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2014 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

A numerical method for a classo of nonlocal boundary value problems

2014 Articolo in rivista metadata only access

Fixed point iterations for a class of nonstandard Sturm -Liouville boundary value problems

The paper examines a particular class of nonlinear integro-differential equations consisting of a Sturm-Liouville boundary value problem on the half-line, where the coefficient of the differential term depends on the unknown function by means of a scalar integral operator. In order to handle the nonlinearity of the problem, we consider a fixed point iteration procedure, which is based on considering a sequence of classical Sturm-Liouville boundary value problems in the weak solution sense. The existence of a solution and the global convergence of the fixed-point iterations are stated without resorting to the Banach fixed point theorem. Moreover, the unique solvability of the problem is discussed and several examples with unique and non-unique solutions are given.

Sturm-Liouville boundary value problem Integro-differential problem Nonlinear problem Nonlocal problem Fixed point iteration
2014 Articolo in rivista metadata only access

Some investigations on a class of nonlinear integrodifferential equations on the half-line

We consider a particular second-order integrodifferential boundary value problem arising from the kinetic theory of dusty plasmas, and we provide information on the existence and other qualitative properties of the solution that have been essential in the numerical investigation.

2014 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

A numerical method for a class of non-local integro-differential equations

2013 Contributo in Atti di convegno metadata only access

On the numerical solution of some nonlinear and nonlocal boundary value problem.

2013 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

Numerical stability theory for Volterra integral equations

E Messina ; A Vecchio
2013 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

On the numerical solution of some nonlinear and nonlocal BVPs

The modeling of various physical questions in plasma kinetics and heat conduction lead to nonlinear boundary value problems involving a nonlocal operator, such as the integral of the unknown solution, which depends on the entire function in the domain rather than at a single point. This talk concerns a particular nonlocal boundary value problem recently studied in [1] by J.R.Cannon and D.J.Galiffa, who proposed a numerical method based on an interval-halving scheme. Starting from their results, we provide a more general convergence theorem and suggest a different iterative procedure to handle the nonlinearity of the discretized problem. References: [1] J.R.Cannon, D.J.Galiffa (2011) On a numerical method for a homogeneous, nonlinear, nonlocal, elliptic boundary problem, Nonlinear Analysis, Vol. 74, pp. 1702-1713.

Non local problem Boundary value problem Numerical method Fixed point
2012 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

Nonlinear stability of Direct Quadrature methods for Volterra integral equations

E Messina ; AVecchio
2012 Poster in Atti di convegno metadata only access

Convergence of a numerical method for the solution of non-standard integro-differential boundary value problems

M Basile ; E Messina ; W Themistoclakis ; A Vecchio
2012 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

Numerical analysis of nonlinear Volterra integral equations: stability with respect to bounded perturbations

E Messina ; A Vecchio
2012 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

An M-matrix iterative procedure for the numerical solution of a nonstandard Sturm-Liouville BVP

P Junghanns W Themistoclakis ; A Vecchio
2012 Articolo in rivista metadata only access

Global dynamics of difference equations for SIR epidemic models with a class of nonlinear incidence rates

Y Enatsu ; Y Nakata ; YMuroya ; GIzzo ; AVecchio

In this paper, by applying a variation of the backward Euler method, we propose a discrete-time SIR epidemic model whose discretization scheme preserves the global asymptotic stability of equilibria for a class of corresponding continuous-time SIR epidemic models. Using discrete-time analogue of Lyapunov functionals, the global asymptotic stability of the equilibria is fully determined by the basic reproduction number, when the infection incidence rate has a suitable monotone property.

backward Euler method basic reproduction number difference equation global asymptotic stability SIR epidemic model
2012 Articolo in rivista metadata only access

Global dynamics of a delayed SIRS epidemic model with a wide class of nonlinear incidence rates

Enatsu Yoichi ; Messina Eleonora ; Nakata Yukihiko ; Muroya Yoshiaki ; Russo Elvira ; Vecchio Antonia

In this paper, by constructing Lyapunov functionals, we consider the global dynamics of an SIRS epidemic model with a wide class of nonlinear incidence rates and distributed delays h 0 p(? )f (S(t), I (t - ?))d? under the condition that the total population converges to 1. By using a technical lemma which is derived from strong condition of strict monotonicity of functions f (S,I) and f (S,I)/I with respect to S >= 0 and I > 0, we extend the global stability result for an SIR epidemic model

Global asymptotic stability Lyapunov functional Nonlinear incidence rate SIRS epidemic model
2012 Articolo in rivista metadata only access

On the solution of a class of nonlinear systems governed by an M -matrix

We consider a weakly nonlinear system of the form (I + phi(x)A)x = p, where phi(x) is a real function of the unknown vector x, and (I + phi(x)A) is an M-matrix. We propose to solve it by means of a sequence of linear systems defined by the iteration procedure (I + phi(x(r))A)x(r + 1) = p, r = 0, 1, ... . The global convergence is proved by considering a related fixed-point problem.

Nonlinear algebraic system M-matrix Iterative methods fixed point problems
2012 Articolo in rivista metadata only access

A numerical method for a class of non-linear integro-differential equations on the half line

Basile M ; Messina E ; Themistoclakis W ; Vecchio A

We design and analyse a numerical method for the solution of a particular second order integro-differential boundary value problem on the semiaxis, which arises in the study of the kinetic theory of dusty plasmas. The method we propose represents a first insight into the numerical solution of more complicated problems and consists of a discretization of the differential and integral terms and of an iteration process to solve the resulting non-linear system. Under suitable hypotheses we prove the convergence. We will show the characteristics of the method by means of some numerical simulations.

Boundary value problems Convergence Finite difference methods Half-line Non-linear non-standard integro-differential equations Quadrature
2011 Presentazione / Comunicazione non pubblicata (convegno, evento, webinar...) metadata only access

A numerical method for a non-linear integro-differential boundary value problem

M Basile ; E Messina ; WThemistoclakis ; AVecchio
2011 Articolo in rivista metadata only access

Permanence and global stability of a class of discrete epidemic models

Muroya Yoshiaki ; Nakata Yukihiko ; Izzo Giuseppe ; Vecchio Antonia

In this paper we investigate the permanence of a system and give a sufficient condition for the endemic equilibrium to be globally asymptotically stable, which are the remaining problems in our previous paper (G. Izzo, Y. Muroya, A. Vecchio, A general discrete time model of population dynamics in the presence of an infection, Discrete Dyn. Nat. Soc. (2009), Article ID 143019, 15 pages. doi:10.1155/2009/143019.) (C) 2011 Elsevier Ltd. All rights reserved.

Discrete epidemic model Permanence Global asymptotic stability Endemic equilibrium
2011 Articolo in rivista metadata only access

Global dynamics of difference equations for SIR epidemic models with a class of nonlinear incidence rates

Enatsu Y ; Nakata Y ; Muroya Y ; Izzo G ; Vecchio A
2011 Articolo in rivista metadata only access

Comparing analytical and numerical solution of a nonlinear two-delay integral equations.

Messina E ; Russo E ; Vecchio A

Numerical solution of two delays Volterra Integral Equations is considered and the stability is studied on a nonlinear test equation by carrying out a parallel investigation both on the continuous and the discrete problem.

Direct Quadrature methods Double delays Stability; Volterra Integral Equations
2010 Poster in Atti di convegno metadata only access

A numerical method for a nonlinear integro-differential boundary value problem

M Basile ; E Messina ; WThemistoclakis ; A Vecchio