GIS and Agent-Based Modelling

ElectionGauge

2012-02-19T11:30:00.000-05:00

A project we have been working on at GMU called ElectionGauge has now gone live (although still under development). The idea about the project is tie geo-spatial analysis, linguistic analysis, and social network analysis to analyze Twitter responses to the upcoming US elections in real time with the aim of predicting election results.

One question we are exploring is do the tweets of users match the speech of candidates? For example, as Maksim Tsvetovat, one of the co-founders says “repeal Obamacare” might identify you as Tea Partier, while “legalize marijuana” puts you in Ron Paul’s camp. While still in beta, below is snapshot from the site:

Find out more see: @maksim2042, @JackieKazil & @ElectionGauge or at Tech Cocktail

Social Media and the Emergence of Open-Source Geospatial Intelligence

2012-01-27T15:48:00.000-05:00

Sample of geolocated tweets referring
Occupy Wall Street.

We have just finished a paper entitled 'Social Media and the Emergence of Open-Source Geospatial Intelligence' for Socio-Cultural Dynamics and Global Security. For those interested below is the abstract:

The emergence of social media has provided the public with an effective and irrepressible real-time mechanism to broadcast information. The great popularity of platforms such as twitter and YouTube, and the substantial amount of content that is communicated through them are making social media an essential component of open-source intelligence. The information communicated through such feeds conveys the interests and opinions of individuals, and reveals links and the complex structure of social networks. However, this information is only partially exploited if one does not consider its geographical aspect. Indeed, social media feeds more often than not have some sort of geographic content, as they may communicate the location from where a particular report is contributed, the geolocation of an image, or they may refer to a specific sociocultural hotspot. By harvesting this geographic content from social media feeds we can transfer the extracted knowledge from the amorphous cyberspace to the geographic space, and gain a unique understanding of the human lansdscape, its structure and organization, and its evolution over time. This new-found opportunity signals the emergence of open-source geospatial intelligence, whereby social media contributions can be analyzed and mined to gain unparalleled situational awareness. In this paper we showcase a number of sample applications that highlight the capabilities of harvesting geospatial intelligence from social media feeds, focusing particularly on twitter as a representative data source.

Selection of geolocated pairs of tweeters and retweeters in Tokyo at the time immediately
following the Sendai earthquake

Full reference:

Stefanidis, A., Crooks, A. T., Radzikowski, J., Croitoru, A. and Rice, M. (in press), Social Media and the Emergence of Open-Source Geospatial Intelligence, in Tucker, C. and Tomes, R. (eds.), Socio-Cultural Dynamics and Global Security: Interdisciplinary Perspectives on Human Geography in an Era of Persistent Conflict, US Geospatial Intelligence Foundation (USGIF). Click here to see a draft of the paper.

Agent-based Models and Geographical Systems at the AAG

2012-01-18T10:24:00.003-05:00

As Agent-based modeling (ABM) within geographical systems is starting to mature as a methodology in geography and across the social sciences. We (Alison Heppenstall, Mike Batty, Mark Birkin, Christopher Bone and Andrew Crooks) have organized several sessions under the topic of "Agent-based Models and Geographical Systems"at the forthcoming AAG Annual meeting in NY. These start nice and early on Saturday the 25th of February and go until Sunday the 26th.

The aim of the sessions is to bring together researchers utilizing agent-based models (and associated methodologies) to discuss topics relating to: theory, technical issues and applications domains of ABM within geographical systems.

If you plan on attending the AAG, feel free to pass by and say hello. For Saturday, all talks will be in the Carnegie Suite West, Third Floor, Sheraton Hotel starting at 8am. For Sunday, all talks will be in the Carnegie Suite East, Third Floor, Sheraton Hotel

Agent-based Models and Geographical Systems: Applications (1)

8:00 AM - 9:40 AM, Chair: Mark Birkin

*Neeraj G Baruah, Robert P. Haining & Mike Bithell,

Using Dynamic Agent Models In Understanding Socio-spatial Patterning Of Health Behaviours

*Ateen Patel

A Crowd Simulation converging Macro and Micro-scopic models

*Elenna R. Dugundji & László Gulyás

Sociodynamic Discrete Choice on Networks in Space: The Role of Utility Parameters and Connectivity in Emergent Outcomes

*Alison Heppenstall & Kirk Harland

Using Agent-Based Models for Education Planning: is the UK education system agent based?

*René Janelle Jordan, Mark Birkin & Andrew Evans

A Social Simulation of Housing Choice and Housing Policy in the EASEL Regeneration District, Leeds UK

Agent-Based Models and Geographical Systems: Applications (2)

10:00 AM - 11:40 AM, Chair: Alison Heppenstall

*Handi Chandra Putra & Clinton J Andrews

Agent based model for efficient operation of HVAC systems in commercial buildings

*Regina Ryan

A Climatic Rendering of Agent-based GIS

*Sebastien Rey Coyrehourcq & *Clara Schmitt

Guided and automated exploration for the calibration of an agent-based model

Agent-Based Models and Geographical Systems: Decision Making

12:40 PM - 2:20 PM, Chair: Andrew Crooks

*David Bennett, Jerry Schnoo, Marian Muste, Silvia Secchi, Deng Ding, Sudipta Mishra & Umashanker Rapol

Modelling Land Use/Land Cover Change in Response to Changing Economic and Environmental Drivers

*Christopher Bone

Integrating multi-objective decision making theory and agent-based modeling for enhancing spatial decision support systems

*Dawn Parker, Tianyi Yang, Qingxu Huang, Shipeng Sun, & Raymond Cabrera

A web-based model output query and visualization tool for the Agent-Based Land Market Model

Tyler Bonnell, *Raja Sengupta, Colin Chapman & Tony Goldberg

Linking Landscapes to Disease: An Agent-Based Model simulating the impact of forest composition on spread of disease in red colobus populations

*Roger White

Predicting the Dynamics of Population and Land Use at High Resolution by Means of a Cellular Automaton Based Model: Problems of Validation and Verification

Agent-Based Models and Geographical Systems: GIS and Geocomputation

2:40 PM - 4:20 PM, Chair: Alison Heppenstall

*Majeed Pooyandeh & Danielle Marceau

A web-based agent based model to simulate the stakeholders' evaluation of different scenarios of land-use change in the Elbow River watershed in southern Alberta

*Gabriel Wainer & Mariano Zapatero

A CELLULAR MODELING ENVIRONMENT FOR BEHAVIOR ANALYSIS IN GIS

*Andrew Crooks, Mark Coletti, Sarah Wise & Keith Sullivan

GeoMason: Integrating GIS and Agent-based modeling - A Gallery of Applications

Christopher McCreadie, David Blackwood, Mark Rounsevell, & *Ruth E Falconer

Rural Sustainability Visualisation Tool (RS-VT): An interactive 3D Agent Based Model using XNA and Protocol Buffers

Agent-Based Models and Geographical Systems: Land Use Change

4:40 PM - 6:20 PM, Chair: Mike Batty

*Shipeng Sun, Dawn Parker, Dan Brown, Qingxu Huang, Tatiana Filatova, Derek Robinson, Meghan Hutchins & Rick Riolo

Explicitly Representing Heterogeneous Land Developers in Agent-based Modeling of Land Use Change: A Preliminary Experiment

*Peter Deadman & Raymond Cabrera

Comparison of Decision-Making Methods in an Agent-based Model of Land Use Change.

*Nicholas Magliocca, Erle Ellis & Daniel Brown

Using an agent-based virtual laboratory to explore smallholder land-use decisions and implications for 'induced intensification' theory

*Fang Wang & Danielle Marceau

A Combined-Patch-Based Cellular Automata Model for Simulating Land-Use Changes Using High-Spatial Resolution Data

*Patrick Harrison & *Seth Spielman

The Co-Evolution of the Built and Social Environment

161 Agent-Based Models and Geographical Systems: Methodological Advances

Sunday, 8:00 AM - 9:40 AM in Carnegie Suite East, Third Floor, Sheraton Hotel, Chair: Andrew Crooks

*Sanna Iltanen

Morphologically structured agent based model of urban retail system

*Kenneth Steif

Simulating Classroom Evacuation: A Pedagogical Exercise in Agent Based Modeling

*David O'Sullivan

Agent-based models: what are they good for? Or: did Schelling really need an ABM?

*Paul Torrens

Modeling human movement with machines, muscles, and morsels of data

*Hyeyoung Kim & Chulmin Jun

Integrating an Agent-based Model with Spatial Databases for Indoor Crowds Simulation

Agent-Based Models and Geographical Systems: Policy Modelling

10:00 AM - 11:40 AM, Chair: Mark Birki

*Claudio Cioffi-Revilla, Andrew Crooks, Kenneth De Jong, Timothy Gulden, William Kennedy, Sean Luke & Mark Coletti

MASON RiftLand: An Agent-Based Model for Analyzing Conflict, Disasters, and Humanitarian Crises in East Africa

*Johannes Flacke

An agent-based model of informal settlement growth in Dar es Salaam, Tanzania

*Atesmachew Hailegiorgis

An Agent-Based Modeling of Climate Change, Land Acquisition, and Household Dynamics in Southern Ethiopia

*Amit Patel, Andrew Crooks & Naoru Koizumi

Integrating GIS and ABM to Explore Spatio-temporal Dynamics of Slum Formation in Mumbai, India

*Elfie Swerts

Simulating the evolution of urban systems in developing countries: the Indian case

Agent-Based Models and Geographical Systems: Urban Networks

12:40 PM - 2:20 PM, Chair: Mike Batty

*Einar Holm & Lena Sanders

Agent-based spatial microsimulation for modeling emergence and long term dynamics of labor markets and settlement systems.

*Clémentine Cottineau

A simulation tool for assessing the specificity of the evolutionary path of Russian cities

Timothy Gulden & *Ross Hammond

Beyond Zipf: An Agent-Based Understanding of City Size Distributions

*Thomas LOUAIL

Consequences of streets networks and accessibility patterns on cities' spatial organization : a computational study

*Marie-Noelle Comin

Analyzing and modelling interactions of actors involved in scientific networks

Agent-based Models and Geographical Systems: Urban Simulation

2:40 PM - 4:20 PM, Chair: Andrew Crooks

*Ed Manley, Tao Cheng, Alan Penn & Andy Emmonds

Integrating Agent-based Models with Macroscopic Traffic Simulation

*Huiye Ma, Theo A. Arentze & Harry Timmermans

Agent-Based Population Generation, Activity Generation, and Scheduling for Dynamic Activity-Travel Scheduling Implementation

*Mark Birkin & Nick Malleson

The calibration of metropolitan dynamics with microsimulation, agent-based models and social network data

*Mike Batty & Erez Hatna

Simulating Residential Dynamics in London's Housing Market

*Denise Pumain

The Simpop family: from an evolutionary urban theory to a computable, agent-based geographical ontology

*Denotes speaker(s)

Occupy Wall Street movement via Twitter

2011-12-16T09:56:00.001-05:00

Following on from our work on harvesting ambient geospatial information (AGI) from social media feeds we have started to explore the Occupy Wall Street movement. The movie below shows just one part of this work, specifically the movement of the protesters in New York during the Action Day (November 17) from Wall Street to Brooklyn Bridge. The red dots denote locations of the tweets. Selected tweets are displayed at the bottom of the screen. Active tweets are marked with a white star.

More ananylsis to follow...

New GeoMason Models

2011-12-12T13:20:00.001-05:00

We been working on adding more spatial agent based models examples to GeoMason, the GIS extension for MASON. These include a vegetation growth model utilizing raster data and a simple disease outbreak model utilizing vector data. See below for more details.

Vegetation Growth Model:

Eastern Africa has undergone sustained drought for over a decade placing a great strain on the local population. This demo introduces an agent-based model of grazing called Turkana South. The model makes use of NDVI data and monthly rainfall data to drive vegetation growth. After describing the model, the paper investigates the effect rainfall has on carrying capacity and how carrying capacity varies based on initial starting conditions. I conclude that carrying capacity is independent of initial population size.

Disease Outbreak:

This demo introduces a new agent-based model (ABM) for studying the spread of influenza through the schools and households of Fairfax County, VA. It is intended to explore the following questions. How does an epidemic outbreak spread through a school system? What containment approaches might be most effective at stopping an outbreak?

To find out more about GeoMason (including the data and source code for these models) click here.

Thanks to Joseph Harrison for sharing these models which where developed for class projects at the Department of Computational Social Science at George Mason University.

Harvesting ambient geospatial information from social media feeds

2011-12-06T09:47:00.000-05:00

A paper I recently co-authored with Anthony Stefanidis and Jacek Radzikowski from George Mason University entitled "Harvesting ambient geospatial information from social media feeds" is now available in GeoJournal.

