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Tag "network"

Ever wondered why the suggestions on shopping websites such as amazon or ebay more often than not appeal to you? Most links are targeted and do related to recent activity linking activity and interest together.

Amazon’s recommendations for products especially books works as a network of relations and starts to groups together similar interest areas. This is based on cross user activity and behaviour with a learning environment. One purchase leads to another and so on.

Christocper Warnow has looked int o creating a network visualisation for the amazon recommendation service and has written a Processing app making use of the open source Gephi API. The tool can take a web link to a book on amazon and create a network around it for up to 100 recommendations associated with the publication.

The tool can be downloaded HERE for a test. It rus in real time and the process of building the network is unfolding on screen, quite interesting to follow. The tool allows for zooming in/out and hovering for information as well as an pdf export function of the created network visualisation.

Image by Christopher Warnow / Recommendation network on amazon.de for Linked

Image by Christopher Warnow / Recommendation network on amazon.com for Linked

Interesting are the differences between the amazon online stores. Warnow points out that there are connection recommendation differences between for example the .de and the .com store in some examples: “I wanted to compare the recommendations given by amazon.de and amazon.com. And another surprise waited. The milieus looked different. The Germans are connecting postmodernism with Deleuze, the buyers from amazon.com are thinking more about the French situationist movement. I tested it again with the awesome book Linked by Albert-Laszlo Barabasi. The similarities are the complex theory and network dynamics. But the differences are interesting as well. The English milieus contain politics and collective systems, where as the Germans are more into successful marketing and economics.”

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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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How does the social network link location as people communicate? It would be very interesting to see how communication pattern link to location and context.

There is already quite some good stuff on this topic. Only recently John Reads defended successfully his PhD on a topic in this field. He was looking at telecommunication patterns in the South East and London region base on land line connections. He found some interesting patterns of linkages and hubs and was able to identify regions according to dominant trades. Also some landscape features showed up. For example the Thames was acting as a barrier even in the realm of phone call connections.

The TwitterNetworks of London, San Francisco or Munich generated from the NCL datasets are quite interesting where we can see how individuals are connected via interaction on te Twitter plattform using @-tweets and RT-tweets. The networks are built establishing the edges using these two direction indicators. Other networks based on twitter data have been focusing on institutions and text as with the ‘Why Mediate Art‘ project.

Image by urbanTick for NCLn / Circular graph showing the connection between the data sets collected for different urban areas in Switzerland. No connections between them exist, each one operates separate.

Recently the NCL network ha been looking at areas in Switzerland and mapped out the four large urban areas Zuerich, Geneva, Basel and Bern. Overall it is quite visible that Twitter is not as popular as it is in other parts of the world. It is still sort of seen as a time waister and something for nerds. This was aso reflected in the language settings with foreign languages dominating the fields. It seems quite popular with people to keep in touch with other parts of the world.

Switzerland is quite small and the linkages between the cities are well established. This is supported by a perfect public transport network and a wealth of political mechanisms to ensure equality and exchange. However socially of course the different languages to separate different communities. French is spoken in the West, German in central and North and Italian in the South of Switzerland. In the middle of sorts there is the dominating geographical landscape feature, the alps acting as barriers.

This complicated setting of barriers and ties makes Switzerland an interesting study object for social networks. It would be great to see how the different urban areas connect via individuals on social networking platforms.

Regarding our Twitter data we have two data sources. One is the individual records for each urban area over the period of one week, the other is a week long record of location based tweets sent across the whole of Switzerland including the south of Germany and the north of Italy with Milan.

Image by urbanTick for NCLn / Showing the social connections as found on Twitter within Switzerland. Data based on a location based Twitter record over the period of one week.
The alps in the centre act as barrier with only a few connections crossing them, either via a celebrity Twitter account, in this case Justin Biber and Jessica Alba or physical travel.

Looking at the first data set with individual records for each urban area, the networks separate out each city with no established connections between them. It was sort of expected, since the sample is small and the parameters are tight with only location based tweets.

Looking at the second dataset where the whole area was simultaneously recorded the big barriers show up clearly and there is a well established separation between North and South showing the alps as mountainous Twitter blockers. Interesting however, are especially the links across this barrier and there are some. Three links connect the norther part consisting of Geneva, Basel, Bern, Zuerich and southern Germany with the southern part consisting of Milan, Como and Turin. They represent different types.

