We show that soliton interaction with finite-width inhomogeneities can
activate a great number of soliton internal modes. We obtain the exac
t stationary soliton solution in the presence of inhomogeneities and s
olve exactly the stability problem. We present a Karhunen-Loeve analys
is of the soliton structure dynamics as a time-dependent force pumps e
nergy into the translational mode of the kink. We show the importance
of the internal modes of the soliton as they can generate shape chaos
for the soliton as well as cases in which the first shape mode leads t
he dynamics. (C) 1998 Elsevier Science B.V. All rights reserved.PACS:
02.30.Jr; 05.45.+b; 52.35.h iw; 52.35.Sb.