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Claude Elwood Shannon (1916 - 2001)
Claude Elwood Shannon is considered as the founding father of
electronic communications age.
While working at Bell
Laboratories, he formulated a theory explaining the communication of
information and worked on the problem of most efficiently transmitting
information.
Claude Elwood Shannon was born in Petoskey, Michigan, on April 30,
1916. He died on Saturday, February 24, 2001, in Medford, Mass. He had
been afflicted with Alzheimer's disease for several years.
Logic
Besides Shannon's theory of communication, he published a classic
paper "A Symbolic Analysis of Relay and Switching Circuits." This
paper point out the identity between the two "truth values" of
symbolic logic and the binary values 1 and 0 of electronic
circuits. Shannon showed how a "logic machine" could be built using
switching circuits corresponding to the propositions of Boolean
algebra.
Entropy
One of the most important feature of Shannon's theory was the concept
of entropy, which he demonstrated to be equivalent to a shortage in
the information content in a message. According to the second law of
thermodynamics, as in the 19th century, entropy is the degree of
randomness in any system always increased. Thus many sentences could
be significantly shortened without losing their meaning. Shannon
proved that in a noisy conversation, signal could always be send
without distortion. If the message is encoded in such a way that it is
self-checking, signals will be received with the same accuracy as if
there were no interference on the line. A language, for example, has a
built in error-correcting code. Therefore, a noisy party conversation
is only partly clear because half the language is redundant. Shannon's
method were soon seen to have applications not only to computer design
but to virtually very subject in which language was important such as
linguistic, psychology, cryptography and phonetics.
Links:
NYU
Bell Labs
Scientific American
Shannon's Noisy Channel Coding Theorem
Scientific Biography
Channel Coding