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1.
In this paper, we present a novel approach for constructing a nonlinear recursive predictor. Given a limited time series data set, our goal is to develop a predictor that is capable of providing reliable long-term forecasting. The approach is based on the use of an artificial neural network and we propose a combination of network architecture, training algorithm, and special procedures for scaling and initializing the weight coefficients. For time series arising from nonlinear dynamical systems, the power of the proposed predictor has been successfully demonstrated by testing on data sets obtained from numerical simulations and actual experiments.  相似文献   

2.
本文对文献[1]中的数据重新以时间序列为变量建立回归模型,通过比较新老模型的检验效果,显示新模型的优良性.又结合新模型重新给出了更为合理的新增用地控制方法  相似文献   

3.
    
This study considers the bootstrap cumulative sum (CUSUM) test for a parameter change in location‐scale time series models with heteroscedasticity. The CUSUM test has been popular for detecting an abrupt change in time series models because it performs well in many applications. However, it has severe size distortions in many situations. As a remedy, we consider the bootstrap CUSUM test, particularly focusing on the CUSUM test based on score vectors, and demonstrate the weak consistency of the bootstrap test for its justification. A simulation study and data analysis are conducted for illustration.  相似文献   

4.
Abstract

Semiparametric linear regression with censored data assumes a linear relationship between failure time and covariates without specifying the distributional form of the error term. This approach has attracted considerable attention recently. Most notably, rank regression methods have been derived for parameter estimation, hypothesis testing, and goodness-of-fit analysis. The implementation of these methods requires minimizing discrete objective functions with multiple local minima. Conventional optimization algorithms cannot be used to solve such minimization problems. We develop computational methods to implement rank regression procedures using simulated annealing. Two real data sets are used for illustration. Applications of the new algorithms to the modified least squares estimator of Buckley and James and several other related problems are also described.  相似文献   

5.
Bounds for higher-order cumulants of statistics arising from a linear time series regression model are investigated. A result given in Brillinger is proved and extended. The bounds permit derivation of asymptotic moments and asymptotic normality for estimators of parameters in the model. Two examples are given as illustrations.  相似文献   

6.
We propose three statistics for testing that a predictor variable has no effect on the response variable in regression analysis. The test statistics are integrals of squared derivatives of various orders of a periodic smoothing spline fit to the data. The large sample properties of the test statistics are investigated under the null hypothesis and sequences of local alternatives and a Monte Carlo study is conducted to assess finite sample power properties.  相似文献   

7.
支持向量机在系统辨识和分类研究方面比较成熟,目前尚没有提出有效的支持向量回归理论来解决非线性、时变、干扰的复杂问题.支持向量回归机主要用于因果关系点对的回归预测,把支持向量回归机应用于水文混沌时间序列的预测研究是一个有意义的工作.在支持向量机一般理论基础上,提出了水文混沌时间序列支持向量回归机模型,并就模型进行仿真计算,讨论了模型参数对支持向量回归机预测精度的影响,为模型参数寻优提供一般指导原则.直门达水文站径流量混沌时间序列支持向量回归机预测实验表明,水文混沌时间序列支持向量回归机模型是有效的.  相似文献   

8.
修建第二机场的必要性以及何时开始修建,取决于该地区的机场旅客吞吐量何时达到饱和.从机场旅客吞吐量的可能影响因素出发,分析各影响因素与旅客吞吐量之间的相关性,并以西南地区某枢纽运输机场为例,建立机场旅客吞吐量的多元线性回归预测模型,预测该机场未来年的旅客吞吐量,并利用时间序列法对所得的预测值进行验证.结果表明,该模型能够较准确的预测出机场未来年的旅客吞吐量,为机场扩建或新建第二机场的必要性提供科学依据.  相似文献   

9.
Approximations for the level probabilities in testing order-restricted hypotheses are examined in this paper for generalized linear models with common slope. It is showed, in particular, that the asymptotic null distribution of the likelihood ratio statistic is a mixture of chi-squared distributions for the cases of simple order and simple tree order. Under a balanced structure, the asymptotic null distribution reduces to the well-known chi-bar-squared distribution. The use of the equal-weights level probabilities is also investigated. This approximation seems to be satisfactory when the sample sizes and the levels of the covariate are not too different among the strata.  相似文献   

10.
The problem of computing the mean squared error (MSE) of the best linear predictor (BLP) in finite discrete spectrum with an additive white noise models(FDSWNMs) for an observed time series is considered. This is done under the assumption that the corresponding vectors in models for finite observation of this time series are not orthogonal. Supported by the VEGA grant of the Slovak Grant Agency. No. 1/3023/06.  相似文献   

