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University of Nottingham
1.
Weston, Caron Olivene.
An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda.
Degree: PhD, 2014, University of Nottingham
URL: http://eprints.nottingham.ac.uk/27824/ 
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647500
► This research examines the preparation made to enable mathematics teachers to appropriately prepare school leavers entering directly into the workforce upon graduation to handle the…
(more)
▼ This research examines the preparation made to enable mathematics teachers to appropriately prepare school leavers entering directly into the workforce upon graduation to handle the different branches of mathematics. The methodology was that of the interpretive qualitative paradigm. The method was that of the multi method case study and the tools included: constructed conversation; interviews; telephone calls; email; focus group; photography; video recording; participatory observation; observation and documentation. The theoretical framework was informed by components of the Engeström (2001) second generation model. The study found that while there was hardly any preparation made in the system to accommodate mathematics teachers in the appropriate preparation of students to cope with rapid changes in technology and mathematical skills in the workplace, because of on-the-job training, the newly employed were able to handle the mathematics at their workplaces. Additionally, the technological tools in use at workplaces allowed employees to handle the mathematics in work: complicated algorithms associated with mathematical operations were hidden in these technological tools. Employees were then only required to perform an operation of a push or a pull of a button (switch) to turn on or to turn off the device. Equally, mathematical knowledge at the workplace was an activity; thus there was no need for the pedagogical format required for school mathematics classes. This research is significant since this is the first of its kind in the Caribbean using components of the Engeström (2001) second generation model as its theoretical framework and for examination of the mathematics informing workplaces in Antigua and Barbuda. It has also served to bridge a gap between school teachers and employers on communication of the different branches of mathematics required in the workplaces of Antigua and Barbuda. Simultaneously it represents a new block in the wall of literature from scholars in the field of workplace mathematics since the Caribbean’s space was empty.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Weston, C. O. (2014). An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda. (Doctoral Dissertation). University of Nottingham. Retrieved from http://eprints.nottingham.ac.uk/27824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647500
Chicago Manual of Style (16th Edition):
Weston, Caron Olivene. “An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda.” 2014. Doctoral Dissertation, University of Nottingham. Accessed April 19, 2018.
http://eprints.nottingham.ac.uk/27824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647500.
MLA Handbook (7th Edition):
Weston, Caron Olivene. “An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda.” 2014. Web. 19 Apr 2018.
Vancouver:
Weston CO. An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda. [Internet] [Doctoral dissertation]. University of Nottingham; 2014. [cited 2018 Apr 19].
Available from: http://eprints.nottingham.ac.uk/27824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647500.
Council of Science Editors:
Weston CO. An examination of the place of school mathematics in preparing pupils for the workplace in Antigua and Barbuda. [Doctoral Dissertation]. University of Nottingham; 2014. Available from: http://eprints.nottingham.ac.uk/27824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647500
University of Warwick
2.
Ali, Adnan.
Stochastic pattern formation in growth models with spatial competition.
Degree: PhD, 2012, University of Warwick
URL: http://wrap.warwick.ac.uk/54323/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574996
► The field of stochastic growth encompasses various different processes which are ubiquitously seen across the physical world. In many systems, stochasticity appears quite naturally, where…
(more)
▼ The field of stochastic growth encompasses various different processes which are ubiquitously seen across the physical world. In many systems, stochasticity appears quite naturally, where inherent randomness provides the right setting for the tone of motion and interaction, whose symphony leads to the surprising emergence of interesting patterns and structure. Although on the microscopic scale one can be overwhelmed by the randomness arising from the fluctuating interactions between components, on the macroscopic scale, however, one is mesmerized by the emergence of mathematical beauty and symmetry, leading to complex structures with fractal architecture. Competition between components adds an extra degree of complexity and leads to the possibility of critical behaviour and phase transitions. It is an important aspect of many systems, and in order to provide a full explanation of many natural phenomena, we have to understand the role it plays on modifying behaviour. The combination of stochastic growth and competition leads to the emergence of interesting complex patterns. They occur in various systems and in many forms, and thus we treat competition in growth models driven by different laws for the stochastic noise. As a consequence our results are widely applicable and we encourage the reader to find good use for them in their respective field. In this thesis we study stochastic systems containing interacting particles whose motion and interplay lead to directed growth structures on a particular geometry. We show how the effect of the overall geometry in many growth processes can be captured elegantly in terms of a time dependent metric. A natural example we treat is isoradial growth in two dimensions, with domain boundaries of competing microbial species as an example of a system with a homogeneously changing metric. In general, we view domain boundaries as space-time trajectories of particles moving on a dynamic surface and map those into more easily tractable systems with constant metric. This leads to establishing a generic relation between locally interacting, scale invariant stochastic space-time trajectories under constant and time dependent metric. Indeed “the book of nature is written in the language of mathematics” (Galileo Galilei) and we provide a mathematical framework for various systems with various interactions and our results are backed with numerical confirmation.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Ali, A. (2012). Stochastic pattern formation in growth models with spatial competition. (Doctoral Dissertation). University of Warwick. Retrieved from http://wrap.warwick.ac.uk/54323/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574996
Chicago Manual of Style (16th Edition):
Ali, Adnan. “Stochastic pattern formation in growth models with spatial competition.” 2012. Doctoral Dissertation, University of Warwick. Accessed April 19, 2018.
http://wrap.warwick.ac.uk/54323/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574996.
MLA Handbook (7th Edition):
Ali, Adnan. “Stochastic pattern formation in growth models with spatial competition.” 2012. Web. 19 Apr 2018.
Vancouver:
Ali A. Stochastic pattern formation in growth models with spatial competition. [Internet] [Doctoral dissertation]. University of Warwick; 2012. [cited 2018 Apr 19].
Available from: http://wrap.warwick.ac.uk/54323/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574996.
Council of Science Editors:
Ali A. Stochastic pattern formation in growth models with spatial competition. [Doctoral Dissertation]. University of Warwick; 2012. Available from: http://wrap.warwick.ac.uk/54323/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574996
City University London
3.
Lloyd, Thomas.
Advancing integrability for strings in AdS3/CFT2.
Degree: PhD, 2016, City University London
URL: http://openaccess.city.ac.uk/14883/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687749
► In this thesis we develop techniques of integrability in the study of dualities between two-dimensional conformal field theories and theories of closed strings on three-dimensional…
(more)
▼ In this thesis we develop techniques of integrability in the study of dualities between two-dimensional conformal field theories and theories of closed strings on three-dimensional Anti-de Sitter background geometries. For several years after integrability was first applied to the 3d/2d dualities, it was an unanswered question how to incorporate the so-called \massless modes" of these theories into the integrability machinery. Here we tackle this problem in several contexts. We show that in the classical integrable description of closed strings the implementation of the string Virasoro constraints needs to be modified for geometries with multiple factors where massless modes are present. We show further that with the correct implementation of the Virasoro constraints, massless modes can be included in integrability techniques for obtaining quantum corrections to physical quantities such as the energies of string solutions. Lastly, we consider the scattering of fundamental string excitations and derive all-loop expressions for the scattering matrix that includes both massless and massive excitations.
Subjects/Keywords: QA Mathematics
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APA ·
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APA (6th Edition):
Lloyd, T. (2016). Advancing integrability for strings in AdS3/CFT2. (Doctoral Dissertation). City University London. Retrieved from http://openaccess.city.ac.uk/14883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687749
Chicago Manual of Style (16th Edition):
Lloyd, Thomas. “Advancing integrability for strings in AdS3/CFT2.” 2016. Doctoral Dissertation, City University London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/14883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687749.
MLA Handbook (7th Edition):
Lloyd, Thomas. “Advancing integrability for strings in AdS3/CFT2.” 2016. Web. 19 Apr 2018.
Vancouver:
Lloyd T. Advancing integrability for strings in AdS3/CFT2. [Internet] [Doctoral dissertation]. City University London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/14883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687749.
Council of Science Editors:
Lloyd T. Advancing integrability for strings in AdS3/CFT2. [Doctoral Dissertation]. City University London; 2016. Available from: http://openaccess.city.ac.uk/14883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687749
City University London
4.
King, Oliver.
The representation theory of diagram algebras.
Degree: PhD, 2014, City University London
URL: http://openaccess.city.ac.uk/5915/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633609
► In this thesis we study the modular representation theory of diagram algebras, in particular the Brauer and partition algebras, along with a brief consideration of…
(more)
▼ In this thesis we study the modular representation theory of diagram algebras, in particular the Brauer and partition algebras, along with a brief consideration of the Temperley-Lieb algebra. The representation theory of these algebras in characteristic zero is well understood, and we show that it can be described through the action of a reflection group on the set of simple modules (a result previously known for the Temperley-Lieb and Brauer algebras). By considering the action of the corresponding affine reflection group, we give a characterisation of the (limiting) blocks of the Brauer and partition algebras in positive characteristic. In the case of the Brauer algebra, we then show that simple reflections give rise to non-zero decomposition numbers. We then restrict our attention to a particular family of Brauer and partition algebras, and use the block result to determine the entire decomposition matrix of the algebras therein.
Subjects/Keywords: QA Mathematics
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APA ·
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APA (6th Edition):
King, O. (2014). The representation theory of diagram algebras. (Doctoral Dissertation). City University London. Retrieved from http://openaccess.city.ac.uk/5915/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633609
Chicago Manual of Style (16th Edition):
King, Oliver. “The representation theory of diagram algebras.” 2014. Doctoral Dissertation, City University London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/5915/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633609.
MLA Handbook (7th Edition):
King, Oliver. “The representation theory of diagram algebras.” 2014. Web. 19 Apr 2018.
Vancouver:
King O. The representation theory of diagram algebras. [Internet] [Doctoral dissertation]. City University London; 2014. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/5915/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633609.
Council of Science Editors:
King O. The representation theory of diagram algebras. [Doctoral Dissertation]. City University London; 2014. Available from: http://openaccess.city.ac.uk/5915/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633609
City University London
5.
Malekpoor, Somayeh.
Optimization methods for deadbeat control design : a state space approach.
