我们研究了机器学习(ML)分类技术的误差概率收敛到零的速率的性能。利用大偏差理论,我们为ML分类器提供了数学条件,以表现出误差概率,这些误差概率呈指数级消失,例如$ \ sim \ exp \ left(-n \,i + o(i + o(n)\ right)$,其中$ n $是可用于测试的信息的数量(或其他相关参数,例如图像中目标的大小),而$ i $是错误率。这样的条件取决于数据驱动的决策功能的累积生成功能的Fenchel-Legendre变换(D3F,即,在做出最终二进制决策之前的阈值)在训练阶段中学到的。因此,D3F以及相关的错误率$ $ $取决于给定的训练集,该集合假定有限。有趣的是,可以根据基础统计模型的可用信息生成的可用数据集或合成数据集对这些条件进行验证和测试。换句话说,分类误差概率收敛到零,其速率可以在可用于培训的数据集的一部分上计算。与大偏差理论一致,我们还可以以足够大的$ n $为高斯分布的归一化D3F统计量来确定收敛性。利用此属性设置所需的渐近错误警报概率,从经验上来说,即使对于$ n $的非常现实的值,该属性也是准确的。此外,提供了近似错误概率曲线$ \ sim \ sim \ sim \ sim \ exp \ left(-n \,i \ right)$,这要归功于精制的渐近导数(通常称为精确的渐近学),其中$ \ zeta_n $代表$ \ zeta_n $误差概率的大多数代表性亚指数项。
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Automatic Text Summarization (ATS) is becoming relevant with the growth of textual data; however, with the popularization of public large-scale datasets, some recent machine learning approaches have focused on dense models and architectures that, despite producing notable results, usually turn out in models difficult to interpret. Given the challenge behind interpretable learning-based text summarization and the importance it may have for evolving the current state of the ATS field, this work studies the application of two modern Generalized Additive Models with interactions, namely Explainable Boosting Machine and GAMI-Net, to the extractive summarization problem based on linguistic features and binary classification.
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Early recognition of clinical deterioration (CD) has vital importance in patients' survival from exacerbation or death. Electronic health records (EHRs) data have been widely employed in Early Warning Scores (EWS) to measure CD risk in hospitalized patients. Recently, EHRs data have been utilized in Machine Learning (ML) models to predict mortality and CD. The ML models have shown superior performance in CD prediction compared to EWS. Since EHRs data are structured and tabular, conventional ML models are generally applied to them, and less effort is put into evaluating the artificial neural network's performance on EHRs data. Thus, in this article, an extremely boosted neural network (XBNet) is used to predict CD, and its performance is compared to eXtreme Gradient Boosting (XGBoost) and random forest (RF) models. For this purpose, 103,105 samples from thirteen Brazilian hospitals are used to generate the models. Moreover, the principal component analysis (PCA) is employed to verify whether it can improve the adopted models' performance. The performance of ML models and Modified Early Warning Score (MEWS), an EWS candidate, are evaluated in CD prediction regarding the accuracy, precision, recall, F1-score, and geometric mean (G-mean) metrics in a 10-fold cross-validation approach. According to the experiments, the XGBoost model obtained the best results in predicting CD among Brazilian hospitals' data.
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We introduce MegaPose, a method to estimate the 6D pose of novel objects, that is, objects unseen during training. At inference time, the method only assumes knowledge of (i) a region of interest displaying the object in the image and (ii) a CAD model of the observed object. The contributions of this work are threefold. First, we present a 6D pose refiner based on a render&compare strategy which can be applied to novel objects. The shape and coordinate system of the novel object are provided as inputs to the network by rendering multiple synthetic views of the object's CAD model. Second, we introduce a novel approach for coarse pose estimation which leverages a network trained to classify whether the pose error between a synthetic rendering and an observed image of the same object can be corrected by the refiner. Third, we introduce a large-scale synthetic dataset of photorealistic images of thousands of objects with diverse visual and shape properties and show that this diversity is crucial to obtain good generalization performance on novel objects. We train our approach on this large synthetic dataset and apply it without retraining to hundreds of novel objects in real images from several pose estimation benchmarks. Our approach achieves state-of-the-art performance on the ModelNet and YCB-Video datasets. An extensive evaluation on the 7 core datasets of the BOP challenge demonstrates that our approach achieves performance competitive with existing approaches that require access to the target objects during training. Code, dataset and trained models are available on the project page: https://megapose6d.github.io/.
