Tuesday, March 31, 2009

Work update

Currently at CASA we are exploring ways to simulate various aspects of city life and visualize such models taking advantage of our London database which we are developing along with the advances in graphic card technology and networked communication. We presented some of this work at the AAG last week (click here to download the presentation and here to see the abstract).

Some of this includes modeling traffic. Following on from an earlier post by Andrew-Hudson Smith of Digital Urban about CityScape, the movie below shows our first attempts with the software.

CityScape: by PixelActive - Real-time Traffic Modeling.

Monday, March 30, 2009

New Developments in GIS for Urban Planning

We just finished writing a brief paper for the April 2009 issue of Geospatial Today entitled "New Developments in GIS for Urban Planning". The paper basically covers new the tools and techniques being developed at CASA which we are targeting at urban planners. Many of the tools are associated with visualising urban problems and their solutions.

Virtual London within Google Earth

The pre-press paper can be found here. As always any thoughts or comments are most welcome.

Tuesday, March 17, 2009

AAG Agent Talk

Next week, I will be attending the AAG annual meeting in Las Vegas, which I am quite looking forward to. There seems to be a good selection of agent-based modelling talks along with others relating to GIS, urban planning etc. I will be presenting a paper with Andrew Hudson-Smith in the Modeling Geographic Complexity 2 session entitled "Agents in the City: Modeling and Visualizing Emergent Phenomena."

The abstract for the talk is:

Agent-based modeling (ABM) is increasingly being used as a tool for the spatial simulation of a wide variety of urban phenomena. As ABM moves into the spatial domain, we need new ways to visualize and communicate such models especially to those who we seek to influence and who we believe that such modeling will inform their activities. Coupled with the above challenge is how we represent agents in space. The use of ABM for geospatial simulation has traditionally been dominated by the 2D view of the world with the third dimension rarely ventured into. We would argue that this is due to the nature of the discipline where the focus is on theory rather than outreach and end user visualization; and that model builders are not taking advantage in improvements in computer technology. We will illustrate our attempts to visualize, share and communicate geospatial agent-based models specifically focusing on the third dimension with several examples utilizing 3D Studio Max and Second Life, a virtual online world. These examples range through the movement of cars and pedestrians in a cityscape to evacuation of pedestrians from buildings and residential segregation. These models demonstrate how through the interaction of individual agents complex phenomena emerges over time and in space. Furthermore they demonstrate how different theories and concepts can be incorporated into 3D environments. Additionally these models provide outputs to which non-expert users can easily relate to, thus allowing them to come under greater scrutiny than was possible in the past.

Agents in the City: building cityscapes

Hope to see you there.

Monday, March 16, 2009

AAG: The Rise of Neogeography

If any readers are attending the AAG next week in Las Vegas, Andrew Hudson-Smith of Digital Urban and myself have organised a session entitled "Concepts, Tools and Applications: The Rise of Neogeography." This session discusses the concepts, tools, applications and challenges arising when collecting, sharing and communicating data for the Neogeographer. The session explores a wide range of topics from Digital Earths, Volunteered Geographic Information and through to Virtual Worlds.

The session will take place on Friday, 27th of March, from 8:00 AM - 9:40 AM in the North Hall N116, Las Vegas Convention Center

The program is as follows:

Hope to see you there.

Tuesday, March 10, 2009

Challenges and Visions in the Social Sciences

I just come across a very interesting site from the 2008 International Workshop on Challenges and Visions in the Social Sciences organised by Dirk Helbing, Lars-Erik Cederman, Andreas Diekmann, Frank Schweitzer and Didier Sornette. The reason I am blogging about it is that there are over 20 talks available on-line (including slides) identifying future trends in the social sciences, and problems that will have to be addressed. Talks include:

Such a resource should be of interest for anyone interested in computational social science. A short report summarising the workshop can be found here. Which includes: modelling and simulation challenges such as parameter calibration, correlation and causality, Realistic vs. toy models. Along with challenges associated with interdisciplinary research such as the use of terminology, networking and cooperation, information exchange and publication.

Friday, March 06, 2009

The Research Potential of Virtual Worlds for ABM

There is a growing interest and use of virtual worlds for both entertainment and academic research. Worlds such as Second Life and World of Warcraft attract thousands of users and have both virtual and real world economies. Such virtual worlds have come a long way since the original text worlds such as Zork (known as MUDS), they have developed into 3D immersive environments, where users can chat using both voice and text.

Virtual worlds can be broadly broken down into two distinct categories, the first being game focused such as World of Warcraft and Star Wars Galaxies (e.g. MMORGs). The second type being socially focused such as Second Life and Active Worlds (e.g. Massively Multiuser Virtual Environments).

Such virtual worlds have a great potential as sites for research in the social, behavioural, and economic sciences (see Bainbridge (2007), The Scientific Research Potential of Virtual Worlds). Universities are using them to promote themselves and exploring there use for teaching (e.g. Ohio University, see the movie below). While others are using virtual worlds for military applications, such as combat simulation (see movie below) or for studying the spread of epidemics (e.g. Kafai et al., 2007). For the geographer, the ability of people to create their own land and build their own houses leads to the creation of a digital geography and research can be carried out in topics such as of urban sprawl and the development of ghost towns were land and buildings have been abandoned by their original inhabitants (see Dodge and Kitchin, 2001 for more information).