Degree: PhD, 2016, City University London
URL: http://openaccess.city.ac.uk/14396/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683774
► This thesis addresses the synthesis problem of state deadbeat regulator using state space techniques. Deadbeat control is a linear control strategy in discrete time systems…
(more)
▼ This thesis addresses the synthesis problem of state deadbeat regulator using state space techniques. Deadbeat control is a linear control strategy in discrete time systems and consists of driving the system from any arbitrary initial state to a desired final state infinite number of time steps. Having described the framework for development of the thesis which is in the form of a lower linear-fractional transformation (LFT), the conditions for internal stability based on the notion of coprime factorization over the set of proper and stable transfer matrices, namely RH, is discussed. This leads to the derivation of the class of all stabilizing linear controllers, which are parameterized affinely in terms of a stable but otherwise free parameter Q, usually known as the Q-parameterization. In this work, the classical Q- parameterization is generalized to deliver a parameterization for the family of deadbeat regulators. Time response characteristics of the deadbeat system are investigated. In particular, the deadbeat regulator design problem in which the system must satisfy time domain specifications and minimize a quadratic (LQG-type) performance criterion is examined. It is shown that the attained parameterization for deadbeat controllers leads to the formulation of the synthesis problem in a quadratic programming framework with Q regarded as the design variable. The equivalent formulation of this objective as a quadratic integral in the frequency domain provides the means for shaping the frequency response characteristics of the system. Using the LMI characterization of the standard H problem, a new scheme for shaping the system frequency response characteristics by minimizing the infinity norm of an appropriate closed-loop transfer function is introduced. As shown, the derived parameterization of deadbeat compensators simplifies considerably the formulation and solution of this problem. The last part of the work described in this thesis is devoted to addressing the synthesis problem of deadbeat regulators in a robust way, when the plant is subject to structured norm-bounded parametric uncertainties. A novel approach which is expressed as an LMI feasibility condition has been proposed and analysed.
Subjects/Keywords: QA Mathematics
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APA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Malekpoor, S. (2016). Optimization methods for deadbeat control design : a state space approach. (Doctoral Dissertation). City University London. Retrieved from http://openaccess.city.ac.uk/14396/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683774
Chicago Manual of Style (16th Edition):
Malekpoor, Somayeh. “Optimization methods for deadbeat control design : a state space approach.” 2016. Doctoral Dissertation, City University London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/14396/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683774.
MLA Handbook (7th Edition):
Malekpoor, Somayeh. “Optimization methods for deadbeat control design : a state space approach.” 2016. Web. 19 Apr 2018.
Vancouver:
Malekpoor S. Optimization methods for deadbeat control design : a state space approach. [Internet] [Doctoral dissertation]. City University London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/14396/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683774.
Council of Science Editors:
Malekpoor S. Optimization methods for deadbeat control design : a state space approach. [Doctoral Dissertation]. City University London; 2016. Available from: http://openaccess.city.ac.uk/14396/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683774
City University London
6.
Wang, Jinghua.
A hybrid model for large scale simulation of unsteady nonlinear waves.
Degree: PhD, 2016, City University London
URL: http://openaccess.city.ac.uk/14575/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685582
► A hybrid model for simulating rogue waves in random seas on a large time and space scale is proposed in this thesis. It is formed…
(more)
▼ A hybrid model for simulating rogue waves in random seas on a large time and space scale is proposed in this thesis. It is formed by combining the derived fifth order Enhanced Nonlinear Schrödinger Equation based on Fourier transform (ENLSE-5F), the fully nonlinear Enhanced Spectral Boundary Integral (ESBI) method and its simplified version. The numerical techniques and algorithm for coupling three models on time scale are provided. Using them, and the switch between the three models during the computation is triggered automatically according to wave nonlinearities. Numerical tests are carried out and the results indicate that this hybrid model could simulate rogue waves both accurately and efficiently. In some cases showed, the hybrid model is more than 10 times faster than just using the ESBI method.
Subjects/Keywords: QA Mathematics
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APA ·
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Manager
APA (6th Edition):
Wang, J. (2016). A hybrid model for large scale simulation of unsteady nonlinear waves. (Doctoral Dissertation). City University London. Retrieved from http://openaccess.city.ac.uk/14575/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685582
Chicago Manual of Style (16th Edition):
Wang, Jinghua. “A hybrid model for large scale simulation of unsteady nonlinear waves.” 2016. Doctoral Dissertation, City University London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/14575/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685582.
MLA Handbook (7th Edition):
Wang, Jinghua. “A hybrid model for large scale simulation of unsteady nonlinear waves.” 2016. Web. 19 Apr 2018.
Vancouver:
Wang J. A hybrid model for large scale simulation of unsteady nonlinear waves. [Internet] [Doctoral dissertation]. City University London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/14575/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685582.
Council of Science Editors:
Wang J. A hybrid model for large scale simulation of unsteady nonlinear waves. [Doctoral Dissertation]. City University London; 2016. Available from: http://openaccess.city.ac.uk/14575/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685582
Cardiff University
7.
Vronskaya, Maria.
Stability of singular spectrum analysis and causality in time series.
Degree: PhD, 2013, Cardiff University
URL: http://orca.cf.ac.uk/52140/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585280
► The concept of causality has been widely studied in econometrics and statistics since 1969, when C. J. Granger published his paper "Investigating causal relations by…
(more)
▼ The concept of causality has been widely studied in econometrics and statistics since 1969, when C. J. Granger published his paper "Investigating causal relations by econometric models and cross-spectral methods". The intuitive basis for his definition of causality is the following: time series Y is causing time series X if the use of the additional information provided by Y improves the forecast of series X. In the present thesis we focus on combining Granger's causality concept with the Singular Spectrum Analysis (SSA) technique. SSA is founded on the idea of transforming the time series into a multidimensional trajectory form (Hankel matrices), Singular Value Decomposition with subsequent projection to a lower-dimensional subspace and diagonal averaging. The main aim of the present thesis is to study the causality concept through SSA prism in details and suggest a novel causality measure, which can be used outside the stationary autoregressive class, which is the framework for Granger's original causality concept. We first apply standard statistical tests directly to simulated data to assess the improvement of forecast quality of bivariate multidimensional SSA (MSSA) of time series X and Y compared with SSA of time series X only. Although the results of performance of these tests are reasonably conclusive, the simulation method is time consuming and, thus, more theoretical understanding is desirable. We solve a fundamental scaling problem of the MSSA approach by introducing so-called linearized MSSA. The linearized MSSA approach shows a way towards a causality measure, calculated from the forecast linear recurrence formula (LRF) coefficients. We finally analyze SSA and (non-linear) bivariate MSSA approach in terms of first order stability analysis under perturbations leading to the construction of a valid suitable measure of causality. The construction of the measure requires some simplifying assumptions in the stability analysis whose validity we verify for both simulated and real data.
Subjects/Keywords: QA Mathematics
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APA ·
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Manager
APA (6th Edition):
Vronskaya, M. (2013). Stability of singular spectrum analysis and causality in time series. (Doctoral Dissertation). Cardiff University. Retrieved from http://orca.cf.ac.uk/52140/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585280
Chicago Manual of Style (16th Edition):
Vronskaya, Maria. “Stability of singular spectrum analysis and causality in time series.” 2013. Doctoral Dissertation, Cardiff University. Accessed April 19, 2018.
http://orca.cf.ac.uk/52140/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585280.
MLA Handbook (7th Edition):
Vronskaya, Maria. “Stability of singular spectrum analysis and causality in time series.” 2013. Web. 19 Apr 2018.
Vancouver:
Vronskaya M. Stability of singular spectrum analysis and causality in time series. [Internet] [Doctoral dissertation]. Cardiff University; 2013. [cited 2018 Apr 19].
Available from: http://orca.cf.ac.uk/52140/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585280.
Council of Science Editors:
Vronskaya M. Stability of singular spectrum analysis and causality in time series. [Doctoral Dissertation]. Cardiff University; 2013. Available from: http://orca.cf.ac.uk/52140/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585280
University of Glasgow
8.
Hao, Yujue.
Solving Eigenproblems with application in collapsible channel flows.
Degree: PhD, 2013, University of Glasgow
URL: http://theses.gla.ac.uk/4589/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586757
► Collapsible channel flows have been attracting the interest of many researchers, because of the physiological applications in the cardiovascular system, the respiratory system and urinary…
(more)
▼ Collapsible channel flows have been attracting the interest of many researchers, because of the physiological applications in the cardiovascular system, the respiratory system and urinary system. The linear stability analysis of the collapsible channel flows in the Fluid-Beam Model can be finalized as a large sparse asymmetric generalized eigenvalue problem, where the stiffness matrix is sparse, asymmetric and nonsingular, and the mass matrix is sparse, asymmetric and singular. The dimensions of the both matrices can reach about ten thousand or more, and the traditional QZ Algorithm is so expensive for this size of eigenvalue problem, due to its large requirement of computational resources and the quite long elapsed time. Unlike the traditional direct methods, the projection methods are much more efficient for solving some specified eigenpairs of the large scale eigenvalue problems, because normally a small subspace is made use of, and the original eigenvalue problem is projected to this small subspace. With this projection, the size of the eigenvalue problem is reduced significantly, and then the small dimensional eigenvalue problem can be easily and rapidly worked out by employing a traditional solver. Combined with a restarting strategy, this can be used to solve large dimensional eigenvalue problem much more rapidly and precisely. So far as we know, the Implicitly Restarted Arnoldi iteration(IRA) is considered as one of the most effective asymmetric eigenvalue solvers. In order to improve the efficiency of linear stability analysis in collapsible channel flows, an IRA method is employed to the linear stability analysis of collapsible channel flows in FBM. A Frontal Solver, which is an efficient solver of large sparse linear system, is also used to replace the process of shift-and-invert transformation. After applying these two efficient solvers, the new eigenvalue solver of collapsible channel flows – Arnoldi method with a Frontal Solver(AR-F), not only gets rid of the restriction of memory storage, but also reduces the computational time observably. Some validating and testing work have been done to variety of meshes. The AR-F can solve the eigenvalues with largest real parts very quickly, and can also solve the large scale eigenvalue problems, which cannot be solved by the QZ Algorithm, whose results have been proved to be correct with the unsteady simulations. Compared with the traditional QZ Algorithm, not only a great deal of elapsed time is saved, but also the increasing rate of the operation numbers is dropped to O(n) from O(n3) of QZ Algorithm. With the powerful AR-F, the stability problems of refined meshes in collapsible channel flows are no long a barrier to the study. So AR-F is used to solve the eigenvalue problems from two refined meshes of the two different boundary conditions(pressure-driven system and flow-driven system), and the two neutral curves obtained are both revised and extended. This is the first time that IRA is made use of in the problem of fluid-structure interaction, and this is…
Subjects/Keywords: QA Mathematics
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APA ·
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MLA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hao, Y. (2013). Solving Eigenproblems with application in collapsible channel flows. (Doctoral Dissertation). University of Glasgow. Retrieved from http://theses.gla.ac.uk/4589/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586757
Chicago Manual of Style (16th Edition):
Hao, Yujue. “Solving Eigenproblems with application in collapsible channel flows.” 2013. Doctoral Dissertation, University of Glasgow. Accessed April 19, 2018.
http://theses.gla.ac.uk/4589/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586757.
MLA Handbook (7th Edition):
Hao, Yujue. “Solving Eigenproblems with application in collapsible channel flows.” 2013. Web. 19 Apr 2018.
