预测流感病毒引起的住院治疗对于公共卫生计划至关重要,因此医院可以为大量患者做好准备。在流感季节中实时使用了许多预测方法,并提交给疾病预防控制中心进行公共交流。预测模型范围从机械模型和自动回归模型到机器学习模型。我们假设我们可以通过使用多个机械模型生成潜在的轨迹并使用机器学习来学习如何将这些轨迹结合到改进的预测中,从而改善预测。我们提出了一种树木合奏模型设计,该设计利用基线模型Sikjalpha的各个预测指标来提高其性能。每个预测因子都是通过更改一组超参数来生成的。我们将为Flusight Challenge(2022)部署的前瞻性预测与所有其他提交的方法进行了比较。我们的方法是完全自动化的,不需要任何手动调整。我们证明,基于森林的随机方法能够根据平均绝对误差,覆盖范围和加权间隔得分来改善单个预测因子的预测。我们的方法根据平均绝对误差和基于当前季节所有每周提交的平均值(2022)的平均值来优于所有其他模型。随机森林(通过对树木的分析)的解释能力使我们能够深入了解其如何改善单个预测因子。
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随着Covid-19影响每个国家的全球和改变日常生活,预测疾病的传播的能力比任何先前的流行病更重要。常规的疾病 - 展开建模方法,隔间模型,基于对病毒的扩散的时空均匀性的假设,这可能导致预测到欠低,特别是在高空间分辨率下。本文采用替代技术 - 时空机器学习方法。我们提出了Covid-LSTM,一种基于长期短期内存深度学习架构的数据驱动模型,用于预测Covid-19在美国县级的发病率。我们使用每周数量的新阳性案例作为时间输入,以及来自Facebook运动和连通数据集的手工工程空间特征,以捕捉时间和空间的疾病的传播。 Covid-LSTM在我们的17周的评估期间优于Covid-19预测集线器集合模型(CovidHub-Ensemble),使其首先比一个或多个预测期更准确的模型。在4周的预测地平线上,我们的型号平均每县平均50例比CovidHub-Ensemble更准确。我们强调,在Covid-19之前,在Covid-19之前的数据驱动预测的未充分利用疾病传播的预测可能是由于以前疾病缺乏足够的数据,除了最近的时尚预测方法的机器学习方法的进步。我们讨论了更广泛的数据驱动预测的障碍,以及将来将使用更多的基于学习的模型。
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Platelet products are both expensive and have very short shelf lives. As usage rates for platelets are highly variable, the effective management of platelet demand and supply is very important yet challenging. The primary goal of this paper is to present an efficient forecasting model for platelet demand at Canadian Blood Services (CBS). To accomplish this goal, four different demand forecasting methods, ARIMA (Auto Regressive Moving Average), Prophet, lasso regression (least absolute shrinkage and selection operator) and LSTM (Long Short-Term Memory) networks are utilized and evaluated. We use a large clinical dataset for a centralized blood distribution centre for four hospitals in Hamilton, Ontario, spanning from 2010 to 2018 and consisting of daily platelet transfusions along with information such as the product specifications, the recipients' characteristics, and the recipients' laboratory test results. This study is the first to utilize different methods from statistical time series models to data-driven regression and a machine learning technique for platelet transfusion using clinical predictors and with different amounts of data. We find that the multivariate approaches have the highest accuracy in general, however, if sufficient data are available, a simpler time series approach such as ARIMA appears to be sufficient. We also comment on the approach to choose clinical indicators (inputs) for the multivariate models.
