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• Vestgården, Jørn Inge; Hjelmervik, Karl Thomas & Østenstad, Petter (2025). Acoustic mapping of Langmuir circulation across a coastal front. Journal of the Acoustical Society of America. ISSN 0001-4966. 158(4), p. 3250–3259. doi: 10.1121/10.0039674. Full text in Research Archive Show summary

  An experimental, acoustical study of the interplay between Langmuir turbulence, surface waves, and fronts in a Norwegian fjord was performed. A multi-beam echo sounder was mounted on the top of an autonomous underwater vehicle, and subsurface air bubbles were used as acoustic tracers. The scanned area was 1500 m along track and 300 m across track. The study found that through the trial area, there was a front with pronounced down-welling currents, down to a depth of 10 m, where Langmuir windrows formed on one side of the front, but not on the other. Based on the orientation in the fjord, the findings suggest that the bubble front coincides with a salinity front. If that is the case, it indicates that stratification prevents formation of Langmuir windrows. This article also argues that the Langmuir turbulence is augmented by the presence of swells.

• Qviller, Atle Jorstad; Qureishy, Thomas; Xu, Y; Suo, H; Mozhaev, PB & Hansen, J.B. [Show all 9 contributors for this article] (2020). Scaling Behavior of Quasi-One-Dimensional Vortex Avalanches in Superconducting Films. Scientific Reports. doi: 10.1038/s41598-020-62601-y. Full text in Research Archive Show summary

  Scaling behaviour of dynamically driven vortex avalanches in superconducting YBa2Cu3O7−δ films deposited on tilted crystalline substrates has been observed using quantitative magneto-optical imaging. Two films with different tilt angles are characterized by the probability distributions of avalanche size in terms of the number of moving vortices. It is found in both samples that these distributions follow power-laws over up to three decades, and have exponents ranging between 1.0 and 1.4. The distributions also show clear finite-size scaling, when the system size is defined by the depth of the flux penetration front – a signature of self-organized criticality. A scaling relation between the avalanche size exponent and the fractal dimension, previously derived theoretically from conservation of the number of magnetic vortices in the stationary state and shown in numerical simulations, is here shown to be satisfied also experimentally.

• Qureishy, Thomas; Vestgården, Jørn Inge; Qviller, Atle Jorstad; Fjellvåg, Asbjørn Slagtern; Meckbach, Johannes Maximilian & Torgovkin, Andrii [Show all 11 contributors for this article] (2018). Energy of dendritic avalanches in thin-film superconductors. AIP Advances. 8:085128(8), p. 085128-1–085128-8. doi: 10.1063/1.5045682. Full text in Research Archive Show summary

  A method for calculating stored magnetic energy in a thin superconducting film based on quantitative magneto-optical imaging is developed. Energy and magnetic moment are determined with these calculations for full hysteresis loops in a thin film of the superconductor NbN. Huge losses in energy are observed when dendritic avalanches occur. Magnetic energy, magnetic moment, sheet current and magnetic flux distributions, all extracted from the same calibrated magneto-optical images, are analyzed and discussed. Dissipated energy and the loss in moment when dendritic avalanches occur are related to each other. Calculating these losses for specific spatially-resolved flux avalanches is a great advantage, because of their unpredictable and non-reproducible nature. The relative losses in energy are much higher than the relative losses in moment.

• Vestgården, Jørn Inge; Johansen, Tom Henning & Galperin, Yuri (2018). Nucleation and propagation of thermomagnetic avalanches in thin-film superconductors (Review Article). Low Temperature Physics. ISSN 1063-777X. doi: 10.1063/1.5037549. Full text in Research Archive Show summary

  Stability of the vortex matter—magnetic flux lines penetrating into the material—in type-II superconductor films is crucially important for their application. If some vortices get detached from pinning centres, the energy dissipated by their motion will facilitate further depinning, and may trigger an electromagnetic breakdown. In this paper, we review recent theoretical and experimental results on development of the above mentioned thermomagnetic instability. Starting from linear stability analysis for the initial critical-state flux distribution we then discuss a numerical procedure allowing to analyze developed flux avalanches. As an example of this approach we consider ultra-fast dendritic flux avalanches in thin superconducting disks. At the initial stage the flux front corresponding to the dendrite's trunk moves with velocity up to 100 km/s. At later stage the almost constant velocity leads to a specific propagation regime similar to ray optics. We discuss this regime observed in superconducting films coated by normal strips. Finally, we discuss dramatic enhancement of the anisotropy of the flux patterns due to specific dynamics. In this way we demonstrate that the combination of the linear stability analysis with the numerical approach provides an efficient framework for understanding the ultra-fast coupled nonlocal dynamics of electromagnetic fields and dissipation in superconductor films.

