Estimation of 2-D ARMA model parameters by using equivalent AR approach

In this paper, the problem of estimating the parameters of a two-dimensional autoregressive moving-average (2-D ARMA) model driven by an unobservable input noise is addressed. In order to solve this problem, the relation between the parameters of a 2-D ARMA model and their 2-D equivalent autoregressive (EAR) model parameters is investigated. Based on this relation, a new algorithm is proposed for determining the 2-D ARMA model parameters from the coefficients of the 2-D EAR model. This algorithm is a three-step approach. In the first step, the parameters of the 2-D EAR model that is approximately equivalent to the 2-D ARMA model are estimated by applying 2-D modified Yule-Walker (MYW) equation to the process under consideration. Then, the moving-average parameters of the 2-D ARMA model are obtained solving the linear equation set constituted by using the EAR coefficients acquired in the first step. Finally, the autoregressive parameters of the 2-D ARMA model are found by exploiting the values obtained in first and second steps. The performance of the proposed algorithm is compared with other 2-D ARMA parameter and spectral estimation algorithms available in the technical literature by means of three different criteria. As a result of this comparison, it is shown that the parameters and the corresponding power spectrums estimated by using the proposed algorithm are converged to the original parameters and the original power spectrums, respectively.     

巴斯卡分布NB(r,p)中参数r的估计

巴斯卡分布NB（r,p)是重要的离散型分布之一，当r已知时，巴斯卡分布NB（r,p)中未知参数p(p∈（0，1））的估计是众所周知的。本文分别在p已知和未知的条件下，研究了参数r(r∈（1，2，…}）的估计，并得到了它们的渐近性质。     

Robust estimator design with an emphasis balance between performance and robustness

From a number of ML estimators (typically unbiased) of practical interest which include the variance for a Gaussian distribution, the standard deviation for a Laplace distribution, the variance for a Rayleigh distribution and a “spread parameter” for a Cauchy distribution, we design robust estimators according to an emphasis balance between normalized performance and normalized robustness. We measure performance with inverted MSE and robustness with a differential geometric approach.     

A large-scale donor attempt to improve educational status of the poor and household income distribution: The experience of PEDC in Vietnam

In 2003, donors combined together in Vietnam to support the provision of quality primary schooling for 226 disadvantaged districts (about a third of the country). US$160 million was invested in infrastructure, materials and training across the 226 districts. The programme has been commended by donors and received good press inside Vietnam. Comparison of achievement surveys in 2001 and 2007 showed, however, that there had been a decline in performance in the targeted districts. This article explores various hypotheses as to how this could have happened; and in particular the increasing amounts spent by better-off households on their children's education.     

识别含水层参数的单纯形-混沌优化算法

以泰斯公式为基础,将单纯形-混沌优化算法应用于分析抽水试验数据,求解含水层参数函数优化问题。采用具有搜索速度快、局部搜索能力强等优点的单纯形算法与全局搜索能力强的混沌优化算法结合的单纯形-混沌优化算法。数值实验结果表明：单纯形-混沌优化算法可有效地应用于求解含水层参数函数优化问题;待估参数导水系数的初始取值范围、粗搜索次数和混沌序列长度对算法的收敛速度有一定的影响,但不会影响算法的收敛性。     

一类乘积形式的差分不等式

建立了一类新的差分不等式,利用差分定义、求和技巧、差分方程比较原理,给出了不等式中未知函数的估计,推广了已有的结果.     

金融时间序列中同积向量的充分改进最小二乘估计研究

以金融时间序列中同积向量的充分改进为对象,分析充分改进的最小二乘估计。在统计量的极限分布非标准时,构造充分改进的最小二乘估计。研究表明,改进的最小二乘估计方法是一种非参数方法,有助于充分的最小二乘估计。     

刑事合规的系统性反思与本土塑造

试点探索中的刑事合规已日渐成为“显学”,但也存在本体内容不够明确、规范构造相对不成熟、理论体系的建设不充分、立法跟进与支持不够、司法化滞后与规则空缺等结构性缺陷。刑事合规应以完整的要素与实施机制为存立前提,以奠定其作为刑事法制度的本体基础。刑事合规必须夯实其规范的本真内容,遵从综合性的规范意义,实现立体的规范评价,夯实合法地位。刑事合规的激励机制立足于功利主义,应当逐一澄清刑事合规的理论动能、激励原理,促进理论素养的持续生长。结合我国企业合规试点进展,有必要加快响应推动刑事合规立法进程,这会使激励机制变得“刚性”有力。为了克服刑事合规仍无“法”适用的试点困境,应在试验性司法模式下全面出台专门的指导意见与实施细则。     

运动补偿图像编码中的并行三步算法

本文提出了一种计算运动图像位移矢量Ｄ的新算法。这种新算法称为并行三步算法，模拟结果表明：这种新算法比现有的同类算法有更好的性能。     

港口吞吐量抽样调查方案设计

讨论了抽样调查在港口吞吐量调查中的应用前景，分析了港口吞吐量抽样调查方案设计的各个环节，包括：方案设计的原则、技术方法、抽样公式、调查时间、分层确定、季节变动处理和非抽样误差控制等。