我们暴露了在离线多代理增强学习（MARL）中奖励中毒的危险，从而使攻击者可以在离线数据集中对不同学习者的奖励向量修改，同时又产生了中毒成本。基于中毒的数据集，所有使用一些基于信心的MARL算法的理性学习者将推断出，目标政策 - 攻击者选择的目标政策最初是解决方案概念 - 是马尔可夫的完美主要策略，用于基础马尔可夫游戏因此，他们将来将采用这种潜在的破坏目标政策。我们表征了攻击者可以安装目标策略的确切条件。我们进一步展示了攻击者如何制定线性程序以最大程度地减少其中毒成本。我们的工作表明需要强大的泥土反对对抗攻击。

分布（OOD）检测是在开放世界中部署机器学习模型的关键任务。基于距离的方法已经证明了有望，如果测试样品离分布（ID）数据相对遥远，则将测试样品视为OOD。但是，先前的方法对基础特征空间施加了强有力的分布假设，这可能并不总是存在。在本文中，我们探讨了非参数最近邻居距离的疗效，以检测OOD，这在文献中很大程度上被忽略了。与先前的工作不同，我们的方法不会施加任何分布假设，因此提供了更强的灵活性和一般性。我们证明了在几个基准测试中基于邻元的OOD检测的有效性，并建立了卓越的性能。在对Imagenet-1K训练的同一模型下，我们的方法将假阳性率（FPR@tpr95）降低了24.77％，与强大的基线SSD+相比，使用参数方法Mahalanobis在检测中。可用代码：https：//github.com/deeplearning-wisc/knn-ood。

联合学习（FL）已成为解决数据筒仓问题的实用解决方案，而不会损害用户隐私。它的一种变体垂直联合学习（VFL）最近引起了人们的关注，因为VFL与企业对利用更有价值的功能的需求相匹配，以构建更好的机器学习模型，同时保留用户隐私。当前在VFL中的工作集中于为特定VFL算法开发特定的保护或攻击机制。在这项工作中，我们提出了一个评估框架，该框架提出了隐私 - 私人评估问题。然后，我们将此框架作为指南，以全面评估针对三种广泛依据的VFL算法的大多数最先进的隐私攻击的广泛保护机制。这些评估可以帮助FL从业人员在特定要求下选择适当的保护机制。我们的评估结果表明：模型反转和大多数标签推理攻击可能会因现有保护机制而挫败；很难防止模型完成（MC）攻击，这需要更高级的MC靶向保护机制。根据我们的评估结果，我们为提高VFL系统的隐私保护能力提供具体建议。

联合学习（FL）使参与方能够在不公开私人数据信息的情况下协作建立一个全球模型。必须采用适当的保护机制，以满足保留\ textit {privacy}并维护高模型\ textit {utility}的相反要求。此外，为了实现大规模的模型培训和部署，联合学习系统实现高\ textit {效率}是一项任务。我们提出了一个统一的联合学习框架，可以调和水平和垂直的联合学习。基于此框架，我们制定和量化了隐私泄漏，公用事业损失和降低效率之间的权衡，这使我们成为了联合学习系统的无午餐定理（NFL）定理。 NFL表示，期望FL算法同时在某些情况下同时提供出色的隐私，实用性和效率是不现实的。然后，我们分析了几种广泛补习的保护机制的隐私泄漏，效用损失和效率降低的下限，包括\ textit {Randomization}，\ textIt {同粒子加密}，\ textit {secretit {secret {sertial {sertion {sertion {compression} {Compression}。我们的分析可以作为选择保护参数以满足特定要求的指南。

在联邦学习方案中，多方共同从其各自的数据中学习模型，有两个相互矛盾的目标是选择适当的算法。一方面，必须在存在\ textit {semi-honest}合作伙伴的情况下尽可能保持私人和敏感的培训数据，而另一方面，必须在不同方之间交换一定数量的信息学习实用程序。这样的挑战要求采用隐私的联合学习解决方案，该解决方案最大程度地提高了学习模型的效用，并维护参与各方的私人数据的可证明的隐私保证。本文说明了一个一般框架，即a）从统一信息理论的角度来制定隐私损失和效用损失之间的权衡，而b）在包括随机化，包括随机性，包括随机的机制，包括随机性，，包括随机性，，包括随机性，，包括随机性，，包括随机性，，包括随机性，，包括随机性，，包括随机性，包括随机性，，使用稀疏性和同态加密。结果表明，一般而言\ textit {没有免费的午餐来进行隐私 - 私人权衡取舍}，并且必须用一定程度的降级效用进行保存隐私。本文中说明的定量分析可以作为实用联合学习算法设计的指导。

Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.

