Wednesday, December 02, 2009

Oxford Circus pedestrian crossing opens

Apologies for the lack of posts in recent weeks but I been busy finishing up my course about Agent-based Modeling of Urban Systems at Department of Computational Social Science at George Mason University, along with writing a few new papers.

One thing I have been meaning to blog about for a while is the opening of the Oxford Circus pedestrian crossing. Actually the crossing opened on the 2 November 2009 but its still worth blogging about. A previous post (click here) shows what the planners had in mind (Click here to read the BBC's coverage of the event).

The two movies below show what the designers had in mind using a pedestrian model created by Atkins Intelligent Space which closely matches how people are actually using the crossing (the second movie) and how at the intersection of the crossing, the density of people restricts movement.

The movie below shows what the designers had in mind:

While the second movie shows what it actually looks like and how people are using it.

More about "Oxford Circus 'X-crossing' opens", posted with vodpod

On a side note there is also a lot of work going on about how placing obstacles near exits to speed up the flow of crowds exiting large events such as rock concerts or football games (click here to read more).

Friday, November 13, 2009

Agents on campus

I thought it was time I started exploring Repast Simphony and GIS data for US. So following the excellent tutorial by Nick Malleson entitled "RepastCity - A demo virtual city" which demonstrates how to load up several shapefiles and move agents around a road network (the code is also very well documented).

The movie below shows the George Mason campus (2005). The GIS data comes from the GMU Library in the form of shapefiles. Within the model we have agents (red stars), one for each building (black polygons). These agents choose a building at random and use the footpaths (thin grey/blue lines) to navigate to the chosen building. Additional layers are also represented including: car parks and roads (grey/blue areas); and streams grey blue) and a pond (green)1.

Another interesting tutorial is by Karl Liebert which discusses how create a basic GIS model in Repast Simphony.

1 For some reason the colors have been messed up in the conversion from computer to Vimeo.

Wednesday, November 11, 2009

TravellerSim: ABM for Growing Settlement Structures and Territories

I just come across another interesting NetLogo model while browsing through the interesting Electric Archaeology: Digital Media for Learning and Research blog written by Shawn Graham. Shawn along with James Steiner (who has a great site called turtleZERO) have created a agent-based model called TravellerSim which explores growing settlement structures and territories.

To quote from the blog post:

"Agent-based modeling presents the opportunity to study phenomena such as the emergence of territories from the perspective of individuals. We present a tool for growing networks of socially-connected settlement structures from distribution map data, using an agent-based model authored in the Netlogo programming language, version 3.1.2. The networks may then be analyzed using social-networks analyzes tools to identify individual sites important on various network-analytic grounds, and at another level, territories of similarly connected settlements. We present two case studies to assess the validity of the tool: Geometric Greece and Protohistoric Central Italy."

The full reference of the model is:

Graham, S. and J. Steiner (2008) “Travellersim: Growing Settlement Structures and Territories with Agent-Based Modelling” in Jeffrey T. Clark and Emily M. Hagemeister (eds) Digital Discovery: Exploring New Frontiers in Human Heritage. CAA 2006. Computer Applications and Quantitative Methods in Archaeology. Proceedings of the 34th Conference, Fargo, United States, April 2006. Budapest: Archaeolingua.

The NetLogo model can be found here and the blog post here. Furthermore, Shawn has a number of other agent-based models which might be of interest. These can be found here.

Thursday, November 05, 2009

TourSim: Agent-based modeling for Tourism Planning

While reading the 7.5th Floor blog, I cam across an interesting post about the use of agent-based modeling for tourism/recreational planning. The post talks about the TourSim model developed by Peter Johnson. The model is created using AnyLogic and explores tourists visiting Nova Scotia and the destinations they visit under different scenarios. Peter provides a tutorial about using the model along with data sources used in creating and verifying this model. As with many other AnyLogic models (click here to see some demos), not only is it highly visual but can be run in a web browser. Further details about TourSim can be found here.

Wednesday, November 04, 2009

Virtual Worlds for teaching GIS

Following on from our previous posts on Second Life (SL), I just came across a post on the ArcUser Online website which talks about how SL can be used for GIS education. The article is by Michael DeMers of New Mexico State University. The paper is entitled "Inside the Metaverse" and has three nice podcasts accompanying it.

The YouTube movie below gives an idea about the potential for teaching GIS within virtual worlds (Thanks to Digital Urban for the link).

Sunday, November 01, 2009

New Paper: Agent Street: An Environment for Exploring Agent-Based Models in Second Life

Our work with agent-based modeling in Second Life has just been published in the Journal of Artificial Societies and Social Simulation (JASSS). The full title of the paper is "Agent Street: An Environment for Exploring Agent-Based Models in Second Life" and the abstract reads as follows:

"Urban models can be seen on a continuum between iconic and symbolic. Generally speaking, iconic models are physical versions of the real world at some scaled down representation, while symbolic models represent the system in terms of the way they function replacing the physical or material system by some logical and/or mathematical formulae. Traditionally iconic and symbolic models were distinct classes of model but due to the rise of digital computing the distinction between the two is becoming blurred, with symbolic models being embedded into iconic models. However, such models tend to be single user. This paper demonstrates how 3D symbolic models in the form of agent-based simulations can be embedded into iconic models using the multi-user virtual world of Second Life. Furthermore, the paper demonstrates Second Life's potential for social science simulation. To demonstrate this, we first introduce Second Life and provide two exemplar models; Conway's Game of Life, and Schelling's Segregation Model which highlight how symbolic models can be viewed in an iconic environment. We then present a simple pedestrian evacuation model which merges the iconic and symbolic together and extends the model to directly incorporate avatars and agents in the same environment illustrating how 'real' participants can influence simulation outcomes. Such examples demonstrate the potential for creating highly visual, immersive, interactive agent-based models for social scientists in multi-user real time virtual worlds. The paper concludes with some final comments on problems with representing models in current virtual worlds and future avenues of research."

Agents reacting to Avatars

Accompanying the paper we have created a dedicated website giving more details about the work including the model source code which can be found here.

Our next steps are to start exploring how such models can be created and extended in OpenSim and carrying out user testing along with online model creation.

The full reference to the paper is:
Crooks, A, Hudson-Smith, A and Dearden, J (2009). 'Agent Street: An Environment for Exploring Agent-Based Models in Second Life'. Journal of Artificial Societies and Social Simulation, 12(4)10:

Friday, October 09, 2009

Visualisation in support of management decisions

Following on from the previous post about SYMAP, its amazing to think that in a short period of time how technologies have developed. For example, take the the 18th World IMACS Congress and MODSIM09 International Congress on Modelling and Simulation. There are a wealth of talks in the visualisation in support of management decisions session, such as the paper presented by Phil Greenwood entitled "Using game engine technology to create real-time interactive environments to assist in planning and visual assessment for infrastructure" part of which I show below:

Further information about this session can be found here. Also for those interested in visualization and game engines, the excellent Digital Urban blog at CASA is worth a look.

Thursday, October 08, 2009

SYMAP movie

I recently been exploring visualization techniques for agent-based modeling and GIS and came across this old movie produced by Allan Schmidt showing urban expansion of Lansing, Michigan between 1850 to 1965.

Whats interesting is its based on the synergraphic mapping system (SYMAP) developed by Howard Fisher in the mid 1960s which was one of the first general-purpose mapping packages. The second movie below gives some background on SYMAP:

How cities drive plants extinct

Readers of the blog might know that I have an interest in cities, actually I just wrote about this for a guest blog post on the Krasnow Institute blog. However, I often focus on how human population increase will effect cities in terms of sprawl, congestion or segregation in its many different forms etc. But the BBC has an interesting article entitled " How cities drive plants extinct." The article explores how urban growth impacts on the global biodiversity of plant species. What I found interesting is the question on how plants and people could coexist in urban areas. But for this to happen we would have to see plants as an "investment rather than as a disposable asset."

The full article can be found here.

Sunday, September 13, 2009

Critical mass: When does a crowd become dangerous

There was an interesting article in the UKs' The Guardian a few months ago entitled "Critical mass: When does a packed but happy crowd become a dangerous, even lethal one?" which discusses as the title suggests when does a crowd become dangerous? The article starts with an incident in occurring at a Walmart's store in the US on Black Friday in 2008 where a crowd rushed into a store searching for bargains and a security guard died in the rush.

The reason I am blogging about it is that the paper sums up quite nicely and in understandable way the use of pedestrian modeling to understand such events and ways to potentially mitigate such occurrences from happening again.

One line I like is this that "in the almost weekly occurrence, somewhere in the world, of someone being injured or killed in a crowd." Other incidents for example, include the opening of the Primark flagship store in London in 2007 (below) or Jamarat bridge incident, where in 2004 more than 250 people were killed during a ritual part of the hajj known as the "stoning of the devil".

Shoppers at the opening of Primark in London tussle to get into the store (see the article).

Muslim pilgrims walk over a Jamarat bridge during the 'Jamarat' ritual, in Mina near Mecca.

The full article can be found here.

Thursday, September 03, 2009

AAG SPECIAL SESSION: Modeling Geographic Complexity

For those interested we are organizing a special session(s) at the forthcoming AAG in Washington DC. See below for details:

Association of American Geographers Annual Meeting
April 14-18, 2010, Washington, DC, USA

Spatial Analysis and Modeling, Geographic Information Systems and Science, Human Dimensions of Global Change Specialty Groups of the AAG and the Geographical Information Science Group of the Royal Geographical Society.

