Publications

2020

F. Scholz, B. Jüttler:
High-order Quadrature on Planar Domains Based on Transport Theorems for Implicitly Defined Moving Curves.
NFN Technical Report No. 89 - [PDF].

Maodong Pan, B. Jüttler, A. Giust:
Fast Formation of Isogeometric Galerkin Matrices via Integration by Interpolation and Look-up.
NFN Technical Report No. 88 - [PDF].

2019

I. Georgieva, C. Hofreither:
Greedy low-rank approximation in Tucker format of solutions of tensor linear systems.
Journal of Computational and Applied Mathematics, Vol. 358, Oct. 2019, pp. 206-220. DOI: 10.1016/j.cam.2019.03.002.
See also NFN Technical Report No. 68 - [PDF].

S. Kargaran, B. Jüttler, S. K. Kleiss, A. Mantzaflaris, T. Takacs:
Overlapping Multi-Patch Structures in Isogeometric Analysis.
NFN Technical Report No. 87 - [PDF]. This technical report replaces report no. 82.

F. Scholz, A. Mantzaflaris, B. Jüttler:
First order error correction for trimmed quadrature in isogeometric analysis.
Advanced Finite Element Methods with Applications - Proceedings of the 30th Chemnitz FEM Symposium 2017. Springer, to appear. Eds. T. Apel, U. Langer, A. Meyer, O. Steinbach: Lecture Notes in Computational Science and Engineering.
See also NFN Technical Report No. 84 - [PDF]

B. Jüttler, S. Maroscheck, Myung-Soo Kim, Q. Youn Hong:
Arc Fibrations of Planar Domains.
Computer Aided Geometric Design, Vol. 71, May 2019, pp. 105 - 118.
See also NFN Technical Report No. 80 - [PDF]

A. Beigl, O. Scherzer, J. Sogn, W. Zulehner:
Preconditioning Inverse Problems for Hyperbolic Equations with Applications to Photoacoustic Tomography.
arXiv:1905.13490 .

K. Birner, B. Jüttler, A. Mantzaflaris:
Approximation power of C¹-smooth isogeometric splines on volumetric two-patch domains.
To appear in Springer's Lecture Notes in Computational Sciences and Engineering series.
NFN Technical Report No. 86 - [PDF].

N. Engleitner, B. Jüttler:
Lofting with Patchwork B-splines.
In: Advanced Methods for Geometric Modeling and Numerical Simulation. Ed. by C. Giannelli and H. Speleers. Vol. 33. INdAM series. To appear. Springer, 2019.
See also NFN Technical Report No. 79 - [PDF]

S. Sajavičius, B.Jüttler and Jaka Špeh:
Template Mapping Using Adaptive Splines and Optimization of the Parameterization.
In: Advanced Methods for Geometric Modeling and Numerical Simulation. Ed. by C. Giannelli and H. Speleers. Vol. 33. INdAM series. To appear. Springer, 2019.
See also NFN Technical Report No. 78 - [PDF]

R. Boţ, D. Guozhi, P. Elbau, O. Scherzer:
Convergence Rates of First and Higher Order Dynamics for Solving Linear Inverse Problems.
In: Tomographic Inverse Problems: Theory and Applications. Oberwolfach reports. to appear. EMS Publishing House, 2019.

P. Gangl, U. Langer, A. Mantzaflaris, R. Schneckenleitner:
Isogeometric Simulation and Shape Optimization with Applications to Electrical Machines.
accepted for publication in the SCEE 2018 proceedings, Springer, 2019;
arXiv. See also NFN technical report No. 75.

C. Hofer, U. Langer, M. Neumüller, R. Schneckenleitner:
Parallel and robust preconditioning for space-time isogeometric analysis of parabolic evolution problems.
SIAM Journal on Scientific Computing, 2019. accepted for publication.

M. Haberleitner, B. Jüttler, Yannick Masson:
Isogeometric Segmentation via Midpoint Subdivision Suitable Solids.
Computer-Aided Design, online May 2019, in press. DOI: 10.1016/j.cad.2019.05.012.
See also NFN Technical Report No. 83 - [PDF]

U. Langer, S. Matculevich, S. Repin:
Adaptive space–time Isogeometric Analysis for parabolic evolution problems.
In U. Langer and O. Steinbach, editors, Space–Time Methods: Applications to Partial Differential Equations, volume 25 of Radon Series on Computational and Applied Mathematics, pages 155–200. de Gruyter, Berlin, 2019. to appear

U. Langer, S. Matculevich, S. Repin:
Guaranteed error bounds and local indicators for adaptive solvers using stabilised space–time IgA approximations to parabolic problems.
Computers & Mathematics with Applications, 2019, in press. DOI: 10.1016/j.camwa.2019.04.009.

F. Scholz, B. Jüttler:
Numerical integration on trimmed three-dimensional domains.
NFN Technical Report No. 85 - [PDF].

F. Scholz, A. Mantzaflaris, B. Jüttler:
First order error correction for trimmed quadrature in isogeometric analysis.
NFN Technical Report No. 84 - [PDF]. This technical report replaces report no. 71.

K. Rafetseder, W. Zulehner:
A new mixed isogeometric approach to Kirchhoff-Love shells.
Computer Methods in Applied Mechanics and Engineering, Vol. 346, April 2019, pp. 440 - 455. DOI: 10.1016/j.cma.2018.11.033. See also NFN Technical Report No. 70 - [PDF].

M. Haberleitner, B. Jüttler, Yannick Masson:
Isogeometric Segmentation via Midpoint Subdivision Suitable Solids.
NFN Technical Report No. 83 - [PDF].

S. Kargaran, B. Jüttler, S. K. Kleiss, A. Mantzaflaris, T. Takacs:
Overlapping Multi-Patch Structures in Isogeometric Analysis.
NFN Technical Report No. 82 - [PDF].

N. Engleitner, B. Jüttler:
Decoupled Patchwork B-splines.
NFN Technical Report No. 81 - [PDF].

Ch. Hofer, U. Langer, I. Toulopoulos:
Isogeometric analysis on non-matching segmentation: discontinuous Galerkin techniques and efficient solvers.
Journal of Applied Mathematics and Computing, Springer 2019, vol. 60 pp. 1-40. DOI: 10.1007/s12190-019-01252-3.

K. Birner, M. Kapl:
The space of C¹-smooth isogeometric spline functions on trilinearly parameterized volumetric two-patch domains.
Journal Computer Aided Geometric Design, vol. 70, pp. 16-30. DOI: 10.1016/j.cagd.2019.03.002. See also NFN technical report No. 69,

B. Jüttler, S. Maroscheck, Myung-Soo Kim, Q Youn Hong:
Arc Fibrations of Planar Domains.
NFN Technical Report No. 80 - [PDF].

R. Ciak, M. Hirzmann, O. Scherzer:
Regularization with Metric Double Integrals of Functions with Values in a Set of High-Dimensional Vectors.
Journal of Mathematical Imaging and Vision, 2019, pp 1 - 25. DOI: 10.1007/s10851-018-00869-6. See also NFN technical report No. 72, arXiv:1805.07552. 2018.

N. Engleitner, B. Jüttler:
Lofting with Patchwork B-splines.
NFN Technical Report No. 79 - [PDF] This technical report replaces report no. 73.

S. Sajavičius, B.Jüttler and Jaka Špeh:
Template Mapping Using Adaptive Splines and Optimization of the Parameterization.
NFN Technical Report No. 78 - [PDF] This technical report replaces report no. 76.

A. Seiler, B.Jüttler:
Approximately C¹-smooth Isogeometric Functions on Two-Patch Domains.
NFN Technical Report No. 77 - [PDF].

J. Sogn, S. Takacs:
Robust multigrid solvers for the biharmonic problem in isogeometric analysis.
Computers & Mathematics with Applications, Vol. 77, Jan. 2019, pp. 105-124. DOI: 10.1016/j.camwa.2018.09.017. See also NFN Technical Report No. 65 - [PDF].

Ch. Hofer, U. Langer, S. Takacs:
Inexact Dual-Primal Isogeometric Tearing and Interconnecting Methods.
In: Bjørstad P. et al. (eds) Domain Decomposition Methods in Science and Engineering XXIV. DD 2017. Lecture Notes in Computational Science and Engineering, vol 125. Springer, Cham DOI: 10.1007/978-3-319-93873-8_37.

K. Rafetseder, W. Zulehner:
On a New Mixed Formulation of Kirchhoff Plates on Curvilinear Polygonal Domains.
In: Radu F., Kumar K., Berre I., Nordbotten J., Pop I. (eds) Numerical Mathematics and Advanced Applications ENUMATH 2017. ENUMATH 2017. Lecture Notes in Computational Science and Engineering, vol 126. Springer, Cham. DOI: 10.1007/978-3-319-96415-7_82 See also NFN Technical Report No. 62 - [PDF].

2018

J. A. Iglesias, G. Mercier, O. Scherzer:
Critical Yield Numbers and Limiting Yield Surfaces of Particle Arrays Settling in a Bingham Fluid.
Applied Mathematics & Optimization, 2018, pp 1- 34. DOI: 10.1007/s00245-018-9531-8.
See also NFN technical report No. 67.

S. Sajavičius, B.Jüttler and Jaka Špeh:
Template Mapping Using Adaptive Splines and Optimal Parameterization.
NFN Technical Report No. 76 - [PDF].

P. Gangl, U. Langer, A. Mantzaflaris, R. Schneckenleitner:
Isogeometric Simulation and Shape Optimization with Applications to Electrical Machines.
NFN Technical Report No. 75 - [PDF].

K. Birner, B. Jüttler, A. Mantzaflaris:
Bases and dimensions of C¹-smooth isogeometric splines on volumetric two-patch domains.
Graphical Models, Vol. 99, 2018, pp. 46-56. DOI: 10.1016/j.gmod.2018.08.001.
See also NFN technical report No. 61.

B. Heeren, C. Zhang, M. Rumpf, W. Smith:
Principal Geodesic Analysis in the Space of Discrete Shells. Computer Graphics Forum, Vol. 37-5, Aug. 2018, pp. 173-184, DOI: 10.1111/cgf.13500.

C. Kirisits, O. Scherzer, E. Setterqvist:
Invariant φ-minimal sets and total variation denoising on graphs.
NFN Technical Report No. 74 - [PDF], arXiv:1807.10514.

N. Engleitner, B. Jüttler:
Lofting with Patchwork B-splines
NFN Technical Report No. 73 - [PDF].

K. Rafetseder, W. Zulehner:
A Decomposition Result for Kirchhoff Plate Bending Problems and a New Discretization Approach.
SIAM Journal on Numerical Analysis, 56(3), pp. 1961–1986. DOI: 10.1137/17M1118427.
See also NFN Technical Report No. 52 - [PDF].

C. Hofer, U. Langer, M. Neumüller, I. Toulopoulos:
Time-multipatch discontinuous Galerkin space-time isogeometric analysis of parabolic evolution problems.
ETNA - Electronic Transactions on Numerical Analysis, 49:126–150, 2018. DOI: 10.1553/etna_vol49s126.

A. Mantzaflaris, F. Scholz, I. Toulopoulos:
Low-Rank Space-Time Decoupled Isogeometric Analysis for Parabolic Problems with Varying Coefficients.
Computational Methods in Applied Mathematics, Vol. 19, Issue 1, pp. 123-136. DOI: 10.1515/cmam-2018-0024.
Also available as NFN technical report No. 64.

R. Ciak, M. Hirzmann, O. Scherzer:
Regularization with Metric Double Integrals of Functions with Values in a Set of High-Dimensional Vectors.
NFN Technical Report No. 72 - [PDF], arXiv:1805.07552. 2018.

F. Scholz, A. Mantzaflaris, B. Jüttler:
Partial tensor decomposition for decoupling isogeometric Galerkin discretizations.
Computer Methods in Applied Mechanics and Engineering, Volume 336, 2018, pp. 485-506. DOI: 10.1016/j.cma.2018.03.026.
See also NFN technical report No. 60.

J. A. Iglesias, G. Mercier, O. Scherzer:
A note on convergence of solutions of total variation regularized linear inverse problems.
Inverse Problems, vol. 34, No 5, 2018. DOI: 10.1088/1361-6420/aab92a.
See also NFN technical report No. 66.

C. Hofreither:
A black-box low-rank approximation algorithm for fast matrix assembly in Isogeometric Analysis.
Computer Methods in Applied Mechanics and Engineering, Vol. 333, May 2018, pp. 311-330. DOI: 10.1016/j.cma.2018.01.014.
See also NFN Technical Report No. 55 - [PDF].

J. Sogn, W. Zulehner:
Schur complement preconditioners for multiple saddle point problems of block tridiagonal form with application to optimization problems.
IMA Journal of Numerical Analysis, dry027, DOI: 10.1093/imanum/dry027 See also NFN Technical Report No. 59 - [PDF].

F. Scholz, A.Mantzflaris, B. Jüttler:
First order error correction for trimmed quadrature in isogeometric analysis.
NFN Technical Report No. 71 - [PDF].

K. Rafetseder, W. Zulehner:
A new mixed isogeometric approach to Kirchhoff-Love shells.
NFN Technical Report No. 70 - [PDF].

K. Birner, M. Kapl:
The space of C¹-smooth isogeometric spline functions on trilinearly parameterized volumetric two-patch domains.
NFN Technical Report No. 69 - [PDF].

I. Georgieva, C. Hofreither:
Greedy low-rank approximation in Tucker format of tensors and solutions of tensor linear systems.
NFN Technical Report No. 68 - [PDF].

C. Kirisits, O. Scherzer:
A range condition for polyconvex variational regularization.
Numerical Functional Analysis and Optimization, 39:10, 1064-1076, 2018. DOI: 10.1080/01630563.2018.1467447.
preprint on arXiv:1802.05449.

I. A. Frigaard, J. A. Iglesias, G. Mercier, C. Pöschl, O. Scherzer:
Critical yield numbers of rigid particles settling in Bingham fluids and Cheeger sets.
SIAM Journal on Applied Mathematics 77(2):638-663, 2017. DOI: 10.1016/10.1137/16M10889770.
See also NFN technical report No. 48

J. A. Iglesias, G. Mercier, O. Scherzer:
Critical yield numbers and limiting yield surfaces of particle arrays settling in a Bingham fluid.
NFN Technical Report No. 67 - [PDF].

J. A. Iglesias, M. Rumpf, O. Scherzer:
Shape-Aware Matching of Implicit Surfaces Based on Thin Shell Energies.
Foundations of Computational Mathematics, 2018, Volume 18, Issue 4, pp 891-927.
DOI: 10.1007/s10208-017-9357-9.

J. Sogn, S. Takacs:
Robust multigrid solvers for the biharmonic problem in isogeometric analysis.
NFN Technical Report No. 65 - [PDF].

A. Mantzaflaris, F. Scholz, I. Toulopoulos:
Low-rank space-time decoupled isogeometric analysis for parabolic problems with varying coefficients.
NFN Technical Report No. 64 - [PDF].

U. Langer, S. Matculevich, S. Repin:
Functional Type Error Control for Stabilised Space-Time IgA Approximations to Parabolic Problems.
In I. Lirkov and S. Margenov, editors, Large-Scale Scientific Computing (LSSC 2017), Springer-Verlag, LNCS vol. 10665, 2018, pp. 55-65. DOI: 10.1007/978-3-319-73441-5_5. also available as RICAM Report 2017-14

U. Langer, M. Neumüller, I. Toulopoulos:
Multipatch space-time isogeometric analysis of parabolic diffusion problems.
In I. Lirkov and S. Margenov, editors, Large-Scale Scientific Computing (LSSC 2017), Springer-Verlag, LNCS vol. 10665, 2018, pp. 21–32. DOI: 10.1007/978-3-319-73441-5_2.
See also NFN technical report No. 56.

