相位检索（PR）是从其仅限强度测量中恢复复杂值信号的长期挑战，由于其在数字成像中的广泛应用，引起了很大的关注。最近，开发了基于深度学习的方法，这些方法在单发PR中取得了成功。这些方法需要单个傅立叶强度测量，而无需对测量数据施加任何其他约束。然而，由于PR问题的输入和输出域之间存在很大的差异，香草深神经网络（DNN）并没有提供良好的性能。物理信息的方法试图将傅立叶强度测量结果纳入提高重建精度的迭代方法。但是，它需要一个冗长的计算过程，并且仍然无法保证准确性。此外，其中许多方法都在模拟数据上工作，这些数据忽略了一些常见问题，例如实用光学PR系统中的饱和度和量化错误。在本文中，提出了一种新型的物理驱动的多尺度DNN结构，称为PPRNET。与其他基于深度学习的PR方法类似，PPRNET仅需要一个傅立叶强度测量。物理驱动的是，网络被指导遵循不同尺度的傅立叶强度测量，以提高重建精度。 PPRNET具有前馈结构，可以端到端训练。因此，它比传统物理驱动的PR方法更快，更准确。进行了实用光学平台上的大量模拟和实验。结果证明了拟议的PPRNET比传统的基于基于学习的PR方法的优势和实用性。

当通过玻璃等半充实介质进行成像时，通常可以在捕获的图像中找到另一个场景的反射。它降低了图像的质量并影响其后续分析。在本文中，提出了一种新的深层神经网络方法来解决成像中的反射问题。传统的反射删除方法不仅需要长时间的计算时间来解决不同的优化功能，而且不能保证其性能。由于如今的成像设备可以轻松获得数组摄像机，因此我们首先在本文中建议使用卷积神经网络（CNN）采用基于多图像的深度估计方法。提出的网络避免了由于图像中的反射而引起的深度歧义问题，并直接估计沿图像边缘的深度。然后，它们被用来将边缘分类为属于背景或反射的边缘。由于具有相似深度值的边缘在分类中易于误差，因此将它们从反射删除过程中删除。我们建议使用生成的对抗网络（GAN）来再生删除的背景边缘。最后，估计的背景边缘图被馈送到另一个自动编码器网络，以帮助从原始图像中提取背景。实验结果表明，与最先进的方法相比，提出的反射去除算法在定量和定性上取得了出色的性能。与使用传统优化方法相比，所提出的算法还显示出比现有方法相比的速度要快得多。

在许多图像处理任务中，深度学习方法的成功，最近还将深度学习方法引入了阶段检索问题。这些方法与传统的迭代优化方法不同，因为它们通常只需要一个强度测量，并且可以实时重建相位图像。但是，由于巨大的领域差异，这些方法给出的重建图像的质量仍然有很大的改进空间来满足一般应用要求。在本文中，我们设计了一种新型的深神经网络结构，名为Sisprnet，以基于单个傅立叶强度测量值进行相检索。为了有效利用测量的光谱信息，我们建议使用多层感知器（MLP）作为前端提出一个新的特征提取单元。它允许将输入强度图像的所有像素一起考虑，以探索其全局表示。 MLP的大小经过精心设计，以促进代表性特征的提取，同时减少噪音和异常值。辍学层还可以减轻训练MLP的过度拟合问题。为了促进重建图像中的全局相关性，将自我注意力的机制引入了提议的Sisprnet的上采样和重建（UR）块。这些UR块被插入残留的学习结构中，以防止由于其复杂的层结构而导致的较弱的信息流和消失的梯度问题。使用线性相关幅度和相位的仅相位图像和图像的不同测试数据集对所提出的模型进行了广泛的评估。在光学实验平台上进行了实验，以了解在实用环境中工作时不同深度学习方法的性能。

多任务学习是基于深度学习的面部表情识别任务的有效学习策略。但是，当在不同任务之间传输信息时，大多数现有方法都考虑了特征选择，这可能在培训多任务网络时可能导致任务干扰。为了解决这个问题，我们提出了一种新颖的选择性特征共享方法，并建立一个用于面部表情识别和面部表达合成的多任务网络。该方法可以有效地转移不同任务之间的有益特征，同时过滤无用和有害信息。此外，我们采用了面部表情综合任务来扩大并平衡训练数据集以进一步提高所提出的方法的泛化能力。实验结果表明，该方法在那些常用的面部表情识别基准上实现了最先进的性能，这使其成为现实世界面部表情识别问题的潜在解决方案。

The performance of inertial navigation systems is largely dependent on the stable flow of external measurements and information to guarantee continuous filter updates and bind the inertial solution drift. Platforms in different operational environments may be prevented at some point from receiving external measurements, thus exposing their navigation solution to drift. Over the years, a wide variety of works have been proposed to overcome this shortcoming, by exploiting knowledge of the system current conditions and turning it into an applicable source of information to update the navigation filter. This paper aims to provide an extensive survey of information aided navigation, broadly classified into direct, indirect, and model aiding. Each approach is described by the notable works that implemented its concept, use cases, relevant state updates, and their corresponding measurement models. By matching the appropriate constraint to a given scenario, one will be able to improve the navigation solution accuracy, compensate for the lost information, and uncover certain internal states, that would otherwise remain unobservable.

