机器学习的最新进展表明,通过自我监督的学习获得的预训练表示形式可以通过小型培训数据实现高精度。与视觉和自然语言处理域不同,基于IMU的应用程序的预培训是具有挑战性的,因为只有少数公开可用的数据集具有足够的规模和多样性来学习可推广的表示。为了克服这个问题,我们提出了IMG2IMU,这是一种新颖的方法,可以适应从大规模图像到不同弹药的IMU感应任务的预训练表示。我们将传感器数据转换为可解释的频谱图,以便模型利用从视觉中获得的知识。此外,我们将对比度学习应用于我们旨在学习用于解释传感器数据的表示形式。我们对五个IMU感应任务的广泛评估表明,IMG2IMU始终优于基准,这说明视力知识可以纳入一些用于IMU感应任务的学习环境中。
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测试时间适应(TTA)是一个新兴范式,可解决培训和测试阶段之间的分布变化,而无需其他数据采集或标签成本;仅使用未标记的测试数据流进行连续模型适应。以前的TTA方案假设测试样本是独立的,并且分布相同(i.i.d.),即使它们在应用程序方案中通常在时间上相关(non-i.i.d。),例如自动驾驶。我们发现,在这种情况下,大多数现有的TTA方法急剧失败。由此激励,我们提出了一种新的测试时间适应方案,该方案对非I.I.D具有强大的态度。测试数据流。我们的新颖性主要是两倍:(a)纠正分布样本的归一化的实例感知批归归量表(IABN),以及(b)模拟I.I.D.的预测均衡储层采样(PBRS)。来自非i.i.d的数据流。以班级平衡的方式流式传输。我们对各种数据集的评估,包括现实世界非i.i.d。流,表明所提出的强大TTA不仅优于非i.i.d的最先进的TTA算法。设置,但也可以实现与I.I.D.下的这些算法相当的性能。假设。
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许多利用移动设备中的传感器的应用以及应用机器学习以提供新颖的服务。然而,诸如不同的用户,设备,环境和超参数之类的各种因素影响了这种应用的性能,从而使域移位(即,来自训练源数据集的目标用户的分发偏移)是一个重要问题。虽然最近的域适应技术试图解决这个问题,但各种因素之间的复杂相互作用通常会限制其有效性。我们认为,准确估算未训练的域中的性能可能会显着降低性能不确定性。我们呈现Dapper(域适配性能估计器),其估计目标域中的适应性能,只有未标记的目标数据。我们的直觉是目标数据上模型的输出提供了模型在目标域中的实际性能的线索。 Dapper不需要昂贵的标签成本,也不需要在部署后涉及额外的培训。与四个基线相比,我们与四个真实世界传感数据集进行了评估,表明,估计精度平均17%平均占据了基线的表现。此外,我们的On-Device实验表明,与基线相比,Dapper达到了多达216倍的计算开销。
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Brain midline shift (MLS) is one of the most critical factors to be considered for clinical diagnosis and treatment decision-making for intracranial hemorrhage. Existing computational methods on MLS quantification not only require intensive labeling in millimeter-level measurement but also suffer from poor performance due to their dependence on specific landmarks or simplified anatomical assumptions. In this paper, we propose a novel semi-supervised framework to accurately measure the scale of MLS from head CT scans. We formulate the MLS measurement task as a deformation estimation problem and solve it using a few MLS slices with sparse labels. Meanwhile, with the help of diffusion models, we are able to use a great number of unlabeled MLS data and 2793 non-MLS cases for representation learning and regularization. The extracted representation reflects how the image is different from a non-MLS image and regularization serves an important role in the sparse-to-dense refinement of the deformation field. Our experiment on a real clinical brain hemorrhage dataset has achieved state-of-the-art performance and can generate interpretable deformation fields.
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Current mainstream object detection methods for large aerial images usually divide large images into patches and then exhaustively detect the objects of interest on all patches, no matter whether there exist objects or not. This paradigm, although effective, is inefficient because the detectors have to go through all patches, severely hindering the inference speed. This paper presents an Objectness Activation Network (OAN) to help detectors focus on fewer patches but achieve more efficient inference and more accurate results, enabling a simple and effective solution to object detection in large images. In brief, OAN is a light fully-convolutional network for judging whether each patch contains objects or not, which can be easily integrated into many object detectors and jointly trained with them end-to-end. We extensively evaluate our OAN with five advanced detectors. Using OAN, all five detectors acquire more than 30.0% speed-up on three large-scale aerial image datasets, meanwhile with consistent accuracy improvements. On extremely large Gaofen-2 images (29200$\times$27620 pixels), our OAN improves the detection speed by 70.5%. Moreover, we extend our OAN to driving-scene object detection and 4K video object detection, boosting the detection speed by 112.1% and 75.0%, respectively, without sacrificing the accuracy. Code is available at https://github.com/Ranchosky/OAN.
