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: Open Access ,
Random Forest-assisted Dynamic TRM Estimation for Improved ATC in Renewable-rich Power Systems
(IEEE, 2026-07-09) Edeh, Uchenna Emmanuel; Lie, Tek Tjing; Mahmud, Md Apel; Zhang, Pei
Accurate Available Transfer Capability (ATC) assessment is critical for reliable operation of renewable-rich power systems. Conventional dynamic Transmission Reliability Margin (TRM) methods based on rolling-window statistics mainly react to recent volatility, limiting responsiveness during rapid system changes. This paper proposes a Random Forest (RF)-assisted dynamic TRM framework where a lightweight RF regression model predicts short-term volatility using historical forecast errors and operating-condition features. The predicted volatility is incorporated into an adaptive confidence factor, K(t), enabling anticipatory TRM adjustment while preserving the original probabilistic framework. Validation on the IEEE 24-bus Reliability Test System with integrated wind generation demonstrates improved performance, achieving 97.2% coverage during ramp events compared with 91.7% for the rolling-window approach and 69.4% for the static method. The RF model achieved RMSE = 3.60 MW and R2 = 0.825 for 3-step-ahead volatility prediction, showing strong potential for renewable-integrated Australasian power systems.
Access status: Open Access ,
Brawn and Brains: An Exploration of Personality Differences Between Strength Sports Athletes
(International Universities Strength and Conditioning Association, 2026-08-28) Black, John; Uthoff, Aaron; Forster, James
Strength sports like bodybuilding, powerlifting, weightlifting, strongman/strongwoman, and CrossFit® all revolve around resistance training but differ in the way they are trained for, performed, and judged. While personality is known to influence physical activity choices, little is known about whether different strength sports attract athletes with distinct personality profiles. This study explored whether personality dimensions and their more specific facets differ between athletes from these five strength disciplines. A total of 187 competitive strength sport athletes (73.8% male, 26.2% female) completed the IPIP-NEO-120 personality inventory. One-way ANCOVAs were used to examine differences across sports, with sex controlled as a covariate. Results showed that while the only significant difference at the dimension level was for neuroticism (ηp² = .076), with CrossFit® athletes scoring lowest, several meaningful differences emerged at the facet level. Bodybuilders scored higher in artistic interest, orderliness, and cautiousness, while strongman/strongwoman athletes scored higher in immoderation and vulnerability, and lower in cautiousness. Weightlifters demonstrated the highest liberalism scores, and CrossFit® athletes showed the lowest vulnerability. Effect sizes for facet-level differences ranged from small to medium (ηp² = .051 to .074). These findings suggest that although athletes may appear similar when grouped under the umbrella of strength sports, there are meaningful psychological differences between disciplines. These insights may help explain sport selection and could inform future research on how personality interacts with training over time.
Access status: Open Access ,
Intelligent Transportation Systems: A Review of Integration of Digital Twin and Machine Learning Control
(MDPI AG, 2026-08-27) Tun, Thit; Sabit, Hakilo
This paper presents a comprehensive review of the integration of Intelligent Transportation Systems (ITS) and Digital Twin (DT) technologies for intelligent traffic management. It examines the role of key enabling technologies, including the Internet of Things (IoT), machine learning (ML), deep learning (DL), reinforcement learning (RL), Graph Neural Networks (GNNs), vehicle-to-everything (V2X) communication, and edge computing. These technologies support real-time traffic monitoring, traffic prediction, and adaptive control in ITS. The review synthesizes recent research on conventional traffic control methods, optimization-based approaches, learning-based techniques, and DT-enabled traffic management solutions. Particular attention is given to the integration of DTs with intelligent traffic signal control, real-time synchronization, multi-intersection coordination, communication latency, sensing uncertainty, and scalability. The reviewed literature demonstrates the potential of DT-enabled ITS to improve traffic efficiency, reduce congestion, enhance transportation safety, and support sustainable mobility through data-driven decision-making. However, significant challenges remain regarding communication delays, sensor and data uncertainty, computational complexity, scalability, and validation under realistic urban conditions. Based on the reviewed literature, this paper identifies key research gaps and outlines future research directions toward scalable, reliable, adaptive, and real-time DT-enabled ITS architectures for next-generation smart cities.
Access status: Open Access ,
Invasive Mammals Disrupt Sea–Land Nutrient Inputs Over 169 Years on Subtropical Oceanic Islands
(Wiley, 2026-09-14) Rayner, MJ; Klemm, MF de A; Nelson, WA; Bury, SJ; Hawke, DJ; Sewell, MA; West, CJ; Morman, KE; Walker, Leilani; Neill, K; Aguirre, JD; Baba, Y; Beggs, JR; Duffy, CAJ; Galbraith, J; Gaskin, CP; Hvid, T; Kirk, M; Liggins, L; McGuigan, EI; Walton, K; Trnski, T; Whitehead, EA; Bellingham, PJ
Invasive mammals have severely impacted oceanic islands, reducing or extirpating seabird populations and driving the collapse of nutrient flows with lasting ecosystem effects. We investigated these dynamics on contrasting subtropical oceanic islands in the South Pacific: Rangitāhua, a large island where goats, cats, and rats caused the extinction of seabird populations, and the small mammal-free Meyer Islands, where seabird colonies remain dense. Using stable isotope analysis (δ13C and δ15N) of 408 contemporary and historical specimens spanning 169 years, across plants to invertebrates and birds, we tested hypotheses about seabird-driven nutrient coupling across space and time. Spatially, we predicted stronger seabird-driven nutrient enrichment on the mammal-free Meyer Islands than on invaded Rangitāhua. Consistent with this, Meyer Islands' soils had higher phosphorus and lower pH, and terrestrial plants and herbivorous invertebrates were enriched in δ13C and δ15N relative to their Rangitāhua counterparts. In the nearshore marine system, δ15N values—but not δ13C—were elevated in macroalgae and herbivorous and omnivorous invertebrates around the Meyer Islands compared with those around Rangitāhua, indicating stronger seabird-driven nutrient inputs to coastal food webs. By contrast, the lower values on Rangitāhua reflect slow seabird recovery more than 20 years after the eradication of invasive mammals. Temporally, we tested whether isotopic values in Rangitāhua plants and birds declined with seabird loss. Values for δ13C declined steadily from the mid-19th century to the present, consistent with reduced seabird subsidies (and possibly volcanic activity), whereas δ15N values showed no long-term change. Together, these spatial and temporal perspectives show that while seabird nutrient pathways can recover within decades on small islands, recovery on large, degraded islands can take much longer. Adjacent islets can provide recolonists but may not serve as true analogues. Restoring sea–land nutrient connectivity on large islands may require not only invasive mammal eradication but also active facilitation of seabird return.
Access status: Open Access ,
Weight Class Management in Powerlifting: An Evidence-informed Practical Review
(SAGE Publications, 2026-08-27) Renner, Alexander; Amdi, Christian Houmann
Weight class management in powerlifting is often guided by the heuristic that athletes should progressively move up in weight classes throughout their careers to accommodate hypertrophy, yet longitudinal competition data indicate that weight class change patterns are not meaningfully associated with peak career relative strength. This review integrates mechanistic and sport-specific evidence to translate this apparent mismatch into applied recommendations. Across observational studies, fat-free mass is consistently positively associated with squat, bench press, deadlift, and total performance, supporting contractile tissue as a key long-term contributor to strength once technical skill is established. However, accumulating functionally relevant mass does not require frequent or permanent weight class changes, because athletes can improve functional-to-nonfunctional mass via recomposition. Accordingly, weight class selection is framed as a conditional, athlete-specific planning decision, with weight class changes indicated primarily when the current weight class constrains sustainable lean mass accretion, training quality, recovery, health, or psychological sustainability. Practical guidance emphasizes conservative body mass changes, modest nutritional surpluses to support muscle mass gain, high protein intake, and slow fat-mass loss when moving down while maintaining heavy, skill-specific training exposures. Predefined stop rules, defined as criteria for slowing, pausing, or abandoning a weight class strategy, are recommended to reduce psychological load and avoid escalation of low energy availability and disordered eating risk, with referral to qualified support when indicated.