光学相干断层扫描（OCT）是一种非侵入性技术，可在微米分辨率中捕获视网膜的横截面区域。它已被广泛用作辅助成像参考，以检测与眼睛有关的病理学并预测疾病特征的纵向进展。视网膜层分割是至关重要的特征提取技术之一，其中视网膜层厚度的变化和由于液体的存在而引起的视网膜层变形高度相关，与多种流行性眼部疾病（如糖尿病性视网膜病）和年龄相关的黄斑疾病高度相关。变性（AMD）。但是，这些图像是从具有不同强度分布或换句话说的不同设备中获取的，属于不同的成像域。本文提出了一种分割引导的域适应方法，以将来自多个设备的图像调整为单个图像域，其中可用的最先进的预训练模型可用。它避免了即将推出的新数据集的手动标签的时间消耗以及现有网络的重新培训。网络的语义一致性和全球特征一致性将最大程度地减少许多研究人员报告的幻觉效果，这些效应对周期矛盾的生成对抗网络（Cyclegan）体系结构。
translated by 谷歌翻译
Recent large-scale image generation models such as Stable Diffusion have exhibited an impressive ability to generate fairly realistic images starting from a very simple text prompt. Could such models render real images obsolete for training image prediction models? In this paper, we answer part of this provocative question by questioning the need for real images when training models for ImageNet classification. More precisely, provided only with the class names that have been used to build the dataset, we explore the ability of Stable Diffusion to generate synthetic clones of ImageNet and measure how useful they are for training classification models from scratch. We show that with minimal and class-agnostic prompt engineering those ImageNet clones we denote as ImageNet-SD are able to close a large part of the gap between models produced by synthetic images and models trained with real images for the several standard classification benchmarks that we consider in this study. More importantly, we show that models trained on synthetic images exhibit strong generalization properties and perform on par with models trained on real data.
translated by 谷歌翻译
Direct speech-to-speech translation (S2ST), in which all components can be optimized jointly, is advantageous over cascaded approaches to achieve fast inference with a simplified pipeline. We present a novel two-pass direct S2ST architecture, {\textit UnitY}, which first generates textual representations and predicts discrete acoustic units subsequently. We enhance the model performance by subword prediction in the first-pass decoder, advanced two-pass decoder architecture design and search strategy, and better training regularization. To leverage large amounts of unlabeled text data, we pre-train the first-pass text decoder based on the self-supervised denoising auto-encoding task. Experimental evaluations on benchmark datasets at various data scales demonstrate that UnitY outperforms a single-pass speech-to-unit translation model by 2.5-4.2 ASR-BLEU with 2.83x decoding speed-up. We show that the proposed methods boost the performance even when predicting spectrogram in the second pass. However, predicting discrete units achieves 2.51x decoding speed-up compared to that case.
translated by 谷歌翻译
Despite significant advances, the performance of state-of-the-art continual learning approaches hinges on the unrealistic scenario of fully labeled data. In this paper, we tackle this challenge and propose an approach for continual semi-supervised learning -- a setting where not all the data samples are labeled. An underlying issue in this scenario is the model forgetting representations of unlabeled data and overfitting the labeled ones. We leverage the power of nearest-neighbor classifiers to non-linearly partition the feature space and learn a strong representation for the current task, as well as distill relevant information from previous tasks. We perform a thorough experimental evaluation and show that our method outperforms all the existing approaches by large margins, setting a strong state of the art on the continual semi-supervised learning paradigm. For example, on CIFAR100 we surpass several others even when using at least 30 times less supervision (0.8% vs. 25% of annotations).
translated by 谷歌翻译
We propose a novel antialiasing method to increase shift invariance in convolutional neural networks (CNNs). More precisely, we replace the conventional combination "real-valued convolutions + max pooling" ($\mathbb R$Max) by "complex-valued convolutions + modulus" ($\mathbb C$Mod), which produce stable feature representations for band-pass filters with well-defined orientations. In a recent work, we proved that, for such filters, the two operators yield similar outputs. Therefore, $\mathbb C$Mod can be viewed as a stable alternative to $\mathbb R$Max. To separate band-pass filters from other freely-trained kernels, in this paper, we designed a "twin" architecture based on the dual-tree complex wavelet packet transform, which generates similar outputs as standard CNNs with fewer trainable parameters. In addition to improving stability to small shifts, our experiments on AlexNet and ResNet showed increased prediction accuracy on natural image datasets such as ImageNet and CIFAR10. Furthermore, our approach outperformed recent antialiasing methods based on low-pass filtering by preserving high-frequency information, while reducing memory usage.