To generate high quality rendering images for real time applications, it is often to trace only a few samples-per-pixel (spp) at a lower resolution and then supersample to the high resolution. Based on the observation that the rendered pixels at a low resolution are typically highly aliased, we present a novel method for neural supersampling based on ray tracing 1/4-spp samples at the high resolution. Our key insight is that the ray-traced samples at the target resolution are accurate and reliable, which makes the supersampling an interpolation problem. We present a mask-reinforced neural network to reconstruct and interpolate high-quality image sequences. First, a novel temporal accumulation network is introduced to compute the correlation between current and previous features to significantly improve their temporal stability. Then a reconstruct network based on a multi-scale U-Net with skip connections is adopted for reconstruction and generation of the desired high-resolution image. Experimental results and comparisons have shown that our proposed method can generate higher quality results of supersampling, without increasing the total number of ray-tracing samples, over current state-of-the-art methods.

Temporal sentence grounding (TSG) aims to identify the temporal boundary of a specific segment from an untrimmed video by a sentence query. All existing works first utilize a sparse sampling strategy to extract a fixed number of video frames and then conduct multi-modal interactions with query sentence for reasoning. However, we argue that these methods have overlooked two indispensable issues: 1) Boundary-bias: The annotated target segment generally refers to two specific frames as corresponding start and end timestamps. The video downsampling process may lose these two frames and take the adjacent irrelevant frames as new boundaries. 2) Reasoning-bias: Such incorrect new boundary frames also lead to the reasoning bias during frame-query interaction, reducing the generalization ability of model. To alleviate above limitations, in this paper, we propose a novel Siamese Sampling and Reasoning Network (SSRN) for TSG, which introduces a siamese sampling mechanism to generate additional contextual frames to enrich and refine the new boundaries. Specifically, a reasoning strategy is developed to learn the inter-relationship among these frames and generate soft labels on boundaries for more accurate frame-query reasoning. Such mechanism is also able to supplement the absent consecutive visual semantics to the sampled sparse frames for fine-grained activity understanding. Extensive experiments demonstrate the effectiveness of SSRN on three challenging datasets.

Representing and synthesizing novel views in real-world dynamic scenes from casual monocular videos is a long-standing problem. Existing solutions typically approach dynamic scenes by applying geometry techniques or utilizing temporal information between several adjacent frames without considering the underlying background distribution in the entire scene or the transmittance over the ray dimension, limiting their performance on static and occlusion areas. Our approach $\textbf{D}$istribution-$\textbf{D}$riven neural radiance fields offers high-quality view synthesis and a 3D solution to $\textbf{D}$etach the background from the entire $\textbf{D}$ynamic scene, which is called $\text{D}^4$NeRF. Specifically, it employs a neural representation to capture the scene distribution in the static background and a 6D-input NeRF to represent dynamic objects, respectively. Each ray sample is given an additional occlusion weight to indicate the transmittance lying in the static and dynamic components. We evaluate $\text{D}^4$NeRF on public dynamic scenes and our urban driving scenes acquired from an autonomous-driving dataset. Extensive experiments demonstrate that our approach outperforms previous methods in rendering texture details and motion areas while also producing a clean static background. Our code will be released at https://github.com/Luciferbobo/D4NeRF.

Deploying reliable deep learning techniques in interdisciplinary applications needs learned models to output accurate and ({even more importantly}) explainable predictions. Existing approaches typically explicate network outputs in a post-hoc fashion, under an implicit assumption that faithful explanations come from accurate predictions/classifications. We have an opposite claim that explanations boost (or even determine) classification. That is, end-to-end learning of explanation factors to augment discriminative representation extraction could be a more intuitive strategy to inversely assure fine-grained explainability, e.g., in those neuroimaging and neuroscience studies with high-dimensional data containing noisy, redundant, and task-irrelevant information. In this paper, we propose such an explainable geometric deep network dubbed as NeuroExplainer, with applications to uncover altered infant cortical development patterns associated with preterm birth. Given fundamental cortical attributes as network input, our NeuroExplainer adopts a hierarchical attention-decoding framework to learn fine-grained attentions and respective discriminative representations to accurately recognize preterm infants from term-born infants at term-equivalent age. NeuroExplainer learns the hierarchical attention-decoding modules under subject-level weak supervision coupled with targeted regularizers deduced from domain knowledge regarding brain development. These prior-guided constraints implicitly maximizes the explainability metrics (i.e., fidelity, sparsity, and stability) in network training, driving the learned network to output detailed explanations and accurate classifications. Experimental results on the public dHCP benchmark suggest that NeuroExplainer led to quantitatively reliable explanation results that are qualitatively consistent with representative neuroimaging studies.