Duplication (redirected from duplicates)

Duplication 

carrying out similar or identical actions to attain the same aim; or making something in two sets, repetition, doubling. An example of duplication is the joint flight of a pilot trainee and of an instructor in a two-seated training aircraft on which the control instruments are firmly coupled and control can be exercised from either seat.

Duplication, as a one-time reserve, is a technique widely used in technology to increase the reliability of a system or unit or its essential elements or parts. The main and the reserve objects form a duplicated group. Duplication may be of two kinds: in permanent duplication, the main and the reserve objects function simultaneously and are in identical operating conditions; in replacement duplication (manual or automatic), the reserve object begins to function only after the main object fails. Under the second method the reserve object is, until the moment of replacement, in a nonfunctioning state and therefore less liable to failure than the main object.

O. G. LOSNITSKII and V. N. FOMIN