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COVID-19的大流行提出了对多个领域决策者的流行预测的重要性,从公共卫生到整个经济。虽然预测流行进展经常被概念化为类似于天气预测,但是它具有一些关键的差异,并且仍然是一项非平凡的任务。疾病的传播受到人类行为,病原体动态,天气和环境条件的多种混杂因素的影响。由于政府公共卫生和资助机构的倡议,捕获以前无法观察到的方面的丰富数据来源的可用性增加了研究的兴趣。这尤其是在“以数据为中心”的解决方案上进行的一系列工作,这些解决方案通过利用非传统数据源以及AI和机器学习的最新创新来增强我们的预测能力的潜力。这项调查研究了各种数据驱动的方法论和实践进步,并介绍了一个概念框架来导航它们。首先,我们列举了与流行病预测相关的大量流行病学数据集和新的数据流,捕获了各种因素,例如有症状的在线调查,零售和商业,流动性,基因组学数据等。接下来,我们将讨论关注最近基于数据驱动的统计和深度学习方法的方法和建模范式,以及将机械模型知识域知识与统计方法的有效性和灵活性相结合的新型混合模型类别。我们还讨论了这些预测系统的现实部署中出现的经验和挑战,包括预测信息。最后,我们重点介绍了整个预测管道中发现的一些挑战和开放问题。
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准确可靠的流行病预测是对公共卫生规划和疾病缓解影响的重要问题。大多数现有的疫情预测模型无视不确定性量化,导致错误校准的预测。近期神经模型的作品,用于不确定感知的时序预测也有几个限制;例如很难在贝叶斯NNS中指定有意义的前瞻,而Deep Leaseming的方法在实践中是计算昂贵的。在本文中,我们填补了这个重要的差距。我们将预测任务模拟为概率生成过程,并提出了一种名为EPIFNP的功能神经过程模型,其直接模拟预测值的概率密度。 EPIFNP利用动态随机相关图来模拟非参数方式之间序列之间的相关性,并设计不同的随机潜变量以捕获不同视角的功能不确定性。我们在实时流感预测环境中的广泛实验表明,EPIFNP在准确性和校准度量中显着优于先前的最先进模型,精度高达2.5倍,校准2.4倍。此外,由于其生成过程的性质,EPIFNP了解当前季节与历史季节类似模式之间的关系,从而实现可解释的预测。超越疫情预测,EPIFNP可以是独立的利益,以便在深度顺序模型中推进预测性分析的深度顺序模型
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Algorithms that involve both forecasting and optimization are at the core of solutions to many difficult real-world problems, such as in supply chains (inventory optimization), traffic, and in the transition towards carbon-free energy generation in battery/load/production scheduling in sustainable energy systems. Typically, in these scenarios we want to solve an optimization problem that depends on unknown future values, which therefore need to be forecast. As both forecasting and optimization are difficult problems in their own right, relatively few research has been done in this area. This paper presents the findings of the ``IEEE-CIS Technical Challenge on Predict+Optimize for Renewable Energy Scheduling," held in 2021. We present a comparison and evaluation of the seven highest-ranked solutions in the competition, to provide researchers with a benchmark problem and to establish the state of the art for this benchmark, with the aim to foster and facilitate research in this area. The competition used data from the Monash Microgrid, as well as weather data and energy market data. It then focused on two main challenges: forecasting renewable energy production and demand, and obtaining an optimal schedule for the activities (lectures) and on-site batteries that lead to the lowest cost of energy. The most accurate forecasts were obtained by gradient-boosted tree and random forest models, and optimization was mostly performed using mixed integer linear and quadratic programming. The winning method predicted different scenarios and optimized over all scenarios jointly using a sample average approximation method.
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Producing high-quality forecasts of key climate variables such as temperature and precipitation on subseasonal time scales has long been a gap in operational forecasting. Recent studies have shown promising results using machine learning (ML) models to advance subseasonal forecasting (SSF), but several open questions remain. First, several past approaches use the average of an ensemble of physics-based forecasts as an input feature of these models. However, ensemble forecasts contain information that can aid prediction beyond only the ensemble mean. Second, past methods have focused on average performance, whereas forecasts of extreme events are far more important for planning and mitigation purposes. Third, climate forecasts correspond to a spatially-varying collection of forecasts, and different methods account for spatial variability in the response differently. Trade-offs between different approaches may be mitigated with model stacking. This paper describes the application of a variety of ML methods used to predict monthly average precipitation and two meter temperature using physics-based predictions (ensemble forecasts) and observational data such as relative humidity, pressure at sea level, or geopotential height, two weeks in advance for the whole continental United States. Regression, quantile regression, and tercile classification tasks using linear models, random forests, convolutional neural networks, and stacked models are considered. The proposed models outperform common baselines such as historical averages (or quantiles) and ensemble averages (or quantiles). This paper further includes an investigation of feature importance, trade-offs between using the full ensemble or only the ensemble average, and different modes of accounting for spatial variability.
