1,004 results for Doctoral, 2013

  • Collaborative Software Visualization in Co-located Environments

    Anslow, Craig (2013)

    Doctoral thesis
    Victoria University of Wellington

    Most software visualization systems and tools are designed from a single-user perspective and are bound to the desktop and IDEs. These design decisions do not allow users to analyse software collaboratively or to easily interact and navigate visualizations within a co-located environment at the same time. This thesis presents an exploratory study of collaborative software visualization using multi-touch tables in a co-located environment. The thesis contributes a richer understanding of how pairs of developers make use of shared visualizations on large multi-touch tables to gain insight into the design of software systems. We designed a collaborative software visualization application, called Source-Vis, that contained a suite of 13 visualization techniques adapted for multi-touch interaction. We built two large multi-touch tables (28 and 48 inches) following existing hardware designs, to explore and evaluate SourceVis. We then conducted both qualitative and quantitative user studies, culminating in a study of 44 professional software developers working in pairs. We found that pairs preferred joint group work, used a variety of coupling styles, and made many transitions between coupling and arrangement styles. For collaborative group work we recommend designing for joint group work over parallel individual work, supporting a flexible variety of coupling styles, and supporting fluid transitions between coupling and arrangement styles. We found that the preferred style for joint group work was closely coupled and arranged side by side. We found some global functionally was not easily accessible. We found some of the user interactions and visual interface elements were not designed consistently. For the design of collaborative software visualizations we recommend designing visualizations for closely coupled arrangements with rotation features, providing functionality in the appropriate locality, and providing consistent user interactions and visual interface design. We found sometimes visualization windows overlapped each other and text was hard to read in windows. We found when pairs were performing joint group work the size of the table was appropriate but not for parallel individual. We found that because the table could not differentiate between different simultaneous users that some pair interactions were limited. For the design of multi-touch tables we recommend providing a high resolution workspace, providing appropriate table space, and differentiating between simultaneous user interactions.

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  • The intraovarian cellular origins of GDF9 and BMP15 in the mouse and aspects of their biological properties

    Mester, Brigitta (2013)

    Doctoral thesis
    Victoria University of Wellington

    Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are both members of the TGF-ß protein superfamily and are known to be essential for normal follicular development in mammals. Several studies have highlighted the species-specific effects of BMP15 and GDF9, which could be attributed, at least in part to the differences in the follicular expression patterns and to different forms of the secreted proteins. In the mouse, GDF9 is required for follicular development, whereas BMP15 appears to be only required near ovulation with contradictory reports as to the timing of BMP15 expression. However, mouse BMP15 and GDF9 are known to have the capability of acting together synergistically. The aims of this thesis were to characterise in the mouse ovary, the expression patterns (localisation and levels) of Bmp15 and Gdf9 mRNA throughout follicular development, and to determine the peri-ovulatory expression of the corresponding proteins. In situ hybridisation and quantitative PCR analyses of ovarian samples and follicular cells collected from control and superovulated mice confirmed that Gdf9 and Bmp15 mRNA are expressed exclusively in oocytes from primary and early secondary stage follicles respectively. qPCR analysis of denuded oocytes (DO) revealed a tight correlation, and therefore co-regulation, between the expression levels of Bmp15 and Gdf9 irrespective of follicular developmental stage, with steady expression until the preovulatory LH surge when down-regulation of Bmp15 and Gdf9 occurred. Throughout the follicular developmental stages examined, Gdf9 was expressed in greater abundance relative to Bmp15, with a Bmp15:Gdf9 mRNA ratio of 1:4.12. [...] In conclusion, oocyte-derived Bmp15 and Gdf9 mRNA expression is co-regulated throughout follicular development in mice, with Gdf9 being more abundant than Bmp15, which might be an important factor in determining high ovulation quota. The expression of the target genes is down-regulated as the oocyte reaches developmental competence following the preovulatory LH surge. Protein expression data provided evidence that in vivo the immature mouse oocyte is capable of secreting all BMP15 protein forms previously detected in vitro. After the preovulatory LH surge, all visible protein forms are associated with the somatic follicular cells, in particular with the expanded cumulus mass. Of particular interest is the presence of the large protein complexes in the cumulus cell lysates, which suggests a storage and activation process involving ECM proteins, similar to the mechanism reported for other TGF-ß superfamily members, such as TGF-ß1 and myostatin. The finding that the BMP15 precursor protein is biologically active with a different activity to that of the processed mature protein form suggests that the full-length precursor protein may regulate or provide at least a portion of the biological activity of BMP15 in mice.

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  • Geospatial process modelling for land use cover change

    Nti, Isaac Kwadwo (2013-11-29)

    Doctoral thesis
    Auckland University of Technology

    Human activities and effects of global warming are increasingly changing the physical landscape. In view of this researchers have developed models to investigate the cause and effect of such variations. Most of these models were developed for specific locations with spatial variables causing change for that location. Also the application areas of these models are mainly binary transitions, not complex models which involve multiple transitions, for example deforestation models which deal with the transition from forest lands to non-forest areas and urban growth transition from non-urban areas to urban. Moreover these land simulation models are closed models because spatial variables cannot be introduced or removed, rather modellers can only modify the coefficients of the fixed variables. Closed models have significant limitations largely because geospatial variables that cause change in a locality may differ from one another. Thus with closed models the modellers are unable to measure and test the significance of variables before their inclusion. This work investigated existing land use cover change (LUCC) models and aimed to find a geospatial workflow process modelling approach for LUCC so that the influence of geospatial variables in LUCC could be measured and tested before inclusion. The derived geospatial workflow process was implemented in DINAMICA EGO, an open generic LUCC modelling environment. For the initial calibration phase of the process the Weight of Evidence (WoE) method was used to measure the influence of spatial variables in LUCC and also to determine the variables significance. A Genetic Algorithm was used to enhance the WoE coefficients and give the best fitness of the coefficients for the model. The model process was then validated using kappa and fuzzy similarity map comparison methods, in order to quantify the similarity between the observed and simulated spatial pattern of LUCC. The performance of the workflow process was successfully evaluated using the Auckland Region of New Zealand and Rondônia State of Brazil as the study areas. The Auckland LUCC model was extended to demonstrate vegetative carbon sequestration scenario. Ten transitions were modelled involving seven Land Use Cover (LUC) classes and a complex dynamic LUCC for Auckland was generated. LUC maps for 1990 and 2000 were used to calibrate the model and 2008 was used to validate the model. The static spatial variables tested were road networks, river networks, slope, elevation, hillshade, reserved lands and soil. The hillshade and soil variables were found to have no significant impact in the LUCC for the Auckland area, therefore they were excluded from the model. If a closed model had been used these insignificant variables would have been included. The calibration phase revealed that wetland and cropland LUC areas in Auckland have not changed between 1990 and 2000. The validated LUCC model of Auckland, served as a foundation for simulating annual LUC maps for advance modelling of Carbon Sequestration by vegetation cover. In order to test the generic nature of the workflow process model a second case study was introduced that had a different data resolution, area extent and fewer LUC transitions. Compared to Auckland, the new Rondônia case study was a simple LUCC model with only one transition, with coarse data resolution (250m) and large area extent. The evaluation of the Rondônia LUCC model also gave good result. It was then concluded that the derived workflow process model is generic and could be applied to any location.

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  • Object-centric Intelligence: Sensor Network and Thermal Mapping

    Yamani, Naresh (2013-11-29)

    Doctoral thesis
    Auckland University of Technology

    Quality of product is an important aspect in many commercial organizations where storage and shipment practices are required. Temperature is one of the main parameters that influence quality and temperature treatments of agricultural products therefore require special attention. The temperature variation in a meat chiller has a significant effect on tenderness, color and microbial status of the meat, therefore thermal mapping during the chilling process and during chilled shipment to overseas markets is vital. The literature indicates that deviations of only a few degrees can lead to significant product deterioration. There are several existing methods for thermal mapping: these includes Computational Fluid Dynamics (CFD), Finite Element Methods (FEM) for examination of the environmental variables in the chiller. These methodologies can work effectively in non real-time. However these methods are quite complex and need high computational overhead when it comes to hard real-time analysis within the context of the process dynamics. The focus of this research work is to develop a method and system towards building an object-centric environment monitoring using collaborative efforts of both wireless sensor networks and artificial neural networks for spatial thermal mapping. Thermal tracking of an object placed anywhere within a predefined space is one of the main objectives here. Sensing data is gathered from restricted sensing points and used for training the Neural Network on the spatial distribution of the temperature at a given time. The solution is based on the development of a generic module that could be used as a basic building block for larger spaces. The Artificial Neural Networks (ANNs) perform dynamic learning using the data it collects from the various sensing points within the specific subspace module. The ANN could then be used to facilitate mapping of any other point in the related sub-space. The distribution of the sensors (nodes placement strategy for better coverage) is used as a parameter for evaluating the ability to predict the temperature at any point within the space. This research work exploits the neuro Wireless Sensor Network (nWSN) architecture in steady-state and transient environments. A conceptual model has been designed and built in a simulation environment and also experiments conducted using a test-bed. A Shepard’s algorithm with modified Euclidian distance is used for comparison with an adaptive neural network solution. An algorithm is developed to divide the overall space into subspaces covered by clusters of neighbouring sensing nodes to identify the thermal profiles. Using this approach, a buffering and Query based nWSN Data Processing (QnDP) algorithm is proposed to fulfil the data synchronization. A case study on the meat plants cool storage has been undertaken to demonstrate the best layout and location identification of the sensing nodes that can be attached to the carcasses to record thermal behavior. This research work assessed the viability of using nWSN architecture. It found that the Mean Absolute Error (MAE) at the infrastructural nodes has a variation of less than 0.5C. The resulting MAE is effective when nWSN can be capable of generating similar applications of predictions.

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  • The effect of stroke rate on performance in flat-water sprint kayaking

    McDonnell, Lisa Kelly (2013-11-29)

    Doctoral thesis
    Auckland University of Technology

    Stroke rate has been implicated as an important determinant of sprint kayaking performance via correlation analysis. This thesis determined the effect of stroke rate on sprint kayaking performance including: (1) What stroke rates are required to achieve medal winning times?; (2) What are typical self-selected stroke rates of New Zealand paddlers?; (3) Do paddlers respond well to stroke rate feedback?; and (4) What is the effect of increasing stroke rate on performance and technique? Two literature reviews, one quantitative descriptive performance analysis, two quantitative experimental reliability studies, two quantitative experimental biomechanical studies, and one quantitative experimental intervention study were completed. Elite K1 200-m world championship medallists’ average stroke rates ranged 144-168 spm for men and 131-147 spm for women in competition. New Zealand elite paddlers (males and females) typically rated 98-101 spm, but tests were limited to 300-m sprint training at “race pace” and during the last stage of an incremental ergometer test. It was best to assess stroke rates using time-trials. The typical self-selected stroke rates of New Zealand male sub-elite paddlers were 122 ±11 spm during K1 200-m time-trials. While metronome feedback targets were not fully achieved when increasing stroke rate by 5-10 spm, the metronome was effective for increasing stroke rate by 4-5 spm (2.9-4.2%). The stroke rate increase led to a 200-m performance time enhancement of 0.9-1.0% for sub-elite paddlers, where a general trend existed that faster paddlers responded better to the stroke rate increase. Other key variables that indicated better performances were shorter water phase times, aerial phase times, entry sub-phase times and exit sub-phase times. Overall, absolute phase and sub-phase times reported in seconds were more associated with performance than relative phase and sub-phase times. Increasing stroke rate using metronome feedback also caused reductions in water and aerial phase times. Water phase times were reduced primarily by reductions in pull sub-phase times. Pull sub-phase times were not significantly associated with performance, possibly indicating variability in the efficiency of the pull phase between skill levels on-water. Key segmental sequencing variables important for inducing a stroke rate increase between intensities were shorter durations of the pull arm, trunk, and leg actions. Decreasing forward reach was inevitable and decreasing pull arm time was the most important variable for increasing stroke rate, so paddlers should focus on reaching as far forward as possible without hindering their ability to quickly direct the paddle backward. Trunk rotation and leg extension movements increased with intensity and are considered important for performance theoretically for achieving greater paddle tip velocity when the blade enters the water by utilising a greater leg pedalling motion. In conclusion, New Zealand paddlers typically rated well below the recommended stroke rates required to achieve medal winning times in the K1 200-m event. Metronome feedback was effective for eliciting an acute stroke rate increase of 4-5 spm (2.9-4.2%), which led to performance enhancements of 0.9-1.0% in K1 200-m time-trials. Further research is needed to determine the ideal training strategies for making larger increases in stroke rate without losing efficiency in the pull sub-phase.

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  • Perceived and measured health benefits of aqua-based exercise for older adults with osteoarthritis

    Fisken, Alison Lesley (2013-11-29)

    Doctoral thesis
    Auckland University of Technology

    Ageing is associated with a number of physiological and psychological changes. These include declines in muscle mass, strength, functional ability, and balance, which are associated with increased risk of falling and reduced quality of life. In addition, many older adults have osteoarthritis and the associated symptoms of joint pain and stiffness may exacerbate the age-related changes in physical function. Regular exercise can help offset the age-related declines in muscle strength, functional ability and balance, however many older adults do not regularly exercise. In particular older adults with osteoarthritis tend to have lower levels of physical activity than older adults without osteoarthritis. Aqua-based exercise is recommended for older adults with osteoarthritis due to the properties of water, however relatively few studies have investigated this type of exercise among this population. The first aim of this thesis was to investigate perceived benefits and barriers to participation in aqua-based exercise among older adults with and without osteoarthritis, who regularly engage in this form of exercise. The key perceived benefit for those with osteoarthritis was pain reduction, whilst those without osteoarthritis identified general health and fitness as the primary benefit. Both groups identified social interaction as an important benefit. Cold changing facilities, particularly during winter, was a key potential barrier for both groups. The second study examined perceived barriers and benefits of aqua-based exercise among older adults with osteoarthritis who had tried, but no longer participated in aqua-based exercise. Key barriers were a lack of suitable classes and insufficient instructor knowledge, as well as cold changing facilities and pool temperature. Benefits included the cushioning effect of the water and the ability to move around more freely. The third study was undertaken to gain greater insight into the effect of different types of aqua-based exercise on pain and heart rate response of older adults with osteoarthritis. In addition, participants’ opinions and attitudes towards each exercise mode were explored. Participants tried different types of aqua-based exercise including: hydrotherapy, which is a therapist-supervised programme which takes place in warm water; aqua-jogging, which simulates running in deep water whilst wearing a flotation device; resisted-aqua jogging, which is similar to aqua jogging but utilises resistance equipment to increase drag; aqua-fitness, which involves strength and cardiovascular exercises to music in the shallow end of the pool and resisted aqua-fitness, which is similar to aqua-fitness but resistance equipment is used to increase drag. Pain scores immediately post-exercise decreased for all modes of aqua-exercises. Heart-rate response and rating of perceived exertion was also similar for all aqua-exercise modes. Overall, participants enjoyed the hydrotherapy session most, however the aqua-fitness session (un-resisted) was also enjoyed and identified as an acceptable alternative to hydrotherapy. The final study explored the potential health benefits of a 12-week aqua-fitness intervention for older adults with osteoarthritis. An active control group, who undertook a seated aqua-based exercise session once a week, was used help minimise any effects of social interaction on the outcome measures. Positive physiological outcomes were associated with the aqua-fitness group who improved scores in several functional measures, as well as significantly reducing their fear of falling compared to the control group. The findings of this thesis are relevant for future design of aqua-based exercise interventions aimed at older adults with osteoarthritis. The research undertaken may help to identify and therefore address barriers to this mode of exercise for this population. Furthermore, the findings of this thesis offers some insight into the acute responses to different modes of aqua-based exercise, as well as long longer-term chronic adaptations to an aqua-based exercise programme similar to those which are readily available in the community.

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  • Structure and function of food webs in acid mine drainage streams

    Hogsden, Kristy Lynn (2013)

    Doctoral thesis
    University of Canterbury Library

    Acid mine drainage (AMD) is a significant environmental issue worldwide, which often causes severe contamination and marked species losses in receiving streams. However, little is known about how this stress alters food webs and ecosystem function. I conducted a literature review, which revealed that AMD-impacted streams generally had depauperate benthic communities dominated by a few tolerant species and impaired ecosystem processes. Next, using survey and experimental-based approaches, I investigated food web structure and energy flow in these highly stressed streams, which typically have low pH (< 3), high concentrations of dissolved metals (Al, Fe), and substrata coated with metal hydroxide precipitates, on the South Island, New Zealand. Inputs of AMD caused substantial loss of consumers and reduced the overall number of links between species generating small and simplified food webs, with few invertebrates and no fish. Comparative analysis of food webs from a survey of 20 streams with either anthropogenic or natural sources of acidity and metals, indicated that anthropogenic sources had a stronger negative effect on food web properties (size, food chain length, number of links); an effect driven primarily by differences in consumer diversity and diet. However, the presence of fewer trophic levels and reduced trophic diversity (detected using isotopic metrics), were common structural attributes in AMD-impacted webs along a pH gradient, regardless of impact level. Furthermore, complementary dietary analyses of consumer gut contents and stable isotope signatures (δ13C and 15N) confirmed that primary consumers fed generally on basal resources and that there were few predatory interactions, which reflected low densities of small-bodied chironomids. This suggests that food quantity was unlikely to limit primary consumers but that reduced prey availability may be an additional stressor for predators. In these radically re-structured food webs, trophic bottlenecks were generated at the primary consumer level and energy flow to higher consumers was disrupted. However, streams still retained some limited function, including slow leaf litter breakdown, which provided detrital resources and supported the small food webs. Overall, my findings have furthered our understanding of these highly stressed stream ecosystems by providing new insights into interactions among species and trophic levels that structure food webs and enable function.

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  • Democratic Vanguardism: Modernity, Intervention and the making of the Bush Doctrine

    Harland, Michael Ian (2013)

    Doctoral thesis
    University of Canterbury Library

    The terrorist attacks of September 11, 2001 transformed the way in which Americans and their leaders viewed the world. The tragic events of that day helped give rise to a foreign policy strategy commonly referred to as the “Bush Doctrine.” At the heart of this doctrine lay a series of propositions about the need to foster liberal democracy as the antidote to terrorism. President George W. Bush proclaimed in a variety of addresses that democracy now represented the “single surviving model” of political life to which all people aspired. In the course of making this argument, President Bush seemed to relate his policies to an overarching “teleology” of progress. This discourse implied that the United States might use force to hasten the emergence of liberal norms and institutions in selected states. With a sense of irony, some commentators soon referred to the Bush administration’s position as “Leninist” because of its determination to bring about the so-called “end of history” today. Yet, surprisingly, these critics had little more to add. This thesis is an attempt to assess in greater depth the Bush administration’s claim to comprehend historical eschatology. Developing a concept termed “democratic vanguardism,” this study investigates the idea of liberal modernity, the role of the United States as a force for democracy, and the implications of using military intervention in the service of idealistic ends. It examines disputes among political theorists, public intellectuals and elected statesmen which help to enrich our understanding of the United States’ efforts under President Bush at bending history to its will.

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  • Effects of the Environment on Physical Activity in New Zealand Children

    Mc Grath, Leslie Julian (2013-11-29)

    Doctoral thesis
    Auckland University of Technology

    Childhood obesity rates have risen steadily in recent decades along with increased urbanisation that has changed where children can play and roam freely, potentially reducing their daily energy expenditure. The relationship between aspects of the built environment and children's physical activity has therefore been identified as a public-health issue. This thesis represents a review, two studies that examined built-environment effects on children's activity, one play intervention study and two studies that investigated issues with accelerometer measurement of physical activity. Chapter two addresses the need for a quantitative review of the effects of objectively measured built-environment factors on children's objectively measured physical activity. The review included studies that used geographical information systems (GIS) or street audits to quantify the built environment with physical activity quantified by accelerometers, pedometers or global positioning systems. A key insight was that danger from vehicle traffic appears to underlie the association between physical activity and some measures of the built environment. There was inadequate research on effects of neighbourhood walkability and on the confounding effects of weather, compliance and the intensity threshold for moderate-vigorous activity. In Study 1, habitual physical activity of 227 children living in 48 residential neighbourhoods within four cities was measured with accelerometers and related to built-environment factors defined using GIS analysis and street-audit measures. Disparate built-environment effects on children’s physical activity were rationalised by classifying neighbourhoods as either safe for children’s walking or play or those where traffic danger constrained activity, which suggests that unsafe neighbourhoods need redesigning. In Study 2 the same data were analysed with a particular focus on children’s daily pattern of accelerometer steps at light and moderate-vigorous intensities. It was revealed that reductions in moderate-vigorous activity were associated with poor weather, darkness and non-school days. These reductions might be offset by interventions that encourage children to self-select outdoor or indoor activities at step cadences of ~80 per minute. Modifying the built environment is a long-term health strategy towards developing child-walkable neighbourhoods where children can roam and play independently to increase their daily physical activity. A short-to-medium term intervention plan was implemented in Study 3, a crossover design for promoting children’s increased physical activity through self-determined play during a supervised play period before school (08:00-09:00) with free access to play equipment. There were no clear changes in total activity, but during the play intervention there were trivial-small reductions in girls’ body-mass index (BMI) while boys’ BMI remained constant when normally BMI would be expected to increase. Reasons for excluding data from analysis in the intervention study were investigated in Study 4 and it was found that non-compliance and discomfort with wearing accelerometers along with monitor failure excluded half of the children from providing activity data for analyses. In the final study, the effect of accelerometer-count thresholds on the amount of activity classified as moderate-vigorous intensity was investigated and thresholds from published articles are recommended rather than manufacturer thresholds. In conclusion, future studies should investigate the effects of neighbourhoods designed to increase safety to encourage children’s habitual activity. Measurement of physical activity should be undertaken by continuously wearing accelerometers (and global positioning system watches) and analysed using published count thresholds.

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  • Development, Validation and Preliminary testing of A Novel Indwelling Wireless Intraoral pH Telemeter

    Lee, Jennifer Jae Won (2013)

    Doctoral thesis
    University of Otago

    Maintaining intraoral pH is important in protecting both hard and soft tissues from acids. When this balance is breached, some detrimental effects can be expected such as demineralisation, tooth erosion and reduced buffering capacity. Telemetric measurements have been previously used for monitoring changes in the intraoral pH in the past but most of the studies included bulky leads in the mouth, limiting optimal measurements outside the laboratory setting. The aim of the current research was to develop a novel wireless device that transmitted data real-­‐time to a smart phone to allow continuous monitoring of changes in the intraoral pH. A number of preliminary in vitro and in vivo (although in one participant) experiments have been carried out to validate the measurements of the wireless device. In vitro experiments included determination of drift over 24 hours and temperature effects to validate the pH probe. In vivo experiments investigated measurements during the daytime and sleep as well as following swallows of acidic drinks. Among various appliances constructed, the clear-­‐retainer type appliance turned out to be of the most time-­‐efficient and successful way of enveloping the wireless device. A distinct difference was observed between the pHs of the upper and lower arches. During sleep, there was a great deal of fluctuations of the pH values in the upper arch, while the recordings from the lower arch showed little change. When an acidic drink was introduced, a pronounced drop in pH in the upper arch was obvious with gradual increase to normal level, compared to minimal changes in the lower arch. An excellent cross-­‐correlation was demonstrated between the reference pH measurement system and the wireless device. The development of the wireless device will lead to exciting applications in the future in the areas of erosive tooth wear, gastro-­‐esophageal reflux and orthodontics.

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  • Nasal drying during pressurised breathing

    White, David Edward (2013-11-19)

    Doctoral thesis
    Auckland University of Technology

    The human nose not only provides the main portal through which air passes to and from our respiratory system, it also plays an important role in maintaining airway health. This function takes the form of heating and humidifying inhaled air to prevent airway drying, as well as trapping and disposing of inhaled particles and pathogens within the mucus lining. The ability of the nose to perform these duties appears compromised during the nasal breathing of pressurised air, with many users reporting symptoms associated with nasal airway drying. There are many situations where nasal breathing of pressurised air occurs. The cause of airway drying is currently not known, but is typically relieved through the use of supplementary humidification. This investigation examines the role air-pressure has on nasal airway drying by the development of a nasal air-conditioning model to predict inter-nasal airway hydration throughout the breathing cycle during ambient and pressurised breathing. Furthermore, the effect air pressure has on mucosal water supply and airway geometry is investigated in tissue experiments as well as in-vivo MRI clinical trials. Together the latter two investigations demonstrate that augmentation in air pressure adversely effects water supply and cause an opposing response in airway geometry between airways. Implementation of these previously unknown behaviours into the nasal air-conditioning model provides additional new insight into the actual function of the nose and its pathophysiology during pressurised air breathing. For the first time, a different airway hydration status during ambient air breathing is identified between the airways. During inhalation, the patent airway experiences drying that likely disables mucocilary transport, while the patent airway remains fully hydrated. This work sheds new light as to the purpose of the nasal cycle. Modelling pressurised nasal breathing demonstrates drying occurring within both airways and that supplementary humidification prevents this from occurring by effectively relieving the nose of its air-conditioning function. Modelling also demonstrates how supplementary humidification assists in the removal of entrapped particles and pathogens by providing ideal conditions for mucus transport to occur. An alternative method to relieve nasal airway drying is proposed. This method maintains normal airway hydration conditions during pressurised air breathing and avoids the problems of perceived stuffiness and congestion commonly encountered with supplementary humidification.

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  • Understanding teaching practice in support of Non-English-Speaking-Background (NESB) students’ mathematics learning

    Gwengo, Martin (2013)

    Doctoral thesis
    University of Waikato

    Research is needed that gives special attention to the experiences of mathematics teachers of Non-English-Speaking-Background (NESB) students. This need prompted me to investigate four of my tertiary mathematics classes that included a number of NESB students, through practitioner research. The main data collection methods for the study were audio-taping classroom discussions, journaling of my experiences, and student group interviews. The data were analysed around three main domains: classroom social norms, sociomathematical norms and classroom mathematical practices. The first key finding was that NESB students can shift from being less-active to more active participants in mathematical activity when the teacher works with them to jointly constitute classroom social norms that attach importance to, make it safe to and encourage student participation. In this study, these were volunteering to share ideas, explaining and justifying contributions, and asking questions. Establishing these social norms occurs gradually, and NESB students can adopt them over time. The second key finding indicates that changes can occur in strategies NESB students use to solve mathematics problems that are embedded in everyday contexts, if they are involved in the joint construction of sociomathematical norms that value the negotiation of mathematical meaning. Over time, and with support, students can develop the ability to support their thinking, and come to understand what counts as mathematical problem-analysis, explaining and justifying mathematically, and communicating mathematically. The authority to evaluate the authenticity of mathematical contributions can be distributed among NESB students and between students and the teacher, if students are positioned as creators and evaluators of mathematical knowledge. The third key finding is that the specific ways of acting and reasoning that are appropriate for a particular mathematics topic evolve when the teacher and NESB students discuss problems and solutions related to that specific mathematical idea. Instead of relying on memorized procedures for solving problems, students progressively rely on their conceptual understanding of specific mathematical ideas and practices. The findings challenge the general view that NESB students will necessarily be passive and prefer to learn by memorising information. They indicate that NESB students can develop as active learners, embracing expectations and obligations that they will contribute ideas and negotiate meaning, rather than follow what the teacher says. Over time, a number of my NESB students developed autonomy in mathematical problem solving and their ability to solve mathematics problems and contribute to class discussion improved. In light of the findings, I propose that NESB students’ mathematics learning may be enhanced by a focus on initiating and guiding joint constitution of classroom social norms that value and encourage student participation in the social construction of knowledge and sociomathematical norms that promote conceptual understanding through negotiation of mathematical meaning. I further propose that NESB students’ mathematics learning may be supported by guiding collective construction of classroom mathematical practices concerned with the specific ways of reasoning and acting needed in particular mathematics topics. The findings of this study have relevance and offer fresh insights for mathematics teachers, researchers and tertiary institutions into how NESB students can be supported to learn mathematics. Further research in this area could examine practices of other mathematics teachers involved with NESB students.

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  • An investigation into the surface chemistry of supported gold phosphine clusters

    Anderson, David Philip (2013)

    Doctoral thesis
    University of Canterbury Library

    This thesis describes the preparation and study of a wide range of supported gold catalysts based on atomically-precise triphenyl phosphine stabilised gold clusters. This selected range of ligand-stabilised gold clusters were prepared in attempt to study the effect of increasing cluster nuclearity on the electronic and catalytic properties of these materials. A novel far-infrared study was conducted on the pure cluster materials in attempt to understand the metal-metal and the metal–ligand vibrations, which was also compared to the simulated spectra for each cluster. The design and activation of these novel catalysts based on gold clusters was discussed and the factors that influence activity were described. A comprehensive photoelectron study of the catalysts was conducted in an attempt to understand the electronic structure of the supported gold clusters and the effect of various activation conditions have on the electronic structure of the gold clusters. A selection of the prepared supported gold catalysts were tested for their catalytic activity for the partial oxidation of styrene and the influence of the several activation conditions on the reactivity of the catalyst is also examined. In collaboration, the application of a selection of ligand-stabilised gold clusters as hydrogen sensors and as catalysts for the photocatalytic generation of hydrogen from ethanol is also investigated.

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  • Footprinting New Zealand urban forms and lifestyles

    Lawton, Ella Susanne (2013)

    Doctoral thesis
    Victoria University of Wellington

    More than 90% of New Zealand’s ecological footprint results from the lifestyle choices of individuals, although the size and impact of their lifestyle footprint depends on the type of urban form in which they live. The aim of this research is to highlight the degree to which New Zealanders are living beyond their fair earth share and how this appears through lifestyles. As the population continues to increase and resources become scarce, it is vital that both governments and communities have effective resource accounting tools to inform further urban development, given its influence on resource use. The thesis highlights how urban form could reduce barriers to people’s future wellbeing and it identifies the types of lifestyles that support a shift towards lower footprint living. To understand how the ecological footprint of New Zealand’s communities is generated by a combination of the community members’ lifestyle choices and interaction with their urban form, the research comprised five steps. 1. Designing a footprint method and calculating local footprint yields for the New Zealand context. 2. Calculating the New Zealand footprint in nine categories: food and beverages, travel, consumer goods, holidays, household energy, housing, infrastructure, government and services. 3. Creating a calculator and survey, and collecting household footprint data from five New Zealand communities. 4. Processing data and analysing community results highlighting differences and similarities between them. 5. Using the community output creating fair earth share scenarios which highlight those footprint categories within each urban form that provide the best opportunity for reducing a community’s footprint. Throughout this project the ecological footprint has been an effective indicator which has provided the means to communicate complex environmental data in a simplified form to diverse groups. The project used the ecological footprint to measure and communicate the trends that are putting pressure on the planet’s finite availability of land; a growing demand and the decreasing supply. It was found to be an effective communication tool for both communities and local government organisations that formed a way of discussing how to reduce their footprint in the future. Although many New Zealand lifestyles exist in a variety of types of urban form, some lifestyle types are more typical in certain urban forms. Food was found to be the predominant driver of a household’s footprint. Use of commercial land for growing, on-farm inputs and food processing made up the largest portion of the food footprint. Holidays and pets were also large contributors to an individual’s footprint. Due to the high amount of renewable energy that goes into producing New Zealand’s electricity, household energy was proportionally much less than found in similar international footprint case studies. The final scenarios show that fair earth share living in New Zealand is possible; some individuals are already doing it. However bringing about large-scale change will require collective community strategic planning, planning tools to develop resource efficient urban design, and immediate action.

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  • The effect of organisational cultures and subcultures on enterprise system implementation

    Stuart, Lindsay (2013)

    Doctoral thesis
    University of Canterbury Library

    Enterprise systems (ES) are important cross-business software that can be difficult to implement. A key factor impacting ES implementation lies with the influence of organisational cultures and subcultures which may enable or hinder such implementations. Existing research has focused on culture as being a stable, homogenous variable and little consideration has been given to the dynamics of cultural and organisational change during ES implementations. This study uses eight cultural dimensions (Detert et al, 2000) to examine instances of dialectic conflict between opposing cultural values and how these can impact ES implementations. This study uses data drawn from four case studies of large organisations that had implemented ES. The results identified five cultural dimensions where there was evidence of a cultural conflict between each organisation and the ES implementation. The results also found evidence that different subcultures within the organisation operated in different ways to facilitate or impede the adoption of the system. The evidence showed that the implementations resulted in cultural changes within each organisation to reflect the values embedded in the ES. This research therefore provides valuable insights into the cultural effects of large-scale implementations at an organisational level and shows that such effects are not necessarily homogenous and may vary due to the cultural values of subgroups involved.

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  • Estimation of the time-varying elastance of the left and right ventricles

    Stevenson, David (2013)

    Doctoral thesis
    University of Canterbury Library

    The intensive care unit treats the most critically ill patients in the hospital, and as such the clinical staff in the intensive care unit have to deal with complex, time-sensitive and life-critical situations. Commonly, patients present with multiple organ dysfunctions, require breathing and cardiovascular support, which make diagnosis and treatment even more challenging. As a result, clinical staff are faced with processing large quantities of often confusing information, and have to rely on experience and trial and error. This occurs despite the wealth of cardiovascular metrics that are available to the clinician. Computer models of the cardiovascular system can help enormously in an intensive care setting, as they can take the monitored data, and aggregate it in such a way as to present a clear and understandable picture of the cardiovascular system. With additional help that such systems can provide, diagnosis can be more accurate and arrived at faster, alone with better optimised treatment that can start sooner, all of which results in decreased mortality, length of stay and cost. This thesis presents a model of the cardiovascular system, which mimics a specific patient’s cardiovascular state, based on only metrics that are commonly measured in an intensive care setting. This intentional limitation gives rise to additional complexities and challenges in identifying the model, but do not stand in the way of achieving a model that can represent and track all the important cardiovascular dynamics of a specific patient. One important complication that comes from limiting the data set is need for an estimation for the ventricular time-varying elastance waveform. This waveform is central to the dynamics of the cardiovascular model and is far too invasive to measure in an intensive care setting. This thesis thus goes on to present a method in which the value-normalised ventricular time-varying elastance is estimated from only metrics which are commonly available in an intensive care setting. Both the left and the right ventricular time-varying elastance are estimated with good accuracy, capturing both the shape and timing through the progress of pulmonary embolism and septic shock. For pulmonary embolism, with the algorithm built from septic shock data, a time-varying elastance waveform with median error of 1.26% and 2.52% results for the left and right ventricles respectively. For septic shock, with the algorithm built from pulmonary embolism data, a time-varying elastance waveform with median error of 2.54% and 2.90% results for the left and right ventricles respectively. These results give confidence that the method will generalise to a wider set of cardiovascular dysfunctions. Furthermore, once the ventricular time-varying elastance is known, or estimated to a adequate degree of accuracy, the time-varying elastance can be used in its own right to access valuable information about the state of the cardiovascular system. Due to the centrality and energetic nature of the time-varying elastance waveform, much of the state of the cardiovascular system can be found within the waveform itself. In this manner this thesis presents three important metrics which can help a clinician distinguish between, and track the progress of, the cardiovascular dysfunctions of pulmonary embolism and septic shock, from estimations based of the monitored pressure waveforms. With these three metrics, a clinician can increase or decrease their probabilistic measure of pulmonary embolism and septic shock.

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  • The Development of Neural Network Based System Identification and Adaptive Flight Control for an AutonomousHelicopter System

    Shamsudin, Syariful Syafiq (2013)

    Doctoral thesis
    University of Canterbury Library

    This thesis presents the development of self adaptive flight controller for an unmanned helicopter system under hovering manoeuvre. The neural network (NN) based model predictive control (MPC) approach is utilised in this work. We use this controller due to its ability to handle system constraints and the time varying nature of the helicopter dynamics. The non-linear NN based MPC controller is known to produce slow solution convergence due to high computation demand in the optimisation process. To solve this problem, the automatic flight controller system is designed using the NN based approximate predictive control (NNAPC) approach that relies on extraction of linear models from the non-linear NN model at each time step. The sequence of control input is generated using the prediction from the linearised model and the optimisation routine of MPC subject to the imposed hard constraints. In this project, the optimisation of the MPC objective criterion is implemented using simple and fast computation of the Hildreth's Quadratic Programming (QP) procedure. The system identification of the helicopter dynamics is typically performed using the time regression network (NNARX) with the input variables. Their time lags are fed into a static feed-forward network such as the multi-layered perceptron (MLP) network. NN based modelling that uses the NNARX structure to represent a dynamical system usually requires a priori knowledge about the model order of the system. Low model order assumption generally leads to deterioration of model prediction accuracy. Furthermore, massive amount of weights in the standard NNARX model can result in an increased NN training time and limit the application of the NNARX model in a real-time application. In this thesis, three types of NN architectures are considered to represent the time regression network: the multi-layered perceptron (MLP), the hybrid multi-layered perceptron (HMLP) and the modified Elman network. The latter two architectures are introduced to improve the training time and the convergence rate of the NN model. The model structures for the proposed architecture are selected using the proposed Lipschitz coefficient and k-cross validation methods to determine the best network configuration that guarantees good generalisation performance for model prediction. Most NN based modelling techniques attempt to model the time varying dynamics of a helicopter system using the off-line modelling approach which are incapable of representing the entire operating points of the flight envelope very well. Past research works attempt to update the NN model during flight using the mini-batch Levenberg-Marquardt (LM) training. However, due to the limited processing power available in the real-time processor, such approaches can only be employed to relatively small networks and they are limited to model uncoupled helicopter dynamics. In order to accommodate the time-varying properties of helicopter dynamics which change frequently during flight, a recursive Gauss-Newton (rGN) algorithm is developed to properly track the dynamics of the system under consideration. It is found that the predicted response from the off-line trained neural network model is suitable for modelling the UAS helicopter dynamics correctly. The model structure of the MLP network can be identified correctly using the proposed validation methods. Further comparison with model structure selection from previous studies shows that the identified model structure using the proposed validation methods offers improvements in terms of generalisation error. Moreover, the minimum number of neurons to be included in the model can be easily determined using the proposed cross validation method. The HMLP and modified Elman networks are proposed in this work to reduce the total number of weights used in the standard MLP network. Reduction in the total number of weights in the network structure contributes significantly to the reduction in the computation time needed to train the NN model. Based on the validation test results, the model structure of the HMLP and modified Elman networks are found to be much smaller than the standard MLP network. Although the total number of weights for both of the HMLP and modified Elman networks are lower than the MLP network, the prediction performance of both of the NN models are on par with the prediction quality of the MLP network. The identification results further indicate that the rGN algorithm is more adaptive to the changes in dynamic properties, although the generalisation error of repeated rGN is slightly higher than the off-line LM method. The rGN method is found capable of producing satisfactory prediction accuracy even though the model structure is not accurately defined. The recursive method presented here in this work is suitable to model the UAS helicopter in real time within the control sampling time and computational resource constraints. Moreover, the implementation of proposed network architectures such as the HMLP and modified Elman networks is found to improve the learning rate of NN prediction. These positive findings inspire the implementation of the real time recursive learning of NN models for the proposed MPC controller. The proposed system identification and hovering control of the unmanned helicopter system are validated in a 6 degree of freedom (DOF) safety test rig. The experimental results confirm the effectiveness and the robustness of the proposed controller under disturbances and parameter changes of the dynamic system.

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  • Cool-water Carbonate Sedimentology and Sequence Stratigraphy of the Waitaki Region, South Island, New Zealand

    Thompson, Nicholas Kim (2013)

    Doctoral thesis
    University of Canterbury Library

    In the mid-Cenozoic, New Zealand underwent slow subsidence interspersed with unconformity development, however significant controversy exists around both the extent of submergence below sea level during this period of maximum drowning, as well as the causes of these unconformities. Detailed field observations, combined with extensive petrographic analyses, stable isotopes, cathodoluminescence, and thin section staining were used to develop lithofacies, depositional, and sequence stratigraphic models of the mid-Cenozoic succession in the Waitaki region, South Island, to address these controversies. Twelve facies types have been described for Late Eocene-Early Miocene sedimentary rocks, leading to the identification of two major (Mid Oligocene & Early Miocene) and one minor (Late Oligocene) sequence boundaries. Surtseyan volcanism in the east produced a palaeohigh, resulting in a submerged rimmed cool-water carbonate platform, with low-lying land to the west. This eastern palaeohigh developed karst during sea-level lowstands, which correlate with silty submarine bored hardgrounds in the west. Glauconitic and phosphatic facies deposited during early marine transgression suggest an authigenic factory supplied by terrigenous clays existed during lowered sea level that was progressively shut down in favour of a carbonate factory as sea level rose and terrigenous supply decreased. The eastern palaeohigh served to nucleate this carbonate factory by raising the sea floor above the influence of siliciclastic sediment supply and providing a shallow substrate for marine colonisation. The higher energy eastern facies display dissolution of aragonitic taxa, while deeper western facies retained an aragonitic assemblage. This early bathymetric high created a barrier to submarine currents, but was gradually reduced by erosion during subsequent lowstands. Calcareous facies were often subjected to minor seafloor cement precipitation to shallow burial diagenesis, while eastern facies developed some meteoric cement during subaerial exposure. Comparisons between sea-level change in the study area and the New Zealand megasequence indicate eustatic changes as the primary driver of water depth in the Waitaki region until the development of the modern plate boundary in the Early Miocene.

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  • An empirical investigation of text-speak processing: Does cost outweigh the benefit?

    Head, James (2013)

    Doctoral thesis
    University of Canterbury Library

    As the popularity of digitally based communication devices increases, so does the propensity for individuals to find clever ways to convey messages in a shorter amount of space and time. Often, individuals use word or phrase shortening techniques known collectively as text-speak. A majority of investigations into the topic of text-speak have only focused on the potential impact text-speak may have on literacy or scholastic achievement (Crystal, 2008; Pinker 1994; Thurlow, 2003). However, there is a void in empirical investigation into how individuals create text-speak and more importantly how they process it (Farrell & Lyddy, 2012). The primary aim of this dissertation is to systematically investigate text-speak using various methodological techniques to gain a better understanding of how people create text-speak and explore how it elicits meaningful comprehension. An additional aim of this dissertation is to determine whether processing text-speak comes at a cognitive cost.

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  • KiwiSpec: The Design and Performance of a High Resolution Echelle Spectrograph for Astronomy

    Gibson, Steven Ross (2013)

    Doctoral thesis
    University of Canterbury Library

    This document describes the design, analysis, construction and testing of KiwiSpec, a fibre-fed, high resolution astronomical spectrograph of an asymmetric white pupil design. The instrument employs an R4, 31.6 groove mm⁻¹ échelle grating for primary dispersion and a 725 lines mm⁻¹ volume phase holographic (VPH) based grism for cross-dispersion. Two versions of the prototype were designed and constructed: an 'in-air' prototype, and a prototype featuring a vacuum chamber (to increase the stability of the instrument). The KiwiSpec optical design is introduced, as well as a description of the theory behind a cross-dispersed échelle spectrograph. The results of tolerancing the optical design are reported for alignment, optical fabrication, and optical surface quality groups of parameters. The optical windows of an iodine cell are also toleranced. The opto-mechanical mounts of both prototypes are described in detail, as is the design of the vacuum chamber system. Given the goal of 1 m/s radial velocity stability, analyses were undertaken to determine the allowable amount of movement of the vacuum windows, and to determine the allowable changes in temperature and pressure within and outside of the vacuum chamber. The spectral efficiency of the instrument was estimated through a predictive model; this was calculated for the as-built instrument and also for an instrument with ideal, high-efficiency coatings. Measurements of the spectral efficiency of various components of the instrument are reported, as well as a description of the measurement system developed to test the efficiency of VPH gratings. On-sky efficiency measurements from use of KiwiSpec on the 1-m McLellan telescope at Mt John University Observatory are reported. Two possible exposure meter locations are explored via an efficiency model, and also through the measurement of the zero-order reflectivity of the échelle grating. Various stability aspects of the design are investigated. These include the stability of the optical mounts with temperature changes, and also the effect of the expansion and contraction of the supporting optical tables. As well, the stability of the in-air prototype was determined through measurement of the movement of thorium-argon emission lines within spectra as the temperature, atmospheric pressure and relative humidity (naturally) varied. Current and planned testing for determining the stability of the vacuum chamber prototype is discussed.

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