Networks in Space, Mark Newman, netsci08

Mark Newman, Networks in Space,

This is about networks in geographic space.

Mark is looking at properties of networks that are tied to geography.

Transport networks are a good example, and we are looking at the

difference between road and air networks.

The road and air networks are very different, even though you use both

of them for getting from A to B.

There is different bahviour, could I say 'driving' the use of these

networks. For roads we want to minimze the length of our journey, but

that's not such an important factor in flight journeys. When we fly we

like to take direct flights, and minimize the number of flight hops that

we take.

If you model this behviour you get out networks that look a lot like

road and flight networks.

Their first model looked at connecting randomly distributed nodes.

In order not to get influenced by population density they made a map

that is rescaled by population density. This is called a cartogram.

You can see some really nice election cartograms that Newmann and

Gastern made here: http://www.cscs.umich.edu/~crshalizi/election/

There is a really nice historical example from Raisz from the

Geographical REview from 1943.

It looks like most recent attempts have been hand-drawn, but they look

pretty shit.

Newman and Gastner made a difffusion algorithm that allows you to do

this quickly.

OK, it looks like this started off as a network talk, but segwayed into

a demo of this mapping technique. Ahh, no, we are back to looking at

airports.

The interesting result from this talk is that the best covering fro

utilities such as airports or post offices does not grow lineraly with

popultaion, but to the power of 2/3.

This was also a pretty nice talk.

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