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在这项工作中,我们评估了人口模型和机器学习模型的合奏,以预测COVID-19大流行的不久的将来的演变,并在西班牙有特殊的用例。我们仅依靠开放和公共数据集,将发生率,疫苗接种,人类流动性和天气数据融合来喂养我们的机器学习模型(随机森林,梯度增强,K-Nearest邻居和内核岭回归)。我们使用发病率数据来调整经典人群模型(Gompertz,Logistic,Richards,Bertalanffy),以便能够更好地捕获数据的趋势。然后,我们整合了这两个模型家族,以获得更强大,更准确的预测。此外,我们已经观察到,当我们添加新功能(疫苗,移动性,气候条件)时,使用机器学习模型获得的预测有所改善,使用Shapley添加说明值分析了每个功能的重要性。就像在任何其他建模工作中一样,数据和预测质量都有多个局限性,因此必须从关键的角度看待它们,如我们在文本中所讨论的那样。我们的工作得出的结论是,这些模型的合奏使用可以改善单个预测(仅使用机器学习模型或仅使用人口模型),并且在由于缺乏相关数据而无法使用隔室模型的情况下,可以谨慎地应用。
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本文介绍了一个集成预测方法,通过减少特征和模型选择假设来显示M4Competitiation数据集的强劲结果,称为甜甜圈(不利用人为假设)。我们的假设减少,主要由自动生成的功能和更多样化的集合模型组成,显着优于Montero-Manso等人的统计特征的集合方法FForma。 (2020)。此外,我们用长短期内存网络(LSTM)AutoEncoder调查特征提取,并发现此类特征包含传统统计特征方法未捕获的重要信息。合奏加权模型使用LSTM功能和统计功能准确地结合模型。特征重要性和交互的分析表明,单独的统计数据的LSTM特征略有优势。聚类分析表明,不同的基本LSTM功能与大多数统计特征不同。我们还发现,通过使用新模型增强合奏来增加加权模型的解决方案空间是加权模型学习使用的东西,解释了准确性的一部分。最后,我们为集合的最佳组合和选择提供了正式的前后事实分析,通过M4数据集的线性优化量化差异。我们还包括一个简短的证据,模型组合优于模型选择,后者。
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PV power forecasting models are predominantly based on machine learning algorithms which do not provide any insight into or explanation about their predictions (black boxes). Therefore, their direct implementation in environments where transparency is required, and the trust associated with their predictions may be questioned. To this end, we propose a two stage probabilistic forecasting framework able to generate highly accurate, reliable, and sharp forecasts yet offering full transparency on both the point forecasts and the prediction intervals (PIs). In the first stage, we exploit natural gradient boosting (NGBoost) for yielding probabilistic forecasts, while in the second stage, we calculate the Shapley additive explanation (SHAP) values in order to fully comprehend why a prediction was made. To highlight the performance and the applicability of the proposed framework, real data from two PV parks located in Southern Germany are employed. Comparative results with two state-of-the-art algorithms, namely Gaussian process and lower upper bound estimation, manifest a significant increase in the point forecast accuracy and in the overall probabilistic performance. Most importantly, a detailed analysis of the model's complex nonlinear relationships and interaction effects between the various features is presented. This allows interpreting the model, identifying some learned physical properties, explaining individual predictions, reducing the computational requirements for the training without jeopardizing the model accuracy, detecting possible bugs, and gaining trust in the model. Finally, we conclude that the model was able to develop complex nonlinear relationships which follow known physical properties as well as human logic and intuition.
