Games as dynamical systems

この論文は国立情報学研究所の電子図書館事業により電子化されました。我々は他者との係わりの中、様々な状況で様々な意思決定を行う。我々が選択した行動は他人に影響を与え、逆に我々自身も他人の行動から影響を受ける。こういった、個人間、企業間、国家間、(あるいは生物間)など複数の意志決定主体が関わる状況を数学的言語で表現し、そして「意思決定を行う複数の主体の合理的な行動とは何か」を問うのがゲーム理論である。生態系型システムの進化ゲームの理論も含めた従来のゲーム理論のモデルでは、設定としてのゲームは固定的(静的)なものが使われることが多かった。しかし、現実の人間社会や生物集団での相互作用は時間構造を含むことが普通で、時間的な側面が重要な役割を果たすことは珍しいことではない。例えば現実世界のプレーヤーは、限られた情報の下でリアルタイムに意思決定を行い、相互作用を通して認知構造を進化させ、社会のルールを形成・発展させていく。利得行列などによる相互作用の代数的・静的記述だけでこういった現象を取り扱うのは困難である。本稿では、まず、ゲームにおける時間構造を考察することの意義について議論する。次に、ゲームの時間構造を自然な形で記述することを目的とした枠組み-「力学系ゲーム(dynamical systems game)」を紹介し、その具体的な適用として社会的ジレンマ問題の分析を行う。そして最後に、社会的ジレンマ状況における協力の発生とその維持の問題について、従来のゲーム理論の枠組みでは原理的に理解し得ないメカニズムについて議論する

Artificial Life IX

Proceedings from the ninth International Conference on Artificial Life; papers by scientists of many disciplines focusing on the principles of organization and applications of complex, life-like systems. Artificial Life is an interdisciplinary effort to investigate the fundamental properties of living systems through the simulation and synthesis of life-like processes. The young field brings a powerful set of tools to the study of how high-level behavior can arise in systems governed by simple rules of interaction. Some of the fundamental questions include: What are the principles of evolution, learning, and growth that can be understood well enough to simulate as an information process? Can robots be built faster and more cheaply by mimicking biology than by the product design process used for automobiles and airplanes? How can we unify theories from dynamical systems, game theory, evolution, computing, geophysics, and cognition? The field has contributed fundamentally to our understanding of life itself through computer models, and has led to novel solutions to complex real-world problems across high technology and human society. This elite biennial meeting has grown from a small workshop in Santa Fe to a major international conference. This ninth volume of the proceedings of the international A-life conference reflects the growing quality and impact of this interdisciplinary scientific community

Iterated mutual observation with genetic programming

"This paper introduces a simple model of interacting agents that learn to predict each other. For learning to predict the other's intended action we apply genetic programming. The strategy of an agent is rational and fixed. It does not change like in classical iterated prisoners dilemma models. Furthermore the number of actions an agent can choose from is infinite. Preliminary simulation results are presented. They show that by varying the population size of genetic programming, different learning characteristics can easily be achieved, which lead to quite different communication patterns." (author's abstract

Local and Global Interactions in an Evolutionary Resource Game

Conditions for the emergence of cooperation in a spatial common-pool resource game are studied. This combines in a unique way local and global interactions. A fixed number of harvesters are located on a spatial grid. Harvesters choose among three strategies: defection, cooperation, and enforcement. Individual payoffs are affected by both global factors, namely, aggregate harvest and resource stock level, and local factors, such as the imposition of sanctions on neighbors by enforcers. The evolution of strategies in the population is driven by social learning through imitation. Numerous types of equilibria exist in these settings. An important new finding is that clusters of cooperators and enforcers can survive among large groups of defectors. We discuss how the results contrast with the non-spatial, but otherwise similar, game of Sethi and Somanathan (1996).Common property, Cooperation, Evolutionary game theory, Global interactions, Local interactions, Social norms

Controlling chaotic transients: Yorke's game of survival

5 pages, 4 figures.-- PACS nr.: 05.45.Gg, 05.45.Pq.-- PMID: 14995689 [PubMed].We consider the tent map as the prototype of a chaotic system with escapes. We show analytically that a small, bounded, but carefully chosen perturbation added to the system can trap forever an orbit close to the chaotic saddle, even in presence of noise of larger, although bounded, amplitude. This problem is focused as a two-person, mathematical game between two players called "the protagonist" and "the adversary." The protagonist's goal is to survive. He can lose but cannot win; the best he can do is survive to play another round, struggling ad infinitum. In the absence of actions by either player, the dynamics diverge, leaving a relatively safe region, and we say the protagonist loses. What makes survival difficult is that the adversary is allowed stronger "actions" than the protagonist. What makes survival possible is (i) the background dynamics (the tent map here) are chaotic and (ii) the protagonist knows the action of the adversary in choosing his response and is permitted to choose the initial point x(0) of the game. We use the "slope 3" tent map in an example of this problem. We show that it is possible for the protagonist to survive.J.A. and M.S.J. acknowledge financial support from the Spanish Ministry of Science and Technology under project BFM2000-0967, and from the Universidad Rey Juan Carlos under projects URJC-PGRAL-2001/02 and URJC-PIGE-02-04. F.d'O. acknowledges financial support from MCyT (Spain) and FEDER, project REN2001-0802-C02-01/MAR (IMAGEN).Peer reviewe

Analysis of the Effect of Reputation on the Various Types of Dilemma based on Theoretical and Experimental Methods.

課題番号：1870022

Manipulating task constraints shapes emergence of herding tendencies in team games performance

The herding phenomenon is observed in nature and has been perceived to be less desirable use of space in impacting overall team play performance. The effective manipulating of rules and task constraints might be able to alter herding tendencies in sport performance. The aim of this study was to determine the impact of altering task constraints on herding tendencies, measured with the use of cluster phase analysis, which has also been used to analyse the synchrony exhibited by performers in invasion games such as professional association football matches. In this study, tracking positional data of individual players in a simulated pass and catch game was undertaken, with no specific verbal instructions provided to participants on how and where to move so that emergent behavioural tendencies could be observed. Data revealed how task constraint manipulations impacted on herding tendencies. Manipulation of task constraints revealed higher levels of clustering tendencies in the herding condition compared to, the non-herding condition. Within the herding condition, between-team synchrony was also strong, especially in the longitudinal direction. Ball possession also seemed to have some impact on within-team synchrony. Findings provided preliminary evidence on how manipulating task constraints can be effective in altering herding tendencies in team games