Network ensemble clustering using latent roles
2010, Brandes, Ulrik, Lerner, Jürgen, Nagel, Uwe
We present a clustering method for collections of graphs based on the assumptions that graphs in the same cluster have a similar role structure and that the respective roles can be founded on implicit vertex types. Given a network ensemble (a collection of attributed graphs with some substantive commonality), we start by partitioning the set of all vertices based on attribute similarity. Projection of each graph onto the resulting vertex types yields feature vectors of equal dimensionality, irrespective of the original graph sizes. These feature vectors are then subjected to standard clustering methods. This approach is motivated by social network concepts, and we demonstrate its utility on an ensemble of personal networks of migrants, where we extract structurally similar groups and show their resemblance to predicted acculturation strategies.
Recognizing modes of acculturation in personal networks of migrants
2010, Brandes, Ulrik, Lerner, Jürgen, Lubbers, Miranda J., McCarty, Chris, Molina, José Luis, Nagel, Uwe
An individual's personal network encodes social contacts as well as relations among them. Personal networks are therefore considered to be characteristic and meaningful variables of individuals supplementing more traditional characteristics such as age, gender, race, or job position.
We analyze an ensemble of several hundred personal networks of migrants using a recently introduced classification method. As a result, individuals are partitioned into groups defined by similarity of their personal networks, and abstract summaries of classes are obtained. From the analysis we can conclude that Berry's modes of acculturation feature prominently in the empirical data.
Pure spreading activation is pointless
2009, Berthold, Michael R., Brandes, Ulrik, Kötter, Tobias, Mader, Martin, Nagel, Uwe, Thiel, Kilian
Almost every application of spreading activation is accompanied by its own set of often heuristic restrictions on the dynamics. We show that in constraint-free scenarios spreading activation would actually yield query-independent results, so that the specific choice of restrictions is not only a pragmatic computational issue, but crucially determines the outcome.