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Investigating the effects of acute photobiomodulation on submaximal rowing performance and physiological responses in trained female rowers
(The University of Waikato, 2026) Barrell, Amelia; Beaven, Christopher Martyn
It is well established that Red Light Therapy (RLT), or Photobiomodulation (PBM), can enhance mitochondrial function, reduce markers of muscle damage, and improve exercise performance and recovery. As a result, RLT has become an increasingly popular non-invasive intervention within sport and exercise settings. Recent research has shown that pre-exercise application of red and near-infrared light may improve time to exhaustion, reduce fatigue, and enhance recovery in activities such as cycling, running, and resistance exercise. However, there is currently no research examining the effects of RLT on rowing performance, particularly during submaximal exercise in trained female rowers. This thesis is separated into three chapters. Chapter one provides a review of the literature on RLT, beginning with its historical development and underlying physiological mechanisms of action. This review includes a discussion of the interaction between RLT and mitochondrial chromophores, effects on adenosine triphosphate (ATP) production, oxidative stress modulation, and nitric oxide-mediated processes. The chapter further examines the role of RLT in exercise performance and recovery, with particular emphasis on muscle fatigue, endurance capacity, and post-exercise recovery markers. The literature review also critically evaluates the application of RLT across a range of exercise modalities, including resistance exercise, cycling, and running, while highlighting the variability in outcomes reported across studies. Particular attention is given to inconsistencies in methodological approaches, including differences in wavelength, dosage, timing of application (pre- versus post-exercise), and participant characteristics. Chapter One also identifies key gaps in the current literature, notably the limited research in endurance -based, sport-specific contexts and the underrepresentation of female athletes. These gaps provide the rationale for the present study, with a specific focus on rowing as an endurance sport requiring sustained submaximal performance and efficient recovery. Rowing has continuous physiological demands on both the upper and lower body and relies heavily on sustained submaximal power output and efficient recovery between repeated efforts. As a result, Chapter Two investigated the acute effects of PBM on submaximal rowing performance and exercise physiology in trained female athletes. Twelve trained female rowers participated in a placebo-controlled, double-blind, randomized crossover design. Each participant completed five laboratory sessions, beginning with a maximal graded exercise test to determine maximal oxygen uptake (VO2max) and establish individualised workload targets for subsequent submaximal trials. The remaining four sessions involved identical rowing protocols performed following one of four treatment conditions: red light (630 and 660 nm), near infrared (810, 830 and 850 nm), combined red and near-infrared light, or placebo condition. Treatment order was randomised, and participants were blinded to the condition. A minimum of 48 hours recovery was maintained between sessions to minimise potential carryover effects. Primary outcome measures included oxygen uptake (VO2), blood lactate concentration, and blood glucose concentration during progressive submaximal exercise. Secondary measures included respiratory exchange ratio (RER) and ratings of perceived exertion (RPE), providing a comprehensive assessment of both physiological and perceptual responses to PBM. Statistical analysis revealed participants completed a greater number of submaximal rowing intervals following the red light (7.25 ± 0.75 intervals; p = 0.046) and infra-red light (7.25 ± 0.45 intervals; p = 0.012) conditions compared with the placebo condition (6.67 ± 0.98 intervals) indicating improved exercise capacity. PBM was also associated with lower blood glucose concentrations during the exercise intensity closest to the lactate threshold in the infra-red condition (p=0.0300; d= 0.58 ±0.51). There were also differences in RER responses between the red light and placebo conditions suggesting alterations in energy utilisation during exercise. However, no significant differences were observed in VO2, blood lactate concentration, or RPE between conditions. These findings suggest that pre-exercise PBM may enhance submaximal rowing performance through alterations in metabolic responses, including utilisation and glucose regulation, while producing only limited changes in broader physiological responses. Chapter Three summarises the findings from Chapter Two, identifies the strengths and limitations for the present study, and provides recommendations for future research. Overall, this thesis identified key gaps within the existing literature on PBM (RLT), particularly in relation to sport-specific endurance performance, female athlete populations and submaximal exercise protocols.
Detection of human and machine-authored fake news in Urdu
(Association for Computational Linguistics, 2025) Ali, Muhammad Zain; Wang, Yuxia; Pfahringer, Bernhard; Smith, Tony C.
The rise of social media has amplified the spread of fake news, now further complicated by large language models (LLMs) like Chat-GPT, which ease the generation of highly convincing, error-free misinformation, making it increasingly challenging for the public to discern truth from falsehood. Traditional fake news detection methods relying on linguistic cues have also become less effective. Moreover, current detectors primarily focus on binary classification and English texts, often overlooking the distinction between machine-generated true vs. fake news and the detection in low-resource languages. To this end, we updated the detection schema to include machine-generated news focusing on Urdu. We further propose a conjoint detection strategy to improve the accuracy and robustness. Experiments show its effectiveness across four datasets in various settings.
Supporting interactive system testing with interaction sequences
(ACM, 2017) Turner, Jessica; Bowen, Judy; Reeves, Steve
In software engineering testing is an important part of the development process. In interactive systems human input introduces the possibility of human error, which increases the testing requirements. In safety-critical systems user or system error can result in injury or death to a user. We propose using interaction sequences as a way of supporting interactive system testing to help address these issues.
Finite element study on the flexural behaviour and edge-stiffening effect of cold-formed steel C-channel beams with elongated web holes
(The University of Waikato, 2026-09-23) Lei, Junhong; Fang, Zhiyuan (Arthur)
Cold-formed steel (CFS) channel beams are commonly provided with web openings to allow building services to pass through the member. In practice, larger openings are often preferred because they provide more space for services. However, increasing the opening size may reduce the flexural resistance of the beam, especially when elongated web holes are used. This thesis investigates the flexural behaviour of CFS channel beams with elongated web holes under four-point bending. The main aim is to examine whether larger web openings can be introduced while maintaining an acceptable level of moment capacity. The effectiveness of edge stiffening around elongated web holes is also evaluated. A nonlinear elasto-plastic finite element model was developed in Abaqus. The modelling approach was first validated against published experimental and numerical results for CFS channel beams with web holes. After validation, a parametric study including 282 finite element models was carried out. Two section sizes, C240 and C290, were considered. Their no-hole moment capacities were 13.591 kN·m and 20.058 kN·m, respectively. The main parameters included hole radius, elongated-hole aspect ratio, number of holes, clear spacing between adjacent holes, edge stiffening, and lip angle. Three hole radii of 70, 75, and 80 mm were examined. The elongated-hole aspect ratio was varied from 1.25 to 2.00. One-hole, two-hole, and three-hole arrangements were included, with clear spacings of 50 and 100 mm for the multi-hole models. For the edge-stiffened models, the stiffener depth and fillet radius were kept as 13 mm and 4 mm, respectively. The results show that increasing the web opening area generally reduced the moment capacity of the unstiffened-hole beams. For the more severe practical cases, the strength retention ratio decreased to about 0.78–0.85. By contrast, edge stiffening was able to recover a considerable part of the lost strength. The maximum stiffening efficiency obtained in this study was approximately 26.6%. In several edge-stiffened three-hole models, the strength retention ratio remained above 0.85 even when the opening ratio exceeded 12%. The lip-angle study also showed that the flange-lip inclination can affect the flexural response. Among the investigated C290 EH1-HS80-ab15 models, the 60° lip-angle model gave the highest moment capacity. Overall, the results indicate that elongated web holes can be used more efficiently when suitable edge stiffening and geometric configurations are adopted.
Investigation of the geometric effects of corrosion pits on the tensile behaviour of structural steel
(The University of Waikato, 2026) Thu, Kaung Myat; Fang, Zhiyuan (Arthur)
Pitting corrosion removes parts of the structural steel’s cross section in a localised manner, therefore introducing localised stress concentrations which can cause decreased tensile and deformation capacity in a more pronounced effect than uniform cross sectional mass loss. With aging infrastructures using structural steel used in chloride environments, there is a growing need for reliable assessment of corroded steel. Therefore, a methodology that can provide insights with the linkage of measurable corrosion parameter such as mass loss to mechanical response of the corroded steel material can prove to be a clear contribution for corrosion analysis. The methodology should also consider the localised and stochastic nature of pit formations. This thesis develops and applies a reproducible numerical workflow for this purpose and evaluates it against an experimental tensile programme on low-carbon structural steel coupons immersed in a 5% sodium-chloride solution for up to 42 days. Flat dog-bone coupons conforming to ISO 6892-1 were corroded for 0, 14, 21, 28, 35 and 42 days, cleaned and weighed gravimetrically, and tested in uniaxial tension. The coupons were protection wrapped for the grip and shoulder regions and only the gauge section were exposed to the chloride immersion. Measured average effective mass losses ranged from 1.29% to 2.49%, with a power-law mass-loss-time relationship indicative of a diffusion-controlled process. Finite element analyses were conducted with a stochastic pit-generation algorithm developed in MATLAB which was used to create randomised distributions of flat-bottomed cylindrical pits, with the total pit volume matched to the measured mass loss. The resulting pit fields were then converted into discrete cavities in an Abaqus/Explicit coupon model using a Python script that conducts automated pit insertion through reading the MATLAB pit generation output data. The material model was calibrated once using a representative lab-tested experimental uncorroded Day-0 tensile response and was subsequently kept unchanged, thereby isolating the simulated influence of corrosion to geometrical material loss. This calibrated geometry-isolated workflow was subsequently applied to a numerical mass-loss projection study, extending the corrosion severity beyond the experimental range to 12% gauge-section mass loss. At this higher severity, the ultimate tensile strength showed a more pronounced decrease compared to lower mass-loss levels, while the ductility loss obtained from the FE simulations remained strongly influenced by the pit geometry and spatial distribution of each stochastic realisation. The uncorroded finite-element model reproduced the experimental ultimate tensile strength to within approximately 0.4% and was shown to be mesh-converged and quasi-static through an energy-balance study. Across the corroded cases, the experimental coupons showed no statistically clear monotonic reduction in either ultimate strength or fracture strain at the studied mass-loss levels. It was observed that the corrosion-induced change was smaller than the coupon-to-coupon scatter. On the other hand, geometry-isolated finite-element model, resolved a small reduction in ultimate strength (of order 2% over the exposure range) and a substantially larger reduction in fracture strain and toughness (of order 7-14%). This suggests that ductility is the corrosion-sensitive quantity and that strain localisation at pits are key factors of the loss of deformation capacity. Based on these findings, simple normalised predictive relationships are proposed in which the residual strength, fracture-strain and toughness factors decrease approximately linearly with mass loss, the ductility coefficient being about an order of magnitude larger than the strength coefficient. These relationships come with limitations which are discussed in the later section. The principal contribution of the thesis is a single, seed-controlled, mass-loss-verified workflow combining stochastic pit generation, idealised-pit finite-element realisation and quasi-static tensile simulation, together with a quantified experimental demonstration which shows that at low-to-moderate mass loss, the geometric effect of pitting on steel coupons is concentrated in ductility rather than strength. The cylindrical pit idealisation, the fixed material card and the coupon scale are acknowledged as part of the limitations of this study.