持久收入假说消费函数的改进

文章以弗里德曼的持久收入假说为理论依据,采用逐步回归构建的收入滞后分布消费函数较好地解决了持久收入预期的问题。实证分析表明,改进的持久收入假说消费函数和现代消费函数都能有效地解释我国居民的收入对消费的决定,具有实际应用价值。     

函数数据聚类及其在金融时序分析中的应用

函数数据分析正成为近年来的研究热点。文章针对函数数据聚类分析方法的研究,首先在LP空间构建函数数据之间相异性度量指标,并利用基函数将函数数据平滑,提出了函数数据的聚类分析方法,指出了通过最小二乘估计得到的正交基函数系数进行聚类的结果接近于直接对原始数据进行聚类的结果。其方法应用于时间序列的模式挖掘,得到了良好的效果。     

函数性数据的统计分析：思想、方法和应用

 摘　　要:实际中，越来越多的研究领域所收集到的样本观测数据具有函数性特征，这种函数性数据是融合时间序列和横截面两者的数据，有些甚是曲线或其他函数图像。虽然计量经济学近二十多年来发展的面板数据分析方法，具有很好的应用价值，但是面板数据只是函数性数据的一种特殊类型，且其分析方法太过于依赖模型的线性结构和假设条件等。本文基于函数性数据的普遍特征，介绍一种对其进行分析的全新方法，并率先使用该方法对经济函数性数据进行分析，拓展了函数性数据分析的应用范围。分析结果表明，函数性数据分析方法，较之计量经济学和其他统计方法具有更多的优越性，尤其能够揭示其他方法所不能揭示的数据特征     

相关性分析中Copula函数的选择

Copula函数在金融分析和风险管理中有广泛的应用,利用Copula函数可以构建组合风险资产的联合收益分布和资产之间的相关性.在构建Copula模型时,一个关键的问题就是如何选择最佳的Copula来拟合实际的金融数据.文章分析了Copula函数选择困难的原因,指出了现有的似然准则选择方法的不足,提出了基于参数Bootstrap技术的对数似然准则检验方法,考虑了更大范围的Copula函数族群,利用模拟实验检验了该方法的选择能力,模拟结果表明对于没有尾部相关性的Copula函数和具有较小的尾部相关性的Copula函数可以较好地进行区分,而且也能区分大部分的具有较大尾部相关系数的Copula函数.同现有的只能区分常见的几类Copula的似然准则选择方法相比,文章提出的方法可以在更大范围内识别不同的Copula函数.     

居民消费函数研究中的若干问题探讨

消费函数,即消费与其决定因素之间的函数关系。对它的研究,西方始于凯恩斯的绝对收入假定,其后随着经济增长理论的不断发展,消费函数理论研究和实证研究的进展也层出不穷,在理论方面又     

函数型死亡率预测模型

人口死亡率反映人口的死亡水平,是人口规模的重要影响因素,同时也是人寿保险精算的重要数据基础。从数据特征来看,死亡率作为年龄的函数,是一种典型的函数型数据。本文使用函数型数据方法分析中国人口数据,基于1994—2010年中国人口分年龄死亡数据,建立函数型死亡率预测模型,对未来分年龄死亡率进行预测,并通过生命表方法计算了未来平均预期寿命。同时通过对历史数据的预测,说明模型预测结果比较可信。     

函数数据聚类分析方法探析

函数数据是目前数据分析中新出现的一种数据类型,它同时具有时间序列和横截面数据的特征,通常可以描述为关于某一变量的函数图像,在实际应用中具有很强的实用性。首先简要分析函数数据的一些基本特征和目前提出的一些函数数据聚类方法,如均匀修正的函数数据K均值聚类方法、函数数据层次聚类方法等,并在此基础上,从函数特征分析的角度探讨了函数数据聚类方法,提出了一种基于导数分析的函数数据区间聚类分析方法,并利用中国中部六省的就业人口数据对该方法进行实证分析,取得了聚类结果。     