Vancouver:
Hao Y. Solving Eigenproblems with application in collapsible channel flows. [Internet] [Doctoral dissertation]. University of Glasgow; 2013. [cited 2018 Apr 19].
Available from: http://theses.gla.ac.uk/4589/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586757.
Council of Science Editors:
Hao Y. Solving Eigenproblems with application in collapsible channel flows. [Doctoral Dissertation]. University of Glasgow; 2013. Available from: http://theses.gla.ac.uk/4589/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586757
9.
Williams, B.
Variational models and algorithms for blind image deconvolution with applications.
Degree: PhD, 2014, University of Liverpool
URL: http://livrepository.liverpool.ac.uk/2007269/1/WilliamsBry_Oct2014_2007269.pdf
► This thesis deals with numerical solutions to partial differential equations (PDEs) and their application in image processing, particularly image deblurring. The PDEs we deal with…
(more)
▼ This thesis deals with numerical solutions to partial differential equations (PDEs) and their application in image processing, particularly image deblurring. The PDEs we deal with arise from the minimisation of variational models for techniques for image restoration from a single image (such as denoising [29, 56, 169, 180], deblurring [149, 9, 44, 94, 119, 178, 54, 176, 212] or inpainting [6, 16, 25, 52]) or reconstruction from several images (such as focus fusion [80, 128, 159] and many techniques aimed at super-resolution [107, 130, 146]) as well as the identification of objects (such as global and selective segmentation [53, 89, 162, 163]) and other tasks such as the restoration of an image from a limited selection of points to facilitate image compression [101, 158, 175]. The aim of image denoising is to remove noise corruption from an image and restore the true image, while the aim of image segmentation is to distinguish the foreground from the background of an image or to select a particular feature in an image automatically. Image deblurring, or deconvolution, aims to restore an image which has been corrupted by blur and noise which remains a particular problem in many areas including remote sensing, medical imaging, and consumer photography. Deblurring tasks can be categorised into 3 types, all of which remain challenging subjects. Non-blind deblurring [15, 18, 152, 207] assumes that we know and can model the cause or degradation of the image precisely. The aim is then to recover the hidden true image using the knowledge of the blur function which is not a trivial task, particularly in the presence of strong blur, limited boundary information and noise. In contrast, blind image deconvolution (BID) [54, 31, 117, 61, 209] is the technique of recovering an image from blur degradation with no assumptions about the blur function. Such techniques commonly involve attempting to minimise a BID functional in order to recover both the true image and blur function simultaneously. Others involve attempting to use multiple images or image statistics in order to gain some knowledge of the blur function before deblurring the image. Semi-blind deblurring [1233, 11, 2, 211] involves recovering an image from blur degradation making some assumptions about the blur function. For example, we might be able to make the assumption from observation that an image has been corrupted by motion blur. The task then would be to estimate the orientation and strength of the blur while recovering the image. Such techniques are often regarded as blind since crucial information is still not known. For example, the above problem might be called blind motion deblurring. While there has been much research in the restoration of images, the performance of such methods remains poor particularly when the level of noise or blur is high. Many techniques also suffer from slow implementation. Identification, whether automatic or visual, of the blurring function can also prove a challenging task. While it is sometimes but not always possible to identify…
Advisors/Committee Members: Chen, K.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Williams, B. (2014). Variational models and algorithms for blind image deconvolution with applications. (Doctoral Dissertation). University of Liverpool. Retrieved from http://livrepository.liverpool.ac.uk/2007269/1/WilliamsBry_Oct2014_2007269.pdf
Chicago Manual of Style (16th Edition):
Williams, B. “Variational models and algorithms for blind image deconvolution with applications.” 2014. Doctoral Dissertation, University of Liverpool. Accessed April 19, 2018.
http://livrepository.liverpool.ac.uk/2007269/1/WilliamsBry_Oct2014_2007269.pdf.
MLA Handbook (7th Edition):
Williams, B. “Variational models and algorithms for blind image deconvolution with applications.” 2014. Web. 19 Apr 2018.
Vancouver:
Williams B. Variational models and algorithms for blind image deconvolution with applications. [Internet] [Doctoral dissertation]. University of Liverpool; 2014. [cited 2018 Apr 19].
Available from: http://livrepository.liverpool.ac.uk/2007269/1/WilliamsBry_Oct2014_2007269.pdf.
Council of Science Editors:
Williams B. Variational models and algorithms for blind image deconvolution with applications. [Doctoral Dissertation]. University of Liverpool; 2014. Available from: http://livrepository.liverpool.ac.uk/2007269/1/WilliamsBry_Oct2014_2007269.pdf
University of Birmingham
10.
Jones, Daniel Lewis.
Special and structured matrices in max-plus algebra.
Degree: PhD, 2017, University of Birmingham
URL: http://etheses.bham.ac.uk/7527/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715663
► The aim of this thesis is to present efficient (strongly polynomial) methods and algorithms for problems in maxalgebra when certain matrices have special entries or…
(more)
▼ The aim of this thesis is to present efficient (strongly polynomial) methods and algorithms for problems in maxalgebra when certain matrices have special entries or are structured. First, we describe all solutions to a one-sided parametrised system. Next, we consider special cases of two-sided systems of equations/inequalities. Usually, we describe a set of generators of all solutions but sometimes we are satisfied with finding a non-trivial solution or being able to say something meaningful about a non-trivial solution should it exist. We look at special cases of the generalised eigenproblem, describing the full spectrum usually. Finally, we prove some results on 2x2 matrix roots and generalise these results to a class of nxn matrices. Main results include: a description of all solutions to the two-dimensional generalised eigenproblem; observations about a non-trivial solution (should it exist) to essential/minimally active two-sided systems of equations; the full spectrum of the generalised eigenproblem when one of the matrices is an outer-product; the unique candidate for the generalised eigenproblem when the difference of two matrices is symmetric and has a saddle point and finally we explicitly say when a 2x2 matrix has a kth root for a fixed positive integer k.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Jones, D. L. (2017). Special and structured matrices in max-plus algebra. (Doctoral Dissertation). University of Birmingham. Retrieved from http://etheses.bham.ac.uk/7527/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715663
Chicago Manual of Style (16th Edition):
Jones, Daniel Lewis. “Special and structured matrices in max-plus algebra.” 2017. Doctoral Dissertation, University of Birmingham. Accessed April 19, 2018.
http://etheses.bham.ac.uk/7527/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715663.
MLA Handbook (7th Edition):
Jones, Daniel Lewis. “Special and structured matrices in max-plus algebra.” 2017. Web. 19 Apr 2018.
Vancouver:
Jones DL. Special and structured matrices in max-plus algebra. [Internet] [Doctoral dissertation]. University of Birmingham; 2017. [cited 2018 Apr 19].
Available from: http://etheses.bham.ac.uk/7527/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715663.
Council of Science Editors:
Jones DL. Special and structured matrices in max-plus algebra. [Doctoral Dissertation]. University of Birmingham; 2017. Available from: http://etheses.bham.ac.uk/7527/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715663
Cardiff University
11.
Holland, Jan W.
Properties of the operator product expansion in quantum field theory.
Degree: 2013, Cardiff University
URL: http://orca.cf.ac.uk/53230/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585305
► We prove that the operator product expansion (OPE), which is usually thought of as an asymptotic short distance expansion, actually converges at arbitrary finite distances…
(more)
▼ We prove that the operator product expansion (OPE), which is usually thought of as an asymptotic short distance expansion, actually converges at arbitrary finite distances within perturbative quantum field theory. The result is derived for the massive scalar field with \varphi4-interaction on Euclidean spacetime. This constitutes a generalisation of an earlier result by Hollands and Kopper, which states that the OPE of exactly two quantum fields converges. We also show that the OPE coefficients satisfy factorisation conditions for certain configurations of the spacetime arguments. Such conditions are known to encode information on the algebraic structure of the underlying quantum field theory. Both results rely on modified versions of the renormalisation group flow equations, which allow us to derive explicit bounds on the remainder of these expansions. Within this framework, we also derive a new formula for the perturbation of OPE coefficients, i.e. an equation relating coefficients at a given perturbation order to those of lower order. By iteration of this formula, a new constructive method for the computation of OPE coefficients in perturbation theory is obtained, which only requires the coefficients of the free theory as initial data. Finally, we investigate a strategy to restrict renormalisation ambiguities in quantum field theory via the condition that the OPE coefficients depend analytically on the coupling constant(s) of the respective model. We apply this strategy to the computation of the vacuum expectation value of the stress energy operator in the two dimensional Gross-Neveu model and we obtain a unique prediction for the non-perturbative contribution to this expectation value, which is of the order \exp(-2π/g2) (here g is the coupling constant). We discuss the possibility that a similar effect, if present in the Standard Model of particle physics, could account for the ''unnatural'' smallness of the cosmological constant.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Holland, J. W. (2013). Properties of the operator product expansion in quantum field theory. (Doctoral Dissertation). Cardiff University. Retrieved from http://orca.cf.ac.uk/53230/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585305
Chicago Manual of Style (16th Edition):
Holland, Jan W. “Properties of the operator product expansion in quantum field theory.” 2013. Doctoral Dissertation, Cardiff University. Accessed April 19, 2018.
http://orca.cf.ac.uk/53230/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585305.
MLA Handbook (7th Edition):
Holland, Jan W. “Properties of the operator product expansion in quantum field theory.” 2013. Web. 19 Apr 2018.
Vancouver:
Holland JW. Properties of the operator product expansion in quantum field theory. [Internet] [Doctoral dissertation]. Cardiff University; 2013. [cited 2018 Apr 19].
Available from: http://orca.cf.ac.uk/53230/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585305.
Council of Science Editors:
Holland JW. Properties of the operator product expansion in quantum field theory. [Doctoral Dissertation]. Cardiff University; 2013. Available from: http://orca.cf.ac.uk/53230/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585305
12.
Wang, Wenfei.
Aspects of wave propagation in anisotropic elastic half-spaces and plates.
