85000 research outputs found
Sort by
Energy-aware Vehicle HVAC Control Strategies for Regulating In-cabin PMV and CO2 Levels
No full textAddressing the complexities of energy-efficient climate control within vehicle cabins, this thesis investigates innovative strategies for managing the heating, ventilation, and air-conditioning (HVAC) systems to optimise occupants’ thermal comfort and indoor air quality (IAQ), while minimising energy consumption. The research pivots around the Predicted Mean Vote (PMV) index and CO2 concentration as primary indicators of thermal comfort and IAQ, respectively.
The first contribution of this study is a comprehensive literature review focusing on common parameters in HVAC system design. It highlights PMV as a critical metric for assessing passenger thermal comfort and adopts CO2 levels to evaluate IAQ. Building upon this foundation, the thesis proposes a dual-focused control strategy to regulate both PMV and CO2 levels without significantly burdening the vehicle's energy resources.
Developing a fuzzy logic control (FLC) system is the second key contribution. This system is engineered to balance the often-conflicting criteria of maintaining PMV, stabilising CO2 concentration levels, and conserving energy. Existing vehicle HVAC FLC controllers primarily aimed to regulate thermal comfort and IAQ based on temperature and humidity. In other closed compartments like buildings and working environments, FLCs typically focused on either thermal comfort or IAQ. Only a few controllers managed to regulate both thermal comfort and IAQ while also considering energy consumption, often facing challenges in balancing all parameters simultaneously. In this research, FLC is designed to incorporate both PMV index and CO2 concentration into its control parameter with minimizing the energy consumption for vehicle HVAC systems. The advantage of the FLC lies in its low computational complexity, enabling efficient operations without requiring significant computational resources. This efficiency is crucial for vehicle HVAC systems, which need to respond rapidly to changes in passenger load and environmental conditions. MATLAB simulation results demonstrate the FLC's superiority over conventional threshold-based control methods, especially in adapting to manage CO2 levels based on passenger count. However, its design and calibration processes are acknowledged as time-consuming and complex.
To address these challenges, the third significant aspect of this thesis is creating a reinforcement learning (RL) based HVAC control strategy. Utilising deep deterministic policy gradient (DDPG) algorithms, this approach dynamically adapts to changing conditions. Comparative analysis under various simulated scenarios reveals the RL strategy's enhanced performance over the FLC method, particularly in its adaptability and efficiency.
Collectively, these strategies present a forward-thinking approach to vehicle climate control, promising to regulate PMV and CO2 levels effectively without incurring high energy costs. This advancement can extend the mileage of internal combustion engine (ICE) and electric vehicles (EV), marking a significant step in sustainable automotive technology.</p
Understanding Blockchain Mediated Changes and Tensions for Improving Traceability and Authenticity: The Food Industry Perspective
No full textThis study aims to understand how the implementation of blockchain in supply chains to achieve traceability and authenticity (TA) results in tensions and changes. Innovative technology blockchain is argued to enable TA and address various issues in the food supply chain. TA is a critical concern for supply chain networks, particularly the global food industry. Food fraud, information asymmetry, quality assurance, disruptions, counterfeited or contaminated products, tempering, different bacterial outbreaks, recalls, and other illegal practices spread due to lack of TA. While existing literature recognises the potential of blockchain to solve current supply chain issues, the resulting tensions and changes that blockchain can introduce in supply chain activities remain an afterthought. So far, most research is atheoretical and inclined toward how blockchain overcomes existing tensions in supply chain activities and neglects how it brings new tensions by demanding changes. This study empirically investigates the changes and tensions that might emerge in the TA activity of the supply chain network. Drawing on activity theory with in-depth qualitative interviews within organisations deploying blockchain implementation to enable TA in the network, this study develops new theoretical insights on how tensions emerge and how organisations handle the tensions to unfold further changes to achieve TA.
Data analysis revealed four major themes. Theme 1 focuses on the evolving categories driving blockchain implementation in the pre-implementation stage and reveals that blockchain implementation motivation is stimulated by three motivation categories including- resolving existing historical tensions, achieving organisational objects and unleashing blockchain benefits and product-centric blockchain implementation motivation. Theme 2 provides insight into emerging changes across all stages and activities with three categories of changes in supply chain activities: preliminary changes, operational changes and subsequent changes. Theme 3 delves into the new tensions arising from blockchain implementation across these stages and activities and points to five categories of tensions. These tensions categories are blockchain technical and data integration tensions, process-related tensions, incongruity-related tensions, governance and compliance-related tensions, and perceived value discrepancy tensions. Finally, Theme 4 categorises findings into solutions for resolving these tensions with two categories of solutions: organisational tensions resolving efforts ad expert recommendations.
