We address the issue of inapproximability of the wavelength assignment problem in wavelength division multiplexing (WDM) optical networks. We prove that in an n-node WDM optical ne...
We define a multivariate polynomial that generalizes in a unified way the twovariable interlace polynomial defined by Arratia, Bollob´as and Sorkin on the one hand, and a one-...
We consider the Minimum Linear Arrangement problem and the (Uniform) Sparsest Cut problem. So far, these two notorious NP-hard graph problems have resisted all attempts to prove in...
The Densest k-subgraph problem (i.e. find a size k subgraph with maximum number of edges), is one of the notorious problems in approximation algorithms. There is a significant g...
In this paper we present two main results about the inapproximability of the exemplar conserved interval distance problem of genomes. First, we prove that it is NP-complete to deci...
Zhixiang Chen, Richard H. Fowler, Bin Fu, Binhai Z...