Degree: PhD, 2013, Keele University
URL: http://eprints.keele.ac.uk/3737/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718473
► The propagation of waves along elastic half-spaces and plates has long been an active research area with lots of applications in seismology andmodern industries. Much…
(more)
▼ The propagation of waves along elastic half-spaces and plates has long been an active research area with lots of applications in seismology andmodern industries. Much attention has been paid to the study of wave propagation in a linear isotropic solid with traction-free or fixed boundary conditions. However, much more investigation is deserved for anisotropic solids under other type of boundary conditions, or even a solid with a hump on its surface. The purpose of the thesis is to investigate the influence of the elastic property and profile of propagation media and boundary conditions on wave speeds, and predict the wave speed in various situations. Chapter 1 is devoted to introducing the governing equations and several specific materials used as examples in subsequent analysis. Chapter 2 is concerned with the propagation of free surface waves on an elastic half-space that has a localized geometric inhomogeneity perpendicular to the direction of wave propagation (such waves are known as topography-guided surface waves). We use the Stroh formalism to examine how such hump modifies the surface wave speed slightly on an anisotropic elastic half-space. In Chapter 3, an asymptotic model is constructed to predict the speed of waves propagating along a thin elastic plate with elastically restrained boundary conditions (ERBC). The Stroh formalism is again applied to deal with general anisotropy, which can be specified later to analyze the case of linear isotropy and the transverse isotropy. Chapter 4 deals again with the case of a thin plate with ERBC as in the previous chapter, but the effects of pre-stress and the condition of incompressibility are also considered.
Subjects/Keywords: QA Mathematics
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APA ·
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APA (6th Edition):
Wang, W. (2013). Aspects of wave propagation in anisotropic elastic half-spaces and plates. (Doctoral Dissertation). Keele University. Retrieved from http://eprints.keele.ac.uk/3737/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718473
Chicago Manual of Style (16th Edition):
Wang, Wenfei. “Aspects of wave propagation in anisotropic elastic half-spaces and plates.” 2013. Doctoral Dissertation, Keele University. Accessed April 19, 2018.
http://eprints.keele.ac.uk/3737/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718473.
MLA Handbook (7th Edition):
Wang, Wenfei. “Aspects of wave propagation in anisotropic elastic half-spaces and plates.” 2013. Web. 19 Apr 2018.
Vancouver:
Wang W. Aspects of wave propagation in anisotropic elastic half-spaces and plates. [Internet] [Doctoral dissertation]. Keele University; 2013. [cited 2018 Apr 19].
Available from: http://eprints.keele.ac.uk/3737/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718473.
Council of Science Editors:
Wang W. Aspects of wave propagation in anisotropic elastic half-spaces and plates. [Doctoral Dissertation]. Keele University; 2013. Available from: http://eprints.keele.ac.uk/3737/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718473
University of Glasgow
13.
Hassan, Waqar Ul.
Fluid mechanics of thermodilution in coronary arteries.
Degree: 2017, University of Glasgow
URL: http://theses.gla.ac.uk/8710/
► Cardiovascular disease is one of the main causes of death in the world and among various cardiovascular diseases, the coronary artery disease is considered to…
(more)
▼ Cardiovascular disease is one of the main causes of death in the world and among various cardiovascular diseases, the coronary artery disease is considered to be the leading cause of death. Atherosclerosis is the primary cause of coronary artery disease. Different diagnostic methods have been developed for the assessment of coronary artery function. Coronary Thermodilution is one of the most recent methods used to find
blood flow, temperature and assess resistance. A diagnostic coronary guidewire with a pressure and temperature sensor is used to measure temperature and pressure of blood simultaneously. For a continuous temperature signal, the rapid reduction in temperature and afterwards recovery in seconds creates a temperature curve which is displayed on the haemodynamic monitoring device.
The objectives of this study were to evaluate the thermodilution waveforms in order to understand microvascular disease of the heart. To investigate these thermodilution curves, a Matlab program was written to assess and to identify the key features of the thermodilution waveforms and different patterns of thermodilution curves were found.
In order to calculate the origin of the features of the double peaks and other thermodilution curves, a simplified computational model of tube with catheter was implemented in Fluent. We observed the temperature curves similar to the thermodilution curves when we took the measurement at the centre of the coronary artery and did not see any pulsatility due to the probe lies within the central axis and lies within the region of cold fluid and may be diffusion is too slow to absorb heat from the surroundings. Double peaks are found if the probe is off-axis. Stenosis is placed inside the coronary artery and the calculations were performed off-axis which resulted in the different shapes as we observed in the actual thermodilution data. Misalignment of the catheter may result in the errors of thermodilution data which may affect the health care cost.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Hassan, W. U. (2017). Fluid mechanics of thermodilution in coronary arteries. (Thesis). University of Glasgow. Retrieved from http://theses.gla.ac.uk/8710/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Hassan, Waqar Ul. “Fluid mechanics of thermodilution in coronary arteries.” 2017. Thesis, University of Glasgow. Accessed April 19, 2018.
http://theses.gla.ac.uk/8710/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hassan, Waqar Ul. “Fluid mechanics of thermodilution in coronary arteries.” 2017. Web. 19 Apr 2018.
Vancouver:
Hassan WU. Fluid mechanics of thermodilution in coronary arteries. [Internet] [Thesis]. University of Glasgow; 2017. [cited 2018 Apr 19].
Available from: http://theses.gla.ac.uk/8710/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hassan WU. Fluid mechanics of thermodilution in coronary arteries. [Thesis]. University of Glasgow; 2017. Available from: http://theses.gla.ac.uk/8710/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Glasgow
14.
Li, Beibei.
Mathematical modelling of aortic dissection.
Degree: 2013, University of Glasgow
URL: http://theses.gla.ac.uk/3968/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566454
► An aortic dissection is a tear of the intima of the aortic wall that spreads into the media or between the media and adventitia. In…
(more)
▼ An aortic dissection is a tear of the intima of the aortic wall that spreads into the media or between the media and adventitia. In addition to the original lumen for blood flow, the dissection creates a new flow channel, the `false' lumen that may cause the artery to narrow or even close over entirely. Aortic dissection is a medical emergency and can quickly lead to death. The mechanical property of the aorta has been described by the strain energy function given by Holzapfel et al. [2000]. The aorta is idealized as an elastic axisymmetric thickwalled tube with 3 layers. We focus on the dissection in media, which is considered as a composite reinforced by two families of fibres. We assume the dissection in the media is axisymmetric. The mathematical model for the dissection is presented. The 2D plane crack problem in linear elastic infinity plane and 2D strip, the axisymmetric crack problem in linear elastic compressible and incompressible tube, the axisymmetric crack problem in an incompressible axisymmetric aorta are applied to obtain solutions to three different problems. And the fluid flow inside the crack has been studied. The 2D plane crack problem in linear elastic infinity plane has been solved analytically. The 2D plane crack problem in linear elastic compressible and incompressible strip is modelled respectively and solved numerically. The models for axisymmetric crack problem in linear elastic compressible and incompressible tube are presented respectively. The numerical solutions for the crack problems are expressed, and the results are analyzed. The mathematical model of the incompressible aorta axisymmetric dissection is given, and the solutions are found numerically. The results change along with the different parameters in the strain energy function, which are analyzed and compared. The fluid flow inside the tear is assumed very thin which is expressed as the lubrication theory. We use the implicit method to model the Stokes equation numerically, and test the crack opening change along with time.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Li, B. (2013). Mathematical modelling of aortic dissection. (Doctoral Dissertation). University of Glasgow. Retrieved from http://theses.gla.ac.uk/3968/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566454
Chicago Manual of Style (16th Edition):
Li, Beibei. “Mathematical modelling of aortic dissection.” 2013. Doctoral Dissertation, University of Glasgow. Accessed April 19, 2018.
http://theses.gla.ac.uk/3968/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566454.
MLA Handbook (7th Edition):
Li, Beibei. “Mathematical modelling of aortic dissection.” 2013. Web. 19 Apr 2018.
Vancouver:
Li B. Mathematical modelling of aortic dissection. [Internet] [Doctoral dissertation]. University of Glasgow; 2013. [cited 2018 Apr 19].
Available from: http://theses.gla.ac.uk/3968/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566454.
Council of Science Editors:
Li B. Mathematical modelling of aortic dissection. [Doctoral Dissertation]. University of Glasgow; 2013. Available from: http://theses.gla.ac.uk/3968/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566454
University of Glasgow
15.
Almahmud, Reem Abdullah J.
Wavelengths in bioconvection patterns.
Degree: PhD, 2016, University of Glasgow
URL: http://theses.gla.ac.uk/7834/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700414
► Unicellular bottom-heavy swimming microorganisms are usually denser than the fluid in which they swim. In shallow suspensions, the bottom heaviness results in a gravitational torque…
(more)
▼ Unicellular bottom-heavy swimming microorganisms are usually denser than the fluid in which they swim. In shallow suspensions, the bottom heaviness results in a gravitational torque that orients the cells to swim vertically upwards in the absence of fluid flow. Swimming cells thus accumulate at the upper surface to form a concentrated layer of cells. When the cell concentration is high enough, the layer overturns to form bioconvection patterns. Thin concentrated plumes of cells descend rapidly and cells return to the upper surface in wide, slowly moving upwelling plumes. When there is fluid flow, a second viscous torque is exerted on the swimming cells. The balance between the local shear flow viscous and the gravitational torques determines the cells' swimming direction, (gyrotaxis). In this thesis, the wavelengths of bioconvection patterns are studied experimentally as well as theoretically as follow; First, in aquasystem it is rare to find one species lives individually and when they swim they can form complex patterns. Thus, a protocol for controlled experiments to mix two species of swimming algal cells of \emph{C. rienhardtii} and \emph{C. augustae} is systematically described and images of bioconvection patterns are captured. A method for analysing images using wavelets and extracting the local dominant wavelength in spatially varying patterns is developed. The variation of the patterns as a function of the total concentration and the relative concentration between two species is analysed. Second, the linear stability theory of bioconvection for a suspension of two mixed species is studied. The dispersion relationship is computed using Fourier modes in order to calculate the neutral curves as a function of wavenumbers k and m. The neutral curves are plotted to compare the instability onset of the suspension of the two mixed species with the instability onset of each species individually. This study could help us to understand which species contributes the most in the process of pattern formation. Finally, predicting the most unstable wavelength was studied previously around a steady state equilibrium situation. Since assuming steady state equilibrium contradicts with reality, the pattern formation in a layer of finite depth of an evolving basic state is studied using the nonnormal modes approach. The nonnormal modes procedure identifies the optimal initial perturbation that can be obtained for a given time t as well as a given set of parameters and wavenumber k. Then, we measure the size of the optimal perturbation as it grows with time considering a range of wavenumbers for the same set of parameters to be able to extract the most unstable wavelength.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Almahmud, R. A. J. (2016). Wavelengths in bioconvection patterns. (Doctoral Dissertation). University of Glasgow. Retrieved from http://theses.gla.ac.uk/7834/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700414
Chicago Manual of Style (16th Edition):
Almahmud, Reem Abdullah J. “Wavelengths in bioconvection patterns.” 2016. Doctoral Dissertation, University of Glasgow. Accessed April 19, 2018.
http://theses.gla.ac.uk/7834/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700414.
MLA Handbook (7th Edition):
Almahmud, Reem Abdullah J. “Wavelengths in bioconvection patterns.” 2016. Web. 19 Apr 2018.
