基于得分的扩散模型是一类生成模型，其动力学由将噪声映射到数据中的随机微分方程描述。尽管最近的作品已经开始为这些模型奠定理论基础，但仍缺乏对扩散时间t的作用的分析理解。当前的最佳实践提倡大型T，以确保正向动力学使扩散足够接近已知和简单的噪声分布。但是，对于更好的分数匹配目标和更高的计算效率，应优选较小的t值。从扩散模型的各种解释开始，在这项工作中，我们量化了这一权衡，并提出了一种新方法，通过采用较小的扩散时间来提高培训和采样的质量和效率。实际上，我们展示了如何使用辅助模型来弥合理想和模拟正向动力学之间的间隙，然后进行标准的反向扩散过程。经验结果支持我们的分析；对于图像数据，我们的方法是竞争性W.R.T.根据标准样本质量指标和对数可能的样本。

我们重新审视汉密尔顿随机微分方程（SDES）的理论属性，为贝叶斯后部采样，我们研究了来自数值SDE仿真的两种类型的误差：在数据附带的上下文中，离散化误差和由于噪声渐变估计而导致的错误。我们的主要结果是对迷你批次通过差分操作员分裂镜片影响的新颖分析，修改了先前的文献结果。Hamiltonian SDE的随机分量与梯度噪声分离，我们没有常规假设。这导致识别收敛瓶颈：在考虑迷你批次时，最佳可实现的错误率是$ \ mathcal {o}（\ eta ^ 2）$，带有$ \ eta $是集成器步长。我们的理论结果得到了贝叶斯神经网络各种回归和分类任务的实证研究。

Graph Neural Networks (GNNs) achieve state-of-the-art performance on graph-structured data across numerous domains. Their underlying ability to represent nodes as summaries of their vicinities has proven effective for homophilous graphs in particular, in which same-type nodes tend to connect. On heterophilous graphs, in which different-type nodes are likely connected, GNNs perform less consistently, as neighborhood information might be less representative or even misleading. On the other hand, GNN performance is not inferior on all heterophilous graphs, and there is a lack of understanding of what other graph properties affect GNN performance. In this work, we highlight the limitations of the widely used homophily ratio and the recent Cross-Class Neighborhood Similarity (CCNS) metric in estimating GNN performance. To overcome these limitations, we introduce 2-hop Neighbor Class Similarity (2NCS), a new quantitative graph structural property that correlates with GNN performance more strongly and consistently than alternative metrics. 2NCS considers two-hop neighborhoods as a theoretically derived consequence of the two-step label propagation process governing GCN's training-inference process. Experiments on one synthetic and eight real-world graph datasets confirm consistent improvements over existing metrics in estimating the accuracy of GCN- and GAT-based architectures on the node classification task.

In this work, we devise robust and efficient learning protocols for orchestrating a Federated Learning (FL) process for the Federated Tumor Segmentation Challenge (FeTS 2022). Enabling FL for FeTS setup is challenging mainly due to data heterogeneity among collaborators and communication cost of training. To tackle these challenges, we propose Robust Learning Protocol (RoLePRO) which is a combination of server-side adaptive optimisation (e.g., server-side Adam) and judicious parameter (weights) aggregation schemes (e.g., adaptive weighted aggregation). RoLePRO takes a two-phase approach, where the first phase consists of vanilla Federated Averaging, while the second phase consists of a judicious aggregation scheme that uses a sophisticated reweighting, all in the presence of an adaptive optimisation algorithm at the server. We draw insights from extensive experimentation to tune learning rates for the two phases.

The study proposes and tests a technique for automated emotion recognition through mouth detection via Convolutional Neural Networks (CNN), meant to be applied for supporting people with health disorders with communication skills issues (e.g. muscle wasting, stroke, autism, or, more simply, pain) in order to recognize emotions and generate real-time feedback, or data feeding supporting systems. The software system starts the computation identifying if a face is present on the acquired image, then it looks for the mouth location and extracts the corresponding features. Both tasks are carried out using Haar Feature-based Classifiers, which guarantee fast execution and promising performance. If our previous works focused on visual micro-expressions for personalized training on a single user, this strategy aims to train the system also on generalized faces data sets.