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预测组合在预测社区中蓬勃发展,近年来,已经成为预测研究和活动主流的一部分。现在,由单个(目标)系列产生的多个预测组合通过整合来自不同来源收集的信息,从而提高准确性,从而减轻了识别单个“最佳”预测的风险。组合方案已从没有估计的简单组合方法演变为涉及时间变化的权重,非线性组合,组件之间的相关性和交叉学习的复杂方法。它们包括结合点预测和结合概率预测。本文提供了有关预测组合的广泛文献的最新评论,并参考可用的开源软件实施。我们讨论了各种方法的潜在和局限性,并突出了这些思想如何随着时间的推移而发展。还调查了有关预测组合实用性的一些重要问题。最后,我们以当前的研究差距和未来研究的潜在见解得出结论。
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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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提出了一种使用天气数据实时太阳生成预测的新方法,同时提出了既有空间结构依赖性的依赖。随着时间的推移,观察到的网络被预测到较低维度的表示,在该表示的情况下,在推理阶段使用天气预报时,使用各种天气测量来训练结构化回归模型。从国家太阳辐射数据库获得的德克萨斯州圣安东尼奥地区的288个地点进行了实验。该模型预测具有良好精度的太阳辐照度(夏季R2 0.91,冬季为0.85,全球模型为0.89)。随机森林回归者获得了最佳准确性。进行了多个实验来表征缺失数据的影响和不同的时间范围的影响,这些范围提供了证据表明,新算法不仅在随机的情况下,而且在机制是空间和时间上都丢失的数据是可靠的。
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预测经济的短期动态 - 对经济代理商决策过程的重要意见 - 经常在线性模型中使用滞后指标。这通常在正常时期就足够了,但在危机期间可能不足。本文旨在证明,在非线性机器学习方法的帮助下,非传统和及时的数据(例如零售和批发付款)可以为决策者提供复杂的模型,以准确地估算几乎实时的关键宏观经济指标。此外,我们提供了一组计量经济学工具,以减轻机器学习模型中的过度拟合和解释性挑战,以提高其政策使用的有效性。我们的模型具有付款数据,非线性方法和量身定制的交叉验证方法,有助于提高宏观经济的启示准确性高达40 \% - 在COVID-19期间的增长较高。我们观察到,付款数据对经济预测的贡献很小,在低和正常增长期间是线性的。但是,在强年或正增长期间,付款数据的贡献很大,不对称和非线性。
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杂交和集合学习技术是改善预测方法的预测能力的流行模型融合技术。通过有限的研究,将这两种有前途的方法结合在一起,本文着重于不同合奏的基础模型池中指数平滑的旋转神经网络(ES-RNN)的实用性。我们将某些最先进的结合技术和算术模型平均作为基准进行比较。我们对M4预测数据集进行了100,000个时间序列,结果表明,基于特征的预测模型平均(FFORFORA)平均是与ES-RNN的晚期数据融合的最佳技术。但是,考虑到M4的每日数据子集,堆叠是处理所有基本模型性能相似的情况下唯一成功的合奏。我们的实验结果表明,与N-Beats作为基准相比,我们达到了艺术的预测结果。我们得出的结论是,模型平均比模型选择和堆叠策略更强大。此外,结果表明,提高梯度对于实施合奏学习策略是优越的。
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This paper proposes a data and Machine Learning-based forecasting solution for the Telecommunications network-rollout planning problem. Milestone completion-time estimation is crucial to network-rollout planning; accurate estimates enable better crew utilisation and optimised cost of materials and logistics. Using historical data of milestone completion times, a model needs to incorporate domain knowledge, handle noise and yet be interpretable to project managers. This paper proposes partition-based regression models that incorporate data-driven statistical models within each partition, as a solution to the problem. Benchmarking experiments demonstrate that the proposed approach obtains competitive to better performance, at a small fraction of the model complexity of the best alternative approach based on Gradient Boosting. Experiments also demonstrate that the proposed approach is effective for both short and long-range forecasts. The proposed idea is applicable in any context requiring time-series regression with noisy and attributed data.
