VictorJuiz/thesis huggingface dataset:
Models of the perception of the pitch of tonal complexes

Theories of pitch perception, and the related literature, are reviewed, with special reference to the residue pitch of tonal complexes. A distinction is drawn between spectral-pattern theories, which propose that pitch is derived from independent internal estimates of component frequency, and periodicity theories, which propose that the pitch of tonal complexes may be derived from a residual periodicity resulting from an incomplete auditory frequency analysis. The Spectral-pattern models described by Goldstein (1973) and Wightman (1973b) are discussed in detail; computer simulation procedures, allowing the prediction of a probability density function for the estimated fundamental frequency of a tonal complex, are described for each. Contrasting predictions concerning the relation between component frequency discrimination and fundamental frequency discrimination for harmonic complexes are developed for the spectral-pattern and periodicity theories.
Component frequency and fundamental frequency discrimination by human observers was measured, under a variety of conditions, for a complex containing the 4th and 5th harmonics of 200 Hz. For a comparison of the pitches of two such complexes of slightly different frequency, the relative fundamental frequency difference limen was no larger, and generally smaller, than the smaller relative component frequency difference limen. Discrimination performance was interpreted in terms of a modified version of Goldstein's (1973) spectral-pattern theory, in which an internal noise limits discrimination between signals with non-coincident components. Further experiments investigated the identification of fundamental frequency by human observers as a function of the variability of internal estimates of component frequency as estimated from the discrimination experiments. The results of these experiments were consistent with the predictions of the spectral-pattern theories.
Component and fundamental frequency discrimination was also considered with respect to temporal and spatial theories of frequency discrimination. The results of the discrimination studies were consistent with a modified Energy Detection model, where discrimination is ultimately limited by an internal noise.

Advisor: Treisman, M
Applications of calcium isotopes in marine carbonates in the Recent and Phanerozoic

The applications of calcium-isotope measurements in marine carbonates are explored in several different contexts within this thesis. As a record of global ion fluxes, seawater calcium-isotope ratios can be used as tracers for large weathering imbalances, which develop as a feedback system in response to intervals of climate change. This approach provides valuable constraints on the complex climatic and oceanographic phenomena known as the Oceanic Anoxic Events. Over much longer timescales, the calcium-isotope ratio of seawater is influenced by steady-state processes that reflect the evolution of seawater chemistry. To understand these influences, the modern calcium-isotope budget is assessed quantitatively using a compilation of marine carbonate samples, revealing several distinctive components of the carbonate burial sink that can affect the steady-state balance of the calcium cycle. Changes in the major ion composition of seawater and in the organisms that contribute to sedimentary carbonate burial are shown to contribute significantly to the geological record of seawater calcium-isotope ratios. The importance of skeletal carbonate in the calcium cycle leads to another application of calcium isotopes towards understanding biomineralization. This large and complex topic is approached with calcium-isotope data from two unique growth experiments that constrain some of the mechanisms by which biogenic aragonite acquires its geochemical signatures. This range of topics presents a diverse, but by no means exclusive, sample of the topics that are accessible for investigation through calcium-isotope analysis. The potential of this isotopic tool is demonstrated by the breadth of environments and timescales represented in this work.

Keywords: Cretaceous
Oceanic Anoxic Events
biomineralization
calcium isotopes
carbonate
Advisor: Henderson, G
Jenkyns, H
Essays in economic and financial history

