Johan Helsing

Sökresultat

• 2024

  Design of Perfectly Conducting Objects That Are Invisible to an Incident Plane Wave

  Helsing, J., Jiang, S. & Karlsson, A., 2024, I: IEEE Journal on Multiscale and Multiphysics Computational Techniques. 9, s. 104-112 9 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Arrays 100%
  • Boundaries 100%
  • Integral Equations 49%
  • Planar Waveguide 49%
• 2023

  Inverse Problem for a Planar Conductivity Inclusion^*

  Choi, D., Helsing, J., Kang, S. & Lim, M., 2023, I: SIAM Journal on Imaging Sciences. 16, 2, s. 969-995 27 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  • Tensor 100%
  • Conformal Mapping 100%
  • Matrix (Mathematics) 33%
  • Factorization 33%
  • Inversion Formula 33%
• 2022

  An efficient full-wave solver for eddy currents

  Helsing, J., Karlsson, A. & Rosén, A., 2022 dec., I: Computers and Mathematics with Applications. 128, s. 145-162 18 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  • Transmission Problem 100%
  • Transmissions 66%
  • Operators 50%
  • Integral Equation 50%
  • Accuracy 33%

• Solving Fredholm second-kind integral equations with singular right-hand sides on non-smooth boundaries

  Helsing, J. & Jiang, S., 2022 jan. 1, I: Journal of Computational Physics. 448, 110714.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Singularities 100%
  • Integral Equation 100%
  • Fredholm 100%
  • Performance 50%
  • Numerical Scheme 50%
• 2021

  Comparison of integral equations for the Maxwell transmission problem with general permittivities

  Helsing, J., Karlsson, A. & Rosén, A., 2021 okt., I: Advances in Computational Mathematics. 47, 5, 76.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  • Integral Equation 100%
  • Transmission Problem 100%
  • Transmissions 100%
  • Surface Density 33%
  • Essential Spectrum 25%

• Dirac Integral Equations for Dielectric and Plasmonic Scattering

  Helsing, J. & Rosén, A., 2021 okt., I: Integral Equations and Operator Theory. 93, 5, 48.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  • Scattering 100%
  • Dielectrics 100%
  • Two Dimensional 100%
  • Transmissions 100%
  • Low Frequency 100%
• 2020

  An extended charge-current formulation of the electromagnetic transmission problem

  Helsing, J. & Karlsson, A., 2020 apr. 20, I: SIAM Journal on Applied Mathematics. 80, 2, s. 951-976 26 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • unique solution φ 100%
  • Transmission Problem 100%
  • Integral Equation 50%
  • Electromagnetic Wave 50%
  • Upper Half Plane 50%
• 2019

  Physical-density integral equation methods for scattering from multi-dielectric cylinders

  Helsing, J. & Karlsson, A., 2019, I: Journal of Computational Physics. 387, s. 14-29 16 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Dielectrics 100%
  • Integral Equations 100%
  • Integral Equation 100%
  • Mathematical Method 33%
  • Electromagnetic Fields 33%
• 2018

  On a Helmholtz transmission problem in planar domains with corners

  Helsing, J. & Karlsson, A., 2018 okt. 15, I: Journal of Computational Physics. 371, s. 315-332 18 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Transmissions 100%
  • Helmholtz's Law 100%
  • Transmission Problem 100%
  • Scattering 33%
  • Dielectrics 33%

• Corner effects on the perturbation of an electric potential

  Choi, D. S., Helsing, J. & Lim, M., 2018 jan. 1, I: SIAM Journal on Applied Mathematics. 78, 3, s. 1577-1601 25 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Tensor 100%
  • Corner Point 100%
  • Electric Potential 100%
  • Geometric Factor 100%
  • Discretization 50%

• On integral equation methods for the first Dirichlet problem of the biharmonic and modified biharmonic equations in nonsmooth domains

  Helsing, J. & Jiang, S., 2018, I: SIAM Journal on Scientific Computing. 40, 4, s. A2609-A2630

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Nonsmooth Domain 100%
  • Integral Equation 100%
  • Dirichlet Problem 100%
  • Dirichlet 100%
  • Modeling 50%

• The spectra of harmonic layer potential operators on domains with rotationally symmetric conical points

  Helsing, J. & Perfekt, K. M., 2018, I: Journal des Mathematiques Pures et Appliquees. 118, s. 235-287

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Points 100%
  • Essential Spectrum 42%
  • Spectral 40%
  • Rapport 40%
  • Tensor 28%
• 2017

  Classification of spectra of the Neumann–Poincaré operator on planar domains with corners by resonance

