混合分布最大值的极限分布

本文研究了独立同有限混合分布的随机变量的极值分布问题,具体讨论了有限混合正态分布,有限混合柯西分布,有限混合指数截尾分布等情形.     

埃尔兰分布极值的收敛速度

设{Xn,n≥1}是服从埃尔兰分布的独立同分布序列,研究了埃尔兰分布的极值分布问题,并得到了相应的收敛速度.

Abstract：

Let { Xn, n ≥ 1 } be an independent identically distributed random sequence with each Xn belonging to the Erlang distribution. In this note, the limiting distribution of the extremes and the associated rates of convergence are derived.     

有限混合短尾对称分布的极值分布

主要研究由短尾对称分布构成的有限混合分布函数的尾部特征及最大值的极限分布.     

有限混合偏t分布极值分布的点点收敛速度

研究了独立同有限混合偏t分布随机变量序列{Tn,n≥1}的规范化最大值的极限分布及其点点收敛速度.     

离散随机变量序列完备及非完备样本最大值的联合分布

设离散随机变量三角阵列{X_(n,k),K≤n,n≥1}存在数据缺失,对给定的n,M_n=max{X_(n,k),K≤n}为第n行的最大值,(~(M)_n)为该行观测到的随机变量的最大值,研究了离散型随机变量的分布函数某一参数变动时(~(M)_n),M_n)的联合渐近分布.

Abstract：

For triangular array discrete random variables {X_(n,k), k ≤ n,n ≥1},there may exist data missing observation. Denote M_n=max{X_(n,k),k ≤ n}the partial maximum and (~(M)_n) is the maximum of the observed random variables in the nth row.In this paper,the asymptotic joint distributions of (~(M)_n),M_n) of some discrete random variables are obtained as their parameters vary along with sample size.     

独立不同分布随机变量乘积的几乎处处中心极限定理

证明了独立不同分布随机变量乘积的几乎处处中心极限定理.

Abstract：

We prove an almost sure limit theorem for the product of sums of independent and non-identically distributed random variables.     

有限混合偏正态极值的极限分布

研究了有限混合偏正态分布极值的极限分布,并给出了相应的规范常数以及极值分布的点点收敛速度.     

Fractal Characteristics of Stagnic Anthrosols and the Relationship with Soil Micro-Structure

The Stagnic Anthrosols developed from quaternary yellow sedimentary parent material occupied an important position in Southwest China. Fractal dimensions of particle size and micro-aggregate size distributions of Stagnie Anthrosols and their relationship to soil micro-structure had been probed. Results showed that the soil particle size distributions were dominated by clay, the fractal dimensions of particle size distributions （Ds） were high and between 2.676-2.925, as the fractal dimensions of micro-aggregate size distributions （Da） were between 2.354-2.853. The fractal dimensions of particlesize distributions were preferably related with the ratio of coarse particles and fine particles （c/f20 ,m） and the micromorphological feature of skeleton grains. The evolution degree of micro-structure among horizons were reflected by the coefficient of variation of Ds within the profile. The fractal dimensions of micro-aggregate size distributions were related with the quantities, distributions of micro-aggregates and micro-pores. Results revealed that the soil micro-structures could be quantified by fractal dimensions preliminarily.     

一类新的含A-单调映像的完全广义集值强非线性混合隐拟变分包含

在Hilbert空间中引入和研究了一类新的包含A-单调映像的完全广义集值强非线性混合隐拟变分包含.通过应用A-单调映像的预解算子技巧,构造了一个新的迭代算法来逼近此类变分包含的解.讨论了由此算法产生的迭代序列的收敛分析.

Abstract：

A new class of completely generalized set-valued strongly nonlinear mixed implicit quasi-variational inclusions involving A-monotone mapping is introduced and investigated in Hilbert spaces. A new iterative algorithm for approximating the solutions of this class of completely generalized set-valued strong nonlinear mixed implict quasivariational inclusions is constructed by applying resolvent operator technique for A-monotone mapp1ng. The convergence analysis of the iterative sequences generated by the algorithm is discussed.     

关于三个问题的混合粘性迭代

在Hilbert空间中,对求解混合平衡问题、非扩张映射不动点问题及单调L-Lipschitz连续映射变分不等式问题解的公共元,引入了由粘性迭代方法确定的迭代序列.在一些参数控制条件下获得了一个强收敛定理.

Abstract：

This paper introduces an iterative sequence for finding a common element of the set of solutions of a mixed equilibrium problem,the set of fixed point problem of nonexpansive mapping and the set of solutions of the variational inequality problem.A strong convergence theorem is obtained under some parameter controlling conditions.     

Size Distributions of Sedimentary Populations

Separate sedimentary populations are not all characterized by lognormal size distributions. Populations of different sizes of material are produced by different mechanisms of abrasion: pebbles and gravel by singlestage crushing; sand by repeated abrasion; and silt and clay by chipping from larger grains. Each mechanism imposes a different size distribution on the product.     

