Spatial-temporal (ST) graph modeling, such as traffic speed forecasting and taxi demand prediction, is an important task in deep learning area. However, for the nodes in graph, their ST patterns can vary greatly in difficulties for modeling, owning to the heterogeneous nature of ST data. We argue that unveiling the nodes to the model in a meaningful order, from easy to complex, can provide performance improvements over traditional training procedure. The idea has its root in Curriculum Learning which suggests in the early stage of training models can be sensitive to noise and difficult samples. In this paper, we propose ST-Curriculum Dropout, a novel and easy-to-implement strategy for spatial-temporal graph modeling. Specifically, we evaluate the learning difficulty of each node in high-level feature space and drop those difficult ones out to ensure the model only needs to handle fundamental ST relations at the beginning, before gradually moving to hard ones. Our strategy can be applied to any canonical deep learning architecture without extra trainable parameters, and extensive experiments on a wide range of datasets are conducted to illustrate that, by controlling the difficulty level of ST relations as the training progresses, the model is able to capture better representation of the data and thus yields better generalization.

估计路径的旅行时间是智能运输系统的重要主题。它是现实世界应用的基础，例如交通监控，路线计划和出租车派遣。但是，为这样的数据驱动任务构建模型需要大量用户的旅行信息，这与其隐私直接相关，因此不太可能共享。数据所有者之间的非独立和相同分布的（非IID）轨迹数据也使一个预测模型变得极具挑战性，如果我们直接应用联合学习。最后，以前关于旅行时间估算的工作并未考虑道路的实时交通状态，我们认为这可以极大地影响预测。为了应对上述挑战，我们为移动用户组引入GOF-TTE，生成的在线联合学习框架以进行旅行时间估计，这是我）使用联合学习方法，允许在培训时将私人数据保存在客户端设备上，并设计设计和设计。所有客户共享的全球模型作为在线生成模型推断实时道路交通状态。 ii）除了在服务器上共享基本模型外，还针对每个客户调整了一个微调的个性化模型来研究其个人驾驶习惯，从而弥补了本地化全球模型预测的残余错误。 ％iii）将全球模型设计为所有客户共享的在线生成模型，以推断实时道路交通状态。我们还对我们的框架采用了简单的隐私攻击，并实施了差异隐私机制，以进一步保证隐私安全。最后，我们对Didi Chengdu和Xi'an的两个现实世界公共出租车数据集进行了实验。实验结果证明了我们提出的框架的有效性。

由于物联网（IoT）技术的快速开发，许多在线Web应用程序（例如Google Map和Uber）估计移动设备收集的轨迹数据的旅行时间。但是，实际上，复杂的因素（例如网络通信和能量限制）使以低采样率收集的多个轨迹。在这种情况下，本文旨在解决稀疏场景中的旅行时间估计问题（TTE）和路线恢复问题，这通常会导致旅行时间的不确定标签以及连续采样的GPS点之间的路线。我们将此问题提出为不进行的监督问题，其中训练数据具有粗糙的标签，并共同解决了TTE和路线恢复的任务。我们认为，这两个任务在模型学习过程中彼此互补并保持这种关系：更精确的旅行时间可以使路由更好地推断，从而导致更准确的时间估计）。基于此假设，我们提出了一种EM算法，以替代E估计通过E步中通过弱监督的推断路线的行进时间，并根据M步骤中的估计行进时间来检索途径，以稀疏轨迹。我们对三个现实世界轨迹数据集进行了实验，并证明了该方法的有效性。

注释大规模数据集以进行监督的视频阴影检测方法是一项挑战。直接使用在标记的图像上训练的模型直接导致高概括错误和时间不一致的结果。在本文中，我们通过提出一个时空插值一致性训练（Stict）框架来解决这些挑战，以合理地将未标记的视频框架以及标记的图像以及图像阴影检测网络训练中进行合理地馈送。具体而言，我们提出了空间和时间ICT，其中定义了两个新的插值方案，\ textit {i.e。}，空间插值和时间插值。然后，我们相应地得出了相应的空间和时间插值一致性约束，以增强像素智能分类任务中的概括和分别鼓励时间一致的预测。此外，我们设计了一个量表感知网络，用于图像中的多尺度阴影知识学习，并提出了比例一致性约束，以最大程度地减少不同尺度上预测之间的差异。我们提出的方法在VISHA数据集和自称数据集上得到了广泛的验证。实验结果表明，即使没有视频标签，我们的方法也比大多数最新的监督，半监督或无监督的图像/视频阴影检测方法以及相关任务中的其他方法更好。代码和数据集可在\ url {https://github.com/yihong-97/stict}上获得。

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.