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1.
Consideringthehigherdimensionalperiodicsystemswithdelayoftheformx′(t)=A(t,x(t))x(t)+f(t,x(t-τ)),(1)x′(t)=gradG(x(t))+f(t,x(t-...  相似文献   

2.
IntroductionOwingtotheextensiveapplicationofneutralequations,moreandmorestudieshavebenmadeonthebehaviorofthesolutions[1,2].Fo...  相似文献   

3.
Stability of a class of neural network models with delay   总被引:6,自引:0,他引:6  
IntroductionRecently,theoreticalandapliedstudiesofneuralnetworkmodelhavebenthenewfocusofstudiesintheworld.Itiswel_knownthatqu...  相似文献   

4.
Let E be a Banach space. We prove the instability of the trivial solution of the differential equation
where f: [0, +∞) × E → ℝ is a continuous mapping for which
__________ Translated from Neliniini Kolyvannya, Vol. 8, No. 3, pp. 404–414, July–September, 2005.  相似文献   

5.
1ProblemsandMainResultsInthispaper,westudythenonlinearvibrationsofinfiniterodswithviscoelasticity.Theconstitutionlawoftherods...  相似文献   

6.
IntroductionIntherecentyears,withalotofapplicationsofneuralnetworkmodels,manyauthors[1~3]areinterestedintheresearchofthestructureandperformanceforthesenetworks.BecauseHopfieldneuralnetworkwellsimulatetheecologicalsystem,manystudiesareconcentratedonth…  相似文献   

7.
IntroductionAtpresent,thereareonlyafewpapers[1~3]havingbenpublishedontheglobalexistenceofperiodicsolutionsforneutraldelaypopu...  相似文献   

8.
1IntroductionandPreliminariesLetXbearealBanachspacewithnormIJ'11andadualX'.ThenormalizeddualitymappingJ:X~ZxisdefinedbyJx={x'eX*I(x,x')=11x112=11x if'},where',')denotesthegeneralizeddualitypairing.Itiswell-knownthatifX isstrictlyconvex,Jissingle-valuedandJ(tx)=tjxforallt201xeX.IfX*isuniformlyconvex,thenJisuniformlycontinuousonanyboundedsubsetSofX(of.Browde,fljandBarbuL2]).AnoperatorTwithdomainD(T)andrangeR(T)inXissaidtobeaccretiveifforeveryx,y6D(T),thereexistsajeJ(x--y)suchthat(T…  相似文献   

9.
In this paper, first a class of fractional differential equations are obtained by using the fractional variational principles. We find a fractional Lagrangian L(x(t), where a c D t α x(t)) and 0<α<1, such that the following is the corresponding Euler–Lagrange
(1)
At last, exact solutions for some Euler–Lagrange equations are presented. In particular, we consider the following equations
(2)
(3)
where g(t) and f(t) are suitable functions. D. Baleanu is on leave of absence from Institute of Space Sciences, P.O. BOX MG-23, 76900 Magurele-Bucharest, Romania. e-mail: baleanu@venus.nipne.ro.  相似文献   

10.
I.IntroductionItiswell-knobal.nthatKorteweg-deVriesequationisacanonicalmodeltodescribethebalanceofthenonlineareffectandthedispersiveeffectofaphysicalsystem.Thisequationpossessestheso-called'soliton"solution,whichhasbeenfoundnumericallybyZabuskyandKruskall'].Ho-c'Jlever,sometimesthebalanceofnonlinearityanddispersionofasystemmayleadtoa,integroditTerentialequationinsteadofadifferentialequation.Forinstance,inthestudyofvortexbreakdownofanunboundedrotatingfluidLeibovich12]derivedfollowingnonline…  相似文献   

11.
On nonlinear hyperbolic equation in unbounded domain   总被引:2,自引:0,他引:2  
The following nonlinear hyperbolic equation is discussed in this paper: where The model comes from the transverse deflection equation of an extensible beam. We prove that there exists a unique local solution of the above equation as M depends on x.  相似文献   

