8,052 results for Thesis, Doctoral

  • Spiritual vegetarianism: identity in everyday life of Thai non-traditional religious cult members

    Makboon, Boonyalakha

    Doctoral thesis
    Auckland University of Technology

    This thesis examines how the participants who are Thai and vegetarians integrate vegetarianism into their lives, and how they produce and maintain their vegetarian identity element. This video-ethnographic study was conducted in Thailand over the course of five months, with particular attention to three participants who are members of non-traditional religious cults in Thailand, where vegetarianism is a normal practice. Utilizing multimodal (inter)action analysis (Norris, 2004, 2011a), I conducted a micro analysis by teasing apart the participants’ real-time interactions, investigating how different modes come to play together to make certain actions possible. The analysis also incorporates other data from observational notes, sociolinguistic interviews and photographs. I discovered that the participants produced a spiritual vegetarian identity element in accordance with their religious belief. The participants produced multiple identity elements, including but not limited to their spiritual vegetarian identity element, at differentiated levels of the participants’ attention/awareness. At the time of the study, my participants did not continuously produce their spiritual vegetarian identity element, and thus a spiritual vegetarian identity was not their most salient identity element. However, I found that vegetarianism plays a significant role in the participants’ lives as they always produced their spiritual vegetarian identity element in connection with other identity elements. This results from the fact that these identity elements were developed within a religious context which was embedded in the historical body (Nishida, 1985) of the participants. Religion has exerted a substantial influence on many aspects of their lives and their resulting identity elements.

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  • Performance analysis of fielding and wicket-keeping in cricket to inform strength and conditioning practice

    MacDonald, Danielle Catherine

    Doctoral thesis
    Auckland University of Technology

    The purpose of this thesis was to contribute to the scientific understanding of the performance demands of One Day International (ODI) fielding and wicket-keeping, and to provide recommendations for improving athlete performance, assessment and coach education. Two comprehensive literature reviews of the physical, technical, physiological and tactical components of fielding and wicket-keeping were conducted. Given the gaps identified in the literature reviews, an online mixed method survey of cricket players, coaches and trainers was designed to investigate the performance requirements of the wicket-keeper, close, inner and outer circle fielders. Players and coaches rated agility the most important physical attribute for the wicket-keeper (4.7/5), close fielders (4.6/5), and inner circle fielders (4.8/5). Speed (4.8/5) and agility (4.6/5) were rated most important for outer circle fielders. Coaches raised the issue of the lack of a cricket specific agility test. An emerging theme for all categories was the importance of the mental aspects of the game such as positive attitude and concentration, particularly for the wicket-keeper. To validate the use of video footage for performance analysis a comparison was made between televised and purposefully collected video for event coding. The variables of interest were derived from the literature reviews and corroborated by the survey. The ICC for intra-coder reliability for all but two variables was between 0.88 and 1.00 the exceptions were lateral footwork (step 0.83 and shuffle 0.55) likely due to the subjectivity of defining footwork patterns. The televised footage under-reported the frequency of wicket-keeping activity (≈4.5%), except for lateral footwork, which was under-reported by the purposefully collected video (≈13.5%) due to the movement being perpendicular to the camera view. Even though fielding activity was under-reported (≈4.25) by televised footage, this footage was deemed to be most appropriate, as the collected footage resulted in a field of view that made the finer details of fielding difficult to distinguish. Performance analysis studies on fielding and wicket-keeping were carried out using televised footage from the 2011 ODI World Cup. The majority of the wicket-keepers movements were lateral (75%); primarily repetitive low intensity movements interspersed with explosive movements such as diving and jumping. Wicket-keeping glove-work skills (69%) were the most performed skill activity, the quality of which was quantified using a catching efficiency measure (93%). Close, inner and outer circle fielders had variable involvement in fielding activities. Close fielders were involved in 20% of the fielding activity, the bowler the most (58%) involved. The inner circle fielders were involved in 50% of fielding contacts; of whom cover was the position most involved (21%) Inner circle fielders had to display the greatest range of skills within the field, such as catching from different heights, varied throwing and ground fielding techniques. Outer circle fielders were involved with 30% of the fielding contacts; the outer circle position most involved was long on (14%). Long sprints were the hallmark of outer circle fielding, following the sprint, they often had to perform explosive movements such as a dive or a jump to field the ball; they rarely had the opportunity to stop and position themselves to perform their skill. Additionally, catching (75%,89%, 85%) throwing (0%,12%, 33%) and overall fielding performance (89%,98%,99% ) were quantified using efficiency calculations for close, inner and outer circle fielders respectively. The findings of the literature reviews and studies expanded upon the only previous study to quantify fielding performance, and informed the development of performance profiles of fielding and wicket-keeping. Subsequently recommendations for assessment, training and coaching have been made, which will be integrated into New Zealand Cricket resources. Most notable are suggestions for improving the existing skill and physical testing batteries

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  • Tricksters, technology and spirit: practising place in Aotearoa-New Zealand

    Buxton, Maggie

    Doctoral thesis
    Auckland University of Technology

    Place is a tricky concept. On the surface it seems a relatively simple notion, yet underneath there are layers of contested meanings. At the same time, places face ‘wicked’ problems – issues difficult to solve by traditional methods and approaches. For these reasons there is a call from across disciplines, for flexibility and creativity in place research. This thesis weaves together technology, art, spirituality and science to create a place practice inspired by tricksters. Tricksters appear in the narratives of most cultures as liminal, paradoxical and indeterminate figures. In this research they have new relevance at a time when the boundaries of life, including the lines between sacred and profane, are no longer clearly defined. They are an inspiration for a new form of place practice which creatively weaves together ubiquitous technologies, indigenous and speculative ontologies, and integral research methodologies. The proposition is that geo-locative mobile technologies can support the work of those who work with spiritual sites, and also support the spirit or spirits of those places, when used within a trickster-inspired place practice. What are the opportunities and issues that arise from this approach? Geo-locative mobile technologies augment physical spaces with digital content and can act as mediators between the self, the physical world, digital worlds and other worlds beyond. Technology is not usually associated with spirit. However, in this research technology paradoxically plays a role in supporting the spirit of place and contributes to a progressive understanding of that term. The place practice that informed this study was situated around three spiritually significant sites: a cemetery, a marae and a public park. Within each case study, a bricolage of inter-, intra-, and transpersonal data collection methods was enacted. Integral philosophies and trickster traits combined to create the unique methodology. This research joins traditionally separate discourses: spirit of place, tricksters, and geo-locative mobile technology. It addresses the need for more creative ways of working in and with place, and raises legal, moral, cultural, and political issues in the use of mobile technologies in indigenous and/or sensitive contexts. Findings demonstrate that mobile technologies can shift perceptions of self and place, make institutional knowledge more accessible, and build connections in the third space where cultures, histories, peoples and realities meet. In these ways the practice supports the spirit of place.

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  • The experiences of Korean immigrants settling in New Zealand: a process of regaining control

    Kim, Hagyun

    Doctoral thesis
    Auckland University of Technology

    The success of all immigrants is significant to the harmony of New Zealand society since the government’s goal is to build an inclusive society. For many Korean immigrants, however, settling in an unfamiliar environment potentially disrupts familiar routines, with deleterious effects on almost all aspects of their well-being. Despite Koreans being the fourth largest group of Asian immigrants, their experiences of settling in this country have been unheard. The purpose of this study is to listen to the voices of Korean immigrants and provide information to the receiving society that will assist with developing ways to make a Korean presence part of the cultural diversity in society. This qualitative, grounded theory study included semi-structured interviews with 25 adult Korean immigrants living in the North Island of New Zealand. Theoretical sampling was used to collect data, which were analysed using methods of constant comparative analysis, conditional matrix and memoing. Through three stages of coding, data were fractured, conceptualised, and integrated to form a substantive grounded theory which has been named; A Process of Regaining Control: A Journey of Valuing Self. Upon arrival, participants confronted circumstances that made realising the anticipated benefits of immigration difficult. They experienced a loss of control in performing previously valued activities. Language barriers and limited social networks, compounded by prejudiced social reception, were associated with their decreased involvement outside the home, leading to fewer options for acquiring knowledge necessary to function autonomously in their new environment. In response, participants worked on Regaining Control by exercising choices over what they do through opting for enacting ‘Korean Ways’ or ‘New Zealand Ways’. They initially sought a culturally familiar environment in which they engaged in activities that involved drawing on previous knowledge and skills. Continuing with accustomed activities utilising ethnic resources provided a pathway to learning about their new surroundings and thus increasing their feeling of mastery in a new country. This experience strengthened participants’ readiness to engage in activities reflective of New Zealand society. The significance of this study is that it discovers that Valuing Self is what the participants wish to accomplish, beyond the scope of mastery in a new environment. Participants continually search for a place whereby they can be accepted and valued as members of society. However, this study reveals that prejudice and discrimination towards immigrants set constraints on engagement in occupations of meaning and choices. Immigrants face socio-environmental restriction when they continue with necessary or meaningful activities, even when they have the ability to execute a particular activity. This finding makes it clear that occupation is inseparable from the societal factors in which it occurs. Further research is necessary to explore societal contexts to enrich knowledge of human occupation and how immigrants’ full participation in civic society can be promoted. Specifically, it is recommended that researchers examine what makes Korean immigrants feel valued as members of society, from the participants’ point of view, in order to assist with the development of the settlement support policy and services that best facilitates their journeys of Valuing Self in New Zealand.

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  • Capturing recurring concepts in high speed data streams

    Sakthithasan, Sripirakas

    Doctoral thesis
    Auckland University of Technology

    This research addresses two key issues in high speed data stream mining that are related to each other. One fundamental issue is the detection of concept change that is an inherent feature of data streams in general in order to make timely and accurate structural changes to classification or prediction models. The shortcomings in the past research were addressed in two versions of a change detector that were produced during this research. The second major issue is the detection of recurring patterns in a supervised learning context to gain significant efficiency and accuracy advantages over systems that have severe time constraints on response time to change due to safety and time critical requirements. Capturing recurrent patterns requires the detection of concept change with minimal false positives. This research addresses this latter problem as a pre-requisite to formulating a novel mechanism for recognizing recurrences in a dynamic data stream environment. The first approach to change detection, termed SeqDrift1 that relies on a detection threshold derived using the Bernstein bound and sequential hypothesis strategy ensured much lower false positive rates and processing time than the most widely used change detector, ADWIN. The second version of the change detector, SeqDrift2, achieved significant improvement on detection sensitivity over SeqDrift1. This was achieved through two separate strategies. The first was the use of reservoir sampling to retain a larger proportion of older instances thus providing for better contrast with newer arriving instances belonging to a changed concept. The second strategy was to trade off false positive rate for detection delay in an optimization procedure. The net result was that SeqDrift2 achieved much lower detection delay than SeqDrift1 but sacrificed some of its false positive rate when compared to SeqDrift1, while still retaining its superiority with respect to this measure vis-à-vis ADWIN and other change detectors. Having proposed a robust and efficient mechanism for change detection two different meta-learning schemes for recurrent concept capture were proposed. A novel framework using the two schemes consists of concept change detectors to locate concept boundaries, a Hoeffding tree compressor to exploit the application of Discrete Fourier Transform on Decision Trees to produce compact Fourier Spectra, a forest of Hoeffding Trees to actively learn and a pool of Fourier spectra to be reused on similar recurring concepts. In the first scheme, termed Fourier Concept Trees (FCT), each Fourier spectrum is separately stored and reused on similar concepts. Accuracy and memory advantages have been empirically shown over an existing method called, MetaCT. In the second scheme, instead of storing each spectrum on its own, an ensemble approach, Ensemble Pool (EP), was adopted whereby several spectra were aggregated into single composite spectrum. The major advantage of this strategy over the first was the reduction in storage overhead as redundancies in separate spectra are eliminated by merging into one single entity. In addition, Fourier spectrum generation is optimized with theoretical guarantees to suit high speed environments. Extensive experimentation that demonstrated the benefits including accuracy stabilization, memory gain, reusability of existing models etc., has been done with a number of synthetic and real world datasets. This includes a case study on a Flight simulator system which is one of the target applications of this research.