Vancouver:
Almahmud RAJ. Wavelengths in bioconvection patterns. [Internet] [Doctoral dissertation]. University of Glasgow; 2016. [cited 2018 Apr 19].
Available from: http://theses.gla.ac.uk/7834/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700414.
Council of Science Editors:
Almahmud RAJ. Wavelengths in bioconvection patterns. [Doctoral Dissertation]. University of Glasgow; 2016. Available from: http://theses.gla.ac.uk/7834/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700414
University of Birmingham
16.
Baragilly, Mohammed Hussein Hassan.
Clustering multivariate and functional data using spatial rank functions.
Degree: PhD, 2016, University of Birmingham
URL: http://etheses.bham.ac.uk/7124/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699175
► In this work, we consider the problem of determining the number of clusters in the multivariate and functional data, where the data are represented by…
(more)
▼ In this work, we consider the problem of determining the number of clusters in the multivariate and functional data, where the data are represented by a mixture model in which each component corresponds to a different cluster without any prior knowledge of the number of clusters. For the multivariate case, we propose a new forward search methodology based on spatial ranks. We also propose a modified algorithm based on the volume of central rank regions. Our numerical examples show that it produces the best results under elliptic symmetry and it outperforms the traditional forward search based on Mahalanobis distances. In addition, a new nonparametric multivariate clustering method based on different weighted spatial ranks (WSR) functions is proposed. The WSR are completely data-driven and easy to compute without any need to parameter estimates of the underlying distributions, which make them robust against distributional assumptions. We have considered parametric and nonparametric weights for comparison. We give some numerical examples based on both simulated and real datasets to illustrate the performance of the proposed method. Moreover, we propose two different clustering methods for functional data. The first method is an extension to the forward search based on functional spatial ranks (FSR) that we proposed for the multivariate case. In the second method, we extend the WSR method to the functional data analysis. The proposed weighted functional spatial ranks (WFSR) method is a filtering method based on FPCA. Comparison between the existing methods has been considered. The results showed that the two proposed methods give a competitive and quite reasonable clustering analysis.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Baragilly, M. H. H. (2016). Clustering multivariate and functional data using spatial rank functions. (Doctoral Dissertation). University of Birmingham. Retrieved from http://etheses.bham.ac.uk/7124/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699175
Chicago Manual of Style (16th Edition):
Baragilly, Mohammed Hussein Hassan. “Clustering multivariate and functional data using spatial rank functions.” 2016. Doctoral Dissertation, University of Birmingham. Accessed April 19, 2018.
http://etheses.bham.ac.uk/7124/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699175.
MLA Handbook (7th Edition):
Baragilly, Mohammed Hussein Hassan. “Clustering multivariate and functional data using spatial rank functions.” 2016. Web. 19 Apr 2018.
Vancouver:
Baragilly MHH. Clustering multivariate and functional data using spatial rank functions. [Internet] [Doctoral dissertation]. University of Birmingham; 2016. [cited 2018 Apr 19].
Available from: http://etheses.bham.ac.uk/7124/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699175.
Council of Science Editors:
Baragilly MHH. Clustering multivariate and functional data using spatial rank functions. [Doctoral Dissertation]. University of Birmingham; 2016. Available from: http://etheses.bham.ac.uk/7124/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699175
17.
Tomic, Ivana.
Distributed LQR control of multi-agent systems.
Degree: PhD, 2016, City, University of London
URL: http://openaccess.city.ac.uk/15883/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699420
► The thesis develops optimal control methods for designing distributed cooperative control schemes in multi-agent networks. First, the model of a completely connected multi-agent network is…
(more)
▼ The thesis develops optimal control methods for designing distributed cooperative control schemes in multi-agent networks. First, the model of a completely connected multi-agent network is presented, consisting of identical dynamically decoupled agents controlled by a centralized LQR (Linear Quadratic Regulator) based controller. The structure of the solution, as well as controller's spectral and robustness properties are presented. A special case of centralized control where the optimal solution for the whole network can be constructed from the solution of single agent LQR system is given. The problem is extended to distributed control where the special structure is imposed onto the information flow between agents and only local interaction is considered. A systematic method is given for computing the performance loss of various distributed control configurations relative to the performance of the optimal centralized controller. Necessary and sufficient conditions are derived for which a distributed control configuration pattern arising from the optimal centralized solution does not entail loss of performance if the initial state vector lies is a certain subspace of state-space which is identified. It is shown that these conditions are always satisfied for systems with communication/control networks corresponding to complete graphs with a single link removed. The procedure is extended for the purposes of analysing the performance loss of an arbitrary distributed configuration. Cost increase due to decentralisation is quantified by introducing three cost measures corresponding to the worst-case, best-case and average directions in which the initial state of the system lies. Finally, a cooperative scheme is presented for controlling arbitrary formations of low speed experimental UAVs (Unmanned Aerial Vehicles) based on a distributed LQR design methodology. Each UAV acts as an independent agent in the formation and its dynamics are described by a 6-DOF (six degrees-offreedom) nonlinear model. This is linearised for control design purposes around an operating point corresponding to straight flight conditions and simulated for longitudinal motion. It is shown that the proposed controller stabilises the overall formation and can control effectively the nonlinear multi-agent system. Also, it is illustrated via numerous simulations that the system provides reference tracking and that is robust to environmental disturbances such as nonuniform wind gusts acting on a formation of UAVs and to the loss of communication between two neighbouring UAVs.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Tomic, I. (2016). Distributed LQR control of multi-agent systems. (Doctoral Dissertation). City, University of London. Retrieved from http://openaccess.city.ac.uk/15883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699420
Chicago Manual of Style (16th Edition):
Tomic, Ivana. “Distributed LQR control of multi-agent systems.” 2016. Doctoral Dissertation, City, University of London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/15883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699420.
MLA Handbook (7th Edition):
Tomic, Ivana. “Distributed LQR control of multi-agent systems.” 2016. Web. 19 Apr 2018.
Vancouver:
Tomic I. Distributed LQR control of multi-agent systems. [Internet] [Doctoral dissertation]. City, University of London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/15883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699420.
Council of Science Editors:
Tomic I. Distributed LQR control of multi-agent systems. [Doctoral Dissertation]. City, University of London; 2016. Available from: http://openaccess.city.ac.uk/15883/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699420
18.
Raza, Mahdi.
Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq.
Degree: PhD, 2016, City, University of London
URL: http://openaccess.city.ac.uk/15877/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699419
► The objective of this thesis is to carry out a survival analysis for patients with breast cancer. Using data from the Nanakaly and Hewa hospitals…
(more)
▼ The objective of this thesis is to carry out a survival analysis for patients with breast cancer. Using data from the Nanakaly and Hewa hospitals in the cities of Erbil and Suleimaniah, respectively, cases where there is hidden censoring on survival time were investigated. The aim of this study was to identify the main risk factors and quantify the overall risk for breast cancer. We developed a new Markov chain-based method for generating survival curves and hazard functions. In particular we adjusted the Kaplan Meier analysis to find a survival curve with hidden censoring of the data, and also estimated a survival function from the biased one obtained directly from the data by generating new models in two cases; with and without censoring. To ensure the validity of the suggested model we considered different simulation techniques applied to the Nanakaly data. Because of the availability of a good survival function, we chose to work with a German data set. As a result we conclude that our model performs well in many circumstances, and its predictions, even when less accurate, are always an improvement on considering the apparent survival curves from the unadjusted data. For the data from Nanakaly hospital, the only variable we had to consider was age at diagnosis and the survival results showed that this was a significant variable. With far more detailed reports available for Hewa hospital, we were able to identify estrogen abundance, smoking habits and tumour grade, as having a statistically significant impact on the incidence of breast cancer. On the other hand, when analysing the Nanakaly and Hewa data for comparison with German data, in all three cases the survival curve is greater among younger patients. The suggested models may be verified using cross validation or by using new data. Finally, we note that it would be preferable to have accurate data to applying our methods to imperfect data. Therefore we established both a general and a specific flowchart to collect the data in the future. Encouraging the implementation of the recommended procedures might serve to obtain the data needed to develop a more comprehensive understanding of breast cancer in Kurdistan.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Raza, M. (2016). Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq. (Doctoral Dissertation). City, University of London. Retrieved from http://openaccess.city.ac.uk/15877/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699419
Chicago Manual of Style (16th Edition):
Raza, Mahdi. “Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq.” 2016. Doctoral Dissertation, City, University of London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/15877/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699419.
MLA Handbook (7th Edition):
Raza, Mahdi. “Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq.” 2016. Web. 19 Apr 2018.
Vancouver:
Raza M. Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq. [Internet] [Doctoral dissertation]. City, University of London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/15877/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699419.
Council of Science Editors:
Raza M. Using survival analysis to investigate breast cancer in the Kurdistan region of Iraq. [Doctoral Dissertation]. City, University of London; 2016. Available from: http://openaccess.city.ac.uk/15877/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699419
19.
Kura, K.
Mathematical modelling of dominance hierarchies.
Degree: PhD, 2016, City, University of London
URL: http://openaccess.city.ac.uk/15838/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699416
► In this research we analyse the formation of dominance hierarchies from different viewpoints and various models of dominance hierarchy formation have been proposed, one important…
(more)
▼ In this research we analyse the formation of dominance hierarchies from different viewpoints and various models of dominance hierarchy formation have been proposed, one important class being winner – loser models and another being Swiss tournaments. We start by understanding the structure of hierarchies emerging under the influence of winner and loser effects and two situations are considered: (i) when each individual has the same, fixed (unchanged) aggression threshold, meaning that all of them use the same rule when deciding whether to fight or retreat, and (ii) when individuals select an aggression threshold comparing their own and their opponent's abilities, and fighting if and only if the situation is sufficiently favourable to themselves. For both situations, we investigate if we can achieve hierarchy linearity, and if so, when it is established. We are particularly interested in the question of how many fights are necessary to establish dominance hierarchy. To examine these questions we use existing and new statistical measures. Besides understanding the structure and the temporal dynamic of the hierarchy formation, we also analyse the effect of the information that each individual has about the strength of their opponents on linearity. For the second situation, where individuals choose different aggression threshold, we find the appropriate level of aggression and examine the conditions when an individual needs to be more aggressive and when not. Lastly, we develop a model which allows only the individuals with the same number of wins and losses to fight each other. We show that linear hierarchies are always established. A formula for the total number of fights is derived, and the effect of group size on the level of aggressiveness is analysed.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Kura, K. (2016). Mathematical modelling of dominance hierarchies. (Doctoral Dissertation). City, University of London. Retrieved from http://openaccess.city.ac.uk/15838/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699416
Chicago Manual of Style (16th Edition):
Kura, K. “Mathematical modelling of dominance hierarchies.” 2016. Doctoral Dissertation, City, University of London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/15838/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699416.
