The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.

A Game Perspective to Complex Adaptive Systems

Marko Sysi-Aho

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Electrical and Communications Engineering for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 21st of June, 2005, at 12 noon.

Overview in PDF format (ISBN 951-22-7732-8)   [546 KB]
Dissertation is also available in print (ISBN 951-22-7731-X)


Understanding the behaviour of a system through the properties of the elements of the system is a central problem in several fields of contemporary research. Appealing approaches for gaining such understanding have been proposed in complex systems studies. One particular approach is based on the scheme of agent-based modelling, in which the elements of the system are described by a set of precise rules which are implemented by computer programs. This dissertation is focused on topics related to two types of agent-based models: minority games and spatial two player games.

The first part of the thesis deals with minority games that have been extensively studied in the physics literature during the past eight years. A minority game describes a society of adaptive individuals with bounded rationality competing for scarce resources. Questions arising from such a model are associated with the efficiency of the system and the success of its individuals in utilizing the scarce resources. Previous studies have indicated that in case the individuals are allowed to evolve, they tend to evolve such that the efficiency of the system improves. However, the actual level of efficiency substantially depends on the type of evolution present in the system. We have applied genetic algorithms to make the system evolving. Our results indicate that natural selection and genetic algorithms can lead the system perform optimally and increase the success of individuals remarkably.

The second part of the thesis describes aspects of games that model strategic interaction situations between individuals. Especially, the focus of this part of the thesis is on models that aim at explaining the emergence and persistence of cooperative behaviour in an animal or human society. Previous studies have indicated that spatial structure of the society largely contributes to the maintenance of cooperation in these models. However, much of the research has been carried out by relying on evolutionary dynamics of the society associated with changes occurring in long times. We have explored a spatial game by allowing the individuals in the system be adaptive and act on short times, and our results show that the characteristic behaviour of the system is different from that observed in studies using evolutionary dynamics.

This thesis consists of an overview and of the following 6 publications:

  1. M. Sysi-Aho, A. Chakraborti, K. Kaski, Intelligent minority game with genetic crossover strategies, The European Physical Journal B 34 (2003) 373-377. © 2003 by authors and © 2003 EDP Sciences. By permission.
  2. M. Sysi-Aho, A. Chakraborti, K. Kaski, Adaptation using hybridized genetic crossover strategies, Physica A 322 (2003) 701-709. © 2003 Elsevier Science. By permission.
  3. M. Sysi-Aho, A. Chakraborti, K. Kaski, Biology helps you to win a game, Physica Scripta T106 (2003) 32-35. © 2003 The Royal Swedish Academy of Sciences. By permission.
  4. M. Sysi-Aho, A. Chakraborti, K. Kaski, Searching for good strategies in adaptive minority games, Physical Review E 69 (2004) 036125. © 2004 American Physical Society. By permission.
  5. M. Sysi-Aho, J. Saramäki, K. Kaski, Invisible hand effect in an evolutionary minority game model, Physica A 347 (2005) 639-652. © 2005 Elsevier Science. By permission.
  6. M. Sysi-Aho, J. Saramäki, J. Kertész, K. Kaski, Spatial snowdrift game with myopic agents, The European Physical Journal B 44 (2005) 129-135. © 2005 by authors and © 2005 EDP Sciences. By permission.

Keywords: complex systems, minority game, snowdrift game, game theory, agent-based model

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© 2005 Helsinki University of Technology

Last update 2011-05-26