Projects
FunDaHD: Function-driven Data Learning in High Dimension

High-dimensional data today plays an increasingly important role in most computer-based measurements and analyses of real-life problems. This development is due to several technological advances, such as in increased physical measurements and storage capabilities, and multiphysics computer simulations of complex phenomena. Analyses of such data can reveal complex interactions between entities in a process in Nature, or in man-made environments such as Instagram or a Google search.
At the same time we are struggling with extracting useful information and derive predictive models. Data-driven modelling is an emerging and challenging area in applied mathematics with an enormous potential, especially if successfully combined with other branches of science, like computer science, engineering, or biomedical computing.
Motivated by the increased demand of robust and predictive methods, we will in this project develop powerful mathematical and numerical machinery to explore new applications in fields such as tractable and robust automatic learning of functions and data structures in high dimension from the minimal number of observed samples. The approach we propose is to obtain lower-dimensional representations of the data and their geometry, to perform the approximation with significantly reduced complexity under realistic assumptions.
The proposed project will be based on both a rigorous theoretical analysis as well as on implementation and numerical tests of the corresponding algorithms to demonstrate their robustness and performance. The realisation of the project will require the deployment of various mathematical techniques, consisting of theory of inverse and ill-posed problems, learning and approximation theories, differential geometry, harmonic analysis, and sparse optimisation. Finally, we will also address problems in computational biomedicine, such as encountered in cardiac modeling, and gene expressions in bioinformatics.
The three-year project, funded by the Research Council of Norway as part of the FRINATEK and IKTPLUSS programs, will be conducted under the supervision of Dr. Valeriya Naumova, in closed collaboration with the research groups at Technical University Munich (Prof. Dr. M. Fornasier), Duke University (Prof. Dr. M. Maggioni), University College London (Prof. Dr. M. Pontil), University of Innsbruck (Dr. K. Schnass), and Norwegian University of Science and Technology (Assoc. Prof. Dr. M. Grasmair).
Funding Source:
Research Council of Norway (FRINATEK, IKTPLUSS)
Project Leader:
Dr. Valeriya Naumova
Publications for FunDaHD: Function-driven Data Learning in High Dimension
Journal Article
Estimating multi-index models with response-conditional least squares
Electronic Journal of Statistics 15 (2021): 589-629.Status: Published
Estimating multi-index models with response-conditional least squares
Afilliation | Scientific Computing, Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2021 |
Journal | Electronic Journal of Statistics |
Volume | 15 |
Number | 1 |
Pagination | 589-629 |
Publisher | The Institute of Mathematical Statistics and the Bernoulli Society |
URL | https://projecteuclid.org/euclid.ejs/1611046876#info |
DOI | 10.1214/20-EJS1785 |
A deep network construction that adapts to intrinsic dimensionality beyond the domain
Neural Networks 141 (2021): 404-419.Status: Published
A deep network construction that adapts to intrinsic dimensionality beyond the domain
Afilliation | Scientific Computing, Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2021 |
Journal | Neural Networks |
Volume | 141 |
Pagination | 404-419 |
Publisher | Elsevier |
URL | https://www.sciencedirect.com/science/article/abs/pii/S0893608021002367 |
DOI | 10.1016/j.neunet.2021.06.004 |
Computational approaches to non-convex, sparsity-inducing multi-penalty regularization
Inverse Problems 37, no. 5 (2021): 055008.Status: Published
Computational approaches to non-convex, sparsity-inducing multi-penalty regularization
Afilliation | Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2021 |
Journal | Inverse Problems |
Volume | 37 |
Issue | 5 |
Pagination | 055008 |
Publisher | IOP Publishing Ltd |
Estimating covariance and precision matrices along subspaces
Electronic Journal of Statistics 15, no. 1 (2021): 554-588.Status: Published
Estimating covariance and precision matrices along subspaces
Afilliation | Scientific Computing, Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2021 |
Journal | Electronic Journal of Statistics |
Volume | 15 |
Issue | 1 |
Pagination | 554-588 |
Publisher | The Institute of Mathematical Statistics and the Bernoulli Society |
URL | https://projecteuclid.org/euclid.ejs/1610420752#info |
DOI | 10.1214/20-EJS1782 |
Robust recovery of low-rank matrices with non-orthogonal sparse decomposition from incomplete measurements
Applied Mathematics and Computation 392 (2021): 125702.Status: Published
Robust recovery of low-rank matrices with non-orthogonal sparse decomposition from incomplete measurements
Afilliation | Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2021 |
Journal | Applied Mathematics and Computation |
Volume | 392 |
Pagination | 125702 |
Publisher | Elsevier |
Proceedings, refereed
Landscape analysis of an improved power method for tensor decomposition
In Thirty-fifth Conference on Neural Information Processing Systems (NeurIPS 2021). NeurIPS, 2021.Status: Published
Landscape analysis of an improved power method for tensor decomposition
Afilliation | Scientific Computing |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Proceedings, refereed |
Year of Publication | 2021 |
Conference Name | Thirty-fifth Conference on Neural Information Processing Systems (NeurIPS 2021) |
Publisher | NeurIPS |
Journal Article
A machine learning approach to optimal Tikhonov regularization I: Affine manifolds
Analysis and Applications (2020).Status: Accepted
A machine learning approach to optimal Tikhonov regularization I: Affine manifolds
Inspired by several real-life applications in audio processing and medical image analysis, where the quantity of interest is generated by several sources to be accurately modeled and separated, as well as by recent advances in regularization theory and optimization, we study the conditions on optimal support recovery in inverse problems of unmixing type by means of multi-penalty regularization.
We consider and analyze a regularization functional composed of a data-fidelity term, where signal and noise are additively mixed, a non-smooth, convex, sparsity promoting term, and a quadratic penalty term to model the noise. We prove not only that the well-established theory for sparse recovery in the single parameter case can be translated to the multi-penalty settings, but we also demonstrate the enhanced properties of multi-penalty regularization in terms of support identification compared to sole $\ell^1$-minimization. We additionally confirm and support the theoretical results by extensive numerical simulations, which give a statistics of robustness of the multi-penalty regularization scheme with respect to the single-parameter counterpart.
Eventually, we confirm a significant improvement in performance compared to standard $\ell^1$-regularization for compressive sensing problems considered in our experiments.
Afilliation | Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2020 |
Journal | Analysis and Applications |
Publisher | MIT Press |
URL | http://arxiv.org/abs/1610.01952 |
PhD Thesis
Model-based function learning in high dimensions
In The University of Oslo, 2020.Status: Published
Model-based function learning in high dimensions
Afilliation | Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | PhD Thesis |
Year of Publication | 2020 |
Degree awarding institution | The University of Oslo |
Poster
Adaptivity of Relu Nets Beyond Low-Dimensional Domains
DeepMath 2020, 2020.Status: Published
Adaptivity of Relu Nets Beyond Low-Dimensional Domains
Afilliation | Scientific Computing, Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Poster |
Year of Publication | 2020 |
Place Published | DeepMath 2020 |
Journal Article
Robust and Resource Efficient Identification of Two Hidden Layer Neural Networks
Constructive Approximation (2019).Status: Published
Robust and Resource Efficient Identification of Two Hidden Layer Neural Networks
Afilliation | Machine Learning |
Project(s) | FunDaHD: Function-driven Data Learning in High Dimension |
Publication Type | Journal Article |
Year of Publication | 2019 |
Journal | Constructive Approximation |
Publisher | Springer |
URL | https://arxiv.org/abs/1907.00485 |
Nordic-Estonian Quantum Computing e-Infrastructure Quest
NordiQuEst is a new collaborative effort between four Nordic countries (Norway, Sweden, Finland, and Denmark) and Estonia to build a dedicated Nordic-Estonian quantum computing (QC) ecosystem that integrates various quantum computers and emulators make them accessible to the Nordic-Estonian region to accelerate QC research, development, and education.
Partners
- Chalmers tekniska högskola AB, Sweden
- CSC - IT Center for Science Ltd. Finland
- DTU – Technical University of Denmark, Denmark
- ETAIS - Estonian Scientific Computing Infrastructure - University of Tartu, Estonia
- SINTEF, Norway
- SRL - Simula Research Laboratory AS, Norway
- VTT - VTT Technical Research Centre of Finland Ltd, Finland
Funding Source
- NeIC, NordForsk. Total funding of the Project: 19.2 Million NOK
Publications for Nordic-Estonian Quantum Computing e-Infrastructure Quest
Talks, contributed
Time for new Simula!
In Towards a Norwegian Quantum Computing Strategy, Simula Research Laboratory, Norway, 2022.Status: Published
Time for new Simula!
Afilliation | Software Engineering |
Project(s) | Department of Engineering Complex Software Systems, Enabling Future Dependable Ubiquitous Services and Data with Novel Testing Methods for Quantum Programs, Nordic-Estonian Quantum Computing e-Infrastructure Quest, Quantum Software Engineering Project |
Publication Type | Talks, contributed |
Year of Publication | 2022 |
Location of Talk | Towards a Norwegian Quantum Computing Strategy, Simula Research Laboratory, Norway |
Talks, invited
Quantum Software Testing Tutorial
In NordIQuEst-ENCCS online HPC-QC workshop, 2022.Status: Published
Quantum Software Testing Tutorial
Afilliation | Software Engineering |
Project(s) | Department of Engineering Complex Software Systems, Enabling Future Dependable Ubiquitous Services and Data with Novel Testing Methods for Quantum Programs, Quantum Software Engineering Project, Nordic-Estonian Quantum Computing e-Infrastructure Quest |
Publication Type | Talks, invited |
Year of Publication | 2022 |
Location of Talk | NordIQuEst-ENCCS online HPC-QC workshop |
Publications
Public outreach
QCNorway: Contributions Towards a Norwegian Quantum Computing Strategy
Simula, 2023.Status: Published
QCNorway: Contributions Towards a Norwegian Quantum Computing Strategy
Norway lacks a national strategy and corresponding investments for the development of its own expertise on quantum computing through educational programmes, active research, business creation, and support from technical infrastructures.
Given the enormous momentum in quantum technology and quantum computing R&D world-wide and in our neighbouring countries, there is an immediate threat that Norway will arrive too late at a technology race that has the potential of redefining the digital society and digital business development.
This position paper presents the most important takeaway messages from the open workshop QCNorway: Towards a Norwegian Quantum Computing Strategy, which took place in Oslo on November 7–8, 2022 with more than 150 participants. The discussion herein is limited to quantum computing and does not claim to address quantum technology in general. Hopefully, this paper and complementary inputs from other stakeholders can inspire the development of a national quantum strategy, in which quantum computing is a principal part.
