Underwater navigation presents several challenges, including unstructured unknown environments, lack of reliable localization systems (e.g., GPS), and poor visibility. Furthermore, good-quality obstacle detection sensors for underwater robots are scant and costly; and many sensors like RGB-D cameras and LiDAR only work in-air. To enable reliable mapless underwater navigation despite these challenges, we propose a low-cost end-to-end navigation system, based on a monocular camera and a fixed single-beam echo-sounder, that efficiently navigates an underwater robot to waypoints while avoiding nearby obstacles. Our proposed method is based on Proximal Policy Optimization (PPO), which takes as input current relative goal information, estimated depth images, echo-sounder readings, and previous executed actions, and outputs 3D robot actions in a normalized scale. End-to-end training was done in simulation, where we adopted domain randomization (varying underwater conditions and visibility) to learn a robust policy against noise and changes in visibility conditions. The experiments in simulation and real-world demonstrated that our proposed method is successful and resilient in navigating a low-cost underwater robot in unknown underwater environments. The implementation is made publicly available at https://github.com/dartmouthrobotics/deeprl-uw-robot-navigation.

This paper proposes a novel model-based policy gradient algorithm for tracking dynamic targets using a mobile robot, equipped with an onboard sensor with limited field of view. The task is to obtain a continuous control policy for the mobile robot to collect sensor measurements that reduce uncertainty in the target states, measured by the target distribution entropy. We design a neural network control policy with the robot $SE(3)$ pose and the mean vector and information matrix of the joint target distribution as inputs and attention layers to handle variable numbers of targets. We also derive the gradient of the target entropy with respect to the network parameters explicitly, allowing efficient model-based policy gradient optimization.

本文提出了一种使用信息理论成本来学习有效地标本地化和探索的连续控制政策的方法。我们考虑一个移动机器人在有限的传感范围内检测地标，并解决学习控制政策的问题，该控制政策最大程度地提高了地标状态与传感器观察之间的相互信息。我们采用Kalman过滤器将地标州的部分可观察到的问题转换为马尔可夫决策过程（MDP），这是一个可区分的视野来塑造奖励，以及基于注意力的神经网络来代表控制策略。除了具有里程碑意义的定位外，该方法通过主动容积映射进一步统一，以促进勘探。与基准方法相比，在几个模拟地标本地化任务中证明了该性能。

在此演示中，我们介绍了聊天设计，这是一种用于个性化时装设计的新的多模式交互系统。与基于关键字的服装推荐服装的经典系统相比，聊天到设计使用户可以通过两个步骤设计衣服：1）通过对话进行粗粒的选择，以及2）通过交互式界面进行精细粒度编辑。它涵盖了三个子系统来提供沉浸式用户体验：通过自然语言理解授权的对话系统，以接受用户的请求并管理对话框；由大规模预处理的语言图像网络授予的多模式时尚检索系统，用于检索所需的服装；一种由新兴生成技术授权的时装设计系统，用于编辑检索到的衣服的属性。

我们介绍了双图：一种简单但有效的训练策略，以提高神经机器翻译（NMT）性能。它由两个程序组成：双向预处理和单向填充。这两个过程均使用SIMCUT，这是一种简单的正则化方法，迫使原始句子对的输出分布之间的一致性。在不利用额外的数据集通过反翻译或集成大规模预认证的模型的情况下，BI-Simcut可以在五个翻译基准（数据尺寸从160K到20.20万）中实现强大的翻译性能：EN-的BLEU得分为31.16，EN-> DE和38.37的BLEU得分为38.37 de-> en在IWSLT14数据集上，en-> de的30.78和35.15在WMT14数据集上进行DE-> en，而WMT17数据集中的ZH-> EN为27.17。 Simcut不是一种新方法，而是简化和适用于NMT的cutoff（Shen等，2020）的版本，可以将其视为基于扰动的方法。鉴于Simcut和Bi-Simcut的普遍性和简单性，我们认为它们可以作为未来NMT研究的强大基准。

对象检测在清洁数据集上取得了有希望的性能，但仍然探讨了如何在对抗性鲁棒性和清洁精度之间实现更好的权衡。对抗性培训是提高稳健性的主流方法，但大多数作品将牺牲清洁精度，以获得比标准训练的坚固性。在本文中，我们提出了统一的解耦特征对准（UDFA），一种新型微调范例，通过完全探索对象检测的自我知识蒸馏和对抗训练之间的组合来实现比现有方法更好的性能。我们首先使用分离的前/后地特征来构建自我知识蒸馏分支，从预磨牙探测器（作为教师）和来自学生探测器的对抗特征表示之间的清洁特征表示之间。然后我们通过将原始分支解耦为自我监督的学习分支和新的自我知识蒸馏分支来探索自我知识蒸馏。通过对Pascal-VOC和MS-Coco基准测试的广泛实验，评估结果表明，UDFA可以超越标准培训和最先进的对抗对象培训方法进行对象检测。例如，与教师探测器相比，我们在GFLV2与RESET-50的方法通过Pascal-Voc上的2.2 AP提高了干净精度;与SOTA对抗性培训方法相比，我们的方法通过1​​.6 AP改善了干净的精度，同时通过0.5 AP改善对抗性鲁棒性。我们的代码将在https://github.com/grispeut/udfa提供。

Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.

Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.

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.

Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.