BUFFALO, N.Y – The amount of time it takes to
mathematically simulate the path of ash from a volcano eruption or
a satellite collision can take hours, even days.
However a new method, the Conjugate Unscented Transform (CUT),
has shortened the process to minutes.
The approach was created by Nagavenkat Adurthi, a University at
Buffalo mechanical engineering doctoral candidate, while completing
a homework assignment. Finding taught methods inaccurate or
time-consuming, Adurthi designed his own.
“I thought: Why do we have to put points on these axes?
Why don’t we put them somewhere else? So, I introduced new
axes,” says Adurthi. “I reduced the number of
evaluations required to get the same amount of accuracy. Once I got
fewer points than the regular methods, I found out CUT’s real
Because conditions that lead to natural disasters are often
unknown, researchers run multiple simulations using different
variables, or points, to more accurately predict events. The
uncertainty is overcome by taking an average.
Under the direction of Puneet Singla, associate professor of
mechanical and aerospace engineering, Adurthi tested the new
approach against existing methods.
The Monte Carlo method, often used to predict space collisions,
requires at least two to three million random points, which take
more than a week to simulate. CUT reduced the number of needed
points to 745, requiring fewer than 10 minutes.
Adurthi’s approach also lowered the required trials of the
volcano ash propagation model from 6500 simulations over several
weeks to 161 simulations over one week.
CUT, detailed in Adurthi’s master’s thesis,
“The Conjugate Unscented Transform: A Method to
Evaluate Multidimensional Expectation Integrals,” was awarded
the Outstanding Master’s Thesis Award for 2014 by the
Northeastern Association of Graduate Schools.
Adurthi also won two best session presentation awards for CUT
during the 2013 American Control Conference, has six peer-reviewed
conference publications and plans to submit two journal manuscripts
on the method.
“Nagavenkat is one of those rare researchers who, with
great ease, can tackle and solve with little supervision complex,
interdisciplinary problems and produce publications of the highest
quality,” says Singla. “It is important to mention that
the computation of probabilistic hazard map for volcano ash
advection would not have been computationally tractable without
making use of his work.”
CUT can also be applied to sensors, GPS tracking, and tsunami
simulation. Adurthi plans to propose the method to NASA scientists