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Design of method for controlling temperature in a central solar thermal receiver
No full textEmpirical thesis.Bibliography: pages 70-73.1. Introduction -- 2.Background -- 3. The squircle -- 4. The mechanism -- 5. Analytical methodology -- 6. Experimental methodology -- 7. Results and discussion -- 8. Conclusions and future work -- 9. Abbreviations -- Appendix -- Bibliography.A novel method for controlling the temperature in a cenrtral cavity solar reciever has been developed. The solution consists of an aperture control mechanism, altering the size of the window through which solar radiation can enter the receiver. It uniquely utilises the circle-like properties of a squircle to form the aperture, leading to a simple yet effective mechanism with motion facilitated by planetary gears and cam-follower pairs. The design has been validated and illustrated through the use of 3-dimensional computer models and prototype construction. Using analytical and experimental data, it has been demonstrated that this mechanism is able to control temperature in a mock receiver as intended. This has the potential to work with existing concentrated solar thermal (CST) technology to bring an effective source of energy to remote communities as well as make existing processes more efficient. Improvements that can be made with future work, such as automation, increased manufacturability and more appropriate materials are also discussed.Mode of access: World wide web.1 online resource (x, 73 pages colour illustrations
Quantitative determination of hypoxia in tumours using MRI for adaptive radiotherapy
No full textEmpirical thesis.Bibliography: pages 63-64.1. Introduction -- 2. Literature review : basic principles of an MRI -- 3. Literature review : cancer, hypoxia and oximetry -- 4. Project model and methods -- 5. Results and discussion 6. Conclusion and future works -- Bibliography -- Appendices.Hypoxia can be defined as the condition in which the body or areas of the body are lacking in adequate supply of oxygen at the tissue level. The condition is not common in normally functioning tissue but frequently appears in tumours and is often described as a characteristic feature of tumours.Tumour hypoxia can originate by means of perfusion, diffusion or anaemia related causes. It is known that the vasculature of tumours is distorted due to inefficient blood flow inside the tumour. As a result the oxygenation status of a tumour varies considerably.It is known that hypoxic regions are three to four times more resistant to radiotherapy as compared to normoxic tumour cells. Therefore in the treatment of cancer, treatment plans need to be designed that take into consideration tumour specific biological data on an individual basis. In order to achieve this, more quantitative data is needed such as cellular density, oxygen concentrations, vascular density, blood fractions, and so on. Therefore, this thesis discussed the methods involved in the quantitative determination of hypoxia in tumours using Magnetic Resonance Imaging (MRI) so that efficient radiotherapy treatment may be administered to cancer patients.Mode of access: World wide web.1 online resource (xiii, 83 pages colour illustrations
Elliptic curve cryptographic protocols: a simulation and implementation of ECDSA and ECDH
No full textEmpirical thesis.Bibliography: pages 205-207.1. Introduction -- 2. Topic background -- 3. Mathematical background -- 4. Modelling ECC protocols -- 5. VHDL implementation -- 6. VHDL simulation -- 7. Future work -- 8. Abbreviations -- BIbliography.Elliptic curve cryptography provides a secure means of implementing the Digital Signature Algorithm protocol through the Elliptic Curve Digital Signature Algorithm scheme. The ECDSA upholds the data security objectives of information authentication and non-reputability. Similarly, the Elliptic Curve Diffie-Hellman upholds information confidentiality and information integrity, are expensive to implement up to certain security standards, with timeliness and size of circuit required to perform either scheme being the main considerations. To have any appreciable speed, they must be implemented in digital hardware design. This project outlines the design methodology and procedure of simulating a generalisable implementation of an Elliptic Curve Cryptographic Processor, able to effectively utilise both the ECDH and ECDSA, over any chosen bit length.Mode of access: World wide web.1 online resource (xvii, 207 pages diagrams
Raspberry ketone as a promising pre-release supplement for the Sterile Insect Technique (SIT) of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)
No full textThesis by publication.Bibliography: pages 15-29, 32-33, 68-75, 94-102, 131-139, 167-176, 192-197 and 207-217.Chapter One: General introduction -- Chapter Two: Raspberry ketone supplement promotes early sexual maturation in male Queensland fruit fly, Bactrocera tryoni (Diptera: Tephritidae) -- Chapter Three: Raspberry ketone supplement accelerates reproductive organ development of Queensland fruit fly, Bactrocera tryoni (Froggatt) -- Chapter Four: Sexual inhibition of female Queensland fruit fly Bactrocera tryoni (Froggatt) mated by young raspberry ketone supplemented males -- Chapter Five: Do raspberry ketone supplements provided to immature Queensland fruit fly Bactrocera tryoni (Froggatt) change sex pheromone quantity or composition? -- Chapter Six: Raspberry ketone feeding affects the tolerance of Queensland fruit fly Bactrocera tryoni (Froggatt) to nutritional and desiccation stress -- Chapter Seven: Suppression of cuelure attraction in male Queensland fruit fly Bactrocera tryoni (Froggatt) provided raspberry ketone