反函数具有极值个数直接超越奇点的亚纯函数的亏值

本文建立了如下结果:设 w=f(z)是一个下级为μ的亚纯函数,z=(w)为其反函数,具有 k(1≤k<∞)个判别直接超越奇点(α_i)i=1,2,…,k。如果 k=2μ,f(z)的亏值数目为 P,则当μ=0时,有 P≤1;当μ>0时,有 P≤2μ。     

高TcBapbO3热敏电阻电极制作及阻温特性测试

本文对高ＴｃＰＴＣ热敏电阻的电极制作和阻湿特性测试问题进行了讨论，对Ｔｃ高达７００－８００℃热敏电阻拟用金属铂作电极。设计了直接将铂丝压入电阻的模具，并利用计算机测试阻温特性。     

PWM法在水文线型假设检验中的应用

本文简述了目前水文计算中水文随机变量如洪峰，洪量等的概率分布函数的型式选择的理论和方法。在此基础上计算了当线型选为Ｐｅａｒｓｏｎ－Ⅲ型，以概率权重矩法估计其中参数时五个常用统计量的临界值表，同时用该表对僵５０个站点洪峰系列的分布线型进行了假设检验，并将检验结果与用适线法估计参数时的检验结果进行了对比，结果表明；采用Ｐ－Ⅲ型分布描述我国的洪峰系列是适合的。     

On Percolation with Fibers or Layers

We consider site percolation on Z ^d, directed edges going from any sZ ^d to s+A ₁,..., s+A _n, where A ₁,..., A _n are the same for all sites and at least two of them are noncollinear. A site is closed if it belongs to p+Block, where p is a point in a Poisson distribution in R ^dZ ^d with a density and Block={sL: |s|M}+{sR ^d: |s|}, where L is a linear subspace of R ^d, |·| is the Euclidean norm, =max(|A ₁|,..., |A _n|) and M is a parameter. We study the behavior of *, the critical value, and P _closed*, corresponding critical percentage of closed sites, when M. Denote R ^d/L the factor space. Call two nonzero vectors U, V codirected if U=kV, where k>0. Theorem. If there are A _i and A _j whose projections to R ^d/L are not codirected, then *1/M ^dim(L) and P _closed* remains separated both from 0 and 1 when M. If projections of all A ₁,..., A _n to R ^d/L are codirected, then *1/M ^dim(L)+1 and P _closed*1/M when M.     

Extremes of a Gaussian Process and the Constant H α

Consider a triangular array of standard Gaussian random variables {_n,i, i 0, n 1} such that {_n,i, i 0} is a stationary normal sequence for each n 1. Let _n,k = corr(_n,i,_n,i+k). If (1-_n,k)log n _k (0,) as n for some k, then the locations where the extreme values occur cluster and the limiting distribution of the maxima is still the Gumbel distribution as in the stationary or i.i.d. case, but shifted by a parameter measuring the clustering. Triangular arrays of Gaussian sequences are used to approximate a continuous Gaussian process X(t), t 0. The cluster behavior of the random sequence refers to the behavior of the extremes values of the continuous process. The relation is analyzed. It reveals a new definition of the constants H used for the limiting distribution of maxima of continuous Gaussian processes and provides further understanding of the limit result for these extremes.     

Compound Poisson Approximation of the Number of Exceedances in Gaussian Sequences

Consider a finite sequence of Gaussian random variables. Count the number of exceedances of some level a, i.e. the number of values exceeding the level. Let this level and the length of the sequence increase simultaneously so that the expected number of exceedances remains fixed. It is well-known that if the long-range dependence is not too strong, the number of exceeding points converges in distribution to a Poisson distribution. However, for sequences with some individual large correlations, the Poisson convergence is slow due to clumping. Using Steins method we show that, at least for m-dependent sequences, the rate of convergence is improved by using compound Poisson as approximating distribution. An explicit bound for the convergence rate is derived for the compound Poisson approximation, and also for a subclass of the compound Poisson distribution, where only clumps of size two are considered. Results from numerical calculations and simulations are also presented.     

Point processes and multivariate extreme values

A new model for point processes is developed which assumes that the interarrival times are exponentially distributed and follow joint multivariate extreme value distributions. It is shown that such processes may arise via natural generating procedures, and that, under very weak assumptions, that they can be approximated as closely as desired by appropriate finite models.     

Limit theorems for records from discrete distributions

Weak and strong functional limit theorems are obtained for record values and record epochs in a sequence of independent random variables with common distribution F. The emphasis is on the case in which F is concentrated on the non-negative integers. For contrast, the well-known case of continuous F is also considered. Analogues of results obtained earlier by Resnick, de Haan and the author for continuous F are presented here for F concentrated on the non-negative integers. Also is investigated under which circumstances the latter case is so close to the continuous F case that the resulting limit theorems are the same.     

Thermodynamic interactions of polypropylene,poly(vinylidene chloride), sulphonyldiphenyl formaldehyde resin and poly(vinyl pyrrolidone) as stationary phases in GLC with some selected solvents

The interaction energies (X₁) between the polymers polypropylene, poly(vinylidene chloride), sulphonyldiphenyl formaldehyde resin and poly(vinyl pyrrolidone) and the solvents toluene, ethylbenzene, isopropylbenzene, ortho, meta, and para-xylene are determined by gas chromatography. As shown in earlier publications, this technique for the determination of X₁, can be extended to similar systems of theoretical as well as of practical importance, although the selection of the present systems was primarly made on the fact that these systems are of industrial interest and have not so far been investigated by gas-liquid chromatography. The studies were carried out at two temperatures and the results obtained show a decrease of X₁ with an increase of temperature.