W. Ross Ashby Digital Archive. Ross Ashby was one of the original members of the Ratio Club, a small informal dining club of young psychologists, physiologists, mathematicians and engineers who met to discuss issues in cybernetics. The club was founded in 1949 by the neurologist John Bates and continued to meet until 1958. The title of his book "An Introduction to Cybernetics" popularised the usage of the term 'cybernetics' to refer to self-regulating systems, originally coined by Norbert Wiener in "". The book dealt primarily with homeostatic processes within living organisms, rather than in an engineering or electronic context. Earlier, in 1946, Alan
Wiener–Lévy theorem pseudo compound Poisson distribution, abbreviated DPCP. We denote it as formula_23. Wiener–Lévy theorem Wiener–Lévy theorem is a theorem in Fourier analysis, which states that a function of an absolutely convergent Fourier series has an absolutely convergent Fourier series under some conditions. The theorem was named after Norbert Wiener and Paul Lévy. Norbert Wiener first proved Wiener's 1/"f" theorem, see Wiener's theorem. It states that if has absolutely convergent Fourier series and is never zero, then its inverse also has an absolutely convergent Fourier series. Paul Levy generalized Wiener's result, showing that Let formula_1 be a absolutely convergent Fourier series with