157082 research outputs found
Sort by
Modeling Trust Dynamics on a Multi-Agent System
No full textThis paper introduces a preliminary agent-based model designed to simulate trust dynamics within a multi-agent scenario where virtual agents navigate unknown environments. The objective is to investigate how trust influences agent performance when they rely on an external source of information, referred to as a robot, versus relying on their peers. In the model, the robot explores the environment and reports the costs associated with different paths. Agents are categorized as either trustful or skeptical, deciding whether to trust the information provided by the robot or rely on their fellow agents. We evaluate three distinct scenarios: No Robot (baseline exploration), Immediate Start (simultaneous exploration by the robot and agents), and Early Start (robot-initiated exploration preceding agents’ involvement). Evaluation metrics include the number of agents successfully reaching the exit, exit times, and path costs. Our findings demonstrate significant advantages associated with the presence of the robot, particularly when exploration begins early. Trustful agents show improved performance by optimizing both the number of successful exits and the efficiency of path selection, resulting in reduced exit times and path costs.</p
In Situ Extrusion Processing of Treated and Untreated Pineapple Leaf Fibre-Reinforced PLA Composites for Improved Impact Performance
No full textMaterial extrusion (MEX) 3D-printed parts are primarily used for prototyping rather than functional components due to lower mechanical strength. To address this limitation and promote sustainability, current work explores the reinforcement of plant-based polylactic acid (PLA) with pineapple leaf fibre (PALF). An in situ approach was proposed to embed continuous PALF within the middle layer of a 3D-printed component during the MEX process. An experimental investigation was conducted to evaluate the impact performance of composites produced via this new fabrication method. To optimize the fibre–matrix interface, an alkaline treatment was applied to the natural fibre, enhancing interfacial adhesion. Neat PLA, along with two types of PALF-reinforced PLA composite, were printed with both single-strand and three-strand fibre configurations. Fracture surfaces were analyzed under a digital microscope and a scanning electron microscope (SEM) to correlate morphological characteristics with the impact strength. The results showed that the impact strength of the three-strand treated PALF-PLA composite (3 PALF-PLA) surpassed that of neat PLA by 2.71% due to reduced porosity. In contrast, the one-strand PALF-PLA composites exhibited lower performance compared to neat PLA due to the presence of the fibre gap caused by the mid-print pause. Treated fibres consistently outperformed untreated ones due to their rougher surface morphology resulting from alkaline treatment. The results demonstrate that the combination of alkaline treatment and continuous fibre reinforcement significantly enhances energy absorption of 3D-printed MEX parts and offers a sustainable pathway for 3D-printed MEX parts
A Feasibility Study to Practically Implement a High-Performance Circularly Polarised Antenna Array for Point-to-Point Wireless Communication
No full textThis article presents the design, fabrication and experimental validation of a compact linear series-fed microstrip antenna array with dual circular polarisation (CP) capability. The proposed structure consists of a (Formula presented.) slotted circular patch array excited via four microstrip lines using a coplanar proximity coupling technique. Dual-CP operation is achieved through two miniaturised and distinct microstrip power divider networks, enabling the generation of either left-hand or right-hand CP based on the excitation port. To maximise gain and efficiency, the design reduces feedline branching and employs optimised slotted patch elements, resulting in low power loss and high radiation efficiency. The antenna achieves a realised peak gain of 19.4 dBic across 12.2–12.7 GHz and a 3-dB axial ratio bandwidth from 11.9 to 13.1 GHz. Simulation and measurement results demonstrate excellent agreement. Thanks to its compact size, wide bandwidth, dual-CP functionality and high gain, the proposed antenna offers a promising solution for point-to-point wireless communication systems. Compared to existing multi- and single-layer microstrip-based CP arrays, this work introduces a simplified feed structure and improved performance, demonstrating clear advancement in antenna array design.</p
The influence of the menstrual cycle on muscle injuries - a systematic review and meta-analysis
No full textThis systematic review and meta-analysis examined the relationship between menstrual cycle phases and the incidence of muscle injuries in female team sport athletes, following PRISMA 2020 and PERSiST guidelines. A comprehensive search was conducted in PubMed, Scopus, and SPORTDiscus from inception to mid-January 2024. Studies were included if they examined female team sport athletes of reproductive age with regular menstrual cycles and compared the occurrence of muscle injuries across at least two menstrual phases. Studies involving hormonal contraceptive use, medications affecting the menstrual cycle or musculoskeletal system, or menstrual dysfunction were excluded. Three studies met the inclusion criteria, involving 318 participants. Meta-analysis yielded a pooled Risk Ratio of 1.18 (95% CI: 0.75 to 1.86, p = 0.46) for injury risk between the luteal and follicular phases, suggesting no statistically significant association. However, the certainty of the cumulative evidence was rated as very low due to methodological limitations, including inconsistent phase classifications and reliance on imprecise methods for identifying menstrual phases. Consequently, no practical or clinical recommendations can be made at this time. Future research employing standardised, physiologically accurate methods for classifying and detecting menstrual cycle phases is necessary to better understand the potential links between hormonal fluctuations and injury risk
