With the progress of sensor technology in wearables, the collection and analysis of PPG signals are gaining more interest. Using Machine Learning, the cardiac rhythm corresponding to PPG signals can be used to predict different tasks such as activity recognition, sleep stage detection, or more general health status. However, supervised learning is often limited by the amount of available labeled data, which is typically expensive to obtain. To address this problem, we propose a Self-Supervised Learning (SSL) method with a pretext task of signal reconstruction to learn an informative generalized PPG representation. The performance of the proposed SSL framework is compared with two fully supervised baselines. The results show that in a very limited label data setting (10 samples per class or less), using SSL is beneficial, and a simple classifier trained on SSL-learned representations outperforms fully supervised deep neural networks. However, the results reveal that the SSL-learned representations are too focused on encoding the subjects. Unfortunately, there is high inter-subject variability in the SSL-learned representations, which makes working with this data more challenging when labeled data is scarce. The high inter-subject variability suggests that there is still room for improvements in learning representations. In general, the results suggest that SSL may pave the way for the broader use of machine learning models on PPG data in label-scarce regimes.
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人的大脑能够依次地学习任务,而无需忘记。但是,深度神经网络(DNN)在学习一项任务时遭受灾难性遗忘。我们考虑了一个挑战,考虑了一个课堂学习方案,在该方案中,DNN看到测试数据而不知道该数据启动的任务。在培训期间,持续的捕获和选择(CP&S)在DNN中找到了负责解决给定任务的子网。然后,在推理期间,CP&S选择正确的子网以对该任务进行预测。通过培训DNN的可用神经元连接(以前未经训练)来创建一个新的子网络,从而通过修剪来学习一项新任务,该连接可以包括以前训练的其他子网络(S),因为它没有更新共享的连接,因为它可以属于其他子网络(S)。这使得通过在DNN中创建专门的区域而不会相互冲突的同时仍允许知识转移在其中,可以消除灾难性的遗忘。 CP&S策略采用不同的子网络选择策略实施,揭示了在各种数据集(CIFAR-100,CUB-200,2011年,Imagenet-100和Imagenet-100)上测试的最先进的持续学习方法的卓越性能。特别是,CP&S能够从Imagenet-1000中依次学习10个任务,以确保94%的精度,而遗忘可忽略不计,这是课堂学习学习的首要结果。据作者所知,与最佳替代方法相比,这表示准确性高于20%的改善。
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当前的深神经网络(DNN)被过度参数化,并在推断每个任务期间使用其大多数神经元连接。然而,人的大脑开发了针对不同任务的专门区域,并通过其神经元连接的一小部分进行推断。我们提出了一种迭代修剪策略,引入了一个简单的重要性评分度量度量,该指标可以停用不重要的连接,解决DNN中的过度参数化并调节射击模式。目的是找到仍然能够以可比精度解决给定任务的最小连接,即更简单的子网。我们在MNIST上实现了LENET体系结构的可比性能,并且与CIFAR-10/100和Tiny-ImageNet上的VGG和Resnet架构的最先进算法相比,参数压缩的性能明显更高。我们的方法对于考虑到ADAM和SGD的两个不同优化器也表现良好。该算法并非旨在在考虑当前的硬件和软件实现时最小化失败,尽管与最新技术相比,该算法的性能合理。
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Wearable sensors for measuring head kinematics can be noisy due to imperfect interfaces with the body. Mouthguards are used to measure head kinematics during impacts in traumatic brain injury (TBI) studies, but deviations from reference kinematics can still occur due to potential looseness. In this study, deep learning is used to compensate for the imperfect interface and improve measurement accuracy. A set of one-dimensional convolutional neural network (1D-CNN) models was developed to denoise mouthguard kinematics measurements along three spatial axes of linear acceleration and angular velocity. The denoised kinematics had significantly reduced errors compared to reference kinematics, and reduced errors in brain injury criteria and tissue strain and strain rate calculated via finite element modeling. The 1D-CNN models were also tested on an on-field dataset of college football impacts and a post-mortem human subject dataset, with similar denoising effects observed. The models can be used to improve detection of head impacts and TBI risk evaluation, and potentially extended to other sensors measuring kinematics.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License.