Division One: “Malthus Gets Fat” (Two Chapters)
Chapter One develops a simple dynamic model to examine the takeoff from a Malthusian economy to a modern growth regime. It finds that several factors, most notably the rate of technological progress and the economic structure, determine the fastest rate at which the population can grow without declining living standards; this is termed maximum sustainable population growth. It is only when this maximum sustainable rate exceeds the peak rate at which a society expands that takeoff can occur. I also investigate the effects of trade and international income transfers on the ability to sustain takeoff. It is also shown that present income growth is not necessarily indicative of the ability to sustain takeoff and that factors which increase current income growth may actually inhibit takeoff, and vice versa.
Chapter Two applies the sustainable population growth framework to Britain during the Industrial Revolution. The model shows a dramatic increase in sustainable population growth at the time of the Industrial Revolution, well before the beginning of modern levels of income growth. The main contributions to the British breakout were technological improvements and structural change away from agricultural production. At least until the middle of the 19th Century, coal, capital and trade played a minor role.
Division Two: “Leverage and Financial Market Instability” (Four Chapters)
Chapter One develops a model of how leverage induces explosive behavior in financial markets. I show that when levered investors become too large relative to the market as a whole, the demand curve for securities can suddenly become upward-sloping as levered investors are exposed to forced liquidations. The size and leverage of all levered investors defines the minimum elasticity-adjusted market size for stability or MinEAMASS, which is the smallest elasticity-adjusted market size that can support the group of levered investors analyzed. This gives rise to a measure of instability that can predict when markets become vulnerable to a leverage-driven market liquidity crisis.
Chapter Two iterates the model of Chapter One forward in time to generate an inflating bubble that suddenly bursts, reproducing many of Kindleberger's (1996) stylized facts about the dynamics of bubbles in a simple framework.
Chapter Three applies my measure of instability in a historical investigation of the 1998 demise of hedge fund Long-Term Capital Management (LTCM). I find that a forced liquidation of LTCM threatened to destabilize some financial markets, particularly for bank funding and equity volatility.
Chapter Four discusses how the model applied to the stock market crash of 1929. There the evidence suggests that a tightening of margin requirements in the first nine months of 1929 combined with price declines in September and early October caused enough investors to become constrained that the market was tipped into instability, triggering the sudden crash of October and November.

Keywords: demographic transition
LTCM
great crash
Leverage
industrial revolution
Malthus
financial crisis
Advisor: Harley, K
Return of high skilled migrants: an empirical investigation into the knowledge transfer process of two organizations in New Delhi, India

Against the backdrop of the brain drain-brain gain debate, this thesis explores certain facets of the return migration phenomenon. Drawing on several theories, the decision to return among high skilled migrants is likely to be influenced by the prospect of using their overseas-acquired knowledge to secure a better livelihood back home. While ample consideration is given to motivations to return, the choice of employer and issues adjusting to the work and social surroundings, the main objective of the research is to understand migrants' transfer of overseas-acquired knowledge upon their return to India.
Given the interdisciplinary nature of the topic, the scope of the thesis is focused on returnees working in two organizations in New Delhi—Fortis Escorts Hospital and Research Centre (EHIRC) and Tata Consultancy Services' Government Industry Solutions Unit (GISU). Adopting a mixed methods approach, survey data and case interviews are analyzed to address the core research question: “How and in which ways do returnees transfer their newly acquired knowledge, skills and experiences in employing organizations?” A key hypothesis is that returnees' social ties affect the extent and nature of knowledge transfers and thus confer intended benefits and may lead to unintended consequences for their organizations.
The analyses pit McPherson's (2001) principle of homophily in social networks against Granovetter's (1973) weak ties hypothesis to grasp the role of returnees in knowledge transfers within EHIRC and GISU. Results drawn from data collected on returnees, non-migrants and transnationals strongly confirm that social ties—strong, intermediate or weak—affect the transfer of knowledge to stakeholders in their organizations. The contribution of this thesis to the existing body of research is to shed light on both the potential and limitations of returnees as a conduit for transferring knowledge, upgrading skills and relaying insights to non-migrants, teams or units in the workplace.

Keywords: Economic Development
Return Migration
Knowledge Transfers
Advisor: Wood, A
Fu, X
Life after guns: the life chances and trajectories of ex-combatant and other post-war youth in Monrovia, Liberia

This thesis is about the life chances and trajectories of ex-combatant and other youth in post-war Monrovia, Liberia. In it I present the results of a qualitative inquiry into the relationship between shifting structural conditions and youth agency in the aftermath of 14 years of civil war. Much of the literature concerned with ex-combatant “reintegration” remains a-theoretical and fails to situate their experience within the contours of transition from structures in armed groups to structures in post-war society. It is rife with normative assumptions about how ex-combatants should “return” to civilian life. The ex-combatant trajectories detailed in this study challenge this literature reflecting neither “reintegration” nor “return.” Instead, they highlight how ex-combatants negotiate a complex environment in which structural norms, values, and relationships converge and conflict after war. To demonstrate this, the thesis presents an analysis of the relationships between structural constraints and youth agency among youth who fought, and others who did not. In so doing, it provides a situated analysis of post-war society which is often missing in the literature concerned with ex-combatants. The empirical material shows the significance of interdependent relationships at the level of the family and the household. It is “wealth in people” at this proximate level that supports survival and enables socio-economic mobility, with implications for social respect. Without patronage through family and kin, socio-economic possibilities diminish significantly. This means that options available to many ex-combatants are limited after war, as they are often unable or unwilling to be incorporated into families and former communities. Their navigation of the post-war social terrain reflects efforts to survive and maintain respect through patrimonial relationships within and outside of their structured networks from war. Some retain the status and respect they achieved in war through relationships maintained from their years of conflict. Others were able to survive and achieve respect through new or renewed relationships with families and extended kin. Life chances and trajectories emerge from embedded positions within structured social relations that are produced and reproduced in the aftermath of conflict. With this work, I argue that social processes are vital to any theorisation about life after war.

