在本文中,我们提出了一种新的端到端方法,以优化能量性能以及大型建筑物的舒适性和空气质量,而无需任何装修工作。我们介绍了基于经常性神经网络的元模型,并训练了使用从模拟程序采样的数据库预测一般大类建筑物的行为。然后将该元模型部署在不同的框架中,并且使用两个真实建筑的特定数据校准其参数。通过使用CMA-ES算法比较从传感器获得的真实数据的比较来估计参数,通过使用CMA-ES算法,衍生免费优化过程。然后,使用NSGA-II多目标优化过程保持目标热舒适度和空气质量的同时优化能量消耗。数值实验说明了该元模型如何确保能效显着增益,高达近10%,同时计算比数值模型更具吸引力,并且足够灵活地适应若干类型的建筑物。
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预测基金绩效对投资者和基金经理都是有益的,但这是一项艰巨的任务。在本文中,我们测试了深度学习模型是否比传统统计技术更准确地预测基金绩效。基金绩效通常通过Sharpe比率进行评估,该比例代表了风险调整的绩效,以确保基金之间有意义的可比性。我们根据每月收益率数据序列数据计算了年度夏普比率,该数据的时间序列数据为600多个投资于美国上市大型股票的开放式共同基金投资。我们发现,经过现代贝叶斯优化训练的长期短期记忆(LSTM)和封闭式复发单元(GRUS)深度学习方法比传统统计量相比,预测基金的Sharpe比率更高。结合了LSTM和GRU的预测的合奏方法,可以实现所有模型的最佳性能。有证据表明,深度学习和结合能提供有希望的解决方案,以应对基金绩效预测的挑战。
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Energy consumption in buildings, both residential and commercial, accounts for approximately 40% of all energy usage in the U.S., and similar numbers are being reported from countries around the world. This significant amount of energy is used to maintain a comfortable, secure, and productive environment for the occupants. So, it is crucial that the energy consumption in buildings must be optimized, all the while maintaining satisfactory levels of occupant comfort, health, and safety. Recently, Machine Learning has been proven to be an invaluable tool in deriving important insights from data and optimizing various systems. In this work, we review the ways in which machine learning has been leveraged to make buildings smart and energy-efficient. For the convenience of readers, we provide a brief introduction of several machine learning paradigms and the components and functioning of each smart building system we cover. Finally, we discuss challenges faced while implementing machine learning algorithms in smart buildings and provide future avenues for research at the intersection of smart buildings and machine learning.
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A well-performing prediction model is vital for a recommendation system suggesting actions for energy-efficient consumer behavior. However, reliable and accurate predictions depend on informative features and a suitable model design to perform well and robustly across different households and appliances. Moreover, customers' unjustifiably high expectations of accurate predictions may discourage them from using the system in the long term. In this paper, we design a three-step forecasting framework to assess predictability, engineering features, and deep learning architectures to forecast 24 hourly load values. First, our predictability analysis provides a tool for expectation management to cushion customers' anticipations. Second, we design several new weather-, time- and appliance-related parameters for the modeling procedure and test their contribution to the model's prediction performance. Third, we examine six deep learning techniques and compare them to tree- and support vector regression benchmarks. We develop a robust and accurate model for the appliance-level load prediction based on four datasets from four different regions (US, UK, Austria, and Canada) with an equal set of appliances. The empirical results show that cyclical encoding of time features and weather indicators alongside a long-short term memory (LSTM) model offer the optimal performance.
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With the evolution of power systems as it is becoming more intelligent and interactive system while increasing in flexibility with a larger penetration of renewable energy sources, demand prediction on a short-term resolution will inevitably become more and more crucial in designing and managing the future grid, especially when it comes to an individual household level. Projecting the demand for electricity for a single energy user, as opposed to the aggregated power consumption of residential load on a wide scale, is difficult because of a considerable number of volatile and uncertain factors. This paper proposes a customized GRU (Gated Recurrent Unit) and Long Short-Term Memory (LSTM) architecture to address this challenging problem. LSTM and GRU are comparatively newer and among the most well-adopted deep learning approaches. The electricity consumption datasets were obtained from individual household smart meters. The comparison shows that the LSTM model performs better for home-level forecasting than alternative prediction techniques-GRU in this case. To compare the NN-based models with contrast to the conventional statistical technique-based model, ARIMA based model was also developed and benchmarked with LSTM and GRU model outcomes in this study to show the performance of the proposed model on the collected time series data.
