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1.
首先利用python3.5对铁路客座率原始数据进行预处理,然后利用ARIMA时间序列和BP神经网络进行单一的模型预测,得出单一预测模型的均方误差.在组合预测求解时,先求出ARIMA时间序列模型的误差向量E_1和BP神经网络的预测误差为E_2,由于这两种预测方法是相互独立的,因此误差向量E_1和E_2线性无关且组合预测误差向量为E=(E_1,E_2),得出组合预测平方和的形式为J-W~TEW,然后根据组合预测误差平方和最小的原则来确定权值w_1,w_2,最后求解凸二次规划问题得到权值并求出组合预测模型和均方误差.通过比较单一模型预测和组合预测的均方误差,得出结论:组合预测模型的精确度高于单一预测模型的精确度.  相似文献   

2.
灰色GM(1.1)模型适合少量数据的系统预测.当随时间序列的数据只有少量几个,无法采用统计和其他的预测方法时,它作为一种少数据的系统预测十分有效.将1999-2003年5年中的邯郸的城镇化水平作为灰色预测的原始数据,建立邯郸市城镇化水平灰色预测模型,并采用残差估计进行模型检验.成功地建立了邯郸市城镇化水平灰色预测模型.  相似文献   

3.
基于灰色马尔科夫模型的平顶山市空气污染物浓度预测   总被引:1,自引:0,他引:1  
选用平顶山市2005—2009年各空气污染物浓度作为原始数据序列,建立灰色马尔科夫预测模型,对未来10年的污染因子浓度进行预测.模型检验结果表明:均方差比值和小误差概率均为一级;运用灰色关联分析法计算各污染物原始数据序列与预测数据序列之间的关联度,定量描述灰色马尔科夫预测模型对于空气质量预测的精确度,平均精度达到99.9%,表明灰色马尔科夫预测模型对于空气质量预测有很高的实用性.  相似文献   

4.
选取上海期货交易所黄金期货价格指数日内10分钟高频收益数据,构造了经调整的已实现极差波动率估计序列,利用6类GARCH模型建模分析,描述了黄金期货价格指数的波动特征.运用多种损失函数比较了GARCH类模型样本外波动率预测精度的优劣,并在此基础上,采用一种渐进正态分布检验法评估了GARCH类模型的预测效果.结果显示,黄金期货已实现极差波动率估计序列具有尖峰厚尾、集聚性、持续性等特征.对于黄金期货市场,ACD-GARCH模型具有相对最好的波动率预测能力.  相似文献   

5.
基于天然气期货价格与现货价格序列间具有强非线性特征,本文将GARCH模型和Copula函数思想进行结合,同时考虑了天然气期货和现货价格间的时变相关结构,构建了时变Copula(GARCH-Normal、GARCH-GED和GARCH-t)模型,利用美国纽约商品交易所(NYMEX)Henry Hub交易中心天然气期货价格和现货价格数据进行实证研究。实证结果表明:GARCH-GED模型能够准确地拟合天然气期货与现货价格时间序列;时变SJC-Copula函数能够更好的描述天然气期货价格与现货价格间的相关性;天然气期货与现货价格间的相关性不是对称的,上尾的相关性小于下尾相的相关性。  相似文献   

6.
道路交通事故预测是道路交通安全研究的一项重要内容,针对灰色GM(1,1)预测模型对波动性较大道路交通事故序列预测精度较低的缺点,引入小波分析理论,在小波分析理论的基础上建立灰色GM(1,1)预测模型.通过小波分析将某省2002-2009年道路交通事故起数分解成多层近似平稳的数据序列,然后对低频重构序列建立GM(1,1)模型进行预测.仿真结果表明,方法的预测结果比直接用灰色GM(1,1)模型更拟合原始数据,预测效果更好.预测结果可以为交通部门科学监管和制定决策提供一定的指导.  相似文献   

7.
Song和Chisson于1993年提出模糊时间序列预测理论.虽然至今已经提出许多模糊时间序列预测模型,但是迄今为止尚未给出预测未知年数据的模糊时间序列预测模型.提出基于逆模糊数的模糊时间序列预测的新方法该模型对广西大学已知的2001~2012年的注册数进行预测分析,平均预报误差率比相关文献的方法有所改善.还对广西大学未知的2013年和2014年注册数进行预测研究.方法是短期预测的一种模糊时间序列预测方法.  相似文献   

8.
基于支持向量机(svm)理论建立沪深300股指期货量化交易模型,与传统对期货价格走势进行绝对预测的回归预测方法不同,模型利用支持向量机在处理非线性系统中的分类优势,将价格未来变化的趋势转化为交易信号,把一个复杂的时间序列回归预测问题转化为二分类问题.接着,把价量信息和技术指标分别作为输入向量,再引入止损机制,在动态预测模型上构建量化交易策略.采用历史数据对策略进行回测仿真,实证结果表明,价量信息交易策略表现要好于技术指标交易策略,量化交易模型总体取得了较好的盈利效果.  相似文献   