• Qureishy, Thomas; Zhao, Yue; Xu, Yan; Vestgården, Jørn Inge; Johansen, Tom Henning & Grivel, Jean-Claude [Show all 8 contributors for this article] (2017). Magnetic flux channelling in YBa2Cu3O7-δ films grown by a chemical solution deposition technique on vicinal and non-vicinal substrates. Advanced Materials Letters. ISSN 0976-3961. 8, p. 1204–1210. doi: 10.5185/amlett.2017.1474. Full text in Research Archive Show summary

  Magneto-optical imaging of YBa2Cu3O7-δ films with high critical current density, synthesized by a cost-effective metal organic decomposition technique reveals inhomogeneous flux penetration in the specimens in the form of thin parallel lines. The origin of such a stripy pattern and its dependence on the sample preparation conditions and state of substrate is discussed. The stripes reflect accumulation of planar defects forming parallel lines of reduced in-plane critical current density, jc , perpendicular to planar defects and enhanced jc parallel to them. Such channel-like reduction and corresponding enhancement of jc is especially expressed in a sample deposited on vicinal substrate, which, as a consequence, demonstrates global temperature-dependent in-plane anisotropy with an anisotropy ratio up to 2.4. The directional enhancement of critical current density due to planar defects could be beneficial for practical use of superconducting films.

• Qureishy, Thomas; Laliena, Carlos; Martínez, Elena; Qviller, Atle Jorstad; Vestgården, Jørn Inge & Johansen, Tom Henning [Show all 8 contributors for this article] (2017). Dendritic flux avalanches in a superconducting MgB2 tape. Superconductors Science and Technology. ISSN 0953-2048. doi: 10.1088/1361-6668/aa9244. Full text in Research Archive Show summary

  Tapes of MgB2 with high critical current have a significant technological potential, but can experience operational breakdown due to thermomagnetic instabilities. Such events are routinely registered by magnetisation measurements, but were never observed by direct imaging techniques. Here we report magneto-optical imaging visualisation of a tape with reduced thickness and enhanced critical current density. The spatial structure of the thermomagnetic avalanche events was resolved, and the reproducibility and nucleation thresholds were determined. Avalanches appearing at low fields are small intrusions at the tape edges, while larger fields create more extensive avalanches having dendritic structures similar to those observed in thin-film superconductors. In contrast to dendritic avalanches in thin films, the avalanches in the tapes show reproducibility to a larger extent.

• Vestgården, Jørn Inge; Hjelmervik, Karl Thomas; Stender, Dan Henrik Sekse & Berg, Henrik (2017). Sonar scattering from the sea bottom near the Norwegian coast. OCEANS. ISSN 0197-7385. Full text in Research Archive Show summary

  High false alarm rates on active sonar systems in shallow waters is a well known problem which may be a limiting factor for the sonar performance. One way to reduce the false alarm rate is through supervised learning and machine learning algorithms applying relevant classification features. Here we propose backscatter intensity as a classification feature. It is calculated from a topographical map under the assumption of omnidirectional scattering for sound, an unrefracted path and iso-velocity sound speed profile. Analysis of historic data for a towed array sonar near the Norwegian coast showed that clutter echoes to a large extent was located at cliffs, escarpments and ridges where the calculated backscatter intensity was high. With a simple thresholding of the estimated backscatter intensity one can correctly classify 60% of terrain echoes at the expense of 10% potential target echo misclassification rate. The classification rate rises to 75% for the echoes of highest signal-to-noise ratio. The proposed classification feature is computationally inexpensive and does not depend on free parameters.

• Mikheenko, Pavlo; Vestgården, Jørn Inge; Chaudhuri, Saumyadip; Maasilta, Ilari J.; Galperin, Yuri & Johansen, Tom Henning (2016). Metal frame as local protection of superconducting films from thermomagnetic avalanches. AIP Advances. 6:032304. doi: 10.1063/1.4943549. Full text in Research Archive Show summary

  Thermomagnetic avalanches in superconducting films propagating extremely fast while forming unpredictable patterns, represent a serious threat for the performance of devices based on such materials. It is shown here that a normal-metal frame surrounding a selected region inside the film area can provide efficient protection from the avalanches during their propagation stage. Protective behavior is confirmed by magneto-optical imaging experiments on NbN films equipped with Cu and Al frames, and also by performing numerical simulations. Experimentally, it is found that while conventional flux creep is not affected by the frames, the dendritic avalanches are partially or fully screened by them. The level of screening depends on the ratio of the sheet conductance of the metal and the superconductor in the resistive state, and for ratios much larger than unity the screening is very efficient.

