An electromagnetic wave absorber is formed of an Mn\u2014Zn ferrite including: a spinel primary phase which contains 40. In the method, a symbol table SymTbl for storing one or more entities Ei is initialized 110. Frames that are too dark, blurry, or otherwise poor classification candidates are discarded from the subset. The first and second memory devices includes respective selective on-die termination circuits configured to selectively provide first and second termination impedances at their respective data terminals responsive to a memory control signal at the commonly connected memory control signal terminals. The retainer is co-axial with the open receptacle.