Probabilistische Topologien

Referring only to closed L-fuzzy sets we introduce a concept of probabilistic topological spaces including random metric spaces ([17]) statistical metric spaces ([9][15]) and fuzzy uniform spaces studied by Lowen [11]. In particular probabilistic topologies in the sense of Frank [5] satisfying the additional property (R3) are equivalent to systems of closed [0, 1]-fuzzy sets. Moreover random topologies as well as fuzzy topologies ([3],[13]) equipped with the property (03) can be considered as probabilistic topologies.     

A remark on gauge symmetries in Ising spin glasses

This paper studies a particular line in the parameter space of the FK random interaction random cluster model for spin glasses following Katsura ([K]) and Mazza ([M]). We show that, after averaging over the random couplings, the occupied FK bonds have exactly a Bernoulli distribution. Comparison with explicit calculations on trees confirms the marginal role of FK percolation in determining phase transitions. Received: 1 October 1997 / Revised version: 18 May 1998     

STRONG LIMIT THEOREMS FOR BLOCKWISE m-DEPENDENT RANDOM VARIABLES AND A GENERALIZATION OF THE CONJECTURES OF MORICZ

The authors introduce the definition of block-wise m-dependent with respect to somepositive real sequence for random variables taking values in a separable Banach space,prove some general results on the strong convergence of blockwise m-dependent randomvariables,and in particular,give positive answers to Móricz conjectures([5])by asharper theorem.     

Recurrent random walks on certain classes of groups

This article is divided into two parts: in the first we give some results about renewal and normality of a recurrent random walk (r.w.) on an abelian group, without the Harris hypothesis, which will extend the theorems of S.C. Port and C.J. Stone ([8]) to a larger class of functions. They are stated in the Theorems 1.14 and 1.15. The technique will be to approximate the recurrent r.w. by a Harris recurrent r.w., for which the recent results of A. Brunel and D. Revuz ([2–4]) hold.the second part the results of the first part are extended to a particular class of nonabelian groups.The author wishes to thank A. Brunel for several very useful conversations and suggestions.     

Random creation and dispersion of mass

Consider evolution of density of a mass or a population, geographically situated in a compact region of space, assuming random creation-annihilation and migration, or dispersion of mass, so the evolution is a random measure. When the creation-annihilation and dispersion are diffusions the situation is described formally by a stochastic partial differential equation; ignoring dispersion make approximations to the initial density by atomic measures and if the corresponding discrete random measures converge “in law” to a unique random measure call it a solution. To account for dispersion Trotter's product formula is applied to semiflows corresponding to dispersion and creation-annihilation. Existence of solutions has been a conjecture for several years despite a claim in ([2], J. Multivariate Anal. 5, 1–52). We show that solutions exist and that non-deterministic solutions are “smeared” continuous-state branching diffusions.     

Multidimensional large deviation local limit theorems

An earlier paper by the author ([4], 97–114) established large deviation local limit theorems for arbitrary sequences of real valued random variables. This work showed clearly the connection between the Cramér series and large deviation rates. In this article we present large deviation local limit theorems for arbitrary multidimensional random variables based solely on conditions imposed on their moment generating functions. These results generalize the theorems of [12], 100–106) for sums of independent and identically distributed random vectors.     

带负顾客和非空竭服务随机休假的M~([x])/G/1可修排队系统

研究了带负顾客和非空竭服务随机休假的M~([X])/G/1可修排队系统.负顾客不仅仅移除一个正在接受服务的正顾客,而且还使得服务器损坏而立即进行修理.通过构造一个具有吸收态的马尔可夫链求得了系统稳态存在的充分必要条件.利用补充变量法求得了系统的排队指标和可靠性指标.最后我们还给出了一个数值实例.     

Estimation of some functional of the population distribution based on a stratified random sample

Summary In the preceding papers ([7], [8] and [9]), one of the authors discussed about the estimation of variances, covariances and correlation coefficients of the population based on a stratified random sample. In this paper we consider more general problem; estimating some functional θ(F) of the population distributionF based on a stratified random sample, which include our previous papers as special cases. We propose an unbiased estimator of θ(F) based on a stratified random sample and give an asymptotic expression of the gain in precision due to stratification in the case of proportional allocation. Furthermore, we present the general form of the optimum stratification in the proportional allocation for the estimation of θ(F).     

Channels with arbitrarily varying channel probability functions in the presence of noiseless feedback

In this article we study a channel with arbitrarily varying channel probability functions in the presence of a noiseless feedback channel (a.v.ch.f.). We determine its capacity by proving a coding theorem and its strong converse. Our proof of the coding theorem is constructive; we give explicitly a coding scheme which performs at any rate below the capacity with an arbitrarily small decoding error probability. The proof makes use of a new method ([1]) to prove the coding theorem for discrete memoryless channels with noiseless feedback (d.m.c.f.). It was emphasized in [1] that the method is not based on random coding or maximal coding ideas, and it is this fact that makes it particularly suited for proving coding theorems for certain systems of channels with noiseless feedback.As a consequence of our results we obtain a formula for the zero-error capacity of a d.m.c.f., which was conjectured by Shannon ([8], p. 19).     

连续可导函数类的最优拉格朗日插值

在构造拉格朗日插值算法时,插值结点的选择是十分重要的.给定一个足够光滑的函数,如果结点选择的不好,当插值结点个数趋于无穷时,插值函数不收敛于函数本身.例如龙格现象:对于龙格函数f(x)=1/1+25x^2,如果拉格朗日插值的结点取[-1,1]上的等距结点,那么逼近的误差会随着结点个数增多而趋于无穷大⑴,由此可知插值结点的选择尤为重要.     

