1,166 results for Doctoral, Modify

  • 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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  • 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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  • 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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  • 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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  • 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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  • Tauhi Vā Māfana: Tongan leadership and culture in the New Zealand Public Service

    Paea, Mele Katea (2015)

    Doctoral thesis
    Victoria University of Wellington

    How does knowledge of cultural practices help us think differently about how leadership is understood and practised in a particular context? This thesis presents a Tongan leadership model from a Tongan perspective. It is based on a study of cultural practices that shape the ways in which Tongans perceive and experience leadership differently. The location of the study is the New Zealand Public Service, and the approach taken here is to reflect on Tongan leadership from a strength-based perspective, promoting the leadership capabilities that Tongans bring with them into another cultural context. The core of this thesis is a deep empirical study of Tongan leadership based on Tongan public servants’ perceptions and experiences of Tongan identity and Tongan leadership practices in New Zealand. The theoretical framework is based primarily on a Tauhi Vā (nurturing relationships) approach that draws on sources, which explore and discuss the key conceptual foundations of Tongan culture. It draws on the central value of māfana (warm love/inner warm passion) as the driver for leadership as Tauhi Vā Māfana (nurturing warm relationships). The thesis also argues that the methodology for exploring leadership as cultural practice should be located in the cultural practices being studied. It further explores the research question, what is the most culturally appropriate way to study leadership as cultural practice? In this case, the methodology for this study is therefore grounded in a Tongan perspective called Talanoa Māfana (talking about the truth in love/warm relationships). This is based on a type of ‘oral communication’, carried out in both group and individual contexts. The thesis set out to build on existing talanoa methodology to develop Talanoa Māfana providing new insights into cultural practice as methodology alongside cultural practice as the topic of study. The study first asked participants what ‘being Tongan’ meant to them and what their experiences of leadership were. Moving into the public service context, it asked how their Tongan identities shaped their work in the New Zealand Public Service, and how they would like to see their leadership practices supported in this context. Drawing on the findings, this study conceptualises Tongan leadership as Tauhi Vā Māfana. It is based on the dynamic interplay between fāmili (familial relationships), māfana, fua fatongia (fulfilling obligations), and faka`apa`apa (sacred wisdom) within a given socio-cultural context. Tauhi Vā Māfana presents leadership as a cultural practice of nurturing warm relationships, in which people are influenced to change in a given context. This concept describes the types of leadership capabilities that Tongan participants bring to the New Zealand Public Service and goes on to explore the challenges that they face in trying to act on these capabilities in a non-Tongan cultural context. This thesis presents a Tongan model of leadership, and so brings to the wider leadership literature an empirical study that considers leadership as cultural practice. It is part of the emerging wider conversation about the importance of understanding leadership in terms of how people perceive and experience it from within their own socio-cultural backgrounds and in specific contexts. It challenges leadership scholars and practitioners to think about how they could use the knowledge of cultural practices to understand and utilise leadership differently, in the face of the dominance of Western leadership models. This study is also a wider invitation to consider the relevance of its themes and methodology to developing alternatives to organisational research based on Western perspectives, such as the emerging literature on Pacific and indigenous perspectives.

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  • A dual-trap optical tweezer approach to study emulsion droplet interactions

    Griffiths, Marjorie (2015)

    Doctoral thesis
    Victoria University of Wellington

    Foods are a highly complex form of soft condensed matter. Their complexity arises from a number of interrelated factors including the natural heterogeneity of raw materials, intricate composition, and the subtle changes in molecular interactions and micro-structural arrangements dictated by food processing and storage. It is highly important to understand the forces dictating the food structure as the assembly and organisation of major structural entities (i.e biopolymers, droplets, bubbles, networks, and particles) are responsible for the foods stability, texture, flow properties and more inclusively their organoleptic properties. The structural entities of foods exhibit numerous forms of self-organization and have significant structure complexity and dynamic behaviour on the mesoscopic length scales from 10 to 1000 nanometres. These dynamic weak interactions between the constituents define the organized state that ranges from simple spatial or temporal ordering to more intricate interactions making up the food microstructure. These interactions are often small in magnitude and are short ranged making them difficult to measure directly. Very few studies have been carried out on direct force measurements in foodstuffs. The focus of this research was to develop a dual-trap optical tweezer method to directly measure interactions between micrometre colloidal particles and ultimately to design an apparatus where interactions between less homogeneous systems, such as emulsion droplets could directly measured as a function of separation. As the name suggests, optical tweezers provide the ability to control the position of particles using a focused laser beam. The general concept of this method is to immobilise two particles in two separate optical traps and step one particle closer to the other stationary particle in a controlled fashion. The droplet’s movement is then recorded using a high-speed camera that provides near-to-real-time images of the particle’s positions. The particle’s positions are determined by a 3-D tracking algorithm developed in-house which determines the position of both particles to a precision of sub-pixel accuracy. The force exerted on each droplet (by the other one) can be extracted as it is proportional to the trap strength (pN/μm) and the displacement of the particle from the centre of the optical trap (μm). To demonstrate the optical tweezer method,the interactions between silica beads of a known size were measured as a function of bead separation. The measured force-distance curves agreed with the electrostatic component of the DLVO theory. Once the method was established it was applied at increasing salt concentrations (decreasing Debye lengths). Interestingly, a salt concentration was found beyond which the experimental data no longer agreed with the predictions of DVLO theory. Above 100 μM sodium chloride the Debye length was reduced to less than the Brownian fluctuations of the particles in the traps, which then dominated the apparent repulsion by restricting their particle trajectories, masking the actual nature of the electrostatic interactions. This resulted in force curves which fitted the exponential function, however, the fitted decay constant bore no resemblance to the actual Debye length. A diffusion experiment was designed to demonstrate the ability to measure interactions in multiple environments using the same pair of beads (at low salt concentrations where Debye lengths are faithfully recovered). The evolution of force-displacement curves was measured as the local salt concentration changed owing to the diffusion of salt from the interface and the results obtained were shown to agree with predictions based on a standard diffusion formalism. Applying the dual-trap optical tweezers method, successfully demonstrated with silica beads, to less homogeneous systems such as emulsion droplets presented challenges which showcased that emulsion design was critical as certain criteria had to be met in order to facilitate undertaking the tweezer experiments. These criteria include particle size (1-3 μm ), low polydispersity, and a reasonable refractive index mismatch between the droplet and continuous phase. In keeping with food systems a protein stabilised oil-in-water emulsion was chosen. Two popular emulsifiers, sodium caseinate and β-lactoglobulin, were investigated at different ionic strength, pH and homogenisation pressures and phase volumes. The emulsion chosen for direct force measurements was a sodium caseinate emulsion when prepared in a 100 mM phosphate buffer at pH 7.0, 60 wt. % soya bean oil and 0.04 wt.% protein which provided an adequate droplet size with minimal polydispersity. Interactions between pairs of sodium caseinate emulsion droplets were measured. Unlike for silica beads, the individual droplet size needed to be measured to deter- mine the surface-to-surface separation of droplet pairs. The droplet’s diameter was determined by measuring the restricted diffusion of the droplet in a weak optical trap and fitting the short time mean squared displacement behaviour to a Brownian motion simulation. It was found that the droplet size can be determined in this fashion to within 50 nm. Moving forward, the interactions between pairs of emulsion droplets were measured in water using the same method gleaned from the silica bead interaction study. The experimental data fitted well to the electrostatic force described by the DLVO theory with reasonable ζ-potentials extracted. To further demonstrate this dual optical tweezer method, interactions between the same pair of droplets were measured at increasing NaCl concentrations by means of diffusion. The expected trend has found to agree from calculations of increased local salt concentration based on a diffusion equation. At salt concentrations above 100 μm significant deviations in the force-curves were observed that may signal salt induced changes of the droplet’s interface or be attributed to the small magnitude of the force being within the noise. This warrants further investigation. In conclusion, the dual-trap optical tweezers have shown incredible potential to become a robust method to measure the interactions between droplets. This method has some clear advantages over current methods including that force, and spatial resolution is superior, sample preparation is straightforward, forces are measured in 3-dimensions, and the droplets are free in solution during measurement, not wetted on surfaces. Accordingly, dual-trap optical tweezer methodology has provided the ability to measure interactions to a precision that has not yet been achieved by any other method for the study of emulsion systems, which in itself is a major achievement. This method is another tool in the toolbox of a colloid chemist, food scientist and physicists to probe interactions in soft materials.

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  • Spatial and temporal regulation of cytokine expression in Type 2 immune responses

    Kyle, Ryan (2015)

    Doctoral thesis
    Victoria University of Wellington

    Type 2 immune responses are generated to provide protection against parasitic helminth infections, however these responses also cause the pathologies associated with allergic inflammation. Studies of the cell types and signalling pathways that mediate Type 2 immune responses have been previously undertaken with the goals of efficient development of vaccines against helminths, and identification of pathways that can be inhibited to decrease the damage caused by allergic inflammation. The cytokines interleukin-4 (IL-4) and interleukin-13 (IL-13) mediate many of the downstream effector functions of the Type 2 immune response. To study the mechanisms that control expression of these two cytokines I have used a novel dual cytokine IL-4 and IL-13 transgenic reporter mouse. Utilising this tool along with other IL-4 reporter mice I have discovered that the amount of T cell receptor (TCR) signalling modulates the allelic expression of IL-4 by CD4⁺ T cells. The transgenic IL-4 reporter mouse has for the first time allowed independent measurement of the effects of IL-4 deficiency on the expression of IL-4 in vivo. Using this system I have found that IL- 4 is not required for the in vivo generation or expansion of IL-4 producing CD4⁺ T cells. Th2 differentiated CD4⁺ T cells also expresses IL-13, however the dual reporter mice have demonstrated that IL-13 is expressed consistently later than IL-4 in vitro, and IL-13 requires constant, or multiple exposures to TCR stimulus for expression to be induced. IL-13 expression is absent from lymph node CD4⁺ T cells during exposure to allergens or helminth infection. Sequestration of CD4⁺ T cells in the lymph node does not impact the number of IL-13 expressing CD4⁺ T cells in the lung during a helminth infection, indicating that adaptive immune cell derived IL-13 may be entirely produced by lung resident cells not requiring transit through the lymph node. I have characterised a population of innate lymphoid cells (ILCs) within the skin and found that the proportion of these cells that constitutively express IL-13 decreases with age. These cells did not drastically change in numbers or IL-13 responses in a range of inflammatory conditions including a model of atopic dermatitis. Basophils were found to respond to the atopic dermatitis model by migrating specifically to the treated skin site and draining lymph node, and producing IL-4 in a thymic stromal lymphopoietin dependant manner. Treatment with exogenous cytokines induced IL-13 expression from group 2 ILCs (ILC2s) in the lung and these cells promoted protective immune responses against Nippostrongylus brasiliensis infection. The immune response generated during a primary infection by Nippostrongylus brasiliensis provides protection from re-infection. Long-term protection is dependent on CD4⁺ T cells but when sufficiently stimulated by cytokine, ILC2s can rescue the protection lost by the depletion of CD4⁺ T cells. This thesis has shown that CD4⁺ T cells and populations of innate immune cells differentially regulate the expression of the closely related Type 2 cytokines IL-4 and IL- 13. These discoveries will help direct future research aiming to boost the effectiveness of anti-helminth vaccines, or decrease the pathology caused by allergic diseases by targeting specific cytokine expression.

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  • Magnetic and electronic properties of iron-based superconducting systems

    Sambale, Sebastian (2015)

    Doctoral thesis
    Victoria University of Wellington

    This thesis is motivated by the large variety of high-temperature superconductors that contain iron in the superconducting layer. This number has grown rapidly since the discovery in 2008 of the iron-pnictides (and chalcogenides), where iron and arsenic form the superconducting layer. Also of interest are the iron-cuprate hybrid materials, where one out of three copper atoms is replaced by iron. The aim is to understand the superconducting, magnetic and electronic properties of these materials in respect to their iron content. This thesis describes some of these properties for the iron-pnictide compounds of CeFeAsO₁₋xFx and AFe₂As₂ (A=Ba, Sr), and for the ironcuprate hybrids of FeSr₂YCu₂O₆₊y and FeSr₂Y₂₋xCexCu₂O₁₀₋y. Here it has been found that CeFeAsO₁₋xFx follows a 3D fluctuation conductivity above the superconducting transition and the thermal activation energy is correlated to the critical current density within a two fluid-flux creep model below the superconducting transition. NMR measurements show that there is considerable charge disorder within the superconducting doping region. The AFe₂As₂ show a positive magnetoresistance, which could be interpreted through three-carrier transport. Superconducting samples of SrFe₂As₂ display a large enhancement in the magnetoresistance below the superconducting transition up to 1600 %, which is due to three-carrier transport through metallic and superconducting regions in an inhomogeneous state. The superconducting properties of the iron-cuprate FeSr₂YCu₂O₆₊y in respect to the location of iron was studied under the influence of electron and hole doping and with additional magnetic impurities. FeSr₂Y₂₋xCexCu₂O₁₀₋y shows a disorder induced spin-glass state and strong localization depending on the doping.

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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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  • Methods and Computational Techniques for Investigating and Monitoring Seismic Velocities in the Earth's Crust

    Shelley, Adrian (2015)

    Doctoral thesis
    Victoria University of Wellington

    This thesis is concerned with scrutinising the source, distribution and detectability of seismic velocity phenomena that may be used as proxies to study conditions in the crust. Specifically, we develop modelling techniques in order to analyse the directional variation of seismic wave speed in the crust and test them at Mt. Asama in Japan and Canterbury, New Zealand. We also implement both active source and noise interferometry to identify velocity variations at Mt. Ruapehu, New Zealand. Observations of temporal variation of anisotropic seismic velocity parameters at Asama volcano in Japan indicate that there is some process (or processes) affecting anisotropy, attributed to closure of microcracks in the rock as it is subjected to volcanic stress in the crust. To test this assertion, a 3D numerical model is created incorporating volcanic stress, ray tracing and estimation of the anisotropy to produce synthetic shear wave splitting results using a dyke stress model. Anisotropy is calculated in two ways; by considering a basic scenario where crack density is uniform and a case where the strength of anisotropy is related to dry crack closure from deviatoric stress. We find that the approach is sensitive to crack density, crack compliance, and the regional stress field. In the case of dry crack closure, modelled stress conditions produce a much smaller degree of anisotropy than indicated by measurements. We propose that the source of anisotropy changes at Asama is tied to more complex processes that may precipitate from stress changes or other volcanic processes, such as the movement of pore fluid. We develop a generalised anisotropy inversion model based on the linearised, iterative least-squares inversion technique of Abt and Fischer [2008]. The model is streamlined for use with results from the MFAST automatic shear wave splitting software [Savage et al., 2010]. The method iteratively solves for the best fitting magnitude and orientation of anisotropy in each element of the model space using numerically calculated partial derivatives. The inversion is applied to the Canterbury plains in the region surrounding the Greendale fault, using shear-wave splitting data from the 2010 Darfield earthquake sequence. Crustal anisotropy is resolved down to a depth of 20 km at a spatial resolution of 5 km, with good resolution near the Greendale fault. We identify a lateral variation in anisotropy strength across the Greendale fault, possibly associated with post-seismic stress changes. We perform active source and noise interferometry at Ruapehu in order to investigate potential seismic velocity changes and assess their use as a possible eruption forecasting method. Six co-located 100 kg ammonium nitrate fuel oil explosives were set off serially at Lake Moawhango, situated approximately 20 km south-east of Mount Ruapehu. Two methods of interferometry, using moving window cross correlation in the time and frequency domains, respectively, were applied to the recorded signal from each explosion pair in order to determine velocity changes from the signal coda waves. We identify possible diurnal velocity variations of ~ 0:7% associated with strain caused by the solid Earth tide. Synthetic testing of velocity variation recoverability was also performed using both methods. Interferometry of noise cross-correlations during the period was also performed using moving window cross correlation in the frequency domain. Analysis of velocity variations in the ZZ, RR and TT component pairs show little coherency. This, combined with results from synthetic testing that show that the frequency domain interferometry technique employed is unstable above velocity variations of 0.1%, indicate that the method may not be suitable for determining velocity variations at Ruapehu.

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  • Bayesian estimation of a phenotype network structure using reversible jump Markov chain Monte Carlo

    Woods, Lisa (2015)

    Doctoral thesis
    Victoria University of Wellington

    In this thesis we aim to estimate the unknown phenotype network structure existing among multiple interacting quantitative traits, assuming the genetic architecture is known. We begin by taking a frequentist approach and implement a score-based greedy hill-climbing search strategy using AICc to estimate an unknown phenotype network structure. This approach was inconsistent and overfitting was common, so we then propose a Bayesian approach that extends on the reversible jump Markov chain Monte Carlo algorithm. Our approach makes use of maximum likelihood estimates in the chain, so we have an efficient sampler using well-tuned proposal distributions. The common approach is to assume uniform priors over all network structures; however, we introduce a prior on the number of edges in the phenotype network structure, which prefers simple models with fewer directed edges. We determine that the relationship between the prior penalty and the joint posterior probability of the true model is not monotonic, there is some interplay between the two. Simulation studies were carried out and our approach is also applied to a published data set. It is determined that larger trait-to-trait effects are required to recover the phenotype network structure; however, mixing is generally slow, a common occurrence with reversible jump Markov chain Monte Carlo methods. We propose the use of a double step to combine two steps that alter the phenotype network structure. This proposes larger steps than the traditional birth and death move types, possibly changing the dimension of the model by more than one. This double step helped the sampler move between different phenotype network structures in simulated data sets.

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  • A Critical Realist Study of Political Identity in Aotearoa New Zealand: Materiality, Discourse and Context

    Woodhams, Jay (2015)

    Doctoral thesis
    Victoria University of Wellington

    Political identity is a complex phenomenon that is generated within a rich sociocultural context. This thesis examines political identity in informal talk which is situated within a relatively under-explored context, New Zealand’s capital city and political centre, Wellington. Grounding the study within the critical realist model of stratified reality provides the philosophical motivation to explore multi-layered discourses alongside the extra-discursive referents that underpin them. The analysis centres on a model of identity, contra postmodernism, which shows that identities, while socially recognised in discourse, are articulated in reference to physical and social structures. I adopt a comprehensive multi-layered approach to discourse by examining the macro sociocultural influences that appear to pattern interaction across the country, the meso-level subnational discourses that influence dialogue at a more situated level and the micro-level interactional stances taken up in everyday communication. Discourse at all levels is implicated in the identities I examine in this thesis and it is against this backdrop that I unpack political identity into its indexed discourses and constitutive stance acts. Framed by my ethnographic immersion in the study context and drawing on in-depth semi-structured interviews with twenty-six individuals, I explore the way in which discourse and stancetaking are implicated in the genesis of the participants’ political selves. I first consider the extra-discursive context, including the geographical, economic and cultural structures that underlie New Zealand discourses. This is followed by detailed analysis of sociocultural discourse as it appears in talk. I identify egalitarianism and tall poppy as two related discourses which are embedded within the historical context of the country. I also explore four subnational discourses relating to Wellington city, including the political town, left-wing and small town discourses, which occur alongside a discourse of contrast. These sociocultural and subnational discourses influence much of the talk that occurs in reference to politics in Wellington and are thus implicated in political identity as it is generated in moment-by-moment interaction. To explore this in further detail I examine the micro-level of interactional discourse, more specifically the processes of stancetaking, in two detailed case studies. The two focus participants demonstrate prominent stance processes which I argue are central to much identity work: intersubjectivity, in which the stances of all those involved in the discussion interact in complex ways; and multiplicity, when participants take numerous stance directions that appear to contribute to different aspects of their identities. The intensive focus on the case studies, alongside analysis of the full discursive and extra-discursive context, provides a multi-layered and philosophically anchored approach that seeks to contribute to current understandings of and approaches to the study of discourse and identity.