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Explicitly accounting for uncertainties is paramount to the safety of engineering structures. Optimization which is often carried out at the early stage of the structural design offers an ideal framework for this task. When the uncertainties are mainly affecting the objective function, robust design optimization is traditionally considered. This work further assumes the existence of multiple and competing objective functions that need to be dealt with simultaneously. The optimization problem is formulated by considering quantiles of the objective functions which allows for the combination of both optimality and robustness in a single metric. By introducing the concept of common random numbers, the resulting nested optimization problem may be solved using a general-purpose solver, herein the non-dominated sorting genetic algorithm (NSGA-II). The computational cost of such an approach is however a serious hurdle to its application in real-world problems. We therefore propose a surrogate-assisted approach using Kriging as an inexpensive approximation of the associated computational model. The proposed approach consists of sequentially carrying out NSGA-II while using an adaptively built Kriging model to estimate the quantiles. Finally, the methodology is adapted to account for mixed categorical-continuous parameters as the applications involve the selection of qualitative design parameters as well. The methodology is first applied to two analytical examples showing its efficiency. The third application relates to the selection of optimal renovation scenarios of a building considering both its life cycle cost and environmental impact. It shows that when it comes to renovation, the heating system replacement should be the priority.
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电力是一种波动的电源,需要短期和长期的精力计划和资源管理。更具体地说,在短期,准确的即时能源消耗中,预测极大地提高了建筑物的效率,为采用可再生能源提供了新的途径。在这方面,数据驱动的方法,即基于机器学习的方法,开始优先于更传统的方法,因为它们不仅提供了更简化的部署方式,而且还提供了最新的结果。从这个意义上讲,这项工作应用和比较了几种深度学习算法,LSTM,CNN,CNN-LSTM和TCN的性能,在制造业内的一个真实测试中。实验结果表明,TCN是预测短期即时能源消耗的最可靠方法。
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评估能源转型和能源市场自由化对资源充足性的影响是一种越来越重要和苛刻的任务。能量系统的上升复杂性需要足够的能量系统建模方法,从而提高计算要求。此外,随着复杂性,同样调用概率评估和场景分析同样增加不确定性。为了充分和高效地解决这些各种要求,需要来自数据科学领域的新方法来加速当前方法。通过我们的系统文献综述,我们希望缩小三个学科之间的差距(1)电力供应安全性评估,(2)人工智能和(3)实验设计。为此,我们对所选应用领域进行大规模的定量审查,并制作彼此不同学科的合成。在其他发现之外,我们使用基于AI的方法和应用程序的AI方法和应用来确定电力供应模型的复杂安全性的元素,并作为未充分涵盖的应用领域的储存调度和(非)可用性。我们结束了推出了一种新的方法管道,以便在评估电力供应安全评估时充分有效地解决当前和即将到来的挑战。
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由于其高能量强度,建筑物在当前全球能源转型中发挥着重要作用。建筑模型是普遍无处不在的,因为在建筑物的每个阶段都需要它们,即设计,改装和控制操作。基于物理方程式的古典白盒式模型必然遵循物理规律,但其底层结构的具体设计可能会阻碍他们的表现力,从而阻碍他们的准确性。另一方面,黑匣子型号更适合捕获非线性建筑动态,因此通常可以实现更好的准确性,但它们需要大量的数据,并且可能不会遵循物理规律,这是神经网络特别常见的问题(NN)模型。为了抵消这种已知的概括问题,最近介绍了物理知识的NNS,研究人员在NNS的结构中介绍了以底层底层物理法律接地,并避免经典的NN概括问题。在这项工作中,我们介绍了一种新的物理信息的NN架构,被称为身体一致的NN(PCNN),其仅需要过去的运行数据并且没有工程开销,包括在并联运行到经典NN的线性模块中的先前知识。我们正式证明,这些网络是物理上一致的 - 通过设计甚至在看不见的数据 - 关于不同的控制输入和邻近区域的温度。我们在案例研究中展示了他们的表现,其中PCNN比3美元的古典物理型电阻电容模型更好地获得高达50美元的准确性。此外,尽管结构受到约束的结构,但PCNNS在验证数据上对古典NNS对古典NNS进行了类似的性能,使训练数据较少,并保留高表达性以解决泛化问题。