Understanding geographical systems represents one of the greatest challenges of our time. Complexity has emerged as a useful paradigm to effectively study linked human, socioeconomic and biophysical systems at a variety of different spatial and temporal scales. As a result, descriptive and predictive models of various levels of sophistication and using mostly agents, genetic algorithms, cellular automata and neural networks are now beginning to regularly appear in the geographic literature. However, there still remains many unresolved conceptual, technical and application challenges associated with these complexity based models. The goal of this session is to focus on the following themes:

  1. Conceptual: shared and unique complexity signatures in geographic systems; existing and emerging geographical and complexity theories; epistemological and ontological influences; complexity based model designs; networks and hybrid models; linking classical and spatial statistics in complexity studies.
  2. Technical: space-time patterns and dynamics; standardizing the development and representation of complex systems; rule selection and implementation; multiple-scale interactions and structure, system evolution and self-organization; learning and adaptation; calibration, validation and verification; path-dependence; non-linearity.
  3. Applications: effectiveness of complexity models when embedded in political, institutional and socio-economic systems; human-environment interactions; earth systems science; land use science; landscape ecology; sustainability analysis.

In order to widely disseminate the ideas emerging from this session, the organizers of the session are exploring the possibility for a special issue of a journal and /or an edited book so that authors will have the opportunity to suitably revise their presentations for publication. Priority will be given for work that has not been published, in review or in press.

Please e-mail the abstract and key words with your expression of intent to Andrew Crooks by October 19th, 2009. Please make sure that your abstract conforms to the AAG guidelines in relation to title, word limit and key words and as specified at <>. An abstract should be no more than 250 words that describes the presentation's purpose, methods, and conclusions as well as to include keywords. Full submissions will be given priority over submissions with just a paper title.


September 3nd, 2009: Call for papers.

October 19th, 2009: Abstract submission and expression of intent to session organizers. E-mail Andrew Crooks by this date if you are interested in being in this session. Please submit an abstract and key words with your expression of intent. Full submissions will be given priority over submissions with just a paper title.

October 22nd, 2009: Session finalization. Session organizers determine session order and content and notify authors.

October 26th, 2009: Final abstract submission to AAG, via All participants must register individually via this site. Upon registration you will be given a participant number (PIN). Send the PIN and a copy of your final abstract to Andrew Crooks . Neither the organizers nor the AAG will edit the abstracts.

October 28th, 2009: AAG registration deadline. Sessions submitted to AAG for approval.

April 14th -18th, 2010: AAG meeting, Washington DC, USA

Wednesday, August 26, 2009

Jobs at CASA

CASA and the UCL Centre for Transport Studies each have a Research Associate vacancy attached to the SCALE project: (Small Changes leAd to Large Effects) Changing Energy Costs in Transport and Location Policy, funded by the EPSRC.

Click here for further details.

Monday, August 24, 2009

New Publication: Random planar graphs and the London street network

We have just had news that the work we did examining the London road network has been accepted in The European Physical Journal B: Condensed Matter and Complex Systems. The paper combines GIS and network analysis (graph theory) by Paolo Masucci, Duncan Smith, Mike Batty and myself to explore the street network of London both in its primary and dual representation.

For this research we took a radius of 27.6Km from the City of London, where the first Roman settlement was located and contains 95 percent of the population of the 33 boroughs that comprise the Greater London Authority which is also bounded by the M25 orbital road. In this way, we obtain a network we obtain a network with 163 878 intersections (the vertices), and 199 931 street segments (the edges) with 184191 nodes and 220688 links.

This data was derived from two Ordnance Survey (OS) dataset products, OS MeridianTM 2 which includes Motorways, A Roads, B Roads and Minor Roads, and the OS Integrated Transport Network (ITN). The latter includes all the above roads but in more detail with respect to a much greater number of minor roads.

Below is the abstract:

"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 paper can be downloaded from here, while the full reference is:

Masucci, A. P., Smith, D., Crooks, A.T. and Batty, M. (2009) Random Planar Graphs and the London Street Network, The European Physical Journal B, 71 (2): 259-271. (pdf)

News of this research also featured in the Russian Newsweek. For those who read Russian the article can be found here.

Friday, August 21, 2009

The spread of pandemics

Following on from some previous posts on the spread of pandemics (1 and 2) such as the swine flu (H1N1) and the recent article in Nature by Joshua Epstein from the Center on Social and Economic Dynamics. I just cam across this movie (below) which explores these issues in a easy to understand way.

The Brookings site is also worth exploring for those interested pandemics and public health.

There is also this spatial model from the Los Alamos National Lab who have modeled Avian flu on a supercomputer which explores vaccine and isolation options for thwarting a pandemic. Full details about the work can be seen here.

On a slightly bizarre side note there was also an interesting article on the BBC entitled "Science ponders 'zombie attack'" where researchers from the University of Ottawa showed if zombies actually existed, an attack by them would lead to the collapse of civilisation unless dealt with quickly and aggressively. The full paper can be read here.

Thursday, August 13, 2009

New paper: NeoGeography and Web 2.0

The current issue of the Journal of Location Based Services is a special edition on Neogeography edited by Sanjay Rana and Thierry Joliveau.

