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§1. IntroductionThispaperisconcernedwiththeasymptoticbehavioroftheoscillatorysolutionsofnonlin-earforcedneutraldelaydifferentialequationsoftheform[x(t)-∑mi=1pi(t)x(t-τi)]′ ∑nj=1qj(t)f(x(t-σj))=r(t), t≥t0,(1)wherepi,qj,r∈C([t0,∞),R),τi,σj≥0,i=1,2,…,m;j=1,2,…,n,f∈C(R,R),xf(x)>0forx≠0.Whenpi(t)≡0,i=1,2,…,m,Eq.(1)reducestox(t) ∑nj=1qj(t)f(x(t-σj))=r(t), t≥t0,(2)whoseasymptoticbehaviorofallsolutionshasbeenstudiedinJ.R.Yan[5].Whenr(t)≡0,f(x)≡xandm=n=1,Eq.(1)reducesto[… 相似文献
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In this paper, we obtain some nonoscillatory theories of the functional differential equation (r(t)ψ(x(t))x (t)) + f(t, x(t), x(σ(t))) = 0, t ≥ t 0 , where r ∈ C 1 ([t 0 , ∞); (0, ∞)), ψ∈ C 1 (R, R) and f ∈ C([t 0 , ∞) × R × R, R). 相似文献
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A new second-order nonlinear neutral delay differential equation r(t) x(t) + P(t)x(t-τ) + cr(t) x(t)-x(t-τ) + F t,x(t-σ1),x(t-σ2),...,x(t-σn) = G(t),t ≥ t0,where τ 0,σ1,σ2,...,σn ≥ 0,P,r ∈ C([t0,+∞),R),F ∈ C([t0,+∞)×Rn,R),G ∈ C([t0,+∞),R) and c is a constant,is studied in this paper,and some sufficient conditions for existence of nonoscillatory solutions for this equation are established and expatiated through five theorems according to the range of value of function P(t).Two examples are presented to illustrate that our works are proper generalizations of the other corresponding results.Furthermore,our results omit the restriction of Q1(t) dominating Q2(t)(See condition C in the text). 相似文献
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一类二次方程组的一个定理及其运用 总被引:1,自引:0,他引:1
定理 在方程组∑ni=1xi=A∑ni=1x2i=B中 ,A、B是实数 ,记Δ=n B-A2 .若 xi∈ R( i=1,2 ,… ,n) ,则Δ≥ 0 ,当且仅当x1 =x2 =… =xn=An时 Δ=0 .证明 ∑1≤ i相似文献
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在文[1]末提出了如下一个猜想:
对于函数Y=f(x)=^n∑i=1ai|x-bi|(ai,bi,x∈R,i=1,2,…,n). 相似文献
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§ 1 IntroductionIn this note we are concerned with the asymptotically periodic second order equation-u″+α( x) u =β( x) uq +γ( x) up, x∈ R,( 1 )where1
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§ 1 . IntroductionSingularperturbationofDirichletproblemsforellipticequationswerediscussedbysomeauthors[1 ] -[4] ,butmostofwhathavebeenconsideredareboundeddomain .InthispapertheauthorconsiderDirichletexteriorproblemsasfollow :εL1 [u]+L2 [u]=f(x ,u ,ε) ,x∈Rn -Ω , ( 1)u(x) =g(x ,ε) ,x∈ Ω ,( 2 )whereL1 issecondorderellipticoperator:L1 [u]=∑ni,j=1aij(x) 2 u xi xj+∑ni=1ai(x) u xi +a(x ,u) ,∑ni,j=1aijζiζj ≥δ0 >0 ,x∈Rn -Ω , ζ∈Rn ,ζ≠ 0 ,L2 isfirstorderdifferentialopera… 相似文献
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本文对随机大系统dx(t)=b(t,x(t))dt σ(t,x(t)dω(t)采用较文[1]更一般的分解形式,利用比较法和分解-集结法得到该随机大系统随机(一致)稳定性和渐近(一致)稳定性的比较准则。 相似文献
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Paulo Xavier Pamplona 《Journal of Mathematical Analysis and Applications》2009,350(1):37-1087
In this paper we study the asymptotic behavior and the analyticity of the solutions of the one-dimensional porous-elasticity problem with thermal effect. Our main result is to prove the lack of exponential stability in case of the porous-elasticity with thermal effect when viscoelasticity is present. We prove the analyticity of the problem when a porous viscosity is present. We conclude by showing the impossibility of localization in time of the solutions in the isothermal case. 相似文献
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Burton Voorhees 《Complexity》2009,15(2):31-44
After a discussion of the importance of stability and instability for complex systems theory, we define the concept of virtual stability as a state in which a system employs self‐monitoring and adaptive control to maintain itself in a configuration that would otherwise be unstable. The energy expended in this gains the system an increase in its flexibility of behavioral response to environmental changes. A model designed to illustrate virtual stability is presented, followed by a brief discussion of the evolutionary advantage this capacity provides. This leads to the suggestion that such advantage gives an argument both for the directionality of evolution and for the emergence of self‐consciousness. © 2008 Wiley Periodicals, Inc. Complexity, 2009 相似文献
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利用Lyapunov泛函方法及线性矩阵不等式,得到了随机时滞混杂区间系统的能失性及鲁棒稳定性的充分判据。 相似文献
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In this paper, we study the existence, uniqueness, continuous dependence, Ulam stabilities and exponential stability of random impulsive semilineax differential equations under sufficient condition. The results are obtained by using the contraction mapping principle. Finally an example is given to illustrate the applications of the abstract results. 相似文献
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In this paper, we study the existence, uniqueness, continuous dependence, Ulam stabilities and exponential stability of random impulsive semilinear differential equations under sufficient condition. The results are obtained by using the contraction mapping principle. Finally an example is given to illustrate the applications of the abstract results. 相似文献
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一类非线性动力系统实用稳定域的研究及应用 总被引:1,自引:0,他引:1
杨玉华 《数学的实践与认识》2012,42(13):189-192
借助于李雅普诺夫函数讨论了一类非线性动力系统的实用稳定性和实用稳定域的估计问题,得到了实用稳定域存在的充分条件,给出了一类动力系统实用稳定域的具体形式.通过具体实例说明了所给条件的实用性,改进了已有的结果. 相似文献