一种基于物体质心的图像自动化校准方法

图像校准是将任意相邻两图像都具有公共部分的一列图像合成一副全图的图像处理过程.而图像自动化校准的难点在于对一组图像公共部分特征信息的提取和自动匹配,尤其是自动匹配和图像校准的误差分析.本文基于放射变换不变性,给出了一种基于特征信息质心的自动匹配方法,与目前国际上主流特征提取和特征校准方法相比,本文方法较准确,且适用于卫星图片及一些MRI和CT 图片.本文方法的另一优点是具有线性计算复杂度.     

VALUE-AT-RISK的核估计理论

如何根据历史数据估计Value-at-Risk（VaR）;是风险分析与管理中一个重要的基本问题.木文基于非参数核估计方法,通过拟合实际数据过程的分布,构造了VaR的估计.在合适的相依数据条件下,证明了该估计量的渐近正态性,并给出了渐近方差的估计.由此表明:本文所构造的估计量不仅比参数模型具有更广泛的适应性,而且如同参数模型具有n~（-1/2）的收敛速度.本文假设的数据过程避免使用混合性,可很好地适用于金融管理中广泛应用的ARMA与GARCH模型族及非线性模型.     

First-order definability and algebraicity of the sets of annihilating and generating collections of elements for some relatively free solvable groups

We study the first-order definable, Diophantine, and algebraic subsets in the set of all ordered sets generating a group or generating a group as a normal subgroup for some relatively free solvable groups.     

种群死亡定律的研究

本文详细了研究了种群纯死定律的概率结构，给出了求解转移概率显式的三种方法及一个定理，最后拟合了一个实例。     

一类随机图的演化

定义一随机图过程:如果图Gt-1不是完全图时,图Gt分别以概率p和q加一个点和一条有向边;如果图Gt-1是完全图时,则以概率1加一个点．研究图Gt顶点和边的概率分布以及当顶点数固定时,边数的期望界值估计．     

密度函数垂直表示及在非均匀随机数生成中的应用

本文给出密度函数垂直表示法,以及利用该方法产生给定概率密度函数的随机向量的一般算法。     

On the Smallest Base of the Stone Space

51.IntroductionandDefinitionIn[l]ithadbeenprovedthat:ifadistributivelatticeLpossessesthesmal1estsetofgen-eratingelements,thenLsatisfiesjointinfinitelydistributivelaw.AndinL2jproved:acom-pletelydistributivelatticepossessesminimalsetofgeneratingelements,thenLisastrongalge-bra.lnthispaper,theconceptofthesetofgeneraingelementsisdifferentfrom[1j.Wewillsolvetheexistenceproblemoftheminimalsetofgeneratingelementsbyuseofthetopologicalrepresentation.Firstwedefinethesmallestbase,strongopensetinthetopol…     

The skew elliptical distributions and their quadratic forms

In this paper, a family of the skew elliptical distributions is defined and investigated. Some basic properties, such as stochastic representation, marginal and conditional distributions, distribution under linear transformations, moments and moment generating function are derived. The joint distribution of several quadratic forms is obtained. An example is given to show that the distributions of some statistics as the functions of the quadratic forms can be derived for various applications.     

On Estimating the Cumulant Generating Function of Linear Processes

We compare two estimates of the cumulant generating function of a stationary linear process. The first estimate is based on the empirical moment generating function. The second estimate uses the linear representation of the process and the empirical moment generating function of the innovations. Asymptotic expressions for the mean square errors are derived under short- and long-range dependence. For long-memory processes, the estimate based on the linear representation turns out to have a better rate of convergence. Thus, exploiting the linear structure of the process leads to an infinite gain in asymptotic efficiency.