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Navigating intersectional identities : the experiences of International Sign interpreters and deaf professionals
Full text linkThis doctoral thesis examines the intersectional experiences of International Sign (IS)
conference interpreters and deaf professionals in high-level positions who work with IS
interpreters. The study includes 33 participants with diverse gender, racial, sexual, linguistic,
and geographical backgrounds. Using a multi-phased, multi-method qualitative approach,
including conversations, observations, and mind map interviews, the study provides an in-depth analysis of IS conference interpreting. The theoretical framework adopts a relational
approach and integrates Gender Studies, Critical Race theory, and the Sociology of Work,
drawing on gender and inequality theories in the workplace, intersectionality, and identity
taxation, alongside insights from Deaf Studies and Sign Language Interpreting Studies.
Findings reveal that access to working as an IS conference interpreter is gendered. Feelings of
not belonging are heightened for those in less privileged positions, influenced by male and
hearing dominance, language background, imposter syndrome, and the lack of diverse role
models. These factors shape their experiences of (not) applying for (pre/full) IS accreditation.
Tokenism impacts Global Majority, female, and deaf interpreters, who often seem to be valued
for their identities rather than their skills. Global Majority women face additional identity
taxation, due to representational responsibilities. Despite appearing cohesive, IS interpreting
networks reinforce exclusivity through selective gatekeeping and support practices.
The study further explores the nature of IS conference interpreting, emphasising close
collaboration with deaf professionals. Hierarchies within the field are shaped by hearing
dominance, gender, age, seniority, and professional settings, including the people involved.
The field demands flexibility, creating challenges for caregiving interpreters. Travel
opportunities are unequally distributed, with safety concerns for female, queer, and gender
nonconforming interpreters. Interpreters engage in aesthetic and gendered labour to conform
to, and occasionally challenge, organisation norms.
Finally, the study examines how social identities shape interpreting practices and interactions.
Deaf professionals experience deaf taxation when managing interpreter attitudes and
navigating tensions. They express gendered preferences, with authentic representation being
critical for deaf professionals of colour and queer deaf professionals, yet they often work with
interpreters who are less aligned in terms of identities. IS interpreters face identity taxation, particularly women who encounter inappropriate behaviour. Team dynamics are shaped by
masculinities and femininities, with queer interpreters challenging hetero/cisnormativity.
Global Majority female interpreters navigate racialised and gendered expectations, often
avoiding confrontation to mitigate professional consequences.
The study contributes to Gender Studies, Critical Race Theory, Sociology of Work, Deaf
Studies, and Sign Language Interpreting Studies. Its findings have implications for both
practice and pedagogy in the sign language interpreting field and may inform other gendered
and mobile fields of work
Continuous and ultra-compact LiDAR mapping and localisation
No full textRecently, Light Detection and Ranging (LiDAR) has gained prominence in robotics
and autonomous driving for capturing precise environmental geometry, essential for
simultaneous localisation and mapping (SLAM) and navigation. However, storing
and updating large-scale high-definition maps presents significant challenges, making
the development of memory-efficient, updatable, and localisable map representations
crucial for advancing SLAM systems in dynamic environments.
In this thesis, we present a series of advancements in LiDAR-based SLAM systems aimed at achieving memory-efficient representation, continuous reconstruction,
and global mapping. The term continuous reconstruction refers to a continuous function that allows sampling 3D points at any resolution. We firstly introduce CURL
(Continuous, Ultra-compact Representation for LiDAR), which leverages spherical
harmonics (SPHARM) basis functions to encode point clouds, achieving effective
compression and continuous reconstruction while outperforming contemporary deep
learning methods. Building on this foundation, we propose CURL-MAP, an extension of CURL for mapping with pose estimation capabilities, utilising a set of
bounding boxes containing SPHARM-encoded patches to construct a global map.
To build a globally consistent map, we develop CURL-SLAM, which contains a
customised CURL-based bundle adjustment (BA) with pose graph to ensure global
consistency, even in large-scale scenarios and further increase the efficiency of the
system by replacing quasi-conformal mapping with a mask-based method for identifying valid regions. These modifications reduce computational requirements and
storage space, facilitating the integration of all newly observed patches and enhancing system robustness.