• Vestgården, Jørn Inge; Galperin, Yuri & Johansen, Tom Henning (2016). Oscillatory regimes of the thermomagnetic instability in superconducting films. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. doi: 10.1103/PhysRevB.93.174511. Full text in Research Archive Show summary

  The stability of superconducting films with respect to oscillatory precursor modes for thermomagnetic avalanches is investigated theoretically. The results for the onset threshold show that previous treatments of nonoscillatory modes have predicted much higher thresholds. Thus, in film superconductors, oscillatory modes are far more likely to cause thermomagnetic breakdown. This explains the experimental fact that flux avalanches in film superconductors can occur even at very small ramping rates of the applied magnetic field. Closed expressions for the threshold magnetic field and temperature, as well oscillation frequency, are derived for different regimes of the oscillatory thermomagnetic instability.

• Vestgården, Jørn Inge; Colauto, Fabiano; Andrade, AMH de; Oliveira, AAM; Ortiz, W. A. & Johansen, Tom Henning (2015). Cascade dynamics of thermomagnetic avalanches in superconducting films with holes. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. doi: 10.1103/PhysRevB.92.144510. Full text in Research Archive Show summary

  The submicrosecond dynamics of thermomagnetic avalanches in superconducting films with nonconducting holes (antidots) is considered. When such an avalanche reaches a hole, it is quickly filled with magnetic flux, and often its rim becomes unstable and a second avalanche is nucleated. In this work the time- and space-resolved behavior of such cascading avalanche behavior is determined using numerical simulations. Results are presented for films with holes of different shape. It is found that holes with sharp corners are those that most frequently create secondary avalanches, and they tend to nucleate in corners. Magneto-optical imaging of Nb films patterned with the same set of holes strongly supports the numerical results.

• Vestgården, Jørn Inge; Mikheenko, Pavlo; Galperin, Yuri & Johansen, Tom Henning (2014). Inductive braking of thermomagnetic avalanches in superconducting films. Superconductors Science and Technology. ISSN 0953-2048. 27(5). doi: 10.1088/0953-2048/27/5/055014. Full text in Research Archive
• Motta, Maycon; Colauto, Fabiano; Vestgården, Jørn Inge; Fritzsche, Joachim; Timmermans, Matias & Cuppens, Jo [Show all 13 contributors for this article] (2014). Controllable morphology of flux avalanches in microstructured superconductors. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 89:135408(13). doi: 10.1103/PhysRevB.89.134508. Full text in Research Archive
• Vestgården, Jørn Inge; Mikheenko, Pavlo; Galperin, Yuri & Johansen, Tom Henning (2013). Nonlocal electrodynamics of normal and superconducting films. New Journal of Physics. 15. doi: 10.1088/1367-2630/15/9/093001. Full text in Research Archive
• Vestgården, Jørn Inge; Galperin, Yuri & Johansen, Tom Henning (2013). The Thermomagnetic Instability in Superconducting Films with Adjacent Metal Layer. Journal of Low Temperature Physics. ISSN 0022-2291. 173(5-6), p. 303–326. doi: 10.1007/s10909-013-0899-1. Full text in Research Archive
• Mikheenko, Pavlo; Qviller, Atle Jorstad; Vestgården, Jørn Inge; Chaudhuri, S.; Maasilta, IJ & Galperin, Yuri [Show all 7 contributors for this article] (2013). Nanosecond voltage pulses from dendritic flux avalanches in superconducting NbN films. Applied Physics Letters. ISSN 0003-6951. 102(2), p. 022601-1–022601-3. doi: 10.1063/1.4775693. Full text in Research Archive Show summary

  Combined voltage and magneto-optical study of magnetic flux flow in superconducting NbN films is reported. The nanosecond-scale voltage pulses appearing during thermomagnetic avalanches have been recorded in films partially coated by a metal layer. Simultaneous magneto-optical imaging and voltage measurements allowed the pulses to be associated with individual flux branches penetrating the superconductor below the metal coating. From detailed characteristics of pulse and flux branches, the electrical field in the superconductor is found to be in the range of 5-50 kV/m, while the propagation speed of the avalanche during its final stage is found to be close to 5 km/s. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.

• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2013). The diversity of flux avalanche patterns in superconducting films. Superconductors Science and Technology. ISSN 0953-2048. 26(5). doi: 10.1088/0953-2048/26/5/055012. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2012). Lightning in superconductors. Scientific Reports. 2, p. Art.Nr.–886. doi: 10.1038/srep00886. Full text in Research Archive
• Vestgården, Jørn Inge & Johansen, Tom Henning (2012). Modeling non-local electrodynamics in superconducting films: the case of a right angle corner. Superconductors Science and Technology. ISSN 0953-2048. 25(10). doi: 10.1088/0953-2048/25/10/104001. Full text in Research Archive
• Vestgården, Jørn Inge; Yurchenko, Vitaliy; Wördenweber, Roger & Johansen, Tom Henning (2012). Mechanism for flux guidance by micrometric antidot arrays in superconducting films. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 85(1). doi: 10.1103/PhysRevB.85.014516. Full text in Research Archive
• Galperin, Yuri; Vestgården, Jørn Inge & Johansen, Tom Henning (2012). Dendritic flux avalanches in rectangular superconducting films - Numerical simulations. Physica. C, Superconductivity. ISSN 0921-4534. 479, p. 92–94. doi: 10.1016/j.physc.2011.12.019. Full text in Research Archive
• Qviller, Atle Jorstad; Yurchenko, Vitaliy; Galperin, Yuri; Vestgården, Jørn Inge; Mozhaev, Peter & Hansen, Jørn Bindslev [Show all 7 contributors for this article] (2012). Quasi-One-Dimensional Intermittent Flux Behavior in Superconducting Films. Physical Review X. 2(1). doi: 10.1103/PhysRevX.2.011007. Full text in Research Archive
• Mikheenko, Pavlo; Yurchenko, Vitaliy; Tanner, John L.; Qviller, Atle Jorstad; Galperin, Yuri & Vestgården, Jørn Inge [Show all 8 contributors for this article] (2012). Magneto-optical imaging of columnar YBCO films. Physics Procedia. 36, p. 623–628. doi: 10.1016/j.phpro.2012.06.179. Full text in Research Archive Show summary

  The columnar growth of superconducting films is a new approach that provides high density of evenly distributed extended defects on the nanometer scale. This growth can be activated by tightly-packed nanoparticles deposited on substrate prior to the pulse deposition of superconducting film. The magnetization measurements demonstrate that critical current density (Jc) in columnar films is higher than in common epitaxial films. However, in magnetization measurements calculation of Jc is model sensitive. An assumption of ideal critical state frequently proves to be wrong giving incorrect Jc averaged over the entire sample. Missing details of current distribution can be obtained by magneto-optical imaging (MOI) that also allows obtaining local Jc in the samples. In this paper we report MOI study of previously not imaged relatively thick (about one micrometer) columnar YBa2Cu3Ox films in order to clarify if they fit a critical state model and to what extent their properties are modified by the columnar growth. MOI demonstrates a homogeneous penetration of magnetic flux that fits a critical state model. The long-length influence of defects, especially those residing on the edges is less pronounced in columnar than in common epitaxial films. The measurement of the depth of flux front at partial flux penetration allows estimating average low-field Jc, which is in good agreement with extrapolated magnetization measurements. The spatial details of the distribution of magnetic flux provide valuable information for tailoring deposition parameters in order to obtain highest possible value of Jc. MOI could be an ideal tool for measuring Jc when other methods are not available or not appropriate. Using MOI and magnetometry, an important effect of the increase in Jc in aged columnar films has been observed.

