Species, Clusters and the 'Tree of Life': A graph-theoretic perspective (2009)
Dress, Andreas, Moulton, Vincent, Steel, Mike, Wu, Taoyang
A hierarchical structure describing the inter-relationships of species has long been a fundamental concept in systematic biology, from Linnean classification through to the more recent quest for a...
The complexity of the Weight Problem for permutation and matrix groups (2008)
Given a metric d on a permutation group G, the corresponding weight problem is to decide whether there exists an element π ∈ G such that d(π, e) = k, for some given value k of d. In this paper we...
On the Subgroup Distance Problem (2008)
Christoph Buchheim, Peter J. Cameron, Taoyang Wu
We investigate the computational complexity of finding an element of a permutation group H ⊆ Sn with a minimal distance to a given π ∈ Sn, for different metrics on Sn. We assume that H is given...
On regular configurations and disjoint cycles in shift graphs (2007)
Configurations are necklaces with prescribed numbers of red and black beads. Among all possible configurations, the regular one plays an important role in many applications. In this paper, several...
Graph homomorphisms II: some examples (2006)
Following the talk on graph homomorphisms given by Peter last week, we continue to discuss some examples of graph homomorphisms. More precisely, the graph parameters which can be represented by...
Graph homomorphisms III: Models (2006)
Following the last talk on graph homomorphisms, we continue to discuss some examples of graph homomorphisms. But this time we will focus on some models, that is, the homomorphism G → H for the...
In this entry we briefly discuss the regular configurations on cycle graphs and an application to find disjoint cycles in shift graphs as well as the corresponding disjoint sequences in extremal...