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1.
李林 《大学数学》2006,22(4):44-49
研究了一个呼吸动力学时滞微分方程模型.x(t)=1-αx(t)xn(t-τ)1+xn(t-τ).通过利用一种映射方法得到了该系统平衡点全局吸引的充分条件.所得结论优于已有的结果.  相似文献   

2.
该文建立了周期时滞Logistic方程N'(t)=r(t)N(t)[1-N(t-τ)/k(t)]的正周期解的存在性,并获得了正周期解的唯一性和全局吸引性的充分条件.所得结果推广和改进了[1]的结果.  相似文献   

3.
Logistic增长的线性反馈控制   总被引:1,自引:0,他引:1  
唐先华 《数学年刊A辑》2003,24(1):101-112
研究非自治时滞Logistic线性反馈控制系统{n'(t)=r(t)n(t)[1-a1n(t)+a2n(t-τ)/K-cu(t-σ)]u'(t)=p(t)[-au(t)+bn(t-δ)]平衡点的3/2-全局吸引性,所获定理大大改进已有结果.  相似文献   

4.
本文考虑变系数变时滞的Hopfield神经网络系统dxi/dt=-bi(t)xi(t) ∑^nj=1aij(t)fj(λjxj(t-τij(t))) Ii(t)的全局惭近稳定性,获得了一个充分条件。  相似文献   

5.
具反馈控制的LOGISTIC增长模型   总被引:2,自引:0,他引:2  
讨论具反馈控制的Logistic增长模型{dn(t)/dt=rn(t)(1-n(t-τ)/k-cμ(t)),dμ(t)/dt=aμ(t) bn(t-τ),其中μ表示反馈控制变量,k,r,τ,a,b,c为正常数,获得了(*)的正平衡点的全局渐近稳定性,改进了已有结果,证明[1]中的猜想在更弱的条件下为真。  相似文献   

6.
运用k-集压缩算子的拓扑度抽象连续定理,研究了如下一类高阶微分方程的周期解存在性问题x(m)(t)= r(t)-a(t)x(t-σ)-b(t)x(m)(t-τ).并将其应用于研究一类中立型对数种群模型dN/dt= N(t) [r(t)-a(t) In N(t-σ-b(t)d/(dt)In N(t-τ)]的正周期解存在性...  相似文献   

7.
利用Lyapunov的方法讨论了时滞微分方程x.(t)=f(t,x(t),x(t-τ(t)))的全局指数渐近稳定性和全局渐近稳定性.  相似文献   

8.
本文研究含有n 个滞量的三维微分差分方程组x(t)=sum from i=1 to ∞(1/i)f[x(t),x(t-τ_i),y(t),y(t-τ_i),z(t),z(t-τ_i)]y(t)=sum from i=1 to ∞(1/i)g[x(t),x(t-τ_i),y(t),y(t-τ_i),z(t),z(t-τ_i)](τ_i>0)z(t)=sum from i=1 to ∞(1/i)h[x(t),x(t-τ_i),y(t),y(t-τ_i),z(t),z(t-τ_i)]周期解的存在性,给出了方程组周期解周期的取值范围.推广并改进了文[1]的结果.  相似文献   

9.
关于中立型时滞模型的周期正解   总被引:6,自引:0,他引:6  
本文利用拓扑度理论和某些新技巧,研究了一类中立型时滞模型N′(t)=N(t)[a(t)-b(t)N(t-τ(t))-c(t)N′(t-τ(t))]周期正解的存在性,得到了一些新结果,解决了一个公开问题,并推广、改进了一些已知文献的结果,同时也改正了文[3]中微分运算的错误和定理2.  相似文献   

10.
刘江  周明儒 《应用数学》2004,17(4):536-543
本文利用拓扑度理论、Liapunov泛函和时延不等式的方法研究了具有时滞的Cohen Grossberg神经网络模型dui(t)dt =ai(ui(t) )bi(ui(t) ) - ∑nj=1Tijfj(uj(t-τj) ) ,i=1 ,2 ,… ,n平衡点的稳定性问题 .文章给出了判定模型平衡点存在唯一性和全局渐近稳定性及全局指数稳定性的几个充分条件 ,这些条件取消了权矩阵 (Tij) n×n 对称性的假设 ,推广了已知文献的一些结果 ,使模型的应用范围更加广泛 .  相似文献   

11.
<正>Submission Authors must use LaTeX for typewriting,and visit our website www.actamath.com to submit your paper.Our address is Editorial Office of Acta Mathematica Sinica,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,P.R.China.  相似文献   

12.
正August 10-14,2015Beijin,China The International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists  相似文献   

13.
14.
The present paper investigates the fractal structure of fractional integrals of Weierstrass functions. The ezact box dimension for such functions many important cases is established. We need to point out that, although the result itself achieved in the present paper is interesting, the new technique and method should be emphasized. These novel ideas might be useful to establish the box dimension or Hausdorff dimension (especially for the lower bounds) for more general groups of functions.  相似文献   

15.
English Series     
正1 Aims and Scope Acta Mathematicae Applicatae Sinica(English Series)is a quarterly journal established by the Chinese Mathematical Society.The journal publishes high quality research papers from all branches of applied mathematics,particularly welcomes those from partial differential equations,computational mathematics,applied probability,mathematical finance,statistics,dynamical systems,optimization and management science.  相似文献   

16.
17.
We characterize congruence lattices of standard QBCC-algebras and their connection with the congruence lattices of congruence kernels. Work on the paper was supported by Council of Czech Government No J14/98:153100011.  相似文献   

18.
A new class of sets in ideal topological spaces is introduced and using these sets, a decomposition of continuity is given.   相似文献   

19.
We obtain (a) necessary and sufficient conditions and (b) sufficient conditions for a compact (countably compact) set to be closed in products (sequential products) and subspaces (sequential subspaces) of normal spaces. As a consequence of these, sufficient conditions are obtained for (i) the closedness of arbitrary (countable) union of closed sets and (ii) the equality of the union of the closures and the closure of the union of arbitrary (countable) families of sets in these spaces. It is also shown that these results do not hold for quotients of even T 4,-spaces.  相似文献   

20.
The current paper considers the problem of recovering a function using a limited number of its Fourier coefficients. Specifically, a method based on Bernoulli-like polynomials suggested and developed by Krylov, Lanczos, Gottlieb and Eckhoff is examined. Asymptotic behavior of approximate calculation of the so-called "jumps" is studied and asymptotic L2 constants of the rate of convergence of the method are computed.  相似文献   

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