• Galperin, Yuri; Mozhaev, PB; Mozhaeva, JE; Hansen, JB; Jacobsen, CS & Qviller, Atle Jorstad [Show all 9 contributors for this article] (2011). Intermittent Flux Penetration at Different Temperatures in YBa2Cu3O7-x on NdGaO3 Substrates. Journal of Superconductivity and Novel Magnetism. ISSN 1557-1939. 24(1-2), p. 179–181. doi: 10.1007/s10948-010-0915-5. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2011). Dynamics and morphology of dendritic flux avalanches in superconducting films. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 84(5), p. 054537–054537. doi: 10.1103/PhysRevB.84.054537. Full text in Research Archive
• Qviller, Atle Jorstad; Yurchenko, Vitaliy; Eliassen, Karl Emil; Vestgården, Jørn Inge; Johansen, Tom Henning & Nevala, MR [Show all 9 contributors for this article] (2010). Irreversibility of the threshold field for dendritic flux avalanches in superconductors. Physica. C, Superconductivity. ISSN 0921-4534. 470(19), p. 897–900. doi: 10.1016/j.physc.2010.02.066. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2008). Flux distribution in superconducting films with holes. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 77. doi: 10.1103/PhysRevB.77.014521. Full text in Research Archive
• Vestgården, Jørn Inge; Bergli, Joakim & Galperin, Yuri (2008). Nonlinearly driven Landau-Zener transition in a qubit with telegraph noise. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 77. doi: 10.1103/PhysRevB.77.014514. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Olsen, Åge Andreas Falnes; Galperin, Yuri; Yurchenko, Vitaliy & Goa, Pål Erik [Show all 7 contributors for this article] (2007). Interaction between superconducting vortices and a bloch wall in ferrite garnet films. Physical Review Letters. ISSN 0031-9007. 98. doi: 10.1103/PhysRevLett.98.117002. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2007). Flux penetration in a superconducting strip with an edge indentation. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 76, p. 174509–174509. doi: 10.1103/PhysRevB.76.174509. Full text in Research Archive
• Yurchenko, Vitaliy; Wordenweber, R; Galperine, Iouri; Shantsev, Daniil; Vestgården, Jørn Inge & Johansen, Tom Henning (2006). Magneto-optical imaging of magnetic flux patterns in superconducting films with antidots. Physica. C, Superconductivity. ISSN 0921-4534. 437-38, p. 357–360. Full text in Research Archive
• Tjøstheim, Ingvar; Thalberg, Svein; Nordlund, Bjørn Kristian & Vestgården, Jørn Inge (2005). Are the mobilephone users ready for MCASI - mobile computer assisted self-interviewing. Ukjent. p. 465–488. Full text in Research Archive
• Tjøstheim, Ingvar; Nordlund, Bjørn Kristian & Vestgården, Jørn Inge (2004). Location-based mobile services and privacy - controlling access to location information. Ukjent. Full text in Research Archive
• Tjøstheim, Ingvar; Thalberg, Svein; Nordlund, Bjørn Kristian & Vestgården, Jørn Inge (2004). Are the mobile phone users ready for MCASI - mobile computer-assisted self-interviewing? Ukjent. Full text in Research Archive
• Aredo, Demissie; Rivertz, Hans Jakob & Vestgården, Jørn Inge (2003). LBS System Architecture with Privacy. Ukjent. 2003, p. 6–6. Full text in Research Archive

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• Hjelmervik, Karl Thomas; Berg, Henrik; Stender, Dan Henrik Sekse; Andreassen, Kristoffer Engedal; Dombestein, Elin Margrethe Bøhler & Vestgården, Jørn Inge (2020). Bayesian occupancy grid for active sonar detection and localization of moving targets. Full text in Research Archive
• Hjelmervik, Karl Thomas; Berg, Henrik; Stender, Dan Henrik Sekse; Andreassen, Kristoffer Engedal; Dombestein, Elin Margrethe Bøhler & Vestgården, Jørn Inge (2020). Bayesian occupancy grid for active sonar detection and localization of moving targets. OCEANS. ISSN 0197-7385. doi: 10.1109/IEEECONF38699.2020.9389044. Full text in Research Archive Show summary

  Active sonar performance is highly dependent on the surrounding environment. Conventional detection algorithms apply thresholds to acoustic data passed through a normalizer in order to detect targets. These methods fail to fully exploit available knowledge of the environment, which leads to higher false alarm rates than necessary, particularly in littoral environments. Furthermore, they do not exploit negative information, e.g. the significance of the repeated lack of threshold crossings in a given area. Sonar performance models may estimate both the probability of detection and false alarm in a known environment. Proper exploitation of this data allows for reduced false alarm rates in cluttering and reverberating environments. Furthermore, areas lacking threshold crossings and with high probability of detection, may be classified as target free. Bayesian occupancy grids is a probabilistic approach that takes into account both sensor information and prior information of surrounding walls or topography for localization of robots. Here we apply the method on synthetic sonar data combined with a sonar performance model. The synthetic sonar data contains moving and stationary targets in a littoral environment. The method's performance is compared to conventional algorithms, and its robustness to errors in the sound speed profile used in the modelling is assessed.