The research findings make crucial multidisciplinary contributions to the blockchain literature, supply chain and traceability literature, workaround literature, and broadly to information systems literature on technological innovation. This study also makes theoretical contributions to activity theory. From insights on the changes and tensions through blockchain implementation, this study further makes practical contributions to the organisations implementing blockchain for TA, to blockchain providers in designing blockchain solutions, and to policymakers for governing the blockchain.</p
Design and Development of Serious Games for Accounting Education
No full textThis thesis describes the design and development of two gamified digital artefacts, a digital assessment artefact and a serious game. These digital artefacts were tested with undergraduate student participants to explore the extent to which they (a) improve student engagement and flow experience in various educational settings, and (b) reduced students’ cognitive loads when learning complex topics. Following design and development, the artefacts were pilot tested with undergraduate student participants.
This research extends cognitive load theory to the examination of how serious games design features can support accounting pedagogy. It contributes to the field of higher education through its development of pedagogical tools for use in the classroom. Both gamified digital artefacts are dynamic research vehicles that can be used for further behavioural and experimental research. By providing a stepped approach to the development of gamified artefacts, this research also enables accounting academics to design and develop their own digital innovations.</p
Direction-of-Arrival (DoA) Estimation Performance in Next-Generation Wireless Systems (5G and Beyond)
No full textThe Direction-of-Arrival (DoA) estimation method facilitates the accurate identification of signal origins, significantly enhancing the efficiency of communication systems. The need for precise and efficient DoA methods has increased due to their complex nature and broad applicability, which arise from varied signal environments, different source counts, and distinctive signal properties that impact accuracy. Evaluation techniques for DoA differ by application in methodology, efficiency, computational requirements, and accuracy, with specific approaches favoring speed and others emphasizing precision at more significant resource expense. Grasping these variations is essential for the optimization of communication system outputs.
This thesis evaluates the performance of DoA estimation methodologies inVehicleto- Everything (V2X) and Satellite Communication systems, emphasizing their application in Next-Generation Wireless technologies (5G and Beyond). The research focuses on integrating Multiple Antenna Systems and millimeter-wave (mm-wave) technologies, demonstrating how these innovations enhance the accuracy of DoA estimation, which is vital for effective localization, beamforming, and tracking functionalities. The work rigorously evaluates how adapting DoA estimation to high-frequency environments improves communication efficiency. It meticulously addresses the challenges of significant path-loss and shadowing effects in these domains, employing advanced beamforming techniques to ensure accurate DoA estimations of transmitting/receiving devices.
The thesis is methodically divided into four segments, providing essential insights for advancing communication systems. In the thesis’s first segment, the research identifies the critical obstacles in implementing the DoA estimation method for V2X applications within a multipath environment. Emphasis is placed on the necessity for precise channel-phase estimation and the consideration of spatial correlation amongst antenna elements, which can significantly enhance the performance of DoA estimations. As such, this initial part evaluates the performance of DoA estimation methods for V2X applications using 5G mm-wave frequency. The environment is characterized by multipath propagation, envelope fading, and spatial correlation. The assessment mainly aims at a single receiver system equipped with multiple antennas. In the thesis’s second segment, the research is expanded to a system with multiple receivers equipped with multi-antennas and leveraging the distinct traits of channel multipath propagation. The proposed model in this segment incorporates the receive diversity techniques and fuses the channel phase modeled as a random variable from the multi-receiver systems. This comprehensive approach markedly enhances the performance of DoA estimation for V2X applications by improving the signal-to-noise ratio (SNR).
In the thesis’s third segment, the investigation pivots to DoA estimation methodologies applicable to different satellite communications, such as Low Earth Orbits (LEO) and Geostationary Earth Orbits (GEO) systems. This part features the application of a closed-form expression that aids in accurately modeling the DoA angle. Besides, the research adapts a correlation model in the signal adapted explicitly to the study of DoA estimations. In the thesis’s fourth segment, the study’s scope extends to exploring DoA Root Mean Square Error (RMSE) performance in satellite downlinks involving multiple targets. A vital aspect of this analysis is the consideration of spatial correlation effects, which have been identified as adversely impacting RMSE performance in multi-target DoA estimation methods for closely spaced targets. A comprehensive model of a multi-target system incorporating spatial correlation within a satellite downlink scenario is presented. Moreover, the research examines how the accuracy of the DoA method, as quantified by RMSE, is affected by the varying distances between targets, particularly under different Signal-to-interference-plus-noise ratio (SINR) conditions. These investigations are crucial to understanding the precision of error estimation in multi-target DoA estimations for satellite communication systems.
