document: Structural and temporal analysis of the blogosphere through community factorization The blogosphere has unique structural and temporal properties since blogs are typically used as communication media among human individuals . In this paper , we propose a novel technique that captures the structure and temporal dynamics of blog communities . In our framework , a community is a set of blogs that communicate with each other triggered by some events ( such as a news article ) . The community is represented by its structure and temporal dynamics : a community graph indicates how often one blog communicates with another , and a community intensity indicates the activity level of the community that varies over time . Our method , community factorization , extracts such communities from the blogosphere , where the communication among blogs is observed as a set of subgraphs ( i.e. , threads of discussion ) . This community extraction is formulated as a factorization problem in the framework of constrained optimization , in which the objective is to best explain the observed interactions in the blogosphere over time . We further provide a scalable algorithm for computing solutions to the constrained optimization problems . Extensive experimental studies on both synthetic and real blog data demonstrate that our technique is able to discover meaningful communities that are not detectable by traditional methods .
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