This dissertation examines the problem of discovering similar objects in two
different settings: (1) discovering similar objects based on the interaction among
them, and (2) discovering similar objects based on their meta-data. We will mainly
focus on the first setting. The interactions among objects are modeled by a network
structure, in which each node represents one object, and an edge is presented if
the two objects have interacted with each other. In the second setting, we examine
the similarity problem where additional information other than interacting history
is available. In the second setting, we targeted digital library objects, such as
papers, authors, published venues (i.e., the published conference or journal), etc.
The meta-data of these objects could be, for example, the citation counts of the
paper, the affiliation of the author, and the topics of the conference. These metadata
are utilized to infer the similar objects, such as similar terms, similar venues,
or relevant authors given a topic.