The method 2, wherein the width of {HEAD ~ the opening portion} of {TAIL ~ the core partition} w is changeable 
of
The method 2 , wherein the width of { HEAD ~ the opening portion } of { TAIL ~ the core partition } w is changeable
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH