ABSTRACT
Delay models are applied in a large variety of cases in many scientific fields. Con-
sequently, it is difficult to classify the particular models used and to study them sys-
tematically. In this section we start with the study of simple delay models, and then
proceed to study more complicated models. Special attention is given to the develop-
ment and presentation of the most frequently used delay models, as well as to related
extensions and new delay models of particular interest. Of major importance are the
applications of delay models in physiological systems (Glass and Pasternack, 1978;
Glass and Mackey, 1988; Glass, 1988, 1991; Glass and Zeng, 1990; de Olivera and
Malta, 1987; Cabrera and de la Rubia, 1996; Celka, 1997; Sharkovsky, 1994; Ueda
et al., 1994; Bunner, 1999).