  Helsing, J., Kang, H. & Lim, M., 2017 juli 1, I: Annales de l'Institut Henri Poincare. Annales: Analyse Non Lineaire/Nonlinear Analysis. 34, 4, s. 991-1011 21 s.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Operators 100%
  • Eigenvalue 42%
  • Point Spectrum 42%
  • Order 14%
  • Discretization 14%

• Resonances in Axially Symmetric Dielectric Objects

  Helsing, J. & Karlsson, A., 2017 juli 1, I: IEEE Transactions on Microwave Theory and Techniques. 65, 7, s. 2214-2227 14 s., 7857810.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  • Performance 100%
  • Accuracy 100%
  • Wavelength 100%
  • Terahertz 100%
  • Microwave 100%
• 2016

  Determination of normalized electric eigenfields in microwave cavities with sharp edges

  Helsing, J. & Karlsson, A., 2016, I: Journal of Computational Physics. 304, s. 465-486

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Fourier Matrix 100%
  • Piecewise Smooth 100%
  • Smooth Surface 100%
  • Microwave 100%
  • Cavity 100%
  371 Nedladdningar (Pure)
• 2015

  Determination of normalized magnetic eigenfields in microwave cavities

  Helsing, J. & Karlsson, A., 2015, I: IEEE Transactions on Microwave Theory and Techniques. 63, 5, s. 1457-1467

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Microwave 100%
  • Cavity 100%
  • Order 100%
  • Integral Equation 100%
  • Fourier Matrix 100%
  397 Nedladdningar (Pure)

• Variants of an explicit kernel-split panel-based Nyström discretization scheme for Helmholtz boundary value problems

  Helsing, J. & Holst, A., 2015, I: Advances in Computational Mathematics. 41, 3, s. 691-708

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Discretization 100%
  • Boundary Value Problems 100%
  • Helmholtz's Law 100%
  • Discretization Scheme 100%
  • Boundary Value 100%
  238 Nedladdningar (Pure)
• 2014

  An explicit kernel-split panel-based Nyström scheme for integral equations on axially symmetric surfaces

  Helsing, J. & Karlsson, A., 2014, I: Journal of Computational Physics. 272, s. 686-703

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Accuracy 100%
  • Helmholtz's Law 100%
  • Computational Domain 100%
  • Discretization Scheme 100%
  • Integral Equation 100%
  241 Nedladdningar (Pure)
• 2013

  An accurate boundary value problem solver applied to scattering from cylinders with corners

  Helsing, J. & Karlsson, A., 2013, I: IEEE Transactions on Antennas and Propagation. 61, 7, s. 3693-3700

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil
  202 Nedladdningar (Pure)

• On the polarizability and capacitance of the cube

  Helsing, J. & Perfekt, K.-M., 2013, I: Applied and Computational Harmonic Analysis. 34, 3, s. 445-468

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Lipschitz Domain 100%
  • Unit Cube 100%
  • Limiting Behavior 100%
  • Mathematical Theory 100%
  • Smooth Domain 100%
  159 Nedladdningar (Pure)

• On the Stability of the Nystrom Method for the Muskhelishvili Equation on Contours with Corners

  Didenko, V. D. & Helsing, J., 2013, I: SIAM Journal on Numerical Analysis. 51, 3, s. 1757-1776

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Operators 100%
  • Contour 100%
  • Toeplitz Operator 33%
  • Numerical Experiment 33%
  • Piecewise Smooth 33%
  204 Nedladdningar (Pure)

• Solving integral equations on piecewise smooth boundaries using the RCIP method: a tutorial

  Helsing, J., 2013, I: Abstract and Applied Analysis. 938167.

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Integral Equation 100%
  • Piecewise Smooth 100%
  • Scattering 50%
  • Numerical Methods 50%
  • Broad Range 50%
  309 Nedladdningar (Pure)
• 2011

  A Fast and Stable Solver for Singular Integral Equations on Piecewise Smooth Curves

  Helsing, J., 2011, I: SIAM Journal on Scientific Computing. 33, 1, s. 153-174

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Piecewise Smooth 100%
  • Discretization 50%
  • Number 50%
  • Integral Equation 50%
  • Quadrature 50%
  269 Nedladdningar (Pure)

• Fast reconstruction of harmonic functions from Cauchy data using the Dirichlet-to-Neumann map and integral equations

  Helsing, J. & Johansson, B. T., 2011, I: Inverse Problems in Science and Engineering. 19, 5, s. 717-727

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Integral Equation 100%
  • Harmonic Function 100%
  • Derivatives 66%
  • Operators 33%
  • Discretization 33%
  165 Nedladdningar (Pure)

• Features of the Nyström method for the Sherman-Lauricella equation on Piecewise Smooth Contours

