Doctoral Theses

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Understanding Situational Factors in Human-centred Phishing Susceptibility
(ResearchSpace@Auckland, 2025) Zhuo, Sijie ; Russello, Giovanni ; Lottridge, Danielle
Phishing is a type of social engineering attack that deceives individuals into disclosing sensitive information or downloading malware. It poses a significant threat to both individuals and organisations, causing substantial financial losses. This thesis aims to enhance the understanding of human-centred phishing susceptibility by investigating the factors influencing users' vulnerability to phishing attacks. The thesis begins by categorising phishing susceptibility factors into long-term stable variables, situational variables, and in-the-moment variables. This categorisation leads to the development of a Phishing Susceptibility Model (PSM) and highlights the research gap in exploring situational factors that influence users' email processing behaviour and phishing susceptibility. To address this gap, we conducted a large-scale simulated phishing campaign to explore the impact of device type and link presentation on users' tendency to click on phishing links. Our study reveals that while the device used (mobile vs. computer) does not significantly influence susceptibility, masking the phishing link with hypertext significantly increases the likelihood of user clicks. Additionally, we identified a novel research method in phishing susceptibility, the Precision Email Interaction Study (PEIS), to closely observe users' interactions with phishing emails in a controlled yet realistic environment. PEIS allows precise measurement of user interactions with phishing emails under various conditions. To support the PEIS, we developed the Precision Email Simulator, which provides customisation for various research needs. Using PEIS, we conducted two user studies to explore the impact of workload on phishing susceptibility. We found that high workload is associated with shorter email reading times and an increased tendency to interact with task-relevant phishing emails. Additionally, paying attention to the email sender can significantly reduce phishing susceptibility. This thesis concludes by discussing the implications of these findings for designing anti-phishing interventions and training programmes. By providing actionable insights into the human factors of phishing susceptibility, this work contributes to developing more effective strategies to mitigate the risk of phishing attacks. We also discuss future research directions that could build on our findings and further enhance email security.
The Systematisation of Safety in Design Implementation in the New Zealand Construction Industry
(ResearchSpace@Auckland, 2024) Shi, Weifang; Chang-Richards, Alice; Ingham, Jason
Compared to other industries, the construction sector performs poorly in health and safety, with a staggering number of injuries and fatalities. A significant percentage of accidents were closely linked to a lack of consideration for ‘Safety in Design’ (SiD) and its implementation. The gaps lie in the unrevealed SiD factors, dynamics interactions, SiD maturity metrics, safe design knowledge shortage, and effective methods to educate designers. This research aims to develop a comprehensive framework for effectively and strategically implementing SiD. The research explored factors influencing SiD and investigated strategies advancing its implementation and improving workers’ health and safety through design activities. This study identifies five aspects of implementing SiD: (1) Critical factors affecting SiD implementation. (2) Motives within system dynamics interactions. (3) Leading indicators measuring the SiD maturity. (4) Significant design features mitigating hazards. (5) A Conceptual framework including safe design practice training. This research applied in-depth interviews with participants with SiD experience in New Zealand and this research proceeded through: (1) Grounded theory to reveal unearthing underpinned theories. (2) System dynamics analysis to investigate inherent motives and interactions. (3) Rigid programmatic triangulation method to decide leading indicators. (4) Computational methods in finalising significant design features. (5) Prototype integrating the elements of high technologies. The results suggested that the potential factors were attributed to a theoretical framework, including critical factors, challenges and opportunities. The identified leading indicators are legislation change and designers’ knowledge, while significant design features mitigating highly lethal hazards were investigated in the built environment, such as accessibility and spatiality. This research added significant value to theory and practice: (1) An analytical framework that includes research trends and potentials guiding future research. (2) A theoretical framework initiated with unified terminology to guide decisionmaking. (3) A system dynamics model revealing motives and interactions. (4) A programmatic method determining leading indicators. (5) The computational method pioneered the generation of significant design features. (6) A framework conceptualised in safe design training with explicit development processes outlined in the prototype. (7) A comprehensive framework encompassing enabling factors and strategies was developed.
Enhancing Reinforcement Learning Efficiency: Novel Distributed Algorithms, Human-Inspired Reward Mechanisms, and State Space Analysis for Simulated and Real-World Applications
(ResearchSpace@Auckland, 2025) Valencia Redrovan, David Patricio; MacDonald, Bruce A. ; Williams, Henry
Reinforcement Learning (RL), a subset of Machine Learning (ML), has garnered significant attention because of its capacity to enable systems to learn problem-solving without the need for pre-collected datasets. Despite its historical roots and its efficacy in tackling tasks, mostly in simulation and video games, RL algorithms encounter various limitations. These include a lack of standardisation in definitions and concepts, sample inefficiency in sparse reward environments, challenges with high-dimensional state spaces, bridging of the sim-to-real gap, complex training strategies, and the necessity for meticulous hyperparameter tuning. Consequently, the widespread application of RL in solving intricate real-world scenarios with straightforward implementations remains an unresolved challenge. This thesis endeavours to address these challenges by first providing clear explanations of RL concepts and definitions. Subsequently, it identifies and analyses the limitations in diverse RL algorithms before presenting two novel solutions inspired by the human brain and the contextual intricacies of the real world. Specifically, two new algorithms named NaSA-TD3 and CTD4 are introduced. NaSA-TD3 explores the impact of human-inspired stimuli presented as a reward bonus to improve the exploration of the environment and sample efficiency in dense and sparse environments. CTD4 mitigates the overestimation bias of the Q-values and eases the implementation and training strategies of traditional categorical RL methods. Further, this thesis critically examines the applicability of Model-Based Reinforcement Learning (MBRL) in a real-world scenario in terms of sample efficiency and hyperparameter robustness by identifying its strengths and weaknesses in using dynamic model representations. Through rigorous experimentation and analysis in both real-world and simulated environments, this thesis contributes to advancing the understanding and application of RL. Validation on physical robots and standardised virtual platforms confirms the applicability of the proposed algorithms. Furthermore, detailed experiences and recommendations are presented. By providing clear definitions, thorough explanations, effective and innovative algorithms with trustworthy implementation, this thesis opens new avenues for the practical implementation of RL in diverse domains where all source codes and clear instructions on their usage are provided.
