Wednesday, August 26, 2009

Jobs at CASA

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

Click here for further details.

Monday, August 24, 2009

New Publication: Random planar graphs and the London street network

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

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

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

Below is the abstract:

"In this paper we analyse the street network of London both in its primary and dual representation. To understand its properties, we consider three idealised models based on a grid, a static random planar graph and a growing random planar graph. Comparing the models and the street network, we find that the streets of London form a self-organising system whose growth is characterised by a strict interaction between the metrical and informational space. In particular, a principle of least effort appears to create a balance between the physical and the mental effort required to navigate the city."

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

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

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

Friday, August 21, 2009

The spread of pandemics

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

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

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

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

Thursday, August 13, 2009

New paper: NeoGeography and Web 2.0

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

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

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

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

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

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

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

Sunday, August 09, 2009

Partitioning Space to generate urban spatial patterns.

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

The abstract of their paper is:

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

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

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

Saturday, August 08, 2009

Treemaps: Hierarchical Layouts to Address Research Questions

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

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

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

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

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

Wednesday, August 05, 2009

Agent-based models in Nature

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

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

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