Neural architectures can be naturally viewed as computational graphs. Motivated by this perspective, we, in this paper, study neural architecture search (NAS) through the lens of learning random graph models. In contrast to existing NAS methods which largely focus on searching for a single best architecture, i.e, point estimation, we propose GraphPNAS a deep graph generative model that learns a distribution of well-performing architectures. Relying on graph neural networks (GNNs), our GraphPNAS can better capture topologies of good neural architectures and relations between operators therein. Moreover, our graph generator leads to a learnable probabilistic search method that is more flexible and efficient than the commonly used RNN generator and random search methods. Finally, we learn our generator via an efficient reinforcement learning formulation for NAS. To assess the effectiveness of our GraphPNAS, we conduct extensive experiments on three search spaces, including the challenging RandWire on TinyImageNet, ENAS on CIFAR10, and NAS-Bench-101/201. The complexity of RandWire is significantly larger than other search spaces in the literature. We show that our proposed graph generator consistently outperforms RNN-based one and achieves better or comparable performances than state-of-the-art NAS methods.

The task of reconstructing 3D human motion has wideranging applications. The gold standard Motion capture (MoCap) systems are accurate but inaccessible to the general public due to their cost, hardware and space constraints. In contrast, monocular human mesh recovery (HMR) methods are much more accessible than MoCap as they take single-view videos as inputs. Replacing the multi-view Mo- Cap systems with a monocular HMR method would break the current barriers to collecting accurate 3D motion thus making exciting applications like motion analysis and motiondriven animation accessible to the general public. However, performance of existing HMR methods degrade when the video contains challenging and dynamic motion that is not in existing MoCap datasets used for training. This reduces its appeal as dynamic motion is frequently the target in 3D motion recovery in the aforementioned applications. Our study aims to bridge the gap between monocular HMR and multi-view MoCap systems by leveraging information shared across multiple video instances of the same action. We introduce the Neural Motion (NeMo) field. It is optimized to represent the underlying 3D motions across a set of videos of the same action. Empirically, we show that NeMo can recover 3D motion in sports using videos from the Penn Action dataset, where NeMo outperforms existing HMR methods in terms of 2D keypoint detection. To further validate NeMo using 3D metrics, we collected a small MoCap dataset mimicking actions in Penn Action,and show that NeMo achieves better 3D reconstruction compared to various baselines.

The emergence of low-cost, small form factor and light-weight solid-state LiDAR sensors have brought new opportunities for autonomous unmanned aerial vehicles (UAVs) by advancing navigation safety and computation efficiency. Yet the successful developments of LiDAR-based UAVs must rely on extensive simulations. Existing simulators can hardly perform simulations of real-world environments due to the requirements of dense mesh maps that are difficult to obtain. In this paper, we develop a point-realistic simulator of real-world scenes for LiDAR-based UAVs. The key idea is the underlying point rendering method, where we construct a depth image directly from the point cloud map and interpolate it to obtain realistic LiDAR point measurements. Our developed simulator is able to run on a light-weight computing platform and supports the simulation of LiDARs with different resolution and scanning patterns, dynamic obstacles, and multi-UAV systems. Developed in the ROS framework, the simulator can easily communicate with other key modules of an autonomous robot, such as perception, state estimation, planning, and control. Finally, the simulator provides 10 high-resolution point cloud maps of various real-world environments, including forests of different densities, historic building, office, parking garage, and various complex indoor environments. These realistic maps provide diverse testing scenarios for an autonomous UAV. Evaluation results show that the developed simulator achieves superior performance in terms of time and memory consumption against Gazebo and that the simulated UAV flights highly match the actual one in real-world environments. We believe such a point-realistic and light-weight simulator is crucial to bridge the gap between UAV simulation and experiments and will significantly facilitate the research of LiDAR-based autonomous UAVs in the future.