“It Belongs to Us”: Chinese Youth’s Imagined Futures
(ResearchSpace@Auckland, 2024) Meng, Fanqi; Showden, Carisa; France, Alan
The imagined future of young people has become a significant area of research in sociology and youth studies, providing insights into youth identities, agency, and autonomy. In western academia, researchers have adopted a dual approach to exploring imagined futures, distinguishing between short-term, personal futures and long-term, societal futures (Cook, 2018; Leahy et al., 2010). This study strives to evaluate the applicability of the western frameworks in a distinctive social context. By examining the future imaginaries of 86 middle-class young people (aged 14-15) in three schools situated in Guangzhou, China, this study posits that there are four categories of future that these adolescents envision: (1) the temporary future; (2) the personal future; (3) the national future; and (4) the societal future. Based on a Bourdieusian analysis, these categories of future imaginaries can be attributed to the hybridity and complexity of Chinese youth’s habitus, field, and capital. Dominated by both western ideologies such as neoliberalism and individualism as well as indigenous philosophies like Confucianism and collectivism, these young people’s imagined futures exhibit diverse constructs, influences, and representations in contrast to those of their western counterparts, contingent on their unique living experiences and socio-cultural circumstances. This research deconstructs the entangled everyday experiences of Chinese youth, providing valuable data to decipher the factors driving the distinctiveness of their imagined futures. Furthermore, this research examines the applicability of western theories in a distinctive social setting, providing perspectives and tools for researchers to study Chinese youth. The practical implications which arise from the methodology of this thesis, centre around a revised adaptation of Pierre Bourdieu’s thinking tools, transforming young people’s imagined futures into processes of social practice rather than simple actions, thus manifesting Bourdieu’s advancement in social research.
The Association of Arterial Stiffness with Diabetes and Microvascular Disease
(ResearchSpace@Auckland, 2024) Beros, Angela Lukrica; Scragg, Robert; Sluyter, John
Aim This thesis aimed to identify if arterial stiffness, predominantly assessed by pulse wave velocity (PWV), is a risk factor for diabetes and microvascular disease, and if so, whether aortic PWV estimated with a single cuff oscillometric device PWV (oPWV), which is easy-to-apply in clinical practice, can predict future disease incidence. Methods Four systematic reviews were conducted based on existing observational studies, incorporating where possible meta-analysis, to investigate the association of arterial stiffness with each of diabetes, chronic kidney disease (CKD), microvascular eye disease and neuropathy. These reviews also investigated the temporality of the associations. Three analyses were undertaken of the Vitamin D Assessment (ViDA) Study, a population-based cohort of 5108 people in Auckland, New Zealand, aged 50-84 years, to determine if arterial stiffness, estimated using oPWV, predicted incident diabetes/prediabetes, CKD and glaucoma. Findings The systematic reviews established that there appears to be a bi-directional association between increased arterial stiffness and diabetes and that increased arterial stiffness may predict incident CKD. Further, increased arterial stiffness appears to be associated with the development of age-related macular degeneration, glaucoma, retinal vein occlusion, and retinopathy. Though there is a lack of longitudinal evidence, increased arterial stiffness also appears to be associated with incident peripheral neuropathy and cardiac autonomic neuropathy. The ViDA Study confirmed that over a mean period of 10.5 years, arterial stiffness, estimated using oPWV, is associated with the development of diabetes/prediabetes, CKD and glaucoma. Conclusions Increased arterial stiffness could be an additional risk factor to be incorporated into clinical practice when determining a person’s future risk of diabetes and microvascular disease. Validated risk-prediction models incorporating increased arterial stiffness, however, must first show the utility of increased arterial stiffness as a risk factor, and investigation must be undertaken as to whether lifestyle and pharmacological interventions which lower arterial stiffness also translate into reduced incidence of these conditions.
Tracking the Path of Alzheimer's Disease: Insights from the Integration of Cognitive and Structural Measures
(ResearchSpace@Auckland, 2023) Chaffey, Tessa Elizabeth; Tippett, Lynette; Roberts, Reece
Mild cognitive impairment (MCI) is recognised as a transitory state between healthy aging and Alzheimer’s disease (AD) dementia, although not all individuals with MCI progress to AD dementia. The cognitive and brain structural profiles of individuals along the at-risk AD clinical continuum remain under investigation, and determinants of whether an individual with MCI will progress to AD dementia remain unclear. The overall aim of this study was to identify markers of early cognitive and structural changes in individuals with subjective cognitive decline (SCD), amnestic MCI (aMCI), multi-domain MCI (mMCI), and AD dementia. We investigated the relationship between these measures and their ability to predict MCI outcomes. Participants from the Dementia Prevention Research Clinics underwent comprehensive neuropsychological assessment and magnetic resonance imaging at baseline (n = 237) and at two-year follow-up (n = 167 for cognitive data, n = 136 for imaging data). T1 weighted scans enabled analyses of structural measures of cortical thickness and volume. We utilised a combination of general linear model and non-parametric partial least squares (PLS) approaches. Our cross-sectional analysis identified early volumetric atrophy and cortical thinning, predominantly observable in the temporal, frontal, and inferior parietal cortices across individuals along the at-risk AD continuum. Our brain-behaviour PLS analysis revealed unique correlations between cognitive domains and structural measures, which were generally stronger in the cognitively impaired group. Our longitudinal PLS analysis indicated that atrophy rates increased along the at-risk AD continuum, particularly in the middle temporal, cingulate, and insula regions. The MCI groups demonstrated differential longitudinal changes in cognitive performance in the Attention/Working Memory, Processing Speed, Language/Semantic, Verbal Learning and Memory, and Executive Function Inhibition domains compared to Cognitively Normal (CN) and SCD groups. Finally, MCI conversion to AD dementia was associated with poorer baseline performance in memory and executive measures and widespread baseline atrophy, particularly in the temporal, middle frontal, and cingulate regions. Understanding the cognitive and structural patterns along the at-risk AD continuum and elucidating the relationship between these measures can aid the differentiability of groups along this continuum and facilitate early detection and intervention of individuals at increased risk of progressing to AD dementia.
Novel Imaging Of Human Fascia in vivo Using Advanced MRI
(ResearchSpace@Auckland, 2024) Perera, Meeghage Randika ; Handsfield, Geoffrey
Fascia is an abundant connective tissue that may be involved in force transmission in ways that are poorly understood. Prior experiments suggest that fascia may play a consid- erable role on musculoskeletal force distribution in animals and humans. There is a growing interest in modelling the mechanical contribution of this tissue, which is challenging con- sidering the thin structure of the tissue and the difficulty of obtaining details from imaging. Here, I use advanced MRI to image the fascia in vivo to create physics-based simulations to explore fascia mechanics and probe its role in force transmission in the musculoskele- tal system. This thesis comprises four primary studies: firstly, the development of an MRI protocol for human fascia, followed by the application of image processing techniques to enhance image quality; an in vivo assessment of fascia and surrounding lower leg muscles in adult humans, followed by the building of a finite element geometry of several lower leg muscles and its surrounding fascia to probe the biomechanics of the tissue. In this work, using advanced MRI, this novel study involves the successful imaging of lower limb fascia in high resolution. This MRI protocol was used to image 30 healthy volunteers to create a first-ever in vivo human fascia dataset. Using this dataset, I measure human fascia thickness in vivo and show that these are consistent with available literature from dissection studies which ranges from 0.7-1.1 mm. Finite element simulations demonstrate that the presence of fascia may increase the forces transmitted from muscle to tendon compared to a system that lacks fascia. We conducted simulations on different lower limb muscles to understand the impacts of different muscle architecture, and consistently, the simulation results arrive at the same conclusion. This work is the first to my knowledge to take advantage of in vivo MRI of human fascia and build physics-based models to explore human muscle-fascia biomechanics.
Deep and Sustained Engagement in Second Language Learning: An Exploration of Directed Motivational Currents among Chinese Adolescents
(ResearchSpace@Auckland, 2024) Huo, Chuanwei; Stephens, Jason; Zhang, (Lawrence) Jun
Motivation has consistently been a central concern in the study of second language (L2) and English as a Foreign Language (EFL) education. In China, many English teachers recognize the importance of motivation in addressing challenges related to low language learning efficiency, diminished learning motivation, and the problem of “dumb English”. Many scholars of second language acquisition (e.g., Larsen-freeman, 2014; Dörnyei et al., 2015; Muir & Dörnyei, 2013; Henry et al., 2015) have drawn on theories from mainstream psychology and educational psychology to understand students’ L2 or EFL learning motivation and behavior. This thesis project used Dörnyei et al.’s (2016) theory of Directed Motivational Currents (DMCs) to explore periods of intense and sustained L2 motivation among Chinese adolescent EFL learners in senior high school and university. DMCs are defined as periods of intense, highly motivated behavior aimed at achieving a specific, personally meaningful goal (Dörnyei et al., 2015). They are marked by sustained effort, deep engagement, and a positive emotional state, leading individuals to exceed initial expectations across various contexts. This thesis project employed a mix-methods sequential explanatory design procedure, consisting of two studies. In Study 1, a cross-sectional survey of Chinese high school (n = 397) and university (n = 343) students, 86.2% of participants recognized the intense motivation characteristic of DMCs, 73.5% reported having a DMC-like experience somewhere, and 64.6% indicated having DMC-like experience while learning English. Results from MANOVA indicated that students majoring in English reported higher DMC scores in English learning compared to students who were not majoring in English. Paired sample t-test showed that participants self- assessed English proficiencies improved after experiencing a DMC in English. Results from correlational analysis, indicated that participants’ expectancy-value appraisals (i.e., expectancy for success, intrinsic interest, utility value), perception of parental encouragement, and evaluation of English teachers and course were significantly correlated with DMC scores. However, after controlling for demographic and personal salience variables, results from regression analysis revealed that only expectancy for success, and parental encouragement were significant correlates of DMC scores. Additionally, qualitative data from the survey highlighted that external influences, outcome-led factors, and intrapersonal reasons initiated DMCs were mainly shaped by Chinese educational environments. Study 2 employed individual interviews with participants (n = 10) from Study 1, to explore more deeply the development and impact of the motivation process on individual EFL learners. Results revealed what conditions led to a DMC, what a DMC-cycle entailed, and how participants made use of a salient structure. Specifically, results indicated that establishing a facilitative structure right at the onset of a DMC was crucial for the sustain of the current. This importance stemmed from the impact of behavioral routines, which played a significant role in maintaining continued engagement and protecting it from potential distractions. Additionally, many participants (six out of ten) reported that their cognitive skills (e.g., attention, processing speed, executive functions, logic, and reasoning) were activated while experiencing a DMC, which encouraged them to engage more deeply in daily English learning activities.
