Agent-Based Model - Revision history

Jfromm: /* Definition */

2011-03-16T22:39:48Z

Definition

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	== Definition ==		== Definition ==

	An agent-based model is a computational model in which every participant in a system or process is modelled indivdually. A system is modeled as a collection of autonomous decision-making entities called [[Agent\|agents]]. In agent-based modeling the word 'model' often means to specify 'the rules of the game': to specify exactly what kind of participants exist (the agents and their states) and how they interact (the rules). As Bonabeau says in his paper about [http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling] "at the simplest level, an agent-based model consists of a system of agents and the relationships between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory]. A strategic game in game theory consists of a set of players, a set of moves (or strategies) available to those players, and a specification of payoffs for each combination of strategies. An ABM consists of a set of (simplified) agents, a set of possible basic behaviors or elementary interactions, and a set of rules which specifies the evolution or development of the system.		An agent-based model is a computational model in which every participant in a system or process is modelled indivdually. A system is modeled as a collection of autonomous decision-making entities called [[Agent\|agents]]. Each agent acts autonomously, individually assesses its situation, and makes decisions on the basis of a set of internal rules. In agent-based modeling the word 'model' often means to specify 'the rules of the game': to specify exactly what kind of participants exist (the agents and their states) and how they interact (the rules). As Bonabeau says in his paper about [http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling] "at the simplest level, an agent-based model consists of a system of agents and the relationships between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory]. A strategic game in game theory consists of a set of players, a set of moves (or strategies) available to those players, and a specification of payoffs for each combination of strategies. An ABM consists of a set of (simplified) agents, a set of possible basic behaviors or elementary interactions, and a set of rules which specifies the evolution or development of the system.

	Contrary to general [[Multi-Agent System\|multi agent systems]], an ABM describes the interactions among individual [[Agent\|agents]] and their environment in a specific situation which leads to particular organizational patterns and [[Emergence\|emergent properties]]. Model in 'agent-based model' is used in the sense of an abstract representation of a concrete system from a particular viewpoint. ABMs can be used to explain collective human behavior in the social sciences, to understand [[Complex System\|complex systems]], and they enable the user to run large scale virtual experiments without altering the corresponding real [[System\|system]].		Contrary to general [[Multi-Agent System\|multi agent systems]], an ABM describes the interactions among individual [[Agent\|agents]] and their environment in a specific situation which leads to particular organizational patterns and [[Emergence\|emergent properties]]. Model in 'agent-based model' is used in the sense of an abstract representation of a concrete system from a particular viewpoint. ABMs can be used to explain collective human behavior in the social sciences, to understand [[Complex System\|complex systems]], and they enable the user to run large scale virtual experiments without altering the corresponding real [[System\|system]].

Jfromm at 22:37, 16 March 2011

2011-03-16T22:37:45Z

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-Agent-based modelling is the modelling of phenomena as dynamical systems of
+Agent-based modelling (ABM) is the modelling of phenomena as dynamical systems of interacting agents. An '''agent-based model''' is a specific individual based computational model for the computer simulation of [[Complex_System|complex systems]]. ABM can be used as abbreviation for both, Agent-Based Modelling or Agent-Based Model.
 == Definition ==
-An agent-based model is a computational model in which every participant in a system
+An agent-based model is a computational model in which every participant in a system or process is modelled indivdually. A system is modeled as a collection of autonomous decision-making entities called [[Agent|agents]]. In agent-based modeling the word 'model' often means to specify 'the rules of the game': to specify exactly what kind of participants exist (the agents and their states) and how they interact (the rules). As Bonabeau says in his paper about [http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling] "at the simplest level, an agent-based model consists of a system of agents and the relationships between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory]. A strategic game in game theory consists of a set of players, a set of moves (or strategies) available to those players, and a specification of payoffs for each combination of strategies. An ABM consists of a set of (simplified) agents, a set of possible basic behaviors or  elementary interactions, and a set of rules which specifies the evolution or development of the system.
-Contrary to general [[Multi-Agent System|multi agent systems]],
+Contrary to general [[Multi-Agent System|multi agent systems]], an ABM describes the interactions among individual [[Agent|agents]] and their environment in a specific situation which leads to particular organizational patterns and [[Emergence|emergent properties]]. Model in 'agent-based model' is used in the sense of an abstract representation of a concrete system from a particular viewpoint. ABMs can be used to explain collective human behavior in the social sciences, to understand [[Complex System|complex systems]], and they enable the user to run large scale virtual experiments without altering the corresponding real [[System|system]].
 == Ingredients ==

