Tuwhera Research Repository

The Tuwhera Research Repository provides sustainable open access and archiving to a broad range of AUT produced research - theses, research outputs and datasets.

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Access status: Restricted ,
Exploring the Test-Retest Reliability of Exercise-Induced Hypoalgesia: A Study of Single-Joint Dynamic and Isometric Resistance Exercises
(Auckland University of Technology, 2026) Regan, Ciaran; Toomey, David; Rice, David
Objective To establish the test-retest reliability of exercise-induced hypoalgesia (EIH) after single-leg knee extension isometric (IRE) and dynamic resistance exercise (DRE), and to examine individual-level between-session heterogeneity, overall proportional bias and heteroscedasticity via Bland-Altman Limits of Agreement (LoA) analysis in healthy, pain-free adults. Background EIH test-retest reliability is poor to fair across several exercise paradigms, undermining its research and clinical applications. No study has examined EIH reliability after DRE or single-joint IRE. Additionally, individual-level EIH measurement error between-sessions remains unexplored. Study Design A single-group test-retest reliability design was used over two identical testing sessions with a target separation of seven days, in 32 participants. A combined familiarisation and maximal strength testing session preceded Session 1 by 72 hours, establishing individualised exercise doses (25% maximal voluntary isometric contraction for IRE; 10-repetition maximum for DRE). Method Pressure pain thresholds (PPT) were assessed via handheld algometry at the index leg’s knee medial joint line and contralateral forearm, directly before and after each condition: quiet rest, DRE, and IRE. Test-retest reliability was determined using an ICC(3,1) single-rater, single-measure, absolute-agreement, two-way mixed-effects models with 95% confidence intervals, and standard error of measurement (SEM). EIH responder agreement was assessed via Cohen’s kappa. Bland-Altman LoA plots examined group-level proportional bias and heteroscedasticity and screened for individual-level outliers. Post-hoc sensitivity analyses examined reliability after adjusting for between-session exercise dose differences and outlier removal. Results Thirty participants completed the study after two participants withdrew due to unforeseen circumstances. Most participants completed Sessions 1 and 2 seven days apart (83%). ANOVA testing confirmed local EIH occurring at the knee for both conditions; remote EIH at the forearm could not be confirmed. Within-session PPT reliability was excellent (ICC ≥ 0.82) across all sites and conditions; between-session baseline PPT reliability was excellent (ICC = 0.81) at the forearm but fair for the knee (ICC = 0.54). Between-session EIH reliability was poor (ICC ≤ 0.39) across all sites and conditions. EIH SEMs generally exceeded mean EIH magnitudes. Responder agreement was fair for IRE at the knee (κ = 0.345) and poor elsewhere. Adjusting for significant between-session differences in exercise parameters did not improve reliability. Bland-Altman analysis showed large mean biases and wide LoAs across all conditions, with no heteroscedasticity or proportional bias. Six participants (20%) were identified as condition-specific outliers. Outlier removal substantially improved knee absolute ICC values for both IRE (ICC = 0.60) and DRE (ICC = 0.58), with IRE knee SEM reducing to below the mean EIH magnitude. However, reliability remained below the COSMIN acceptability threshold (ICC ≥ 0.70) across all conditions. Conclusion EIH after single-joint IRE and DRE demonstrated poor between-session reliability. Group-level estimates were substantially influenced by six condition-specific outliers. However, even after removal, reliability estimates remained insufficient for individual-level use. These findings extend EIH reliability evidence to previously untested resistance exercise modalities and provide the first evidence that individual-level heterogeneity can substantially suppress group-level EIH reliability. Future studies should incorporate Bland-Altman LoA analysis alongside ICC and SEM to detect individual-level measurement heterogeneity not identifiable by group-level statistics alone.
Access status: Open Access ,
Advancing the Measurement and Understanding of Composite Sleep Health in Shift-Working Populations
(Auckland University of Technology, 2026) Passfield, Geoffrey; Stewart, Tom; Crofts, Catherine; Schofield, Grant
Introduction: Sleep is a fundamental biological process that supports mental and physical functioning. Its restorative value depends not only on sufficient duration, but also on sleep being consolidated, efficient, regular, and timed appropriately within environmental and physiological rhythms. These dimensions can be understood through the framework of sleep health, which conceptualises sleep as a multidimensional construct. This framework is particularly relevant for shift-workers, whose work schedules can disrupt circadian alignment, constrain sleep opportunity, and alter the distribution of behaviours across the 24-hour day. However, existing research has tended to examine individual sleep metrics or subjective sleep outcomes, with limited attention to objectively measured sleep health in real-world shift-working populations. This thesis investigated the measurement, distribution, and behavioural context of objectively measured composite sleep health (CSH) in shift-workers. Methods: This thesis comprised five interconnected studies using accelerometery and diary data from free-living adult workers. An initial agreement study compared sleep metrics derived from wrist, mid-thigh, and low-back accelerometers. Subsequent studies applied a five-dimension CSH framework, comprising duration, variability, efficiency, timing, and regularity, to examine differences across work-pattern groups, associations with self-reported health and well-being outcomes, relationships with health behaviours, and associations with 24-hour time-use composition. Results: Mid-thigh accelerometery produced sleep estimates broadly comparable to wrist-derived estimates, supporting its use for group-level CSH assessment. Objectively measured CSH was generally poor across the cohort, with night shift-workers showing the poorest multidimensional sleep health. CSH showed limited associations with self-reported psychosocial and health outcomes, although subjective sleeping troubles showed the clearest relationship. Most self-reported health behaviours explained little variance in CSH. The 24-hour time-use profile of shift-workers was dominated by sedentary time, followed by sleep, with smaller proportions of the day spent in light and moderate-to-vigorous physical activity. In compositional analyses, greater relative sedentary time was associated with lower CSH, while greater relative sleep was associated with higher CSH. Conclusions: Objective CSH provides a practical framework for multidimensional sleep health, moving beyond single sleep metrics to show how sleep duration, variability, efficiency, timing, and regularity combine within real-world working conditions. By linking objectively measured sleep health with work-pattern differences, self-reported health outcomes, health behaviours, and 24-hour time use, this thesis demonstrates that poor sleep health in shift-workers is not simply a sleep-duration problem, but part of a broader behavioural and occupational context. These findings support the value of objective, multidimensional sleep assessment for identifying sleep-health burden in shift-working populations and for informing future research focused on feasible, context-sensitive strategies to improve sleep health.
Access status: Open Access ,
I Roto I Te Tohu: An Exploration of Identity Through Heaven and Earth
(Auckland University of Technology, 2026) Harris, Tohu Wairua Aroha; Tapuni, Nooroa; Luke, Bobby
This practice-led research project explores my identity grounded by my whakapapa Māori and connection to God. I seek to find harmony between these two worlds, culture and religion, establishing wairua as the common thread that binds them both. I navigate the complexities of this multi-dimensional state of being through painting and videography; highlighting the wairua that exists in waiata, in the whenua and therefore within me. Using whenua pigments, collected from my mārae in Mōtukaraka, and documenting mundane moments of home life in Mangamuka, I ground my practice in whakapapa. These modes of making provide two different perspectives, a public perception and one that is more personal; showcasing how I engage with my whanau, in wairua and worship of Ātua Māori and God.
Access status: Restricted ,
Factors Influencing Tourist Expenditure Among Different Spending Groups: Empirical Evidence from the Cook Islands
(Auckland University of Technology, 2026) Mohan, Sooraj; Kim, Peter; Zhu, Dan; Kim, Chloe
This research investigates the factors influencing tourist expenditure which is essential for sustainable destination development and enterprise growth in the Cook Islands. This study examines how economic, socio-demographic, and trip-related characteristics influence tourists' on-site expenditure across different spending groups in the Cook Islands. The study utilises secondary data obtained from the Cook Islands International Visitor Survey (IVS) conducted between July 2022 and June 2023, comprising 942 international visitors. Multiple analytical tools, such as descriptive statistics, Pearson correlation analysis, multiple linear regression, and quantile regression were employed to examine expenditure behaviour across low-, medium-, and high-spending tourists. The findings indicate that household income and prepaid expenditure are positively related to tourist expenditure, whereas travel party size and length of stay are negatively related to daily on-site spending. Education and repeat visitor status exhibit modest effects, while age, gender, purpose of visit, and online decision influence do not significantly explain expenditure in the overall regression model. Quantile regression further reveals that the effects of expenditure determinants vary among different spending groups, demonstrating that household income is more influential among low- and medium-spending tourists than among high-spending visitors, whereas prepaid expenditure appears to be a salient determinant for high-spending visitors. The study contributes to the tourism expenditure literature by providing empirical evidence from a small island destination and demonstrating the value of quantile regression in identifying heterogeneous spending behaviour. The findings offer practical implications for destination managers, tourism enterprises, and policymakers seeking to increase visitor yield through targeted marketing strategies and product development.
Access status: Open Access ,
Access Controls for IIOT Work Systems – Biometric Mechanisms
(Auckland University of Technology, 2026) Anyanka, Francis Ebere; Cusack, Brian; Lutui, Raymond
This research aims to address security challenges in the IIoT (Industrial Internet of Things) work environment. The increasing digitalisation of industrial workplaces through the Industrial Internet of Things (IIoT) has transformed the way organisations manage physical access to critical infrastructure, manufacturing plants, and hazardous operational environments. Despite these advances, existing access control mechanisms, including passwords, RFID cards, tokens, PINs, and unimodal biometric systems, remain vulnerable to credential theft, spoofing attacks, environmental interference, and operational constraints. Industrial environments further complicate authentication due to the use of personal protective equipment (PPE), variable lighting, dust, machinery noise, worker movement, and harsh working conditions, which significantly reduce biometric recognition accuracy. Existing authentication solutions, therefore, fail to provide the level of security, usability, and resilience required for reliable contactless physical access control in modern IIoT environments. This research addresses these limitations by designing, developing, and evaluating a contactless multimodal biometric fusion framework for secure physical access to industrial work sites. The proposed framework integrates facial, iris, ear, gait, palmprint, fingerprint, and voice biometrics within a deep learning-based fusion architecture capable of improving authentication robustness under dynamic operational conditions. To strengthen biometric template security, the framework incorporates biometric watermarking to protect identities and ensure data integrity. The research delivers three complementary Design Science Research artefacts: Artefact 1, a conceptual framework derived from a systematic literature review that establishes the theoretical foundations of contactless multimodal biometric authentication; Artefact 2, an experimentally validated prototype implemented within the Second Life virtual environment to simulate realistic industrial access control scenarios; and Artefact 3, a refined adaptive authentication framework informed by industrial expert evaluation, integrating contextual intelligence and adaptive biometric fusion to improve authentication resilience in complex industrial environments. The study adopted the Design Science Research Methodology (DSRM) to create three prototypes, to guide the iterative design, development, demonstration, and evaluation of the proposed solution. The research combined a systematic literature review, conceptual framework development, prototype implementation, controlled experimentation, and expert evaluation. A virtual industrial environment developed within Second Life enabled safe, repeatable, and cost-effective simulation of industrial access control without disrupting operational facilities. The proposed artefacts were evaluated for authentication accuracy, precision, recall, computational performance, environmental robustness, and usability, in accordance with ISO 9241-11. The findings demonstrate that multimodal biometric fusion substantially improves authentication performance compared with conventional unimodal biometric systems while reducing authentication errors and increasing resilience against spoofing and operational variability. Experimental results confirmed that environmental conditions, including PPE occlusion, worker movement, poor illumination, and industrial noise, remain major factors influencing biometric reliability, thereby validating the need for adaptive authentication mechanisms. Although multimodal fusion significantly enhanced recognition performance, the research further established that static fusion alone is insufficient under highly dynamic industrial conditions. Instead, adaptive contextual weighting and intelligent decision-making were shown to improve authentication robustness by responding to changing biometric quality and environmental constraints. Expert evaluation further confirmed the practical feasibility, scalability, and industrial relevance of the proposed framework for future IIoT deployments. This research contributes a validated contactless biometric access control framework, a comprehensive experimental evaluation methodology, and three rigorously developed Design Science Research artefacts that collectively advance knowledge in secure IIoT authentication. The research demonstrates how contactless multimodal biometric fusion can provide secure, usable, and scalable physical access control for industrial work sites while addressing real-world operational challenges. Beyond its immediate contribution to industrial cybersecurity and access management, the research establishes a foundation for future investigations into explainable artificial intelligence, adaptive biometric fusion, continuous authentication, privacy-preserving biometric protection, federated learning, and deployment within real-world cyber-physical industrial systems. The proposed framework, therefore, offers both a significant academic contribution and a practical pathway towards next-generation secure contactless biometric authentication for Industry 4.0 and emerging Industry 5.0 environments.