Preface to Second Edition From the time that the original edition was published in 1985, multidimensional systems theory has matured into a discipline of research and teaching with an expanding array of applications. The international journal on Multidimensional Systems and Signal Processing, founded in 1990, is now in its fourteenth year. A biannual international workshop on n-D systems was launched in 1998 and the impressive number of special sessions, mini-symposia, monographs and special issues that have emerged bear testimony to the growing popularity and importance of the subject...