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  • Human inspired robotic path planning and heterogeneous robotic mapping

    Williams, Henry (2016)

    Doctoral thesis
    Victoria University of Wellington

    One of the biggest challenges facing robotics is the ability for a robot to autonomously navigate real-world unknown environments and is considered by many to be a key prerequisite of truly autonomous robots. Autonomous navigation is a complex problem that requires a robot to solve the three problems of navigation: localisation, goal recognition, and path-planning. Conventional approaches to these problems rely on computational techniques that are inherently rigid and brittle. That is, the underlying models cannot adapt to novel input, nor can they account for all potential external conditions, which could result in erroneous or misleading decision making. In contrast, humans are capable of learning from their prior experiences and adapting to novel situations. Humans are also capable of sharing their experiences and knowledge with other humans to bootstrap their learning. This is widely thought to underlie the success of humanity by allowing high-fidelity transmission of information and skills between individuals, facilitating cumulative knowledge gain. Furthermore, human cognition is influenced by internal emotion states. Historically considered to be a detriment to a person's cognitive process, recent research is regarding emotions as a beneficial mechanism in the decision making process by facilitating the communication of simple, but high-impact information. Human created control approaches are inherently rigid and cannot account for the complexity of behaviours required for autonomous navigation. The proposed thesis is that cognitive inspired mechanisms can address limitations in current robotic navigation techniques by allowing robots to autonomously learn beneficial behaviours from interacting with its environment. The first objective is to enable the sharing of navigation information between heterogeneous robotic platforms. The second objective is to add flexibility to rigid path-planning approaches by utilising emotions as low-level but high-impact behavioural responses. Inspired by cognitive sciences, a novel cognitive mapping approach is presented that functions in conjunction with current localisation techniques. The cognitive mapping stage utilises an Anticipatory Classifier System (ACS) to learn the novel Cognitive Action Map (CAM) of decision points, areas in which a robot must determine its next action (direction of travel). These physical actions provide a shared means of understanding the environment to allow for communicating learned navigation information. The presented cognitive mapping approach has been trained and evaluated on real-world robotic platforms. The results show the successful sharing of navigation information between two heterogeneous robotic platforms with different sensing capabilities. The results have also demonstrated the novel contribution of autonomously sharing navigation information between a range-based (GMapping) and vision-based (RatSLAM) localisation approach for the first time. The advantage of sharing information between localisation techniques allows an individual robotic platform to utilise the best fit localisation approach for its sensors while still being able to provide useful navigation information for robots with different sensor types. Inspired by theories on natural emotions, this work presents a novel emotion model designed to improve a robot's navigation performance through learning to adapt a rigid path-planning approach. The model is based on the concept of a bow-tie structure, linking emotional reinforcers and behavioural modifiers through intermediary emotion states. An important function of the emotions in the model is to provide a compact set of high-impact behaviour adaptations, reducing an otherwise tangled web of stimulus-response patterns. Crucially, the system learns these emotional responses with no human pre-specifying the behaviour of the robot, hence avoiding human bias. The results of training the emotion model demonstrate that it is capable of learning up to three emotion states for robotic navigation without human bias: fear, apprehension, and happiness. The fear and apprehension responses slow the robot's speed and drive the robot away from obstacles when the robot experiences pain, or is uncertain of its current position. The happiness response increases the speed of the robot and reduces the safety margins around obstacles when pain is absent, allowing the robot to drive closer to obstacles. These learned emotion responses have improved the navigation performance of the robot by reducing collisions and navigation times, in both simulated and real-world experiments. The two emotion model (fear and happiness) improved performance the most, indicating that a robot may only require two emotion states (fear and happiness) for navigation in common, static domains.

