Black Contributions to Unites States of America

[patrici...@my-dejanews.com]

African American history is American history. Check out Philip Emeagwali's
speech posted at http://emeagwali.com celebrating the contributions of African
Americans to American history.

Enjoy,
Patricia Turner

ONE OF THE WORLD'S FASTEST HUMANS

Faster supercomputers are needed to solve important
scientific and engineering problems. Computing twice
as fast would be impressive; ten times faster would be
even more impressive.

Philip Emeagwali, a doctoral candidate in scientific
computing in the College of Engineering and the 1989
recipient of the Gordon Bell Prize for his
supercomputing research, has increased the speed of a
massively parallel supercomputer to as much as 1,000
times faster than a mainframe computer and 1,000,000
times faster than a personal computer.

Almost as impressive as its speed of operation is the
massively parallel computer's thrift. It costs only about
one-fiftieth of the money to perform computations on a
massively parallel computer as on a conventional
supercomputer.

"The supercomputer industry and much of the
academic establishment have claimed that massively
parallel computers were suited only for certain types of
problems," Emeagwali says. "But in the past few
months, reports at scientific gatherings and in the news
media have indicated that some investigators using the
Connection Machine--- the largest massively parallel
supercomputer now available ---- have proved the
establishment wrong."

Emeagwali had already been looking at
computation-intensive problems from a theoretical
standpoint. When he learned of a $1,000 prize offered
by the Institute of Electrical and Electronic Engineers
Computer Society for the fastest computation in a
scientific and engineering problem requiring trillions of
calculations, he decided to compete.

Emeagwali studied the U.S. government's list of the 20
most computationally difficult problems. The one that
interested him most involved calculating oil. Even
before the onset of war in the Persian Gulf, American
experts recognized the importance of improving the
efficiency of oil extraction.

"The oil industry purchases 10 percent of all
supercomputers and is keenly aware of the difficulty of
computing oil-field flow," Emeagwali says. Oil has
properties that make calculating its flow patterns within
an oil field more difficult than modeling the flow of
groundwater. To model oil-field flow in a computer
requires the simulation of the distribution of the oil at
tens of thousands of locations throughout the far-flung
field. At each location, the computer must be
programmed to make hundreds of simultaneous
calculations at regular intervals of time to determine
such variables as temperature, direction of oil flow,
viscosity, pressure and several geological properties of
the basin holding the oil.

"Even a supercomputer working at the rate of millions
of calculations a second is far too slow to reach a result
that can be acted on in a timely fashion," Emeagwali
explains. "The oil companies need the results quickly
enough to decide how to recover the maximum amount
of oil."

Since an average of only 30 percent of oil is recovered
in an oil field, Emeagwali notes, "It's easy to
understand why the industry is keenly interested in
more accurate simulations of oil flow. An improvement
to even a 31 percent recovery rate --- just one
percentage point --- translates into billions of dollars of
savings."

Emeagwali attracted the attention of many industries
and investigators when he won the Gordon Bell Prize
by showing how he used a $6 million massively parallel
computer to perform the trillions of oil field-modeling
computations at three times the speed of the mightiest
$30 million supercomputer. He hit a computational
speed of 3.1 billion calculations per second.

How did he do it? It took some creative mathematical
thinking for Emeagwali, who was renowned for
mathematical prowess even as a child in Nigeria, to hit
upon a `new' technique that resurrected some
equations that had grown dusty in the computing field
for 50 years.

Rather than use the equations that have been used
throughout the century to calculate oil-field flow and
similar phenomena, Emeagwali asked himself, "When
did we start using these equations, and why did we
start using them?"

He researched those equations and learned that in the
late 19th century "a type of partial differential equation
similar to the classical `heat equation' was derived to
perform the kinds of calculations required to describe
oil-field flow."