• Qureishy, Thomas; Laliena, Carlos; Martínez, Elena; Qviller, Atle Jorstad; Vestgården, Jørn Inge & Johansen, Tom Henning [Show all 8 contributors for this article] (2018). Magneto-optical imaging of dendritic flux avalanches in a superconducting MgB2 tape. Full text in Research Archive
• Mikheenko, Pavlo; Vestgården, Jørn Inge; Tyse, Knut & Johansen, Tom Henning (2017). Magneto-optical imaging of superconductors: science and applications. Full text in Research Archive
• Qureishy, Thomas; Zhao, Yue; Xu, Yan; Vestgården, Jørn Inge; Johansen, Tom Henning & Grivel, Jean-Claude [Show all 8 contributors for this article] (2017). Visualisation of magnetic flux in high-quality YBCO films synthesized by cost-effective environmental-friendly techniques. Full text in Research Archive
• Vestgården, Jørn Inge; Hjelmervik, Karl Thomas; Stender, Dan Henrik Sekse & Berg, Henrik (2017). Sonar scattering from the sea bottom near the Norwegian coast. Full text in Research Archive
• Såstad, Tale Solberg; Dombestein, Elin Margrethe Bøhler; Hermansen, Fredrik; Hjelmervik, Karl Thomas; Kloster, Morten & Langset, Frode [Show all 9 contributors for this article] (2016). SIMSON - visualization and analysis of ASW sonar data. Full text in Research Archive
• Såstad, Tale Solberg; Hermansen, Fredrik; Hjelmervik, Karl Thomas; Kloster, Morten; Langset, Frode & Oxholm, Wenche [Show all 8 contributors for this article] (2016). SIMSON – a sonar analysis tool for Underwater Warfare. Full text in Research Archive
• Vestgården, Jørn Inge; Karlsen, Marcus; Synnes, Stig Asle Vaksvik & Lorentzen, Ole J. (2016). Ship Wake Signatures measured by AUV with upward looking high-frequency sonar. Full text in Research Archive
• Qureishy, Thomas; Zhao, Yue; Xu, Y; Vestgården, Jørn Inge; Johansen, Tom Henning & Grivel, Jean-Claude [Show all 8 contributors for this article] (2016). Magnetic flux channelling in YBa2Cu3O7-δ films. Full text in Research Archive
• Mikheenko, Pavlo; Vestgården, Jørn Inge; Chaudhuri, S.; Maasilta, IJ; Galperin, Yuri & Cardwell, David A. [Show all 14 contributors for this article] (2015). Magneto-Optical Imaging: a tool for fundamental physics and applications of superconductivity. Full text in Research Archive
• Qureishy, Thomas Håbu; Tyse, Knut; Zhao, Yue; Vestgården, Jørn Inge; Grivel, Jean-Claude & Johansen, Tom Henning [Show all 7 contributors for this article] (2015). Local critical current density in YBa2Cu3O7-δ films. Full text in Research Archive
• Galperin, Yuri; Johansen, Tom Henning & Vestgården, Jørn Inge (2014). Magnetic dendrites in superconductors. Full text in Research Archive
• Mikheenko, Pavlo; Vestgården, Jørn Inge; Chaudhuri, S.; Maasilta, IJ; Galperin, Yuri & Johansen, Tom Henning (2014). Complex flux flow in superconducting films. Full text in Research Archive
• Johansen, Tom Henning; Galperin, Yuri; Vestgården, Jørn Inge & Mikheenko, Pavlo (2013). Lightning in superconductors. Full text in Research Archive
• Mikheenko, Pavlo; Qviller, Atle Jorstad; Vestgården, Jørn Inge; Chaudhuri, S.; Maasilta, IJ & Galperin, Yuri [Show all 7 contributors for this article] (2013). Magnetic flux avalanches in superconducting films. Full text in Research Archive
• Silhanek, A. V.; Motta, M.; Colauto, F.; Fritsche, J.; Vestgården, Jørn Inge & Moshchalkov, V. V. [Show all 8 contributors for this article] (2013). Current crowding effects in nanostructured superconductors. Full text in Research Archive
• Mikheenko, Pavlo; Yurchenko, Vitaliy; Qviller, Atle Jorstad; Galperin, Yuri; Vestgården, Jørn Inge & Johansen, Tom Henning (2011). Magneto-optical imaging of advanced superconductors. Full text in Research Archive
• Yurchenko, Vitaliy; Qviller, Atle Jorstad; Mikheenko, Pavlo; Vestgården, Jørn Inge; Galperin, Yuri & Johansen, Tom Henning (2011). High speed magneto-optical imaging of flux dynamics in superconductors. Full text in Research Archive
• Yurchenko, Vitaliy; Qviller, Atle Jorstad; Mikheenko, Pavlo; Galperin, Yuri; Vestgården, Jørn Inge & Johansen, Tom Henning (2011). Visualization of magnetic flux avalanches in superconductors: dynamic vs. thermo-magnetic avalanches. Full text in Research Archive
• Yurchenko, Vitaliy; Qviller, Atle Jorstad; Mikheenko, Pavlo; Vestgården, Jørn Inge; Shantsev, Daniil & Baziljevich, Michael [Show all 8 contributors for this article] (2011). Experimental observation of dendritic flux avalanches in superconducting films. Full text in Research Archive
• Yurchenko, Vitaliy; Qviller, Atle Jorstad; Galperin, Yuri; Vestgården, Jørn Inge & Johansen, Tom Henning (2011). Magneto-optical Imaging of Flux Distribution in Superconducting Pnictide Films. Full text in Research Archive
