Agent-based Model
and
NetLogo
成功大學數學系
陳旻宏
Agent-based model
 An agent-based model (ABM) is a class of computational
models for simulating the actions and interactions of
autonomous agents .
 It combines elements of game theory, complex systems,
emergence, computational sociology, multi-agent systems, and
evolutionary programming.
 Monte Carlo Methods are used to introduce randomness.
http://en.wikipedia.org/wiki/Agent-based_model
 From the lower (micro) level of systems to a higher (macro)
level: The models simulate the simultaneous operations and
interactions of multiple agents, in an attempt to re-create and
predict the appearance of complex phenomena.
 Simple behavioral rules generate complex behavior. This
principle, known as K.I.S.S. ("Keep it simple, stupid") is
extensively adopted in the modeling community.
 Bounded rational: Individual agents are typically presumed to
be acting in what they perceive as their own interests, such as
reproduction, economic benefit, or social status using
heuristics or simple decision-making rules.
 ABM agents may experience "learning", adaptation, and
reproduction.
Models of Segregation 謝林實驗
Thomas Schelling提出的種族隔離的動態模型 (Models of
Segregation)，以棋盤作為住宅，兩種不同硬幣分別對映黑人
白人， 給定原則決定是否遷移：一種是種族歧視，只要相鄰格
子有不同膚色的人, 就會想搬家； 另一種則是不希望自己是少
數；若在住家附近自己是少數，則會想搬家。結果發現，固然
種族歧視會造成種族隔離的現象，不希望自己是少數的傾向也
會造成種族隔離的現象。
建議閱讀：
隱藏的邏輯：掌握群眾行為的不敗公式 by 布侃南
The Social Atom：Why the Rich Get Richer, Cheaters Get Caught, and Your
Neighbor Usually Looks Like You by Mark Buchanan
初始分佈
因偏好而產生的
Segregation
NetLogo
 NetLogo is an agent-based programming language and
integrated modeling environment.
 NetLogo was designed, in the spirit of the Logo programming
language, to be "low threshold and no ceiling". It teaches
programming concepts using agents in the form
of turtles, patches, and the observer.
http://en.wikipedia.org/wiki/NetLogo
NetLogo Examples
 Fireflies (Biology): Synchronization of the flashing of
fireflies.
 Wolf-sheep predation (Biology): predator-prey
ecosystems.
 Segregation (Social Science):
 PD Basic Evolutionary (Social Science/Prisoner's Dilemma)
 Virus on a Network (Network): the spread of a virus
through a network.
http://ccl.northwestern.edu/netlogo/models/