VictorJuiz/thesis huggingface dataset:
Shaping single photons
Keywords: quantum computing
quantum simulation
cavity QED

The possibility of creating a scaleable quantum network by interconverting photonic and atomic qubits shows great promise. The fundamental requirement for such a network is deterministic control over the emission and absorption of photons from single atoms. This thesis reports on the experi-mental construction of a photon source that can emit single-photons with arbitrary spatio-temporal shape, phase, and frequency.
The photon source itself is a strongly-coupled atom cavity system based on a single 87 Rb atom within a macroscopic high-finesse Fabry-Perot cavity. It operates intermittently for periods of up to 100µs, with single-photon repetition rates of 1.0 MHz and an efficiency of almost 80%. Atoms are loaded into the cavity using an atomic fountain, with the upper turning point near the centre of the cavity mode. This ensures long interaction times without any disturbances introduced by trapping potentials. The photons’ indistinguishability was tested, with a two-photon Hong-Ou-Mandel visibility of 87%.
This ability to both generate, and control, the photons’ properties, for example producing photons with symmetric or multi-peaked spatio-temporal shapes, allows for the production of photons in an n-time-bin superposition state where each time-bin has an arbitrarily defined amplitude and phase. These photons can be used as photonic qubits, qutrits and qquads, and their properties have been tested using a small linear-optics network.
Irish cultural politics, Thomas McGreevy and the Avant-Garde, 1922-1941
Keywords: Ireland
Jack Yeats
literary criticism
art history
political theory
Irish independence
James Joyce
Samuel Beckett
Thomas McGreevy
avant-garde

This thesis analyses the responses of Irish writers and painters to a phase of national self-assertion that had arguably lost its liberating potential. It shows how the exhaustion of revolutionary pressures in Ireland after independence complicates the ties between creative activity and political activism. Drawing on a wide range of scholarship within political theory, literary criticism and art history, I chart an emerging network of literary and artistic techniques that confronts the representational aesthetics of the nation with strategies of paradox, reversal and renewal. My readings of the work of Denis Devlin, Samuel Beckett, James Joyce, Mainie Jellett, Jack Butler Yeats and, in particular, Thomas McGreevy, provide a means by which to distinguish other cultural possibilities that were imagined and pursued from 1922 to 1941, including McGreevy’s own aspiration to remould 'A Cultural Irish Republic'. The thesis argues that Ireland's political and artistic avant-garde were forcibly divided during this period: two factions that had been split apart by the effects of civil war and censorship. As such it will be preoccupied with a central question: how to sustain cultural strategies of revolutionary significance when the frontier between creative activity and political activism can no longer be straightforwardly crossed.
Canonical extensions of bounded lattices and natural duality for default bilattices
Keywords: bounded lattice
canonical extension
natural duality
bilattice

This thesis presents results concerning canonical extensions of bounded lattices and natural dualities for quasivarieties of default bilattices. Part I is dedicated to canonical extensions, while Part II focuses on natural duality for default bilattices.
A canonical extension of a lattice-based algebra consists of a completion of the underlying lattice and extensions of the additional operations to the completion. Canonical extensions find rich application in providing an algebraic method for obtaining relational semantics for non-classical logics.
Part I gives a new construction of the canonical extension of a bounded lattice. The construction is done via successive applications of functors and thus provides an elegant exposition of the fact that the canonical extension is functorial.
Many existing constructions are described via representation and duality theorems. We demonstrate precisely how our new formulation relates to existing constructions as well as proving new results about complete lattices constructed from graphs. Part I ends with an analysis of the untopologised structures used in two methods of construction of canonical extensions of bounded lattices: the untopologised graphs used in our new construction, and the so-called `intermediate structure'. We provide sufficient conditions for the intermediate structure to be a lattice and, for the case of finite lattices, identify when the dual graph is not a minimal representation of the lattice.
Part II applies techniques from natural duality theory to obtain dualities for quasivarieties of bilattices used in default logic. Bilattices are doubly-ordered algebraic structures which find application in reasoning about inconsistent and incomplete information. This account is the first attempt to provide dualities or representations when there is little interaction required between the two orders. Our investigations begin by using computer programs to calculate dualities for specific examples, before using purely theoretical techniques to obtain dualities for more general cases. The results obtained are extremely revealing, demonstrating how one of the lattice orders from the original algebra is encoded in the dual structure.
We conclude Part II by describing a new class of default bilattices. These provide an alternative way of interpreting contradictory information. We obtain dualities for two newly-described quasivarieties and provide insights into how these dual structures relate to previously described classes of dual structures for bilattices.
A top quark mass measurement using a matrix element method
Keywords: top
quark
transfer function
Higgs
matrix element
top quark
JES
Tevatron
CDF
W+jets
likelihood
lepton+jets
jet energy scale
mass

A measurement of the mass of the top quark is presented, using top-antitop pair (t-tbar) candidate events for the lepton+jets decay channel. The measurement makes use of Tevatron proton-antiproton collision data at centre-of-mass energy 1.96 TeV, collected at the CDF detector. The top quark mass is measured by employing an unbinned maximum likelihood method where the event probability density functions are calculated using signal (t-tbar) and background (W+jets) matrix elements, as well as a set of parameterised jet-to-parton mapping functions. The likelihood function is maximised with respect to the top quark mass, the fraction of signal events, and a correction to the jet energy scale (JES) of the calorimeter jets. The simultaneous measurement of the JES correction (ΔJES) provides an in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using 578 lepton+jets candidate events corresponding to 3.2 inverse femtobarns of integrated luminosity, the top quark mass is measured to be 172.4 ± 1.4(stat+ΔJES) ± 1.3(syst) GeV/c², one of the most precise single measurements to date.
Implicit shape representation for 2d/3d tracking and reconstruction
Keywords: real-time
3D tracking
3D reconstruction

This thesis develops and describes methods for real-time tracking, segmentation and 3-dimensional (3D) model acquisition, in the context of developing games for stroke patients that are rehabilitating at home. Real-time tracking and reconstruction of a stroke patient's feet, hands and the control objects that they are touching can enable not only the graphical visualization of the virtual avatar in the rehabilitation games, but also permits measurement of the patient's performs.
Depth or combined colour and depth imagery from a Kinect sensor is used as input data. The 3D signed distance function (SDF) is used as implicit shape representation, and a series of probabilistic graphical models are developed for the problem of model-based 3D tracking, simultaneous 3D tracking and reconstruction and 3D tracking of multiple objects with identical appearance. The work is based on the assumption that the observed imagery is generated jointly by the pose(s) and the shape(s). The depth of each pixel is randomly and independently sampled from the likelihood of the pose(s) and the shape(s). The pose(s) tracking and 3D shape reconstruction problems are then cast as the maximum likelihood (ML) or maximum a posterior (MAP) estimate of the pose(s) or 3D shape.
This methodology first leads to a novel probabilistic model for tracking rigid 3D objects with only depth data. For a known 3D shape, optimization aims to find the optimal pose that back projects all object region pixels onto the zero level set of the 3D shape, thus effectively maximising the likelihood of the pose. The method is extended to consider colour information for more robust tracking in the presence of outliers and occlusions. Initialised with a coarse 3D model, the extended method is also able to simultaneously reconstruct and track an unknown 3D object in real time. Finally, the concept of `shape union' is introduced to solve the problem of tracking multiple 3D objects with identical appearance. This is formulated as the minimum value of all SDFs in camera coordinates, which (i) leads to a per-pixel soft membership weight for each object thus providing an elegant solution for the data association in multi-target tracking and (ii) it allows for probabilistic physical constraints that avoid collisions between objects to be naturally enforced.
The thesis also explore the possibility of using implicit shape representation for online shape learning. We use the harmonics of 2D discrete cosine transform (DCT) to represent 2D shapes. High frequency harmonics are decoupled from low ones to represent the coarse information and the details of the 2D shape. A regression model is learnt online to model the relationship between the high and low frequency harmonics using Locally Weighted Projection Regression (LWPR). We have demonstrated that the learned regression model is able to detect occlusion and recover them to the complete shape.
Morphodynamics of sand mounds in shallow flows
Keywords: numerical modelling
physical modelling
coastal
sand
morphodynamics
marine
sandbanks
sediment transport

