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Is rivals’ misfortune our joy? A study of strategic leaders’ schadenfreude
No full textThe abstract for this item has not been populated.</p
Enhancing PV Hosting Capacity in Electricity Distribution Networks
No full textSurging integration rates of rooftop photovoltaic (PV) systems into electricity distribution networks play a crucial part in the decarbonisation of the energy sector and its transition toward a more sustainable system. Despite the benefits of adopting PV systems, such as reduced electricity costs for customers and lesser reliance on fossil fuels, they can cause various challenges to the electricity distribution system if suitable planning and management approaches are not adopted. Some of the adverse impacts of high PV penetration are overvoltage, revenue loss due to curtailments, increased network unbalance, and thermal overloading of feeders and transformers.The hosting capacity of an electricity distribution network is defined as the maximum distributed generation that can be safely and reliably integrated without causing any adverse impacts to the grid. Undertaking a hosting capacity assessment allows distribution network service providers to plan investments more effectively and integrate more distributed energy resources into the grid, ensuring cost-effective grid expansion. Over-voltage is the most common constraint which limits the hosting capacity of distribution networks. New technologies for hosting capacity enhancement more effectively regulate the voltage of the grid, allowing more energy exports to the grid without leading to the tripping of the inverters of consumer PV systems.The research work undertaken in this thesis leverages recent advancements in artificial intelligence and applies them to the domains of hosting capacity assessment, coordinated voltage control, and dynamic operating envelopes. Software tools have been developed to model and quantify the hosting capacity of electricity distribution networks in both model-based and model-free manners. Model-based methods involve the development of power flow models using the network topology and element data available to the distribution network service provider, while model-free methods utilize a smart meter data-driven, artificial intelligence-based approach to model the electricity distribution networks. Model-free methods excel in situations where topological and network element data is unavailable.A coordinated voltage control scheme utilizing artificial intelligence is proposed in this thesis to enhance the hosting capacity of electricity distribution networks. Coordinated voltage control adopts a holistic approach to optimally regulate voltage, in contrast to commonly used local voltage schemes in the industry. The local voltage schemes were identified as performing sub-optimally when applied to unbalanced low-voltage distribution networks. This was investigated in detail through an analytical assessment. Furthermore, this thesis presents an artificial intelligence-based approach to quantify the enhanced real-time hosting capacity when such a coordinated voltage scheme is implemented. This approach is robust and scalable, offering faster hosting capacity estimates without the need for extensive simulations.In contrast to coordinated voltage control, which requires a sophisticated communication infrastructure and assumes direct control of consumer energy systems at higher time resolutions, dynamic operating envelopes offer an indirect form of control over consumer energy systems that is less susceptible to communication breakdowns and is executed at higher time resolutions, typically between 5-30 minutes. Dynamic operating envelopes are generally defined as time- and location-specific limits on import and export, adjusted based on the available capacity of the local network or the broader power system. In the context of Australian energy systems, dynamic operating envelopes are generally evaluated and deployed by the distribution network service providers. Dynamic envelopes are a key technology that enables the transition to a more decentralized energy system, fostering the wholesale energy market participation of consumers. Such decentralized market frameworks are more competitive, and as a result, energy costs for consumers will be significantly reduced.As artificial intelligence revolutionizes industries worldwide, its applications in power distribution systems remain largely untapped. This thesis proposes a novel methodology to estimate dynamic operating envelopes by leveraging artificial intelligence. The proposed approach is model-free, scalable, and robust, as proven by the numerical study undertaken, and demonstrates remarkable improvements over traditional dynamic operating envelope estimation strategies. Furthermore, this thesis presents a critical, unbiased discussion of the impact of artificial intelligence on power distribution networks and offers a fair evaluation of its advantages and pitfalls.This thesis aims to illuminate new possibilities and uncover novel approaches that enhance the hosting capacity of electricity distribution networks, contributing to the achievement of Net Zero energy targets.</p
Late Pleistocene Equilibrium Line Altitudes of Coastal and Inland Glaciers in Midlatitude USA
