The resultant normalized frequency has units of half-cycles/sample or equivalently cycles per 2 samples. Sometimes, the unnormalized frequency is represented in units of radians/second (angular frequency), and denoted by When is normalized by the sample-rate (samples/sec), the resulting units are radians/sample.ometimes, the unnormalized frequency is represented in units of radians/second (angular frequency), and denoted by When is normalized by the sample-rate (samples/sec), the resulting units are radians/sample.
Hilum (noun). the eye of a bean or other seed; the mark or scar at the point of attachment of an ovule or seed to its base or support; -- called also hile. Hilum (noun). the part of a gland, or similar organ, where the blood vessels and nerves enter; the hilus; as, the hilum of the kidney.
The hilum overlay sign (3) is present when the normal hilar structures project through a mass, such that the mass can be understood as being either anterior or posterior to the hilum (Fig 3). Preservation or disruption of posterior mediastinal lines can help further clarify the location of the mass.