Apart from the editorial there are three papers in this special issue. The first is by Michael Goodchild, entitiled "NeoGeography and the nature of geographic expertise" The abstract of the paper is below:

"NeoGeography has been defined as a blurring of the distinctions between producer, communicator and consumer of geographic information. The relationship between professional and amateur varies across disciplines. The subject matter of geography is familiar to everyone, and the acquisition and compilation of geographic data have become vastly easier as technology has advanced. The authority of traditional mapping agencies can be attributed to their specifications, production mechanisms and programs for quality control. Very different mechanisms work to ensure the quality of data volunteered by amateurs. Academic geographers are concerned with the extraction of knowledge from geographic data using a combination of analytic tools and accumulated theory. The definition of NeoGeography implies a misunderstanding of this role of the professional, but English lacks a basis for a better term. "

The second article is by Marcus Foth et al., entitled "The Second Life of urban planning? Using NeoGeography tools for community engagement" The abstract of the paper reads:

"The majority of the world's citizens now live in cities. Although urban planning can thus be thought of as a field with significant ramifications on the human condition, many practitioners feel that it has reached the crossroads in thought leadership between traditional practice and a new, more participatory and open approach. Conventional ways to engage people in participatory planning exercises are limited in reach and scope. At the same time, socio-cultural trends and technology innovation offer opportunities to re-think the status quo in urban planning. NeoGeography introduces tools and services that allow non-geographers to use advanced geographical information systems. Similarly, is there a potential for the emergence of a neo-planning paradigm in which urban planning is carried out through active civic engagement aided by Web 2.0 and new media technologies thus redefining the role of practicing planners? This paper traces a number of evolving links between urban planning, NeoGeography and information and communication technology. Two significant trends - participation and visualisation - with direct implications for urban planning are discussed. Combining advanced participation and visualisation features, the popular virtual reality environment Second Life is then introduced as a test bed to explore a planning workshop and an integrated software event framework to assist narrative generation. We discuss an approach to harness and analyse narratives using virtual reality logging to make transparent how users understand and interpret proposed urban designs".

While the third paper is by Andrew Hudson-Smith, Maurizio Gibin; Richard Milton; Michael Batty and myself entitled "NeoGeography and Web 2.0: concepts, tools and applications" in which we explore the concepts and applications of Web 2.0 through the new media of NeoGeography and its impact on how we collect, interact and search for spatial information. We argue that location and space are becoming increasingly important in the information technology revolution. To this end, we present a series of software tools which we have designed to facilitate the non-expert user to develop online visualisations which are essentially map-based. These are based on Google Map Creator, which can produce any number of thematic maps which can be overlaid on Google Maps. We then introduce MapTube, a technology to generate an archive of shared maps, before introducing Google Earth Creator, Image Cutter and PhotoOverlay Creator. All these tools allow users to display and share information over the web. Finally, we present how Second Life has the potential to combine all aspects of Web 2.0, visualisation and NeoGeography in a single multi-user three-dimensional collaborative environment.

If you are interested in reading our paper, see below.
Hudson-Smith, A., Crooks, A.T., Gibin, M., Milton, R., and Batty, M. (2009), Neogeography and Web 2.0: Concepts, Tools and Applications, Journal of Location Based Services, 3(2) 118 - 145. (pdf)

Sunday, August 09, 2009

Partitioning Space to generate urban spatial patterns.

Fraser Morgan and David O'Sullivan have recently written a paper entitled "Using binary space partitioning to generate urban spatial patterns" which was presented at the 4th International Conference on Computers in Urban Planning and Urban Management (CUPUM).

The abstract of their paper is:

Creating a realistic representation of urban spatial patterns is often problematic. Using existing development as a starting point for testing models of urban growth may introduce inherent biases based on the city chosen. To address this issue, we have used binary space partitioning (BSP) trees to quickly generate a representation of the cadastral spatial pattern seen in cities. This approach, which has links to quadtrees and binary trees used in computer science, includes the standard topologic elements (leaf nodes, children, root node, ancestors, descendants and levels) while also incorporating the spatial element of territory. The substantial flexibility in the resulting urban structure belies the small number of parameters used to control the creation of the tree.

This BSP tree approach was developed to create many similar and realistic urban spatial patterns on which an agent-based model of the purchase, subdivision, building and disposal behaviours of property developers would operate. The motivation for implementing a BSP tree approach was the ability for the developer agents to be able to understand, analyse and enact the mechanism of subdivision upon the urban environment. Through the formalised node structure, the BSP tree approach also enables the straight forward implementation of developer territoriality, neighbourhood attractiveness and spatial metrics for analysis."

Click here to read the full paper which is very interesting. To accompany the paper there is also a NetLogo model is just a small aspect of the wider ABM model that Fraser is working on which provides an interesting representation of an random urban cadastral pattern upon which the ABM does its work.

Saturday, August 08, 2009

Treemaps: Hierarchical Layouts to Address Research Questions

Effectively visualising and understanding complex datasets is an extremely difficult task so I thought it worth highlighting the recent work of Aidan Slingsby, Jason Dykes and Jo Wood (who has also written a nice book about Java Programming for Spatial Sciences) , who are all from the giCentre at City University London on treemaps, especially how treemaps can be used for displaying and understanding hierarchical data.