深度学习已在许多神经影像应用中有效。但是，在许多情况下，捕获与小血管疾病有关的信息的成像序列的数量不足以支持数据驱动的技术。此外，基于队列的研究可能并不总是具有用于准确病变检测的最佳或必需成像序列。因此，有必要确定哪些成像序列对于准确检测至关重要。在这项研究中，我们旨在找到磁共振成像（MRI）序列的最佳组合，以深入基于学习的肿瘤周围空间（EPV）。为此，我们实施了一个有效的轻巧U-NET，适用于EPVS检测，并全面研究了来自易感加权成像（SWI），流体侵入的反转恢复（FLAIR），T1加权（T1W）和T2的不同信息组合 - 加权（T2W）MRI序列。我们得出的结论是，T2W MRI对于准确的EPV检测最为重要，并且在深神经网络中掺入SWI，FLAIR和T1W MRI可能会使精度的提高无关。

了解强化学习（RL）代理的新兴行为可能很困难，因为这种代理通常使用高度复杂的决策程序在复杂的环境中进行训练。这引起了RL中解释性的多种方法，旨在调和可能在主体行为与观察者预期的行为之间产生的差异。最近的方法取决于域知识，这可能并非总是可用的，分析代理商的策略，或者是对基础环境的特定要素的分析，通常被建模为马尔可夫决策过程（MDP）。我们的主要主张是，即使基本的MDP尚不完全了解（例如，尚未准确地了解过渡概率），也没有由代理商维护（即，在使用无模型方法时），但仍可以利用它为自动生成解释。为此，我们建议使用以前在文献中使用的正式MDP抽象和转换来加快寻找最佳策略的搜索，以自动产生解释。由于这种转换通常基于环境的符号表示，因此它们可能代表了预期和实际代理行为之间差距的有意义的解释。我们正式定义了这个问题，建议一类可用于解释新兴行为的转换，并提出了有效搜索解释的方法。我们演示了一组标准基准测试的方法。

图像引导放射疗法中的CBCT为患者的设置和计划评估提供了关键的解剖学信息。纵向CBCT图像登记可以量化分裂间的解剖变化。这项研究的目的是提出一个无监督的基于深度学习的CBCT-CBCT变形图像登记。提出的可变形注册工作流程包括训练和推理阶段，这些培训和推理阶段通过基于空间转换的网络（STN）共享相同的进率前路。 STN由全球生成对抗网络（Globalgan）和本地GAN（Localgan）组成，分别预测了粗略和细尺度运动。通过最小化图像相似性损失和可变形矢量场（DVF）正则化损失，而无需监督地面真实DVF的训练，对网络进行了训练。在推理阶段，训练有素的Localgan预测了局部DVF的斑块，并融合形成全图像DVF。随后将局部全图像DVF与Globalgan生成的DVF合并以获得最终的DVF。在实验中，使用来自20名腹部癌症患者的100个分数CBCT评估了该方法，并在保持测试中来自21名不同腹部癌症患者的队列中的105个分数CBCT。从定性上讲，注册结果显示了变形的CBCT图像与目标CBCT图像之间的对齐。定量地，在基准标记和手动确定的地标计算的平均目标注册误差（TRE）为1.91+-1.11 mm。变形CBCT和目标CBCT之间的平均平均绝对误差（MAE），归一化的跨相关性（NCC）分别为33.42+-7.48 HU，0.94+-0.04。这种有希望的注册方法可以提供快速准确的纵向CBCT对准，以促进分流的解剖变化分析和预测。