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本文调查了股票回购,特别是分享回购公告。它解决了如何识别此类公告,股票回购的超额回报以及股票回购公告后的回报的预测。我们说明了两种NLP方法,用于自动检测股票回购公告。即使有少量的培训数据,我们也可以达到高达90%的准确性。该论文利用这些NLP方法生成一个由57,155个股票回购公告组成的大数据集。通过分析该数据集,本论文的目的是表明大多数宣布回购的公司的大多数公司都表现不佳。但是,少数公司的表现极大地超过了MSCI世界。当查看所有公司的平均值时,这种重要的表现过高会导致净收益。如果根据公司的规模调整了基准指数,则平均表现过高,并且大多数表现不佳。但是,发现宣布股票回购的公司至少占其市值的1%,即使使用调整后的基准,也平均交付了显着的表现。还发现,在危机时期宣布股票回购的公司比整个市场更好。此外,生成的数据集用于训练72个机器学习模型。通过此,它能够找到许多可以达到高达77%并产生大量超额回报的策略。可以在六个不同的时间范围内改善各种性能指标,并确定明显的表现。这是通过训练多个模型的不同任务和时间范围以及结合这些不同模型的方法来实现的,从而通过融合弱学习者来产生重大改进,以创造一个强大的学习者。
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我们介绍了数据科学预测生命周期中各个阶段开发和采用自动化的技术和文化挑战的说明概述,从而将重点限制为使用结构化数据集的监督学习。此外,我们回顾了流行的开源Python工具,这些工具实施了针对自动化挑战的通用解决方案模式,并突出了我们认为进步仍然需要的差距。
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The cyber-physical convergence is opening up new business opportunities for industrial operators. The need for deep integration of the cyber and the physical worlds establishes a rich business agenda towards consolidating new system and network engineering approaches. This revolution would not be possible without the rich and heterogeneous sources of data, as well as the ability of their intelligent exploitation, mainly due to the fact that data will serve as a fundamental resource to promote Industry 4.0. One of the most fruitful research and practice areas emerging from this data-rich, cyber-physical, smart factory environment is the data-driven process monitoring field, which applies machine learning methodologies to enable predictive maintenance applications. In this paper, we examine popular time series forecasting techniques as well as supervised machine learning algorithms in the applied context of Industry 4.0, by transforming and preprocessing the historical industrial dataset of a packing machine's operational state recordings (real data coming from the production line of a manufacturing plant from the food and beverage domain). In our methodology, we use only a single signal concerning the machine's operational status to make our predictions, without considering other operational variables or fault and warning signals, hence its characterization as ``agnostic''. In this respect, the results demonstrate that the adopted methods achieve a quite promising performance on three targeted use cases.
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在环境中,从天气预报到财务预测的政治预测,未来二元成果的概率估计通常随着时间的推移而发展。例如,随着新信息可用的时间,特定日期的估计可能性在特定日变化。鉴于这种概率路径的集合,我们介绍了一个贝叶斯框架 - 我们称之为高斯潜在信息鞅,或粘合 - 用于模拟动态预测的结构随着时间的推移。例如,假设一个星期下雨的可能性是50%,并考虑两个假设情景。首先,人们希望预测同样可能成为明天的25%或75%;第二,人们预计预测将在未来几天保持不变。一个时间敏感的决策者可以在后一种情况下立即选择一个行动方案,但可能会推迟他们在前者的决定,知道新信息迫在眉睫。我们通过假设根据信息流的潜在进程的预测更新来模拟这些轨迹,从历史数据推断出来。与时间序列分析的一般方法相比,这种方法保留了诸如Martingale结构的概率路径的重要属性,以及适当的挥发性,并且更好地量化了概率路径周围的未来不确定性。我们表明光泽优于三种流行的基线方法,产生了由三种不同度量测量的更高估计的后验概率路径分布。通过阐明时间随着时间的推移来解除预测的动态结构,希望能帮助个人做出更明智的选择。
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