2017

C. Kirisits, O. Scherzer:
Convergence rates for functionals with polyconvex integrands.
Inverse Problems, 33(8): 085008, 2017. Url iopscience

J. A. Iglesias, G. Mercier, O. Scherzer:
A note on convergence of solutions of total variation regularized linear inverse problems.
NFN Technical Report No. 66 - [PDF].

Nira Dyn, Bert Jüttler, D. Mokriš:
On Transfinite Interpolation by Low-Rank Functions.
NFN Technical Report No. 63 - [PDF].

N. Engleitner, B. Jüttler, U. Zore:
Partially Nested Hierarchical Refinement of Bivariate Tensor-product Splines with Highest Order Smoothness.
Mathematical Methods for Curves and Surfaces, 2017, M. Floater eds, Springer, LNCS 10521, pp. 126-144. DOI: 10.1007/978-3-319-67885-6_7.
See also NFN technical report No. 49

N. Engleitner, B. Jüttler:
Patchwork B-spline refinement.
Computer-Aided Design, Vol. 90, 2017, pp. 168-179. DOI: 10.1016/j.cad.2017.05.021.
See also NFN technical report No. 57

A. Bressan, D. Mokriš:
A Versatile Strategy for the Implementation of Adaptive Splines.
In: Floater M., Lyche T., Mazure ML., Mørken K., Schumaker L. (eds) Mathematical Methods for Curves and Surfaces. MMCS 2016. LNCS, vol 10521. Springer, Cham. pp 42-73. DOI: 10.1007/978-3-319-67885-6_3.
Also available as NFN Technical Report No. 54 - [PDF].

K. Rafetseder, W. Zulehner:
On a new mixed formulation of Kirchhoff plates on curvilinear polygonal domains.
NFN Technical Report No. 62 - [PDF].

K. Birner, B. Jüttler, A. Mantzaflaris:
Bases and dimensions of C¹-smooth isogeometric splines on volumetric two-patch domains.
NFN Technical Report No. 61 - [PDF].

B. Jüttler, S. Kleiss:
Coupling adaptively refined multi-patch spline discretizations via boundary compatibility.
Computers&Mathematics with Applications, Vol 74-7, 2017, pp. 1626-1647. DOI: 10.1016/j.camwa.2017.04.010. Also available as Tech. rep. 37. RICAM, 2016

F. Scholz, A. Mantzaflaris, B. Jüttler:
Partial Tensor Decomposition for Decoupling Isogeometric Galerkin Discretizations.
NFN Technical Report No. 60 - [PDF].

B. Strodthoff, B. Jüttler:
Automatic decomposition of 3D solids into contractible pieces using Reeb raphs.
Computer-Aided Design, Vol. 90, 2017, pp. 157 - 167.
DOI: 10.1016/j.cad.2017.05.006. [PDF]

J. Sogn, W. Zulehner:
Schur complement preconditioners for multiple saddle point problems of block tridiagonal form with application to optimization problems.
NFN Technical Report No. 59 - [PDF].

B. Jüttler, D. Mokriš:
Low rank interpolation of boundary spline curves.
Comp. Aided Geometric Design, Vol 55, 2017, pp. 48-68. DOI: 10.1016/j.cagd.2017.03.012.
See also NFN technical report No. 53

M. Haberleitner, B. Jüttler, M.A. Scott, D.C. Thomas:
Isogeometric Analysis: Representation of Geometry.
Encyclopedia of Computational Mechanics, Wiley, eds. E. Stein and R. de Borst and T.J.R. Hughes, 2017, 2: 1-24, DOI: 10.1002/9781119176817.ecm2106.

M. Haberleitner, B. Jüttler:
Isogeometric segmentation: Construction of cutting surfaces.
Computer-Aided Design, Vol. 90, 2017, pp. 135-145. DOI: 10.1016/j.cad.2017.05.007. [PDF]

G. Dong, O. Scherzer:
Nonlinear Flows for Displacement Correction and Applications in Tomography.
In: Lauze F., Dong Y., Dahl A. (eds) Scale Space and Variational Methods in Computer Vision. SSVM 2017. Lecture Notes in Computer Science, vol 10302. Springer, DOI: 10.1007/978-3-319-58771-4_23.

C. Hofreither, S. Takacs:
Robust Multigrid for Isogeometric Analysis Based on Stable Splittings of Spline Spaces.
SIAM Journal on Numerical Analysis, 55(4), pp. 2004–2024. DOI: 10.1137/16M1085425.
See also NFN Technical Report No. 45 - [PDF]

Ioannis Toulopoulos:
Stabilized space-time finite element methods of parabolic evolution problems.
NFN Technical Report No. 58 - [PDF].

N. Engleitner, B. Jüttler:
Patchwork B-Spline Refinement.
NFN Technical Report No. 57 - [PDF].

C. Hofreither, S. Takacs, W. Zulehner:
A robust multigrid method for Isogeometric Analysis in two dimensions using boundary correction.
Computer Methods in Applied Mechanics and Engineering, Vol. 316, April 2017, pp. 22-42. DOI: 10.1016/j.cma.2016.04.003 See also NFN Technical Report No. 33 - [PDF]

U. Langer, M. Neumüller, I. Toulopoulos:
Multipatch Space-Time Isogeometric Analysis of Parabolic Diffusion Problems.
NFN Technical Report No. 56 - [PDF].

G. Dong, B. Jüttler, O. Scherzer, T. Takacs:
Convergence of Tikhonov regularization for solving ill-posed operator equations with solutions defined on surfaces.
Inverse Problems and Imaging, 11(2): 221-246, 2017. arXiv:1510.07028. DOI: 10.3934/ipi.2017011

M. Kapl, F. Buchegger, M. Bercovier, Bert Jüttler:
Isogeometric Analysis with Geometrically Continuous Functions on Planar Multi-Patch Geometries.
Comp. Meth. Appl. Mech. Engrg., 2017, vol. 316, pp. 209-234. DOI: 10.1016/j.cma.2016.06.002
Also available as NFN Technical Report No. 35 - [PDF].

C. Hofreither:
A Black-Box Algorithm for Fast Matrix Assembly in Isogeometric Analysis.
NFN Technical Report No. 55 - [PDF].

A. Bressan, D. Mokriš:
A Versatile Strategy for the Implementation of Adaptive Splines.
NFN Technical Report No. 54 - [PDF]. This report supersedes NFN Technical Report No. 50.

B. Jüttler, D. Mokriš:
Low rank interpolation of boundary spline curves.
Comput. Aided. Geom. Design, Vol. 55, 2017, pp. 48-68. DOI: 10.1016/j.cagd.2017.03.012.
Also available as NFN Technical Report No. 53 - [PDF].

B. Jüttler, D. Mokriš:
Low rank interpolation of boundary spline curves.
NFN Technical Report No. 53 - [PDF]. This report supersedes NFN Technical Report No. 47.

C. Hofer, U. Langer:
Dual-Primal Isogeometric Tearing and Interconnecting solvers for multipatch dG-IgA equations.
Comput. Methods in Applied Mechanics and Engineering, 2017, vol 316, pp 2-21, DOI: 10.1016/j.cma.2016.03.031.
Also available as NFN Technical Report No. 43 - [PDF].

P. Huber, R. Perl, M. Rumpf:
Smooth interpolation of key frames in a Riemannian shell space.
Computer Aided Geometric Design, Vol. 52–53, March–April 2017, pp. 313-328, DOI: 10.1016/j.cagd.2017.02.008.

K. Rafetseder, W. Zulehner:
A decomposition result for Kirchhoff plate bending problems and a new discretization approach.
NFN Technical Report No. 52 - [PDF]

I. Georgieva, C. Hofreither:
An Algorithm for Low-rank Approximation of Bivariate Functions using Splines.
Journal of Computational and Applied Mathematics, Vol. 310, January 2017, pp. 80-91. DOI: 10.1016/j.cam.2016.03.023.
See also NFN Technical Report No. 28 - [PDF]

A. Mantzaflaris, B. Jüttler, B. N. Khoromskij, U. Langer:
Low rank tensor methods in Galerkin-based isogeometric analysis.
Computer Methods in Applied Mechanics and Engineering, 316 (2017) pp. 1062 - 1085, Special Issue on Isogeometric Analysis: Progress and Challenges, DOI: 10.1016/j.cma.2016.11.013.
See also NFN Technical Report No. 46 - pdf.

2016

C. Hofer, U. Langer:
Dual-primal isogeometric tearing and interconnecting solvers for multipatch continuous and discontinuous Galerkin IgA equations.
PAMM 2016, Vol. 16 (1), pp. 747 - 478, DOI: 10.1002/pamm.201610362.

C. Hofer, U. Langer, I. Toulopoulos:
Discontinuous Galerkin isogeometric analysis of elliptic diffusion problems on segmentations with gaps.
SIAM Journal on Scientific Computing, 38(6):A3430–A3460, 2016, DOI: 10.1137/15M1048574.

C. Hofer, I. Toulopoulos:
Discontinuous Galerkin Isogeometric Analysis of elliptic problems on segmentations with non-matching interfaces.
Computers and Mathematics with Applications 72 (2016) pp. 1811–1827, DOI: 10.1016/j.camwa.2016.07.039.
See also NFN Technical Report No. 42 - pdf.

A. Bressan, D. Mokriš:
A Versatile Strategy for the Implementation of Adaptive Splines.
NFN Technical Report No. 50 - [PDF] This report is superseded by NFN Technical Report No. 54 - [PDF].

N. Engleitner, B. Jüttler, U. Zore:
Partially Nested Hierarchical Refinement of Bivariate Tensor-product Splines with Highest Order Smoothness.
NFN Technical Report No. 49 - [PDF]

C. Hofreither, B. Jüttler, G. Kiss, W. Zulehner:
Multigrid Methods for Isogeometric Analysis with THB-Splines.
Computer Methods in Applied Mechanics and Engineering, Vol. 308, Aug. 2016, pp. 96-112, DOI: 10.1016/j.cma.2016.05.005.
See also NFN Technical Report No. 32 - [PDF]

A. Mantzaflaris:
Low rank tensor methods in isogeometric analysis.
Mathematical Foundations of Isogeometric Analysis, Oberwolfach Reports, 13, 2016, pp.368 - 370 joint work with B. Jüttler, B. N. Khoromskij and U. Langer. DOI: 10.4171/OWR/2016/8,
PDF.

B. Heeren, M. Rumpf, P. Schröder, M. Wardetzky, B. Wirth:
Splines in the Space of Shells.
Computer Graphics Forum, Vol. 35-5, Aug. 2016, pp. 111-120, DOI: 10.1111/cgf.12968.

I. A. Frigaard, J. A. Iglesias, G. Mercier, Ch. Pöschl, O. Scherzer:
Critical yield numbers of rigid particles settling in Bingham fluids and Cheeger sets.
NFN Technical Report No. 48 - [PDF] and at arXiv:1608.01200

W. Krendl, K. Rafetseder, W. Zulehner:
A decomposition result for biharmonic problems and the Hellan-Herrmann-Johnson Method.
ETNA, EElectronic Transactions on Numerical Analysis, Vol. 45, pp. 257 - 282, 2016. etna.ricam.oeaw.ac.at/vol.45.2016/pp257-282.dir/pp257-282.pdf.

B. Jüttler, D. Mokriš, U. Zore:
Completeness of generating systems for quadratic splines on adaptively refined criss-cross triangulations.
Computer Aided Geometric Design, Vol. 45, July 2016, pp. 91-107, DOI: 10.1016/j.cagd.2016.03.005.
See also NFN Technical Report No. 41 - [PDF]

B. Jüttler, D. Mokriš:
Low rank spline interpolation of boundary spline curves.
NFN Technical Report No. 47 - [PDF]. This report is superseded by NFN Technical Report No. 53 - [PDF].

U. Langer, I. Toulopoulos: Analysis of multipatch discontinuous Galerkin IgA approximations to elliptic boundary value problems. Computing and Visualization in Science.
Vol 17-5, pp. 217-233, DOI: 10.1007/s00791-016-0262-6.
See also NFN Technical Report No. 15 - [PDF]

A. Mantzaflaris, B. Jüttler, B. N. Khoromskij, U. Langer:
Low Rank Tensor Methods in Galerkin-based Isogeometric Analysis.
NFN Technical Report No. 46 - [PDF]

C. Hofreither, S. Takacs:
Robust Multigrid for Isogeometric Analysis Based on Stable Splittings of Spline Spaces.
NFN Technical Report No. 45 - [PDF]

U. Langer, S. E. Moore, M. Neumüller:
Space-Time Isogeometric Analysis of Parabolic Evolution Equations.
Comput. Methods Appl. Mech. Engrg., 306:342–363, 2016, DOI: 10.1016/j.cma.2016.03.042.
Also available as NFN Technical Report No. 36 - [PDF] and at arXiv:1509.02008

B. Jüttler, A. Mantzaflaris, R. Perl, M. Rumpf:
On numerical integration in isogeometric subdivision methods for PDEs on surfaces.
Computer Methods in Applied Mechanics and Engineering, Vol. 302, 15 April 2016, pp. 131-146
DOI: 10.1016/j.cma.2016.01.005.
See also NFN Technical Report No. 27 - [PDF]

F. Buchegger, B. Jüttler:
Planar Multi-Patch Domain Parameterization via Patch Adjacency Graphs.
NFN Technical Report No. 44 - [PDF].

B. Jüttler, D. Mokriš, U. Zore:
Completeness of Generating Systems for Quadratic Splines on Adaptively Refined Criss-Cross Triangulations.
NFN Technical Report No. 41 - [PDF].

N. Villamizar, A. Mantzaflaris, B. Jüttler:
Characterization of bivariate hierarchical quartic box splines on a three-directional grid .
Computer Aided Geometric Design, Vol. 41, January 2016, pp. 47–61, DOI: 10.1016/j.cagd.2015.11.004
Also available as Tech. rep. 10. RICAM, 2014

V. Albani, P. Elbau, M. V. de Hoop, O. Scherzer:
Optimal Convergence Rates Results for Linear Inverse Problems in Hilbert Spaces
Numerical Functional Analysis and Optimization, 2016, 37:5, pp. 521-540, DOI: 10.1080/01630563.2016.1144070

2015

C. Hofer, U. Langer:
Dual-Primal Isogeometric Tearing and Interconnecting solvers for multipatch dG-IgA equations.
NFN Technical Report No. 43 - [PDF].

C. Hofer, I. Toulopoulos:
Discontinuous Galerkin Isogeometric Analysis of Elliptic Problems on Segmentations with Non-matching Interfaces.
NFN Technical Report No. 42 - [PDF].

U. Zore, B. Jüttler, J. Kosinka:
On the Linear Independence of (Truncated) Hierarchical Subdivision Splines.
NFN Technical Report No. 40 - [PDF]. This technical report replaces report no. 17.

