Self-supervised learning via masked prediction pre-training (MPPT) has shown impressive performance on a range of speech-processing tasks. This paper proposes a method to bias self-supervised learning towards a specific task. The core idea is to slightly finetune the model that is used to obtain the target sequence. This leads to better performance and a substantial increase in training speed. Furthermore, this paper proposes a variant of MPPT that allows low-footprint streaming models to be trained effectively by computing the MPPT loss on masked and unmasked frames. These approaches are evaluated for automatic speech recognition on the Librispeech corpus, where 100 hours of data served as the labelled data and 860 hours as the unlabelled data. The biased training outperforms the unbiased training by 15.5% after 250k updates and 23.8% after 100k updates on test-other. For the streaming models, the pre-training approach yields a reduction in word error rate of 44.1%.
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医学图像分割的深度学习模型可能会出乎意料地且出乎意料地失败,而与训练图像相比,在不同中心获得的病理案例和图像,标签错误违反了专家知识。此类错误破坏了对医学图像细分的深度学习模型的可信赖性。检测和纠正此类故障的机制对于将该技术安全地转化为诊所至关重要,并且可能是对未来人工智能法规(AI)的要求。在这项工作中,我们提出了一个值得信赖的AI理论框架和一个实用系统,该系统可以使用后备方法和基于Dempster-Shafer理论的失败机制增强任何骨干AI系统。我们的方法依赖于可信赖的AI的可行定义。我们的方法会自动放弃由骨干AI预测的体素级标签,该标签违反了专家知识,并依赖于这些体素的后备。我们证明了拟议的值得信赖的AI方法在最大的报告的胎儿MRI的注释数据集中,由13个中心的540个手动注释的胎儿脑3D T2W MRI组成。我们值得信赖的AI方法改善了在各个中心获得的胎儿脑MRI和各种脑异常的胎儿的最先进的主链AI的鲁棒性。
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放射线学使用定量医学成像特征来预测临床结果。目前,在新的临床应用中,必须通过启发式试验和纠正过程手动完成各种可用选项的最佳放射组方法。在这项研究中,我们提出了一个框架,以自动优化每个应用程序的放射线工作流程的构建。为此,我们将放射线学作为模块化工作流程,并为每个组件包含大量的常见算法。为了优化每个应用程序的工作流程,我们使用随机搜索和结合使用自动化机器学习。我们在十二个不同的临床应用中评估我们的方法,从而在曲线下导致以下区域:1)脂肪肉瘤(0.83); 2)脱粘型纤维瘤病(0.82); 3)原发性肝肿瘤(0.80); 4)胃肠道肿瘤(0.77); 5)结直肠肝转移(0.61); 6)黑色素瘤转移(0.45); 7)肝细胞癌(0.75); 8)肠系膜纤维化(0.80); 9)前列腺癌(0.72); 10)神经胶质瘤(0.71); 11)阿尔茨海默氏病(0.87);和12)头颈癌(0.84)。我们表明,我们的框架具有比较人类专家的竞争性能,优于放射线基线,并且表现相似或优于贝叶斯优化和更高级的合奏方法。最后,我们的方法完全自动优化了放射线工作流的构建,从而简化了在新应用程序中对放射线生物标志物的搜索。为了促进可重复性和未来的研究,我们公开发布了六个数据集,框架的软件实施以及重现这项研究的代码。
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$ \ Texit {Fermi} $数据中的银河系中多余(GCE)的两个领先假设是一个未解决的微弱毫秒脉冲条件(MSP)和暗物质(DM)湮灭。这些解释之间的二分法通常通过将它们建模为两个单独的发射组分来反映。然而,诸如MSP的点源(PSS)在超微弱的极限中具有统计变质的泊松发射(正式的位置,预期每个来源平均贡献远低于一个光子),导致可能提出问题的歧义如排放是否是PS样或性质中的泊松人。我们提出了一种概念上的新方法,以统一的方式描述PS和泊松发射,并且刚刚从此获得的结果中获得了对泊松组件的约束。为了实现这种方法,我们利用深度学习技术,围绕基于神经网络的方法,用于直方图回归,其表达量数量的不确定性。我们证明我们的方法对许多困扰先前接近的系统,特别是DM / PS误操作来稳健。在$ \ texit {fermi} $数据中,我们发现由$ \ sim4 \ times 10 ^ {-11} \ \ text {counts} \ {counts} \ text {counts} \ text {counts} \ \ text {cm} ^ { - 2} \ \ text {s} ^ { - 1} $(对应于$ \ sim3 - 4 $每pL期望计数),这需要$ n \ sim \ mathcal {o}( 10 ^ 4)$源来解释整个过剩(中位数价值$ n = \文本{29,300} $横跨天空)。虽然微弱,但这种SCD允许我们获得95%信心的Poissonian比赛的约束$ \ eta_p \ leq 66 \%$。这表明大量的GCE通量是由于PSS 。
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Federated learning (FL) is a machine learning setting where many clients (e.g. mobile devices or whole organizations) collaboratively train a model under the orchestration of a central server (e.g. service provider), while keeping the training data decentralized. FL embodies the principles of focused data collection and minimization, and can mitigate many of the systemic privacy risks and costs resulting from traditional, centralized machine learning and data science approaches. Motivated by the explosive growth in FL research, this paper discusses recent advances and presents an extensive collection of open problems and challenges.