Emeagwali with the Connection Machine in Cambridge,
Massachusetts. Massively parallel computers are a young
technology. Only a few universities have acquired their own
models. The U-M is now considering venturing into this
field, Emeagwali says. (Photo by Jon Chomitz for
Thinking Machine Corp.)

There are three families of partial differential equations
--- elliptical, parabolic and hyperbolic. The equations
usually used to simulate and oil reservoir fall into the
parabolic category. Oil reservoir equations take into
account three of the four major forces affecting flow:
pressure, gravitation and viscosity (or drag). They
ignore the fourth force --- inertia (or acceleration).

In 1938 a Soviet mathematician, B. K. Risenkampf,
derived a set of partial differential equations that
included the fourth force. The Risenkampf equations
belong to the hyperbolic category.

Until the invention of the massively parallel computer,
it made no sense to try to apply Risenkampf's
equations to problems like oil-field flow; it would have
taken too many computations for existing computing
technology --- from calculating machines to
supercomputers.

"The fourth, or inertial, force affecting the slow flow of
oil in the ground is about 10,000 times smaller than the
three other forces," Emeagwali explains, "so neglecting
inertia didn`t result in much error even though the
solutions still resembled those of the parabolic
equations,

"If I put 10,000 dollar bills on the table in ones and you
take a dollar, I'm not likely to detect and report the
crime. In the same way, it was reasonable to ignore the
inertial force back then."

Emeagwali had become
interested in the Risenkampf
equations while working at
the National Weather
Service, and decided to take
a "top-down approach" by
seeing if the hyperbolic
equations would result in a
better model of the oil-field
flow.

"I knew that hyperbolic
equations result in solutions
that more accurately reflect
the real world," Emeagwali
says, and so he expected
them to yield a better
representation of the real
properties of oil-field flow.

Even though they are more complex, Emeagwali
theorized, hyperbolic equations would open "a shorter
and quicker path" to the solution of modeling flow.
And in terms of his academic goals, using hyperbolic
equations on a massively parallel computer would show
that "calculations that could take months, even years,
to perform on a personal computer could be done in
seconds or minutes.

"If we had massively parallel computers a hundred
years ago," Emeagwali continues, "we would have used
hyperbolic equations instead of parabolic. The serial
computer hardware we have today reflects the absence
of a need to go the hyperbolic route. But once you
have a certain kind of hardware, it reinforces the
methods you`ve used. It`s not that anyone is to blame
for it, but in a sense computers have developed down a
blind alley."

In the future, Emeagwali says --- and the very near
future at that --- the architecture of massively parallel
computers like the Connection Machine will trickle
down to the personal computer level. They will
increase realism in what computer buffs call artificial
reality (AR).

More important for civilization will be the impart of
massive parallelism at the supercomputer level.
Emeagwali expects to see quite soon "automakers using
these computers to fully simulate car crashes on the
computer rather than crashing expensive rigged-out
models at up to $750,000 a test."

In medicine, "Investigators will find that using
computers based on the technology of massive
parallelism will permit them to study human diseases
by studying humans without compromising human
health, instead of using mice, chimpanzees and the
like."

"Any way you look at it, " Emeagwali concludes, "the
computer industry will have no choice. They will have
to switch to massive parallelism."

Emeagwali hopes to give the industry a big nudge in
early 1991 if his latest submission for the international
computing contest is as convincing as last year's.

"I'm trying to prove that we know how to reach the
Holy Grail of computing --- computing at the teraflops
level by performing trillions of calculations in a second"
[see main article].

Emeagwali says massively parallel supercomputers are
approximately five times faster than conventional
machines now, but he forecasts that the advantage will
approach 100-to-1 in 10 years. If he's right, you can
expect radical changes in the computer industry very
soon.

Reported by John Woodford in the February 1991
issue of the Michigan Today.

Philip Emeagwali can be reached at
500-437-2330 or phi...@emeagwali.com

African American history is American history. Check out Philip Emeagwali's
speech posted at http://emeagwali.com celebrating the contributions of African
Americans to American history.

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