2003 Fiscal Year Final Research Report Summary
Algorithms on Graphs, Networks, and Discrete Geomerty
| Project/Area Number |
14580373
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
計算機科学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
ITO Hiroo Kyoto University, Graduate School of Informatics, Associate Professor, 情報学研究科, 助教授 (50283487)
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| Co-Investigator(Kenkyū-buntansha) |
IWAMA Kazuo Kyoto University, Graduate School of Informatics, Professor, 情報学研究科, 教授 (50131272)
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| Project Period (FY) |
2002 – 2003
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| Keywords | graphs / networks / the Internet / shortest path / routing / hypergraphs / convex polygons / location problems |
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| Research Abstract |
1.Source Location Problems
For a source location problem on digraphs and with constraints of edge-connectivity of both directions, we gave a polynomial-time algorithm.
2.Fault-tolerant Routing Method of the Internet
For avoiding the "routing loop problem," which occurs when a network condition have been changed, we proposed a routing method to broadcast the information of the change gradually. We proved that this method avoids routing loops at all, and moreover we find the minimum number of steps of the broadcasting.
3.File Transfer Tree Problem
For a given digraph, a specified vertex (root), and an upper bound of out-degree for each vertex, we consider a problem of finding a shortest path tree rooted on the root satisfying the out-degree constraint. We presented a polynomial time algorithm for this problem.
4.Properties of Hypergraphs Drawn on a Convex Polygon
We consider hypergraph drawing on a convex polygon and found equivalence between a condition on the sum of areas of hyperedges and a condition on convex three-cuts of the hypergraph.
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