神经网络修剪技术可以大大降低应用卷积神经网络(CNN)的计算成本。常见的修剪方法决定了通过单独对过滤器进行排名,即不考虑其相互依赖性来消除哪种卷积过滤器。在本文中,我们提倡的观点是,修剪应考虑连续运算符系列之间的相互依赖性。我们提出了最长的链(精益)方法,该方法通过使用基于图的算法选择相关的卷积链来修剪CNN。 CNN被解释为图形,每个操作员的操作员标准为边缘的距离度量。精益修剪迭代从图表中提取最高的值路径。在我们的实验中,我们测试了几个图像到图像任务的精益修剪,包括著名的Camvid数据集和现实世界中的X射线CT数据集。结果表明,精益修剪可以导致网络具有相似的精度,而卷积过滤器的使用率比现有方法少1.7-12x。
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通常向用户提出自动模型选择,以选择用于应用给定回归任务的机器学习模型(或方法)。在本文中,我们表明,组合不同的回归模型比选择单个(“最佳”)回归模型可以产生更好的结果,并概述了一种有效的方法,该方法从异质性回归模型集中获得最佳加权凸线性组合。更具体地说,在本文中,在上一篇论文中使用的启发式权重优化被使用凸二次编程的精确优化算法取代。我们证明了直接配方的二次编程公式和具有加权数据点的配方的凸度。新颖的重量优化不仅(更多)精确,而且更有效。我们在本文中开发的方法是通过github-open源实现和提供的。它们可以在常见的硬件上执行,并提供透明且易于解释的接口。结果表明,该方法在一系列数据集上的表现优于模型选择方法,包括来自药物发现应用程序的混合变量类型的数据集。
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多光谱探测器的进步导致X射线计算机断层扫描(CT)的范式偏移。从这些检测器获取的光谱信息可用于提取感兴趣对象的体积材料成分图。如果已知材料及其光谱响应是先验的,则图像重建步骤相当简单。但是,如果他们不知道,则需要共同估计地图以及响应。频谱CT中的传统工作流程涉及执行卷重建,然后进行材料分解,反之亦然。然而,这些方法本身遭受了联合重建问题的缺陷。为了解决这个问题,我们提出了一种基于词典的联合重建和解密方法的光谱断层扫描(调整)。我们的配方依赖于形成CT中常见的材料的光谱签名词典以及对象中存在的材料数的先验知识。特别地,我们在空间材料映射,光谱词典和字典元素的材料的指示符方面对光谱体积线性分解。我们提出了一种记忆有效的加速交替的近端梯度方法,以找到所得到的Bi-convex问题的近似解。根据几种合成幻影的数值示范,我们观察到与其他最先进的方法相比,调整非常好。此外,我们解决了针对有限测量模式调整的鲁棒性。
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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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The existing methods for video anomaly detection mostly utilize videos containing identifiable facial and appearance-based features. The use of videos with identifiable faces raises privacy concerns, especially when used in a hospital or community-based setting. Appearance-based features can also be sensitive to pixel-based noise, straining the anomaly detection methods to model the changes in the background and making it difficult to focus on the actions of humans in the foreground. Structural information in the form of skeletons describing the human motion in the videos is privacy-protecting and can overcome some of the problems posed by appearance-based features. In this paper, we present a survey of privacy-protecting deep learning anomaly detection methods using skeletons extracted from videos. We present a novel taxonomy of algorithms based on the various learning approaches. We conclude that skeleton-based approaches for anomaly detection can be a plausible privacy-protecting alternative for video anomaly detection. Lastly, we identify major open research questions and provide guidelines to address them.
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The Government of Kerala had increased the frequency of supply of free food kits owing to the pandemic, however, these items were static and not indicative of the personal preferences of the consumers. This paper conducts a comparative analysis of various clustering techniques on a scaled-down version of a real-world dataset obtained through a conjoint analysis-based survey. Clustering carried out by centroid-based methods such as k means is analyzed and the results are plotted along with SVD, and finally, a conclusion is reached as to which among the two is better. Once the clusters have been formulated, commodities are also decided upon for each cluster. Also, clustering is further enhanced by reassignment, based on a specific cluster loss threshold. Thus, the most efficacious clustering technique for designing a food kit tailored to the needs of individuals is finally obtained.
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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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