再生核支持向量机在非线性系统中的应用

为了提高非线性系统辨识的精度,提出用Walsh函数作为空间V0的尺度函数,构造出L2(R)空间的正交规范序列。结合小波多分辨分析,将Hilbert空间分为一系列子空间,并由可分Hilbert空间与L2(R)的等价性,利用内积同构的线性算子,可以把V0子空间的尺度函数折算为Hilbert空间的子空间V0的尺度函数,构造出新的Walsh序列再生核。通过仿真实验,与传统的RBF核函数、高斯核函数等比较,该尺度再生核函数具有更高的辨识精度,较少支持向量数目,充分体现了支持向量机较好的推广性能。     

社会主义核心价值体系的实现路径——基于价值认同的角度

社会主义核心价值体系的实现过程,不仅是一个教育灌输的过程,更是一个价值认同的过程。要实现对社会主义核心价值体系的价值认同,真正把社会主义核心价值体系“转化为人民的自觉追求”,需要把握好“尊重多样差异,坚持一元导向”的价值引导、“坚持平等沟通,实现渐进渗透”的价值转化和“寻求社会共识,凝聚发展合力”的价值整合三个环节。     

Nonparametric density estimation from data with a mixture of Berkson and classical errors

The author considers density estimation from contaminated data where the measurement errors come from two very different sources. A first error, of Berkson type, is incurred before the experiment: the variable X of interest is unobservable and only a surrogate can be measured. A second error, of classical type, is incurred after the experiment: the surrogate can only be observed with measurement error. The author develops two nonparametric estimators of the density of X, valid whenever Berkson, classical or a mixture of both errors are present. Rates of convergence of the estimators are derived and a fully data‐driven procedure is proposed. Finite sample performance is investigated via simulations and on a real data example.     

Estimating the Upper Support Point in Deconvolution

Abstract.  We consider estimation of the upper boundary point F ⁻¹ (1) of a distribution function F with finite upper boundary or 'frontier' in deconvolution problems, primarily focusing on deconvolution models where the noise density is decreasing on the positive halfline. Our estimates are based on the (non-parametric) maximum likelihood estimator (MLE) of F . We show that (1) is asymptotically never too small. If the convolution kernel has bounded support the estimator (1) can generally be expected to be consistent. In this case, we establish a relation between the extreme value index of F and the rate of convergence of (1) to the upper support point for the 'boxcar' deconvolution model. If the convolution density has unbounded support, (1) can be expected to overestimate the upper support point. We define consistent estimators , for appropriately chosen vanishing sequences ( β _n ) and study these in a particular case.     

虚拟企业在我国的发展论析

以核心能力为主要形式的、对企业外部资源进行优化整合的一种有效手段———虚拟企业正伴随着经济全球化趋势和信息技术的不断发展,成为许多企业的现实选择。我国虚拟企业的发展面临"难产、难受、难处"的难题。应采取加快信息基础设施建设,加强企业集团组建、提高虚拟制造的应用程度、建立国家信用管理体系等措施推进企业的虚拟化进程。     

认知语言学概念合成理论研究述评

概念合成理论是由Fauconnier提出的心理空间理论(Mental Spaces Theory)经过十多年的发展而来。该理论主要用于研究语言运用背后的认知活动,成为解释语言现象过程中重要的理论原则。研究该理论的发展过程和研究成果,介绍该理论的理论解释特征和语言解释力。     

Non-parametric estimation of reciprocal coordinate subtangent for right censored dependent scheme

The concept of reciprocal coordinate subtangent (RCST) has been used as a useful tool to study the monotone behavior of a continuous density function and for characterizing probability distributions. In this paper, we propose a non-parametric estimator for RCST based on the censored dependent data. Asymptotic properties of the estimator are established under suitable regularity conditions. A simulation study is carried out to examine the performance of the estimator. The usefulness of the estimator is also examined through a real data.     

中国生产性服务业TFP的时空差异与影响因素分析

在利用Malmquist指数法测算2005-2013年中国30个省份生产性服务业的全要素生产率(TFP)的基础上,采用核密度估计法分析了TFP的动态演变,并运用分位数回归方法对中国生产性服务业TFP的影响因素进行了实证分析。研究发现:在考察期内中国生产性服务业TFP总体呈下降态势,技术效率下降是其下降的主要原因;核密度曲线说明中国生产性服务业TFP省际差距扩大,技术效率和技术进步逐渐呈现两极分化的趋势;分位数回归结果表明,工业化水平和人力资本水平对生产性服务业TFP提升具有普遍的促进作用,而信息化水平、对外开放水平、制造业集中度对生产性服务业TFP提高的贡献大小均与地区生产性服务业TFP的水平有关。     

Empirical likelihood tests for two‐sample problems via nonparametric density estimation

The authors study the problem of testing whether two populations have the same law by comparing kernel estimators of the two density functions. The proposed test statistic is based on a local empirical likelihood approach. They obtain the asymptotic distribution of the test statistic and propose a bootstrap approximation to calibrate the test. A simulation study is carried out in which the proposed method is compared with two competitors, and a procedure to select the bandwidth parameter is studied. The proposed test can be extended to more than two samples and to multivariate distributions.     

Confidence Intervals for Current Status Data

Abstract.  The likelihood ratio statistic for testing pointwise hypotheses about the survival time distribution in the current status model can be inverted to yield confidence intervals (CIs). One advantage of this procedure is that CIs can be formed without estimating the unknown parameters that figure in the asymptotic distribution of the maximum likelihood estimator (MLE) of the distribution function. We discuss the likelihood ratio-based CIs for the distribution function and the quantile function and compare these intervals to several different intervals based on the MLE. The quantiles of the limiting distribution of the MLE are estimated using various methods including parametric fitting, kernel smoothing and subsampling techniques. Comparisons are carried out both for simulated data and on a data set involving time to immunization against rubella. The comparisons indicate that the likelihood ratio-based intervals are preferable from several perspectives.