GM(1,N)模型的病态矩阵的产生及主成分估计改进法

本文在文献[1]的基础上给出了更为一般的探讨,并且用主成分估计法改进了灰色系统模型。     

最佳线性无偏估计中的一个影响度量

本文讨论数据的剔除对最佳线性无偏估计的影响大小。用方差比做为判定影响大小的度量,并找到了它与相关系数之间的精确关系。     

学习曲线在建筑施工工期预测中的应用研究

学习曲线体现的是累计生产量和单位平均生产时间之间的关系 ,经常用于企业生产中生产效率提高及成本降低等方面。根据某施工企业工程实际生产情况 ,利用一元线性回归分析法建立了学习曲线方程 ,以此估算人工工日及预测工期 ,并结合人工工日单价 ,估算人工费和确定投标报价 ,同时可应用学习曲线制定企业定额 ,进行项目成本核算。进一步探讨了应用学习曲线时应考虑的因素     

A Note on Ergodic Processes Prediction via Estimation of the Conditional Mode Function

We establish the uniform almost-sure convergence of a kernel estimate of the conditional density for an ergodic process. A useful application to the prediction of the ergodic process via the conditional mode function is also given.     

Kernel estimations for multivariate density functional with bootstrap

In this article the bootstrap method is discussed for the kernel estimation of the multivariate density function. We have considered sample mean functional and constructed its consistency and asymptotic normality by bootstrap estimator. It has been shown that the bootstrap works for kernel estimates of multivariate density functional. The convergence rate with bootstrap for density has been proved. Finally, two simulations of application are given.     

Pareto analysis for the lifetime performance index of products on the basis of progressively first-failure-censored batches under balanced symmetric and asymmetric loss functions

One of the most important topics in manufacturing industries is the evaluation of performance lifetimes of products. Based on a given lifetime performance index, this paper deals with evaluating the performance of a process subject to a given lower specification limit. We confine ourselves to the progressively first-failure-censored data coming from a common Pareto distribution. With both the Bayesian and the non-Bayesian approaches being investigated here, we pay more attention to Bayesian estimators under balanced type loss functions. The results are presented under the balanced versions of two well-known loss functions, namely the squared error loss and the Varian's linear-exponential (LINEX) loss. Moreover, based on the Bayesian and the non-Bayesian approaches, the problem of testing hypotheses on the lifetime performance index is studied. Also, a simulation study is performed to assess the obtained results. Finally, two illustrative examples are given.     

Some Second-Order Asymptotics for Extreme Value Linear Regression Models

ABSTRACT

In this article we derive finite-sample corrections in matrix notation for likelihood ratio and score statistics in extreme-value linear regression models. We consider three corrected score tests that perform better than the usual score test. We also derive general formulae for second-order biases of maximum likelihood estimates of the linear parameters. Some simulations are performed to compare the likelihood ratio and score statistics with their modified versions and to illustrate the bias correction.     

Normalization in Econometrics

The issue of normalization arises whenever two different values for a vector of unknown parameters imply the identical economic model. A normalization implies not just a rule for selecting which among equivalent points to call the maximum likelihood estimate (MLE), but also governs the topography of the set of points that go into a small-sample confidence interval associated with that MLE. A poor normalization can lead to multimodal distributions, disjoint confidence intervals, and very misleading characterizations of the true statistical uncertainty. This paper introduces an identification principle as a framework upon which a normalization should be imposed, according to which the boundaries of the allowable parameter space should correspond to loci along which the model is locally unidentified. We illustrate these issues with examples taken from mixture models, structural vector autoregressions, and cointegration models.     

中国未观测经济规模估算方法新探

对未观测经济的规模估算是一个十分复杂的研究领域，中国在运用国外的方法估算时，往往受到基础数据、核算体系和经济运行体制等诸多方面的限制，所以必须探索适合中国国情的估算方法。货币作为流通于经济体制之外的血液，是研究未观测经济的一种很好的工具。分析中国的货币供给量与经济增长间的关系、研究中国的货币需求模式、尝试模拟出被未观测经济活动所吸收的货币量，再估计出货币流通速度，两者相乘就可以大致估测其规模，以期为估测未观测经济规模提供新的思路。     

OPTIMAL SEMIPARAMETRIC INFERENCE FOR THE TAIL INDEX BASED ON RATIOS OF THE LARGEST EXTREMES

The k largest order statistics in a random sample from a common heavy‐tailed parent distribution with a regularly varying tail can be characterized as Fréchet extremes. This paper establishes that consecutive ratios of such Fréchet extremes are mutually independent and distributed as functions of beta random variables. The maximum likelihood estimator of the tail index based on these ratios is derived, and the exact distribution of the maximum likelihood estimator is determined for fixed k, and the asymptotic distribution as k →∞ . Inferential procedures based upon the maximum likelihood estimator are shown to be optimal. The Fréchet extremes are not directly observable, but a feasible version of the maximum likelihood estimator is equivalent to Hill's statistic. A simple diagnostic is presented that can be used to decide on the largest value of k for which an assumption of Fréchet extremes is sustainable. The results are illustrated using data on commercial insurance claims arising from fires and explosions, and from hurricanes.