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Monstrous Musical Moonshine: Explorations of Harmonic Spaces
Get PDFThis commentary provides context for a collection of compositions whose underlying structures are derived from and extend the harmonic theory based on rational intervals between pitches introduced by composer and music theorist James Tenney. The core component taken from Tenney is the measure of harmonic distance (distinct from pitch distance) between two notes. I have extended this to a measure of harmonic dispersion within any number of notes and applied this to developing chord sequences that are either gradually increasing or decreasing in harmonic dispersion. Furthermore, within such sequences the gradation in dispersion is as smooth as possible, both in terms of voicing (usually only one voice in the chord changes at a time) and dispersion level changing by a minimal amount at each stage. A further structural change, developed in later works, is what I term ‘unfolding’, by which a controlled level of repetition is introduced into the sequence, determined by both parametrised and aleatoric elements. The musical results are often microtonal but take into account the pragmatics of performance, and so are often quarter-tonal or based on the usual twelve-tone equal-tempered system. The resulting compositions are scored for live performers (soloists and ensembles), electronic synthesis, and hybrid scoring. The
culminating work is a setting of texts from Zen Buddhist sources for vocal soloists, choir, chanters, an instrumental ensemble and electronic synthesisers. Aside from the structural technicalities, my music focuses on non-narrative, often long-duration expressions, influenced by composers such as Morton Feldman and Eliane Radigue. While technicalities are interesting, the key objective is always to produce music, not mathematics, with the hope that the work will be of interest to listeners, not mathematicians. Ultimately, this project has been experimental, researching how complex structures could be manifest in music.
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The accompanying data can be accessed at: https://collections.durham.ac.uk/collections/r20k225b12
Deep Learning Applications in Flavour Tagging
Get PDFMotivated by the application of data-driven solutions to the field of particle physics, in particular flavour tagging, we study the effectiveness of deep learning (DL) approaches for inclusive \ensuremath{|V_{ub}|}\xspace measurement within the Belle II environment and strangness tagging in the LHCb environment.\\
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In the \ensuremath{|V_{ub}|}\xspace study, we compare the performance of an existing Boosted Decision Tree approach with a Bayesian neural network. In addition, we perform an in depth study on the selected features, investigating the signal inclusivity of DL models which gives insights into behaviours of the models.\\
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We aim for classification speed and precision in the strange-quark jets tagging study. Therefore, we explore using a simple fully connected feedforward neural network to classify -jets among all light jet backgrounds. A comprehensive feature investigation is performed to understand the discriminating power of jet observable and the importance of particle identification.\\
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Additionally, data-driven methodologies are also reshaping industrial practices. A study investigating the potential of DL in predicting realised volatility of a financial index is included. It is a collaborative project with Optiver where neural networks along with various training schemes are studied to maximise profits
The Priesthood of All Students? Historical, Theological and Missiological Foundations of a University Ministry: The International Fellowship of Evangelical Students (IFES)
Get PDFThis dissertation explores the development of the theology and missiology of the International Fellowship of Evangelical Students, IFES. Drawing on archival records and writings by authors close to IFES, it shows how the priesthood of all believers has served as a fundamental building stone of the ministry of IFES and can continue to help the organization navigate opportunities and challenges facing its ministry.
The priesthood of all believers involves lay students examining Scripture together. It involves manifold expressions of mission which are constantly reshaped in the encounter with the diversity of cultures and theologies characteristic of World Christianity. Missionary engagement framed by the priesthood of all believers presupposes immediacy, mediation, and participation.
Immediacy presupposes individuals can encounter God directly, primarily in Scripture, hence the legitimacy of student-led missionary activities. Missiologically, lay leadership is congruent with the fact that university students spend most of their time developing skills as thinkers and leaders.
Students, staff and Christian university employees are mediators of their beliefs to the university, inviting others to consider the message of the Gospel. They also mediate some of the universities’ concerns back to the Church, inviting theological thinking about significant academic issues. Such mediation happens at the margins of the structured ecclesial world.
In IFES, these commitments to immediacy and to mediation allowed the development of a missional ecclesiology that presupposes that God is already at work in the university. IFES people are participating in the mission of God (missio Dei). Hence, the work of IFES, as an expression of the priesthood of all believers, can be understood as an extension of the presence of the Church in places and ideological realms to which traditional ecclesial structures have only limited access
Cosmological redshift surveys, big data and semi-analytical galaxy formation models
Get PDFThe focus of this thesis is to connect observations from different galaxy redshift surveys to physically motivated models of galaxy formation. The Physics of the Accelerating Universe Survey (PAUS) and the VIMOS Public Extragalactic Redshift Survey (VIPERS) are the two major surveys used in this thesis. For both, I use the semi-analytical model GALFORM to create a physically motivated scenario and explore the evolution of some observational galaxy properties starting from an epoch when the Universe was approximately half of the current age. In particular, for PAUS, we used GALFORM implemented in the Planck Millennium N-body simulation, to build a mock PAUS galaxy catalogue on an observer’s past lightcone. The increased mass resolution and the higher frequency of simulation outputs allow us to make improved galaxy property predictions. We compared the mock catalogue predictions with the observed number counts, redshift distributions and the redshift evolution of the observer frame colours. The red and blue populations of the model galaxies are roughly in agreement with the observed ones.
The interest in galaxy colours and the relation to their star formation histories lead us to exploit VIPERS for a galaxy evolution study. In particular, we analysed the evolution of the rest frame colour-magnitude relation tracking the evolution of the bright edge with the aim of deriving constraints on the quenching of star formation activity in galaxies in 0.5 < z < 1.1. Through the modelling of parametrised star formation histories (SFHs) we estimated the average time-scale of the suppression of the star formation. We showed that modelling a fast suppression of the star formation activity in galaxies, we are able to reproduce better the observational data. We created a physically motivated mock with GALFORM and we obtained a similar qualitative trend. We tested that AGN feedback, as the main quenching process in GALFORM, is crucial in reproducing the trend of the bright-edge.
As part of the Centre for Doctoral Training (CDT), I developed data analysis techniques, during an internship with Procter & Gamble (P&G) and with the National Health Service (NHS), in two projects described in this thesis. In the P&G project the aim was to model the density of the laundry powder in order to understand the chemical ingredients that mostly contribute to the density and hence changing the industrial process accordingly. In the NHS project, we aimed at establishing new normative ranges for vital signs of newborn babies. The results of this project have the potential of helping doctors in making critical decisions for the treatment that can save the life of babies in critical conditions
Optical Transients in Atomic Vapours
Get PDFThe propagation of light through atomic vapours gives rise to a variety of interesting effects including self-induced transparency (SIT), optical simultons and the formation of transient trains of light pulses. In this thesis, we investigate such effects using numerical simulations and theoretical techniques. We first study the dynamics of SIT solitons, comparing our numerical results with analytical predictions and previous numerical studies. We then explore the propagation of continuous wave (CW) fields, focusing on the transient dynamics that occur during and shortly after the fields are turned on. We show that a CW field breaks up into a train of pulses as it propagates into a medium, but that these oscillations are dampened in the presence of homogeneous broadening. In the absence of homogeneous broadening, we observe that the pulses become increasingly separated as the field moves deeper into the medium, in contrast to what was concluded in previous studies. We also present original results in which transient pulse trains are seen to form from two CW fields propagating through a medium of three-level V-type resonators and discuss the mechanisms behind their formation
Evaluation of total-body-less-head dual energy X-ray absorptiometry for the assessment of lean, fat and bone mass in athletes
Get PDFAbstract
Introduction: The routine assessment of body composition is common practice in athletic populations, particularly at the elite level. DXA is a criterion method of body composition assessment, providing precise measurements of bone mineral content (BMC), lean mass (LM) and fat mass (FM) from the standard total-body scan. More recently, a new scan application has been introduced, which measures body composition excluding the head region. The aim of this study was to investigate the precision of the new total-body less head (TBLH) application for the measurement of total body composition in athletes and compare precision with that of the standard total-body scan. The second aim was to compare the differences in total body composition outcomes between standard DXA total-body scans and TBLH scans.
Methods: This study compared in-vivo precision and total body composition outcomes from the standard total-body scan and the new TBLH scan (Lunar iDXA, GE Healthcare, Madison, WI). A total of 95 athletes (mixed sports) received repeated TBLH scans and 58 of these athletes also received standard total-body scans (overall mean age: 26.3 ± 8.8 years; male n = 63, female n=41). Participants ranged in body mass (42.7 to 129.1 kg), stature (1.55 to 2.04 m) and BMI (16.4 to 46.9 kg/m2). Precision was derived from repeat scans with re-positioning, and precision error was reported as the root mean square standard deviation (RMS±SD) and percentage co-efficient of variation (%CV).
Results: Precision error ranged from 0.38 % to 1.15 % (%CV) for standard total-body and 0.39 % to 1.28 % (%CV) for the TBLH application, depending on the body composition compartment. Body composition outcomes for the TBLH were significant lower than for the standard total body for BMC (2,865 g v 2,308 g), LM (50,276 g v 46,954 g) and FM (15,888 g v 15,183 g) , all p<0.05. Regional composition precision error was consistently lower for the TBLH application, particularly at the trunk region (TBLH = 0.54 - 2.86 %CV vs. standard total body = 0.78 - 2.57 %CV).