  Didenko, V. & Helsing, J., 2011, I: East Asian Journal on Applied Mathematics. 1, 4, s. 403-414

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Corner Point 100%
  • Invertibility 100%
  • Approximation Method 33%
  172 Nedladdningar (Pure)

• Spectral super-resolution in metamaterial composites

  Helsing, J., McPhedran, R. & Milton, G., 2011, I: New Journal of Physics. 13, 11

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Composite Material 100%
  • Metamaterial 100%
  • Composite 100%
  • Permittivity 33%
  • Wavelength 25%
  232 Nedladdningar (Pure)

• Stability of the Nyström Method for the Sherman–Lauricella Equation

  Didenko, V. & Helsing, J., 2011, I: SIAM Journal on Numerical Analysis. 49, 3, s. 1127-1148

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Corner Point 100%
  • Operators 50%
  • Contour 50%
  • Numerical Experiment 50%
  • Piecewise Smooth 50%
  190 Nedladdningar (Pure)

• The effective conductivity of arrays of squares: Large random unit cells and extreme contrast ratios

  Helsing, J., 2011, I: Journal of Computational Physics. 230, 20, s. 7533-7547

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Effective Conductivity 100%
  • Checkerboard 100%
  • Contrast Ratio 100%
  • Number 33%
  • Integral Equation 33%
  183 Nedladdningar (Pure)

• The effective conductivity of random checkerboards

  Helsing, J., 2011, I: Journal of Computational Physics. 230, 4, s. 1171-1181

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Effective Conductivity 100%
  • Checkerboard 100%
  • Relative Precision 33%
  • Random Component 33%
  201 Nedladdningar (Pure)
• 2010

  Fast reconstruction of harmonic functions from Cauchy data using integral equation techniques

  Helsing, J. & Johansson, B. T., 2010, I: Inverse Problems in Science and Engineering. 18, 3, s. 381-399

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Integral Equation 100%
  • Harmonic Function 100%
  • Approximation 66%
  • Derivatives 66%
  • Discretization 33%
  190 Nedladdningar (Pure)
• 2009

  Elastostatic computations on aggregates of grains with sharp interfaces, corners, and triple-junctions

  Helsing, J. & Ojala, R., 2009, I: International Journal of Solids and Structures. 46, 25-26, s. 4437-4450

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Assembly 100%
  • Aggregate 100%
  • Triple Junction 100%
  • Corner 100%
  • Basis Function 50%
  214 Nedladdningar (Pure)

• Faster convergence and higher accuracy for the Dirichlet-Neumann map

  Helsing, J., 2009, I: Journal of Computational Physics. 228, 7, s. 2578-2586

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil
  207 Nedladdningar (Pure)

• Integral equation methods for elliptic problems with boundary conditions of mixed type

  Helsing, J., 2009, I: Journal of Computational Physics. 228, 23, s. 8892-8907

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Mixed Boundary Condition 100%
  • Neumann Condition 50%
  • Compact Operators 50%
  363 Nedladdningar (Pure)
• 2008

  Corner singularities for elliptic problems: Integral equations, graded meshes, quadrature, and compressed inverse preconditioning

  Helsing, J. & Ojala, R., 2008, I: Journal of Computational Physics. 227, 20, s. 8820-8840

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Mesh 100%
  • Singularities 100%
  • Integral Equation 100%
  • Quadrature 100%
  • Relative Error 66%
  427 Nedladdningar (Pure)

• On the evaluation of layer potentials close to their sources

  Helsing, J. & Ojala, R., 2008, I: Journal of Computational Physics. 227, 5, s. 2899-2921

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Quadrature 100%
  • Density 100%
  • Polynomial 66%
  • Laplace Equation 50%
  • Hierarchical Method 50%
  406 Nedladdningar (Pure)
• 2006

  Approximate inverse preconditioners for some large dense random electrostatic interaction matrices

  Helsing, J., 2006, I: BIT Numerical Mathematics. 46, 2, s. 307-323

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Matrix (Mathematics) 100%
  • Approximates 100%
  • Points 20%
  • Diagonal 20%
  • Linear System 20%
  173 Nedladdningar (Pure)
• 2005

  Laplace's equation and the Dirichlet-Neumann map: a new mode for Mikhlin's method

  Helsing, J. & Wadbro, E., 2005, I: Journal of Computational Physics. 202, 2, s. 391-410

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Tyrothricin 100%
  • Number 66%
  • Exterior Domain 66%
  352 Nedladdningar (Pure)
• 2004

  A comparison of splittings and integral equation solvers for a nonseparable elliptic equation

