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New interval oscillation criteria for second-order functional differential equations with nonlinear damping

Süleyman Öǧrekçi (2015)

Open Mathematics

This paper concerns the oscillation problem of second-order nonlinear damped ODE with functional terms.We give some new interval oscillation criteria which is not only based on constructing a lower solution of a Riccati type equation but also based on constructing an upper solution for corresponding Riccati type equation. We use a recently developed pointwise comparison principle between those lower and upper solutions to obtain our results. Some illustrative examples are also provided to demonstrate...

New method for computation of discrete spectrum of radical Schrödinger operator

Ivan Úlehla, Miloslav Havlíček (1980)

Aplikace matematiky

A new method for computation of eigenvalues of the radial Schrödinger operator - d 2 / d x 2 + v ( x ) , x 0 is presented. The potential v ( x ) is assumed to behave as x - 2 + ϵ if x 0 + and as x - 2 - ϵ if x + , ϵ 0 . The Schrödinger equation is transformed to a non-linear differential equation of the first order for a function z ( x , ) . It is shown that the eigenvalues are the discontinuity points of the function z ( , ) . Moreover, it is shown how to obtain an arbitrarily accurate approximation of eigenvalues. The method seems to be much more economical in comparison...

New optimal conditions for unique solvability of the Cauchy problem for first order linear functional differential equations

Robert Hakl, Alexander Lomtatidze, Bedřich Půža (2002)

Mathematica Bohemica

The nonimprovable sufficient conditions for the unique solvability of the problem u ' ( t ) = ( u ) ( t ) + q ( t ) , u ( a ) = c , where C ( I ; ) L ( I ; ) is a linear bounded operator, q L ( I ; ) , c , are established which are different from the previous results. More precisely, they are interesting especially in the case where the operator is not of Volterra’s type with respect to the point a .

New oscillation criteria for first order nonlinear delay differential equations

Xianhua Tang, Jianhua Shen (2000)

Colloquium Mathematicae

New oscillation criteria are obtained for all solutions of a class of first order nonlinear delay differential equations. Our results extend and improve the results recently obtained by Li and Kuang [7]. Some examples are given to demonstrate the advantage of our results over those in [7].

New qualitative methods for stability of delay systems

Erik I. Verriest (2001)

Kybernetika

A qualitative method is explored for analyzing the stability of systems. The approach is a generalization of the celebrated Lyapunov method. Whereas classically, the Lyapunov method is based on the simple comparison theorem, deriving suitable candidate Lyapunov functions remains mostly an art. As a result, in the realm of delay equations, such Lyapunov methods can be quite conservative. The generalization is here in using the comparison theorem directly with a different scalar equation with known...

New result on the ultimate boundedness of solutions of certain third-order vector differential equations

Mathew Omonigho Omeike, A. U. Afuwape (2010)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

Sufficient conditions are established for ultimate boundedness of solutions of certain nonlinear vector differential equations of third-order. Our result improves on Tunc’s [C. Tunc, On the stability and boundedness of solutions of nonlinear vector differential equations of third order].

New results on global exponential stability of almost periodic solutions for a delayed Nicholson blowflies model

Bingwen Liu (2015)

Annales Polonici Mathematici

This paper is concerned with a class of Nicholson's blowflies models with multiple time-varying delays, which is defined on the nonnegative function space. Under appropriate conditions, we establish some criteria to ensure that all solutions of this model converge globally exponentially to a positive almost periodic solution. Moreover, we give an example with numerical simulations to illustrate our main results.

New results on periodic solutions for a kind of Rayleigh equation

Mei-Lan Tang, Xin-Ge Liu, Xin-Bi Liu (2009)

Applications of Mathematics

The paper deals with the existence of periodic solutions for a kind of non-autonomous time-delay Rayleigh equation. With the continuation theorem of the coincidence degree and a priori estimates, some new results on the existence of periodic solutions for this kind of Rayleigh equation are established.

New results on stability of periodic solution for CNNs with proportional delays and D operator

Bo Du (2019)

Kybernetika

The problems related to periodic solutions of cellular neural networks (CNNs) involving D operator and proportional delays are considered. We shall present Topology degree theory and differential inequality technique for obtaining the existence of periodic solution to the considered neural networks. Furthermore, Laypunov functional method is used for studying global asymptotic stability of periodic solutions to the above system.

Currently displaying 61 – 80 of 355