supplements as immature adults -- Chapter Eight: General discussion.Queensland fruit fly, Bactrocera tryoni Froggatt (Qfly) (Tephritidae), Australia’s most economically damaging fruit fly, infests more than 100 hosts including many commercially important crops. Control of this pest is based on insecticides, bait sprays, male annihilation technique (MAT), and in some regions sterile insect technique (SIT). SIT can be a highly effective control method, and is used around the world to control some of the worst fruit fly pests, but high field mortality of the sterile flies can constrain the success of Qfly SIT. Improved quality of released males and acceleration of sexual maturation can help to overcome this problem. In this thesis I investigated potential beneficial effects of supplementing immature Qflies with raspberry ketone (RK), a metabolic enhancer. RK was mixed with the diet for 48 hours, a duration consistent with standard pre-release holding periods.When RK was provided together with yeast hydrolysate (YH), RK-fed males exhibited accelerated development of reproductive organs and increased mating propensity when 6 - 9 days of age. Positive effects of RK were not evident in males that were fed only sugar, and no positive effects of RK were evident for female development regardless of diet. As sex pheromone plays important role in calling and courtship, I investigated effects of RK on pheromone production. RK-fed males produced significantly more pheromone, and RK was detected in the pheromone blend. Increased pheromone production and presence of RK in pheromone blend may be an important factor in elevated mating propensity of RK-fed male Qflies. While mating is an important step in SIT, female remating behaviour is also important as females that mate with a released male and then a wild male will likely retain fertility. Females that mated with RK-fed males, including during the period of accelerated development, exhibited remating tendency that was similar to females mated by control males. That is, not only does RK feeding increase development rate and early mating propensity of male Qflies, the early matings of RK-fed males are of undiminished effectiveness. SIT could potentially be greatly enhanced if combined with MAT, and my studies have identified a potential new way to enable this. In some other Bactrocera, mature males that feed on lures are then unresponsive to lures for substantial periods, and so would not be attracted to MAT devices. However, combination of SIT and MAT has been considered unsuitable for Qfly owing to long adult maturation period and high mortality in attempts to hold the flies to maturity before release. I found that RK-fed males exhibit a persistent reduction in responsiveness to cuelure traps, opening the possibility of simultaneous MAT and SIT application in Qfly control programmes. In addition to considering potential beneficial effects of pre-release RK supplements it is also important to consider potential drawbacks for survival. When a source of protein + sugar was available throughout life, RK supplements did not affect survival. However, RK supplements did increase susceptibility to desiccation and food deprivation in the period immediately following pre-release treatment. This thesis comprises the first series of studies to consider RK as a potential pre-release treatment for SIT in the context of a standard 2 - 3 day pre-release holding period. The substantial beneficial effects of RK supplements on development, mating, and lure response support a strong case for further investigation and consideration for trial deployment on operational SIT programs.1 online resource (v, 218 pages
Working age population and regional economic growth in China
No full textEmpirical thesis.Bibliography: pages 61-62.1. Introduction -- 2. Literature reviews -- 3. The Chinese economy -- 4. Theoretical framework -- 5. Descriptions of data -- 6. Empirical results and discussions -- 7. Concluding remark and limitations -- 8. References -- 9. Appendix.This thesis examines the effects of changes in the working-age population on the regional economic growth of China, using provincial-level panel data from 1996 to 2015. The empirical model is based on the Solow’s economic growth model, where the key determinants of economic growth are capital intensity per labour, savings rate, and population growth. The model is estimated using the fixed-effects estimator with Mundlak-device and the Arellano-Bond method to overcome the endogeneity of labour and population. The share of working age population growth and employment growth both have significant and positive effects on the economic growth. The empirical evidence supports the hypothesis that demographic factors are one of the key factors that could explain the differences in regional economic growth.Mode of access: World wide web1 online resource (70 pages) colour map
Assessment of anxiety in children and adolescents including children with Autism spectrum disorder