Conclusion: In-vivo total body composition precision of the TBLH iDXA scan is comparable to that of the standard total-body scan, and superior for regional composition assessment, in a mixed cohort of athletes. The TBLH scan may be particularly useful for monitoring body composition in athletes due to the exclusion of the head. However, new baseline measurements should be performed if centres are to adopt the TBLH method, in order to ensure consistency and validity of longitudinal measurements for the monitoring of athlete body composition. Previous body composition assessments implementing the standard total-body application should not be compared with assessments using the TBLH application
The Hidden God of Isaiah 45:15: Whose Voice? Which Meaning?
Get PDFThis thesis provides a fresh answer to a deceptively simple question in the history of interpretation: In what sense is God hidden as confessed in Isaiah 45:15? To answer this question this thesis explores the dynamic relationship between the confession itself, “Surely you are God who hides himself…” (Isa 45.15a), and its interpretation in recent scholarly literature. The present work is, on the one hand, an exegetical investigation of a perennially problematic pericope, Isa 45:14–17, in its immediate literary context of Isa 40–49:13. In chapter two it is demonstrated how divine hiddenness as articulated in this poetry is made more coherent by understanding the often overlooked, yet contextually organic, juxtaposition of the addressee to the divine image (especially in the wider symbolic discourse of the Mesopotamian Mīs pî ritual). On the other hand, this thesis is a meta-critical reflection and hermeneutical case-study on the moves interpreters make towards meaning, to answer the question, “Whose voice are we hearing?” while rendering a contingent construal of divine hiddenness. The ambiguous referential features of this pericope are shown to be constructive, serving to place the audience/reader within an experience of relational dislocation and estrangement. This opens up a way of understanding Isaiah 45:15 that stresses the dynamic relationship between readerly self-involvement in the poetry’s progression, which is facilitated by key moments of dialogue in which the twin topoi of blindness/sight and hiddenness/glory figure prominently
In-Work Poverty in the UK: The Stories of Working Women Using Food Banks
Get PDFThe aim of this thesis is to give voice to women who, despite being active in the labour market, continued to depend on charitable provisions from a food bank in Britain. Theoretically the thesis addresses this phenomenon as a matter of social injustice, and it does so by exposing and exploring the experiences of women who despite employment were still driven to need charity from a food bank. The thesis therefore engages with a gendered experience of in-work poverty and presents various lessons learning relating to social injustice in Britain. I adopt a feminist ethnographic study in two independent food banks, with the methodology comprising of both participant observation and in-depth interviews across multiple group sets. The feminist underpinning signals an innovative methodological advance in the field. The data collection was immersive to meet the objectives of the study, and intense due to the themes explored. I show how food bank usage has become a necessity for some women grappling with the precarious labour market and the in-work benefit system. This experience is degrading for women who are also workers, and this is deepened for those who are single mothers. Nevertheless, I demonstrate the honourable role of the food bank and its volunteers in a support that goes beyond the sole provision of food. The thesis explores both challenges and developments in accessing vulnerable populations, additional to the value of reflexivity in ethnography carried out in settings where the researcher and the researched are demographically diverse
Essays on household financial decision-making: Evidence from Indian households
Get PDFThis dissertation aims to understand the role of financial knowledge in India and its role in explaining financial participation within the human development framework. It contributes to the literature on understanding social and behavioral attributes influencing the financial decisions of the households. The dissertation chapters explore the household's financial decisions related to their selection of financial products. Financial product choice has been an intriguing question for household finance experts across the years and has paramount importance in influencing households' lifetime utility. Underlining the socioeconomic heterogeneity of an emerging market such as India, the dissertation explores how financial knowledge can help boost financial participation and act as a social enabler in healing societal discrimination.
The dissertation has four substantive chapters. The first of the four chapters examine the role of financial knowledge in helping financial awareness about the existence of financial products in India. The chapter introduces a novel scoring methodology summarizing the understanding of seven dimensions of financial concepts. The empirical results of the chapter show that financial knowledge helps in financial awareness related to the availability of financial products. It further helps in financial participation. The emergence of financial markets and the adoption of financial austerity by governments worldwide have shifted the financial responsibility on the households. In the backdrop of their increased role in financial decision-making, households' financial knowledge and financial awareness have gained paramount importance in shaping their lifetime utility by helping them in financial participation. The chapter concludes by underscoring financial knowledge as a policy instrument in boosting financial participation.
