联邦学习（FL）引起了人们对在存储在多个用户中的数据中启用隐私的机器学习的兴趣，同时避免将数据移动到偏离设备上。但是，尽管数据永远不会留下用户的设备，但仍然无法保证隐私，因为用户培训数据的重大计算以训练有素的本地模型的形式共享。最近，这些本地模型通过不同的隐私攻击（例如模型反演攻击）构成了实质性的隐私威胁。作为一种补救措施，通过保证服务器只能学习全局聚合模型更新，而不是单个模型更新，从而开发了安全汇总（SA）作为保护佛罗里达隐私的框架。尽管SA确保没有泄漏有关单个模型更新超出汇总模型更新的其他信息，但对于SA实际上可以提供多少私密性fl，没有正式的保证；由于有关单个数据集的信息仍然可以通过在服务器上计算的汇总模型泄漏。在这项工作中，我们对使用SA的FL的正式隐私保证进行了首次分析。具体而言，我们使用共同信息（MI）作为定量度量，并在每个用户数据集的信息上可以通过汇总的模型更新泄漏有关多少信息。当使用FEDSGD聚合算法时，我们的理论界限表明，隐私泄漏量随着SA参与FL的用户数量而线性减少。为了验证我们的理论界限，我们使用MI神经估计量来凭经验评估MNIST和CIFAR10数据集的不同FL设置下的隐私泄漏。我们的实验验证了FEDSGD的理论界限，随着用户数量和本地批量的增长，隐私泄漏的减少，并且随着培训回合的数量，隐私泄漏的增加。

蜂窝提供商和数据聚合公司从用户设备中占群体的Celluar信号强度测量以生成信号映射，可用于提高网络性能。认识到这种数据收集可能与越来越多的隐私问题的认识可能存在赔率，我们考虑在数据离开移动设备之前混淆这些数据。目标是提高隐私，使得难以从混淆的数据（例如用户ID和用户行踪）中恢复敏感功能，同时仍然允许网络提供商使用用于改进网络服务的数据（即创建准确的信号映射）。要检查本隐私实用程序权衡，我们识别适用于信号强度测量的隐私和公用事业度量和威胁模型。然后，我们使用几种卓越的技术，跨越差异隐私，生成的对抗性隐私和信息隐私技术进行了衡量测量，以便基准，以基准获得各种有前景的混淆方法，并为真实世界的工程师提供指导，这些工程师是负责构建信号映射的现实工程师在不伤害效用的情况下保护隐私。我们的评估结果基于多个不同的现实世界信号映射数据集，展示了同时实现了充足的隐私和实用程序的可行性，并使用了使用该结构和预期使用数据集的策略以及目标平均案例的策略，而不是最坏的情况，保证。

我们考虑从多个移动设备收集的测量预测蜂窝网络性能（信号映射）的问题。我们制定在线联合学习框架内的问题：（i）联合学习（FL）使用户能够协作培训模型，同时保持其培训数据; （ii）由于用户移动随着时间的推移，并且用于以在线方式用于本地培训，因此收集测量。我们考虑一个诚实但很好的服务器，他们使用梯度（DLG）类型的攻击深泄漏来观察来自目标用户的更新，并使用深度泄漏（DLG）类型的攻击，最初开发的是重建DNN图像分类器的训练数据。我们使应用于我们的设置的DLG攻击的关键观察，Infers Infers Infers批次的本地数据的平均位置，因此可以用于以粗糙粒度重建目标用户的轨迹。我们表明，已经通过梯度的平均来提供适度的隐私保护，这是联合平均所固有的。此外，我们提出了一种算法，该算法可以在本地应用，以策划用于本地更新的批次，以便在不伤害实用程序的情况下有效保护其位置隐私。最后，我们表明，参与FL的多个用户的效果取决于其轨迹的相似性。据我们所知，这是第一次研究DLG攻击在众群时空数据的环境中。

