The method 13 wherein determining {HEAD ~ a respective second intensity variation step} comprises {TAIL ~ the substeps} of: 
comprises
The method 13 wherein determining { HEAD ~ a respective second intensity variation step } comprises { TAIL ~ the substeps } of :
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH