SOME GENERALIZATION OF GRONWALL-BIHARI INTEGRAL INEQUALITIES AND THEIR APPLICATIONS

The interest of this paper lies in the estimates of solutions of the three kinds of Gronwail-Bihari integral inequalities:(Ⅰ) y(x)≤f(x) sum from i=1 to n(g_i(x)integral from n=0 to x(h_i(d)y(s)ds)),(Ⅱ) y(x)≤f(x) g(x)φ(integral from n=0 to x(h(s)w(y(s))ds))(Ⅲ) y(x)≤f(x) sum from i=1 to n(g_i(x)integral from n=0 to a(h_i(s)y(s)ds g_(n 1)φ(integral from n=0 to x(h_(n 1)(s)w(y(t))ds)).The results include some modifications and generalizations of the results of D. Willett, U. D. Dhongade and Zhang Binggen. Furthermore, applying the conclusion on the above inequalities to a Volterra integral equation and a differential equation, the authors obtain some new better results.     

一类非线性微分方程的可积性准则

本文考虑二阶线微分方程 y″+t~2f(t)g(y)=0 (1) 的可积性,设G(y)=integral from n=0 to y(g(s)ds),我们证明了在一定的条件下,方程(1)的一切解满足估计: integral from n=t_0 to ∞((G(y(t))/f(t))dt)〈+∞。     

EXISTENCE OF PERIODIC SOLUTIONS OF SYSTEM OF DIFFERENCE EQUATIONS

This paper studies the nonautonomous nonlinear system of difference equationsΔx(n)=A(n)x(n)+f(n,x(n)),n∈Z,(*) where x(n)∈R~N,A(n)=(a_(ij)(n))N×N is an N×N matrix,with a-(ij)∈C(R,R) for i,j= 1,2,3,...,N,and f=(f_1,f_2,...,f_N)~T∈C(R×R~N,R~N),satisfying A(t+ω)=A(t),f(t+ω,z)=f(t,z) for any t∈R,(t,z)∈R×R~N andωis a positive integer.Sufficient conditions for the existence ofω-periodic solutions to equations (*) are obtained.     

Fejèr-Korovkin算子及一种内插线性算子的渐近展开

设f(x)∈C_(2π)。本文讨论两种线性算子对f(x)的逼近,全文分两个部分。 在第一部分中,我们考虑在正卷积型三角多项式线性算子中占重要地位的Fejr-Korovkin算子K_n(f,x)=1/π integral from -x to π (f(x+t)k_n(t)dt),其中k_n(t)≡1/2+sum from k=1 to n (ρ_k~((n)) cos kt)=1/2+sum from k=1 to n (F_n(k/n+2)coskt),F_n(x)=(1-x)cosπX+1/n+2 cot π/n+2·sinπx.由于它满足Korovkin条件:所以有下述结果:设f(x)∈C_(2π),f″(x)∈C_(2π)。那么,当n→∞时,成立着     

LARGE DEVIATIONS FOR SYMMETRIC DIFFUSION PROCESSES

Let a(x)=(a_(ij)(x)) be a uniformly continuous, symmetric and matrix-valued function satisfying uniformly elliptic condition, p(t, x, y) be the transition density function of the diffusion process associated with the Diriehlet space (, H_0~1 (R~d)), where(u, v)=1/2 integral from n=R~d sum from i=j to d(u(x)/x_i v(x)/x_ja_(ij)(x)dx).Then by using the sharpened Arouson's estimates established by D. W. Stroock, it is shown that2t ln p(t, x, y)=-d~2(x, y).Moreover, it is proved that P_y~6 has large deviation property with rate functionI(ω)=1/2 integral from n=0 to 1<(t), α~(-1)(ω(t)),(t)>dtas s→0 and y→x, where P_y~6 denotes the diffusion measure family associated with the Dirichlet form (ε, H_0~1(R~d)).     

Oscillatory Strongly Singular Integral Associated to the Convex Surfaces of Revolution

Here we consider the following strongly singular integral T_(?,γ,α,β)f (x, t) =∫ _(R~n)e~[i|y|~(-β)]?(y/|y|)/|y|~(n+α)f (x - y, t - γ(|y|))dy,where ? ∈ L~p(S~(n-1)), p 1, n 1, α 0 and γ is convex on(0,∞).We prove that there exists A( p, n) 0 such that if β A( p, n)(1 + α), then T_(?,γ,α,β)is bounded from L~2(R~(n+1)) to itself and the constant is independent of γ. Furthermore,when ? ∈ C~∞(S~(n-1)), we will show that T?,γ,α,βis bounded from L~2(R~(n+1)) to itself only if β 2α and the constant is independent of γ.     

