• Automatic Grading of Retinal Blood Vessel in Deep Retinal Image Diagnosis 

      Debasis, Maji; Sekh, Arif Ahmed (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-01)
      Automatic grading of retinal blood vessels from fundus image can be a useful tool for diagnosis, planning and treatment of eye. Automatic diagnosis of retinal images for early detection of glaucoma, stroke, and blindness is emerging in intelligent health care system. The method primarily depends on various abnormal signs, such as area of hard exudates, area of blood vessels, bifurcation points, ...
    • Automatic question generation and answer assessment: a survey 

      Das, Bidyut; Majumder, Mukta; Phadikar, Santanu; Sekh, Arif Ahmed (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-18)
      Learning through the internet becomes popular that facilitates learners to learn anything, anytime, anywhere from the web resources. Assessment is most important in any learning system. An assessment system can find the self-learning gaps of learners and improve the progress of learning. The manual question generation takes much time and labor. Therefore, automatic question generation from learning ...
    • Automatic Selection of Relevant Attributes for Multi-Sensor Remote Sensing Analysis: A Case Study on Sea Ice Classification 

      Khachatrian, Eduard; Chlaily, Saloua; Eltoft, Torbjørn; Dierking, Wolfgang Fritz Otto; Dinessen, Frode; Marinoni, Andrea (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-26)
      It is of considerable benefit to combine information obtained from different satellite sensors to achieve advanced and improved characterization of sea ice conditions. However, it is also true that not all the information is relevant. It may be redundant, corrupted, or unnecessary for the given task, hence decreasing the performance of the algorithms. Therefore, it is crucial to select an optimal ...
    • An Automatic U-distribution and Markov Random Field Segmentation Algorithm for PolSAR Images 

      Doulgeris, Anthony Paul (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
    • Axial and radial development of the hot electron distribution in a helicon plasma source, measured by a retarding field energy analyzer (RFEA) 

      Buschmann, Lisa Marie; Fredriksen, Åshild (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-10)
      The information about the electron population of a helicon source plasma that expands along a magnetic nozzle is important for understanding the plasma acceleration across the potential drop that forms in the nozzle. The electrons need an energy higher than the potential drop to escape from the source. At these energies the signal of a Langmuir probe is less accurate. An inverted RFEA measures the ...
    • Barents-2.5km v2.0: an operational data-assimilative coupled ocean and sea ice ensemble prediction model for the Barents Sea and Svalbard 

      Röhrs, Johannes; Gusdal, Yvonne; Rikardsen, Edel S. U.; Durán Moro, Marina; Brændshøi, Jostein; Kristensen, Nils Melsom; Fritzner, Sindre Markus; Wang, Keguang; Sperrevik, Ann Kristin; Idzanovic, Martina; Lavergne, Thomas; Debernard, Jens Boldingh; Christensen, Kai Håkon (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-22)
      An operational ocean and sea ice forecast model, Barents-2.5, is implemented for short-term forecasting at the coast off northern Norway, the Barents Sea, and the waters around Svalbard. Primary forecast parameters are sea ice concentration (SIC), sea surface temperature (SST), and ocean currents. The model also provides input data for drift modeling of pollutants, icebergs, and search-and-rescue ...
    • The behavior of electron density and temperature during ionospheric heating near the fifth electron gyrofrequency 

      Wu, Jun; Wu, Jian; Rietveld, Michael T.; Häggström, I.; Zhao, Haisheng; Xu, Zhengwen (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-27)
      The experimental phenomena involving the changes in electron temperature and electron density as a function of pump frequency during an ionospheric heating campaign at European Incoherent Scatter near Tromsø, Norway, are reported. When the pump frequency is slightly above the fifth electron gyrofrequency, the UHF radar observation shows some apparent enhancements over a wide altitude range in radar ...
    • Better synoptic and subseasonal sea ice thickness predictions are urgently required: a lesson learned from the YOPP data validation 

      Yang, Qinghua; Xiu, Yongwu; Luo, Hao; Wang, Jinfei; Landy, Jack Christopher; Bushuk, Mitchell; Wang, Yiguo; Liu, Jiping; Chen, Dake (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-20)
      In the context of global warming, Arctic sea ice has declined substantially during the satellite era (Kwok 2018). The retreating and thinning of Arctic sea ice provide opportunities for human activities in the Arctic, such as tourism, fisheries, shipping, natural resource exploitation, and wildlife management; however, new risks emerge. To ensure the safety and emergency management of human activities ...
    • Beyond the grid: The promise of solar concentration for non-electrical energy generation 