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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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超参数优化构成了典型的现代机器学习工作流程的很大一部分。这是由于这样一个事实,即机器学习方法和相应的预处理步骤通常只有在正确调整超参数时就会产生最佳性能。但是在许多应用中,我们不仅有兴趣仅仅为了预测精度而优化ML管道;确定最佳配置时,必须考虑其他指标或约束,从而导致多目标优化问题。由于缺乏知识和用于多目标超参数优化的知识和容易获得的软件实现,因此通常在实践中被忽略。在这项工作中,我们向读者介绍了多个客观超参数优化的基础知识,并激励其在应用ML中的实用性。此外,我们从进化算法和贝叶斯优化的领域提供了现有优化策略的广泛调查。我们说明了MOO在几个特定ML应用中的实用性,考虑了诸如操作条件,预测时间,稀疏,公平,可解释性和鲁棒性之类的目标。
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负载预测是能源行业中执行的一项重要任务,以帮助平衡供应并保持电网的稳定负载。随着供应过渡向不太可靠的可再生能源产生,智能电表将证明是促进这些预测任务的重要组成部分。但是,在隐私意识的消费者中,智能电表的采用率很低,这些消费者害怕侵犯其细粒度的消费数据。在这项工作中,我们建议并探索一种基于联合学习的方法(FL)方法,以分布式协作方式培训预测模型,同时保留基础数据的隐私。我们比较了两种方法:FL和聚集的变体FL+HC与非私有的,集中的学习方法和完全私人的本地化学习方法。在这些方法中,我们使用RMSE和计算效率测量模型性能。此外,我们建议FL策略之后是个性化步骤,并表明可以通过这样做可以提高模型性能。我们表明,FL+HC紧随其后的是个性化可以实现$ \ sim $ 5 \%的模型性能提高,而与本地化学习相比,计算$ \ sim $ 10倍。最后,我们提供有关私人汇总预测的建议,以构建私人端到端负载预测应用程序。
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HyperParameter Optimization(HPO)是一种确保机器学习(ML)算法最佳性能的必要步骤。已经开发了几种方法来执行HPO;其中大部分都集中在优化一个性能措施(通常是基于错误的措施),并且在这种单一目标HPO问题上的文献是巨大的。然而,最近似乎似乎侧重于同时优化多个冲突目标的算法。本文提出了对2014年至2020年的文献的系统调查,在多目标HPO算法上发布,区分了基于成逐的算法,Metamodel的算法以及使用两者混合的方法。我们还讨论了用于比较多目标HPO程序和今后的研究方向的质量指标。
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在早期设计阶段,应为所需室内环境质量(IEQ)进行太阳阴凉设计。这个领域可能非常具有挑战性和耗时需要专家,复杂的软件和大量的钱。本研究的主要目的是设计一个简单的工具来研究各种型号的太阳阴影,并在早期阶段更容易且更快地做出决定。数据库生成方法,人工智能和优化已被用于实现这一目标。该工具包括两个主要部分。预测用户所选模型的性能以及提出有效参数和2.向用户提出最佳预准备模型。在这方面,最初,具有可变参数的侧向升鞋盒模型是参数建模的,并且将五种常见的太阳阴影模型应用于空间。对于每个太阳阴影和没有阴影的状态,模拟了与日光和眩光,视图和初始成本有关的指标。本研究中生成的数据库包括87912个替代和六个计算的指标,引入优化的机器学习模型,包括神经网络,随机Forrest,支持向量回归和K最近邻居。根据结果​​,最准确和最快的估计模型是随机的Forrest,R2_Score为0.967至1.然后,进行敏感性分析以确定每个阴影模型的最有影响力的参数和没有它的状态。这种分析区分了最有效的参数,包括窗口方向,WWR,房间宽度,长度和阴影深度。最后,通过利用NSGA II算法优化机器学习模型的估计功能,识别了大约7300个最佳模型。开发的工具可以为每个设计的各种设计替代品评估各种设计替代品。
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物理信息的神经网络(PINN)是神经网络(NNS),它们作为神经网络本身的组成部分编码模型方程,例如部分微分方程(PDE)。如今,PINN是用于求解PDE,分数方程,积分分化方程和随机PDE的。这种新颖的方法已成为一个多任务学习框架,在该框架中,NN必须在减少PDE残差的同时拟合观察到的数据。本文对PINNS的文献进行了全面的综述:虽然该研究的主要目标是表征这些网络及其相关的优势和缺点。该综述还试图将出版物纳入更广泛的基于搭配的物理知识的神经网络,这些神经网络构成了香草·皮恩(Vanilla Pinn)以及许多其他变体,例如物理受限的神经网络(PCNN),各种HP-VPINN,变量HP-VPINN,VPINN,VPINN,变体。和保守的Pinn(CPINN)。该研究表明,大多数研究都集中在通过不同的激活功能,梯度优化技术,神经网络结构和损耗功能结构来定制PINN。尽管使用PINN的应用范围广泛,但通过证明其在某些情况下比有限元方法(FEM)等经典数值技术更可行的能力,但仍有可能的进步,最著名的是尚未解决的理论问题。
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基于时间序列观测数据,数据同化技术广泛用于预测具有不确定性的复杂动态系统。错误协方差矩阵建模是数据同化算法中的重要元素,其可以大大影响预测精度。这些协方差通常依赖于经验假设和物理限制的估计通常是不精确的,并且计算昂贵的昂贵,特别是对于大维度的系统。在这项工作中,我们提出了一种基于长短短期存储器(LSTM)经常性神经网络(RNN)的数据驱动方法,以提高观察协方差规范的准确性和效率的动态系统中的数据同化。与观察/模拟时间序列数据学习协方差矩阵,不同的方法不需要任何关于先前错误分布的知识或假设,而不是经典的后调整方法。我们将新的方法与两个最先进的协方差调谐算法进行了比较,即DI01和D05,首先在Lorenz动态系统中,然后在2D浅水双实验框架中,使用集合同化使用不同的协方差参数化。这种新方法在观察协方差规范,同化精度和计算效率方面具有显着的优势。
