Dr Paul Ledger

Cymrawd Ymchwil Er Anrhydedd, Science and Engineering

p.d.ledger@abertawe.ac.uk

Ar gael ar gyfer Goruchwyliaeth Ôl-raddedig

Trosolwg

Pynciau Arbenigol: Elfennau Cyfyngedig Hp, Electromagneteg Gyfrifiannol, amcangyfrif gwallau, Modelu Trefn Lai, Rhag-amodau Effeithlon, problemau gwrthdro.
Rhaglennu a datblygu meddalwedd elfennau cyfyngedig sy'n cydymffurfio â H(curl) sy'n gallu mireinio hp mewn dau a thri dimensiwn.

Diddordebau pellach mewn datblygu rhag-amodau ar gyfer systemau llinol amhenodol, problemau gwrthdro, meintioli ansicrwydd, cynlluniau amcangyfrif gwallau a-posteriori, addasrwydd sy'n canolbwyntio ar nodau, modelu trefn lai a chynlluniau newydd ar gyfer lleihau gwasgariad mewn problemau lluosogi tonnau.

Cymwysiadau i broblemau mewn electromagneteg gyfrifiannol, gan gynnwys cyfrifiadura gwasgaredig, cyfrifiannu cerrynt trolif, cyfrifiannu gwerth eigen ac yn fwy diweddar modelu dyfeisiau delweddu biofeddygol.

Gallwch weld fy mhroffil Orchid yma

Darllenwch fyw ar fy nhudalen bersonol

Cyhoeddiadau

Uchafbwyntiau Ymchwil

Ledger, P. & Lionheart, W. (2020). The spectral properties of the magnetic polarizability tensor for metallic object characterisation. Mathematical Methods in the Applied Sciences, 43(1), 78-113.
https://doi.org/10.1002/mma.5830, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50948
http://dx.doi.org/10.1002/mma.5830
Seoane, M., Ledger, P., Gil, A., Mallett, M., Ledger, P., & Gil, A. (2019). An accurate and efficient three‐dimensional high order finite element methodology for the simulation of magneto‐mechanical coupling in MRI scanners. International Journal for Numerical Methods in Engineering
https://doi.org/10.1002/nme.6088, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50137
Walker, D., Kramer, S., Biebl, F., Ledger, P., & Brown, M. (2019). Accelerating magnetic induction tomography‐based imaging through heterogeneous parallel computing. Concurrency and Computation: Practice and Experience, 31(17), e5265
https://doi.org/10.1002/cpe.5265, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa49975
Ledger, P., Lionheart, W., & Amad, A. (2019). Characterisation of multiple conducting permeable objects in metal detection by polarizability tensors. Mathematical Methods in the Applied Sciences, 42(3), 830-860.
https://doi.org/10.1002/mma.5387, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa45292
Bagwell, S., Ledger, P., Gil, A., & Mallett, M. (2018). Transient solutions to nonlinear acousto-magneto-mechanical coupling for axisymmetric MRI scanner design. International Journal for Numerical Methods in Engineering, 115(2), 209-237.
https://doi.org/10.1002/nme.5802, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa39052
Ledger, P. & Lionheart, W. (2018). An Explicit Formula for the Magnetic Polarizability Tensor for Object Characterization. IEEE Transactions on Geoscience and Remote Sensing, 56(6), 3520-3533.
https://doi.org/10.1109/TGRS.2018.2801359, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa38335
http://ieeexplore.ieee.org/document/8328014/
Ledger, P. & Lionheart, W. (2018). Generalised magnetic polarizability tensors. Mathematical Methods in the Applied Sciences, 41(8), 3175-3196.
https://doi.org/10.1002/mma.4809, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa38104
Kynch, R., Ledger, P., & Ledger, P. (2017). Resolving the sign conflict problem for hp–hexahedral Nédélec elements with application to eddy current problems. Computers & Structures, 181, 41-54.
https://doi.org/10.1016/j.compstruc.2016.05.021, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa29408
Bagwell, S., Ledger, P., Gil, A., Mallett, M., & Kruip, M. (2017). A linearised hp-finite element framework for acousto-magneto-mechanical coupling in axisymmetric MRI scanners. International Journal for Numerical Methods in Engineering, 112(10), 1323-1352.
https://doi.org/10.1002/nme.5559, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa29689
Ledger, P. & Lionheart, W. (2016). Understanding the magnetic polarizability tensor. IEEE Transactions on Magnetics, 52(5), 1-16.
https://doi.org/10.1109/TMAG.2015.2507169, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa26710
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7350159

Holl Ymchwil

Erthyglau Cylchgronau

Zhang, L., Cameron, I., Ledger, P., Belblidia, F., Pearson, N., Charlton, P., & Sienz, J. (2023). Effect of Scanning Acceleration on the Leakage Signal in Magnetic Flux Leakage Type of Non-destructive Testing. Journal of Nondestructive Evaluation, 42(1)
https://doi.org/10.1007/s10921-023-00925-1, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa62387
Barroso, G., Seoane, M., Gil, A., Ledger, P., Mallett, M., & Huerta, A. (2020). A staggered high-dimensional Proper Generalised Decomposition for coupled magneto-mechanical problems with application to MRI scanners. Computer Methods in Applied Mechanics and Engineering, 370, 113271
https://doi.org/10.1016/j.cma.2020.113271, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa54652
Seoane, M., Ledger, P., Gil, A., Zlotnik, S., & Mallett, M. (2020). A combined reduced order‐full order methodology for the solution of 3D magneto‐mechanical problems with application to magnetic resonance imaging scanners. International Journal for Numerical Methods in Engineering, 121(16), 3529-3559.
https://doi.org/10.1002/nme.6369, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa53849
Ledger, P. & Lionheart, W. (2020). The spectral properties of the magnetic polarizability tensor for metallic object characterisation. Mathematical Methods in the Applied Sciences, 43(1), 78-113.
https://doi.org/10.1002/mma.5830, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50948
http://dx.doi.org/10.1002/mma.5830
Barroso, G., Gil, A., Ledger, P., Mallett, M., & Huerta, A. (2020). A regularised-adaptive Proper Generalised Decomposition implementation for coupled magneto-mechanical problems with application to MRI scanners. Computer Methods in Applied Mechanics and Engineering, 358, 112640
https://doi.org/10.1016/j.cma.2019.112640, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa51902
Seoane, M., Ledger, P., Gil, A., Mallett, M., Ledger, P., & Gil, A. (2019). An accurate and efficient three‐dimensional high order finite element methodology for the simulation of magneto‐mechanical coupling in MRI scanners. International Journal for Numerical Methods in Engineering
https://doi.org/10.1002/nme.6088, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50137
Walker, D., Kramer, S., Biebl, F., Ledger, P., & Brown, M. (2019). Accelerating magnetic induction tomography‐based imaging through heterogeneous parallel computing. Concurrency and Computation: Practice and Experience, 31(17), e5265
https://doi.org/10.1002/cpe.5265, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa49975
Ledger, P., Lionheart, W., & Amad, A. (2019). Characterisation of multiple conducting permeable objects in metal detection by polarizability tensors. Mathematical Methods in the Applied Sciences, 42(3), 830-860.
https://doi.org/10.1002/mma.5387, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa45292
Ledger, P. & Lionheart, W. (2018). An Explicit Formula for the Magnetic Polarizability Tensor for Object Characterization. IEEE Transactions on Geoscience and Remote Sensing, 56(6), 3520-3533.
https://doi.org/10.1109/TGRS.2018.2801359, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa38335
http://ieeexplore.ieee.org/document/8328014/
Bagwell, S., Ledger, P., Gil, A., & Mallett, M. (2018). Transient solutions to nonlinear acousto-magneto-mechanical coupling for axisymmetric MRI scanner design. International Journal for Numerical Methods in Engineering, 115(2), 209-237.
https://doi.org/10.1002/nme.5802, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa39052
Ledger, P. & Lionheart, W. (2018). Generalised magnetic polarizability tensors. Mathematical Methods in the Applied Sciences, 41(8), 3175-3196.
https://doi.org/10.1002/mma.4809, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa38104
Bagwell, S., Ledger, P., Gil, A., Mallett, M., & Kruip, M. (2017). A linearised hp-finite element framework for acousto-magneto-mechanical coupling in axisymmetric MRI scanners. International Journal for Numerical Methods in Engineering, 112(10), 1323-1352.
https://doi.org/10.1002/nme.5559, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa29689
Kynch, R., Ledger, P., & Ledger, P. (2017). Resolving the sign conflict problem for hp–hexahedral Nédélec elements with application to eddy current problems. Computers & Structures, 181, 41-54.
https://doi.org/10.1016/j.compstruc.2016.05.021, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa29408
Ledger, P. & Lionheart, W. (2016). Understanding the magnetic polarizability tensor. IEEE Transactions on Magnetics, 52(5), 1-16.
https://doi.org/10.1109/TMAG.2015.2507169, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa26710
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7350159
Jin, D., Ledger, P., & Gil, A. (2016). hp-Finite element solution of coupled stationary magnetohydrodynamics problems including magnetostrictive effects. Computers & Structures, 164, 161-180.
https://doi.org/10.1016/j.compstruc.2015.11.008, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa25085
Ledger, P. & Lionheart, W. (2015). Characterizing the shape and material properties of hidden targets from magnetic induction data. IMA Journal of Applied Mathematics, 80(6), 1776-1798.
https://doi.org/10.1093/imamat/hxv015, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa22806
http://imamat.oxfordjournals.org/content/early/2015/06/25/imamat.hxv015
Ledger, P., Lionheart, W., & Ledger, P. (2015). The perturbation of electromagnetic fields at distances that are large compared with the object's size. IMA Journal of Applied Mathematics, 80(3), 865-892.
https://doi.org/10.1093/imamat/hxu009, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa20763
http://imamat.oxfordjournals.org/content/80/3/865
Poya, R., Gil, A., & Ledger, P. (2015). A computational framework for the analysis of linear piezoelectric beams using hp-FEM. Computers & Structures, 152, 155-172.
https://doi.org/10.1016/j.compstruc.2015.01.012, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa20762
Ledger, P., Gil, A., Poya, R., Kruip, M., Wilkinson, I., Bagwell, S., Ledger, P., Gil, A., & Poya, R. (2015). Solution of an industrially relevant coupled magneto–mechanical problem set on an axisymmetric domain. Applied Mathematical Modelling, 40(3), 1959-1971.
https://doi.org/10.1016/j.apm.2015.09.030, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa23807
Jin, D., Ledger, P., Gil, A., Ledger, P., & Gil, A. (2014). An hp-fem framework for the simulation of electrostrictive and magnetostrictive materials. Computers & Structures, 133, 131-148.
https://doi.org/10.1016/j.compstruc.2013.10.009, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa18293
Priewald, R., Magele, C., Ledger, P., Pearson, N., & Mason, J. (2013). Fast Magnetic Flux Leakage Signal Inversion for the Reconstruction of Arbitrary Defect Profiles in Steel Using Finite Elements. IEEE Transactions on Magnetics, 49(1), 506-516.
https://doi.org/10.1109/tmag.2012.2208119, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12684
Gil, A., Ledger, P., Ledger, P., & Gil, A. (2012). A coupled hp-finite element scheme for the solution of two-dimensional electrostrictive materials. International Journal for Numerical Methods in Engineering, 91(11), 1158
https://doi.org/10.1002/nme.4308, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa14279
Ledger, P. & Ledger, P. (2012). hp-Finite element discretisation of the electrical impedance tomography problem. Computer Methods in Applied Mechanics and Engineering, 225-228, 154-176.
https://doi.org/10.1016/j.cma.2012.02.015, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa10548
Zolgharni, M., Griffiths, H., Ledger, P., & Ledger, P. (2010). Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling. Physiological Measurement, 31(8), S111-S125.