The abstract for the paper reads as follows: "Social media generated from many individuals is playing a greater role in our daily lives and provides a unique opportunity to gain valuable insight on information flow and social networking within a society. Through data collection and analysis of its content, it supports a greater mapping and understanding of the evolving human landscape. The information disseminated through such media represents a deviation from volunteered geography, in the sense that it is not geographic information per se. Nevertheless, the message often has geographic footprints, for example, in the form of locations from where the tweets originate, or references in their content to geographic entities. We argue that such data conveys ambient geospatial information, capturing for example, people’s references to locations that represent momentary social hotspots. In this paper we address a framework to harvest such ambient geospatial information, and resulting hybrid capabilities to analyze it to support situational awareness as it relates to human activities. We argue that this emergence of ambient geospatial analysis represents a second step in the evolution of geospatial data availability, following on the heels of volunteered geographical information."

Geolocating pairs of tweeters and retweeters

Project Geppetto

2011-11-30T14:04:00.001-05:00

Project Geppetto from Autodesk attempts to make it it easy, fast, and fun to add crowds to 3ds Max scenes. It is part of Autodesk's "People Power" concept, where the basic idea is to try to assemble all the components one needs to create, manage, and control large crowds of characters. Specificcally it attempts to create believable motion, allow for cultural influences (Evolver) and to create a framework for thousands of characters to interact in. Below are some examples of the project.

New Book: Agent-Based Models of Geographical Systems

2011-11-29T13:20:00.003-05:00

Agent-Based Models of Geographical Systems, is editied by Alison Heppenstall, Andrew Crooks, Linda See and Mike Batty; and brings together a comprehensive set of papers on the background, theory, technical issues and applications of agent-based modelling (ABM) within geographical systems. This collection of papers (see below) is an invaluable reference point for the experienced agent-based modeller as well those new to the area. Specific geographical issues such as handling scale and space are dealt with as well as practical advice from leading experts about designing and creating ABMs, handling complexity, visualising and validating model outputs. With contributions from many of the world’s leading research institutions (see map below), the latest applied research (micro and macro applications) from around the globe exemplify what can be achieved in geographical context.

This book is relevant to researchers, postgraduate and advanced undergraduate students, and professionals in the areas of quantitative geography, spatial analysis, spatial modelling, social simulation modelling and geographical information sciences.

Book Contents:

Part 1: Computational Modelling: Techniques for Simulating Geographical Systems

Perspectives on Agent-Based Models and Geographical Systems.
A Generic Framework for Computational Spatial Modelling.
A Review of Microsimulation and Hybrid Agent Based Approach.
Cellular Automata in Urban Spatial Modelling.
Introduction to Agent-Based Modelling.

Part 2: Principles and Concepts of Agent-Based Modelling.

Agent-Based Models - Because they're Worth it?
Agent-Based Modelling and Complexity.
Designing and Building an Agent-Based Model.
Modelling Human Behaviour in Agent-Based Models.
Calibration and Validation of Agent-Based Models of Land Cover Change.
Networks in Agent-Based Social Simulation.

Part 3: Methods, Techniques and Tools for the Design and Construction of Agent-Based Models:

The Integration of Agent-Based Modelling and Geographical Information for Geospatial Simulation.
Space in Agent-Based Models.-
Large Scale Agent-Based Modelling: A Review and Guidelines for Model Scaling.
Uncertainty and Error.-
Agent-Based Extensions to a Spatial Microsimulation Model of Demographic Change.
Designing, Formulating, and Communicating Agent-Based Models.-
Agent Tools Techniques and Methods for Macro and Microscopic Simulation.

Part 4: Fine-Scale, Micro Applications of Agent-Based Models:

Using Agent-Based Models to Simulate Crime.
Urban Geosimulation.
Applied Pedestrian Modelling.
Business Applications and Research Questions using Spatial Agent-Based Models.
Using Agent-Based Models for Education Planning. Is the UK Education System Agent Based?
Simulating Spatial Health Inequalities.
ABM of Residential Mobility, Housing Choice and Regeneration.-
Do Land Markets Matter? A Modelling Ontology and Experimental Design to Test the Effects of Land Markets for an Agent-Based Model of Ex-urban Residential Land-Use Change.
Exploring Coupled Housing and Land Market Interactions Through an Economic Agent-Based Model (CHALMS).

Part 5: Linking Agent-Based Models to Aggregate Applications Macro:

Exploring Urban Dynamics in Latin American Cities using an Agent-Based Simulation Approach.
An Agent-Based/Network Approach to Spatial Epidemics.
An Agent-Based Modelling Application of Shifting Cultivation.
Towards New Metrics for Urban Road Networks. Some Preliminary Evidence from Agent-Based Simulations.
A Logistic Based Cellular Automata Model for Continuous Urban Growth Simulation: A Case Study of the Gold Coast City, Australia.
Exploring Demographic and Lot Effects in an ABM/LUCC of Agriculture in the Brazilian Amazon.
Beyond Zipf: An Agent Based Understanding of City Size Distributions.
The Relationship of Dynamic Entropy Maximising and Agent Based Approaches in Urban Modelling.
Multi-Agent System Modelling for Urban Systems: The Series of SIMPOP Models.
Reflections and Conclusions: Geographical Models to Address Grand Challenges

World Map of authors who contributed to Agent-Based Models of Geographical Systems

View Contributors to Agent-Based Models of Geographical Systems in a larger map

1st International Workshop on Advances in Computational Social Science

2011-11-10T12:53:00.003-05:00

Call for papers for the 1st International Workshop on Advances in Computational Social Science in conjunction with 12th International Conference on Computational Science, June 4–6, 2012, Omaha, Nebraska, USA.

The workshop webpage is at http://www1.spms.ntu.edu.sg/~cheongsa/acss.html

Advances in computational systems and methods (parallel, distributed, cloud; agents, networks) are revolutionizing how social science research is done. It is now possible to simulate entire cities, for example, in tremendous detail, not only in terms of technical infrastructures like traffic, but also in terms of the social choices of individuals and how these interact with each other to produce complex phenomena. At the same time, advances in informatics infrastructures mean that more data and more detailed data are collected. These data are not just on our physical environment, but are also along social dimensions. The confluence of these two developments open up many possibilities, and social scientists are now probing questions that they could never ask before. Frequently, asking these questions generate even more inquiry into the interfaces between social science, computer science, information science, and engineering.

In this workshop, we aim to provide a forum for computational social scientists to share advances made in their respective fields, and the innovations they have developed across disciplinary boundaries: on models, methods, data integration and analysis, as well as interpretation of diverse social phenomena. We also hope to foster an environment for earnest dialogue between social scientists keen to employ sophisticated computational models and methods in their research, and computer/information scientists and engineers interested in understanding social science problems.

We invite original research papers on the following topics:

Modeling methodologies
Simulation strategies and algorithms
Organization of heterogeneous social data
Data-mining and machine learning on social, behavioral, and economic data
Integration of social data into simulations
Computational studies of specific social science problems

Computational social science papers that are relevant to this workshop, but cannot be easily classified based on the topics above will also be considered.

Papers should be written in English, up to a page limit of 10 pages. The papers should follow the Procedia format, and be submitted electronically through the ICCS submission engine.

Please remember to select the workshop ADVANCES IN COMPUTATIONAL SOCIAL SCIENCES in the last field of the submissions page.

We ask authors to also send a note to cheongsa@ntu.edu.sg after their submission.

All papers will be peer reviewed. Accepted papers will be published by Elsevier in the open-access Procedia Computer Science series. The proceedings will be available at the conference.

At least one author of an accepted paper must register for the ICCS 2012 conference to present the paper at the workshop.

A selected number of papers will be invited to be extended for inclusion in a special issue of the Journal of Computational Science.

Important Dates

Full paper submission: January 9, 2012
Notification of acceptance: February 9, 2012
Camera-ready papers: March 1, 2012
Early registration ends: April 15, 2012
Conference: June 4–6, 2012

Organizing Committee
Heiko AYDT Nanyang Technological University, Singapore
Tibor BOSSE Vrije Universiteit Amsterdam, the Netherlands
Siew Ann CHEONG Nanyang Technological University, Singapore
Andrew CROOKS George Mason University, USA
Nicolas MALLESON University of Leeds, UK
Paul TORRENS University of Maryland, College Park, USA

GeoMason Examples

2011-10-21T17:00:00.005-04:00

GeoMason has recently been updated to support changes to MASON itself and I have contributed a few models to highlight the basic functionality of GeoMason and act as examples for how geographically explicit models can be built. Below are some of the new models that now come with GeoMason.

Sillypeds

This model demonstrates how one can use GeoMason to explore evacuations from a building. The simulation starts by reading raster data describing a building layout (converted from CAD files). The simulation randomly places a number of agents on walkable areas within side of the building. Once the agents have been placed on the ground, they follow the lowest cost path to the exit (in this example there is only one). The movie below demonstrates how the agents (red dots) move through the space, and through this movement congestion emerges around the exit. The yellow paths are traces of pedestrian moment.

Water World

Inspired by NetLogo's Grand Canyon Model. The aim of the model is to show how data in the form of a elevation, can be used as a foundation of a simple spatial agent-based model. Similar to the Netlogo model, the elevation data comes from the National Elevation Dataset. It was converted from an ESRI Grid into an ASCII grid file using ArcGIS.

Similar to Sillypeds, the elevation data acts as our terrain, in this case its Crater Lake in Oregon. Agents within the model (in this case water) fall at random over the terrain and then flows downhill over the terrain. If the water cannot flow downhill, it pools up and once the gradient is sufficient, the water flows. For example, water falling in Crater Lake, initially has to pool up until the water level is sufficient to breach the caldera. Once this occurs water flows out of the lake as highlighted in the movie below.

In the second movie (below) highlights the testing of the inner logic of the model, in the sense are the raindrops doing as they are expected to do. If you want to test this, uncomment out (e.g. remove '//') from either one of the two lines below:

//landscape = setupLandscape(); // uniform landscape, completely flat

//landscape = setupLandscapeGradientIn(); // landscape that slopes in

These lines can be found in the start method of WaterWorld.java file but ensure you comment out the (e.g. add '//' ) to the following line:

landscape = setupLandscapeReadIn("elevation.txt"); // read landscape from file

GridLock

This basic traffic model explores how agents travel to Tyson's Corner, Virginia for work. The idea is that if you increased the number of agents (people) more congestion will arise. To some extent this is similar to the GeoMason sim.app.geo.campusworld example.The model demonstrates how you can make agents move along networks (in this case road lines in the form of ESRI shapefiles) from their origin to their destination via a shortest path algorithm.

The number of agents is based census tract information i.e. the number of people who work in Tyson's Corner and their corresponding home locations which is restricted to Washington DC, Virginia and Maryland. The movie below shows the fully functional model.

Schelling Polygon

In this model we demonstrate how one can use polygons (such as census tracks) to create an abstract Schelling model stylized on Washington DC. The model reads in a ESRI Polygon shapefile and uses attributes of the shapefile to create Red and Blue agents and a number of Unoccupied areas. As with the traditional Schelling model, Red and Blue agents want to be located in neighborhoods were a certain percentage of their neighbors are of the same type. However, instead of using a Moore or Von Neumann which is common practice in cell based models. Here neighborhoods are calculated using the neighbors that share a common edge to the agent in question. If an agent is dissatisfied with its current neighborhood, it will move to a random Unoccupied polygon, regardless of whether or not this new location meets its preference. The movie below shows this movement.

Point Schelling Model

This model in a sense extends the Schelling Polygon model, however, instead of the polygon being the agent we take attribute data from the polygon model and create individual agents (see Crooks, 2010). This is based on the notion that much of the data we have comes at an aggregate level and often in some sort of vector representation of space such as census data. However, if we want to model the individuals or groups of individuals, we need to disaggregate the data.

To do this we create a number of Red and Blue agents based on population counts held within the polygon shapefile. As with the previous model, all agents want to be located in neighborhoods were a certain percentage of their neighbors are of the same type. However, instead of using a Moore or Von Neumann which is common practice in cell based models. Here neighborhoods are calculated using buffer distance from the agent in question. If an agent is dissatisfied with its current neighborhood, it will move to a random location, regardless of whether or not this new location meets its preference. Moreover, the model demonstrates how to link points (agents) to polygons along with some other basic geographical operations (such as union, point in polygon, buffer). The movie below shows this movement both at the individual level and at the aggregate (census track level).