Keywords: Ex-combatants
Liberia
Youth
Post-war
Advisor: Boyden, J
Chatty, D
Computer simulation of the homogeneous nucleation of ice

In this work, we wish to determine the free energy landscape and the nucleation rate associated with the process of homogeneous ice nucleation. To do this, we simulate the homogeneous nucleation of ice with the mW monatomic model of water and with all-atom models of water using primarily the umbrella sampling rare event method. We find that the use of the mW model of water, which has simpler dynamics compared to all-atom models of water, but is nevertheless surprisingly good at reproducing experimental data, results in very reasonable agreement with classical nucleation theory, in contrast to some previous simulations of homogeneous ice nucleation. We suggest that previous simulations did not observe the lowest free energy pathway in order parameter space because of their use of global order parameters, leading to a deviation from classical nucleation theory predictions.
Whilst monatomic water can nucleate reasonably quickly, all-atom models of water are considerably more difficult to simulate, primarily because of their slow dynamics of ice growth and the fact that standard order parameters do not work well in driving nucleation when such models are being used. In this thesis, we describe a local, rotationally invariant order parameter that is capable of growing ice homogeneously in a biassed simulation without the unnatural effects introduced by global order parameters, and without leading to non-physical chain-like growth of 'ice' clusters that results from a naïve implementation of the standard Steinhardt-Ten Wolde order parameter. We have successfully used this order parameter to force the growth of ice clusters in simulations of all-atom models of water.
However, although ice growth can be achieved, equilibrating simulations with all-atom models of water is extremely difficult. We describe several approaches to speeding up the equilibration in all-atom models of water to enable the computation of free energy profiles for homogeneous ice nucleation.

Keywords: ice
homogeneous nucleation
rare event
Monte Carlo
simulation
water
Advisor: Doye, J
The geography of dust storms

Dust storms have a great many environmental implications in the world's dry lands where they are particularly common. Four main classes of dust event are identified and defined: dust storms, dust haze, blowing dust and dust devils.
The geography of dust storms is analysed in each of eight major world regions: Africa, the Middle East, South-west Asia, Europe and the USSR, China, Australia, North America and Latin America. Terrestrially observed meteorological data and data from remote sensing platforms are employed to identify the major source areas in each region, their seasonality, diurnal patterns of activity and trajectories of long-range transport.
Among the important controls on the frequency distribution of dust storm activity are the meteorological conditions that generate dust-raising winds, and a number of meteorological systems commonly cause dust storms in all global regions. These include low pressure fronts with intense baroclinal gradients, pressure gradient winds between moving or stationary air masses, katabatic winds and convectional cells.
The nature of the surface upon which deflation occurs is also important; typical dust-producing geomorpholological units include alluvial spreads, lacustrine deposits, desert depressions, loess deposits and reactivated fossil dunes.
Dust storm activity is prone to considerable variation. The seasonal characteristics are explicable with reference to the meteorological systems generating dust, the state of ground cover, particularly vegetation, and the effects of seasonal rainfall. Substantial variations also occur from year to year, and land use and climatic variations can substantially affect their occurrence.
Methods, rules and limits of successful self-assembly

