Following one of the options for Swedish Ph.D. theses, the
present thesis is a collection of articles, where the first one
introduces the topic of research, and the following ones are
articles which report specific results. In most cases, they
have previously been published in international conferences or
journals with strict peer review.
The following is a list of the contents of the thesis. The files have
been defined in such a way that if printed in succession, they produce
the entire thesis. Alternatively, please