• Mikheenko, Pavlo; Yurchenko, Vitaliy; Tanner, John L.; Qviller, Atle Jorstad; Galperin, Yuri & Vestgården, Jørn Inge [Show all 8 contributors for this article] (2011). Magneto-optical imaging of columnar YBCO films. Full text in Research Archive
• Qviller, Atle Jorstad; Yurchenko, Vitaliy; Vestgården, Jørn Inge & Johansen, Tom Henning (2010). Flux penetration in YBCO on miscut substrates. Full text in Research Archive
• Abie, Habtamu & Vestgården, Jørn Inge (2008). Meldingsformidling er en milliardbransje - i euro! ComputerWorld Norge. ISSN 1501-6595. Full text in Research Archive
• Yurchenko, Vitaliy; Woerdenweber, R.; Galperin, Yuri; Shantsev, Daniil; Vestgården, Jørn Inge & Johansen, Tom Henning (2006). Magneto-Optical Imaging of Guided Vortex Motion in YBCO Films with One-dimensional Antidot Arrays. Full text in Research Archive
• Johansen, Tom Henning; Vestgården, Jørn Inge; Olsen, Åge Andreas Falnes; Shantsev, Daniil; Goa, Pål Erik & Galperin, Yuri (2006). Magneto-Optical Observation of Vortices in Superconductors. Full text in Research Archive
• Yurchenko, Vitaliy; Woerdenweber, R.; Vestgården, Jørn Inge; Galperin, Yuri; Shantsev, Daniil & Johansen, Tom Henning (2006). Direct experimental visualization of magnetic flux guidance in artificially patterned YBa_2Cu_3O_7-x thin films. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Johansen, Tom Henning; Galperin, Yuri; Goa, Pål Erik & Yurchenko, Vitaliy (2006). Vortices interacting with domain wall in magneto-optical film. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Olsen, Åge Andreas Falnes; Johansen, Tom Henning & Goa, Pål Erik (2006). Domain wall - vortex interaction. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Olsen, Åge Andreas Falnes; Galperin, Yuri; Yurchenko, Vitaliy & Goa, Pål Erik [Show all 7 contributors for this article] (2006). Interaction Between a Magnetic Domain Wall and Superconducting Vortices. Full text in Research Archive
• Shantsev, Daniil; Yurchenko, Vitaliy; Vestgården, Jørn Inge; Olsen, Åge Andreas Falnes; Goa, Pål Erik & Johansen, Tom Henning [Show all 7 contributors for this article] (2006). Superconducting and magnetic nanodevices. Full text in Research Archive
• Yurchenko, V. V.; Galperin, Yuri; Vestgården, Jørn Inge; Johansen, Tom Henning & Woerdenweber, R. (2005). Visualization of guided flux motion in mesoscopically patterned high temperature superconductors. Full text in Research Archive
• Vestgården, Jørn Inge; Shantsev, Daniil; Galperin, Yuri & Johansen, Tom Henning (2005). Flux Penetration in Thin Superconductors with Holes: Simulations. Full text in Research Archive
• Vogt, Yngve; Arnesen, Ragni Ryvold & Vestgården, Jørn Inge (2002). Krypterer på mobiltelefon. Ukjent. Full text in Research Archive
• Røe, Per; Arnesen, Ragni Ryvold; Danielsson, Jerker; Vestgården, Jørn Inge; Rivertz, Hans Jakob & Boudko, Svetlana [Show all 7 contributors for this article] (2012). TrueGen 4.0 Design. Norsk Regnesentral. Full text in Research Archive
• Danielsson, Jerker; Vestgården, Jørn Inge; Røe, Per; Kristoffersen, Thor & Boudko, Svetlana (2012). TrueGen 4.0 User Guide. Norsk Regnesentral. Full text in Research Archive
• Røe, Per; Vestgården, Jørn Inge & Kristoffersen, Thor (2012). TrueGen 4.0 Developer’s Guide. Norsk Regnesentral. Full text in Research Archive
• Abie, Habtamu; Vestgården, Jørn Inge; Kristoffersen, Thor & Novkovic, Milan (2009). D.4.4 – Integration with JMS, Tibco’s, Reuters, and IBM’s MQ Series. Full text in Research Archive
• Abie, Habtamu & Vestgården, Jørn Inge (2009). D6.3 - Security Implementation. Full text in Research Archive
• Abie, Habtamu; Vestgården, Jørn Inge; Leister, Wolfgang; Bigham, John; Blasi, Lorenzo & Topham, Shaun [Show all 19 contributors for this article] (2008). D6.1 - QoS and Security Requirements Specification. Full text in Research Archive
• Novkovic, Milan; Dattani, Ilesh; Abie, Habtamu; Vestgården, Jørn Inge; Leister, Wolfgang & Bigham, John [Show all 12 contributors for this article] (2008). D5.1 – Design Document for Broker Managing Agent. Full text in Research Archive
• Abie, Habtamu; Vestgården, Jørn Inge; Leister, Wolfgang; Bigham, John; Karppinen, Kaarina & Savola, Reijo M. [Show all 12 contributors for this article] (2008). D6.2 – Trust Model and Security Architecture. Full text in Research Archive
• Vestgården, Jørn Inge; Galperin, Yuri & Shantsev, Daniil (2007). Magnetic dynamics in superconducting films and devices. Universitetet i Oslo. Full text in Research Archive
• Arnesen, Ragni Ryvold; Danielsson, Jerker; Vestgården, Jørn Inge & Ølnes, Jon (2005). Wireless Health and Care Security Architecture. Norsk Regnesentral. ISSN 9788253905143. Full text in Research Archive Show summary