在线行为广告和相关的跟踪疗法，构成了真正的隐私威胁。不幸的是，现有的隐私增强工具并不总是对在线广告和跟踪有效的。我们提出了基于基于学习的基于学习的方法来通过混淆来颠覆在线行为广告。 Harpo使用强化学习来自适应地交织使用虚假页面的真实页面访问，以扭曲跟踪器的用户浏览配置文件的视图。我们评估Harpo反对用于在线行为广告的现实世界用户分析和广告目标模型。结果表明，Harpo通过触发超过40％的不正确的兴趣和6倍的出价值来提高隐私。 Harpo优于现有的混淆工具，在相同的开销中多达16倍。 Harpo还能够实现比现有的混淆工具更好地对抗对抗性检测。 Harpo有意义地推进利用混淆来颠覆在线行为广告

Differentiable Architecture Search (DARTS) has attracted considerable attention as a gradient-based Neural Architecture Search (NAS) method. Since the introduction of DARTS, there has been little work done on adapting the action space based on state-of-art architecture design principles for CNNs. In this work, we aim to address this gap by incrementally augmenting the DARTS search space with micro-design changes inspired by ConvNeXt and studying the trade-off between accuracy, evaluation layer count, and computational cost. To this end, we introduce the Pseudo-Inverted Bottleneck conv block intending to reduce the computational footprint of the inverted bottleneck block proposed in ConvNeXt. Our proposed architecture is much less sensitive to evaluation layer count and outperforms a DARTS network with similar size significantly, at layer counts as small as 2. Furthermore, with less layers, not only does it achieve higher accuracy with lower GMACs and parameter count, GradCAM comparisons show that our network is able to better detect distinctive features of target objects compared to DARTS.

This paper deals with the problem of statistical and system heterogeneity in a cross-silo Federated Learning (FL) framework where there exist a limited number of Consumer Internet of Things (CIoT) devices in a smart building. We propose a novel Graph Signal Processing (GSP)-inspired aggregation rule based on graph filtering dubbed ``G-Fedfilt''. The proposed aggregator enables a structured flow of information based on the graph's topology. This behavior allows capturing the interconnection of CIoT devices and training domain-specific models. The embedded graph filter is equipped with a tunable parameter which enables a continuous trade-off between domain-agnostic and domain-specific FL. In the case of domain-agnostic, it forces G-Fedfilt to act similar to the conventional Federated Averaging (FedAvg) aggregation rule. The proposed G-Fedfilt also enables an intrinsic smooth clustering based on the graph connectivity without explicitly specified which further boosts the personalization of the models in the framework. In addition, the proposed scheme enjoys a communication-efficient time-scheduling to alleviate the system heterogeneity. This is accomplished by adaptively adjusting the amount of training data samples and sparsity of the models' gradients to reduce communication desynchronization and latency. Simulation results show that the proposed G-Fedfilt achieves up to $3.99\% $ better classification accuracy than the conventional FedAvg when concerning model personalization on the statistically heterogeneous local datasets, while it is capable of yielding up to $2.41\%$ higher accuracy than FedAvg in the case of testing the generalization of the models.

Mapping the seafloor with underwater imaging cameras is of significant importance for various applications including marine engineering, geology, geomorphology, archaeology and biology. For shallow waters, among the underwater imaging challenges, caustics i.e., the complex physical phenomena resulting from the projection of light rays being refracted by the wavy surface, is likely the most crucial one. Caustics is the main factor during underwater imaging campaigns that massively degrade image quality and affect severely any 2D mosaicking or 3D reconstruction of the seabed. In this work, we propose a novel method for correcting the radiometric effects of caustics on shallow underwater imagery. Contrary to the state-of-the-art, the developed method can handle seabed and riverbed of any anaglyph, correcting the images using real pixel information, thus, improving image matching and 3D reconstruction processes. In particular, the developed method employs deep learning architectures in order to classify image pixels to "non-caustics" and "caustics". Then, exploits the 3D geometry of the scene to achieve a pixel-wise correction, by transferring appropriate color values between the overlapping underwater images. Moreover, to fill the current gap, we have collected, annotated and structured a real-world caustic dataset, namely R-CAUSTIC, which is openly available. Overall, based on the experimental results and validation the developed methodology is quite promising in both detecting caustics and reconstructing their intensity.

360-degree panoramic videos have gained considerable attention in recent years due to the rapid development of head-mounted displays (HMDs) and panoramic cameras. One major problem in streaming panoramic videos is that panoramic videos are much larger in size compared to traditional ones. Moreover, the user devices are often in a wireless environment, with limited battery, computation power, and bandwidth. To reduce resource consumption, researchers have proposed ways to predict the users' viewports so that only part of the entire video needs to be transmitted from the server. However, the robustness of such prediction approaches has been overlooked in the literature: it is usually assumed that only a few models, pre-trained on past users' experiences, are applied for prediction to all users. We observe that those pre-trained models can perform poorly for some users because they might have drastically different behaviors from the majority, and the pre-trained models cannot capture the features in unseen videos. In this work, we propose a novel meta learning based viewport prediction paradigm to alleviate the worst prediction performance and ensure the robustness of viewport prediction. This paradigm uses two machine learning models, where the first model predicts the viewing direction, and the second model predicts the minimum video prefetch size that can include the actual viewport. We first train two meta models so that they are sensitive to new training data, and then quickly adapt them to users while they are watching the videos. Evaluation results reveal that the meta models can adapt quickly to each user, and can significantly increase the prediction accuracy, especially for the worst-performing predictions.

Background samples provide key contextual information for segmenting regions of interest (ROIs). However, they always cover a diverse set of structures, causing difficulties for the segmentation model to learn good decision boundaries with high sensitivity and precision. The issue concerns the highly heterogeneous nature of the background class, resulting in multi-modal distributions. Empirically, we find that neural networks trained with heterogeneous background struggle to map the corresponding contextual samples to compact clusters in feature space. As a result, the distribution over background logit activations may shift across the decision boundary, leading to systematic over-segmentation across different datasets and tasks. In this study, we propose context label learning (CoLab) to improve the context representations by decomposing the background class into several subclasses. Specifically, we train an auxiliary network as a task generator, along with the primary segmentation model, to automatically generate context labels that positively affect the ROI segmentation accuracy. Extensive experiments are conducted on several challenging segmentation tasks and datasets. The results demonstrate that CoLab can guide the segmentation model to map the logits of background samples away from the decision boundary, resulting in significantly improved segmentation accuracy. Code is available.

Reinforcement learning (RL) gained considerable attention by creating decision-making agents that maximize rewards received from fully observable environments. However, many real-world problems are partially or noisily observable by nature, where agents do not receive the true and complete state of the environment. Such problems are formulated as partially observable Markov decision processes (POMDPs). Some studies applied RL to POMDPs by recalling previous decisions and observations or inferring the true state of the environment from received observations. Nevertheless, aggregating observations and decisions over time is impractical for environments with high-dimensional continuous state and action spaces. Moreover, so-called inference-based RL approaches require large number of samples to perform well since agents eschew uncertainty in the inferred state for the decision-making. Active inference is a framework that is naturally formulated in POMDPs and directs agents to select decisions by minimising expected free energy (EFE). This supplies reward-maximising (exploitative) behaviour in RL, with an information-seeking (exploratory) behaviour. Despite this exploratory behaviour of active inference, its usage is limited to discrete state and action spaces due to the computational difficulty of the EFE. We propose a unified principle for joint information-seeking and reward maximization that clarifies a theoretical connection between active inference and RL, unifies active inference and RL, and overcomes their aforementioned limitations. Our findings are supported by strong theoretical analysis. The proposed framework's superior exploration property is also validated by experimental results on partial observable tasks with high-dimensional continuous state and action spaces. Moreover, the results show that our model solves reward-free problems, making task reward design optional.