近年来,基于属性的访问控制(ABAC)已经变得非常受欢迎,有效地在动态和协作环境中强制访问访问控制。 ABAC的实现需要创建一组基于属性的规则,累积地形成策略。设计ABAC策略AB INITIO要求从系统管理员提供大量的努力。此外,组织变革可能需要在已经部署的政策中列入新规则。在这种情况下,重新开采整个ABAC政策需要相当大的时间和行政努力。相反,最好逐步增加政策。在本文中,保持这些方面可以减少行政开销,在本文中,我们提出了使用机器学习的策略管理方法来帮助系统管理员创建新的ABAC政策以及增强现有的帕克拉。 Pammela可以通过学习目前在类似组织中强制执行的政策规则来为组织产生新的政策。对于政策增强,Pammela可以根据现有规则收集的知识推断出新规则。实验结果表明,我们所提出的方法在各种机器学习评估度量和执行时间方面提供了合理良好的性能。
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We introduce a machine-learning (ML)-based weather simulator--called "GraphCast"--which outperforms the most accurate deterministic operational medium-range weather forecasting system in the world, as well as all previous ML baselines. GraphCast is an autoregressive model, based on graph neural networks and a novel high-resolution multi-scale mesh representation, which we trained on historical weather data from the European Centre for Medium-Range Weather Forecasts (ECMWF)'s ERA5 reanalysis archive. It can make 10-day forecasts, at 6-hour time intervals, of five surface variables and six atmospheric variables, each at 37 vertical pressure levels, on a 0.25-degree latitude-longitude grid, which corresponds to roughly 25 x 25 kilometer resolution at the equator. Our results show GraphCast is more accurate than ECMWF's deterministic operational forecasting system, HRES, on 90.0% of the 2760 variable and lead time combinations we evaluated. GraphCast also outperforms the most accurate previous ML-based weather forecasting model on 99.2% of the 252 targets it reported. GraphCast can generate a 10-day forecast (35 gigabytes of data) in under 60 seconds on Cloud TPU v4 hardware. Unlike traditional forecasting methods, ML-based forecasting scales well with data: by training on bigger, higher quality, and more recent data, the skill of the forecasts can improve. Together these results represent a key step forward in complementing and improving weather modeling with ML, open new opportunities for fast, accurate forecasting, and help realize the promise of ML-based simulation in the physical sciences.
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In recent years, there has been a surge of interest in research on automatic mental health detection (MHD) from social media data leveraging advances in natural language processing and machine learning techniques. While significant progress has been achieved in this interdisciplinary research area, the vast majority of work has treated MHD as a binary classification task. The multiclass classification setup is, however, essential if we are to uncover the subtle differences among the statistical patterns of language use associated with particular mental health conditions. Here, we report on experiments aimed at predicting six conditions (anxiety, attention deficit hyperactivity disorder, bipolar disorder, post-traumatic stress disorder, depression, and psychological stress) from Reddit social media posts. We explore and compare the performance of hybrid and ensemble models leveraging transformer-based architectures (BERT and RoBERTa) and BiLSTM neural networks trained on within-text distributions of a diverse set of linguistic features. This set encompasses measures of syntactic complexity, lexical sophistication and diversity, readability, and register-specific ngram frequencies, as well as sentiment and emotion lexicons. In addition, we conduct feature ablation experiments to investigate which types of features are most indicative of particular mental health conditions.
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In recent years, there has been increased interest in building predictive models that harness natural language processing and machine learning techniques to detect emotions from various text sources, including social media posts, micro-blogs or news articles. Yet, deployment of such models in real-world sentiment and emotion applications faces challenges, in particular poor out-of-domain generalizability. This is likely due to domain-specific differences (e.g., topics, communicative goals, and annotation schemes) that make transfer between different models of emotion recognition difficult. In this work we propose approaches for text-based emotion detection that leverage transformer models (BERT and RoBERTa) in combination with Bidirectional Long Short-Term Memory (BiLSTM) networks trained on a comprehensive set of psycholinguistic features. First, we evaluate the performance of our models within-domain on two benchmark datasets: GoEmotion and ISEAR. Second, we conduct transfer learning experiments on six datasets from the Unified Emotion Dataset to evaluate their out-of-domain robustness. We find that the proposed hybrid models improve the ability to generalize to out-of-distribution data compared to a standard transformer-based approach. Moreover, we observe that these models perform competitively on in-domain data.
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Climate change is causing the intensification of rainfall extremes. Precipitation projections with high spatial resolution are important for society to prepare for these changes, e.g. to model flooding impacts. Physics-based simulations for creating such projections are very computationally expensive. This work demonstrates the effectiveness of diffusion models, a form of deep generative models, for generating much more cheaply realistic high resolution rainfall samples for the UK conditioned on data from a low resolution simulation. We show for the first time a machine learning model that is able to produce realistic samples of high-resolution rainfall based on a physical model that resolves atmospheric convection, a key process behind extreme rainfall. By adding self-learnt, location-specific information to low resolution relative vorticity, quantiles and time-mean of the samples match well their counterparts from the high-resolution simulation.