The Berry-Esseen Theorem and Non-Uniform Estimate for U-Statistics

Let X_1,X_2,…,X_n be independent random variables. Define a U-statistic by U_n(?)~(-1)sum from 1≤i≤j≤n (h(X_i,X_j), where h(x,y) is a symmetric function of two variables x,y and that Eh(X_i,X_j)=0(i≠j, i,j=1,2,…,n). Write g_j(X_i)=E(h(x_i,x_j)|x_i),g(X_1)=1/n-1 sum from j=1 j≠i to n g_j(X_i) We give the following two theorem: Theorem 1 Suppore that     

ON MULTILINEAR FRACTIONAL INTEGRALS

§1 Introduction In this paper we consider the boundedness of the followingoperators T_α(A_1, …, A_m, f) (x)=∫_(IR~n) multiply from j=1 to m((R_(K_j+1)(A_j, x, y))/(|x-y|~K_j))f(y)/(|x-y|~(n-α))dy (1)     

一类积分不等式及其应用

研究了一类新的非线性延迟积分不等式φ(u(t))≤(n_1(t)+∫_o~(a(t)) f_1(s)w_1(u(s))ds)(n_2(t)+∫_o~t f_2(s)w_2)(u9(s))ds),t∈R_+得到了新的结论,推广了已有的若干结果.并举例说明其应用.     

关于重节点多元B样条的构造

1.引言 设x~0,x~1,…,x~n∈R~s是互异的点,n≥s,vol_s[x~0,…,x~n]>0,这里[x~0,…,x~n]={x=sum from j=0 to n(υ_jx~j|(υ_0,…,υ_n)∈S~n),S~n={(υ_0,…,υ_n)|sum from j=0 to n(υ_j=1,υ_j≥0,j=0,…,n}。 以x~i为m_i 1重节点,m_i≥0,i=0,…,n,的多元B样条M(x|(x~0)~(m_0 1),…,(x~n)~(m_n 1))由下式定义(见C.A.Micchelli[1]):     

Classification of positive solutions to an integral system with the poly-harmonic extension operator

In this paper, we investigate the positive solutions to the following integral system with a polyharmonic extension operator on R~+_n:{u(x)=c_n,a∫_?R_+~n(x_n~(1-a_v)(y)/|x-y|~(n-a))dy,x∈R_+~n,v(y)=c_n,a∫_R_+~n(x_n~(1-a_uθ)(x)/|x-y|~(n-a))dx,y∈ ?R_+~n,where n 2, 2-n a 1, κ, θ 0. This integral system arises from the Euler-Lagrange equation corresponding to an integral inequality on the upper half space established by Chen(2014). The explicit formulations of positive solutions are obtained by the method of moving spheres for the critical case κ =n-2+a/n-a,θ =n+2-a/ n-2+a. Moreover,we also give the nonexistence of positive solutions in the subcritical case for the above system.     

正平均曲率的一个注记

设Ω是R~n(n≥2)中的单连通有界开集,其边界骪Ω是无限可微的封闭超曲面。设H(S)是Ω的平均曲率(n=2,H(s)是曲率)。假定s∈Ω,H(s)>0。记 则我们证明 ii)H_0/H_1≤(1-1/n)~2|Ω|/|Ω|~2 integral from n=Ω to (ds)/(H(s))~2, iii)|Ω|≤(1-1/n)integral from n=Ω to (ds)/H(s), 我们有如下未解决问题:是否成立不等式     

用〔F,d_n〕平均逼近周期函数

设f(x)∈L_(2π)的Fourier级数为 f(x)～a_0/2+sum from n=1 to ∞ (a_ncosnx+b_nsinnx)sum from n=0 to ∞(A_n(f,x)) (1)以s_n(f,x)sum from i=0 to n(f,x)表示(1)第n部分和。称序列     

关于凸函数的Hadamard不等式的拓广(英文)

设,是区间[a,b]上连续的凸函数。我们证明了Hadamard的不等式 f(a+b/2)≤1/b-a integral from a to b (f(x)dx)≤f(a)+f(b)/2可以拓广成对[a,b]中任意n+1个点x_0,…,x_n和正数组p_0,…,p_n都成立的下列不等式 f(sum from i=0 to n (p_ix_i)/sum from i=0 to n (p_i))≤|Ω|~(-1) integral from Ω (f(x(t))dt)≤sum from i=0 to n (p_if(x_i)/sum from i=0 to n (p_i),式中Ω是一个包含于n维单位立方体的n维长方体,其重心的第i个坐标为sum from i=i to n (p_i)/sum from i=i-1 (p_i),|Ω|为Ω的体积,对Ω中的任意点t=(t_1,…,t_n) ω(t)=x_0(1-t_1)+sum from i=1 to n-1 (x_i(1-t_(i+1))) multiply from i=1 to i (t_i+x_n) multiply from i=1 to n (t_i)。不等式中两个等号分别成立的情形亦已被分离出来。 此不等式是著名的Jensen不等式的精密化。     

一类非线性Volterra积分微分方程的周期解

本文借助laplace变换及不动点理论,研究了系统(?)=Ax+integral from n=0 to t(c(t-s)x(s)ds)+F(t,x)的周期解的存在性。唯一性问题,给出了一组充分条件.     

