A GENERALIZATION OF LEBESGUE DIFFERENTIAL THEOREM AND ITS APPLICATION

1 IntroductionLet fl C Rn. Classical Lebesgue differential theorem says:u(x) = liny IB.(x)l--' j u(y)dy a.e. in fl Vu E L'(fl),r-o js.(.)"(y)dy a.e. in fl Vu E L'(fl),where, Br(x) is the euclidean metric ball witl1 radius r and center x; IB.(x)I is the Lebesguemeasure of B.(x). Taking use of it, one can deduce Canpanato's integral chaxacterization ofH5lder continuous f[1nctions and Morrey's growing theorem of Dirichlet integration which playan imPortant role in regularity theories of …     

A SINGLE STEP SCHEME WITH HIGH ACCURACY FOR PARABOLIC PROBLEM

1 IntroductionConsider one-dimellsional parabolic problem in fl = (0, 1)and its weak formulatioll: find u(t) E S0 = {v 6 H'(fl), v(0) = 0} 8uch thatwhere the coefficients a(x) and b(x) are independent of t, Au = --(au')' ha, a(x) 2 ao > 0, b 20, and bilinear fOrm A(u, v) = fol(au'V' buv)dx i8 So-coercive, i.e. A(u, v) 2 ullu1li, u ESO, u > 0.Make in n = (0, 1) a subdivision: xo = 0 < x1 < x2 <.' < xn = 1. Set an elenlentry = (xj--l, xj), nddpoint xj--1/2 = (ry n--1)/2 and steplengt…     

Oscillatory and Asymptotic Behavior for Second Order Quasilinear Difference Equations

1 IntroductionConsider the second order quasilinear difference equationA(g(Ay.--l)) + f(n,y.) = 0, for n E N(no), (l'l)where A is defined by Ay. = Vn+1--yn, n E N(no) = {no, no + 1,'' }, nO E N = {l, 2,'. }.The following hold throughout the paPer:(H0) (i) g: R-R is a continuous increasing fUnction with propertiessgng(y) = sgny) g(R) = R;(il) f: N(no) x R--+ R is continuous as a function of y E R;(iii) yf(n,y) > 0 for n E N and y / 0.By a solution of the equation (1.l) we mean a non…     

STATIONARY STRUCTURES FOR A WEAKLY COUPLED ELLIPTIC SYSTEM ARISING IN TWO-PREDATOR, TWO-PREY MODELS

1 IntroductionIn tl1is paper we coIlsider positive steady-statc solutiolls to the fOllowi1lg weakly-c()uI)ledparabolic systenlwllere fl is a bouuded don1ain in Rn with sufficiently smooth bouudary, t1T = n x [0, T) and0f1T = 0fl x [0, T) l' is the olltward ul1it 11orIIlaJ vector. The col1stants ai, bi, (i = 1. 2, 3, 4, j =l, 2, 3, 4) are positive.The systenl (1.1) describes tlle LotkaVOlterra two-predator, two-prey nlodcl. u1 a11d u2represeIlt tl1e del1sitie8 of twDeprey wllile u3, '('4 …     

Comparison of variance estimators for the ratio estimator based on small sample

1. Introduction and Main ResultsSuppose the population of interest consists of N distinct units labelled by 1,' f N.Associated with unit i are two values K and Xi, with Xi > 0 (i = 1,' t N). Denote thepopulation means of K and X, by Y and X respectively. To estimate Y, it is customaryto select a simple raPdom sample of size n and to use the ratio estimatNn = RX if Xis available, where R = y/x is an estimator for population ratio R = Y/X, y and x arerespectively the 8ample mean8 of…     

EXISTENCE OF MULTIPLE SOLUTIONS FOR NONLINEAR ELLIPTIC EQUATIONS WITH MIXED BOUNDARY CONDITIONS

1 IntroductionWe deal with the problem{ it:;,."--'"'::3of (11)where 9 C RN, N 2 3 is a bounded domain with smooth boundary 0fl, 0n = ro U r1, ro andYl have (N -- 1)-dinlensiollal Hausdorff nleasuret r E L'(r1), yt 2 0, V * 0 on r1, 7 denotesthe u11it outward normal and p = 2* = ee is the critical SoboleY exponent fOr the Sobolevembedding V(O) - H(O), V(fl) = {u E H'(fl) l u = 0 on ro}'The case ro and r1 have positive (N -- 1)-dimellsional Hausdoor measure aud p = 0on r1 in (1.1), has…     

A NOTE ON THE CONSISTENCY OF LS ESTIMATES IN LINEAR MODELS

Consider,the linear regression modelyi = x'iβ ei, 1≤i≤n, n≥1, (1)where x1, x2,' are known Hvectors, P is the unknown pdimensional vector of regressioncoefficiellts, e13 e2,' is a seqdence of iid. random errors, and y1, y2t' are known obser-vations of the dependellt variable. Denote by F the common distribution of e1, e2,' t andwrite9. = {F: j:xar=0, 0< j:lxl'aF< oo}, 1 5 r 5 2.The Least Squares (LS) estimate of P isn rs)n = Z SJ'x.ui, Sn = Zxix:.. i=1 i=1Here we tacitly assum…     