中国农村消费函数分析

文章以 1978～ 1997年间我国农村居民家庭预算数据检验了持久收入假说与随机行走假说。由于制度和经济的原因 ,中国农村居民家庭消费行为并非完全符合发达经济的消费函数假说。分析认为 :1978年以来 ,我国农村居民家庭经济收入与财富显著增加 ,农村民间信用和转移支付 ,也为农民降低流动性约束提供了部分条件 ,进行跨时预算的条件逐步成熟。然而由于短缺经济的制度惯性等因素决定了农民很难获得官方的消费信贷支持 ,农民消费主要取决于其收入特别是持久收入 ,目前在过剩经济形势下更应该承认居民消费行为的合理性 ,纠正舆论以“人情风”、“建房热”等对农民理性消费的责难。     

基于基函数展开的函数型数据聚类方法

文章在一个一般性的框架下研究了利用基函数展开进行函数型数据聚类的问题.在这个框架之下,大量传统的聚类方法都可以直接应用到函数型数据分析.另外,我们将Pearson相似系数引入函数型数据聚类分析,解决了欧式距离无法刻画曲线之间形态差异的问题.     

中国城镇居民消费函数模型解析——基于误差修正模型的检验

文章回顾了西方国家有关消费函数的理论和模型,并对我国经济理论界有关消费函数的理论和模型作了综述,在误差修正模型的基础上建立了中国城镇居民消费函数模型,最后对提高我国居民消费倾向,刺激需求扩大提出了政策建议.     

Functional data analysis: estimation of the relative error in functional regression under random left-truncation model

In this paper, we investigate the relationship between a functional random covariable and a scalar response which is subject to left-truncation by another random variable. Precisely, we use the mean squared relative error as a loss function to construct a nonparametric estimator of the regression operator of these functional truncated data. Under some standard assumptions in functional data analysis, we establish the almost sure consistency, with rates, of the constructed estimator as well as its asymptotic normality. Then, a simulation study, on finite-sized samples, was carried out in order to show the efficiency of our estimation procedure and to highlight its superiority over the classical kernel estimation, for different levels of simulated truncated data.     

Depth Measures for Multivariate Functional Data

In this article, we address the problem of mining and analyzing multivariate functional data. That is, data where each observation is a set of possibly correlated functions. Complex data of this kind is more and more common in many research fields, particularly in the biomedical context. In this work, we propose and apply a new concept of depth measure for multivariate functional data. With this new depth measure it is possible to generalize robust statistics, such as the median, to the multivariate functional framework, which in turn allows the application of outlier detection, boxplots construction, and nonparametric tests also in this more general framework. We present an application to Electrocardiographic (ECG) signals.     

图像数据挖掘相关研究综述—概念和应用

图像挖掘是数据挖掘领域中新兴的领域。随着数字照相技术的发展和在多学科中的广泛应用,对大量图像数据的分析和研究越来越重要。由于图像挖掘的对象、内容不同于传统数据,方法上也不同于传统技术。本文旨在介绍图像挖掘的基本概念和体系以及国际上最新的研究成果。本文回顾了图像挖掘的相关问题及建模框架,并与模式识别、图像处理等相关领域进行了比较,在此基础上,还介绍了近年来图像挖掘领域在卫星遥感、医学影像和生物显微照片研究的相关应用。     

Identifying ecosystem patterns from time series of anchovy (Engraulis ringens) and sardine (Sardinops sagax) landings in northern Chile

ABSTRACT

Useful knowledge acquisition from known and systematized information (data) is a big challenge for researchers, users and finally, decision makers. In this sense, knowledge discovery from data (KDD) process represents a valuable tool for information analysis. Moreover, this work presents an approach through KDD in time series pattern identification for anchovy and sardine fisheries and environmental data, in northern Chile. Time series, multivariate analysis and data mining techniques, along with technical literature review for results validation. The KDD approach and the data mining techniques implemented achieved an integration between these variables, identifying relevant patterns associated with fisheries abundance fluctuations and strong association with environmental changes such as El Niño and long-term cold–warm regimes between them, establishing anchovy and sardine pre-dominant time-periods, associated with environmental conditions are identified. The latter establishes groundwork for studying underlying functional relationships that could reduce gaps in the national fisheries management policies for those fisheries.     