Hinenuitepō, Nui Te Ao Mana Tinana, Mana Mōmona A Fat Wāhine Māori Pūrākau of Body Sovereignty
(ResearchSpace@Auckland, 2024) Gillon, Ashlea; McIntosh, Tracey; Le Grice, Jade; Webber, Melinda; Pausé, Cat
Fat Indigenous Wāhine and our bodies are subject to multiple forms of discrimination and intersecting oppressions. The ways in which fat wāhine Māori are re-presented as (un)deserving, (un)well, (dis)eased, unDesir(e)able, and (un)(re)liable perpetuate how (in)access is enabled for some groups and not others through biopower, biopolitics, healthism, racism, sexism, and fatism. Pūrākau of Hinenuitepō, Papatūānuku, and Hinemoana have been utilised to inform and guide this kaupapa. In their kōrero, as well as in our te reo Māori, are complexities of experiences, relationships, and illustrations of agency, sovereignty, and mana. These pūrākau offer insight into how we can and have previously conceptualised mana (tinana) and rangatiratanga. Despite the various ways in which our mana (tinana, motuhake, mōmona) have been oppressed and (re)classified, our Indigenous knowledge, our Mātauranga Māori offers alternatives. While the english discourse we have available to us is limited (and concepts are not ours), notions of sovereignty are not new phenomena for Indigenous Peoples, however, this thesis highlights the importance of accessibility, rights, body sovereignty, and further, mana tinana. Pātaitai? The question that initially informed this research project was: • How do Indigenous wāhine experience and enact body sovereignty (as resistance) within multiple systems of oppression? The question that was actually being asked was: • What does body sovereignty mean to you? This question is utilised throughout this thesis as it informs the research and extends into in depth critical (self)reflection and theorising about these lived experiences and realities. Methods: This research embodied Kaupapa Māori, Mana Wa/āhine, Pūrākau, Hinenuitepō, and Tohu as theory, methodology, method, and analysis. This thesis embodied a Te Ao Māori, Mātauranga Māori epistemology to inform every step of the research, theorising, relating, and re-connecting. These guided the building of relationship with thirteen research whanaunga who self-identify as fat wāhine Māori. Concluding Comments: Presented are research whanaunga kōrero as components of Hinenuitepō’s reality. Here, research whanaunga Become Hineahuone, Become Pīwaiwaka, Become Hinenuitepō, and (Un)Become Te Pō. The kōrero shared here offer insights, perspectives, pain, strength, triumphs, losses, frustrations, excitements, and ultimately, ways of enacting, embodying, and reclaiming body sovereignty, reclaiming mana tinana for fat wāhine Māori.
Unveiling Insights in Healthcare Operations: Analysing Dynamic Inventory Management and Prescription Patterns with Hidden Markov Models
(ResearchSpace@Auckland, 2024) Lindamullage Don Charls, Shirekha Layangani; Oliveira, Fernando S.; Pavlov, Valery
This thesis explores three key aspects of healthcare operations management: hospital inventory management, oncology drug prescription patterns, and physician prescription behaviour. The first study addresses hospital inventory management using the Hidden Markov Model (HMM) and Markov Decision Processes (MDP). The main contribution of this study is the method used to determine the optimal number of hidden demand states in the HMM. This approach explores the interaction between the HMM and the MDP during the development of the inventory management model. We illustrate the performance of our approach through a case study, showing that additional hidden states increase inventory costs beyond an optimal threshold. The optimal number of hidden states depends on demand patterns, inventory shortage, and wastage costs. Therefore, it suggests that inventory clusters should be managed with models designed for various demand patterns and service levels. The second study investigates the prescription patterns of oncology Named Patient Drugs (NPDs), a complex issue due to uncertainties. The study introduces an approach using convolutional HMMs. The model enables comparison and analysis of cancer diagnoses and treatment patterns over time, uncovering prescription patterns by calculating state transition and joint probabilities. This provides information on the evolution of NPD selection strategies, improving decision-making in inventory management, informing prescription guidelines, and improving patient care and resource allocation, especially under budget constraints. The third study uses a multivariate HMM to analyse the complexities of doctors’ prescription behaviours when treating breast cancer patients. This differs from the second study as it focuses on how these behaviours have evolved and the factors influencing the sequential nature of these behaviours. The study analyses data from a Sri Lankan hospital, revealing sequential patterns in prescribed treatments and how oncologists’ prescription decisions vary based on the unit price and dosage of drugs and the age of patients. The model uncovers heterogeneity in prescription behaviour, highlighting the need for personalised treatment strategies that consider unique prescribing behaviours. Overall, the three articles improve hospital inventory management, explain the hospital’s drug prescription patterns, and uncover patterns in the physicians’ prescription behaviour.
An Integrated Approach to Keratoconus Management to Reduce Eye Health Inequity: Investigating Diagnosis, Referral, and Cost
(ResearchSpace@Auckland, 2024) Angelo, Lize; McGhee, Charles; Ziaei, Mohammed; Gokul, Akilesh
Purpose: Assess health disparities and inequities spanning from referral, diagnosis, and treatment including crosslinking, of subjects with keratoconus in New Zealand. Design, methods, approach: This PhD is divided into four main studies; examining the repeatability of commonly used diagnostic devices (topographers and tomographers), examining the referral patterns of optometrists, assessing possible barriers to accessing keratoconus and crosslinking clinics in Auckland, and assessing the financial impact via yearly and lifetime costs of subjects with keratoconus. Data was collected prospectively through online anonymous questionnaires or data collection directly from clinics. We recruited subjects through advertisements at conferences and optometrist magazines, and clinic and private room posters/flyers. Findings: This project identified the Medmont-E300, Revo-NX, and Pentacam-AXL, as the most used corneal imaging devices, and showed low agreeability but high repeatability of devices, suggesting they cannot be used interchangeably when diagnosing or monitoring subjects with keratoconus. Only 56% of optometrists owned a device, of which 81% were topographers. Results identified lack of standardisation in referral patterns, for tertiary assessment or CXL, likely creating heterogeneity in care received by patients. Once referred, attendance was poor (69%) to crosslinking clinics. Results showed Māori and Pacific Peoples present with worse visual acuity, disease severity, and attendance. Low attendance was associated with ethnicity, worse visual acuity, and lower socioeconomic status, and worse visual outcomes were correlated with ethnicity, unemployment, and lack of access to a car. Finally, the estimated cost for patients with keratoconus was estimated to be NZD 1,258 per keratoconus patient per year, totalling an estimated lifetime per capita cost of NZD 79,254 and a total country cost of approximately NZD 30.9 million per year. Originality/value: There is limited research on these specific topics related to keratoconus. Two of the studies have been previously conducted in Australia, however, have not been replicated in New Zealand therefore providing valuable insight into keratoconus management in New Zealand. Our diagnostic device repeatability and barriers to clinic access studies have not previously been investigated and provide valuable insight into keratoconus management in New Zealand and worldwide.