SLEUTH: Urban Growth Model

This model shows a basic urban growth model based loosely on the SLEUTH model. In the sense, that we have only implemented the four growth rules (spontaneous, new spreading centers, edge and road-influenced growth) and not the self modification element of the SLUETH model. The model demonstrates how different layers (e.g. slope, land use, exclusion, urban extent - urbanized or non-urbanized, transportation, hillshade) can be read into a model to provide cells with multiple values. The movie below shows a specific growth scenario under specific coefficients (parameters) for Santa Fe, New Mexico.

More information about GeoMason can be found here along with the source code and data for all the models presented in this post.

Alice: 3D programming environment

2011-10-13T17:18:00.002-04:00

Alice is a easy to use 3D programming environment where one can create an animation for telling a story or be used for playing an interactive game. It is designed to teach the fundamentals of object-oriented programming.

In Alice, people, animals, and vehicles etc are 3D objects that populate a virtual world which one can then animate. What is nice about Alice is its interactive interface, where one can drag and drop graphic tiles to create a program (similar in a way to StarLogo TNG). Below is our (Ernesto Carrella and myself) first brief attempt of modeling agents exiting a room (we quite like the funny walk which reminds us of a John Cleese's silly walks sketch).

Another nice feature of Alice is one can import models from Sketchup to Alice, opening up many possibilities, as shown in the movie below.

Complex Adaptive Systems

2011-10-12T10:32:00.001-04:00

The other day I was teaching a class in the Introduction of Computational Social Science at GMU on complex adaptive systems and I came across the talk below by John Holland and thought it was worth sharing.

Fluid Dynamics and ABM used for the evacuation of a city

2011-10-12T09:30:00.000-04:00

Emergencies are times of great uncertainty and while GIS has been used for a long time for planning evacuations, it has only been during the last few years that agent-based modeling (ABM) has been used to study peoples behavior in such situations. In a recent article by Epstein et al. (2011), they combine Computational Fluid Dynamics (CFD) and ABM to study urban evacuation planning.

CFD is used to model the airborne transport of contaminants, while the ABM models the social dynamics of the population. Coupling of the two allows for simulating how populations might respond to a physically realistic contaminant plume.

The movie below shows a hypothetical aerosol release in Los Angeles.

More information can be found at:

Epstein JM, Pankajakshan R, Hammond RA, 2011 Combining Computational Fluid Dynamics and Agent-Based Modeling: A New Approach to Evacuation Planning. PLoS ONE 6(5): e20139. doi:10.1371/journal.pone.0020139

FuturICT

2011-10-10T09:54:00.000-04:00

What a great idea:

"The FuturICT flagship proposal intends to unify hundreds of the best scientists in Europe in a 10 year 1 billion EUR program to explore social life on earth and everything it relates to."

The movie below gives a nice overview of its aim:

More movies about the project can be found here or follow them on twitter

Virtual Geographic Environments

2011-10-02T18:56:00.001-04:00

A quick note for a new book entitled "Virtual Geographic Environments" from ESRI Press who write:

"Virtual Geographic Environments, edited by Hui Lin and Michael Batty, collects key papers that define the current momentum in GIS and "virtual geographies." 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. The four-part organization leads from a primer on VGEs to virtual cities and landscapes, interface design and public participation, and finally mobile and networked VGEs. Current topics, such as crowd sourcing and related services, point to the development of new business models that merge proprietary and nonproprietary systems."

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."

Advanced GeoSimulation Models

2011-09-26T09:19:00.000-04:00

Advanced GeoSimulation Models edited by Danielle Marceau and Itzhak Benenson brings together a number of authors that highlight the the frontier in geosimulation in particular, and in cellular automata and agent-based modelling in general.

Click here to see the forward by Mike Batty.

The author of this blog also has a chapter in the book entitled "Advances and Techniques for Building 3D Agent-Based Models for Urban Systems" with Andrew Hudson-Smith and Ateen Patel

An agent-based model of the housing market

2011-09-19T17:48:00.001-04:00

Why agent-based modeling? In the interview below Doyne Farmer discuses his work with Rob Axtell and John Geanakoplos, who aim to create an agent-based model of the U.S. economy that will people make better understand past, and future, financial crises.

But going back to the question above, why agents? to quote from the SFI website: "Whereas a traditional economic model makes future predictions based on past market behavior and thus fails in unprecedented situations, their agent-based model takes into account the actions of individual decision makers, assigning behavioral rules to each agent in the model"

Agent-Based Models and Geographical Systems Session at AAG

2011-06-22T10:19:00.001-04:00

AAG 2012 - CALL FOR PAPERS

SPECIAL SESSION(S): Agent-Based Models and Geographical Systems

LOCATION AND DATES
Association of American Geographers Annual Meeting
February, 24-28th, 2012, New York, USA

DESCRIPTION
Agent-based modeling (ABM) within geographical systems is starting to mature as a methodology in geography and across the social sciences. The aim of this session(s) is to bring together researchers utilizing agent-based models (and associated methodologies) to discuss topics relating to: theory, technical issues and applications domains of ABM within geographical systems.

We would particularly welcome papers relating to:

Validation, verification and calibration of Agent-based models
Hybrid modeling approaches (e.g. utilizing Cellular Automata, Spatial Interaction, Microsimulation, etc.)
Handling scale and space issues
Visualization of agent-based models (along with their outputs)
Ways of representing behavior within models of geographical systems
Participatory modeling and simulation
Applications: Ranging from the micro to macro scale

Please e-mail the abstract and key words with your expression of intent to Alison Heppenstall <A.J.Heppenstall@leeds.ac.uk> by September 15th, 2011. Please make sure that your abstract conforms to the AAG guidelines in relation to title, word limit and key words and as specified at <http://www.aag.org/cs/annualmeeting/call_for_papers/abstract_guidelines>. 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.

We are currently investigating journals (e.g. Environment and Planning B) in order to widely disseminate the ideas emerging from this session(s). Authors will have the opportunity to suitably revise their presentations for publication.

ORGANIZERS:

Alison Heppenstall, School of Geography, University of Leeds, Leeds, UK .

Andrew Crooks, Krasnow Institute for Advanced Study, George Mason University, USA,

Linda See, International Institute of Applied Systems Analysis (IIASA), Laxenburg, Austria

Mark Birkin, School of Geography, University of Leeds, Leeds, UK .

Michael Batty, Centre for Advanced Spatial Analysis (CASA), University College London, London, UK

TIMELINE:

September 15th, 2011: Abstract submission and expression of intent to session organizers. E-mail Alison Heppenstall <A.J.Heppenstall@leeds.ac.uk> 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.

September 22th, 2011: Session finalization. Session organizers determine session order and content and notify authors.

September 26th, 2011: Final abstract submission to AAG, via www.aag.org. 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 Alison Heppenstall . Neither the organizers nor the AAG will edit the abstracts.

September 28th, 2011: AAG registration deadline. Sessions submitted to AAG for approval.

February 24-28th, 2012: AAG meeting, New York, USA

5th Annual French Complex Systems Summer School

2011-05-06T10:01:00.000-04:00

This might be of interest to some.

5th Annual French Complex Systems Summer School

"Complex Systems and Complex Networks"

Paris, July 4th to 16th, 2011

Website: http://iscpif.fr/CSSS2011

The school will provide in-depth reference courses to a multi-disciplinary audience of researchers and students. The level of lectures will range from introductory to advanced, as attendees are not expected to be familiar with all the fields covered. Lecture topics will address specific complex systems methods and tools and their relevance to various disciplines (physics, biology, computer science, geography, sociology, linguistic, etc.). An emphasis will be given to complex networks both as objects of study and as a framework for modeling social and natural phenomena.

Group projects

During the school participants will have to conduct a group project to which about 50% of their time will be dedicated. Small size groups will be constituted on the basis of personal motivations. Groups will have to present their project collectively at the end of school. According to group preferences, projects will be oriented towards some particular aspects of complex networks and particular objects: dynamics reconstruction from data, network analysis and visualization (GEPHI), modeling (NetLogo). Distributed computing facilities will be made available for projects (OpenMole), so that projects requiring intensive simulations and processing can be led.

Tutorials

Specific tutorials (GEPHI, NetLogo and OpenMole) will be given, so that attendees could quickly converge towards the required knowledge on these shared platforms. Each work group will be followed daily by a dedicated teacher, to make sure methodological and technical gaps are filled in. Therefore, no specific knowledge, either in GEPHI, NetLogo or OpenMole is required to attend this school.

This new series of international Complex Systems Summer School (CSSS2011) is organized by the Complex Systems Institute Paris Île-de-France (ISC-PIF), in coordination with the overarching National Network of Complex Systems (RNSC) and & the Complex Systems Institute Rhône-Alpes (IXXI). Our Summer School is also one of the "Thematic School" supported by the CNRS.

The summer school will take place in Paris at the ISC-PIF: 57-59 rue Lhomond,75005, Paris, France

Invited Teachers

Lectures

Marc barthelemy, CEA (IPhT)/EHESS (CAMS), France
Nathalie Corson, Laboratoire de Mathématiques Appliquées du Havre, France
René Doursat, ISC-PIF, France
Sebastian Grauwin, ENS Lyon/IXXI, France
Jean-Loup Guillaume, LIP6, France
Hidde de Jong, INRIA, France
Luciano Pietronero, Physics Department, Rome University "La Sapienza", Italy
Camille Roth, CAMS/ISC-PIF, France

Tutorials and/or group projects following
Netlogo Arnaud Banos | Nathalie Corson | Jeremy Fiegel | Sebastian Grauwin |Nicolas Marilleau | Clara Schmitt
GEPHI Julian Bilcke | David Chavalarias
Open Mole Mathieu Leclaire | Romain Reuillon

Applying to the Summer School

The application tuition rate is €500 for the whole school. Tuition rate includes:

attendance to all courses
housing in Paris at the Cité Internationale Universitaire de Paris
lunches and coffee breaks
transport tickets in Paris during school days

Important:

From the first announcement day until the registration deadline (31 May), each application will be studied as soon as we receive it (first-come, first-served). If the applicant is selected, a registration confirmation will be quickly sent. We expect each selected applicant to confirm its registration in the week after reception of our email - and to pay the school fees when the dedicated web site will be open (15 May).

Why these rules? Because the school is organized for 25 people only, due to the importance of group projects during this summer school (50% of the total time). Moreover, the sooner you are confirmed, the sooner you can book your flight tickets!

Overview of important dates:

Application deadline: May 31
Notification of acceptance of applications: after reception of each application (first-come, first-served)
Payment website opening: May 15

WE STRONGLY RECOMMEND YOU TO APPLY AS SOON AS YOU CAN (the school is limited to 25!).

GO TO THE APPLICATION FORM

Final Geospatial Revolution Episode

2011-05-03T17:34:00.004-04:00

Over the last few months the Geospatial Revolution Project from Penn State has created some great short documentaries about the use of GIS in our daily lives.

To quote from the site:

"The mission of the Geospatial Revolution Project is to expand public knowledge about the history, applications, related privacy and legal issues, and the potential future of location-based technologies"

The final episode focuses on monitoring global climate change, preventing famine, tracking disease and mapping communities never before seen on a map.

The other three episodes are:

If you not seen any of these, they really are worth checking out.

Using agents to explore traffic: Part Two-Micro to Macro

2011-04-29T14:44:00.018-04:00

Following on from a previous post on traffic modeling with agent-based models, I have been thinking of other work in this area and came across the following movies on Youtube. The first is a traffic simulator from Martin Treiber. What is interesting is the "coffeemeter" that gives an impression of the accelerations and jerks in the traffic. You can investigate this model further here: http://www.traffic-simulation.de/ or watch the movie below.

The question you might be asking in yourselves is, do such models work in reality? The mathematical theory behind these so-called "shockwave" jams was developed more than 15 years ago using models that show jams appear from nowhere on roads carrying their maximum capacity of free-flowing traffic – typically triggered by a single driver slowing down. Below is a movie of the NetLogo Traffic Basic Model exploring this principle.

Hopefully the movie above helps add something to your question. But if not check out the next movie (make sure the sound is on). In which a team of Japanese researchers recreated the phenomenon on a test-track by putting 22 vehicles on a 230-meter single-lane circuit. Drivers were asked to cruise steadily at 30 kilometers per hour, and at first the traffic moved freely. But small fluctuations soon appeared in distances between cars, breaking down the free flow, until finally a cluster of several vehicles was forced to stop completely for a moment. That cluster spread backwards through the traffic like a shockwave. Every time a vehicle at the front of the cluster was able to escape at up to 40 km/h, another vehicle joined the back of the jam. The full article can be read in New Scientist (click here).

Moving away from traffic jams, as the previous post highlighted we can also use agent-based models to look at traffic intersections. The movie shows a more complicated intersection than in the last post and shows how different intersections can be visualized and modeled.