The first type is the link via a common third party that is not necessarily in the area. This is most likely a very active and popular twitter acount. In this case there are three celebrities that establish the connections. They are Justin Biber, Jessica Alba and some guy Kenny Hamilton. These are the hubs that individual Twitter users from both sides of the mountains tweet at and establish a sort of second grade connection.

There is also the other type of first hand connections. this is established by an individua traveling around and tweeting both to connections in Milan, the southern part and users in Zuerich, the northern part. The fact that the individual has actually physically traveled between the two parts enforces these connections.

Image by urbanTick for NCLn / Switzerland with the locations of recorded tweets. This has been collected over a period of one week. The purple line shows the route travels by one individual users tweeting along the way and interacting with other user from both sides of the mountainous barrier.

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Milan based Mousse magazine is running a series with the title ‘Ten Fundamental Questions of Curating‘. The editor of the series, Jens Hoffmann explains: “it emerged from a desire to trace the coordinates of contemporary curatorial practice, to take stock of a profession that is constantly evolving. Through the contributions of ten curators, the ten essays in the project examine ten fundamental themes in curating. The booklets are structured as hypothetical chapters in a book that once completed, through the reflections of some of the leading figures in the contemporary scene, will try to offer an answer to the question of “what it means to be a curator today”

I was invited by the London based artist Marysia Lewandowska to collaborate on her contribution to the fourth edition.

Mousse 4/10 Why Mediate Art?
Image taken from Mousse / Page one of ‘4/10 Why Mediate Art?’.

The fourth instalment of “Ten Fundamental Questions of Curating” looks for an answer to the question “Why Mediate Art?”. The editor Jens Hoffmann invited Maria Lind to contribute who in turn proposed to work with Marysia Lewandowska as an artist curator collaboration. In her text Maria Lind examines the seeming paradoxes that revolve around art institutions: an overabundance of traditional educational activities, aimed at engaging an ever broader public; marketing departments and press offices that take on a strategic role; curators who have no real interest in making their project known outside the professional sphere. The Swedish curator explains the importance of weaving connections between works, curatorial projects and the public, for a new kind of artistic “mediation”. Marysia Lewandowska proposal extends the meaning of mediation in our networked culture by connecting the ‘followers’ of major contemporary art museum and public galleries and Maria Lind’s text through twitter.

Mousse 4/10 Why Mediate Art?
Image taken from Mousse / Page one of ‘4/10 Why Mediate Art?’. Click Image for the interactive version.

This is the time when art is mediated to its audience not only through lectures, seminars, artists’ talks, guided tours and publications but when mediation intervenes as a pulsating stream of immediacy, mixing the promotional intentions of the institution with the visitors’ desires of sharing their observations and responses. The banal is closely entangled with the political, the randomness is attached to a system as announced by the ubiquitous banner: Twitter is a rich source of instantly updated information. It’s easy to stay updated on an incredibly wide variety of topics. By utilising the social networking platforms such as Facebook, YouTube and Twitter that emerged over the past few years, the communication between the art institutions and their audiences has grown into a real time stream of information snippets.

Interactive version created by urbanTick using the GMap Image Cutter / Twitter Education. Tweets collected using 140kit, to visualise the network Gephi was used. Click HERE for the full screen version.

What appears on the visuals are graphs mapping tweets sent by three major art institutions, Tate in London, MOMA in New York and Moderna Museet in Stockholm to communicate and mediate their activities as they are enmeshed together with Maria Lind’s text. The two text streams have been aggregated as a word chain, where each word is connected with a link to the following word in the sentence. Each word is represented only once as a node in the chain, but in many cases with multiple connections, edges, to the following words. The resulting visualisation is of a network based on the structure of the words in use. The two different sources are distinguished where red lines represent the links between the words in the tweets sent by the art institutions, while the black lines show the flow of the essay written by Maria Lind. The tweets cover the period between 2009-09-16,15:18 and 2010-11-29 16:03.

Mousse 4/10 Why Mediate Art?
Image taken from Mousse / Page one of ‘4/10 Why Mediate Art?’. Tweets collected using 140kit, to visualise the network Gephi was used. Click Image for the interactive version.

For artist Marysia Lewandowska the mapping of this flow expresses a desire and interest in distributive networks without restriction; it is the desire of being in touch and engaged, of organising one’s thoughts and sharing them instantly. The knowledge ecologies of a wider world intersect in unexpected ways and point to the role mediation plays in shaping our current social and political life.

Publication – Mousse, Editor – Jens Hoffmann, Text – Maria Lind, Art – Marysia Lewandowska, published 2011.

Ten Fundamental Questions of Curating, edited by Jens Hoffmann and published by Mousse in collaboration with the Fiorucci Art Trust, is distributed with the international edition of Mousse and with subscription copies.

Interactive version created by urbanTick using the GMap Image Cutter / Twitter Education. Tweets collected using 140kit, to visualise the network Gephi was used. Click HERE for the full screen version.

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The news that Egypt has gone of the internet last Thursday night, stunned the internet community. The news swooshed around quickly and questions were asked. How is this possible, is there a switch?

Over the past years we have learned to appreciate the net as a distributed network of hubs and servers with its own rules. Those being that the internet is not centrally managed and therefore very difficult to govern, even navigate. However, the net of nets is still connected via physical routers, as Andrew Blum in post over at the Atlantic points out.

The move by the Egyptian government was intended to help regain controle over the masses of people who protested for change on the streets of the major cities. The government seemed to believe that the internet and especially social media platforms such as Facebook a and Twitter are increasingly playing a role in the organisation of protests. Cutting Egypt off the web would leave the protesters unable to organise themselves.

Shortly after midnight, about 22h00 UTS, the Egyptian internet providers were asked to take down their routers. One after the other, over a timespan of about 20 minutes, went offline. As a result international IP addresses were unavailable from Egypt.

Image taken from renesys.com / The following plot shows the number of available networks for each of the significant providers, between 22:00 and 23:00 UTC last night (midnight to 1am Cairo time). Our new observation is that this was not an instantaneous event on the front end; each service provider approached the task of shutting down its part of the Egyptian Internet separately.
Telecom Egypt (AS8452), the national incumbent, starts the process at 22:12:43. Raya joins in a minute later, at 22:13:26. Link Egypt (AS24863) begins taking themselves down 4 minutes later, at 22:17:10.
Etisalat Misr (AS32992) goes two minutes later, at 22:19:02. Internet Egypt (AS5536) goes six minutes later, at 22:25:10.

The New York Times called it “Egypt, to an unprecedented extent, pulled itself off the grid.” and Jim Cowie, chief technology officer of Renesys said “In a fundamental sense, it’s as if you rewrote the map and they are no longer a country.”

The controle of internet content as well as accessibility is not new. Countries around the globe have developed different methods to do this. The most prominent examples are China or Iran, where twitter in 2009 played an important role in organising the political protests as well as distributing information after a disputed election. Earlier urbanTick coverage on mashups HERE.

As part of the New City Landscape (NCL) project we are collecting location based tweets in urban areas. For the last week we also recorded twitter activity in Cairo. And surprisingly twitter activity does not reflect the sudden drop off of international internet connection from Egypt. There is no dramatic reduction of tweets, however there is a continuous reduction of tweets reflected in the data. Over the past five days the location based twitter activity in Cairo has gone from about 250 to 300 messages per hour on Tuesday 27th and Friday 28th down to spikes of 50 on Monday the first of February.

Graph by urbanTick / Tweets collected using the TOM tool written by Steven Gray. The tool collects geolocated tweets originating within a 30km radius around the centre of Cairo. The graph shows number of tweets sent per hour.

This is not exactly as expected. There are different possible explanations for this. One of them could be that the internet is a difficult beast to tame and a few routers down don’t mean the end of this versatile construct. Via very slow channels it must in this case still be possible to send mainly mobile tweets, even though mobile networks were also reported partially down.

Then on the first of February new information circulated the news channels. Google has put live a new service to allow people in Egypt to tweets via a phone call. After calling a speciall number, +16504194196 , +390662207294, +97316199855, a message can be left that will be posted as a tweet including the hashtag #egypt. The tweet will contain a link to the recorded message. Messages are pushed through this speakToTweet account. Somehow a very political move “We hope that this will go some way to helping people in Egypt stay connected at this very difficult time. Our thoughts are with everyone there.”

Regarding out NCL collection this would not change anything since we are only looking at actual geolocated tweets send with Lat/Lon information included.

