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--- geopro:pedro:gamesongrids [2007/11/07 15:29] – pedro
+++ geopro:pedro:gamesongrids [2008/02/26 22:18] (atual) – 150.163.67.167
@@ Linha 1: / Linha 1: @@
 ====== Games on Grids ======
+====Prisoner's dilemma and clusters on small-world networks====
+|X. Thibert-Plante, L. Parrott, 2007| Complexity 12(6)22-36|
+\\
+**Abstract:** The structure of interaction plays an important role in the outcome of evolutionary games. This study investigates the evolution of stochastic strategies of the prisoner's dilemma played on structures ranging from lattices to small world networks. Strategies and payoffs are analyzed as a function of the network characteristics of the node they are playing on. Nodes with lattice-like neighborhoods tend to perform better than the nodes modified during the rewiring process of the construction of the small-world network.
+\\
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 Each additional benefit may be discounted or synergistically enhanced by a factor w. [Forçando a barra para a cooperação? FIXME: Verificar no artigo]
+====The Arithmetics of Mutual Help====
+|M. A. Nowak, R. M. May and K. Sigmund, 1995| Scientific American| [[http://www.leg.ufpr.br/~pedro/papers/sciam/SciAm95a.pdf|pdf]]|
+{{ http://www.leg.ufpr.br/~pedro/figures/cooperators-generations.jpg?300}}
+\\
+But what of the creatures, such as many invertebrates, that seem to exhibit
+forms of reciprocal cooperation, even though they often cannot recognize individual
+players or remember their actions? Or what if future payoffs are heavily discounted? How can altruistic
+arrangements be established and maintained in these circumstances? One possible
+solution is that these players find a fixed set of fellow contestants and make
+sure the game is played largely with them. In general, this selectivity will be
+hard to attain. But there is one circumstance in which it is not only easy, it is
+automatic. **If the players occupy fixed sites, and if they interact only with close
+neighbours, there will be no need to recognize and remember, because the other
+players are fixed by the geometry.** Whereas in many of our simulations
+players always encounter a representative sample of the population, we have
+also looked specifically at scenarios in which every player interacts only with
+a few neighbours on a two-dimensional grid. Such "spatial games" are very recent.
+They give an altogether new twist to the Prisoner's Dilemma.
+\\
 ====The geometrical patterns of cooperation evolution in the spatial prisoner’s dilemma: An intra-group model====
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 \\
 ====Prisoner's Dilemma Game with Heterogeneous Influential Effect on Regular Small-World Networks====
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 Cells that do not proliferate or migrate automatically enter a reversible, quiescent state.
@@ Linha 138: / Linha 175: @@
 **Abstract:** We consider the prisoner’s dilemma being played repeatedly on a dynamic network,
-where agents may choose their actions as well as their co-players. In the course
+where **agents may choose their actions as well as their co-players**. In the course
 of the evolution of the system, agents act fully rationally and base their decisions
 only on local information. Individual decisions are made such that links to defecting
@@ Linha 147: / Linha 184: @@
 other if the players are perfectly synchronized. The cyclical behavior is lost and the
 system is stabilized when agents react ’slower’ to new information. Our results show,
-that within a fully rational setting in a licentious society, the prisoner’s dilemma
+that within a fully rational setting in a licentious society, **the prisoner’s dilemma
-leads to overall cooperation and thus loses much of its fatality when a larger range
+leads to overall cooperation** and thus loses much of its fatality when a larger range
 of dynamics of social interaction is taken into account. We also comment on the
 emergent network structures.
@@ Linha 154: / Linha 191: @@
 \\
-====Evolutionary prisoner’s dilemma game on hierarchical lattices====
-|J. Vukov and G. Szabó, 2005|Physica|[[http://leg.ufpr.br/~pedro/papers/physica/vukov_hierarchical_lattices_05.pdf|pdf]]|
-{{  http://leg.ufpr.br/~pedro/figures/hierarchical_lattices.jpg?400|Hierarchical lattices}}
-\\
+====Evolutionary Prisoner's Dilemma in Random Graphs====
-**Abstract:** An evolutionary prisoner’s dilemma sPDd game is studied with players located on a hierarchical structure of
-layered square lattices. The players can follow two strategies fD sdefectord and C scooperatordg and their
-income comes from PD games with the “neighbors.” The adoption of one of the neighboring strategies is
-allowed with a probability dependent on the payoff difference. Monte Carlo simulations are performed to study
-how the measure of cooperation is affected by the number of hierarchical levels sQd and by the temptation to
-defect. According to the simulations the highest frequency of cooperation can be observed at the top level if the
-number of hierarchical levels is low sQ,4d. For larger Q, however, the highest frequency of cooperators
-occurs in the middle layers. The four-level hierarchical structure provides the highest average stotald income for
-the whole community.
-\\
-====Evolutionary Prisioner's Dilemma in Random Graphs====
 |O. Duran and R. Mulet, 2005| Physica| [[http://leg.ufpr.br/~pedro/papers/physica/duran_random_graphs_05.pdf|pdf]]|
@@ Linha 188: / Linha 208: @@
 fixed and equal number alpha of neighbors. RG 2: Poisson random graph, links distributed with a mean value alpha.
-The evolution of cooperation depends on the connectivity and on the game payoff, but it is independent of the
+**The evolution of cooperation depends on the connectivity and on the game payoff, but it is independent of the
-initial conditions. Poisson random graphs lead to more cooperation then with graphs of fixed degree.
+initial conditions. Poisson random graphs lead to more cooperation then with graphs of fixed degree.**
+====Evolutionary prisoner’s dilemma game on hierarchical lattices====
+|J. Vukov and G. Szabó, 2005|Physica|[[http://leg.ufpr.br/~pedro/papers/physica/vukov_hierarchical_lattices_05.pdf|pdf]]|
+{{  http://leg.ufpr.br/~pedro/figures/hierarchical_lattices.jpg?400|Hierarchical lattices}}
+\\
+**Abstract:** An evolutionary prisoner’s dilemma (PD) game is studied with players located on a hierarchical structure of
+layered square lattices. The players can follow two strategies D (defector) and C (cooperator) and their
+income comes from PD games with the “neighbors.” The adoption of one of the neighboring strategies is
+allowed with a probability dependent on the payoff difference. Monte Carlo simulations are performed to study
+how the measure of cooperation is affected by the number of hierarchical levels Q and by the temptation to
+defect. According to the simulations the highest frequency of cooperation can be observed at the top level if the
+number of hierarchical levels is low. For larger Q, however, **the highest frequency of cooperators
+occurs in the middle layers**. The four-level hierarchical structure provides the highest average (total) income for
+the whole community.
+\\
@@ Linha 205: / Linha 248: @@
 in small populations.
-On the other side, this letter emphasizes indirectly the important role of spatial structures in the evolution of mutualism.
+On the other side, **this letter emphasizes indirectly the important role of spatial structures in the evolution of mutualism.**
@@ Linha 373: / Linha 416: @@
 \\
+====The Arithmetics of Mutual Help====
+|M. A. Nowak and R. M. May and K. Sigmund, 1995| Scientific American|[[http://leg.ufpr.br/~pedro/papers/sciam/SciAm95a.pdf|pdf]]|
+If the players occupy fixed sites, and if they interact only with close
+neighbours, there will be no need to recognize
+and remember, because the other players are fixed by the geometry.
+"spatial games"
+grid with cooperators and defectors. the figures have four colours:
+cooperators, defectors, new cooperators and new defectors (those who
+changed their strategies in the last round).