{HEAD ~ A method} 1, characterized in that said other periodic movement has {TAIL ~ a frequency} other than that of the rotating movement 
{ HEAD ~ A method } 1 , characterized in that said other periodic movement has { TAIL ~ a frequency } other than that of the rotating movement
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH