方向数据密度函数核估计的重对数律

本文讨论方向数据密度函数核估计的逐点收敛速度问题,在较为温和的条件下建立了该核估计的重对数律并给出了它的逐点最优收敛速度.     

条件中位数L_1－模核估计的逐点相合性

设（Ｘ，Ｙ）．（Ｘ１，Ｙ１），（Ｘ２，Ｙ２），…为Ｒｄ×Ｒ１上ｉ．ｉ．ｄ．随机向量序列。Ｙ对Ｘ的条件中位数θ（ｘ）定义为在Ｘ＝ｘ时Ｙ的条件分布函数的中位数．校函数Ｋ（·）是Ｒｄ上正实值函数，对ｘ∈Ｒｄ，θ（ｘ）的Ｌ１－模核估计θｎ（ｘ）定义由（１）给出．本文中，我们将文献［４］的均匀核法推广至一般核的情况，并在定义了θ的Ｌ１－模核估计基础之上，研究了其逐点相合性质．     

随机加权法在密度估计中的应用

本文给出了概率密度函数的椭机加权估计，证明了承机加权分布与密度估计的标准化估计量的分布的逼近精度可达到ｏ（１／√ｎｈ），并且构造了Ｅｆｎ（ｘ）的置信区间，其中ｆｎ（ｘ）为密度函数的核估计，ｈ＝ｈｎ炒估计的窗宽。     

密度泛函核估计的Bootstrap逼近

设Ｘ１，．．．，Ｘｎ是从分布密度函数为ｆ的总中抽取的ｉｉｄ样本，μ＝ＥＸ１本文研究了密度泛函θ＝ｆ（μ）的核型估计，ｆｎ（ｘ）为通常的Ｒｏｓｅｎｂｌａｔｔ－Ｐａｒｚｅｎ核估计。     

三类密度估计收敛速度的比较

为估计某未知密度函数,我们有三种常用的估计法——最近邻法、核估计法和经验密度法。对前两类估计法,陈希孺给出了最好的强收敛速度。本文用向 Brownianbridge 强逼近的方法证明了经验密度估计也可达到上述收敛速度,且所需条件比[2]稍弱。     

一种近邻密度估计的强收敛速度

本文讨论了俞军（１９８６）提出的一种近邻密度估计的逐点强收敛速度和一致强收敛速度．并证明了收敛速度的主阶部分不能达到．     

正态分布族的参数的经验Bayes估计的收敛速度

对于正态分布族｛Ｎ（μ，σ￣２）：－∞＜μ＜＋∞，σ￣２＞０｝，该文利用密度函数及其偏导数的核估计构造出参数θ＝（μ，σ￣２）的经验Ｂａｙｅｓ（ＥＢ）估计，并在一定条件下证明了θ的ＥＢ估计的收敛速度可任意接近于１．最后给出了一个实例．     

左截断右删失下乘积限过程的振动模的强极限定理

本文在左截断右删失模型下获得了乘积限过程和累积失效率过程的振动模和Ｌｉｐｓｃｈｉｔｚ－１２模的强一致收敛的精确速度．作为定理的应用，推导了各种核密度估计和失效率估计的强一致收敛的精确速度．     

非时齐Poisson过程MLE的重对数律

在时间区间（０，Ｔ）上，我们观察到Ｘ（Ｔ）＝（Ｘ（ｔ，θ）０≤ｔ≤Ｔ），其中θ∈⊙为参数，且未知，Ｋｕｔｏｙａｎｔｓ讨论了非时齐过程参数θ的最大似然估计（ＭＬＥ）的性质，他给出了极限分布，并且得到了弱收敛及矩收敛等结果，但他要求参数空间为有限区间（α，β）。本文讨论了非时齐Ｐｏｉｓｓｏｎ过程ＭＬＥ的性质，我们允许参数空间随时间而不渐增大，即θｔ是θ在Ｔ＝（α，βＴ）上的最大似然估计，其中ｌｉｍβＴ     

m（n）－相依样本非参数回归残差密度的相合估计

考虑非参数回归模型：Ｙｉ＝Ｍ（Ｘｉ）＋ｅｉ，其中Ｍ（ｘ）为Ｂ（Ｒ）上的未知实函数，（Ｘｉ，Ｙｉ）为来自（Ｘ，Ｙ）的ｍ（ｎ）相依样本，残差（ｅｉ）具有公共的未知密度ｆ（ｘ）．本文基于残差估计给出了ｆ（ｘ）的一种非参估计，并证明该估计具有逐点相合性，一致相合性及Ｌ１相合性．     

