Cybernetics Forrester at MIT in the 1950s, is a related field. Cybernetics has been defined in a variety of ways, by a variety of people, from a variety of disciplines. Cybernetician Stuart Umpleby reports some notable definitions: Other notable definitions include: The term "cybernetics" stems from κυβερνήτης ("cybernḗtēs") "steersman, governor, pilot, or rudder". As with the ancient Greek pilot, independence of thought is important in cybernetics. French physicist and mathematician André-Marie Ampère first coined the word "cybernetique" in his 1834 essay "Essai sur la philosophie des sciences" to describe the science of civil government. The term was borrowed by Norbert Wiener,
Wiener algebra Wiener algebra In mathematics, the Wiener algebra, named after Norbert Wiener and usually denoted by , is the space of absolutely convergent Fourier series. Here denotes the circle group. The norm of a function is given by where is the th Fourier coefficient of . The Wiener algebra is closed under pointwise multiplication of functions. Indeed, therefore Thus the Wiener algebra is a commutative unitary Banach algebra. Also, is isomorphic to the Banach algebra , with the isomorphism given by the Fourier transform. The sum of an absolutely convergent Fourier series is continuous, so where is the ring of continuous