^pof;
Mathematics,;
Swansea;
University,;
Singleton;
Park,;
Swansea;
SA28PP,;
UK;
^pM.;
Glushkov;
Institute;
of;
Cybernetics;
NAS;
of;
Ukraine,;
03187,;
Kiev,;
Ukraine;
^pHeine;
University;
Diisseldorf,;
German;
Diabetes;
Center;
at;
the;
Heinrich;
Heine;
University;
Diisseldorf,;
Leibniz;
Center;
for;
Diabetes;
Research,;
Institute;
of;
Biometrics;
and;
Epiderniology,;
Auf'rn;
Hennekarnp;
65,;
40225;
Diisseldorf,;
Gerrnany;
^pfiir;
Mathematische;
Stochastik,;
Technisehe;
Universitiit;
Dresden,;
01062;
Dresden,;
Germany;