Overall, CURL, CURL-MAP, and CURL-SLAM collectively offer a memory-efficient, updatable, and localisable 3D dense map representation, supporting continuous reconstruction for robust SLAM applications
Accurate estimation of macroscopic flow properties in porous media : from REV to upscaling
Full text linkRepresentative Elementary Volume (REV) is the smallest volume of a porous media
above which further size increases do not yield any changes in the measurements of a
specific property. It is well established that the REV can vary across geological scales for
different static (e.g., porosity) and flow-based properties (e.g., permeability). Most REV
studies available in the literature are focused on static properties at the pore scale.
However, in this study, we have focused on determining REV for single-phase flow
parameters at the core scale to investigate whether SCAL experiments are performed on
a representative volume. Also, the feasibility of using tracer tests for determining core scale REV was investigated since the shape of the effluent tracer tests can be a good
qualitative indication of the heterogeneity, and the Peclet number can be a quantitative
measure.
For this purpose, several heterogeneous reservoir sections were generated, and tracer
flood simulations were conducted on sub-samples of various sizes. It was demonstrated
that, in general, permeability-based REV based on the common approach in the literature
closely match the corresponding REV figures showing the accuracy of the novel tracer-based technique. As part of this study, the numerical dispersion associated with various
techniques available for the simulation of tracer flow were also investigated and
quantified.
After identifying REV and performing SCAL experiments on a representative volume,
an upscaling method is needed to use the results in reservoir-scale simulations. In this
study, a complete set of two-phase numerical coreflood tests, along with a Gaussian
Process Regression algorithm (GPR), was used to obtain a data-driven model. This model
relates the measured oil production and pressure drop to the basic fluid and rock
properties through dimensionless groups. Using dimensionless groups eliminate the
impact of sample size on the results. Therefore, a new oil production and pressure drop
curve can be calculated using the data-driven model for any larger or smaller sample. The
obtained curves can be history matched to find the relative permeability at a larger scale.
Next, the proposed upscaling method is extended to three-phase flow by introducing
relevant dimensionless groups. The three-phase upscaling methodology is validated
against large-scale numerical tests representing different reservoir heterogeneity patterns
and fluid properties. The proposed approach demonstrates excellent performance in predicting oil recovery, water production, and pressure drop in three-phase flow systems
and also upscaling three-phase relative permeability functions in heterogeneous porous
media.
In summary, this study contributes to the advancement of REV characterisation and
relative permeability upscaling techniques for multi-phase flow in porous media. The
developed tracer technique and dimensional analysis approach, coupled with the GPR
algorithm, provide an accurate and reliable framework for capturing reservoir
heterogeneity and predicting flow behaviour at larger scales. Also, the proposed approach
demonstrates superior performance compared to the existing methods. The findings of
this study have implications for optimising sampling strategies and enhancing the
predictive capabilities of reservoir upscaling models
Management of scallop fisheries to reduce the environmental impact on seabed habitats
Full text linkThe king scallop (Pecten maximus) fishery in the UK is a significant economic resource,
contributing over £50 million annually in first sales. However, the primary harvesting
method—scallop dredging—raises major environmental concerns due to its impact on seabed
habitats. Current management strategies primarily focus on conserving target species,
neglecting broader ecosystem protection. This thesis critically reviews global and UK-specific
scallop fisheries management practices, revealing the inadequacies of existing measures in
addressing environmental damage.
By utilising vessel monitoring system (VMS) data, the spatial distribution and intensity of
scallop dredging in the UK Exclusive Economic Zone (EEZ) are mapped, highlighting the most
affected habitats. A risk assessment framework is developed to identify and prioritise the
management of Vulnerable Marine Ecosystems (VMEs) at greatest risk from dredging,
highlighting gaps in Marine Protected Area (MPA) management. The thesis also examines the
concept of 'marginal' fishing grounds—areas that offer significant conservation benefits while
carrying low economic value—suggesting that their protection could minimise ecological harm
with minimal economic impact.
In addition to spatial and effort-based management, a gear modification aimed at reducing
seabed impact was assessed. The addition of skids onto scallop dredges to reduce seabed
contact showed promise, though increased bycatch and undersized scallops indicate further
refinement is needed. The research emphasises the need for continuous innovation in fishing
gear design as part of a comprehensive management strategy.
The thesis concludes with recommendations for a holistic, integrated approach to UK scallop
fishery management. Combining spatial, effort-based, and technical interventions, this
approach offers a sustainable path forward that balances environmental conservation with the
economic viability of the fishery for future generations
Retrofit ready : redefining energy and carbon life cycle methods
Full text linkRetrofits are a necessity for reducing the UK’s energy demand and carbon emissions.
However, with 26 million homes to treat and massive implications for material
consumption, life cycle energy and carbon impacts demand close attention; this refers to
the operating impacts, as well as the embodied impacts, i.e. those expended in products
for resource extraction, manufacture, and end-of-life waste treatment and disposal. Sparse
data on retrofits and inconsistency in life cycle methods confounds the relationship
between operating and embodied impacts at a population-level, meaning that
identification of the dominant factor, and hence retrofit’s overall benefit, remains
ambiguous. Variability of embodied impact data, and underrepresentation of prominent
retrofit materials were found to present further barriers to robust analysis. A redefined
approach for a “retrofit life cycle analysis” (RLCA) is proposed, alleviating
inconsistencies present in previous studies, and pinpointing the focus on the life cycle
performance of thermal measures. This enables the derivation of an operating savings and
embodied expenditure balance (O:E), which facilitates better evaluation of the life cycle
performance than simply describing the resulting operating or embodied impacts.
Through RLCA and the O:E balance, quantifiable parameters for proceeding,
redesigning, or discontinuing the retrofit may be established, described as the “Retrofit
Tipping Point”. The approach is tested with two archetypal UK case study houses and
proposed retrofits, plus variants. Operating impact savings were found to dominate the
O:E balance in all variants, demonstrating that the retrofits achieved operating savings in
excess of the embodied expenditure, indicative of a favourable energy and carbon life
cycle impact. Insulation materials made the largest embodied contribution in most cases.
Case study data was comparable in magnitude to other literature studies; linear
regressions relating operating and embodied impacts revealed line gradients close to zero,
indicating very minimal change in embodied impacts as operating energies reduce. This
suggests that even extensive retrofits can be beneficial over their life cycle.EPSRC Doctoral Training Partnership fundin
3D and 4D inversion for rock and fluid properties using deep learning
Full text linkThis thesis focuses on estimating rock and fluid properties from the perspective of 3D and 4D
seismic inversion. I developed two techniques that enable seamless integration of 3D and 4D
seismic data. The first technique emphasises the estimation of porosity, Vclay, and hydrocarbon
saturation directly from 3D seismic data using deep learning. Additionally, I propose an
approach to enhance the lateral continuity of these estimated petrophysical properties. The
products from this first technique are subsequently integrated into the 4D domain, leading to
the development of the second technique that enables the inversion for reservoir pressure and
saturation changes from 4D seismic data using deep learning. Both techniques involve the use
of synthetic training datasets for network training, where the detailed processes for building
realistic training datasets are presented. The first technique was tested across four fields with
diverse deposition environments, covering meandering fluvial systems, fluvial estuaries,
deepwater settings, and carbonate platforms. The second technique was applied to the
meandering fluvial field with available 4D seismic data. This technique successfully
distinguishes pressure effects from saturation-related effects in the 4D seismic response. It also
highlights the importance of incorporating fluid flow information into the training dataset,
enabling the network to capture the relationship between the superimposed effects of dynamic
property changes and the corresponding 4D seismic response. Finally, I present a summary of
the cost-benefit analysis of these developed techniques, demonstrating their ability to
accelerate the inversion process in terms of turnaround time while providing robust solutions
when applied to field applications
(Non)-Morse directions in groups
Full text linkIn this thesis, we study Morse directions and the Morse boundary of groups. We
start by classifying the Morse boundary of all 3-manifold groups and showing that
the Morse boundary of an orientable 3-manifold group only depends on the geometric
decomposition of said manifold. This classification requires deep understanding of what
it means to be Morse and how to manipulate Morse geodesics.
