共查询到20条相似文献,搜索用时 822 毫秒
1.
讨论具分布时滞的微分方程x′(t)=-a(t,x)x(t)+∫-0τf(t,r,x(t+r))dr,x′(t)=a(t,x)x(t)-∫0-τf(t,r,x(t+r))drx′(t)=-g(t,x(t))+∫0-τf(t,r,x(t+r))dr,x′(t)=g(t,x(t))-∫0-τf(t,r,x(t+r))dr正周期解问题,利用锥不动点定理,获得了这类问题正解存在性和多重性的充分条件,推广了已有文献的相关结果. 相似文献
2.
利用Mawhin重合度理论,获得了一类具有多个偏差变元的高阶中立型微分方程(x(t)-cx(t-r))~(l)+h(x(t))x′(t)+■α~i(t)f(x′(t-μ_i(t))+■β_j(t)g(x(t-τ_i(t)))=p(t)周期解存在性的新结果,推广和改进了已有文献的相关结果. 相似文献
3.
具有时滞的高维周期系统的周期解 总被引:6,自引:1,他引:5
本文研究具有时滞的高维周期系统x'(t)=A(t,x(t))x(t)+f(t,x(t-τ))与x'(t)=gradG(x(t))+f(t,x(t-τ))的周期解,利用重合度理论,得到保证其存在周期解的充分条件.作为应用,建立了一类对数种群模型周期正解的存在性. 相似文献
4.
具有无穷时滞泛函微分方程的周期解 总被引:14,自引:0,他引:14
讨论具有无穷时滞中立型泛函微分方程d/dt(x(t))-∫0∞Q(s)x(t+s)ds)=A(t,x(t))x(t)+f(t,xt)的周期解问题.利用矩阵测度和Kranoselski不动点定理得到了周期解的存在性和唯一性定理;特别地,当Q(s)为零矩阵,A(t,x)=A(t)时给出了存在唯一稳定的周期解的条件. 相似文献
5.
1 Illtroduction and Statement of the Main ResultIn this paper, we shall study the existence of periodic solutions for the twofOllowing differential delay equationsX'(t) = --f(x(t -- r1))g(x(t -- r2)) -- f(x(t -- r2))g(x(t -- r1)), (1)andX'(t) = f(x(t -- rl))g(x(t -- r2)) f(x(t -- r2))g(x(t -- rl)), (2)where ri (i = l,2) are positive constants. When the function g(x) = 1,equations (1) and (2) become respectivelyIn 1974, Kaplan and Yorke (see [101) proved the existence of periodic so1utions… 相似文献
6.
本文给出了微分差分方程及 x′(t)=-g(x(t))F(x(t),x(t-1))x′(t)=-g(x(t))F(x(t),x(t-1),…,x(t-n))存在非平凡周期解的充分条件。 相似文献
7.
利用Mawhin重合度理论,本文研究如下变参数的高阶中立型泛函微分方程[x(t)+c(t)x(t-τ)](n)+f1(x(t))x′(t)+f2(x′(t))x″(t)+g(t,x(t-σ))=p(t)周期解的存在性,给出这类高阶微分方程至少存在一个T周期解的充分性条件. 相似文献
8.
线性泛函方程解的振动性的新结果 总被引:1,自引:0,他引:1
本文研究高阶泛函方程x(g(t))=P(t)x(t)+Q1(t)x(g2(t))+…+Qk(t)x(gk+1(t))解的振动性,得到了一些新的振动条件.改进和推广了已有结果. 相似文献
9.
10.
二阶非线性中立型时滞微分方程的振动性 总被引:3,自引:0,他引:3
考虑二阶非线性中立型时滞分方程[a(t)|(z(t) p(t)x(t-τ))‘|^a-1(x(t) p(t)x(t-τ))‘]‘ q(t)|x(t-σ)|^a-1x(t-σ)=0(*)本文获得了方程(*)所有解振动的充分条件,推广并改进了[1]的结果。 相似文献
11.