But while the above movie is rather simplistic, agent-based models can be developed from such simple situations to more complex one. For example, if you can model one type of intersection what is stopping you for modeling more? The movie below shows a more complex set of intersections using Paramics (however, this is noted to be a microsimulation model, if you are interested in finding out the difference between microsimulation and ABM see here).

From a local scene we can also turn to exploring more larger scenes such as entire metropolitan regions. The movie below is of that of TRANSIMS microsimulation-agent based model applied to downtown Chicago:

What I find so interesting about such traffic models is how one can go from basic models at the micro level and scale up such models (and of adding more complexity) to explore more macro phenomena such as traffic jams at metropolitan scales.

Using agents to explore traffic

2011-03-29T18:18:00.007-04:00

After spending time in the US, I am amazed how much one has to drive and this got me thinking about using agent-based models for traffic simulations (which is a large body of literature accompanying it). It also relates to my interests in urban systems and the fact that as cities have grown, transportation technologies have evolved (from walking, to trains etc), and now the automobile has become the dominant mode of transport for moving within and between cities. Trips range from journeys to work to shopping trips. The wide spread adoption and use of automobile is also one of the contributors to sprawl (in its many shapes and forms) as the car is not restrained by frequent stops or set routes, for instance such as trains are. Thus, if one can understand the relationships between land use and transportation one can investigate issues relating to urban sustainability. This is where agent-based models come in, in the sense they allow one to focus on the behavior of people. For example, how people decide to go to work.

ABM also allows us to explore simple thought experiments and how more aggregate results emerge from individual interactions such as: what is more effective, a four way stop or a traffic lights at a road intersection? The simple agent-based model presented below utilizes MASON and was created by Omar Guerrero of the CSS department at GMU. The rules of the model are simple, in the sense that at a four way stop, the vehicle that is first to arrive, it is first to move, unless two vehicles arrive at the intersection at the same time and then the vehicle has to give way to the car on the right. While at traffic lights vehicles must stop at red lights. The movie below shows part of the graphical user interface for a particular model run of both a four way stop and traffic light.

Even though this is a simple model, one can explore a number of issues such as how these different intersection configurations impact on the flow of traffic under different volumes of traffic. For example, at low traffic volumes in general, the stop sign is more effective (i.e. allows more cars to cross) than the traffic light. However, at greater traffic volumes the traffic lights out performs the four way stop (in the sense there are more cars in queues) but also with high traffic volumes, one can see oscillations in traffic waiting at the lights while the four way stops create long queues of traffic as shown in the figure below:

Moving away from micro patterns of traffic flows one can use ABM to explore daily commuting. For example, traffic models such as TRANSIMS or MATSim allow for the study of entire metropolitan regions and how traffic jams etc. form. To give a simple example of such a movement, the model presented below illustrates how many individuals can cause traffic jams. The model (using GeoMason) is based on commuters working within the Tyson’s Corner area of Virginia which boarders Washington DC. We take road and travel to work data from the US census and use this as the basis for our model.

The road data acts as a basis for our agents (red) to move from their homes (areas shaded green) to Tyson’s corner and the census data provides us with the number of agents who travel to the area on a daily basis. The agents attempt to find the shortest path from their home to the destination with preferential attachment to highways and freeways over smaller country roads. By running the model, cars start at homes and travel towards Tyson’s Corner and as more cars join certain sections of roads, traffic jams start to form (as speed is a function of the number of cars on a specific section of road). For example in the movie above, individual cars can be distinguished when they are not clustered but when traffic density increases, larger clusters develop.

The Business Assessment Model

2011-02-28T17:46:00.005-05:00

The Business Assessment Model (BAM) evaluates trajectories of People, Performance and Planet (3P) of a single company as well as of the whole market system as a function of business decision of actors, exogenous events in the broader socioeconomic environment or both.

BAM computes the cumulative di difference between predictions of the perturbed and original 3P trajectories in order to conduct analysis of decisions within the medium run planning horizon.

Figure: Integrated 3P trajectories comparing system-level dynamics of both Baseline and Variant scenarios

Who is behind BAM?

This project has been developed by Robert Axtell and Maciej Latek from the Department of Computational Social Science, at George Mason University and Francesco Cordaro from Mars Corporation. Funding has been provided by Mars Inc. through it's Economics of Mutality initiative.

Where can I see BAM?

The project website https://www.assembla.com/wiki/show/sweetmutuality/ on which you can:

Read an early working paper (pdf, 13 pages);
Download self contained, ready to run version of the BAM simulation used in the "Comprehensive Assessment of Businesss Decisions" working paper (zip file) and associated presentation (ppt file) on running and interpreting outputs;
See Validation Verification experiments we have performed with the current revision of the BAM, not included in the working paper;

BAM is implemented in MASON simulation framework.

Summer Course - Decision Maker Short Course - Computational Social Science & Policy

2011-02-09T19:05:00.002-05:00

The Krasnow Institute at George Mason University is offering a Computational Social Science & Policy short course from June 19 - Jun 24, 2011. Click here to see more details.

The course description is as follows:

This six-day, non-credit, course is a unique opportunity to work with a team of experienced computational social scientists to explore and understand the application of new interdisciplinary approaches to modeling and making decisions involving the operations of social systems. Participants will imerse themselves in an intensive tour of the field of Computational Social Science, a broad set of efforts that seek to explain and predict how large-scale human systems from organizations to urban systems, from economies to society as a whole, evolve, react to stresses and stimuli, and cooperate and compete. Participants will hear presentations from experts in the field and engage in intensive dialoguing, demonstrations, and policy scenarios.

For further information and details see: http://krasnow.gmu.edu/DMSC/dmsc-css.html

Computational Social Science Concentration in the Master of Arts in Interdisciplinary Studies

2011-02-09T18:05:00.007-05:00

We have recently received approval for a Master of Arts in Interdisciplinary Studies MAIS with a concentration in Computational Social Science starting in the Fall of 2011. Click here to to see the full details or read below.

Computational Social Science (CSS) is a relatively new interdisciplinary science in which social science questions are investigated with modern computational tools. Computational social scientists investigate complex social phenomenon such as economic markets, traffic control, and political systems by simulating the interactions of the many actors in such systems, on computers. They hope to gain insights which will lead to better management of the behavior of the larger social systems, i.e., prevention of market crashes, smoothed traffic flow, or maintenance of political stability. The intractability of many social problems calls for the new approaches provided by computational social science.

CSS is a highly interdisciplinary field that requires teams to plan and complete projects, be they undertaken by government, industry, or non-profit entities. Project managers of such teams, overseeing all elements of project design and execution, tend to hold PhDs. The MAIS concentration will train students to be members of these project teams, able to meaningfully contribute to background research and to project design, execution, and communication.

Prior background should include a bachelor’s degree in one of the social sciences, in computer science, in engineering, or in a relevant discipline, as well as undergraduate courses in these and related areas. Bachelor’s degrees in other areas are also eligible, but the student may be required to take additional courses in social science, mathematics, or computer science as prerequisites to admission.

This concentration will be available in fall 2011.

Concentration Requirements (Catalog Year 2010-2011)

Six core courses (18 credits)
Three required courses (9 credits): CSS 600, 605, 610
The required CSS courses provide an understanding of the conceptual, technical, and practical foundations of computational social science.
Three elective courses (9 credits) chosen from: CSS 620, 625, 645, 692, 739
The electives provide an understanding of the technical foundations and current work in at least two subfields of computational social science.

One research courses (3 credits) chosen from: CSS 796, 898, 899
The research course provides students with exposure to the most current ongoing research in the field and allows them to further develop their computational research expertise.
Three-four elective courses (9-12 credits)
The electives allow students to acquire a substantive specialization as well as additional training in social and computational science. Because of the broad spectrum of social science phenomena, methodologies, and student backgrounds, there is a large pool of potential courses. Electives may include any Mason master’s-level course in computational social science, social science, computer science, statistics, or other quantitative methods such as data visualization, information technology, and geographic information science. Electives should be selected in conjunction with and approval of the student’s advisor and the Director of CSS Graduate Studies. If the student does not have prior coursework in multivariate statistical analysis, the electives should include at least one such course relevant for the student’s chosen specialization.
Students who elect to do a 5-credit project or a thesis take 9 elective credits. Students who do a 2-credit project take 12 credits.
Proposal (1 credit): MAIS 797

Project (2-5 credits) or thesis (5 credits): MAIS 798 or MAIS 799.

Total: 36 Credits

Requirements may be different for earlier catalog years. See the University Catalog archives.

Director
Claire Snyder-Hall
mais@gmu.edu

Contact information
Robert Axtell
Head of the Concentration in Computational Social Science

Contact: Karen Underwood
Academic Department Coordinator
Department of Computational Social Science
Research 1, Room 373, MSN 6B2
Fairfax, VA 22030
703-993-9298
cssgrad@gmu.edu

Urban Growth and Change

2011-01-31T17:42:00.005-05:00

As many of us know more people are now living in cities than ever before. Over half (3.3 billion people) of the world’s population are located in urban areas and this proportion is predicted to increase to over 75 percent by the year 2100 (United Nations, 2007). What I find most interesting is that while cities are growing they are also constantly changing.

The reason I bring this up are twofold. First I recently stumbled upon a site from the NY Times entitled "Mapping America: Every City, Every Block" which shows data from the US Census Bureau's American Community Survey from 2005 to 2009. What is interesting is that there are several maps showing the distribution of racial and ethnic groups throughout the US along with the percentage of foreign born and how neighborhood have changed over time (similar work is also being done at CASA for the UK's population). Such data could come in handy for residential segregation models.

Secondly, as cities grow, the question is where will such growth occur or in some instances where will urban areas decline (e.g. urban shrinkage). Recently we started using GeoMason to explore urban growth using the SLEUTH model as our basis. In the movie below we explore a simple growth scenario around Santa Fe, New Mexico. The model, like the original has the 5 growth coefficients (Dispersion, Breed Spread, Slope, Road) which affect how the growth rules are applied. We also implement the same growth rules (that of Spontaneous Growth, New Spreading Centers, Edge Growth,Road-Influenced Growth) as described on the SLEUTH website. The only thing missing from the model is the self modification procedures during the run time of the model. Data for the model comes a variety of sources including the National Map, the New Mexico Atlas and ESRI.

GeoMason: Geospatial Support for MASON

2010-12-30T09:38:00.005-05:00

MASON (Multi-Agent Simulator Of Neighborhoods) developed jointly at George Mason University's Evolutionary Computation Laboratory and the Center for Social Complexity has recently added an extension called GeoMason which allows spatially explicit models to be incorporated into the MASON.

Over the last few months I have been experimenting with GeoMason in terms of using both raster and vector data to build spatially explicit agent-based models. Overall, I have been impressed by the speed of which such models run at and the example models that come with it GeoMason are really useful.

Below are some of the test models we have developed for a course on entitled GIS and Agent-based modeling which was taught in the Department of Computational Social Science at GMU.

The first model is based on importing a geotiff of the National Elevation Dataset at 1 arc second from the National Map of Crater Lake, Oregon. After which water is added (which could be considered loosely as agents) and flows from high to low elevations, if the water can not flow over the surface it pools. As the movie below shows, over time, Crater Lake slowly fills up until the water breaches the caldera rim which allows the water to flow out. This model was inspired by the NetLogo Grand Canyon Model.

Moving towards vector data, below is a simple example of using GeoMason for a spatially explicit Schelling style of model of segregation where neighborhoods are not based on a regular square lattice but on irregular cells and in this case stylized on Washington DC. The model uses polygon boundaries of census tracks from the 2000 US census. In the model, each census track knows which other census tracts are its neighbors and only one agent occupies such a track. As in the normal Schelling styles of models, agents want to be located in neighborhoods where a certain percentage of their neighbors are of the same type. If an agent is dissatisfied with its neighborhood it moves to a new location. This movement causes more movement and the result is that areas become segregated.

The next movie, highlights a variant of the Schelling model. Whereby we take aggregate data and use this to populate the model with agents. The reason for this is that much of the data we have comes at an aggregate level and often in some sort of vector representation of space such as census data. However, if we want to model the individuals or groups of individuals we can take this data along with other information and use it as a basis of spatially explicit agent-based model. Basically, this model extends the polygon model above and creates agents based on attribute data held within the shapefile. While the model is highly stylized it demonstrates how data can be read into the model, how to create agents based on this data and how to link points (agents) to polygons along with some basic geographical operations (such as union, point in polygon, buffer).

To download GeoMason click here (note there a number of model examples here). For more information on GeoMason there is a technical report:

Sullivan, K., Coletti, M. and Luke, S. (2010), GeoMason: GeoSpatial Support for MASON, Department of Computer Science, George Mason University, Technical Report Series, Fairfax, VA.

