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传统时序预测方法其预测过程无法在相同数据集上推出共享模式, 而机器学习方法无法较好地处理非线性和大规模数据集, 并且需要手动设计特征工程. 深度学习方法弥补了传统预测方法需要高计算高人力的弊端, 用自动学习特征工程代替了手动设计特征工程. 但仅使用深度学习的预测方法所作结构假设较少, 通常需要较高的计算资源以及大量的数据来学习得到准确的模型. 针对上述问题, 本文提出通过采用融合t检验的EMD经验模态将序列分为高频分量和低频分量, 对高频分量使用传统STL序列分解方法进一步对数据做处理, 对高频、低频分量分别进行Prophet预测. 实验结果表明, 相较于传统的LSTM以及Prophet预测模型, 经过STL序列分解后的周期数据能够提升模型的整体预测精确度而融合EMD经验模态的Prophet模型则大大提升了训练效率. 相似文献
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准确预测风电机组各项指标对准确管控机组和调控电网的供需有着重要意义. 预测指标任务可抽象为风电时间序列预测任务. 目前时间序列预测模型主要采用深度学习模型, 但是风电时间序列具有较强的波动性和随机性, 导致绝大部分模型不能较好挖掘风电时间序列的复杂演化特性. 为解决上述问题, 提出了一种基于渐进式分解架构的风电时间序列预测方法, 该方法首先应用神经网络池化分解方法将复杂的依赖关系简化并应用注意力机制学习长期趋势, 然后运用多变量融合捕捉模块增强了网络整体的多变量关联挖掘能力, 最后, 融合趋势项和周期项对风电时间序列做出准确的预测. 实验结果表明, 该方法在风电时间序列的多步预测中均方误差相比基线模型至高可提升24%, 在多尺度预测长度下表现出预测性能稳定提升的同时, 计算效率显著优于同类模型. 相似文献
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基于小波分解和聚类模糊系统的时间序列预测 总被引:1,自引:0,他引:1
结合小波分析的多分辨特性和模糊规则的可解释性,提出了一种非平稳时间序列预测方法。首先将时间序列信号分解为各尺度上的细节信号和平滑信号,使用软、硬阈值折衷法消除噪声,并对各层重构信号单独使用聚类模糊系统进行预测,最后将各预测结果累加得到对整个时间序列的预测。仿真试验表明此方法是有效的。 相似文献
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任何复杂系统都要受到某些基本规律的约束,包括宏观、中观与微观的多层次规律的约束.怎样从一个系统的这些偶然现象(观测数据)中找出它的必然规律,是知识发现(KDD)与数据挖掘(DM)的首要任务,也是研究目标.建立了一个基于演化计算与自然分形相结合的多尺度的动态预测系统.它以微分方程描述系统的宏观行为,以自然分形刻画系统的微观行为.同时,以股票市场数据(君安证券股票数据)和科学观测数据(武汉汛期雨量数据)为例,进行了分析与预测模拟.数值实验表明,该系统的描述(拟合)性能优越,即使是对起伏波动很大的时间序列,也能拟合得很好,预测效果也较好. 相似文献
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提出一种基于小波分解的网络流量时间序列的分析和预测方法。将非平稳的网络流量时间序列通过小波分解成为多个平稳分量,采用自回归滑动平均方法分别对各平稳分量进行建模,将所有分量的模型进行组合,得到原始非平稳网络流量时间序列的预测模型。在仿真实验中,利用网络流量文库的时间序列数据建立了预测模型,并对其进行独立测试检验。仿真结果表明,本预测方法提高了网络流量时间序列的预测准确率,是一种有效、稳健的网络流量预测方法。 相似文献
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支持向量机理论是20世纪90年代由Vapnik提出的一种基于统计学习理论的新的机器学习方法,其具有全局最优解和较好的泛化能力,可将其用于求解时间序列预测间题.但是对于非平稳时间序列的顶测,利用支持向量机算法单独建立一个模型的预测结果不如平稳时间序列那样明显,可以采用经验模式分解法作为时序预测的预处理工具.先将非平稳时间序列进行经验模式分解,再对各个分量分别建模,最后将各分量预测结果进行组合.同时通过仿真实验验证了该方法是有效的. 相似文献
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《国际计算机数学杂志》2012,89(7):781-789
This article presents an improved method of fuzzy time series to forecast university enrollments. The historical enrollment data of the University of Alabama were first adopted by Song and Chissom (Song, Q. and Chissom, B. S. (1993). Forecasting enrollment with fuzzy time series-part I, Fuzzy Sets and Systems, 54, 1–9; Song, Q. and Chissom, B. S. (1994). Forecasting enrollment with fuzzy time series-part II, Fuzzy Sets and Systems, 54, 267–277) to illustrate the forecasting process of the fuzzy time series. Later, Chen proposed a simpler method. In this article, we show that our method is as simple as Chen's method but more accurate. In forecasting the enrollment of the University of Alabama, the root mean square percentage error (RMSPE) of our method is 3.1113% while the RMSPE of Chen's method is 4.0516%, which shows that our method is doing much better. 相似文献
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在高端制造企业的运维业务中,配件需求随机发生,且伴随有大量的零需求阶段,同时,对应的配件需求数据量小,且呈现出间歇性和块状分布的特点,导致现有时间序列预测方法难以有效预测配件需求走势。为解决该问题,提出了一种间歇性时间序列的可预测性评估及联合预测方法。首先,提出了一种新的间歇相似度指标,通过统计两条序列中“0”元素出现的频次和位置,并结合最大信息系数和平均需求间隔等度量指标,有效评估了序列的趋势信息和波动规律,并实现了对间歇性序列可预测性的量化;其次,基于该指标,构建了一个间歇相似度层次聚类方法来自适应地筛选相似性高、可预测性强的序列,剔除极度稀疏、无法预测的序列;此外,探索利用序列间的结构化信息,并构建多输出支持向量回归(M-SVR)模型,从而实现小样本下的间歇性序列联合预测;最后,分别在两个公开数据集(UCI礼品零售数据集和华为电脑配件数据集)和某大型制造企业实际配件售后数据集上进行实验。实验结果表明,相比多个典型的时间序列预测方法,所提方法可有效挖掘各类间歇性序列的可预测性,提高小样本间歇性序列的预测精度,从而为制造企业配件需求预测提供了一种新的解决方案。 相似文献
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Selmo Eduardo Rodrigues Júnior Ginalber Luiz de Oliveira Serra 《Computational Intelligence》2020,36(3):1394-1413
An evolving methodology based on Neuro-Fuzzy Takagi-Sugeno network (NF-TS) for distributed forecasting of univariate time series, is proposed. First, the unobservable components, or hidden patterns, are extracted from experimental data of the time series. Then, a distributed forecasting is performed separately for each component, considering an evolving NF-TS associated with each extracted pattern. The evolving NF-TS uses components data to adapt and adjust its structure, as the number of fuzzy rules increases or decreases according the behavior of the unobservable components. A recursive version of singular spectral analysis (SSA) technique is formulated, as one of the main contributions of this article, and it is applied to extract the components. The efficiency of proposed methodology is illustrated from results of comparison to others state-of-the-art techniques for forecasting of various univariate time series. 相似文献
