The family name distribution in Korea is investigated in comparison with previous studies in other countries. In Korea, both the family name and its birthplace, where the ancestor of the family originated, are commonly used to distinguish one family name from the others. The family name...

Threshold models try to explain the consequences of social influence like the spread of fads and opinions. Along with models of epidemics, they constitute a major theoretical framework of social spreading processes. In threshold models on static networks, an individual changes her state if a...

Contact networks are extracted for 295,108 inpatients over a two-year period from a database used for administering a local public healthcare system that serves 1.8 million individuals in Stockholm county. Structural and dynamic properties of the network that are important for the transmission...

The central points of communication network flow have often been identified using graph theoretical centrality measures. In real networks, the state of traffic density arises from an interplay between the dynamics of the flow and the underlying network structure. In this work we investigate the...

We investigate the behavior of a threshold model for the spreading of fads and similar phenomena in society. The model gives the fad dynamics and is intended to be confined to an underlying network structure. We investigate the whole parameter space of the fad dynamics on three types of network...

The graph-navigability problem concerns how one can find as short paths as possible between a pair of vertices, given an incomplete picture of a graph. We study the navigability of graphs where the vertices are tagged by a number (between 1 and the total number of vertices) in a way to aid...

Recently there has been a tremendous interest in models of networks with a power-law distribution of degree—so-called “scale-free networks.” It has been observed that such networks, normally, have extremely short path-lengths, scaling logarithmically or slower with system size. As an...

Most research of online communication focuses on modes of communication that are either open (like forums, bulletin boards, Twitter, etc.) or direct (like e-mails). In this work, we study a dataset that has both types of communication channels. We relate our findings to theories of social...

Data sets of online communication often take the form of contact sequences—ordered lists contacts (where a contact is defined as a triple of a sender, a recipient and a time). We propose measures of attractiveness and activity for such data sets and analyze these quantities for anonymized...