学习辐射场对新型视图综合显示出了显着的结果。学习过程通常会花费大量时间，这激发了最新方法，通过没有神经网络或使用更有效的数据结构来通过学习来加快学习过程。但是，这些专门设计的方法不适用于大多数基于辐射的方法的方法。为了解决此问题，我们引入了一项一般策略，以加快几乎所有基于辐射的方法的学习过程。我们的关键想法是通过在多视图卷渲染过程中拍摄较少的射线来减少冗余，这是几乎所有基于辐射的方法的基础。我们发现，在具有巨大色彩变化的像素上的射击不仅显着减轻了训练负担，而且几乎不会影响学到的辐射场的准确性。此外，我们还根据树中每个节点的平均渲染误差将每个视图自适应地细分为Quadtree，这使我们在更复杂的区域中动态射击更多的射线，并具有较大的渲染误差。我们在广泛使用的基准下使用不同的基于辐射的方法评估我们的方法。实验结果表明，我们的方法通过更快的训练获得了与最先进的可比精度。

我们提出了一种新的概率方法，用于检测称为贝叶斯光源分离器（BLISS）的天文来源，进行分类和分类。Bliss基于深层生成模型，该模型将神经网络嵌入贝叶斯模型中。对于后推断，Bliss使用一种新形式的变分推断，称为正向摊销变异推断。幸福推理例程很快，一旦训练了编码器网络，就需要GPU上的编码网络的单个正向通行证。Bliss可以在几秒钟内对百万像素图像执行完全贝叶斯的推断，并产生高度准确的目录。Bliss是高度可扩展的，除了产生概率目录外，还可以直接回答下游科学问题。

随着在高风险决策中引入机器学习，确保算法公平已成为越来越重要的问题。为此，已经提出了许多关于公平性的数学定义，并且已经开发了多种优化技术，所有这些都旨在最大化明确的公平概念。但是，公平解决方案取决于训练数据的质量，并且对噪声高度敏感。最近的研究表明，鲁棒性（模型在看不见的数据上表现良好的能力）在解决新问题时应使用的策略类型起着重要作用，因此，测量这些策略的鲁棒性已成为一种基本问题。因此，在这项工作中，我们提出了一个新标准，以衡量各种公平优化策略的鲁棒性 - \ textit {稳健性比率}。我们使用三种最受欢迎​​的公平策略在五个最受欢迎的公平定义方面，在五个基准标记公平数据集上进行了多次广泛的实验。我们的实验从经验上表明，依赖阈值优化的公平方法对所有评估的数据集中的噪声非常敏感，尽管大多数表现优于其他方法。这与其他两种方法相反，这对于低噪声方案而言不太公平，但对于高噪声方案而言更公平。据我们所知，我们是第一个定量评估公平优化策略的鲁棒性的人。这可以作为选择各种数据集的最合适的公平策略的指南。

Many real-world problems are inherently multimodal, from the communicative modalities humans use to express social and emotional states to the force, proprioception, and visual sensors ubiquitous on robots. While there has been an explosion of interest in multimodal representation learning, these methods are still largely focused on a small set of modalities, primarily in the language, vision, and audio space. In order to accelerate generalization towards diverse and understudied modalities, this paper studies efficient representation learning for high-modality scenarios. Since adding new models for every new modality or task becomes prohibitively expensive, a critical technical challenge is heterogeneity quantification: how can we measure which modalities encode similar information and interactions in order to permit parameter sharing with previous modalities? We propose two new information-theoretic metrics for heterogeneity quantification: (1) modality heterogeneity studies how similar 2 modalities $\{X_1,X_2\}$ are by measuring how much information can be transferred from $X_1$ to $X_2$, while (2) interaction heterogeneity studies how similarly pairs of modalities $\{X_1,X_2\}, \{X_3,X_4\}$ interact by measuring how much interaction information can be transferred from $\{X_1,X_2\}$ to $\{X_3,X_4\}$. We show the importance of these proposed metrics in high-modality scenarios as a way to automatically prioritize the fusion of modalities that contain unique information or interactions. The result is a single model, HighMMT, that scales up to $10$ modalities and $15$ tasks from $5$ different research areas. Not only does HighMMT outperform prior methods on the tradeoff between performance and efficiency, it also demonstrates a crucial scaling behavior: performance continues to improve with each modality added, and transfers to entirely new modalities and tasks during fine-tuning.