流式数据挖掘的现状及统计的研究趋势

摘　　要:本文对近年来在国内外学术界涌现出的流式数据挖掘的研究成果进行剖析,分析了流式数据挖掘的研究现状。在此基础上,提出了统计学在流式数据挖掘研究中的发展趋势,以便更好地促进统计学和数据挖掘的结合,拓展统计学方法的研究思路。     

A novel feature selection scheme for high-dimensional data sets: four-Staged Feature Selection

Classification of high-dimensional data set is a big challenge for statistical learning and data mining algorithms. To effectively apply classification methods to high-dimensional data sets, feature selection is an indispensable pre-processing step of learning process. In this study, we consider the problem of constructing an effective feature selection and classification scheme for data set which has a small number of sample size with a large number of features. A novel feature selection approach, named four-Staged Feature Selection, has been proposed to overcome high-dimensional data classification problem by selecting informative features. The proposed method first selects candidate features with number of filtering methods which are based on different metrics, and then it applies semi-wrapper, union and voting stages, respectively, to obtain final feature subsets. Several statistical learning and data mining methods have been carried out to verify the efficiency of the selected features. In order to test the adequacy of the proposed method, 10 different microarray data sets are employed due to their high number of features and small sample size.     

一种基于函数型数据的综合评价方法研究

 在经济管理与决策中, 经常遇到大量的函数型数据。当指标为函数型数据时，提出了一种基于函数型数据的综合评价方法，而综合评价的核心是评价指标在不同时刻的权重系数的确定。针对由函数型数据表支持的综合评价问题的特殊性，提出了一种新的确定权重系数的“全局”拉开档次法，利用Matlab编程，使得该方法具有可操作性，并给出一个实际例子。最后将该方法与传统方法进行比较，得出本文所提方法的优势。     

Variance Estimation and Asymptotic Confidence Bands for the Mean Estimator of Sampled Functional Data with High Entropy Unequal Probability Sampling Designs

For fixed size sampling designs with high entropy, it is well known that the variance of the Horvitz–Thompson estimator can be approximated by the Hájek formula. The interest of this asymptotic variance approximation is that it only involves the first order inclusion probabilities of the statistical units. We extend this variance formula when the variable under study is functional, and we prove, under general conditions on the regularity of the individual trajectories and the sampling design, that we can get a uniformly convergent estimator of the variance function of the Horvitz–Thompson estimator of the mean function. Rates of convergence to the true variance function are given for the rejective sampling. We deduce, under conditions on the entropy of the sampling design, that it is possible to build confidence bands whose coverage is asymptotically the desired one via simulation of Gaussian processes with variance function given by the Hájek formula. Finally, the accuracy of the proposed variance estimator is evaluated on samples of electricity consumption data measured every half an hour over a period of 1 week.     

Minimax powerful functional analysis of covariance tests with application to longitudinal genome-wide association studies

We model the Alzheimer's disease-related phenotype response variables observed on irregular time points in longitudinal Genome-Wide Association Studies as sparse functional data and propose nonparametric test procedures to detect functional genotype effects while controlling the confounding effects of environmental covariates. Our new functional analysis of covariance tests are based on a seemingly unrelated kernel smoother, which takes into account the within-subject temporal correlations, and thus enjoy improved power over existing functional tests. We show that the proposed test combined with a uniformly consistent nonparametric covariance function estimator enjoys the Wilks phenomenon and is minimax most powerful. Data used in the preparation of this article were obtained from the Alzheimer's Disease Neuroimaging Initiative database, where an application of the proposed test lead to the discovery of new genes that may be related to Alzheimer's disease.     

Functional sliced inverse regression analysis

Most of the usual multivariate methods have been extended to the context of functional data analysis. Our contribution concerns the study of sliced inverse regression (SIR) when the response variable is real but the regressor is a function. In the first part, we show how the relevant properties of SIR remain essentially the same in the functional context under suitable conditions. Unfortunately, the estimation procedure used in the multivariate case cannot be directly transposed to the functional one. Then, we propose a solution that overcomes this difficulty and we show the consistency of the estimates of the parameters of the model.