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大数据和深度学习的结合是一项破坏世界的技术,如果正确使用,可以极大地影响任何目标。随着深度学习技术中大量医疗保健数据集和进步的可用性,系统现在可以很好地预测任何健康问题的未来趋势。从文献调查中,我们发现SVM用于预测心力衰竭的情况,而无需关联客观因素。利用电子健康记录(EHR)中重要历史信息的强度,我们利用长期记忆(LSTM)建立了一个智能和预测的模型,并根据该健康记录预测心力衰竭的未来趋势。因此,这项工作的基本承诺是使用基于患者的电子药用信息的LSTM来预测心脏的失败。我们已经分析了一个数据集,该数据集包含在Faisalabad心脏病学研究所和Faisalabad(巴基斯坦旁遮普邦)的盟军医院收集的299例心力衰竭患者的病历。这些患者由105名女性和194名男性组成,年龄在40岁和95岁之间。该数据集包含13个功能,这些功能报告了负责心力衰竭的临床,身体和生活方式信息。我们发现我们的分析趋势越来越多,这将有助于促进心中预测领域的知识。
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近年来,多任务学习在各种应用程序中都取得了巨大的成功。尽管这些年来,单个模型培训已承诺取得出色的成果,但它忽略了有价值的信息,这些信息可能有助于我们更好地估计一个指标。在与学习相关的任务下,多任务学习能够更好地概括模型。我们试图通过在相关任务和归纳转移学习之间共享功能来增强多任务模型的功能映射。此外,我们的兴趣是学习各种任务之间的任务关系,以从多任务学习中获得更好的收益。在本章中,我们的目标是可视化现有的多任务模型,比较其性能,用于评估多任务模型性能的方法,讨论在各个领域的设计和实施过程中所面临的问题,以及他们实现的优势和里程碑
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我们提出了一个新的灵敏度分析模型,该模型结合了Copulas和在未观察到的混杂状态下的因果推断的标准化。我们将新模型称为$ \ rho $ -gnf($ \ rho $ - graphical正常化流),其中$ \ rho {\ in} [ - 1,+1] $是一个有界灵敏度参数,表示后门非 - 由于未观察到的混杂而引起的因果关系,使用研究最丰富且广泛流行的高斯副群建模。具体而言,$ \ rho $ -gnf使我们能够估计和分析前门因果效应或平均因果效应(ACE)作为$ \ rho $的函数。我们将其称为$ \ rho_ {curve} $。 $ \ rho_ {curve} $使我们能够指定无王牌所需的混杂力量。我们将其称为$ \ rho_ {value} $。此外,$ \ rho_ {curve} $还使我们能够为$ \ rho $ values的间隔提供ACE的界限。我们说明了$ \ rho $ -gnf的好处,并通过对我们的经验王牌界限的实验比其他流行的王牌范围更狭窄。
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当前的时空动作管检测方法通常将一个给定键框的边界框提案扩展到附近帧的3D颞轴和池特征。但是,如果演员的位置或形状通过大型的2D运动和可变性,由于大型摄像机运动,大型演员形状变形,快速演员的动作等,这种合并就无法积累有意义的时空特征。在这项工作中,我们旨在研究在大动作下的动作检测中观察到Cuboid感知特征聚集的性能。此外,我们建议通过跟踪参与者并沿各个轨道进行时间特征聚集来增强演员特征表示。我们在各种固定时间尺度的动作管/轨道框之间使用相交的行动者(IOU)定义了演员运动。随着时间的推移,具有较大运动的动作将导致较低的IOU,并且较慢的动作将保持更高的IOU。我们发现,轨道感知功能聚集始终取得了巨大的改善,尤其是对于与Cuboid感知的基线相比,在大型运动下进行的动作。结果,我们还报告了大规模多运动数据集的最先进。
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当与分支和界限结合使用时,结合的传播方法是正式验证深神经网络(例如正确性,鲁棒性和安全性)的最有效方法之一。但是,现有作品无法处理在传统求解器中广泛接受的切割平面限制的一般形式,这对于通过凸出凸松弛的加强验证者至关重要。在本文中,我们概括了结合的传播程序,以允许添加任意切割平面的约束,包括涉及放宽整数变量的限制,这些变量未出现在现有的结合传播公式中。我们的广义结合传播方法GCP-crown为应用一般切割平面方法}开辟了一个机会进行神经网络验证,同时受益于结合传播方法的效率和GPU加速。作为案例研究,我们研究了由现成的混合整数编程(MIP)求解器生成的切割平面的使用。我们发现,MIP求解器可以生成高质量的切割平面,以使用我们的新配方来增强基于界限的验证者。由于以分支为重点的绑定传播程序和切削平面的MIP求解器可以使用不同类型的硬件(GPU和CPU)并行运行,因此它们的组合可以迅速探索大量具有强切割平面的分支,从而导致强大的分支验证性能。实验表明,与VNN-Comp 2021中最佳工具相比,我们的方法是第一个可以完全求解椭圆形的基准并验证椭圆21基准的两倍的验证者,并且在oval21基准测试中的最佳工具也明显超过了最先进的验证器。广泛的基准。 GCP-Crown是$ \ alpha $,$ \ beta $ -Crown验证者,VNN-COMP 2022获奖者的一部分。代码可在http://papercode.cc/gcp-crown上获得
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