Recently, many Web services such as social networking services, blogs, and collaborative tagging have become widely popular. Many attempts are being made to investigate user interactions by analyzing social networks among users. However, analyzing a social network with attributional data is often not an easy task because numerous ways exist to define features through aggregation of different ta...

One way of getting a better view of data is by using frequent patterns. In this paper frequent patterns are (sub)sets that occur a minimal number of times in a stream of itemsets. However, the discovery of frequent patterns in streams has always been problematic. Because streams are potentially endless it is harder to say if a pattern is frequent or not. Furthermore, the number of patterns can ...

Obtaining user opinion (using votes) is essential to ranking user-generated online content. However, any content voting system is susceptible to the Sybil attack where adversaries can out-vote real users by creating many Sybil identities. In this paper, we present SumUp, a Sybilresilient vote aggregation system that leverages the trust network among users to defend against Sybil attacks. SumUp ...

This paper summarizes randomized experiment to study the effects of an Internetbased intervention on type 2 diabetes patients in Montevideo, Uruguay. The intervention consisted of a specially designed website and an electronic social network where participants were able to navigate freely, download materials, and interact with other diabetics and with specialists. No significant impact was foun...

In this paper we describe Digg, a successful social news aggregator web site. Digg allows users to submit links to news stories, as well as vote and comment on other submitted stories. It also enables users to designate other users as friends and makes it easy to track their activities, thereby creating a social network within Digg. We perform a statistical analysis of a sample of 1000 popular ...

Data in the form of approximately 5 million No Limit Texas Hold’em hand histories collected from the online poker website PokerStars.com is used to model a game playing social network. Each player represents a node in the network, and weighted, directed edges represent the flow of money from the source to the target node, where the weight is equal to the amount of money transferred, normalized ...

Large-scale mobilization of individuals across social networks is becoming increasingly influential in society. However, little is known about what traits of recruiters and recruits and affect the speed at which one mobilizes the other. Here we identify and measure traits of individuals and their relationships that predict mobilization speed. We ran a global social mobilization contest and reco...