complexitystudies » complexity

Agent-Based Modelling – some platforms reviewed

guenther — Sat, 13 Oct 2007 18:04:54 +0000

Gisagents review Swarm, Mason and Repast. Plus: a load of references, most of them linked (to PDF files of the papers). Have fun.

GIS and Agent-Based Modelling: Open Source Simulation / Modelling Systems for ABM

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Primate Behavior and Agent-based Modelling

guenther — Mon, 24 Sep 2007 10:26:34 +0000

ABM models primate behaviour:

ScienceDaily: Primate Behavior Explained By Computer ‘Agents’

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Order From Chaos Using Graphs

guenther — Sat, 21 Jul 2007 11:23:50 +0000

Good Math Bad Math talks about how order arises naturally out of disorder and a simple way of seeing it via Ramsey’s Theorem. He uses the Theorem as an argument against creationism. As good a refutation of creationism as one can desire, I would say, as it is really evident and nicely transferable to the other domain – as an explanation heuristic.

Good Math, Bad Math : Order From Chaos Using Graphs: Ramsey Theory

Technorati Tags: complexity, mathematics, philosophy of science

Photosynthesis and QM

guenther — Sun, 22 Apr 2007 10:22:37 +0000

This result is widely reported on the net lately, and while we can’t yet be sure it actually occurs in plants at normal temperatures (so there is room for speculation – it shows one thing for sure – something I have been advocating for a long time: that the boundaries between the scientific disciplines are highly artificial, and it is time to look beyond the textbook demarcations. Maybe it is time for quantum biology?

Photosynthesis takes a leaf out of the quantum book (April 2007) – News – PhysicsWeb

The here the Nature paper.

Technorati Tags: complexity, philosophy of science, physics

Non-Newtonian fluid

guenther — Mon, 16 Apr 2007 15:43:07 +0000

Here is a nice example of what systems that exhibit non-linear dynamic behaviour “do”:

Cornstarch – Phenomena

Walk on cornstarch

Non-Newtonian fluid – Wikipedia, the free encyclopedia

(This was discussed on the Rosen List recently.)

Technorati Tags: complexity, nonlinearity

Visualization Methods

guenther — Tue, 27 Feb 2007 18:51:25 +0000

Making sense of data requires visualization methods – here is an ingenious overview:

A Periodic Table of Visualization Methods

Technorati Tags: complexity, statistics

Useless Arithmetic

guenther — Thu, 22 Feb 2007 20:40:13 +0000

A new book has come out which casts into serious doubt some of the models which have influenced policy-makers so far. This further convinces me that it is time to lay a serious philosophy of science foundation for modelling; especially the semantics of models, which have not yet received due attention (interpretation is more of an ad hoc art than a science).

Useless Arithmetic; Why Environmental Scientists Can’t Predict the Future; Orrin H. Pilkey and Linda Pilkey-Jarvis

Noted coastal geologist Orrin Pilkey and environmental scientist Linda Pilkey-Jarvis show that the quantitative mathematical models policy makers and government administrators use to form environmental policies are seriously flawed. Based on unrealistic and sometimes false assumptions, these models often yield answers that support unwise policies.

There is also an interesting comment on Overcoming Bias, one of my favourite blogs.

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Buckminster Fuller

guenther — Sun, 18 Feb 2007 09:11:29 +0000

Buckminster Fuller seems to have been a very remarkable person, so I would like to introduce him here on my blog. I like his word creations (text from Wikipedia, retrieved 18 Feb 2007):

Use of language and neologisms

Buckminster Fuller spoke and wrote in a unique style and thought it crucial to describe the world as accurately as possible. [2] Fuller often created long run-on sentences and used unusual compound words (omniwell-informed, intertransformative, omni-interaccommodative, omniself-regenerative) as well as terms he himself coined. [3] Fuller used the word ‘Universe’ without the definite or indefinite articles (a or the) and always capitalized the word. Universe to Fuller meant the sum of all experience. [4]

Fuller replaced the words ‘up’ and ‘down’ with ‘in’ and ‘out’ of a gravitational centre, holding that ‘up’ and ‘down’ referred only to a planar concept inconsistent with how humans experience the world. [5] ‘World-around’ is a term coined by Fuller to replace worldwide. The general belief in a flat Earth died out in the Middle Ages, so using wide is an anachronism when referring to the surface of the Earth â€” a spheroidal surface has area and encloses a volume, but has no width. Fuller held that unthinking use of obsolete scientific ideas detracts from and misleads intuition. The terms sunsight and sunclipse are other neologisms, according to Allegra Fuller Snyder collectively coined by the Fuller family, replacing sunrise and sunset in order to overturn the geocentric bias of most pre-Copernican celestial mechanics. Fuller also coined the phrase Spaceship Earth, and coined the term (but did not invent) tensegrity.

