共查询到20条相似文献，搜索用时 375 毫秒
1.
Eva Špániková 《Czechoslovak Mathematical Journal》2000,50(4):879-887
The purpose of this paper is to obtain oscillation criteria for the differential system
相似文献
2.
Bhagat Singh 《Czechoslovak Mathematical Journal》2000,50(3):627-639
Qualitative comparison of the nonoscillatory behavior of the equations
and
is sought by way of finding different nonoscillation criteria for the above equations, L
n is a disconjugate operator of the form
Both canonical and noncanonical forms of L
n have been studied. 相似文献
3.
4.
Satoshi Tanaka 《Czechoslovak Mathematical Journal》2001,51(3):573-583
The higher order neutral functional differential equation
is considered under the following conditions:
is strictly increasing in
is nonnegative on
and nondecreasing in
. A necessary and sufficient condition is derived for the existence of certain positive solutions of (1). 相似文献
5.
We consider parabolic variational inequalities having the strong formulation
where
for some admissible initial datum, V is a separable Banach space with separable dual
is an appropriate monotone operator, and
is a convex,
lower semicontinuous functional. Well-posedness of (1) follows from an explicit construction of the related semigroup
Illustrative applications to free boundary problems and to parabolic problems in Orlicz-Sobolev spaces are given. 相似文献
| ((1)) |
6.
In this paper we establish the existence of nontrivial solutions to
with V
x superlinear in x. 相似文献
7.
Ya. M. Chabanyuk 《Ukrainian Mathematical Journal》2004,56(5):862-872
Using the Lyapunov function for an averaged system, we establish conditions for the convergence of the procedure of stochastic approximation
in a random semi-Markov medium described by an ergodic semi-Markov process x(t).Translated from Ukrainskyi Matematychnyi Zhurnal, Vol. 56, No. 5, pp. 713–720, May, 2004. 相似文献
8.
Let S = x
1,...,x
n} be a finite subset of a partially ordered set P. Let f be an incidence function of P. Let
denote the n × n matrix having f evaluated at the meet
of x
i and x
j as its i, j-entry and
denote the n × n matrix having f evaluated at the join
of x
i and x
j as its i, j-entry. The set S is said to be meet-closed if
for all 1 i, j n. In this paper we get explicit combinatorial formulas for the determinants of matrices
and
on any meet-closed set S. We also obtain necessary and sufficient conditions for the matrices
and
on any meet-closed set S to be nonsingular. Finally, we give some number-theoretic applications. 相似文献
9.
The paper is concerned with oscillation properties of n-th order neutral differential equations of the form
where c is a real number with
with (t) < t and
.Sufficient conditions are established for the existence of positive solutions and for oscillation of bounded solutions of the above equation. Combination of these conditions provides necessary and sufficient conditions for oscillation of bounded solutions of the equation. Furthermore, the results are generalized to equations in which c is a function of t and a certain type of a forcing term is present. 相似文献
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10.
Moharram A. Khan 《Czechoslovak Mathematical Journal》2000,50(4):791-801
In this paper we investigate commutativity of rings with unity satisfying any one of the properties:
for some f(X) in
and g(X), h(X) in
where m 0, r 0, s 0, n > 0, t > 0 are non-negative integers. We also extend these results to the case when integral exponents in the underlying conditions are no longer fixed, rather they depend on the pair of ring elements x and y for their values. Further, under different appropriate constraints on commutators, commutativity of rings has been studied. These results generalize a number of commutativity theorems established recently. 相似文献
11.
O. L. Vinogradov 《Journal of Mathematical Sciences》2004,120(5):1662-1671
Let
be the Jacobi polynomials and let C[a,b] be the space of continuous functions on [a,b] with the uniform norm. In this paper, we study sequences of Lebesgue constants, i.e., of the norms of linear operators
generated by a multiplier matrix
defined by the following relations:
and
In the case || = || = 1/2, we prove the following statements for the Jacobi polynomials (these statements are similar to known results for the trigonometrical system). Consider the cases
and
Under some conditions on a function , the values
and
equal
and
In addition, we show that for the Fourier–Legendre summation methods ( = = 0) generated by the multiplier function
, the limit and supremum of the sequence of Lebesgue constants may differ. Bibliography: 11 titles. 相似文献
12.
In this paper, we consider a problem of the form
where d3, f is a positive locally Lipschitz bounded function and g is assumed to change sign. We give some conditions of integral type to get the existence of positive solutions for large enough. 相似文献
13.
C. S. Lin 《Czechoslovak Mathematical Journal》2002,52(3):665-672
In this paper we prove two results. The first is an extension of the result of G. D. Jones [4[:Every nontrivial solution for
must be unbounded, provided
, in
and for every bounded subset I, f(t, z) is bounded in E × I.(B) Every bounded solution for
, in
, must be constant, provided
in
and for every bounded subset I,
is bounded in
. 相似文献
14.
Ram U. Verma 《Journal of Computational Analysis and Applications》2002,4(3):177-192
Consider the convergence of the projection methods based on an extension of a special class of algorithms for the approximation--solvability of the following class of nonlinear quasivariational inequality (NQVI) problems: find an element
such that
and
where
are mappings on H and K is a nonempty closed convex subset of a real Hilbert space H. The iterative procedure is characterized as a nonlinear quasivariational inequality: for any arbitrarily chosen initial point x
0 K and, for constants
0$$
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and
0$$
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, we have
where
This nonlinear quasivariational inequality type algorithm has an equivalent projection formula
where
for the projection P
K
of H onto K. 相似文献
15.
G. P. Kukhta 《Journal of Mathematical Sciences》1992,60(2):1396-1398
By the Fourier method a solution of the equation
|
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16.
Ondřej Došlý 《Czechoslovak Mathematical Journal》2000,50(3):657-671
In this paper we investigate oscillatory properties of the second order half-linear equation
17.
L. A. Medeiros J. Limaco S. B. Menezes 《Journal of Computational Analysis and Applications》2002,4(3):211-263
Dedicated to Professor Jacque-Louis Lions on the occasion of his 70th birthday
We consider a mixed problem for the operator
18.
In this paper we prove an existence theorem for the Cauchy problem
19.
In this work the authors study the conditions for the existence of diffusion equations
20.
In this paper we consider the weakly coupled elliptic system with critical growth
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