Collaborative tagging has been quickly gaining ground because of its ability to recruit the activity of web users into effectively organizing and sharing vast amounts of information. Here we collect data from a popular system and investigate the statistical properties of tag cooccurrence. We introduce a stochastic model of user behavior embodying two main aspects of collaborative tagging: (i) a...

Online socializing technologies have given rise to new social behaviors. We focus on the effect of reiteration tool (tools that enable us to redistribute a copy of content that others have posted) on users’ online persona building. Specifically, we study retweeting behavior on Twitter and ask: (1) Do users expand the breadth of topics they discuss? (2) Do users change the distribution of the to...

the aim of this research is to investigate the relationship between leader – member exchange and organizational citizenship behavior, and considering the mediating role of psychological empowerment and organizational commitment. the sample consisted of 250 employees of marun oil and gas producing company who were selected by simple random sampling method. the instruments which used in this rese...

Social tagging systems provide an open platform for users to share and annotate their resources such as photos and URLs. Due to their open nature, however, these systems present a security problem. Malicious users may try to distort the system’s behavior by inserting erroneous or misleading annotations, thus altering the way in which information is presented to legitimate users. This paper addr...

In this paper we study the implications of end-user behavior in applying software updates and patches on information-security vulnerabilities. To this end we tap into a large data set of measurements conducted on more than 400,000 Windows machines over four client-side applications, and separate out the impact of user and vendor behavior on the vulnerability states of hosts. Our modeling of use...