In the paper entitled "Configuring Hierarchical Layouts to Address Research Questions, to quote the authors "explore(s) the effects of selecting alternative layouts in hierarchical displays that show multiple aspects of large multivariate datasets, including spatial and temporal characteristics" For further information (including a paper) about the work, readers are advised to read the site:

Below is a short movie created by Aidan Slingsby demonstrating their work for the IEEE InfoVis Conference in Atlantic City this coming October:

Thanks to Aidan Slingsby for allowing us to use the movie.

Full reference: 
Slingsby, A., Dykes, J., Wood, J. and Crooks, A.T. (2009), The Role of Layout and Order in Treemaps for Showing Spatial and Temporal Variation in House Prices. GeoViz, Hamburg Germany. (pdf)

Wednesday, August 05, 2009

Agent-based models in Nature

I just came across a few articles in this weeks Nature about the use of agent-based modelling which I found interesting and thought worth sharing.

To quote Nature, "two Opinion pieces explore the promise of Agent-Based Models (ABMs): J. Doyne Farmer and Duncan Foley on what they can do for economics and Josh Epstein on how the models are being used in pandemic planning. In a News Feature, Mark Buchanan finds out what went so badly wrong with the economy and whether ABMs could have predicted the crunch. These pieces are accompanied by an editorial and an interview on the Nature Podcast."

The discussion of ABM is about 13 minutes into the podcast and well worth listening to as it describes ABM and there potential in a simple way.

Thursday, July 30, 2009

Book Review: The Dynamics of Complex Urban Systems

I just finished reading "The Dynamics of Complex Urban Systems: An Interdisciplinary Approach" edited by Albeverio, S., Andrey, D., Giordano, P. and Vancheri, A. and I thought I would share my thoughts about it.

As we are all aware, cities play a crucial role in our lives, providing habitats for over half of the world?s population. However, understanding such systems is extremely complex as they are composed of many parts, with many dynamically changing parameters and large numbers of discrete actors interacting within space. The heterogeneous nature of cities makes it difficult to generalise localised problems from that of citywide problems. As Wilson (2000) writes, such understanding of cities represents "one of the major scientific challenges of our time". Such understanding how cities function is of crucial importance if we are attempting to tackle problems that such systems face (e.g. urban sprawl, congestion, segregation, etc.) or to make them more sustainable for future generations of inhabitants. One has to understand the complex interactions between urban systems in terms of internal factors (e.g. from the decisions of individuals such as deciding where to locate) to more external factors (such as international economics) along with social developments. Such underlying process can be slow or fast, acting locally or globally. Most urban theory until now has been based on the assumption of slowly varying spatial and social structures. However these notions are now being questioned giving rise to various types of models, such as those employing dissipative dynamics, stochastic cellular automata and agent-based models, fractal geometry, and evolutionary change models, and to further mathematically oriented approaches. In "The Dynamics of Complex Urban Systems", Albeverio et al. (2008) present a range of articles from leading scholars focusing on the above types of models and how approaches developed by different communities can be used to study urban systems and thus gain a greater understanding of how such systems operate.

"The Dynamics of Complex Urban Systems" book is a result of an international workshop which had clear sessions ranging from general dynamical models (e.g. urban growth, pedestrian dynamics), models from economics and models for megacities (e.g. large-scale city formation, socio dynamics), models from information science and data management (e.g. data mining, GIS, data availability), related mathematical and physical theories and models (e.g. neural networks, power laws and phase transitions), models of calibration/validation and forecasts (e.g. comparison of empirical data and simulations), and dynamical models and case studies of real world systems. The chapters presented within this book are arranged alphabetically because the editors of the book believed that there was much overlap between the sessions and the subsequent papers. The only exception is that of the first chapter by Mike Batty entitled "Fifty Years of Urban Modelling: Macro-Statics to Micro-Dynamics" which provides an extensive, chronological and conceptual overview of urban modelling over the last fifty years in the context of current developments and which subsequent chapters explore in greater depth. From reading the edited book this is a well-made decision by the editors. Many of the chapters cross many of the sessions and range from modelling individual movement such as pedestrian models through to traffic simulations and transport networks to the study of systems of cities and innovation processes along the way linking socio-economic and cultural factors (such as employment and housing) to various types of models.

Overall the book is well written and makes a good source of reference of current research, specifically for those interested in studying urban systems using a variety of computational modelling approaches. Furthermore, the book highlights the need for cross-disciplinary research between the natural (e.g. physics, mathematics, computer science, biology, etc) and regional sciences (e.g. geography, economics, architecture, etc) with respect to improving our understanding of the complexities seen within urban systems and how such systems operate.


Albeverio, S., Andrey, D., Giordano, P. and Vancheri, A. (Eds.)(2008), The Dynamics of Complex Urban Systems: An Interdisciplinary Approach, Physica-Verlag Heidelberg, NY.