R. Andreev, O. Scherzer, W. Zulehner:
Simultaneous optical flow and source estimation: space-time discretization and preconditioning.
Applied Numerical Mathematics, Vol. 96, Oct. 2015, pp. 72-81. DOI: 10.1016/j.apnum.2015.04.007
See also NFN Technical Report No. 20 - [PDF]

C. Hofer, U. Langer:
Dual-Primal Isogeometric Tearing and Interconnecting Solvers for large-scale systems of multipatch continuous Galerkin IgA equations.
NFN Technical Report No. 39 - [PDF]

C. Hofer, U. Langer, I. Toulopoulos:
Discontinuous Galerkin Isogeometric Analysis of Elliptic Problems on Non-matching Interfaces.
NFN Technical Report No. 38 - [PDF]

J. Sogn, W. Zulehner:
Robust preconditioners for PDE-constrained optimization with limited observations using isogeometric discretization.
NFN Technical Report No. 34 - [PDF]

J. Iglesias, M. Rumpf, O. Scherzer:
Shape Aware Matching of Implicit Surfaces based on Thin Shell Energies.
arXiv:1509.06559, NFN Technical Report No. 37 - [PDF]

Ulrich Langer, Stephen E. Moore, Martin Neumüller:
Space-Time Isogeometric Analysis of Parabolic Evolution Equations.
NFN Technical Report No. 36 - [PDF] and at arXiv:1509.02008

Mario Kapl, Florian Buchegger, Michel Bercovier, Bert Jüttler:
Isogeometric Analysis with Geometrically Continuous Functions on Multi-Patch Geometries.
NFN Technical Report No. 35 - [PDF]

Dang Manh Nguyen, M. Pauley, B. Jüttler.
Isogeometric Segmentation. Construction of auxiliary curves.
Computer-Aided Design, Vol. 70, 2016, pp. 89–99, DOI: 10.1016/j.cad.2015.06.014, [PDF]

O. Azencot, O. Vantzos, M. Wardetzky, M. Rumpf, M. Ben-Chen:
Functional Thin Films on Surfaces.
SCA '15 Proceedings of the 14th ACM SIGGRAPH / Eurographics Symposium on Computer Animation pp. 137-146. DOI: 10.1145/2786784.2786793

S. Conti, J. Ginster, M. Rumpf:
A BV Functional and its Relaxation for Joint Motion Estimation and Image Sequence Recovery.
ESAIM: Mathematical Modelling and Numerical Analysis (2015). Volume 49, Number 5, September-October 2015, pp. 1463 - 1487. DOI: 10.1051/m2an/2015036

U. Langer, A. Mantzaflaris, S. E. Moore, I. Toulopoulos:
Mesh Grading in Isogeometric Analysis.
Computers & Mathematics with Applications, Volume 70, Issue 7, Oct., pp. 1685-1700. DOI: 10.1016/j.camwa.2015.03.011.
Also available as NFN Technical Report No. 21 - [PDF]

M. Kapl, V. Vitrih, B. Jüttler, K. Birner:
Isogeometric Analysis with Geometrically Continuous Functions on Two-Patch Geometries.
Computers & Mathematics with Applications. Vol. 70, Issue 7, 2015, pp. 1518–1538. DOI: 10.1016/j.camwa.2015.04.004, [PDF]

U. Langer, A. Mantzaflaris, S.E. Moore, I. Toulopoulos:
Multipatch Discontinuous Galerkin Isogeometric Analysis.
Isogeometric Analysis and Applications IGAA 2014. Ed. by B. Jüttler and B. Simeon. Springer LNCSE Vol 107 2015, pp. 1-32. DOI: 10.1007/978-3-319-23315-4_1.
Also available as NFN Technical Report No. 18 - [PDF] and at arXiv:1505.03505

A. Patrone, O. Scherzer:
On a spatial-temporal decomposition of the optical flow.
Inverse Problems & Imaging, 2017, 11(4), pp. 761-781. DOI: 10.3934/ipi.2017036.
arXiv:1411.2478, [PDF]

J. A. Iglesias, C. Kirisits:
Convective regularization for optical flow.
In: Variational methods in Imaging Geometric Control, vol. 18 of Radon Series on Computational and Applied Mathematics, pp. 184-201, de Gruyter, 2017. DOI: 10.1007/978-3-319-23315-4_1.
arXiv:1505.04938

L. F. Lang, O. Scherzer:
Optical Flow on Evolving Sphere-Like Surfaces.
Inverse Problems & Imaging, 2017, 11(2), pp. 305-338. DOI: 10.3934/ipi.2017015 .
Preprint on arXiv:1506.03358

C. Hofreither, W. Zulehner:
Mass Smoothers in Geometric Multigrid for Isogeometric Analysis.
In: Boissonnat JD. et al. (eds) Curves and Surfaces. Curves and Surfaces 2014. Lecture Notes in Computer Science, vol 9213. Springer, Cham. DOI: 10.1007/978-3-319-22804-4_20.
See also NFN Technical Report No. 25 - [PDF]

A. Bressan, B. Jüttler:
A Hierarchical Construction of LR Meshes in 2D.
Comput. Aided Geom. Design 37 (2015) pp. 9 - 24. DOI: 10.1016/j.cagd.2015.06.002.
Also available as NFN Technical Report No. 23 - [PDF]

B. Jüttler.
A primer on splines and NURBS for isogeometric analysis.
Isogeometric Methods for Numerical Simulation. Ed. by G. Beer and S. Bordas. Vol. 561. CISM International Centre for Mechanical Sciences. Springer, 2015, pp. 1 - 19. DOI: 10.1007/978-3-7091-1843-6_1

U. Langer, S.E. Moore:
Discontinuous Galerkin Isogeometric Analysis of Elliptic PDEs on Surfaces.
In: Dickopf T., Gander M., Halpern L., Krause R., Pavarino L. (eds) Domain Decomposition Methods in Science and Engineering XXII (DD22). Lecture Notes in Computational Science and Engineering, vol 104. Springer, Cham. DOI: 10.1007/978-3-319-18827-0_31 Available at arXiv:1402.1185 and as NFN Technical Report No. 12 - [PDF]

G. Dong, A. Patrone, O. Scherzer, O. Öktem:
Infinite Dimensional Optimization Methods and PDEs for Image Dejittering.
Lecture Notes in Computer Science 9087 (2015). Ed. by J.-F. Aujol, M. Nikolova, and N. Papadakis, pp. 678 - 689. DOI: 10.1007/978-3-319-18461-6, [PDF]

V. Korneev, U. Langer:
Dirichlet-Dirichlet Domain Decomposition Methods for Elliptic Problems: H and HP Finite Element Discretizations.
New Jersey - London - Singapore: World Scientific Publishing Company Incorporated, 2015. ISBN: 9789814578455. url

A. Mantzaflaris, B. Jüttler, B. Khoromskij, U. Langer:
Matrix Generation in Isogeometric Analysis by Low Rank Tensor Approximation.
Curves and Surfaces. Ed. by J.-D. Boissonat et al. LNCS, Springer, 2015. LNCS 9213, pp. 321-340. DOI: 10.1007/978-3-319-22804-4_24.
Also available as NFN Technical Report No. 19 - [PDF]

C. Hofreither, W. Zulehner:
On full multigrid schemes for isogeometric analysis.
In: Dickopf T., Gander M., Halpern L., Krause R., Pavarino L. (eds). Domain decomposition methods in science and engineering XXII. LNCSE. Vol 104, pp. 267-274. Springer, Cham. DOI: 10.1007/978-3-319-18827-0_25.
Also available as NFN Technical Report No. 13 - [PDF]

R. Andreev, O. Scherzer, W. Zulehner:
Simultaneous optical fl ow and source estimation: Spacetime discretization and preconditioning.
Applied Numerical Mathematics 96 (2015), pp. 72 - 81. DOI: 10.1016/j.apnum.2015.04.007.
Also available as NFN Technical Report No. 20 - [PDF]

C. Hofreither, S. Takacs, W. Zulehner:
A Robust Multigrid Method for Isogeometric Analysis using Boundary Correction.
NFN Technical Report No. 33 - [PDF]

