Advances in Difference Equations
Volume 2008 (2008), Article ID 816091, 11 pages
doi:10.1155/2008/816091
Research Article

Almost-Periodic Weak Solutions of Second-Order Neutral Delay-Differential Equations with Piecewise Constant Argument

Li Wang and Chuanyi Zhang

Department of Mathematics, Harbin Institute of Technology, Harbin 150001, China

Received 10 December 2007; Accepted 4 June 2008

Academic Editor: Ondrej Dosly

Copyright © 2008 Li Wang and Chuanyi Zhang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We investigate the existence of almost-periodic weak solutions of second-order neutral delay-differential equations with piecewise constant argument of the form (x(t)+x(t−1))′′=qx(2[(t+1)/2])+f(t), where [⋅] denotes the greatest integer function, q is a real nonzero constant, and f(t) is almost periodic.