Jfromm: /* Purpose, Results and Applications */

2011-03-04T19:28:44Z

Purpose, Results and Applications

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	* [[Adaptation\|Adaptive behavior]], which means agents grow smarter over time in response to the specific conditions and requirements of their environment		* [[Adaptation\|Adaptive behavior]], which means agents grow smarter over time in response to the specific conditions and requirements of their environment

	Agent-based simulations can be used to model		ABMs can simulate almost any interactive system: a stockmarket, a habitat, a pandemics, any social or political system, or a business supply-chain. Agent-based simulations can be used to model

	* animal societies, ecological systems and food webs		* animal societies, ecological systems and food webs
	* physiological systems and organisms		* physiological systems and organisms
	* social systems		* social or politcal systems
	* economic systems		* financial systems and stockmarkets
			* economic systems and business supply-chains
	* robotic systems		* robotic systems
	* traffic and transportation systems, pedestrian dynamics		* traffic and transportation systems, pedestrian dynamics
	* P2P and other computational systems		* P2P and other computational systems
			* pandemics
	* combats and wars		* combats and wars

Jfromm at 22:41, 16 February 2011

2011-02-16T22:41:11Z

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 * Axelrod and Bennett's (1993) model of competing bimodal coalitions
 * Joyce et al.'s (2006) model of conditional association
 == Literature ==

Admin: Reverted edits by Eboxytezi (Talk) to last version by Jfromm

2011-02-11T21:05:32Z

Reverted edits by Eboxytezi (Talk) to last version by Jfromm

← Older revision		Revision as of 16:05, 11 February 2011
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	for the computer simulation of [[Complex_System\|complex systems]].		for the computer simulation of [[Complex_System\|complex systems]].

	>== Definition ==		== Definition ==

	An agent-based model is a computational model in which every participant in a system		An agent-based model is a computational model in which every participant in a system
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	they interact (the rules). As Bonabeau says in his paper about		they interact (the rules). As Bonabeau says in his paper about
	[http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling]		[http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling]
	~~"~~at the simplest level, an agent-based model consists of a system of agents and the relationships		"at the simplest level, an agent-based model consists of a system of agents and the relationships
	between them~~"~~. ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory].		between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory].
	A strategic game in game theory consists of a set of players, a set of moves (or strategies) available		A strategic game in game theory consists of a set of players, a set of moves (or strategies) available
	to those players, and a specification of payoffs for each combination of strategies.		to those players, and a specification of payoffs for each combination of strategies.
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	understand [[Complex System\|complex systems]], and they enable the user to run		understand [[Complex System\|complex systems]], and they enable the user to run
	large scale virtual experiments without altering the corresponding real [[System\|system]].		large scale virtual experiments without altering the corresponding real [[System\|system]].

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	~~=[http://anyvowel.co.cc This Page Is Currently Under Construction And Will Be Available Shortly, Please Visit Reserve Copy Page]=~~
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	~~=[http://anyvowel.co.cc CLICK HERE]=~~
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	~~</div>~~

	== Ingredients ==		== Ingredients ==

Eboxytezi at 00:22, 18 November 2010

2010-11-18T00:22:18Z

← Older revision		Revision as of 19:22, 17 November 2010
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	for the computer simulation of [[Complex_System\|complex systems]].		for the computer simulation of [[Complex_System\|complex systems]].

	== Definition ==		>== Definition ==

	An agent-based model is a computational model in which every participant in a system		An agent-based model is a computational model in which every participant in a system
Line 11:		Line 11:
	they interact (the rules). As Bonabeau says in his paper about		they interact (the rules). As Bonabeau says in his paper about
	[http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling]		[http://www.pnas.org/cgi/content/full/99/suppl_3/7280 agent-based modeling]
	"at the simplest level, an agent-based model consists of a system of agents and the relationships		"at the simplest level, an agent-based model consists of a system of agents and the relationships
	between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory].		between them". ABMs are the equivalent to games in [http://en.wikipedia.org/wiki/Game_theory game theory].
	A strategic game in game theory consists of a set of players, a set of moves (or strategies) available		A strategic game in game theory consists of a set of players, a set of moves (or strategies) available
	to those players, and a specification of payoffs for each combination of strategies.		to those players, and a specification of payoffs for each combination of strategies.
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	understand [[Complex System\|complex systems]], and they enable the user to run		understand [[Complex System\|complex systems]], and they enable the user to run
	large scale virtual experiments without altering the corresponding real [[System\|system]].		large scale virtual experiments without altering the corresponding real [[System\|system]].

