3D场景由大量背景点主导，这对于主要需要集中在前景对象的检测任务是多余的。在本文中，我们分析了现有的稀疏3D CNN的主要组成部分，发现3D CNN忽略了数据的冗余，并在下降过程中进一步扩大了数据，这带来了大量的多余和不必要的计算间开销。受到这一点的启发，我们提出了一个名为“空间修剪稀疏卷积”（SPS-CONV）的新型卷积操作员，其中包括两个变体，空间修剪的Submanifold稀疏卷积（SPSS-CONV）和空间修剪的常规稀疏卷积（SPRS-CONV），包括这是基于动态确定冗余降低关键领域的想法。我们验证该幅度可以作为确定摆脱基于学习方法的额外计算的关键领域的重要提示。提出的模块可以轻松地将其纳入现有的稀疏3D CNN中，而无需额外的架构修改。关于Kitti，Waymo和Nuscenes数据集的广泛实验表明，我们的方法可以在不损害性能的情况下实现超过50％的GFLOPS。

2D CNN和视觉变压器（VIT）的最新进展表明，大型内核对于足够的接受场和高性能至关重要。受这些文献的启发，我们研究了3D大型设计的可行性和挑战。我们证明，在3D CNN中应用大型卷积内核在性能和效率方面都有更多困难。在2D CNN中运行良好的现有技术在3D网络中无效，包括流行的深度卷积。为了克服这些障碍，我们介绍了空间团体卷积及其大内核模块（SW-LK块）。它避免了幼稚3D大核的优化和效率问题。我们的大型内核3D CNN网络，即grounkernel3d，对各种3D任务（包括语义分割和对象检测）产生了非平凡的改进。值得注意的是，它在ScannETV2语义细分和72.8％的NDS NUSCENES对象检测基准上获得了73.9％的MIOU，在Nuscenes Lidar Leadar排行榜上排名第一。具有简单的多模式融合，将其进一步提高到74.2％NDS。与其CNN和Transformer对应物相比，bamekernel3d获得了可比或优越的结果。我们第一次表明，大型内核是可行的，对于3D网络至关重要。

在这项研究中，我们提出了一个新的3D对象检测器，具有可信赖的深度估计，称为bevdepth，用于基于摄像机的鸟类视图（BEV）3D对象检测。通过对最近方法的彻底分析，我们发现没有摄像头信息的深度估计是隐式学习的，这使其成为创建以下伪点云的事实伪造深度。使用编码的内在和外在参数，BevDepth获得了明确的深度监督。进一步引入了深度校正子网络，以抵消深度地面真理中的投影引起的干扰。为了减少速度瓶颈，同时使用估计的深度将功能从图像视图投影到BEV中，还提出了快速的视频转换操作。此外，我们的bevdepth可以通过多帧的输入轻松扩展。 Bevdepth没有任何铃铛和哨子，可以在具有挑战性的Nuscenes测试套装上实现新的最新60.0％NDS，同时保持高效率。相机和激光雷达之间的性能差距首次在10％NDS之内大大降低。

深度可以为显着对象检测（SOD）提供有用的地理线索，并已证明对最近的RGB-D SOD方法有所帮助。但是，现有的视频显着对象检测（VSOD）方法仅利用时空信息，很少利用深度信息进行检测。在本文中，我们提出了一个深度合并的三峰网络，称为VSOD的DCTNet，这是一项开创性的工作，旨在合并深度信息以帮助VSOD。为此，我们首先从RGB框架中生成深度，然后提出一种方法来不平等地处理这三种方式。具体而言，多模式注意模块（MAM）设计为对主模态（RGB）和两个辅助模态（深度，光流）之间的多模式远程依赖性建模。我们还引入了一个细化融合模块（RFM），以抑制每种模式中的噪音，并动态选择有用的信息以进行进一步的优化。最后，在精制特征以实现最终的跨模式融合后采用了渐进式融合策略。五个基准数据集的实验证明了我们的深度合并模型与12种最先进方法的优越性，并且还验证了深度的必要性。