CLASSIFICATION OF POSITIVE SOLUTIONS FOR NONLINEAR DIFFERENTIAL AND INTEGRAL SYSTEMS WITH CRITICAL EXPONENTS

We classify all positive solutions for the following integral system：{ui（x）=∫Rn1/│x-y│^n-α fi（u（y））dy,x∈R^n,i=1,…,m,0〈α〈n,and u（x）=（u1（x）,u2（x）…,um（x））.Here fi（u）, 1 ≤ i ≤m, monotone nondecreasing are real-valued functions of homogeneous degree n＋α/n-α and are monotone nondecreasing with respect to all the independent variables U1, u2, ..., urn.In the special case n ≥ 3 and α = 2. we show that the above system is equivalent to thefollowing elliptic PDE system：This system is closely related to the stationary SchrSdinger system with critical exponents for Bose-Einstein condensate     

OPTIMAL CONTROL PROBLEM FOR PARABOLIC VARIATIONAL INEQUALITIES

1 IntroductionThroughout this paPer, we denote n an opell bounded domain in Rn with smooth boulldary0fl, let Q = fl x (0,T) and r = 0n x (0,T). Let H = L'(n).We shall study the optimal control problems governed by the following system:y'(t) Ay(t) p(y(t) -- rk(t)) 9 B1u(t) I1(t), (1.1)y(0) = u0,rk'(t) Aop(f) 7(op(f)) = B2u(t) f2(f), (1.2)op(0) = op0with the state constrchtF(y) C W' (1.3)The pay-off functional is given byJ(y, u) = l"[,(,, y) h(u)]dt. (1.4)JoNote that y' and…     

一类高阶半线性椭圆型方程奇摄动广义边值问题

讨论了半线性椭圆型方程奇摄动广义边值问题.在适当的条件下研究了对应的边值问题广义解的存在唯一性及其渐近性态.     

一类广义解析函数的Riemann边值逆问题

本文给出了一类有关广义解析函数Riemann边值逆问题的数学提法．在将此边值逆问题转化为边值问题的基础上，借助于广义解析函数边值问题的相关理论，分别获得了此边值逆问题在正则型和非正则型情况下的解．     

THE BOUNDARY VALUE PROBLEMS OF A CLASS OF ELLIPTIC EQUATION WITH A CURVE OF TURNING POINT

The boundary value problems of a class of elliptic equation with a curveof turning point are considered. Using the method of multiple scales and thecomparison theorem, the asymptotic behavior of solution for the boundary valueproblem is studied.     

椭圆问题的非线性边界条件均匀化

在本文我们讨论了在等值面边值问题中的非线性边界条件的均匀化,推广了相应的边界条件均匀化结果,而且可应用到用于处理热敏电阻问题中的一类非线性非局部边值问题的边界条件均匀化问题。     

一类奇异方程两点边值问题的差分—样条校正解

本文考虑一类奇异方程两点边值问题的差分解和样条数值解法,证明了差分解,样条解分别从两侧逼近精确解,从而得到高精度的差分-样条校正解. 考虑如下形式的奇异边值问题:     

ON THE REGULARITY UP TO THE BOUNDARY OF SOLUTIONS OF ELLIPTIC BOUNDARY VALUE PROBLEMS

Abstract

We consider the regularity up to the boundary of solutions of those elliptic boundary value problems that can be treated by the non-variational theory developed by Schechter and others. The usual method of differential quotients is replaced by a method of Schappel [5] which is based on the properties of a Laplace-type operator 1-?2. In this paper the results of Schappel, which are given for boundary value problems in variational form, are extended to the non-variational case. We make important use of fractional order Sobolev spaces on the boundary and trace theorems.     

一类具有非局部边界条件的半线性椭圆型方程奇摄动问题

本文研究了一类具有非局部边界条件的奇摄动半线性椭圆型方程边值问题。在适当的条件下，利用比较定理讨论了问题解的渐近性态。     

A KIND OF NONLOCAL PROBLEMS FOR SINGULARLY PERTURBED REACTION DIFFUSION SYSTEMS

1991MRSubjectClassification35B2535K57Theauthorsstudiedakilldofsingularlypertllrbedproblemsin[1]-[61.Nowwe't()llsiderthefollowingsingularlyperturbedproblemforthenonlocalboulldaryconditionsouteof~Li'Ui=.fi(X,.UljUZj'',JINN,~),0相似文献   

NUMERICAL VERIFICATION METHODS FOR SOLUTIONS OF ORDINARY AND PARTIAL DIFFERENTIAL EQUATIONS

In this article, we describe on a state of the art of validated numerical computations for solutions of differential equations. A brief overview of the main techniques for self-validating numerics for initial and boundary value problems in ordinary and partial differential equations including eigenvalue problems will be presented. A fairly detailed introductions are given for the author's own method related to second-order elliptic boundary value problems. Many references which seem to be useful for readers are supplied at the end of the article.     

EXISTENCE AND NONEXISTENCE OF POSITIVE SOLUTIONS TO A THREE-POINT BOUNDARY VALUE PROBLEM

In this paper, we are concerned with the existence and nonexistence of positive solutions to a three-point boundary value problems. By Krasnoselskii’s fixed point theorem in Banach space, we obtain sufficient conditions for the existence and non-existence of positive solutions to the above three-point boundary value problems.