Also when I have time I will provide more details on the models above and others using GeoMason.

Multi-disciplinary approach of complexity, networks, geosimulations

2010-10-03T17:26:00.003-04:00

A short note to say that the videos and presentations from the Multi-disciplinary approach of complexity, networks, geosimulations workshop held between 9th - 11th June 2010 at the University of Lausanne are available online and for download: http://www.unil.ch/citadyne/page78227.html. Presentations include those from Prof. Peter Allen entitled "The Complexity of Structure, Strategy and Decision Making" and Prof. Itzhak Benenson entitled "Geo-simulations of urban phenomena"

Space-Time Dynamics in Scaling Systems

2010-09-24T09:28:00.005-04:00

To quote from Mike Batty:

"A rank clock is a device for visualising the changes over time in the ranked order of any set of objects where the ordering is usually from large to small. The size of cities, of firms, the distribution of incomes, and such-like social and economic phenomena display highly ordered distributions. If you rank order these phenomena by size from largest to smallest, the objects follow a power law over much of their size range, or at least follow a log normal distribution which is a power law in the upper tail."

The idea behind the Rank Clock is:

"... despite the fact that such distributions are so regular even through time, when one examines how objects within these distributions change over time, it is quite clear that somehow these systems remain stable at the aggregate level but with objects which composes them shifting quite dramatically from time period to time period. The Rank Clock is a device that shows how such distributions change over time and it is a natural complement to the rank size distribution which is called a Zipf Plot."

Below are some movies of the Rank Clock in action (further details can be found here). The first is an animated rank clock showing how the rank of cities in the USA changed between 1790 and 2000.

While the movie below shows an animation of a rank clock showing how the ranks of the top 100 high buildings in New York change between 1912 and 2008.

The Rank Clock Software can be downloaded from the CASA Web Site (here), more information can also be found here and more animations here

Geospatial Revolution - Episode 1

2010-09-15T10:05:00.004-04:00

Via the VerySpatial Blog I came across the first episode (below) of the Geospatial Revolution Project and thought it was worth sharing. To quote from the site:

"The mission of the Geospatial Revolution Project is to expand public knowledge about the history, applications, related privacy and legal issues, and the potential future of location-based technologies"

A prototype migration model

2010-09-08T08:50:00.024-04:00

This week saw many members of the Computational Social Science Department and the Center of Social Complexity attend the 3rd World Congress on Social Simulation in Kassel, Germany. Chris Rouly and myself presented some ongoing work entitled "A prototype, multi-agent system for the study of the Peopling of the Western Hemisphere". Below is the abstract of the paper:

"We describe the interim state of development of a prototype, multiagent system (MAS) model for studying the Peopling of the Western Hemisphere. The model is part of a computational analysis of proxy evidence associable with late Pleistocene human migrations. In particular, we examine an out-of-Europe migratory theory some suggest occurred late in the Pleistocene.

The migratory theory we examine is the Bradley-Stanford Solutrean-Clovis Hypothesis [1]. To date, natural decay and terrestrial location has produced only limited circumstantial [3], genomic [2], and lithic [4] evidence supporting conclusions pertaining to this specific theoretic event. The work described here constitutes the foundation steps for a coherent body of computational social science whose intent is a thorough investigation of the several hypothesized routes often suggested as migratory thoroughfares for early hunter-gatherer peoples into the Western Hemisphere. We use a biologically detailed, temporally articulated, spatially accurate, and empirically driven MAS."

While this research is ongoing if you would like to read more, see the paper below:

Part of the model is modeling the extent of the ice sheet ("Deep Freeze") component of the model. The movie below shows the growth of the simplified ice sheet used in the simulation during the last ice age (from 25,000 to 16,000 years ago):

In addition to showing the total simulation of the Ice Sheet we also model the annual ice sheet movement (fluctuation), in the sense that while we model the growth and decline of the ice during the last glaciation we also model the ice sheets yearly flux:

The agents in the model are individual hunter-gatherers who move around the spatially explicit environment. The can form cohorts/groups. They forage for food and can migrate over the environment. We try to highlight this in the movie below:

To provide an idea of the simulation environment we are currently developing the movie below shows the GUI of the model focusing on a simulated year where our hunter-gatherers forage for food:

As noted at the beginning of this post, this is some initial research, a foray if you like and the model is classed as a prototype. It is not the final model by any stretch of the imagination. Any thoughts or comments are most welcome.

References

1. Bradley, B., Stanford, D.: The North Atlantic Ice-edge Corridor: A Possible Paleolithic Route to the New World. World Archaeology. 36 (2004) 459–478
2. Fagundes, N. J. R., Kanitz, R., Eckert, R., Valls, A. C. S., Bogo, M. R., Salzano, F. M., Smith, D. G., Silva Jr., W. A., Zago, M. A., Ribeiro-dos-Santos, A. K., Santos, S. E. B., Petzl-Erler, M. L., Bonatto, S. L.: Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a Coastal Route for the Peopling of the Americas. The American Journal of Human Genetics. 82 (2008) 583–592
3. Goebel, T., Waters, T., O’Rourke, D.: The Late Pleistocene Dispersal of Modern Humans in the Americas. Science. 319 (2008) 1497–1502
4. Lowery, O., O’Neal, M., Wah, J., Wagner, D., Stanford, D.: Late Pleistocene Upland
Stratigraphy of the Western Delmarva Peninsula, USA. Quaternary Science Reviews. 29 (2010) 1472–1480

New Report: Data mash-ups and the future of mapping

2010-09-06T08:18:00.007-04:00

Several months ago we (Suchith Anand, Michael Batty, Andrew Crooks, Andrew Hudson-Smith, Mike Jackson, Richard Milton, Jeremy Morley) where commissioned by the UK's Joint Information Systems Committee (JISC) to produce a TechWatch horizon scanning report entitled "Data mash-ups and the future of mapping."

Below is the executive summary of the report:

"The term 'mash-up' refers to websites that weave data from different sources into new Web services. The key to a successful Web service is to gather and use large datasets and harness the scale of the Internet through what is known as network effects. This means that data sources are just as important as the software that 'mashes' them, and one of the most profound pieces of data that a user has at any one time is his or her location. In the past this was a somewhat fuzzy concept, perhaps as vague as a verbal reference to being in a particular shop or café or an actual street address. Recent events, however, have changed this. In the 1990s, President Bill Clinton's policy decision to open up military GPS satellite technology for 'dual-use' (military and civilian) resulted in a whole new generation of location-aware devices. Around the same time, cartography and GIScience were also undergoing dramatic, Internet-induced changes. Traditional, resource intensive processes and established organizations, in both the public and private sectors, were being challenged by new, lightweight methods. The upshot has been that map making, geospatial analysis and related activities are undergoing a process of profound change. New players have entered established markets and disrupted routes to knowledge and, as we have already seen with Web 2.0, newly empowered amateurs are part of these processes. Volunteers are quite literally grabbing a GPS unit and hitting the streets of their local town to help create crowdsourced datasets that are uploaded to both open source and proprietary databases.

The upshot is an evolving landscape which Tim O'Reilly, proponent of Web 2.0 and always ready with a handy moniker, has labelled Where 2.0. Others prefer the GeoWeb, Spatial Data Infrastructure, Location Infrastructure, or perhaps just location based services. Whatever one might call it, there are a number of reasons why its development should be of interest to those in higher and further education. Firstly, since a person's location is such a profound unit of information and of such value to, for example, the process of targeting advertising, there has been considerable investment in Web 2.0-style services that make use of it. Understanding these developments may provide useful insights for how other forms of data might be used. Secondly, education, particularly research, is beginning to realize the huge potential of the data mash-up concept. As Government, too, begins to get involved, it is likely that education will be expected to take advantage of, and indeed come to relish, the new opportunities for working with data.

This TechWatch report describes the context for the changes that are taking place and explains why the education community needs to understand the issues around how to open up data, how to create mash-ups that do not compromise accuracy and quality and how to deal with issues such as privacy and working with commercial and non-profit third parties. It also shows how data mash-ups in education and research are part of an emerging, richer information environment with greater integration of mobile applications, sensor platforms, e-science, mixed reality, and semantic, machine-computable data and speculates on how this is likely to develop in the future."

The full report can be downloaded from here.

Fractals

2010-08-18T10:23:00.005-04:00

Vlasios Voudouris of the Object-Field Model blog linked to the following talk by Benoit Mandelbrot about "Fractals and the art of roughness." Like Vlasios I found it interesting so I thought I would share it, like him.

On a side note, anyone interested in fractals and want to see them in the context of cities should check out “Fractal Cities: A Geometry of Form and Function” by Professors Mike Batty and Paul Longley. It is a well written, a must read and often cited book for anyone interested in or writing about fractals, urban modeling and complexity sciences. The nice thing about the book is it is freely available at: http://www.fractalcities.org/

agent-based-models.com

2010-08-17T08:19:00.002-04:00

Professor Jeff Schank of the Department of Psychology at the University of California is compiling a great website and a resource for those interested in ABM: agent-based-models.com. The site has a plethora of resources for agent-based modelers, including a blog, a list of ABM blogs, simulation environments, Organizations, Centers, and Institutes involved with ABM, a growing list of researchers involved with ABM.

Modeling Housing Markets: Update

2010-08-17T08:04:00.003-04:00

A while ago I blogged about the a simple NetLogo model by Nigel Gilbert et al. which 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). I have just come across an audio recording with accompanying slide presentation by Nigel Gilbert’s which enhances the previous post and thought it was worth sharing. Click here to listen and see the slides. The talk is hosted on the SIMIAN (Simulation Innovation: a Node) project website which aims to promote and develop social simulation methods in the UK.

Reference:
Gilbert, N, Hawksworth, J C, and Sweeney, P (2008) 'An Agent-based Model of the UK Housing Market'. University of Surrey http://cress.soc.surrey.ac.uk/housingmarket/ukhm.html or click here to read the paper.

New Working Paper: From Buildings to Cities

2010-07-20T14:43:00.005-04:00

Duncan Smith and myself have just finished a new working paper entitled "From Buildings to Cities: Techniques for the Multi-Scale Analysis of Urban Form and Function."

Below is the the abstract for this paper:

The built environment is a significant factor in many urban processes, yet direct measures of built form are seldom used in geographical studies. Representation and analysis of urban form and function could provide new insights and improve the evidence base for research. So far progress has been slow due to limited data availability, computational demands, and a lack of methods to integrate built environment data with aggregate geographical analysis. Spatial data and computational improvements are overcoming some of these problems, but there remains a need for techniques to process and aggregate urban form data. Here we develop a Built Environment Model of urban function and dwelling type classifications for Greater London, based on detailed topographic and address-based data (sourced from Ordnance Survey MasterMap). The multi-scale approach allows the Built Environment Model to be viewed at fine-scales for local planning contexts, and at city-wide scales for aggregate geographical analysis, allowing an improved understanding of urban processes. This flexibility is illustrated in the two examples, that of urban function and residential type analysis, where both local-scale urban clustering and city-wide trends in density and agglomeration are shown. While we demonstrate the multi-scale Built Environment Model to be a viable approach, a number of accuracy issues are identified, including the limitations of 2D data, inaccuracies in commercial function data and problems with temporal attribution. These limitations currently restrict the more advanced applications of the Built Environment Model.

The full title of the paper and reference is:

Smith, D.A. and Crooks, A.T. (2010), From Buildings to Cities: Techniques for the Multi-Scale Analysis of Urban Form and Function, Centre for Advanced Spatial Analysis (University College London): Working Paper 155, London, UK.

NetLogo GIS Examples from backspaces.net

2010-07-15T16:54:00.005-04:00

While searching for some NetLogo GIS examples I came across this excellent web page by Owen Densmore from Backspaces.net called "NetLogo Bag of Tricks" showcasing NetLogo's GIS functionality. There is a model of water traffic in Venice model and a simple model that reads census data and extracts features,showing them in different colors (both of which can be downloaded).

If any readers know of any other good NetLogo models using GIS data please leave a comment pointing us in the direction of them.

Agent-based models: Why Use them?

2010-06-25T09:51:00.011-04:00

I have just come across a few movies on YouTube by Miles Parker on "Why Agent-Based modeling?". These short movies offer a good introduction to agent-based models. The first part (below) explains why we might be interested into ABM and what they are.

The second movie (below) follows on from the first, looking at a specific application ABM, that of modeling H1N1 and contrasts ABM with a more traditional equation-based approaches to looking at disease transmission.

More movies by Miles on YouTube can be found here, while his blog (meta beta) is here. For more details about his H1N1 agent-based models click here.