No full textEmpirical thesis."Submitted for the degree of Doctor of Clinical Psychology/Master of Philosophy in Psychology" -- title page.Includes bibliographical references.Chapter 1. General introduction -- Chapter 2. Assessment of anxiety in children and adolescents : a comparative study on the validity and reliability of the Spence Children’s Anxiety Scale in children and adolescents with anxiety and Autism Spectrum Disorder -- Chapter 3. Development of the Macquarie Anxiety Behavioural Scale (MABS) : a parent measure to assess anxiety in children and adolescents including young people with Autism Spectrum Disorder -- Chapter 4. General discussion.Children and adolescents with Autism Spectrum Disorder (ASD) are at increased risk of anxiety disorders. Current assessment measures used to assess anxiety in children with ASD are standardized for neurotypical children posing a limitation to accurate assessment of anxiety in children with ASD. The aim of this thesis was to assess suitability of a currently used measure to assess anxiety in children and adolescents with ASD as well as to develop a new and improved parent measure to assess anxiety in children and adolescents with and without ASD. The thesis is comprised of two separate papers utilising two different samples (Study 1: N = 426; Study 2: N = 734). In study one, the measurement invariance of the Spence Children’s Anxiety Scale (Parent Form, SCAS-P) in a sample of children with anxiety or ASD was assessed. It was hypothesised that the SCAS-P would perform differently in the ASD population than it did in the anxious population. Study two replicated findings of measurement variance for ASD in the SCAS-P in a new sample and also developed and evaluated a parent report measure for anxiety that will be suitable for clinical and non-clinical populations of children and youth including children with ASD. The newly developed measure, the Macquarie Anxiety Behavioural Scale (MABS) focuses on observable cognitive, behavioural and physiological symptoms of anxiety in children and adolescents including individuals with ASD. A confirmatory factor-analytic approach was used to establish the factor structure of the MABS and assess measurement invariance of the SCAS-P and MABS across a group of children with anxiety and ASD in Study 1 and a different group of children with and without ASD in Study 1. Both studies demonstrated measurement variance (difference) for both the SCAS-P and the MABS indicating that at least parts of both parent measures cannot be interpreted in the same way in an ASD population compared to typically developing children. The findings build upon a growing body of evidence which indicates that anxiety may present differently in young people with ASD compared to typically developing children and youth. Future research can utilise findings from the present studies to refine and further develop an assessment measure that will be useful for children and adolescents including children with ASD.Mode of access: World wide web1 online resource (x, 124 pages) table
Multi-channel routing protocols for wireless body area networks
No full textEmpirical thesis.Bibliography: pages 211-237.1. Introductionn -- 2. Literature review -- 3. A multi-channel routing protocol based on RSSI channel selection for wireless body area networks -- 4. A multi-channel routing protocol based on LQI channel selection for wireless body-area networks with mobile nodes -- 5. A multi-channel routing protocol based on a diversity path metric for wireless body-area networks -- 6. A multi-channel routing protocol based on remaining energy and link quality for wireless body-area networks --7. Thesis conclusion and future work -- Appendix --References.Wearable sensors connected through Wireless Body Area Networks (WBANs) have emerged as a promising enabling technology for many healthcare applications in recent years. A WBAN utilises wearable sensors on the human body to route information between a sensor and a central control unit (CCU) which can be connected to remote stations for further analysis. The routing schemes used in WBANs face challenges due to limited energy and excessive traffic overhead constraints. Most routing protocols for WBANs use a single-channel which limits network performance in terms of interference among links, throughput, end-to-end delay, and congestion. As opposed to single-channel communication, multiple channels increase the number of paths that can be active simultaneously between nodes and increase bandwidth capacity with reduced inter and intrachannel interference. Multi-channel routing protocols can overcome many of the limitations mentioned above for single-channel routing protocols improving traffic congestion, energy consumption, network lifetime, and link stability. However, several challenges still need to be solved when utilising multiple channels, such as channel selection methods for multiple routes and optimising routing metric. In this thesis, various multi-channel routing protocols have been proposed for WBANs to improve the performance over traditional single-channel protocols commonly used in WBANs. Firstly, the thesis develops multi-channel versions of existing routing protocols, such as single-path, single-channel AODV (Ad-hoc On-demand Distance Vector) and REL (Routing based on Remaining Energy and Link quality indicator) to overcome bottlenecks at intermediate nodes. Secondly, new performance metrics are proposed such as a channel-diversity metric named Weighted Multi-Channel Hop-Count (WMHC) and a lexical composite metric named Dual-CHannel REL (DCHREL) for route selection combining hop count, link quality, and nodes residual energy. Lastly, channel selection methods based on Link Quality Estimators (LQEs) such as Link Quality Indicator (LQI) and Received Signal Strength Indicator (RSSI) for static as well as mobile nodes are proposed, which outperform random channel selection in WBANs with a small number of channels.The implementation of the proposed multi-channel routing protocols was carried out in the OMNet++ based Castalia. Simulation results show that the multi-channel routing protocols with the LQE based channel selection at network layer outperform their corresponding single-channel protocols. Similarly, it is shown that the multi-channel routing protocols with the LQE based channel selection efficiently utilise multiple channels to reduce the number of retransmissions needed for route establishment and data forwarding. Moreover, significant improvements in network performance are observed in terms of packet delivery with less control overhead, routing stability in the presence of link fluctuations caused by mobility, and less co-channel interference with balanced and low energy consumption.Mode of access: World wide web1 online resource (xxii, 237 pages) diagrams, graphs, table