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Fuzzy time series model has been successfully employed in predicting stock prices and foreign exchange rates. In this paper, we propose a new fuzzy time series model termed as distance-based fuzzy time series (DBFTS) to predict the exchange rate. Unlike the existing fuzzy time series models which require exact match of the fuzzy logic relationships (FLRs), the distance-based fuzzy time series model uses the distance between two FLRs in selecting prediction rules. To predict the exchange rate, a two factors distance-based fuzzy time series model is constructed. The first factor of the model is the exchange rate itself and the second factor comprises many candidate variables affecting the fluctuation of exchange rates. Using the exchange rate data released by the Central Bank of Taiwan, we conducted several experiments on exchange rate forecasting. The experiment results showed that the distance-based fuzzy time series outperformed the random walk model and the artificial neural network model in terms of mean square error. 相似文献
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基于证据理论的模糊时间序列预测模型 总被引:1,自引:1,他引:1
在分析经典模糊时间序列预测模型的基础上,指出了传统的模型不能处理多因素的情形;然后分析并改进了证据理论中关于证据合成的方法,提出了基于证据理论的多因素模糊时间序列预测模型;最后用1997年~2006年10年间的上海股指数据对所提出的模型进行了实践检验,实验结果表明该模型是可行的,其预测效果优于所参照的预测模型. 相似文献
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The availability of high frequency data sets in finance has allowed the use of very data intensive techniques using large data sets in forecasting. An algorithm requiring fast k-NN type search has been implemented using AURA, a binary neural network based upon Correlation Matrix Memories. This work has also constructed probability distribution forecasts, the volume of data allowing this to be done in a nonparametric manner. In assistance to standard statistical error measures the implementation of simulations has allowed actual measures of profit to be calculated. 相似文献
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Pritpal Singh Bhogeswar Borah 《Engineering Applications of Artificial Intelligence》2013,26(10):2443-2457
In this paper, we present a new model to handle four major issues of fuzzy time series forecasting, viz., determination of effective length of intervals, handling of fuzzy logical relationships (FLRs), determination of weight for each FLR, and defuzzification of fuzzified time series values. To resolve the problem associated with the determination of length of intervals, this study suggests a new time series data discretization technique. After generating the intervals, the historical time series data set is fuzzified based on fuzzy time series theory. Each fuzzified time series values are then used to create the FLRs. Most of the existing fuzzy time series models simply ignore the repeated FLRs without any proper justification. Since FLRs represent the patterns of historical events as well as reflect the possibility of appearances of these types of patterns in the future. If we simply discard the repeated FLRs, then there may be a chance of information lost. Therefore, in this model, it is recommended to consider the repeated FLRs during forecasting. It is also suggested to assign weights on the FLRs based on their severity rather than their patterns of occurrences. For this purpose, a new technique is incorporated in the model. This technique determines the weight for each FLR based on the index of the fuzzy set associated with the current state of the FLR. To handle these weighted FLRs and to obtain the forecasted results, this study proposes a new defuzzification technique. The proposed model is verified and validated with three different time series data sets. Empirical analyses signify that the proposed model have the robustness to handle one-factor time series data set very efficiently than the conventional fuzzy time series models. Experimental results show that the proposed model also outperforms over the conventional statistical models. 相似文献
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针对小波分析存在的边界问题,提出一种基于提升方案的冗余Haar小波变换(Haar_RLWT)。使用该方法得到的系数序列,在具备时移不变性的同时,消除了右侧边界存在数据畸变的现象,使小波分析技术结合神经网络等传统预测模型的方法应用于时间序列预测任务具备可行性。同时为进一步提高预测效果,引入神经网络集成技术以改善网络泛化能力。实验表明,该综合预测模型预测效果与稳定性优于传统预测模型。 相似文献
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提出一种将Granger相关信息用于时间序列预测的方法,以解决时间序列预测过程中信息利用不完全的问题.首先,通过Granger相关性检验确定时间序列系统中的可利用信息;然后,利用神经网络将可利用信息抽取出来;最后,将抽取的可利用信息融入到时间序列的预测中.实验结果验证了所提出预测方法的有效性和稳定性. 相似文献