ABSTRACT
It is conventionally recognized that modern computers permit, in principle, efcient calcu› lation of wave elds by direct numerical methods for arbitrary boundary value problems. This is especially true for the cases of low and moderate frequencies. In the Preface to this book it was outlined why the high›frequency regime is so distinct from ordinary cases, when implemented on computers. Briey speaking, this requires too large number of mesh nodes with the frequency increasing.