11.
回归信度模型在保险研究中具有重要的作用.本文分险种内部,险种之间,险种内部及之间三种情形讨论了具有线性趋势回归信度模型异方差的score检验问题.首先推导了异方差存在性检验的score检验统计量,然后利用Monte-Carlo方法模拟了这几种检验统计量的功效,功效模拟结果显示:这几种检验统计量都有很好的检验效果.最后利用文中所得到的检验方法对旅客意外身体伤害保险数据进行了实例分析.  相似文献   

12.
To detect and estimate a shift in either the mean and the deviation or both for the preliminary analysis, the statistical process control (SPC) tool, the control chart based on the likelihood ratio test (LRT), is the most popular method. Sullivan and woodall pointed out the test statistic lrt(n1, n2) is approximately distributed as x2(2) as the sample size n,n1 and n2 are very large, and the value of n1 = 2,3,..., n - 2 and that of n2 = n - n1. So it is inevitable that n1 or n2 is not large. In this paper the limit distribution of lrt(n1, n2) for fixed n1 or n2 is figured out, and the exactly analytic formulae for evaluating the expectation and the variance of the limit distribution are also obtained. In addition, the properties of the standardized likelihood ratio statistic slr(n1, n) are discussed in this paper. Although slr(n1, n) contains the most important information, slr(i, n)(i≠n1) also contains lots of information. The cumulative sum (CUSUM) control chart can obtain more information in this condition. So we propose two CUSUM control charts based on the likelihood ratio statistics for the preliminary analysis on the individual observations. One focuses on detecting the shifts in location in the historical data and the other is more general in detecting a shift in either the location and the scale or both. Moreover, the simulated results show that the proposed two control charts are, respectively, superior to their competitors not only in the detection of the sustained shifts but also in the detection of some other out-of-control situations considered in this paper.  相似文献   

13.
运用时间序列分析和回归分析的方法 ,定量分析了读者群的变化趋势 ,并讨论了变化趋势的成因  相似文献   

14.
Changes in the joint distribution of influence functions for the mean vector and the covariance matrix are examined when the true probability distribution is contaminated. In particular, the formulas for influence functions of the first and second moments with respect to the above joint distribution are obtained and used to derive reasonable test statistics for multivariate normality. The formulas are extended by using the joint distribution of score functions for population parameters. An application of the extended formulas to the usual linear regression analysis leads to a measure of multivariate skewness which can be used to reduce the effect of non-normality of the response variable. Also, some relationship between the extended formulas and goodness-of-fit statistics is discussed and used to derive test statistics for multivariate normality.  相似文献   

15.
A complete solution is provided to a problem posed by [5] and reformulated by [1] regarding a characterization of (positive and negative) multinomial distributions based, among other things, on the properties of regression in power series distributions.  相似文献   

16.
山西省商品房市场的发展规律   总被引:4,自引:0,他引:4  
本文通过对山西省 1998年至 2002年共 50个月份的月度商品房销售面积 (使用商品房销售面积克服了价格波动的影响 )的实证分析,建立了一个结合普通线性模型 (OLS)、非参数核估计(KernelEstimation)、以及时间序列分析(TimeSeries)的统计预测模型。此模型既能够很好地分离出商品房销售面积随时间的增长趋势,又能够很好地刻画它在各个年度周期内部光滑的季节规律。基于此模型,山西省每年商品房销售面积的规律被刻画为四个周期,即:增长期、衰退期、调整期、以及结束期。从中不难看出商品房销售规律的个性。在分析各地区商品房市场规律时,不能照搬全国商品房市场的相关规律,更不能照搬国外的测算结果。  相似文献   

17.
带季节线性趋势的季节时间序列的单位根检验   总被引:1,自引:0,他引:1  
本文为检验带季节线性趋势的季节时间序列的单位根,提出了调整季节线性趋势的统计量,导出这些统计量的极限分布,并用Monte Carlo方法比较研究这些统计量的检验势.  相似文献   

18.
给出了标题中所述文章的一个注记.首先否定了该文中的一个断语,其次指出了该文中的"新的判别法"的适用范围并没有超过Cauchy根值判别法.  相似文献   

19.
Goodness-of-fit test for regression modes has received much attention in literature. In this paper, empirical likelihood (EL) goodness-of-fit tests for regression models including classical parametric and autoregressive (AR) time series models are proposed. Unlike the existing locally smoothing and globally smoothing methodologies, the new method has the advantage that the tests are self-scale invariant and that the asymptotic null distribution is chi-squared. Simulations are carried out to illustrate the methodology.  相似文献   

20.
考虑多元分布的正态性检验问题,用投影寻踪方法,给出了两个检验统计量,模拟计算也表明所提出的检验统计量具有良好的功效.  相似文献   

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