Afilliation | Communication Systems, Software Engineering, Scientific Computing, Cryptography, Machine Learning |
Project(s) | Department of Engineering Complex Software Systems |
Publication Type | Public outreach |
Year of Publication | 2023 |
Date Published | 06/2023 |
Publisher | Simula |
Type of Work | Position Paper |
Keywords | national strategy, quantum computing |
URL | https://www.qcnorway.no/finalpaper |
Book Chapter
Data aggregation and anonymization for mathematical modeling and epidemiological studies
In Smittestopp - A Case Study on Digital Contact Tracing, 121-141. Vol. 11. Cham: Springer International Publishing, 2022.Status: Published
Data aggregation and anonymization for mathematical modeling and epidemiological studies
An important secondary purpose of the Smittestopp development was to provide aggregated data sets describing mobility and social interactions in Norway's population. The data were to be used to monitor the effect of government regulations and recommendations, provide input to advanced computational models to predict the pandemic's spread, and provide input to fundamental epidemiology research. In this chapter we describe the challenges and technical solutions of Smittestopp's data aggregation, as well as preliminary results from the time period when the app was active.We first give a detailed overview of the requirements, specifying the types of data to be collected and the level of spatial and temporal aggregation. We then proceed to describe the concepts for anonymization via :-anonymity and Y-differential privacy (Y-DP ), and the technical solutions for collecting and aggregating data from the database. In particular, we present details of how GPS- and Bluetooth events were mapped to geographical regions and points of interest, and the solutions employed for efficient data retrieval and processing. The preliminary results demonstrate how the recorded GPS- and Bluetooth events match with expected temporal and spatial variations in mobility and social interactions, and indicate the usefulness of the aggregated data as a tool for pandemic monitoring and research. One of the main criticisms of Smittestopp concerns the centralized storage of individuals' movements, even if such data were used and presented only at an aggregated and anonymized level. In this chapter, we also outline a completely different approach, where the GPS data do not leave the user's phone but are, instead, pre-processed to a much higher level of privacy before being dispatched to a server-side data aggregation algorithm. This approach, which would make the app significantly less intrusive, is made possible by recent advances in determining close contacts from Bluetooth data, either by a revised Smittestopp algorithm or by means of the Google/Apple Exposure Notification framework.
Afilliation | Scientific Computing |
Project(s) | Department of Computational Physiology |
Publication Type | Book Chapter |
Year of Publication | 2022 |
Book Title | Smittestopp - A Case Study on Digital Contact Tracing |
Volume | 11 |
Pagination | 121–141 |
Publisher | Springer International Publishing |
Place Published | Cham |
ISBN Number | 978-3-031-05466-2 |
URL | https://doi.org/10.1007/978-3-031-05466-2_7 |
DOI | 10.1007/978-3-031-05466-2_7 |
Book Chapter
Counting Heads: Individual-Based Models of Disease Dynamics
In Math in the Time of Corona, 209-217. Cham: Springer International Publishing, 2021.Status: Published
Counting Heads: Individual-Based Models of Disease Dynamics
Afilliation | Scientific Computing |
Project(s) | No Simula project |
Publication Type | Book Chapter |
Year of Publication | 2021 |
Book Title | Math in the Time of Corona |
Pagination | 209-217 |
Date Published | 02/2021 |
Publisher | Springer International Publishing |
Place Published | Cham |
ISBN | 2730-633X |
URL | https://link.springer.com/10.1007/16618_2020_34https://link.springer.com... |
DOI | 10.1007/16618_2020_34 |
Journal Article
Parallel Solutions of Static Hamilton-Jacobi Equations for Simulations of Geological Folds
Journal of Mathematics in Industry 4 (2014).Status: Published
Parallel Solutions of Static Hamilton-Jacobi Equations for Simulations of Geological Folds
Two new algorithms for numerical solution of static Hamilton-Jacobi equations are presented. These algorithms are designed to work efficiently on different parallel computing architectures, and numerical results for multicore CPU and GPU implementations are reported and discussed. The numerical experiments show that the proposed solution strategies scale well with the computational power of the hardware. The performance of the new methods are investigate for tow types of static Hamilton-Jacobi formulations are investigated, the isotropic eikonal equation and an anisotropic formulation used to simulate different types of geological folding. Simulations of geological folding is a key component in an industrial software used in oil and gas exploration. In particular, our experiments indicate that the new algorithms would be capable of accelerating an existing industrial simulator substantially. Direct comparison with the current industry code shows that computing times can be reduced from several minutes to a few seconds. The new methods are now being migrated to the industrial software.
Afilliation | Scientific Computing, , Scientific Computing, Scientific Computing |
Publication Type | Journal Article |
Year of Publication | 2014 |
Journal | Journal of Mathematics in Industry |
Volume | 4 |
Number | 10 |
Publisher | Springer |
DOI | 10.1186/2190-5983-4-10 |
Journal Article
A Numerical Framework for Modelling Folds in Structural Geology
Mathematical Geosciences 45, no. 3 (2013): 255-276.Status: Published
A Numerical Framework for Modelling Folds in Structural Geology
A numerical framework for modelling folds in structural geology is presented. This framework is based on a novel and recently published Hamilton-Jacobi formulation by which a continuum of layer boundaries of a fold is modelled as a propagating front. All the fold classes from the classical literature (parallel folds, similar folds, and other fold types with convergent and divergent dip isogons) are modelled in 3D space as continua defined on a finite difference grid. The propagating front describing the fold geometry is governed by a static Hamilton-Jacobi equation, which is discretized by upwind finite differences and a dynamic stencil construction. This forms the basis of numerical solution by finite difference solvers such as fast marching and fast sweeping methods. A new robust and accurate scheme for initialization of finite difference solvers for the static Hamilton-Jacobi equation is also derived. The framework has been integrated in simulation software, and a numerical example is presented based on seismic data collected from the Karama Block in the North Makassar Strait outside Sulawesi.
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Journal Article |
Year of Publication | 2013 |
Journal | Mathematical Geosciences |
Volume | 45 |
Issue | 3 |
Number | 3 |
Pagination | 255-276 |
Date Published | April |
Publisher | Springer |
Keywords | Workshop |
Edited books
Conversations About Challenges in Computing
Springer, 2013.Status: Published
Conversations About Challenges in Computing
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Edited books |
Year of Publication | 2013 |
Publisher | Springer |
ISBN Number | 978-3-319-00208-8 |
DOI | 10.1007/978-3-319-00209-5 |
Technical reports
Parallel Solvers for Static Hamilton-Jacobi Equations in Three Dimensions
Simula Research Laboratory, 2013.Status: Published
Parallel Solvers for Static Hamilton-Jacobi Equations in Three Dimensions
Three algorithms for numerical solution of static Hamilton-Jacobi equations on parallel computers are presented in this paper. The proposed algorithms are applicable to both isotropic and anisotropic problems, and are here used to simulate folded geological structures of high complexity. Our algorithms are designed to work efficiently on different parallel computing architectures, and numerical results for multicore CPU and GPU implementations are reported and discussed. The numerical experiments show that the proposed solution strategies scale well on parallel architectures. In particular, these experiments indicate that the new algorithms would be capable of accelerate an existing industrial simulator to a level where detailed three-dimensional studies of complicated geological scenarios can be performed interactively. Direct comparison with the current industry code shows that computing times can be reduced from several minutes to a few seconds.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Technical reports |
Year of Publication | 2013 |
Date Published | September |
Publisher | Simula Research Laboratory |
Proceedings, refereed
A Parallel 3D Front Propagation Algorithm for Simulation of Geological Folding on GPUs
In EAGE 74th Conference & Exhibition, Copenhagen. Extended Abstracts. EAGE, 2012.Status: Published
A Parallel 3D Front Propagation Algorithm for Simulation of Geological Folding on GPUs
A 3D front propagation algorithm for the simulation of geological folding is presented. The algorithm is implemented on multicore and GPU architectures. Numerical experiments based on OpenMP show an almost perfect scaling. Using the automatic code translator Mint, Cuda code is created from seqential C code. On a GPU the Cuda code runs 67-95 times faster than sequential code, and allows 3D grids to be computed at interactive times.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2012 |
Conference Name | EAGE 74th Conference & Exhibition, Copenhagen |
Date Published | June |
Publisher | EAGE |
Keywords | Conference |
Journal Article
Accuracy and Efficiency of Stencils for the Eikonal Equation in Earth Modelling
Computational Geosciences 16 (2012): 933-952.Status: Published
Accuracy and Efficiency of Stencils for the Eikonal Equation in Earth Modelling
Motivated by the needs for creating fast and accurate models of complex geological scenarios, accuracy and efficiency of three stencils for the isotropic eikonal equation on rectangular grids are evaluated using a Fast Marching implementation. The stencils are derived by direct modelling of the wave front, resulting in new and valuable insight in terms of improved upwind and causality conditions. After intro- ducing a method for generalising first order upwind stencils to higher order, a new second order Diagonal stencil is presented. Similarly to the Multistencils Fast Marching ap- proach, the Diagonal stencil makes use of nodes in the diagonal directions, whereas the traditional Godunov stencil uses solely edge-connected neighbours. The Diagonal stencil uses nodes close to each other, reaching upwind, to get a more accurate estimate of the angle of incidence of the arriving wave front. Although the stencils are evaluated in a Fast Marching setting, they can be adapted to other efficient eikonal solvers. All first and second order stencils are evaluated in a range of tests. The first test case models a folded structure from the Zagros fold belt in Iran. The other test cases are constructed to investigate specific properties of the examined stencils. The numerical investigation considers convergence rates and CPU times for non-constant and constant speed first-arrival computations. In conclusion, the Diagonal stencil is the most efficient and accurate of the three alternatives.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Journal Article |
Year of Publication | 2012 |
Journal | Computational Geosciences |
Volume | 16 |
Number | 4 |
Pagination | 933-952 |
Date Published | September |
Keywords | Workshop |
DOI | 10.1007/s10596-012-9296-0 |
On the Fly Visualization of Multilayer Geoscientific Datasets Using 4DPlates
Computers & Geosciences 47 (2012): 46-51.Status: Published
On the Fly Visualization of Multilayer Geoscientific Datasets Using 4DPlates
This paper presents the 4DPlates, an application designed to display high resolution data and reconstruct their positions in the geologic past. 4DPlates makes use of level of detail (LoD) grids with a 4-8 tree structure to store the data so only the require resolution for a particular viewpoint is used. This facility means that the user can interact with large data sets on the fly, achieving between 30 and 50 frames per second with a large test data set. The article presents the design and functionality of the application, from view-dependent visualization to the ability to reconstruct data in the distant past. Finally, we apply the application in two geoscientific settings. In the first, we calculate the tectonic subsidence from sediment loading and test the variation of the sediment density to the resulting subsidence grid. Secondly, we examine two South Atlantic reconstructions and highlight minor differences between them visible in the closeness of the fit of the topographic grids. The application excels at providing an interactive manipulation of high resolution data, whether it be reconstructing the data, setting the lighting angle or vertical exaggeration, or modifying parameters in the underlying formulas.
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Journal Article |
Year of Publication | 2012 |
Journal | Computers & Geosciences |
Volume | 47 |
Number | 1 |
Pagination | 46-51 |
Date Published | August |
Publisher | Elsevier |
DOI | 10.1016/j.cageo.2012.03.015 |
Journal Article
Particle Collisions in a Lumped Particle Model
Communications in Computational Physics 10 (2011): 823-843.Status: Published
Particle Collisions in a Lumped Particle Model
{This paper presents an extension of the lumped particle model in [1] to include the effects of particle collisions. The lumped particle model is a flexible framework for the model- ing of particle laden flows, that takes into account fundamental features, including advection, diffusion and dispersion of the particles. In this paper, we transform a binary collision model and concepts from kinetic theory into a collision procedure for the lumped particle framework. We apply this new collision procedure to investigate numerically the role of particle collisions in the hindered settling effect. The hindered settling effect is characterized by an increase in the effective drag coefficient CD that influences each particle in the flow. This coefficient is given by CD = (1 {-} \varphi){-}n CD , where \varphi is the volume fraction of particles, CD is the drag coefficient for a single particle, and n \simeq 4.67 for creeping flow. We obtain an approximation for CD /CD by calculating the effective work done by collisions, and comparing that to the work done by the drag force. In our numerical experiments, we observe a minimal value of n = 3.0. Moreover, by allowing high energy dissipation, an approximation for the classical value for creeping flow
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Journal Article |
Year of Publication | 2011 |
Journal | Communications in Computational Physics |
Volume | 10 |
Number | 4 |
Pagination | 823-843 |
Date Published | October |
DOI | 10.4208 |
Journal Article
A Lumped Particle Modeling Framework for Simulating Particle Transport in Fluids
Communications in Computational Physics 8 (2010): 115-142.Status: Published
A Lumped Particle Modeling Framework for Simulating Particle Transport in Fluids
This paper presents a lumped particle model for simulating a large number of particles. The lumped particle model is a flexible framework in modeling particle flows, embodying fundamental features that are intrinsic in particle laden flow, including advection, diffusion and dispersion. In this paper, the particles obey a simplified version of the Bassinet-Boussinesq-Oseen equation for a single spherical particle. However, instead of tracking the individual dynamics of each particle, a weighted spatial averaging procedure is used where the external forces are applied to a ``lump'' of particles, from which an average position and velocity is derived. The temporal evolution of the particles is computed by partitioning the lumped particle into smaller entities, which are then transported throughout the physical domain. These smaller entities recombine into new particle lumps at their target destinations. For particles prone to the effects of Brownian motion or similar phenomena, a symmetric spreading of the particles is included as well. Numerical experiments show that the lumped particle model reproduces the effects of Brownian diffusion and uniform particle transport by a fluid and gravity. The late time scale diffusive nature of particle motion is also reproduced.
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Journal Article |
Year of Publication | 2010 |
Journal | Communications in Computational Physics |
Volume | 8 |
Number | 1 |
Pagination | 115-142 |
Technical reports
Extrapolation From a Very Low Number of Computer Experiments
Simula Research Laboratory, 2010.Status: Published
Extrapolation From a Very Low Number of Computer Experiments
Afilliation | Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Technical reports |
Year of Publication | 2010 |
Publisher | Simula Research Laboratory |
Simula Graduate School of Computing - a Proposal From Simula Research Laboratory for an Educational Collaboration With UiO and UCSD
Simula Research Laboratory, 2010.Status: Published
Simula Graduate School of Computing - a Proposal From Simula Research Laboratory for an Educational Collaboration With UiO and UCSD
Publication Type | Technical reports |
Year of Publication | 2010 |
Publisher | Simula Research Laboratory |
Patent
Geological Modelling
2010.Status: Published
Geological Modelling
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Patent |
Year of Publication | 2010 |
Proceedings, refereed
A Flexible Stochastic Approach to Constraining Uncertainty in Forward Stratigraphic Models
In 18th World IMACS Congress and MODSIM09 International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand and International Association for Mathematics and Computers in Simulation, 2009.Status: Published
A Flexible Stochastic Approach to Constraining Uncertainty in Forward Stratigraphic Models
Pinpointing the location of reservoir rocks and stratigraphic traps is crucial to the cost-effective extraction of oil. Forward stratigraphic models have been used to aid interpretations of these rocks and traps by determining their potential sand, shale and silt content. These stratigraphic models often rely on diffusion as a basis for simulating the processes of rock-erosion and the deposition of sediment, which forms the basis for rock formation. Diffusion-based modelling is consistent with observations in sedimentary environments over long time-scales. However, a persistent problem with these models is the determination of coefficients that specify the effectiveness of diffusion for each sediment type.
These coefficients, the so-called transport coefficients, are usually determined by a manual inversion to fit the data. In many cases, varying the transport coefficients by orders of magnitude can still achieve consistency with observations of sediment thickness from seismic data. By mapping the uncertainty in these transport coefficients to probability distributions, a probabilistic method can be used to determine the uncertainty in the output of the model, the basin bathymetry and the location of rocks and their original sediment compositions. We provide an example from the Ebro Basin, located off the east coast of the Iberian Peninsula.
The stochastic approach consists of generating a surface response of the stratigraphic forward model for each point in the domain. The building blocks, in our case, are Hermite polynomials, an orthogonal set. The surface response is a function of the uncertain parameters in the stratigraphic model, the most prominent of which are the diffusion coefficients. Assigning probability distributions to the uncertain parameters then determines the statistical properties of the surface response model. We show the time-dependent development of uncertainty in the Ebro Basin in the sand, silt and shale content of deposited sediment using this methodology.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2009 |
Conference Name | 18th World IMACS Congress and MODSIM09 International Congress on Modelling and Simulation |
Publisher | Modelling and Simulation Society of Australia and New Zealand and International Association for Mathematics and Computers in Simulation |
ISBN Number | 978-0-9758400-7-8 |
Development of a National Workshop to Teach Norwegian Ph.D. Students in Engineering and Science How to Communicate Research
In 2009 ASEE Annual Conference & Exposition. American Society of Engineering Education, 2009.Status: Published
Development of a National Workshop to Teach Norwegian Ph.D. Students in Engineering and Science How to Communicate Research
Afilliation | Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2009 |
Conference Name | 2009 ASEE Annual Conference & Exposition |
Publisher | American Society of Engineering Education |
Teaching PhD Students Effective Communication of Scientific Research
In ICERI2009 Proceedings CD. International Association for Technology, Education and Development, 2009.Status: Published
Teaching PhD Students Effective Communication of Scientific Research
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2009 |
Conference Name | ICERI2009 Proceedings CD |
Publisher | International Association for Technology, Education and Development |
ISBN Number | 978-84-613-2955-7 |
Book Chapter
A Series of Controlled Experiments on Software Maintenance
In Simula Research Laboratory - by thinking constantly about it, 459-479. Heidelberg: Springer, 2009.Status: Published
A Series of Controlled Experiments on Software Maintenance
Research background Software maintenance is both difficult and costly, and software organizations have little tangible evidence with regards to how they can improve their software maintenance practices and precisely what elements comprise the tradeoffs, the expected costs, and the benefits of alternative solutions. Scientific challenges The effort required to maintain software systems depends on many interacting factors, such as the software system's structural properties; the use of analysis, design principles and patterns; available documentation of requirements; design and code; tool support; and developer skills. Given the complexities of the problems at hand, empirical studies in realistic yet controlled settings are needed to better understand how such factors drive the costs of software maintenance and the quality of the software artefacts. In the Maintenance of Object-Oriented Software (MOOSE) project at Simula Research Laboratory, we have pursued large-scale, controlled experiments that combine a high degree of realism with the necessary degree of control, so as to obtain credible results that are applicable to the problems faced by the software industry. Obtained and expected results The studies reported herein contribute to a significantly improved understanding of software maintenance performance by pushing the boundaries of state-of-the-art empirical software engineering research. The results can help software maintenance organizations improve the efficiency of their maintenance processes and the quality of the products being maintained. Specifically, the results provide empirical evidence on tradeoffs and expected costs and benefits when applying design principles and patterns, simple task prioritization techniques, the Unified Modelling Language (UML), and pair programming in different maintenance contexts.
Afilliation | Software Engineering, Software Engineering |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 30 |
Pagination | 459-479 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Bridging the Gap Between Industry and Research
In Simula Research Laboratory - by thinking constantly about it, 533-540. Springer, 2009.Status: Published
Bridging the Gap Between Industry and Research
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 38 |
Pagination | 533-540 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Bridging the Gap Between Industry and Research
In Simula Research Laboratory - by thinking constantly about it, 533-540. Springer, 2009.Status: Published
Bridging the Gap Between Industry and Research
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 38 |
Pagination | 533-540 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Can ECG Recordings and Mathematics Tell the Condition of Your Heart?
In Simula Research Laboratory - by thinking constantly about it, 287-319. Heidelberg: Springer, 2009.Status: Published
Can ECG Recordings and Mathematics Tell the Condition of Your Heart?