Large-scale bed features are often encountered in coastal waters, and include sandbanks and spoil heaps. The morphodynamic development of such features involves complicated nonlinear interactions between the flow hydrodynamics, sediment transport, and bed profile. Numerical modelling of the morphodynamic evolution and migration of large-scale bed features is necessary in order to understand their long-term behaviour in response to changing environmental conditions. This thesis describes detailed measurements of the morphodynamics of sand mounds in unidirectional and oscillatory (tidal) flows, undertaken at the U.K. Coastal Research Facility (UKCRF). High quality data were collected, including water velocities, water levels and overhead images. The parameters tested are: three types of mound shape (circular and elliptical in plan shape, and Gaussian, cosine and triangular in cross-section); underlying fixed or mobile bed conditions; and initial crest height (submerged, surface-touching and surface-piercing). Peak flow velocities are about 0.5 m/s, the sand median grain size is 0.454 mm, and transport occurring mostly as bedload. When analysing the data, the bed contours are determined by digitising the shoreline at different water levels. From these plots, the volume, height, and centroid position of the mound are calculated. A large-scale fit method, based on a Gaussian function has been used to separate small-scale ripples from the large-scale bed structure during the evolution of an isolated sand mound or spoil heap. The bed profile after the ripples are removed is comparable to typical predictions by shallow-flow numerical solvers. The UKCRF experiments investigated the morphodynamic response of a bed mound to hydrodynamic forcing: shape changes, migration rates, volume decay and sediment transport rates. The measured migration rate and decay of a submerged sand mound in the UKCRF are found to be in satisfactory agreement with results from various theoretical models, such as the analytical solution derived by De Vriend. Numerical predictions of mound evolution by a commercial code, PISCES, are also presented for a fully submerged sand mound; the bed evolution is reasonably similar to that observed in the UKCRF. The data provided as a result of the research reported in this thesis provide insight into the behaviour of sand mounds in steady and unsteady flows at laboratory scale, and should also be useful for benchmark (validation) purposes to numerical modellers of large-scale morphodynamics.
Yoga as a complex intervention and its development for health-related quality of life in adult cancer
Keywords: evidence-based health care
cancer
yoga
complex intervention

The aim of this thesis was to develop yoga as a complex intervention in health care for the improvement of health-related quality of life (HRQoL) in adult cancer. As the Indian tradition of practising yoga increases in popularity worldwide, populations in the West are beginning to see yoga as an opportunity to prevent and treat health conditions. The Medical Research Council’s framework has provided a methodology to address a paucity of coherent evidence for the myriad of unsupported health claims made by yoga enthusiasts. The thesis structure included a step-by-step approach to investigate biomedical theories of how yoga might work to improve health, to synthesise evidence of yoga interventions, to model their process and outcomes, and to test evaluation procedures in the context of a randomised controlled trial (RCT). The results of a bibliometric analysis indicated an overall increase in the publication rate of yoga research in health care, and in 2005 this research began to focus on cancer. A component analysis, semi-structured patient interviews (n=10) and oncologist surveys (n=29) were successively designed, implemented and analysed to advance a model of yoga intervention specific to adult cancer. The cumulative results were applied to design three yoga interventions randomly allocated to men and women receiving treatment for cancer (n=15). Outcomes of the feasibility study demonstrated that yoga intervention is appropriate for adult patients and can be administered safely in a clinical setting. In its conclusion, this thesis produces evidence-based support for the optimisation of yoga intervention in the context of a large-scale RCT for HRQoL in adult cancer, and it provides recommendations to improve research methodology and reporting of complex interventions in health care.
Early effects of fluoxetine on emotional processing: implications for adolescent depression
Keywords: adolescent depression
antidepressants
psychopharmacology
affective neuroscience