The second chapter examines the role of financial unawareness in impeding financial participation. It characterizes the conditions for conscious and unconscious non-participation decisions using a theoretical framework. The framework classifies the overall awareness of a household into two components. The first component is innate awareness, which household acquires as an outcome of their natural ability to pay attention. The second component of awareness is acquired awareness, which households receive at a cost by investing their physical endowments such as financial knowledge. The framework characterizes two scenarios of financial non-participation, namely conscious non-participation, and unconscious non-participation. In the case of conscious non-participation, household consciously chooses not to hold the financial product when they are sufficiently aware of the financial product's costs and benefits. In unconscious non-participation, the household lacks the necessary knowledge about the cost and benefits of the products. Due to a lack of sufficient awareness about the product, they do not participate. Also, they choose not to acquire additional awareness by selling their physical endowments as they think that even after selling their physical endowment, they cannot acquire sufficient awareness about the cost and benefits of the products. As a result, they remain out of financial markets due to insufficient financial awareness. In the backdrop of these two scenarios of non-participation, the chapter has a policy implication about reducing the cost of acquiring financial knowledge, so households have to sell less to earn financial awareness and avoid non-participation due to lack of awareness.
The third chapter of the dissertation examines the role of financially literate women in managing their household finances. The empirical results show that responsible, financially literate men and women constitute a healthy decision-making team when they work to their strength. Jointly men and women outperform the other decision-making peers such as sole men or women. The responsible, financially literate women participate more in saving schemes, insurance products, and alternative investments and are less involved in saving money at home/informally and borrowing money from money lenders. On the other hand, financially literate male decision-makers participate more in investment products, stocks/shares, and debt products. The chapter observes considerable heterogeneity in the role of women in household decision-making across castes. It finds financial literacy's effective gains diminish going down the caste hierarchy from the privileged caste to lower caste households, where cultural norms are more binding. The chapter recommends a policy intervention to equip women with financial literacy and encourage a husband-and-wife team to manage their household's financial portfolios jointly.
The fourth chapter investigates how the caste-based discrimination in economic outcomes (namely, financial awareness and product holdings) hinders the financialization of the administrative districts. The empirical results show the districts with a higher level of caste-based discrimination suffer from a lower degree of financialization. The chapter considers crime reporting in India as a measure of institutional development as there are independent studies which suggest that a majority of crime incident does not get reported in India. Empirical results from the chapter show that caste-based discrimination fuels caste-based riots and discourages the reporting of general crimes such as burglary, cheating, dacoity, forgery, kidnapping, robbery, and theft. Together with the earlier three chapters, the dissertation advocates financial knowledge as a policy tool that not only helps individuals attain their full economic potential but also helps the social and institutional development of society
Development of Fluid-Curtain Sealing Technology to Improve the Efficiency and Operational Flexibility of Large Power Generation Turbines
Get PDFFluidic curtain sealing has recently been shown to offer significantly reduced leakage in rotating turbomachinery seals. The seal type uses an additional flow injected into the leakage path to reduce some existing leakage flow. Shrouded steam turbine tip seals were the focus of research in this thesis, but the seal has potential applications in blade tip seals, stator root seals, shaft seals, and end gland seals in steam turbines as well as in gas turbines. The implementation of such a seal may be simplified in the case of gas turbines since secondary flows of air are already built into the machine to provide cooling flows to high temperature components. The fluidic curtain seal is especially effective when a combination of fluidic curtain and a conventional labyrinth seal is used, and the research presented will generally feature a fluidic curtain placed upstream of a labyrinth fin type restriction. The new addition to knowledge on fluidic curtain sealing described in this work is in characterising seal performance in terms of its design parameters. Better characterisation of the seal allows the development of a set of realistic design rules to specify how fluidic curtains may be applied to the design of new, high performance turbomachinery seals.
Two main advances in characterising fluidic curtain seals resulted from the research. The first advance was to numerically and experimentally test basic geometric parameters and their influence on performance to identify design rules which maximize the performance gain of incorporating a fluidic curtain. A series of fundamental dimensionless geometric ratios were proposed and the design space created by these parameters was explored and validated experimentally using a simple annular test rig. CFD was then used to demonstrate that it is possible to incorporate a high performance design into a labyrinth seal independent of the existing labyrinth seal geometry. The second advance is to explore the effect of swirl velocity at the leakage channel inlet on overall seal performance. This was first achieved using CFD to model the selected realistic tip seal design with different levels of inlet swirl. This CFD study was then validated by building the design in a rotating annular test rig where the inlet swirl velocity was controlled. The research findings resulted in a proposed design process for new fluidic curtain seals (Section 8.2) which considers; the geometry of an existing seal, fluid conditions in the leakage path and elsewhere in the turbine stage, rotational speed, and minimum allowable physical clearances
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