MLA Handbook (7th Edition):
Kura, K. “Mathematical modelling of dominance hierarchies.” 2016. Web. 19 Apr 2018.
Vancouver:
Kura K. Mathematical modelling of dominance hierarchies. [Internet] [Doctoral dissertation]. City, University of London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/15838/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699416.
Council of Science Editors:
Kura K. Mathematical modelling of dominance hierarchies. [Doctoral Dissertation]. City, University of London; 2016. Available from: http://openaccess.city.ac.uk/15838/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699416
20.
Pagani, Alfonso.
Strong-form governing equations and solutions for variable kinematic beam theories with practical applications.
Degree: PhD, 2016, City, University of London
URL: http://openaccess.city.ac.uk/15963/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699424
► Due to the work of pioneering scientists of the past centuries, the three-dimensional theory of elasticity is now a well-established, mature science. Nevertheless, analytical solutions…
(more)
▼ Due to the work of pioneering scientists of the past centuries, the three-dimensional theory of elasticity is now a well-established, mature science. Nevertheless, analytical solutions for three-dimensional elastic bodies are generally available only for a few particular cases which represent rather coarse simplifications of reality. Against this background, the recent development of advanced techniques and progresses in theories of structures and symbolic computation have made it possible to obtain exact and quasi-exact resolution of the strongform governing equations of beam, plate and shell structures. In this thesis, attention is primarily focused on strong-form solutions of refined beam theories. In particular, higher-order beam models are developed within the framework of the Carrera Unified Formulation (CUF), according to which the three-dimensional displacement field can be expressed as an arbitrary expansion of the generalized displacements. The governing differential equations for static, free vibration and linearized buckling analysis of beams and beam-columns made of both isotropic and anisotropic materials are obtained by applying the principle of virtual work. Subsequently, by imposing appropriate boundary conditions, closed-form analytical solutions are provided wherever possible in the case of structures with uncoupled axial and in-plane displacements. The solutions are also provided for a wider range of structures by employing collocation schemes that make use of radial basis functions. Such method may be seriously affected by numerical errors, thus, a robust and efficient method is also proposed in this thesis by formulating a frequency dependant dynamic stiffness matrix and using the Wittrick-Williams algorithm as solution technique. The theories developed in this thesis are validated by using some selected results from the literature. The analyses suggest that CUF furnishes a reliable method to implement refined theories capable of providing almost three-dimensional elasticity solution and that the dynamic stiffness method is extremely powerful and versatile when applied in conjunction with CUF.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Pagani, A. (2016). Strong-form governing equations and solutions for variable kinematic beam theories with practical applications. (Doctoral Dissertation). City, University of London. Retrieved from http://openaccess.city.ac.uk/15963/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699424
Chicago Manual of Style (16th Edition):
Pagani, Alfonso. “Strong-form governing equations and solutions for variable kinematic beam theories with practical applications.” 2016. Doctoral Dissertation, City, University of London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/15963/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699424.
MLA Handbook (7th Edition):
Pagani, Alfonso. “Strong-form governing equations and solutions for variable kinematic beam theories with practical applications.” 2016. Web. 19 Apr 2018.
Vancouver:
Pagani A. Strong-form governing equations and solutions for variable kinematic beam theories with practical applications. [Internet] [Doctoral dissertation]. City, University of London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/15963/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699424.
Council of Science Editors:
Pagani A. Strong-form governing equations and solutions for variable kinematic beam theories with practical applications. [Doctoral Dissertation]. City, University of London; 2016. Available from: http://openaccess.city.ac.uk/15963/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699424
21.
Wong, William Hon Yin.
The derived category of representations of the special linear group of degree two over a finite field.
Degree: PhD, 2016, City, University of London
URL: http://openaccess.city.ac.uk/15824/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699413
► In this thesis, we study the modular representations of the special linear group of degree two over a finite field in defining characteristic. In particular,…
(more)
▼ In this thesis, we study the modular representations of the special linear group of degree two over a finite field in defining characteristic. In particular, we study the automorphisms of derived category of representations. We have been able to obtain a new type of autoequivalence. This autoequivalence has some uncommon features. It is more conveniently conceived and proved using the representation theory of its Brauer subgroup but at the same time it can be very neatly described, using a type of derived equivalence called perverse equivalence, in global settings.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Wong, W. H. Y. (2016). The derived category of representations of the special linear group of degree two over a finite field. (Doctoral Dissertation). City, University of London. Retrieved from http://openaccess.city.ac.uk/15824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699413
Chicago Manual of Style (16th Edition):
Wong, William Hon Yin. “The derived category of representations of the special linear group of degree two over a finite field.” 2016. Doctoral Dissertation, City, University of London. Accessed April 19, 2018.
http://openaccess.city.ac.uk/15824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699413.
MLA Handbook (7th Edition):
Wong, William Hon Yin. “The derived category of representations of the special linear group of degree two over a finite field.” 2016. Web. 19 Apr 2018.
Vancouver:
Wong WHY. The derived category of representations of the special linear group of degree two over a finite field. [Internet] [Doctoral dissertation]. City, University of London; 2016. [cited 2018 Apr 19].
Available from: http://openaccess.city.ac.uk/15824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699413.
Council of Science Editors:
Wong WHY. The derived category of representations of the special linear group of degree two over a finite field. [Doctoral Dissertation]. City, University of London; 2016. Available from: http://openaccess.city.ac.uk/15824/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699413
University of Warwick
22.
Robinson, Leigh.
Invariant object recognition : biologically plausible and machine learning approaches.
Degree: PhD, 2015, University of Warwick
URL: http://wrap.warwick.ac.uk/83167/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698750
► Understanding the processes that facilitate object recognition is a task that draws on a wide range of fields, integrating knowledge from neuroscience, psychology, computer science…
(more)
▼ Understanding the processes that facilitate object recognition is a task that draws on a wide range of fields, integrating knowledge from neuroscience, psychology, computer science and mathematics. The substantial work done in these fields has lead to two major outcomes: Firstly, a rich interplay between computational models and biological experiments that seek to explain the biological processes that underpin object recognition. Secondly, engineered vision systems that on many tasks are approaching the performance of humans. This work first highlights the importance of ensuring models which are aiming for biological relevance actually produce biologically plausible representations that are consistent with what has been measured within the primate visual cortex. To accomplish this two leading biologically plausible models, HMAX and VisNet are compared on a set of visual processing tasks. The work then changes approach, focusing on models that do not explicitly seek to model any biological process, but rather solve a particular vision task with the goal being increased performance. This section explores the recently discovered problem convolution networks being susceptible to adversarial exemplars. An extension of previous work is shown that allows state-of-the-art networks to be fooled to classify any image as any label while leaving that original image visually unchanged. Secondly an efficient implementation of applying dropout in a batchwise fashion is introduced that approximately halves the computational cost, allowing models twice as large to be trained. Finally an extension to Deep Belief Networks is proposed that constrains the connectivity of the a given layer to that of a topologically local region of the previous one.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Robinson, L. (2015). Invariant object recognition : biologically plausible and machine learning approaches. (Doctoral Dissertation). University of Warwick. Retrieved from http://wrap.warwick.ac.uk/83167/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698750
Chicago Manual of Style (16th Edition):
Robinson, Leigh. “Invariant object recognition : biologically plausible and machine learning approaches.” 2015. Doctoral Dissertation, University of Warwick. Accessed April 19, 2018.
http://wrap.warwick.ac.uk/83167/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698750.
MLA Handbook (7th Edition):
Robinson, Leigh. “Invariant object recognition : biologically plausible and machine learning approaches.” 2015. Web. 19 Apr 2018.
Vancouver:
Robinson L. Invariant object recognition : biologically plausible and machine learning approaches. [Internet] [Doctoral dissertation]. University of Warwick; 2015. [cited 2018 Apr 19].
Available from: http://wrap.warwick.ac.uk/83167/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698750.
Council of Science Editors:
Robinson L. Invariant object recognition : biologically plausible and machine learning approaches. [Doctoral Dissertation]. University of Warwick; 2015. Available from: http://wrap.warwick.ac.uk/83167/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698750
University of Warwick
23.
Lees, Benjamin T.
Quantum spin systems, probabilistic representations and phase transitions.
Degree: PhD, 2016, University of Warwick
URL: http://wrap.warwick.ac.uk/82123/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698756
► This thesis investigates properties of classical and quantum spin systems on lattices. These models have been widely studied due to their relevance to condensed matter…
(more)
▼ This thesis investigates properties of classical and quantum spin systems on lattices. These models have been widely studied due to their relevance to condensed matter physics. We identify the ground states of an antiferromagnetic RP2 model, these ground states are very di�erent from the ferromagnetic model and there was some disagreement over their structure, we settle this disagreement. Correlation inequalities are proved for the spin- 1/2 XY model and the ground state of the spin-1 XY model. This provides fresh results in a topic that had been stagnant and allows the proof of some new results, for example existence of some correlation functions in the thermodynamic limit. The occurrence of nematic order at low temperature in a quantum nematic model is proved using the method of reflection positivity and infrared bounds. Previous results on this nematic order were achieved indirectly via a probabilistic representation. This result is maintained in the presence of a small antiferromagnetic interaction, this case was not previously covered. Probabilistic representations for quantum spin systems are introduced and some consequences are presented. In particular, N´eel order is proved in a bilinear-biquadratic spin-1 system at low temperature. This result extends the famous result of Dyson, Lieb and Simon [35]. Dilute spin systems are introduced and the occurrence of a phase transition at low temperature characterised by preferential occupation of the even or odd sublattice of a cubic box is proved. This result is the first of its type for such a mixed classical and quantum system. A probabilistic representation of the spin-1 Bose-Hubbard model is also presented and some consequences are proved.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Lees, B. T. (2016). Quantum spin systems, probabilistic representations and phase transitions. (Doctoral Dissertation). University of Warwick. Retrieved from http://wrap.warwick.ac.uk/82123/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698756
Chicago Manual of Style (16th Edition):
Lees, Benjamin T. “Quantum spin systems, probabilistic representations and phase transitions.” 2016. Doctoral Dissertation, University of Warwick. Accessed April 19, 2018.
http://wrap.warwick.ac.uk/82123/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698756.
MLA Handbook (7th Edition):
Lees, Benjamin T. “Quantum spin systems, probabilistic representations and phase transitions.” 2016. Web. 19 Apr 2018.
Vancouver:
Lees BT. Quantum spin systems, probabilistic representations and phase transitions. [Internet] [Doctoral dissertation]. University of Warwick; 2016. [cited 2018 Apr 19].
Available from: http://wrap.warwick.ac.uk/82123/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698756.
