VictorJuiz/thesis huggingface dataset:
Algorithms for decision making

We investigate algorithms for different steps in the decision making process, focusing on systems where we are uncertain about the outcomes but can quantify how probable they are using random variables. Any decision one makes in such a situation leads to a distribution of outcomes and requires a way to evaluate a decision. The standard approach is to marginalise the distribution of outcomes into a single number that tries in some way to summarise the value of each decision. After selecting a marginalisation approach, mathematicians and decision makers focus their analysis on the marginalised value but ignore the distribution. We argue that we should also be investigating the implications of the chosen mathematical approach for the whole distribution of outcomes.
We illustrate the effect different mathematical formulations have on the distribution with one-stage and sequential decision problems. We show that different ways to marginalise the distributions can result in very similar decisions but each way has a different complexity and computational cost. It is often computationally intractable to approximate optimal decisions to high precision and much research goes into developing algorithms that are suboptimal in the marginalised sense, but work within the computational budget available. If the performance of these algorithms is evaluated they are mainly judged based on the marginalised values, however, comparing the performance using the full distribution provides interesting information: We provide numerical examples from dynamic pricing applications where the suboptimal algorithm results in higher profit than the optimal algorithm in more than half of the realisations, which is paid for with a more significant underperformance in the remaining realisations.
All the problems discussed in this thesis lead to continuous optimisation problems. We develop a new algorithm that can be used on top of existing optimisation algorithms to reduce the cost of approximating solutions. The algorithm is tested on a range of optimisation problems and is shown to be competitive with existing methods.

Keywords: decision making
optimisation
optimal control
Advisor: Dewynne, J
Farmer, C
Biogenic silica diagenesis under early burial in hemipelagic marine sediments

Four aspects of biogenic silica diagenesis are researched under this project: signatures of ongoing silica diagenesis in pore water, drivers leading to anomalous compaction (abrupt petrophysical changes), bottom-water temperature controls on silica dissolution and recycling, and temperature-time relationships in silica later diagenesis. Results of this project are discussed in Chapters 4–7.
Chapter 4 demonstrates, based on pore chemistry, mineralogy, and thermodynamic analyses, that solubility equilibrium is reached for diagenetic silica in pore water at opal-A to opal-CT transition zone captured by Ocean Drilling Program Sites 794 and 795 in Japan Sea; thus opal-CT is precipitating across the transition. It is also argued that ion transport mechanisms have failed to erase signatures of ongoing diagenesis.
Chapter 5 utilises texture and mineralogical analyses of hemipelagic sediments from Sites 794 and 795 to place anomalous compaction across the transition zone in a diagenetic context. A sharp decrease in opal-A content in the transition under dissolution causes a significant decrease in sediment stability which results in a porosity drop and other petrophysical variations. Subsequent precipitation of opal- CT has, however, had far less effects on porosity.
Chapter 6 models variations in silica dissolution and recycling with bottom-water temperatures using data from 22 representative Ocean Drilling Program sites. Though model expression of early diagenesis confirms a relationship between temperature and opal-CT formation in young sediments (&LT; 4 Ma) near the seabed in the Antarctic, the established inverse temperature-time correlation in silica diagenesis contradicts main controls from low bottom temperature over a short geological time.
Chapter 7 investigates temperature-time relationships in silica diagenesis by examining 67 scientific drill sites where the opal-A to opal-CT transition zone lies in Cenozoic sediments. Based on these constraints, the reference opal-CT stability field is modified. The chapter also applies a model that formulates time-temperature dependence of silica diagenesis in representative Sites 794 and 795.

Advisor: Tosca, N
Cartwright, J
Respectable banking: the search for stability in London’s money and credit markets since the great currency crisis of 1695

The history of London’s money and credit markets is one of intermittent crises interspersed with successive attempts to find ways and means of stabilizing the system. The currency reforms of the eighteenth century, and the banking ones of the nineteenth, culminated in a century of stability which lasted until 1971. Recent scholarship has emphasized the importance of the Bank of England’s role as lender of last resort, and its modern extension, deposit insurance. Less heed has been paid to various market practices introduced in the late nineteenth century that had the effect of restricting competition. These practices included curbs on liability management and rediscounting, prohibitions against speculative lending, liquidity requirements, and limits on maturity mismatching. In the 1930s, the building societies broke most of these rules, combining liability management with maturity mismatching, and the resultant housing boom could have led to a bust, but for the war. Cartel control of the mortgage lending rate after the Second World War helped to limit liability management, and provided a mechanism for managing liquidity in a sector that faced considerable maturity mismatching.
A tendency to downplay the importance of these restrictions has encouraged a degree of complacency about their removal, and the deregulation that started in 1971 created a banking model that disregarded these principles of sound banking. The events of 2007-8 suggest a reappraisal is needed, and this study offers a revised interpretation of developments in the London market since the great currency crisis of 1695. Currency stability was achieved in the eighteenth century by keeping the price of gold aligned with the nominal value of guineas. In the late nineteenth century, banking practices likewise sought to stabilize the prices of assets used to support paper money. This culminated in the clearing bank model of the 1890s and the building societies model of the 1950s, both of which lasted until the onset of deregulation in the 1970s and 1980s.

Advisor: Dimsdale, N
The Eoan Group and the politics of coloured opera in apartheid South Africa

The Eoan Group, founded in 1933 in Cape Town, was South Africa’s first and only all-coloured opera, dance and theatre company. Its 1956 production of La Traviata was the first opera produced by non-white people in South Africa, and initiated an operatic career that spanned twelve opera seasons and ten operas. The group was under the administration of white directors and received funding from the apartheid government. In return, they agreed to honour the regime’s racial laws by performing for segregated audiences. Their acquiescence to segregation and their complicity in the promotion of apartheid ideology caused political problems: they were ostracised by their own community and boycotted by members of the white and coloured racial groupings. After the group’s operatic activities came to a permanent halt in 1980, their history sank into obscurity, despite their importance in the establishment of an operatic culture in the country. The memorialisation of South Africa’s cultural-political past continues to maintain a binary of complicity and resistance, with those who are remembered grouped neatly into either of these categories. These labels, however, do not map tidily onto the Eoan Group, with its bewildering narrative of self-empowerment-through-collusion. Consequently, their story presents a problem for the writing of South African music history.
Drawing extensively on material from the Eoan Group Archive, this dissertation considers the socio-political ambiguities of the Eoan narrative from musicological and post-colonial theoretical angles, to show how the group’s operatic activities disrupted the cultural and material determinism of apartheid’s racialised ideology. It calls for a disavowal of the Manichean ethics by which subaltern agency is measured, and proposes instead a turn to Njabulo S. Ndebele’s ‘politics of the ordinary’. From the sonic and material residue of the Eoan Group’s productions, this project forges a newly conceived decolonial writing of apartheid operatic history.

Keywords: Race
Opera
Apartheid
Eoan Group
South Africa
Advisor: Grimley, D
Experience-based object detection for robot perception

A fundamental challenge in deploying vision-based object detection on a robotic platform is achieving sufficient perceptual performance for safe and effective operation. While general purpose object detectors have steadily improved in performance, we are still some way from being able to rely solely on purely vision-based robotic perception systems.
This thesis seeks to resolve this problem by exploiting a characteristic of computer vision unique to robotic applications, with a particular focus on pedestrian detection for autonomous driving. Robots - even mobile ones - typically have some inherent structure to the visual data they process. Firstly, they operate in the same environment (for example, regular commuting or errands with autonomous cars), and secondly, they are able to localise within that environment.
Place matters in robotics, as we can exploit this additional context to boost perceptual performance by constructing object detector models fitted to a mobile robot’s place of operation. We demonstrate that, in an ideal scenario with ground truth labels, we can significantly improve the detection performance of lightweight object detectors by exploiting place. Our results suggest that a key factor limiting detection performance is the model capacity, suggesting that this approach could equally be applied to higher capacity models as the computational budget dictates.
This local expert detector is developed into a deployable, self-supervised system, using offline image segmentation and spatial heuristics to construct the detector models and a visual localisation system to retrieve them at run time. This approach boosts the perceptual performance of our lightweight object detector models.
Finally, this ensemble approach to local expert object detection is extended further with a neural network trained to generate detector models conditioned on the input image, an approach we refer to as a Dynamic Detection Filter Network. The network learns a representation of the operating environment, generating model parameters based on the input image. This offers a general approach to constructing place specific object detectors independently of localisation, with the potential to operate on larger scales with many different environments.

