The success of deep learning is partly attributed to the availability of massive data downloaded freely from the Internet. However, it also means that users' private data may be collected by commercial organizations without consent and used to train their models. Therefore, it's important and necessary to develop a method or tool to prevent unauthorized data exploitation. In this paper, we propose ConfounderGAN, a generative adversarial network (GAN) that can make personal image data unlearnable to protect the data privacy of its owners. Specifically, the noise produced by the generator for each image has the confounder property. It can build spurious correlations between images and labels, so that the model cannot learn the correct mapping from images to labels in this noise-added dataset. Meanwhile, the discriminator is used to ensure that the generated noise is small and imperceptible, thereby remaining the normal utility of the encrypted image for humans. The experiments are conducted in six image classification datasets, consisting of three natural object datasets and three medical datasets. The results demonstrate that our method not only outperforms state-of-the-art methods in standard settings, but can also be applied to fast encryption scenarios. Moreover, we show a series of transferability and stability experiments to further illustrate the effectiveness and superiority of our method.

Offline multi-agent reinforcement learning (MARL) aims to learn effective multi-agent policies from pre-collected datasets, which is an important step toward the deployment of multi-agent systems in real-world applications. However, in practice, each individual behavior policy that generates multi-agent joint trajectories usually has a different level of how well it performs. e.g., an agent is a random policy while other agents are medium policies. In the cooperative game with global reward, one agent learned by existing offline MARL often inherits this random policy, jeopardizing the performance of the entire team. In this paper, we investigate offline MARL with explicit consideration on the diversity of agent-wise trajectories and propose a novel framework called Shared Individual Trajectories (SIT) to address this problem. Specifically, an attention-based reward decomposition network assigns the credit to each agent through a differentiable key-value memory mechanism in an offline manner. These decomposed credits are then used to reconstruct the joint offline datasets into prioritized experience replay with individual trajectories, thereafter agents can share their good trajectories and conservatively train their policies with a graph attention network (GAT) based critic. We evaluate our method in both discrete control (i.e., StarCraft II and multi-agent particle environment) and continuous control (i.e, multi-agent mujoco). The results indicate that our method achieves significantly better results in complex and mixed offline multi-agent datasets, especially when the difference of data quality between individual trajectories is large.

延时摄影是在电影和宣传电影中使用的，因为它可以在短时间内反映时间的流逝并增强视觉吸引力。但是，由于需要很长时间才需要稳定的射击，因此对摄影师来说是一个巨大的挑战。在本文中，我们提出了一个带有虚拟和真实机器人的延时摄影系统。为了帮助用户有效拍摄延时视频，我们首先参数化延时摄影并提出参数优化方法。对于不同的参数，使用不同的美学模型，包括图像和视频美学质量评估网络，用于生成最佳参数。然后，我们提出了一个延时摄影界面，以促进用户查看和调整参数，并使用虚拟机器人在三维场景中进行虚拟摄影。该系统还可以导出参数并将其提供给真实的机器人，以便可以在现实世界中拍摄延时视频。此外，我们提出了一种延时摄影美学评估方法，该方法可以自动评估及时视频的美学质量。实验结果表明，我们的方法可以有效地获得延时视频。我们还进行了用户研究。结果表明，我们的系统具有与专业摄影师相似的效果，并且更有效。

低计数正电子发射断层扫描（PET）数据的图像重建是具有挑战性的。内核方法通过在迭代宠物图像重建的前向模型中结合图像先前信息来解决挑战。已经开发出并证明了内核预期的最大化（KEM）算法是有效且易于实施的。进一步改进内核方法的常见方法是添加明确的正则化，但是导致复杂的优化问题。在本文中，我们通过使用深度系数来提出内核方法的隐含正则化，其使用卷积神经网络表示宠物前进模型中的内核系数图像。为解决基于最大似然性的神经网络的重建问题，我们应用优化转移原理来推导神经KEM算法。算法的每次迭代包括两个单独的步骤：从投影数据的图像更新的KEM步骤和图像域中的深度学习步骤，用于使用神经网络更新内核系数图像。这种优化算法保证单调地增加数据可能性。计算机模拟和实际患者数据的结果表明神经KEM可以优于现有的KEM和深度图像的先前方法。

由于源极和目标环境之间的差异，深增强学习算法可以在现实世界的任务中表现不佳。这种差异通常被视为过渡动态的干扰。许多现有算法通过将干扰和应用于训练期间将其应用于源环境来学习强大的政策，这通常需要先验知识对模拟器的干扰和控制。然而，这些算法在目标环境中的干扰未知的情况下可能会失败，或者在模拟器中的模型中难以解决。为了解决这个问题，我们提出了一种新型的无模型演员 - 评论家算法 - 即状态保守政策优化（SCPO） - 学习强大的政策，而不会提前建立干扰。具体地，SCPO将转换动态的干扰降低到状态空间中的干扰，然后通过简单的基于梯度的常规器近似。 SCPO的吸引人的功能包括实施简单，不需要额外了解干扰或专门设计的模拟器。在若干机器人控制任务中的实验表明，SCPO了解抵抗过渡动态的干扰的强大政策。