Depression in adolescence is a major health problem, associated with poor psychological function and key risk factors both for later illness and suicidal behaviours. The antidepressant fluoxetine is commonly used in this population and it is shown to have a favourable benefit-to-risk profile. However, controversy still exists about the use of antidepressants in young people and there is little research focusing on underlying mechanisms of wanted and unwanted actions in this group.
This doctoral thesis aims to investigate, for the first time, the acute effects of fluoxetine on emotional processing, using a combination of behavioural and neuroimaging techniques. The aim is to achieve a greater understanding of the mechanisms underlying fluoxetine use in depressed adolescents, in light of differences seen in their clinical presentation and response to antidepressant drugs.
In the first study (Chapter Two), a single dose of fluoxetine was shown to decrease the recognition of anger in a sample of young adult volunteers, an effect not previously seen in acute studies of older participants. This effect may be particularly relevant for the treatment of adolescent depression, in which symptoms of anger and irritability are often prominent. Beyond this, fluoxetine was shown to increase the recognition of positive vs. negative facial information, and also exerted an anxiolytic-like influence, eliminating the emotion-potentiated startle effect. However, no influence was seen in measures of attentional vigilance to threat. In an attempt to overcome methodological limitations of this study, a paradigm was developed that is particularly sensitive to the detection of automatic biases towards threatening information (Chapter Three).
Chapter Four describes a neuroimaging study with depressed adolescents, in which a single dose of fluoxetine was found to reduce amygdala activity in response to anger. Early changes in amygdala activity to fear correlated with decreased symptoms of anxiety and depression in the first 7-10 days of treatment.
Chapter Five explores the effects of acute fluoxetine in a sample of high trait anger males. This study replicated the finding that fluoxetine acts to increase the recognition of positive information, whilst showing preliminary evidence for a reduction in attentional vigilance to angry faces.
Overall, fluoxetine was found to decrease the processing of anger across studies. This effect was seen alongside a broader influence on positive vs. negative information and anxiolytic-like properties. Together, these results indicate that fluoxetine has direct effects on processes that are especially relevant to adolescent depression and suggest a potential cognitive mechanism for the efficacy of this particular antidepressant in adolescent patients.
Studies in Atticistic lexica of the second and third centuries AD
Keywords: Second Sophistic
Atticism
lexicography

This thesis provides individual studies in and a comparison of the Atticistic lexica of the second and third centuries AD. Modern European classicists have looked at the lexicogra-phers separately, but never as a group or in direct comparison. German philologists of the 19th and early 20th centuries looked at them in depth, but did not draw conclusions for their social context, other than the supposed rivalry between Phrynichus and Pollux, while modern classicists of the late 20th century referred to them mainly as source to strengthen their theories for the broader social context of the Second Sophistic.
Most extant Atticistic lexica stem from the second and third centuries AD, and it seems natural to concentrate on this period of time in this context. The first chapter of this thesis summarises the linguistic developments leading up to this period of time to provide a bet-ter understanding of Atticism. Atticism cannot be understood fully without special consid-eration of the Atticistic lexicographical movement and vice versa. Chapter II discusses Ae-lius Dionysius and Pausanias, the so-called “forefathers of Atticistic lexicography”, and establishes their neutral approach to the promotion of Atticism. Philemon and the Antiatti-cist are briefly introduced in Chapters III and IV, [but not discussed in length due to exist-ing literature and fragmentary character of the former and the unusual approach of the sub-ject matter and the weak manuscript tradition of the latter.] Chapters V, VI and VII form the core of this analysis with the discussion of Phrynichus’ feisty promotion of Atticism, Moeris’ close links to Phrynichus and his unusual tripartite criteria (Ἀττικόν, Ἑλλήνικον, κοινόν), and Pollux��� Onomasticon which provides us with a unique insight to the lexicog-rapher’s methods, intentions and readership. Chapter VIII reveals that there was harsh crit-icism of those who “over-Atticised,” and discusses who of these lexicographers might have fallen under this criticism. Just as there was no standardised approach to the imitation of Attic Greek, there was no standardised lexicographical approach to providing guidance.
Cationic rhodium complexes with chelating phosphine and phosphine alkene ligands. Application in dehydrogenation and dehydrocoupling reactions
Keywords: amine-boranes
reaction mechanisms
catalysis
dehydrogenation
dehydrocoupling
rhodium
phosphine-alkene

