索CAD。我们发现:$ i $)估计似然比的学习效率更高,并且比密度估计更好。 $ ii $)提前选择少量任务以学习任务嵌入模型,然后使用它来启动所有任务嵌入是有益的。因此,这些嵌入可以捕获任务之间的相关性并推广到新的相关任务。
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