| Claude Shannon |
Article Index for Claude |
Website Links For Claude |
Information AboutClaude Shannon |
|
Claude Elwood Shannon ( design theory. BIOGRAPHY Shannon was born in Petoskey, Michigan . His father, Claude Sr (1862-1934), a descendant of early New Jersey settlers, was a businessman and for a while, Judge of Probate. His mother, Mabel Wolf Shannon (1890-1945), daughter of German immigrants, was a language teacher and for a number of years Principal of Gaylord High School, in Michigan. The first sixteen years of Shannon's life were spent in Gaylord, Michigan , where he attended public school, graduating from Gaylord High School in 1932. Shannon showed an inclination towards mechanical things. His best subjects were science and mathematics, and at home he constructed such devices as models of planes, a radio-controlled model boat and a telegraph system to a friend's house half a mile away. While growing up, he worked as a messenger for Western Union . His childhood hero was Thomas Edison , who he later learned was a distant cousin. Both were descendants of John Ogden, an important colonial leader and an ancestor of many distinguished people. [http://web.mit.edu/newsoffice/2001/shannon.html M.I.T obituary website] CLAUDE ELWOOD SHANNON, Collected Papers, Edited by N.J.A Sloane and Aaron D. Wyner, IEEE press, ISBN 0-7803-0434-9 Boolean theory In 1932 he entered the University Of Michigan , where he took a course that introduced him to the works of George Boole . He graduated in 1936 with two Bachelor's Degree s, one in Electrical Engineering and one in Mathematics , then began graduate study at the Massachusetts Institute Of Technology , where he worked on Vannevar Bush 's Differential Analyzer , an Analog Computer . While studying the complicated ad hoc circuits of the differential analyzer, Shannon saw that Boole's concepts could be used to great utility. A paper drawn from his 1937 master's Thesis , '' A Symbolic Analysis Of Relay And Switching Circuits '', was published in the 1938 issue of the ''Transactions of the American Institute of Electrical Engineers''. It also earned Shannon the Alfred Noble American Institute Of American Engineers Award in 1940 . Howard Gardner , of Harvard University , called Shannon's thesis "possibly the most important, and also the most famous, master's thesis of the century." In this work, Shannon proved that Boolean Algebra and Binary Arithmetic could be used to simplify the arrangement of the electromechanical Relay s then used in telephone routing switches, then turned the concept upside down and also proved that it should be possible to use arrangements of relays to solve Boolean algebra problems. Exploiting this property of electrical switches to do logic is the basic concept that underlies all electronic digital computers. Shannon's work became the foundation of practical Digital Circuit design when it became widely known among the electrical engineering community during and after World War II . The theoretical rigor of Shannon's work completely replaced the ad hoc methods that had previously prevailed. Flush with this success, Vannevar Bush suggested that Shannon work on his dissertation at Cold Spring Harbor Laboratory , funded by the Carnegie Institution headed by Bush, to develop similar mathematical relationships for Mendelian Genetics , which resulted in Shannon's 1940 PhD thesis at MIT, '' An Algebra For Theoretical Genetics .'' Wartime research Shannon then joined Bell Labs to work on fire-control systems and cryptography during World War II, under a contract with section D-2 (Control Systems section) of the National Defense Research Committee ( NDRC ). In 1945, as the war was coming to an end, the NDRC was issuing a summary of technical reports as a last step prior to its eventual closing down. Inside the volume on Fire Control a special essay titled ''Data Smoothing and Prediction in Fire-Control Systems'', coauthored by Ralph Beebe Blackman , Hendrik Wade Bode , and Claude Shannon, formally introduced the problem of fire control as a special case of ''transmission, manipulation and utilization of intelligence'', in other words it modeled the problem in terms of Data and Signal Processing and thus heralded the coming of the Information Age . Shannon was greatly influenced by this work. It is clear that the Technological Convergence of the information age was preceded by the Synergy between these scientific minds and their collaborators. Postwar contributions In 1948 Shannon published '' A Mathematical Theory Of Communication '' article in two parts in the July and October issues of the '' Bell System Technical Journal ''. This work focuses on the problem of how best to encode the Information a sender wants to transmit. In this fundamental work he used tools in probability theory, developed by Norbert Wiener , which were in their nascent stages of being applied to communication theory at that time. Shannon developed Information Entropy as a measure for the uncertainty in a message while essentially inventing the field of Information Theory . The book, co-authored with Warren Weaver , ''The Mathematical Theory of Communication'', reprints Shannon's 1948 article and Weaver's popularization of it, which is accessible to the non-specialist. Shannon's concepts were also popularized, subject to his own proofreading, in John Robinson Pierce 's ''Symbols, Signals, and Noise''. Information Theory's fundamental contribution to Natural Language Processing and Computational Linguistics was further concretized in 1951, in his article "Prediction and Entropy of Printed English", proving that treating white space as the 27th letter of the alphabet actually lowers uncertainty in written language, providing a