A series of cationic Rh(I) diphosphine and phosphine-alkene complexes have been isolated and fully characterised. The reactivity of these species towards hydrogenation, dehydrogenation and dehydrocoupling reactions has been investigated.
The use of potentially hemilabile ligands DPEphos and XANTphos in the intramolecular dehydrogenation chemistry of tricyclopentylphosphine is reported. The comparison in reactivity of these isolated diphosphine phosphine-alkene complexes towards hydrogenation and with acetonitrile is discussed along with their ability to dehydrocouple secondary silane, Ph₂SiH₂, and amine-borane H₃B·NMe₂H. The acceptorless dehydrogenation of a tethered cyclopentane with cationic Rh(I) diphosphine complexes has also been extended to include thioethers.
Isolated cationic Rh(I) phosphine-alkene complexes with labile fluorobenzene ligands are found to act as a source of the reactive 12-electron [Rh{PR₂(ƞ²-C₅H₇)}]+ (R = cyclopentyl (Cyp)/ iPr) fragment in solution and can coordinate two amine-borane ligands (either H₃B·NMe₃, H₃B·NMe₂H or H₃B·NMeH₂) in a novel and unique bis-σ-binding mode. The catalytic activity of some of these isolated complexes in the dehydrocoupling of H₃B·NMe₂H and H₃B·NMeH₂ has been determined. With a view to further understanding the mechanism of catalytic transition metal assisted amine-borane dehydrogenation and dehydrocoupling, known B-N intermediates H₃B·NMe₂BH₂·NMe₂H and [H₂B·NMeH]₃ were also coordinated to the [Rh{PCyp₂(ƞ²-C₅H₇)}]+ fragment and investigated with regard to their role in the catalytic cycle.
Structure activity relationships determined from stoichiometric reactions of cationic Rh(I) diphosphine fluorobenzene complexes with amine-boranes enabled the design of a highly efficient homogeneous catalyst capable of dehydrogenating H₃B·NMe₂H to [H₂BNMe₂]₂ at 0.2 mol% loading in 30 minutes at 298 K. Rapid dehydrogenation and dehydrocoupling of H₃B·NMeH₂ to form high molecular weight poly(N-methylaminoborane) with a low PDI has also been achieved. Investigations using model aminoborane H₂B=NiPr₂ and intermediate B-N species H₃B·NMe₂BH₂·NMe₂H and [H₂B·NMeH]₃ has helped establish an overall mechanistic rationale for this process.
Varieties and politics of skill protection: a micro level analysis of unemployment protection systems in Europe
Keywords: vocational and professional training
human capital
social policy preferences
VoC
Varieties of Capitalism
labour economics
skill specificity

Varieties of Capitalism theory predicts that the skill specificity of workers determines their demand for social protection. In this thesis, I test this assumption using a measure of occupational mobility between pre- and post-unemployment, which I apply to European workers in different skill groups as defined by Fleckenstein et al., (2011). Using this measure as an indicator of the portability of workers' skills, I then evaluate whether the lower marketability of human capital investments is associated with greater demand for unemployment protection. The findings demonstrate that whilst this relationship is apparent in certain countries, notably Coordinated Market Economies such as Germany, the assumptions do not apply across institutional settings. Consequently, skill specificity cannot explain variation in attitudes towards unemployment protection policies between countries.