779 results for University of Canterbury Library, 2006

  • Walter Laqueur (ed.), Voices of Terror: Manifestos, Writings, and Manuals of Al Qaeda, Hamas, and Other Terrorists from Around the World and Throughout the Ages (New York: Reed Press, 2004), 520 pp.

    Moses, J. (2006)

    Unclassified
    University of Canterbury Library

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  • A Study of the Geelong Local Learning and Employment Network

    Kamp, A. (2006)

    Theses / Dissertations
    University of Canterbury Library

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  • On an inverse problem from magnetic resonance elastic imaging

    Wall, David J. N.; Olsson, Peter; Van Houten, Elijah E. W. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    The imaging problem of elastography is an inverse problem. The nature of an inverse problem is that it is illconditioned. We consider properties of the mathematical map which describes how the elastic properties of the tissue being reconstructed vary with the field measured by Magnetic Resonance Imaging (MRI). This map is a nonlinear mapping and our interest is in proving certain conditioning and regularity results for this operator which occurs naturally in this problem of imaging in elastography. In this treatment we consider the tissue to be linearly elastic, isotropic and spatially heterogeneous. We determine the conditioning of this problem of function reconstruction; in particular for the density and stiffness functions. We examine the Fn!chet derivative of the nonlinear mapping, which enables us to describe the properties of how the field affects the individual maps to the density and stiffness functions. We illustrate how use of the implicit function theorem can considerably simplify the analysis of Frechet differentiability and regularity properties of this underlying operator. We present new results which show that the stiffness map is mildly ill-posed, whereas the density map suffers from medium ill-conditioning. Computational work has been done previously to study the sensitivity of these maps but our work here is analytical. The validity of the Newton-Kantorovich methods for the computational solution of this inverse problem is directly linked to the Frechet differentiability of the appropriate nonlinear operator, which we justify.

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  • Wild triangles in 3-connected matroids

    Oxley, J.; Semple, C.; Whittle, G. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    Tutte's Triangle Lemma proves that if {a, b, c} is a triangle in a 3-connected matroid and neither M\a nor M\b is 3-connected, then M has a triad that contains a and exactly one of b and c. Hence {a, b, c} is contained in a fan of M with at least four elements. In this paper we ask for a somewhat stronger conclusion. When is it that, for each t in { a, b, c}, either M\t is not 3-connected, or M\t has a 3-separation that is not equivalent to a 3-separation induced by M? The main result describes the structure of M relative to { a, b, c} when this occurs. This theorem generalizes a result of Geelen and Whittle for sequentially 4-connected matroids. The motivation for proving this result was for use as an inductive tool for connectivity results aimed at representability questions. In particular, Geelen, Gerards, and Whittle use it in their proof of Kahn's Conjecture for 4-connected matroids.

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  • A chain theorem for matroids

    Oxley, J.; Semple, C.; Whittle, G. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    Tutte's Wheels-and-Whirls Theorem proves that if M is a 3-connected matroid other than a wheel or a whirl, then M has a 3-connected minor N such that |E(M)| - |E(N)| = 1. Geelen and Whittle extended this theorem by showing that when M is sequentially 4-connected, the minor N can also be guaranteed to be sequentially 4-connected, that is, for every 3-separation (X, Y) of N, the set E(N) can be obtained from X or Y by successively applying the operations of closure and coclosure. Hall proved a chain theorem for a different class of 4-connected matroids, those for which every 3-separation has at most five elements on one side. This paper proves a chain theorem for those sequentially 4-connected matroids that also obey this size condition.

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  • Optimizing phylogenetic diversity under constraints

    Moulton, Vincent; Semple, Charles; Steel, Mike (2006)

    Discussion / Working Papers
    University of Canterbury Library

    Phylogenetic diversity (PD) is a measure of the extent to which different subsets of taxa span an evolutionary tree, and provides a quantitative tool for studying biodiversity conservation. Recently, it was shown that the problem of finding subsets of taxa of given size to maximize PD can be efficiently solved by a greedy algorithm. In this paper, we extend this earlier work, beginning with a more explicit description of the underlying combinatorial structure of the problem and its connection to greedoid theory. Next we show that an extension of the PD optimization problem to a phylogeographic setting is NP-hard, although a special case has a polynomial-time solution based on the greedy algorithm. We also show how the greedy algorithm can be used to solve some special cases of the PD optimization problem when the sets that are restricted to are ecologically 'viable'. Finally, we show that three measures related to PD fail to be optimized by a greedy algorithm.

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  • Computing the hybridization number is fixed-parameter tractable

    Semple, Charles; Bordewich, Magnus (2006)

    Discussion / Working Papers
    University of Canterbury Library

    Reticulation processes in evolution mean that the ancestral history of certain groups of present-day species is non-tree-like. These processes include hybridization, lateral gene transfer, and recombination. Despite the existence of reticulation, such events are relatively rare and so a fundamental problem for biologists is the following: given a collection of rooted binary phylogenetic trees on sets of species that correctly represent the tree-like evolution of different parts of their genomes, what is the smallest number of "reticulation" vertices in any network that explains the evolution of the species under consideration. It has been previously shown that this problem is NP-hard even when the collection consists of only two rooted binary phylogenetic trees; however, in this paper, we show that it is fixed-parameter tractable.

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  • Encoding phylogenetic trees in terms of weighted quartets

    Grünewald, S.; Huber, Katharina T.; Moulton, Vincent; Semple, C. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    For a finite set X, an edge-weighted phylogenetic X -tree, or phylogenetic tree for short, is a tree T having leaf set X and no degree 2 vertices, together with a map from the edge set of T to ℝ≥₀. Within the field of phylogenetics, several methods have been proposed for constructing such trees (where X is usually a set of species) that work by trying to piece together quartet trees on X, i.e. edge-weighted phylogenetic Y-trees with Y ⊆ X and IYI = 4. Thus it is of interest to characterise when a collection of quartet trees corresponds to a (unique) phylogenetic tree. Recently, Dress and Erdös provided such a characterisation for binary phylogenetic trees, that is, phylogenetic trees all of whose internal vertices have degree 3. Here we provide a new characterisation for arbitrary phylogenetic trees.

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  • A nonlinear model of size-structured populations with applications to cell cycles

    Chapman, Jon; James, Alex; Plank, M. J. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    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 growth term, allowing the population to be structured by size or weight rather than age, and a general solution is presented. Various examples are then considered, including the case of cell growth where cells divide at a given size.

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  • Experimental and theoretical analysis of hybridization

    Linz, Simone; St. John, K.; Semple, Charles (2006)

    Discussion / Working Papers
    University of Canterbury Library

    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 to understanding the modeling of reticulation processes such as hybridization, horizontal gene transfer, and recombination. We give new lower bounds for the hybridization number that are very useful in limiting search times for exact answers and in conjunction with existing upper bounds to "sandwich" the true answer. We analyze the algorithms experimentally on both biological and simulated data.

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  • The evaluation of the effectiveness of traffic calming devices in reducing speeds on "local" urban roads in New Zealand

    Minnema, Ron (2006)

    Theses / Dissertations
    University of Canterbury Library

    Austroads (2004) promotes speed based design when installing LATM's and states that "there is very little systematic information available on device crossing speeds; there is even less reliable information on whether or not 'operating speeds' can be given for a given type of device". This research investigates the effectiveness of traffic calming devices on local roads in New Zealand, and compares the installation criteria and the resultant effects with the findings sourced from a literature review and complements work undertaken by the LTSA (2004) who recommended that: a. A set of guidelines on traffic calming devices should be developed. b. RCA's should assess the effects of the traffic calming devices. c. Its Standards and Guidelines Steering Group, should develop a set of case studies to evaluate the overall effect of various types of traffic calming devices. The findings of the literature review was that: • Traffic calming devices must only be installed after considering the resultant effects, e.g. traffic volumes, speed, noise, vehicle type, community attitudes, vibration and comfort. • Several devices conclusively reduce speed, and can be used without undertaking further analysis, i.e. raised tables, road humps, road cushions, slow points and perimeter threshold treatments. • Limited information exists within New Zealand that can be readily accessed and the author has been unable • to conclusively demonstrate their effectiveness in reducing speeds, i.e. centre blisters, kerb extensions, • parking; mid-block medians, reduced lane width and carriageway narrowing. • Several websites exist overseas with useful information. The findings of the case studies was that: • Of the 21 schemes, 10 resulted in a statistically significant reduction in speed, while 2 resulted in a statistically significant increase in speeds. • The majority of devices that have been installed have not always being installed in accordance with the findings of the literature review. • Many RCA's install traffic calming devices without monitoring the resultant effects. • The turnover in staff and lack of record keeping means that the industry as a whole is not learning, a situation compounded by no central database existing and being maintained. • The spacing of devices often exceeded recommended guidelines. It is recommended that: • Land Transport develops a design guide focusing on the devices that conclusively reduce speed and the resultant effects. • Further research is undertaken into the community acceptability of devices. • A design guide is produced for new developments, in order to avoid storing an LA TM at a later date. • A 'traffic calming' website and discussion group should be set up similar to the ITE website.

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  • Barriers to Post Disaster Reconstruction: Report on Workshop

    Le Masurier, J.; Seville, E. (2006)

    Discussion / Working Papers
    University of Canterbury Library

    A workshop was held to identify the challenges and barriers to post-disaster reconstruction in New Zealand to help guide research under Objective 3 of the Resilient Organisations project. The workshop brought together people with relevant experience in post-disaster reconstruction and/or specialist knowledge of the regulatory, legislative and contractual issues that could influence reconstruction. A list of attendees is given in Appendix A. This report summarises the key issues from the workshop and develops these issues into research directions. On the basis of both student and funding resources available, the report identifies the research that will be carried out as part of the current FRST funded research project. Other research from the priority list could potentially be carried out in the future if further research resources become available. The report is organised into the four key areas considered during the workshop: legislative and regulatory issues, coordination of reconstruction, contractual issues and resource issues.

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  • The distributors of change points in long memory processes

    Guan, Yu Zheng (2006)


    University of Canterbury Library

    In this paper we present the properties of empirical distributions of different statistics (e.g. standard deviation and number of breaks) related to the presence of structural breaks in simulated Fractional Gaussian Noise series with various Hurst parameters. Structural Breaks are detected with Atheoretical Regression Trees, a structural break identification method. The simulation results were applied to four case studies to check whether a Regime Switching or Fractional Gaussian Noise model is more adequate.

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  • A predator from East Africa that chooses malaria vectors as preferred prey

    Nelson, X.J.; Jackson, R.R. (2006)

    Journal Articles
    University of Canterbury Library

    Background. All vectors of human malaria, a disease responsible for more than one million deaths per year, are female mosquitoes from the genus Anopheles. Evarcha culicivora is an East African jumping spider (Salticidae) that feeds indirectly on vertebrate blood by selecting blood-carrying female mosquitoes as preferred prey. Methodology/Principal Findings. By testing with motionless lures made from mounting dead insects in lifelike posture on cork discs, we show that E. culicivora selects Anopheles mosquitoes in preference to other mosquitoes and that this predator can identify Anopheles by static appearance alone. Tests using active (grooming) virtual mosquitoes rendered in 3-D animation show that Anopheles’ characteristic resting posture is an important prey-choice cue for E. culicivora. Expression of the spider’s preference for Anopheles varies with the spider’s size, varies with its prior feeding condition and is independent of the spider gaining a blood meal. Conclusions/Significance. This is the first experimental study to show that a predator of any type actively chooses Anopheles as preferred prey, suggesting that specialized predators having a role in the biological control of disease vectors is a realistic possibility.

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  • Using Online Delivery to Support Students During Practicum Placements

    Maidment, J. (2006)

    Journal Articles
    University of Canterbury Library

    Finding ways to effectively support students while on placement remains a continuing endeavor for those who teach in professional education programs. In this article the multiple challenges and learning opportunities that social work students encounter during practicum learning will be discussed. Next, drawing from constructivist pedagogy and using authentic examples from an online discussion board, ways to supplement the support and educational input provided to students on placement will be demonstrated. Finally, some of the risks and limitations in engaging with online delivery are examined with the view to understanding how e-learning can be facilitated most effectively for students during the practicum.

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  • Developing a hidden Markov model for assessing the health of preterm babies

    Roscoe, James (2006)


    University of Canterbury Library

    Premature babies, because of their underdeveloped biological systems, often display cardiorespiratory instabilities. Yet, at the same time, many paediatric illnesses also affect cardiorespiratory functions. For a certain baby, it can therefore be difficult to determine the cause of such instabilities, and this ramifies on treatment decisions. We look to develop a Hidden Markov Model for modelling the health of preterm babies, as this is useful for uncovering information on the hidden states of a system - in this case, the health of a premature baby. First, we provide a background for the study of Hidden Markov Models; meanwhile, we develop the variants of Hidden Markov Models that are most desirable for our application, and describe how inference can be made in each case.

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  • Antarctica in the Year 2105: What Physical Changes Might We Expect?

    Kowalewski, Stefan; Mason, Anna; Newton, Nadine (2006)

    Postgraduate Certificate thesis
    University of Canterbury Library

    This report investigates possible changes to the Antarctic environment due to climate change over the next one hundred years. Three scenarios have been developed in order to assess the response of the Antarctic to different rates of climate change resulting from anthropogenic influences. According to the predictions made in this report, there are no significant differences between the pessimistic scenario (which assumes a further increase in greenhouse gas emissions) and the realistic scenario (which assumes no strengthening in greenhouse gas emission rates). The optimistic scenario (which assumes global effort in reducing greenhouse gas emissions) results in slower and more gradual changes to the physical environment. However, due to the slow response of the Earth’s climate system, a significant global warming is still expected by the year 2105. All scenarios predict dramatic changes over the Antarctic Peninsula in 2105. The West Antarctic Ice Sheet is not expected to collapse, and the East Antarctic Ice Sheet will remain relatively unaffected.

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  • A Big Commitment for a Small Country: Is Scott Base Necessary ?

    Thomson, Bex; Fortune, David; Hicks, Stephen (2006)

    Postgraduate Certificate thesis
    University of Canterbury Library

    'A Big Commitment for a Small Country — Is Scott Base Necessary?' This is an important and perhaps fundamental question for New Zealand and its role in the Antarctic. The Oxford dictionary defines 'necessary' as follows: 'that which is indispensable, an essential, cannot be done without. 'l We think the question needs to be rephrased or at least explained. We are not trying to decide whether Antarctica matters to New Zealand. Nor are we asking whether New Zealand should be involved in Antarctic matters. What we are concerned with however is whether, or not, New Zealand must have its own 'national base' in order to fulfil its objectives in the Antarctic? We have examined this question from a number Of perspectives and have attempted to produce a fair evaluation of the arguments both 'for' and 'against' the continuation Of Scott Base in its present form. We begin our report with background information about Scott Base. This is followed by a discussion around each Of six dimensions or 'issues' that we believe are most pertinent to the questlon. These dimensions are: 2. 3. 4. 5. 6. Sovereignty and the political dimension The dependence Of New Zealand on the United States Science in Antarctica The spirit Of the Antarctic Treaty System The resources that New Zealand has available Costs - What can New Zealand afford? After the dimensions have been discussed we present our conclusions and recommendation. 'A Big Commitment for a Small Country — Is Scott Base Necessary?' This is an important and perhaps fundamental question for New Zealand and its role in the Antarctic. The Oxford dictionary defines 'necessary' as follows: 'that which is indispensable, an essential, cannot be done without. 'l We think the question needs to be rephrased or at least explained. We are not trying to decide whether Antarctica matters to New Zealand. Nor are we asking whether New Zealand should be involved in Antarctic matters. What we are concerned with however is whether, or not, New Zealand must have its own 'national base' in order to fulfil its objectives in the Antarctic? We have examined this question from a number Of perspectives and have attempted to produce a fair evaluation of the arguments both 'for' and 'against' the continuation Of Scott Base in its present form. We begin our report with background information about Scott Base. This is followed by a discussion around each Of six dimensions or 'issues' that we believe are most pertinent to the questlon. These dimensions are: 2. 3. 4. 5. 6. Sovereignty and the political dimension The dependence Of New Zealand on the United States Science in Antarctica The spirit Of the Antarctic Treaty System The resources that New Zealand has available Costs - What can New Zealand afford? After the dimensions have been discussed we present our conclusions and recommendation.

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  • The re-emergence of the Krill Harvesting Industry

    Beruldsen, Kylie; Carter, Holly; Godfrey, Myfanwy; Smith, Tonya (2006)

    Postgraduate Certificate thesis
    University of Canterbury Library

    Krill Harvesting has been a fisheries industry since the 1970s and was at its height in the early 1980s. The rapid increase in Krill harvests during this time were a cause for much concern and a major reason for the formation of the Commission for the Conservation of Marine Living Resources (CCAMLR) in 1982. Since then, CCAMLR has been the main governing body for the Krill harvesting industry but management practices have changed as scientific research has uncovered a basic lack of understanding of the effects removal of significant Krill biomass would have on the ecosystem. Political influences and technological constraints have been limiting factors for the expansion of the Krill industry, resulting in season catches having not yet reached the total allowable catch set by the CCAMLR. In fact Krill harvests have not yet reached again the peak seen in the 1980s. Increased market demand for Krill products in recent times has bought about the re-emergence of the Krill industry and as interest in this fishery has expanded so too has technology advancements and processing methods. The increase in Krill Harvests that these technology advancements could bring, coupled with an increased market demand, show a trend towards higher and higher levels of Krill extraction from the worlds oceans. This paper will focus on the harvesting of Krill in the Southern Ocean and how this relates to potential issues needing to be examined in the future.

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  • Antarctic Biosecurity

    Gousmett, Katrina; Hood, Christina; Lamers, Machiel; O'Reilly, Jessica (2006)

    Postgraduate Certificate thesis
    University of Canterbury Library

    The protection of Antarctic ecosystems from alien and invasive species is one of the key aims of the Environmental Protocol (1991) to the Antarctic Treaty System. Despite the patchy nature of different domestic policy implementations and management strategies regarding this issue, recent research has shown that the threats of biological invasions in Antarctica are real. Introductions of nonnative and invasive species in the Subantarctic Islands provide a useful analogue for discussing the potential risks in the Antarctic Peninsula and continent. The increase in human activities and their subsequent logistics support provides increasing opportunities for alien species to hitch-hike to the Antarctic, and for the dispersal of indigenous species around the continent. Moreover, rapid environmental changes the Antarctic Peninsula in particular may provide nonnative species with the environment they are looking for and contributes to the complexity and uncertainties involved. Regardless of the overall lack of knowledge and ill-defined scope of this problem, precautionary measures need to be taken urgently.

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