Generalizations of two formulas of Crofton's in the theory of geometric probabilities

From a method which Crofton developed for the solution of certain problems in the theory of geometric probabilities ([1] pp. 785–6), Deltheil ([2] pp. 47–65, [3] pp. 35–50), and later Kendall and Moran, following Deltheil closely ([5] pp. 24–27, 41–42), derived two formulas which they named after Crofton. In [7], generalizations of those formulas were given and conditions for their validity were stated explicitly, apparently for the first time. It thus became evident that, e.g., no hypotheses concerning «invariance under translation and rotation» ([3] p. 24) are needed (strictly, they are even not consistent); in fact, no special assumption whatsoever about the probability field need be made. In the present note these results are still further extended.     

Anneaux polynomiaux a deux variables

Some types of extensions of skew fields are now known: Galois quadratic extensions ([7]), cyclic extensions ([1]), general quadratic extensions ([4]), binomial extensions ([5]). All these extensions belong to the class of pseudolinear extensions ([8]). A new class of extensions, the so-called «hexaphic extensions», which extends the class of pseudo-linear extensions, will be studied in the other papers in future. For this study, we introduce in this paper skew polynomials rings in two variables over a ring, which extend the well-known skew polynomial rings in one variable (pseudolinear) first studied by O. Ore ([10]).     

Multiplicities of singular points on arcs and curves of cyclic order four

It is known that a strongly differentiable ([3], 3.1) curveC ₄ of cyclic order four in the real conformal plane contains at most (in fact exactly) four singular points ([4], 3.6 and [1], 4.1.4.3). Assuming no differentiability conditions the best bound obtained was eleven ([4] and [1], 4.1.3) and then reduced to the best possible bound; namely four ([5], 4.1). In this paper multiplicities are introduced for singular points on such arcs and curves. It is shown that the sum of the multiplicities of all singular points on arcs and curves of cyclic order four is indeed at most four; cf.5.5.     

可加广义代数格上的 Tietze 扩张定理

可加的广义代数格范畴与 T₀ 拓扑空间范畴相等价, 从这个观点出发, 作者把可加广义代数格作为一个闭集格, 在其上建立 Urysohn 引理和 Tietze 扩张定理. 这是拓扑理论在格上的一种新推广, 有助于格上拓扑理论的研究和广义连续格理论的应用.     

Semigroups which contain magnifying elements are factorizable

A semigroup S is factorizable if it contains two proper subsemigroups A and B such that S = AB. An element a of a semigroup 5 is a left ( resp. right) magnifier if there exists a proper subset M of S such that S = aM (resp. S - Ma).

In this paper we prove that every semigroup containing magnifying elements is factorizable. Thus we solve a problem raised up by F. Catino and F. Migliorini in [2], namely to find necessary and sufficient conditions in order that a semigroup with magnifying elements be factorizable. Partial answers to this problem have been obtained by K. Tolo ([14]), F. Catino and F. Migliorini ([2]), for semigroups with left magnifiers and which are regular or have left units or right magnifiers, by V. M. Klimov ([9]), for Baer-Levi and Croisot-Teissier semigroups, and by M. Gutan ([4]), for right cancellative, right simple, idempotent free semigroups.     

Convergence of logarithmic means of multiple Walsh-Fourier series

Norlund logarithmic means of multiple Walsh-Fourier series acting from space Llnd-1 L ([0, 1)d) ,d≥1 into space weak-L1([0,1)d) are studied. The maximal Orlicz space such that the Norlund logarithmic means of multiple Walsh-Fourier series for the functions from this space converge in d-dimensional measure is found.     

Higher-order Nonlinear System of Equations of Changing Type

In practical problems there appears higher-order equations of changing type([1]). But, there are only a few of papers concerning this type of equations ([2]-[6]). In this paper, the global existence of regular solutions to the Initial-boundary value problem for a class of higher-order system of equations of changing type with a strong nonlinear term is studied.     

An exact rate of convergence in the functional central limit theorem for special martingale difference arrays

Summary Since the topology of weak convergence of probability distributions on the Borel -field of the space C= C([0, 1]) is metrizable, it is natural to describe the speed of convergence in weak functional limit theorems by means of an appropriate metric. Using the metric proposed by Prokhorov it is shown that under suitable conditions the rate of convergence in the functional central limit theorem for C-valued partial sum processes based on martingale difference arrays is the same as in the special case of row-wise independent random variables where this rate is known to be an optimal one.     

确定性与随机化框架下的Sobolev类上的嵌入与积分的复杂性

本文研究各向异性Sobolev类上的嵌入以及积分问题的复杂性.我们得到这些问题在确定性、随机化框架以及平均框架下n-重最小误差的精确阶.所得结果表明在非嵌入连续函数空间情形,随机误差与平均误差实质性地小于确定性误差.从数量级看,对于嵌入问题,收敛阶最大改进可达到n-1+ε,这里ε是任意正数.对于积分问题最大改进可达到n...     

一种构造可积Hamilton系统的新方法

建议了一种新的构造可积Hamilton系统的方法。对于给定的Poisson流形,本文利用Dirac-Poisson结构构造其上的新Poisson括号[1],进而获得了新的可积Hamilton系统。构造的Poisson括号一般是非线的,并且这种方法也不同于通常的方法[2～4]。本文还给出了两个实例。