Council of Science Editors:
Lees BT. Quantum spin systems, probabilistic representations and phase transitions. [Doctoral Dissertation]. University of Warwick; 2016. Available from: http://wrap.warwick.ac.uk/82123/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698756
Cardiff University
24.
Moore, Stephen.
Non-semisimple planar algebras from Ūq(sl2).
Degree: PhD, 2016, Cardiff University
URL: http://orca.cf.ac.uk/97662/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702022
► We construct examples of non-semisimple tensor categories using planar algebras, with our main focus being on a construction from the restricted quantum group Ūq(sl_2). We…
(more)
▼ We construct examples of non-semisimple tensor categories using planar algebras, with our main focus being on a construction from the restricted quantum group Ūq(sl_2). We describe the generators and prove a number of relations for the Ūq(sl_2) planar algebra, as well as describing diagrammatically various homomorphisms between modules, and conjecture a formula for projections onto indecomposable modules.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Moore, S. (2016). Non-semisimple planar algebras from Ūq(sl2). (Doctoral Dissertation). Cardiff University. Retrieved from http://orca.cf.ac.uk/97662/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702022
Chicago Manual of Style (16th Edition):
Moore, Stephen. “Non-semisimple planar algebras from Ūq(sl2).” 2016. Doctoral Dissertation, Cardiff University. Accessed April 19, 2018.
http://orca.cf.ac.uk/97662/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702022.
MLA Handbook (7th Edition):
Moore, Stephen. “Non-semisimple planar algebras from Ūq(sl2).” 2016. Web. 19 Apr 2018.
Vancouver:
Moore S. Non-semisimple planar algebras from Ūq(sl2). [Internet] [Doctoral dissertation]. Cardiff University; 2016. [cited 2018 Apr 19].
Available from: http://orca.cf.ac.uk/97662/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702022.
Council of Science Editors:
Moore S. Non-semisimple planar algebras from Ūq(sl2). [Doctoral Dissertation]. Cardiff University; 2016. Available from: http://orca.cf.ac.uk/97662/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702022
25.
Xu, C.
Markov denumerable process and queue theory.
Degree: PhD, 2013, University of Liverpool
URL: http://livrepository.liverpool.ac.uk/12573/1/XuCho_Apr2013_12573.pdf
► In this thesis, we study a modified Markovian batch-arrival and bulk- service queue including finite states for dependent control. We first consider the stopped batch-arrival…
(more)
▼ In this thesis, we study a modified Markovian batch-arrival and bulk- service queue including finite states for dependent control. We first consider the stopped batch-arrival and bulk-service queue process Q∗, which is the process with the restriction of the state-dependent control. After we obtain the expression of the Q∗-resolvent, the extinction probability and the mean extinction time are explored. Then, we apply a decomposition theorem to resume the stopped queue process back to our initial queueing model, that is to find the expression of Q-resolvent. After that, the criteria for the recurrence and ergodicity are also explored, and then, the generating function of equilibrium distribution is obtained. Additionally, the Laplace transform of the mean queue length is presented. The hitting time behaviors including the hitting probability and the hitting time distribution are also established. Furthermore, the busy period distribution is also obtained by the expression of Laplace transform. To conclude the discussion of the queue properties, a special case that m = 3 for our queueing model is discussed. Furthermore, we consider the decay parameter and decay properties of our initial queue process. First of all, similarly we consider the case of the stopped queue process Q∗. Based on this q-matrix, the exact value of the decay parameter λC is obtained theoretically. Then, we apply this result back to our initial queue model and find the decay parameter of our initial queueing model. More specifically, we prove that the decay parameter can be expressed accurately. After that, under the assumption of transient Q, the criteria for λC -recurrence are established. For λC -positive recurrent examples, the generating function of the λC-invariant measure and vector are explored. Finally, a simple example is provided to end this thesis.
Advisors/Committee Members: Chen, A, Liu, K.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Xu, C. (2013). Markov denumerable process and queue theory. (Doctoral Dissertation). University of Liverpool. Retrieved from http://livrepository.liverpool.ac.uk/12573/1/XuCho_Apr2013_12573.pdf
Chicago Manual of Style (16th Edition):
Xu, C. “Markov denumerable process and queue theory.” 2013. Doctoral Dissertation, University of Liverpool. Accessed April 19, 2018.
http://livrepository.liverpool.ac.uk/12573/1/XuCho_Apr2013_12573.pdf.
MLA Handbook (7th Edition):
Xu, C. “Markov denumerable process and queue theory.” 2013. Web. 19 Apr 2018.
Vancouver:
Xu C. Markov denumerable process and queue theory. [Internet] [Doctoral dissertation]. University of Liverpool; 2013. [cited 2018 Apr 19].
Available from: http://livrepository.liverpool.ac.uk/12573/1/XuCho_Apr2013_12573.pdf.
Council of Science Editors:
Xu C. Markov denumerable process and queue theory. [Doctoral Dissertation]. University of Liverpool; 2013. Available from: http://livrepository.liverpool.ac.uk/12573/1/XuCho_Apr2013_12573.pdf
26.
Colquitt, DJ.
Mathematical modelling of the dynamic response of metamaterial structures.
Degree: PhD, 2013, University of Liverpool
URL: http://livrepository.liverpool.ac.uk/12593/1/ColquittDan_July2013_12593.pdf
► This thesis constitutes an exposition of the work carried out by the author whilst examining several physical problems under the broad theme of the dynamic…
(more)
▼ This thesis constitutes an exposition of the work carried out by the author whilst examining several physical problems under the broad theme of the dynamic response of metamaterial structures. An outline of the thesis is provided in chapter one. Chapter two introduces some notation and preliminary results on general lattice equations. Chapter three examines the dispersive behaviour of non-classical discrete elastic lattice systems. In particular, the effect of distributing the inertial properties of the lattice over the elastic rods, in addition to at the junctions, is considered. It is demonstrated that the effective material properties in the long wavelength limit are not what one would expect from the static response of the lattice. The effect of various interactions on the dispersive properties of the triangular cell lattice is considered, including so-called truss, frame, and micro-polar interactions. Compact analytical estimates for the band widths are presented, allowing the design of metamaterial structures possessing pass and/or stop bands at specific frequencies and in specified directions. The finite frequency response of several lattice structures is considered in chapter four. In particular, the dynamic anisotropy of both scalar and elastic lattices is examined. The resulting strongly anisotropic material response is linked, explicitly, to the dispersive properties of the lattice. A novel application of dynamic anisotropy to the focusing, shielding, and negative refraction of elastic waves using a flat discrete "metamaterial lens'' is presented. Chapter five is devoted to the analysis, using the dynamic Green's function, of a finite rectilinear inclusion in an infinite square lattice. Several representations of the Green's function are presented, including expression in terms of hypergeometric functions, which are employed in deriving band edge expansions. It is shown that localised defect modes, characterised by displacements which decay rapidly away from the defect, can be initiated by reducing the mass of one or more lattice nodes, whilst ensuring that the mass of the nodes remains positive. For one- and three-dimensional multi-atomic lattices, there exists a bound on the contrast in mass between the defect and ambient lattice such that localised defect modes exist. However, it is shown that for the two-dimensional lattice, no such bound exists, provided that the masses remain positive. The analysis of a finite-sized defect region is accompanied by the waveguide modes that may exist in a lattice containing an infinite chain of point defects. A numerical simulation illustrates that the solution of the problem for an infinite chain can be used to predict the range of eigenfrequencies of localised modes for a finite but, sufficiently long, array of masses representing a rectilinear defect in a square lattice. Continuing with the theme of defects, chapter six examines response of a triangular thermoelastic lattice, with an edge crack under mode I loading. The response of the triangular lattice is compared…
Advisors/Committee Members: Movchan, A, Jones, I, Movchan, N.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Colquitt, D. (2013). Mathematical modelling of the dynamic response of metamaterial structures. (Doctoral Dissertation). University of Liverpool. Retrieved from http://livrepository.liverpool.ac.uk/12593/1/ColquittDan_July2013_12593.pdf
Chicago Manual of Style (16th Edition):
Colquitt, DJ. “Mathematical modelling of the dynamic response of metamaterial structures.” 2013. Doctoral Dissertation, University of Liverpool. Accessed April 19, 2018.
http://livrepository.liverpool.ac.uk/12593/1/ColquittDan_July2013_12593.pdf.
MLA Handbook (7th Edition):
Colquitt, DJ. “Mathematical modelling of the dynamic response of metamaterial structures.” 2013. Web. 19 Apr 2018.
Vancouver:
Colquitt D. Mathematical modelling of the dynamic response of metamaterial structures. [Internet] [Doctoral dissertation]. University of Liverpool; 2013. [cited 2018 Apr 19].
Available from: http://livrepository.liverpool.ac.uk/12593/1/ColquittDan_July2013_12593.pdf.
Council of Science Editors:
Colquitt D. Mathematical modelling of the dynamic response of metamaterial structures. [Doctoral Dissertation]. University of Liverpool; 2013. Available from: http://livrepository.liverpool.ac.uk/12593/1/ColquittDan_July2013_12593.pdf
University of Greenwich
27.
Lebon, Gerard Serge Bruno.
Unstructured finite volume algorithms for compressible multiphase flow.
Degree: phd, School of Computing and Mathematical Sciences, 2011, University of Greenwich
URL: http://gala.gre.ac.uk/8077/
► This research presents novel algorithms for computing flow within an unstructured, collocated, finite volume solver in the presence of non-orthogonality and compressibility in order to…
(more)
▼ This research presents novel algorithms for computing flow within an unstructured, collocated, finite volume solver in the presence of non-orthogonality and compressibility in order to extend the range of problems which can be modelled with the University's in-house CFD code: PHYSICA.
A new non-orthogonality diffusion correction relaxation parameter has been successfully introduced and tested with benchmarks from the literature. Cases involving geometries meshed with commercial packages have been successfully run with the diffusion correction methods, variable bounding and proper under-relaxation practices. The applicability of a pressure interpolation method has also been tested with these cases.
A procedure for solving compressible flow within a finite volume, pressure correction type scheme, has been devised and successfully implemented in different test cases. This method is however prone to numerical diffusion in the presence of shocks, but does work even in the presence of skewed meshes. The method was then tested with the case of an oxygen jet entering a heated furnace, for which experimental data is available for comparison. The method was successful in predicting the axial variables of the jet, and used to develop a turbulence modification model for such jets.
The method was finally used to model the deformation of a free surface impinged by a compressible jet, using a novel zonal method called zonal Gas And Liquid Analyser (GALA). Convergence was achieved with the method developed in this research, together with the application of the counter diffusion method to model the moving interface.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Lebon, G. S. B. (2011). Unstructured finite volume algorithms for compressible multiphase flow. (Doctoral Dissertation). University of Greenwich. Retrieved from http://gala.gre.ac.uk/8077/
Chicago Manual of Style (16th Edition):
Lebon, Gerard Serge Bruno. “Unstructured finite volume algorithms for compressible multiphase flow.” 2011. Doctoral Dissertation, University of Greenwich. Accessed April 19, 2018.
http://gala.gre.ac.uk/8077/.