C. Hofreither, B. Jüttler, G. Kiss, W. Zulehner:
Multigrid Methods for Isogeometric Analysis with THB-Splines.
NFN Technical Report No. 32 - [PDF]

M. Pauley, Dang-Manh Nguyen, D. Mayer, J. Špeh, O. Weeger, Bert Jüttler:
The isogeometric segmentation pipeline.
Isogeometric Analysis and Applications IGAA 2014. Ed. by B. Jüttler and B. Simeon. Springer LNCSE Vol 107 2015, pp. 51-72. DOI: 10.1007/978-3-319-23315-4_3.
Also available as NFN Technical Report No. 31 - [PDF]

C. Giannelli, B. Jüttler, S. K. Kleiss, A. Mantzaflaris, B. Simeon, J. Špeh:
THB-splines: An Effective Mathematical Technology for Adaptive Refinement in Geometric Design and Isogeometric Analysis.
Computer Methods in Applied Mechanics and Engineering, Vol. 299, 2016, pp. 337–365. DOI: 10.1016/j.cma.2015.11.002.
Also available as NFN Technical Report NFN Technical Report No. 30 - [PDF]

I. Georgieva, C. Hofreither:
An Algorithm for Low-rank Approximation of Bivariate Functions using Splines.
NFN Technical Report No. 28 - [PDF]

A. Falini, J. Špeh, B. Jüttler:
Planar domain parameterization with THB-splines.
Computer Aided Geometric Design 35-36 (2015), pp. 95 - 108. DOI: 10.1016/j.cagd.2015.03.014, [PDF]

B. Jüttler, A. Mantzaflaris, R. Perl, M. Rumpf:
On Isogeometric Subdivision Methods for PDEs on Surfaces.
NFN Technical Report No. 27 - [PDF], arXiv:1503.03730

F. Buchegger, B. Jüttler, A. Mantzaflaris:
Adaptively Refined Multi-Patch B-splines with Enhanced Smoothness.
Applied Mathematics and Computation. Vol., Jan. 2016, pp. 159–172. DOI: 10.1016/j.amc.2015.06.055.
Also available as NFN Technical Report No. 26 - [PDF]

S. Takacs, T. Takacs:
Approximation error estimates and inverse inequalities for B-splines of maximum smoothness.
Math. Models Methods Appl. Sci. 26, 1411 (2016). DOI: 10.1142/S0218202516500342. arXiv:1502.03733. [PDF]

S. Stoykov, C. Hofreither, S. Margenov:
Isogeometric Analysis for Nonlinear Dynamics of Timoshenko Beams.
Numerical Methods and Applications. Ed. by I. Dimov, S. Fidanova, and I. Lirkov. Vol. 8962. LNCS. Springer International Publishing, 2015, pp. 138 - 146. DOI: 10.1007/978-3-319-15585-2_16. [PDF]

C. Hofreither, W. Zulehner:
Spectral Analysis of Geometric Multigrid Methods for Isogeometric Analysis.
Numerical Methods and Applications. Ed. by I. Dimov, S. Fidanova, and I. Lirkov. Vol. 8962. LNCS. Springer International Publishing, 2015, pp. 123 - 129. DOI: 10.1007/978-3-319-15585-2_14.
Also available as NFN Technical Report No. 24 - [PDF]

R. Andreev, P. Elbau, Maarten V. de Hoop, Lingyun Qiu, O. Scherzer:
Generalized Convergence Rates Results for Linear Inverse Problems in Hilbert Spaces.
Numerical Functional Analysis and Optimization 36.5 (2015), pp. 549 - 566. DOI: 10.1080/01630563.2015.1021422, arXiv:1409.7610.

Maarten V. de Hoop, Lingyun Qiu, O. Scherzer:
An analysis of a multi-level projected steepest descent iteration for nonlinear inverse problems in Banach spaces subject to stability constraints.
Numerische Mathematik, January 2015, vol. 129, Issue 1, pp. 127 - 148. DOI: 10.1007/s00211-014-0629-x, [PDF]

A. Bressan, B. Jüttler:
A Hierarchical Construction of LR Meshes in 2D.
NFN Technical Report No. 23 - [PDF]

C. Pöschl, O. Scherzer:
Exact solutions of one-dimensional total generalized variation.
Communications in Mathematical Sciences, vol. 13.1 (2015), International Press, pp. 171-202. DOI: 10.4310/CMS.2015.v13.n1.a9, [PDF]

A. Mantzaflaris, Bert Jüttler:
Integration by Interpolation and Look-up for Galerkin-based Isogeometric Analysis.
Computer Methods in Applied Mechanics and Engineering, Vol 284, Feb. 2015, pp. 373 - 400. DOI: 10.1016/j.cma.2014.09.014.
Also available as NFN Technical Report No. 14 - [PDF]

2014

C. Hofreither, W. Zulehner:
Mass Smoothers in Geometric Multigrid for Isogeometric Analysis.
NFN Technical Report No. 25 - [PDF]

C. Hofreither, W. Zulehner:
Spectral analysis of geometric multigrid methods for isogeometric analysis.
NFN Technical Report No. 24 - [PDF]

B. Heeren, M. Rumpf, P. Schröder, M. Wardetzky, B. Wirth:
Exploring the geometry of the space of shells.
Computer Graphics Forum, 33(5): pp. 247 - 256, 2014. [PDF]

L. Diening, D. Kröner, M. Růžička, I. Toulopoulos:
A local discontinuous Galerkin approximation for systems with p-structure.
IMA Journal Numerical Analysis 34.4 (2014), pp. 1447 - 1488. DOI: 10.1093/imanum/drt040

B. Jüttler, U. Langer, A. Mantzaflaris, St. E. Moore, W. Zulehner:
Geometry + Simulation Modules: Implementing Isogeometric Analysis.
Proceedings in Applied Mathematics and Mechanics, vol. 14, pp. 961 - 962, Dec. 2014. DOI: 10.1002/pamm.201410461, [PDF]

B. Jüttler, M. Kapl, Dang-Manh Nguyen, Q. Pan, M. Pauley:
Isogeometric Segmentation: The case of contractible solids without non-convex edges.
Computer-Aided Design 57 (2014), pp. 74 - 90. DOI: 10.1016/j.cad.2014.07.005, [PDF]

M. Kapl, V. Vitrih, B. Jüttler:
Isogeometric Analysis with Geometrically Continuous Functions.
NFN Technical Report No. 22 - [PDF]

U. Langer, A. Mantzaflaris, S. E. Moore, I. Toulopoulos:
Mesh Grading in Isogeometric Analysis.
NFN Technical Report No. 21 - [PDF]

G. Kiss, C. Giannelli, U. Zore, B. Jüttler, D. Grossmann, J. Barner:
Adaptive CAD model (re-)construction with THB-splines.
Graphical Models, 2014, vol 76, (iss. 5), pp. 273-288. DOI: 10.1016/j.gmod.2014.03.017

M. Rumpf, M. Wardetzky:
Geometry Processing from an Elastic Perspective.
GAMM Mitteilungen 37.2 (2014), pp. 184 - 216. DOI: 10.1002/gamm.201410009

R. Andreev, O. Scherzer, W. Zulehner:
Simultaneous optical flow and source estimation: space-time discretization and preconditioning.
NFN Technical Report No. 20 - [PDF]

F. Buchegger, B. Jüttler, M. Kapl:
Total Curvature Variation Fairing for Medial Axis regularization.
Graphical Models 76 (2013), pp. 633 - 647. DOI: 10.1016/j.gmod.2014.06.004, [PDF]

Ioannis Toulopoulos:
An Interior Penalty Discontinuous Galerkin Finite Element Method for Quasilinear Parabolic Problems.
Finite Elements in Analysis and Design, volume 95, March 2015, pp. 42-50. DOI: 10.1016/j.finel.2014.11.001, [PDF]