Advisor: Posner, I
Newman, P
Singular representation

This thesis is a study of aboutness. It defends the claim that we have singular thoughts about ordinary objects and argues that an essential part of how we do so is by maintaining singular representations. This proposal allows us to avoid traditional, unsatisfying conceptions of the scope of singular thought while restoring the sense in which such thought is a distinctively epistemic achievement. Reconnecting the study of aboutness with epistemology promises to alleviate the sense of directionlessness in the contemporary literature, offering a firmer grip on the phenomenon along with new, systematic resources for its investigation.
Chapters 1–2 explore the effects of contextualist machinery on orthodox views about singular thought. It is widely thought that if there is to be a plausible connection between the truth of a de re attitude report about a subject and that subject’s possession of a singular thought, then there can be no acquaintance requirement(s) on singular thought. Chapter 1 shows that this view rests on a faulty picture of how we talk about attitudes. Indeed, the truth of a de re attitude report cannot be taken to track the singular/non-singular distinction without collapsing it. A new, contextualist picture is needed. That there must be a distinction between singular and non-singular intentionality is emphasized in Chapter 2, where a key explanatory role for singular thought—brought out by a thought experiment due to Strawson—is examined. I show that the role does not call for any distinctive kind of mental content.
Once we abandon the two widespread views questioned in Chapters 1–2, our grip on the phenomenon of singular aboutness is loosened: it is not constitutively tied to the kinds of attitude-reporting data or mental content by which it is often assumed to be revealed. Where are we to look for insight? What makes something the object of a singular thought?
According to Russell, it is a datum of intuition that singular thought involves a kind of knowledge; a theory of aboutness will precisify the intuitive notion of ‘knowing which thing one is thinking about’ in order to capture this demand in a philosophically revealing way. If Russell is right, teasing out this connection to knowledge will allow us to see what it takes for a particular thing to be the immediate subject matter of thought. Chapter 3 discusses Evans’s theory of this kind. Chapter 4 examines recent work by Dickie. While serious concerns emerge in each case, insights recovered are used to precisify Russell’s requirement, leading to a novel picture of singular representation and the epistemic character of this achievement.
While the chapters follow a narrative, providing an extended rationale for the proposal in Chapter 4, each may be read in isolation by those familiar with the philosophical issues. For those who are not, the Introduction provides sufficient background.

Keywords: Representation
Contextualism
Attitude reports
Knowing which
Reference
Singular thought
Aboutness
Acquaintance
Advisor: Hawthorne, J
Williamson, T
The stability of host-pathogen multi-strain models

Previous multi-strain mathematical models have elucidated that the degree of cross-protective responses between similar strains, acting as a form of immune selection, generates different behavioural states of the pathogen population. This thesis explores these multi-strain dynamic states, to examine their robustness and stability in the face of pathogenic intrinsic phenotypic variation, and the extrinsic force of immune selection. This is achieved in two main ways: Chapter 2 introduces phenotypic variation in pathogen transmissibility, testing the robustness of a stable pathogen population to the emergence of an introduced strain of higher transmission potential; and Chapter 3 introduces a new model with a possibility of immunity to both strain-specific and cross-strain (conserved) determinants, to investigate how heterogeneity in the specificity of a host immune response alters the pathogen population structure. A final investigation in Chapter 4 develops a method of reverse-pattern oriented modelling using a machine learning algorithm to determine which intrinsic properties of the pathogen, and their combinations, lead to particular disease-like population patterns. This research offers novel techniques to complement previous and ongoing work on multi-strain modelling, with direct applications to a range of infectious agents such as Plasmodium falciparum, influenza A, and rotavirus, but also with a wider potential for other multi-strain systems.

Keywords: pathogen
invasion
random forest
influenza
rotavirus
multi-strain
Advisor: Gupta, S
Lorenco, J
Finite element analysis of short-term and long-term building response to tunnelling

Tunnelling in urban areas causes short-term and long-term ground movements under existing buildings. Finite element analysis provides a useful option for assessing the likely extent of damage induced in these buildings. Although finite element analysis is suggested to be used in the later phases of the building damage assessment procedures employed in practice, only the effect of short-term ground movements is typically considered and there are no detailed guidelines on the specification and complexity of the modelling. This thesis addresses the tunnel-soil-building interaction problem and the effect of long-term consolidation, as well as demonstrating the application of 3D finite element analysis with appropriate simplifications for practical assessment purposes.
Finite element models are developed to quantify the effect of shallow tunnelling on an example masonry building founded on strip footings, considering both single- and twin-tunnel scenarios in a typical London soil profile. Total stress and effective stress analyses are adopted with specific modelling procedures to focus on the short-term and long-term response respectively. The analyses use a non-linear model for the masonry, and allow slippage and gapping at the soil-footing interface. Two advanced constitutive models for the soil (the extended Mohr-Coulomb model and the modified two-surface kinematic hardening model) are implemented with customized stress update schemes.
The finite element results present the interaction between the soil and the building by comparing with the greenfield ground response. The horizontal coupling between the foundation and the ground is shown to be relatively weak. The dominant deformation mode of the building varies with the tunnel configuration (i.e. single or twin tunnels) and the tunnel eccentricity. Strain localization is found around the explicitly modelled window and door openings. The long-term consolidation is sensitive to the permeability of the tunnel lining. The building response to long-term ground movements is further affected by the tunnel-tunnel interaction in the case of twin-tunnel configuration.
Performing 3D analysis of a single facade and foundation provides useful damage predictions, without the need to model a complete building. The proposed result processing methods such as characteristic strain and damage bar chart are practical tools for assessment. The study highlights some limitations of the elastic beam assessment method, which is often adopted in the early phase of the damage assessment process.