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  • Dynamic process of user adaptation to complex mandatory information systems

    Wanchai, Paweena

    Doctoral thesis
    Auckland University of Technology

    The introduction of a complex system, such as an Enterprise Resource Planning (ERP) system, requires users to adapt to the simultaneous requirements of the new system and the associated organisational and business process changes. Unsuccessful adaptation to complex mandatory systems generates significant financial and opportunity costs to organisations and makes some employees feel dissatisfied with their jobs. Previous information systems (IS) research provides important insight into IS use. However, there is a lack of an in-depth study of the process of user adaptation that explains how user adaptation behaviours change over time and what triggers users to modify their system use behaviours. This study unveils the dynamic adaptation process and offers an explanation of how adaptation behaviours unfold over time. The fieldwork was conducted in four organisations in Thailand: one private, one state-owned, one non-profit and one multinational. An embedded multiple-case study design was applied in this research. Using the critical incident technique, 46 in-depth interviews were conducted with ERP users, managers and IT specialists. Grounded theory informed both the method of data analysis and the technique for theory building. As a result of an inductive theorising process, three intertwined core themes emerged. The first theme, user adaptation behaviours, reflects the different ways in which users respond to the evolving work practices that an ERP system imposes. The second theme, situational conditions, reveals the underlying conditions that influence the user adaptation process including social-task-user conditions and system-business process comprehension. The third theme, triggers, refers to events that change user perceptions towards the system or changes in the work environment. This study produces an emergent, substantive theory that explains how individuals dynamically adapt to complex mandatory IS. These adaptation behaviours, which are shaped by situational conditions, manifest in the form of reluctant, compliance, faithful and enthusiastic adaptation behaviours. Through their interaction with the system, individuals are constantly assessing the system in relation to the existing situational conditions. The adaptation behaviours espoused at any given time can be subsequently modified through task-related, organisational-related and system-related triggers.

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  • Comparative analysis of construction procurement systems based on transaction costs

    Rajeh, Mohammed

    Doctoral thesis
    Auckland University of Technology

    Within construction procurement, Transaction cost economics (TCE), offers a mechanism to understand ‘unseen’ costs associated with the pre and post-contract work. Pre-contract, these include costs related to information gathering and procurement. Post-contract they include activities of contract administration and enforcement. This research investigates the relationship between procurement system and transaction costs (TCs) in the New Zealand construction industry, developing a theoretical model of relationship between procurement systems and TC. The model was operationalized and developed into a questionnaire. A cross-sectional sample approach was deployed, involving questionnaire survey, interviews, and research verification through ‘real world’ cases. Data was sought from professionals in management, design and operations (i.e. project managers, architects, engineers, quantity surveyors, and procurement officers). These professionals represented several construction organizations and NZ Councils (Auckland, Hamilton, Wellington, Christchurch, Dunedin). TCs were measured using time-spent conducting procurement related activities as a surrogate for cost. Professionals evaluated their time spent on procurement activities using a 5-point Likert scale, comparing the Traditional and Design-Build delivery systems. 96 responses (74 usable) were received from a sampled population of 360 (27% response). This data was triangulated with interviews to test and explain the model. The tests included Validity and Reliability Tests, Path Analysis, Regression Analysis, Factor Analysis, and Structural Equation Modeling (SEM). The primary analytical technique used was Structural Equation Modelling to yield information on Goodness-of-Fit, model development and comparison, and confirmatory strategies. SPSS Amos 21 statistical software was used for data analysis and model development. The data demonstrated univariate and multivariate normality assumptions underlying SEM testing of research hypotheses. Of 43 hypotheses tested, six null hypotheses were rejected, demonstrating a positive relationship between the costs of information, procurement, administration, and enforcement with TCs. Additionally environmental uncertainties have indirect significant impact on TCs. The results suggest procurement systems have indirect impact on TCs, which is fully mediated by costs of information, procurement, administration, and enforcement. Finally, for research results verification, the models were applied to real-life cases (four Traditional, two Design-Build). TCs were calculated using regression equations based on factor loadings in the Traditional and Design-Build models. It was found that TCs in the Traditional system amounts to 18.5% of the annual salary cost of a project manager (as an indicator quantum), while in the Design-Build system, it amounts to 14.5% of the annual salary cost of a project manager. This study applies a new theoretical model for procurement selection based on TCs, investigating and empirically demonstrating the influence of procurement system on TCs in construction. It also offers a new plausible explanation for the factors influencing TCs in procurement. The findings have practical implications on construction business practice due to their robust empirical nature and theoretical framework, which might enhance the performance of the construction industry. The study contributes to the procurement selection in construction, by introducing a new conceptual model for the link between procurement systems and TCs. It has extended the current practices for procurement selection by estimating TCs for different procurement systems, specifically for the Traditional and Design-Build systems for comparison. This study emphasizes ‘in-house’ TCs from the perspective of the client, consequently the study recommends that the work be expanded to determine the ‘out-of-house’ TCs from the contractor perspective. Furthermore that to expand the relevance of the findings further work using the same methodology should be used to measure TCs for other procurement systems for comparison purposes. Finally, this study calculates TCs within projects, so it was recommended to further explore intra-organizational TCs in construction.

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  • An investigation of droplet evaporation characteristics in an ultrasound environment

    Protheroe, Michael Desmond

    Doctoral thesis
    Auckland University of Technology

    This study investigates and quantifies the effect of an imposed ultrasound field on the evaporation of water droplets in, for example, humidifiers used in medical respiratory treatments. The purpose of the ultrasound field is to accelerate the droplet evaporation process. This would have benefits in terms of improved efficiencies, more compact equipment sizes and better process controllability. A preliminary investigation was carried out to identify the most promising mechanisms for the effect of the imposed ultrasound field on the evaporating droplets – this being the enhancement of the normal mass and heat transfer processes involved. From this, theoretical models of normal and ultrasound enhanced droplet evaporation were developed to predict the rates of water evaporation and also changes to the droplet size distribution during evaporation. An experimental investigation was carried out to measure water droplet evaporation rates and changes to the droplet size distribution under normal and ultrasound enhanced conditions. It was found that the ultrasound field improved droplet evaporation rates in all cases tested, even at very low power levels. Improvements varied from 1 – 30%. An increase in the strength of the ultrasound field increased the improvement in evaporation rate. However, air flow above a certain threshold diminished this improvement by disrupting the ultrasound field. Investigation of the changes to the droplet size distribution indicated that at high ultrasound power levels and low air flow rates a significant amount of droplet coalescence occurred which caused the droplet distribution for the remaining droplets to shift to much larger droplet sizes. Results from theoretical models compared well to the experimental results for most experimental conditions. Differences between model and experiment occurred for the very small droplet sizes and where the effect of the ultrasound field caused maximum droplet coalescence and heating of the air and these areas warrant further future investigation. It was concluded that the ultrasound enhancement of water droplet evaporation does occur by enhancing the heat and mass transfer processes involved, that improvements in evaporation rate up to 30% could be achieved and that this could be applied to medical respiratory equipment to improve its operation and efficiency.

