Interesting Articles

Going through my RSS feeds I came across three articles which are quite interesting and I thought worth sharing.

The first is "Design Guidelines for Agent Based Model Visualization" by Kornhauser et. al., (2009) which discusses the importance of visualizing agent-based models. Specifically the importance of visualization in identifying, communicating and understanding the behaviour of the modelled phenomenon. In this article Kornhauser et. al. (2009) comment that many agent-based modellers create ineffective visualizations of their models. This paper provides ABM visualization design guidelines in order to improve visual design with ABM toolkits

The images to the above and below are examples from the article about are clear and aesthetic visualizations from the NetLogo model library.

The second article entitled 'Tools of the Trade: A Survey of Various Agent Based Modeling Platforms' by Nikolai and Madey (2009), which offers advice for choosing the appropriate agent-based platform for a specific modelling endeavour. The paper references and extends our own work at CASA "Principles and Concepts of Agent-Based Modelling for Developing Geospatial Simulations." Specifically the paper reviews a number of toolkits and characterize each based on 5 characteristics users might consider when choosing a toolkit (e.g. programming language , type of license, operating system, domain, user support), and then we categorize the characteristics into user-friendly taxonomies that aid in rapid indexing and easy reference.

The authors have also developed a web-based tool that incorporates all their findings, users input a range of characteristics, and the tool returns a list of candidate platforms that contain those characteristics (such as operating system). The tool is available at http://agent.cse.nd.edu/abmsearchengine.php. Furthermore, Nikolai and Madey (2009), have created a wiki page entitled "ABM Software Comparison," and it is linked from the main "Agent Based Model" post on Wikipedia which anyone can alter or expand.

The third paper by Heikkila and Wang, which is in press in Environment and Planning B, entitled "Fujita and Ogawa revisited: an agent-based modeling approach" which builds on and extends the work of Masahisa Fujita and Hideaki Ogawa in 1982. The authors employ an ABM approach that seeks to replicate the individual household and firm behaviours that lead to equilibrium or nonequilibrium outcomes but more specifically addresses questions of path dependency and bounded rationality that lie well beyond the scope of the original work of Fujita and Ogawa (1982).

On a side note there appears to be two interesting courses for agent-based modelling this summer. The first is the Lipari International School on Computational Social Sciences, July 18 - 25. The second is Capturing Business Complexity with Agent-Based Modeling and Simulation, May 18- 22, 2009.

References:

Fujita, M. and Ogawa, H. (1982), 'Multiple Equilibria and Structural Transition of Non-monocentric Urban Configurations', Regional Science and Urban Economics, 12(2): 161-196.

Heikkila, E.G. and Wang, Y. (In Press), 'Fujita and Ogawa Revisited: An Agent-Based Modeling Approach', Environment and Planning B: Planning and Design.

Kornhauser, D., Wilensky, U. and Rand, D. (2009), 'Design Guidelines for Agent Based Model Visualization', Journal of Artificial Societies and Social Simulation, 12(2), Available at http://jasss.soc.surrey.ac.uk/12/2/1.html.

Nikolai, C. and Madey, G. (2009), 'Tools of the Trade: A Survey of Various Agent Based Modeling Platforms', Journal of Artificial Societies and Social Simulation, 12(2), Available at http://jasss.soc.surrey.ac.uk/12/2/2.html.

Battys Urban Modelling Book

Mike Batty of CASA has made his book "Urban Modelling: Algorithms, Calibrations, Predictions" which was published in 1976 freely available. Click here to download it.

The book covers a plethora of topics, introducing the reader to simulation models and the need for such methods. For example, "simulation methods are used to derive the behaviour of the system when the system is too complex to be modelled using the more direct analytic approach (Batty, 1976)."

The book provides a summary of the first generation of urban models referring to the key authors and models such as Lowry (1964) model and it successor including the Pittsburgh Time-Oriented Metropolitan Model (TOMM), the Projective Land Use Model (PLUM) for the San Francisco area, and a wide variety of Activity Allocation and Stocks-Activities models. The book presents how such models were mainly developed for practical planning situations through metropolitan planning agencies or consultants in North America and in several European cities. How at first, these models where developed with the aim of solving land-use and transportation questions, later being employed to address a wider range of urban problems.

Anyone interested in urban modelling and spatial interaction models is recommended to explore this book.

Reference:
Lowry, I.S. (1964), A Model of Metropolis, Rand Corporation, Santa Monica, CA.

Public Profiler: My Name Profiler

Researchers at UCL have created a Facebook application called mynameprofiler which works alongside your Facebook profile to tell you what your name, the names of your friends and family, and the names of your neighbours say about you. For example, in my neighbourhood, people have higher status surnames than 66% of the population (one has to remember that this is for fun).

If you have a Facebook account, the application can be downloaded from http://apps.facebook.com/mynameprofiler/ however, it only works for the UK at the moment and some data is stored.

Below is Alex Singleton's presentation entitled "Geographic data mining of online social networks" which explains a bit about the project and was presented at GISRUK 2009. Further information about the application can be found on the PublicProfiler site. On a side note the Economist has an interesting article on about the size of friend networks in Facebook and parallels with evolutionary sociology.

View more presentations from Alex Singleton.

The London Street Network

We have just finished a new working paper entitled "Random planar graphs and the London street network." The abstract for the paper is below:

"In this paper we analyse the street network of London both in its primary and dual representation. To understand its properties, we consider three idealised models based on a grid, a static random planar graph and a growing random planar graph. Comparing the models and the street network, we find that the streets of London form a self-organising system whose growth is characterised by a strict interaction between the metrical and informational space. In particular, a principle of least effort appears to create a balance between the physical and the mental effort required to navigate the city."

The full reference is:

Masucci, A. P., Smith, D., Crooks, A. T. and Batty, M. (2009) Random Planar Graphs and the London Street Network, Centre for Advanced Spatial Analysis (University College London): Working Paper 146, London, England. (pdf)

Map of Complexity Science

Brian Castellani of the Sociology and Complexity Science blog and the art & science factory website has created a nice diagram entitled "the map of complexity science." The map is a conceptual and historical overview of complexity science from the 1940s to the current day. Not only does the map highlight important players in the field (such as Stuart Kauffman) but also demonstrates how agent-based modeling, cellular automata, and genetic algorithms are linked together and more generally with complexity science. The map is well worth exploring as it has many hyperlinks to other sites.

The map of complexity science