The self-assembly of structured particles into monodisperse clusters is a challenge on the nano-, micro- and even macro-scale. While biological systems are able to self-assemble with comparative ease, many aspects of this self-assembly are not fully understood. In this thesis, we look at the strategies and rules that can be applied to encourage the formation of monodisperse clusters. Though much of the inspiration is biological in nature, the simulations use a simple minimal patchy particle model and are thus applicable to a wide range of systems. The topics that this thesis addresses include: Encapsulation: We show how clusters can be used to encapsulate objects and demonstrate that such `templates' can be used to control the assembly mechanisms and enhance the formation of more complex objects. Hierarchical self-assembly: We investigate the use of hierarchical mechanisms in enhancing the formation of clusters. We find that, while we are able to extend the ranges where we see successful assembly by using a hierarchical assembly pathway, it does not straightforwardly provide a route to enhance the complexity of structures that can be formed. Pore formation: We use our simple model to investigate a particular biological example, namely the self-assembly and formation of heptameric alpha-haemolysin pores, and show that pore insertion is key to rationalising experimental results on this system. Phase re-entrance: We look at the computation of equilibrium phase diagrams for self-assembling systems, particularly focusing on the possible presence of an unusual liquid-vapour phase re-entrance that has been suggested by dynamical simulations, using a variety of techniques.

Keywords: simulations
Monte Carlo
proteins
Colloids
self-assembly
Advisor: Doye, J
Art after Auschwitz. Dimensions of ethics and agency in responses to genocide in post World War II art practice

Rather than being located in a field of art that addresses genocide through assumptions connected with identity issues or activism, this thesis of an artist’s exploration of artistic response to genocide in post World War II art practice, is informed by the emerging field of genocide scholarship. Seeing a parallelism between the concerns of genocide scholars and artists who respond to genocide, this thesis is an interdisciplinary study of art positioned alongside the field of genocide scholarship, as theorised by scholars such as Donald Bloxham and A. Dirk Moses. In addressing genocide through broader historical trends, periods and structures, it assumes that artists who respond to genocide share with genocide scholars a concern about genocide at a secondary level and share the potential to create illumination in the field. This thesis explores art practices that address genocide conceptually through structure and material. The central claim of this thesis is that recent and contemporary art practices, here discussed, show a concern to respond to genocide as an ethical response, and that they do so by engaging with the complexity of abstract issues such as complicity and agency. The initial analysis of Adorno’s discourse on ethics, as it relates to response in art, sets up a level of complexity for two further investigations that interrogate the discourses of victim representation and lens-based documents of genocide through ethics and agency. Together these provide an analytical framework for the project. Close readings informed by genocide scholarship, of art practices including those of Jimmie Durham and Francis Alÿs, take forward notions in the existing critical field. These readings yield not only the evidence that demonstrates a commitment to creating ethically based art through conceptually informed practice, in artists responding to genocide, but also the value of a cultural critique that is informed by genocide scholarship.

Keywords: visual cultures
art
genocide scholarship
cultural studies
Adorno
memory
art and resistance
critical theory
art practice
art history
genocide
genocide studies
art and complicity
Advisor: Archer, M
Inscribed within the image: the visual character of early Christian mosaic inscriptions

Between the fourth and the seventh centuries CE, Christian patrons erected thousands of churches, chapels, and monasteries in cities and villages across the Mediterranean, decorating the apses, walls and floors of many of these structures with figural and geometric mosaics. These late antique Christian mosaics have been studied for their iconography, their Graeco-Roman components, and as evidence for the religious beliefs of newly-Christian patrons. However, art historians largely have ignored the ways that texts, inscribed within the visual field and composed of the same mosaic material, functioned as images in Christian spaces. For the first time, this thesis assembles the foundations of a comprehensive catalogue of early Christian mosaic inscriptions, places them back into the physical spaces in which they were meant to be read, and analyzes how these texts functioned both verbally and visually for the late antique reader/viewer, against the backdrop of Graeco-Roman traditions. I first examine the ekphrastic components of Christian inscriptions and look more closely at the different ways in which texts work with and against images and spaces, encouraging the viewer to react physically and mentally. Second, I study the language of light used by the inscriptions, and argue that this language linked text to the material of mosaic and enabled patrons to make complex statements about their cultural erudition and religious affiliation. Third, I investigate the functions and visual forms of short tituli which label scenes or name figures to simplify, authenticate or transform static images into narratives in motion. Finally, I turn to the frames of the inscriptions and contend that different forms conveyed powerful visual arguments. By writing these texts back into their mosaics, this thesis argues that texts and images were inseparable in the period, and that text written into images performed and played in more complex ways than has been previously thought.

Keywords: epigraphy
inscriptions
Latin
Greek
mosaics
Late antique art
Advisor: Elsner, J