Avatars in OpenSim

2010-06-24T09:00:00.009-04:00

OpenSim (OpenSimulator) "is a 3D Application Server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols." In a sense its similar to Second Life (SL) but one can host environment on ones own web server (Click here to see some of ourt previous work with SL).

One of the problems with using SL is that one has to own/rent the land in which the environment is created and housed. While with OpenSim one only needs a web server which in a sense is highly appealing for creating permanent environments. Another problem we encountered when using SL was the time it took to execute our agent-based models due to the SL servers. So when I was shown by Chris Rouly this latest test on the ScienceSim Beta Grid by Nebadon Izumi showing 1000 Avatars of mostly bots but some human controlled avatars in real time (as shown below), this got me thinking again about agent-based modeling in virtual worlds.

It would be nice to see Avatars (agents) populating real buildings such as the Ajax FC stadium below. Where the agents are programed to react to changing conditions such as evacuation in times of crisis.

The Ajax FC stadium (Source: KZero Worldswide)

One of our initial tests on using SL for the evacuation of buildings can be seen below. But in our example we only use a maximum of 100 agents but using 1000s of agents with real anthropomorphic dimensions in a 3D space and in real time is highly appealing.

Hurricane Landfall Game

2010-06-24T08:38:00.000-04:00

With the hurricane season starting I was looking for models which explored the impacts of hurricanes when they make landfall and came across a game from University Corporation for Atmospheric Research (UCAR) called "Disaster Dynamics: Hurricane Landfall: an experiential learning game." To quote from the website:

The game..."teaches players about interactions between natural hazards and human decisions in a Gulf Coast barrier island community. It is a strategy and negotiation computer game intended for use in undergraduate classes, and is designed for four players who are connected to one another via the Internet."

More information about the game can be found here: http://www.dd.ucar.edu/

GMU Fiarfax Campus created with CityScape

2010-06-17T10:55:00.004-04:00

I have just been exploring the demo version of CityScape from PixelActive and I am quite impressed. CityScape is an urban modeling tool that allows users to build both custom and real-world environments quickly and easily. The focus of the modeler is on allowing developers to concentrate on design rather than the labor involved in creation.

The movie below show my initial attempt of creating a agent-based traffic model around the Fairfax Campus of George Mason University. The model utilizes a real world elevation data downloaded from the U.S. Geological Survey 's (USGS) National Map, the road data comes from OpenStreetMap and the building footprints from the Geospatial Data Collection at Mason.

Some readers might find the movie below from an earlier post created in Repast Simphony an interesting comparison. Basically in this model, agents are pedestrians and they choose the shortest route between two buildings.

50 Facts about Agent-Based Computing

2010-06-16T06:26:00.002-04:00

I just found out about an interesting pamphlet entitled " 50 Facts about Agent-Based Computing" by Michael Luck and thought it was worth sharing. The pdf can be downloaded from here.

Urban Modelling: Algorithms, Calibrations, Predictions

2010-06-14T08:36:00.001-04:00

Mike Batty of CASA "Urban Modelling: Algorithms, Calibrations, Predictions" which was originally published in 1976 has been republished by popular demand!

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 P rojective 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.

Agent Analyst Bird Migration Model

2010-05-21T18:10:00.004-04:00

While I have blogged about Agent Analyst before (see here), the Redlands Institute have created some movies showing a simulation of bird migration patterns. While the exact details are not abundant, it appears they where developed to learn and demonstrate concepts relating to linking agent-based models with a GIS. Specifically using the Agent Analyst toolkit with Tracking Analyst in ArcMap (as shown in the movie below):

While this movie shows a live model run:

Finally the movie below shows how one can visualize the results in ESRI's ArcGlobe.

More movies from the Redlands Institute on YouTube can be found here.

Cormas and ComMod

2010-05-20T09:24:00.010-04:00

Following on from the UVA Bay Game post I thought it was about time to blog about Cormas and the ComMod (Companion Modeling Approach) which focus on participatory agent-based modeling for resource management.

Why the interest? Take ecosystem management as an example, there are often many actors (stakeholders) who influence and control ecosystem management. For example, in the Chesapeake Bay there are farmers, local policy-makers, watermen, and developers. Such stakeholders have many different goals, associated feedbacks, negotiations etc... The question is how does one build models of such interactions?

Often when we build models of such interactions we do not always engage with stakeholders directly. Participatory modeling approaches such as companion modeling offers one way for such engagement. It uses various techniques, including role playing games in the sense that models are built with the direct involvement of stakeholders. Where modelers develop and validate model rules in conjunction with those one is modeling. Such a direct involvement of stakeholders focuses our attention on how decisions are made and what are the problems rather than just simulating the effects (e.g. Gimblett et al., 2002).

This brings me back to the ComMod approach and Cormas (an agent-based simulation framework, often used in conjunction with the ComMod approach). In the sense that ComMod is a iterative modeling process from the “bottom up.” ComMod provides an endless cycle of "field work and data analysis -> role playing games -> agent-based model development and implementation -> simulation -> field work again (Barreteau, 2003) as depicted below:

Some references for further reading:

Barreteau, F.O. and others (2003), 'Our Companion Modelling Approach', Journal of Artificial Societies and Social Simulation, 6(1), Available at http://jasss.soc.surrey.ac.uk/6/2/1.html.
Etienne, M. (2003), 'SYLVOPAST: A Multiple Target Role-Playing Game to Assess Negotiation Processes in Sylvopastoral Management Planning', Journal of Artificial Societies and Social Simulation, 6(2), Available at http://jasss.soc.surrey.ac.uk/6/2/5.html.
Gilbert, N., Maltby, S. and Asakawa, T. (2002), 'Participatory Simulations for Developing Scenarios in Environmental Resource Management', in Urban, C. (ed.), Third Workshop on Agent-Based Simulation, SCS European Publishing House, Passau, Germany, pp. 67-72.
Ramanath, A.M. and Gilbert, N. (2004), 'The Design of Participatory Agent-Based Social Simulations', Journal of Artificial Societies and Social Simulation, 7(4), Available at http://jasss.soc.surrey.ac.uk/7/4/1.html.

To see some Cormas examples (Click here). Click here to see the ComMod program at work and here for the ComMod site. While the movie below shows one application of Cormas:

Agent-based model the Chesapeake Bay watershed

2010-05-19T17:23:00.001-04:00

The Chesapeake Bay watershed is the largest estuary in the United States, its drainage basin covers 166,534 km2 in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia (Wikipedia). It is home to around 27 million residents and is suffering many deteriorating environmental conditions brought on by a broad range of individuals, communities and industries that live and work in its boundaries.

The University of Virgina (UVA) has developed an agent-based model called Bay Game to explore the issues relating to the Chesapeake Bay watershed. To quote the site, the UVA Bay Game "allows players to take the roles of stakeholders, such as farmers, local policy-makers, watermen, and developers, make decisions about their livelihoods and professional expertise, and see the impacts of these decisions on the watershed and on each other over a twenty-year period. The Game is an educational tool for raising awareness about watershed stewardship; a tool for exploring and testing policy choices; and a tool for basic research in complex systems modeling."

More information about the UVA Bay Game can be found here. Below is a news clip featuring Philippe Cousteau who talks about the project.

Jobs and PhD studentships at CASA, UCL

2010-04-19T13:23:00.001-04:00

ENFOLD-ing: Explaining, Modelling and Forecasting Global Dynamics

ENFOLD-ing is a major new multi-discliplinary EPSRC research grant which has been awarded to UCL under the direction of Sir Alan Wilson. Seven UCL departments are involved in the project. Here is a summary of the 5 Research Associate vacancies and 3 PhD studentships:

Research Associate (Complexity Tools workstream) Ref: 1133129
Funded for three years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)

This post is working with Steven Bishop and Frank Smith from UCL Mathematics. The main purpose is to initiate, develop, design and be responsible for the delivery of a programme of high quality research into the applied mathematics relevant to migration, trade, security and related issues of most interest to the overall aims of the ENFOLD-ing project. Essential skills include substantial knowledge & programming experience in any of the programming languages C#, C++, Java (or evidence of ability to learn new programming languages), a postgraduate qualification in mathematics or a mathematical science related area,and expertise in mathematical modelling and /or complex systems and ability to develop models related to migration, trade, security. For full details and to apply for this job, please review the advert on the UCL HR website.

Research Associate (Trade workstream) Ref: 1132947
Funded for three years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)

This post is working with Francesca Medda from the UCL Centre for Transport Studies and Sir Alan Wilson from the Centre for Advanced Spatial Analysis. The main purpose is to develop models of international trade on a global scale and to contribute to the delivery of a global intelligence system to support the overall aims of the ENFOLD-ing project. Essential skills include expertise in mathematical modelling and /or complex systems, expertise in international trade and/or economics and substantial knowledge & programming experience in any of the programming languages C#, C++, Java, or evidence of ability to learn new programming languages. For full details and to apply for this job, please review the advert on the UCL HR website.

Research Associate (Migration workstream) Ref: 1132973
Funded for two years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)

This post is primarily working with Pablo Mateos from UCL Geography and Michael Batty from the Centre for Advanced Spatial Analysis. The main purpose is to initiate, develop, design and be responsible for the delivery of a programme of high quality quantitative research into the relevant statistical, geographical and theoretical aspects related to migration analysis. Essential skills include substantial knowledge & programming experience in any of the following programming languages: C#, C++, Java, Python, knowledge and experience of designing, constructing and analysing large databases and a postgraduate qualification in either a quantitative speciality within a social science discipline (such as statistics, geography, economics, sociology, epidemiology/ public health, GIS, spatial analysis) or a science discipline with experience in social science applications (such as computer science, maths, physics, medicine, and any other relevant disciplines).

For full details and to apply for this job, please review the advert on the UCL HR website.

Research Associate (Security workstream) Ref: 1133143
Funded for five years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)

This post is primarily working with Shane Johnson from UCL Jill Dando Institute of Security and Crime Science. The main purpose of the job, under the guidance of the investigators, is to initiate, develop, design and be responsible for the delivery of a programme of high quality research into security and related issues of most interest to the overall aims of the ENFOLD-ing project. Essential skills include expertise in statistical modelling and /or complex systems and ability to develop models related to security and crime, substantial knowledge & programming experience in any of the programming languages C#, C++, Java, Stata, R or evidence of ability to learn new programming languages and knowledge and experience of constructing and manipulating, or of making valuable use of, large databases. For full details and to apply for this job, please review the advert on the UCL HR website.

Research Associate (Synthesis workstream) Ref: 1132977
Funded for three years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)

This post is primarily working with Sir Alan Wilson and Francesca Medda from the UCL Centre for Transport Studies. The main purpose is to initiate, develop, design and be responsible for the delivery of a global intelligence system, and some associated modelling, of most interest to the overall aims of the ENFOLD-ing project; this includes working in and contributing to the ENFOLD-ing team effort. Essential skills include expertise in mathematical modelling and/or complex systems, a postgraduate qualification in an area related to the ENFOLD project, skills in computer visualisation and substantial knowledge & programming experience in any of the programming languages C#, C++, Java, or evidence of ability to learn new programming languages. For full details and to apply for this job, please review the advert on the UCL HR website.

PhD STUDENTSHIPS
3 x PhD studentships are also available linked to the ENFOLD-ing project.
The studentship lasting for three years will cover tuition fees at home rate plus standard living expenses of £15,290 per annum. The studentships are linked to the following workstreams:

Trade workstream: Ref: 1133138
The applicants should possess a good honours degree (1st Class or 2:1 minimum) in any of the following disciplines: Economics, Statistics, Physics, Mathematics, Finance, or any related field. Knowledge in econometric and statistical analysis is highly desirable. It is beneficial if applicants have experience in numerical modelling and programming.
Full details, including eligibility and how to apply, are available on the UCL HR website.

Security workstream: Ref: 1133195
The applicants should posess:
(1) an MSc in a quantitative social science topic within political science, crime science, statistics, geography, economics, sociology, or a relevant discipline.
(2) strong motivation to conduct independent research on the field of security, and basic knowledge on contemporary security concerns
(3) excellent quantitative research skills in social sciences, including a good command of statistical analysis and programming knowledge of relevant packages (R, SAS, Stata, SPSS)
(4) the ability to work independently and take responsibility of a programme of work
(5) excellent written communication skills
Full details, including eligibility and how to apply, are available on the UCL HR website.

