“For the most part even to this day, a great gulf exists between man’s aspirations and his...

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t part even to this day, a great man’s aspirations and his actio -- George B. Dantzig

Transcript of “For the most part even to this day, a great gulf exists between man’s aspirations and his...

Page 1: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

“For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig

Page 2: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1939. University of California, Berkeley.

George B. DantzigAge: 25

Jerzy NeymanProfessor of Statistics

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not the same personThesis on Lagrange multipliers (i.e. duality)

Page 3: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1941. The Pentagon, Washington.

1941-1946: Dantzig works for the US government developing methods for logistical and operational planning… (using desk calculators)

Page 4: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1946. USS Air Force, Washington.

“Non-computability was the chief reason, I believe, for a total lack of interest in optimization prior to 1947.”

Danzig formulated a formal model for “planning” problems: Solving a linear objective function subject to linear constraints.

Invented the simplex method for finding optimal solutions to “linear programs” in a bounded number of steps.

Air Force intiated SCOOP (Scientific Computing of Optimum Programs)

Page 5: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

A General linear program.

Page 6: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

The Simplex Method.

Every constraint specifies ann-dimensional half-space.

Travel along “edges” untilno improvement can be made.

Page 7: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1947. Institute for Advanced Study, Princeton.

“Then, for the next hour and a half, he proceeded to give me a lecture on the mathematical theory of linear programs.” -- Dantzig about von Neumann

Page 8: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1949. The University of Chicago.

The Zero Symposium

Page 9: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

A rapidly changing world.

“It has been argued that (before pornography invaded the internet) the majority of CPU time used by computers world wide was devoted to running the simplex algorithm.”

Page 10: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

But what will the theorists do?

In 1970, Klee and Minty showed thatthe simplex method could takeexponentially many steps to solve anLP in the worst case…

Is there aprovablyefficient

algorithm?

Page 11: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

The cold war.

Page 12: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

1979. Khachiyan proves that Linear Programming is in P.

“Despite the assumed mediocrity of Soviet hardware, they could win the cold war, economically and militarily, if they had superior mathematical algorithms…”

Page 13: “For the most part even to this day, a great gulf exists between man’s aspirations and his actions.” -- George B. Dantzig.

2004. A strongly polynomial algorithm?