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While the brain connectivity network can inform the understanding and diagnosis of developmental dyslexia, its cause-effect relationships have not yet enough been examined. Employing electroencephalography signals and band-limited white noise stimulus at 4.8 Hz (prosodic-syllabic frequency), we measure the phase Granger causalities among channels to identify differences between dyslexic learners and controls, thereby proposing a method to calculate directional connectivity. As causal relationships run in both directions, we explore three scenarios, namely channels' activity as sources, as sinks, and in total. Our proposed method can be used for both classification and exploratory analysis. In all scenarios, we find confirmation of the established right-lateralized Theta sampling network anomaly, in line with the temporal sampling framework's assumption of oscillatory differences in the Theta and Gamma bands. Further, we show that this anomaly primarily occurs in the causal relationships of channels acting as sinks, where it is significantly more pronounced than when only total activity is observed. In the sink scenario, our classifier obtains 0.84 and 0.88 accuracy and 0.87 and 0.93 AUC for the Theta and Gamma bands, respectively.
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There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .
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Machine learning models are typically evaluated by computing similarity with reference annotations and trained by maximizing similarity with such. Especially in the bio-medical domain, annotations are subjective and suffer from low inter- and intra-rater reliability. Since annotations only reflect the annotation entity's interpretation of the real world, this can lead to sub-optimal predictions even though the model achieves high similarity scores. Here, the theoretical concept of Peak Ground Truth (PGT) is introduced. PGT marks the point beyond which an increase in similarity with the reference annotation stops translating to better Real World Model Performance (RWMP). Additionally, a quantitative technique to approximate PGT by computing inter- and intra-rater reliability is proposed. Finally, three categories of PGT-aware strategies to evaluate and improve model performance are reviewed.
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Mixtures of von Mises-Fisher distributions can be used to cluster data on the unit hypersphere. This is particularly adapted for high-dimensional directional data such as texts. We propose in this article to estimate a von Mises mixture using a l 1 penalized likelihood. This leads to sparse prototypes that improve clustering interpretability. We introduce an expectation-maximisation (EM) algorithm for this estimation and explore the trade-off between the sparsity term and the likelihood one with a path following algorithm. The model's behaviour is studied on simulated data and, we show the advantages of the approach on real data benchmark. We also introduce a new data set on financial reports and exhibit the benefits of our method for exploratory analysis.
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Passive monitoring of acoustic or radio sources has important applications in modern convenience, public safety, and surveillance. A key task in passive monitoring is multiobject tracking (MOT). This paper presents a Bayesian method for multisensor MOT for challenging tracking problems where the object states are high-dimensional, and the measurements follow a nonlinear model. Our method is developed in the framework of factor graphs and the sum-product algorithm (SPA). The multimodal probability density functions (pdfs) provided by the SPA are effectively represented by a Gaussian mixture model (GMM). To perform the operations of the SPA in high-dimensional spaces, we make use of Particle flow (PFL). Here, particles are migrated towards regions of high likelihood based on the solution of a partial differential equation. This makes it possible to obtain good object detection and tracking performance even in challenging multisensor MOT scenarios with single sensor measurements that have a lower dimension than the object positions. We perform a numerical evaluation in a passive acoustic monitoring scenario where multiple sources are tracked in 3-D from 1-D time-difference-of-arrival (TDOA) measurements provided by pairs of hydrophones. Our numerical results demonstrate favorable detection and estimation accuracy compared to state-of-the-art reference techniques.
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