我们研究了点击流行为中预测在线课程中学生知识获取的问题。通过电子学习讲座交付的激增，我们专注于讲座视频中的学生在视频活动中，由内容和视频测验组成。我们预测视频测验性能的方法基于我们开发的三个关键思路。首先，我们通过在原始事件数据上运行的时间序列学习架构模拟学生的点击行为，而不是定义可能在现有方法中定义手工制作的功能，可能丢失在单击序列内的重要信息。其次，我们开发了一个自我监督的Clickstream预培训，以学习Clickstream事件的信息表示，可以有效地初始化预测模型。第三，我们提出了一种基于聚类的基于元学习的培训，可以优化预测模型，以利用学生点击流序列中的频繁模式集群。通过对三个现实世界数据集的实验，我们证明我们的方法在预测学生的视频测验性能方面的两个基线模型中获得了大量改进。此外，我们通过消融研究验证了我们框架的预培训和元学习组成部分的重要性。最后，我们展示了我们的方法论如何了解与有用的学习分析有用的知识获取相关的视频监视行为的见解。

Intelligently extracting and linking complex scientific information from unstructured text is a challenging endeavor particularly for those inexperienced with natural language processing. Here, we present a simple sequence-to-sequence approach to joint named entity recognition and relation extraction for complex hierarchical information in scientific text. The approach leverages a pre-trained large language model (LLM), GPT-3, that is fine-tuned on approximately 500 pairs of prompts (inputs) and completions (outputs). Information is extracted either from single sentences or across sentences in abstracts/passages, and the output can be returned as simple English sentences or a more structured format, such as a list of JSON objects. We demonstrate that LLMs trained in this way are capable of accurately extracting useful records of complex scientific knowledge for three representative tasks in materials chemistry: linking dopants with their host materials, cataloging metal-organic frameworks, and general chemistry/phase/morphology/application information extraction. This approach represents a simple, accessible, and highly-flexible route to obtaining large databases of structured knowledge extracted from unstructured text. An online demo is available at http://www.matscholar.com/info-extraction.

This paper presents a state-of-the-art optimal controller for quadruped locomotion. The robot dynamics is represented using a single rigid body (SRB) model. A linear time-varying model predictive controller (LTV MPC) is proposed by using linearization schemes. Simulation results show that the LTV MPC can execute various gaits, such as trot and crawl, and is capable of tracking desired reference trajectories even under unknown external disturbances. The LTV MPC is implemented as a quadratic program using qpOASES through the CasADi interface at 50 Hz. The proposed MPC can reach up to 1 m/s top speed with an acceleration of 0.5 m/s2 executing a trot gait. The implementation is available at https:// github.com/AndrewZheng-1011/Quad_ConvexMPC

Two contrasting algorithmic paradigms for constraint satisfaction problems are successive local explorations of neighboring configurations versus producing new configurations using global information about the problem (e.g. approximating the marginals of the probability distribution which is uniform over satisfying configurations). This paper presents new algorithms for the latter framework, ultimately producing estimates for satisfying configurations using methods from Boolean Fourier analysis. The approach is broadly inspired by the quantum amplitude amplification algorithm in that it maximally increases the amplitude of the approximation function over satisfying configurations given sequential refinements. We demonstrate that satisfying solutions may be retrieved in a process analogous to quantum measurement made efficient by sparsity in the Fourier domain, and present a complete solver construction using this novel approximation. Freedom in the refinement strategy invites further opportunities to design solvers in an evolutionary computing framework. Results demonstrate competitive performance against local solvers for the Boolean satisfiability (SAT) problem, encouraging future work in understanding the connections between Boolean Fourier analysis and constraint satisfaction.

