Vibration frequency response function can be calculated, thereby characterizing the system. This technique is used in the field of experimental modal analysis to determine the vibration characteristics of a structure. The simple mass–spring–damper model is the foundation of vibration analysis, but what about more complex systems? The mass–spring–damper model described above is called a single degree of freedom (SDOF) model since the mass is assumed to only move up and down. In more complex systems, the system must be discretized into more masses that move in more than one direction, adding degrees of freedom. The major concepts of multiple degrees of
Oh Dear! What Can the Matter Be? And nobody knew she was there. The second old lady was Abigail Splatter. She went there 'cause something was definitely the matter. But when she got there, it was only her bladder, And nobody knew she was there. </poem> One suggested precursor to the bawdy song, recorded in William's "Upper Thames" collection is the following "old morris fragment": <poem> Oh, dear, what can the matter be? Three old women tied to an apple tree! One ran away, the others stopped till Saturday. Oh, dear, what can the matter be? </poem> As with many folk songs and tall tales each verse