Emergent Tendencies in
Multi-Agent-based Simulations:
using Constraint-based Methods to
Effect Practical Proofs over Finite
Subsets of Simulation Outcomes
By: Oswaldo Terán
Date: 16th November 2001
Also CPM Report No.: 99-86
Published as:
Terán, O. (2001). Emergent Tendencies in
Multi-Agent-based Simulations: using Constraint-based
Methods to Effect Practical Proofs over Finite
Subsets of Simulation Outcomes. Doctoral Thesis,
Manchester Metropolitan University, Manchester, UK.
Abstract
This thesis suggests a methodology for studying complex
systems. This method is intended to be particularly useful
for searching and proving tendencies (whether considered
emergent or not) in those systems whose dynamics seem to
be strongly dependent on the system’s components’
interaction (such as social systems). These systems are
commonly simulated in Multi-Agent Systems (MAS).
It begins by examining the formal notions of simulation,
modelling, and theorem-proving. Then it reviews some
notions of complexity and proposes a notion of the
emergence of tendencies as based on the trade-off between
subjective and objective factors of complexity. It next
moves on to investigate the dynamics of a system via a
platform consisting in a (logical) model constraint-based
exploration of the dynamics of a simulation. This platform
is suggested for systematically exploring the subspace of
simulation trajectories associated with a range of
parameters of the model, a range of choices of the
processes (e.g., agents’ choices), and the logic of the
simulation program. Following this, we suggest using this
architecture in addition to the higher architectural level
given by a MAS and an even lower level, a syntactic
constraint-based architecture, as complementary means to
investigate aspects of the dynamics of a MAS simulation.
The proposed methods are compared with other
approaches for exploring the dynamics of a simulation. In
particular, differences in terms of the notions of morphism
among models, the generality of the conclusions, and the
measures of behaviour that each approach allows are
emphasised. In addition, enveloping the simulation outputs
is proposed as an alternative to statistical summaries. This
seems to be especially convenient for studying complex
systems and for analysing outputs in case of applying
theorem-proving techniques.
This model constraint-based architecture is applied to a
MAS-based model exemplifying a typical interaction
trader-distributor. A tendency is identified in the
MAS-based model and then a constrained proof is
performed in the model constraint-based architecture.
Afterwards, some implications of this thesis for related
areas of science are reviewed. Finally, the appendices
include an analysis of the complexity of this model
constraint-based exploration of trajectories and two papers
particularly relevant to the social simulation and the MAS
communities.
Accessible at:
http://www.cpm.mmu.ac.uk/cpmrep86.html
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