Migration workstream: Ref: 1133333
The applicants should possess a good honours degree (1st Class or 2:1 minimum) in any of the following disciplines: Economics, Statistics, Physics, Mathematics, Finance, or in any social science program with a strong quantitative component within Geography, Sociology, Epidemiology/ Public Health, GIS, Spatial Analysis or any other closely relevant subject area. An MSc in one of these areas or/and knowledge in econometric and statistical analysis is highly desirable. They should also have excellent quantitative research skills in social sciences including a good command of statistical analysis and programming knowledge of relevant packages (R, SAS,SPSS). As well as strong motivation to conduct independent research on the field of migration and basic knowledge of contemporary issues on migration.

Full details, including eligibility and how to apply, are available on the UCL HR website.

AAG Sessions Finalized

2010-03-11T08:43:00.000-05:00

The AAG has released their preliminary program for its up and coming Annual Meeting in Washington DC. Part of which are several sessions entitled Perspectives on Geographic Complexity. These sessions where organized by Arika Ligmann-Zielinska, Andrew Crooks, Alison Heppenstall, Moira Zellner, Suzana Dragicevic, Debarchana Ghosh, Tom Evans and Seth Spielman. The session description is as follows:

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, health, 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:

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.
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.
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; infectious and chronic disease; neighborhood effects on health.

We had numerous papers submitted and we have divided them up into 7 sessions as you can see below. The sessions start on Saturday, 4/17/10 and conclude on Sunday, 4/18/10.

Perspectives on Geographic Complexity (1): Theories and Methods

Saturday, 4/17/10, from 8:00 AM - 9:40 AM in Washington Room 5, Marriott Exhibition Level

Chair: Alison Heppenstall - University of Leeds

Abstracts:

Authors: *Sara Metcalf & Michael Widener - University at Buffalo

Title: S(t)imulating (S)pace: Cultivating a Postmodern Geographic (Con)science

Authors: *Amit Patel, School of Public Policy, George Mason University, Phoram Shah - MPA

Title: Slum Formation Theory: A Simulation Approach

Authors: *Itzhak Benenson - Tel Aviv University, Israel, Erez Hatna - Wageningen University, The Netherlands

Title: Warning, the Rationality of Spatial Agents is Bounded!

Authors: *Monica Wachowicz - Wageningen UR, Jack Owens - Idaho State University

Abstract Title: Space-Time Representation of Narrative Knowledge

Author: *Claudio Cioffi-Revilla, - George Mason University

Title: MASON AfriLand: A Regional Multi-Country Agent-Based Model with Cultural and Environmental Dynamics

Perspectives on Geographic Complexity (2): Methods and Data Issues

Saturday, 4/17/10, from 10:00 AM - 11:40 AM in Washington Room 5, Marriott Exhibition Level

Chair: Alison Heppenstall - University of Leeds

Abstracts:

Authors: *H. Van Dyke Parunak & Sven A. Brueckner- Vector Research Center, Division of TTGSI

Title: Polyagent-Based Mapping of Aleatoric Uncertainty in Geospatial Trajectories

Author: *Geoffrey Jacquez - BioMedware, Inc.

Title: space-time intelligence system software for the analysis of complex geographic systems

Authors: *Wenwu Tang - University of Illinois at Urbana-Champaign, David A. Bennett - University of Iowa, Shaowen Wang - University of Illinois at Urbana-Champaign

Title: Parallel Agent-based Modeling for Large-scale Geographic Systems

Authors: *Burak Güneralp - Yale University, Michael K. Reilly - Stanford University, & Karen C. Seto - Yale University

Abstract Title: Simulating feedbacks across and among scales in land change science: An operational framework

Author: *Arika Ligmann-Zielinska - Michigan State University

Title: Variance-Based Global Sensitivity Analysis of Decision Making Mechanisms in an Agent-Based Model of Land Use Change

Perspectives on Geographic Complexity (3): Disease and Health Modeling

Saturday, 4/17/10, from 12:40 PM - 2:20 PM in Washington Room 5, Marriott Exhibition Level

Chair: Seth Spielman - Brown University

Abstracts:

12:40 PM Author(s): *Debarchana Ghosh - Kent State University, Rajarshi Guha - National Institute of Health

Title: Identifying optimal risk factors for prediction and interpretation of West Nile virus occurrences using Neural Network

Author: *Gabriela Alcaraz V. - University of Hohenheim

Title: Use of GIS for the analysis of food and nutrition security. An application to Guatemala.

Authors: Joshua King - Department of Geography and Environmental Management, University of Waterloo, *Peter J. Deadman - University of Waterloo

Title: An Agent Based Approach to Epidemiological Modelling of Malaria

Author: *Lara J. Iverson - SUNY University at Buffalo

Title: Incorporating Gender and Stigma in Modeling Tuberculosis Transmission: A Complex Systems Approach

Authors: *Monica Teran-Hernandez - Universidad Nacional Autonoma De Mexico, Unam, Miguel Aguilar Robledo - Universidad AutÓnoma De San Luis Potosl, Jaqueline Calderon Hernandez - Universidad Autonoma De San Luis Potosl, Carlos Felix Garrocho Rangel - Colegio Mexiquense, Ac

Title: The Spatial Dynamics of oncogenic Human Papillomavirus Infection in women from San Luis Potosí, Mexico: Some Preliminary Results

Perspectives on Geographic Complexity (4): Agent-Based Modeling and Sustainability Science

Saturday, 4/17/10, from 2:40 PM - 4:20 PM in Washington Room 5, Marriott Exhibition Level

Chair: Steven M. Manson - University Of Minnesota

Abstracts:

Author: *Qing Tian & Dan Brown - University of Michigan

Abstract Title: Exploring the Dynamics of Sustainability of Coupled Human-Environment Systems using Agent-based Modeling: A Case Study in the Poyang Lake Region of China

Authors: *Dawn C. Parker - University of Waterloo, Daniel G. Brown - University of Michigan
Tatiana Filatova - University of Twente, Rick Riolo - University of Michigan, Derek T. Robinson - University of Michigan, Shipeng Sun - University of Minnesota

Title: A first assessment of the role of land-market dynamics in agent-based land exchange models

Authors: *David A. Bennett - Department of Geography, University of Iowa, Wenwu Tang - Department of Geography and National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign

Title: Modeling the Sustainable Use of Common-Pool Resources Using Spatially Aware Intelligent Agents

Author: *Luis E. Fernandez - Carnegie Institution for Science

Title: A Coupled Agent Based Model Platform Examining the Sustainability of Biofuels Production in the Brazilian Cerrado

Authors: *Stephen J. Walsh - University of North Carolina at Chapel Hill & Carlos F. Mena - Universidad San Francisco de Quito

Title: Land Use Change on Household Farms in the Ecuadorian Amazon

Perspectives on Geographic Complexity (5): Modeling Land Use and Land Cover Change

Saturday, 4/17/10, from 4:40 PM - 6:20 PM in Washington Room 5, Marriott Exhibition Level

Chair: Suzana Dragicevic - Simon Fraser University

Abstracts:

4:40 PM Authors: *Moira Zellner - University of Illinois-Chicago & Antonio Aguilera - Colegio de San Luis

Abstract Title: Exploring the effects of land use policies in urban-rural fringe areas in the Mexican context: An agent-based approach

5:00 PM Authors: *Tom Evans - Indiana University, Kellly Caylor - Princeton University
Sean Sweeney - Indiana University, Mateus Batistella - EMBRAPA, Juliana Farinaci - University of Campinas, Emilio Moran - Indiana University

Abstract Title: Balancing Social and Ecological Complexity in Models of Reforestation in Indiana (USA) and São Paulo (Brazil)

5:20 PM Authors: *Christopher Bone, Lilian Alessa, Andy Kliskey - Resilience and Adaptive Management Group, University of Alaska Anchorage & Mark Altaweel - University of Chicago

Abstract Title: Simulating Community Resilience to Freshwater Dynamics with Social Agents

5:40 PM Authors: *Tim Gulden, Gabriel Balan, Jeffrey Bassett, Atesmachew B Hailegiorgis, William G Kennedy - George Mason University & Mark Rouleau - Michigan Technological University

Abstract Title: An agent-based model of land-use driven conflict among pastoralists in the Mandera region of East Africa

6:00 PM Author: *David Donato - United States Geological Survey

Abstract Title: Measuring Conformance of a Grid State to a Stochastic Cellular-Automata Land-Change Model

Perspectives on Geographic Complexity (6): Urban Systems I

Sunday, 4/18/10, from 8:00 AM - 9:40 AM in Washington Room 5, Marriott Exhibition Level

Chair: Moira Zellner - University of Illinois-Chicago

Abstracts:

8:00 AM Authors: *Suzana Dragicevic & Liliana Perez - Simon Fraser University

Abstract Title: Simulating Disease Outbreak in an Urban Environment: Agent Based Approach

8:20 AM Author: *Atesmachew Hailegiorgis - Department of Computational Social Science, Center of Social Complexity, George Mason University

Abstract Title: Changing Residence in the City: An agent based model of Residential Mobility in Arlington County

8:40 AM Author: *Yichun Xie - Eastern Michigan University

Abstract Title: Simulating Urban Development in Water-constrained Northwest China: A Case Study along the Mid-Section of Silk Road

9:00 AM Authors: *Ninghua Wang - San Diego Stata University/University of California Santa Barbara & Lin Liu - University of Cincinnati

Abstract Title: Analyzing spatial effects of hotspot policing with a simulation approach

9:20 AM Authors: *Dominik P.H. Kalisch, *Hermann Koehler, Reinhard Koenig, Jens Steinhoefel & Frauke Anders - Bauhaus University, Weimar

Abstract Title: Computer-Based Methods for a Socially Sustainable Urban and Regional Planing

Perspectives on Geographic Complexity (7): Urban Systems II

Sunday, 4/18/10, from 10:00 AM - 11:40 AM in Washington Room 5, Marriott Exhibition Level

Chair: Andrew Crooks - George Mason University

Abstracts:

Authors: *Fraser Morgan & David O’Sullivan - University of Auckland

Abstract Title: Residential developers: Competition, behaviour and the resulting urban landscape

Authors: *Christian Urich, Robert Sitzenfrei, & Wolfgang Rauch - Unit of Environmental Engineering, University of Innsbruck

Abstract Title: Stochastic Design of Urban Areas for Benchmarking Energy Strategies

Authors: *Raymond Cabrera & Peter J Deadman - University of Waterloo

Abstract Title: Household networks and urbanization in an agent-based model of the Amazonian varzea

Authors: *Jing Wu & Zheng Wang - Chinese Academy of Sciences

Abstract Title: Agent-based simulation of the spatial evolution of the historical population in China

Author: *Hoda Osman - George Mason University

Title: Urban Growth and Land Titling: An agent-based comparative model of two Informal Settlements in Cairo, Egypt

All the sessions are sponsored by the AAG's
Spatial Analysis and Modeling Specialty Group
Geographic Information Science and Systems Specialty Group
Human Dimensions of Global Change Specialty Group

Note * represents the speaker

CulturalComplexity.net

2010-03-09T19:01:00.002-05:00

I just been exploring culturalcomplexity.net, a website based on the research lab of Cultural Complexity at The University of Western Ontario, Canada.

The lab is interested in understanding processes related "...to the creation, transmission, and representation of culture, and how these processes shape the human experience" combing different academic disciplines (e.g. philosophy, mathematics, computer science, and economics). One thing that caught my attention is the Virtual Laboratory for the Study of Cultural Dynamics (VCL), a NetLogo model which explores how information changes when exchanged among individuals (click here to read more about the model).

The models are a nice example on how different .txt files can be loaded into NetLogo along with how altering certain parameters at run time alters the results. The VCL editor (used to define the world one wishes to simulate) can be found here, while the VCL machine (which then runs the simulation, generating results) can be found here.

Advances in Spatial Analysis & e-Social Science

2010-02-12T13:12:00.005-05:00

CASA at UCL are running a one day conference on 13th April which will feature the work of their group on projects associated with their research funded by various UK research councils. The conference is free but you have to register. It is also the day before the UK’s annual conference on GIS called GISRUK which is on the 14-16th April. This conference is chargeable and details can be got from the CASA conference site.

