Browsing by Author "Brueni, Dennis J."

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    Minimal PMU placement for graph observability: a decomposition approach
    Brueni, Dennis J. (Virginia Tech, 1993-12-06)
    This thesis explores the PMU placement problem, that is, the placement of a minimal number of Phase Measurement Units (PMUs) on the nodes of a power system graph such that the entire graph is observed. The NP-completeness of PMU placement for planar bipartite graphs is shown. PMU placement algorithms are developed for graphs of bounded tree width, such as trees and outer planar graphs. Graph decompositions are used to develop efficient algorithms that produce minimal PMU covers. These algorithms are developed, analyzed, and compared theoretically. Algorithm animations were used in the study to develop insight into the problem and to understand algorithm behavior.
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    The PMU placement problem
    Brueni, Dennis J.; Heath, Lenwood S. (Siam Publications, 2005)
    PMU placement problem is an optimization problem abstracted from an approach to supervising an electrical power system. The power system is modeled as a graph, and adequate supervision of the system requires that the voltage at each node and the current through each edge be observable. A phasor measurement unit ( PMU) is a monitor that can be placed at a node to directly observe the voltage at that node, as well as the current and its phase through all incident edges. The PMU placement problem is to place PMUs at a minimum number of nodes so that the entire electric power system is observed. A new simpler definition of graph observability and several complexity results for the PMU placement problem are presented. The PMU placement problem is shown to be NP-complete even for planar bipartite graphs. Several fundamental properties of PMU placements are proven, including the property that a minimum PMU placement requires no more than 1/3 of the nodes in a connected graph of at least 3 nodes.
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    What if There Were Desktop Access to the Computer Science Literature?
    Brueni, Dennis J.; Fox, Edward A.; Heath, Lenwood S.; Hix, Deborah; Nowell, Lucy Terry; Wake, William C. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1992)
    What if there was an electronic computer science library? Consider the possibilities of having your favorite publications available within finger's reach. Consider project Envision, an ongoing effort to build a user-centered database from the computer science literature. This paper describes our first year progress, stressing the motivation underlying project Envision, user-centered development, and overall design.