我们考虑在线学习设置中的顺序稀疏子集选择的问题。假设集合$ [n] $由$ n $不同的元素组成。在$ t^{\ text {th}} $ round上,单调奖励函数$ f_t:2^{[n]} \ to \ m athbb {r} _+,$,为每个子集分配非阴性奖励$ [n],向学习者透露$。学习者在奖励功能$ f_t $ for $ f_t $之前(k \ leq n)$选择(也许是随机的)子集$ s_t \ subseteq [n] $ of $ k $元素。由于选择的结果,学习者在$ t^{\ text {th}} $ round上获得了$ f_t(s_t)$的奖励。学习者的目标是设计一项在线子集选择策略,以最大程度地提高其在给定时间范围内产生的预期累积奖励。在这方面,我们提出了一种称为Score的在线学习策略(带有Core的子集选择),以解决大量奖励功能的问题。拟议的分数策略基于$ \ alpha $ core的新概念,这是对合作游戏理论文献中核心概念的概括。我们根据一个名为$ \ alpha $的遗憾的新绩效指标为分数政策建立学习保证。在这个新的指标中,与在线政策相比,离线基准的功能适当增强。我们给出了几个说明性示例,以表明可以使用分数策略有效地学习包括子模型在内的广泛奖励功能。我们还概述了如何在半伴奏反馈模型下使用得分策略,并以许多开放问题的总结结束了论文。
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随着视频录制的越来越多的流行率,对可以维护记录人员隐私的工具的需求日益增长。在本文中,我们定义了一种使用光学角色识别(OCR)和自然语言处理(NLP)技术的组合从视频中编辑个人身份文本的方法。当与不同的OCR模型,特别是Tesseract和Google Cloud Vision(GCV)的OCR系统时,我们检查了这种方法的相对性能。对于拟议的方法,GCV的性能以准确性和速度显着高于Tesseract。最后,我们探讨了现实世界应用中这两种模型的优势和缺点。
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在智能交通系统中,交通拥堵异常检测至关重要。运输机构的目标有两个方面:监视感兴趣领域的一般交通状况,并在异常拥堵状态下定位道路细分市场。建模拥塞模式可以实现这些目标,以实现全市道路的目标,相当于学习多元时间序列(MTS)的分布。但是,现有作品要么不可伸缩,要么无法同时捕获MTS中的空间信息。为此,我们提出了一个由数据驱动的生成方法组成的原则性和全面的框架,该方法可以执行可拖动的密度估计来检测流量异常。我们的方法在特征空间中的第一群段段,然后使用条件归一化流以在无监督的设置下在群集级别识别异常的时间快照。然后,我们通过在异常群集上使用内核密度估计器来识别段级别的异常。关于合成数据集的广泛实验表明,我们的方法在召回和F1得分方面显着优于几种最新的拥塞异常检测和诊断方法。我们还使用生成模型来采样标记的数据,该数据可以在有监督的环境中训练分类器,从而减轻缺乏在稀疏设置中进行异常检测的标记数据。
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每年有超过500万五岁以下的儿童死于大部分可预防或可治疗的医疗状况,而在疫苗接种率低的欠发达国家中,死亡人数大部分大部分发生。联合国可持续发展目标之一(SDG 3)旨在结束五岁以下的新生儿和儿童的可预防死亡。我们专注于尼日利亚,在尼日利亚,婴儿死亡率令人震惊。我们与尼日利亚的大型非营利组织Helpmum合作设计和优化了不确定性下的异质健康干预措施的分配,以增加疫苗接种的吸收,这是尼日利亚的首次此类合作。我们的框架,顾问:AI驱动的疫苗接种干预优化器基于整数线性程序,该计划旨在最大程度地提高成功疫苗接种的累积概率。我们的优化公式在实践中是棘手的。我们提出了一种启发式方法,使我们能够解决现实世界中用例的问题。我们还为启发式方法提出了理论界限。最后,我们表明,通过实验评估,所提出的方法在疫苗接种方面优于基线方法。 Helpmum目前正在计划基于我们在最大的尼日利亚城市部署的方法,这将是该国AI驱动的疫苗接种吸收计划的首次部署,并希望为其他数据驱动计划铺平道路改善尼日利亚的健康状况。
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应急响应高度依赖事件报告的时间。不幸的是,接收事故报告的传统方法(例如,在美国拨打911)的时间延迟。 Waze等众包平台为早期识别事故提供了机会。然而,由于与此类数据相关的噪声和不确定性的挑战,从众包数据流中的检测事件是困难的。此外,简单地通过检测精度优化可以损害推断的空间 - 时间定位,从而使得现实世界部署的这种方法不可行。本文介绍了采用众群数据作为征集数据作为征用数据的新的问题配方和解决方案方法,以应急响应管理作为案例研究。所提出的方法CROME(众包多目标事件检测)量化了事件分类(例如,F1得分)的性能度量与模型从业者的要求之间的关系(例如,1公里。入射检测的半径)。首先,我们展示了众包报告,地面真实历史数据和其他相关决定因素,如交通和天气,可以在卷积神经网络(CNN)架构中一起使用,以便早期检测紧急事故。然后,我们使用Pareto优化的方法来优化CNN的输出,以便以从业者为中心的参数来平衡检测精度和空间 - 时间本地化。最后,我们展示了这种方法使用来自美国纳什维尔的Waze和交通事故报告的众群数据的适用性。我们的实验表明,所提出的方法优于事件检测的现有方法,同时优化现实世界部署和可用性的需求。
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在过去的五十年中,研究人员已经开发了设计和改进了应急响应管理(ERM)系统的统计,数据驱动,分析和算法方法。该问题已被认为是本质上的困难,并且构成了不确定性下的时空决策,这在文献中已经解决了不同的假设和方法。该调查提供了对这些方法的详细审查,重点关注有关四个子流程的关键挑战和问题:(a)事件预测,(b)入射检测,(c)资源分配,和(c)计算机辅助调度紧急响应。我们突出了该领域前后工作的优势和缺点,并探讨了不同建模范式之间的相似之处和差异。我们通过说明这种复杂领域未来研究的开放挑战和机会的结论。
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Coronary Computed Tomography Angiography (CCTA) provides information on the presence, extent, and severity of obstructive coronary artery disease. Large-scale clinical studies analyzing CCTA-derived metrics typically require ground-truth validation in the form of high-fidelity 3D intravascular imaging. However, manual rigid alignment of intravascular images to corresponding CCTA images is both time consuming and user-dependent. Moreover, intravascular modalities suffer from several non-rigid motion-induced distortions arising from distortions in the imaging catheter path. To address these issues, we here present a semi-automatic segmentation-based framework for both rigid and non-rigid matching of intravascular images to CCTA images. We formulate the problem in terms of finding the optimal \emph{virtual catheter path} that samples the CCTA data to recapitulate the coronary artery morphology found in the intravascular image. We validate our co-registration framework on a cohort of $n=40$ patients using bifurcation landmarks as ground