Machine learning-based segmentation in medical imaging is widely used in clinical applications from diagnostics to radiotherapy treatment planning. Segmented medical images with ground truth are useful for investigating the properties of different segmentation performance metrics to inform metric selection. Regular geometrical shapes are often used to synthesize segmentation errors and illustrate properties of performance metrics, but they lack the complexity of anatomical variations in real images. In this study, we present a tool to emulate segmentations by adjusting the reference (truth) masks of anatomical objects extracted from real medical images. Our tool is designed to modify the defined truth contours and emulate different types of segmentation errors with a set of user-configurable parameters. We defined the ground truth objects from 230 patient images in the Glioma Image Segmentation for Radiotherapy (GLIS-RT) database. For each object, we used our segmentation synthesis tool to synthesize 10 versions of segmentation (i.e., 10 simulated segmentors or algorithms), where each version has a pre-defined combination of segmentation errors. We then applied 20 performance metrics to evaluate all synthetic segmentations. We demonstrated the properties of these metrics, including their ability to capture specific types of segmentation errors. By analyzing the intrinsic properties of these metrics and categorizing the segmentation errors, we are working toward the goal of developing a decision-tree tool for assisting in the selection of segmentation performance metrics.
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Of late, insurance fraud detection has assumed immense significance owing to the huge financial & reputational losses fraud entails and the phenomenal success of the fraud detection techniques. Insurance is majorly divided into two categories: (i) Life and (ii) Non-life. Non-life insurance in turn includes health insurance and auto insurance among other things. In either of the categories, the fraud detection techniques should be designed in such a way that they capture as many fraudulent transactions as possible. Owing to the rarity of fraudulent transactions, in this paper, we propose a chaotic variational autoencoder (C-VAE to perform one-class classification (OCC) on genuine transactions. Here, we employed the logistic chaotic map to generate random noise in the latent space. The effectiveness of C-VAE is demonstrated on the health insurance fraud and auto insurance datasets. We considered vanilla Variational Auto Encoder (VAE) as the baseline. It is observed that C-VAE outperformed VAE in both datasets. C-VAE achieved a classification rate of 77.9% and 87.25% in health and automobile insurance datasets respectively. Further, the t-test conducted at 1% level of significance and 18 degrees of freedom infers that C-VAE is statistically significant than the VAE.
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与计算机视觉合并的基于无人机的遥感系统(UAV)遥感系统具有协助建筑物建设和灾难管理的潜力,例如地震期间的损害评估。可以通过检查来评估建筑物到地震的脆弱性,该检查考虑到相关组件的预期损害进展以及组件对结构系统性能的贡献。这些检查中的大多数是手动进行的,导致高利用人力,时间和成本。本文提出了一种通过基于无人机的图像数据收集和用于后处理的软件库来自动化这些检查的方法,该方法有助于估算地震结构参数。这里考虑的关键参数是相邻建筑物,建筑计划形状,建筑计划区域,屋顶上的对象和屋顶布局之间的距离。通过使用距离测量传感器以及通过Google Earth获得的数据进行的现场测量,可以验证所提出的方法在估计上述参数估算上述参数方面的准确性。可以从https://uvrsabi.github.io/访问其他详细信息和代码。
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循环贸易是商品和服务税的逃税形式,其中一组欺诈性纳税人(交易者)的目标是通过在短期内将几项虚拟交易(在商品或服务中添加价值不高)来掩盖非法交易,以掩盖非法交易。。由于纳税人的庞大数据库,当局可以手动识别循环交易者和他们所涉及的非法交易的群体是不可行的。这项工作使用大数据分析和图形表示技术来提出一个框架来识别循环交易者社区并隔离各个社区的非法交易。我们的方法经过印度特兰加纳政府商业税部提供的现实生活数据,在那里我们发现了几个循环商人社区。
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科学数据的一套简洁且可衡量的公平(可访问,可互操作和可重复使用的)原则正在转变用于数据管理和管理的最新实践,以支持和支持发现和创新。从这项计划中学习,并承认人工智能(AI)在科学和工程实践中的影响,我们为AI模型引入了一套实用,简洁和可衡量的公平原则。我们展示了如何在统一的计算框架内创建和共享公平的数据和AI模型,结合了以下要素:Argonne国家实验室的高级光子源,材料数据设施,科学数据和学习中心,Funcx和Argonne Leadersition的数据和学习中心计算设施(ALCF),尤其是ALCF AI测试台的Thetagpu SuperCuputer和Sambanova Datascale系统。我们描述了如何利用这种域 - 不足的计算框架来实现自主AI驱动的发现。
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该调查侧重于地球系统科学中的当前问题,其中可以应用机器学习算法。它概述了以前的工作,在地球科学部,印度政府的持续工作,以及ML算法的未来应用到一些重要的地球科学问题。我们提供了与本次调查的比较的比较,这是与机器学习相关的多维地区的思想地图,以及地球系统科学(ESS)中机器学习的Gartner的炒作周期。我们主要关注地球科学的关键组成部分,包括大气,海洋,地震学和生物圈,以及覆盖AI / ML应用程序统计侦查和预测问题。