Afilliation | Scientific Computing, , Scientific Computing, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 22 |
Pagination | 287-319 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01156-6 |
Computer Simulations of the Heart
In Simula Research Laboratory - by thinking constantly about it, 259-276. Heidelberg: Springer, 2009.Status: Published
Computer Simulations of the Heart
Afilliation | , Scientific Computing, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 20 |
Pagination | 259-276 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Educating Researchers - a Virtue of Necessity
In Simula Research Laboratory - by thinking constantly about it, 483-494. Springer, 2009.Status: Published
Educating Researchers - a Virtue of Necessity
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 31 |
Pagination | 483-494 |
Publisher | Springer |
ISBN Number | ISBN 978-3-642-01155-9 |
Educating Researchers - a Virtue of Necessity
In Simula Research Laboratory - by thinking constantly about it, 483-494. Springer, 2009.Status: Published
Educating Researchers - a Virtue of Necessity
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 31 |
Pagination | 483-494 |
Publisher | Springer |
ISBN Number | ISBN 978-3-642-01155-9 |
Networks and Distributed Systems - Why, What, How and What's Next
In Simula Research Laboratory - by thinking constantly about it, 123-128. Heidelberg: Springer, 2009.Status: Published
Networks and Distributed Systems - Why, What, How and What's Next
Afilliation | Communication Systems, , Communication Systems, Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 13 |
Pagination | 123-128 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3642011559 |
Past and Future Perspectives on Scientific Software
In Simula Research Laboratory - by thinking constantly about it, 321-362. Heidelberg: Springer, 2009.Status: Published
Past and Future Perspectives on Scientific Software
Afilliation | Scientific Computing, , , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 23 |
Pagination | 321-362 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Providing Resilience in Communications Networks
In Simula Research Laboratory - by thinking constantly about it, 163-188. Heidelberg: Springer, 2009.Status: Published
Providing Resilience in Communications Networks
The purpose of the Resilient Networks Project at Simula is to provide resilience in communications networks with cost-efficient approaches. In particular, we identify and solve challenges for both Internet and wireless networks. In the Internet context, we focus on scalable solutions for maintaining network operations during failures or other challenging scenarios. This includes providing fast recovery from component failures, increasing robustness to failures and traffic fluctuations by spreading traffic on multiple paths, and investigating the scalability limitations of the current interdomain routing protocol BGP. Wireless resilience is highly dependent on a specific kind of wireless system and it is closely related to Quality-of-Service (QoS) provisioning. For this, we have investigated the resilience in resource-constrained sensor networks and QoS in OFDM-based wireless networks. It has been shown that the proposed strategies are able to substantially enhance network throughput and increase service reliability. In this chapter, we give an overview of the recent activities in the project, and briefly discuss future plans. Further technical details can be found in our journal and conference papers.
Afilliation | , Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 15 |
Pagination | 163-188 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01156-6 |
RELAY - on the Performance and Resource Utilization of Time-Dependent Large-Scale Distributed Systems
In Simula Research Laboratory - by thinking constantly about it, 199-236. Heidelberg: Springer, 2009.Status: Published
RELAY - on the Performance and Resource Utilization of Time-Dependent Large-Scale Distributed Systems
Powerful end-systems and faster access networks make large-scale distributed multimedia applications such as streaming and gaming increasingly popular. This popularity does, of course, also mean that the increase in available computing power and network bandwidth does not solve all existing problems, but rather that other parts of distributed systems will become bottlenecks. To relieve these, RELAY addresses issues of resource utilization in such distributed systems by investigating network and operating system support that provides quantifiably better support than the state-of-the-art. One of our main goals is to integrate and combine mechanisms to get more scalable, less resource demanding, high performance systems for time-dependent large-scale distributed multimedia systems. RELAY designs, implements and evaluates algorithms, mechanisms and tools to improve resource utilization, increase throughput, reduce/hide latency and support soft Quality-of-Service. The development takes user experience into account, since adaptation specific to this can reduce the necessary resource consumption considerably. We consider architectural, application-level, kernel and protocol support to achieve our goals, and we investigate combinations of performance-enhancing mechanisms such that they do not counteract each other. RELAY's approach is application-driven, where the best way of achieving performance improvements determines the research methodology. As an example, we report several of our findings in investigating support for distributed interactive applications, and massive multiplayer games in particular.
Afilliation | Communication Systems, Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 17 |
Pagination | 199-236 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3642011559 |
Scalable Interconnection Networks
In Simula Research Laboratory - by thinking constantly about it, 129-162. Heidelberg: Springer, 2009.Status: Published
Scalable Interconnection Networks
A modern supercomputer or large scale server consists of a huge set of processing units and units that perform different forms of input/output and memory functions. These components unite in a complex collaboration to perform the main tasks of the system. Such collaboration requires communication between the components, which is supported by an infrastructure called the interconnection network. This book chapter describes the interconnection networks research activity at Simula the last five years done by the ICON group. ICON has focused on how to connect point-to-point links and switches into scalable network topologies, and how to route packets efficiently in order to yield the highest possible performance. This also poses various requirements regarding fault tolerance, quality of service (QoS), congestion control, virtualization, and other non-functional aspects. ICON's research results have been published in several of the most respected IEEE journals and magazines within our field. Furthermore, some of ICON's solutions have had a major impact on the routing architecture of modern supercomputers.
Afilliation | Communication Systems, Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 14 |
Pagination | 129-162 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Scientific Computing: Why - How - What - What's Next
In Simula Research Laboratory - by thinking constantly about it, 237-248. Springer, 2009.Status: Published
Scientific Computing: Why - How - What - What's Next
Afilliation | Scientific Computing, , Scientific Computing, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 18 |
Pagination | 237-248 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Simula - the Language
In Simula Research Laboratory - by thinking constantly about it, 113-118. Springer, 2009.Status: Published
Simula - the Language
Afilliation | , Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 11 |
Pagination | 113-118 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Simula - the Language
In Simula Research Laboratory - by thinking constantly about it, 113-118. Springer, 2009.Status: Published
Simula - the Language
Afilliation | , Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 11 |
Pagination | 113-118 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Software Development Effort Estimation: Demystifying and Improving Expert Estimation
In Simula Research Laboratory - by thinking constantly about it, 381-404. Heidelberg: Springer, 2009.Status: Published
Software Development Effort Estimation: Demystifying and Improving Expert Estimation
Research background: Inaccurate estimation of software development effort is one of the most important reasons of IT-project failures. While too low effort estimates may lead to project management problems, delayed deliveries, budget overruns and low software quality, too high effort estimates may lead to lost business opportunities and inefficient use of resources. These IT-project problems motivated the BEST (Better Estimation of Software Tasks) project at Simula Research Laboratory to conduct research with the goal of improving effort estimation methods. Scientific challenges: The project's main focus is to improve judgment-based effort estimation (expert estimation), which is the estimation approach most frequently used by the software industry. We argue that a better understanding of the mental steps involved in expert estimation is necessary to achieve robust improvement of software development estimation processes. A great challenge when studying expert judgment is to understand the unconscious steps involved. To study these steps, we make use of multidisciplinary competencies, especially psychology and software engineering, and financial resources enabling studies in realistic software development effort estimation contexts. Obtained and expected results: In this section, we present the main results of the project from its beginnings in 2001 until today and describe how the project has benefited from being an integrated part of Simula Research Laboratory, especially through the opportunity to conduct large-scale, controlled experiments in field settings. The section includes practical results on how to improve estimation methods, scientific results leading to a better understanding of the mental processes involved in judgment-based effort estimation, and our innovative research methods in the field of empirical software engineering. Results of the BEST project are currently in use by several software companies, as well as by researchers in forecasting and psychology, and they are also included in project management and software engineering textbooks. The BEST project plans to continue its multidisciplinary effort with the goal of constructing and evaluating better models of the mental steps involved in judgment-based effort estimation. An improved model of these steps will enhance our ability to accurately estimate software development effort and to predict when different types of estimation methods can be expected to deliver accurate effort estimates. This will in turn lead to a reduction of the number of IT-project failures and make better use of scarce financial and human resources.
Afilliation | Software Engineering, Software Engineering |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 26 |
Pagination | 381-404 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3642011559 |
Software Engineering: Why - How - What - What's Next
In Simula Research Laboratory - by thinking constantly about it, 363-368. Springer, 2009.Status: Published
Software Engineering: Why - How - What - What's Next
Afilliation | Software Engineering, Software Engineering |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 24 |
Pagination | 363-368 |
Publisher | Springer |
ISBN Number | ISBN: 978-3642011559 |
Software Verification: a Scalable, Model-Driven, Empirically Grounded Approach
In Simula Research Laboratory - by thinking constantly about it, 415-442. Heidelberg: Springer, 2009.Status: Published
Software Verification: a Scalable, Model-Driven, Empirically Grounded Approach
Afilliation | Software Engineering, Software Engineering |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 28 |
Pagination | 415-442 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Spinning Off From Simula
In Simula Research Laboratory - by thinking constantly about it, 613-626. Springer, 2009.Status: Published
Spinning Off From Simula
Afilliation | Communication Systems, Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 42 |
Pagination | 613-626 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
Spinning Off From Simula
In Simula Research Laboratory - by thinking constantly about it, 613-626. Springer, 2009.Status: Published
Spinning Off From Simula
Afilliation | Communication Systems, Communication Systems |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 42 |
Pagination | 613-626 |
Publisher | Springer |
ISBN Number | 978-3-642-01155-9 |
The Hamming Experience
In Simula Research Laboratory - by thinking constantly about it, 33-36. Springer, 2009.Status: Published
The Hamming Experience
Afilliation | Scientific Computing, , , Communication Systems, Scientific Computing |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 5 |
Pagination | 33-36 |
Publisher | Springer |
ISBN Number | ISBN 978-3-642-01155-9 |
The Industry Is Our Lab - Organization and Conducting of Empirical Studies in Software Engineering at Simula
In Simula Research Laboratory - by thinking constantly about it, 443-458. Heidelberg: Springer, 2009.Status: Published
The Industry Is Our Lab - Organization and Conducting of Empirical Studies in Software Engineering at Simula
The society is completely dependent on reliable and efficient software. Development of such software requires the use of appropriate processes, method and tools. To evaluate their appropriateness in various industrial settings, empirical studies are needed. At present, most studies in software engineering are run with students in artificial settings. The strategy of Simula Research Laboratory to invest in experiment infrastructures and hire professionals as subjects has contributed to a significant improvement of state of the art regarding the realism and scale of experiments and control in real-life case studies. During its first eight years, Simula has conducted studies that have included about 6000 professional software developers and managers from 273 companies in 25 countries. However, increasing the realism of tasks and systems in experiments and control in case studies is still a challenge for Simula and the rest of the research community.
Afilliation | Software Engineering, Software Engineering |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 29 |
Pagination | 443-458 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | 978-3-642-01155-9 |
Turning Rocks Into Knowledge - Experiences and Results From an Industrial Collaboration in Computational Geosciences
In Simula Research Laboratory - by thinking constantly about it, 553-600. Heidelberg: Springer, 2009.Status: Published
Turning Rocks Into Knowledge - Experiences and Results From an Industrial Collaboration in Computational Geosciences
Since early 2005, Simula Research Laboratory and StatoilHydro have built a strong and long-term research collaboration in computational geosciences. The main goal for this collaboration is to strengthen the procedures in oil and gas exploration through new and improved computer-based models of geological and geophysical processes. So far, the 4D Lithosphere Model and a new generation of the Compound Modelling technology have been sucessfully established, and the collaboration has become strategically important for both organisations. Even more contributions are in fast progress, possibly leading to improved reliability of depositional models, better insight in the physics of underwater gravity flows of sediments, and more accurate descriptions of deformations in sedimentary basins. This paper describes the background for the research collaboration, as well as the contents of the ongoing scientific activities. Using the obtained academic and industrial results as a backdrop, we also summarize the key factors for the successful implementation of a close link between the basic research community and industry. The coupling between research tasks of academic nature and technology development has proven to be bidirectional, in that development-oriented activities lead to new PhD and postdoctoral research projects, and vice versa. The intimate connection between the axes of research and development is a particular strength in the StatoilHydro-Simula collaboration. This feature is a consequence of both companies being committed to long-term research, and the flexibility offered by Simula's organisation.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 40 |
Pagination | 553-600 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | ISBN 978-3-642-01155-9 |
Turning Rocks Into Knowledge - Experiences and Results From an Industrial Collaboration in Computational Geosciences
In Simula Research Laboratory - by thinking constantly about it, 553-600. Heidelberg: Springer, 2009.Status: Published
Turning Rocks Into Knowledge - Experiences and Results From an Industrial Collaboration in Computational Geosciences
Since early 2005, Simula Research Laboratory and StatoilHydro have built a strong and long-term research collaboration in computational geosciences. The main goal for this collaboration is to strengthen the procedures in oil and gas exploration through new and improved computer-based models of geological and geophysical processes. So far, the 4D Lithosphere Model and a new generation of the Compound Modelling technology have been sucessfully established, and the collaboration has become strategically important for both organisations. Even more contributions are in fast progress, possibly leading to improved reliability of depositional models, better insight in the physics of underwater gravity flows of sediments, and more accurate descriptions of deformations in sedimentary basins. This paper describes the background for the research collaboration, as well as the contents of the ongoing scientific activities. Using the obtained academic and industrial results as a backdrop, we also summarize the key factors for the successful implementation of a close link between the basic research community and industry. The coupling between research tasks of academic nature and technology development has proven to be bidirectional, in that development-oriented activities lead to new PhD and postdoctoral research projects, and vice versa. The intimate connection between the axes of research and development is a particular strength in the StatoilHydro-Simula collaboration. This feature is a consequence of both companies being committed to long-term research, and the flexibility offered by Simula's organisation.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Book Chapter |
Year of Publication | 2009 |
Book Title | Simula Research Laboratory - by thinking constantly about it |
Chapter | 40 |
Pagination | 553-600 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | ISBN 978-3-642-01155-9 |
Technical reports
CSRW - Assessmentreport
Simula Research Laboratory, 2009.Status: Published
CSRW - Assessmentreport
Afilliation | Scientific Computing |
Project(s) | No Simula project |
Publication Type | Technical reports |
Year of Publication | 2009 |
Publisher | Simula Research Laboratory |
Poster
Parallel Simulation of Dual Lithology Sedimentation
2009.Status: Published
Parallel Simulation of Dual Lithology Sedimentation
Afilliation | , , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Poster |
Year of Publication | 2009 |
Notes | Second prize winner of the poster competition at the conference. |
Edited books
Simula Research Laboratory - by Thinking Constantly About It
Heidelberg: Springer, 2009.Status: Published
Simula Research Laboratory - by Thinking Constantly About It
Through a mix of articles and interviews, this book describes the philosophy behind Simula Research Laboratory; how it has been implement, and the results that have come out of it. Most of the book is intended for anyone interested in research, whereas some of the articles are written for experts interested in Simula's research subjects. Read more about the book at http://simula.no/about/the-simula-book
Afilliation | , Scientific Computing, , Communication Systems, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Edited books |
Year of Publication | 2009 |
Publisher | Springer |
Place Published | Heidelberg |
ISBN Number | ISBN 978-3-642-01155-9 |
Talks, contributed
A Coupled Lattice Boltzmann Model for a Turbulent Sand-Laden Fluid Flow
In Talk at the DSFD conference in Brazil, 2008.Status: Published
A Coupled Lattice Boltzmann Model for a Turbulent Sand-Laden Fluid Flow
his talk describes a novel numerical modelling approach to simulate a sand-laden, highly turbulent fluid flow, also known as a turbidity current, with the Lattice Boltzmann method. Turbidity currents are sediment laden, highly turbulent submarine flows that are often triggered by catastrophic events like tsunamis or earthquakes. When a tur- bidity current comes to rest, the heaviest, coarsest grains settle first and the finest, lightest grains settle last. These deposits are called Turbidites. Turbidity currents constitute an important factor in the transport of clastic sediments into deep waters . Deposits from such flows are common in the deep water areas throughout the world and many of them constitute important petroleum reservoirs. The modelling and prediction of such deposits are therefore of prime interest both in the academic community and in the industry.Traditionally, turbidity currents have been modelled as a multiphase fluid flow in terms of continuum physics in a partial differential equation setting. Numerous models exist, and they are almost without exception based on traditional computational fluid dynamics (CFD). These are based on the assumption that the fluid and other quantities are in principle a continuum. Although improvement has been made, such models are associated with challenges. It is for instance difficult phenomenologically to describe and model the dynamics, deposition and erosion of sand particles in complex fluid flow from a traditional CFD approach.We will introduce a framework for modelling turbidity currents and turbidite development. The fluid phase is modeled by the Lattice Boltzmann equation, and the sand dynamics is described by the Basset-Boussinesq-Oseen (BBO) for spherical particles in a turbulent fluid. The two phases interact non-linearly through momentum exchange. We will describe basic features of the model and give an overview of the numerical implementation. Current status and outlook on the development process will be reported as well.
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2008 |
Location of Talk | Talk at the DSFD conference in Brazil |
Handling Uncertainty in Numerical Models of Sedimentary Deposition: a Stochastic Approach
In Talk given at the 33rd International Geological Congress, 2008.Status: Published
Handling Uncertainty in Numerical Models of Sedimentary Deposition: a Stochastic Approach
Forward stratigraphic models simulates the process of sedimentary deposition over geological time periods and helps geoscientists and engineers to understand the location of reservoir rocks and stratigraphic traps. The most popular and commonly used models are diffusion-based. A major draw-back with such models is that diffusion coefficients, that largely control the outcome of the simulations, are highly uncertain and difficult to derive., This clearly reduces their usefulness at describing the evolution of a basin. Diffusion coefficients represent conglomerations of physical processes in sedimentation and basin morphology that depend, for instance, on slope. By considering the diffusion coefficients as randomly distributed fields, the uncertainty in the morphology of a basin can be constrained. We use a Polynomial Chaos Expansion (PCE) to approximate the model at each spatial and temporal point of interest. The Probabilistic Collocation Method (PCM) is used to calculate the coefficients of the PCE, based on a few, specifically chosen, calculations of the underlying model of sedimentation. In contrast to the Monte Carlo approach, which may require hundreds or thousands of runs of the simulator, the PCM requires only a dozen or so, depending on the number of inputs and the desired accuracy. Furthermore, the PCM is not tied to a particular implementation of a sedimentation model, as it treats the model as a blackbox, and can be placed upon any depositional simulator. This method allows for the quantification of the stochastic moments of the height and the fractional distribution of the materials. By understanding the spatial distribution of the uncertainty in basin evolution, these depositional models can begin to have real meaning in industrial applications. Our approach is not dependent on depositional modelling, but can be applied to any process-oriented geological simulation.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2008 |
Location of Talk | Talk given at the 33rd International Geological Congress |
Numerical Modeling of Turbidity Flow With the Lattice Boltzmann Method
In Talk at the Computational Geoscience workshop, 2008.Status: Published
Numerical Modeling of Turbidity Flow With the Lattice Boltzmann Method
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2008 |
Location of Talk | Talk at the Computational Geoscience workshop |
Numerical Python
In Four day course at the University of Erlangen, 2008.Status: Published
Numerical Python
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2008 |
Location of Talk | Four day course at the University of Erlangen |
Particle-Based Methods in the Modelling of Turbidity Currents and Turbidites
In Talk at the 33rd IGC Congress in Oslo, 2008.Status: Published
Particle-Based Methods in the Modelling of Turbidity Currents and Turbidites
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2008 |
Location of Talk | Talk at the 33rd IGC Congress in Oslo |
Talks, contributed
By Thinking Constantly About It - Scientific Computing in Simula
In Invited talk at College of Engineering, Pennsylvania State University, 2007.Status: Published
By Thinking Constantly About It - Scientific Computing in Simula
Simula Research Laboratory conducts research in the fields of scientific computing, software engineering, and networks and distributed systems. In addition, the organization has a strong focus on education and innovation. Recently, the educational efforts have been strengthened through the foundation of the Simula School of Research and Innovation, a graduate school that collaborates closely with the University of Oslo and is co-owned by industrial partners.
The scientific computing research at Simula spans from development of generic software tools, via numerical methods, to a variety of applications in science and technology. The field of scientific computing is characterized by being interdisciplinary, involving mathematics, computer science, and the relevant application field(s).
In this talk I will briefly present the Simula organization and the principles on which our research activities are based. Thereafter, I will give an overview of the ongoing projects in scientific computing. In particular, I will discuss our research on computational middleware, simulation of electromechanical behavior of the heart, use of inverse modeling for determination of myocardial infarction, biomedical flow simulations, and different applications in geoscience. These applications range from simulation of the deformation in sedimentary basins to 4D modeling of the lithosphere. The research in computational geosciences is financed by one of the leading technological innovators in the oil and gas business, StatoilHydro.
Afilliation | , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2007 |
Location of Talk | Invited talk at College of Engineering, Pennsylvania State University |
Lattice Boltzmann Method and Turbidity Flow Modeling
In Talk at MekIT'07: Fourth National Conference on Computational Mechanics, 2007.Status: Published
Lattice Boltzmann Method and Turbidity Flow Modeling
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2007 |
Location of Talk | Talk at MekIT'07: Fourth National Conference on Computational Mechanics |
Parallelisation and Numerical Performance of a 3D Model for Coupled Deformation, Fluid Flow, and Heat Transport in Porous Geological Formations
In Talk at the Fourth National Conference on Computational Mechanics (MekIT'07), Trondheim, Norway, 2007.Status: Published
Parallelisation and Numerical Performance of a 3D Model for Coupled Deformation, Fluid Flow, and Heat Transport in Porous Geological Formations
In this paper, we present some parallel performance results for a 3D simulator of coupled deformation, fluid flow and heat transfer in sedimentary basins. The model parameters are derived from an industry simulator, with realistic material properties and complex irregular grids of up to 1.5 million nodes with 7.3 million degrees of freedom. We have performed parallelisation on the linear algebra level using the ML algebraic multigrid preconditioner with iterative methods in the Diffpack finite element framework. Implementation and speedup results are presented.
