K-relative neighborhood graphs and their applications to some euclidean bottleneck optimization problems

博士 === 國立清華大學 === 資訊科學研究所 === 78 === A Bottleneck optimization problem on general graphs with edge costs is the problem of finding a subgraph of a certain kind that minimizes the mzximum edge cost in the subgraph. a Euclidean bottleneck optimization problem is a bott...

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Bibliographic Details
Main Authors: ZHANG,MAO-XIANG, 張貿翔
Other Authors: LI,JIA-TONG
Format: Others
Language:zh-TW
Published: 1990
Online Access:http://ndltd.ncl.edu.tw/handle/28862109953433864007
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Summary:博士 === 國立清華大學 === 資訊科學研究所 === 78 === A Bottleneck optimization problem on general graphs with edge costs is the problem of finding a subgraph of a certain kind that minimizes the mzximum edge cost in the subgraph. a Euclidean bottleneck optimization problem is a bottleneck optimization problem on complete graphs which are constructed from a set of points in the plane and whose edge cost are Euclidean distances between points connected by edges. In this dissertation, we define a special graph called k7 relative Neighborhood Graph, denoted as kRNG, where k is a positive number, and use it to solve the following three Euclidean bottleneck optimization problems: (A) The Euclidean bottleneck matching problem. (B) The Euclidean bottleneck biconnected edge subgraph problem. (C) The Euclidean bottleneck traveling salesperson problem. We prove the following three theorems: (1) For any instance of Problem A, there exists an optimal solution which   is a subgraph of a 17RNG. (2) For any instance of Problem A, there exists an optimal solution which   is a subgraph of a 2RNG. (3) For any instance of Problem A, there exists an optimal solution which   is a subgraph of a 20RNG. All numbers of edges of these three special graphs are O(n). Therefore we can find optimal solutions for the above three problems from three k7 relative neighborhood graphs. In this way, we can solve Problem A and Problem B in O(n2)time, and also an efficient approximation algorithm for Problem C is developed. The third theorem above gives us an interesting graph theoretic result: 20RNGs are Hamiltonian.