  Englund, J. & Helsing, J., 2004, I: BIT Numerical Mathematics. 44, 4, s. 675-697

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Order 100%
  • Partial Differential Equation 100%
  • Integral Equation 100%
  • Variables 100%
  • Elliptic Equation 100%
  184 Nedladdningar (Pure)

• A seventh-Order Accurate and Stable Algorithm for the Computation of Stress Inside Cracked Rectangular Domains

  Helsing, J. & Jonsson, A., 2004, I: International Journal for Multiscale Computational Engineering. 2, 1, s. 47-68

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Stable Algorithm 100%
  • Order 100%
  • Discretization 66%
  • Relative Error 66%
  • Stress Field 66%
  169 Nedladdningar (Pure)
• 2003

  Stress computations on perforated polygonal domains

  Englund, J. & Helsing, J., 2003, I: Engineering Analysis with Boundary Elements. 27, 5, s. 533-546

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Order 100%
  • Integral Equation 100%
  • Edge 100%
  • Fredholm Equation 100%
  • Tradeoff 100%
  155 Nedladdningar (Pure)
• 2002

  On the accuracy of benchmark tables and graphical results in the applied mechanics literature

  Helsing, J. & Jonsson, A., 2002, I: Journal of Applied Mechanics. 69, 1, s. 88-90

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Error 100%
  • Fracture Mechanics 100%
  • Accuracy 100%
  • Stress-Intensity Factor 100%
  • Applied Mechanics 100%
  165 Nedladdningar (Pure)

• On the computation of stress fields on polygonal domains with V-notches

  Helsing, J. & Jonsson, A., 2002, I: International Journal for Numerical Methods in Engineering. 53, 2, s. 433-453

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Stress Field 100%
  • Stress-Intensity Factor 66%
  • Basis Function 33%
  • Illustrates 33%
  • Numerical Example 33%
  186 Nedladdningar (Pure)

• Stress calculations on multiply connected domains

  Helsing, J. & Jonsson, A., 2002, I: Journal of Computational Physics. 176, 2, s. 456-482

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Domain 100%
  • Stress Analysis 100%
  • Error 50%
  • Square 50%
  • Inclusion 50%
  278 Nedladdningar (Pure)
• 2001

  Complex variable boundary integral equations for perforated infinite planes

  Helsing, J. & Jonsson, A., 2001, I: Engineering Analysis with Boundary Elements. 25, 3, s. 191-202

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Plane 100%
  • Algorithm 100%
  • Boundaries 100%
  • Integral Equations 100%
  • Integral Equation 100%
  123 Nedladdningar (Pure)
• 2000

  An Efficient Numerical Algorithm for Cracks Partly in Frictionless Contact

  Helsing, J. & Peters, G., 2000, I: SIAM Journal on Applied Mathematics. 61, 2, s. 551-566

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Öppen tillgång

  Fil

  • Crack Problem 100%
  • Contact Zone 100%
  • Linear Elasticity 100%
  196 Nedladdningar (Pure)

• Corner singularities for elliptic problems: special basis functions versus ‘brute force’

  Helsing, J., 2000, I: Communications in Numerical Methods in Engineering. 16, 1, s. 37-46

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Prism 100%
  • Pointwise 100%
  • Elliptic Boundary Value Problem 100%
  146 Nedladdningar (Pure)

• On the Interior Stress Problem for Elastic Bodies

  Helsing, J., 2000, I: Journal of Applied Mechanics. 67, 4, s. 658-662

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Elastic Body 100%
  • Integral Equation 100%
  • Numerical Example 50%
  • Computational Domain 50%
  • Greater Stability 50%
  140 Nedladdningar (Pure)
• 1999

  Fast and accurate numerical solution to an elastostatic problem involving ten thousand randomly oriented cracks

  Helsing, J., 1999, I: International Journal of Fracture. 100, 4, s. 321-327

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Crack 100%
  • Elasticity 100%
  • Numerical Example 50%
  • High Accuracy 50%
  • Computing Time 50%
  149 Nedladdningar (Pure)

• Integral equation methods and numerical solutions of crack and inclusion problems in planar elastostatics

  Helsing, J. & Peters, G., 1999, I: SIAM Journal on Applied Mathematics. 59, 3, s. 965-982

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

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  Fil

  • Investigator 100%
  • Greater Stability 100%
  • Crack Problem 100%
  214 Nedladdningar (Pure)

• On the numerical evaluation of stress intensity factors for an interface crack of a general shape

  Helsing, J., 1999, I: International Journal for Numerical Methods in Engineering. 44, 5, s. 729-741

  Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review

  Fil

  • Stress-Intensity Factor 100%
  • Interface Crack 100%
  • Numerical Evaluation 100%
  • Crack Opening Displacement 50%
  174 Nedladdningar (Pure)