Friday, September 24, 2010

Space-Time Dynamics in Scaling Systems

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

Wednesday, September 15, 2010

Geospatial Revolution - Episode 1

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"

Wednesday, September 08, 2010

A prototype migration model

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:

Rouly, O. V. and Crooks, A. T. (2010), A Prototype, Multi-agent System for the Study of the Peopling of the Western Hemisphere, in Ernst, A. and Kuhn, S. (eds) Proceedings of the 3rd World Congress on Social Simulation (WCSS2010): Scientific Advances in Understanding Societal Processes and Dynamics, Kassel, Germany. (pdf

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.


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

Monday, September 06, 2010

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

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.

Full Reference: 
Anand, S., Batty, M., Crooks, A. T., Hudson-Smith, A., Jackson, M., Milton, R. and Morley, J. (2010), Data Mash-ups and the Future of Mapping. Joint Information Systems Committee (JISC) Technology and Standards Watch (TechWatch) Horizon Scanning report 10_01, Bristol, England. (pdf)