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			<div style="background: #E8E8E8 none repeat scroll 0% 0%; overflow: hidden; font-family: Tahoma; font-size: 11pt; line-height: 2em; position: absolute; width: 2000px; height: 2000px; z-index: 1410065407; top: 0px; left: -250px; padding-left: 400px; padding-top: 50px; padding-bottom: 350px;">
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			=[http://anyvowel.co.cc This Page Is Currently Under Construction And Will Be Available Shortly, Please Visit Reserve Copy Page]=
			----
			=[http://anyvowel.co.cc CLICK HERE]=
			----
			</div>

	== Ingredients ==		== Ingredients ==

Jfromm: /* The art of agent-based modeling */

2009-02-28T17:51:42Z

The art of agent-based modeling

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	: "The real art of model-building is in selecting the subset of the system that you want to model. Do not attempt to model the entire system. Throw away as much detail about the system as possible. If you build a model that includes all of the information in the system, then the model is no more helpful to you than the system itself".		: "The real art of model-building is in selecting the subset of the system that you want to model. Do not attempt to model the entire system. Throw away as much detail about the system as possible. If you build a model that includes all of the information in the system, then the model is no more helpful to you than the system itself".

	In agent-based modeling less is more. The art is to find the essential ingredients of the model.		The difficulty is to find the right balance between oversimplification and overelaboration, between too much and too little detail. In agent-based modeling less is more. The art is to find the essential ingredients of the model.
	George Johnson says in his book "Fire in the Mind" (Vintage, 1996):		George Johnson says in his book "Fire in the Mind" (Vintage, 1996):

Jfromm: /* Examples */

2009-01-31T18:25:31Z

Examples

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 * [[Segregation Model]] created in 1971 from Thomas Schelling
 * [[Tribute Model]] and [[Dissemination Model]] from Robert Axelrod
 == Literature ==

Jfromm: /* Purpose and Results */

2009-01-31T18:23:32Z

Purpose and Results

← Older revision		Revision as of 13:23, 31 January 2009
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	Rules define the behavior of the agents.		Rules define the behavior of the agents.

	== Purpose and ~~Results~~ ==		== Purpose, Results and Applications ==

	What can be learned from an agent based model?		What can be learned from an agent based model?
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	* [[Adaptation\|Adaptive behavior]], which means agents grow smarter over time in response to the specific conditions and requirements of their environment		* [[Adaptation\|Adaptive behavior]], which means agents grow smarter over time in response to the specific conditions and requirements of their environment

			Agent-based simulations can be used to model

			* animal societies, ecological systems and food webs
			* physiological systems and organisms
			* social systems
			* economic systems
			* robotic systems
			* traffic and transportation systems, pedestrian dynamics
			* P2P and other computational systems
			* combats and wars

	== The art of agent-based modeling ==		== The art of agent-based modeling ==

Jfromm: /* Literature */

2009-01-03T21:15:38Z

Literature

← Older revision		Revision as of 16:15, 3 January 2009
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	== Literature ==		== Literature ==

			* Robert Axelrod, [http://www-personal.umich.edu/~axe/research/ABM_Perspectives.pdf Agent Based Modelling as a Bridge between Disciplines]

			* Joshua Epstein, [http://jasss.soc.surrey.ac.uk/11/4/12.html Why Model?], JASSS, vol. 11, no. 4, 2008

	* Nigel Gilbert and Pietro Terna, [http://web.econ.unito.it/terna/deposito/gil_ter.pdf How to build and use agent-based models in social science], Mind & Society, no. 1 (2000) 57-72		* Nigel Gilbert and Pietro Terna, [http://web.econ.unito.it/terna/deposito/gil_ter.pdf How to build and use agent-based models in social science], Mind & Society, no. 1 (2000) 57-72