clear quantifiable link between cultural practice and probabilistic cognition. Another notable paper published in 1949 is '' Communication Theory Of Secrecy Systems '', a major contribution to the development of a mathematical theory of Cryptography where he also proved that all theoretically unbreakable ciphers must have the same requirements as the One-time Pad . He is also credited with the introduction of Sampling Theory , which is concerned with representing a continuous-time signal from a (uniform) discrete set of samples. This theory was essential in enabling telecommunications to move from analog to digital transmissions systems in the 1960s and later. He returned to MIT to hold an endowed chair in 1956. Hobbies and inventions Outside of his academic pursuits, Shannon was interested in Juggling , Unicycling , and Chess . He also invented many devices, including rocket-powered Flying Disc s, a motorized pogo stick, and a flame-throwing trumpet for a science exhibition. One of his more humorous devices was a box kept on his desk called the "Ultimate Machine", based on an idea by Marvin Minsky . Otherwise featureless, the box possessed a single switch on its side. When the switch was flipped, the lid of the box opened and a mechanical hand reached out, flipped off the switch, then retracted back inside the box. In addition he built a device that could solve the Rubik's Cube puzzle.[http://web.mit.edu/newsoffice/2001/shannon.html ...and a device that could solve the Rubik's Cube puzzle (M.I.T obituary website)] He is also considered the co-inventor of the first . Legacy and tributes Shannon came to the ; one at MIT in the Laboratory For Information And Decision Systems ; one in Gaylord, Michigan ; one at the University of California at San Diego; and another at Bell Labs. After the breakup of the Bell system, the part of Bell Labs that remained with AT&T was named Shannon Labs in his honor. . Without him, none of the things we know today would exist. The whole Digital Revolution started with him." Bell Labs digital guru dead at 84 -- Pioneer scientist led high-tech revolution ('' The Star-Ledger '', obituary by Kevin Coughlin 27 February , 2001 ) However, Shannon was oblivious to the marvels of the digital revolution because his mind was ravaged by Alzheimer's Disease . His wife mentioned in his obituary that "he would have been bemused" by it all. Bell Labs digital guru dead at 84 -- Pioneer scientist led high-tech revolution ('' The Star-Ledger '', obituary by Kevin Coughlin 27 February , 2001 ) SHANNON MISCELLANY mouse '' Theseus '', named after the Greek Mythology hero of Minotaur and Labyrinth fame, and which he tried to teach to come out of the maze in one of the first experiments in Artificial Intelligence .]] Shannon's mouse Theseus, created in 1950, was a magnetic mouse controlled by a relay circuit that enabled it to move around a maze of 25 squares. Its dimensions were the same as an average mouse. The maze configuration was flexible and it could be modified at will. The mouse was designed to search through the corridors until it found the target. Having travelled through the maze, the mouse would then be placed anywhere it had been before and because of its prior ''experience'' it could go directly to the target. If placed in unfamiliar territory, it was programmed to search until it reached a known location and then it would proceed to the target, adding the new knowledge to its memory thus ''learning''. Shannon's mouse appears to have been the first learning device of its kind. Shannon's computer chess program In 1950 Shannon published a groundbreaking paper on Computer Chess entitled ''Programming a Computer for Playing Chess''. It describes how a machine or computer could be made to play a reasonable game of Chess . His process for having the computer decide on which move to make is a Minimax procedure, based on an Evaluation Function of a given chess position. Shannon gave a rough example of an evaluation function in which the value of the black position was subtracted from that of the white position. ''Material'' was counted according to the usual relative Chess Piece Point Value (1 point for a pawn, 3 points for a knight or bishop, 5 points for a rook, and 9 points for a queen). He considered some positional factors, subtracting ½ point for each Doubled Pawn , Backward Pawn , and Isolated Pawn . Another positional factor in the evaluation function was ''mobility'', adding 0.1 point for each legal move available. Finally, he considered Checkmate to be the capture of the king, and gave it the artificial value of 200 points. Quoting from the paper: The coefficients .5 and .1 are merely the writer's rough estimate. Furthermore, there are many other terms that should be included. The formula is given only for illustrative purposes. Checkmate has been artificially included here by giving the king the large value 200 (anything greater than the maximum of all other terms would do). The evaluation function is clearly for illustrative purposes, as Shannon stated. For example, according to the function, pawns that are doubled as well as isolated would have no value at all, which is clearly unrealistic. The Las Vegas connection: Information theory and its applications to game theory Shannon and his wife Betty also used to go on weekends to '', to the stock market with even better results. William Poundstone website Shannon's maxim Shannon formulated a version of Kerckhoffs' Principle as "the enemy knows the system". In this form it is known as "Shannon's maxim". Other trivia He met his wife Betty when she was a numerical analyst at Bell Labs . AWARDS AND HONORS LIST
SEE ALSO
REFERENCES Cited references General references
EXTERNAL LINKS
|
|
|