Efficient, dynamic, digital twin models of process unit operations using modern regression
(ResearchSpace@Auckland, 2024) Severinsen, Isaac; Young, Brent; Yu, Wei
This thesis aims to establish the necessity of digital twins and outline a roadmap for their creation. This work focusses on the behaviour of a system, creating process models suitable for deployment as part of a digital twin. Traditional process modelling tools, relics of the floppy disk era, are unsuitable for a digital twin but can be modernized with advancements in machine learning capabilities. The study examines data from a geothermal power station, revealing archaic data compression practices and poor suitability for machine learning due to a lack of variety. A novel data rebalancing technique is developed to address this imbalance, improving the robustness of data-driven models. First principles models of unit operations are developed using traditional process modelling. In tandem, boutique models are developed in Python with a higher level of fidelity. These models are regressed against plant data with mixed success owing to the rigidity of model structure. Machine learning surrogate models are very successful, with many techniques providing sufficient accuracy. Further model discrimination required artificially restricting the training and testing dataset spatially. This proved successful in identifying strategies for improving model extrapolation. Finally, hybrid models are developed, accounting for issues with regression earlier. Averaging and additive models are compared with both found lacking in traditional forms. Novel advanced combinatorics are proposed utilising spatial information to great success. The resulting hybrid model fulfills the requirements of a digital twin achieving the overarching goal of this work. My original contributions to the field include: 1. Developing a novel data rebalancing technique for classless datasets 2. Implementing a testing/training split that can help analyse extrapolation accuracy for surrogate model. 3. Trialling a novel hybrid modelling combinatory technique that blends two models relative to datapoints’ rarity. The thesis itself serves as a roadmap of the journey to create a digital twin, including many of the pitfalls experienced. Following this recipe, digital twins can be created for any unit operation. Future work will likely involve applying and generalizing the techniques to more complex units. With these tools, industry can analyse processes in real time, improving efficiency and reducing carbon emissions.
Aligning a Carer Support Intervention to the Needs of Chinese Carers of People Living with Dementia in New Zealand
(ResearchSpace@Auckland, 2024) Li, Fei; Parsons, John; Cheung, Gary
Aims: The overall aim of my PhD study was to develop and evaluate the feasibility of a tailored virtual group intervention to reduce carer stress among Chinese carers of people living with dementia (PLwD). Methods: Three inner-connect studies over three phases were conducted to address the overall aim. For Phase 1, semi-structured interviews were conducted to explore the support needs of Chinese carers of PLwD during the COVID-19 pandemic, which informed the intervention design. For Phase 2, semi-structured interviews were conducted to explore perceptions of the adapted version of the iSupport manual, which contributed to developing the intervention contents and protocol. For Phase 3, a 12-week tailored iSupport virtual group intervention was delivered and evaluated through a mixed-method one-group pre-post-follow-up study. Results: For Phase 1, twelve participants highlighted four prominent themes: (1) social isolation; (2) emotional loneliness; (3) ambivalent feelings of being a carer; and (4) a variety of unmet needs. For Phase 2, twelve participants expressed three overarching perceptions on the iSupport manual: (1) usefulness, (2) complexities of using iSupport, and (3) suggestions for improvement. For Phase 3, four participants completed pre- and post-intervention assessments and interviews, but three participants completed the follow-up assessments and interviews. The overall attendance rate was 93.8%, with a median attendance rate of 11.3 out of 12 weekly sessions. Post-intervention assessment scores showed improvements in resilience, culture, social support, and quality of life, while levels of stress and burden decreased compared to the pre-intervention assessment. However, follow-up assessments demonstrated increases in levels of burden, stress, resilience, culture, and social support. Four key themes emerged from the post-intervention interviews: motivations, the usefulness of the intervention, negative experiences, and recommendations. Two main themes emerged from the follow-up interviews: usefulness and various needs. Additionally, several refinements were identified for both the research design and the intervention. Conclusions: The tailored iSupport virtual intervention shows promise for Chinese carers of PLwD. The contents and design of the intervention are feasible and have the potential to deliver effective support for Chinese carers of PLwD. However, further refinements are needed before conducting a large-scale, higher-quality trial to investigate its efficacy.
