808 results for ResearchCommons@Waikato, Doctoral

  • Pervasive Personal Information Spaces

    Krishnan, Aparna (2010)

    Doctoral thesis
    University of Waikato

    Each user’s electronic information-interaction uniquely matches their information behaviour, activities and work context. In the ubiquitous computing environment, this information-interaction and the underlying personal information is distributed across multiple personal devices. This thesis investigates the idea of Pervasive Personal Information Spaces for improving ubiquitous personal information-interaction. Pervasive Personal Information Spaces integrate information distributed across multiple personal devices to support anytime-anywhere access to an individual’s information. This information is then visualised through context-based, flexible views that are personalised through user activities, diverse annotations and spontaneous information associations. The Spaces model embodies the characteristics of Pervasive Personal Information Spaces, which emphasise integration of the user’s information space, automation and communication, and flexible views. The model forms the basis for InfoMesh, an example implementation developed for desktops, laptops and PDAs. The design of the system was supported by a tool developed during the research called activity snaps that captures realistic user activity information for aiding the design and evaluation of interactive systems. User evaluation of InfoMesh elicited a positive response from participants for the ideas underlying Pervasive Personal Information Spaces, especially for carrying out work naturally and visualising, interpreting and retrieving information according to personalised contexts, associations and annotations. The user studies supported the research hypothesis, revealing that context-based flexible views may indeed provide better contextual, ubiquitous access and visualisation of information than current-day systems.

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  • Organomanganese compounds in organic synthesis

    Prasad, Narendra Jai (2009)

    Doctoral thesis
    University of Waikato

    This thesis describes the preparation and reactions of some cyclomanganated chalcones, dienones and aryl ketones. Investigation has previously been undertaken into the reaction of cyclomanganated chalcones and dienones with alkynes to give both pyranyl and cycloheptadienyl Mn(CO)₃ complexes. In the current study, the reaction was further investigated with a cyclomanganated dienone derived from a cyclic ketone which gave only the (pyranyl)Mn(CO)₃ complex (2-6) and not the cycloheptadienyl product as consistent with a mechanism previously proposed. Also extended in the current study was previous work involving the methylmanganese pentacarbonyl-mediated transformation of enynes to cyclopropanated bicyclic compounds and cyclopentanes bearing an exocyclic double bond. In the current study, benzylmanganese pentacarbonyl was used instead of methylmanganese pentacarbonyl under similar conditions. In the current study however, the type of product that formed in diethyl ether (3-4) was the one dominant in acetonitrile in the MeMn(CO)₅ study, and that formed in acetonitrile (3-5) was the dominant product type in diethyl ether (3-4). There was no apparent explanation for this reverse reactivity. Ferrocenyl pyrylium salts of the type 5-5 have been prepared using a new route to ferrocenyl pyrylium from cyclomanganated chalcones and ferrocenylethyne. UV-visible and electrochemical properties of the pyrylium salts have been investigated. The ferrocenyl pyrylium salt (5-5) was obtained by the oxidation of [2-ferrocenyl-4,6-diphenyl-ɳ₅]-pyranyltricarbonylmanganese (5-6). The crystal structure of 5-6 was also determined.

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  • Investigation and Modelling of Fetal Sheep Maturation

    Xu, Yanyang (2010)

    Doctoral thesis
    University of Waikato

    In this thesis, I study the maturational changes of the fetal sheep ECoG (electrocorticogram) in its third-trimester of gestation (95-140 days of gestation), investigate three continuum models for electrical behaviour of the cortex, and tune the parameters in one of these models to generate the discontinuous EEG waves in the immature cortex. Visual inspection of the ECoG time-series shows that the third-trimester of fetal sheep is comprised of two stages: early third-trimester characterised by bursting activity separated by silent intervals, and late third-trimester with well-defined SWS (slow wave sleep) and REM (rapid eye movement) sleep states. For the late third-trimester, the results of power, correlation time, and SVD (singular value decomposition) entropy analysis demonstrate that the sleep state change is a cortical phase transition—with SWS-to-REM transition being a first-order transition, and REM-to-SWS second-order. Further analyses by correlation time, SVD entropy, and spectral edge frequency display that the differentiation of the two distinct SWS and REM sleep states occurs at about 125 dGA (day gestational age). Spectral analysis divides the third-trimester into four stages in terms of the frequency and amplitude variations of the major resonances. Spindle-like resonances only occur in the first stage. A power surge is observed immediately prior to the emergence of the two sleep states. Most significant changes of the spectrum occur during the fourth stage for both SWS (in amplitude) and REM (in frequency) sleep states. For the modelling of the immature cortex, different theoretical descriptions of cortical behaviour are investigated, including the ccf (cortical column field) model of J. J. Wright, and the Waikato cortical model. For the ccf model at centimetric scale, the time-series, fluctuation power, power law relation, gamma oscillation, phase relation between excitatory and inhibitory elements, power spectral density, and spatial Fourier spectrum are quantified from numerical simulations. From these simulations, I determined that the physiologically sophisticated ccf model is too large and unwieldy for easy tuning to match the electrical response of the immature cortex. The Waikato near-far fast-soma model is constructed by incorporating the back-propagation effect of the action potential into the Waikato fast-soma model, state equations are listed and stability prediction are performed by varying the gap junction diffusion strength, subcortical drive, and the rate constants of the near- and far-dendritic tree. In the end, I selected the classic and simpler Waikato slow-soma mean-field model to use for my immature cortex simulations. Model parameters are customised based on the physiology of the immature cortex, including GABA (an inhibitory neurotransmitter in adult) excitatory effect, number of synaptic connections, and rate constants of the IPSPs (inhibitory postsynaptic potential). After hyperpolarising the neuron resting voltage sufficiently to cause the immature inhibitory neuron to act as an excitatory agent, I alter the rate constant of the IPSP, and study the stability of the immature cortex. The bursting activity and quiet states of the discontinuous EEG are simulated and the gap junction diffusion effect in the immature cortex is also examined. For a rate constant of 18.6 s-1, slow oscillations in the quiet states are generated, and for rate constant of 25 s-1, a possible cortical network oscillation emerges. As far as I know, this is the first time that the GABA excitatory effect has been integrated into a mean-field cortical model and the discontinuous EEG wave successfully simulated in a qualitative way.

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  • Beyond certification: The maintenance of ISO 9000 in Malaysian service organisations

    Ab Wahid, Roslina (2010)

    Doctoral thesis
    University of Waikato

    This research is an in-depth study of the quality management systems of two Malaysian "government-linked companies" (GLCs) classified as being in the service industry. Both are mature holders of ISO 9000 certification and the research focuses on how they have gone about maintaining and improving their quality management system (QMS), the extent to which they have succeeded, and what management and employees of the companies feel have been critical success factors and problems to be overcome. A case study approach is used for this study. The study has been comprehensive in its data collection with 30 individual face-to-face interviews with top management, middle management, lower management in charge of operations and quality, the management representative responsible for the implementation of ISO 9000 in the case companies being conducted, 300 questionnaires being distributed to employees of both companies, and a thorough review of ISO 9000 and other quality documents carried out. The results of the study showed that the two companies maintain their ISO 9000 based on the requirements of the standard. However, to support the technical requirements and in order to maintain the quality system more effectively and strive for excellence, the study highlights the need for integrating the human resource aspects of quality management into the quality system. Critical success factors of ISO 9000 maintenance identified are top management commitment, employee involvement, recognition and reward, teamwork, continuous improvement, and quality culture. The main problems associated with maintaining ISO 9000 faced by the companies are lack of cooperation and commitment from people, lack of knowledge and training, lack of communication, and lack of awareness and understanding on ISO 9000. Measures outlined to overcome the problems include closer interaction between people, training of management and employee on ISO 9000 and related subjects, skill and competency, and better communication. The study has identified lessons to be drawn by similar companies facing similar challenges and those striving for excellence. It has provided insights into the improvements and changes brought by the continued maintenance of the ISO 9000 after certification. It has also added to the knowledge on aspects of organisational development for service companies and casting new light on various theories put forward in the quality management literature. Further, the development of a framework for effective ISO 9000 maintenance in service organisations will enable it to be tested and compared with other industry frameworks in future studies.

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  • Exploring Knowledge Transfer and Knowledge Building at Offshore Technical Support Centers

    Chen, Jihong (2010)

    Doctoral thesis
    University of Waikato

    This is an exploratory investigation into knowledge transfer and knowledge building processes observed at offshore Technical Support Centers (TSCs) in China. Utilizing a multiple case study approach, the study examines how knowledge was transferred from the US-based support center to the China-based offshore support center, and how individuals and the organization built and expanded knowledge in a dynamic changing business context. The field cases were three Technical Support Centers in China. Three models were developed from the qualitative analysis of the field data to explain how knowledge is transferred and built in offshore TSCs. The knowledge transfer type adoption model identifies the relationships amongst the levels of knowledge (novice, advanced beginner, competency, and proficiency), the types of knowledge and the knowledge transfer approaches (structured transfer stages, unstructured copy, unstructured adaptation, and unstructured fusion). The basic individual tacit knowledge building model shows that tacit knowledge is acquired and built through two continuous knowledge building loops, an explicit learning loop and an implicit learning loop. The organizational knowledge building model demonstrates the interaction amongst knowledge flow, absorptive capacity, knowledge stock and knowledge intermediary in offshore knowledge transfer and building within the three levels (individual, group and organization levels) of the SECI spiral (socialization, externalization, combination and internalization). The three models provide new insights into the knowledge transfer process for different levels of knowledge acquisition, individual tacit knowledge building processes and organizational knowledge building processes in an offshore outsourcing business context. By applying these models to appropriate field situations, both practitioners and academics may be able to gain a deeper understanding of knowledge transfer approaches, be able to better guide new employees’ expertise and confidence building through controlled and monitored experiential learning process, and be able to improve understanding of how knowledge is built and evolves within organizations.

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  • Realistic electronic books

    Liesaputra, Veronica (2010)

    Doctoral thesis
    University of Waikato

    People like books. They are convenient and can be accessed easily and enjoyably. In contrast, many view the experience of accessing and exploring electronic documents as dull, cumbersome and disorientating. This thesis claims that modelling digital documents as physical books can significantly improve reading performance. To investigate this claim, a realistic electronic book model was developed and evaluated. In this model, a range of properties associated with physical books---analogue page turning, bookmarks and annotations---are emulated. Advantage is also taken of the digital environment by supporting hyperlinks, multimedia, full-text search over terms and synonyms, automatically cross referencing documents with an online encyclopaedia, and producing a back-of-the-book index. The main technical challenge of simulating physical books is finding a suitable technique for page turning that is sufficiently realistic, yet lightweight, responsive, scalable and accessible. Several techniques were surveyed, implemented and evaluated. The chosen technique allows realistic books to be presented in the Adobe Flash Player, the most widely used browser plug-in on the Web. A series of usability studies were conducted to compare reading performance while performing various tasks with HTML, PDF, physical books, and simulated books. They revealed that participants not only preferred the new interface, but completed the tasks more efficiently, without any loss in accuracy.

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  • Pākehā counsellors consider their positioning: Towards postcolonial praxis

    Crocket, Alastair Robert (2010)

    Doctoral thesis
    University of Waikato

    The challenges of achieving the potential, which the Treaty of Waitangi offers for a postcolonial present and future, have shaped life in Aotearoa New Zealand over the last four decades. This thesis draws on this history and challenge to consider the practice possibilities for Pākehā counsellors when they work with clients and colleagues of other cultures. It is strongly influenced by the Treaty of Waitangi but seeks not to be limited to a Māori/Pākehā binary. It has been undertaken in the hopes of informing developments in the practice of students seeking to qualify to work as counsellors and more experienced practitioners. The first theoretical foundation for this study is poststructuralism which is considered as a braided stream of theorizing where braids divide and unite. A Foucauldian social constructionism underlies this project, which extends to a consideration of subjectification, agency and positioning theory. This study is also intentionally postcolonial drawing on Said’s seminal works, Orientalism (1979) and Culture and Imperialism (1993) and North American and European writing about identity politics and intersectionality. It views the centring of the Treaty of Waitangi in this land as postcolonial work. These two emphases, poststructuralism and postcolonialism, provide the theoretical base for an exploration of the context of professional counselling practice in Aotearoa New Zealand. Five experienced counsellors constituted a research group who firstly discussed practising as a Pākehā counsellor and then acknowledged their hopes and fears for their practice with clients of other cultures. In later stages of the data generation the participants were invited to join in processes of discourse analysis and deconstruction which produced shifts in practice and practice identity. This study identifies two forms of praxis that might inform a counselling practice which seeks to achieve a postcolonial purpose: these are named as critical discursive praxis and critical Pākehā praxis.

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  • An Assessment of Contemporary Dining Out Behaviour: The Moderating Factors of Culture and Food Selection within Chinese Full-Service Restaurants in Shanghai, China

    Zhang, LingHao (2011)

    Doctoral thesis
    University of Waikato

    Shanghai can be described as metropolitan, a gateway, a hub of international traffic and a multi-cultural city. Given these facts, it can be expected that the Shanghai population is comprised of people from not only different regions of China, but also from other countries. It is been asserted by many researchers (e.g. Bojanic and Xu, 2006) that culture affects one’s dining behavior and people are subject to the influence of other cultures. Shanghai, as a place with a population of mixed cultural background, is therefore an ideal research subject for this study. The main purpose of this study is to understand the dining out behaviour of Shanghai residents in Chinese full-service restaurants in Shanghai, China. This study seeks to understand how other cultures have integrated into the Shanghai culture and how that affects the dining habits of Shanghai people. The study proposes that different people are subject to different levels of acculturation. Past research in the hospitality field indicates that the level of acculturation may affect the food practices and preferences of an individual (Sukalakamala and Brittin, 2006; Maamoun et al, 2007; Kremmyda, et al., 2008). However, most studies about acculturation affecting food habits focus on how people adapt themselves when they move overseas (e.g. Chinese people living in the USA). Little attention has been attributed to studying acculturation within the same country, which is important since people may exhibit different behaviour even within the same culture (Chang, 1979). Therefore, it is the intention of this study to contribute to what is a gap in the literature. This study collected 2103 responses from 42 Chinese full-service restaurants in Shanghai. Both qualitative and quantitative research methods were used in this study. The techniques that this study relied on to analyse the data included statistical computer software AMO S (structural equation modelling), CATPAC (artificial neural network software), SPSS 16.0 which was used for frequency analysis, descriptive analysis, independent sample t-test, one way ANOVA, factor analysis and cluster analysis. Results indicate that culture is a strong predictor of Shanghai people’s dining out behaviour, which includes their motives, restaurant choice, food choice and dining evaluation. It is also evident that Shanghai people are showing a growing awareness towards health food.