Wilson, A.G. (2000), Complex Spatial Systems: The Modelling Foundations of Urban and Regional Analysis, Pearson Education, Harlow, UK.

New Publication in Virtual Geographic Environments

We just received a copy of Virtual Geographic Environments, the book has contributions by Jack Dangermond, Mike Goodchild, Mike Batty, Hui Lin and many others (including ourselves) and provides a unique guide to the current state of play in GIS and virtual environs.

Andrew Hudson-Smith and myself have contributed a chapter entitled "The Renaissance of Geographic Information: Neogeography, Gaming and Second Life". The abstract for our paper is:

"Web 2.0, specifically The Cloud, GeoWeb and Wikitecture are revolutionising the way in which we present, share and analyse geographic data. In this paper we outline and provide working examples a suite of tools which are detailed below, aimed at developing new applications of GIS and related technologies. GeoVUE is one of seven nodes in the National Centre for e-Social Science whose mission it is to develop web-based technologies for the social and geographical sciences. The Node, based at the Centre for Advanced Spatial Analysis, University College London has developed a suite of free software allowing quick and easy visualisation of geographic data in systems such as Google Maps, Google Earth, Crysis and Second Life. These tools address two issues, firstly that spatial data is still inherently difficult to share and visualise for the non-GIS trained academic or professional and secondly that a geographic data social network has the potential to dramatically open up data sources for both the public and professional geographer. With our applications of GMap Creator, and MapTube to name but two, we detail ways to intelligently visualise and share spatial data. This paper concludes with detailing usage and outreach as well as an insight into how such tools are already providing a significant impact to the outreach of geographic information."

What ESRI says about the book:

"Virtual geographic environments are essential to using GIS in design. For example, before a design for a city or landscape can be produced, an environment must be created through GIS. Thisbook cover is then fashioned into a form where users have access to it, first to enhance their understanding through exploration, and then to enable them to change various components in the effort to solve problems that can realize better designs. Only now, through the development of virtual city models and through new ways of enabling users to interact with geographic information using new screen technologies, is the point being approached where design is possible. Virtual Geographic Environments, edited by Hui Lin and Michael Batty, collects key papers that define the current momentum in GIS and "virtual geographies." In some sense, such environments are the natural consequence of linking GIS to other technologies that deal with information, design, and service provision, and this will undoubtedly grow as it becomes ever easier to integrate diverse software and data across the Web. The idea that geographic information can be both collected and made available through Web-based services, using Web 2.0 technologies that network many millions of people together, has formed a major research thrust in software development over the last decade. The numerous contributions by leading members of the geospatial community to Virtual Geographic Environments illustrate the cutting edge of GIScience, as well as new applications of GIS with the processing and delivery of geographic information through the Web and handheld devices, forming two major directions to these developments. But the notion that these Web-based systems can be used to collect information of a voluntary kind through methods of crowd sourcing is also an exciting and widely unanticipated development that is driving the field. As these services gain ground, new business models are being invented that merge proprietary and nonproprietary systems and novel ways of integrating diverse software through many different processes of software development from map hacks to open system architectures. Virtual Geographic Environments is published by Science Press, China (, 350 pages, hardcover. For more information, contact the responsible editors Peng Shengchao and Guan Yan, Science Press (e-mail:"

Digital Urban has a competition to win a copy of the book, click here to read the question.

Full Reference:
Hudson-Smith, A. and Crooks, A. T. (2011), The Renaissance of Geographic Information: Neogeography, Gaming and Second Life, in Lin, H. and Batty, M. (eds.), Virtual Geographic Environments, ESRI Press, Redlands, CA. pp 25-36.  (pdf)

Au revoir CASA

A decision to move is never easy but I am about to leave CASA and start working in the Department of Computational Social Science at George Mason University in the USA. Over the last several years at CASA, not only have I learnt a lot and developed my skills in agent-based modelling and GIS, but also made some great friends. The CASA collective of Mike, Alan and Paul have given me much to think about, while the rest of the gang (both past and present, you know who you are!) has made my everyday life fun and challenging.

One thing I will miss is the CASA fish tank and while walking around the National Zoo in DC the other day I thought how lucky the fish in CASA are:

I wonder how long did these fish last?

So, au revoir CASA and thanks for all the fish...

Thursday, June 25, 2009

Modelling large crowds

The last few days I been reading up on pedestrian models, 3D cityscapes and the simulation of large crowds. One such paper that caught my eye was by Treuille et al. (2006) entitled Continuum Crowds. The abstract of the paper is:

"We present a real-time crowd model based on continuum dynamics. In our model, a dynamic potential field simultaneously integrates global navigation with moving obstacles such as other people, efficiently solving for the motion of large crowds without the need for explicit collision avoidance. Simulations created with our system run at interactive rates, demonstrate smooth flow under a variety of conditions, and naturally exhibit emergent phenomena that have been observed in real crowds."

