在核非参数回归中Cross Validation的渐近最优性

给定Y_i=f(t_i)+ε_i,i=1,2,…,n,令f_n(t_jλ~*)是回归函数f(t)的核估计并且λ~*是窗宽基于均方预测误差的Cross—Validation选择.在较弱的矩的条件E_(ε_i)~2<∞下,我们研究了f_n(t_iλ~*)的藉助于均方误差的强相合性以及渐近最优性.     

二次损失下带约束增长曲线模型的线性容许Minimax估计

在二次损失下,讨论了带等式约束的增长曲线模型的参数阵在适当的线性估计类中是线性Minimax容许估计的充分必要条件.     

抛物障碍问题的余量型后验误差估计

1 Introduction Since the finite element method was proposed ,there has been plenty of work about it (see [1 -4]) .They deeply analyzed and studied the finite elementmethod and gave us the feasibility of it on the theoryside . On the practice side ,the finite element methodhas successfully solved various problems ,especiallyinphysical and engineering fields[5 ,6]. Variational inequalities appear in a variety of nonlin-ear physical models .In particular ,variational inequali-ties have been used…     

企业经营与军事战略的异质同构

学习《孙子兵法》,要善于把握这部兵学圣典的主旨,也即归纳其精神实质,这是《孙子兵法》学以致用的要点所在。具体到企业经营实践中,《孙子兵法》中的系统论、效益论、授权论和权变论都是值得企业经营管理者深刻体会和熟练掌握的纲领性要点。企业经营与军事战略其性质、目的虽然不同,但有其相通之处,运用《孙子兵法》指导企业经营,要分清各自的特点而灵活运用。     

一类长短波方程的Cauchy问题

利用Galerkin方法讨论了一类长短波方程的初值问题解的存在性和唯一性。     

What we can learn from the use of student data in efficiency analysis within the context of higher education?

The main purpose of the paper is to estimate the efficiency of a big public university in Italy using individual student-level data, modeling exogenous variables in human capital formation through a heteroscedastic stochastic frontier approach. Specifically, a production function for tertiary education has been estimated with emphasis on inefficiency and its determinants, taking explicitly into account the role played by students’ socio-economic and educational background. The empirical evidence, based on 48,338 freshmen, leads towards the use of individual-level data in order to control for the portion of the student academic achievement affected by the personal characteristics and effort, and the portion ascribable to the resources or organization of the institutional activities. Within the limit of external validity allowed by operating within only one university, efficiency scores derived from using both individual-level and aggregate level data do offer an important instrument to the university and governance structures.     

会计估计、会计估计变更的审计

随着一个国家社会生产力的发展,会计在日常经济生活中的作用将日益显著。作为会计知识的一部分,会计估计及会计估计的变更,在整个会计体系中的作用也就越来越重要了。如何正确使用会计估计、会计估计的变更,如何加强会计估计变更的审计便成为会计工作的重中之重。     

一类偏微分方程特征值的带权估计

考虑一类偏微分方程特征值的带权估计,利用分部积分、Rayleigh定理和不等式估计等方法,获得了用前n个特征值来估计第N＋1个特征值的上界的不等式,其估计系数与区域的度量无关,这个结果在力学和物理学中有着广泛的应用。     

一类偏微分方程特征值的上界估计

考虑一类偏微分方程特征值的上界估计,利用分部积分、Rayleigh定理和不等式估计等方法,获得了用前n个特征值来估计第n＋1个特征值的上界的不等式,其估计系数与区域的度量无关,这个结果在力学和物理学中有着广泛的应用。     

一类二维HM方程弱解的存在性

本文先利用Galёrkin方法得到二维HM方程△ut-ut+vduy+J(u,△u)+△u=0的近似解,并得到该方程的先验估计,最后证明了该方程弱解的存在性.