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  • Long term nitrate removal in a denitrification wall

    Long, Lauren M. (2011)

    Doctoral thesis
    University of Waikato

    Nitrogen (N) inputs to groundwater are one of the most widespread environmental problems globally. However, as N is important for crop production to support the current global population, it is difficult to limit N input to an extent where groundwater contamination is completely avoided. Researchers have been testing new ways to remove N (in the form of nitrate (NO3-)) from groundwater, primarily through enhancing microbial denitrification. One technology utilizing this microbial process is a denitrification wall, which is an inexpensive, low-maintenance technology compared to other options to treat NO3--contaminated groundwater. Denitrification walls have been shown to be effective for removing NO3- from groundwater through denitrification for seven years in New Zealand, nine years in Iowa, and 15 years in Canada; however, long-term data on the efficacy of denitrification walls remain limited. In order to understand how these systems function in the long term, the performance of a New Zealand denitrification wall installed in 1996 was examined. Field sampling was carried out during the winter of 2010 at the denitrification wall at Bardowie Farm in Cambridge, New Zealand. This farm had received relatively high N inputs from spray-irrigation of effluent from the nearby Hautapu Dairy Factory for over 30 years. The denitrification wall was originally constructed by mixing 40 m3 Pinus radiata sawdust with soil down to a depth of 1.5 m where it intercepted groundwater flow. Groundwater samples were collected from wells installed upslope and within the wall and samples were analyzed for NO3- concentrations on five occasions. Soil samples were collected on four occasions from below the water table and analyzed for denitrifying enzyme activity (DEA), total carbon (C), available C, and microbial biomass C. Results were compared to previous measurements. Groundwater NO3- concentrations entering the wall averaged 2.6 mg N L-1, which was a decrease from 2002 where NO3- entered the wall at an average of 9 mg N L-1. Despite this decrease, NO3- concentrations within the wall averaged 0.2 mg N L-1, which corresponded to 92% NO3- removal. DEA rates in the wall were nearly as high as the first year of construction. In contrast, total C and microbial biomass C had decreased by half, while available C remained the same as measured two years after construction. Denitrification in the wall remained NO3- limited suggesting that C was still sufficiently available to the denitrifiers. These data indicated that the denitrification wall was still effective after 14 years. To predict denitrification wall longevity, a first-order decay curve was fitted to the total C data through time (R2 = 0.92; p < 0.05). The decay curve was used to predict the time until total C reached 0.1%, although it is unclear at what %C denitrification will become C limited. Using this decay curve, it was estimated that C in the wall would not be depleted for 66 years, although it is possible that C will become limiting to denitrifiers before that time. This long-term study suggested that denitrification walls are cost-effective solutions to removing NO3- from groundwater as they can be effective for a number of years without any maintenance.

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  • Re-energising Knowledge Management: Communication challenges, interdisciplinary intersections, and paradigm change

    Jones, Rachel Anne (2011)

    Doctoral thesis
    University of Waikato

    Knowledge Management (KM) in the 1990s was a key upwardly-mobile management discipline. Indeed, a proliferation of articles suggested KM had the potential to make a radical departure from conventional views of organisational assets and resources, and even held the promise of transforming economies. Instead, however, KM has tended to become incorporated as a subset of traditional management. This thesis suggests that, as a result, knowledge has been perceived simply as another resource to be managed for competitive advantage. It further argues that KM need not subscribe to conventional views of management and that knowledge need not be just another resource to be exploited, hoarded, and traded. Instead, it contends that knowledge is an outcome of the process of connecting to one another in new ways and explores the field’s still-unrealised potential for generating fresh approaches relevant to contemporary conditions. In seeking to revive the excitement, and rekindle the potential, that originally surrounded the field, the thesis intervenes in current debates in KM. It attends to, and expands, the existing discourses of KM while presenting the case for a re-energised understanding of the communication of knowledge. Exploring intersections with other disciplines as well as KM’s own multidisciplinary base, it proposes transdisciplinary research as a productive focus for KM. In making these recommendations for KM’s future, the thesis seeks to make the field more responsive to current complex and dynamic academic, organisational, and social contexts. Its overall goal is not only to ensure KM’s ongoing relevance and effectiveness as a field, but to direct KM towards fulfilling its early potential.

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  • The Social Implications of Rights-Based Fisheries Management in New Zealand for Some Hauraki Gulf Fishermen and their Communities

    Duncan, Leith Stuart Willson (2011)

    Doctoral thesis
    University of Waikato

    This dissertation examines the social implications of a neoliberal `rights-based‘, fisheries management system introduced in New Zealand on 1 October 1986 in the form of the Quota Management System (QMS) using Individual Transferable Quotas (ITQs). Ongoing biological and economic monitoring has endeavoured to ensure the status of fish and the well-being of the industry but relatively little social research on the fishermen and their communities. This thesis begins to address this discrepancy. It considers four ―components, The Fishing, now Seafood, Industry (corporates), Fisheries Management (MAF/MFish), which have more market and national perspectives respectively, often influenced by international considerations, while social implications impinge more particularly on Fishermen and their Communities, both generally having more local perspectives. Communities, mainly Waiheke Island (my own community) but with reference to Coromandel, and Leigh, that had been active in the Hauraki Gulf snapper fishery before the QMS, were selected, initially as case studies but later as less distinctive variants. The dissertation argues that permitting the `Big Boats‘ on the coast constructed a crisis which was aggravated by loan schemes. The exclusion of the part-timers and aggregation of quota to the corporates has deprived coastal communities. Once they had access to fish through rights of propinquity and usufruct for livelihood and food. Now access to fish is commodified and controlled by corporates supplying an international market. Some fishermen retained their own quota, are passionate and debt free: others are contractors and financially marginal so that what was once an expressive vocation is now a more instrumental and in many cases marginal job. For social justice the QMS must provide better livelihoods for fishermen and better access to fresh locally caught fish at a fair affordable price for local consumers, especially in coastal communities.

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  • The Economic Impacts of Migrant Maids in Malaysia

    Tan, Peck Leong (2011)

    Doctoral thesis
    University of Waikato

    Demand for migrant maids by households in Malaysia has increased rapidly as more married women choose to participate in the workforce. Simple comparisons of households with maids and those without suggest that hiring maids raises female labour force participation rates of their employers by 26 percentage points. But such comparisons are not of like with like because households that employ maids differ in many ways from those who do not. When propensity score matching (PSM) methods are used to estimate the treatment effect of having a foreign maid the rise in female labour force participation is estimated to be only 18 percentage points in 1993/94. Moreover, this treatment effect appears to have fallen to only 13 percentage points by 2004/05. This decline is not apparent when simpler but potentially biased methods are used to estimate treatment effects. The small impact of hiring maids suggests financial losses to the host households and higher leisure time for Malaysian women. Another side effect of hiring migrant maids may be that human capital formation is negatively influenced, since these foreign maids have lower education levels than the mothers of the children they are employed to look after. This is a feature in many households in Malaysia where the inputs into children‟s human capital formation include maids and private tutors, in addition to the more typical inputs of parents and teachers. Previous studies of these atypical inputs from other Asian countries ignore the cumulative nature of learning by just examining contemporaneous impacts of maids, private tutoring and maternal employment. In this thesis, especially collected retrospective data are used to examine impacts on academic performance of Malaysian children in Year 6 (ages 12 to 13). The results suggest children from households that have ever had a foreign maid have higher Year 6 results, with maid impacts having a long lag. Private tutoring in the three years prior to Year 6 has significant positive impacts on academic results but earlier tutoring is associated with poorer results. When effects at various quantiles are studied, the positive impact of maids and private tutoring is most apparent for students below the median. Hiring foreign maids in Malaysia also has impacts on the maids themselves and their families in their country of origin (which is predominantly Indonesia). To examine the effect of this temporary emigration to Malaysia on income levels of the emigrant and the migrant-sending households a survey of Indonesian maids and factory workers in Malaysia was conducted by the author of this thesis. Data from this survey were then combined with data from three rounds of the Indonesian Family Life Survey (IFLS) to estimate that these young women may gain an additional US$80 to US$130 per month compared to earnings had they stayed in Indonesia. The decision to remit depends on duration and earnings in Malaysia more than on household characteristics in Indonesia. The main use of remittances is to accumulate fixed assets in Indonesia. Fixed effects models of household expenditure and assets using three rounds of IFLS data also confirm that the main impact of migration and remittances is on assets rather than consumption, and is more apparent for urban households than for rural households.

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  • Study of Titanium based Composite Coatings for Resistance against Molten Aluminium Soldering on H13 Tool Steel

    Salman, Asma Siddiq (2011)

    Doctoral thesis
    University of Waikato

    The service life of industrial components is limited predominantly by chemical corrosion, mechanical failure or mechanical wear. In the aluminium high pressure die casting industry, liquid aluminium is extremely reactive with the constituents of H13 die steel and has a tendency to form intermetallic layers. This chemical interaction results in sticking of molten metal to the die surface which produces defective castings and also damages the die surface. The use of thermal spray coatings provides protection to the surfaces operating in severe environments. An HVOF thermally sprayed coating has the advantage of having excellent bond strength and very low porosity levels (< 1%). This research work is concerned with producing and evaluating the performance of titanium/alumina based composite coatings to improve the service life of tool steel (H13) used for dies in aluminium high pressure die casting and dummy blocks used in Al extrusion. In this research work, the powder feedstocks for making the composite coatings were produced by high energy mechanical milling of a mixture of Al and TiO₂ powders in two different molar ratios followed by a thermal reaction process. The feedstock powder was then thermally sprayed using a high velocity oxygen fuel (HVOF) technique on H13 steel substrates to produce Ti(Al,O)/Al₂O₃ and TiAl/Al₂O₃ composite coatings. The performance of the coatings was assessed in terms of Al soldering, liquid metal corrosion resistance, thermal shock resistance and wear resistance. In an immersion test, the coated specimens were dipped into molten Al at a temperature of 700 ± 10 °C for different intervals of time. The performance of the coatings was tested in terms of liquid metal corrosion resistance and propensity to Al soldering. The dissolution behaviour of the coatings was evaluated by measuring weight loss after dipping the samples in to molten aluminium. The immersion test results showed that the coated samples have relatively few locations where aluminium soldering (reactive/chemical) occurred, however, an H13 steel surface showed more tendency for aluminium soldering. It was found that composite coatings changed the molten Al attack on H13 tool steel from a generalized to a localized one. No reaction between molten aluminium and a Ti(Al,O)/Al₂O₃ composite coating was identified. The TiAl/Al2O₃ composite coating was found to be attacked by molten aluminium as a result of a reaction between the coating and molten aluminium. The metallic phase TiAl in the composite coating is believed to be attacked by the molten Al. A Ti(Al,O)/Al₂O₃ composite coating was found to be a better protective coating than the TiAl/Al₂O₃ composite coating due its stability against molten aluminium attack. The thermal shock behaviour of the composite coatings was investigated by subjecting the coated coupons to a number of cycles, each cycle consisting of a holding time of 30 seconds in molten aluminium at 700 ± 10 °C followed by quenching into water. The surfaces of the coupons were examined for Al soldering and an evaluation of surface spallation. Any cracks found in the coatings were studied to explain their thermal shock behaviour. A Ti(Al,O)/Al₂O₃ composite coating on H13 tool steel produced from a fine feedstock has better thermal shock resistance than the Ti(Al,O)/Al₂O₃ TiAl/Al₂O₃ composite coatings produced from the agglomerated feedstocks. The study also describes and compares the tribological properties such as friction and sliding wear rate of the composite coatings both at room and high temperature (700.°C) under dry and lubricating conditions. The wear resistance of the coatings was investigated by a tribometer using a spherical ended alumina, flat ended high speed steel and spherical ended hardened steel pins as counter bodies. The experimental results show that the composite coatings look promising for high temperature applications due to their low wear rate at high temperature. However room temperature applications of the composite coatings can be improved under lubricated conditions. Successful trials of a Ti(Al,O)/Al₂O₃ composite coated dummy block revealed that the coating has potential as an industrial coating.

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  • Chinese Reality TV- A Case Study of GDTV’s The Great Challenge for Survival

    Luo, Wei (2011)

    Doctoral thesis
    University of Waikato

    The emergence of reality programming has a parallel development with Chinese television media at the beginning of this century. This study of Chinese “Reality TV” is based on a case study of a pioneer Chinese reality production, namely The Great Challenge for Survivor (GDTV, 2000-2006). The general concern of this thesis is an examination of the localizing of popular foreign outdoor survival formats (the Japanese top-rating Airway Boys and the international format Survivor) within a Chinese context. The study of this subject consists of field research into a major Party-state owned television broadcaster and a comparative analysis of the six broadcast seasons of the selected example. The research outcome presented here highlights some distinctive Chinese patterns in the outdoor survival reality strand prevailing early in this century and articulates the complex roles that a nationalized television station was required to play in the industrialized reform era. By recognizing the GDTV crew’s continuous efforts to improve production quality and to satisfy their assumed audiences’ needs, the thesis further addresses some key factors of the specific institutional system and broad media environment shaping local reality programme makers' decision making. Facing a “special television zone” in China, the local producer’s continuous modification of their reality programming was on the cutting edge of commercialization and globalization in the early 2000s. The production of the studied case was an exploratory enterprise which involved a set of negotiations, arguments and compromises while dealing with a range of issues which emerged in such areas as the cultural landscape, social environment, political discourse and economic power. To a large extent, the manifested transition taking place in this studied local production mirrors unprecedented social and economic changes occurring in contemporary China.

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  • Fast Monte Carlo Simulation of ⁹⁰Y Bremsstrahlung using a Kernel-based Photon Source

    Zakariah, Suhaili (2011)

    Doctoral thesis
    University of Waikato

    In targeted radionuclide therapy using ⁹⁰Y, bremsstrahlung photons can be used for imaging and subsequently for absorbed dose estimation. Monte Carlo simulation is a reliable method to study bremsstrahlung imaging but it takes a long computation time as not all ⁹⁰Y disintegrations result in emission of a bremsstrahlung photon. Furthermore the electron transport simulation is particularly time consuming. This research proposes that bremsstrahlung photons produced from the decay of a ⁹⁰Y point source are replaced with a kernel-based photon source for faster Monte Carlo simulation. This study is divided into three main parts. First, a ⁹⁰Y point source in a spherical water phantom is fully simulated using Monte Carlo simulation. The characteristics of the bremsstrahlung photons produced from the ⁹⁰Y decay are investigated. The full Monte Carlo simulation of ⁹⁰Y point source provides the relationships between the emission position, energy and emission angle of the bremsstrahlung photon. These are recorded as probability distribution functions (PDFs). Then, a kernel-based photon source which comprises of an array of photon-emitting concentric spherical shells is developed. The energy spectrum and angular distributions of the emitted photons are defined for each shell using the PDFs obtained previously from the full ⁹⁰Y Monte Carlo simulation. The kernel-based photon source shows a very close approximation to the distribution of bremsstrahlung photons generated by the full Monte Carlo simulation of ⁹⁰Y point source if the shells are sufficiently closely spaced. Finally, the accuracy and speed of the kernel-based photon source are evaluated. A simplified gamma camera model, which consists of a collimator and NaI(Tl) detector is simulated to obtain the point spread function (PSF) of the point source ‘image’. The PSF can be represented as a Gaussian function. Estimation of σ of the Gaussian function and thus the full-width half-maximum (FWHM) is used to compare the different kernel-based photon source models to represent a ‘real’ source generated by a full Monte Carlo ⁹⁰Y simulation. The results show that the FWHMs of the photon source with kernels are comparable to full Monte Carlo simulation of ⁹⁰Y point source. The FWHM determined for a photon point source with the spectrum of ⁹⁰Y bremsstrahlung underestimates the full Monte Carlo simulation of the true ⁹⁰Y point source. This demonstrates that it is important to account for the photons being emitted at a distance away from the source and all of the photons cannot be assumed to come from a single point. It is more computationally efficient to use this source model than the kernel-based photon sources as it has the shortest computation time, however it is quite inaccurate. Simplifying the kernel-based source by assuming the photon emission as isotropic reduces the accuracy of the model slightly, though the reduction in simulation time is sufficiently small that the more accurate anisotropic kernel should be preferred. The kernel-based photon source proposed in this study can be used to accurately represent the bremsstrahlung photons produced from the beta decay of a ⁹⁰Y point source. This approach greatly improves the simulation speed by almost 30 times.