Afilliation | Scientific Computing, , Scientific Computing, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Talks, contributed |
Year of Publication | 2007 |
Location of Talk | Talk at the Fourth National Conference on Computational Mechanics (MekIT'07), Trondheim, Norway |
Notes | Presented by J. B. Haga |
Proceedings, refereed
Lattice Boltzmann Method and Turbidity Flow Modeling
In MekIT'07 : Fourth National Conference in Computational Mechanics. Tapir Academic Press, 2007.Status: Published
Lattice Boltzmann Method and Turbidity Flow Modeling
We discuss the Lattice Boltzmann method (LBM), which provides a new way of thinking on complex, multiphase fluid flow problems. We present the basics of the LBM as well as its origins in the Cellular Automata. The particle-based nature of the LBM makes it well suited to study fluid-boundary interfaces. We then commence to sketch advanced applications like particle suspension problems and we show how the LBM can be applied on turbidity currents, a challenging fluid flow problem. We show that the LBM has a good deal of versatility in modeling physical systems.
Afilliation | Scientific Computing, , Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2007 |
Conference Name | MekIT'07 : Fourth National Conference in Computational Mechanics |
Pagination | 213-228 |
Date Published | May |
Publisher | Tapir Academic Press |
ISBN Number | 978-82-519-2235-7 |
Parallelisation and Numerical Performance of a 3D Model for Coupled Deformation, Fluid Flow and Heat Transfer in Sedimentary Basins
In MekIT'07. Fourth National Conference on Computational Mechanics. Trondheim: Tapir Academic Press, 2007.Status: Published
Parallelisation and Numerical Performance of a 3D Model for Coupled Deformation, Fluid Flow and Heat Transfer in Sedimentary Basins
In this paper, we present some parallel performance results for a 3D simulator of coupled deformation, fluid flow and heat transfer in sedimentary basins. The model parameters are derived from an industry simulator, with realistic material properties and complex irregular grids of up to 1.5 million nodes with 7.3 million degrees of freedom. We have performed parallelisation on the linear algebra level using the ML algebraic multigrid preconditioner with iterative methods in the Diffpack finite element framework. Implementation and speedup results are presented.
Afilliation | Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Proceedings, refereed |
Year of Publication | 2007 |
Conference Name | MekIT'07. Fourth National Conference on Computational Mechanics |
Pagination | 151-162 |
Date Published | May |
Publisher | Tapir Academic Press |
Place Published | Trondheim |
ISBN Number | 978-82-519-2235-7 |
Technical reports
PhD: Simulation of Deformation and Heat Flow in Sedimentary Basins
Simula, 2007.Status: Published
PhD: Simulation of Deformation and Heat Flow in Sedimentary Basins
Afilliation | Scientific Computing, , Scientific Computing, Scientific Computing |
Project(s) | Center for Biomedical Computing (SFF) |
Publication Type | Technical reports |
Year of Publication | 2007 |
Date Published | December |
Publisher | Simula |
Notes | StatoilHydro collaboration (contract \#5377415) |
Book Chapter
Full-Scale Simulation of Cardiac Electrophysiology on Parallel Computers
In Numerical Solution of Partial Differential Equations on Parallel Computers, 385-411. Lecture Notes in Computational Science and Engineering. Springer, 2006.Status: Published
Full-Scale Simulation of Cardiac Electrophysiology on Parallel Computers
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Book Chapter |
Year of Publication | 2006 |
Book Title | Numerical Solution of Partial Differential Equations on Parallel Computers |
Secondary Title | Lecture Notes in Computational Science and Engineering |
Pagination | 385-411 |
Publisher | Springer |
Parallelizing PDE Solvers Using the Python Programming Language
In Numerical Solution of Partial Differential Equations on Parallel Computers, 295-325. Lecture Notes in Computational Science and Engineering. Springer, 2006.Status: Published
Parallelizing PDE Solvers Using the Python Programming Language
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Book Chapter |
Year of Publication | 2006 |
Book Title | Numerical Solution of Partial Differential Equations on Parallel Computers |
Secondary Title | Lecture Notes in Computational Science and Engineering |
Pagination | 295-325 |
Publisher | Springer |
Edited books
Numerical Solution of Partial Differential Equations on Parallel Computers
Vol. LNCSE 51. Springer, 2006.Status: Published
Numerical Solution of Partial Differential Equations on Parallel Computers
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Edited books |
Year of Publication | 2006 |
Volume | LNCSE 51 |
Publisher | Springer |
ISBN Number | 3-540-29076-1 |
Talks, contributed
Python in High Performance Computing
In Tutorial presented at the Para06 Workshop, 2006.Status: Published
Python in High Performance Computing
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2006 |
Location of Talk | Tutorial presented at the Para06 Workshop |
Talks, contributed
Scientific Computing in Python
In Tutorial ASIM 2005, 2005.Status: Published
Scientific Computing in Python
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2005 |
Location of Talk | Tutorial ASIM 2005 |
Technical reports
Diffpack Implementation of Edge-Based Non-Standard Finite Element Methods
Simula Research Laboratory, 2004.Status: Published
Diffpack Implementation of Edge-Based Non-Standard Finite Element Methods
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Technical reports |
Year of Publication | 2004 |
Number | 2004-11 |
Publisher | Simula Research Laboratory |
Talks, contributed
High Performance Computing in Python
In Tutorial, SC2004, 2004.Status: Published
High Performance Computing in Python
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2004 |
Location of Talk | Tutorial, SC2004 |
Talks, contributed
A Multi-Physics Solid Oxide Fuel Cell Simulator As a Diffpack Application
In Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany, 2003.Status: Published
A Multi-Physics Solid Oxide Fuel Cell Simulator As a Diffpack Application
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2003 |
Location of Talk | Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany |
Notes | Presented by A. M. Bruaset |
Future Development of Diffpack at Simula
In Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany, 2003.Status: Published
Future Development of Diffpack at Simula
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2003 |
Location of Talk | Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany |
Notes | Presented by A. M. Bruaset |
The History and Philosophy of Diffpack
In Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany, 2003.Status: Published
The History and Philosophy of Diffpack
Afilliation | Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2003 |
Location of Talk | Invited minisymposium talk at the 21st CAD-FEM User's Meeting, Potsdam, Germany |
Notes | Presented by H. P. Langtangen |
Book Chapter
Performance Modeling of PDE Solvers
In Advanced Topics in Computational Partial Differential Equations - Numerical Methods and Diffpack Programming, 361-399. Lecture Notes in Computational Science and Engineering. Springer, 2003.Status: Published
Performance Modeling of PDE Solvers
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Book Chapter |
Year of Publication | 2003 |
Book Title | Advanced Topics in Computational Partial Differential Equations - Numerical Methods and Diffpack Programming |
Secondary Title | Lecture Notes in Computational Science and Engineering |
Pagination | 361-399 |
Publisher | Springer |
Talks, contributed
Diffpack Simulation of the Electrical Activity in the Heart
In Invited minisymposium talk at the 20th CAD-FEM User's Meeting, Friedrichshafen, Germany, 2002.Status: Published
Diffpack Simulation of the Electrical Activity in the Heart
Afilliation | Scientific Computing, Scientific Computing, Scientific Computing |
Publication Type | Talks, contributed |
Year of Publication | 2002 |
Location of Talk | Invited minisymposium talk at the 20th CAD-FEM User's Meeting, Friedrichshafen, Germany |
Notes | Presented by A. M. Bruaset |
EXTRUD - Aluminium Extrusion Software Built on Diffpack
In Invited minisymposium talk at the 20th CAD-FEM User's Meeting, Friedrichshafen, Germany, 2002.Status: Published
EXTRUD - Aluminium Extrusion Software Built on Diffpack
Publication Type | Talks, contributed |
Year of Publication | 2002 |
Location of Talk | Invited minisymposium talk at the 20th CAD-FEM User's Meeting, Friedrichshafen, Germany |
Notes | Presented by A. M. Bruaset |
Finite Volume Methods in Diffpack
In Internal seminar at ChevronTexaco in San Ramon, California, USA discussing a prototype implementation of a finite volume framework in Diffpack, 2002.Status: Published
Finite Volume Methods in Diffpack
Publication Type | Talks, contributed |
Year of Publication | 2002 |
Location of Talk | Internal seminar at ChevronTexaco in San Ramon, California, USA discussing a prototype implementation of a finite volume framework in Diffpack |
Technical reports
Heat Flow Phenomenon in a SOFC Unit Cell
Numerical Objects A.S, 2001.Status: Published
Heat Flow Phenomenon in a SOFC Unit Cell
Publication Type | Technical reports |
Year of Publication | 2001 |
Publisher | Numerical Objects A.S. |
Notes | Report on simulation of solid oxide fuel cells written for Mitsubishi Material Corporation in Japan |
Talks, contributed
PDEWizard - Integration of Diffpack and Mathematica
In Internal seminar at Wolfram Research Inc. in Champaign, Illinois, USA discussing a prototype implementation of a PDE-oriented software environment based on integration of Diffpack and Mathematica, 2001.Status: Published
PDEWizard - Integration of Diffpack and Mathematica
Publication Type | Talks, contributed |
Year of Publication | 2001 |
Location of Talk | Internal seminar at Wolfram Research Inc. in Champaign, Illinois, USA discussing a prototype implementation of a PDE-oriented software environment based on integration of Diffpack and Mathematica |
Talks, contributed
Diffpack: Object-Oriented Software Solutions for PDEs
In Invited SCCM seminar talk at Stanford University, Palo Alto, California, USA, 2000.Status: Published
Diffpack: Object-Oriented Software Solutions for PDEs
Publication Type | Talks, contributed |
Year of Publication | 2000 |
Location of Talk | Invited SCCM seminar talk at Stanford University, Palo Alto, California, USA |
Diffpack: Object-Oriented Software Solutions for PDEs
In Invited ISCR/CASC seminar talk at Lawrence Livermore National Laboratory, Livermore, California, USA, 2000.Status: Published
Diffpack: Object-Oriented Software Solutions for PDEs
Publication Type | Talks, contributed |
Year of Publication | 2000 |
