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Grubb, Thomas

Publications and source records attributed to Grubb, Thomas.

Community detection in hypergraphs via mutual information maximization

Abstract The hypergraph community detection problem seeks to identify groups of related vertices in hypergraph data. We propose an information-theoretic hypergraph community detection algorithm which compresses the observed data in terms of community labels and community-edge intersections. This algorithm can also be viewed as maximum-likelihood inference in a degree-corrected microcanonical stochastic blockmodel. We perform the compression/inference step via simulated annealing. Unlike several recent algorithms based on canonical models, our microcanonical algorithm does not require inference of statistical parameters such as vertex degrees or pairwise group connection rates. Through synthetic experiments, we find that our algorithm succeeds down to recently-conjectured thresholds for sparse random hypergraphs. We also find competitive performance in cluster recovery tasks on several hypergraph data sets.

97 MATHEMATICS AND COMPUTING↗

IMAGESEER - IMAGEs for Education and Research

IMAGESEER is a new Web portal that brings easy access to NASA image data for non-NASA researchers, educators, and students. The IMAGESEER Web site and database are specifically designed to be utilized by the university community, to enable teaching image processing (IP) techniques on NASA data, as well as to provide reference benchmark data to validate new IP algorithms. Along with the data and a Web user interface front-end, basic knowledge of the application domains, benchmark information, and specific NASA IP challenges (or case studies) are provided.

Le Moigne, Jacqueline↗

Linking and Combining Distributed Operations Facilities using NASA's "GMSEC" Systems Architectures

NASA's Goddard Mission Services Evolution Center (GMSEC) ground system architecture has been in development since late 2001, has successfully supported eight orbiting satellites and is being applied to many of NASA's future missions. GMSEC can be considered an event-driven service-oriented architecture built around a publish/subscribe message bus middleware. This paper briefly discusses the GMSEC technical approaches which have led to significant cost savings and risk reduction for NASA missions operated at the Goddard Space Flight Center (GSFC). The paper then focuses on the development and operational impacts of extending the architecture across multiple mission operations facilities.

Smith, Danford↗