translated by 谷歌翻译
Vision Transformers (ViTs) have become a dominant paradigm for visual representation learning with self-attention operators. Although these operators provide flexibility to the model with their adjustable attention kernels, they suffer from inherent limitations: (1) the attention kernel is not discriminative enough, resulting in high redundancy of the ViT layers, and (2) the complexity in computation and memory is quadratic in the sequence length. In this paper, we propose a novel attention operator, called lightweight structure-aware attention (LiSA), which has a better representation power with log-linear complexity. Our operator learns structural patterns by using a set of relative position embeddings (RPEs). To achieve log-linear complexity, the RPEs are approximated with fast Fourier transforms. Our experiments and ablation studies demonstrate that ViTs based on the proposed operator outperform self-attention and other existing operators, achieving state-of-the-art results on ImageNet, and competitive results on other visual understanding benchmarks such as COCO and Something-Something-V2. The source code of our approach will be released online.
translated by 谷歌翻译
随机森林（RF）是一种流行的机器学习方法，用于分类和回归问题。它涉及对决策树模型的行李申请。随机森林模型的主要优点之一是预测的方差降低。在具有数百万个数据点和数百个功能的模型的大规模应用中，拟合对象的大小可能会变得很大，并取决于生产设置中可用空间的限制，具体取决于树木的数量和深度。当需要按需下载训练有素的型号到具有有限内存的小型设备时，这可能尤其具有挑战性。有必要近似训练有素的RF模型，以显着降低模型大小而不会失去过多的预测准确性。在这个项目中，我们研究了使用数据点对叶子的多项式分配，该方法在随机森林模型中近似于每个拟合的树。具体而言，我们首先研究拟合多项式逻辑回归（随后将广义添加剂模型（GAM）扩展）拟合到每棵树的输出中是否有助于降低尺寸，同时保留预测质量。
translated by 谷歌翻译
我们考虑在给定的分类任务（例如Imagenet-1k（IN1K））上训练深神网络的问题，以便它在该任务以及其他（未来）转移任务方面擅长。这两个看似矛盾的属性在改善模型的概括的同时保持其在原始任务上的性能之间实现了权衡。接受自我监督学习训练的模型（SSL）倾向于比其受监督的转移学习更好地概括。但是，他们仍然落后于In1k上的监督模型。在本文中，我们提出了一个有监督的学习设置，以利用两全其美的方式。我们使用最近的SSL模型的两个关键组成部分丰富了普通的监督培训框架：多尺度农作物用于数据增强和使用可消耗的投影仪。我们用内存库在即时计算的类原型中代替了班级权重的最后一层。我们表明，这三个改进导致IN1K培训任务和13个转移任务之间的权衡取决于更加有利的权衡。在所有探索的配置中，我们都会挑出两种模型：T-Rex实现了转移学习的新状态，并且超过了In1k上的Dino和Paws等最佳方法，以及与高度优化的RSB--相匹配的T-Rex*在IN1K上的A1模型，同时在转移任务上表现更好。项目页面和预估计的模型：https：//europe.naverlabs.com/t-rex
translated by 谷歌翻译
自主驾驶的最新作品已广泛采用了鸟眼视图（BEV）语义图作为世界的中间表示。这些BEV地图的在线预测涉及非平凡操作，例如多摄像机数据提取以及融合和投影到常见的顶级网格中。这通常是通过易易错的几何操作（例如，单眼深度估计的同构图或反射）或BEV中图像像素和像素（例如，具有MLP或注意力）之间的昂贵直接密集映射来完成。在这项工作中，我们提出了“ Lara”，这是一种有效的编码器编码器，基于变压器的模型，用于从多个摄像机中进行车辆语义分割。我们的方法使用交叉注意的系统将信息通过多个传感器汇总为紧凑而丰富的潜在表示。这些潜在的表示在通过一系列自我发场块处理后，在BEV空间中进行了第二次交叉注意。我们证明，我们的模型在Nuscenes上的表现优于使用变压器的最佳先前作品。
translated by 谷歌翻译
通过与环境进行互动而没有任何外部监督是一个重要的挑战，可以通过与环境进行互动来学习各种技能。特别是，获得可以达到任何给定状态的目标条件的代理在许多应用中都有用。我们提出了一种新的方法，用于训练这种目标条件的代理，而没有任何外部奖励或任何领域知识。我们使用随机步行来训练可及性网络，以预测两个状态之间的相似性。然后，该可达性网络将用于构建目标记忆，其中包含过去的观察结果，这些观察值多样化且平衡。最后，我们训练一个目标条件条件的政策网络，其目标是从目标记忆中取得的目标，并通过可达性网络和目标记忆进行奖励。当代理商发现并学习新目标时，所有组件在整个培训中都进行了更新。我们将方法应用于连续的控制导航和机器人操纵任务。
translated by 谷歌翻译