Location of Talk | Invited ISCR/CASC seminar talk at Lawrence Livermore National Laboratory, Livermore, California, USA |
Edited books
Advances in Software Tools for Scientific Computing
Vol. 10. Springer, 1999.Status: Published
Advances in Software Tools for Scientific Computing
Publication Type | Edited books |
Year of Publication | 1999 |
Volume | 10 |
Publisher | Springer |
Notes | 356 p. |
Technical reports
Coupling of PDEs in Diffpack Environments
SINTEF, 1999.Status: Published
Coupling of PDEs in Diffpack Environments
Publication Type | Technical reports |
Year of Publication | 1999 |
Publisher | SINTEF |
Book Chapter
Generalized Maps in Geological Modeling: Object-Oriented Design of Topological Kernels
In Advances in Software Tools for Scientific Computing, 339-356. Springer, 1999.Status: Published
Generalized Maps in Geological Modeling: Object-Oriented Design of Topological Kernels
Publication Type | Book Chapter |
Year of Publication | 1999 |
Book Title | Advances in Software Tools for Scientific Computing |
Pagination | 339 - 356 |
Publisher | Springer |
Technical reports
Performance Modeling of PDE Solvers
Department of Informatics, University of Oslo, 1998.Status: Published
Performance Modeling of PDE Solvers
Publication Type | Technical reports |
Year of Publication | 1998 |
Number | 1998-3 |
Publisher | Department of Informatics, University of Oslo |
Proceedings, refereed
A Comprehensive Set of Tools for Solving Partial Differential Equations; Diffpack
In Numerical Methods and Software Tools in Industrial Mathematics. Birkhäuser,, 1997.Status: Published
A Comprehensive Set of Tools for Solving Partial Differential Equations; Diffpack
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Numerical Methods and Software Tools in Industrial Mathematics |
Pagination | 61-90 |
Publisher | Birkhäuser, |
Diffpack: a Software Environment for Rapid Prototyping of PDE Solvers
In Proceedings of the 15th IMACS World Congress on Scientific Computation, Modeling and Applied Mathematics, 1997.Status: Published
Diffpack: a Software Environment for Rapid Prototyping of PDE Solvers
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Proceedings of the 15th IMACS World Congress on Scientific Computation, Modeling and Applied Mathematics |
Pagination | 553-558 |
Domain Decomposition and Multilevel Methods in Diffpack
In Proceedings of the 9th Conference on Domain Decomposition. Cambridge,, 1997.Status: Published
Domain Decomposition and Multilevel Methods in Diffpack
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Proceedings of the 9th Conference on Domain Decomposition |
Pagination | 77-662 |
Publisher | Cambridge, |
Increasing the Efficiency and Reliability of Numerical Software Development
In Modern Software Tools for Scientific Computing. Birkhäuser,, 1997.Status: Published
Increasing the Efficiency and Reliability of Numerical Software Development
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Modern Software Tools for Scientific Computing |
Pagination | 247-268 |
Publisher | Birkhäuser, |
Increasing the Efficiency and Reliability of Numerical Software Development
In Modern Software Tools for Scientific Computing. Birkhäuser,, 1997.Status: Published
Increasing the Efficiency and Reliability of Numerical Software Development
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Modern Software Tools for Scientific Computing |
Pagination | 247-268 |
Publisher | Birkhäuser, |
Krylov Subspace Iterations for Sparse Linear Systems
In Numerical Methods and Software Tools in Industrial Mathematics. Birkhäuser,, 1997.Status: Published
Krylov Subspace Iterations for Sparse Linear Systems
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Numerical Methods and Software Tools in Industrial Mathematics |
Pagination | 255-280 |
Publisher | Birkhäuser, |
Numerical Solution of PDEs on Parallel Computers Utilizing Sequential Simulators
In Scientific Computing in Object-Oriented Parallel Environments. Lecture Notes in Computer Science. Springer-Verlag, 1997.Status: Published
Numerical Solution of PDEs on Parallel Computers Utilizing Sequential Simulators
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Scientific Computing in Object-Oriented Parallel Environments |
Pagination | 161-168 |
Publisher | Springer-Verlag |
Object-Oriented Numerics
In Numerical Methods and Software Tools in Industrial Mathematics. Birkhäuser,, 1997.Status: Published
Object-Oriented Numerics
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Numerical Methods and Software Tools in Industrial Mathematics |
Pagination | 7-26 |
Publisher | Birkhäuser, |
On the Numerical Efficiency of C++ in Scientific Computing
In Numerical Methods and Software Tools in Industrial Mathematics. Birkhäuser,, 1997.Status: Published
On the Numerical Efficiency of C++ in Scientific Computing
Publication Type | Proceedings, refereed |
Year of Publication | 1997 |
Conference Name | Numerical Methods and Software Tools in Industrial Mathematics |
Pagination | 91-118 |
Publisher | Birkhäuser, |
Book Chapter
Basic Tools for Linear Algebra
In Numerical methods and Software Tools in Industrial Mathematics, 27-44,. Birkhäuser, 1997.Status: Published
Basic Tools for Linear Algebra
Publication Type | Book Chapter |
Year of Publication | 1997 |
Book Title | Numerical methods and Software Tools in Industrial Mathematics |
Pagination | 27-44, |
Publisher | Birkhäuser |
Object-Oriented Scattered Data Modelling With Siscat.
In Modern Software Tools for Scientific Computing, 289-308. Birkhäuser, 1997.Status: Published
Object-Oriented Scattered Data Modelling With Siscat.
Publication Type | Book Chapter |
Year of Publication | 1997 |
Book Title | Modern Software Tools for Scientific Computing |
Pagination | 289-308 |
Publisher | Birkhäuser |
Talks, contributed
Design Issues and Recent Developments in Diffpack
In Invited minisymposium talk at the SIAM Annual meeting, Stanford University, California, USA, 1997.Status: Published
Design Issues and Recent Developments in Diffpack
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Invited minisymposium talk at the SIAM Annual meeting, Stanford University, California, USA |
Notes | Presented by A. M. Bruaset |
Diffpack: a Software Environment for Rapid Prototyping of PDE Solvers
In Invited minisymposium talk at the 15th IMACS World Congress on Scientific Computation, Modelling and Applied Mathematics, Berlin, Germany, 1997.Status: Published
Diffpack: a Software Environment for Rapid Prototyping of PDE Solvers
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Invited minisymposium talk at the 15th IMACS World Congress on Scientific Computation, Modelling and Applied Mathematics, Berlin, Germany |
Notes | Presented by H. P. Langtangen |
Diffpack: an Object-Oriented Software Environment for Scientific Computing
In Invited minisymposium talk at the Fourth US National Congress on Computational Mechanics, San Fransisco, 1997.Status: Published
Diffpack: an Object-Oriented Software Environment for Scientific Computing
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Invited minisymposium talk at the Fourth US National Congress on Computational Mechanics, San Fransisco |
Notes | Presented by X. Cai |
Numerical Solution of PDEs on Parallel Computers Utilizing Sequential Simulators
In Talk at the ISCOPE Conference 1997, California, 1997.Status: Published
Numerical Solution of PDEs on Parallel Computers Utilizing Sequential Simulators
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Talk at the ISCOPE Conference 1997, California |
Notes | Presented by X. Cai |
Software Design for Multiphase Flow Problems
In Talk at the Fourth SIAM Conference on Computational and Mathematical Issues in the Geosciences, Albuquerque, New Mexico, USA, 1997.Status: Published
Software Design for Multiphase Flow Problems
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Talk at the Fourth SIAM Conference on Computational and Mathematical Issues in the Geosciences, Albuquerque, New Mexico, USA |
Notes | Presented by L. Ingebrigtsen |
The Diffpack Software
In Invited talk at the Workshop on PDE Software, Institute of Mathematics and Its Applications, Minneapolis, Minnesota, USA, 1997.Status: Published
The Diffpack Software
Publication Type | Talks, contributed |
Year of Publication | 1997 |
Location of Talk | Invited talk at the Workshop on PDE Software, Institute of Mathematics and Its Applications, Minneapolis, Minnesota, USA |
Notes | Presented by H. P. Langtangen |
Edited books
Modern Software Tools for Scientific Computing
Birkhäuser, 1997.Status: Published
Modern Software Tools for Scientific Computing
Publication Type | Edited books |
Year of Publication | 1997 |
Publisher | Birkhäuser |
Notes | 380 p. |
Journal Article
Object-Oriented Design of Preconditioned Iterative Methods in Diffpack
ACM Transactions on Mathematical Software 23 (1997): 50-80,.Status: Published
Object-Oriented Design of Preconditioned Iterative Methods in Diffpack
Publication Type | Journal Article |
Year of Publication | 1997 |
Journal | ACM Transactions on Mathematical Software |
Volume | 23 |
Number | 1 |
Pagination | 50-80, |
Talks, contributed
Domain Decomposition and Multilevel Methods in Diffpack
In Talk at the 9th International Conference on Domain Decomposition Methods, Ullensvang, Norway, 1996.Status: Published
Domain Decomposition and Multilevel Methods in Diffpack
Publication Type | Talks, contributed |
Year of Publication | 1996 |
Location of Talk | Talk at the 9th International Conference on Domain Decomposition Methods, Ullensvang, Norway |
Notes | Presented by G. W. Zumbusch |
Increasing the Efficiency and Reliability of Numerical Software Development
In Talk at the International Workshop for Modern Software Tools in Scientific Computing, Oslo, Norway, 1996.Status: Published
Increasing the Efficiency and Reliability of Numerical Software Development
Publication Type | Talks, contributed |
Year of Publication | 1996 |
Location of Talk | Talk at the International Workshop for Modern Software Tools in Scientific Computing, Oslo, Norway |
Notes | Presented by E. Holm |
Industrial Demands on Numerical Software; a Case Study
In Talk at the International Workshop for Modern Software Tools in Scientific Computing, Oslo, Norway, 1996.Status: Published
Industrial Demands on Numerical Software; a Case Study
Publication Type | Talks, contributed |
Year of Publication | 1996 |
Location of Talk | Talk at the International Workshop for Modern Software Tools in Scientific Computing, Oslo, Norway |
Notes | Presented by P. H. Merz |
Numerical Efficiency of C++ in Scientific Computing
In Poster at the Conference on Advanced Simulation and Subsurface Flow and Transport, North Carolina Supercomputing Center, Research Triangle Park, North Carolina, USA, 1996.Status: Published
Numerical Efficiency of C++ in Scientific Computing
Publication Type | Talks, contributed |
Year of Publication | 1996 |
