1,028 results for Doctoral, 2016

  • Improving Clustering Methods By Exploiting Richness Of Text Data

    Wahid, Abdul (2016)

    Doctoral thesis
    Victoria University of Wellington

    Clustering is an unsupervised machine learning technique, which involves discovering different clusters (groups) of similar objects in unlabeled data and is generally considered to be a NP hard problem. Clustering methods are widely used in a verity of disciplines for analyzing different types of data, and a small improvement in clustering method can cause a ripple effect in advancing research of multiple fields. Clustering any type of data is challenging and there are many open research questions. The clustering problem is exacerbated in the case of text data because of the additional challenges such as issues in capturing semantics of a document, handling rich features of text data and dealing with the well known problem of the curse of dimensionality. In this thesis, we investigate the limitations of existing text clustering methods and address these limitations by providing five new text clustering methods--Query Sense Clustering (QSC), Dirichlet Weighted K-means (DWKM), Multi-View Multi-Objective Evolutionary Algorithm (MMOEA), Multi-objective Document Clustering (MDC) and Multi-Objective Multi-View Ensemble Clustering (MOMVEC). These five new clustering methods showed that the use of rich features in text clustering methods could outperform the existing state-of-the-art text clustering methods. The first new text clustering method QSC exploits user queries (one of the rich features in text data) to generate better quality clusters and cluster labels. The second text clustering method DWKM uses probability based weighting scheme to formulate a semantically weighted distance measure to improve the clustering results. The third text clustering method MMOEA is based on a multi-objective evolutionary algorithm. MMOEA exploits rich features to generate a diverse set of candidate clustering solutions, and forms a better clustering solution using a cluster-oriented approach. The fourth and the fifth text clustering method MDC and MOMVEC address the limitations of MMOEA. MDC and MOMVEC differ in terms of the implementation of their multi-objective evolutionary approaches. All five methods are compared with existing state-of-the-art methods. The results of the comparisons show that the newly developed text clustering methods out-perform existing methods by achieving up to 16\% improvement for some comparisons. In general, almost all newly developed clustering algorithms showed statistically significant improvements over other existing methods. The key ideas of the thesis highlight that exploiting user queries improves Search Result Clustering(SRC); utilizing rich features in weighting schemes and distance measures improves soft subspace clustering; utilizing multiple views and a multi-objective cluster oriented method improves clustering ensemble methods; and better evolutionary operators and objective functions improve multi-objective evolutionary clustering ensemble methods. The new text clustering methods introduced in this thesis can be widely applied in various domains that involve analysis of text data. The contributions of this thesis which include five new text clustering methods, will not only help researchers in the data mining field but also to help a wide range of researchers in other fields.

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  • Palaeomagnetic secular variation recorded by lavas from the Taupo Volcanic Zone, New Zealand

    Greve, Annika (2016)

    Doctoral thesis
    Victoria University of Wellington

    In order to understand the origin, temporal behaviour and spatial characteristics of Earth’s magnetic field, globally distributed records of the palaeomagnetic direction and absolute palaeointensity are required. However a paucity of data from the southern hemisphere significantly limits the resolution of global field models, particularly on short time-scales. In this thesis new, high quality palaeomagnetic data from volcanic materials sampled within the Taupo Volcanic Zone, New Zealand are presented, with a focus on the Tongariro and Okataina Volcanic Centre. New palaeomagnetic directions were obtained from 19 andesitic or rhyolitic lavas, of which 10 also produced successful palaeointensity results. Palaeointensity experiments were conducted using a combination of traditional Thellier-type thermal, and microwave techniques. Detailed magneto-mineralogical investigations carried out alongside these experiments helped to characterise the primary remanence carriers and to justify the reliability of the results. The study also revises the age controls and results from earlier palaeomagnetic studies on Holocene volcanic materials from the area. All new or revised data are summarized into a new data compilation for New Zealand, which includes 24 directions and ten palaeointensities dated between 1886 AD and 15,000 yrs BP. The new directional data reproduces the features of the most recently published continuous record from Lake Mavora (Fiordland, New Zealand), although with directions ranging in their extremes from 321° (west) to 26° (east) declination and -82 to -49° in inclination, the discrete dataset describes somewhat larger amplitude swings. With few exceptions, the new palaeointensity dataset describes a steady increase in the palaeointensity throughout the Holocene, from 37.0 ± 5.7 μT obtained from a pre-8 ka lava to 70.6 ± 4.1 μT from the youngest (≤ 500 yrs BP) flows sampled. A similar trend is also predicted by the latest global field model pfm9k. Furthermore, the data falls within the range of palaeointensity variation suggested by the Mavora record. The dataset roughly agrees with a global VADM reconstruction in the early Holocene (> 5000 yrs BP), but yields values significantly above the global trend in the late Holocene (< 1000 yrs BP) which supports the presence of significant non-dipolar components over the SW Pacific region in the time period, visible in global field models and from continuous PSV records. A comparison of the directional records with the Mavora Curve provided refinement of age estimates of five lava flows from the Tongariro Volcanic Centre, from uncertainties in the range of 2-3000 years. The new palaeomagnetic emplacement age estimates for these flows have age brackets as short as 500 years and thus highlight different phases of the young cone building eruptive activity on Ruapehu volcano.

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  • Tensions and Possibilities. The Interplay of 'Traditional' Cultural Elements and the Creation of 'Contemporary' Rapa Nui, Māori and Samoan Diasporic Theatre

    Fortin Cornejo, Moira (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis focuses on notions of ‘traditional’ and ‘contemporary’ theatre in two Pacific Island contexts, Aotearoa and Rapa Nui. It explores how notions of ‘tradition’ are imagined, recreated, and performed through the ‘contemporary’ creative arts, with a particular focus on theatre. It offers insight about culturally-situated understandings of ‘tradition’, and seeks to acknowledge diverse meanings and perceptions of theatre that exist across diverse Pacific Island cultures, languages, and epistemologies. Ideas about what constitutes ‘tradition’ have been significantly impacted by colonial histories, and that these culturally and historically situated ideas have wide-ranging implications for creative possibilities in the ‘contemporary’ performing arts. ‘Traditional’ performances are often seen as acceptable and relevant to Indigenous communities in Aotearoa and Rapa Nui, contributing to processes of cultural reclaiming and revitalisation. Although cultural continuity is a significant theme in Indigenous theatre in Aotearoa and Rapa Nui, the different emphasis placed upon notions of ‘tradition’ across these comparative contexts has led to very different artistic possibilities being available. In Rapa Nui there is a general reluctance in the performing arts to deviate from ‘tradition’ or to declare work as ‘contemporary.’ The reproduction of ‘traditional’ styles and stories is one response to ongoing colonialism in Rapa Nui, and to the ever present demands of the tourist industry. Māori and Samoan theatre practitioners in Aotearoa have developed theatre forms and processes that are based in cultural values and epistemologies while also being integrated with European theatre techniques, creating innovative approaches to ‘contemporary’ themes and understandings. These developments in the creative arts are supported by the availability of a wide range of theatre education opportunities. Culturally reflective and situated approaches to theatre education have enabled Indigenous theatre practitioners in Aotearoa to use theatre as a forum to express ideas and issues to the community weaving in a variety of different cultural influences, and techniques. This thesis utilised a case-study methodology and open-ended interviews, framed under the research methodology of talanoa, to interact with Māori, Samoan diasporic and Rapanui theatre practitioners, in order to explore their perceptions towards ‘traditional’ and ‘contemporary’ practices. This research focuses on the positives of cultural dialogue, and it emerges from a desire to support intercultural theatre practices in Aotearoa and Rapa Nui.

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  • Parasite Ecology and the Conservation Biology of Black Rhinoceros (Diceros bicornis)

    Stringer, Andrew Paul (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis combines investigations of parasite ecology and rhinoceros conservation biology to advance our understanding and management of the host-parasite relationship for the critically endangered black rhinoceros (Diceros bicornis). My central aim was to determine the key influences on parasite abundance within black rhinoceros, investigate the effects of parasitism on black rhinoceros and how they can be measured, and to provide a balanced summary of the advantages and disadvantages of interventions to control parasites within threatened host species. Two intestinal helminth parasites were the primary focus of this study; the strongyle nematodes and an Anoplocephala sp. tapeworm. The non-invasive assessment of parasite abundance within black rhinoceros is challenging due to the rhinoceros’s elusive nature and rarity. Hence, protocols for faecal egg counts (FECs) where defecation could not be observed were tested. This included testing for the impacts of time since defecation on FECs, and whether sampling location within a bolus influenced FECs. Also, the optimum sample size needed to reliably capture the variation in parasite abundance on a population level was estimated. To identify the key influences on parasite abundance, the black rhinoceros meta-population in South Africa presented an extraordinary and fortuitous research opportunity. Translocation and reintroduction have created multiple populations from the same two source populations, providing a variety of comparable populations with the same host-parasite relationship. I applied my population-level faecal sampling and egg count protocol to collect 160 samples from 18 black rhinoceros populations over two summer sampling periods between 2010 and 2012. I test hypotheses for the influence of a variety of ecological and abiotic factors on parasite abundance. To test for the influence of individual-level host characteristics on parasite abundance, such as age and sex, I collected rectal faecal samples at the translocation of 39 black rhinoceros. At that time I also investigated the influence of body condition on a variety of measures of host resources, such as the size of sexually selected characteristics. Finally I developed a logical and robust approach to debate whether parasites of threatened host species should be controlled. For faecal egg counts, samples taken from the centre of faecal boluses did not change significantly up to six hours after defecation. The only factor which significantly affected the size of confidence intervals of the mean parasite abundance for a host population for both parasite groups was the level of parasite aggregation. The accuracy of estimates of mean parasite abundance increased with increasing sample size, with >9 samples having little further effect on accuracy. As host defecation no longer needs to be observed the efficiency of fieldwork for studies investigating elusive host species is greatly increased. On a population level, host density was the leading model explaining the abundance of both a directly and an indirectly transmitted parasite. For instance, doubling host density led to a 47% rise in strongyle parasite abundance. I found no support for competing hypotheses, such as climate-related variables, that were thought to affect the abundance of free-living stages of macroparasites. This result will be useful to conservationists as it will allow them to predict where parasite abundance will be greatest and may also reveal potential avenues for parasite control. On an individual level, younger individuals may have harboured higher levels of parasitism (p = 0.07). This result would be widely supported by the literature, but a larger host age range is needed to verify the result. I identified four sexual dimorphisms, with anterior horn volume and circumference, and body size, all showing a sex difference in both the slope and intercept of regression lines. Although sexually selected traits are implicated as most vulnerable to parasite impacts, I did not find an influence of parasite abundance on the size of these potentially sexually-selected characteristics or other measures of body condition. This may be because of numerous different factors affecting host resources, of which the parasite groups studied are a relatively small proportion. Parasites can be an important cause of population decline in threatened species. However, the conservation of potentially threatened parasites within host species is rarely considered. Here, I debated the potential benefits and pitfalls of parasite control to help identify the principles behind parasite control within threatened species. I rank 11 identified different types of parasite control by their potentially detrimental effects on host populations and ecosystems. I conclude that as the risk a parasite poses to host extinction increases, so does the justification for using parasite control methods with potentially detrimental effects. Also, the extinction risk of the parasite should determine the need for dedicated parasite conservation programs. These principles may be predominantly intuitive, but there are a number of examples in the literature where they have not been used, such as the treatment of parasites with low levels of virulence in host species of ‘least concern’. The principles provide a framework for the adaptive implementation of parasite control strategies in conservation-reliant species, like rhinoceros. I embarked on the first multi-population and comparative study of host-parasite relationships in the critically endangered black rhinoceros. This was made possible by empirically testing and refining field sampling protocols to overcome concerns about sample identification, number, and age. Through these well-developed, efficient sampling methodologies I was able to determine that host density was the main influence on parasite abundance within black rhinoceros on a population level – a result not previously proven for macroparasites. Influences on individual level variation need further investigation. In particular genetic factors, such as inbreeding, were not researched as part of this study. I successfully identified a number of sexual dimorphisms, but found no evidence that they were influenced by individual parasite abundance. Finally I use a targeted review of the literature to propose some principles behind whether parasites should be controlled within threatened host species. These principles should allow conservation managers to focus resources on those situations where parasite control is needed, and also help conservation managers avoid the potentially detrimental effects of parasite control. In these ways this thesis has advanced the study and understanding of parasites, their ecology, and their relationship to conservation-reliant hosts.

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  • Digital service problems: Prevention and user persistence in solving them

    Nili, Alireza (2016)

    Doctoral thesis
    Victoria University of Wellington

    The service sector is an important and consistently growing sector of the world economy. It is estimated that the sector will make up two thirds of the total world Gross Domestic Product (GDP). Information Technology (IT) has been an important contributor to the fast and high grow of the sector by increasingly digitising the production, delivery and use of services. IT has enabled multiple parties, including user support service staff, employees (internal IT users) and customers (external IT users) of an organisation, to engage in the production, delivery and use of digital services. Consequently, both users and user support service staff of the organisations have an increased responsibility to both prevent IT problems from occurring, and solve them when they do occur. Problems with ITs can occur at different stages of a digital service value chain (i.e. sequential steps/stages required to produce and deliver a digital service), and may lead to a service failure in the user’s mind. Examples include problems with a self-check-out machine at a library, problems with an online registration system that occurs for university students, or a website that does not include an online payment functionality a user expects. Numerous studies in both Information Systems (IS) and service literature have focused on the role of the service staff in both preventing and solving digital service failures, but few have considered the user’s role in these. This thesis includes four original articles. The first article emphasises that prevention from digital service failures must be considered before establishing effective approaches to solving the problems. The article presents a typology of technologies and technological approaches that customers and businesses can use to support prevention from these failures. The rest of the articles consider situations where an IT-related service problem has occurred, and address the user’s behaviour of persistence in solving their own IT problem. From the user’s perspective, their persistence in solving the problem contributes to achieving a satisfactory outcome, and from the organisational perspective, such an outcome is important for maintaining their user satisfaction. User persistence is important both when trying to solve an IT problem alone, and when using support services. Studying user persistence can help organisations to design their user support services in a way that encourages user persistence, resolves the problems more efficiently and cheaply; and maintains their user satisfaction. The study of user persistence included the use of focus groups for data collection purposes. Surprisingly, qualitative methodology literature has little to say on analytical approaches to focus group data – particularly interactive participant data. Therefore, a focus group analysis framework was designed (presented in the second article) and was used in the analysis phase of the user persistence study. The third article uses the framework in its analysis phase, and (a) presents a conceptual clarification of user persistence in IT problem solving, (b) identifies the factors that contribute to user persistence, (c) develops a theory to explain that why a user decides to persist with a method of solving IT problems, and (d) develops a theory to explain that why the user decides to persist with the overall process (collective methods) of solving the problem. The fourth article presents the results of evaluating the robustness of the two theories and shows that the two theories are confirmed. The thesis concludes with the ‘contributions and conclusion’ chapter where it presents a summary of the contributions of the four articles to IS theory, methodology and practice.

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  • Language learner cognition: Exploring adult migrants’ L2 activity beyond the classroom

    Navarro, Diego (2016)

    Doctoral thesis
    Victoria University of Wellington

    For years, understanding the relationship between behaviour and cognition has been a central concern of research conducted in the social sciences. In fields as diverse as anthropology, business, medicine, and education it is widely accepted that the development of practice (as a type of behaviour), depends on a precise understanding of how thought gets carried into action. However, studies investigating the complex interplay between a learner’s cognition (i.e. thoughts, knowledge, beliefs, and feelings about L2 learning) and their behaviour (i.e. language-related activity) are only recently garnering attention. In addition, only few studies have looked at this dynamic process with adult participants beyond the language learning classroom. Framed within the context of naturalistic language learning, this investigation explores the social construction of adult (over 30 years of age) L2 learners’ cognition in an ESOL setting. Specifically it aimed to answer the following research questions: RQ 1. What are the prior language learning experiences of a group of adult migrant learners living in New Zealand? RQ 2. How have these prior language learning experiences influenced the construction and development of their beliefs, assumptions, knowledge (BAK) about language learning? RQ 3. What is their perceived need for English in their current socio-cultural context? RQ 4. How do adult migrant language learners engage in language related activities beyond the classroom? RQ 5. How can this language learning behaviour be reflected in a model of language learner cognition? The study combined a longitudinal, ethnographic approach, with elements of narrative and case study inquiry. Six ‘recently arrived’ (Dunstan, Roz, & Shorland, 2004a) Colombian migrants (five refugees; one immigrant) were asked to talk about and discuss both prior and current experiences learning and using an L2. Through these lengthy in-depth, conversation-like interviews conducted in Spanish (the participants’ L1), told over time, a nuanced picture of the participants’ L2-related cognition emerged. As a result, I was able to more clearly observe the dynamic process in which a language learner’s mental life both impacts and is impacted on by language-related activity throughout their day-to day interactions. The participants are seen engaging in the L2 across a range of settings including at home, the doctor’s office, supermarkets and work. Moreover, in their accounts of this engagement we see change and revision (i.e. development) in their thinking about L2 learning and themselves as language learners, as well as their feelings toward the L2, other L2s and L2 users. A single participant was selected as an exemplary case to examine in detail, and facilitate understanding of this development. A case study approach allowed for a more intricate exploration of how the interplay between thought, emotion, and context impacted on the learner’s approaches to language-related activities. Issues regarding readiness to interact in the L2, intelligibility, language variety, and aversion to the ‘sound of English’ were seen as playing significant roles in the learner’s language development. This analysis resulted in the construction of a framework depicting language learner cognition in action. In terms of implications, this research supports the case for more qualitative research in SLA which centres learners’ perspectives of their L2 related experiences, particularly when so much of what seems to be affecting learning is the learners understanding of themselves and their actions. It also argues that studies in L2 cognition should focus their investigations on the developmental processes involved in the social construction of the mental factors which impact language learning and use. Finally, while belief studies in SLA are expanding the scope of their investigations – by looking to include more emotion and other affective factors, as well as by branching out into self-related constructs such as self-concept and self-efficacy in the foreign language domain – these studies remain limited in their almost microscopic view of learners’ mental lives. The picture of cognition I offer provides a more holistic understanding of this phenomenon which helps account at a macro-level for L2 behaviour. The study also highlights the potential and power of data gathering methods which foreground the participants’ voices and ideas (i.e. in-depth, unstructured interviews told over time) – reminding us that it is important when looking for what drives language learning behaviour to consider what the learners feel and think.

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  • Accessibility and development in rural Sarawak. A case study of the Baleh river basin, Kapit District, Sarawak, Malaysia

    Abdullah, Regina Garai (2016)

    Doctoral thesis
    Victoria University of Wellington

    To what degree does accessibility to markets correlate with levels of development? This is an important question for those living in remote, underdeveloped parts of Southeast Asia during the final phases of de-agrarianisation. My study recounts the experience of rural-based Iban households living in the Baleh river basin of the Kapit District (population of 54,200) within a day or less travel by river to the small market town of Kapit (with a population of 18,000). With no connecting roads to the rest of Sarawak and reliant almost entirely on river transport, the local economy remains underdeveloped and is losing population. My field work among 20 villages in three accessibility zones of the Baleh river basin was undertaken over the three month period of May-July 2014. Structured interviews were conducted with 20 village headmen (tuai rumah), 82 heads of household, and 82 individuals within the households. Data was also systematically collected on 153 other individuals, including both residents and non-resident members of these bilik-families. My conceptual framework draws on von Thünen’s model of agricultural land use in order to generate expectations about the possible effects of market accessibility. While the sale of vegetables and other commodities accords with expected patterns, most rural households are in fact dependent on other, largely non-agricultural sources of income. As a result there has emerged a disjuncture between the nominal and actual residence as those working age family members with residential rights to the bilik undertake paid work well beyond the agricultural margin. Unable to achieve desired standards of living by accessing local markets and services in a division with no cities or roads, the working age members of the bilik sustain their families by dividing their residence between two or more locations in what I call multi-local living. The income of nominally rural households is being increasingly determined by the human capital that individuals now apply to non-agricultural labour markets. This, in turn, is leading to a widening distribution of levels of ‘development’, across individuals, their multi-generational families and their rural communities. Multi-local living is unsustainable beyond the transitional phase of de-agrarianisation and as labour shifts out of agriculture and people move to towns, connections with rural residence are likely to diminish, notwithstanding the cultural ties, and disputes over realising market values of largely untitled land will continue to complicate the transition.

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  • The geochemistry of antimony in hydrothermal solutions

    Olsen, Nellie J. (2016)

    Doctoral thesis
    Victoria University of Wellington

    In this thesis, 30°C stibnite solubility experiments, ambient temperature X-ray absorption spectroscopic measurements of antimony in solution, and high temperature (70 to 400°C) stibnite solubility experiments were carried out in order to determine the aqueous antimony species present in equilibrium with stibnite in hydrosulfide solutions from pH = 3.5 to 12 and reduced sulfur concentrations from 0.001 to 0.1 mol kg⁻¹. Both ambient and elevated temperature solubility studies were conducted using a flow-through apparatus containing a column of stibnite grains though which solutions were pumped. Above 100°C, solubility experiments were conducted at slightly above saturated water vapour pressure to pressures of 300 bar. At 30°C, the stibnite solubility curve was best reproduced by a scheme of five species: Sb₂S₄²⁻, HSb₂S₄⁻, H₂Sb₂S₅²⁻, H₃SbS₂O, and Sb(OH)₃. At higher temperatures (≥ 70 °C), stibnite solubility at the conditions of the experiments was due to the following four species: Sb₂S₄²⁻, HSb₂S₄⁻, H₃SbS₂O, and Sb(OH)₃. Equilibrium constants were determined for the following five heterogeneous solubility reactions for the temperature ranges listed: [Please consult the thesis for details.] Stibnite solubility was independent of pressure at ≤ 350°C. At ~ 400°C, the solubility of stibnite was strongly dependent on pressure and decreased from Sbtotal = 0.015 to 0.0003 mol kg⁻¹ (~2000 to 40 ppm) with a pressure decrease from 300 to 160 bars. The Sb K-edge X-ray absorption spectroscopic (XAS) measurements of antimony in alkaline (pH = 10. 9 to 12) hydrosulfide solutions gave average first shell coordination environments that were consistent with the speciation model derived from solubility experiments for strongly alkaline solutions (i.e., Sb₂S₄²⁻ and Sb(OH)₃). XAS data enable the elimination of a speciation model involving only monomeric antimony complexes at strongly alkaline pH. Antimony speciation in near neutral to strongly alkaline pH’s is dominated by dimeric antimony-sulfide complexes at 30°C and sulfide concentrations > 0.001 mol kg⁻¹. With increasing temperature, antimony speciation becomes increasingly dominated by Sb(OH)₃. For hydrothermal solutions with sulfide concentrations between 0.0001 and 0.01 mol kg⁻¹, antimony-sulfide complexes are predominant at < 100°C, whereas antimonous acid, Sb(OH)₃, is the main aqueous species at contributing to stibnite solubility at > 200°C with the speciation in the intervening temperature range being dependent on the pH and sulfide concentration of the solution. For higher sulfide concentrations (i.e., ~ 0.1 mol kg⁻¹), HSb₂S₄⁻ and Sb₂S₄²⁻ control stibnite solubility to higher temperatures.

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  • Phylogenetic Networks that Display a Tree Twice

    Cordue, Paul Joseph (2016)

    Doctoral thesis
    University of Canterbury Library

    In the study of phylogenetics, which is the study of how forms of life evolve and relate to each other, there is great scope for mathematics to get involved. One such study of phylogenetics that currently employs mathematics is the study of phylogenetic networks and phylogenetic trees. Phylogenetic networks and trees can be used to represent how life evolved with the former having the ability to represent biological processes such as hybridization, horizontal gene transfer, and gene recombination. In terms of mathematics, one sees phylogenetic networks and trees as directed graphs. A phylogenetic network N displays a rooted phylogenetic tree T if all of the ancestral history inferred by T is also inferred by N. The main result of this thesis is a quartic-time, in terms of the number of leaves in the network, algorithm that decides whether or not a given phylogenetic network displays a tree twice. As a consequence of the work leading to the main result, a class of phylogenetic networks is discovered such that there is a quadratic-time, in terms of the number of leaves in the network, algorithm for counting the number of distinct trees displayed by a given network in the class. These results are interesting because it has been shown that in general counting the number of trees displayed by a given phylogenetic network is #P-complete. Thus the main result of this thesis opens the door to insights regarding a computationally hard problem.

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  • Geopolitical anomalies : exceptionalities and regularities of international politics.

    Knotter, Lucas (2016)

    Doctoral thesis
    University of Canterbury Library

    As international law and legally recognised states have been generally taken as the primary structures and actors of international politics, polities without those legal rights and privileges have been subordinated as rather insignificant in international relations. Over the past few years, however, events in Ukraine, as well as in Iraq and Syria, have reminded us of the persistence of such unrecognised polities claiming a semblance of statehood in international politics. This thesis, therefore, contends that the abundance and tenacity of these unrecognised political entities suggests a reconsideration of purely “legal” notions of international political life. It employs the term “geopolitical anomalies” (McConnell 2009a; 2009b; 2010) – political entities without the recognised rights and privileges of legal states, but with state-like structures and manifestations nonetheless – to call for a more serious consideration of these “actual” political exercises in international relations. This concept of geopolitical anomalies is utilised as a signifier of the physical and spatial manifestations of a wide array of political communities that demonstrate the essential irregularity of the international legal and political system. By specifically focusing on the differences between conceptualisations of juridical (de jure) and material (de facto) of sovereignty, this thesis aims to demonstrate how geopolitical anomalies help us gain a clearer understanding of the differences between legal and normative power, material power relationships, and specific manifestations of de facto sovereign power. Utilising classical realist perspectives on the nature of de facto sovereignty, based in the ideas of Thomas Hobbes, Carl Schmitt, and Hans Morgenthau, this thesis argues that geopolitical anomalies are best understood as manifestations of exceptions and crises in international law and international politics. In order to shed light on these theoretical contentions, and draw out different aspects of the existence of geopolitical anomalies in international politics, two examples – Somaliland and Kosovo – are thoroughly examined in three chapters. This thesis concludes, subsequently, that in spite of persistent assumptions about the (trans)formative and regulatory capacity of international norms and legalities, precisely these assumptions are rebuked by geopolitical anomalies. As a consequence, any possible future vision for the dissolution of geopolitical anomalies from international politics will have to come to terms with its own exceptions.

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  • Application of process factors to the inter-video modality : an examination of expectations and the therapeutic relationship in therapy conducted through a video-link.

    Wiingaard, Signe Uldall (2016)

    Doctoral thesis
    University of Canterbury Library

    Background. This thesis reports the findings of four studies that examined the effect of different variables (e.g., video-link use, shame, therapist eye-contact) on expectations and the therapeutic relationship in the context of Inter-video therapy. Results are discussed with respect to promotion of Inter-video therapy, improvement of clients’ Inter-video therapy experience, and recommendations regarding therapist style of eye-contact. Method. One survey study and three experimental studies were performed. Study 1 (N = 197), a survey study, examined Inter-video therapy preferences and expectations. Study 2 (N = 36) evaluated the effect of therapist-participant physical similarity on Inter-video therapist expectations. Study 3 (N = 19) manipulated therapist eye-contact to evaluate the effect of eyecontact on the therapeutic relationship. Study 4 (N = 49) examined both the effect of eye-contact on the therapeutic relationship and the influence of expectations on this relationship and on outcome. Study 4 also evaluated the association between session measures (empathy, alliance, session evaluation) and outcome. Results and implications. There was a clear discrepancy between participants’ perception of Inter-video therapy (hesitant) and their experience of it (positive), indicating more positive information about this e-therapy modality may be important to enhance expectations and hence use. Therapist rather than therapy expectations had an effect on Inter-video therapy experiences and outcome. As reported in the studies, more visual, factual and personal information about the therapist may increase Inter-video therapist expectations. Therapist-participant physical similarity did not appear to have a positive influence on expectations; indeed it had a negative influence for males with prior therapy experience. Consistent with prior research, participants rated their Intervideo therapy experiences positively, reflected in high rating of working alliance and empathy across the eye-contact conditions. There was no clear positive effect of more direct eye-contact. Instead, there was an interaction effect between eye-contact and shame, indicating the downcast eye-contact associated with video-link communication might assist initial engagement with clients who struggle with shame. Unexpectedly, there was a significant difference in the relationship between the session measures and one of the outcome measures as a function of eye-contact. The difference indicated eye-contact might moderate the relationship between alliance and outcome and this might be important for future research to consider. Conclusions. Participants in this research experienced Inter-video therapy very positively, and results indicated the eye-contact distortion associated with Inter-video therapy should not be a cause for concern regarding the therapeutic relationship. Indeed the downcast eye-contact might facilitate therapy engagement for some clients and could be one reason why some clients perceive Inter-video therapy as more comfortable than in-person therapy. However, the research also indicated participants’ perceptions and expectations toward Inter-video therapy were tentative, especially as compared to perceptions and expectations toward in-person therapy. This latter finding will be important to address to further develop the use and outreach of Inter-video therapy.

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  • Assessment of individual trees using aerial laser scanning in New Zealand radiata pine forests.

    Pont, David (2016)

    Doctoral thesis
    University of Canterbury Library

    Forest managers aim to maximise the productivity, profitability, health, and sustainability of New Zealand’s plantation forests. There is an increasing need for high quality information about forest stands to support effective management. This is exemplified in the concept of precision forestry, which maps variation at a fine scale to allow targeted management, and in the concept of tree-level phenotyping, which quantifies the genetic and environmental drivers of tree growth. Remotely sensed data, in particular airborne laser scanning (ALS), was identified as having strong potential to provide tree level information to assist in attaining the goals of phenotyping and precision forestry. Tree-based, rather than area-based, analyses of ALS were identified as being essential to separate and quantify genetic and environmental factors on individual tree growth, and therefore critical to the development of novel phenotyping methods supporting precision forestry. The aim of this study was therefore to develop methods to characterise individual trees using remotely sensed airborne laser scanning data. The research was focussed on evaluating the utility of ALS data to estimate key operationally relevant tree attributes for New Zealand plantation-grown radiata pine. Review of the literature identified three key research questions within which to frame the study. The first research question addressed the need to obtain accurate estimates of tree size, form, wood quality and disease attributes from ALS. A set of 36 individual tree crown metrics were derived from ALS data and evaluated for their correlations with ground measurements of the attributes. The second research question was aimed at evaluating the utility of tree-level ALS data in the analysis of genetic and environmental variance components and the estimation of genetic parameters, including genetic gains. The third research question evaluated the effects of ALS pulse density on estimates obtained from tree-level analyses of ALS data. Strong correlations were established between morphological crown metrics and tree size attributes (r=0.90, 0.82, and 0.84 for H, DBH and V respectively), but not for tree form and wood quality attributes. A moderate correlation (r=0.50) with the level of Dothistroma infection was attributed to the effect of the disease on tree growth, indicating potential for disease phenotyping using remote sensing. Accurate estimates of variance components and genetic parameters were obtained from ALS for tree size attributes, but not for tree form, wood quality and disease attributes. For H, DBH, and V crown-based versus ground-based estimates of narrow sense heritabilities were within 5.0%, 19.5% and 23.9%, and estimates of genetic gains (96 tree selection level) were within 19%, 25%, and 25% respectively. Manually corrected tree segmentations were found to provide negligible improvements to correlations and estimates of genetic parameters, supporting the operational use of automated methods. Exponential reductions in tree detection accuracy, correlations, and estimates of genetic parameters were observed with reducing pulse density. A minimum pulse density of 6 Pu.m2 was recommended for tree-based analysis of ALS in New Zealand radiata pine stands, and results indicated exponential increases in pulse density will be required to significantly improve estimates. This study has successfully addressed the research questions and produced important findings regarding tree-based analysis of remotely sensed ALS data. Morphological crown metrics have been derived, representing allometric relationships, which are therefore are expected to have general utility in estimating tree size attributes. Novel features of this research included: the wide range of operationally relevant tree attributes including tree size, form, wood quality and disease; quantification of genetic and environmental factors from ALS; comparison of the effects of automated and manually corrected tree delineations; and the quantification of the effects of pulse density on tree-based analyses. This research provides significant findings in support of the use of remotely sensed ALS data for phenotyping trees in genetics and research trials, and the development precision forestry methods, nationally and internationally.

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  • Comparisons of the influence of phonological and morphological processing on Chinese reading developmen t: a cross-sectional and longitudinal study

    Ma, Shaowei (2016)

    Doctoral thesis
    University of Canterbury Library

    The underlying rationale behind alphabetic orthographies is that graphemes roughly correspond to phonemes. However, in the Chinese writing system, the basic unit is a character that usually represents one syllable and corresponds to one morpheme. Given that phonological awareness plays a central role in reading acquisition for alphabets that follow regular grapheme-phoneme correspondence rules, it seems likely that morphological awareness should be more important for learning to read scripts in which the mappings between orthography and meaning are often systematic. Such fundamental differences in the orthographies may have significant implications for the way written words are recognized and, hence, the way reading is acquired. In mainland China, children learn Chinese characters through being taught the more alphabetic script of Pinyin. It is, therefore, likely that the Pinyin system, as well as the Chinese characters system, will influence reading development. Therefore, a complex relationship between reading, phonological and morphological processing may be predicted, with the influence of the latter two on the former varying with development – as Pinyin becomes less important for decoding, phonological influences may be superseded by morphological. The present research investigated the early development of Chinese reading skills to assess potential changes in phonological and morphological influences. Measures of reading Pinyin and Chinese characters were given to children in primary-level school grades in Mainland China. Over the course of the study, grades 1 to 5 were assessed with about 50 children in each grade tested. Measures of word and non-word reading, as well as reading comprehension were used. In addition, a range of phonological and morphological tasks were developed, and these were contrasted with Chinese vocabulary and rapid naming, to measure the potential impact of these language skills on Chinese reading. Cross-sectional and longitudinal analyses were conducted to assess such impacts. Both cross-sectional and longitudinal data indicated a change in relationships across grades such that early phonological predictors of Chinese character and text reading were replaced by morphological processing skills and measures of rapid naming. The results argue that phonological awareness plays an important role in reading acquisition at the beginning of acquisition for these Mainland Chinese students, whereas morphological processing is more important for intermediate and upper graders in later stages of reading development. These findings are discussed in relation to current general models of reading and specific influences of orthography, as well as the context of literacy learning within Mainland China.

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  • Light morphology and arabic information retrieval.

    Algarni, Mohammed (2016)

    Doctoral thesis
    University of Canterbury Library

    The chief purpose of this study is to investigate the impact of mor- phology on Arabic Information Retrieval (AIR). In doing so, different forms of the surface word have to be examined as indexing terms in order to learn which is the most effective in performance. Exper- iments are needed starting with the root all the way to the surface form so that we can evaluate the difference each selection makes. This has resulted in the development of two experimental stemmers for the Modern Standard Arabic (MSA), one light and the other root-based, which will be referred to hereafter as the Simple Arabic Stemmer (SAS). The stemmers were based on the Quran morphology and con- structed according to its rules. They conform to the Quran guidelines in terms of segmenting a word into its correct morphological combi- nation (prefix-pattern-suffix). The reason for leveraging the Quran as a morphological knowledge base was that the Arabic morphological rules were documented according to the Quran relatively soon af- ter it became known. Using the Text REtrieval Conference (TREC) 2002 Arabic corpus, which contains 383,872 documents, 75 topics, and 10,031 manually-judged documents, we test our approach against two widely-used root stemmers, Khoja and Sebawai. In the experi- ments, our root algorithm has generated better Mean Average Preci- sion (MAP), giving a 13% relative gain over the other stemmers. The Simple Arabic Stemmer outperformed both stemmers in producing more accurate roots for the TREC corpus. We demonstrated that, by placing a restriction on what prefix-pattern-suffix combinations are permissible on the surface, the stemming process would be enhanced, and fewer stemming errors are produced. Another experiment was conducted to measure the difference between the stem and the root as indexing terms. Due to the fact that a root conflates so many stems under one form, its precision degraded when used as an indexing term. The results obtained favoured choosing the stem as an indexing term.

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  • Bacterial sialic acid degradation: membrane transport and enzymology

    North, Rachel Aimee (2016)

    Doctoral thesis
    University of Canterbury Library

    The overarching aim of this thesis is to understand how sialic acids are transported into the bacterial cell and then degraded by bacterial pathogens. In heavily sialylated environments, bacterial pathogens utilise host-derived sialic acid as a nutrient source, and this pathway constitutes a novel and unexploited target for antibiotic drug design. Three sialic acid transporters, from two distinct gene families were investigated to probe how sialic acid is transported across the cytoplasmic membrane. The Yersinia pestis sugar proton symporter (NanT) exists as a single species in solution, while the Staphylococcus aureus sodium solute symporter (SSS) and Proteus mirabilis SSS appear to be in a selfassociation. It is likely that the SSS sialic acid transporters exist in a monomer-dimer equilibrium, although higher oligomeric structures cannot be ruled out. The structure of the P. mirabilis SSS sialic acid transporter was solved, which is the first known structure of a sialic acid transporter to be presented. It was solved in complex with sialic acid and two sodium ions, providing insight into how this transporter mediates the movement of sialic acid across the membrane. In addition, the structure presents a novel conformation among sodium symporters and the structural basis for the movement of sialic acid across the membrane is elucidated. Following the import of sialic acid into the bacterial cell, N-acetylneuraminate lyase is the first enzyme involved in its degradation. The structure, function and inhibition of methicillin-resistant S. aureus (MRSA) N-acetylneuraminate lyase were investigated. Solution and structural studies confirmed that this enzyme is tetrameric. Kinetic analysis was employed to test an inhibitor of N-acetylneuraminate lyase enzymes. This molecule demonstrated strong species-specific inhibition against MRSA N-acetylneuraminate lyase. The structure of MRSA N-acetylneuraminate lyase in complex with this inhibitor demonstrated that altered binding modes between N-acetylneuraminate lyase enzymes may account for variable inhibition between species. In addition, evidence for a protein-protein interaction between the S. aureus SSS sialic acid transporter and MRSA Nacetylneuraminate lyase is presented. Thus, these proteins may interact at the cytoplasmic membrane, allowing the degradation of sialic acid to be initiated upon entering the cell. The structure, function and catalytic mechanism of the third enzyme involved in sialic acid degradation, N-acetylmannosamine-6-phosphate 2-epimerase, were explored from MRSA. This enzyme was demonstrated to adopt a dimeric architecture in solution, consistent with the crystal structure that was solved and presented. A multi-enzyme coupled assay was developed to assess N-acetylmannosamine-6-phosphate 2-epimerase activity in real time. Residues were probed that may be important for catalysis and tested by mutagenesis and kinetic analysis. A novel mechanism of carbohydrate epimerisation is proposed for this enzyme, whereby catalysis occurs via a proton displacement mechanism mediated by the substrate. Overall, this work provides new data that enriches our understanding of the import and degradation of sialic acid in clinically important human bacterial pathogens.

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  • Paleoseismicity and Rupture Characteristics of the Greendale Fault and Formation of the Canterbury Plains

    Hornblow, Sharon (2016)

    Doctoral thesis
    University of Canterbury Library

    The previously unknown Greendale Fault was buried beneath the Canterbury Plains and ruptured in the September 4th 2010 moment magnitude (Mw) 7.1 Darfield Earthquake. The Darfield Earthquake and subsequent Mw 6 or greater events that caused damage to Christchurch highlight the importance of unmapped faults near urban areas. This thesis examines the morphology, age and origin of the Canterbury Plains together with the paleoseismology and surface-rupture displacement distributions of the Greendale Fault. It offers new insights into the surface-rupture characteristics, paleoseismology and recurrence interval of the Greendale Fault and related structures involved in the 2010 Darfield Earthquake. To help constrain the timing of the penultimate event on the Greendale Fault the origin and age of the faulted glacial outwash deposits have been examined using sedimentological analysis of gravels and optically stimulated luminescence (OSL) dating combined with analysis of GPS and LiDAR survey data. OSL ages from this and other studies, and the analysis of surface paleochannel morphology and subsurface gravel deposits indicate distinct episodes of glacial outwash activity across the Canterbury Plains, at ~20 to 24 and ~28 to 33 kyr separated by a hiatus in sedimentation possibly indicating an interstadial period. These data suggest multiple glacial periods between ~18 and 35 kyr which may have occurred throughout the Canterbury region and wider New Zealand. A new model for the Waimakariri Fan is proposed where aggradation is mainly achieved during episodic sheet flooding with the primary river channel location remaining approximately fixed. The timing, recurrence interval and displacements of the penultimate surface-rupturing earthquake on the Greendale Fault have been constrained by trenching the scarp produced in 2010 at two locations. These excavations reveal a doubling of the magnitude of surface displacement at depths of 2-4 m. Aided by OSL ages of sand lenses in the gravel deposits, this factor-of-two increase is interpreted to indicate that in the central section of the Greendale Fault the penultimate surface-rupturing event occurred between ca. 20 and 30 kyr ago. The Greendale Fault remained undetected prior to the Darfield earthquake because the penultimate fault scarp was eroded and buried during Late Pleistocene alluvial activity. The Darfield earthquake rupture terminated against the Hororata Anticline Fault (HAF) in the west and resulted in up to 400 mm of uplift on the Hororata Anticline immediately above the HAF. Folding in 2010 is compared to Quaternary and younger deformation across the anticline recorded by a seismic reflection line, GPS-measured topographic profiles along fluvial surfaces, and river channel sinuosity and morphology. It is concluded that the HAF can rupture during earthquakes dissimilar to the 2010 event that may not be triggered by slip on the Greendale Fault. Like the Greendale Fault geomorphic analyses provide no evidence for rupture of the HAF in the last 18 kyr, with the average recurrence interval for the late Quaternary inferred to be at least ~10 kyr. Surface rupture of the Greendale Fault during the Darfield Earthquake produced one of the most accessible and best documented active fault displacement and geometry datasets in the world. Surface rupture fracture patterns and displacements along the fault were measured with high precision using real time kinematic (RTK) GPS, tape and compass, airborne light detection and ranging (LiDAR), and aerial photos. This allowed for detailed analysis of the cumulative strike-slip displacement across the fault zone, displacement gradient (ground shear strain) and the type of displacement (i.e. faulting or folding). These strain profiles confirm that the rupture zone is generally wide (~30 to ~300 metres) with >50% of displacement (often 70-80%) accommodated by ground flexure rather than discrete fault slip and ground cracking. The greatest fault-zone widths and highest proportions of folding are observed at fault stepovers.

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  • Oocyte-derived forms of ruminant BMP15 and GDF9 and a theoretical model to explain their synergistic response

    Heath, Derek (2016)

    Doctoral thesis
    Victoria University of Wellington

    Bone morphogenetic factor 15 (BMP15) and growth differentiation factor 9 (GDF9) are two oocyte-secreted factors with well documented effects on ovarian follicular development and ovulation-rate. The aims of these studies were to: (i) identify the molecular forms of BMP15 and GDF9 that are produced and secreted by both the ovine and bovine oocyte using highly specific monclonal antibodies; (ii) assess the biological activity of some recombinant molecular forms of BMP15 and GDF9; (iii) visualise the various molecular forms using protein modelling techniques and; (iv) provide a hypothetical model of how oocyte-secreted form(s) of BMP15, GDF9 and their cell surface receptors may interact. Using genetic modifications and transformations of HEK293 cells, recombinant forms of ovine (o) BMP15, including a BMP15 (S356C) mutant capable of forming covalent dimers, and oGDF9 were produced. The bioactivity of these proteins was established using a rat granulosa cell proliferation bioassay. The specificity of the monoclonal antibodies MN2-61A (anti-BMP15) and 37A (anti-GDF9) used in these studies, and determination of the forms they recognise, was examined by Western blotting. The recombinant forms of oBMP15 were further interrogated by purification using both immobilised metal affinity chromatography (IMAC) and reverse phase HPLC. The BMP15 and GDF9 proteins produced and/or secreted by ovine and bovine oocytes, before and after in vitro incubation, were identified and compared with the molecular forms(s) of recombinant oBMP15 or oGDF9 using Western blotting under non-reducing, reducing and cross-linking conditions. The molecular forms of recombinant oBMP15 and oGDF9 comprise mainly mature monomers with a lesser amount of the uncleaved pro-mature form. Mature domains, in the dimeric mature form, were detected for oGDF9 and oBMP15 (S356C), but not oBMP15. These mature domains were almost entirely located within high molecular weight multimeric complexes, which likely also contain the pro-region. In contrast, BMP15 and GDF9 secreted from ruminant oocytes under in vitro conditions were found mainly in an unprocessed promature form, along with some fully processed mature domains that did not interact to form detectable mature homodimers or heterodimers. Throughout ovarian follicular development, BMP15 and GDF9 are co-expressed and it has been established that these two factors have synergistic effects on granulosa cell proliferation both in vitro and in vivo and also on follicular maturation and ovulation-rate in vivo. Moreover, the recombinant proteins oBMP15 and oGDF9 generated for this study, when added together, also demonstrated a synergistic effect in the granulosa cell proliferation assay but this was not observed for oBMP15 (S356C) and oGDF9. Currently, no adequate model has been proposed to explain how interactions between the cell membrane and forms of oocyte-derived BMP15 and GDF9 achieve their synergistic effects. To investigate this, two homology models of the promature BMP15 and GDF9 proteins were generated using promature porcine TGFB1 and human BMP9 as templates. These models, together with the previously determined forms of GDF9 and BMP15 produced by the ruminant oocyte, were used to visualise their potential interactions, both with each other and with their receptors. This report describes a model showing the possible interactions involved in a synergistic response. In this model, the mature domain is presented to the type II receptor by the proregion and heterodimers form at the level of the receptor. Differences, following heterodimerisation in the conformation and orientation between GDF9 and its type I receptor, as well as between type I and type II receptors, relative to that in homodimers, could explain how heterodimerisation leads to increased Smad3 phosphorylation and subsequent down-stream somatic cell responses.

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  • Improving the Performance of Cloud-based Scientific Services

    Chard, Ryan (2016)

    Doctoral thesis
    Victoria University of Wellington

    Cloud computing provides access to a large scale set of readily available computing resources at the click of a button. The cloud paradigm has commoditised computing capacity and is often touted as a low-cost model for executing and scaling applications. However, there are significant technical challenges associated with selecting, acquiring, configuring, and managing cloud resources which can restrict the efficient utilisation of cloud capabilities. Scientific computing is increasingly hosted on cloud infrastructure—in which scientific capabilities are delivered to the broad scientific community via Internet-accessible services. This migration from on-premise to on-demand cloud infrastructure is motivated by the sporadic usage patterns of scientific workloads and the associated potential cost savings without the need to purchase, operate, and manage compute infrastructure—a task that few scientific users are trained to perform. However, cloud platforms are not an automatic solution. Their flexibility is derived from an enormous number of services and configuration options, which in turn result in significant complexity for the user. In fact, naïve cloud usage can result in poor performance and excessive costs, which are then directly passed on to researchers. This thesis presents methods for developing efficient cloud-based scientific services. Three real-world scientific services are analysed and a set of common requirements are derived. To address these requirements, this thesis explores automated and scalable methods for inferring network performance, considers various trade-offs (e.g., cost and performance) when provisioning instances, and profiles application performance, all in heterogeneous and dynamic cloud environments. Specifically, network tomography provides the mechanisms to infer network performance in dynamic and opaque cloud networks; cost-aware automated provisioning approaches enable services to consider, in real-time, various trade-offs such as cost, performance, and reliability; and automated application profiling allows a huge search space of applications, instance types, and configurations to be analysed to determine resource requirements and application performance. Finally, these contributions are integrated into an extensible and modular cloud provisioning and resource management service called SCRIMP. Cloud-based scientific applications and services can subscribe to SCRIMP to outsource their provisioning, usage, and management of cloud infrastructures. Collectively, the approaches presented in this thesis are shown to provide order of magnitude cost savings and significant performance improvement when employed by production scientific services.

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  • Intertextuality in Kenyan Policy Discourse on the Rights of Women

    Aberi, George (2016)

    Doctoral thesis
    Victoria University of Wellington

    The investigative aim of this thesis is to explore the recontextualization of the normative discourse of gender equality in Kenya’s policy discourse of women’s rights. Its purpose is threefold: Firstly, it attempts to examine the different ways in which policy makers use language in the course of interpreting and implementing gender equality policies. This includes a focus on both the linguistic and rhetorical/discursive strategies that these policy makers employ for such functions as endorsing, negotiating, legitimating, or even contesting given policy proposals. Secondly, the thesis endeavours to bring to light the different and changing conceptions of gender (in)equality espoused by the various policy actors involved in Kenya’s policy discourse of women’s rights over a critical ten-year period between 1995 and 2005. These policy actors include the Kenyan government; women’s non-governmental organizations (NGOs) who actively seek to influence government policy; and the United Nations’ organizations with responsibility for ensuring the implementation of women’s human rights. Thirdly, the thesis attempts to show the extent to which policy initiatives proposed by the human rights-based women’s NGOs in Kenya are taken up in the texts produced by the Kenyan government. In order to gain a better understanding of the discursive interactions between and amongst the policy actors in this study, an intertextual approach to Norman Fairclough’s model of critical discourse analysis (CDA) was used. The thesis drew discourse samples for analysis from the Kenyan government’s periodic reports detailing progress towards fully meeting the terms of the Convention on the Elimination of Discrimination Against Women (CEDAW); the documents produced by the Committee overseeing the Convention that provided assessment of the Kenyan government’s reports; the Kenyan government’s official texts on gender policy; and Kenyan women NGOs’ annual reports and other texts. Though many scholars and researchers of women’s rights praise the UN Committee’s imperatives for bringing about policy changes concerning women’s rights globally, the findings from this study confirm that the Committee for CEDAW has only textual power, and that it lacks enforcement powers to ensure the implementation of the universal rights of women within the local milieu. In a similar vein, this study demonstrates that though the women’s NGOs play a significant role both in terms of identifying important areas of concern for policy intervention, and in necessitating changes in the genres of the national government, their participation has largely failed to ensure the Kenyan government’s epistemological shift from its current state of recognizing the existence of women’s rights, to the phase of implementing them. This thesis also establishes that differing conceptions of gender (in)equality and ideological differences between the Committee for CEDAW and the Kenyan government tend to influence both the Committee’s and the Kenyan government’s use of varied discourses, genres, and styles, with the intent of manipulating to outmanoeuvre one another. This means that both the Kenyan government and the Committee live in different worlds, suggesting a continuing gap between the Committee’s normative knowledge of women’s rights to gender equality, and the Kenyan government’s cultural relativist perspectives concerning such rights. As a solution to these power struggles and political differences that derail policy making on gender equality, this study recommends the need both for the Committee and the Kenyan government to employ a reflexive and pragmatic mix of both the universalist and cultural relativist approaches to gender equality. This will bring forth shared areas of interest concerning women’s rights between the UN and the Kenyan government, based on their applicability within the local context. Moreover, such an approach will create a possibility for the Committee to understand the Kenyan government’s cultural relativist/competing discourse of women’s rights as another way of conceiving gender equality (i.e. productive power-knowledges), rather than viewing them as irrelevant cultural claims that stand in stark opposition to the universal understandings of women’s rights to gender equality. Likewise, the aforesaid reflexive and pragmatic mix of approaches will help the Kenyan policy makers to develop a more critical and nuanced view of the universal approaches to gender equality, thereby reducing their varied forms of resistance to gender equality via subtle evasive strategies. Methodologically, this thesis shows how a comparative intertextual approach to Fairclough’s model of critical discourse analysis can be used as a framework for establishing the relations between policy text and context. This framework includes the micro-level of textual/linguistic analysis, the meso level of discursive interactions, and the macro level of socio-cultural practice at the local, institutional, and societal levels. Theoretically, the thesis demonstrates the different ways in which particular philosophical arguments and emancipatory concepts from Foucault’s theory of governmentality and transnational feminist rhetorical theory can be combined and exploited by linguists to promote different ways of theorizing and thinking concerning the development of policies for promoting gender equality.

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  • Receiver design for OFDM transmission with insufficient cyclic prefix.

    Pham, Tri (2016)

    Doctoral thesis
    University of Canterbury Library

    Orthogonal frequency division multiplexing (OFDM) is desirable for broad-band communication because of its high spectral efficiency and resistance to multipath fading. The latter is achieved by adding a cyclic prefix to the beginning of each OFDM symbol. The cyclic prefix length must be equal to or greater than the channel delay spread to avoid multipath interference. For long range transmission, this criterion leads to bandwidth inefficiency. If a shorter cyclic prefix is used, the interference caused corrupts both pilot and data sub-carriers leading to degradation in channel estimation and data detection. This thesis focuses on developing effective receiver designs for multiple antenna orthogonal frequency division multiplexing systems when the cyclic prefix is insufficient. Closed form expressions for the short cyclic prefix induced interference are formulated and analyzed. Based on the analysis, we propose an iterative structure for channel estimation and data detection using a limited number of pilot sub-carriers. First, the number of channel paths is estimated from the channel least squares estimates at the pilot sub-carriers. We then formulate a maximum likelihood process to approximate the channel delay profile and subsequently the individual path coefficients. A search procedure is designed to reduce the estimator's complexity. High performance trellis based equalization schemes are proposed. Two additional data detection methods based on the zero forcing and minimum mean square error criteria are introduced with lower complexity than the trellis equalizers at the cost of performance. Simulation results indicate that the proposed techniques outperform conventional receivers, especially when the trellis equalizer is utilized for data detection. The mean square error of the channel estimate converges to the Cramer-Rao bound after two iterations; and the achieved bit error rate can reach that of the sufficient cyclic prefix case even when the delay spread is significantly longer than the cyclic prefix.

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