本文介绍了Omnicity，这是一种从多层次和多视图图像中了解无所不能的城市理解的新数据集。更确切地说，Omnicity包含多视图的卫星图像以及街道级全景图和单视图图像，构成了超过100k像素的注释图像，这些图像是从纽约市的25k Geo-Locations中良好的一致性和收集的。为了减轻大量像素的注释努力，我们提出了一个有效的街景图像注释管道，该管道利用了卫星视图的现有标签地图以及不同观点之间的转换关系（卫星，Panorama和Mono-View）。有了新的Omnicity数据集，我们为各种任务提供基准，包括构建足迹提取，高度估计以及构建平面/实例/细粒细分。我们还分析了视图对每个任务的影响，不同模型的性能，现有方法的局限性等。与现有的多层次和多视图基准相比，我们的Omnicity包含更多具有更丰富注释类型和更丰富的图像更多的视图，提供了从最先进的模型获得的更多基线结果，并为街道级全景图像中的细粒度建筑实例细分介绍了一项新颖的任务。此外，Omnicity为现有任务提供了新的问题设置，例如跨视图匹配，合成，分割，检测等，并促进开发新方法，以了解大规模的城市理解，重建和仿真。 Omnicity数据集以及基准将在https://city-super.github.io/omnicity上找到。

神经辐射场（NERF）在建模3D对象和受控场景中取得了出色的性能，通常在单一的范围内。在这项工作中，我们首次尝试将NERF带到城市规模，观点包括卫星级，旨在捕获一个城市的概览，到地面图像，显示架构的复杂细节。到现场的相机距离的广泛跨度产生了具有不同细节水平和空间覆盖率的多尺度数据，这对Vanilla Nerf产生了极大的挑战，并将其偏向于受损结果。为了解决这些问题，我们介绍了CitynerF，这是一个渐进式学习范例，可以同步地增长NERF模型和训练。从拟合浅景层的遥远的视图开始，随着训练的进展，附加新的块以在越来越近的视图中适应新兴细节。该策略有效地激活了位置编码中的高频信道，并将更复杂的细节展开，因为训练进行了。我们展示了CitalnerF在模拟各种城市规模场景中的优越性，具有巨大的不同视图，以及在不同级别的细节中渲染视图的支持。

Information Extraction (IE) aims to extract structured information from heterogeneous sources. IE from natural language texts include sub-tasks such as Named Entity Recognition (NER), Relation Extraction (RE), and Event Extraction (EE). Most IE systems require comprehensive understandings of sentence structure, implied semantics, and domain knowledge to perform well; thus, IE tasks always need adequate external resources and annotations. However, it takes time and effort to obtain more human annotations. Low-Resource Information Extraction (LRIE) strives to use unsupervised data, reducing the required resources and human annotation. In practice, existing systems either utilize self-training schemes to generate pseudo labels that will cause the gradual drift problem, or leverage consistency regularization methods which inevitably possess confirmation bias. To alleviate confirmation bias due to the lack of feedback loops in existing LRIE learning paradigms, we develop a Gradient Imitation Reinforcement Learning (GIRL) method to encourage pseudo-labeled data to imitate the gradient descent direction on labeled data, which can force pseudo-labeled data to achieve better optimization capabilities similar to labeled data. Based on how well the pseudo-labeled data imitates the instructive gradient descent direction obtained from labeled data, we design a reward to quantify the imitation process and bootstrap the optimization capability of pseudo-labeled data through trial and error. In addition to learning paradigms, GIRL is not limited to specific sub-tasks, and we leverage GIRL to solve all IE sub-tasks (named entity recognition, relation extraction, and event extraction) in low-resource settings (semi-supervised IE and few-shot IE).

Besides the complex nature of colonoscopy frames with intrinsic frame formation artefacts such as light reflections and the diversity of polyp types/shapes, the publicly available polyp segmentation training datasets are limited, small and imbalanced. In this case, the automated polyp segmentation using a deep neural network remains an open challenge due to the overfitting of training on small datasets. We proposed a simple yet effective polyp segmentation pipeline that couples the segmentation (FCN) and classification (CNN) tasks. We find the effectiveness of interactive weight transfer between dense and coarse vision tasks that mitigates the overfitting in learning. And It motivates us to design a new training scheme within our segmentation pipeline. Our method is evaluated on CVC-EndoSceneStill and Kvasir-SEG datasets. It achieves 4.34% and 5.70% Polyp-IoU improvements compared to the state-of-the-art methods on the EndoSceneStill and Kvasir-SEG datasets, respectively.

Context-aware decision support in the operating room can foster surgical safety and efficiency by leveraging real-time feedback from surgical workflow analysis. Most existing works recognize surgical activities at a coarse-grained level, such as phases, steps or events, leaving out fine-grained interaction details about the surgical activity; yet those are needed for more helpful AI assistance in the operating room. Recognizing surgical actions as triplets of <instrument, verb, target> combination delivers comprehensive details about the activities taking place in surgical videos. This paper presents CholecTriplet2021: an endoscopic vision challenge organized at MICCAI 2021 for the recognition of surgical action triplets in laparoscopic videos. The challenge granted private access to the large-scale CholecT50 dataset, which is annotated with action triplet information. In this paper, we present the challenge setup and assessment of the state-of-the-art deep learning methods proposed by the participants during the challenge. A total of 4 baseline methods from the challenge organizers and 19 new deep learning algorithms by competing teams are presented to recognize surgical action triplets directly from surgical videos, achieving mean average precision (mAP) ranging from 4.2% to 38.1%. This study also analyzes the significance of the results obtained by the presented approaches, performs a thorough methodological comparison between them, in-depth result analysis, and proposes a novel ensemble method for enhanced recognition. Our analysis shows that surgical workflow analysis is not yet solved, and also highlights interesting directions for future research on fine-grained surgical activity recognition which is of utmost importance for the development of AI in surgery.

信息爆炸的时代促使累积巨大的时间序列数据，包括静止和非静止时间序列数据。最先进的算法在处理静止时间数据方面取得了体面的性能。然而，解决静止​​时间系列的传统算法不适用于外汇交易的非静止系列。本文调查了适用的模型，可以提高预测未来非静止时间序列序列趋势的准确性。特别是，我们专注于识别潜在模型，并调查识别模式从历史数据的影响。我们提出了基于RNN的\ Rebuttal {The} SEQ2Seq模型的组合，以及通过动态时间翘曲和Zigzag峰谷指示器提取的注重机制和富集的集合特征。定制损失函数和评估指标旨在更加关注预测序列的峰值和谷点。我们的研究结果表明，我们的模型可以在外汇数据集中预测高精度的4小时未来趋势，这在逼真的情况下至关重要，以协助外汇交易决策。我们进一步提供了对各种损失函数，评估指标，模型变体和组件对模型性能的影响的评估。