R. Ling, J. Huang, B. Jüttler, F. Sun, H. Bao, Wenping Wang:
Spectral Quadrangulation with Tight Feature-Alignment and Local-Size Control.
ACM Trans. on Graphics 34 (2014). article no. 11. DOI: 10.1145/2653476

A. Mantzaflaris, B. Jüttler, B.N. Khoromskij, U. Langer:
Matrix Generation in Isogeometric Analysis by Low Rank Tensor Approximation.
NFN Technical Report No. 19 - [PDF]

U. Langer, A. Mantzaflaris, S. E. Moore, I. Toulopoulos:
Multipatch Discontinuous Galerkin Isogeometric Analysis.
NFN Technical Report No. 18 - [PDF]

A. Mantzaflaris, B. Mourrain:
Singular Zeros of Polynomial Systems.
SAGA Advances - in ShApes, Geometry, and Algebra. Ed. by T. Dokken and G. Muntingh. Vol. 10. Geometry and Computing. Springer International Publishing, 2014, pp. 77 - 103. DOI: 10.1007/978-3-319-08635-4_5, [PDF]

T. Takacs, B. Jüttler, O. Scherzer:
Derivatives of Isogeometric Functions on n-dimensional Rational Patches in R^d.
Computer Aided Geometrci Design, Volume 31, Issues7-8 (2014), pp. 567 - 581. DOI: 10.1016/j.cagd.2014.06.005, [PDF]

U. Zore, B. Jüttler:
Adaptively Refined Multilevel Spline Spaces from Generating Systems.
Computer Aided Geometric Design 31 (2014), pp. 545 - 566. DOI: 10.1016/j.cagd.2014.04.003, [PDF]

D. Mokriš, B. Jüttler:
TDHB-splines: The Truncated Decoupled Basis of Hierarchical Tensor-Product Splines.
Computer Aided Geometric Design 31 (2014), pp. 531 - 544.
Also available as NFN Technical Report No. 10 - [PDF], DOI: 10.1016/j.cagd.2014.05.004

D. Kröner, M. Růžička, I. Toulopoulos:
Numerical solutions of systems with (p, δ) - structure using local discontinuous Galerkin finite element methods.
International Journal for Numerical Methods in Fluids 76.11 (2014), pp. 855 - 874. DOI: 10.1002/fld.3955, [PDF]

Dang-Manh Nguyen, M. Pauley, B. Jüttler:
Isogeometric Segmentation. Part II: On the segmentability of contractible solids with non-convex edges.
Graphical Models 76 (2014), pp. 426 - 439. DOI: 10.1016/j.gmod.2014.03.013, [PDF]

Y. Zhu, F. Sun, Y.-K. Choi, B. Jüttler, Wenping Wang:
Computing a Compact Spline Representation of the Medial Axis of a 2D Shape.
Graphical Models 76 (2014), pp. 252 - 262. DOI: 10.1016/j.gmod.2014.03.007

U. Zore, B. Jüttler, J. Kosinka:
On the Linear Independence of (Truncated) Hierarchical Subdivision Splines.
NFN Technical Report No. 17. This report has been replaced by NFN Technical Report No. 40.

B. Jüttler, M. Kapl, Dang-Manh Nguyen, Qing Pan, M. Pauley:
Isogeometric Segmentation: The case of contractible solids without non-convex edges.
NFN Technical Report No. 16 - [PDF]

U. Langer, I. Toulopoulos:
Analysis of Discontinuous Galerkin IgA Approximations to Elliptic Boundary Value Problems.
NFN Technical Report No. 15 - [PDF], RICAM Reports 2014-08. Submitted to arXiv:1408.0182

B. Bastl, B. Jüttler, M. Lávička, T. Schulz, Z. Šír:
On the parameterization of rational ringed surfaces and rational canal surfaces.
Mathematics in Computer Science 8 (2014), pp. 299 - 319. DOI: 10.1007/s11786-014-0192-y, [PDF]

C. Kirisits, L. F. Lang, O. Scherzer:
Optical flow on evolving surfaces with space and time regularisation.
Journal of Mathematical Imaging and Vision, 2015, vol. 52, pp. 55-70. DOI: 10.1007/s10851-014-0513-4.
Also available as NFN Technical Report No. 6 - Preprint on arXiv:1301.0322

A. Mantzaflaris, Bert Jüttler:
Integration by Interpolation and Look-up for Galerkin-based Isogeometric Analysis.
NFN Technical Report No. 14 - [PDF]

C. Kirisits, C. Pöschl, E. Resmerita, O. Scherzer:
Finite-dimensional approximation of convex regularization via hexagonal pixel grids.
Applicable Analysis: An International Journal, Taylor & Francis, vol. 94.3 (2015), pp. 612 - 636. DOI: 10.1080/00036811.2014.958998. Published online: Oct. 2014

E. Beretta, M. Grasmair, M. Muszkieta, O. Scherzer:
A variational algorithm for the detection of line segments.
Inverse Problems and Imaging (IPI), 2014, vol. 8-2, pp. 389 - 408. DOI: 10.3934/ipi.2014.8.389, [PDF]

C. Hofreither, W. Zulehner:
On Full Multigrid Schemes for Isogeometric Analysis.
NFN Technical Report No. 13 - [PDF]

N. Villamizar, A. Mantzaflaris, B. Jüttler.
Characterization of bivariate hierarchical quartic box splines on a three-directional grid.
Tech. rep. 10. RICAM, 2014

C. Kirisits, L. F. Lang, O. Scherzer:
Decomposition of optical flow on the sphere.
GEM. Int. J. Geomath., 5.1 (2014), pp. 117 - 141. DOI: 10.1007/s13137-013-0055-8. Preprint on ArXiv arXiv:1312.4354, University of Vienna, Austria, 2013

G. Kiss, C. Giannelli, B. Jüttler:
Algorithms and Data structures for truncated hierarchical B-splines.
Mathematical Methods for Curves and Surfaces. Ed. by M. Floater et al. Vol. 8177. Lecture Notes in Computer Science. Springer, 2014, pp. 304 - 323, DOI: 10.1007/978-3-642-54382-1_18, [PDF]

A. Mantzaflaris, B. Jüttler:
Exploring Matrix Generation Strategies in Isogeometric Analysis.
Mathematical Methods for Curves and Surfaces, 2014, M. Floater et al., Springer, Lecture Notes in Computer Science, 8177, 2014, pp. 364-382. DOI: 10.1007/978-3-642-54382-1_21.
Also available as NFN Technical Report No. 1 - [PDF]

C. Giannelli, B. Jüttler, H. Speleers:
Strongly stable bases for adaptively refined multilevel spline spaces.
Advances in Computational Mathematics, 40 (2014), pp. 459 - 490. DOI: 10.1007/s10444-013-9315-2, [PDF]

D. Mokriš, B. Jüttler, C. Giannelli:
On the completeness of hierarchical tensor-product B-splines.
Journal of Computational and Applied Mathematics, vol. 271, 2014, pp. 53-70. DOI 10.1016/j.cam.2014.04.001, [PDF]

E. Pilgerstorfer, B. Jüttler:
Bounding the Influence of Domain Parameterization and Knot Spacing on Numerical Stability in Isogeometric Analysis.
Computer Methods in Applied Mechanics and Engineering, vol. 268, January 2014, pp. 589-613. DOI 10.1016/j.cma.2013.09.019, [PDF]

U. Langer, S. E. Moore:
Discontinuous Galerkin Isogeometric Analysis of Elliptic PDEs on Surfaces.
NFN Technical Report No. 12 - [PDF] - Preprint on arXiv:1402.1185

2013

T. Takacs, B. Jüttler, O. Scherzer:
Derivatives of Isogeometric Functions on Rational Patches.
NFN Technical Report No. 11 - [PDF]

