Title
An approach for proving lower bounds: solution of Gilbert-Pollak's conjecture on Steiner ratio
Abstract
A family of finitely many continuous functions on a polytope X, namely (g/sub i/(x))/sub i in I/, is considered, and the problem of minimizing the function f(x)=max/sub i in I/g/sub i/(x) on X is treated. It is shown that if every g/sub i/(x) is a concave function, then the minimum value of f(x) is achieved at finitely many special points in X. As an application, a long-standing problem about Steiner minimum trees and minimum spanning trees is solved. In particular, if P is a set of n points on the Euclidean plane and L/sub s/(P) and L/sub m/(P) denote the lengths of a Steiner minimum tree and a minimum spanning tree on P, respectively, it is proved that, for any P, L/sub S/(P)or= square root 3L/sub m/(P)/2, as conjectured by E.N. Gilbert and H.O. Pollak (1968).
Year
DOI
Venue
1990
10.1109/FSCS.1990.89526
St. Louis, MO
Keywords
Field
DocType
continuous function,sub i,minimum value,n point,long-standing problem,sub m,euclidean plane,polytope x,steiner minimum tree,concave function,lower bound,steiner ratio,np hard problem,minimum spanning tree,computer science,continuous functions,polytope,steiner trees,minimisation,mathematics
Continuous function,Discrete mathematics,Combinatorics,Steiner tree problem,Concave function,Polytope,Spanning tree,Square root,Conjecture,Mathematics,Minimum spanning tree
Conference
ISBN
Citations 
PageRank 
0-8186-2082-X
25
11.08
References 
Authors
3
2
Name
Order
Citations
PageRank
D.-Z. Du121952.53
F. K. Hwang2332100.54