While the theory of Morse boundaries and Morse geodesics is largely developed in
analogy with Gromov boundaries, in the rest of this thesis, we focus on phenomena
which are unique to the Morse boundary and non-hyperbolic groups. Firstly, we study
the (non)-σ-compactness of the Morse boundary. The Gromov boundary of a group
is always compact. In contrast, the Morse boundary of a group is only compact if
it is empty or the group is hyperbolic. However, the Morse boundary exhibits more
nuanced behaviour. Namely, we show that there are groups whose Morse boundary is
σ-compact and groups where it is not. We give a full characterisation, which is purely
combinatorial in terms of the presentation, of σ-compactness of the Morse boundary
for classical small-cancellation groups. This can be used as a way to distinguish small-cancellation groups up to quasi-isometry. Furthermore, we show that for C
′
(1/9)–
small-cancellation groups, the group satisfying the Morse local-to-global property is
equivalent to its Morse boundary being σ-compact, implying that the topology of the
Morse boundary has surprising implications on the concatenability of Morse geodesics.
Secondly, in hyperbolic groups all geodesics are strongly contracting. This is precisely not the case for non-hyperbolic groups. We develop the notion of “anti-contracting
geodesics segments”, that is, geodesic segments which are intrinsically not strongly
contracting. We not only show that for any geodesic metric space, coning-off all anti-contracting geodesic segments results in a hyperbolic space (which we call the contraction space) but also show that if a finitely generated group acted properly on
the geodesic metric space, then its action on the contraction space is non-uniformly
acylindrical. Moreover, if the action was geometric and the original space was Morse-dichotomous (that is, all Morse geodesics are strongly contracting; this is the case in
CAT(0) spaces and injective metric spaces), then the action on the contraction space
is a universal WPD action
An assessment of factors that influence coalition size of horizontal collaborations in the UK FMCG road freight transport sector
Full text linkRoad freight transport plays a crucial role in supporting the UK economy, accounting for 79% of
all domestic freight movements. However, there are inefficiencies in road freight operations, with
30% of vehicles running empty and only 63% of vehicles loaded to their capacity during their
journeys. These inefficiencies not only impact operating costs but also contribute to higher carbon
emissions. Transport is the largest GHG emission sector contributing 24% of the overall carbon
emissions in the UK. Governments are setting decarbonisation targets to reduce carbon emissions
from their economy and in the UK, the government has announced a plan to reduce carbon
emissions to net-zero by 2050. Most companies primarily rely on internal measures to enhance
efficiency from transport operations, but they have exhausted opportunities for further process
optimisation within their existing operational boundaries.
Horizontal collaboration is one of the solutions that go beyond organisational boundaries and has
the potential to provide efficiency improvements, such as carbon and cost savings between 10-
30%. Theoretically, cooperative game theory suggests companies can achieve optimal cost savings
by forming a grand coalition. Despite the benefits associated with a grand coalition, coalition size
exceeding more than four companies is rare in practice and many collaborations fail during the
implementation stage. The aim of this study is to assess the factors influencing coalition size of
horizontal collaboration and evaluate coalition maximising strategies in the UK FMCG road
freight transport operations to enable large size coalition.
Methodologically, a systematic literature review conducted to identify the factors that influence
coalition size of horizontal collaborations. Additionally, underpinning theories to horizontal
collaboration such as cooperative game theory, social exchange theory and transaction cost
economies were used to develop the conceptual framework. A mixed-methods approach is applied
in this study, integrating focus group discussions to gain qualitative insights into factors
influencing coalition size, and the Analytic Hierarchy Process (AHP) to systematically evaluate
horizontal collaboration strategies and prioritise factors influencing coalition size of horizontal
collaborations.