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From concept to practice Enabling blue economy: Lessons learnt from the Seychelles experience
No full textThe ocean is increasingly considered as development space. Although a contested term, the ‘blue economy’ is a concept that has gained popularity and political capital as a mechanism to support the sustainable development of the ocean, particularly for countries with large ocean domains such as the Small Island Developing States. The framing of the blue economy concept within broader ocean governance regimes is, however, poorly understood and there is limited research into how blue economy governance interventions are being implemented and experienced on the ground. This research explores the relationship between the blue economy and existing global governance frameworks applicable to the ocean, with a focus on the United Nations Convention on the Law of the Sea and the United Nations 2030 Sustainable Development Goals. It identifies the potential added value that the blue economy might offer these existing frameworks, such as an integrating mechanism and a driver of investment in sustainable development of the ocean. Using the Seychelles blue economy as a case study, the research further investigates how the blue economy has been enacted and financed in practice. Through a combination of desktop analyses, semi-structured interviews and the researcher’s experiential knowledge as an adviser to the Seychelles government, the research investigates the roles of governance and blue finance as critical enabling conditions of the blue economy. The results show that the Seychelles blue economy has achieved significant outcomes in advancing integrated policy settings, including the completion of its Marine Spatial Plan and designation of marine protected areas, and as a mechanism for securing private finance (e.g., a blue bond and debt swap). Nonetheless, the Seychelles experience highlights several governance and financing implementation challenges, some unique to its status as a small island, others common in other settings. These include challenges in overcoming silos and achieving policy coherence, inclusiveness, capacity and legitimacy, and securing long-term affordable finance for implementation. The study further reveals limitations of debt-based finance in a context of an unequal global financing system. Although there are opportunities to improve the local enabling environment, small islands’ governance and financing capabilities are, overall, not commensurate with their large ocean domain responsibilities. The research identifies several opportunities and areas for further investigation to enhance the enabling environment for the blue economy and both unlock its full potential and promote more equitable outcomes for Small Island Developing States.</p
Biomolecular Condensates as Emerging Biomaterials: Functional Mechanisms and Advances in Computational and Experimental Approaches
No full textBiomolecular condensates, a ubiquitous class of biomaterials found in living cells, have been shown to be responsible for key physiological processes, such as gene regulation, signal transduction, and stress response. Since their discovery, extensive efforts have been devoted to this field to better understand the underlying mechanisms using both computational and experimental techniques. While great progress has been achieved, the key challenges still exist. With advancements in computational power and methods and improvements in experimental precision, the gap between computation and experimentation is gradually narrowing. By integrating these approaches, researchers can elucidate the molecular mechanisms governing biomolecular condensates. This review summarizes the recent progress in utilizing computational and experimental techniques to study biomolecular condensates. Detailed discussions are provided on the key advantages and limitations of each technique, along with their successful applications to specific systems. Moreover, further discussions are focused on the possibility of utilizing biomolecular condensates as a versatile platform for drug delivery and novel bioreactor design with the help of these techniques. Finally, future directions are outlined for technique development to better understand the role of biomolecular condensates in health and disease and enable their applications as tunable biomaterials.</p
A Systematic Examination of Listener Experiences During the Shepard-Risset Glissando: Auditory Vection, Motion Sickness, Postural Activity, and Emotional Arousal
No full textThe Shepard-Risset glissando (SRG) is an auditory illusion of pitch discrimination that produces an infinitely falling or rising sound that paradoxically never gets any higher or lower. Anecdotal reports have suggested that the SRG can evoke a range of sensations and symptoms in listeners; from feelings of falling, disrupted equilibrium, disorientation, nausea, and emotional arousal. This thesis aimed to establish an objective foundation for these anecdotal claims for the first time by systematically investigating these reported listener experiences. The experiment outlined in Chapter 2 aimed to identify the origins of the auditory illusions of self-motion (vection) and motion sickness induced by SRG. We found that the metaphorical auditory vection induced by the SRG was stronger than the