If you want to go to the one day CASA meeting “Advances in Spatial Analysis & e-Social Science”, then please go to the registration site at:

http://www.casa.ucl.ac.uk/conference/ and register.
You can get to the GISRUK site from here at http://gisruk2010.spatial-literacy.org/registration/

If you need any more information about this meeting email s.curtis@ucl.ac.uk. The programme for the CASA meeting is listed below

Session One (AM)

Online exploration of cultural regions, migration and ethnicity using the geography of personal names - Paul Longley & Pablo Mateos
Spatial Interaction Models for Higher Education - Alex Singleton & Ollie O’Brien
The Dynamics of Skyscrapers: Scaling, Allometry, and Sustainability - Michael Batty
Development of an urban growth model using high-resolution historical data - Kiril Stanilov

Session Two (PM)

The research frontier in urban modelling: the agenda and the challenges - Alan Wilson
On-line Spatio-Temporal Analysis of Network Data and Road Developments - Tao Cheng
Twitter Tags and Real-Time Visualisation of Complex Geographic Data with MapTube - Richard Milton
Tales of Things and Electronic Memory – Creating and Mapping The Geography of Everything - Andrew Hudson-Smith

Panel Discussion with Mike Goodchild, Keith Clarke, David Maguire, Carl Steinitz

Coffee at convenient points, find you own lunch, then Reception in the Wilkins Building, main quad

Slime Mold and rail links in Japan

2010-01-29T10:32:00.003-05:00

Maybe a bit off topic but recently in the NY Times there was an interesting article that highlighted researchers in Japan have used slime mold (single-celled amoeboid organism) to grow networks which show high correspondence to the rail network in the area. around Tokyo. They did this by placing 36 bits of food in a pattern corresponding to cities in the Tokyo area and letting the slime mold grow from a spot corresponding to Tokyo.

The abstract for those interested in Science is:

"Transport networks are ubiquitous in both social and biological systems. Robust network performance involves a complex trade-off involving cost, transport efficiency, and fault tolerance. Biological networks have been honed by many cycles of evolutionary selection pressure and are likely to yield reasonable solutions to such combinatorial optimization problems. Furthermore, they develop without centralized control and may represent a readily scalable solution for growing networks in general. We show that the slime mold Physarum polycephalum forms networks with comparable efficiency, fault tolerance, and cost to those of real-world infrastructure networks—in this case, the Tokyo rail system. The core mechanisms needed for adaptive network formation can be captured in a biologically inspired mathematical model that may be useful to guide network construction in other domains."

Science 22 January 2010: Vol. 327. no. 5964, pp. 439 - 442

Read the full report in Science or in the NY Times

Ph.D Program in Computational Social Sciences

2010-01-14T09:15:00.003-05:00

This might be of interest to some readers of the blog. Its a Ph.D program offered by the Department of Computational Social Science at George Mason University.

George Mason University - Ph.D Program in Computational Social Sciences

The core objective of the Ph.D. program in Computational Social Science is to train graduate students to be professional computational social scientists in academia, government or business. Our program offers students a unique and innovative interdisciplinary academic environment for systematically exploring, discovering, and developing their skills to successfully follow careers in one of the areas of computational social science.

Examples of areas of concentrations and potential specializations include but are not limited to the following:

Agent-based computational economics: trade, finance, decision-making under risk
Computational political economy: voting, institutions, norms, inequality
Computational linguistics: generative grammars, parsing, classifiers, inference
Social network analysis: connectivity, structure, evolution of the WWW, cyberwarfare
Computational anthropology: emergence of hierarchy, settlement patterns
Computational political science: systems of government, conflict and war, cooperation
Computational sociology: segregation, collective action, leadership, trust
Complexity theory: power laws, potential theory, criticality, bifurcation
Computational methodology: multi-agent systems, evolutionary computation, UML, GIS, visualization, sonification, computational epistemology

Admission Requirements and Procedures

The application deadline is February 1st of each year for students seeking financial aid, or April 1 for all other students.

Applicants should have as background a bachelor's degree in either one of the social sciences, in computer science, engineering, or in a relevant discipline, as well as undergraduate courses in these and related areas. Bachelor's degrees in the physical or biological sciences are also eligible, but applicant may be advised to take additional courses in social science or computer science as prerequisites to admission. Minimal requirements also include one undergraduate course in calculus and knowledge of a computer programming language preferably object-based. While in the program students are expected to develop significant expertise in the utilization of computational social science resources such as agent-based simulations or other computational tools. The program maintains a simulation environment, the Multi-Agent Simulator of Neighborhoods and Networks (MASON), in collaboration with the Evolutionary Computation Laboratory (EC Lab) of the Department of Computer Science. Mathematics training beyond basic calculus is not required, but may be useful in some areas of specialization.

For more information, please see http://www.css.gmu.edu/

Online applications can be submitted to http://admissions.gmu.edu/grad/.

Dynamic Modeling in a GIS Environment Seminars Online

2010-01-06T13:11:00.006-05:00

Just a quick post to highlight that the presentations from the "Dynamic Modeling in a GIS Environment" Virtual Seminars from the Global GIS Academy are now availble online. For those interested in GIS and various aspects of modelling these seminars give a glimpse into some current research.

Also if you like to look at online seminars the 2008 Autumn seminar series on Neogeography is also available.

modelling4All update

2010-01-04T13:23:00.007-05:00

I been following the progress of modelling4All for a while now and thought it worth highlighting again (click here to see an earlier post), especially after a post on the modelling4All blog noting some improvements.

The aim of modelling4All is to reduce the difficulty and effort needed to make agent-based models therefore enabling non-programmers to collaboratively build and analyze computer models. modelling4All allows one to create agent-based models over the web, models are constructed by composing and parametizing model fragments (bits of code) as shown in the movie below.

The model fragment library can be searched and model fragments can be added and combined to a model to create an agent-based model in a very short period of time by just clicking on the fragment (such as a behavior) which is required for the task at hand. Click here to see such a model, in this case its an epidemic model where people go to work, school, and home. A neat feature is also the ability to export the models as NetLogo models.

Oxford Circus pedestrian crossing opens

2009-12-02T10:58:00.000-05:00

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).

Agents on campus

2009-11-13T09:52:00.007-05:00

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.

TravellerSim: ABM for Growing Settlement Structures and Territories

2009-11-11T11:55:00.004-05:00

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.

TourSim: Agent-based modeling for Tourism Planning

2009-11-05T15:42:00.003-05:00

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.

Virtual Worlds for teaching GIS

2009-11-04T11:19:00.003-05:00

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).

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

2009-11-01T13:46:00.005-05:00

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 <http://jasss.soc.surrey.ac.uk/12/4/10.html>.

Visualisation in support of management decisions

2009-10-09T09:14:00.002-04:00

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.

SYMAP movie

2009-10-08T16:24:00.002-04:00

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

2009-10-08T16:06:00.003-04:00

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.

Critical mass: When does a crowd become dangerous

2009-09-13T11:20:00.002-04:00

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.

AAG SPECIAL SESSION: Modeling Geographic Complexity

2009-09-03T10:48:00.006-04:00

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

LOCATION AND DATES:
Association of American Geographers Annual Meeting
April 14-18, 2010, Washington, DC, USA

SPONSORS:
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.

DESCRIPTION:

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:

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.
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.
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 <http://www.aag.org/annualmeetings/2010/papers.htm#instructions>. 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.

ORGANIZERS:

Arika Ligmann-Zielinska, Michigan State University <ligmannz@msu.edu>
Andrew Crooks, George Mason University <acrooks2@gmu.edu>
Alison Heppenstall, University of Leeds <A.J.Heppenstall@leeds.ac.uk>
Moira Zellner, University of Illinois at Chicago <mzellner@uic.edu>
Suzana Dragicevic, Simon Fraser University <suzanad@sfu.ca>,

TIMELINE:
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 www.aag.org. 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

Jobs at CASA

2009-08-26T11:13:00.000-04:00

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.

New Publication: Random planar graphs and the London street network

2009-08-24T09:38:00.002-04:00

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 Meridian^TM 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:
A.P. Masucci, D. Smith, A. Crooks and M. Batty (2009) Random planar graphs and the London street network, Eur. Phys. J. B (2009) DOI: 10.1140/epjb/e2009-00290-4

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

The spread of pandemics

2009-08-21T08:51:00.009-04:00

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.

New paper: NeoGeography and Web 2.0

2009-08-13T12:49:00.003-04:00

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 and can not access it, drop us an email.

Partitioning Space to generate urban spatial patterns.

2009-08-09T13:48:00.000-04:00

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.

Treemaps: Hierarchical Layouts to Address Research Questions

2009-08-08T08:01:00.003-04:00

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: http://www.gicentre.org/hierarchical_layouts/.

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.

Agent-based models in Nature

2009-08-05T18:47:00.004-04:00

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.

Book Review: The Dynamics of Complex Urban Systems

2009-07-30T18:40:00.006-04:00

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.

References

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

2009-07-30T12:51:00.008-04:00

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 (www.sciencep.com), 350 pages, hardcover. For more information, contact the responsible editors Peng Shengchao and Guan Yan, Science Press (e-mail: guanyan@mail.sciencep.com)."

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

Au revoir CASA

2009-07-30T07:01:00.000-04:00

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...

Modelling large crowds

2009-06-25T07:28:00.003-04:00

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:

Reference

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

Geospatial Analysis 3rd Edition

2009-06-22T06:25:00.005-04:00

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 .

Where 2.0 Conference Talks

2009-06-18T06:32:00.005-04:00

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."

World's Most Realistic 3D City Models?

DIY City: An Operating System for Cities

Useful Link:
GIS and Science blog

SLEUTH model used in Finland

2009-06-15T08:38:00.007-04:00

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

Game of Life on a globe

2009-06-10T10:15:00.006-04:00

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.

Modelling Housing Markets

2009-06-09T05:56:00.002-04:00

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.

Micropolis: Open source SimCity

2009-06-08T08:37:00.007-04:00

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.

References:

Adams, P.C. (1998), 'Teaching and Learning with SimCity 2000', Journal of Geography 97(2): 45-55.
Wikipedia entry on SimCity

Agent Analyst movies

2009-05-22T10:00:00.004-04:00

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

2009-05-22T07:30:00.008-04:00

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.

NetLogo to 3D Max

2009-05-20T04:57:00.003-04:00

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.

Update: Agent-based models in Second Life

2009-05-19T09:46:00.002-04:00

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.

SIMPOP Models

2009-05-15T06:31:00.000-04:00

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).

Tracking Pedestrians

2009-05-14T07:04:00.006-04:00

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.

References

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

The Urban Experience

2009-04-27T10:15:00.006-04:00

Reading up on American cities, I just come across a very interesting book entitled "The Urban Experience: Economics, Society, and Public Policy" by Barry Bluestone, Mary Huff Stevenson and Russell Williams.

The books description: The Urban Experience provides a study of metropolitan areas by combining economic principles, social insight, and political realities with an appreciation of public policy to understand how U.S. cities and suburbs function in the 21st century (click here to read more).

New Paper: Mapping for Masses

2009-04-24T06:16:00.004-04:00

Andrew Hudson-Smith, Michael Batty, Richard Milton and myself from CASA have just found out that our paper "Mapping for the Masses Accessing Web 2.0 Through Crowdsourcing" in Social Science Computer Review which comes out later this year can be downloaded from OnlineFirst.

For those interested the abstract is:

"The authors describe how we are harnessing the power of web 2.0 technologies to create new approaches to collecting, mapping, and sharing geocoded data. The authors begin with GMapCreator that lets users fashion new maps using Google Maps as a base. The authors then describe MapTube that enables users to archive maps and demonstrate how it can be used in a variety of contexts to share map information, to put existing maps into a form that can be shared, and to create new maps from the bottom-up using a combination of crowdcasting, crowdsourcing, and traditional broadcasting. The authors conclude by arguing that such tools are helping to define a neogeography that is essentially ‘‘mapping for the masses,’’ while noting that there are many issues of quality, accuracy, copyright, and trust that will influence the impact of these tools on map-based communication."

Keywords: network economies; web-based services; map mashups; crowdsourcing; crowdcasting; online GIS.

The paper can be downloaded from here.

Pedestrian modelling of Oxford Circus redesign

2009-04-15T05:20:00.000-04:00

Oxford Circus in London is a busy intersection between Regent Street and Oxford Street with more than 200m visitors a year (BBC). Work is to begin on a £5m project to pedestrianise part of Oxford Circus. Based on crossings in Tokyo, the new design will stop all traffic in all directions, and allow people to cross diagonally as well as straight ahead. Street clutter and barriers at the junction of Oxford Street and Regent Street will also be removed.

Graphic showing the Oxford Circus redesign

Why blog about this? The movie below created by Designhive shows how Atkins' two-dimensional traffic and pedestrian models can be coupled with 3D Studio Max in such a way it is difficult to distinguish the model from a real piece of video footage. Combining the models in the simulation in this way makes the finished product particularly compelling. Furthermore it has the benefit of being based on the technical models developed to test the proposals prior to their implementation (such as the removal of street clutter).

The pedestrian model is a particle-based system controlling 5000 agents to match up the data produced by Atkins Intelligent Space. When the final simulation was rendered, the 'particles' were replaced with animated people, programmed to walk while the points were moving and idle when the points stopped for traffic lights.

Thanks to Duncan Smith for flagging this. Further information: