1,531 results for Doctoral, Share

  • "I just find it awkward": Girls' negotiations of sexualised pop music media

    Goddard, Sarah (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis examines girls’ relationship with and consumption of female pop stars’ music media. It is contextualised within a period of extensive academic and media debate about girls’ engagement with what has been termed the sexualisation of culture. Much of the alarm concerning girls’ premature sexualisation is underpinned by the presumption of girls as passive media consumers who are uniformly influenced by sexually saturated female pop music, particularly its ubiquitous representation of hyper (hetero) sexually desiring femininity. The notion of girls as precociously sexualised by hypersexual female pop music media has gained homogenous status within mainstream media and popular psychology texts. Girls’ pleasurable consumption and negotiation of a sexually laden media landscape is approached in this research as complicated by their contradictory positioning as savvy consumers within the postfeminist girlhood consumer market and simultaneously as victims within mainstream media and academic literature. Grounded in feminist poststructuralist understandings of girls’ subjectivity, the thesis explores the possibilities of self that representations within female pop music media enable and constrain for girls. Furthermore, the thesis explores ways in which girls make sense of these discourses while carefully managing their positioning as consumers. The research upon which this thesis is based has two parts. Part one of the research involved focus groups within which 30 pre-teen girls, identifying as ‘Kiwis’ or ‘New Zealanders’ discussed their engagement with female popular music media. The second part comprises a thematic discursive and semiotic analysis of girls’ self-recorded group video performances to a favourite pop song by a female artist. Discursive analysis of the professional music videos on which girls’ performances were based accompanied analyses of girls’ videos. The thesis contributes to a growing body of critical feminist research which responds to sexualisation claims that underpin hegemonic understandings of contemporary girlhood. The analyses presented in the research challenge moralistic notions of girls as uniformly influenced by pop music media by highlighting their navigation of this media as a contradictory process of appropriation and rejection. This complex negotiation, while seen in previous feminist literature, is uniquely captured within this thesis through the innovative employment of a performance method that extends feminist theorisations which problematise binary assumptions of girls’ engagement with sexualised media. This research identifies girls’ meaning making as a contradictory and plural process and provides novel insights about girls’ negotiation of postfeminist femininities in their own self-making in relation to self. Crucially, the thesis highlights the way in which girls’ navigation of sexualised media can be understood as occurring through both rejection and reproduction of postfeminist femininity ideals. Contextualised in New Zealand, the research extends knowledge about girls’ navigation of sexualised media beyond a US/UK social context. It also advances the small body of New Zealand literature about girls’ media engagement broadly and about the ways they experience sexualised media in particular.

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  • Seismic investigations of the lithosphere in an amagmatic back-arc region: North Island, New Zealand

    Dimech, Jesse-Lee (2016)

    Doctoral thesis
    Victoria University of Wellington

    New seismic constraints on crustal and upper mantle structures, kinematics, and lithospheric rheology are reported from an amagmatic back-arc region: the southwest North Island of New Zealand. Robust earthquake locations reveal a hypocentre 'downwarp' beneath the east-west trending Taranaki–Ruapehu Line. These earthquakes occur in the uppermost mantle, at depths of 30–50 km, and are distinct from shallower 8–25 km-deep earthquakes near Mt. Ruapehu in terms of focal mechanisms and principal stress directions. A receiver function CCP stack shows that the mantle earthquakes occur beneath a large change in crustal thickness, where the Moho 'steps' from 28 to 35 km-deep and the steepest part of that step has a 20–50° dip. The mantle earthquakes are dominated by strike-slip fault movement and have a maximum compressive stress direction of NE–SW. The existence of mantle earthquakes beneath a steeply-dipping Moho step implies some sort of dynamic modication is occurring in the mantle lithosphere. One possibility to explain these features is the convective removal of the mantle lithosphere due to a Rayleigh–Taylor-type instability. South of the Taranaki–Ruapehu Line, the Moho conversion weakens on both the receiver function CCP stack, and marine seismic reflection data under most of the Wanganui Basin (SAHKE02 and GD100 seismic lines). However, localised bright reflections at Moho depths can be seen in both near-vertical and wide-angle seismic data. Attribute analysis of near-vertical seismic reflections suggests that the rocks beneath the reflectivity are strongly-attenuating (Q ~20) with a negative velocity contrast relative to the lower crust. These observations are interpreted to be related to the presence of serpentinite (antigorite) and/or high pore fluid pressures in the mantle wedge. The links between hydration of amagmatic back-arcs, serpentinisation and/or high pore fluid pressures, rock viscosity, and mantle instabilities are documented here for the southwest North Island of New Zealand. These associations may be applicable to other amagmatic back-arcs around the world.

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  • Directing: A Mirror to Solo Performance Provocation, Collaboration and Proxy Audience

    Richards, Sally (2016)

    Doctoral thesis
    Victoria University of Wellington

    Solo performance is a challenging, immediate and exhilarating form of theatre. Its popularity in the field of westernised contemporary theatre is evidenced in the increasing programming of solo performances at international festivals and in commercial theatres. However, whilst there is considerable analysis of the genre of solo performance there is little examination of the relationship between director and solo performer in the rehearsal room. Prior research has focused on the theoretical or on the practical, but rarely have the two approaches actively engaged with each other. This thesis contributes a much-needed analysis of directing practice in this area, and an integration of theory and practice that offers tangible approaches in the rehearsal room. In what ways can the director best serve the solo performer to create a theatrical experience that can hold the audience's attention, imagination and memory? Solo performance is characterised by a heightened presence in both performer and audience, incited by a minimalism that abandons the theatrical premise of artifice and turns to primary storytelling. The rehearsal room relationship between director and solo performer also shares these qualities, heightened and focused by the one-one engagements. Directing in this context contrasts from that of a multi-cast, with distinctly different dynamics arising from an artistic collaboration between two people, rather than with many. This thesis considers how the director is placed as a flexible paradigm as proxy audience and as a bidirectional-mirroring device in the rehearsal process – situating the director as an articulated reflection to the transforming solo performer. I analyse this unique partnership and focus primarily on strategies that directors use to create effective solo performance. This thesis is comprised of 80% critical writing and 20% for the creative/practice-based research project. I examine the particular qualities of solo performance as a genre; its theatrical origins, function and purpose, the scope of styles and forms and its potential for political and social meaning. However, my focus is on the rehearsal room processes, working predominantly with a director, rather than an analysis of the end product - the performance. I interview practitioners in the field about their rehearsal room experiences, across the spectrum of styles and forms of solo performance. My theoretical framework is centred on Practice as Research (PaR). In order to scrutinise the relationship between director and solo performer I have gained access to the rehearsal room as both director/practitioner and researcher. The PaR component of this thesis includes the analysis of the experimental rehearsal process and performance of PocaHAUNTus - a new autobiographical solo play. In addition I draw on a body of retrospective work – re-examining my direction of five solo performances that occurred prior to this thesis. Production journals, rehearsal and performance footage, interviews, communications and photographs evidence all components. My research question is not simply “Does a solo performer need a director?” Instead, my research pursues how the relationship between the two might be negotiated, asking: “In what ways can the director best serve the solo performer?” The research examines the fundamental challenges of the genre, namely: the delineation of multiple characters by a single performer, immediacy of the audience relationship to the lone performer, stage geography and scenographic choices. The research also identifies and refines practical strategies to accommodate the intensity of working one-on-one. At its best, the director-solo performer relationship is a vibrant and supportive partnership but because of its intimacy, it is often also a complex and challenging engagement. The contribution of this thesis and its originality is in a PaR model that utilises my past experience of directing solo performance, expands on this foundation through the collection of extensive interview material from a diverse range of significant directors and performers of solo work, and then pursues a new creative laboratory where I test key approaches to directing solo performance.

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  • Characterization of Groundwater with Complementary Age Tracers

    Beyer, Monique (2015)

    Doctoral thesis
    Victoria University of Wellington

    Groundwater age or residence time is the time water has resided in the subsurface since recharge. Depending on the application, this definition may or may not include travel through the unsaturated zone. The determination of groundwater age can aid understanding and characterization of groundwater resources, because it can provide information on e.g. groundwater mixing and flow, and volumes of groundwater and recharge. Groundwater age can be inferred from environmental tracers, such as SF₆ and tritium, that have a known input to groundwater and/or undergo known alteration processes in groundwater. The currently used age tracers face limitations regarding their application range and reliability. For example, some age tracers have local sources that can lead to contamination of groundwater. This contamination can result in misleading estimates of age. Other tracers have ambiguous inputs to groundwater, which can result in ambiguous age estimations. To reduce these limitations, it is now recognized that multiple tracers should be applied complementarily. There is also a need for new groundwater age tracers and/or new groundwater dating techniques to supplement the existing ones. Cost-effective and easily applicable tracers/techniques are preferred, since most established groundwater dating techniques are very costly and/or complex. Commonly measured hydrochemistry parameters , such as the concentrations of major ions and pH, have been suggested as cost-effective and easily determinable potential age tracers. To date, the use of commonly measured hydrochemistry parameters as independent age tracer has only been demonstrated for water recharged weeks to months ago relying on seasonal changes. Other studies applied commonly measured hydrochemistry complementarily to established age tracers to better constrain groundwater age and/or better understand and predict anthropogenic effects on groundwater quality. Further study is needed to assess the extent to which commonly measured hydrochemistry can be used to reduce uncertainty in tracer-inferred age as well as the extent to which commonly measured hydrochemistry can be used to extrapolate tracer-inferred age. In addition to tracer specific limitations, quantification of uncertainty and ambiguity is not standard in age modelling. Although a few studies have attempted to quantify uncertainty in age modelling with the aid of probabilistic approaches, their methods are often relatively complex and not transferrable to the many cases with little available data. Uncertainties in the tracer’s recharge estimate and identification of appropriate model components, such as the objective function, have not been considered. Studies in other areas of hydrological modelling, where probabilistic approaches are more commonly used, have highlighted the need for careful identification of model components.

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  • Learning Feature Selection and Combination Strategies for Generic Salient Object Detection

    Naqvi, Syed (2016)

    Doctoral thesis
    Victoria University of Wellington

    For a diverse range of applications in machine vision from social media searches to robotic home care providers, it is important to replicate the mechanism by which the human brain selects the most important visual information, while suppressing the remaining non-usable information. Many computational methods attempt to model this process by following the traditional model of visual attention. The traditional model of attention involves feature extraction, conditioning and combination to capture this behaviour of human visual attention. Consequently, the model has inherent design choices at its various stages. These choices include selection of parameters related to the feature computation process, setting a conditioning approach, feature importance and setting a combination approach. Despite rapid research and substantial improvements in benchmark performance, the performance of many models depends upon tuning these design choices in an ad hoc fashion. Additionally, these design choices are heuristic in nature, thus resulting in good performance only in certain settings. Consequentially, many such models exhibit low robustness to difficult stimuli and the complexities of real-world imagery. Machine learning and optimisation technique have long been used to increase the generalisability of a system to unseen data. Surprisingly, artificial learning techniques have not been investigated to their full potential to improve generalisation of visual attention methods. The proposed thesis is that artificial learning can increase the generalisability of the traditional model of visual attention by effective selection and optimal combination of features. The following new techniques have been introduced at various stages of the traditional model of visual attention to improve its generalisation performance, specifically on challenging cases of saliency detection: 1. Joint optimisation of feature related parameters and feature importance weights is introduced for the first time to improve the generalisation of the traditional model of visual attention. To evaluate the joint learning hypothesis, a new method namely GAOVSM is introduced for the tasks of eye fixation prediction. By finding the relationships between feature related parameters and feature importance, the developed method improves the generalisation performance of baseline method (that employ human encoded parameters). 2. Spectral matting based figure-ground segregation is introduced to overcome the artifacts encountered by region-based salient object detection approaches. By suppressing the unwanted background information and assigning saliency to object parts in a uniform manner, the developed FGS approach overcomes the limitations of region based approaches. 3. Joint optimisation of feature computation parameters and feature importance weights is introduced for optimal combination of FGS with complementary features for the first time for salient object detection. By learning feature related parameters and their respective importance at multiple segmentation thresholds and by considering the performance gaps amongst features, the developed FGSopt method improves the object detection performance of the FGS technique also improving upon several state-of-the-art salient object detection models. 4. The introduction of multiple combination schemes/rules further extends the generalisability of the traditional attention model beyond that of joint optimisation based single rules. The introduction of feature composition based grouping of images, enables the developed IGA method to autonomously identify an appropriate combination strategy for an unseen image. The results of a pair-wise ranksum test confirm that the IGA method is significantly better than the deterministic and classification based benchmark methods on the 99% confidence interval level. Extending this line of research, a novel relative encoding approach enables the adapted XCSCA method to group images having similar saliency prediction ability. By keeping track of previous inputs, the introduced action part of the XCSCA approach enables learning of generalised feature importance rules. By more accurate grouping of images as compared with IGA, generalised learnt rules and appropriate application of feature importance rules, the XCSCA approach improves upon the generalisation performance of the IGA method. 5. The introduced uniform saliency assignment and segmentation quality cues enable label free evaluation of a feature/saliency map. By accurate ranking and effective clustering, the developed DFS method successfully solves the complex problem of finding appropriate features for combination (on an-image-by-image basis) for the first time in saliency detection. The DFS method enables ground truth free evaluation of saliency methods and advances the state-of-the-art in data driven saliency aggregation by detection and deselection of redundant information. The final contribution is that the developed methods are formed into a complete system where analysis shows the effects of their interactions on the system. Based on the saliency prediction accuracy versus computational time trade-off, specialised variants of the proposed methods are presented along with the recommendations for further use by other saliency detection systems. This research work has shown that artificial learning can increase the generalisation of the traditional model of attention by effective selection and optimal combination of features. Overall, this thesis has shown that it is the ability to autonomously segregate images based on their types and subsequent learning of appropriate combinations that aid generalisation on difficult unseen stimuli.

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  • Feedback and revision: A protocol analysis

    Rajoo, Margaret (2009-10-20)

    Doctoral thesis
    University of Otago

    Written feedback is a widespread practice and has garnered considerable positive and negative attention. The responses that teachers provide on students’ writing are essential to encourage and develop students’ writing. However, an in-depth understanding of the thought processes of student writers as they attend to written feedback is lacking in the literature. The purpose of this study was to investigate the thought processes and reactions of student writers towards written teacher feedback. Using a case study methodology, verbal protocols of eight postgraduate students were recorded as they attended to teacher feedback on their essays. Written texts, written teacher comments, and a questionnaire survey supplemented the data. The findings from this study indicate that the participants attended to written feedback recursively. Second, the act of thinking aloud led to noticing the disparities highlighted in the feedback. Finally the results suggest that students’ engagement with written teacher feedback is a social activity that encompasses a complex and dynamic interpersonal process between student writers and their feedback provider. This study concludes by raising several implications for teaching and learning. It suggests that it is important for teachers to be aware of the impact of feedback. Additionally, this study proposes that the think-aloud technique is useful as an implement in teaching writing, being a means of helping students reflect on feedback and develop their writing. Finally, it points out that both cognitive and sociocultural approaches to think-aloud data offer insights into the thought processes of writers.

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  • Effects of Exercise Training Modalities on Fat Oxidation in Overweight and Obese Women

    Phillips, Vicky (2009-11-27)

    Doctoral thesis
    University of Otago

    View Appendix J of this thesis via the DOI provided in this record: Phillips, V.K., Legge, M., & Jones, L. M. (2008). Maximal Physiological Responses between Aquatic and Land Exercise in Overweight Women. Medicine and Science in Sports and Exercise, 40, 959-964.

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  • A Perceptual Basis for Noun Phrase Syntax

    Walles, Hayden (2009-06-25)

    Doctoral thesis
    University of Otago

    Human language is the result of both biological and cultural evolution. To have the best chance of understanding language we must seek all the constraints of that evolution. In the first part of my thesis I propose the general hypothesis that the sensorimotor system is one of those constraints and argue that regardless of whether language is the result of biological evolution, cultural evolution, or both, we should expect idiosyncrasies of the sensorimotor system to be reflected in linguistic structure. The bulk of the thesis explores a particular version of this hypothesis – namely that visual attention and classification of objects are reflected in noun phrase syntax. Within the noun phrase the noun stem (e.g. “dog”) and number morphology (e.g. “-s”) are contributed by separate syntactic elements; I argue that this reflects a separation of functionality in the sensorimotor system. To begin an exploration of this hypothesis I draw upon existing models of visual attention by Itti and Koch (2000) and object classification by Mozer and Sitton (1998), adapting and combining them into a new computational model. The key new idea in the model is that object classification is cardinality blind which means its output is the same whether presented with one token of a class or many tokens of the class. This allows groups of similar objects to be handled at once. I implement a model of classification which, like primate object classification, is location invariant. In my model cardinality blindness emerges naturally from location invariance. I argue the same thing happens in primates, reviewing neurophysiological evidence for this. To cater for a cardinality-blind classifier I also implement extensions to a standard model of visual attention. The combined classifier and attentional models elegantly reproduce a number of human results, including Gestalt grouping by similarity, global precedence (Navon, 1977) and the role of stimulus similarity in visual search (Duncan and Humphreys, 1989). These results show that the model does useful work in an account of the visual system. With the visual foundation established I propose a simple model of the interface between visual cognition and noun phrase syntax. Within my model the information corresponding to the noun stem is produced by the classifier and is cardinality blind so carries no number information. The information corresponding to singular or plural number morphology is produced separately by the attentional system. The decomposition of information in my model corresponds to the same decomposition of information in noun phrases. I conclude that cardinality blindness in the visual system can explain this aspect of noun phrase syntax, supporting the general hypothesis that natural language syntax reflects properties of the sensorimotor system and inviting further theories of this nature.

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  • Epigenetic Programming and In Vitro Fertilisation

    Oliver, Verity Frances (2010-04-08)

    Doctoral thesis
    University of Otago

    In vitro fertilisation (IVF) potentially provides a profoundly abnormal environment for an embryo. Studies with mice, sheep and cattle have indicated that the culture environment of the embryo can affect the imprinting of genes and the phenotype of the animal. Recent studies have suggested that IVF causes a small but increased risk of epigenetic imprinting aberrations such as Angelman syndrome and Beckwith-Wiedemann syndrome. Our previously published IVF cohort is taller, has higher levels of growth hormones and a better lipid profile than age-matched controls. Mosaicism for the imprinting defect at SNRPN has been observed in Angelman syndrome. We hypothesised that mosaic imprinting defects may be present in phenotypically normal individuals conceived using IVF. DNA samples from peripheral blood were obtained from 66 IVF-conceived children and 69 matched controls. DNA methylation of CpG sites within the Beckwith-Wiedemann syndrome region (H19, KCNQ1OT1 and IGF2) and the Angelman syndrome region (SNRPN) were quantified using methylation-sensitive restriction digest followed by real-time quantitative PCR (MSQ-PCR). Global DNA methylation was also examined by using MSQ-PCR on Satellite 2 repeats. No differences in the percentage of methylation between the IVF and naturally conceived children were observed at H19 (P = 0.75; unpaired t-test), KCNQ1OT1 (P = 0.98), SNRPN (P = 0.33), IGF2 (P = 0.44) or Satellite 2 (P = 0.79). These results were confirmed using bisulfite sequencing. An individual with Prader-Willi syndrome was identified during the recruitment of this cohort. Five Prader-Willi syndrome cases have previously been identified in the IVF population. The underlying cause of Prader-Willi syndrome was identified to be a deletion of the chromosome 15q11-q13 region. This case did not provide evidence that aberrant methylation can occur during IVF. Pyrosequencing technology was used to measure the methylation at multiple CpG sites within H19. No methylation defects were identified at H19 in the IVF group compared to naturally conceived controls. This technology proved to be prone to inaccuracies and was not used for subsequent analyses. Genome-wide methylation analysis was examined using microarray technology and methylated DNA immunoprecipitation (MeDIP). Thirteen candidate differentially methylated genes between the IVF-conceived and control children were identified. Detailed examination of candidate genes using the Sequenom MassARRAY® EpiTYPER® system did not reveal any differential methylation at these genes assessed in the IVF and naturally conceived children. Although anthropomorphic and endocrinological data suggested a phenotypic difference between IVF and naturally conceived children, no differentially methylated genes were identified that could account for these differences. We concluded that low-level imprinting errors are not a common occurrence in children conceived using IVF. Our data also provides reassurance that IVF-associated epigenetic errors are sporadic and rare.

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  • The Influence of Contextual Factors on Revision Strategies: The Case of Four Malaysian Native Speakers of English in a Mainstream E.S.L. Classroom

    Mallan, Vijay Kumar (2005-07-27)

    Doctoral thesis
    University of Otago

    This case study explored the revision strategies of four Malaysian native speakers of English when they composed aloud while writing an argumentative essay. Think aloud verbal protocols were analysed using the grounded theory approach in conjunction with written texts. The findings suggest that contextual factors influenced classroom practices. The contextual factors included a teacher who was not provided with adequate training, administrative policies which did not provide support for the development of writers based on their abilities, writing instruction which viewed revision as a process of error correction and public assessment practices which were non-transparent. These classroom practices influenced the participants' beliefs about revision. These beliefs affected the quality of their essays as judged by Malaysian public examiners. Additionally, the findings suggest a mismatch between classroom instruction and public examination. Suggestions are made to address these concerns by considering the theoretical underpinnings of the cognitive process, socio-cultural and community of practice models of writing and learning. These include instruction on revision strategies, considering alternative assessment practices, providing formative feedback, ability streaming, focussing on critical reading skills and providing adequate support to the teacher.

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  • Private finance and governance of REDD+ projects in Indonesia

    Dixon, Rowan (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis explores the role of private finance within REDD+ (Reducing Emissions from Deforestation and forest Degradation) programmes in Indonesia. Since its debut in 2007 as a potential investment opportunity, enterprising and innovative private sector actors have moved to establish REDD+ projects within a voluntary carbon market, while the United Nations Convention on Climate Change continues negotiations to establish a comprehensive global mechanism. These profit-seeking actors have invested millions of dollars developing REDD+ projects within a rapidly evolving voluntary market that has emerged alongside the turmoil of global climate change negotiations. This dynamic market context brought about a wide variety of expressions of REDD+ in Indonesia, which this research seeks to untangle and illuminate. The thesis yields insights into the workings of market environmentalism, and complicates widespread notions of ‘private finance’ as a homogenous and predictable category of actor. In order to better understand the emergent REDD+ industry in Indonesia, and the role of private finance in shaping it, this research draws on the global value chain (GVC) framework to analyse processes of commodification and governance within REDD+ projects and ‘supply chains’. This approach identifies key private finance actors, and explores why they are involved across motivations for social, environmental and financial outcomes. It also reveals REDD+ projects as a produced commodity and provides insight into the multiple ways they are valued. The research thus highlights how private finance actors evaluate REDD+ commodities as they engage with them. These logics, and the profit-seeking rationale of private finance actors, are seen to have important governance implications in shaping the characteristics of REDD+ projects and the networks of actors involved in them. However, simultaneously, the malleable and selective characteristics of the REDD+ commodity itself shapes certain governing implications of private finance. This thesis contributes to debates concerning the commodification of nature within market environmentalism and the neoliberalisation of nature, providing insights into the nature and agency of private finance.

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  • 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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  • An investigation of foreign exchange risk management by exporting small and medium sized enterprises

    Dang, Vu (2015)

    Doctoral thesis
    Victoria University of Wellington

    Previous studies on foreign exchange (forex) risk management have tended to focus on multinational enterprises; while how SMEs manage their forex risk is still largely unexplored. As small and medium sized enterprises (SMEs) are increasingly involved in international markets, they have become a new research setting on forex risk management. Given that SMEs have limited access to resources, skills and capabilities, internal hedging techniques could be favoured by SMEs. There is limited research on this matter, and the extant literature on forex management generally considers derivatives as major hedging techniques for large firms. This thesis primarily investigates how exporting SMEs manage forex risk. In addition, approaches to forex management could be changed as a firm becomes more experienced internationally. Following the basic principles of internationalisation theory, the thesis also examines the impact of the internationalisation degree of the firm on forex management decisions. This thesis sheds new light on SMEs’ hedging practices by providing a better understanding of SMEs’ choices of forex risk management. Three research questions have been raised: (1) what determinants influence SMEs’ choice to hedge as a way of managing forex risk; (2) what strategies do SMEs use when they choose hedging to manage forex exposure; and (3) how does the degree of internationalisation impact the choice of forex management. The thesis draws on two theoretical perspectives to help address these overarching questions. It extends the use of the resource-based view (RBV), and combines this with internationalisation theory. The setting of SMEs is a context for using the RBV. New Zealand and Australian exporting SMEs provide the sample for testing the hypotheses. The contributions of this thesis are twofold. Firstly, the thesis identifies four determinants of forex risk strategy by exporting SMEs, i.e. degree of internationalisation (specifically, export ratio), forex exposure, perceived forex risk, and resources. Secondly, it extends the use of the RBV and the internationalisation theory in forex risk management of SMEs. In addition, the thesis uses a research approach combining an exploratory qualitative study and a main quantitative study.

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  • Characterising the Anthropocene: Ecological Degradation in Italian Twenty-First Century Literary Writing

    Macilenti, Alessandro (2015)

    Doctoral thesis
    Victoria University of Wellington

    The twenty-first century has witnessed the exacerbation of ecological issues that began to manifest themselves in the mid-twentieth century. It has become increasingly clear that the current environmental crisis poses an unprecedented existential threat to civilization as well as to Homo sapiens itself. Whereas the physical and social sciences have been defining the now inevitable transition to a different (and more inhospitable) Earth, the humanities have yet to assert their role as a transformative force within the context of global environmental change. Turning abstract issues into narrative form, literary writing can increase awareness of environmental issues as well as have a deep emotive influence on its readership. To showcase this type of writing as well as the methodological frameworks that best highlights the social and ethical relevance of such texts alongside their literary value, I have selected the following twenty-first century Italian literary works: Roberto Saviano’s Gomorra, Kai Zen’s Delta blues,Wu Ming’s Previsioni del tempo, Simona Vinci’s Rovina, Giancarlo di Cataldo’s Fuoco!, Laura Pugno’s Sirene, and Alessandra Montrucchio’s E poi la sete, all published between 2006 and 2011. The main goal of this study is to demonstrate how these works offer an invaluable opportunity to communicate meaningfully and accessibly the discomforting truths of global environmental change, including ecomafia, waste trafficking, illegal building, arson, ozone depletion, global warming and the dysfunctional relationship between humanity and the biosphere.

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  • Twisted magnetization phases in orbital-dominant rare-earth nitrides

    McNulty, James (2015)

    Doctoral thesis
    Victoria University of Wellington

    In this thesis we investigate the magnetic properties of NdN and SmN, members of the rare-earth nitrides, a series of intrinsic ferromagnetic semiconductors. In rare-earth systems, the strong spin-orbit coupling of the partially filled 4ƒ shell ensures that there is a substantial orbital contribution to the ferromagnetic moment, in contrast to many transition metal systems where the orbital moment is usually quenched. In SmN and NdN the orbital moment actually exceeds the spin moment, and the resulting orbital dominant magnetization allows for the fabrication of a magnetic heterostructures showing novel behavior. We report a new theoretical study of the magnetic properties on both SmN and NdN by considering the atomic-like 4ƒ electrons. These calculations incorporate spin-orbit coupling, the exchange interaction in a self-consistent mean-field approach, and crystal field interactions in an arbitrary-multiplet point-charge model. Our findings show excellent agreement with the experimentally measured ferromagnetic moments of SmN and NdN, representing an advance from previous theoretical studies. We also report an experimental study on SmN/GdN heterostructures using the element-resolved method of x-ray magnetic circular dichroism (XMCD) to probe the magnetism. The competition between the orbital-dominant Zeeman coupling in SmN and the ferromagnetic spin-based interface exchange with GdN, which has purely a spin moment, results in a twisted magnetization profile. The depth profile of the magnetization derived from XMCD measurements showed good agreement with an analytical model developed to describe the competing interactions. In a second study, a superlattice of NdN/GdN was investigated via XMCD and standard magnetometry techniques. A twisted magnetization was shown to be present due to the same mechanism as in the SmN/GdN system. By varying the maximum applied field and temperature, twisted phases were shown to develop in both GdN and NdN layers. These twisted phases in orbital-dominant ferromagnetic semiconductors represent a departure from previously explored spin-dominant metallic systems displaying similar twisted phases.

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  • Factors Influencing Participant Satisfaction with Free/Libre and Open Source Software Projects

    Chawner, Brenda (2011)

    Doctoral thesis
    Victoria University of Wellington

    The purpose of this research was to identify factors that affect participants’ satisfaction with their experience of a free/libre open source software (FLOSS) project. The research built on existing models of user satisfaction from the information systems literature, and also incorporated two characteristics of FLOSS projects first identified by Ye, Nakakoji, Yamamoto, and Kishida (2005), product openness and process openness. The central research question it answered was, What factors influence participant satisfaction with a free/libre and open source application software project? Richard Stallman’s reasons for setting up the GNU project and the Free Software Foundation arose from his frustration at being forced to be a passive user of software used for a Xerox printer. These suggest that being able to be an active participant in a FLOSS project is one factor that should be examined, and therefore the first sub-question this project answers is, What types of contributions do participants make to free/libre and open source software projects? Several studies have shown that the extent of participation in a FLOSS project varies from individual to individual, and this variation leads to the second sub-question, Do the factors that influence satisfaction vary for different types of participation? If so, in what way? A preliminary conceptual model of factors affecting participant satisfaction was developed, reflecting the key concepts identified in the literature. The main theoretical goal of this research was to test the model using empirical data. The research used a sequential, mixed methods approach. The first, qualitative stage involved reviewing documents from selected projects and interviewing a purposive sample of FLOSS project participants. The second, quantitative stage involved an online survey of FLOSS project participants, and the data gathered were used to test the conceptual model. The results of the first stage showed that participation in FLOSS projects was a more complex construct than previously reported in the literature. Seven distinct categories of activities were identified: • use; • interaction with code; • supporting the community; • outreach; • sponsorship; • management; and • governance. Four attributes that modified these categories were also identified: organisational focus, role formality, remuneration, and time commitment. Data from 154 responses to the online survey were used to test the model using stepwise multiple regression, which determined the effect of each of the variables on overall participant satisfaction. Moderated regression analysis was used to test the effects of three potential moderating variables. The results showed that that perceived system complexity had the largest effect, decreasing satisfaction if respondents perceived that the software was complex, while project openness and perceived developer communication quality accounted for the most variance in satisfaction. The main theoretical contribution of this research lies in its extension of satisfaction studies to FLOSS communities, showing that communication and openness are more important than in conventional software projects. Its practical contribution will help people involved in the management and governance of FLOSS projects to identify ways of increasing their participants’ satisfaction, which may in turn encourage them to contribute more.

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  • Self-improvement books: A genre analysis

    Koay, Dong Liang (2015)

    Doctoral thesis
    Victoria University of Wellington

    The aim of the thesis is to explore the characteristics of self-improvement books as a genre. Although self-improvement books are a widely read genre, particularly in the Western world, none to my knowledge has examined the linguistic features of this genre in detail. The thesis draws on the three main schools of genre theory: English for Specific Purposes, Systemic Functional Linguistics, and the New Rhetoric, and begins by investigating the sections (e.g., acknowledgement, introduction chapter) in self-improvement books and the typicality of the sections. Focusing on three sections: introduction chapters, body chapters, and about the author sections, the thesis examines how authors structure the sections by analysing the moves and steps. This study also examines the stories in self-improvement books by analysing the purpose of the stories and their structure. Stories were chosen because they seemed to be a feature of self-improvement books based on my observation and as suggested by interview data. To analyse self-improvement books at a register level, the thesis examines the most unambiguous aspects of engagement: personal pronouns focusing on you, imperative clauses, and questions. It also examines the lexicogrammatical features of self-improvement book titles and compares them to the titles of historical biographies, showing that imperative clauses and ing-clause are found only in self-improvement book titles. Drawing on interview data and literature on the American Dream, American individualism, Neoliberalism, and New Age beliefs, the thesis explains how the linguistic characteristics of the genre of self-improvement books reflect these ideologies. The dataset for the study is 40 self-improvement books, selected on the basis of a set of criteria that I developed. Subsets were selected from the main dataset for specific analyses. The text analysis part of the study is supplemented by interview data from specialist informants, who come from three categories: readers of the genre, non-readers of the genre, and authors of the genre. Move analysis identifies obligatory rhetorical moves and indicates that the main purposes of introduction chapters and about the author sections are persuading readers to read the book, and establishing credibility, respectively. Authors always persuade readers to read their books by listing reasons to read them. To demonstrate authors’ credibility, they refer to their areas of expertise. Unlike the introduction chapters and about the author sections, the body chapters have more than one obligatory rhetorical move. The body chapters present the problem that readers potentially experience, present the authors’ message, recommend practical applications, and encourage readers to apply them. From a genre perspective, the purpose of all the stories in my analysis is to illustrate the authors’ message. Register analysis, and drawing on interview data, suggests that authors use the personal pronoun you, imperative clauses, and questions to engage readers. The abundance of the personal pronoun you suggests that self-improvement books are a reader-oriented genre. The analysis of the imperative clauses using Halliday’s process types suggests that the main way to improve our lives, the authors recommend, is to change how we think. Finally, my thesis shows that the social purpose of self-improvement books is to help potential readers improve their lives, and the approach of improving one’s life has an individualistic orientation.

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  • Corticosterone secretion in tuatara (Sphenodon punctatus): Influential factors and conservation applications

    Anderson, Lindsay Erin (2015)

    Doctoral thesis
    Victoria University of Wellington

    Animals are regularly exposed to environmental, social and physiological challenges. In reaction to these challenges, individuals adjust their physiology and behaviour to maintain essential processes and optimise fitness. The most widely used indicators of physiological stress in vertebrates are glucocorticoid hormones (corticosterone (CORT) or cortisol), which are commonly referred to as ‘stress hormones’. The use of CORT as a tool to understand how individuals respond to natural or human-caused challenges is central to stress physiology research. Here, I investigated intrinsic and extrinsic factors associated with CORT secretion, CORT secretion as an indicator of physiological response to challenges/stressors, and the value of CORT secretion as conservation tool in an iconic protected reptile (the tuatara, Sphenodon punctatus). A capture-restraint time series revealed a significant CORT response over a 24 h period in male and female (non-gravid and gravid) tuatara. Baseline CORT and the CORT response to capture and restraint (i.e. a standardised capture-stress protocol) were similar between sexes; however, female reproductive condition was correlated with CORT secretion in that higher baseline CORT and a lower CORT response were observed in gravid females. An observational study incorporating data across a wide range of ambient temperatures (from four island sites) confirmed that body temperature (Tb) is positively correlated with baseline CORT in gravid females only, and revealed a positive correlation between the CORT response and higher Tb in all adults. A supporting experimental study showed that acute ambient temperature increase (in which mean Tb reached 21.4±0.4°C) elicits a significant CORT response to capture-restraint in gravid females. These results confirmed that gravid females are not secreting CORT maximally during nesting, but actively modulate secretion. An inter-island comparison of CORT secretion (for four populations) revealed that baseline CORT secretion was similar among populations during the non-breeding and breeding seasons; however, the CORT response to capture-restraint varied significantly among populations. Inter-population variation in testosterone (T) was observed in males (but not females) and was positively linked with increased baseline CORT from the non-breeding season to the breeding season, suggesting male reproductive activity may drive seasonal change of baseline CORT. Significant correlations were observed between the CORT response to capture-restraint (but not baseline CORT) and habitat elements of latitude, tuatara density and seabird abundance and 2) demogenetic factors of sex ratio and genetic diversity. The measurement of CORT as a physiological monitoring tool indicated that short- and long- term dynamics of CORT secretion in tuatara are not altered through translocation to a new island, as the acute CORT response remained stable throughout exposure to cumulative stressors and long-term dynamics of CORT secretion in translocated populations simultaneously mirrored those in source populations. These findings deliver the most detailed study of CORT secretion patterns in tuatara to date. Moreover, as the first study to apply CORT secretion data as an conservation physiology monitoring tool in tuatara, these results serve as a baseline reference for future research and monitoring of conservation efforts.

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  • First Principles Study of Ga₍₂₀₋x₎Alx⁺ Nanoalloys: Structure, Thermodynamics and Phase Diagram

    Ojha, Udbhav (2015)

    Doctoral thesis
    Victoria University of Wellington

    Nanoalloys (a finite framework of two or more metal atoms) represent a rapidly growing field owing to the possibilities of tuning its properties as desired for various applications. Their properties are size, shape, composition, chemical ordering, and temperature dependent, thereby offering a large playground for varied research motivations. This thesis documents the investigations on how the addition of aluminium affects the cationic gallium clusters, both in terms of geometric & electronic structure and thermodynamics, which have been observed to show greater-than-bulk melting behaviour for small sizes. A specific cluster size of 20 atoms is selected, Ga₍₂₀₋x₎Alx⁺, with the overall intention of creating a phase diagram which is the most reliable way to predict the phase changes in the system. All the first principles (density functional theory) based Born-Oppenheimer molecular dynamics calculations have been performed in the microcanonical ensemble. Melting behaviour is first studied in the pure Al₂₀⁺ clusters and then in three representative clusters of Ga₍₂₀₋x₎Alx⁺ series: Ga₁₉Al⁺, Ga₁₁Al₉⁺ and Ga₃Al₁₇⁺ clusters. We observe that all the three nanoalloy compositions show greater-than-bulk melting behaviour behaviour as well and in Ga₁₉Al⁺, specifically, Al prefers the internal sites, contrary to the previous arguments. We go on to complete the solid-liquid-like melting phase diagram using the calculated information and further propose a model of these greater-than-bulk melting clusters to be components of the corresponding bulk phases, whether metals or alloys, with additional size-dependent contributions added to it.

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  • Science Museum in a Pizza Box - Performance, museum tour guiding, and science communication

    Fontana, Michele (2015)

    Doctoral thesis
    Victoria University of Wellington

    This study focuses on the relationship between performance and museum tour guiding. Building on the analysis of this relationship, the author of this study has created a performance that is inspired by museum guided tours. The aim of the performance is to encourage a critical reflection on the role and the function of science in contemporary society, while giving insight into how science is socially constructed. The performance is based on participation. The participants define their own experiences, actively reflecting on the value that science has in their lives through a dialogue with the other participants and the performer. This dialogue starts with exhibits based on science that are presented to the participants. To develop this performance, this research has utilised action research, and qualitative methods to explore the participants’ experiences of the performance. This study is interdisciplinary, and connects performance studies, museum studies and science communication, while using applied research to explore its topics. The outcomes of this study are an innovative conceptualisation of the museum guided tour, and an original approach to science communication based on dialogic, live performance.

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