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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Artificial Intelligence (AI) has become commonplace to solve routine everyday tasks. Because of the exponential growth in medical imaging data volume and complexity, the workload on radiologists is steadily increasing. We project that the gap between the number of imaging exams and the number of expert radiologist readers required to cover this increase will continue to expand, consequently introducing a demand for AI-based tools that improve the efficiency with which radiologists can comfortably interpret these exams. AI has been shown to improve efficiency in medical-image generation, processing, and interpretation, and a variety of such AI models have been developed across research labs worldwide. However, very few of these, if any, find their way into routine clinical use, a discrepancy that reflects the divide between AI research and successful AI translation. To address the barrier to clinical deployment, we have formed MONAI Consortium, an open-source community which is building standards for AI deployment in healthcare institutions, and developing tools and infrastructure to facilitate their implementation. This report represents several years of weekly discussions and hands-on problem solving experience by groups of industry experts and clinicians in the MONAI Consortium. We identify barriers between AI-model development in research labs and subsequent clinical deployment and propose solutions. Our report provides guidance on processes which take an imaging AI model from development to clinical implementation in a healthcare institution. We discuss various AI integration points in a clinical Radiology workflow. We also present a taxonomy of Radiology AI use-cases. Through this report, we intend to educate the stakeholders in healthcare and AI (AI researchers, radiologists, imaging informaticists, and regulators) about cross-disciplinary challenges and possible solutions.
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Image analysis technologies empowered by artificial intelligence (AI) have proved images and videos to be an opportune source of data to learn about humpback whale (Megaptera novaeangliae) population sizes and dynamics. With the advent of social media, platforms such as YouTube present an abundance of video data across spatiotemporal contexts documenting humpback whale encounters from users worldwide. In our work, we focus on automating the classification of YouTube videos as relevant or irrelevant based on whether they document a true humpback whale encounter or not via deep learning. We use a CNN-RNN architecture pretrained on the ImageNet dataset for classification of YouTube videos as relevant or irrelevant. We achieve an average 85.7% accuracy, and 84.7% (irrelevant)/ 86.6% (relevant) F1 scores using five-fold cross validation for evaluation on the dataset. We show that deep learning can be used as a time-efficient step to make social media a viable source of image and video data for biodiversity assessments.
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本文介绍了经典懒惰的概率路线图算法(Lazy PRM)的修订,该算法是由配对PRM和一种新颖的分支和切割(BC)算法产生的。切割是动态生成的约束,这些约束在PRM选择的几何图上施加的最低成本路径。削减消除无法映射到满足适当定义运动学约束的平滑计划中的路径。我们通过在最低成本路径中将花键拟合到顶点来生成候选平滑计划。使用最近提出的算法对计划进行了验证,该算法将它们映射到有限的痕迹中,而无需选择固定的离散步骤。痕量元素准确地描述了计划交叉约束边界何时模拟算术精度。我们使用我们最近提出的谷仓基准的方法评估了几个计划者,我们报告了方法可扩展性的证据。
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人类仍在执行许多高精度(DIS)任务,而这是自动化的理想机会。本文提供了一个框架,该框架使非专家的人类操作员能够教机器人手臂执行复杂的精确任务。该框架使用可变的笛卡尔阻抗控制器来执行从动力学人类示范中学到的轨迹。可以给出反馈以进行交互重塑或加快原始演示。董事会本地化是通过对任务委员会位置的视觉估算来完成的,并通过触觉反馈进行了完善。我们的框架在机器人基准拆卸挑战上进行了测试,该机器人必须执行复杂的精确任务,例如关键插入。结果显示每个操纵子任务的成功率很高,包括盒子中新型姿势的情况。还进行了消融研究以评估框架的组成部分。
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我们提出了X-NERF,这是一种基于神经辐射场公式,从具有不同光谱敏感性的相机捕获的跨光谱场景表示的新颖方法,给出了从具有不同光谱灵敏度的相机捕获的图像。X-NERF在训练过程中优化了整个光谱的相机姿势,并利用归一化的跨设备坐标(NXDC)从任意观点呈现不同模态的图像,这些观点是对齐的,并以相同的分辨率对齐。在16个前面的场景上进行的实验,具有颜色,多光谱和红外图像,证实了X-NERF在建模跨光谱场景表示方面的有效性。
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训练有素的神经网络的性能至关重要。加上深度学习模型的不断增长的规模,这种观察激发了对学习稀疏模型的广泛研究。在这项工作中,我们专注于控制稀疏学习时的稀疏水平的任务。基于稀疏性惩罚的现有方法涉及对罚款因素的昂贵反复试验调整,因此缺乏直接控制所得模型的稀疏性。作为响应,我们采用了一个约束的公式:使用Louizos等人提出的栅极机制。 (2018年),我们制定了一个受约束的优化问题,其中稀疏以训练目标和所需的稀疏目标以端到端的方式指导。使用WIDERESNET和RESNET {18,50}模型进行了CIFAR-10/100,Tinyimagenet和ImageNet的实验验证了我们的提案的有效性,并证明我们可以可靠地实现预定的稀疏目标,而不会损害预测性能。
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隐式神经表示(INR)的进步已经激发了对域 - 不足的压缩技术的研究。这些方法训练神经网络以近似对象,然后存储训练有素的模型的权重。例如,给定图像,训练网络以学习从像素位置到RGB值的映射。在本文中,我们提出了L $ _0 $ ONIE,这是硬币压缩方法的稀疏限制扩展。稀疏性可以利用过度参数化网络的更快学习,同时保留较小模型的理想压缩率。此外,我们的约束配方可确保最终模型尊重预定的压缩率,分配昂贵的体系结构搜索的需求。
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增强学习(RL)是多能管理系统的有前途的最佳控制技术。它不需要先验模型 - 降低了前期和正在进行的项目特定工程工作,并且能够学习基础系统动力学的更好表示。但是,香草RL不能提供约束满意度的保证 - 导致其在安全至关重要的环境中产生各种不安全的互动。在本文中,我们介绍了两种新颖的安全RL方法,即SafeFallback和Afvafe,其中安全约束配方与RL配方脱钩,并且提供了硬构成满意度,可以保证在培训(探索)和开发过程中(近距离) )最佳政策。在模拟的多能系统案例研究中,我们已经表明,这两种方法均与香草RL基准相比(94,6%和82,8%,而35.5%)和香草RL基准相比明显更高的效用(即有用的政策)开始。提出的SafeFallback方法甚至可以胜过香草RL基准(102,9%至100%)。我们得出的结论是,这两种方法都是超越RL的安全限制处理技术,正如随机代理所证明的,同时仍提供坚硬的保证。最后,我们向I.A.提出了基本的未来工作。随着更多数据可用,改善约束功能本身。
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我们介绍了一种新的算法,基于回归的监督学习(RSL),用于每个实例神经网络(NN)为经典计划问题定义的启发式功能。RSL使用回归来选择与目标不同距离的相关状态集。然后,RSL制定了一个监督的学习问题,以获取定义NN启发式的参数,并使用标记为目标状态的精确或估计距离的选定状态。我们的实验研究表明,RSL在覆盖范围内优于先前的经典计划NN启发式功能,同时需要减少两个数量级的训练时间。
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