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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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Modelling and forecasting real-life human behaviour using online social media is an active endeavour of interest in politics, government, academia, and industry. Since its creation in 2006, Twitter has been proposed as a potential laboratory that could be used to gauge and predict social behaviour. During the last decade, the user base of Twitter has been growing and becoming more representative of the general population. Here we analyse this user base in the context of the 2021 Mexican Legislative Election. To do so, we use a dataset of 15 million election-related tweets in the six months preceding election day. We explore different election models that assign political preference to either the ruling parties or the opposition. We find that models using data with geographical attributes determine the results of the election with better precision and accuracy than conventional polling methods. These results demonstrate that analysis of public online data can outperform conventional polling methods, and that political analysis and general forecasting would likely benefit from incorporating such data in the immediate future. Moreover, the same Twitter dataset with geographical attributes is positively correlated with results from official census data on population and internet usage in Mexico. These findings suggest that we have reached a period in time when online activity, appropriately curated, can provide an accurate representation of offline behaviour.
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Existing federated classification algorithms typically assume the local annotations at every client cover the same set of classes. In this paper, we aim to lift such an assumption and focus on a more general yet practical non-IID setting where every client can work on non-identical and even disjoint sets of classes (i.e., client-exclusive classes), and the clients have a common goal which is to build a global classification model to identify the union of these classes. Such heterogeneity in client class sets poses a new challenge: how to ensure different clients are operating in the same latent space so as to avoid the drift after aggregation? We observe that the classes can be described in natural languages (i.e., class names) and these names are typically safe to share with all parties. Thus, we formulate the classification problem as a matching process between data representations and class representations and break the classification model into a data encoder and a label encoder. We leverage the natural-language class names as the common ground to anchor the class representations in the label encoder. In each iteration, the label encoder updates the class representations and regulates the data representations through matching. We further use the updated class representations at each round to annotate data samples for locally-unaware classes according to similarity and distill knowledge to local models. Extensive experiments on four real-world datasets show that the proposed method can outperform various classical and state-of-the-art federated learning methods designed for learning with non-IID data.
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This is paper for the smooth function approximation by neural networks (NN). Mathematical or physical functions can be replaced by NN models through regression. In this study, we get NNs that generate highly accurate and highly smooth function, which only comprised of a few weight parameters, through discussing a few topics about regression. First, we reinterpret inside of NNs for regression; consequently, we propose a new activation function--integrated sigmoid linear unit (ISLU). Then special charateristics of metadata for regression, which is different from other data like image or sound, is discussed for improving the performance of neural networks. Finally, the one of a simple hierarchical NN that generate models substituting mathematical function is presented, and the new batch concept ``meta-batch" which improves the performance of NN several times more is introduced. The new activation function, meta-batch method, features of numerical data, meta-augmentation with metaparameters, and a structure of NN generating a compact multi-layer perceptron(MLP) are essential in this study.
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