9.
世界石油期货价格是否存在价格的波动性随到期日的临近而上升的趋势,对于投机商和市场监管都至关重要.研究根据中外石油期货合约的收盘价格得到较为平稳的日收益率,以37个合约的收益率为样本,分别建立时间序列ARM A主模型,并进一步建立带"到期时间"哑变量的GARCH模型.实证分析了世界石油期货收益率的到期日效应.在分析产生到期日效应原因的时,建立了带"成交量"与"国际价格"变量的GARCH模型,对成交量与国际石油期货价格对中国期货价格到期日的影响进行研究.  相似文献   

10.
非等间距组合灰色预测模型   总被引:6,自引:1,他引:5  
对于非等间距原始数据序列,根据灰色预测模型建模特点,提出了一类非等间距灰色组合预测方法,弥补了传统非等间距原始数据预测模型的不足,提高了灰色预测的精度.实例表明结果理想可靠,有较好的实际意义.  相似文献   

11.
随着我国经济快速成长,衍生性金融商品的投资分析,已成为国内财务数学研究热门课题。以股票市场而言,人们总希望比别人早一步掌握行情的脉动,以获取最高的报酬率,然而,影响股市加权股价指数波动的因素众多,要如何进行趋势分析与预测,是很多学者相当感兴趣与研究的主题。本文考虑以模糊统计方法,作模糊时间数列的趋势分析与预测。其望应用模糊统计分析方法比传统的时间数列分析方法能得到更合理的解释,且预测结果可以提供决策者更多的信息,做出正确的决策。最后以台湾地区加权股票指数为例,做一实证上的详细探讨。  相似文献   

12.
针对原油现货价格的非线性和时变性特征,提出一种小波变换结合Elman神经网络和广义自回归条件异方差(GARCH)模型的混沌预测方法。首先利用小波变换将原油现货价格序列分解和重构成概貌序列和细节序列。其次对概貌序列和原油期货价格序列进行相空间重构,建立Elman神经网络的混沌时间序列模型预测概貌序列的未来值;同时以细节序列为历史数据,构建GARCH模型预测细节序列的未来值;最后将概貌序列和细节序列的未来值求和作为最终的预测值。实验证明该方法能够提供更准确的预测结果。  相似文献   

13.
In real time, one observation always relies on several observations. To improve the forecasting accuracy, all these observations can be incorporated in forecasting models. Therefore, in this study, we have intended to introduce a new Type-2 fuzzy time series model that can utilize more observations in forecasting. Later, this Type-2 model is enhanced by employing particle swarm optimization (PSO) technique. The main motive behind the utilization of the PSO with the Type-2 model is to adjust the lengths of intervals in the universe of discourse that are employed in forecasting, without increasing the number of intervals. The daily stock index price data set of SBI (State Bank of India) is used to evaluate the performance of the proposed model. The proposed model is also validated by forecasting the daily stock index price of Google. Our experimental results demonstrate the effectiveness and robustness of the proposed model in comparison with existing fuzzy time series models and conventional time series models.  相似文献   

14.
Neural networks have been widely used as a promising method for time series forecasting. However, limited empirical studies on seasonal time series forecasting with neural networks yield mixed results. While some find that neural networks are able to model seasonality directly and prior deseasonalization is not necessary, others conclude just the opposite. In this paper, we investigate the issue of how to effectively model time series with both seasonal and trend patterns. In particular, we study the effectiveness of data preprocessing, including deseasonalization and detrending, on neural network modeling and forecasting performance. Both simulation and real data are examined and results are compared to those obtained from the Box–Jenkins seasonal autoregressive integrated moving average models. We find that neural networks are not able to capture seasonal or trend variations effectively with the unpreprocessed raw data and either detrending or deseasonalization can dramatically reduce forecasting errors. Moreover, a combined detrending and deseasonalization is found to be the most effective data preprocessing approach.  相似文献   

15.
基于EMD-GA-BP与EMD-PSO-LSSVM的中国碳市场价格预测   总被引:1,自引:0,他引:1       下载免费PDF全文
由于碳交易市场价格的波动性大及相互影响关系的复杂性,本文试图构建碳价格长期和短期的最优预测模型。考虑到碳交易价格波动的趋势性和周期性特点,基于经验模态分解算法(EMD)、遗传算法(GA)—神经网络(BP)模型、粒子群算法(PSO)—最小二乘支持向量机(LSSVM)模型及由它们构建的组合预测模型,对中国碳市场交易价格进行短期预测和长期预测。实证分析中将影响碳交易价格的不同宏观经济因素和碳价格时间序列因素做为输入变量,分别代入组合模型进行预测。研究结果表明,在短期预测中,EMD-GA-BP模型预测效果优于GA-BP模型和PSO-LSSVM模型;而在长期预测中,组合模型EMD-PSO-LSSVM模型预测效果优于只考虑碳价格波动趋势性或周期性预测效果。  相似文献   