Traditional learning-based approaches to student modeling (e.g., predicting grades based on measured activities) generalize poorly to underrepresented/minority student groups due to biases in data availability. In this paper, we propose a Multi-Layer Personalized Federated Learning (MLPFL) methodology which optimizes inference accuracy over different layers of student grouping criteria, such as by course and by demographic subgroups within each course. In our approach, personalized models for individual student subgroups are derived from a global model, which is trained in a distributed fashion via meta-gradient updates that account for subgroup heterogeneity while preserving modeling commonalities that exist across the full dataset. To evaluate our methodology, we consider case studies of two popular downstream student modeling tasks, knowledge tracing and outcome prediction, which leverage multiple modalities of student behavior (e.g., visits to lecture videos and participation on forums) in model training. Experiments on three real-world datasets from online courses demonstrate that our approach obtains substantial improvements over existing student modeling baselines in terms of increasing the average and decreasing the variance of prediction quality across different student subgroups. Visual analysis of the resulting students' knowledge state embeddings confirm that our personalization methodology extracts activity patterns which cluster into different student subgroups, consistent with the performance enhancements we obtain over the baselines.

Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.

跟踪控制一直是机器人技术的重要研究主题。本文为基于生物启发的神经动力学模型提供了一种新型的混合控制策略（UUV）。首先开发了增强的反向运动控制策略，以避免急速速度跳跃，并提供相对于常规方法的光滑速度命令。然后，提出了一种新颖的滑动模式控制，该控制能够提供平滑而连续的扭矩命令，没有颤动。在比较研究中，提出的合并混合控制策略确保了控制信号的平滑度，这在现实世界中至关重要，尤其是对于需要在复杂的水下环境中运行的无人水下车辆。

由于数据可用性的偏见，基于学习的学生建模的传统方法对代表性不足的学生群体的推广不佳。在本文中，我们提出了一种方法，用于预测其在线学习活动中的学生表现，以优化与种族和性别等不同人口组的推论准确性。在我们的方法中，基于联合学习的最新基础，单个学生子组的个性化模型是从在所有学生模型中通过元学级更新汇总的全球模型得出的，该模型通过说明亚组异质性。为了了解学生活动的更好代表，我们通过一种自我监督的行为预处理方法来增强我们的方法，该方法利用了多种学生行为方式（例如，访问教授视频和在论坛上的参与），并在模型中包括神经网络注意力聚合阶段。通过从在线课程中对三个现实世界数据集进行实验，我们证明我们的方法在预测所有子组的学生学习成果方面对现有的学生建模基准进行了实质性改进。对最终学生嵌入的视觉分析证实，我们的个性化方法确实确定了不同亚组中的不同活动模式，与基准相比其更强的推理能力一致。

可穿戴机器人设备有可能协助和保护用户。为了设计智能头盔，本文研究了音频和视觉警告的有效性，以帮助参与者振作起来。一项用户研究检查了运行时对用户应用的不同警告和影响。从不同的方向应用了缩放到用户质量的扰动力，并测量用户位移以表征警告的有效性。这是使用适应于运动循环期间精确矩，向前，向后，右或左侧扰动力来向前，向后，右或左侧扰动力进行的踏板活动的活动风洞来完成的。本文介绍了该系统的概述，并展示了步态过程中精确发出一致警告和扰动的能力。用户研究结果突出了视觉和音频警告的有效性，以帮助用户振作起来，从而导致指南，从而为未来的人类机器人警告系统提供信息。

对抗贴片是旨在欺骗其他表现良好的基于​​神经网络的计算机视觉模型的图像。尽管这些攻击最初是通过数字方式构想和研究的，但由于图像的原始像素值受到干扰，但最近的工作表明，这些攻击可以成功地转移到物理世界中。可以通过打印补丁并将其添加到新捕获的图像或视频素材的场景中来实现。在这项工作中，我们进一步测试了在更具挑战性的条件下物理世界中对抗斑块攻击的功效。我们考虑通过空中或卫星摄像机获得的高架图像训练的对象检测模型，并测试插入沙漠环境场景中的物理对抗斑块。我们的主要发现是，在这些条件下成功实施对抗贴片攻击要比在先前考虑的条件下更难。这对AI安全具有重要意义，因为可能被夸大了对抗性例子所带来的现实世界威胁。