It has also been claimed that Fuller coined the phrase debunk in 1927, however many credit William Woodward for the term in 1923.

Buckminster Fuller – Wikipedia, the free encyclopedia

Technorati Tags: complexity, people

Introduction to Complexity Concepts

guenther — Fri, 16 Feb 2007 12:28:07 +0000

This is a very nice paper, especially well suited for a first introduction:

Heylighen F. (2001): “The Science of Self-organization and Adaptivity”, in: L. D. Kiel, (ed.) Knowledge Management, Organizational Intelligence and Learning, and Complexity, in: The Encyclopedia of Life Support Systems ((EOLSS), (Eolss Publishers, Oxford)

@INCOLLECTION {Heylighen2001,
title = {The science of self-organization and adaptivity},
author = {Heylighen, Francis},
editor = {Kiel, L. D. },
booktitle = {Knowledge Management, Organizational Intelligence and Learning, and Complexity},
series = {The Encyclopedia of Life Support Systems},
year = {2001},
publisher = {EOLSS Publishers},
address = {Oxford},
}

I would like to let the abstract speak for itself:

The theory of self-organization and adaptivity has grown out of a variety of disciplines,
including thermodynamics, cybernetics and computer modelling. The present article reviews its
most important concepts and principles. It starts with an intuitive overview, illustrated by the
examples of magnetization and B{\’e}nard convection, and concludes with the basics of mathematical
modelling. Self-organization can be defined as the spontaneous creation of a globally coherent
pattern out of local interactions. Because of its distributed character, this organization tends to be
robust, resisting perturbations. The dynamics of a self-organizing system is typically non-linear,
because of circular or feedback relations between the components. Positive feedback leads to an
explosive growth, which ends when all components have been absorbed into the new
configuration, leaving the system in a stable, negative feedback state. Non-linear systems have in
general several stable states, and this number tends to increase (bifurcate) as an increasing input of
energy pushes the system farther from its thermodynamic equilibrium. To adapt to a changing
environment, the system needs a variety of stable states that is large enough to react to all
perturbations but not so large as to make its evolution uncontrollably chaotic. The most adequate
states are selected according to their fitness, either directly by the environment, or by subsystems
that have adapted to the environment at an earlier stage. Formally, the basic mechanism
underlying self-organization is the (often noise-driven) variation which explores different regions in
the systemâ€™s state space until it enters an attractor. This precludes further variation outside the
attractor, and thus restricts the freedom of the systemâ€™s components to behave independently. This
is equivalent to the increase of coherence, or decrease of statistical entropy, that defines selforganization.

The author’s homepage.

Technorati Tags: complexity, paper of the week, phd

The History of Complexity Science

guenther — Fri, 16 Feb 2007 12:16:15 +0000

I’m starting a new category: paper of the week. Here, I want to introduce papers important to complexity science and my research, together with related weblinks. Please note that paper of the week means neither at minimum nor at maximum a paper a week, it’s just more of a moniker with a hint to the update frequency.

First I would like to introduce

Abraham, R. H. 2002. The Genesis of Complexity.

@INCOLLECTION {Abraham2002,
title = {The Genesis of Complexity},
author = {Abraham, Ralph H. },
editor = {Montuori, Alfonso},
booktitle = {Advances in Systems Theory, Complexity, and the Human Sciences},
year = {2002},
note ={verify citation: only from pdf file, not original source}
}

The article gives a nice historical overview from 1925 to early 90s.

He develops a beautiful tree metaphor regarding complex systems science – Complexity Science is described as a trunk with many branches, and three roots (in braces some important researchers):

Cybernetics (Math: Wiener, von Neumann, Pitts; Engineer.: Bigelow, Shannon; Neuro: Rosenblueth, McCulloch, de No Anthro: Gregory Bateson and Margaret Mead -> Macy Conferences 46-53),
General Systems Theory (von Bertalanffy, Waddington -> Serbelloni meetings 66-70),
System Dynamics (Chaos, Catastrophe Theory; Poincare, Jay Forrester -> SD Group 1968 -> Sloane School of Mgmt of MIT)

Some of the branches of complexity according to the article: Artificial Neural Networks, Cellular Automata, Cellular Dynamical Systems, Catastrophe Theory, Chaos, Theoretical Biology, Biospherics, Ecology, Synergetics, Autopoiese, General Evolution Theory, and Gaia Theory.

The website cited in the article:
VMI Complexity

The site of Ralph Abraham, where you can also download the article.

Technorati Tags: complexity, paper of the week, phd