Significant progress has been made in learning image classification neural networks under long-tail data distribution using robust training algorithms such as data re-sampling, re-weighting, and margin adjustment. Those methods, however, ignore the impact of data imbalance on feature normalization. The dominance of majority classes (head classes) in estimating statistics and affine parameters causes internal covariate shifts within less-frequent categories to be overlooked. To alleviate this challenge, we propose a compound batch normalization method based on a Gaussian mixture. It can model the feature space more comprehensively and reduce the dominance of head classes. In addition, a moving average-based expectation maximization (EM) algorithm is employed to estimate the statistical parameters of multiple Gaussian distributions. However, the EM algorithm is sensitive to initialization and can easily become stuck in local minima where the multiple Gaussian components continue to focus on majority classes. To tackle this issue, we developed a dual-path learning framework that employs class-aware split feature normalization to diversify the estimated Gaussian distributions, allowing the Gaussian components to fit with training samples of less-frequent classes more comprehensively. Extensive experiments on commonly used datasets demonstrated that the proposed method outperforms existing methods on long-tailed image classification.
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Zero-shot relation triplet extraction (ZeroRTE) aims to extract relation triplets from unstructured texts under the zero-shot setting, where the relation sets at the training and testing stages are disjoint. Previous state-of-the-art method handles this challenging task by leveraging pretrained language models to generate data as additional training samples, which increases the training cost and severely constrains the model performance. To address the above issues, we propose a novel method named PCRED for ZeroRTE with Potential Candidate Relation Selection and Entity Boundary Detection. The remarkable characteristic of PCRED is that it does not rely on additional data and still achieves promising performance. The model adopts a relation-first paradigm, recognizing unseen relations through candidate relation selection. With this approach, the semantics of relations are naturally infused in the context. Entities are extracted based on the context and the semantics of relations subsequently. We evaluate our model on two ZeroRTE datasets. The experiment results show that our method consistently outperforms previous works. Our code will be available at https://anonymous.4open.science/r/PCRED.
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The image captioning task is typically realized by an auto-regressive method that decodes the text tokens one by one. We present a diffusion-based captioning model, dubbed the name DDCap, to allow more decoding flexibility. Unlike image generation, where the output is continuous and redundant with a fixed length, texts in image captions are categorical and short with varied lengths. Therefore, naively applying the discrete diffusion model to text decoding does not work well, as shown in our experiments. To address the performance gap, we propose several key techniques including best-first inference, concentrated attention mask, text length prediction, and image-free training. On COCO without additional caption pre-training, it achieves a CIDEr score of 117.8, which is +5.0 higher than the auto-regressive baseline with the same architecture in the controlled setting. It also performs +26.8 higher CIDEr score than the auto-regressive baseline (230.3 v.s.203.5) on a caption infilling task. With 4M vision-language pre-training images and the base-sized model, we reach a CIDEr score of 125.1 on COCO, which is competitive to the best well-developed auto-regressive frameworks. The code is available at https://github.com/buxiangzhiren/DDCap.
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Various depth estimation models are now widely used on many mobile and IoT devices for image segmentation, bokeh effect rendering, object tracking and many other mobile tasks. Thus, it is very crucial to have efficient and accurate depth estimation models that can run fast on low-power mobile chipsets. In this Mobile AI challenge, the target was to develop deep learning-based single image depth estimation solutions that can show a real-time performance on IoT platforms and smartphones. For this, the participants used a large-scale RGB-to-depth dataset that was collected with the ZED stereo camera capable to generated depth maps for objects located at up to 50 meters. The runtime of all models was evaluated on the Raspberry Pi 4 platform, where the developed solutions were able to generate VGA resolution depth maps at up to 27 FPS while achieving high fidelity results. All models developed in the challenge are also compatible with any Android or Linux-based mobile devices, their detailed description is provided in this paper.
