流行病学中的数学模型是一种不可或缺的工具,可以确定传染病的动态和重要特征。除了他们的科学价值之外,这些模型通常用于在正在进行的爆发期间提供政治决策和干预措施。然而,通过将复杂模型连接到真实数据来可靠地推断正在进行的爆发的动态仍然很难,并且需要费力的手动参数拟合或昂贵的优化方法,这些方法必须从划痕中重复给定模型的每个应用。在这项工作中,我们用专门的神经网络的流行病学建模的新组合来解决这个问题。我们的方法需要两个计算阶段:在初始训练阶段中,描述该流行病的数学模型被用作神经网络的教练,该主管是关于全球可能疾病动态的全球知识。在随后的推理阶段,训练有素的神经网络处理实际爆发的观察到的数据,并且揭示了模型的参数,以便实际地再现观察到的动态并可可靠地预测未来的进展。通过其灵活的框架,我们的仿真方法适用于各种流行病学模型。此外,由于我们的方法是完全贝叶斯的,它旨在纳入所有可用的关于合理参数值的先前知识,并返回这些参数上的完整关节后部分布。我们的方法在德国的早期Covid-19爆发阶段的应用表明,我们能够获得可靠的概率估计对重要疾病特征,例如生成时间,未检测到的感染部分,症状发作前的传播可能性,以及报告延迟非常适中的现实观测。
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Cashews are grown by over 3 million smallholders in more than 40 countries worldwide as a principal source of income. As the third largest cashew producer in Africa, Benin has nearly 200,000 smallholder cashew growers contributing 15% of the country's national export earnings. However, a lack of information on where and how cashew trees grow across the country hinders decision-making that could support increased cashew production and poverty alleviation. By leveraging 2.4-m Planet Basemaps and 0.5-m aerial imagery, newly developed deep learning algorithms, and large-scale ground truth datasets, we successfully produced the first national map of cashew in Benin and characterized the expansion of cashew plantations between 2015 and 2021. In particular, we developed a SpatioTemporal Classification with Attention (STCA) model to map the distribution of cashew plantations, which can fully capture texture information from discriminative time steps during a growing season. We further developed a Clustering Augmented Self-supervised Temporal Classification (CASTC) model to distinguish high-density versus low-density cashew plantations by automatic feature extraction and optimized clustering. Results show that the STCA model has an overall accuracy of 80% and the CASTC model achieved an overall accuracy of 77.9%. We found that the cashew area in Benin has doubled from 2015 to 2021 with 60% of new plantation development coming from cropland or fallow land, while encroachment of cashew plantations into protected areas has increased by 70%. Only half of cashew plantations were high-density in 2021, suggesting high potential for intensification. Our study illustrates the power of combining high-resolution remote sensing imagery and state-of-the-art deep learning algorithms to better understand tree crops in the heterogeneous smallholder landscape.
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Recent large-scale image generation models such as Stable Diffusion have exhibited an impressive ability to generate fairly realistic images starting from a very simple text prompt. Could such models render real images obsolete for training image prediction models? In this paper, we answer part of this provocative question by questioning the need for real images when training models for ImageNet classification. More precisely, provided only with the class names that have been used to build the dataset, we explore the ability of Stable Diffusion to generate synthetic clones of ImageNet and measure how useful they are for training classification models from scratch. We show that with minimal and class-agnostic prompt engineering those ImageNet clones we denote as ImageNet-SD are able to close a large part of the gap between models produced by synthetic images and models trained with real images for the several standard classification benchmarks that we consider in this study. More importantly, we show that models trained on synthetic images exhibit strong generalization properties and perform on par with models trained on real data.
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Reliable application of machine learning-based decision systems in the wild is one of the major challenges currently investigated by the field. A large portion of established approaches aims to detect erroneous predictions by means of assigning confidence scores. This confidence may be obtained by either quantifying the model's predictive uncertainty, learning explicit scoring functions, or assessing whether the input is in line with the training distribution. Curiously, while these approaches all state to address the same eventual goal of detecting failures of a classifier upon real-life application, they currently constitute largely separated research fields with individual evaluation protocols, which either exclude a substantial part of relevant methods or ignore large parts of relevant failure sources. In this work, we systematically reveal current pitfalls caused by these inconsistencies and derive requirements for a holistic and realistic evaluation of failure detection. To demonstrate the relevance of this unified perspective, we present a large-scale empirical study for the first time enabling benchmarking confidence scoring functions w.r.t all relevant methods and failure sources. The revelation of a simple softmax response baseline as the overall best performing method underlines the drastic shortcomings of current evaluation in the abundance of publicized research on confidence scoring. Code and trained models are at https://github.com/IML-DKFZ/fd-shifts.