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We study the problem of semantic segmentation calibration. For image classification, lots of existing solutions are proposed to alleviate model miscalibration of confidence. However, to date, confidence calibration research on semantic segmentation is still limited. We provide a systematic study on the calibration of semantic segmentation models and propose a simple yet effective approach. First, we find that model capacity, crop size, multi-scale testing, and prediction correctness have impact on calibration. Among them, prediction correctness, especially misprediction, is more important to miscalibration due to over-confidence. Next, we propose a simple, unifying, and effective approach, namely selective scaling, by separating correct/incorrect prediction for scaling and more focusing on misprediction logit smoothing. Then, we study popular existing calibration methods and compare them with selective scaling on semantic segmentation calibration. We conduct extensive experiments with a variety of benchmarks on both in-domain and domain-shift calibration, and show that selective scaling consistently outperforms other methods.
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In this paper, we propose a large-scale language pre-training for text GENeration using dIffusion modEl, which is named GENIE. GENIE is a pre-training sequence-to-sequence text generation model which combines Transformer and diffusion. The diffusion model accepts the latent information from the encoder, which is used to guide the denoising of the current time step. After multiple such denoise iterations, the diffusion model can restore the Gaussian noise to the diverse output text which is controlled by the input text. Moreover, such architecture design also allows us to adopt large scale pre-training on the GENIE. We propose a novel pre-training method named continuous paragraph denoise based on the characteristics of the diffusion model. Extensive experiments on the XSum, CNN/DailyMail, and Gigaword benchmarks shows that GENIE can achieves comparable performance with various strong baselines, especially after pre-training, the generation quality of GENIE is greatly improved. We have also conduct a lot of experiments on the generation diversity and parameter impact of GENIE. The code for GENIE will be made publicly available.
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Developing autonomous vehicles (AVs) helps improve the road safety and traffic efficiency of intelligent transportation systems (ITS). Accurately predicting the trajectories of traffic participants is essential to the decision-making and motion planning of AVs in interactive scenarios. Recently, learning-based trajectory predictors have shown state-of-the-art performance in highway or urban areas. However, most existing learning-based models trained with fixed datasets may perform poorly in continuously changing scenarios. Specifically, they may not perform well in learned scenarios after learning the new one. This phenomenon is called "catastrophic forgetting". Few studies investigate trajectory predictions in continuous scenarios, where catastrophic forgetting may happen. To handle this problem, first, a novel continual learning (CL) approach for vehicle trajectory prediction is proposed in this paper. Then, inspired by brain science, a dynamic memory mechanism is developed by utilizing the measurement of traffic divergence between scenarios, which balances the performance and training efficiency of the proposed CL approach. Finally, datasets collected from different locations are used to design continual training and testing methods in experiments. Experimental results show that the proposed approach achieves consistently high prediction accuracy in continuous scenarios without re-training, which mitigates catastrophic forgetting compared to non-CL approaches. The implementation of the proposed approach is publicly available at https://github.com/BIT-Jack/D-GSM
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Data compression is becoming critical for storing scientific data because many scientific applications need to store large amounts of data and post process this data for scientific discovery. Unlike image and video compression algorithms that limit errors to primary data, scientists require compression techniques that accurately preserve derived quantities of interest (QoIs). This paper presents a physics-informed compression technique implemented as an end-to-end, scalable, GPU-based pipeline for data compression that addresses this requirement. Our hybrid compression technique combines machine learning techniques and standard compression methods. Specifically, we combine an autoencoder, an error-bounded lossy compressor to provide guarantees on raw data error, and a constraint satisfaction post-processing step to preserve the QoIs within a minimal error (generally less than floating point error). The effectiveness of the data compression pipeline is demonstrated by compressing nuclear fusion simulation data generated by a large-scale fusion code, XGC, which produces hundreds of terabytes of data in a single day. Our approach works within the ADIOS framework and results in compression by a factor of more than 150 while requiring only a few percent of the computational resources necessary for generating the data, making the overall approach highly effective for practical scenarios.
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Inspired by the recent success of Transformers for Natural Language Processing and vision Transformer for Computer Vision, many researchers in the medical imaging community have flocked to Transformer-based networks for various main stream medical tasks such as classification, segmentation, and estimation. In this study, we analyze, two recently published Transformer-based network architectures for the task of multimodal head-and-tumor segmentation and compare their performance to the de facto standard 3D segmentation network - the nnU-Net. Our results showed that modeling long-range dependencies may be helpful in cases where large structures are present and/or large field of view is needed. However, for small structures such as head-and-neck tumor, the convolution-based U-Net architecture seemed to perform well, especially when training dataset is small and computational resource is limited.
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