12.
Let X be a uniformly smooth real Banach space. Let T:X → X be continuos and strongly accretive operator. For a given f ε X, define S: X → X by Sx =f−Tx+x, for all x ε X. Let {an} n=0 , {βn} n=0 be two real sequences in (0, 1) satisfying:
((i))
;
((ii))
Assume that {un} n=0 and {υn} n=0 are two sequences in X satisfying ‖un‖ = 0(αn) and ‖υn‖ → 0 as n → ∞. For arbitrary x0 ε X, the iteration sequence {xn} is defined by
(1)
Moreover, suppose that {Sxn} and {Syn} are bounded, then {xn} converges strongly to the unique fixed point of S.  相似文献   

13.
This paper considers the second-order differential difference equation
with the constant delay > 0 and the piecewise constant function with
Differential equations of this type occur in control systems, e.g., in heating systems and the pupil light reflex, if the controlling function is determined by a constant delay > 0 and the switch recognizes only the positions on [f(>) = a] and off [f(>) = b], depending on a constant threshold value . By the nonsmooth nonlinearity the differential equation allows detailed analysis. It turns out that there is a rich solution structure. For a fixed set of parameters a, b, , , infinitely many different periodic orbits of different minimal periods exist. There may be coexistence of three asymptotically stable periodic orbits (multistability of limit cycles). Stability or instability of orbits can be proven.  相似文献   

14.
We prove the following statement: Theorem 1. Let E and be an arbitrary infinite-dimensional Banach space and a continuous mapping, respectively. Then, for every and > 0, there exists a continuous mapping such that
and the Cauchy problem
does not have a solution for every > 0.  相似文献   

15.
In this paper, the solution of a 2-D weak singular integral equation of the first kind
  相似文献   

16.
Using an Orlicz–Sobolev Space setting, we consider an eigenvalue problem for a system of the form
We prove that the solution to a suitable minimizing problem, with a restriction, yields a solution to this problem for a certain λ. The differential operators involved lack homogeneity and in addition the Orlicz–Sobolev spaces needed may not be reflexive and the corresponding functional in the minimization problem is in general neither everywhere defined nor a fortiori C 1.  相似文献   

17.
For a linear operator generated by the differential equation
we prove that its graph is closed and determine the adjoint operator . For elements of the linear manifolds and , we propose an analog of the formula of integration by parts. We establish a criterion for the existence of a pseudosolution of the operator equation and formulate sufficient conditions for the normal solvability of the operator in terms of relations for blocks of the matrix C(t). The results obtained are illustrated by examples. __________ Translated from Neliniini Kolyvannya, Vol. 10, No. 4, pp. 464–480, October–December, 2007.  相似文献   

18.
We study the limit of the hyperbolic–parabolic approximation
The function is defined in such a way as to guarantee that the initial boundary value problem is well posed even if is not invertible. The data and are constant. When is invertible, the previous problem takes the simpler form
Again, the data and are constant. The conservative case is included in the previous formulations. Convergence of the , smallness of the total variation and other technical hypotheses are assumed, and a complete characterization of the limit is provided. The most interesting points are the following: First, the boundary characteristic case is considered, that is, one eigenvalue of can be 0. Second, as pointed out before, we take into account the possibility that is not invertible. To deal with this case, we take as hypotheses conditions that were introduced by Kawashima and Shizuta relying on physically meaningful examples. We also introduce a new condition of block linear degeneracy. We prove that, if this condition is not satisfied, then pathological behaviors may occur.  相似文献   

19.
Existence of a Solution “in the Large” for Ocean Dynamics Equations   总被引:1,自引:0,他引:1  
For the system of equations describing the large-scale ocean dynamics, an existence and uniqueness theorem is proved “in the large”. This system is obtained from the 3D Navier–Stokes equations by changing the equation for the vertical velocity component u 3 under the assumption of smallness of a domain in z-direction, and a nonlinear equation for the density function ρ is added. More precisely, it is proved that for an arbitrary time interval [0, T], any viscosity coefficients and any initial conditions
a weak solution exists and is unique and and the norms are continuous in t. The work was carried out under partial support of Russian Foundation for Basic Research (project 05-01-00864).  相似文献   

20.
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