Introduction
SARBayes is a small research project organized by Charles
Twardy. Our goal is to generate accurate probability
maps, and use them quickly, automatically, and well to find missing
people on land more quickly. As the name suggests, we use a Bayesian
approach to modeling and statistics.
We develop models
and algorithms to support missing-persons searches on land, using
data that we and others have collected about missing-person
behavior and search operations. In 2008 the large
ISRID database become available, and in 2009 we have made a copy
clean enough for machine learning.
Some of our past projects
include:
- collecting data on Australian searches into an
online database
- making and testing Bayesian network models
to predict lost-person behavior
- developing a general-purpose library for optimal resource
allocation (SORAL)
We have discovered by experience that we are not well-suited to
end-user software development, but we have developed some
prototypes, and are always looking for real programmers.
Search is a classic case of Reasoning Under Uncertainty and the
core of the problem is generating and maintaining a probability map
for the current location of the lost person. Search theory and
optimal resource allocation presume that such a map exists, but
there has been no good way to make one for land
search.
The database of lost-person incidents is one approach to generating
such a probability map — by matching current case data to a statistical
profile generated from past incidents. We use Bayesian networks to
turn the bare statistics into dynamic models, and hopefully improve on
the very rough statistical profiles now used. There are other
approaches besides case-history, such as modified random walk
simulations, and of course, expert scenario analysis at the scene.
An ideal system would combine all of these approaches. And Bayesian
statistics provide a clear and principled way to do that too.
Our goal is to be of real use to the SAR community. We expect our
models to beat the current state of the art, and we hope to contribute
to software that makes it possible to use those models on live
searches.
History
SARBayes began in late 2000 in the Reasoning
Under Uncertainty Group, a part of the Monash Data Mining
Centre) at Monash
University in Melbourne, Australia, with the cooperation of
the Victorian
Police Search & Rescue Squad, and VicWalk's Bushwalkers' Search &
Rescue. The project has received invaluable assistance from other
individuals and organizations, especially Bob Koester, Jack Frost,
and Alan Washburn.
In 2005, Charles returned to the U.S. on a SBIR grant with Jim Donovan and Bob Koester, and finished the Australian Lost Person Behaviour Report (2006). Those cases helped to prototype the ISRID database. In 2008, Charles joined George Mason University as research faculty, where he hopes to create an active research project again. Online collaboration is also welcome.
Comments are welcome (remove the underscores):
c_t_w_a_r_d_y at sarbayes.org |