The primary contribution to knowledge is identification of factors using literature review and
theoretical foundation. Moreover, it prioritises identified factors that influence coalition size of
horizontal collaboration and evaluate coalition maximising strategies in the UK FMCG road
freight transport sector.
This thesis provide AHP model for assessment of factors that enable practitioners to optimise their
resource allocation by focussing on the most significant factors before joining a coalition.
Moreover, it supports decision-makers by evaluating coalition maximising strategies for
implementation of large size coalition
Benthic foraminifera as proxies for reconstructing past seawater oxygenation in the Southeast Pacific
No full textIn the current ocean, deoxygenation significantly threatens marine life and ecosystems,
particularly in regions with oxygen depleted zones like the Southeast Pacific (SEP). While
the response of benthic foraminifera to low oxygen environments has been studied, it
remains poorly understood how effectively they can be used to quantitatively reconstruct
past oxygen levels, especially in the dynamic SEP with steep oxygen gradients. This
thesis addresses this gap by calibrating and applying two benthic foraminifera-based
proxies to reconstruct bottom water dissolved oxygen concentrations (BWDO)
quantitatively: (i) the test porosity of epifaunal species, mainly Cibicidoides wuellerstorfi,
and (ii) the carbon isotope gradient Δδ13C between epifaunal (C. wuellerstorfi) and infaunal
(Globobulimina spp.) species, using specimens from surface sediments along the Chilean
and Peruvian coasts. A taxonomic revision of the key species used in the calibrations is
presented, refining their identification and enabling accurate proxy calibration. Age
evaluation of specimens is applied to ensure that specimens accurately reflect modern
conditions. Results indicate that both porosity and Δδ13C are reliable proxies for
reconstructing BWDO, each with limitations and strengths. The porosity proxy is reliable
for BWDO values less than 100 µmol kg-1, and its accuracy in estimating BWDO depends
on the number of specimens analyzed and their standard deviation. The Δδ13C proxy is
contingent on the availability of Globobulimina species in the samples. It can be applied
in waters deeper than 500 m; in shallower low oxygen settings, denitrification may
influence the δ13C values of Globobulimina tests. Both proxies were applied to assess the
influence of warmer/cooler climates during the Marine Isotope Stage (MIS) 9 and 13 on
deep waters in the SEP. Compared with the Holocene, the results show deoxygenation
during the warm interglacial period of the Marine Isotope Stage (MIS) 9 and likely higher
oxygen levels during the cooler MIS 13. This research refines the application of benthic
foraminifera as paleoxygenation proxies, outlining their advantages and disadvantages.
Both proxies offer an insightful tool to understand past deoxygenation and to provide
potential analogues for future scenarios in a warming worl
Modelling the impact of shared pathogens in wildlife communities
Full text linkThe thesis uses mathematical modelling to answer important eco-epidemiologial questions in scenarios where interacting species share an infectious disease. These questions
are important as shared disease is often linked to successful species invasion and so the
disease increases the threat for native species. Shared disease is also linked to spillover
and zoonotic infection and so can pose a threat to human health.
We develop a model to assess the threat of the shared disease, squirrelpox, carried by
the invasive grey squirrel to the conservation of red squirrels in the UK. We show that the
grey squirrel epidemiological dynamics include reinfection and partial immunity and that
squirrelpox infection levels can be high. This can lead to spillover to red squirrels when
the species are sympatric, leading to epidemic outbreaks in red squirrel populations.
We analyse general models that examine the role of shared infectious disease on the
spatial spread of invasive species and the replacement of native species. We show that
shared infectious disease can increase the rate of replacement of a native species even
when the disease is not supported in the native species system.
We develop a model for a prey, specialist predator, and generalist predator system in
which the predators can become infected through consumption of infected prey and can
transmit infection back to the prey species. The analysis shows that predators can increase
the persistence of infectious disease and may act as epidemic bridges that support the
infection during low density phases in the prey species.UK Engineering and Physical Sciences Research Council grant EP/S023291/
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