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CMU-CS-98-146
Computer Science Department
School of Computer Science, Carnegie Mellon University
CMU-CS-98-146
On Distributed Network Resource Allocation
Andrea Werneck Richa
August 1998
Ph.D. Thesis
CMU-CS-98-146.ps
CMU-CS-98-146.pdf
Keywords: Distributed network, resource allocation, approximation
algorithm, randomized algorithm, shared object, wide-area network,
hierarchical model, expected cost, packet routing, scheduling, Lovasz
Local Lemma, optimal schedule, network emulation, embedding, congestion,
dilation, ordering, linear arrangement, linear array, combinatorial
optimization, interval graph, storage-time product, spreading metric, planar graph
This thesis addresses several resource allocation problems that arise in
the context of distributed networks. First, we present a scheme for
accessing shared copies of objects in a network that has asymptotically
optimal expected cost per access for a class of cost functions that
captures the hierarchical structure of most wide-area networks. Second, we
present an off-line polynomial-time algorithm that finds an asymptotically
optimal schedule for the movement of packets whose paths through a network
have already been determined. This is an improvement on a previous
result by Leighton, Maggs, and Rao, who proved the existance of such
schedules; their proof, however, was not constructive. Finally we present
a polynomial-time O(log n)-approximation algorithm for finding an
embedding of a network with nprocessors into an n-node
linear array so as to minimize the weighted sum of the edge dilations --
i.e., for the minimum linear arrangement problem. This problem is NP-hard,
and the previous best approximation bound known was O(log n log log n).
In the case of planar networks, we bring the approximation factor down to
O(log log n). We also extend our approximation techniques to the
minimum storage-time product and the minimum containing interval graph
problem.
122 pages
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