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我们提出了一种新颖的方法,用于生成语音音频和单个“身份”图像的高分辨率视频。我们的方法基于卷积神经网络模型,该模型结合了预训练的样式Gener。我们将每个帧建模为Stylegan潜在空间中的一个点,以便视频对应于潜在空间的轨迹。培训网络分为两个阶段。第一阶段是根据语音话语调节潜在空间中的轨迹。为此,我们使用现有的编码器倒转发电机,将每个视频框架映射到潜在空间中。我们训练一个经常性的神经网络,以从语音话语绘制到图像发生器潜在空间中的位移。这些位移是相对于从训练数据集中所描绘的个体选择的身份图像的潜在空间的反向预测的。在第二阶段,我们通过在单个图像或任何选择的身份的简短视频上调整图像生成器来提高生成视频的视觉质量。我们对标准度量(PSNR,SSIM,FID和LMD)的模型进行评估,并表明它在两个常用数据集之一上的最新方法明显优于最新的最新方法,另一方面给出了可比的性能。最后,我们报告了验证模型组成部分的消融实验。可以在https://mohammedalghamdi.github.io/talking-heads-acm-mm上找到实验的代码和视频
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脑小血管疾病的成像标记提供了有关脑部健康的宝贵信息,但是它们的手动评估既耗时又受到实质性内部和间际变异性的阻碍。自动化评级可能受益于生物医学研究以及临床评估,但是现有算法的诊断可靠性尚不清楚。在这里,我们介绍了\ textIt {血管病变检测和分割}(\ textit {v textit {where valdo?})挑战,该挑战是在国际医学图像计算和计算机辅助干预措施(MICCAI)的卫星事件中运行的挑战(MICCAI) 2021.这一挑战旨在促进大脑小血管疾病的小而稀疏成像标记的自动检测和分割方法的开发,即周围空间扩大(EPVS)(任务1),脑微粒(任务2)和预先塑造的鞋类血管起源(任务3),同时利用弱和嘈杂的标签。总体而言,有12个团队参与了针对一个或多个任务的解决方案的挑战(任务1 -EPVS 4,任务2 -Microbleeds的9个,任务3 -lacunes的6个)。多方数据都用于培训和评估。结果表明,整个团队和跨任务的性能都有很大的差异,对于任务1- EPV和任务2-微型微型且对任务3 -lacunes尚无实际的结果,其结果尤其有望。它还强调了可能阻止个人级别使用的情况的性能不一致,同时仍证明在人群层面上有用。
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通过归纳逻辑编程(ILP)综合大型逻辑程序通常需要中间定义。但是,用强化谓词混乱假设空间通常会降低性能。相比之下,梯度下降提供了一种有效的方法来在此类高维空间中找到溶液。到目前为止,神经符号ILP方法尚未完全利用这一点。我们提出了一种基于ILP的合成方法,该方法受益于大规模谓词发明,利用了高维梯度下降的功效。我们发现包含十个辅助定义以上的符号解决方案。这超出了现有的神经符号ILP系统的成就,因此构成了该领域的里程碑。
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骨肉瘤是最常见的原发性骨癌,其标准治疗包括术前化疗,然后切除。化学疗法反应用于预测患者的预后和进一步治疗。坏死在切除标本上的组织学幻灯片通常评估了坏死比定义为坏死肿瘤与总体肿瘤之比。已知坏死比> = 90%的患者的预后更好。多个载玻片对坏死比的手动微观综述是半定量性的,并且可能具有观察者间和观察者间的变异性。我们提出了一种基于目标和可再现的深度学习方法,以估计坏死比,并从扫描的苏木精和曙红全幻灯片图像预测结果。我们以3134个WSI的速度收集了103例骨肉瘤病例,以训练我们的深度学习模型,验证坏死比评估并评估结果预测。我们训练了深层多磁化网络,以分割多个组织亚型,包括生存的肿瘤和像素级中的坏死肿瘤,并计算来自多个WSI的病例级坏死比。我们显示了通过分割模型估算的坏死比,高度与由专家手动评估的病理报告中的坏死比高度相关,其中IV级的平均绝对差异(100%),III(> = 90%)和II(> = 50%和<50%和< 90%)坏死反应分别为4.4%,4.5%和17.8%。我们成功地对患者进行了分层,以预测P = 10^-6的总生存率,而P = 0.012的无进展生存率。我们没有可变性的可重现方法使我们能够调整截止阈值,特别是用于模型和数据集的截止阈值,为OS的80%,PFS为60%。我们的研究表明,深度学习可以支持病理学家作为一种客观的工具,可以分析组织学中骨肉瘤,以评估治疗反应并预测患者结果。
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