背景：以自我为中心的视频已成为监测社区中四肢瘫痪者的手部功能的潜在解决方案，尤其是因为它在家庭环境中检测功能使用的能力。目的：开发和验证一个基于可穿戴视力的系统，以测量四肢植物患者的家庭使用。方法：开发并比较了几种用于检测功能手动相互作用的深度学习算法。最精确的算法用于从20名参与者在家庭中记录的65小时的无脚本视频中提取手部功能的度量。这些措施是：总记录时间（PERC）的交互时间百分比；单个相互作用的平均持续时间（DUR）；每小时互动数（NUM）。为了证明技术的临床有效性，以验证的措施与经过验证的手部功能和独立性的临床评估相关（逐渐定义了强度，敏感性和预性的评估 - GRASSP，上肢运动评分 - UEM和脊髓独立措施 - SICIM- SICIM- SICIM） 。结果：手动相互作用以0.80（0.67-0.87）的中位数得分自动检测到手动相互作用。我们的结果表明，较高的UEM和更好的预性与花费更长的时间相互作用有关，而较高的cim和更好的手动感觉会导致在以eg中心的视频记录期间进行的更多相互作用。结论：第一次，在四肢瘫痪者中，在不受约束的环境中自动估计的手部功能的度量已得到了国际接受的手部功能量度的验证。未来的工作将需要对基于以自我为中心的手工使用的绩效指标的可靠性和响应能力进行正式评估。

荧光吞咽研究（VFSS）是一种用于评估吞咽的金标成像技术，但VFSS录音的分析和评级是耗时，需要专门的培训和专业知识。研究人员已经证明，可以通过计算机视觉方法自动检测吞咽的咽部阶段，并通过计算机视觉方法本地化推注中的推注，促进新颖的自动VFSS分析技术的开发。但是，培训算法以执行这些任务需要很少可用的大量注释数据。我们证明，可以使用单一方法在一起解决咽期检测和推注定位的挑战。我们提出了一个深入学习的框架，以弱监督的方式共同解决咽期检测和推注定位，只需要临时阶段的初始和最终框架作为培训的地面真理注释。我们的方法源于观察结果，即咽部中的推注存在是最突出的视觉特征，在其上推断单个VFSS帧是否属于咽部阶段。我们在来自59个健康受试者的1245 VFS剪辑的数据集中进行了大量卷积神经网络（CNNS）进行了广泛的实验。我们证明，可以检测咽部阶段，其F1分数高于0.9。此外，通过处理CNN的类激活图，我们能够通过有前途的结果本地化推注，从未获得高于0.9的地面真理轨迹的相关性，而无需用于训练目的的推注定位的任何手动注释。一旦验证了吞咽障碍的更大的参与者样本，我们的框架将为VFSS分析开发智能工具的开发，以支持临床医生吞咽评估。

由于价格合理的可穿戴摄像头和大型注释数据集的可用性，在过去几年中，Egintric Vision（又名第一人称视觉-FPV）的应用程序在过去几年中蓬勃发展。可穿戴摄像机的位置（通常安装在头部上）允许准确记录摄像头佩戴者在其前面的摄像头，尤其是手和操纵物体。这种内在的优势可以从多个角度研究手：将手及其部分定位在图像中；了解双手涉及哪些行动和活动；并开发依靠手势的人类计算机界面。在这项调查中，我们回顾了使用以自我为中心的愿景专注于手的文献，将现有方法分类为：本地化（其中的手或部分在哪里？）；解释（手在做什么？）；和应用程序（例如，使用以上为中心的手提示解决特定问题的系统）。此外，还提供了带有手基注释的最突出的数据集的列表。

Computational units in artificial neural networks follow a simplified model of biological neurons. In the biological model, the output signal of a neuron runs down the axon, splits following the many branches at its end, and passes identically to all the downward neurons of the network. Each of the downward neurons will use their copy of this signal as one of many inputs dendrites, integrate them all and fire an output, if above some threshold. In the artificial neural network, this translates to the fact that the nonlinear filtering of the signal is performed in the upward neuron, meaning that in practice the same activation is shared between all the downward neurons that use that signal as their input. Dendrites thus play a passive role. We propose a slightly more complex model for the biological neuron, where dendrites play an active role: the activation in the output of the upward neuron becomes optional, and instead the signals going through each dendrite undergo independent nonlinear filterings, before the linear combination. We implement this new model into a ReLU computational unit and discuss its biological plausibility. We compare this new computational unit with the standard one and describe it from a geometrical point of view. We provide a Keras implementation of this unit into fully connected and convolutional layers and estimate their FLOPs and weights change. We then use these layers in ResNet architectures on CIFAR-10, CIFAR-100, Imagenette, and Imagewoof, obtaining performance improvements over standard ResNets up to 1.73%. Finally, we prove a universal representation theorem for continuous functions on compact sets and show that this new unit has more representational power than its standard counterpart.