Renewable energy strategies for achieving net zero
No full textThe increasing risk of climate change has further strengthened global initiatives to achieve net-zero carbon emissions through a strategic transition away from fossil-fuel-based systems toward sustainable ones. This chapter critically evaluates renewable energy strategies based on policy integration, technology push, economic instruments, and stakeholder engagement, to enable the transition. The study aims to identify the conditions that favour successful deployment, analyse infrastructure requirements, and develop an overall framework for achieving net-zero goals. The research employs a multidisciplinary approach that combines techno-economic analysis, policy analysis, and strategic planning models. Empirical evidence shows that countries that invested over 3% of their gross domestic product in renewable infrastructure achieved grid decarbonization at a 22% higher transition rate. The application of integrated energy-storage systems enhanced grid stability by 30% and reduced curtailment by 17%. Public-private partnership-based implementation projects finished financing 30% earlier and reported an 8–15% ROI, depending on the technology. Additionally, nations that adopt smart grid and predictive maintenance technologies reduce downtime by up to 35%. This chapter is innovative for synthesising socio-political, economic, and technological factors within a single analytic framework, addressing gaps left by previous literature that focuses on independent dimensions. The solutions presented are adaptable both geographically and developmentally, serving as a practical guide for different stakeholders. The outcomes provide actionable insights for designing scalable, resilient renewable energy systems in line with the Sustainable Development Goals (SDGs). Future applications include optimising hybrid energy systems, enhancing AI-driven decentralised grid efficiency and establishing region-specific transition models. The value of this work lies in converting strategic visions into measurable avenues towards achieving a net-zero sustainable future worldwide
From fabric to process: An integrated study of deformed quartz-rich carbonates
No full textThis study investigates the presence and nature of diffuse deformation in a low-porosity carbonate rock that underwent polyphase tectonics and contains a network of veins, tectonic stylolites, and deformation bands. By using a non-destructive methodology based on Electron Backscatter Diffraction, X-ray computed tomography, coupled with results from Anisotropy of Magnetic Susceptibility and the Fry technique, we examine the grain fabric and strain distribution within the rock. Our investigation reveals evidence of quartz reorientation with respect to the polyphase contractional history of the area. Several mechanisms of quartz reorientation were proposed, including rigid reorientation during rotation and diffusion-related processes. The coexistence of ductile and brittle deformation mechanisms in the carbonate matrix indicates a complex response to compaction which can be recorded by the matrix, but does not appear to have a direct effect on the actual amount of shortening, as this is predominantly affected by the deformation bands. Our findings highlight the complexity of strain accommodation, with diffuse deformation creating subtle variations in grain size, shape, and orientation within the carbonate matrix. The study enhances our understanding of deformation processes in poly-deformed carbonate rocks and provides valuable insights into the geological context of the studied locations, by using a novel technique that can be useful for gaining qualitative and quantitative information from the rock samples. However, linking specific reorientation mechanisms to individual tectonic events remains challenging due to the multifaceted nature of deformation processes operating over different magnitudes and timescales
A novel approach to balancing stakeholder interests in construction waste landfill charges for advancing a circular economy
No full textLandfill charging schemes effectively reduce construction and demolition waste (C&DW) sent to landfills, advancing the global circular economy. Their success, however, depends on scientifically sound charging standards. Current methods for setting landfill charges largely rely on waste generators’ willingness to pay, with little consideration for landfill operators’ interests. To address this gap, this study proposes a novel, stakeholder-inclusive approach to develop waste landfill charging standards. Distinct from methods centered on willingness to pay, this approach integrates both generators’ cost considerations and operators’ revenue needs, alongside market realities (e.g., costs of alternative disposal facilities, transportation expenses). It comprises four progressive steps: (1) identifying the generation area and specific locations of the C&DW to be landfilled; (2) calculating the total disposal costs at alternative facilities; (3) estimating transportation costs from waste sources to the target landfill; (4) determining the final charging standard by balancing cost-efficiency for generators and operational sustainability for operators. Validated through a case study of the Litoushan Landfill in Shenzhen, China, the approach yielded an optimal charging standard ranging from CNY 106 to CNY 112/m3. This method provides a valuable, and actionable reference for policymakers worldwide to establish evidence-based C&DW landfill charging standards, strengthening waste management practices globally. Additionally, its adaptable framework can be extended to determine charging standards for other waste types (e.g., municipal solid waste, industrial solid waste), further supporting the global transition to a circular economy