截断密度函数分布的数字特征

目的 通过对一些典型分布的数字特征的讨论得到具有截断密度函数的连续型分布的数字特征与原分布数值特征的关系.方法 对正态分布、指数分布与Pareto分布,分别计算其截尾型、截头型与两头截型这3种类型的数学期望与方差.计算过程中利用了数学特征与方差的定义与性质.结果 正态分布中原分布的数学期望和方差分别是μ与σ2;截尾型的数学期望和方差分别是μ+σ2f(a)与σ2[(a-μ)f(a)+1-σ2f2(a)] ;截头型的数学期望和方差分别是μ-σ2f(b)与σ2[(μ-b)f(b)+1-σ2f2(b)];两头截型数学期望和方差是μ+σ2[f(a)-f(b)]与σ2-σ2bf(b)+μσ2f(b)+σ2af(a)-σ2μf(a)+σ4[f(a)-f(b)]2.指数分布与Pareto分布也相应地得到了截断前与截断后不同场合的数学期望与方差.结论 截断分布与原分布的数字特征既有联系又有区别.     

太湖磷化氢分布的相关性研究

以太湖为研究对象,考察了富营养化浅水湖泊中磷化氢的空间分布相关性.结果表明,湖水中磷化氢的浓度和大气中磷化氢的浓度有明显的相关性,它们之间的平均相关系数(r2)是0.43±0.25(n=40,P<0.05),底层湖水中磷化氢和湖底底泥中的磷化氢的相关性差,它们之间的平均相关系数(r2)只有0.050±0.057(n=40,P<0.05).湖泊磷化氢的空间分布相关性也表明湖泊底泥是磷化氢产生的重要来源,是导致湖泊水域磷化氢广泛分布的主要源.     

Distributions of microbial activities in deep subseafloor sediments

Diverse microbial communities and numerous energy-yielding activities occur in deeply buried sediments of the eastern Pacific Ocean. Distributions of metabolic activities often deviate from the standard model. Rates of activities, cell concentrations, and populations of cultured bacteria vary consistently from one subseafloor environment to another. Net rates of major activities principally rely on electron acceptors and electron donors from the photosynthetic surface world. At open-ocean sites, nitrate and oxygen are supplied to the deepest sedimentary communities through the underlying basaltic aquifer. In turn, these sedimentary communities may supply dissolved electron donors and nutrients to the underlying crustal biosphere.     

Distributions of phytoplankton blooms in the southern ocean

A regional pigment retrieval algorithm for the Nimbus-7 Coastal Zone Color Scanner (CZCS) has been tested for the Southern Ocean. The pigment concentrations estimated with this algorithm agree to within 5 percent with in situ values and are more than twice as high as those previously reported. The CZCS data also revealed an asymmetric distribution of enhanced pigments in the waters surrounding Antarctica; in contrast, most surface geophysical properties are symmetrically distributed. The asymmetry is coherent with circumpolar current patterns and the availability of silicic acid in surface waters. Intense blooms (>1 milligram of pigment per cubic meter) that occur downcurrent from continental masses result from dissolved trace elements such as iron derived from shelf sediments and glacial melt.     

混合广义伽马分布的渐进性质

讨论了独立同混合广义伽马分布随机变量序列的规范化最大值的极限分布及其点点收敛速度.     

一类推广伽玛分布秩序统计量的随机比较

本文将伽玛分布推广到变换伽玛分布,并验证韦伯分布,指数分布都是其特殊情况,令X=(X1,X2,...,Xn),Y=(Y1,Y2,...,Yn)是具有相同参数α(0<α<1),τ(0<τ<1)和分别具有不同参数(λ1,λ2,...,λn),(μ1,μ2,...,μn)的互相独立的服从变换伽玛分布的随机向量,则当时可以得到X(1)≥stY(1),X(n)≥stY(n)。     

哈尔滨沙尘沉降物的粒度组成及其源地分析

对2002年3月20日和2006年3月10日哈尔滨沙尘沉降物进行收集,同时还对城市松散的地表裸土进行了采样.粒度分析结果显示,沙尘沉降物粒度组成存在一定的差异.2002年沉降物的粉砂占71.2%,砂粒组分占21.7%,粘粒组分含量仅占7.1%;2006年沉降物的粉砂含量占73.6%,粘粒占19.8%,砂粒占6.6%.总体上看,2002年沉降物粒度比2006年沉降物明显偏粗.2002年沙尘沉降物粒度组成表现出明显的三峰分布特征,而2006年沉降物则呈双峰分布特征,说明哈尔滨沙尘沉降物是由多种不同成因的组分构成.城市地表裸土中可供远程搬运的细颗粒物质(＜63μm)含量较多,在60%以上,可为沙尘天气提供较多的粉尘物质.认为哈尔滨沙尘沉降物中砂粒级的粗颗粒物质是就地起沙,属于近源堆积;长期悬浮颗粒(＜18 μm)主要来源于远距离的外源输入,包括黄土高原在内的西北地区可能为哈尔滨沙尘提供了一定量的粉尘物质;而短期悬浮颗粒(18～63μm)主要是区域内部沙尘天气产生,来源于城市地表裸土.2002年沙尘以内源输入为主,但外源输入也占据一定比例,而2006年沙尘主要以外源输入为主,内源输入占据的比例相对较小.