Also referred to as quota control, it is a method of selecting subjects for a study. The subjects are already chosen for specific characteristics such as age, sex, education, etc.The quota sampling assures the proper proportion of these traits in the group.lso referred to as quota control, it is a method of selecting subjects for a study. The subjects are already chosen for specific characteristics such as age, sex, education, etc.
In contrast, a broadband signal is a signal which does not occupy the lowest range, but instead a higher range, 1MHz to 3MHz, for example. A wire may have only one baseband signal, but it may hold any number of broadband signals, because they can occur anywhere in the spectrum.
Sidebands are spectral components that are the result of amplitude or frequency modulation. The frequency spacing of the sidebands is equal to the modulating frequency, and this fact is used in diagnosing machine problems by examining sideband families in the vibration spectrum. For instance, a defective gear will exhibit sidebands at the gear rpm around the gear mesh frequency.