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石油场和地震成像的储层模拟被称为石油和天然气(O&G)行业中高性能计算(HPC)最苛刻的工作量。模拟器数值参数的优化起着至关重要的作用,因为它可以节省大量的计算工作。最先进的优化技术基于运行大量模拟,特定于该目的,以找到良好的参数候选者。但是,在时间和计算资源方面,使用这种方法的成本高昂。这项工作提出了金枪鱼,这是一种新方法,可增强使用性能模型的储层流仿真的最佳数值参数的搜索。在O&G行业中,通常使用不同工作流程中的模型合奏来减少与预测O&G生产相关的不确定性。我们利用此类工作流程中这些合奏的运行来从每个模拟中提取信息,并在其后续运行中优化数值参数。为了验证该方法,我们在历史匹配(HM)过程中实现了它,该过程使用Kalman滤波器算法来调整储层模型的集合以匹配实际字段中观察到的数据。我们从许多具有不同数值配置的模拟中挖掘了过去的执行日志,并根据数据提取的功能构建机器学习模型。这些功能包括储层模型本身的属性,例如活动单元的数量,即模拟行为的统计数据,例如线性求解器的迭代次数。采样技术用于查询甲骨文以找到可以减少经过的时间的数值参数,而不会显着影响结果的质量。我们的实验表明,预测可以平均将HM工作流程运行时提高31%。
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通过机器学习在所有设计和工程领域的机器学习增益创建的数据驱动模型。他们有很高的潜力,以协助决策者创造具有更好的性能和可持续性的新人工制品。然而,有限的泛化和这些模型的黑匣子性质诱导有限的解释性和可重用性。这些缺点在工程设计中提供了延迟采用的显着障碍。为了克服这种情况,我们提出了一种基于组件的方法来通过机器学习(ml)来创建部分组件模型。该基于组件的方法对齐深入学习到系统工程(SE)。借助于节能建筑设计的示例,我们首先通过准确地预测与训练数据不同的随机结构的设计性能来证明基于组件的方法的概括。其次,我们通过从工程设计的角度来看,从低深度决策树派生的本地采样,敏感性信息和规则来说明解释性,灵敏度信息和规则。解释性的关键是,组件之间的接口处的激活是可解释的工程量。以这种方式,分层组件系统形成深度神经网络(DNN),该网络(DNN)直接集成了工程解释性的信息。组合组件中的大量可能配置允许使用可理解的数据驱动模型进行新颖的未经设计案例。通过类似的概率分布的参数范围的匹配会产生可重复使用的,普遍性和可信赖的模型。该方法适应了系统工程和域知识的工程方法模型结构。
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Data Centers are huge power consumers, both because of the energy required for computation and the cooling needed to keep servers below thermal redlining. The most common technique to minimize cooling costs is increasing data room temperature. However, to avoid reliability issues, and to enhance energy efficiency, there is a need to predict the temperature attained by servers under variable cooling setups. Due to the complex thermal dynamics of data rooms, accurate runtime data center temperature prediction has remained as an important challenge. By using Gramatical Evolution techniques, this paper presents a methodology for the generation of temperature models for data centers and the runtime prediction of CPU and inlet temperature under variable cooling setups. As opposed to time costly Computational Fluid Dynamics techniques, our models do not need specific knowledge about the problem, can be used in arbitrary data centers, re-trained if conditions change and have negligible overhead during runtime prediction. Our models have been trained and tested by using traces from real Data Center scenarios. Our results show how we can fully predict the temperature of the servers in a data rooms, with prediction errors below 2 C and 0.5 C in CPU and server inlet temperature respectively.
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建筑物和校园的电力负荷预测随着分布式能源(DERs)的渗透而越来越重要。高效的操作和调度DER需要合理准确的未来能耗预测,以便进行现场发电和存储资产的近实时优化派遣。电力公用事业公司传统上对跨越地理区域的负载口袋进行了负荷预测,因此预测不是建筑物和校园运营商的常见做法。鉴于电网交互式高效建筑域中的研究和原型趋势不断发展,超出简单算法预测精度的特点对于确定智能建筑算法的真正效用很重要。其他特性包括部署架构的整体设计和预测系统的运行效率。在这项工作中,我们介绍了一个基于深度学习的负载预测系统,将来预测1小时的时间间隔18小时。我们还讨论了与此类系统的实时部署相关的挑战,以及通过在国家可再生能源实验室智能校园计划中开发的全功能预测系统提供的研究机会。
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