The relationship between teaching presence and online instructor satisfaction in an online teacher training program
No full textTheoretical thesis.Bibliography: pages 82-88.Chapter 1. Introduction -- Chapter 2. Background -- Chapter 3. Literature review -- Chapter 4. Methodology -- Chapter 5. Results -- Chapter 6. Discussion -- Chapter 7. Conclusion -- Bibliography -- List of appendices.As the number and frequency of online programs being offered in higher education continue to increase, so too does the amount of research dedicated to examining and exploring their impact on learners and learner outcomes. Yet in the literature there is less research dedicated to examining instructor outcomes in online programs, especially with regard to the feelings and perceptions of satisfaction instructors derive from their online teaching.This thesis reports the results of a case study that examined a cohort of instructors engaged in synchronous, online videoconference instruction in a graduate teacher training program at a mid-sized private university in Seoul, South Korea. Using a mixed methods approach, instructor responses gathered from interviews, the Online Instructor Satisfaction Measure, and observation of videoconference lessons were triangulated to establish whether or not a relationship might exist between teaching presence and instructor satisfaction with the aim of describing that relationship.Overall, the findings presented in this thesis represent an exploration into the impact of instructor satisfaction on teacher actions in online videoconference contexts. In addition to finding that satisfied instructors show more teaching presence indicators than instructors who are not satisfied, two related issues emerged from the case study that have implications for future research. First, the overall context of the teaching program must be taken into account when describing online teaching and learning. Second, existing indicators of teaching presence based on text-based instances of online teaching may need to be revised to take into account the increased volume of synchronous, videoconference lessons that are quickly becoming mainstream in online teaching and learning.Mode of access: World wide web1 online resource (108 pages) diagrams graphs, table
A chronological investigation of the Middle Kingdom tombs at Meir
No full textTheoretical thesis.Bibliography: pages 280-294.Chapter One. Overview and scope -- Chapter Two. Theory and methodology -- Chapter Three. Chronological framework : analysis of texts -- Chapter Four. The Meir tombs : architecture and archaeology -- Chapter Five. The Meir tombs : artistic style and execution -- Chapter Six. Iconography of the tomb owners in scenes of daily life -- Chapter Seven. Data synthesis and conclusions -- Bibliography -- Appendix.In the early to mid- Twelfth Dynasty, the provincial governors of the region downstream of Asyut developed a strong local culture, maintaining a degree of independence from the royal court that lasted until the reign of Senusret III. Located geographically in the middle of this group of four provinces is the fourteenth Upper Egyptian Nome, with the tombs of its governors situated in the necropolis of Meir. While the Meir tombs, along with the contemporary tombs of the other three provincial centres of Beni Hasan, Bersheh and Asyut have been the subjects of extensive prior study, aspects of the modes of artistic transmission between these provinces (and possible driving influences, including external factors) have not been fully addressed.This thesis is arranged as a comparative chronological investigation, with the governors’ tombs at Meir as the primary focus, and the tombs of the governors of the neighbouring provinces making up the comparison sites. Contemporaneous tombs from other provincial sites and the royal courts of Western Thebes and Lisht are also included, for assessment of influences on Meir from these sources, as well as sources from earlier periods in Egyptian history (including Old Kingdom influences from Meir and the Memphite court and First Intermediate period / Eleventh Dynasty influences from various sites).The chronological framework of the study is established from textual sources in chapter three, primarily relying on fixed dating via regnal references and relative dating via genealogical references. Other attributes of the tomb texts are investigated for their chronological dimension, confirming that changes in the phrases of the hetep-di-nesu formula established in prior studies are observed in the tombs of the study, and that epithets and titles of the tomb owner (with the exception of the title ‘Great Overlord of the N Nome’) are less variable from a chronological perspective.Chapter four compares the architectural features of the Meir tombs with those of the comparison sites, with the finding that architectural styles are largely driven by local influences, but some common elements are identified which emphasise a longitudinal axis of orientation towards a cult focus (shrine) on the rear wall. Part two of chapter four compares the governors’ tombs at Meir with the burials of their direct subordinates (extended family and officials) by textual comparisons with the coffins from the lesser burials. Three distinct clusters of coffins