This thesis introduces innovative advancements in DoA estimation by exploring various system configurations that enhance the robustness and scalability of techniques across diverse environments. It focuses on improving accuracy and efficiency, which is crucial for advancing modern communication systems. The findings, validated through computer simulations and Monte Carlo analysis, contribute significantly to DoA estimation performance, particularly in Next-Generation Wireless Systems (5G and beyond). Additionally, the findings presented in this thesis have been published in peer-reviewed journals, presented at conferences, or are currently under review, as detailed in the respective chapters of the thesis. Lastly, The authors hope this work will provide valuable insights and contribute meaningfully to the advancement of DoA estimation in 5G Networks and future wireless technologies.</p
VR-BESO: A VR-based structural design tool
No full textVR-BESO is a novel interactive structural design tool based on virtual reality (VR). This tool integrates VR sculpting and topology optimisation techniques to generate innovative, lightweight, and efficient 3D structural designs. VR-BESO allows designers to immersively and intuitively observe and interact with 3D models. By alternatively using VR sculpting and executing topology optimisation, a human–computer collaboration is established to improve the efficiency of design exploration and the quality of optimised structures.</p
Solid-liquid interfacial nanostructure of ionic liquids and deep eutectic solvents
No full textNeoteric solvents such as ionic liquids and deep eutectic solvents have many potential applications in numerous fields, from drug delivery to catalysis. However, to optimize these solvents for specific applications, their nanostructure, in particular at the interface, must be understood.
The following chapter summarizes our current understanding of ionic liquid- and deep eutectic solvent-interfacial nanostructure, with a particular focus on the solid interface. The techniques used to explore interfacial nanostructure are also discussed, with the advantages and disadvantages of each highlighted.
Ultimately both ionic liquids and deep eutectic solvents exhibit strong nanostructure, both in the bulk and at the interface. However, this nanostructure is influenced by the solvent components, and their particular interactions, as well as by the specific substrate and its surface charge. Thus, the solid–liquid interfacial nanostructure of neoteric solvents is complex, and as this chapter highlights, requires further research
Recent Trends in Sustainable Clothing and Textile Manufacturing
No full textManufacturing of clothing and textiles are considered to be at odds when sustainability is considered. The three pillars of sustainability are breached in the supply chain process of clothing and textiles. Environmental pollution, excessive resource use, generation of large amount of waste, greenhouse gas generation, excessive chemical use, child labour and forced labour are some of the problems associated with the manufacturing of clothing and textiles. This chapter focuses on various approaches that can be implemented to become sustainable in the supply chain process of clothing and textiles. Some of these approaches include the use of newer technologies such as laser, RFID (Radio Frequency Identification), carbon dioxide dyeing, air dyeing and ozone applications; use of eco-friendly processes; and waste management to reduce the environmental impacts. Furthermore, the use of lean principles to reduce in the process waste and materials waste will also be discussed in brief. Some examples from the global fashion brands are also included in this chapter. Finally, the approaches taken during sewing operations such as energy saving and waste management have also been discussed in detail
Vietnam Digital Music Landscape 2024
No full textIn the times of exploding digital entertainment and media, the music industry in Vietnam is inevitably at its peaking
era in both quantity and quality. As such, digital music reflects momentum growth with diversity in music products,
derivate services, and support from music labels, distributors, and enablers. This shapes the new generation of
music with talented artists, unique forms of digital music performances, and unique content formats.
The emergence of the digital music industry in Vietnam requires an overview report to summarize the overall
landscape of the contemporary music market and future development trends. What are the factors driving the
digital music market's success? What are the advanced music business models based on disruptive technology?
What are the next trends for development in this industry? The report "Vietnam Digital Music 2024: Transformation,
Trends & Potentials" conducted by the research team of the School of Communication and Design at RMIT
University Vietnam will provide the latest overview of the Vietnamese musicscape and forecast the industry's
development trends in 2024.
Dr. Long Nguyen
Comparative evaluation of gold nanoparticles as contrast agent in multimodality diagnostic imaging
No full textA contrast agent is clinically employed to aid the visualization of organs and structures when imaged by radiation based diagnostic imaging modalities. Iodinated contrast agents have been used for decades, but they carry a heightened risk of adverse allergy reactions and contrast-induced nephropathy. This study investigated the contrast enhancement characteristics of gold nanoparticles (AuNPs) through diverse cancer diagnostic imaging modalities as a potential alternative to the iodine-based contrasts. Solutions of 1.9 nm and 15 nm AuNPs, ranging from 3 to 20 mM concentrations, were prepared, alongside a low osmolar non-ionic iodine contrast agent as a control. All samples were scanned and imaged using x-ray computed tomography scanner (CT-Scan), digital mammography, digital radiography, and fluoroscopy modalities. The contrast-to-noise ratio (CNR) was measured to study the relationship between the size, the concentrations, and the influence of the tube voltage over the image contrast enhancement efficacy of the agents. A lower concentration of AuNPs produced lower CNR values. In addition, the 1.9 nm size of AuNPs caused lower CNR than the 15 nm AuNPs when tested with the highest concentration of 20 mM. High CT's HU values for both sizes of AuNPs indicated substantial contrast enhancement compare to iodine. Although the 15 nm AuNPs might set off higher CNR, a better quality of image contrast enhancement was also observed compared to the 1.9 nm AuNPs. The findings also suggested that the contrast enhancement by AuNPs is highly dependent on the modalities' type and x-rays energy. In conclusion, AuNPs could be applied as a contrast agent in various diagnostic imaging modalities representing promising approach in cancer detection particularly in cases of patients having adverse reactions towards the iodine based contrast agents.</p