To analyze this characteristic of vulnerability, we developed an automated deep learning method for detecting microvessels in intravascular optical coherence tomography (IVOCT) images. A total of 8,403 IVOCT image frames from 85 lesions and 37 normal segments were analyzed. Manual annotation was done using a dedicated software (OCTOPUS) previously developed by our group. Data augmentation in the polar (r,{\theta}) domain was applied to raw IVOCT images to ensure that microvessels appear at all possible angles. Pre-processing methods included guidewire/shadow detection, lumen segmentation, pixel shifting, and noise reduction. DeepLab v3+ was used to segment microvessel candidates. A bounding box on each candidate was classified as either microvessel or non-microvessel using a shallow convolutional neural network. For better classification, we used data augmentation (i.e., angle rotation) on bounding boxes with a microvessel during network training. Data augmentation and pre-processing steps improved microvessel segmentation performance significantly, yielding a method with Dice of 0.71+/-0.10 and pixel-wise sensitivity/specificity of 87.7+/-6.6%/99.8+/-0.1%. The network for classifying microvessels from candidates performed exceptionally well, with sensitivity of 99.5+/-0.3%, specificity of 98.8+/-1.0%, and accuracy of 99.1+/-0.5%. The classification step eliminated the majority of residual false positives, and the Dice coefficient increased from 0.71 to 0.73. In addition, our method produced 698 image frames with microvessels present, compared to 730 from manual analysis, representing a 4.4% difference. When compared to the manual method, the automated method improved microvessel continuity, implying improved segmentation performance. The method will be useful for research purposes as well as potential future treatment planning.

随着车身可穿戴感应技术的发展，人类活动的识别已成为一个有吸引力的研究领域。借助舒适的电子质地，传感器可以嵌入衣服中，以便可以长期记录人类运动。但是，一个长期存在的问题是如何处理通过相对于身体运动引入的运动人工制品。令人惊讶的是，最近的经验发现表明，与刚性连接的传感器相比，与固定的传感器相比，布置的传感器实际上可以实现更高的活动识别精度，尤其是在从短时间窗口中预测时。在这项工作中，引入了概率模型，其中通过织物传感记录的运动之间的统计距离增加了这种提高的准确性和呼吸。模型的预测在模拟和真实的人类运动捕获实验中得到了验证，很明显，这种反直觉效应是紧密捕获的。

人类仍在执行许多高精度（DIS）任务，而这是自动化的理想机会。本文提供了一个框架，该框架使非专家的人类操作员能够教机器人手臂执行复杂的精确任务。该框架使用可变的笛卡尔阻抗控制器来执行从动力学人类示范中学到的轨迹。可以给出反馈以进行交互重塑或加快原始演示。董事会本地化是通过对任务委员会位置的视觉估算来完成的，并通过触觉反馈进行了完善。我们的框架在机器人基准拆卸挑战上进行了测试，该机器人必须执行复杂的精确任务，例如关键插入。结果显示每个操纵子任务的成功率很高，包括盒子中新型姿势的情况。还进行了消融研究以评估框架的组成部分。

对于移动机器人而言，与铰接式对象的交互是一项具有挑战性但重要的任务。为了应对这一挑战，我们提出了一条新型的闭环控制管道，该管道将负担能力估计的操纵先验与基于采样的全身控制相结合。我们介绍了完全反映了代理的能力和体现的代理意识提供的概念，我们表明它们的表现优于其最先进的对应物，这些对应物仅以最终效果的几何形状为条件。此外，发现闭环负担推论使代理可以将任务分为多个非连续运动，并从失败和意外状态中恢复。最后，管道能够执行长途移动操作任务，即在现实世界中开放和关闭烤箱，成功率很高（开放：71％，关闭：72％）。

由于存在对抗性攻击，因此在安全至关重要系统中使用神经网络需要安全，可靠的模型。了解任何输入X的最小对抗扰动，或等效地知道X与分类边界的距离，可以评估分类鲁棒性，从而提供可认证的预测。不幸的是，计算此类距离的最新技术在计算上很昂贵，因此不适合在线应用程序。这项工作提出了一个新型的分类器家族，即签名的距离分类器（SDC），从理论的角度来看，它直接输出X与分类边界的确切距离，而不是概率分数（例如SoftMax）。 SDC代表一个强大的设计分类器家庭。为了实际解决SDC的理论要求，提出了一种名为Unitary级别神经网络的新型网络体系结构。实验结果表明，所提出的体系结构近似于签名的距离分类器，因此允许以单个推断为代价对X进行在线认证分类。