Thursday, March 29, 2007

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/



Wednesday, March 21, 2007

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.

Reading List

When starting our research, books were invaluable to our understanding of the basics of agent-based modelling and GIS. However the quality of books varies. As a result we are creating a “Reading List” of books that we have found extremely informative to our work. Within the list we includ books focusing on agent-based modelling, GIS, Urban modelling and other general books. If you are interested, check out the link under the “Recommended books” on the right-hand side bar.

Monday, March 19, 2007

Guidelines for Assessing Pedestrian Evacuation Software Applications

Christian has just finished a comprehensive working paper entitled “Guidelines for Assessing Pedestrian Evacuation Software Applications”. His abstract for this is written below:

“This paper serves to clearly identify and explain criteria to consider when evaluating the suitability of a pedestrian evacuation software application to assess the evacuation process of a building. Guidelines in the form of nine topic areas identify different modelling approaches adopted, as well as features / functionality provided by applications designed specifically for simulating the egress of pedestrians from inside a building. The paper concludes with a synopsis of these guidelines, identifying key questions (by topic area) to found an evaluation”.

Key Words: Pedestrian evacuation, software applications, models, modelling, buildings, egress, simulation, guidelines, evaluation criteria, pedestrian movement and behaviour.
The paper can be downloaded from CASA: click here

In relation to this paper Christian also gave a presentation at CASA entitled "King’s Cross Under -ground Station Pedestrian Evacuation Model" outlining his research specifically how the criteria from the working paper above can be used, types of spaces that can be used to develop models and how agents move in space.


The talk slides can be downloaded by clicking here.

Further Information: Christians personal website and research project website