期刊名称：International Journal of Mathematics and Mathematical Sciences
印刷版ISSN：0161-1712
电子版ISSN：1687-0425
出版年度：1999
卷号：22
DOI：10.1155/S0161171299223137
出版社：Hindawi Publishing Corporation
摘要：We examine a PDE with piecewise constant time delay. The equation
is of neutral type since it contains the derivative ut at different values of the t-argument. Furthermore, the argument deviation changes its sign within intervals of unit length, so that the given PDE is alternately of retarded and advanced type. It is shown that the argument deviation generates, under certain conditions, oscillations of the solutions, which is an impossible phenomenon for the corresponding equation without delay. Of special interest is the appearance of periodic solutions as well as solutions asymptotically approaching closed curves which are not solutions of the equation studied.