https://doi.org/10.1088/0967-3334/31/8/S09, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa6223
Ledger, P., Zaglmayr, S., & Ledger, P. (2010). hp-Finite element simulation of three-dimensional eddy current problems on multiply connected domains. Computer Methods in Applied Mechanics and Engineering, 199(49-52), 3386-3401.
https://doi.org/10.1016/j.cma.2010.07.010, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5699
Ledger, P. & Ledger, P. (2010). An Investigation of a Preconditioner for High-Frequency Maxwell Problems. Electromagnetics, 30(1-2), 94-126.
https://doi.org/10.1080/02726340903485364, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5701
Ledger, P. (2009). Forward modelling of magnetic induction tomography: a sensitivity study for detecting haemorrhagic cerebral stroke. Medical & Biological Engineering & Computing, 47(12), 1301-1313.
https://doi.org/10.1007/s11517-009-0541-1, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5702
Ledger, P. (2009). Preconditioners for the indefinite linear system arising from thehpdiscretization of Maxwell's equations. Communications in Numerical Methods in Engineering
https://doi.org/10.1002/cnm.1131, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5697
Ledger, P. (2009). Imaging cerebral haemorrhage with magnetic induction tomography: numerical modelling. Physiological Measurement
https://doi.org/10.1088/0967-3334/30/6/S13, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5698
Morgan, K. & Ledger, P. (2008). An Adjoint Enhanced Reduced-Order Model for Monostatic RCS Computation. Electromagnetics
https://doi.org/10.1080/02726340701818063, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5343
Hiptmair, R., Ledger, P., & Ledger, P. (2005). Computation of resonant modes for axisymmetric Maxwell cavities using hp-version edge finite elements. , 1652-1676.
https://doi.org/10.1002/nme.1241, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa1912
Ledger, P., Peraire, J., Morgan, K., Hassan, O., Weatherill, N., Hassan, O., & Ledger, P. (2004). Parameterised electromagnetic scattering solutions for a range of incident wave angles. , 3587-3605.
https://doi.org/10.1016/j.cma.2004.01.032, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa1913
Ainsworth, M., Coyle, J., Ledger, P., Morgan, K., & Ledger, P. (2003). Computing maxwell eigenvalues by using higher order edge elements in three dimensions. IEEE Transactions on Magnetics, 39(5), 2149-2153.
https://doi.org/10.1109/TMAG.2003.817097, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa28006
Ledger, P., Peraire, J., Morgan, K., Hassan, O., & Weatherill, N. (2003). Adaptive hp finite element computations of the scattering width output of Maxwell's equations. International Journal for Numerical Methods in Fluids, 43, 953-978.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa28008
Ledger, P., Morgan, K., Hassan, O., & Weatherill, N. (2003). Plane wave H(curl) conforming finite elements for Maxwell’s equations.. Computational Mechanics, 31, 272-283.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa28009
Ledger, P., Morgan, K., Peraire, J., Hassan, O., Weatherill, N., Hassan, O., & Ledger, P. (2003). The development of an hp-adaptive finite element procedure for electromagnetic scattering problems. Finite Elements in Analysis and Design, 39(8), 751-764.
https://doi.org/10.1016/S0168-874X(03)00057-X, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12448
Ledger, P., Morgan, K., Hassan, O., & Weatherill, N. (2002). Arbitrary order edge elements for electromagnetic scattering simulations using hybrid meshes and a PML. International Journal for Numerical Methods in Engineering, 55(3), 339-358.
https://doi.org/10.1002/nme.501, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa25283

Goruchwyliaeth

A new computational tool for the analysis of Floor Borne Vibrations on the performance and image quality of MRI scanners. (cyfredol)

PhD

Goruchwyliwr arall: Prof Antonio Gil