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The 1$^{\text{st}}$ Workshop on Maritime Computer Vision (MaCVi) 2023 focused on maritime computer vision for Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicle (USV), and organized several subchallenges in this domain: (i) UAV-based Maritime Object Detection, (ii) UAV-based Maritime Object Tracking, (iii) USV-based Maritime Obstacle Segmentation and (iv) USV-based Maritime Obstacle Detection. The subchallenges were based on the SeaDronesSee and MODS benchmarks. This report summarizes the main findings of the individual subchallenges and introduces a new benchmark, called SeaDronesSee Object Detection v2, which extends the previous benchmark by including more classes and footage. We provide statistical and qualitative analyses, and assess trends in the best-performing methodologies of over 130 submissions. The methods are summarized in the appendix. The datasets, evaluation code and the leaderboard are publicly available at https://seadronessee.cs.uni-tuebingen.de/macvi.
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在复杂,非结构化和动态环境中导航的董事会机器人基于在线事件的感知技术可能会遭受进入事件速率及其处理时间的不可预测的变化,这可能会导致计算溢出或响应能力损失。本文提出了尽快的:一种新型的事件处理框架,该框架将事件传输到处理算法,保持系统响应能力并防止溢出。尽快由两种自适应机制组成。第一个通过丢弃传入事件的自适应百分比来防止事件处理溢出。第二种机制动态调整事件软件包的大小,以减少事件生成和处理之间的延迟。ASAP保证了收敛性,并且对处理算法具有灵活性。它已在具有挑战性的条件下在船上进行了验证。
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事件摄像机可以通过非常高的时间分辨率和动态范围来捕获像素级照明变化。由于对照明条件和运动模糊的稳健性,他们获得了越来越多的研究兴趣。文献中存在两种主要方法,用于喂养基于事件的处理算法:在事件软件包中包装触发的事件并将它们逐一发送作为单个事件。这些方法因处理溢出或缺乏响应性而受到限制。当算法无法实时处理所有事件时,处理溢出是由高事件产生速率引起的。相反,当事件包的频率太低时,事件包的生成率低时,缺乏响应率会发生。本文提出了尽快的自适应方案,该方案是通过可容纳事件软件包处理时间的可变大小软件包来管理事件流的。实验结果表明,ASAP能够以响应性和有效的方式喂食异步事件聚类算法,同时又可以防止溢出。
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接受经验风险最小化(ERM)训练的机器学习模型的预测性能可以大大降解分配变化。在训练数据集中存在虚假相关性的存在导致ERM训练的模型在对不存在此类相关性的少数群体评估时表现出很高的损失。已经进行了广泛的尝试来开发改善最差的鲁棒性的方法。但是,他们需要每个培训输入的组信息,或者至少需要一个带有组标签的验证设置来调整其超参数,这可能是昂贵的或未知的。在本文中,我们应对在培训或验证期间没有小组注释的情况下提高组鲁棒性的挑战。为此,我们建议根据``识别''模型提取的特征的革兰氏集矩阵将训练数据集分为组,并根据这些伪组应用强大的优化。在不可用的小组标签的现实情况下,我们的实验表明,我们的方法不仅可以改善对ERM的稳健性,而且还优于所有最近的基线
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我们研究了图结构识别的问题,即在时间序列之间恢复依赖图的图。我们将这些时间序列数据建模为线性随机网络动力学系统状态的组成部分。我们假设部分可观察性,其中仅观察到一个包含网络的节点子集的状态演变。我们设计了一个从观察到的时间序列计算的新功能向量,并证明这些特征是线性可分离的,即存在一个超平面,该超平面将与连接的节点成对相关的特征群体与与断开对相关的节点相关联。这使得可以训练各种分类器进行因果推理的功能。特别是,我们使用这些功能来训练卷积神经网络(CNN)。由此产生的因果推理机制优于最先进的W.R.T.样品复杂性。受过训练的CNN概括了结构上不同的网络(密集或稀疏)和噪声级别的轮廓。值得注意的是,他们在通过合成网络(随机图的实现)训练时也很好地概括了现实世界网络。最后,提出的方法始终以成对的方式重建图,也就是说,通过确定每对相应的时间序列中的每对节点中是否存在边缘或箭头或不存在箭头。这符合大规模系统的框架,在该系统中,网络中所有节点的观察或处理都令人难以置信。
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使用机器学习算法从未标记的文本中提取知识可能很复杂。文档分类和信息检索是两个应用程序,可以从无监督的学习(例如文本聚类和主题建模)中受益,包括探索性数据分析。但是,无监督的学习范式提出了可重复性问题。初始化可能会导致可变性,具体取决于机器学习算法。此外,关于群集几何形状,扭曲可能会产生误导。在原因中,异常值和异常的存在可能是决定因素。尽管初始化和异常问题与文本群集和主题建模相关,但作者并未找到对它们的深入分析。这项调查提供了这些亚地区的系统文献综述(2011-2022),并提出了共同的术语,因为类似的程序具有不同的术语。作者描述了研究机会,趋势和开放问题。附录总结了与审查的作品直接或间接相关的文本矢量化,分解和聚类算法的理论背景。
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