1,014 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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  • 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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  • 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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  • 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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  • What makes feedback work for primary school students? An investigation of the views of some Year 8 students.

    Williams, Judith Airini (2013)

    Doctoral thesis
    University of Canterbury Library

    I investigated the problem of why some students do not implement the feedback they are given, when the feedback they receive is formulated in accordance with what we know about best practice in the giving of feedback. I was interested in exploring the factors which may influence students as they do or do not take some form of action to ‘close the gap’ between the standard they have attained and the standard they need to reach. I worked with seven Year 8 boys who were enrolled at an intermediate school in the South Island of New Zealand. The study is qualitative because the methodologies associated with that paradigm are more likely to provide insights into the problem, situated as it is in the experience of students in a classroom setting. I used phenomenography to identify the qualitatively different ways in which the participants viewed the importance and helpfulness of feedback as well as identifying the factors which influenced their acceptance or rejection of the feedback received from their classroom teacher. The categories I identified included supporting progress towards short- and long-term learning goals; the effect of feedback on personal attitudes towards learning; the relationship between the student and the teacher; the type and timing of feedback; the perceived ownership of the work to which the feedback related; and the conditions and understandings of the student. I discussed each of these and formed a phenomenographic outcome space for each of the three basic areas of importance, helpfulness, and factors affecting response. I then used a case approach to prepare case reports on two of the participants, in order to show how the categories identified through the phenomenographic analysis might be manifested in individuals as well as to allow the voices of the students to be heard. I found that each individual embodies a unique combination of the categories, and that it is this unique profile which affects his or her reception and subsequent use of feedback. I then combined the three phenomenographic outcome spaces to form a model of feedback, arranged in four levels, which may be of interest to classroom teachers as they endeavour to improve the learning outcome of the students through tailoring the feedback they give to them. I illustrated the potential use of the model by mapping onto it the profile of the two boys included in the case reports. The differences in, and similarities of, responses of the two boys to feedback are easily discerned. I discussed how these similarities and differences may offer some explanation for differing responses to feedback. To a certain extent the boys have similar outlooks, and may respond in similar ways to feedback which matches with these outlooks. However, at a deeper level, their differences are marked. Feedback which matches the preferences of one is not likely to match those of the other. I argue that in such a case one may accept and act on the feedback while the other may not. I have identified some areas for further research and development which could build on these findings. These include the need to explore the views of girls and other groups of boys on this subject, together with undertaking a project which allows the academic progress of individuals to be tracked once their preferences were identified and mapped onto the model. It would also be useful to construct a suitable instrument for classroom teachers to use for mapping the preferences of their own class members, and to identify any differences in the modifications to their feedback processes which teachers may make to their classroom practice following their use of such an instrument.

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  • Spillover and species interactions across habitat edges between managed and natural forests

    Frost, Carol Margaret (2013)

    Doctoral thesis
    University of Canterbury Library

    We are currently faced with the global challenge of conserving biological diversity while also increasing food production to meet the demands of a growing human population. Land-use change, primarily resulting from conversion to production land, is currently the leading cause of biodiversity loss. This occurs through habitat loss, fragmentation of remaining natural habitats, and resulting edge effects. Land-sparing and land-sharing approaches have been discussed as alternative ways to engineer landscapes to mitigate biodiversity loss while meeting production objectives. However, these represent extremes on a continuum of real-world landscapes, and it will be important to understand the mechanisms by which adjacent land use affects natural remnant ecosystems in order to make local land-management decisions that achieve conservation, as well as production, objectives. This thesis investigates the impact of juxtaposing production and natural forest on the community-wide interactions between lepidopteran herbivores and their parasitoids, as mediated by parasitoid spillover between habitats. The first and overarching objective was to determine whether herbivore productivity drives asymmetrical spillover of predators and parasitoids, primarily from managed to natural habitats, and whether this spillover alters trophic interactions in the recipient habitat. The study of trophic interactions at a community level requires understanding of both direct and indirect interactions. However, community-level indirect interactions are generally difficult to predict and measure, and these have therefore remained understudied. Apparent competition is an indirect interaction mechanism thought to be very important in structuring host-parasitoid assemblages. However, this is known primarily from studies of single species pairs, and its community-wide impacts are less clear. Therefore, my second objective was to determine whether apparent competition could be predicted for all species pairs within an herbivore assemblage, based on a measure of parasitoid overlap. My third objective was to determine whether certain host or parasitoid species traits can predict the involvement of those species in apparent competition. My key findings were that there is a net spillover of generalist predators and parasitoids from plantation to native forest, and that for generalists, this depends on herbivore abundance in the plantation forest. Herbivore populations across the edge were linked by shared parasitoids in apparent competition. Consequently, an experimental reduction of herbivore density in the plantation forest changed parasitism rates in the natural forest, as predicted based on parasitoid overlap. Finally, several host and parasitoid traits were identified that can predict the degree to which host or parasitoid species will be involved in apparent competition, a finding which may have extensive application in biological control, as well as in predicting spillover edge effects. Overall, this work suggests that asymmetrical spillover between production and natural habitats occurs in relation to productivity differences, with greater movement of predators and parasitoids in the managed-to-natural forest direction. The degree to which this affected species interactions has implications for landscape design to achieve conservation objectives in production landscapes.

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  • The effects of land use on stream communities in highland tropical Nigeria

    Umar, Danladi (2013)

    Doctoral thesis
    University of Canterbury Library

    Globally, stream invertebrate communities have been shown to respond to habitat degradation as a result of land use hanges. The effects of land use changes on stream communities have been well documented in temperate regions, however, their effects in the tropics are relatively unknown, particularly where land use activities can differ markedly (e.g., tea, maize and Eucalyptus plantations). To understand how land use affects tropical highland Nigerian stream communities, I surveyed 55 second and third order streams across four land use categories, ranging from continuous tropical montane forest to intensive crops/pasture. Streams were sampled in the dry season (October to March) for physico-chemical parameters (i.e., temperature, pH, conductivity, turbidity, current velocity, channel morphometry and riparian characteristics) and ecological characteristics (i.e., fine particulate organic matter [FPOM], coarse particulate organic matter [CPOM], algae and benthic invertebrates). Water temperature in all streams was high (up to 25oC) while levels of dissolved oxygen were frequently low (15–79 %). Physico-chemical conditions varied across land uses with continuous forested streams being cooler, with higher dissolved oxygen, larger bed substrate and more stable channels. Similarly, benthic invertebrate communities showed a strong response with the highest taxonomic diversity in forested streams and the lowest in streams within intensive crops (e.g., cabbage crops). Several of the taxa which occurred in forested streams (e.g., the mayflies Heptageniidae and Oligoneuridae and brachyuran crabs) were rare or absent in streams with more intensive land use. In contrast, damselflies and several true bugs (e.g., Notonectidae and Corixidae) were rare in forested streams but more common in other land uses. In order to test land use impacts on stream processes leaf litter decomposition experiments were carried out in nine streams, three in forest, three in tea plantations and three in maize fields. Leaf breakdown rates were slow compared with other reports for tropical streams, however leaves in forested streams broke down significantly faster (on a degree day basis) than in other land uses. This faster break down seemed to be driven by greater shredder densities in forested streams. Significantly lower densities of invertebrates were found in leaf bags incubated in streams draining tea plantation and maize fields than in forest streams. In the same nine streams food web components were sampled and analysed using gut content and stable isotope (N and C) analyses. Stream food webs in continuous forest were more complex than plantation and maize field streams. Stable isotope analysis indicated that primary consumers assimilated a mixture of autochthonous and allochthonous carbon resources, but the proportion varied among sites. Overall, my results suggest that in Nigerian highland tropical streams more intensive land use activities strongly affect the diversity and composition of benthic stream communities and ecosystem function, in similar ways to those reported in temperate streams.

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  • Caught between 'Dublin' and the deep blue sea: 'small' Member States and European Union 'burden-sharing' responses to the unauthorized entry of seabourne asylum seekers in the Mediterranean from 2005-2010.

    Warner, Frendehl Sipaco (2013)

    Doctoral thesis
    University of Canterbury Library

    The Dublin Regulation determines the Member State responsible for accepting and making a decision on asylum claims lodged in the European Union (‘EU’), Norway and Iceland. It aims to ensure that each asylum claim is examined by one and only one Member State, to put an end to the practice of ‘asylum shopping’ and to prevent repeated applications, both of which have been costly for the receiving Member States and caused severe inefficiencies in the determination processes in the EU in the past. With the first Member State of entry being the major determinant for the allocation of asylum responsibility under the Dublin Regulation, there has been growing discontent among Member States at the external borders of the EU, particularly the southern Member States in the Mediterranean, over what they see as a system that has unjustly placed disproportionate burdens on them regarding the admission of seaborne asylum seekers and the costs associated with it. As a result of changes in migration rules and consequent adjustments in the entry strategy employed by irregular migrants and people smugglers, the Member States at the EU’s ‘southern frontline’ have unwillingly played the role of reluctant hosts to boatloads of unwelcome asylum seekers. This thesis aims to examine how the EU has attempted to tackle the challenging situation of the unauthorised migration of asylum seekers into its territory by sea, and in particular, how it has responded to demands from affected Member States for a more equitable system of asylum responsibility allocation in spite of and outside the Dublin framework. It would argue that the ‘small’ EU Member States in the Mediterranean themselves have, over the last five years at least, become the unexpected drivers of the EU’s declared commitment to the principles of ‘solidarity’, ‘fair sharing of responsibility’ and ‘effective multilateralism’. ‘ Small’ as they may be in terms of resources, size or influence vis-à-vis the larger Member States, the former have been able to create their own mark in a global regime that has traditionally been resistant to the idea of burden-sharing. The measures taken by the EU’s ‘southern frontline’ have collectively changed the landscape of a global protection regime where not only is asylum ‘burden sharing’ highly elusive – its terms and conditions are also dictated by the more powerful sovereign states. While the theoretical point of departure in this study is the influence wielded by the ‘small’ EU Member States in the burden-sharing debate, the degree or level of ‘influence’ small Mediterranean Member States can exercise in pushing for cooperative arrangements is itself determined by a system that is biased towards large states, increasingly securitised, and is therefore limited in both nature and scope. Nevertheless, the experience of ‘burden-sharing’ in the EU between 2005 and 2010 demonstrates that the Member States at the periphery have proactively taken the responsibility for the operationalisation of the founding values and principles of the EU, and through active norm advocacy and related strategies, have been able to achieve what has eluded the global protection regime so far – a refugee burden sharing scheme.

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  • Transnational Migration, Diaspora and Religion: Inscribing Identity through the Sacred (the Filipino Diaspora in New Zealand and Singapore)

    Tondo, Josefina Socorro Flores (2013)

    Doctoral thesis
    University of Canterbury Library

    The thesis is an anthropological exploration of the role of religion in Filipino transnational migration and diaspora. The thesis takes the interpretive approach, drawing from a variety of disciplines such as religious studies, sociology, and geography to frame a holistic view of religion as a “lived” experience that connects religious dispositions, symbols and ritual performance to the diaspora’s place-making and home-making. It weaves together anthropology’s conceptual strands of space, place, symbols and ritual to present a view of Filipino migrant sociality and personhood not as constituted by disparate fragmented experiences but as as a tapestry of woven symbols and meanings that shape their diasporic life, even as they themselves continuously shape their own experiences. The thesis’ ethnography is based on participant observation among Filipino migrants between 2007 and 2010 in New Zealand and Singapore. It focuses on the celebration of the Santacruzan and Santo Niño-Sinulog fiesta in New Zealand and Simbang Gabi novena masses in Singapore to examine how Filipino cultural forms of expression connect and mix with notions of homeland, family, home, sacred domain and identity as these have been adapted, recreated, and spatially inscribed in their transnational journeys. 6 The ethnography examines the interplay and connection between Filipino folk religiosity, family and social networks. It looks at how the deeply held folk Christian notions of kapalaran (destiny), swerte (luck), bahala na (whatever God allows will happen /come what may God will take care) and imagery of may awa ang Diyos (a compassionate God) are enmeshed in the migrant exercise of agency, reflexive discourse, risk-taking, resilience and meaningmaking in the diaspora. It demonstrates that among Filipino migrants, material and communication flows are manifestations of religious dispositions that support enduring family commitment and reciprocity. It shows that financial and social capital provided by families and social networks for migrants are supported by prayers for sacred assistance and blessings, indicating that the Filipino migrants’ exercise of agency is familial and sacral rather than individual and secular. As a dominant Philippine lowland tradition, the fiesta is the locus of sacralmaterial linkages constituted by Filipino home symbols, such as sacred icons, costumes, cultural performance, semantic expressions, and food. By examining the fiesta, its organisation and structure of power relations, the thesis explores the metaphoric parallels and symbolic articulations between two homes in migrants’ diasporic consciousness, and the significant role of sacred symbols in aiding and facilitating the maintenance and inscription of ‘Filipino’ identity in a foreign land. Diaspora identity is a socially and spatially inscribed identity. For Filipinos, it is inscribed through sacred icons and fiesta celebrations in sacred sites.

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  • Seismic performance of high-strength self-compacting concrete in reinforced concrete structures.

    Soleymani Ashtiani, Mohammad (2013)

    Doctoral thesis
    University of Canterbury Library

    Self-compacting concrete (SCC) was first developed in Japan about two decades ago. Since then, it has been offered as a solution to various challenges inherently associated with traditional concrete construction; i.e. quality and speed of construction, impact of unskilled labour force and noise pollution etc. SCC flows into a uniform level under its own weight and fills in all recesses and corners of the formwork even in highly congested reinforcement areas. In recent years the interest in using SCC in structural members has increased manifold; therefore many researchers have started investigating its characteristics. Nevertheless, before this special concrete is widely accepted and globally used in structures, its structural performance under different conditions should be investigated. This research focuses on investigating the behaviour of high strength self-compacting concrete (HSSCC) in reinforced concrete (RC) structures through a systematic approach in order to bridge part of an existing gap in the available literature. The dissertation is comprised of four main stages; namely, mix design development and mechanical properties of HSSCC, bond performance of deformed bars in HSSCC, experimental investigation on interior RC beam-column joints (BCJs) cast with HSSCC under reversed cyclic excitations, and finally finite element (FE) modelling and analysis of interior BCJs. First, a HSSCC mix proportion yielding compressive strength greater than 100 MPa was developed in the laboratory using locally available materials in New Zealand. Two benchmark concrete mixes of conventionally-vibrated high-strength concrete (CVHSC) and normal-strength conventionally vibrated concrete (CVC) were also designed for comparison purposes. Material characteristics (such as compressive, splitting tensile and flexural strengths as well as modulus of elasticity, shrinkage and microstructural properties) of all mixes were evaluated. It was found that, once the lower quality of material in normal strength concrete is offset by achieving a denser mix in high-strength concrete, mechanical properties of HSSCC are equivalent to or higher than those in CVHSC. Given that the performance of RC structures (and in specific BCJs) is highly dependent on bond between reinforcement and concrete, understanding the bond behaviour in HSSCC was an imperative link between the first and third phases of this research. Therefore, the second phase focused on scrutinizing bond properties of deformed bars in HSSCC using monotonic pull-out and innovative cyclic beam tests. Processing of the pull-out results revealed that a shorter development length may be utilized in HSSCC. In addition, the grade (or ductility) of reinforcing steel was found to substantially influence the post-yield bond performance. Important modifications to the bond model used in the CEB-FIP model code and Maekawa’s bond-slip-strain relationship were suggested from the results of this phase. An innovative cyclic beam specimen and test setup were also designed such that a more realistic bond performance could be observed in the laboratory tests compared to that in real RC structures. Deleterious impact of cyclic loading and buckling of reinforcement on bond performance were investigated using this testing protocol. The third phase of this research focused on the design, fabrication and testing of seven full-size BCJs. BCJs are one of the most critical parts in RC frame structures and their response substantially affects the overall behaviour of the structure. In seismically active regions like New Zealand, the criticality of BCJs is exacerbated with the complexities involved in seismic resistance. The already congested intersection of RC beam and column looks more like a solid steel connection after consideration of earthquake requirements, and placement of concrete becomes problematic in such areas. At the same time, in many of the high-rise structures, normal strength concrete does not meet the capacity requirements; this requires the usage of high-strength concrete. Therefore, once the seismic performance of HSSCC is guaranteed, it can possibly be a solution to both the capacity and compaction problems. Variables such as axial load, concrete type, steel grade, casting direction, and joint shear reinforcement were considered variable in the experimental investigations. It was found that HSSCC has similar seismic performance to that of CVHSC and it can also be incorporated in the joint area of CVC for an enhanced performance. Finally, DIANA (a nonlinear FE program) was used to simulate the experimental results obtained in the third phase of this research. All BCJs were successfully modelled using their relevant attributes (such as the mechanical properties of HSSCC, steel stress-strain response, test setup and loading protocol) and nonlinear FE analyses (FEA) were performed on each model. FE results were compared to those obtained in the laboratory which showed a reasonable agreement between the two. The capabilities of the FEA were scrutinized with respect to the hysteresis loops, energy dissipation, joint shear deformations, stress development in the concrete and steel, and drift components. Integrating the results of all stages of this research provided better understanding of the performance of HSSCC both at the material and structural levels. Not only were none of the seismically important features compromised by using HSSCC in BCJs, but also many other associated benefits were added to their performance. Therefore, HSSCC can be confidently implemented in design of RC structures even in seismically active regions of the world.

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  • Anti-Specker Properties in Constructive Reverse Mathematics

    Dent, James Edgar (2013)

    Doctoral thesis
    University of Canterbury Library

    Constructive reverse mathematics is a programme in which non- and semi-constructive principles are classified in accordance with which other principles they imply or are implied by, relative to the framework of Bishop-style constructive mathematics. One such principle that has come under focus in recent years is an antithesis of Specker's theorem (that theorem being a characteristic result of Russian recursive mathematics): this so-called anti-Specker property is intuitionistically valid, and of considerable utility in proving results of real and complex analysis. We introduce several new weakenings of the anti-Specker property and explore their role in constructive reverse mathematics, identifying implication relationships that they stand in to other notable principles. These include, but are not limited to: variations upon Brouwer's fan theorem, certain compactness properties, and so-called zero-stability properties. We also give similar classification results for principles arising directly from Specker's theorem itself, and present new, direct proofs of related fan-theoretic results. We investigate how anti-Specker properties, alongside power-series-based arguments, enable us to recover information about the structure of holomorphic functions: in particular, they allow us to streamline a sequence of maximum-modulus theorems.

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