最近的研究表明，引入代理商之间的沟通可以显着提高合作多智能体增强学习（MARL）的整体性能。在许多现实世界的情景中，通信可能是昂贵的，多代理系统的带宽受到某些约束。占据通信资源的冗余消息可以阻止信息性消息的传输，从而危及性能。在本文中，我们的目标是学习最小的足够的通信信息。首先，我们通过完整的图表启动代理之间的通信。然后我们将图形信息瓶颈（GIB）原则介绍到这个完整的图表中，并从图形结构上获得优化。基于优化，提出了一种名为CommGIB的新型多代理通信模块，其有效地压缩了通信图中的结构信息和节点信息来处理带宽约束的设置。进行了交通管制和斯坦径II的广泛实验。结果表明，与最先进的算法相比，所提出的方法可以在带宽限制的环境中实现更好的性能，具有尤其是大型多功能机构任务中的尤其是大的边距。

Inspired by the recent success of Transformers for Natural Language Processing and vision Transformer for Computer Vision, many researchers in the medical imaging community have flocked to Transformer-based networks for various main stream medical tasks such as classification, segmentation, and estimation. In this study, we analyze, two recently published Transformer-based network architectures for the task of multimodal head-and-tumor segmentation and compare their performance to the de facto standard 3D segmentation network - the nnU-Net. Our results showed that modeling long-range dependencies may be helpful in cases where large structures are present and/or large field of view is needed. However, for small structures such as head-and-neck tumor, the convolution-based U-Net architecture seemed to perform well, especially when training dataset is small and computational resource is limited.

Recent advances in neural radiance fields have enabled the high-fidelity 3D reconstruction of complex scenes for novel view synthesis. However, it remains underexplored how the appearance of such representations can be efficiently edited while maintaining photorealism. In this work, we present PaletteNeRF, a novel method for photorealistic appearance editing of neural radiance fields (NeRF) based on 3D color decomposition. Our method decomposes the appearance of each 3D point into a linear combination of palette-based bases (i.e., 3D segmentations defined by a group of NeRF-type functions) that are shared across the scene. While our palette-based bases are view-independent, we also predict a view-dependent function to capture the color residual (e.g., specular shading). During training, we jointly optimize the basis functions and the color palettes, and we also introduce novel regularizers to encourage the spatial coherence of the decomposition. Our method allows users to efficiently edit the appearance of the 3D scene by modifying the color palettes. We also extend our framework with compressed semantic features for semantic-aware appearance editing. We demonstrate that our technique is superior to baseline methods both quantitatively and qualitatively for appearance editing of complex real-world scenes.

By transferring knowledge from large, diverse, task-agnostic datasets, modern machine learning models can solve specific downstream tasks either zero-shot or with small task-specific datasets to a high level of performance. While this capability has been demonstrated in other fields such as computer vision, natural language processing or speech recognition, it remains to be shown in robotics, where the generalization capabilities of the models are particularly critical due to the difficulty of collecting real-world robotic data. We argue that one of the keys to the success of such general robotic models lies with open-ended task-agnostic training, combined with high-capacity architectures that can absorb all of the diverse, robotic data. In this paper, we present a model class, dubbed Robotics Transformer, that exhibits promising scalable model properties. We verify our conclusions in a study of different model classes and their ability to generalize as a function of the data size, model size, and data diversity based on a large-scale data collection on real robots performing real-world tasks. The project's website and videos can be found at robotics-transformer.github.io

Causal inference is the process of using assumptions, study designs, and estimation strategies to draw conclusions about the causal relationships between variables based on data. This allows researchers to better understand the underlying mechanisms at work in complex systems and make more informed decisions. In many settings, we may not fully observe all the confounders that affect both the treatment and outcome variables, complicating the estimation of causal effects. To address this problem, a growing literature in both causal inference and machine learning proposes to use Instrumental Variables (IV). This paper serves as the first effort to systematically and comprehensively introduce and discuss the IV methods and their applications in both causal inference and machine learning. First, we provide the formal definition of IVs and discuss the identification problem of IV regression methods under different assumptions. Second, we categorize the existing work on IV methods into three streams according to the focus on the proposed methods, including two-stage least squares with IVs, control function with IVs, and evaluation of IVs. For each stream, we present both the classical causal inference methods, and recent developments in the machine learning literature. Then, we introduce a variety of applications of IV methods in real-world scenarios and provide a summary of the available datasets and algorithms. Finally, we summarize the literature, discuss the open problems and suggest promising future research directions for IV methods and their applications. We also develop a toolkit of IVs methods reviewed in this survey at https://github.com/causal-machine-learning-lab/mliv.