William Ross Ashby was a major contributor to the field of cybernetics. His achievements are referenced repeatedly in the cybernetics literature. He pioneered the concept of a
"homeostatic machine" which is as fundamental to the development of the mathematical models of cybernetics as the concept of the "black body" has been to astrophysics, thermodynamics, and quantum mechanics. Indeed his influence was sufficiently great to have induced Ludwig von Bertalanffly to devote several pages in his book to explaining how they differed on methods of study.
1http://es.wikipedia.org/wiki/W._Ross_Ashbyhttp://www.gwu.edu/~asc/biographies/ashby/ashby.htmlhttp://pcp.vub.ac.be/ASHBBOOK.html