Foraging Ecology of Cephalorhynchus Dolphins in Aotearoa New Zealand
(ResearchSpace@Auckland, 2024) Ogilvy, Courtney Rita; Constantine, Rochelle; Carroll, Emma
Understanding the foraging ecology of large marine predators gives insights into trophic relationships and habitat use. This typically requires knowledge of diet and environmental factors influencing spatiotemporal distribution of prey. Hector’s and Māui dolphins (Cephalorhynchus hectori hectori, and C. h. maui) are coastal species endemic to Aotearoa New Zealand. The critically endangered Māui dolphin is distributed along the west coast of the North Island (WCNI). Hector’s dolphins are discontinuously distributed around the coast of the South Island; an area where these dolphins are vulnerable and poorly understood is the north coast of the South Island (NCSI). This region has complex bathymetry and geochemistry, and oceanographic variability gives rise to very different local environments at fine-scales. Here I focus on Māui and NCSI Hector’s dolphins; these populations were identified by the Department of Conservation as high research priorities. The aim of this thesis was to investigate broad-scale temporal trends and fine-scale spatial patterns in foraging ecology of Māui and NCSI Hector’s dolphins, respectively. To achieve this I used stable isotope analysis; a method where biochemical markers in tissue can provide dietary information. Analyses used dolphin tissue from a long-term archive (~30 years) curated at the University of Auckland. For Māui dolphins, I found significant interannual variation over time, where the largest variation coincided with an intense El Niño event and was likely driven by a climate-mediated shift in prey distribution. Subsequently I used trawl survey data and remotely sensed environmental data in a species distribution model, to explore the distribution of key prey species along the WCNI, and identified environmental relationships affecting prey species richness. For NCSI Hector’s dolphins, I found significantly different isotope values between west and east NCSI, likely driven by different prey distributions and underlying oceanographic variability of each region. This work addressed key knowledge gaps in the foraging ecology of two vulnerable populations of Cephalorhynchus dolphins, and highlighted areas of data paucity in coastal New Zealand. Future research should focus on collection of long-term isotopic and environmental data to better characterise the dynamic coastal environments, which can benefit future studies of marine predators and other coastal species.
Synergising Anaerobic Membrane Bioreactor and Microbial Electrochemical Cell in Anaerobic Electrochemical Membrane Bioreactor for Low-Strength Wastewater Treatment
(ResearchSpace@Auckland, 2024) Lim, Michael; Wicaksana, Filicia
Water scarcity has become pervasive in numerous regions worldwide over the past few decades. The exacerbation of water scarcity is expected to increase due to the compounding factors of climate change and the discharge of inadequately treated wastewater into water bodies. A contemporary perspective recognises wastewater, including low-strength wastewater, as a valuable resource for water, nutrients, and renewable energy. Consequently, there is an urgent need to develop sustainable and effective technologies for wastewater treatment. This thesis investigated the efficacy of an anaerobic membrane bioreactor (AnMBR) utilising a submerged hollow fibre membrane (HFM) module to treat low-strength wastewater, emphasising fouling behaviour across different organic loading rates (OLRs). Furthermore, this thesis delved into examining the efficiency of single-chamber microbial electrolysis cells (MEC) as a potential technology to be integrated with an AnMBR, focusing on the influence of the applied electric field on organic and nutrient removal, biogas quality, and shifts in microbial communities. Finally, this thesis explored the viability of integrating dual-function nickel-HFM (Ni-HFM) into a hybrid AnMBR and MEC system, termed an anaerobic electrochemical membrane bioreactor (AnEMBR), for low-strength wastewater treatment. The results of the AnMBR study demonstrated a significant impact of OLRs on the specific production rates of Extracellular Polymeric Substances (EPS) and Soluble Microbial Products (SMP), affecting fouling behaviour at different OLRs. The MEC study showed up to 9.5% enhancement in organic removal efficiency, 13.3-fold increase in ion and nutrient removal, and 8.4% rise in methane content in biogas compared to conventional anaerobic digestion at 0.9 V. A slight reduction in overall treatment efficiency occurred at 1.2 V due to severe plasmatorrhexis, which potentially disrupting microorganism metabolism activities in the system. Finally, the study on AnEMBR showcased its viability as a promising technology for treating low-strength wastewater with up to 9% improvement in organic removal, 60% increase in membrane filtration efficiency, 12.4% - 16.7% enhancement in ions and nutrient removal, and 8% increase in methane content in biogas as compared to non-electrochemically induced system (AnMBR). The findings derived from these investigations provide crucial insights into the integration of AnMBR and MEC into AnEMBR for the treatment of low-strength wastewater.
New Zealand’s Relationship with the Pacific 1840-1940
(ResearchSpace@Auckland, 2024) Turnbull, Chris; Bryder, Linda; Barnes, Felicity
From 1840, New Zealand became increasingly engaged with the Pacific through a progression of shared imperial and colonial experiences; however, the Pacific is seldom featured in New Zealand history. This thesis asks why New Zealand gave prominence to Pacific relationships and it examines what those relationships tell us about New Zealand imperialism and colonialism. New Zealand was drawn to the Pacific, as the Pacific was drawn to New Zealand, because it was proximate and relevant. Early imperial relationships were shaped by political and commercial interests and then subsumed by more strategic and opportunistic considerations within a rapidly changing Pacific context. New Zealand colonialism in the Pacific was a consequence of that imperialism and followed distinct trajectories and patterns. Colonial outcomes reflected the cumulative consequences of a multitude of relationships with all participants having an interest and a role in shaping outcomes. The Pacific was a site of complex cultural interaction, exchange and innovation. This thesis examines the nineteenth-century imperial relationships that shaped New Zealand’s interest and understanding of the Pacific and then subsequent colonial relationships in the Cook Islands and Samoa in particular. Emphasis is placed on the formative periods of those relationships as cultural encounter, compromise and adaptation shaped structures that became the basis for more routine implementation. Drivers of colonial outcomes are located within relationships, an approach that focuses attention on the motives, interests and actions of participants and highlights significant Pacific agency. Pacific people engaged intellectually and culturally as they variously cooperated with or opposed colonialism to protect their interests and shape their futures. A final section builds on this analysis and introduces new material from New Zealand’s colonial experience in Niue and Tokelau to examine components of the colonial relationship. Overall, this thesis offers a new perspective of New Zealand’s engagement with the Pacific between 1840 and 1940 and new insights into the nature of New Zealand imperialism and colonialism.
Improved Understanding of Extreme Precipitation over Indonesia and Future Projections Using GCMs
(ResearchSpace@Auckland, 2024) Kurniadi, Ari; Salmond, Jennifer; Weller, Evan; Aldrian, Edvin
Global warming is expected to cause a non-uniform increase in the distribution of extreme rainfall events, posing significant hydro-meteorological hazards. Understanding past and future extreme rainfall events is vital for Indonesia due to the socio-economic implications of such hazards. This study investigates historical variations in extreme rainfall patterns in Indonesia, particularly their association with prominent climatic phenomena such as El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). Subsequently, we aim to simulate the projected alterations in extreme rainfall patterns for Indonesia, utilising Global Climate Models (GCMs), after evaluating their historical performance in depicting the extreme events. In the past, extreme rainfall in Indonesia has been significantly influenced by natural variability, resulting in drier (during El Niño and positive IOD events) and wetter conditions (during La Niña and negative IOD). These findings elucidate that extreme rainfall is influenced by independent ENSO and IOD more on the northeast and southwest of the country, respectively. Notably, historical extreme rainfall events exhibit their most pronounced effects during the dry seasons (JJA-SON) with comparatively weaker impacts during the wet seasons (DJF-MAM) when subjected to the influences of ENSO and IOD. In the future, extreme rainfall events in Indonesian are simulated using the most recent GCMs. With the better performance of Multi-Model Ensemble Mean (MMEM) of GCMs compared to individual models, future extreme rainfall events are projected using MMEM to vary seasonally across time periods, spatial resolutions, and climate scenarios. Future extreme wet events are simulated to increase during the wet season across most of Indonesia. Conversely, extreme dry events are expected to increase countrywide during the dry season but decrease (increase) in the half-north (half-south) of the country during the wet season. The medium-resolution (MR) models project smaller changes in extreme wet indices than the low-resolution (LR) models but simulate a more prolonged extreme dry index. Future extreme wet and dry events are anticipated to become more frequent and intense, exceeding historical records, particularly under a "business-as-usual" scenario. These projections necessitate policymakers' careful planning and judicious policy formulation for effective climate change adaptation and mitigation, which is crucial for the country's future development.
Expectations Matter: Relations Between Teacher Expectations, Student Perceptions, Classroom Climate, Student Self-Efficacy, Emotions, and Achievement
(ResearchSpace@Auckland, 2023) Li, Ya; Rubie-Davies, Christine; Stephens, Jason
Teachers’ expectations, which act as a self-fulfilling prophecy, have been found to be influential on students’ academic outcomes and motivation. Student perceptions play a key role in this process. Hence, this research project involved three studies using mixed methods to explore teacher expectation effects from their formation to confirmation in Chinese classrooms in senior high schools in Mainland China. Study One used individual interviews to explore the formation of Chinese teachers’ expectations and classify them into class-level high-, average- and low-expectation groups for analysis for the subsequent studies. Study Two aimed to investigate the connection between student perceptions of teacher expectations and teachers’ actual expectations, as well as the longitudinal changes in student-perceived classroom climate across different teacher expectation groups and relations with teacher expectations and student achievement. Finally, Study Three investigated the dynamic relations between student emotions and self-efficacy throughout one academic year. Associations with teacher expectations and student outcomes were also examined. The findings of Study One demonstrated that teachers with higher expectations and more years of experience tended to have a higher level of self-efficacy and were more likely to create an enjoyable classroom climate, whereas less experienced teachers had lower self-efficacy and were more likely to struggle with classroom management. In Study Two, compared to students in classes of teachers with medium and low teacher expectations, those whose teachers held higher class-level expectations were found to experience a warmer and more stable learning environment. In Study Three, during the first half of the school year, students’ positive emotions at Time 1 negatively predicted their self-efficacy at Time 2. In contrast, during the second half of the school year, their self-efficacy at Time 2 positively predicted their positive emotions at Time 3. The final chapter discusses findings from the three studies, includes implications for theory and practice, and includes recommendations for future research. Collectively, this research project explored teacher expectation effects from both teacher and student perspectives. This thesis provided evidence and meaningful insights into the process of teacher expectations from formation to confirmation, which could be used to make teachers aware of their expectations and empower them with high-expectation knowledge, in order to hinder the negative effects of low teacher expectations and promote educational progress.
Relationships of Influence? An Institutional Ethnography of Alcohol, Food, Gambling, and Tobacco Lobbying in Aotearoa New Zealand
(ResearchSpace@Auckland, 2024) Gregan, Melissa-Jade; Adams, Peter; Wiles, Janine; Kypri, Kypros
Background: Despite a growing body of international literature on how corporate entities and public health communities attempt influence public health policy, little is known about these activities in Aotearoa New Zealand (NZ). Unlike most developed countries, lobbying is unregulated and primarily unseen. Aims: To explicate how and where public health actors and industry actors work to influence alcohol, food, gambling, and tobacco policymaking in Aotearoa New Zealand (NZ) through direct interactions, and how this work is institutionally coordinated to happen as it does. Examining the spaces or settings in which political insiders and outside interests interact can help to reveal the power dynamics that exist in these political relationships. Methods: This study drew on institutional ethnography, a critical method of inquiry. Data were obtained through 21 interviews with current and former MPs, Ministers, public servants, and political journalists, and well-established public health experts, and analysis of pertinent texts, such as legislation, and parliamentary rules. Texts and interviews were analysed to identify and reveal the institutional complex of direct lobbying in NZ. Results: Industry actors dominate the lobbying space, building long-term relationships with political insiders through repeated, friendly, and low-pressure interactions. These occur in a range of informal settings such as hospitality-related events where there is ample opportunity for social interaction. Political informants spoke of receiving little guidance about these interactions. Moreover, textual analysis highlighted ways in which the NZ political system organises these to occur with little public oversight. By contrast, public health experts strive to meaningfully engage with politicians in official policy settings. Their policy involvement is established by standardising texts such as their contracts for government funding. Discussion: This research documents the crucial ways in which industry actors use relationship building to influence political decisions. Aotearoa New Zealand needs to enact comprehensive lobbying regulations. Without this, industry actors will continue to dominate public health political decision-making.
Structure and Reactivity in Nanostructured Ionic Solvents
(ResearchSpace@Auckland, 2024) Kahlon, Navjot Kaur; Weber, Cameron
Deep eutectic solvents (DESs) are low melting mixtures, often prepared from a hydrogen bond acceptor (HBA) salt and a molecular hydrogen bond donor (HBD) at a specific molar ratio. These unique solvents are of increasing research interest due to their potential for simple, 100% atom economical preparation from cheap, commercially available, environmentally benign components. Though DESs are now recognized as an individual class of solvents, they were previously categorized within the family of ionic liquids (ILs) due to similarities between these solvents including typical physical properties such as their low vapor pressures, wide liquid-state ranges, low flammability, and inherent electrical conductivity. However, ILs and DESs fundamentally differ in their chemical nature since ILs are pure liquid salts whereas DESs are mixtures. Like ILs, DESs that contain at least one sufficiently amphiphilic component can form bicontinuous nanostructures consisting of polar and non-polar domains. The ability of DESs to form amphiphilic bulk nanostructures similar to ILs is exciting given its implications in a wide range of applications, including catalysis, electrodeposition, chemical extraction, self-assembly, bioprocessing, energy storage, and lubrication. But these bulk nanostructures have not been widely explored for many DES combinations. So, the lack of characterisation of the nanostructure of DES hinders the development of essential structure-property relationships, which severely restrict the utility of this class of solvents. Here, the bulk nanostructures of DESs comprising tetraalkylammonium bromide salts (tetrabutylammonium bromide, tetraoctylammonium bromide and methyltrioctylammonium bromide) with alkanols and alkanoic acids of systematically varied chain lengths (C2, C6, C8 and C10) as hydrogen bond donors have been studied. Small-angle X-ray scattering techniques were used to identify the relationship between alkyl chain length and functionality of the hydrogen bond donor on the nature of the amphiphilic nanostructures formed. All the DESs investigated featured amphiphilic nanostructures, with the bulk arrangement varying between the three tetraalkylammonium salts used. Also, the findings from this study demonstrated that the amphiphilic nanostructures of the DESs were not affected by the functional group on the hydrogen bond donor but are primarily influenced by both the absolute and relative alkyl chain lengths of the salt and hydrogen bond donor. Due to the hygroscopic nature of the DES, the presence of water (at least in small quantities) is often unavoidable and may even be deliberately added to the DESs in order to leverage favourable physiochemical properties, such as lower viscosity, during an application. There have been several experimental and theoretical investigations on the hydration behaviour of DESs based on non-amphiphilic choline chloride (CholCl) salt, which highlighted the presence of two key regimes (association and hydration) with a distinct transition point between the two on the gradual hydration of DES. However, the amphiphilic DESs featuring polar-nonpolar domains could potentially lead to different solvation behaviour than the CholCl DESs or, at the very least, affect the transition point between the association and hydration regimes of DES-water mixtures. Apart from water, the solvation of other molecular or ionic solutes, co-solvents, or reactants can also be required in certain applications of structured DESs as reaction media or extraction solvents. Here, the resilience of the amphiphilic nanostructures of the tetraalkylammonium DESs was assessed through the addition of various solutes. The solutes include water (H2O), propan-2-ol/ isopropanol (IPA), acetone (Ace), dimethyl sulfoxide (DMSO), ethyl acetate (EtOAc), cyclohexanol (CyOH), cyclohexanone (Cyone), and cyclohexyl acetate (CyHxAc). The findings suggested the nanostructures to be remarkably resilient, with solute concentrations of 70 mol% or more tolerated before any breakdown. The partitioning behaviour of these solutes within the nanostructured domains was also analysed. Based on their nature (such as hydrogen bond accepting or donating ability or high dipolarity) and size, solutes exhibited different solvation affinity for the polar and nonpolar DES domains. Furthermore, the effect of the HBA:HBD stoichiometry on the DES amphiphilic nanostructure was also investigated using SAXS, which highlighted the sensitivity of these nanostructures to compositional changes. The overall findings illustrated the potential of these DES nanostructures to be fine-tuned through both salt: HBD composition and the deliberate addition of solutes for a specific application. The effects of the amphiphilic nanostructures of ILs have been previously explored for a small number of chemical processes, such as Diels-alder reactions, polymerization reactions, nucleophilic substitution reactions, condensation reactions, and elimination reactions. The results of those investigations highlighted the untapped potential of using structured media to control the course of reactions. It also encouraged the prospect of developing such reactions as probe systems to obtain nanostructural information, like the degree of domain segregation or the preferred orientation of reactive species in such solvents. Because the inherent structural organization in these soft matter systems (ILs or DESs) can potentially place electronic or steric constraints on reactants, transition states, or products, it can directly affect organic reactivity and reaction rates. Here, the kinetics of the inverse-electron demand Diels-Alder (DAinv) reaction were probed to develop structure-reactivity relationships with the tetraalkylammonium DESs investigated alongside selected molecular solvents and ILs. The key finding was the stronger effect of amphiphilic n-alkanols compared to the other solvent systems (amphiphilic ILs or DESs), including the corresponding alkanoic acids, on the reaction. The rationalizations were drawn based on solvent-solute interactions, solvophobic effects, and general polarity effects. It provided the basis for further in-depth investigations into the impact of domain structures and specific solute-solvent interactions on chemical reactivity.

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