Research
My research has been much interdisciplinary or cross-disciplinary in nature. I looked at urban structure and dynamics using massive geographic information and based on complexity modelling tools such as agent-based modelling and complex networks. In particular, I developed a topological analysis of urban street networks, and found some interesting scaling pattern, as demonstrated in many other complex networks including biological, information and technological. My recent work based on 40 US cities illustrated a universal pattern that can be simply, yet elegantly, characterized by the 80/20 principle, i.e. 80 percent of streets are less connected (below the average), while 20 percent of streets are well connected (above the average); out of the 20 percent, there is 1 percent of streets that are extremely well connected. More recently, we have explored such street hierarchies based on massive GPS tracking log, and proved that streets are indeed hierarchically organized in the sense that a minority of streets accounts for a majority of traffic flow. All the research leads to the belief that cities, although artefacts in nature, are self-organized in the same way as biological entities.
Relevant websites of projects I involved in the past include Town Centres project, VENUE project , and agent-based modelling.
Herewith a few screenshots and links
(GPS traces showing a street hierarchy)
(The University of Gävle campus in 3D view)
(The city of Gävle in 3D view)
(Street topology in 3D view)