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  • Essays on Disaster Risk and Economic Development

    Karim, Azreen (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis consists of four self-contained papers in the areas of disaster risk and economic development. Chapter One provides a qualitative survey of the empirical literature on the nexus among poverty, inequality and natural disasters. The last few years have seen an explosion of economic research on the consequences of natural disasters. This new interest is attributable first and foremost to a growing awareness of the potentially catastrophic nature of these events, but also a result of the increasing awareness that natural disasters are social and economic events. Here, we survey the literature that examines the direct and indirect impact of natural disaster events specifically on the poor and their impact on the distribution of income within affected communities and societies. With a meta-regression analysis of the existing literature on the impacts of disasters on households in Chapter Two, we observe several general patterns. Incomes are clearly impacted adversely, with the impact observed specifically in per-capita measures. Consumption is also reduced, but to a lesser extent than incomes. Poor households appear to smooth their food consumption by reducing the consumption of non-food items; in particular health and education, and this suggests potentially long-term adverse consequences. Given the limits of our methodology and the paucity of research, we find no consistent patterns in long-term outcomes. We place disaster risk to the poor within the context of sustainable development and future climatic change. Our objective In Chapter Three is to identify all of the directly observable determinants’ of publicly allocated and realized spending for disaster risk reduction (DRR) at the local government (sub-district) level in Bangladesh. We employ the Heckman two-stage selection model with detailed public finance and other data from 483 sub-districts (Upazilas) across the country. While some of our results conform with our priors, our estimations surprisingly find that government does not respond to the sub-district’s risk exposure as a factor affecting the DRR financing mechanism. This variable is consistently counter-intuitively statistically insignificant. The DRR regional allocations do not seem to be determined by risk and exposure, only weakly by vulnerability, nor even by more transparent political economy motivations. In Chapter Four, we examine the short-run economic impacts of recurrent flooding on Bangladeshi households surveyed in 2000, 2005 and 2010. In 2010 Household Income and Expenditure Survey (HIES), households answered a set of questions’ on whether they were affected by flood and its likely impacts. We identify two treatment (affected) groups by using the self-reported data and historical rainfall data based flood risk index. We estimate a difference-in-difference (DID) model to quantify the impacts on income, expenditure, asset and labour market outcomes and further extend our analysis to different income and expenditure brackets. Overall, we find robust evidence of negative impacts on agricultural income and expenditure. Intriguingly, the extreme poor (i.e. the bottom 15th quintile) experience significant positive impacts on agricultural income in the self-reported treatment case.

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  • Tama Samoa Stories: Experiences and Perceptions of Identity, Belonging and Future Aspirations at Secondary School

    Rimoni, Fuapepe (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis investigates the experiences of twelve strong, articulate and thoughtful tama Samoa (Samoan boys) through their participation in secondary schools and lives outside the classroom and through the stories of others. The study looked at how the students enacted their identities as Samoans, as learners and as young men who are anticipating the future. The study is premised on the view that Pacific identities are fluid, diverse, multi-dimensional and include a range of different perspectives relating to social class, ethnicity, culture and gender. Such a view of identity as complex is not generally taken into consideration in the literature on educational success and achievement of Pacific students in New Zealand. The study employed a phenomenological qualitative design, using focus groups and semi-structured interviews by talanoa (conversations). As the study involved a group of indigenous tama Samoa, the Samoan fa’afaletui method was used. Participants were a group of twelve tama Samoa in three Wellington secondary schools and their twelve nominated persons. The study found that there are key aspects to making the experiences of tama Samoa positive and successful within the secondary school. These include acknowledging tama Samoa and their multiple identities while attending secondary school; supporting the development of a sense of belonging through everyday interactions with peers and teachers, and affirming the belief by tama Samoa that secondary school socialisation serves to help them make future decisions. This study argues that the experiences of tama Samoa are deeply embedded within wider social, economic and political trends. Indeed, their “voices” are shaped in part by these broader forces that construct and represent them as being historically “disadvantaged” and socio-economically “underserved.” Further, this study advocates for the diverse voices of tama Samoa, along with their experiences, stories, hopes, aspirations and dreams to be brought to light and placed alongside the official accounts of Pacific “disadvantage” to enable more balanced critical discourses taking place. It is hoped that this study will offer further insights into the experiences of tama Samoa in the New Zealand secondary school context, from which valuable knowledge is derived to inform and support schools in improving the New Zealand secondary school experiences of Samoan adolescent boys.

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