The growth of cities within virtual worlds (Source Chapter 4 in the Atlas of Cyberspace)

Military applications within virtual worlds: large scale simulation of real world battle fields in Second Life -Iraq.

My own interest in virtual worlds arises because they offer a new arena to explore agent-based modeling for the social scientist, they can be viewed as a digital laboratory where real world landscapes (including buildings, roads, terrain) can be imported and explored thus moving away from an artificial laboratory on ones desktop into a more collaborative 3D environment comparable to a real-world laboratory accessible by others, who are able to visualize and discuss issues such as pedestrian egress from buildings in real time or taking one of the examples above, imagine using agents as the enemy within combat simulations.

Examples of agent-based models in virtual worlds include ant foraging (Tectonic 2007, see the movie below) or herding behavior of sheep (Merrick and Maher, 2007). While our own work at CASA explores three simple agent-based models as pedagogic demonstrators and as a “proof-of-concept” (see the movie below), including Conway’s Game of Life, Schelling’s (1978) Segregation model. These models were chosen as they highlight how classical automata styles of models which have inspired a generation of modelers can be created and explored in Second Life. The third model is a prototype pedestrian evacuation model which is more complex than the previous two and highlights how a variety of models that can be created in Second Life and potentially linked to real world places such as football or underground stations. This model relates to the genus of such models of which the social forces model developed and popularised by Helbing and Molnár (1995) is typical.

Ants in Second Life (Tectonic)

Agent-Based Modelling in Second Life by CASA.

While virtual worlds offer much potential there are still problems such as the need of land (maybe OpenSim can help here?), deficiencies of the internet (e.g. bandwidth, package delivery etc.), server side delays, limited script sizes, etc. Nevertheless, there is the potential to build realistic cities using real world data, populate such cities with agents and see how the city might evolve over time.

There is also the potential to use evolutionary computation for such modeling. For example the movie below is by Karl Sims and shows results involving simulated Darwinian evolutions of virtual block creatures who are tested for their ability to perform a given task. The successful survive and make offspring for a new population. As this cycle of variation and selection continues, creatures with more and more successful behaviours can emerge (see Evolved Virtual Creatures,1994).

Darwinian evolutions of virtual block creatures (Evolved Virtual Creatures,1994).

For those interested, I found this site a useful resource for understanding virtual worlds entitled "Designing Virtual Worlds" by Kathryn Merrick.

Any thoughts, comments or links are more than welcome.

References that might be of interest:

Bainbridge, W.S. (2007) The Scientific Research Potential of Virtual Worlds. Science. 317(5837): 472-476.

Dodge, M. and Kitchin, R. (2001) Atlas of Cyberspace, Addison-Wesley, London, UK.

Kafai, Y.B., Feldon, D., Fields, D., Giang, M. and Quintero, M.
(2007) 'Life in the Times of Whypox: A Virtual Epidemic as a Community Event', in Steinfeld, C., Pentland, B., Ackermann, M. and Contractor, N. (eds.), Proceedings of the Third International Conference on Communities and Technology, Springer, New York, pp. 171-190.

Helbing, D. and Molnár, P. (1995) Social Force Model for Pedestrian Dynamics, Physical Review E, 51(5): 4282-4286.

Merrick, K. and Maher, M. (2007) Motivated Reinforcement Learning for Adaptive Characters in Open-Ended Simulation Games. Proceedings of the International Conference on Advances in Computer Entertainment Technology. Salzburg, Austria, pp. 127-134.

Schelling, T.C. (1978) Micromotives and Macrobehavior, WW Norton and Company, New York, NY.

Thursday, March 05, 2009

Simulating Crime with Agent-Based Models

Crime is seen in all cities but understanding crime is extremely complex as it is highly diverse and has many causes. A greater understanding of such phenomena is crucial for improving polices and developing effective crime prevention strategies. The use of agent-based modelling allows one to study individuals who are involved in each crime event and how these individuals interact with each other and their environment.

Nick Malleson of the CrimeSim Blog has had some good posts recently on his recent research regarding crime and agent-based modelling. He has released a new working paper entitled "Simulating Burglary with an Agent-Based Model" (click here) which focuses on the inclusion of the PECS (Physical conditions, Emotional states, Cognitive capabilities and Social status) framework for simulating human behaviour within agent-based models and how this differs from previous approaches to crime modelling. Nick also has some excellent posts/tutorials on using GIS and Repast Simphony (Click here to see them).


Simulating Burglary with an Agent-Based Model prototype using NetLogo by Nick Malleson.

Wednesday, March 04, 2009

Segregation within Social Networks

Readers of the blog might know that I have an interest in segregation and the use of agent-based models to explore such phenomena. There are many types of segregation, for example, by race, income, social class etc. Research commissioned by More4 News shows that social networks sites such as Facebook, Bebo and MySpace are respectively attracting specific social groups, of certain ages, living in different areas thus resulting in segregated social networks. Below is a movie, and if you what closely you will see Schelling's model of segregation, which Andrew Hudson-Smith uses to explain how such online segregation might occur.

Further information about the research including the poll results used in the news report can be found here.