Flows Across Scales

At the Complex-City Workshop held at the Tinbergen Institute in the Free University of Amsterdam held 5-6 December 2011, CASA presented a variety of papers. Alan Wilson presented a paper by Hannah Fry and himself on a 4 sector world trade model calibrated so far on 50 countries. The model essentially computes demand for trade across the four sectors and then balances demand and supply keeping supply fixed and adjusting demand using the balancing factor as prices. This deals with the fast synamics and thence it is embedded into a slower dynamic framework based on Lotka-Volterra dynamics that adjust supply in which prices are also key.

Francesca Medda presented a model of urban evolution based on Turing’s morphogenesis ideas showing how shocks could rock the locational dynamics which emerge in a hypothetical world of locations around a central business district. Mike Batty presented his speculation that there are seven laws of scaling, a variant of his paper last week to the Scaling in Social Systems conference at Oxford (click here for the pdf) and today Simone Cashili’s paper with Alessandro Chessa and Andre de Montis on commuter networks and community detection will be presented by Andrea. Papers will be posted in due course and will be published in various forums’.

 As an adjunct to our concern for flows across space, Joan Serras on CASA’s SCALE project has generated some interesting visualising of food aid which we will post here very soon. These parallel the flows of food which is one sector in the Fry-Wilson model noted above