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1.
We consider the following system of discrete equations
. Criteria for the existence of three constant-sign solutions of the system will be developed. To illustrate the generality of the results obtained, we include applications to several well-known boundary value problems. Parallel results are also established for a system on {0,1,...}
.  相似文献   

2.
In this paper we are going to study the convergence and acceleration properties of the vector E-algorithm when applied to some families of vector sequences of the form
  相似文献   

3.
In this paper, we are concerned with the global behavior ofthe solutions of the difference equation
where
and . Necessary and sufficient conditions for boundedness, persistence,and periodicity of all solutions will be established. The oscillatorybehavior will be investigated.  相似文献   

4.
In questo lavoro si considera il problema
  相似文献   

5.
We prove the existence of continuously differentiable solutions such that
or
where
  相似文献   

6.
A class of partial integrodifferential equation from viscoelasticity is formulated as the abstract integrodifferental equations in Banach space :
  相似文献   

7.
This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form  相似文献   

8.
For the functions f(a), f L2, where a is a m-dimensional vector expectation of the vector , we derive the equation
  相似文献   

9.
10.
We obtain an integral representation for the solution to the Cauchy problem
  相似文献   

11.
FINITEDIFFERENCESCHEMESOFTHENONLINEARPSEUDO-PARABOLICSYSTEMDUMINGSHENG(杜明笙)(InstituteofAppliedPhysicsandComputationalMathemat...  相似文献   

12.
It is proved that the boundary-value problem
, has a solution, provided that the following conditions are fulfilled:
, and, for ϕ(u) ≡ 0, the Galerkin method converges in the norm of the space H1(a, b; a). Several theorems of a similar kind are presented. Bibliography: 4 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 334, 2006, pp. 246–266.  相似文献   

13.
We consider the parabolic SPDE
with the Neuman boundary condition
and some initial condition.We use the Malliavin calculus in order to prove that, if the coefficients and are smooth and > 0, then the law of any vector (X(t,x1),..., X(t,xd)), 0 x1 ... xd 1, has a smooth, strictly positive density with respect to Lebesgue measure.  相似文献   

14.
We consider follwing mixed boundary-value problem:
  相似文献   

15.
We consider the Cauchy problem for the nonlinear dissipative evolution system with ellipticity on one dimensional space
with S. Q. Tang and H. Zhao [4] have considered the problem and obtained the optimal decay property for suitably small data. In this paper we derive the asymptotic profile using the Gauss kernel G(t, x), which shows the precise behavior of solution as time tends to infinity. In fact, we will show that the asymptotic formula
holds, where D0, β0 are determined by the data. It is the key point to reformulate the system to the nonlinear parabolic one by suitable changing variables. (Received: January 8, 2005)  相似文献   

16.
Let M be either the space of 2π-periodic functions Lp, where 1 ≤ p < ∞, or C; let ωr(f, h) be the continuity modulus of order r of the function f, and let
, where
, be the generalized Jackson-Vallée-Poussin integral. Denote
. The paper studies the quantity Km(f − Dn,r,l(f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 350, 2007, pp. 52–69.  相似文献   

17.
This article improves results of Hamada, Helleseth and Maekawa on minihypers in projective spaces and linear codes meeting the Griesmer bound.In [10,12],it was shown that any -minihyper, with , where , is the disjoint union of points, lines,..., -dimensional subspaces. For q large, we improve on this result by increasing the upper bound on non-square, to non-square, square, , and (4) for square, p prime, p<3, to . In the case q non-square, the conclusion is the same as written above; the minihyper is the disjoint union of subspaces. When q is square however, the minihyper is either the disjoint union of subspaces, or the disjoint union of subspaces and one subgeometry . For the coding-theoretical problem, our results classify the corresponding codes meeting the Griesmer bound.  相似文献   

18.
We study into the question of whether some rings and their associated matrix rings have equal decidability boundaries in the scheme and scheme-alternative hierarchies. Let be a decidability boundary for an algebraic system A; w.r.t. the hierarchy H. For a ring R, denote by an algebra with universe . On this algebra, define the operations + and in such a way as to extend, if necessary, the initial matrices by suitably many zero rows and columns added to the underside and to the right of each matrix, followed by ordinary addition and multiplication of the matrices obtained. The main results are collected in Theorems 1-3. Theorem 1 holds that if R is a division or an integral ring, and R has zero or odd characteristic, then the equalities hold for any n1. And if R is an arbitrary associative ring with identity then for any n 1 and i,j { 1,..., n}, where e ij is a matrix identity. Theorem 2 maintains that if R is an associative ring with identity then . Theorem 3 proves that for any n 1.  相似文献   

19.
For f L n (T d ) and , the modulus of smoothness
is shown to be equivalent to
where T n is the best trigonometric polynomial approximant of degree n to f in L p and is the Laplacian. The above result is shown to be incorrect for 0 < p .  相似文献   

20.
We theoretically investigate the asymptotical stability, local bifurcations and chaos of discrete-time recurrent neural networks with the form of
, where the input-output function is defined as a generalized sigmoid function, such asv i =2/π arctan(π/2μiμi), and , etc. Numerical simulations are also provided to demonstrate the theoretical results.  相似文献   

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