The movie below shows their work:


Treuille, A., Cooper, S. and Popovic, Z. (2006), 'Continuum Crowds', in Dorsey, J. (ed.), Proceedings of ACM SIGGRAPH 2006 ACM, Boston, MA, pp. 1160-1168

Monday, June 22, 2009

Geospatial Analysis 3rd Edition

Just a quick post to say that the 3rd edition of Geospatial Analysis has been released on the Web and PDF version plus advance orders for 3rd edition printed version can now be made.

Within this 3rd edition there has been many updates including the Geocomputational methods and modelling chapter which contains a wealth of information on geosimulation.

Click here to see the web version.

Below is a review from the 2nd Edition:

"Written in an engaging and accessible manner, this book does a marvelous job of balancing its coverage on principles, techniques, and software tools for spatial analysis. ... It is truly a tour de force of geospatial analysis and is likely to become a classic ...I would highly recommend this book to anyone who is interested in learning about the latest developments in geospatial analysis and modeling." Prof D Z Sui, Review in: Annals, Association of American Geographers, April 2009 .

Thursday, June 18, 2009

Where 2.0 Conference Talks

The presentations from the Where 2.0 conference always blow me away. I just been looking at some, and three in particular caught my attention. The first was Jack Dangermond's "Realizing spatial intelligence on the GeoWeb" The idea behind the talk was that geographic knowledge created in GIS environments is increasingly being made available to Web 2.0 users.

Other interesting talks with regard to building city models and understanding cities was Ludvig Emgård "World's Most Realistic 3D City Models?" and John Geraci's "DIY City: An Operating System for Cities."

Useful Link:
GIS and Science blog

Monday, June 15, 2009

SLEUTH model used in Finland

Sanna Iltanen from the EDGE Laboratory for Architecture and Urban Research (Tampere University of Technology) and currently a visitor at our lab gave a talk the other day entitled "Experiments with SLEUTH-model" where she discussed the SLEUTH model, the input data needed to initialize the model, its calibration and explored some simmulation results from different land-use policies in the Helsinki and Turku city regions of Finland. More information about her talk can be found here.

A previous post on SLEUTH can be found here

Wednesday, June 10, 2009

Game of Life on a globe

Always interested in ways to visualize models, I just seen Richard Milton's version of John Conway's Game of Life on a globe model. Richard has has written a short tutorial on how it was done (click here). The the Java applet allows you to explore how different configurations of automata evolve around the globe.

To view the applet click here. Another similar model (shown below) was created by Ventrella to celebrate Earth Day. Click here to see more details about the model.

Tuesday, June 09, 2009

Modelling Housing Markets

After reading about land markets I come across this simple NetLogo model by Nigel Gilbert et al. The model explores how some of the main features of the English housing market emerges from the interactions between buyers, realtors and sellers (click here to run the model).

There is a paper that accompanies the model (click here) which discusses the potential advantages of agent-based modeling over more traditional 'top down' techniques for exploring the housing market. While the model is not based on any particular geographical location or attempts to represent either the characteristics of individual housing units, nor spatial attributes such as proximity to services. It is still a very interesting paper investigating the complicated interactions that create a housing market in a simple model.

Gilbert, N, Hawksworth, J C, and Sweeney, P (2008) 'An Agent-based Model of the UK Housing Market'. University of Surrey or click here to read the paper.

Monday, June 08, 2009

Micropolis: Open source SimCity

SimCity is a city-building simulation game whose objective as the name suggests is to build and design a city. The original SimCity has now been released under the name Micropolis through a GPL license, therefore allowing people to experiment with the original model, maybe even adding more complex behaviors and rules?

Adams (1998) highlights how SimCity provides a valuable teaching tool for urban geography, planners, designers and policy makers. The GUI of the game facilitate the learning about the complex, dynamic, and interrelated nature of urban problems.


Friday, May 22, 2009

Agent Analyst movies

Agent Analyst is an Agent-based modelling extension that allows users to create, edit, and run RepastJ and RepastPy models from within ArcGIS. The Agent Analyst toolkit was developed by Argonne National Laboratory’s Center for Complex Adaptive Agent Systems Simulation in collaboration with ESRI and to promote cooperation and collaboration between GIS professionals and agent-based modellers

While its been around for some time, I have recently just come across two videos from the Redlands Institute, however the actual models and further details is limited, they show the potential of the extension for agent-based modelling. The first demonstrates the integration of Agent Analyst and Tracking Analyst within ArcGIS Desktop. Specifically the model shows a simulation of bird migration patterns of 2 species. The second model uses Agent Analyst to compare two urban growth scenarios.

Bird migration patterns

Comparing two urban growth scenarios

For more information including tutorials on how to use Agent-Analyst see the Agent Analyst website.

meta beta's Flu Model

Miles Parker writer of the meta beta blog has had some interesting posts recently about modeling influenza using agent-based models. In his first post he explained the design of simple agent-based model of influenza (including agents attributes and behaviours), in a second post he details some experiments (including the importance of carrying out batch runs) and the third post allows users to interact with the model through a applet. The model itself was developed using metaABM.

