SIMSEG

The SIMSEG model is an extension of the Thomas Schellings segregation model. It allows users to explore ethnic diversity in terms of number of groups and the relative sizes of each group, specify ethnic preferences, specify the level of socio-economic inequality within and between ethnic populations and to specify agents preferences for neighbourhood status and housing quality within a cellular space. Neighbourhoods are bounded by larger areas to evaluate neighbourhood ethnic mix and agents can only move to areas where they can afford.

A free trial version of the SimSeg Learning Edition can be downloaded from the website: http://simseg.com/download/index.htm and the site also provides a useful review article of theoretical perspectives on residential segregation in American urban areas along with other resources.

If you interested in segregation, there are a whole host of other models available on the internet. For example Schelling Segregation Model created by Chris Cook, written is C# (the source code is available), A java applet created by Raj Singh, A NetLogo model or a Repast model created byGirardin et al., (2006) .

Further Reading:

Fossett, M. and Senft, R. (2004), 'SIMSEG and Generative Models: A Typology of Model-Generated Segregation Patterns', Proceedings of the Agent 2004 Conference on Social Dynamics: Interaction, Reflexivity and Emergence, Chicago, USA, pp. 39-78, Available at http://www.agent2005.anl.gov/Agent2004.pdf

EpiSIM

Joana Simoes, has recently completed a PhD at CASA. Her thesis was on An Agent-Based Approach to Spatial Epidemics through GIS in which she simulated the diffusion of mumps in Portugal in the late 1990s at regional and local level using a SEIR (susceptible- exposed- infected removed) infection model built in a spatial network of small worlds.

The model she created is called EpiSIM written in C++. Two sets of libraries were used to build this software: Qt, for the graphical API and Shapelib for accessing geographic data. Further information can be seen on the project website and on Joana’s personal website.

PropertyWindow class

There was this message on the Repast mailing list the other day:

Dear list,
I want to probe some variables of my agents of the OpenMap Layer. I did this by making the following method:

public String[] gisPropertyList() {

String []gisPropertyList = {"Lat/Lon","getLatLonPointString","nativeCountry","getNativeCountry",

"residence","getResidence","age","getAge","gender","getGender" };


return gisPropertyList;

It works, however when I probe one of my agents I get the screen below. It seems like something is on top of the last fields. How can I fix this? Thanks!

I had exactly the same problem as this is to do with the PropertyWindow class which only permits 4 items to be displayed in the anl.repast.gis.display package. Click here to see my modification that works around this problem. I hope this helps.

ped-net.org

ped-net.org is a new site to help people who are interested in the field of pedestrian and evacuation dynamics. The site provides a comprehensive list of literature and links to models pertaining to pedestrian modelling, forthcoming conferences, a bulletin board and a series of java applets.

If you interested in this sort of thing, its worth having a look at the site: http://www.ped-net.org/

DUEM

The Dynamic Urban Evolutionary Model (DUEM) (Batty et al., 1999) is described by as a typical Cellular Automata/Cellular Space model (Batty and Xie, 2005). Its purpose is to simulate urban growth (sprawl) thus exploring urban development. It does this by providing five different land-uses. That of housing, manufacturing/primary industry, commerce and services, transport in the form of street and road networks and vacant land. Land-use changes due to specific rules. Land-use also has a life cycle, which results in land-uses spawning new ones. The model operates on three different spatial scales: local neighbourhood, through to district to the region.

The DUEM software is written from scratch using Visual C++ with loose coupling to GIS through the importation of raster files. Figure 1 demonstrates the typical user interface which allows users to plant various land-use seeds and watch the environment evolve both in space and time (compare Figures 1 and 2). The software additionally shows how various trajectories of different land-uses change over time (Bottom three windows of Figures 1 and 2). This highly visual interface conveys a large amount of information such as aggregated outcomes, and statistical trends, in an easy to digest way, which helps with the understanding on how the model works. 

Figure 1: Evoluction of the landscape

Figure 2: Further evolution of the landscape

If you interested in running the model it can be downloaded from here.

References for further Reading:

Batty, M. and Xie, Y. (2005), 'Urban Growth Using Cellular Automata Models', in Maguire, D.J., Batty, M. and Goodchild M, F. (eds.), GIS, Spatial Analysis and Modelling, ESRI Press, Redlands, California, pp. 151-172.

Batty, M., Xie, Y. and Sun, Z. (1999), 'Modelling Urban Dynamics through GIS-Based Cellular Automata', Computers, Environment and Urban Systems, 23(3): 205-233.

Xie, Y. and Batty, M. (2003), Integrated Urban Evolutionary Modeling, Centre for Advanced Spatial Analysis (University College London): Working Paper 68, London, England.