Humans have internal models of robots (like their physical capabilities), the world (like what will happen next), and their tasks (like a preferred goal). However, human internal models are not always perfect: for example, it is easy to underestimate a robot's inertia. Nevertheless, these models change and improve over time as humans gather more experience. Interestingly, robot actions influence what this experience is, and therefore influence how people's internal models change. In this work we take a step towards enabling robots to understand the influence they have, leverage it to better assist people, and help human models more quickly align with reality. Our key idea is to model the human's learning as a nonlinear dynamical system which evolves the human's internal model given new observations. We formulate a novel optimization problem to infer the human's learning dynamics from demonstrations that naturally exhibit human learning. We then formalize how robots can influence human learning by embedding the human's learning dynamics model into the robot planning problem. Although our formulations provide concrete problem statements, they are intractable to solve in full generality. We contribute an approximation that sacrifices the complexity of the human internal models we can represent, but enables robots to learn the nonlinear dynamics of these internal models. We evaluate our inference and planning methods in a suite of simulated environments and an in-person user study, where a 7DOF robotic arm teaches participants to be better teleoperators. While influencing human learning remains an open problem, our results demonstrate that this influence is possible and can be helpful in real human-robot interaction.

Explainability is a vibrant research topic in the artificial intelligence community, with growing interest across methods and domains. Much has been written about the topic, yet explainability still lacks shared terminology and a framework capable of providing structural soundness to explanations. In our work, we address these issues by proposing a novel definition of explanation that is a synthesis of what can be found in the literature. We recognize that explanations are not atomic but the product of evidence stemming from the model and its input-output and the human interpretation of this evidence. Furthermore, we fit explanations into the properties of faithfulness (i.e., the explanation being a true description of the model's decision-making) and plausibility (i.e., how much the explanation looks convincing to the user). Using our proposed theoretical framework simplifies how these properties are ope rationalized and provide new insight into common explanation methods that we analyze as case studies.

Fruit is a key crop in worldwide agriculture feeding millions of people. The standard supply chain of fruit products involves quality checks to guarantee freshness, taste, and, most of all, safety. An important factor that determines fruit quality is its stage of ripening. This is usually manually classified by experts in the field, which makes it a labor-intensive and error-prone process. Thus, there is an arising need for automation in the process of fruit ripeness classification. Many automatic methods have been proposed that employ a variety of feature descriptors for the food item to be graded. Machine learning and deep learning techniques dominate the top-performing methods. Furthermore, deep learning can operate on raw data and thus relieve the users from having to compute complex engineered features, which are often crop-specific. In this survey, we review the latest methods proposed in the literature to automatize fruit ripeness classification, highlighting the most common feature descriptors they operate on.

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 recent years, reinforcement learning (RL) has become increasingly successful in its application to science and the process of scientific discovery in general. However, while RL algorithms learn to solve increasingly complex problems, interpreting the solutions they provide becomes ever more challenging. In this work, we gain insights into an RL agent's learned behavior through a post-hoc analysis based on sequence mining and clustering. Specifically, frequent and compact subroutines, used by the agent to solve a given task, are distilled as gadgets and then grouped by various metrics. This process of gadget discovery develops in three stages: First, we use an RL agent to generate data, then, we employ a mining algorithm to extract gadgets and finally, the obtained gadgets are grouped by a density-based clustering algorithm. We demonstrate our method by applying it to two quantum-inspired RL environments. First, we consider simulated quantum optics experiments for the design of high-dimensional multipartite entangled states where the algorithm finds gadgets that correspond to modern interferometer setups. Second, we consider a circuit-based quantum computing environment where the algorithm discovers various gadgets for quantum information processing, such as quantum teleportation. This approach for analyzing the policy of a learned agent is agent and environment agnostic and can yield interesting insights into any agent's policy.

This paper presents a methodology for integrating machine learning techniques into metaheuristics for solving combinatorial optimization problems. Namely, we propose a general machine learning framework for neighbor generation in metaheuristic search. We first define an efficient neighborhood structure constructed by applying a transformation to a selected subset of variables from the current solution. Then, the key of the proposed methodology is to generate promising neighbors by selecting a proper subset of variables that contains a descent of the objective in the solution space. To learn a good variable selection strategy, we formulate the problem as a classification task that exploits structural information from the characteristics of the problem and from high-quality solutions. We validate our methodology on two metaheuristic applications: a Tabu Search scheme for solving a Wireless Network Optimization problem and a Large Neighborhood Search heuristic for solving Mixed-Integer Programs. The experimental results show that our approach is able to achieve a satisfactory trade-off between the exploration of a larger solution space and the exploitation of high-quality solution regions on both applications.