Deep learning models can achieve high accuracy when trained on large amounts of labeled data. However, real-world scenarios often involve several challenges: Training data may become available in installments, may originate from multiple different domains, and may not contain labels for training. Certain settings, for instance medical applications, often involve further restrictions that prohibit retention of previously seen data due to privacy regulations. In this work, to address such challenges, we study unsupervised segmentation in continual learning scenarios that involve domain shift. To that end, we introduce GarDA (Generative Appearance Replay for continual Domain Adaptation), a generative-replay based approach that can adapt a segmentation model sequentially to new domains with unlabeled data. In contrast to single-step unsupervised domain adaptation (UDA), continual adaptation to a sequence of domains enables leveraging and consolidation of information from multiple domains. Unlike previous approaches in incremental UDA, our method does not require access to previously seen data, making it applicable in many practical scenarios. We evaluate GarDA on two datasets with different organs and modalities, where it substantially outperforms existing techniques.

The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.

As one of the prevalent methods to achieve automation systems, Imitation Learning (IL) presents a promising performance in a wide range of domains. However, despite the considerable improvement in policy performance, the corresponding research on the explainability of IL models is still limited. Inspired by the recent approaches in explainable artificial intelligence methods, we proposed a model-agnostic explaining framework for IL models called R2RISE. R2RISE aims to explain the overall policy performance with respect to the frames in demonstrations. It iteratively retrains the black-box IL model from the randomized masked demonstrations and uses the conventional evaluation outcome environment returns as the coefficient to build an importance map. We also conducted experiments to investigate three major questions concerning frames' importance equality, the effectiveness of the importance map, and connections between importance maps from different IL models. The result shows that R2RISE successfully distinguishes important frames from the demonstrations.

Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.

We propose a distributionally robust return-risk model for Markov decision processes (MDPs) under risk and reward ambiguity. The proposed model optimizes the weighted average of mean and percentile performances, and it covers the distributionally robust MDPs and the distributionally robust chance-constrained MDPs (both under reward ambiguity) as special cases. By considering that the unknown reward distribution lies in a Wasserstein ambiguity set, we derive the tractable reformulation for our model. In particular, we show that that the return-risk model can also account for risk from uncertain transition kernel when one only seeks deterministic policies, and that a distributionally robust MDP under the percentile criterion can be reformulated as its nominal counterpart at an adjusted risk level. A scalable first-order algorithm is designed to solve large-scale problems, and we demonstrate the advantages of our proposed model and algorithm through numerical experiments.

Witnessing the impressive achievements of pre-training techniques on large-scale data in the field of computer vision and natural language processing, we wonder whether this idea could be adapted in a grab-and-go spirit, and mitigate the sample inefficiency problem for visuomotor driving. Given the highly dynamic and variant nature of the input, the visuomotor driving task inherently lacks view and translation invariance, and the visual input contains massive irrelevant information for decision making, resulting in predominant pre-training approaches from general vision less suitable for the autonomous driving task. To this end, we propose PPGeo (Policy Pre-training via Geometric modeling), an intuitive and straightforward fully self-supervised framework curated for the policy pretraining in visuomotor driving. We aim at learning policy representations as a powerful abstraction by modeling 3D geometric scenes on large-scale unlabeled and uncalibrated YouTube driving videos. The proposed PPGeo is performed in two stages to support effective self-supervised training. In the first stage, the geometric modeling framework generates pose and depth predictions simultaneously, with two consecutive frames as input. In the second stage, the visual encoder learns driving policy representation by predicting the future ego-motion and optimizing with the photometric error based on current visual observation only. As such, the pre-trained visual encoder is equipped with rich driving policy related representations and thereby competent for multiple visuomotor driving tasks. Extensive experiments covering a wide span of challenging scenarios have demonstrated the superiority of our proposed approach, where improvements range from 2% to even over 100% with very limited data. Code and models will be available at https://github.com/OpenDriveLab/PPGeo.