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.
A Fourier series is an expansion of a periodic function in terms of an infinite sum of sines and cosines. Fourier series make use of the orthogonality relationships of the sine and cosine functions.