are identified, with the names of the owners of the later group suggesting probable intermixing of individuals from this social class with their contemporaries from Beni Hasan (possibly via intermarriage and associated migration).Chapter five compares the artistic styles and techniques observed in the Meir tombs with those of the comparison sites, noting that canonical techniques are universally applied, but are subject to local conventions and varying artistic capabilities. Case studies outline selected stylistic and compositional features of Meir tomb B2, highlighting the significant achievements of that particular artist in advancing the Meir artistic style from Eleventh and early Twelfth Dynasty royal styles, as well as the development of the artists’ grids through the Twelfth Dynasty as observed in tombs B2 and C1 (taking advantage of the unique existence at Meir of two chronologically separate tombs attesting surviving grids).The iconography of the desert hunt and the tomb owner fishing and fowling is examined in Chapter six. Influences on the depiction of these themes at Meir are traced from royal and elite examples from the Fifth and Sixth Dynasty Memphite cemeteries, via the Sixth Dynasty tombs at Meir. Alignment of key attributes of these scenes are noted between Meir and all of the comparison sites towards the mid Twelfth Dynasty.The data from the above analyses are synthesised in chapter seven, which illustrates points at which the paternal line of succession is interrupted at Beni Hasan and Meir, and similarities in how royal legitimacy was invoked at both sites to support the new incumbent. Routes of artistic transmission to and from Meir are presented for the iconographic themes of the desert hunt and the tomb owner fishing and fowling, demonstrating a tendency towards horizontal transmission processes which correlate with the evidence of intermarriage and migration between nomes during the Twelfth Dynasty, particularly noting evidence of this between Beni Hasan and Meir. Changes in technique can also be aligned chronologically with evidence of intermarriage and migration between nomes, particularly the change in technique in Meir tomb C1 from cut relief to purely painted representation (following the long-standing technique of artistic execution at Beni Hasan).Mode of access: World wide web1 online resource (viii, 296 pages) black & white illustration
The impact of recent changes in the audit regulations and auditing standards on auditors’ judgement and decision making
No full textEmpirical thesis.Bibliography: pages 222-244.Chapter 1. Overview of the thesis -- Chapter 2. (Paper 1) The changing face of the auditor’s report : implications for suppliers and users of financial statements -- Chapter 3. (Paper 2) The effects of preference for quantitative information and utilisation of quantitative versus qualitative information on auditors’ materiality judgements -- Chapter 4. (Paper 3) The impact of client pressure and client’s financial condition on auditors’ judgements to report KAMs in the auditor’s report -- Chapter 5. (Paper 4) The impact of director liability regime, national culture and the quality of the audit environment and enforcement of accounting regulations on audit fees -- Chapter 6. Conclusions and implications -- Bibliography -- Appendices.The auditing profession has experienced significant transformations in the past fifteen years, in efforts to boost public confidence. In particular, auditing standards and corporate law have undergone significant changes. These reforms and changes were driven by large-scale corporate failures, financial scandals and dwindling public confidence in the craft of external assurance.The aim of this thesis is to identify and examine empirically the impact of various factors that may impede the implementation of the numerous reforms in auditing standards and legislations. Specifically, this thesis has undertaken the following four research projects in the domain of audit regulations and auditor judgements: (1) to critically analyse the current audit report reforms and investigate the implications of the changes for the suppliers and users of the financial reports; (2) to examine the factors that affect the materiality judgements of auditors and identify interventions that could mitigate their effects; (3) to examine the factors that influence auditors’ judgements to present key audit matters in an auditor’s reports; and (4) to investigate the extent and causes of differences in audit fees between companies across countries.This thesis employs both qualitative and quantitative research methods to examine the various factors affecting the adoption of new auditing standards and the impact of differences in legislation across countries on audit fees. The findings of this thesis provide evidence that reforms in auditing standards have significant implications for stakeholders such as the users of financial statements and the accounting firms who have to implement the changes. Furthermore, various factors such as personality traits of accountants, pressures from their clients and characteristics of the client have significant effect on the decision-making process and judgements of accountants. Finally, the findings show that differences in legal liability laws, national culture and the quality of audit environment and enforcement of accounting regulations have an impact on audit fees that auditors charge across countries. These findings have important implications for various stakeholders such as the auditing standard-setters and legislators, accounting firms and the users of the financial reports and auditor’s reports.Mode of access: World wide web1 online resource (338 pages) table