The Endocrine System Essentials. 1  The endocrine system is made up of a network of glands. 2  These glands secrete hormones to regulate many bodily functions, including growth and metabolism. 3  Endocrine diseases are common and usually occur when glands produce an incorrect amount of hormones.
The Fourier transform is called the frequency domain representation of the original signal. The term Fourier transform refers to both the frequency domain representation and the mathematical operation that associates the frequency domain representation to a function of time.
The Discrete Time Fourier Transform. The Discrete Time Fourier Transform (DTFT) is the member of the Fourier transform family that operates on aperiodic, discrete signals. The best way to understand the DTFT is how it relates to the DFT. To start, imagine that you acquire an N sample signal, and want to find its frequency spectrum.