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Notice and Invitation Oral Defense of Doctoral Dissertation The Volgenau School of Engineering, George Mason University
Kenneth W. Comer
Bachelor of Arts, Cornell University, 1974
Master of Arts, Georgetown University, 1983
Master of Science, The George Washington University, 1989
Who Goes First?
An Examination of the Impact of Activation on Outcome Behavior
in Applied Agent-based Models
Monday, March 10,
2014, 10:00AM - Noon
Room 2901
Nguyen Engineering
Building
All are invited to
attend.
Committee
Dr. Andrew G. Loerch, Chair
Dr. Chun-Hung Chen
Dr. Rajesh
Ganesan
Dr. Robert
Axtell
Agent-based models have become the tool of
choice for
modeling self-organizing systems. In fact, for some domains they
have
supplanted traditional discrete event simulations as
decision-support elements
to explore the potential outcome space. In creating a specific
agent-based
model, there are several choices the simulation designer must
make. Often these
design decisions are implicit, but they may be important in the
performance of
the simulation. One such choice is the sequence with which the
agents will
execute their methods or change their state. This is the
'activation' question,
and its impact on three different models is examined in this
dissertation.
Three agent-based models described in the
literature
in three separate domains (civil unrest, market execution, and
social
interactions) were replicated, and the impact of various
activation schemes on
the emergent population patterns and dynamics was analyzed. It was
demonstrated
that the choice of activation type is important for the outcome
behavior of the
model and should be stipulated in any published description of an
agent-based
model. In some experiments the differences noted, while
significant, were only
statistical. In others they led to substantial differences in
either outcomes
or model behavior. Further investigation showed that sophisticated
activation
schemes can become powerful tools to produce unexpected or
unpredicted behavior
of multi-agent systems. Thus, activation becomes more than an
inconvenient
detail to be dealt with during design, and is shown to be a source
of
exploratory variation as modelers of self-organizing social
systems seek to
match the behavior of natural systems.
A copy of
this doctoral dissertation is on reserve at the Johnson Center
Library.