16.
Effective analysis and forecasting of carbon prices, which is an essential endeavor for the carbon trading market, is still considered a difficult task because of the nonlinearity and nonstationarity inherent in carbon prices. Previous studies have failed at the analysis and interval prediction of carbon prices and are limited to point forecasts. Therefore, an improved carbon price analysis and forecasting system that consists of an analysis module and a forecasting module is established in this study; more importantly, the forecasting module includes point forecasting and interval forecasting as well. Aimed at investigating the characteristics of the carbon price series, a chaotic analysis based on the maximum Lyapunov exponent is performed, the determination of appropriate distribution functions based on our newly proposed hybrid optimization algorithm is conducted, and different distribution functions are effectively designed in the analysis module. Furthermore, in the point forecasting model, the phase space reconstruction technique is applied to reconstruct the sequences decomposed by variational mode decomposition due to the chaotic characteristics of the carbon price series, and the reconstructed sequences are considered as the optimal input–output variables of the forecasting model. Then, an adaptive neuro-fuzzy inference system model is trained by the newly proposed hybrid optimization algorithm, which is developed for the first time in the domain of carbon price point forecasting. Moreover, based on the results of point forecasting and the distribution function of the carbon price series determined by the analysis module, the interval forecasting results can be obtained and implemented to provide more reliable information for decision making. Empirical results based on the carbon price data of the European Union Emissions Trading System and Shenzhen of China demonstrate that the proposed system achieves better results than other benchmark models in point forecasting as well as interval forecasting.  相似文献   

17.
This paper presents a dynamic forecasting model that accommodates asymmetric market responses to marketing mix variable—price promotion—by threshold models. As a threshold variable to generate a mechanism for different market responses, we use the counterpart to the concept of a price threshold applied to a representative consumer in a store. A Bayesian approach is taken for statistical modelling because of advantages that it offers over estimation and forecasting. The proposed model incorporates the lagged effects of a price variable. Thereby, myriad pricing strategies can be implemented in the time horizon. Their effectiveness can be evaluated using the predictive density. We intend to improve the forecasting performance over conventional linear time series models. Furthermore, we discuss efficient dynamic pricing in a store using strategic simulations under some scenarios suggested by an estimated structure of the models. Empirical studies illustrate the superior forecasting performance of our model against conventional linear models in terms of the root mean square error of the forecasts. Useful information for dynamic pricing is derived from its structural parameter estimates. This paper develops a dynamic forecasting model that accommodates asymmetric market responses to marketing mix variable—price promotion—by the threshold models. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

18.
Traditional forecasting models are not very effective in most financial time series. To address the problem, this study proposes a novel system for financial modeling and forecasting. In the first stage, wavelet analysis transforms the input space of raw data to a time-scale feature space suitable for financial modeling and forecasting. A spectral clustering algorithm is then used to partition the feature space into several disjointed regions according to their time series dynamics. In the second stage, multiple kernel partial least square regressors ideally suited to each partitioned region are constructed for final forecasting. The proposed model outperforms neural networks, SVMs, and traditional GARCH models, significantly reducing root-mean-squared forecasting errors.  相似文献   

19.
碳市场价格呈现非线性、非平稳的复杂特性,准确预测具有较大的挑战。基于“分而治之”的思想,提出了一种基于局部回归的多尺度碳市场价格预测模型。提出的模型利用集成经验模态分解(EEMD)对碳市场价格时间序列进行分解。启发于EEMD局部特征分解的特点,对分解后的分量采用局部回归方法进行预测,然后将分量预测结果进行集成。采用的局部回归方法包括局部线性回归(LLP)、局部多项式回归、局部岭回归、局部主成分回归、局部偏最小二乘回归和局部套索回归。实验结果表明基于局部回归的多尺度预测模型具有优异的预测性能。在提出的模型中,EEMD-LLP结构简单且性能更为突出,进一步对EEMD-LLP参数的适应性进行探讨。与新近提出模型的对比结果表明了EEMD-LLP在碳市场价格预测中的有效性。  相似文献   

20.
将时间序列分析引入到气温时间序列预测的研究中,深入分析气温样本数据,并对其建立ARMA模型.采用最佳准则函数法确定模型的阶数,并利用自相关函数对模型的残差进行了检验.通过条件期望预测和适时修正预测方法求得预测值,与真实值的比较得到适时修正预测精确度比条件期望预测的精确度高.  相似文献   

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