According to Renesys, Egypt has just this morning around 09h32 UTS returned to the internet after an absence of almost a week. How this will affect the tweeting activity we will see by tomorrow. It will be interesting to see weather this brings back up the numbers to a level of around 100 tweets per hour, we will see. New data and NCL maps are under way.

Image taken from renesys.com / All major Egyptian ISPs appear to have readvertised routes to their domestic customer networks in the global routing table, with the exception of Noor Group (AS20928). Recall that Noor was the exception (until Monday) to the Internet blackout, so they are as much an anomaly in restoration as they were in outage. (Update: Noor group back online with a full complement of prefixes as of 12:52pm Cairo time. Better late than never.)

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The rise of network research and visualisation in the past ten years was dramatic. From initial ideas and clunky software programs we now see a number of great open source platforms appearing.

The concept of network visualisation is rather simple, there are two elements, nodes and they have a relationship, called edge. From here both nodes and edges between them are added and complicated systems can be represented in terms of how the identified elements are connected, simple.

Nicholas Christakis talks in his TED talk at the top of his voice about the basics of social networks and outlines the dreams, implicating the power of network.

However this is on the visualisation level, where it looks simple. The real task lies before and after this. How are the nodes and edges actually defined and identified in the run up to the funky visualisation of clusters and groups? This question in both a practical definition sense as well as in a technical sense of how is the input file generated is the real task.

This is to some extend reflected in the file standards of these network visualisation softwares, there aren’t any. The whole area might be to young and the big player is missing, like ESRI in GIS or Autodesk in CAD. This might be part of the explanation, but the other part is that the simplicity of node and edge hasn’t put pressure on the file formats.

Since last year the Gephi platform is setting standards for this group of open source network visualisation softwares. It offers great functions and juicy looking visuals with a easily manageable interface.

Developed by a consortium of universities and research companies, including the University of California San Francisco and the University of Toronto, comes a second very powerfull and flexible network software called Cytoscape. The software is not new as new, development reaches back to 2002 where version v0.8 was released. Currently version 2.8 is available for download and work on version 3.0 in underway although there is no release date as of now.

Image taken from cytoscape / Visualization of Gene Ontology Term Tree (DAG). More images can be fond in this flickr group

Cytoscape initially was developed for biology and molecular research, has however developed into a multipurpose network visualisation platform. The software is JAVA based and therefore rund across platforms with a lot of plugIns freely available. Basicaly everyone can contribute their own plugIns.

Cytoscape suport variety of standarts, see above, but for quick and dirty the text or table import is extremely useful. If you have a table or CSV with three columns, defining the start node end node and the type of relationship you are good to go. This addresses some of the issues discussed above.

Running the visualisation algorithms can be processing intensive especially once the network goes above 10’000 nodes. Here Cytoscape performs very good also from a interface perspective. The progress is clearly indicated and each process can be stopped at anytime. Usually it is very stable and would not crash on you all of a sudden, even with large network calculations.

The package comes with a lot of preset layout algorithms. These sets hold the definitions of how the graph is going to evolve and the nodes and edges are laid out. The selection ranges from force directed, weighted to circular or grid layouts. Each preset layout can be fully adjusted.

Regarding the visualisations graphically, here Cytoscape is extremely flexible and every single aspect of the graph can be manually set. This is great and makes for a dramatic flexibility, but on the other hand it is painstakingly difficult and time consuming. Especially if working on a dataset early on and results are not yet clear it is not were you put your effort and ugly visuals can be depressing.
Anyway the great examples on the website should be consulted for motivation.

Some of the other great features include Cytoscape works as a Web Service Client, great search functionality for nodes and edges as well as extensive filter functions, useful not only to hide or show, but to highlight. Furthermore it allows for custom node representation. This means Cytoscape can display images and icons individually for each node. Cytoscape also supports networks within networks, quite a tricky thing.

Image by urbanTick / Visualisation of two text snippets as a network.

Two things are crucial now that the data is compiled and graphed, the analysis and the output. In both cases Cytoscape is very powerful. Extensive analysis function very detailed spits out numbers and even puts them on graphs. All these tables and calculations can be exported too to further analysis in external packages. Regarding the output of the graph a palett of formats are offered, covering both image formats as well as graphic formats such a s PDF, EPS and SVG.

If you are into network visualisation and keen on a good alternative to established packeges such a Pajek this might be one for you. More recources on Cytoscape can be found on pubMed or GenomeResearch.

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