We consider infinite horizon Markov decision processes (MDPs) with fast-slow structure, meaning that certain parts of the state space move "fast" (and in a sense, are more influential) while other parts transition more "slowly." Such structure is common in real-world problems where sequential decisions need to be made at high frequencies, yet information that varies at a slower timescale also influences the optimal policy. Examples include: (1) service allocation for a multi-class queue with (slowly varying) stochastic costs, (2) a restless multi-armed bandit with an environmental state, and (3) energy demand response, where both day-ahead and real-time prices play a role in the firm's revenue. Models that fully capture these problems often result in MDPs with large state spaces and large effective time horizons (due to frequent decisions), rendering them computationally intractable. We propose an approximate dynamic programming algorithmic framework based on the idea of "freezing" the slow states, solving a set of simpler finite-horizon MDPs (the lower-level MDPs), and applying value iteration (VI) to an auxiliary MDP that transitions on a slower timescale (the upper-level MDP). We also extend the technique to a function approximation setting, where a feature-based linear architecture is used. On the theoretical side, we analyze the regret incurred by each variant of our frozen-state approach. Finally, we give empirical evidence that the frozen-state approach generates effective policies using just a fraction of the computational cost, while illustrating that simply omitting slow states from the decision modeling is often not a viable heuristic.

In the present work we propose an unsupervised ensemble method consisting of oblique trees that can address the task of auto-encoding, namely Oblique Forest AutoEncoders (briefly OF-AE). Our method is a natural extension of the eForest encoder introduced in [1]. More precisely, by employing oblique splits consisting in multivariate linear combination of features instead of the axis-parallel ones, we will devise an auto-encoder method through the computation of a sparse solution of a set of linear inequalities consisting of feature values constraints. The code for reproducing our results is available at https://github.com/CDAlecsa/Oblique-Forest-AutoEncoders.

When robots learn reward functions using high capacity models that take raw state directly as input, they need to both learn a representation for what matters in the task -- the task ``features" -- as well as how to combine these features into a single objective. If they try to do both at once from input designed to teach the full reward function, it is easy to end up with a representation that contains spurious correlations in the data, which fails to generalize to new settings. Instead, our ultimate goal is to enable robots to identify and isolate the causal features that people actually care about and use when they represent states and behavior. Our idea is that we can tune into this representation by asking users what behaviors they consider similar: behaviors will be similar if the features that matter are similar, even if low-level behavior is different; conversely, behaviors will be different if even one of the features that matter differs. This, in turn, is what enables the robot to disambiguate between what needs to go into the representation versus what is spurious, as well as what aspects of behavior can be compressed together versus not. The notion of learning representations based on similarity has a nice parallel in contrastive learning, a self-supervised representation learning technique that maps visually similar data points to similar embeddings, where similarity is defined by a designer through data augmentation heuristics. By contrast, in order to learn the representations that people use, so we can learn their preferences and objectives, we use their definition of similarity. In simulation as well as in a user study, we show that learning through such similarity queries leads to representations that, while far from perfect, are indeed more generalizable than self-supervised and task-input alternatives.

While the capabilities of autonomous systems have been steadily improving in recent years, these systems still struggle to rapidly explore previously unknown environments without the aid of GPS-assisted navigation. The DARPA Subterranean (SubT) Challenge aimed to fast track the development of autonomous exploration systems by evaluating their performance in real-world underground search-and-rescue scenarios. Subterranean environments present a plethora of challenges for robotic systems, such as limited communications, complex topology, visually-degraded sensing, and harsh terrain. The presented solution enables long-term autonomy with minimal human supervision by combining a powerful and independent single-agent autonomy stack, with higher level mission management operating over a flexible mesh network. The autonomy suite deployed on quadruped and wheeled robots was fully independent, freeing the human supervision to loosely supervise the mission and make high-impact strategic decisions. We also discuss lessons learned from fielding our system at the SubT Final Event, relating to vehicle versatility, system adaptability, and re-configurable communications.

Deep learning models are known to put the privacy of their training data at risk, which poses challenges for their safe and ethical release to the public. Differentially private stochastic gradient descent is the de facto standard for training neural networks without leaking sensitive information about the training data. However, applying it to models for graph-structured data poses a novel challenge: unlike with i.i.d. data, sensitive information about a node in a graph cannot only leak through its gradients, but also through the gradients of all nodes within a larger neighborhood. In practice, this limits privacy-preserving deep learning on graphs to very shallow graph neural networks. We propose to solve this issue by training graph neural networks on disjoint subgraphs of a given training graph. We develop three random-walk-based methods for generating such disjoint subgraphs and perform a careful analysis of the data-generating distributions to provide strong privacy guarantees. Through extensive experiments, we show that our method greatly outperforms the state-of-the-art baseline on three large graphs, and matches or outperforms it on four smaller ones.