Information overload in structured data

<p>Information overload refers to the difficulty of making decisions caused by too much information. In this dissertation, we address information overload problem in two separate structured domains, namely, graphs and text.</p> <p>Graph kernels have been proposed as an efficient and theoretically sound approach to compute graph similarity. They decompose graphs into certain sub-structures, such as subtrees, or subgraphs. However, existing graph kernels suffer from a few drawbacks. First, the dimension of the feature space associated with the kernel often grows exponentially as the complexity of sub-structures increase. One immediate consequence of this behavior is that small, non-informative, sub-structures occur more frequently and cause information overload. Second, as the number of features increase, we encounter sparsity: only a few informative sub-structures will co-occur in multiple graphs. In the first part of this dissertation, we propose to tackle the above problems by exploiting the dependency relationship among sub-structures. First, we propose a novel framework that <em>learns</em> the latent representations of sub-structures by leveraging recent advancements in deep learning. Second, we propose a general smoothing framework that takes <em>structural</em> similarity into account, inspired by state-of-the-art smoothing techniques used in natural language processing. Both the proposed frameworks are applicable to popular graph kernel families, and achieve significant performance improvements over state-of-the-art graph kernels.</p> <p>In the second part of this dissertation, we tackle information overload in text. We first focus on a popular social news aggregation website, Reddit, and design a submodular recommender system that tailors a <em>personalized </em>frontpage for individual users. Second, we propose a novel submodular framework to summarize videos, where both transcript and comments are available. Third, we demonstrate how to apply filtering techniques to select a small subset of informative features from virtual machine logs in order to predict resource usage.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Computer Science

Year

2016

Author dc:creator

• Yanardag Delul, Pinar

Contributors dc:contributor

• Jennifer Neville
• SVN Vishwanathan
• Buster Dunsmore
• Elena Grigorescu

• Applied sciences
• Graphs
• Information overload
• Structured data
• Text
• Computer Sciences

Repository record dc:identifier

https://docs.lib.purdue.edu/open_access_dissertations/729

OAI identifier oai:identifier

oai:docs.lib.purdue.edu:open_access_dissertations-1899