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We present a strong object detector with encoder-decoder pretraining and finetuning. Our method, called Group DETR v2, is built upon a vision transformer encoder ViT-Huge~\cite{dosovitskiy2020image}, a DETR variant DINO~\cite{zhang2022dino}, and an efficient DETR training method Group DETR~\cite{chen2022group}. The training process consists of self-supervised pretraining and finetuning a ViT-Huge encoder on ImageNet-1K, pretraining the detector on Object365, and finally finetuning it on COCO. Group DETR v2 achieves $\textbf{64.5}$ mAP on COCO test-dev, and establishes a new SoTA on the COCO leaderboard https://paperswithcode.com/sota/object-detection-on-coco
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本文提出了一种新方法,该方法融合了混响场中的声学测量和低临界性惯性测量单元(IMU)运动报告,以同时定位和映射(SLAM)。与仅使用声学数据进行到达方向(DOA)估计的现有研究不同,源与传感器的距离是通过直接到依次的能量比(DRR)计算的,并用作新约束以消除非线性噪声从运动报告。应用粒子过滤器估计临界距离,这是将源距离与DRR关联的关键。使用密钥帧方法来消除源位置估计向机器人的偏差。拟议的DOA-DRR声学大满贯(D-D大满贯)设计用于三维运动,适合大多数机器人。该方法是第一个在现实世界中仅包含声学数据和IMU测量值的现实世界室内场景数据集上验证的声学大满贯算法。与以前的方法相比,D-D SLAM在定位机器人和从现实世界室内数据集中构建源地图方面具有可接受的性能。平均位置精度为0.48 m,而源位置误差在2.8 s内收敛到小于0.25 m。这些结果证明了D-D SLAM在现实世界室内场景中的有效性,这可能在环境有雾(即不适合光或激光辐照的环境)之后特别有用。
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在卷积神经网络(CNN)的动力下,医学图像分类迅速发展。由于卷积内核的接受场的固定尺寸,很难捕获医学图像的全局特征。尽管基于自发的变压器可以对远程依赖性进行建模,但它具有很高的计算复杂性,并且缺乏局部电感偏见。许多研究表明,全球和本地特征对于图像分类至关重要。但是,医学图像具有许多嘈杂,分散的特征,类内的变化和类间的相似性。本文提出了三个分支分层的多尺度特征融合网络结构,称为医学图像分类为新方法。它可以融合多尺度层次结构的变压器和CNN的优势,而不会破坏各自的建模,从而提高各种医学图像的分类精度。局部和全局特征块的平行层次结构旨在有效地提取各种语义尺度的本地特征和全局表示,并灵活地在不同的尺度上建模,并与图像大小相关的线性计算复杂性。此外,自适应分层特征融合块(HFF块)旨在全面利用在不同层次级别获得的功能。 HFF块包含空间注意力,通道注意力,残留的倒置MLP和快捷方式,以在每个分支的各个规模特征之间适应融合语义信息。我们在ISIC2018数据集上提出的模型的准确性比基线高7.6%,COVID-19数据集的准确性为21.5%,Kvasir数据集的准确性为10.4%。与其他高级模型相比,HIFUSE模型表现最好。我们的代码是开源的,可从https://github.com/huoxiangzuo/hifuse获得。
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尽管在各种应用中取得了突出的性能,但点云识别模型经常遭受自然腐败和对抗性扰动的困扰。在本文中,我们深入研究了点云识别模型的一般鲁棒性,并提出了点云对比对抗训练(PointCat)。 PointCat的主要直觉是鼓励目标识别模型缩小清洁点云和损坏点云之间的决策差距。具体而言,我们利用有监督的对比损失来促进识别模型提取的超晶体特征的对齐和均匀性,并设计一对带有动态原型指南的集中式损失,以避免这些特征与其属于其属于其归属类别群的偏离。为了提供更具挑战性的损坏点云,我们对噪声生成器以及从头开始的识别模型进行了对手训练,而不是将基于梯度的攻击用作内部循环,例如以前的对手训练方法。全面的实验表明,在包括各种损坏的情况下,所提出的PointCat优于基线方法,并显着提高不同点云识别模型的稳健性,包括各向同性点噪声,LIDAR模拟的噪声,随机点掉落和对抗性扰动。
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安全的加强学习(RL)研究智能代理人不仅必须最大程度地提高奖励,而且还要避免探索不安全领域的问题。在这项研究中,我们提出了CUP,这是一种基于约束更新投影框架的新型政策优化方法,享有严格的安全保证。我们杯杯发展的核心是新提出的替代功能以及性能结合。与以前的安全RL方法相比,杯子的好处1)杯子将代孕功能推广到广义优势估计量(GAE),从而导致强烈的经验性能。 2)杯赛统一性界限,为某些现有算法提供更好的理解和解释性; 3)CUP仅通过一阶优化器提供非凸的实现,该优化器不需要在目标的凸面上进行任何强近似。为了验证我们的杯子方法,我们将杯子与在各种任务上进行的安全RL基线的全面列表进行了比较。实验表明杯子在奖励和安全限制满意度方面的有效性。我们已经在https://github.com/rl-boxes/safe-rl/tree/ main/cup上打开了杯子源代码。
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具有高分辨率(HR)的磁共振成像(MRI)提供了更详细的信息,以进行准确的诊断和定量图像分析。尽管取得了重大进展,但大多数现有的医学图像重建网络都有两个缺陷:1)所有这些缺陷都是在黑盒原理中设计的,因此缺乏足够的解释性并进一步限制其实际应用。可解释的神经网络模型引起了重大兴趣,因为它们在处理医学图像时增强了临床实践所需的可信赖性。 2)大多数现有的SR重建方法仅使用单个对比度或使用简单的多对比度融合机制,从而忽略了对SR改进至关重要的不同对比度之间的复杂关系。为了解决这些问题,在本文中,提出了一种新颖的模型引导的可解释的深层展开网络(MGDUN),用于医学图像SR重建。模型引导的图像SR重建方法求解手动设计的目标函数以重建HR MRI。我们通过将MRI观察矩阵和显式多对比度关系矩阵考虑到末端到端优化期间,将迭代的MGDUN算法展示为新型模型引导的深层展开网络。多对比度IXI数据集和Brats 2019数据集进行了广泛的实验,证明了我们提出的模型的优势。
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