other auditory controls tested, and the stepwise Shepard scale. However, vection strength was not found to differ between the multi-tonal SRG and the single toned auditory sweep signal. This suggests that the continuous, gliding pitch of both these auditory stimuli was integral to the induction of vection. Consistent with anecdotal reports that the SRG is also capable of generating motion sickness; the likelihood and severity of sickness for these stimuli was found to increase with the strength of the auditory vection. The experiment outlined in Chapter 3 re-examined vection while continuously measuring the postural responses induced by SRG while standing. As expected, vection was again found to be stronger during SRG than the other auditory control stimuli. Individual differences in spontaneous postural instability (observed before sound) and auditorily-induced sway (observed during the sound) were both found to predict the strength of this vection. The patterns of sway induced by SRG also differed significantly from those during our auditory control stimuli, but only in terms of their temporal dynamics. Chapter 4 presents two experiments investigating vection and emotional arousal in response to the SRG in terms of: (1) its intensity (skin conductance); and (2) its valence (pleasant/unpleasant). The first experiment confirmed that: (1) the presence of sound increased overall arousal levels (compared to no sound); (2) the amount of arousal increased with the strength of vection (for all sound types tested); and (3) the SRG elicited a distinct physiological response from the other sounds before vection onset. The second experiment revealed that: (4) while all five sounds were perceived to be unpleasant, listener experiences were generally less negative during the SRG; and (5) the degree of unpleasantness was also related to their experiences of vection (positive) and motion sickness (negative). Taken together these findings showed that SRG are capable of reliably inducing illusions of self-motion in participants. Also, the experience of vection appears to be related to individual differences in motion-sickness susceptibility, postural activity and both the intensity and valence of emotional arousal during listening. This research carries significant theoretical and applied implications for understanding self-motion perception, postural stability, music psychology, and sound design, and may practically inform the creation of more immersive multimedia user experiences (such as in VR) and developing sound-based therapies for emotional regulation.</p
Optimising Radiation Exposure in Synchrotron Phase Contrast CT for Breast Imaging: A Patient-Specific Study
No full textBreast cancer remains the second leading cause of cancer-related deaths among women, and mammography contributes to a reduction of 30% in mortality rates. Recent advances in synchrotron-based phase contrast CT (PBCT) have shown significant improvements in image quality, and clinical trials at the Australian Synchrotron are set to begin in early 2025. This thesis evaluates the potential of synchrotron-based PBCT in the context of patient-specific dosimetry, comparing it with conventional imaging modalities. The study integrates both experimental and simulation-based approaches to assess how breast size, glandularity, and composition influence the radiation dose delivered during imaging.A custom breast phantom was developed that replicates the average breast size of the patient for dosimetric analysis. This allowed for a detailed examination of radiation exposure during both planar and 3D breast imaging procedures. The study also focused on determining the dose delivered to the breast using various monoenergetic X-ray energies commonly employed in PBCT. Radiation transport simulations, performed with the GEANT4 Monte Carlo toolkit, were used to model the mean glandular dose (MGD) for different breast anatomies. Experimental dosimetric measurements were conducted using ion chambers and the MOSkin™ dosimeter to provide a reliable basis for comparison.</p
The Unexpected Vection Hypothesis: Exploring New Relationships Between Vection, Postural Instability, and Cybersickness in Virtual Reality
No full textHead mounted display Virtual Reality (HMD-VR) systems use advanced computer technology to create immersive, simulated environments that allow users to experience the sensation of being physically present in a digital space. While VR is increasingly employed in entertainment, training, and therapeutic applications, its widespread adoption is hindered by cybersickness—a condition characterised by a range of adverse symptoms, including nausea, dizziness, and visual discomfort. Cybersickness, which shares similarities with motion sickness, is unique to virtual environments and presents a significant challenge to maintaining user comfort and immersion. One factor often argued to cause cybersickness is vection, the illusion of self-motion that occurs when large-field visual motion induces a sense of movement in a stationary observer. While vection can be a positive aspect of VR and enhancing the sense of presence and realism of virtual environments, the widespread belief that it plays a causal role in cybersickness has made it seen to be a problem that should be avoided. However, the precise nature of the relationship between vection and cybersickness remains unclear, with conflicting evidence suggesting that vection can either contribute to, have no effect on, or even mitigate cybersickness. This thesis aimed to address these inconsistences in the literature and identify exactly which types of vection (if any) contribute to cybersickness. It first outlined the ‘unexpected vection hypothesis', which proposes that cybersickness only occurs when these illusions of self-motion are perceived in ways that violate user expectations. This new theory of cybersickness was tested alongside the postural instability theory, which proposes that cybersickness occurs when users are unable to maintain stable control of their posture in response to conflicting visual/vestibular information. The thesis consisted of 4 experiments, where participants engaged with commercially available HMD-VR video games for up to 14 minutes. Across all of these experiments, the results consistently supported the notion that unexpected vection serves as a reliable and robust predictor of cybersickness occurrence and severity. In the first three thesis experiments (Chapters 2-4), active participants were instructed to play one of two video games (either Mission: ISS or Aircar), and their experiences of vection type and strength, as well as their cybersickness, were assessed. In all 3 experiments, cybersickness was found to increase with the strength of any unexpected (but not expected) vection. In the final thesis experiment (Chapter 5), participants were passively exposed to stereoscopic first-person 360° videos of pre-recorded gameplay (from Project Cars), with their experiences of vection (expected/unexpected) and cybersickness being assessed every minute throughout each exposure. Its different experimental conditions were designed to generate either more or less instances of unexpected vection. Consistent with the unexpected vection hypothesis, conditions which generated more instances of unexpected vection were also found to provoke more severe cybersickness (compared to conditions designed to favour the induction of smooth, expected vection). Importantly, reports of unexpected vection were also found to be linked to an increased likelihood of a subsequent rise in sickness severity, suggesting that unexpected vection preceded and likely caused this sickness. While postural instability also predicted sickness in some contexts, unexpected vection consistently emerged as the strongest predictor. These results challenge the assumption that vection is inherently problematic, demonstrating instead that its unpredictability—rather than its presence or strength alone—determines its impact on sickness. Managing unexpected vection—whether through anticipatory cues, improved motion predictability, or adaptive design strategies—may serve as a crucial intervention for reducing cybersickness and improving user comfort. Future work should investigate how cognitive and sensory processes interact to produce unexpected vection, explore its relationship with other motion cues, and test targeted mitigation strategies.</p
Pore-scale simulation of three-phase displacement in 3D porous media using advanced LBM: insights into CO2 enhanced oil recovery and storage
No full textCarbon dioxide enhanced oil recovery (CO2-EOR) is a promising technology that simultaneously increases oil production and facilitates CO2 sequestration, addressing energy and environmental challenges. This study develops an advanced multiphase lattice Boltzmann model to simulate CO2-water–oil displacement in three-dimensional porous media, incorporating realistic fluid properties and dynamic interfacial behaviors. By systematically analyzing the effects of water saturation (Sw), wettability (θ), and capillary number (Ca), the study reveals critical insights into optimizing oil recovery and CO2 storage efficiency. Results demonstrate that at lower water saturation (Sw = 0.4), enhanced oil phase connectivity leads to maximum oil recovery efficiency of 33.5 %, while higher water saturation (Sw = 0.8) facilitates CO2 storage, achieving a storage efficiency of 64.1 %. Wettability exhibits a dual regulatory effect: water-wet conditions maximize oil recovery, whereas oil-wet conditions enhance CO2 storage efficiency. Furthermore, increasing the Ca from −3.2 to −2.2 significantly improves oil recovery and CO2 storage efficiency, highlighting the importance of viscous forces in overcoming capillary barriers. The study introduces a novel Ca-θ-So/Sg color diagram, allowing precise quantification of oil recovery and CO2 storage efficiencies across varying wettability and Ca conditions. A binomial empirical formula for the color diagram enables rapid estimation of efficiencies, with R2 values exceeding 0.92. Notably, the nonlinear relationship between oil recovery and CO2 storage efficiency underscores the complex interplay of multiphase flow mechanisms. This work provides a robust theoretical framework and practical tools for reservoir engineering, offering actionable strategies for optimizing CO2 injection schemes and enhancing geological CO2 storage. These findings advance the understanding of multiphase displacement dynamics and establish a foundation for the further development of CO2-EOR and storage technologies.</p
On the Corporate-Governance Role of Investors’ Corporate Site Visits
No full textCorporate misconduct, such as tax avoidance, earnings management, and fraud, remains a significant concern in the global market, threatening corporate transparency, investor confidence, and market integrity. Traditional governance mechanisms, including legal regulations and internal controls, often fall short in detecting and preventing such behaviours, particularly in regions with weak legal systems or high information asymmetry. As a result, there is growing interest in the role of external monitoring mechanisms, such as investor site visits, in addressing these governance challenges. However, while the importance of site visits as a tool for reducing information asymmetry and improving corporate governance is increasingly recognised, empirical evidence on their effectiveness in mitigating specific corporate misconduct remains limited. In this thesis, I seek to address this gap by examining the impact of investor site visits on corporate tax avoidance, earnings management, and fraud, as well as exploring the mechanisms through which site visits influence these behaviours.Following the introduction chapter, the second chapter of this thesis focuses on the relationship between investor site visits and corporate tax avoidance. Tax avoidance, often viewed as a gray area of corporate behaviour, represents a deliberate attempt to reduce tax liabilities within the boundaries of the law, but can result in significant societal and governance concerns. This study investigates whether investor site visits, as an external monitoring mechanism, can serve as an effective tool to mitigate corporate tax avoidance by enhancing transparency and reducing information asymmetry. The study employs a range of regression models and robustness tests to analyse listed companies on the Shenzhen Stock Exchange and assess the impact of site visits on levels of tax avoidance. The findings reveal a consistent and significant negative relationship between site visits and tax avoidance, suggesting that the presence of external stakeholders actively engaging with firms curtails opportunistic tax-related practices. Furthermore, the study highlights that the mitigating effect of site visits on tax avoidance is more pronounced under specific conditions: when the visiting investors are from reputable institutions, when firms operate in weaker legal or information environments, and when the firms are non-state-owned enterprises. Importantly, the study also finds that reduced tax avoidance contributes to improved firm value, demonstrating the broader implications of investor site visits for corporate performance and market integrity.The third chapter explores the relationship between investor site visits and earnings management, providing insights into how site visits influence corporate financial reporting behaviours. Using firm-level data, the study finds that firms receiving site visits engage in significantly lower levels of both accrual-based and real earnings management compared to firms not visited. This suggests that investor site visits enhance corporate transparency and constrain managerial behaviours, reducing the likelihood of earnings manipulation. The study findings reveal that the frequency and depth of these visits correlate with reductions in earnings manipulation, highlighting the role of investor engagement as a crucial external governance mechanism. Furthermore, the study finds that the disciplinary effect of site visits is more pronounced in firms facing severe agency problems, where management has a higher incentive to exploit information asymmetry. Employing robust methodologies, including difference-in-differences analysis and two-stage least squares, the study establishes a causal relationship between site visits and improved earnings quality. This chapter contributes to the literature on corporate governance by elucidating the mechanisms through which investor interactions can mitigate information asymmetry and enhance corporate accountability.The fourth chapter investigates the role of investor site visits in mitigating corporate violations, analysing both preventive (ex ante) and corrective (ex post) effects. From the ex ante perspective, the findings reveal that site visits significantly reduce the likelihood of corporate violations by enhancing the information environment and deterring opportunistic behaviours. From the ex post perspective, the study demonstrates that site visits improve the efficiency of audits, reducing the time needed to detect and address violations that have already occurred. These dual effects underscore the comprehensive governance role of investor site visits in curbing corporate misconduct.The analysis also highlights regional differences, showing that the governance effect of site visits is more pronounced in areas with weaker legal environments, where external monitoring compensates for institutional deficiencies. By examining the mechanisms through which site visits influence corporate violations and exploring both preventive and corrective governance pathways, this chapter extends the understanding of site visits as an external governance tool. The findings provide important implications for regulators and policymakers, emphasising the potential of investor site visits to enhance corporate governance quality, improve market efficiency, and strengthen trust in capital markets.</p