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  • Veitalatala: Mātanga ‘o e Talanoa

    Toluta'u, Talita Kiume

    Doctoral thesis
    Auckland University of Technology

    This study is concerned with representation. It considers the nature of a culturally located, discursive form called veitalatala and its creative translation into designed artifacts that consider the lyrical and graceful nature of Tongan women’s talanoa. The designed outcomes of the project consider the memories of three hou’eiki fafine (Tongan women) who left their homeland to settle abroad. Veitalatala: Mātanga ‘o e Talanoa is a creative synthesis of their talanoa, into new forms of artistic narrative, designed to capture the cultural and emotional resonance of their identities. The lyrical works orchestrate photography, animation, musical composition, sound design, filmed interviews, graphic design, sublimation printing on ngatu, and extensive postproduction experimentation, into unique texts that move the parameters of traditional documentation beyond conventional audio/visual interview. In so doing, the ngatu portraits and filmic veitalatala conceptually, contribute to the Tongan concept of luva (giving). Although Churchward (1959) defines veitalatala as a distinctly poetic form of talanoa, recent interviews with Havea (2014), Puloka (2014), Taliai (2014), Manu’atu, (2014), Taufa (2014), and Taumoepeau (2014) suggest that veitalatala is a complex and nuanced form of communication with diverse origins. Significantly, Tongia (2014) associates the term veitalatala with hou’eiki fafine. He suggests that it is a harmonious form of communication historically and socially related to the female gender. This thesis proposes through practice, that the tenets of veitalatala may be extended into artistic artifacts to create a contemporary, lyrical, yet culturally consistent means of representing histories and memories of Tongan hou’eiki fafine.

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  • Factors influencing the airport customer experience: a case study of Auckland International Airport's customers

    Losekoot, Erwin

    Doctoral thesis
    Auckland University of Technology

    The aim of this study was to investigate the factors influencing the airport customer experience. Much current research and management effort on airports focuses on efficiency, effectiveness, speed of processing and rankings on international league tables. These measures seem to reward those airports which can best move the largest number of passengers and their luggage. The writer of this study believed that the ‘experience’ of the ‘airport customer’ (passengers and those meeting or farewelling them) is not being given sufficient prominence at a time when it is recognised that the ‘experience economy’ can add value and create customer loyalty. New Zealand’s largest airport was the case study location for this research, and 120 interviews were undertaken in the airport environment with people who were experiencing the airport, either as arriving or departing passengers, or those greeting or farewelling them. In addition, 10 interviews were undertaken with airport management to explore their perceptions of the airport customer experience. All interviews with airport customers were undertaken in the land-side food court area of the international terminal. A plan of the airport is provided in Appendix 2 to assist the reader in understanding the layout of the airport. The guided conversations were focused on encouraging participants to share their perspective of the airport customer experience in order to build on what is already known from the quantitative surveys of passengers which are the more common form of research into airports. Together with the above data, the writer also kept a detailed research diary with observations made over the course of the data gathering phase. Hermeneutics guided the interpretive process which resulted in a number of overarching themes or notions which form the basis of this study’s findings. These include processes, people, physical environment and ‘placeness’. However, the research also uncovered what the writer has termed a ‘personal travel philosophy’. There was a significant number of people who, despite delays and other obstacles to their travel plans, appeared to be remarkably content with their lot at the airport, and this term is used to describe that group. The research concludes with a proposed model of the airport customer experience addressing five aspects – physical environment, processing, people, placeness and personal travel philosophy – and provides recommendations for airport management and opportunities for further academic research both in airports and in congruous areas such as hospitals. Airport management must spend time making people feel welcome if these spaces are to be perceived as hospitable places. The contribution that this thesis makes to the body of knowledge is a deeper understanding of the factors influencing the airport customer experience in the customers’ own words. It allows the voices of airport customers to be heard in a way that has not previously happened, in part because the dominant paradigm is a positivist one of facts, figures, benchmarks and league tables. By taking the time to listen carefully in an open-ended discussion, this research has identified much of what the airport customer really feels about the space they are obliged to spend an increasing amount of time in.

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  • The influence of Confucian values: students’ understandings of classroom behaviours and learning practices in a university in Central China

    Song, Jinhua

    Doctoral thesis
    Auckland University of Technology

    The research aims to investigate the influences of Confucian values on university students’ classroom behaviours and learning practices in Central China. Using a Foucauldian 'genealogical approach' the thesis investigated the extent to which contemporary students in a Western/central university still employ Confucius's ideas in their thinking about education, and in their own learning practices, in the classroom and outside it. The interviews showed how deeply embedded Confucian ideas were: to the extent that they were part of the students' conception of their own identities, despite the inroads of competing ideologies. The results highlighted individual students’ ability to reflect on Confucian values, and demonstrated the significant role played by students’ notice of their own identities in dealing with the influence of Confucian values. The study identified some similarities to and differences from existing literature. It made a new contribution to knowledge by exploring the overlooked element of Confucius' emphasis on joy in learning. It broke new grounds by exploring the tensions in student’s minds as they reconciled Confucian traditions, Maoist ideas and western ideas. The students’ views gave fresh insights into students’ agential powers and structural or cultural influences in the area of learning. This research provided an opportunity for students to reflect on their individual practices in their environment, to voice their concerns, and to uncover their own deep assumptions and tradition by unearthing the influence of Confucian values on their learning ideas, behaviours and practices. All teachers of Chinese students can benefit by being aware of these influences on their students. The research results could be used to develop university policies. Also learning skills support and teaching pace might be made culturally relevant, especially when students come from a Chinese cultural background.

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  • Identification of fall-risk factor degradations using quality of balance measurements

    Bassement, Jennifer

    Doctoral thesis
    Auckland University of Technology

    Falls concern a third of the people aged over 65y and lead to the loss of functional ability. The detection of risks factors of falls is essential for early interven- tion. Six intrinsic risk factors of fall: vision, vestibular system, joint range of motion, leg muscle strength, joint proprioception and foot cutaneous propriocep- tion were assessed with clinical tests before and after temporarily degradation. Standing balance was recorded on a force plate. From the force plate, 198 parameters of the centre of pressure displacement were computed. The parame- ters were used as variables to build neural network and logistic regression model for discriminating conditions. Feature selection analysis was per- formed to reduce the number of variables. Several models were built including 3 to 10 condi- tions. Models with 5 or less conditions appeared acceptable but better performance was found with models including 3 conditions. The best accuracy was 92% for a model including ankle range of motion, fatigue and vision contrast conditions. Qualities of balance parameters were able to diag- nose impairments. However, the efficient models included only a few conditions. Models with more conditions could be built but would require a larger number of cases to reach high accuracy. The study showed that a neural network or a logistic model could be used for the diagnosis of balance impairments. Such a tool could seriously improve the prevention and rehabilitation practice.

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  • Multi-level voltage and current reinjection ac-dc conversion.

    Liu, Yonghe (2003)

    Doctoral thesis
    University of Canterbury Library

    This thesis describes a new concept of multi-level reinjection ac-dc conversion, its main purpose being a further reduction of the harmonic content, a solution of dynamic voltage balancing for direct series connected switching devices and an improvement of high power converter efficiency and reliability. It is a combination of the multi-level, soft switching and reinjection concepts. A variety of configurations are proposed, based on the new concept, to achieve efficient voltage and current conversion. For each configuration the firing sequences, waveform analysis, steady and dynamic performances and close-loop control strategies are presented, and particular applications suggested. The ideal reinjection waveforms are first derived for perfect harmonic cancellation and then fully symmetrical approximations are made for more practical implementations. This is followed by a description and comparison of the generation circuits required for the implementation of the multi-level symmetrical reinjection waveforms. A three-level voltage reinjection scheme, implemented by adding a reinjection bridge and a reinj ection transformer to the standard twelve-pulse converter, is discussed in great detail, both for the series and parallel connections. This is followed by an investigation into the possible application of these converters to Back to Back VSC HV de interconnection; the analysis is validated by EMTDC simulations. A multi-level voltage reinjection VSC is also proposed, which uses a controllable de voltage divider to distribute the de source voltage to the two main bridges and produces high quality output waveforms. The voltage and current waveforms, the firing sequences and the capacitor voltage balancing are analyzed and verified by EMTDC simulations. In particular, the proposed VSC is shown to be an ideal solution for the STATCOM application. The multi-level reinjection CSC alternative is also described and shown to exhibit an excellent performance in the STATCOM application.

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  • Consumer Engagement With the C2C Online Auction Experience: Conceptualisation and Measurement

    Abdul-Ghani, Eathar

    Doctoral thesis
    Auckland University of Technology

    This research investigates the role that engagement plays as a comprehensive theoretical explanation for consumers? on-going use of consumer-to-consumer (C2C) online auctions. Online auctions have become a societal phenomenon in which millions of consumers worldwide participate to browse, compete, win, lose, buy, and sell goods. The online auction experience goes beyond interacting with the website to include consumer activities and events before and after going online. Research has yet to fully explain what makes consumers want to return and repeat the auction experience. Consumer behaviour has changed over the last two decades due, inter alia, to Web 2.0 interactive technology. Marketers have sought to understand today?s Web 2.0 consumer. Engagement has emerged as an important new concept in this regard, and has been identified as a Tier 1 research priority by the Marketing Science Institute (2014). Many marketing studies conceptualise engagement from a firm-centric view and examine customer engagement with the brand or the firm; however, as yet there is no conceptualisation of engagement that takes a completely consumer-centric view. Today?s consumers engage with any object: a brand, a firm, an experience, a community, or other consumers. This research looks at engagement with the C2C online auction experience. What drives consumer engagement with the auction experience, and what effect does engagement have on consumers? on-going use of online auctions? This research conceptualises consumer engagement with the online auction experience (CE-OAE) based on an Experiential View of the Consumer (Holbrook & Hirschman, 1982), provides in-depth insights into this engagement, develops a measure of the construct, and identifies the antecedents and consequences of CE-OAE. Consumer engagement with the online auction experience is defined as the enthusiasm, reflection of self-image, passion and interest a consumer has that drives their future participation in online auctions. Consumer engagement arises as a result of the value consumers derive from their memorable auction experiences. Five studies of online auction consumers in New Zealand were undertaken to measure and test CE-OAE. Study One was a qualitative, in-depth study that provided insights into consumers? engagement and produced items for the draft CE-OAE scale. In Studies Two to Five, the draft CE-OAE scale was subjected to exploratory and confirmatory factor analysis. Study hypotheses were tested with longitudinal data using structural equation modelling, Hayes (2013) process analysis, and multiple regression analyses. The findings show that consumers who have memorable auction experiences derive several types of value from these experiences, and that value drives consumer engagement. Engagement is shown to predict four behavioural outcomes: consumers who are highly engaged buy more, browse more, sell more, return to the auction site more often, and participate in the auction community more than those who are less engaged. Importantly, the findings also show that engagement remains stable for almost 50% of consumers over a period of six months. Changes to the levels of value that consumers derive from their online auction experiences impact levels of engagement over time. The thesis contributes to theoretical understanding of consumer behaviour and engagement in a C2C context, by developing a new conceptualisation of engagement taking the point of view of the consumer. A conceptual framework for CE-OAE is established, with consumer experiences and value derived from these experiences as the antecedents to CE-OAE, and on-going use as the consequence. Risk is shown not to have an impact on the formation of engagement. In addition, a typology and valid measure of value in online auctions are presented, and the critical role that value plays in the formation and duration of consumer engagement is recognised. Engagement is conceptualised as a motivational construct, and established as an important determinant of consumer behaviour in a C2C context; engagement endures for an extended period of time for many consumers. This research provides important insights for marketers and Web 2.0 companies. The CE-OAE measure can be used by businesses to predict customers? future buying and selling activities, suggest new strategies for engaging customers, and measure the success of a business?s engagement strategies. The CE-OAE scale has potential for use in research into other Web 2.0 C2C contexts, including engagement with social media, sharing, and collaborative consumption.

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  • Melanoma Detection Using Image Processing and Computer Vision Algorithms

    Sabouri, Peyman

    Doctoral thesis
    Auckland University of Technology

    Melanoma is the most serious form of skin cancer and is estimated to be the 19th most frequently occurring type of cancer worldwide, with approximately 232,000 new cases diagnosed in 2012. It is widely accepted that early diagnosis of melanoma significantly reduces morbidity, mortality and the cost of medication. Computer-aided systems can be applied for a quantitative and objective evaluation of pigmented skin lesions to assist the clinical assessment process. Increasing innovation in non-invasive methods can be of significant help in the early detection of malignant melanoma, thus minimising the need for biopsies. The initial step is to analyse and develop efficient algorithms for melanoma detection. This thesis is mainly focused on two main areas: a) developing an efficient lesion border detection algorithm, and b) developing an efficient classification system. For lesion border detection, several edge detection techniques are evaluated. We implemented a basic border detection algorithm on the ZYNQ-7000 System-on-Chips, which suggests a proper portable vision system could be designed for early detection of melanoma with high resolution and performance. A semi-automatic algorithm consisting of eight steps is proposed for detecting the borders of skin lesions in clinical images. Using this approach, the user selects a small patch of the lesion to specify the foreground lesion area. The results show that the proposed method achieved the accuracy of 89.32%. We present a multi-layer feed-forward deep neural networks (DNN) as a preferred lesion segmentation and recognition method. The algorithm can detect lesion borders without using any pre-processing algorithms; however, a pre-processing step hair removal and illumination correction has been essential in the previous systems. In order to develop a classification system, we investigated two different approaches: a) using hand-engineered feature data that are extracted from the segmented lesion and b) using a deep learning method which learns features automatically from the original images. The feature extraction algorithms that are used in this study are shape, colour and texture features. Correlation-based feature selection method is applied for feature selection. A performance evaluation of several supervised classifiers are discussed based on different feature sets. Two novel cascade classification architectures are proposed to improve accuracy. The second proposed cascade classifier achieved an overall accuracy of 83.3%, sensitivity of 85.1%, specificity of 80% and ROC area of 90% using ten-fold cross-validation. Finally, we present a multi-layer DNN to distinguish melanoma from benign nevi as our preferred method for classification. Our preliminary work shows that networks trained with no pre-processed and segmented images, using directly learned features instead of applying feature extraction; achieved an average accuracy of 72.53%. However, a larger dataset and more investigations are required to train a better classifier.

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  • Predicting the Distribution of Acid Volatile Sulfide in Marine Sediment From Colour Analysis of Sediment Profile Images

    Wilson, Peter Stanley

    Doctoral thesis
    Auckland University of Technology

    Measuring the sediment content of acid volatile sulfides (AVS), one indicator of coastal ecosystem functioning and the remineralisation of organic matter, is laborious and therefore rarely considered in routine coastal monitoring. In this thesis, I further develop an approach presented by Bull and Williamson (2001) to estimate the in situ distribution of AVS in subtidal soft sediment from sediment-profile images. I then determine whether this approach is valid at multiple locations in the Hauraki Gulf, New Zealand and investigate sediment chemical properties that may affect the approach. Finally, I apply this approach to assess soft coastal sediment that had been organically enriched by a long-line mussel farm. I first established a strong correlation (R² = 0.95) between sediment AVS concentration (extracted by cold 1 M HCl) and the colour intensity of sediment collected at 12 m water depth off the eastern coast of Waiheke Island, New Zealand. I then used this AVS/colour correlation to estimate the distribution of AVS in the upper 20 cm of this sediment from sediment profile images. These images were obtained in situ with a lightweight imaging device consisting of a modified flatbed scanner housed inside a watertight acrylic tube (SPI-Scan™, Benthic Science Ltd.). I made two types of estimates from the acquired images: First, I obtained a vertical AVS concentration profile by averaging the colour intensities of horizontally aligned pixels. Second, I created a two-dimensional distribution plot of AVS concentration by assigning individual pixel colour intensities. I determined whether this approach was valid at other locations by establishing an AVS/colour correlation at each of three locations in the Hauraki Gulf, New Zealand. The slopes of the fits that best described the data at each location were similar, however, the positions of the fits along the grey scale axis were offset. That is, the AVS/colour correlation was site specific and, consequently, combining the data from three locations did not produce an AVS/colour correlation that could accurately predict the sediment AVS concentration at all three locations. I suggested that the observed grey value offsets were caused by differences in the background colour of the sediment, that is, caused by sediment components other than AVS. I investigated the sediment sulfur chemistry at these three locations to determine the cause of differences in the AVS/colour correlation between locations. Using a sequential extraction technique, I measured three pools of sedimentary sulfides: dissolved porewater sulfide, AVS, and sequentially extracted chromium reducible sulfide (CRSs). Dissolved porewater sulfides contribute to the total AVS concentration but not to the sediment colour. The constituents of CRSs, however, contribute to the sediment colour but not to the total AVS concentration. The analysis revealed that the concentration of dissolved porewater sulfides was negligible. It also revealed that the relative proportions of AVS and CRSs were functions of sediment age. Sediment at greater depth in the sediment column contained greater proportions of CRSs than surficial sediment because it was older. Black mineral pyrite was the main constituent of CRSs. The transformation of pyrite from its precursors can take up to several years. Contrastingly, the minerals that primarily comprise AVS (mackinawite and greigite) form from their precursors over hours or days. I suggested that the reason for the non-linear AVS/colour correlation was because of a change in the relative proportions of AVS and CRSs with sediment depth. The slope of the fit describing data from a site with a high AVS concentration and low CRSs concentration will be steep because the majority of the change in sediment colour arises from a change in the concentration of AVS minerals. Contrastingly, the slope of the fit describing data from a site with a low AVS concentration and high CRSs concentration will be less steep because a change in sediment colour intensity will be largely from a change in the concentration of CRSs minerals, rather than AVS minerals. Finally, I used this approach investigate temporal changes in the extent of the seafloor area underneath a New Zealand long-line mussel farm of elevated sediment AVS content. Such assessment requires accurate detection of the AVS footprint boundary. I demonstrated how to detect this boundary with sediment profile imagery. I analysed 182 sediment profile images taken along three transects leading from approximately 50 m inside to 200 m outside the long-line mussel farm and found that the mean sediment colour intensity inside the farm boundary was almost 1.5 times lower than that of the sediment away from the farm. Segmented regression analysis of the combined colour intensity data revealed a breakpoint in the trend of increasing grey values with increasing distance from the farm at 56±13 m (± 95% confidence interval of the breakpoint) outside the mussel farm. Mapping of grey value data with ArcMap (ESRI, ArcGIS) indicated that the extent of the AVS footprint is a function of water column depth; organic particles disperse further in a deeper seawater column. I conclude that for soft coastal sediment, the described sampling and data analysis techniques may provide a rapid and reliable supplement to existing benthic surveys that assess environmental effects of marine farms or other organic enrichment sources.

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  • Learning to Program: The Development of Knowledge in Novice Programmers

    Kasto, Nadia

    Doctoral thesis
    Auckland University of Technology

    This thesis presents a longitudinal study of novice programmers during their first year learning to program at university. The purpose of this research was to gain a deeper understanding of the ways in which novice programmers learn to program with an emphasis on their cognitive development processes. The intended outcome was a better understanding of the learning processes of novice programmers, which should enhance the ability of educators to teach, design courses, and assess programming. A key aspect of this research focused on cognitive development theories of Piaget, Vygotsky, Sfard and Cognitive Load and to what degree these theories could explain observations of novice programmers learning to write code. In order to observe and investigate how novice programmers integrate new programming structure, concepts or elements into their current understanding of code it is necessary to be able to measure how difficult writing tasks are. Thus, the first aim of this research was to develop a task difficulty framework, which consisted of a new empirically verified software metric (code structure and readability) and a SOLO classification (task complexity) for code writing tasks. This framework was then used to design nineteen code writing tasks which were of increasing difficulty and complexity so as to trigger situations that required some form of knowledge adaptation or acquisition. Over one academic year, students were observed attempting to solve these programming tasks using a think aloud protocol and were interviewed retrospectively using a stimulated recall method. These observations were then linked to the cognitive theories in a way that provides an explanation of how programming was learned by these students. The results of this research indicate that both cognitive and sociocultural approaches are important in the development of knowledge of novice programmers. Of the theories examined two were found to be the most useful. The first is Vygotsky’s notions of the Zone of Proximal Development, the role of more knowledgeable others, and recent ideas about scaffolding. The second is Sfard’s theory of concept development that contributes to a deeper understanding of the way novice programmers’ develop patterns and reuse them in solving another programming task. The evidence about learning obtained during this study provides strong support for a change in the size and organization of the classes in which novice programmers are typically taught and in the teaching methods used.

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  • A Multi-level Theory of Post-Adoptive Adaptation and Organisational Change in Enterprise System Implementation: The Case of CRM

    Techakriengkrai, Wallayaporn

    Doctoral thesis
    Auckland University of Technology

    The implementation of a new enterprise system is a major change event for end-users. Users must adapt themselves to learn and understand the new enterprise system as well as engage with the system in their work practices. In addition, organisations need to modify organisational processes and structures to support the new enterprise system. Past research has largely focused on initial organisational adoption decisions concerning an enterprise system. However, there has been little research concerning the use of the enterprise system and the associated change process in the post-adoption stage. This study addresses this gap by developing a multi-level theory of post-adoptive adaptation and organisational change associated with enterprise system implementation in organisations. This study focuses on enterprise system implementation in the context of the Customer Relationship Management (CRM) system. The research questions are: (1) How do organisational changes unfold in enterprise system implementation in the context of CRM systems? (2) How do individuals adapt to an enterprise system in the context of CRM systems at the post-adoptive stage? The study adopted a qualitative interpretive case study method to develop a multi-level theory. Multiple sources of data including interviews and supporting documents were collected and analysed in order to understand individuals’ adaptation behaviours and organisational changes in the post-adoption stage of enterprise system implementation. This study employed an embedded multiple-case design and multi-level analysis. Semi-structured interviews were conducted with 43 participants in three different types of business organisations: innovative office automation solutions, an insurance business, and a hospital. The participants were management, users, and IT support staff. Three concurrent data analysis processes (data reduction, data display, and conclusion drawing and verification) were conducted to analyse data and to build a multi-level theory. In addition, the data analysis processes were carried out to identify critical events and gaps which occurred during the change process. During the data analysis stage, low-level codes, interpretive codes, and pattern codes were developed to answer the research questions and build theory. Within-case and cross-case analysis was conducted to explore individuals’ adaptation behaviours and organisational change in each organisation and compared with the other organisations to identify similarities and differences. The study develops new knowledge based on how an integrated theoretical perspective using coping theory and a socio-technical perspective can inform ICT-enabled changes in organisations. The findings revealed five core pattern codes. The pattern codes of changing structure of work, consequences of CRM implementation, and transparency tool and control mechanism revealed organisations change. The pattern codes of adaptation behaviours and factors influencing adaptation behaviours reflected individual adaptation. These two levels of analysis were interrelated. This research contributes to the literature of user adaptation, organisational change, and enterprise systems by presenting a multi-level theory of post-adoptive adaptation and organisational change following enterprise system implementation. The results showed that organisations changed their structure of work after enterprise system implementation, which led to the generation of gaps in socio-technical components and consequences. The generation of gaps had a significant impact on individual adaptation behaviours. The findings will assist organisations in providing appropriate resources and support for successful enterprise system implementations at the post-adoption stage.

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  • Implications of Software as a Service Adoption for IT Workers’ Roles and Skill Sets from a Sociomateriality Perspective

    Mbuba, Freddie Haita

    Doctoral thesis
    Auckland University of Technology

    This study broadly seeks to explain the implications of software as a service (SaaS) for information technology (IT) workers from a sociomateriality perspective. SaaS is a cloud-computing model based on IT capabilities of a utility model that enhances the scalability of computing resources at a lower cost than on-premise IT systems. Unlike the on-premise IT system, through the SaaS model, customers no longer need to purchase software licences. Instead, they can subscribe to and access software via an Internet connection. Based on these potential benefits, customers, particularly large organisations such as tertiary institutions for whom IT may not be their core functional systems, are migrating their on-premise IT systems to the SaaS model. However, this may have effects on the roles and skill sets of IT workers, as support and future developments of SaaS shifts to the SaaS service provider. Researchers have raised concerns about these implications and predicted that cloud adoption would change IT workers’ roles and diminish their jobs, leading to job losses worldwide, as IT departments within organisations lose control of IT resources. Similarly, studies report that IT workers believe by turning IT resources and support to a cloud service provider pose significant risks to their roles and skill sets. However, these anecdotal claims are not supported by substantial empirical and theoretical evidence. Researchers have called for more studies on these implications and the associated human management issues. Previous information system studies on the changing IT workers’ skill sets related to cloud computing adoption are rather generic in that there is a scarcity of in-depth conceptual and empirical analyses to ascertain how these implications are related to SaaS adoption in particular. Therefore, the migration process of IT from on-premise to the SaaS model presents an ideal environment in which to not only understand the implications for IT workers but to contrast the features of the insights offered into how human and technology or human and material agencies interact in work practices. Sociomateriality literature claims that human and material become constitutively entangled in work practices. However, less is known about how human and material interact, and at what level these interactions happen. Therefore, this research draws empirical data from IT implementation projects related to moving on-premise IT systems to a SaaS system, to explain the implications of a SaaS system for IT workers, and employs the concepts of sociomateriality to help explain how human and technology interact in work practices. To narrow the scope, diversity, and context of the research focus, the current study draws empirical data from four case studies of tertiary institutions in New Zealand that migrated their on-premise email systems to a SaaS system such as Google Apps for Education (GAE) or hosted Office 365 (O365). This approach addresses the main research questions posed in this thesis: why the migration of an on-premise IT system to SaaS changes the roles and skill sets requirements for IT workers; what implications there are for functions of the IT department; and how IT workers interact with these technologies from a sociomateriality perspective. In answering these questions and build an in-depth understanding, this study employs a punctuated sociotechnical information system change (PSIC) model as a tool for analysing and displaying the empirical data. In addition, the research applies the concepts of sociomateriality to provide in-depth explanations of the interactions between human and technology. An interpretive approach is adopted, with 17 participants interviewed from four case studies. The participants included IT workers and IT managers who participated in the SaaS migration process. The findings suggest that SaaS has some effects on IT workers’ roles and skill sets, and drawing on the sociomateriality theory, the thesis elaborates and conceptualises levels of the human and technology interaction in the context of SaaS. In addition, the study provides contextual, methodological and theoretical contributions to the body of knowledge.

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  • Nutrition and Reproductive Condition of Wild and Cultured New Zealand Scallops (Pecten novaezelandiae)

    Wong, Ka Lai Clara

    Doctoral thesis
    Auckland University of Technology

    The New Zealand native scallop, Pecten novaezelandiae, is a species with a high economic value as a wild catch and has good potential for cultivation. As a mean to enhance the future of this growing shellfish industry, this thesis set out to investigate the nutritional requirements of P. novaezelandiae in relation to reproductive conditions, and determined the physical and biological factors that affect the condition of this scallop species in the wild and cultivated environments. Adult scallops (Pecten novaezelandiae) were sampled from six populations in the Hauraki Gulf (Auckland, New Zealand) in the spawning season (October 2014), in order to evaluate the scallop reproductive condition and nutritional state across the populations. Results showed a spatial variation in reproduction condition (VGI and gonad index), with a higher number of mature scallops in populations closer to the shoreline, where higher food availability may be found. Conversely, nutrient content in scallop somatic tissues (adductor muscle carbohydrates and digestive gland lipids) did not vary across the populations, but was strongly associated with reproductive status of individual scallops (VGI). Nutrient (carbohydrates, proteins and lipids) storage and utilization were investigated within scallops from two sites in the Hauraki Gulf, bi-monthly over a year (2012−2013). In addition, sediment samples were also taken to evaluate the potential for re-suspended nutrients as a food source for scallops. Water samples were collected for seston and chlorophyll a analyses. Isotope analyses (carbon and nitrogen) and proximate analyses were conducted for the gonad, adductor muscle and digestive gland of wild P. novaezelandiae, sediment samples and the seston (1.2−5μm, >5μm). Isotope analyses revealed distinctly different signatures in suspended sediment and scallop tissues, indicating that re-suspended nutrients were unlikely to contribute to the diet of scallops. Nevertheless, seston (particularly the small fractions) signatures were closely related to scallop tissue samples, suggesting that it is likely to be the main food source for the wild P. novaezelandiae. Scallops from the two sampling sites exhibited similar reproductive cycles and utilization of nutrients. Gametogenesis started in winter, and took place at the expense of carbohydrates stored in adductor muscles. Spawning events were recorded in spring (October−November) and summer (January−March), and the energy demand required during spawning events was supported by digestive gland protein. Gonad re-maturation between spring and summer spawnings were supported by the utilization of digestive gland lipids. The reproductive condition and nutrient content of scallops were then studied during the spawning season (October 2013) in wild populations and within experimental conditions (fed with a commercial microalgal diet; Shellfish Diet 1800®) in an aquaculture laboratory, in order to identify condition and nutrient requirements for scallop cultivation in New Zealand. Field scallops (feeding on natural food sources) spawned just before the end of the experiment, while experimental animals reached gonad maturity at the end of the experiment, but did not spawn. The trend in gonad maturation for field and experimental animals indicates that there was a lag time of about 2 weeks, and that this lag is likely due to nutritional stress associated with the shift from natural food sources to the mixed microalgal formulated diet provided in the laboratory. Results indicate that experimental scallops had lower nutrient (carbohydrates, protein, lipids and total energy) reserves stored in adductor muscle tissues compared to wild animals, but both field and experimental animals utilized muscular reserves (especially carbohydrates and protein) to support reproductive activity. The fatty acid profiles revealed that polyunsaturated fatty acids (PUFA) were found in significantly lower quantities in gonad tissues of scallops from the laboratory compared to those in the field. This thesis shows that P. novaezelandiae utilizes energy reserves from both adductor muscle and digestive gland to cover the full cost of gametogenesis. In addition, cultivation environments using microalgal diets are conducive to condition P. novaezelandiae, but the optimal nutrient requirements for an efficient aquaculture production of this species needs further investigation. It is recommended by this thesis that future investigation on the conditioning requirements for P. novaezelandiae will be the next step for New Zealand scallop fisheries.

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