Efficient simulation of synchronous automata by multi-speed systems 
         Tomasz Judrdzinski, Miroslaw Kutylowski, Jan Zatopianski

We consider systems  consisting  of  finite  automata  communicating  by
exchanging messages. We investigate the situation in which automata work
with constant but different speeds. We  assume  furthermore  that  these
speeds  are  unknown  to the devices and cannot be measured directly. In
particular, it may happen that some speed cannot be expressed exactly by
the means of internal states of automata. Nevertheless, automata have to
compute the correct output. We call this model  multi-speed  systems  of
finite automata}.

The main result of  this  paper  is  that  multi-speed  systems  are  as
powerful  as  synchronous systems, where all automata work with the same
speed.