Recent Submissions

  • A smalltalk queueing network simulator 

    Irwin, Warwick (University of Canterbury, 1989)
    This report gives complete documentation for a working implementation of a discrete, event driven Smalltalk-80 modelling context described in Goldberg and Robson "Smalltalk-80: The Language and its Implementation". It also ...
  • The difficulty of constructing a leaf-labelled tree including or avoiding given subtrees 

    Ng, Meei Pyng; Steel, M.; Wormald, N. (University of Canterbury, 1995)
    Given a set of trees with leaves labelled from a set L, is there a tree T with leaves labelled by L such that each of the given trees is homeomorphic to a subtree of T? This question is known to be NPcomplete in general, ...
  • Tree representations of non-symmetric group-valued proximities 

    Semple, Charles; Steel, M. (University of Canterbury, 1999)
    Let X be a finite set and let d be a function from X x X into an arbitrary group Q. An example of such a function arises by taking a tree T whose vertices include X, assigning two elements of Q to each edge of T ( one for ...
  • Experimental and theoretical analysis of hybridization 

    Linz, Simone; St. John, K.; Semple, Charles (University of Canterbury, 2006)
    We develop new heuristics and an exact algorithm for calculating the amount of hybridization between two rooted binary phylogenetic trees. Calculating the minimum number of hybridization events is NP-hard, but essential ...
  • Random autocatalytic networks 

    Mossel, E.; Steel, M. A. (University of Canterbury, 2004)
    We determine conditions under which a random biochemical system is likely to contain a subsystem that is both autocatalytic and able to survive on some ambient 'food' source. Such systems have previously been investigated ...
  • A nonlinear model of size-structured populations with applications to cell cycles 

    Chapman, Jon; James, Alex; Plank, M. J. (University of Canterbury, 2006)
    The Sharpe-Lotka-McKendrick (or von Foerster) equations for an age-structured population, with a nonlinear term to represent overcrowding or competition for resources, are considered. The model is extended to include a ...
  • Shape Based Image Retrieval 

    Brown, Michael (University of Canterbury, 2000)
    A new technique is proposed for representing shape features for the purpose of image retrieval. This project defines the properties of this representation, and implements software that extracts the relevant features from ...
  • Traditional Database Implementations in HyperCard 

    Sinton, R. J. P. (University of Canterbury, 1988)
    This project attempts to evaluate the viability of performing one particular computer application in the HyperCard environment. It examines in a non-empirical fashion the benefits and advantages of using HyperCard for the ...
  • Cyclic permutations and evolutionary trees 

    Semple, Charles; Steel, M. A. (University of Canterbury, 2002)
    Given a tree T with leaf set X, there are certain ways of arranging the elements of X in a circular order so that T can be embedded in the plane and 'preserve' this ordering. We investigate some new combinatorial ...
  • Reconstructing minimal rooted trees 

    Semple, Charles (University of Canterbury, 1999)
    For a set T of rooted binary leaf-labelled trees, we present an algorithm that finds all of the minor-minimal trees that are compatible with T. The running time of this algorithm is polynomial up to the number of trees with ...
  • Two further links between MP and ML under the Poisson model 

    Steel, M. A.; Penny, David (University of Canterbury, 2003)
    Maximum parsimony and maximum likelihood are two contrasting approaches for reconstructing phylogenetic trees from sequence and character data. We establish analytic links between these methods (extending connections reported ...
  • On approximation of optimizing phylogenetic diversity for cluster systems 

    Faller, Beáta; Semple, Charles; Steel, M. A. (University of Canterbury, 2009)
    A basic question in conservation biology is how to maximize future biodiversity as species face extinction. One way to approach this question is by measuring the diversity of a set of species in terms of the evolutiona ...
  • Phylogenetic diversity and the greedy algorithm 

    Steel, M. A. (University of Canterbury, 2004)
    Given a phylogenetic tree with leaves labelled by a collection of species, and with weighted edges, the 'phylogenetic diversity' of any subset of the species is the sum of the edge weights of the minimal subtree ...
  • A cluster reduction for computing the subtree distance between phylogenies 

    Linz, Simone; Semple, Charles (University of Canterbury, 2008)
    Calculating the rooted subtree prune and regraft (rSPR) distance between two rooted binary phylogenetic trees is a frequently applied process in various areas of molecular evolution. However, computing this distance is ...
  • Locating a tree in a phylogenetic network 

    Iersel, Leo van; Semple, Charles; Steel, M. A. (University of Canterbury, 2010)
    Phylogenetic trees and networks are leaf-labelled graphs that are used to describe evolutionary histories of species. The TREE CONTAINMENT problem asks whether a given phylogenetic tree is embedded in a given phylogenetic ...
  • Peeling phylogenetic 'oranges' 

    Moulton, Vincent; Steel, M. (University of Canterbury, 2003)
    We investigate the combinatorics of a topological space that is generated by the set of edge-weighted finite trees. This space arises by multiplying the weights of edges on paths in trees and is closely connected to tree ...
  • Fork-decompositions of matroids 

    Hall, R.; Oxley, J.; Semple, C.; Whittle, G. (University of Canterbury, 2002)
    One of the central problems in matroid theory is Rota's conjecture that, for all prime powers q, the class of GF(q)-representable matroids has a finite set of excluded minors. This conjecture has been settled for q ≤ 4 ...
  • Active network security 

    Verwoerd, T. (University of Canterbury, 1999)
    Most discussions of network security focus on the tools and techniques used to fortify networks: firewalls, biometrics, access controls, encryption. This paper presents an outline of tools that assist an administrator in ...
  • Social presence on the internet 

    Bosley, Ian (University of Canterbury, 1994)
    The purpose of this project is research methods of providing a low level awareness of the presence and activity of colleagues. This functionality should be independent of geographic proximity, without requiring specialist ...
  • N-S chart honours project report : a Nassi-Scneiderman cartographer 

    Couch, A. B. (University of Canterbury, 1988)
    This project involved the development of N-S Chart; a NassiShneiderman Cartographer for the Apple Macintosh. N-S Chart is a tool for drawing and maintaining Nassi-Shneiderman diagrams, and incorporates the beneficial ...

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