D. Mokriš, B. Jüttler:
TDHB-splines: The Truncated Decoupled Basis of Hierarchical Tensor-product Splines.
NFN Technical Report No. 10 - [PDF]

U. Zore, B. Jüttler:
Generalized Hierarchical Spline Spaces.
NFN Technical Report No. 9 - [PDF]

K. Kalimeris, O. Scherzer:
Photoacoustic imaging in attenuating acoustic media based on strongly causal models.
Mathematical Methods in the Applied Sciences, 2013, vol. 36-16, pp. 2254 - 2264. DOI: 10.1002/mma.2756

C. Giannelli, B. Jüttler:
Local and Adaptive Refinement with Hierarchical B-Splines.
Bolletino della Unione Matematica Italiana, Series IX VI.3 (2013), pp. 735 - 740. [PDF]

D. Mokriš, B. Jüttler, C. Giannelli:
On the Completeness of Hierarchical Tensor-Product B-Splines.
NFN Technical Report No. 8 - [PDF]

R. Perl, P. Pozzi, M. Rumpf:
A Nested Variational Time Discretization for Parametric Anisotropic Willmore Flow.
In: Singular Phenomena and Scaling in Mathematical Models. Ed. by M. Griebel. Springer, 2014, pp. 221 - 241. DOI: 10.1007/978-3-319-00786-1_10

Guozhi Dong, M. Grasmair, Sung Ha Kang, O. Scherzer:
Scale and Edge Detection with Topological Derivatives.
In A. Kuijper, editor, SSVM'13: Proceedings of the fourth International Conference on Scale Space and Variational Methods in Computer Vision, volume 7893 of Lecture Notes in Computer Science, pp. 404-415, Berlin, Heidelberg, 2013. Springer-Verlag. DOI: 10.1007/978-3-642-38267-3_34, [PDF]

B. Jüttler, M. Kapl, Qing Pan:
Isogeometric Segmentation. Part I: Decomposing contractible solids without non-convex edges.
NFN Technical Report No. 7 - [PDF]

C. Kirisits, L. F. Lang, O. Scherzer:
Optical flow on evolving surfaces with an application to the analysis of 4D microscopy data.
In A. Kuijper, editor, SSVM'13: Proceedings of the fourth International Conference on Scale Space and Variational Methods in Computer Vision, volume 7893 of Lecture Notes in Computer Science, 2013, Springer-Verlag Berlin Heidelberg, pp. 246-257. DOI: 10.1007/978-3-642-38267-3_21, [PDF]

J.A. Iglesias, B. Berkels, M. Rumpf, O. Scherzer:
A thin shell approach to the registration of implicit surfaces.
In M. Bronstein, J. Favre, and K. Hormann, editors, VMV 2013 : Vision, Modeling and Visualization. Eurographics Association, 2013, pp. 89 - 96. DOI: 10.2312/PE.VMV.VMV13.089-096, [PDF]

C. Kirisits, L. F. Lang, O. Scherzer:
Optical flow on evolving surfaces with space and time regularisation.
NFN Technical Report No. 6 - Preprint on arXiv:1301.0322, University of Vienna, Austria, 2013.

M. Grasmair, M. Muszkieta, O. Scherzer:
An approach to the minimization of the Mumford-Shah functional using Γ-convergence and topological asymptotic expansion.
Jour. Interfaces and Free Boundaries, 2013, vol. 15 - 2, pp. 141 - 166. DOI: 10.4171/IFB/298, [PDF]

D. Mokriš B. Jüttler:
Dimensions and Bases of Hierarchical Tensor-Product Spline Spaces.
NFN Technical Report No. 5 - [PDF], superseded by NFN Technical Report No. 8

T. Takacs, B. Jüttler:
Derivatives of Isogeometric Test Functions.
NFN Technical Report No. 4 - [PDF].
Also in: Proc. Mathematics of Surfaces XIV. on CD. IMA, 2013, pp. 345 - 364.

C. Giannelli, B. Jüttler, H. Speleers:
Strongly stable bases for adaptively refined multilevel spline spaces.
NFN Technical Report No. 3 - [PDF]

E. Pilgerstorfer, B. Jüttler:
Quantifying the Influence of Domain Parameterization and Knot Spacing on Numerical Stability in Isogeometric Analysis.
NFN Technical Report No. 2 - [PDF]

G. Bal, W. Naetar, O. Scherzer, J. Schotland:
The Levenberg-Marquardt iteration for numerical inversion of the power density operator.
Journal of Inverse and Ill-posed Problems, 2013, Band 21, Heft 2, pp. 265-280. DOI: 10.1515/jip-2012-0091

A. Mantzaflaris, B. Jüttler:
Exploring matrix generation strategies in isogeometric analysis.
Technical Report No. 1 - [PDF]

C. Giannelli, B. Jüttler:
Bases and dimensions of bivariate hierarchical tensor-product splines.
Journal of Computational and Applied Mathematics 239 (2013), pp. 162 - 178. DOI: 10.1016/j.cam.2012.09.031, [PDF]

I. Z. Emiris, A. Mantzaflaris, B. Mourrain:
Voronoi diagrams of algebraic distance fuelds.
Computer-Aided Design 45.2 (2013). Solid and Physical Modeling 2012, pp. 511 - 516. ISSN: 0010-4485. DOI: 10.1016/j.cad.2012.10.043, [PDF]

2012

S. Kleiss, C. Pechstein, B. Jüttler, S. Tomar:
IETI - Isogeometric Tearing and Interconnecting.
Computer Methods in Applied Mechanics and Engineering 247- 248 (2012), pp. 201 - 215. DOI: 10.1016/j.cma.2012.08.007. [PDF]

T. Takacs, B. Jüttler:
H² regularity properties of singular parameterizations in isogeometric analysis.
Graphical Models, 2012:74, pp 361-372. [PDF], DOI: 10.1016/j.gmod.2012.05.006.

C. Giannelli, B. Jüttler, H. Speleers:
THB-splines: The truncated basis for hierarchical splines.
Computer Aided Geometric Design 29 (2012), pp. 485 - 498, DOI: 10.1016/j.cagd.2012.03.025. [PDF]

B. Heeren, M. Rumpf, M. Wardetzky, B. Wirth:
Time-discrete geodesics in the space of shells.
Computer Graphics Forum, 31(5): pp. 1755 - 1764, August 2012. DOI: 10.1111/j.1467-8659.2012.03180.x

M. Rossgatterer, B. Jüttler, M. Kapl, G. Della Vecchia:
Medial design of blades for hydroelectric turbines and ship propellers.
Computers & Graphics, 2012, 36, pp. 434-444. DOI: 10.1016/j.cag.2012.03.022, [PDF]

S. Kleiss, B. Jüttler, W. Zulehner:
Enhancing isogeometric analysis by a finite element-based local refinement strategy.
Computer Methods in Applied Mechanics and Engineering 213-216 (2012), pp. 168 - 182. DOI: 10.1016/j.cma.2011.11.013, [PDF]

F. Brunero:
Discontinuous Galerkin Methods for Isogeometric Analysis.
Master thesis, Linz and Milano, 2012. [PDF]

Thien Tuan Nguyen, B. Jüttler:
Parameterization of Contractible Domains using Sequences of Harmonic Maps.
Curves and Surfaces - 7th International Conference, Avignon 2010, Springer, J.-D. Boissonat et al., Lecture Notes in Computer Science 6920, 2012, pp 501-514. [PDF], DOI: 10.1007/978-3-642-27413-8.

D. Großmann, B. Jüttler:
Volumetric Geometry Reconstruction of Turbine Blades for Aircraft Engines.
Curves and Surfaces - 7th International Conference, Avignon 2010, Springer, J.-D. Boissonat et al., Lecture Notes in Computer Science 6920, 2012, pp 280-295. [PDF], DOI: 10.1007/978-3-642-27413-8.

Geometry + Simulation

Important