The effect of movement on the maximum infection Level (21 runs) (Source meta beta)

Miles is also the founder of Metascape and metaABM. metaABM is an opensource project which provides tools to allow for models to be visually edited without reqiring programming experience. Along with being tightly integrated within the Eclipse IDE toolset and can be linked to Repast Simphony. For more details readers are referred to the metascape website which has more information about the metaABM project along with some interesting videos on the overview of metaABM how one can install and design agent-based models in a relatively visual environment.

metaABM from Metascape

On a related note I found the movie below of an interview of Josh Epstein, were he talks about agent-based modelling and the spread of smallpox.

Wednesday, May 20, 2009

NetLogo to 3D Max

I am a great fan of NetLogo for the development of agent-based models. At CASA we have been exploring how one can loosely couple NetLogo models with 3D Max. The reason being that 3D Max offers a means of visualization which is beyond NetLogo's for example, building 3D city scapes.

Ateen Patel a PhD student at CASA and author of the Crowd Simulation Blog has written a short tutorial (including the code) and several other posts on how to get information from a simple NetLogo Traffic Model and to visualize the model in 3D Max.

Such outputs can be seen in the movie below from Digital Urban:

The Crowd Simulation Blog is worth keeping an eye on for those interested in pedestrian modeling as Ateen's research and his blog explores new methods for rendering very large crowd scenes that contain the correct kinds of physics and dynamics that enable realistic simulations to be generated.

Tuesday, May 19, 2009

Update: Agent-based models in Second Life

We just finished another part of Agent-Street where agents and avatars can interact with each other. The idea here is to merge iconic and symbolic urban models in a multi-user real time environment.

The movie below shows Agent-Street and how one can download the models we have created by clicking on the model vending machines. By clicking on the vending machines, models can be downloaded and saved. Such vending machines are common features in Second Life and allow users to store objects and scripts in their personal inventory for later use such as rebuilding the models on their own Land or in free sand-boxes. We have been using the Mauve Land for this (SLURL).

In our previous models avatars could only visualise and initiate the models. For example, in the pedestrian evacuation model users could only observe how agents exited the building (in a similar way to professionally developed 3D pedestrian modelling software packages such as STEPS). In this new model, we extend the basic pedestrian evacuation model, so that agents not only consider their environments but also other avatars. In this sense we are not only incorporating iconic and symbolic modelling styles but also adding a further human dimension, moving towards an augmented reality (i.e. as if the agents and the humans were in the same crowd). The movie below shows how pedestrian paths change when avoiding an avatar. The movie shows a how an avatar stationed near the exit impacts on pedestrian egress as agents have to move around it.

Previous posts on our and others work on Second Life can be found by clicking here. We have also set up a website outlining the work in detail (click here) or alternatively if you have a Second Life account this SLurl will take you to the Land, once you teleport to the area, follow the red arrow (beam of red light) into the sky to find Agent-Street. If the models are running slow let us know as we having problems with fish entering our land from a neighbouring island.

Friday, May 15, 2009


I been meaning to highlight the SIMPOP models for a while, and after listening to Denise Pumain talk at the AAG annual meeting a few months ago entitled "Modelling spatial evolution: the example of urban systems." I thought it was about time.

The SIMPOP model is basically a multi-agent model of cities systems evolution. In the model, agents are geographical entities: towns and cities. "This choice refers to evolutionary urban theory : the hypothesis is that the dynamics of a town or a city depends on its ability to interact with other towns and cities, which in turn depends on its relative situation in the settlement system (in terms of hierarchical level, specialization, accessibility). The city is then seen as a coherent entity, whose potential of growth depends first on its external interactions (core rules of the model) and second on internal specificities (governance). The interurban interactions are the driving forces shaping the emergence and evolution of the system of cities. (SIMPOP website)."

The model has been developed since 1996 and has been used to model the growth of Europe from 1300 and the United States of America from 1650.

To find out more about the models visit the SIMPOP Project website which has an introduction to the generic model, application domains and a list of publications resulting from the work (however, some of the links are currently not working).

Thursday, May 14, 2009

Tracking Pedestrians

Tracking peoples movement is an extremely time consuming task to do by hand however such analysis informs our ability to realistically model peoples moment in pedestrian models.

Researchers at the Computer Vision Laboratory, ETH have been working on multi-object tracking which combines object detection and space-time trajectory estimation. The ability to automate such a process obviously has benefits for understanding pedestrian movement in cities

To see a video of the work click here.


B. Leibe, K. Schindler, N. Cornelis, L. Van Gool. (2008). Coupled Object Detection and Tracking from Static Cameras and Moving Vehicles. In IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 30, No. 10, pp. 1683-1698.

A. Ess, B. Leibe, K. Schindler, L. Van Gool. (2008). A Mobile Vision System for Robust Multi-Person Tracking. In IEEE Conference on Computer Vision and Pattern Recognition (CVPR'08), Anchorage, USA, June 2008.

Digital Urban pedestrian tracking tags