一类非线性三点边值问题两个正解的存在性

通过运用锥拉伸压缩型的不动点定理,对于一类非线性二阶三点边值问题建立了两个正解的两个存在性定理.     

一类非线性Klein-Gordon系统解的生命跨度

考虑如下非线性Klein-Gordon系统初边值问题解的生命跨度:utt-Δu α2u λuv2=0,vtt-Δv β2u λu2v=0,(x,t)∈Ω×[0,T),这里,Ω是R3中具有光滑边界的有界域,α,β为非零实数,λ<0,T>0.得到了其解的生命跨度的上界估计,且当能量为正时得到了一个新的能量上界.     

彩色等离子体显示器准备期动态修正技术

开发了一种彩色等离子体显示器的新型准备期动态修正技术,具有高对比度、低能量寻址、消除动态假轮廓(CLEAR)的特点,利用输入图像灰度的加权平均值与预置的灰度阈值比较,动态地调整准备期在1场中的位置,使动态调整后的灰度值能够更加真实地反映输入图像灰度的分布情况.同时,利用相邻两场采用不同子场编码与准备期动态修正相结合的改进技术,大幅度增加了显示灰度级数目.仿真结果表明,准备期动态修正CLEAR技术在消除动态假轮廓的同时,增强了对低灰度级图像的显示能力,并且最大限度地提高了整幅图像的显示质量.     

振动系统非线性特性的神经网络识别法

本文介绍了振动系统非线性特性识别的一种结构化神经网络方法，与标准的前馈网络融进了人们对系统的已知认识，神经网络仅仅用来学习未知部分，本文将其应用于振动系统非线性特性的识别，结果表明该法是可行的。     

THE UPWIND FINITE DIFFERENCE FRACTIONAL STEPS METHOD FOR NONLINEAR COUPLED SYSTEM OF DYNAMICS OF FLUIDS IN POROUS MEDIA

For nonlinear coupled system of multilayer dynamics of fluids in porous media,the secondorder and first order upwind finite difference fractional steps schemes applicable to parallel arithmeticare put forward,and two-dimensional and three-dimensional schemes are used to form a completeset.Some techniques,such as calculus of variations,multiplicative commutation rule of differenceoperators,decomposition of high order difference operators and prior estimates,are adopted.Optimalorder estimates in L~2 norm are derived to determine the error in the second order approximate solution.This method has already been applied to the numerical simulation of migration-accumulation of oilresources.     

Blind separation of sources in nonlinear convolved mixture based on a novel network

Blind separation of independent sources from their nonlinear convoluted mixtures is a more realistic problem than from linear ones. A solution to this problem based on the Entropy Maximization principle is presented. First we propose a novel two-layer network as the de-mixing system to separate sources in nonlinear convolved mixture. In output layer of our network we use feedback network architecture to cope with convoluted mixtures. Then we derive learning algorithms for the two-layer network by maximizing the information entropy. Based on the comparison of the computer simulation results, it can be concluded that the proposed algorithm has a better nonlinear convolved blind signal separation effect than the H.H. Y' s algorithm.     

非线性中立型控制系统的鲁棒稳定与鲁棒镇定

研究了一类不确定性的非线性中立型动态系统,系统具有多重时不变状态时滞。其不确定性满足范数有界条件。采用LyapunovV泛函的方法。建立了一类Lyapunov泛函。通过对控制系统(B,D,C)的分析,得出只要矩阵对(B,D)是完全可控的,或者是可稳定的,则在相应的条件下便得出相应的非线性中立型动态控制系统及滞后型动态系统可镇定的充分条件。建立了非线性中立型微分系统的时滞无关的渐近稳定性判别条件,以及非线性中立型动态控制系统的时滞无关鲁棒镇定的判据。同时,给出了相应的非线性滞后微分系统的时滞无关鲁棒稳定性的判据,以及非线性滞后动态控制系统的时滞无关鲁棒镇定性的代数判据。     

CORRECTION NYSTROM SOLUTIONS OF NON-SMOOTH FREDHOLM EQUATIONS

1.IntroductionTherearemanynumericalresultsaboutthenon-smoothintegralequationswherek(s,t)=k.(t)~k(s/t)/tandf(s)aregiven,uistheunknownsolution(e.g.[1-6]).Buttherearefewresultsaboutthehighorderandadaptivemethodscorrespondingly.Becauseoftheefficiencyinsolving…     

积分补偿的滑模控制器设计方法

对于一类具有不确定性扰动的非线性系统,提出了一种积分补偿的滑模控制器设计方法。为消除抖动现象,在切换面的邻近设置一边界层,在边界层外部,采用滑模控制方法驱动系统状态进入边界层。在边界层内部,在传统连续控制的基础上,引入积分补偿作用,以改善系统的稳态性能。对控制系统的稳定性进行了分析,并以倒立摆为对象进行了仿真验证,结果表明该控制方法是有效的。