胎儿镜检查激光​​光凝是一种广泛采用的方法,用于治疗双胞胎输血综合征(TTTS)。该过程涉及光凝病理吻合术以调节双胞胎之间的血液交换。由于观点有限,胎儿镜的可操作性差,可见性差和照明的可变性,因此该程序尤其具有挑战性。这些挑战可能导致手术时间增加和消融不完全。计算机辅助干预措施(CAI)可以通过识别场景中的关键结构并通过视频马赛克来扩展胎儿镜观景领域,从而为外科医生提供决策支持和背景意识。由于缺乏设计,开发和测试CAI算法的高质量数据,该领域的研究受到了阻碍。通过作为MICCAI2021内窥镜视觉挑战组织的胎儿镜胎盘胎盘分割和注册(FETREG2021)挑战,我们发布了第一个Largescale Multencentre TTTS数据集,用于开发广义和可靠的语义分割和视频摩擦质量algorithms。对于这一挑战,我们发布了一个2060张图像的数据集,该数据集是从18个体内TTTS胎儿镜检查程序和18个简短视频剪辑的船只,工具,胎儿和背景类别的像素通道。七个团队参与了这一挑战,他们的模型性能在一个看不见的测试数据集中评估了658个从6个胎儿镜程序和6个短剪辑的图像的图像。这项挑战为创建通用解决方案提供了用于胎儿镜面场景的理解和摩西式解决方案的机会。在本文中,我们介绍了FETREG2021挑战的发现,以及报告TTTS胎儿镜检查中CAI的详细文献综述。通过这一挑战,它的分析和多中心胎儿镜数据的发布,我们为该领域的未来研究提供了基准。
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偏光成像以及深度学习,在包括场景分析在内的不同任务上显示了改进的性能。但是,由于培训数据集的尺寸很小,因此可能会质疑其稳健性。尽管该问题可以通过数据增强来解决,但两极分化的方式受到经典数据增强技术未解决的身体可行性约束。为了解决这个问题,我们建议使用Cyclegan,这是一种基于深层生成模型的图像翻译技术,仅依靠未配对的数据,将大型标记的路现场数据集传输到极化域。我们设计了几个辅助损失项,与自行车损失一起处理极化图像的物理约束。在道路场景对象检测任务上证明了该解决方案的效率,在该任务中,生成的逼真的极化图像允许改善汽车的性能和行人检测高达9%。由此产生的约束周期内公开释放,使任何人都可以生成自己的极化图像。
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Mixtures of von Mises-Fisher distributions can be used to cluster data on the unit hypersphere. This is particularly adapted for high-dimensional directional data such as texts. We propose in this article to estimate a von Mises mixture using a l 1 penalized likelihood. This leads to sparse prototypes that improve clustering interpretability. We introduce an expectation-maximisation (EM) algorithm for this estimation and explore the trade-off between the sparsity term and the likelihood one with a path following algorithm. The model's behaviour is studied on simulated data and, we show the advantages of the approach on real data benchmark. We also introduce a new data set on financial reports and exhibit the benefits of our method for exploratory analysis.
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G-Enum histograms are a new fast and fully automated method for irregular histogram construction. By framing histogram construction as a density estimation problem and its automation as a model selection task, these histograms leverage the Minimum Description Length principle (MDL) to derive two different model selection criteria. Several proven theoretical results about these criteria give insights about their asymptotic behavior and are used to speed up their optimisation. These insights, combined to a greedy search heuristic, are used to construct histograms in linearithmic time rather than the polynomial time incurred by previous works. The capabilities of the proposed MDL density estimation method are illustrated with reference to other fully automated methods in the literature, both on synthetic and large real-world data sets.
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This paper presents an introduction to the state-of-the-art in anomaly and change-point detection. On the one hand, the main concepts needed to understand the vast scientific literature on those subjects are introduced. On the other, a selection of important surveys and books, as well as two selected active research topics in the field, are presented.
