Wednesday, 3 August 2011

Networks Networks


The main buzz word of the 2011 discussion in urban and spatial research is networks. Networks start to appear everywhere and everything is linked in to most other things. This is however, in fact not new. The network discussion has started at least ten or fifteen years ago.

It is very fascinating how network are entering the repertoire of scientists and with the tools to construct analyse and draw them more and more data is analysed towards its network structure. Some of the platfomrs like Gephi or Cytoscape, but also the integration of network analysis capacity with existing software such a GeoTime in version 5.1 makes this emerging branch accessible to a wider research community. The basic elements of nodes as the actors and links as the activity are a pretty simple, but very powerful way of describing very complex structures.

Some three interesting examples of recent weeks shall be presented in the following. The examples chosen are very divers, but show how the term and the idea is unfolding in many disciplines leading to new discoveries of previous unknown aspect. This is not to dismiss anything known previously, but to add another puzzle piece to the picture from a 'network' perspective.

15m social network
Image taken from 15m.bifi.es / The figure represents the evolution of the network of Twitter users that exchange messages during the 10 days following the beginning (May 15, 2011) of camp in Puerta del Sol in Madrid, Spain. Each node in the network represents an individual, and the node size is proportional to the total number of messages he/she sent or received in the period analyzed. Two nodes are connected if they have exchanged at least one message. The colors encode the "age" of the node: the first active users are represented in yellow, while black color is used for the latecomers..

Social network analysis i probably the biggest and most obvious branch of network analysis. Since the concept of social connection is part of our everyday experience this is the area easies accessible for a general audience. With the data from digital social networks becoming available as for example the NCLn maps using Twitter show or also the Facebook global connection by Paul Buttler it is opening new possibilities for social sciences. The overwhelmingly massive amount of detail could potentially provide a different understanding of social mechanisms.

The project by he BIFI (Institute for Biocomputation and Physics of Complex Systems) is focusing on Twitter data collected between end of April and beginning of May 2011 during the youth movement 15m in Spain. The researchers have collected data over a period of three weeks as the activities are unfolding on Twitter across the country. The visualisation show how the information spreads across the digital social network, more and more groups joining in pushing the converation and the use of specific # hash tags as indicators. In total, 581.749 messages coming from 87.569 users were identified and used for the study.


Clip taken from 15m.bifi.es / video is a visual representation of the tweets exchanged between users involved in the 15M movement. All the information received/generated reflect the actual spreading dynamics in the period analysed.

Another obvious source of network information is to be found in science itself, mapping out the collaboration across the world. The institutions or the individual research groups can act as nodes and a collaboration is establishing a link between the nodes. Similar scientific citation are another established source of network data.

A lot of this work has been collected and presented in the MIT publications Atlas of Science by Katy Boerner. An online version of a research collaboration from 2005 to 2009 network is computed by Olivier H. Beauchesne at Science-Metrix, Inc. At wired explains "analysed the extracts of all of these articles to find where there was collaboration. So if a Cambridge University researcher published a paper with a colleague at the University of Arizona then that would create the pairing of Cambridge and Tuscon."

global science collaborations
Image taken from flowingdata / Map showing global science collaborations. Click for full screen interactive version.

In a third example scientist have discovered network of trees. In which the threes are actively exchanging and scientists believe that this network provides an advantage to connected trees over unconnected tree of the same species in the same area. The soundfoundation explains: "Graduate student Kevin Beiler has found that all trees in dry interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests are interconnected, with the largest, oldest trees serving as hubs, much like the hub of a spoked wheel, where younger trees establish within the mycorrhizal network of the old trees." The original presentation can be found here. It is pretty amazing that networks form such a fashion between plants previously thought of as static and dull in a spatial activity sense.

Tree network
Image taken from abject.ca / Map showing connected and unconnected trees in the study area.

The networks can extend to many other areas and the built environment being on of them. Just like the trees the buildings are al interconnected with a network of cables and pipes, services and goods, linking across the city and the country. In this context one of the obvious example is the transport network and how a bus service links to a tub service bringing you to your destination via a short walk some gates and Oyster card operated barriers. At CASA, Jon Reads is currently working with some Oyster Card data visualising and analysing public transport networks across London. There is definitely more to come in this area in the next few weeks and month.

London public transport network
Image taken from Simulacra Bog / Map showing Central London Detail of public transport network based on TfL segments.

Networks will be with us for the foreseeable future being stronger an stronger embedded in out everyday thinking of objects and actions. It is definitely linking into a growing awareness of connectivity very much in line with the current sustainability debate as well as the of similar age system thinking theories.

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