Location of Talk | Poster at the Conference on Advanced Simulation and Subsurface Flow and Transport, North Carolina Supercomputing Center, Research Triangle Park, North Carolina, USA |
Notes | Presented by J. F. Kanney |
Proceedings, refereed
Efficient Solution of Linear Equations Arising in a Nonlinear Economic Model
In Computational Economic Systems. Models Methods and Econometrics. Kluwer Academic Publishers, 1996.Status: Published
Efficient Solution of Linear Equations Arising in a Nonlinear Economic Model
Publication Type | Proceedings, refereed |
Year of Publication | 1996 |
Conference Name | Computational Economic Systems. Models Methods and Econometrics |
Pagination | 243-255 |
Publisher | Kluwer Academic Publishers |
On the Stability of Solutions of the Pressure Equation With Respect to Perturbations in the Mobility Tensor
In Proceedings of the Third International Congress on Industrial and Applied Mathematics. Akademie Verlag, 1996.Status: Published
On the Stability of Solutions of the Pressure Equation With Respect to Perturbations in the Mobility Tensor
Publication Type | Proceedings, refereed |
Year of Publication | 1996 |
Conference Name | Proceedings of the Third International Congress on Industrial and Applied Mathematics |
Pagination | 491-492 |
Publisher | Akademie Verlag |
Notes | Special issue 2 of Zeitschrift für Angewandte Mathematik und Mechanik ("Applied Analysis") |
Technical reports
Noen Numeriske Eksempler I C++
Department of Informatics, University of Oslo, 1996.Status: Published
Noen Numeriske Eksempler I C++
Publication Type | Technical reports |
Year of Publication | 1996 |
Publisher | Department of Informatics, University of Oslo |
Notes | In Norwegian (English title: Some numerical examples in C++) |
Prosjektoppgave in 218
Department of Informatics, University of Oslo, 1996.Status: Published
Prosjektoppgave in 218
Publication Type | Technical reports |
Year of Publication | 1996 |
Publisher | Department of Informatics, University of Oslo |
Notes | In Norwegian (English title: Project for the course In 218) |
Journal Article
On the Stability of Pressure and Velocity Computations for Heterogeneous Reservoirs
SIAM J. Appl. Math. 56 (1996): 991-1007,.Status: Published
On the Stability of Pressure and Velocity Computations for Heterogeneous Reservoirs
Publication Type | Journal Article |
Year of Publication | 1996 |
Journal | SIAM J. Appl. Math. |
Volume | 56 |
Number | 4 |
Pagination | 991-1007, |
Book
A Survey of Preconditioned Iterative Methods
Vol. 324. Addison-Wesley Longman, 1995.Status: Published
A Survey of Preconditioned Iterative Methods
Publication Type | Book |
Year of Publication | 1995 |
Volume | 324 |
Publisher | Addison-Wesley Longman |
Notes | 162 p. |
Talks, contributed
Generic Software Tools for PDEs
In Invited seminar talk at the University of North Carolina, Chapel Hill, North Carolina, USA, 1995.Status: Published
Generic Software Tools for PDEs
Publication Type | Talks, contributed |
Year of Publication | 1995 |
Location of Talk | Invited seminar talk at the University of North Carolina, Chapel Hill, North Carolina, USA |
Notes | Presented by H. P. Langtangen |
Generic Software Tools for PDEs
In Invited minisymposium talk at SIAM Annual Meeting, Charlotte, North Carolina, USA, 1995.Status: Published
Generic Software Tools for PDEs
Publication Type | Talks, contributed |
Year of Publication | 1995 |
Location of Talk | Invited minisymposium talk at SIAM Annual Meeting, Charlotte, North Carolina, USA |
Notes | Presented by A. M. Bruaset |
On the Stability of Pressure and Velocity Computations for Heterogeneous Reservoirs
In Talk at the Third SIAM Conference on Mathematical and Computational Issues in the Geosciences, San Antonio, Texas, USA, 1995.Status: Published
On the Stability of Pressure and Velocity Computations for Heterogeneous Reservoirs
Publication Type | Talks, contributed |
Year of Publication | 1995 |
Location of Talk | Talk at the Third SIAM Conference on Mathematical and Computational Issues in the Geosciences, San Antonio, Texas, USA |
Notes | Presented by A. M. Bruaset |
On the Stability of Solutions of the Pressure Equation With Respect to Perturbations in the Mobility Tensor
In Talk at ICIAM 95, Hamburg, Germany, 1995.Status: Published
On the Stability of Solutions of the Pressure Equation With Respect to Perturbations in the Mobility Tensor
Publication Type | Talks, contributed |
Year of Publication | 1995 |
Location of Talk | Talk at ICIAM 95, Hamburg, Germany |
Notes | Presented by B. F. Nielsen |
Technical reports
How to Write STIM Working Notes
SINTEF, 1995.Status: Published
How to Write STIM Working Notes
Publication Type | Technical reports |
Year of Publication | 1995 |
Number | STF33 S95034 |
Publisher | SINTEF |
Journal Article
A Numerical Study of Optimized Sparse Preconditioners
BIT 34 (1994): 177-204,.Status: Published
A Numerical Study of Optimized Sparse Preconditioners
Publication Type | Journal Article |
Year of Publication | 1994 |
Journal | BIT |
Volume | 34 |
Number | 2 |
Pagination | 177-204, |
Technical reports
Diffpack Tools for Automatic Generation of Result Reports
SINTEF, 1994.Status: Published
Diffpack Tools for Automatic Generation of Result Reports
Publication Type | Technical reports |
Year of Publication | 1994 |
Number | STF33 A94057 |
Publisher | SINTEF |
Mixed Finite Element Solution of Elliptic Boundary Value Problems
SINTEF, 1994.Status: Published
Mixed Finite Element Solution of Elliptic Boundary Value Problems
Publication Type | Technical reports |
Year of Publication | 1994 |
Number | STF33 A94018 |
Publisher | SINTEF |
Talks, contributed
Object-Oriented Design of Preconditioned Iterative Methods
In Talk at the Colorado Conference on Iterative Methods, Breckenridge, Colorado, USA, 1994.Status: Published
Object-Oriented Design of Preconditioned Iterative Methods
Publication Type | Talks, contributed |
Year of Publication | 1994 |
Location of Talk | Talk at the Colorado Conference on Iterative Methods, Breckenridge, Colorado, USA |
Notes | Presented by A. M. Bruaset |
On the Application of Fourier-Based Techniques for Investigating the Performance of Preconditioners
In Talk at Second Hellenic Conference on Mathematics and Informatics (HERMIS'94), Athens, Greece, 1994.Status: Published
On the Application of Fourier-Based Techniques for Investigating the Performance of Preconditioners
Publication Type | Talks, contributed |
Year of Publication | 1994 |
Location of Talk | Talk at Second Hellenic Conference on Mathematics and Informatics (HERMIS'94), Athens, Greece |
Notes | Presented by A. M. Bruaset |
Proceedings, refereed
On the Application of Fourier-Based Techniques for Investigating the Performance of Preconditioners
In Proceedings of the Second Hellenic Conference on Mathematics and Informatics (HERMIS'94). Hellenic Mathematical Society,, 1994.Status: Published
On the Application of Fourier-Based Techniques for Investigating the Performance of Preconditioners
Publication Type | Proceedings, refereed |
Year of Publication | 1994 |
Conference Name | Proceedings of the Second Hellenic Conference on Mathematics and Informatics (HERMIS'94) |
Pagination | 301-308 |
Publisher | Hellenic Mathematical Society, |
Technical reports
Efficient Solution of Linear Equations Arising in a Nonlinear Economic Model
SINTEF, 1993.Status: Published
Efficient Solution of Linear Equations Arising in a Nonlinear Economic Model
Publication Type | Technical reports |
Year of Publication | 1993 |
Number | STF33 A93021 |
Publisher | SINTEF |
Technical reports
In 104: Naturvitenskapelig Programmeringslaboratorium
Department of Informatics, University of Oslo, 1992.Status: Published
In 104: Naturvitenskapelig Programmeringslaboratorium
Publication Type | Technical reports |
Year of Publication | 1992 |
Number | 54 |
Publisher | Department of Informatics, University of Oslo |
Notes | In Norwegian (English title: In 104: Programming laboratory for the natural sciences) |
PhD Thesis
Preconditioners for Discretized Elliptic Problems
Department of Informatics, University of Oslo, 1992.Status: Published
Preconditioners for Discretized Elliptic Problems
Publication Type | PhD Thesis |
Year of Publication | 1992 |
Publisher | Department of Informatics, University of Oslo |
Thesis Type | phd |
Notes | Available as Research Report 172 |
Journal Article
RILU Preconditioning; a Computational Study
J. Comput. Appl. Math. 39 (1992): 259-275,.Status: Published
RILU Preconditioning; a Computational Study
Publication Type | Journal Article |
Year of Publication | 1992 |
Journal | J. Comput. Appl. Math. |
Volume | 39 |
Pagination | 259-275, |
Talks, contributed
A Simplified MILU-Like Preconditioner for Elliptic Problems
In Talk at the IMACS International Symposium on Iterative Methods in Linear Algera, Brussels, Belgium, 1991.Status: Published
A Simplified MILU-Like Preconditioner for Elliptic Problems
Publication Type | Talks, contributed |
Year of Publication | 1991 |
Location of Talk | Talk at the IMACS International Symposium on Iterative Methods in Linear Algera, Brussels, Belgium |
Notes | Presented by A. M. Bruaset |
Is MILU Optimal?
In Talk at the Fifth Annual Meeting of the Nordic Society for Applied Mathematics (NORTIM), 1991.Status: Published
Is MILU Optimal?
Publication Type | Talks, contributed |
Year of Publication | 1991 |
Location of Talk | Talk at the Fifth Annual Meeting of the Nordic Society for Applied Mathematics (NORTIM) |
Notes | Presented by A. M. Bruaset |
MILU-Like Preconditioners for Elliptic Problems
In Talk at the Third Seminar on Mathematical Models and Methods in Reservoir Simulation, Ustaoset, Norway, 1991.Status: Published
MILU-Like Preconditioners for Elliptic Problems
Publication Type | Talks, contributed |
Year of Publication | 1991 |
Location of Talk | Talk at the Third Seminar on Mathematical Models and Methods in Reservoir Simulation, Ustaoset, Norway |
Notes | Presented by A. M. Bruaset |
Technical reports
A Simplified MILU-Like Preconditioner for Elliptic Problems
Center for Industrial Research, 1991.Status: Published
A Simplified MILU-Like Preconditioner for Elliptic Problems
Publication Type | Technical reports |
Year of Publication | 1991 |
Number | 91689-1 |
Publisher | Center for Industrial Research |
Journal Article
On the Stability of Relaxed Incomplete LU Factorizations
Math. Comp. 54 (1990): 701-719,.Status: Published
On the Stability of Relaxed Incomplete LU Factorizations
Publication Type | Journal Article |
Year of Publication | 1990 |
Journal | Math. Comp. |
Volume | 54 |
Pagination | 701-719, |
Master's thesis
Prekondisjonering Av Symmetriske Likningssystem
Department of Informatics, University of Oslo, 1988.Status: Published
Prekondisjonering Av Symmetriske Likningssystem
Publication Type | Master's thesis |
Year of Publication | 1988 |
Publisher | Department of Informatics, University of Oslo |
Notes | Cand.Scient. thesis (in Norwegian). English title: Preconditioning symmetric systems of equations |