Keywords: Constitutive models
Immediate settlement &amp; consolidation
Tunnels &amp; tunnelling
Finite element analysis
Building damage assessment
Masonry structures
Soil-structure interaction
Advisor: Burd, H
Martin, C
A study of protein regulation by mass spectrometry-based methods

Understanding the function and regulation of proteins is critical to medical and physiological research. To achieve this, the modification status, as well as the interactions of proteins need to be defined. Mass spectrometry is often used to catalogue modifications but their effect on interactions is less often reported. In this thesis these two strands are combined to address a series of challenging complexes that underpin cellular processes from stress responses to energy production.
Following an introduction to mass spectrometry and its applications to the study of protein interactions (Chapters 1 and 2), three protein assemblies are considered; Hsp70 chaperones, eukaryotic translation initiation factors, and F- and V-type ATP synthases. First, the oligomerisation of Hsp70 is studied (Chapter 3). Dimerisation is shown to be dependent on a highly-conserved phosphorylation site, suggesting a role for this modification in the regulation of protein complex assembly and targeting to antagonistic pathways.
A study of eukaryotic translation initiation factor 2B (eIF2B) is presented (Chapter 4), with proteomics revealing clusters of modifications at protein interfaces. Chemical cross-linking is applied, eliminating proposed structural models and supporting a decameric assembly. A cognition-enhancing drug (known as ISRIB) is an inhibitor of the integrated stress response, and was found to stabilise the active decameric eIF2B assembly, rationalising the observed therapeutic effects of ISRIB.
Finally, ATP synthases, membrane protein complexes which exhibit multiple forms of regulation, are investigated (Chapter 5). Positional information of small membrane subunits and the effect of post-translational modifications is deduced. The role of an endogenous inhibitor protein is investigated providing insights into its location, oligomeric state, and influence on nucleotide binding.
Overall this thesis applies mass spectrometry to three critical protein assemblies and contributes a more complete understanding of their activity by uncovering aspects of their carefully-tuned regulatory mechanisms.

Advisor: Robinson, C
Electronic and steric modification of divalent group 14 compounds using peripheral boryl substituents

This thesis examines the use of sterically demanding boryl groups as peripheral substituents on N-heterocyclic carbenes and Group 14 tetrelenes.
Chapter III focuses on the syntheses of borylated imidazoles and imidazolium salts. With the aim of accessing an N,N’-bisborylated NHC or its metal complexes, the reactivity of bisborylated imidazolium salts with Brønsted bases and metal complexes was studied. The results highlight the lability of the N–B bond and electrophilicity of the boryl group as displacement of the boryl group was repeatedly observed.
Chapter IV deals with the syntheses and reactivity of unsymmetrical borylated imidazolium salts and the corresponding carbenes. An unsymmetrical bisborylated carbene has been observed and characterized both in situ and with a range of trapping experiments. This system is however characterized by a 1,2-shift of the N-bound boryl group to the C2 position. Slow rearrangement allowed for assessment of the kinetic properties of the reaction experimentally; computational studies provide consistent activation barriers and suggest an intramolecular migration pathway. Structural and spectroscopic studies of transition metal complexes and a selenium adduct of the carbene allowed for investigation of the steric and electronic properties of the carbene.
Chapter V examines the attempts to synthesize N,N’-bisborylated saturated N-heterocyclic carbenes and tetrelenes. Bisborylated N-heterocyclic germylenes and stannylenes were successfully synthesized and structurally characterized. Their reactivity towards small molecules was examined, with the pursuit of a germanone being of particular interest.

Advisor: Aldridge, S