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Machine learning (ML) models are nowadays used in complex applications in various domains, such as medicine, bioinformatics, and other sciences. Due to their black box nature, however, it may sometimes be hard to understand and trust the results they provide. This has increased the demand for reliable visualization tools related to enhancing trust in ML models, which has become a prominent topic of research in the visualization community over the past decades. To provide an overview and present the frontiers of current research on the topic, we present a State-of-the-Art Report (STAR) on enhancing trust in ML models with the use of interactive visualization. We define and describe the background of the topic, introduce a categorization for visualization techniques that aim to accomplish this goal, and discuss insights and opportunities for future research directions. Among our contributions is a categorization of trust against different facets of interactive ML, expanded and improved from previous research. Our results are investigated from different analytical perspectives: (a) providing a statistical overview, (b) summarizing key findings, (c) performing topic analyses, and (d) exploring the data sets used in the individual papers, all with the support of an interactive web-based survey browser. We intend this survey to be beneficial for visualization researchers whose interests involve making ML models more trustworthy, as well as researchers and practitioners from other disciplines in their search for effective visualization techniques suitable for solving their tasks with confidence and conveying meaning to their data.
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In recent years the applications of machine learning models have increased rapidly, due to the large amount of available data and technological progress.While some domains like web analysis can benefit from this with only minor restrictions, other fields like in medicine with patient data are strongerregulated. In particular \emph{data privacy} plays an important role as recently highlighted by the trustworthy AI initiative of the EU or general privacy regulations in legislation. Another major challenge is, that the required training \emph{data is} often \emph{distributed} in terms of features or samples and unavailable for classicalbatch learning approaches. In 2016 Google came up with a framework, called \emph{Federated Learning} to solve both of these problems. We provide a brief overview on existing Methods and Applications in the field of vertical and horizontal \emph{Federated Learning}, as well as \emph{Fderated Transfer Learning}.
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Co-clustering is a class of unsupervised data analysis techniques that extract the existing underlying dependency structure between the instances and variables of a data table as homogeneous blocks. Most of those techniques are limited to variables of the same type. In this paper, we propose a mixed data co-clustering method based on a two-step methodology. In the first step, all the variables are binarized according to a number of bins chosen by the analyst, by equal frequency discretization in the numerical case, or keeping the most frequent values in the categorical case. The second step applies a co-clustering to the instances and the binary variables, leading to groups of instances and groups of variable parts. We apply this methodology on several data sets and compare with the results of a Multiple Correspondence Analysis applied to the same data.
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Co-clustering is a data mining technique used to extract the underlying block structure between the rows and columns of a data matrix. Many approaches have been studied and have shown their capacity to extract such structures in continuous, binary or contingency tables. However, very little work has been done to perform co-clustering on mixed type data. In this article, we extend the latent block models based co-clustering to the case of mixed data (continuous and binary variables). We then evaluate the effectiveness of the proposed approach on simulated data and we discuss its advantages and potential limits.
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In the upcoming years, artificial intelligence (AI) is going to transform the practice of medicine in most of its specialties. Deep learning can help achieve better and earlier problem detection, while reducing errors on diagnosis. By feeding a deep neural network (DNN) with the data from a low-cost and low-accuracy sensor array, we demonstrate that it becomes possible to significantly improve the measurements' precision and accuracy. The data collection is done with an array composed of 32 temperature sensors, including 16 analog and 16 digital sensors. All sensors have accuracies between 0.5-2.0$^\circ$C. 800 vectors are extracted, covering a range from to 30 to 45$^\circ$C. In order to improve the temperature readings, we use machine learning to perform a linear regression analysis through a DNN. In an attempt to minimize the model's complexity in order to eventually run inferences locally, the network with the best results involves only three layers using the hyperbolic tangent activation function and the Adam Stochastic Gradient Descent (SGD) optimizer. The model is trained with a randomly-selected dataset using 640 vectors (80% of the data) and tested with 160 vectors (20%). Using the mean squared error as a loss function between the data and the model's prediction, we achieve a loss of only 1.47x10$^{-4}$ on the training set and 1.22x10$^{-4}$ on the test set. As such, we believe this appealing approach offers a new pathway towards significantly better datasets using readily-available ultra low-cost sensors.
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