Neural Network Verification for Gliding Drone Control:A Case Study
No full textAs machine learning is increasingly deployed in autonomous systems, verification of neural network controllers is becoming an active research domain. Existing tools and annual verification competitions suggest that soon this technology will become effective for real-world applications. Our application comes from the emerging field of microflyers that are passively transported by the wind, which may have various uses in weather or pollution monitoring. Specifically, we investigate centimetre-scale bio-inspired gliding drones that resemble Alsomitra macrocarpa diaspores. In this paper, we propose a new case study on verifying Alsomitra-inspired drones with neural network controllers, with the aim of adhering closely to a target trajectory. We show that our system differs substantially from existing VNN and ARCH competition benchmarks, and show that a combination of tools holds promise for verifying such systems in the future, if certain shortcomings can be overcome. We propose a novel method for robust training of regression networks, and investigate formalisations of this case study in Vehicle and CORA. Our verification results suggest that the investigated training methods do improve performance and robustness of neural network controllers in this application, but are limited in scope and usefulness. This is due to systematic limitations of both Vehicle and CORA, and the complexity of our system reducing the scale of reachability, which we investigate in detail. If these limitations can be overcome, it will enable engineers to develop safe and robust technologies that improve people’s lives and reduce our impact on the environment.</p
The Effect of Sewer-Derived Airflows on Air Pressure Dynamics in Building Drainage Systems
No full textThe performance of a building drainage system, “BDS”, is determined by the complexity of internal airflow and pressure dynamics, governed by unsteady wastewater flows from randomly discharging appliances such as WCs, sinks, and baths. Designers attempt to optimise system safety by equalising pressure and incorporating ventilation pipes and active devices such as AAVs and positive pressure reduction devices (PPRDs). However, failures within these systems can lead to foul gases and potentially hazardous microbes entering habitable spaces and posing a risk to public health. This study, for the first time, develops a novel model that simulates the effect of air from the sewer on BDS performance, which describes the correlation between system airflow and air pressure under the influence of air from the sewer. A combination of full-scale laboratory experiments representing a 3-storey building and real-world data from a 32-storey test rig configured as a building demonstrated that sewer air significantly modifies airflow and air pressure within a BDS. These findings are crucial for modern urban environments, where the prevalence of tall buildings amplifies the risks associated with air pressure transients. This work paves the way for updating codes to more effectively address real-world challenges
Cultural transmission of attitudes and behaviours from parents, peers and grandparents
No full textThis study investigates how attitudes and behaviours are transmitted across generations and social networks, focusing on the relative influence of parents, grandparents, and peers. Building on the influential work of Cavalli-Sforza and Feldman (1982), we aimed to disentangle vertical and horizontal pathways of cultural transmission and assess their contribution to the stability and variation of cultural traits in a contemporary population. We conducted a large-scale survey involving 1905 university students in Australia and 4000 of their parents, grandparents, and friends. Participants reported their attitudes and behaviours across domains such as religiosity, politics, environmentalism, health, and leisure. Responses were analysed using factor analysis, path modelling, correlational analysis, and simulations based on additive transmission models. Our results show that cultural resemblance is strongest for religiosity, political orientation, environmentalism, and health behaviours. These traits exhibited clear vertical transmission from parents to children, with additional indirect influence from grandparents. Peer similarity was also evident, suggesting horizontal transmission and/or peer selection. Traits such as media use, music, and reading habits showed weaker familial resemblance and appeared more influenced by non-familial or contextual factors. Simulations confirmed that cultural traits are more likely to be adopted when shared by both parents and peers, though for some traits (especially left-wing political views and non-religiosity) external influences predominated. The findings demonstrate that cultural transmission is domain-specific and shaped by both family structure and social networks. Vertical and horizontal pathways contribute jointly, but their strength varies by trait. These results underscore the importance of integrating biological, psychological, and sociocultural factors to understand the persistence and evolution of beliefs and behaviours over generations
Access Repository Dashboard
Do you manage Heriot Watt Pure? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!