THE EXISTENCE AND MOMENTS OF CANONICAL BRANCHING CHAIN IN RANDOM ENVIRONMENT

The concepts of branching chain in random environmnet and canonical branch-ing chain in random environment are introduced. Moreover the existence of these chains is proved. Finally the exact formulas of mathematical expectation and variance of branching chain in random environment are also given.  

具P-Laplacian算子型周期边值问题解的存在性

本文利用拓扑度理论和一些分析技巧讨论了具p—Laplacian算子型周期边值问题(φp(χ’))’+d/dt gradF(χ)+gradG(χ)=e(t),χ(0)=χ(T),χ’(0)=χ’(T)解的存在性,在对阻尼项d/dtgradF(χ)没有任何限制的前提下,给出了解存在的充分条件.  

Existence of at Least Two Periodic Solutions of a Ratio-dependent Predator-prey Model with Exploited Term

In this paper, we study a non-autonomous ratio-dependent predator-prey model with exploited term. By means of the coincidence degree theory, we establish a sufficient condition for the existence of at least two positive periodic solutions of this model.  

统计自相似集的重分形分解

设K是由Graf定义的统计自相似集.本文构造了一支撑在K上的随机测 度p,并研究了结合P的K的重分形分解,得到了分形谱函数f(α)的表达式.  

实Clifford分析中超正则函数列和函数空间的性质

定义了实Clifford分析中超正则函数列的一致有界、内闭一致有界及内闭一致收敛等概念,并讨论了超正则函数列及超正则函数空间的几条性质.  

非粘性土壤中溶质运移问题的守恒混合有限元法及其数值模拟

奉文建立了非粘性土壤水中溶质运移问题的守恒混合元格式,讨论了广义解和混合元解的存在唯一性,并给出了误差估计.数值模拟结果表叫,用该方法模拟溶质运移问题是合理有效的,不仅提高了通量的模拟精度,而且使计算稳定.  

一种修正的HS共轭梯度法及全局收敛性

1 引言 考虑无约束极小化问题: min x∈Rn f(x) 其中f(x)连续可微,其梯度函数用g(x)表示.共轭梯度法求解(1)的常用迭代格式为: xk+1=xk+αkdk, dk={-gk,k=1,-gk+βkdk-1,k≥2.(3)  

一种修正的谱CD共轭梯度算法的全局收敛性

In this paper,we present a new nonlinear modified spectral CD conjugate gradient method for solving large scale unconstrained optimization problems.The direction generated by the method is a descent direction for the objective function,and this property depends neither on the line search rule,nor on the convexity of the objective function.Moreover,the modified method reduces to the standard CD method if line search is exact.Under some mild conditions,we prove that the modified method with line search is globally convergent even if the objective function is nonconvex.Preliminary numerical results show that the proposed method is very promising.  

从p—m链到随机环境中的马氏链

第一节引进了p一m链的概念,并用之构造了与它相应的随机环境中的马氏链和绕积马氏链、第二节引进了一系列与随机环境中的马氏链相关的概率特性函数,并得到了这些函数之间的一系列关系.这些结果是经典马氏链的相应结果的一般化,它们在随机环境中的马氏链的极限理论的研究中是很有用的。  

Multifractal Decomposition of Statistically Self-Similar Sets

Let K be a statistically self-similar set defined by Graf. In this paper, we construct a random measure ρ which is supported by K and study the multifractal decomposition for K with ρ. Under such a decomposition, we obtain the expression of the spectrum function ƒ(α). Received July 18, 1997, Accepted October 13, 2000