MLA Handbook (7th Edition):
Lebon, Gerard Serge Bruno. “Unstructured finite volume algorithms for compressible multiphase flow.” 2011. Web. 19 Apr 2018.
Vancouver:
Lebon GSB. Unstructured finite volume algorithms for compressible multiphase flow. [Internet] [Doctoral dissertation]. University of Greenwich; 2011. [cited 2018 Apr 19].
Available from: http://gala.gre.ac.uk/8077/.
Council of Science Editors:
Lebon GSB. Unstructured finite volume algorithms for compressible multiphase flow. [Doctoral Dissertation]. University of Greenwich; 2011. Available from: http://gala.gre.ac.uk/8077/
University of Greenwich
28.
Tian, Na.
Novel optimisation methods for numerical inverse problems.
Degree: phd, School of Computing and Mathematical Sciences, 2011, University of Greenwich
URL: http://gala.gre.ac.uk/9099/
► Inverse problems involve the determination of one or more unknown quantities usually appearing in the mathematical formulation of a physical problem. These unknown quantities may…
(more)
▼ Inverse problems involve the determination of one or more unknown quantities usually appearing in the mathematical formulation of a physical problem. These unknown quantities may be boundary heat flux, various source terms, thermal and material properties, boundary shape and size. Solving inverse problems requires additional information through in-situ data measurements of the field variables of the physical problems. These problems are also ill-posed because the solution itself is sensitive to random errors in the measured input data. Regularisation techniques are usually used in order to deal with the instability of the solution. In the past decades, many methods based on the nonlinear least squares model, both deterministic (CGM) and stochastic (GA, PSO), have been investigated for numerical inverse problems.
The goal of this thesis is to examine and explore new techniques for numerical inverse problems. The background theory of population-based heuristic algorithm known as quantum-behaved particle swarm optimisation (QPSO) is re-visited and examined. To enhance the global search ability of QPSO for complex multi-modal problems, several modifications to QPSO are proposed. These include perturbation operation, Gaussian mutation and ring topology model. Several parameter selection methods for these algorithms are proposed. Benchmark functions were used to test the performance of the modified algorithms. To address the high computational cost of complex engineering optimisation problems, two parallel models of the QPSO (master-slave, static subpopulation) were developed for different distributed systems. A hybrid method, which makes use of deterministic (CGM) and stochastic (QPSO) methods, is proposed to improve the estimated solution and the performance of the algorithms for solving the inverse problems.
Finally, the proposed methods are used to solve typical problems as appeared in many research papers. The numerical results demonstrate the feasibility and efficiency of QPSO and the global search ability and stability of the modified versions of QPSO. Two novel methods of providing initial guess to CGM with approximated data from QPSO are also proposed for use in the hybrid method and were applied to estimate heat fluxes and boundary shapes. The simultaneous estimation of temperature dependent thermal conductivity and heat capacity was addressed by using QPSO with Gaussian mutation. This combination provides a stable algorithm even with noisy measurements. Comparison of the performance between different methods for solving inverse problems is also presented in this thesis.
Subjects/Keywords: QA Mathematics
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APA (6th Edition):
Tian, N. (2011). Novel optimisation methods for numerical inverse problems. (Doctoral Dissertation). University of Greenwich. Retrieved from http://gala.gre.ac.uk/9099/
Chicago Manual of Style (16th Edition):
Tian, Na. “Novel optimisation methods for numerical inverse problems.” 2011. Doctoral Dissertation, University of Greenwich. Accessed April 19, 2018.
http://gala.gre.ac.uk/9099/.
MLA Handbook (7th Edition):
Tian, Na. “Novel optimisation methods for numerical inverse problems.” 2011. Web. 19 Apr 2018.
Vancouver:
Tian N. Novel optimisation methods for numerical inverse problems. [Internet] [Doctoral dissertation]. University of Greenwich; 2011. [cited 2018 Apr 19].
Available from: http://gala.gre.ac.uk/9099/.
Council of Science Editors:
Tian N. Novel optimisation methods for numerical inverse problems. [Doctoral Dissertation]. University of Greenwich; 2011. Available from: http://gala.gre.ac.uk/9099/
University of Greenwich
29.
Than Soe, Muang.
Vibration-based finite element model updating and structural damage identification.
Degree: phd, School of Engineering, 2013, University of Greenwich
URL: http://gala.gre.ac.uk/11451/
► Damage and material deterioration could lead to structural failure with unknown consequences. Structural health monitoring strategy based on vibration measurements for existing aging structures offers…
(more)
▼ Damage and material deterioration could lead to structural failure with unknown consequences. Structural health monitoring strategy based on vibration measurements for existing aging structures offers a promising technique for effectively managing the deteriorating structures. The main objectives of this research are to develop a procedure for finite element model updating by using incomplete modal data identified from vibration measurements, to develop real time structural damage detecting method by directly using vibration measurements and then identify the damage at detailed location and extend in the structure on the basis of the validated numerical model.
A steel frame model structure was constructed in the laboratory for finite element model updating and structural damage detection. Forced vibration testing was undertaken on the model structure and dynamic response such as accelerations were measured by using sensors installed. Modal analyses are then carried out to identify modal parameters such as frequencies, mode shapes and damping from the vibration measurements. Structural damage scenarios were simulated by breaking bracing members of the model structure, and modal parameter of the damaged structures were also identified and analysed.
An effective approach for directly updating finite element model from measured incomplete modal data with a regularised iterative algorithm is then presented. The exact relationship between the perturbation of structural parameters and the modal properties of the dynamic structure is developed. Numerical simulation investigations and experimental study of a laboratory tested space steel frame model and practical application to the Canton Tower benchmark problem are undertaken to verify the accuracy and effectiveness of the proposed model updating method.
Finally, a new approach for real time structural damage detection by using acceleration measurements is presented. Structural damage is characterised at element level by introducing damage parameters which can indicate the location and severity of damage in the structure. The relationship between the damage parameters and the measured dynamic response is then established from the governing equation of the dynamic structure. Numerical examples of cantilever beams, plane frame, and braced frames are adopted to demonstrate the effectiveness of the proposed method. The new proposed technique performs well and produces stable and reliable results, which could be used for real time damage assessment during the event of earthquake and explosion.
Subjects/Keywords: QA Mathematics
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APA ·
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Export
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APA (6th Edition):
Than Soe, M. (2013). Vibration-based finite element model updating and structural damage identification. (Doctoral Dissertation). University of Greenwich. Retrieved from http://gala.gre.ac.uk/11451/
Chicago Manual of Style (16th Edition):
Than Soe, Muang. “Vibration-based finite element model updating and structural damage identification.” 2013. Doctoral Dissertation, University of Greenwich. Accessed April 19, 2018.
http://gala.gre.ac.uk/11451/.
MLA Handbook (7th Edition):
Than Soe, Muang. “Vibration-based finite element model updating and structural damage identification.” 2013. Web. 19 Apr 2018.
Vancouver:
Than Soe M. Vibration-based finite element model updating and structural damage identification. [Internet] [Doctoral dissertation]. University of Greenwich; 2013. [cited 2018 Apr 19].
Available from: http://gala.gre.ac.uk/11451/.
Council of Science Editors:
Than Soe M. Vibration-based finite element model updating and structural damage identification. [Doctoral Dissertation]. University of Greenwich; 2013. Available from: http://gala.gre.ac.uk/11451/
University of Greenwich
30.
Lai, Liang Simon.
Defect correction methods for computational aeroacoustics.
Degree: phd, School of Computing and Mathematical Sciences, 2013, University of Greenwich
URL: http://gala.gre.ac.uk/11452/
► The idea of Defect Correction Method (DCM) has been around for a long time. It can be used in a number of different ways and…
(more)
▼ The idea of Defect Correction Method (DCM) has been around for a long time. It can be used in a number of different ways and can be applied to solve various linear and non-linear problems. Most defect correction related methods were used in conjunction with discretisation methods and two-level multigrid methods. This thesis examines how various iterative methods, both for linear and nonlinear problems, may be built into a unified framework through the use of defect correction. The framework is extended to the area of Computational Aeroacoustics (CAA) where sound waves generated by the pressure fluctuations are typically several orders of magnitude smaller than the pressure variations in the main flow field that accounts for flow acceleration. A decomposition of variables is used to break down the components of a typical flow variable into (1) the mean flow, (2) flow perturbations or aerodynamic sources of sound, and (3) the acoustic perturbation. The framework as discussed in this thesis would incorporate such variable decomposition. The basic principle of DCM can be applied to recover the propagating acoustic perturbation through a coupling technique. This provides an excellent concept in the re-use of existing commercial CFD software based on the framework and in the retrieval of acoustic pressure. Numerical examples demonstrating the defect correction framework for a typical car sun-roof problem was examined with promising numerical results. To this end the complete process of coupling Reynolds average Navier-Stokes and the Helmholtz equation is also presented using the DCM framework.
The DCM framework is also extended to handle higher order numerical methods for the numerical solutions of partial differential equations leading to an easy re-use of existing software approximating derivatives with a lower order discretisation. Numerical experiments were performed to demonstrate the capability of the DCM framework. It is also used to a simplified 2-D problems aiming at the understanding of Large Eddy Simulation (LES) and filtering techniques. To this end the framework of DCM leads to an efficient and robust software implementation for many CFD and aeroacoustic computation in a simple nutshell.
Subjects/Keywords: QA Mathematics
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Lai, L. S. (2013). Defect correction methods for computational aeroacoustics. (Doctoral Dissertation). University of Greenwich. Retrieved from http://gala.gre.ac.uk/11452/
Chicago Manual of Style (16th Edition):
Lai, Liang Simon. “Defect correction methods for computational aeroacoustics.” 2013. Doctoral Dissertation, University of Greenwich. Accessed April 19, 2018.
http://gala.gre.ac.uk/11452/.
MLA Handbook (7th Edition):
Lai, Liang Simon. “Defect correction methods for computational aeroacoustics.” 2013. Web. 19 Apr 2018.
Vancouver:
Lai LS. Defect correction methods for computational aeroacoustics. [Internet] [Doctoral dissertation]. University of Greenwich; 2013. [cited 2018 Apr 19].
Available from: http://gala.gre.ac.uk/11452/.
Council of Science Editors:
Lai LS. Defect correction methods for computational aeroacoustics. [Doctoral Dissertation]. University of Greenwich; 2013. Available from: http://gala.gre.ac.uk/11452/
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