Browsing by Author "Chang, Gerard J."

Now showing 1 - 4 of 4

Isometric path numbers of graphs
(2006-09-06)
Pan, Jun-Jie
;
Chang, Gerard J.
;
應用數學系
;
Department of Applied Mathematics
An isometric path between two vertices in a graph G is a shortest path joining them. The isometric path number of G, denoted by ip(G), is the minimum number of isometric paths needed to cover all vertices of G. In this paper, we determine exact values of isometric path numbers of complete r-partite graphs and Cartesian products of 2 or 3 complete graphs. (c) 2006 Elsevier B.V. All rights reserved.
Profile minimization on compositions of graphs
(2007-10-01)
Tsao, Yu-Ping
;
Chang, Gerard J.
;
應用數學系
;
Department of Applied Mathematics
The profile minimization problem arose from the study of sparse matrix technique. In terms of graphs, the problem is to determine the profile of a graph G which is defined as P(G) = min(f) Sigma(v epsilon V(G)) max(x epsilon N[v]) (f(v) - f(x)), where f runs over all bijections from V(G) to {1,2,...,vertical bar V(G)vertical bar} and N[v] = {v} boolean OR {x epsilon V(G): xv epsilon E(G)}. This is equivalent to the interval graph completion problem, which is to find a super-graph of a graph G with as few number of edges as possible. The purpose of this paper is to study the profiles of compositions of two graphs.
Strong edge-coloring for jellyfish graphs
(2015-12-06)
Chang, Gerard J.
;
Chen, Sheng-Hua
;
Hsu, Chi-Yun
;
Hung, Chia-Man
;
Lai, Huei-Ling
A strong edge-coloring of a graph is a function that assigns to each edge a color such that two edges within distance two apart receive different colors. The strong chromatic index of a graph is the minimum number of colors used in a strong edge-coloring. This paper determines strong chromatic indices of cacti, which are graphs whose blocks are cycles or complete graphs of two vertices. The proof is by means of jellyfish graphs. (C) 2015 Elsevier B.V. All rights reserved.
Untitled
(2007-10-01)
Chang, Gerard J.
;
Fu, Hung-Lin
;
Zhu, Xuding
;
應用數學系
;
Department of Applied Mathematics