  This document describes the general security architecture of the Wireless Health and Care project (WsHC). First a system model that encompasses all the demonstrators in the project is described; next, a corresponding security architecture is proposed. Finally, the security requirements on the elements of the system model, listed in the document “WsHC Security Requirements” ([1]), are discussed with respect to the proposed security architecture.

• Leister, Wolfgang; Mazaher, Shahrzade; Vestgården, Jørn Inge; Johansen, Bent Østebø & Nordlund, Bjørn Kristian (2004). Grid and related technologies. Norsk Regnesentral. Full text in Research Archive
• Arnesen, Ragni Ryvold; Danielsson, Jerker; Vestgården, Jørn Inge & Ølnes, Jon (2004). WsHC Security Requirements. Norsk Regnesentral. Full text in Research Archive
• Kristoffersen, Thor; Vestgården, Jørn Inge & Rivertz, Hans Jakob (2004). Design and Implementation of the Channel-S Streaming System. Norsk Regnesentral. Full text in Research Archive
• Leister, Wolfgang; Røe, Per; Vestgården, Jørn Inge & Aamot, Ole (2003). mediAkit and the NR Open Source Software Center. Norsk Regnesentral. ISSN 9788253905037. Full text in Research Archive
• Arnesen, Ragni Ryvold; Huseby, Ragnar Bang; Rivertz, Hans Jakob; Røe, Per; Snekkenes, Einar & Vestgården, Jørn Inge (2002). Replacement of random number generator in Norsk Tipping's random number draw system. Norsk Regnesentral. Full text in Research Archive
• Arnesen, Ragni Ryvold; Aredo, Demissie; Huseby, Ragnar Bang; Rivertz, Hans Jakob; Rue, Håvard & Snekkenes, Einar [Show all 7 contributors for this article] (2001). Random Number Draw System - Design. Norsk Regnesentral. Full text in Research Archive

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