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  • The everyday Bogans: Identity and community amongst Heavy Metal fans

    Snell, Dave (2012)

    Doctoral thesis
    University of Waikato

    Since the mid-twentieth century some social psychologists have demarcated communities as static entities; conceptual and physical boundaries were placed around communities to facilitate scholarly analysis. This theoretical and methodological bias is contrasted against the consideration of the dynamic flow of communities and, by association, identity formation. The application of social interactionism provides one method through which to remedy the partiality of preferred approaches to community as practised in contemporary social psychology. Opening up analysis to the consideration of processes of communing exposes the interconnection of identity and community, symbiosis that develops through social interactions across places via the creative use of music and material objects. Evidence collected through auto-ethnographic engagement with New Zealand Heavy Metal fans clarifies the complex associations that shape and maintain individual identity and community associations. Social ties are negotiated and maintained across online and offline spaces, through personal interactions and shared experiences, via object recognition, and threshold maintenance. Social psychological research needs to return to early works of psychology and symbolic interactionism to account more fully for the complex and emplaced nature of identity and community.

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  • Augmenting Autobiographical Memory: An Approach Based on Cognitive Psychology

    Schweer, Andrea (2011)

    Doctoral thesis
    University of Waikato

    This thesis investigates how an interactive software system can support a person in remembering their past experiences and information related to these experiences. It proposes design recommendations for augmented autobiographical memory systems derived from Cognitive Psychology research into human memory – a perspective missing from prior work. Based on these recommendations, a conceptual design of an augmented autobiographical memory system is developed that aims to support users in retrieving cues and factual information related to experiences as well as in reconstructing those experiences. The retrieval aspects of this design are operationalised in an interactive software system called the Digital Parrot. Three important factors in the design and implementation are the context of an experience, semantic information about items in the system and associations between items. Two user studies evaluated the design and implementation of the Digital Parrot. The first study focused on the system's usability. It showed that the participants could use the Digital Parrot to accurately answer questions about an example memory data set and revealed a number of usability issues in the Digital Parrot's user interface. The second study embodied a novel approach to evaluating systems of this type and tested how an improved version of the Digital Parrot supported the participants in remembering experiences after an extended time period of two years. The study found that the Digital Parrot allowed the participants to answer questions about their own past experiences more completely and more correctly than unaided memory and that it allowed them to answer questions for which the participants' established strategies to counteract memory failures were likely to be unsuccessful. In the studies, associations between items were the most helpful factor for accessing memory-related information. The inclusion of semantic information was found to be promising especially in combination with textual search. Context was used to access information by the participants in both studies less often than expected, which suggests the need for further research. Identifying how to appropriately augment autobiographical memory is an important goal given the increasing volume of information to which users are exposed. This thesis contributes to achievement of this goal by stating the problem in Cognitive Psychology terms and by making design recommendations for augmented autobiographical memory systems. The recommendations are confirmed by the design and implementation of such a system and by empirical evaluations using an evaluation method appropriate for the field.

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  • Form-focused instruction: A case study of Vietnamese teachers’ beliefs and practices

    Le, Van Canh (2011)