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实现自动化车辆和外部服务器,智能基础设施和其他道路使用者之间的安全可靠的高带宽低度连通性是使全自动驾驶成为可能的核心步骤。允许这种连接性的数据接口的可用性有可能区分人造代理在连接,合作和自动化的移动性系统中的功能与不具有此类接口的人类操作员的能力。连接的代理可以例如共享数据以构建集体环境模型,计划集体行为,并从集中组合的共享数据集体学习。本文提出了多种解决方案,允许连接的实体交换数据。特别是,我们提出了一个新的通用通信界面,该界面使用消息排队遥测传输(MQTT)协议连接运行机器人操作系统(ROS)的代理。我们的工作整合了以各种关键绩效指标的形式评估连接质量的方法。我们比较了各种方法,这些方法提供了5G网络中Edge-Cloud LiDAR对象检测的示例性用例所需的连接性。我们表明,基于车辆的传感器测量值的可用性与从边缘云中接收到相应的对象列表之间的平均延迟低于87毫秒。所有实施的解决方案均可为开源并免费使用。源代码可在https://github.com/ika-rwth-aachen/ros-v2x-benchmarking-suite上获得。
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由于它们在建模复杂的问题和处理高维数据集的有效性,因此已显示深神网络(DNN)在广泛的应用领域中的传统机器学习算法优于传统的机器学习算法。但是,许多现实生活数据集具有越来越高的维度,其中大量功能可能与手头的任务无关。包含此类功能不仅会引入不必要的噪声,还会提高计算复杂性。此外,由于许多特征之间的非线性和依赖性高,DNN模型往往不可避免地是不透明的,并且被视为黑盒方法,因为它们的内部功能不佳。解释良好的模型可以识别具有统计学意义的特征,并解释其影响模型结果的方式。在本文中,我们提出了一种有效的方法,可以在高维数据集的情况下提高黑框模型的分类任务。为此,我们首先在高维数据集上训练黑框模型,以了解执行分类的嵌入。为了分解黑框模型的内部工作原理并确定TOP-K重要特征,我们采用了不同的探测和扰动技术。然后,我们通过在TOP-K特征空间上通过可解释的替代模型来近似黑框模型的行为。最后,我们从替代模型中得出决策规则和本地解释,以解释个人决策。当在不同数据集上测试,尺寸在50到20,000之间的不同数据集上进行测试时,我们的方法优于最先进的方法,例如TABNET,XGBOOST和基于Shap的可解释性技术。
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我们实施了两个不同的三维深度学习神经网络,并评估了它们在非对比度计算机断层扫描(CT)上看到的颅内出血(ICH)的能力。一种模型,称为“沿正交关注u-net沿正交级别的素隔离”(Viola-Unet),其体系结构元素可适应2022年实例的数据挑战。第二个比较模型是从No-New U-NET(NNU-NET)得出的。输入图像和地面真理分割图用于以监督方式分别训练两个网络。验证数据随后用于半监督培训。在5倍交叉验证期间比较了模型预测。中提琴 - UNET的表现优于四个性能指标中的两个(即NSD和RVD)的比较网络。将中提琴和NNU-NET网络组合的合奏模型在DSC和HD方面的性能最高。我们证明,与3D U-NET相关的ICH分割性能优势有效地合并了U-NET的解码分支期间的空间正交特征。 Viola-Unet AI工具的代码基础,预估计的权重和Docker图像将在https://github.com/samleoqh/viola-unet上公开获得。
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机器人的动作本质上是随机的,因为它的传感器很嘈杂,其动作并不总是具有预期效果。因此,代理语言已扩展到具有信念和随机行动程度的模型。尽管这允许更精确的机器人模型,但最终的程序很难理解,因为它们需要处理噪声,例如,通过循环循环直到确定达到所需的状态,并且因为由此产生的动作痕迹由一个大的动作痕迹组成动作数量混乱,传感器噪声。为了减轻这些问题,我们建议使用抽象。我们定义机器人的高级和非稳态模型,然后将高级模型映射到较低级别的随机模型中。最终的程序更容易理解,通常不需要信仰操作员或循环,并且会产生更短的动作迹线。
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{g} {ustav} Fechner 1860年的心理物理学描述,即对其刺激的感觉的测量,被广泛认为是现代心理科学的出现。在心理物理学中,研究人员的参数会改变刺激的某些方面,并衡量人类受试者对该刺激的经历的变化;这样做可以深入了解感觉与唤起它的物理输入之间的关系。这种方法在感知域中大量使用,包括信号检测,阈值测量和理想的观察者分析。像视觉科学这样的科学领域始终依靠心理物理学的方法和程序,但是现在,机器学习研究人员对它们的越来越多,通过在生物学和人工感知之间扩大重叠\ cite \ cite {rojas2011automation {scheireratom,scheirer2014Perceptial2014Perceptual,Escalera2014ChaleAr2014Chalearearearearearnnag,Zhangy2018Agic, grieggs2021measuring}。由行为测量所指导的机器感知,而不是仅限于任意分配人类标签的指导,具有为人工智能进一步进步的巨大潜力。
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研究深度学习的鲁棒性的一个主要挑战是定义了给定神经网络(NN)不变的``毫无意义''扰动集。关于鲁棒性的大多数工作隐含地将人作为参考模型来定义这种扰动。我们的工作通过使用另一个参考NN来定义给定的NN应该不变,从而使对任何NN的依赖概述对任何NN的依赖。这使得衡量鲁棒性等同于衡量两个NN共享不稳定的程度,我们提出了一种称为搅拌的措施。搅拌重新调整现有的表示相似性措施,使其适合衡量共享的不稳定。使用我们的度量,我们能够深入了解共享的不断增长,随着重量初始化,体系结构,损失功能和培训数据集的变化如何变化。我们的实现可在:\ url {https://github.com/nvedant07/stir}中获得。
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