truth for longitudinal and rotational registration. Our results indicate that our non-rigid registration significantly outperforms other co-registration approaches for luminal bifurcation alignment in both longitudinal (mean mismatch: 3.3 frames) and rotational directions (mean mismatch: 28.6 degrees). By providing a differentiable framework for automatic multi-modal intravascular data fusion, our developed co-registration modules significantly reduces the manual effort required to conduct large-scale multi-modal clinical studies while also providing a solid foundation for the development of machine learning-based co-registration approaches.
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The Information Bottleneck theory provides a theoretical and computational framework for finding approximate minimum sufficient statistics. Analysis of the Stochastic Gradient Descent (SGD) training of a neural network on a toy problem has shown the existence of two phases, fitting and compression. In this work, we analyze the SGD training process of a Deep Neural Network on MNIST classification and confirm the existence of two phases of SGD training. We also propose a setup for estimating the mutual information for a Deep Neural Network through Variational Inference.
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Modern telecom systems are monitored with performance and system logs from multiple application layers and components. Detecting anomalous events from these logs is key to identify security breaches, resource over-utilization, critical/fatal errors, etc. Current supervised log anomaly detection frameworks tend to perform poorly on new types or signatures of anomalies with few or unseen samples in the training data. In this work, we propose a meta-learning-based log anomaly detection framework (LogAnMeta) for detecting anomalies from sequence of log events with few samples. LoganMeta train a hybrid few-shot classifier in an episodic manner. The experimental results demonstrate the efficacy of our proposed method
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Complex and contact-rich robotic manipulation tasks, particularly those that involve multi-fingered hands and underactuated object manipulation, present a significant challenge to any control method. Methods based on reinforcement learning offer an appealing choice for such settings, as they can enable robots to learn to delicately balance contact forces and dexterously reposition objects without strong modeling assumptions. However, running reinforcement learning on real-world dexterous manipulation systems often requires significant manual engineering. This negates the benefits of autonomous data collection and ease of use that reinforcement learning should in principle provide. In this paper, we describe a system for vision-based dexterous manipulation that provides a "programming-free" approach for users to define new tasks and enable robots with complex multi-fingered hands to learn to perform them through interaction. The core principle underlying our system is that, in a vision-based setting, users should be able to provide high-level intermediate supervision that circumvents challenges in teleoperation or kinesthetic teaching which allow a robot to not only learn a task efficiently but also to autonomously practice. Our system includes a framework for users to define a final task and intermediate sub-tasks with image examples, a reinforcement learning procedure that learns the task autonomously without interventions, and experimental results with a four-finger robotic hand learning multi-stage object manipulation tasks directly in the real world, without simulation, manual modeling, or reward engineering.
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