    Doctoral thesis
    University of Waikato

    Despite the reported powerful influence of teachers’ beliefs on their pedagogical practices in the classroom, very few in-depth case studies of foreign language teachers’ beliefs and the correspondence between their beliefs and instructional strategies have been internationally published – Woods (1996) being an important exception. Moreover, not a single in-depth study has ever been conducted in the context of Vietnamese state secondary schools, where teachers are non-native speakers, resources are minimal, and access to published scholarship and research is very limited. The present qualitative case study seeks to occupy this research space because contextual factors such as limited access to expert knowledge, teachers’ isolation, a prescribed curriculum, time constraints, and high-stake examinations need to be part of any analysis of teachers’ beliefs and the correlation between beliefs and practices. It has explored the beliefs about form-focused instruction held by a group of eight teachers with teaching experience ranging from 24 to 2 years and the relationship between their beliefs and practices as well as factors shaping their beliefs. Eighteen interviews (ranging from 30 to 60 minutes long) and observations of 24 naturally occurring form-focused lessons in 12 groups of 10th, 11th, and 12th graders, i.e., all grades of the upper secondary school level, and 18 hours of stimulated recall interviews were conducted to collect the data. The audio- and video-recorded data were fully transcribed and translated from Vietnamese into English, and were subjected to a process of interpretative analysis through a constant comparison and contrast of the various data. As it is revealed in the study that teachers showed a strong inclination to adopt a deductive approach to grammar with pupils memorising of grammatical rules and terminology, and doing the controlled grammar exercises in the textbook as the best way of learning grammar. Neither their beliefs nor practices were related to either current theories of language learning within the mainstream Second Language Acquisition (SLA) research or to the methodology promoted in the prescribed curriculum. Findings of the study also indiate that while teachers’ beliefs were affected by multiple contetxual factors, experiences which were accumulated through the process of socialisation in their professional community played the most influential role. Such beliefs constituted their personal theories for practice, which shaped what they did in the classroom and how they did it. Thus, these teachers shared a ‘collectively normative pedagogy’, which was underpinned by their common beliefs and justified by their common pattern of beliefs and practices. Although this is a case study and as such it is not valid to make generalisations, it has some significant contributions to add to an understanding of teachers’ beliefs in terms of research methodology and theoretical understanding with reference to teacher cognition and teacher professional development in the specific educational context where the teaching of English is undertaken by non-native-English-speaking teachers. These are discussed in the concluding chapter, Chapter VII.

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  • Fibre Degrading Enzymes from Butyrivibrio proteoclasticus

    Till, Marisa (2011)

    Doctoral thesis
    University of Waikato

    The rumen harbours a large and diverse microbial population that is responsible for the breakdown of plant material into smaller compounds, which can then be utilised by the animal. Butyrivibrio proteoclasticus is an anaerobic, Gram-positive bacterium originally isolated from the rumen of New Zealand cows. The entire genome of B. proteoclasticus has been sequenced. This revealed that a large proportion of the genome is devoted to polysaccharide degradation and reassembly1. Prior to the start of the research described in this thesis, 44 of the genes from the B. proteoclasticus genome annotated as being involved in fibre degradation had been cloned and expression of many has been tested. Two of these enzymes were expressed, purified and had had their 3D structures determined. Further characterisation of these two enzymes is presented here, with site directed mutagenesis used to probe the proposed mechanism for each. The results support the proposed catalytic mechanisms of both enzymes. Kinetic parameters were measured with model substrates for both enzymes and this allowed comparison with similar enzymes produced by other organisms. A further nine fibre degrading enzymes from B. proteoclasticus were chosen for structural and/or functional investigation. Preliminary structural investigation gave crystallisation conditions for one enzyme, Xsa43E. The structure of Xsa43E is presented along with functional analysis of the enzyme. Four residues were found to be important for catalysis, three previously identified catalytic acidic residues common to all GH43 enzymes and a fourth residue, a histidine that is important for pKa modulation of the catalytic acid. The large central ion present in the structure of Xsa43E is identified as calcium and shown to be important both for activity and structural stability.

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  • Discursive dissonance: Critical reflexivity for counselling supervision

    Esler, Ireni (2011)

    Doctoral thesis
    University of Waikato

    When practitioners and supervisors do not share the same counselling language or theoretical orientation, how is shared meaning achieved and relational connection sustained in supervision? How are differences in theoretical orientation negotiated in supervision in ways that open space for collaborative, generative dialogue and critical reflection on the politics of practice? In response to these questions, this thesis presents a critical, reflexive practitioner-inquiry exploring the possibilities and limitations a social constructionist and narrative approach to supervision makes possible for students learning apolitical, humanistic approaches to counselling. Positioned in theoretical landscapes of social constructionism, feminist poststructuralism and Narrative Therapy, this study is a reflection-in-action of a supervisor’s practice. Central to the study’s argument is discursive positioning theory; the associated concepts of relational identity, authorship and agency; and the self as a storying subject. Two student counsellors and two newly qualified counsellors, whose practice was shaped by structuralist, humanistic theories, and who were already engaged in supervision, participated in the study. Employing narrative practices of co-inquiry to generate data, a series of supervision sessions were recorded, reviewed individually by supervisor and practitioner/participant and later discussed in reflective/research meetings. Using a critically reflexive approach to discourse analysis, selected data-texts were explored for moments of discursive dissonance and moments of movement in practice development and professional identity. Research findings highlighted the need for explicit supervision working agreements, theoretical transparency, and encouragement by counsellor training/education providers for students to make fuller use of supervision as a critical learning space. It identifies three processes that might inform supervision when theoretical orientations are non-aligned. These are: supervision as critical reflexivity, supervision as a socio-political conversation, and supervision as a storying practice.

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