i.i.d情况下非参数回归模型的误差密度估计的收敛性质

本文研究了i．i．d情况下非参数回归的误差密度估计的一致收敛和均方收敛，给出了一定条件下误差密度的估计量f^n(x)的一致收敛速度和均方收敛速度。     

线性模型回归系数EB估计的一致收敛速度

利用多元密度函数及其导数的核估计方法，建立了多元线性模型回归系数的经验Ｂａｙｅｓ估计，并给出了这种估计的一致收敛速度。     

Rate of convergence of a convolution-type estimator of the marginal density of a MA(1) process

In this paper moving-average processes with no parametric assumption on the error distribution are considered. A new convolution-type estimator of the marginal density of a MA(1) is presented. This estimator is closely related to some previous ones used to estimate the integrated squared density and has a structure similar to the ordinary kernel density estimator. For second-order kernels, the rate of convergence of this new estimator is investigated and the rate of the optimal bandwidth obtained. Under limit conditions on the smoothing parameter the convolution-type estimator is proved to be -consistent, which contrasts with the asymptotic behavior of the ordinary kernel density estimator, that is only -consistent.     

A family of minimax rates for density estimators in continuous time

In continuous time, rates of convergence of density estimators fluctuate with the nature of observed sample paths. In this paper, we give a family of rates reached by the kernel estimator and we show that these rates are minimax. Finally, we study applications of these results for specific classes of processes including the Gaussian ones     

A semiparametric density estimator based on elliptical distributions

In the paper we study a semiparametric density estimation method based on the model of an elliptical distribution. The method considered here shows a way to overcome problems arising from the curse of dimensionality. The optimal rate of the uniform strong convergence of the estimator under consideration coincides with the optimal rate for the usual one-dimensional kernel density estimator except in a neighbourhood of the mean. Therefore the optimal rate does not depend on the dimension. Moreover, asymptotic normality of the estimator is proved.     

Asymptotic Properties of a Nonparametric Regression Function Estimator with Randomly Truncated Data

In this paper, we define a new kernel estimator of the regression function under a left truncation model. We establish the pointwise and uniform strong consistency over a compact set and give a rate of convergence of the estimate. The pointwise asymptotic normality of the estimate is also given. Some simulations are given to show the asymptotic behavior of the estimate in different cases. The distribution function and the covariable’s density are also estimated.     

Convergence rates in density estimation for data from infinite-order moving average processes

Summary The effect of long-range dependence in nonparametric probability density estimation is investigated under the assumption that the observed data are a sample from a stationary, infinite-order moving average process. It is shown that to first order, the mean integrated squared error (MISE) of a kernel estimator for moving average data may be expanded as the sum of MISE of the kernel estimator for a same-sizerandom sample, plus a term proportional to the variance of the moving average sample mean. The latter term does not depend on bandwidth, and so imposes a ceiling on the convergence rate of a kernel estimator regardless of how bandwidth is chosen. This ceiling can be quite significant in the case of long-range dependence. We show thatall density estimators have the convergence rate ceiling possessed by kernel estimators.The research of Dr. Hart was done while he was visiting the Australian National University, and was supported in part by ONR Contract N00014-85-K-0723     

Estimating and Visualizing Conditional Densities

Abstract

We consider the kernel estimator of conditional density and derive its asymptotic bias, variance, and mean-square error. Optimal bandwidths (with respect to integrated mean-square error) are found and it is shown that the convergence rate of the density estimator is order n ^–2/3. We also note that the conditional mean function obtained from the estimator is equivalent to a kernel smoother. Given the undesirable bias properties of kernel smoothers, we seek a modified conditional density estimator that has mean equivalent to some other nonparametric regression smoother with better bias properties. It is also shown that our modified estimator has smaller mean square error than the standard estimator in some commonly occurring situations. Finally, three graphical methods for visualizing conditional density estimators are discussed and applied to a data set consisting of maximum daily temperatures in Melbourne, Australia.     

连续时间下非参数回归模型的误差密度估计的渐近均方误差

本文研究了连续时间下非参数回归的误差官度估计的收敛速度，给出了一定条件下误差密度的估计量^fT(x)的均方收敛速度，详细说明了以下重要结果：E[^fT(x)-f(x)]^2＝O(T^-1/4)其中f(x)表示误差过程｛et,t≥0｝的未知密度。