We study the asymptotic behavior at large time of a solution to a system of nonlinear integro-differential equations which arises in mathematical modeling of diffusion of a magnetic field into a substance. We establish the corresponding stabilization rate. 相似文献
12.
É. N. Sokol 《Journal of Mathematical Sciences》1993,65(6):2007-2011
The problem of the motion of a container in a curved section of a horizontal pipeline is solved using second-order Lagrange equations in the presence of nonholonous couplings. The special case of the motion of a container in a circular curve is examined.Translated from Matematicheskie Metody i Fiziko-Mekhanicheskie Polya, No. 25, pp. 90–95, 1987. 相似文献
13.
Symmetry-based solution of a model for a combination of a risky investment and a riskless investment
Benth and Karlsen [F.E. Benth, K.H. Karlsen, A note on Merton's portfolio selection problem for the Schwartz mean-reversion model, Stoch. Anal. Appl. 23 (2005) 687-704] treated a problem of the optimisation of the selection of a portfolio based upon the Schwartz mean-reversion model. The resulting Hamilton-Jacobi-Bellman equation in 1+2 dimensions is quite nonlinear. The solution obtained by Benth and Karlsen was very ingenious. We provide a solution of the problem based on the application of the Lie theory of continuous groups to the partial differential equation and its associated boundary and terminal conditions. 相似文献
14.
We exhibit a probabilistic algorithm which computes a rational point of an absolutely irreducible variety over a finite field defined by a reduced regular sequence. Its time-space complexity is roughly quadratic in the logarithm of the cardinality of the field and a geometric invariant of the input system. This invariant, called the degree, is bounded by the Bézout number of the system. Our algorithm works for fields of any characteristic, but requires the cardinality of the field to be greater than a quantity which is roughly the fourth power of the degree of the input variety.
15.
V. P. Maslov 《Theoretical and Mathematical Physics》2008,155(3):959-963
The problem has a large parameter, the number N of particles (outside the condensate), and a small parameter, Planck’s constant
ħ (more precisely, a dimensionless parameter containing ħ in the numerator). They turn out to be interrelated for Bose particles.
Using the exact solution of the variational equation for a bosonic system in a capillary, we can obtain precise criteria restricting
the superfluidity of a classical liquid in the capillary.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 155, No. 3, pp. 524–528, June, 2008. 相似文献
16.
Yu. B. Zelinskii 《Ukrainian Mathematical Journal》2010,62(7):1090-1097
We obtain an exact estimate for the minimum multiplicity of a continuous finite-to-one mapping of a projective space into
a sphere for all dimensions. For finite-to-one mappings of a projective space into a Euclidean space, we obtain an exact estimate
for this multiplicity for n = 2, 3. For n ≥ 4, we prove that this estimate does not exceed 4. Several open questions are formulated. 相似文献
17.
A. M. Samoilenko V. E. Slyusarchuk V. V. Slyusarchuk 《Ukrainian Mathematical Journal》1997,49(12):1872-1890
We investigate the behavior of a diserete dynamical system in a neighborhood of a quasiperiodic trajeetory for the case of
an infinite-dimensional Banach space We find conditions sufficient for the system considered to reduce, in such a neighborhood,
to a system with quasiperiodic coefficients.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49, No. 12, pp. 1661–1676, December, 1997. 相似文献
18.
We consider the problem of the two-dimensional motion of a nonviscous incompressible fluid in the field of gravity. To calculate the flow field, we use the method of the asymptotic expansion of the solution with respect to a small parameter. The constructed algorithm allows one to obtain a picture of the flow functions for the exact (nonlinear) problem of a perturbed flow of a stratified fluid. The main limitations of the algorithm are the absence of backflow zones (rotors) and a large typical horizontal size of the solution as compared with the depth of the flow. We give results of the calculations. 相似文献
19.
20.
S. B. Bodnaruk 《Ukrainian Mathematical Journal》1995,47(3):487-490
We study the dependence of the Green's function of a linear extension of a dynamical system on a torus upon a parameter.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 47, No. 3, pp. 419–421, March, 1995. 相似文献