ON THE EXISTENCE OF INFINITELY MANY CRITICAL POINTS OF THE EVEN FUNCTIONAL integral from n=Q to (F(x,u,Du)) integral from n=■Q to (G(x,u))

In this paper we deal with the existence of infinitely many critical points of the even functional I(u)=integral from n=Q to (F(x,u,Du)) integral from n=(?)Q to (G(x,u)), u∈W~(1,p)(Ω),where G(x, u)=integral from n=o to u (g(x,t)dt), under the weak structure conditions on F(x, u, q) by the Mountain Pass Lemma.     

奇异积分方程的逼近解法

对于奇异积分方程a(x)y(x)+((b(x))/π)integral from n=-1 to 1 ((y(t))/(t-x))dt+λ integral from n=-1 to 1 K(x,t)y(t)dt=f(x) -1≤x≤1本文通过对核函数K(x,t)进行二元样条插逼近,利用退化核的Fredbolm方程的基本理论,给出了奇异积分方程的逼近解,证明了其收敛性,本文给出的方法克服了用配位法和伽辽金方法须对b(x)所加的限制(b(x)为多项式),同时克服了的方法在计算过程中的不稳定性,便于实际应用。     

用拉氏变换极限求一类广义积分

<正> 当函数f(t)的拉氏变换F(s)存在.且积分integral from 0 to -∞(f(t)/t)dt 也存在时,有integral from 0 to -∞(f(t)/t)dt=integral from 0 to -∞f(s)ds     

条件L泛函的核估计及其Bootstrap逼近

设(X,y)为取值于 R~d×R~1的随机变量,X 具有边缘分布 F(x),Y 关于 X 的条件分布为 F(y|x).对于条件 L 泛函θ_1(x)=integral from n=0 to 1 J(y)F~(-1)(y|x)dy(1)θ(x)=integral from n=0 to 1 J(y)F~(-1)(y|x)dy+sum from j=1 to k a_jF~(-1)(p_j|x)(2)在[1]中曾给出了它们的近邻估计,并讨论了估计的渐近性质(其中 F~(-1)(x)=inf{t:F(t)≥x}).在本文中,我们将用核函数方法构造它们的另一类估计,并讨论估计的一些渐近性质.设(X_1,Y_1),(X_2,Y_2),…是(X,Y)的一个样本列,取 w_n_i(x)=K((x-X_i)/h_n)/sum from i=1 to n K((x-X_i)/h_n),其中 K 为 R~d 上的概率密度函数,并有0相似文献   

关于Burton渐近稳定性定理的注记(英文)

讨论泛函微分方程((?)=f(t,x_t)的解的渐近稳定性理论,往往需要假定f的某种全连续性。Burton在他的论文中讨论了f是一般R×C→R~n的连续泛函的情况。本文的目的是改进Burton的工作。证明方法采取更简单的直接证法,证明结果不但同样获得有关解的一致渐近稳定性的结论,而且得到一个有趣的不等式,从中能够导出解的收敛于0的估计式。 设f是R×C→R~n连续泛函。η:R~+→R~+是严格上升的连续函数,η(0)=0。设u,v,w是单调不减的连续函数,u(0)=v(0)=w(0)=0,且对s>0有u(s),v(s),w(s)>0,又设|Φ‖_η=η(|Φ(0)|)+1/r integral from -r to 0 η(|Φ(θ)|)dθ, w_1(s)=w(η~(-1)(s)), h(s)=integral from 0 to 2 w_1(s)ds,K(s)=v(s)+w_1(1)/2rs,那么有如下定理: 定理1 设Ⅴ:R×C→R是连续泛函,使得 u(|φ(0)|)≦Ⅴ(t, φ)≤v(‖φ‖η), (?)(t, φ)≦-w(|φ(0)|),那么必有另一个连续泛函G:R×C→R,使得对η(|μ|)<1有 (?)(t,φ)≤-g(G(t, φ)), Ⅴ(t, φ)≤G(t, φ),其中g:R~+→R~+定义为g(s)=h(1/2K~(-1)(s)) 定理2 设定理1的条件均满足,设F(y)=integral from 1 to v dz/g(z),那么存在ε>0使得对于|φ_0|<ε有 |x(t; t_0, φ_0)|≤u~(-1)(F~(-1)(F(G(t_0, φ_0))+t_0—t)),且x=0一致渐近稳定。 文章最后给出两个实