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.
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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。
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基于深卷积神经网络(CNN)的面部识别表现出归因于提取的高判别特征的卓越精度性能。然而,经常忽略了深度学习模型(深度特征)提取的功能的安全性和隐私。本文提出了从深度功能中重建面部图像,而无需访问CNN网络配置作为约束优化问题。这种优化可最大程度地减少从原始面部图像中提取的特征与重建的面部图像之间的距离。我们没有直接解决图像空间中的优化问题,而是通过寻找GAN发电机的潜在向量来重新重新制定问题,然后使用它来生成面部图像。 GAN发电机在这个新颖的框架中起着双重作用,即优化目标和面部发电机的面部分布约束。除了新颖的优化任务之外,我们还提出了一条攻击管道,以基于生成的面部图像模拟目标用户。我们的结果表明,生成的面部图像可以达到最先进的攻击率在LFW上的最先进的攻击率在I型攻击下为0.1 \%。我们的工作阐明了生物识别部署,以符合隐私和安全政策。
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开放的太空草地越来越耕种或建造,导致针对路边边缘的保护工作逐渐增加。在该国500,000公里的道路上,大约有一半的英国草原物种可以找到,约有91种威胁要么受到威胁。因此,仔细管理这些“野生动植物走廊”对于防止物种灭绝和维持草地栖息地的生物多样性至关重要。野生动植物信托基金经常获得志愿者的支持,以调查路边的边缘,并确定新的“当地野生动植物场所”是具有高保护潜力的地区。使用来自3,900公里的路边潮流的志愿者调查数据以及公开可用的街景图像,我们介绍Deepverge;一种基于深度学习的方法,可以通过检测阳性指标物种的存在来自动调查路边的段。 Deepverge使用来自林肯郡农村县的图像和地面真相调查数据的平均准确性为88%。地方当局可以使用这种方法来确定新的当地野生动植物站点,并根据法律和政府的政策义务一致,援助管理和环境计划,从而节省了数千小时的体力劳动。
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自动简短答案分级是探索如何使用人工智能(AI)的工具来改善教育的重要研究方向。当前的最新方法使用神经语言模型来创建学生响应的矢量表示,然后是分类器以预测分数。但是,这些方法有几个关键的局限性,包括i)他们使用的预培训的语言模型不适合教育主题领域和/或学生生成的文本和ii)它们几乎总是每个问题训练一个模型,而忽略了该模型由于高级语言模型的大小,跨越问题的联系并导致了重要的模型存储问题。在本文中,我们研究了学生对数学问题的回答的自动简短答案分级问题,并为这项任务提出了一个新颖的框架。首先,我们使用Mathbert,这是流行语言模型BERT的一种变体,该模型适合数学内容,并将其微调为学生响应分级的下游任务。其次,我们使用一种文字学习方法,提供评分示例作为语言模型的输入,以提供其他上下文信息并促进对以前看不见的问题的概括。我们在研究学生对开放式数学问题的回答的现实数据集上评估了我们的框架,并表明我们的框架(通常非常明显)优于现有方法,尤其是对于培训期间没有看到的新问题。
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知识追踪是指估计每个学生的知识组成部分/技能掌握水平的问题,从他们过去对教育应用中的问题的回答。一种直接的收益知识追踪方法提供的是能够在未来问题上预测每个学生的表现。但是,大多数现有知识追踪方法的一个关键限制是,他们将学生对问题的回答视为二进制评估,即是正确的还是不正确的。响应正确性分析/预测易于导航,但会丢失重要信息,尤其是对于开放式问题:确切的学生回答可能会提供有关其知识状态的更多信息,而不是仅仅是响应正确性。在本文中,我们首次介绍了对开放式知识追踪的探索,即,在知识跟踪设置中,学生对学生对问题的开放式回答的分析和预测。我们首先制定了一个通用框架,用于开放式知识跟踪,然后通过编程问题详细介绍其在计算机科学教育领域的应用。我们在该域中定义了一系列评估指标,并进行了一系列定量和定性实验,以测试现实世界中学生代码数据集中开放式知识跟踪方法的边界。
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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。
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The recent increase in public and academic interest in preserving biodiversity has led to the growth of the field of conservation technology. This field involves designing and constructing tools that utilize technology to aid in the conservation of wildlife. In this article, we will use case studies to demonstrate the importance of designing conservation tools with human-wildlife interaction in mind and provide a framework for creating successful tools. These case studies include a range of complexities, from simple cat collars to machine learning and game theory methodologies. Our goal is to introduce and inform current and future researchers in the field of conservation technology and provide references for educating the next generation of conservation technologists. Conservation technology not only has the potential to benefit biodiversity but also has broader impacts on fields such as sustainability and environmental protection. By using innovative technologies to address conservation challenges, we can find more effective and efficient solutions to protect and preserve our planet's resources.
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Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.
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A Digital Twin (DT) is a simulation of a physical system that provides information to make decisions that add economic, social or commercial value. The behaviour of a physical system changes over time, a DT must therefore be continually updated with data from the physical systems to reflect its changing behaviour. For resource-constrained systems, updating a DT is non-trivial because of challenges such as on-board learning and the off-board data transfer. This paper presents a framework for updating data-driven DTs of resource-constrained systems geared towards system health monitoring. The proposed solution consists of: (1) an on-board system running a light-weight DT allowing the prioritisation and parsimonious transfer of data generated by the physical system; and (2) off-board robust updating of the DT and detection of anomalous behaviours. Two case studies are considered using a production gas turbine engine system to demonstrate the digital representation accuracy for real-world, time-varying physical systems.
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