      Apostoleris, Harry; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-09)
      As electricity from both photovoltaics and concentrating solar power has become dramatically more affordable in the last several years, the prospect of converting entire national electrical grids to run almost entirely on renewable energy has become feasible in any location with a strong solar resource. However, focusing only on the electric grid neglects the large portion of our energy usage which ...
    • Bistatic Observations of the Ocean Surface with HF Radar, Satellite and Airborne Receivers 

      Bernhardt, Paul A.; Siefring, Carl; Briczinski, Stanley; Vierinen, Juha; Miller, Ethan; Howarth, Andrew; James, H. Gordon; Blincoe, Eugene (Peer reviewed; Book; Bok; Bokkapittel; Chapter, 2017-12-25)
      A new concept has been developed which can view vast regions of the Earth's surface. Ground HF transmissions are reflected by the ionosphere to illuminate the ocean over a few thousand kilometers. HF receivers detect the radio waves scattered by the sea and land surface. Using the theory of radio wave scatter from ocean surfaces, the HF data is then processed to yield the directional wave-height ...
    • Bistatic Observations of the Ocean Surface with HF Radar, Satellite and Airborne Receivers 

      Bernhardt, Paul A.; Siefring, Carl L.; Briczinski, Stanley C.; Vierinen, Juha; Miller, Ethan; Howarth, Andrew; James, H. Gordon; Blincoe, Eugene (Journal article; Peer reviewed, 2017-12-25)
      A new concept has been developed which can view vast regions of the Earth’s surface. Ground HF transmissions are reflected by the ionosphere to illuminate the ocean over a few thousand kilometers. HF receivers detect the radio waves scattered by the sea and land surface. Using the theory of radio wave scatter from ocean surfaces, the HF data is then processed to yield the directional wave-height ...
    • Blind Super-Resolution Approach for Exploiting Illumination Variety in Optical-Lattice Illumination Microscopy 

      Samanta, Krishnendu; Sarkar, Swagato; Acuña, Sebastian; Joseph, Joby; Ahluwalia, Balpreet Singh; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-19)
      Optical-lattice illumination patterns help in pushing high spatial frequency components of the sample into the optical transfer function of a collection microscope. However, exploiting these high-frequency components require precise knowledge of illumination if reconstruction approaches similar to structured illumination microscopy are employed. Here, we present an alternate blind reconstruction ...
    • Blob interactions in 2D scrape-off layer simulations 

      Decristoforo, Gregor; Militello, Fulvio; Nicholas, Thomas; Omotani, John; Marsden, Chris; Walkden, Nick; Garcia, Odd Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-01)
      Interaction of coherent structures known as blobs in the scrape-off layer of magnetically confined plasmas is investigated. Isolated and interacting seeded blobs, as well as full plasma turbulence, are studied by two-dimensional numerical simulations. The features of the blobs (position, size, amplitude) are determined with a blob tracking algorithm, which identifies them as coherent structures with ...
    • Blob shapes in the scrape-off layer: Comparison of measurements to simulations 

      Kube, Ralph; Garcia, Odd Erik; Theodorsen, Audun; Brunner, Dan; Kuang, Adam; LaBombard, Brian; Terry, Jim L. (Conference object; Konferansebidrag, 2017)
    • Blob sizes and velocities in the Alcator C-Mod scrape-off layer 

      Kube, Ralph; Garcia, Odd Erik; LaBombard, Brian; Terry, J.L; Zweben, Stewart (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Gas-puff imaging data is used to investigate the dynamics of blob-like structures in the scrape-off layer of Alcator C-Mod. A blob-tracking algorithm is developed and used to compute blob propagation velocities and cross-field sizes for a series of discharges where the line-averaged particle density View the MathML source is varied. We find that the mean radial blob velocity increases from View the ...
    • Blob Sizes and Velocities in the Alcator C-Mod Scrape-Off Layer 

      Kube, Ralph; Garcia, Odd Erik; LaBombard, Brian; Madsen, Jens; Terry, James L.; Zweben, Stewart (Conference object; Konferansebidrag, 2012)
      A new blob-tracking algorithm for the GPI diagnostic installed in the outboard-midplane of Alcator C-Mod is developed. I t tracks large-amplitude fluctuations propagating through the scrape-off layer and calculates blob sizes and velocities. We compare the results of this method to a blob velocity scaling from a simple blob-model for sheath-connected blobs. We further present initial results from a ...
    • Borealis: An Advanced Digital Hardware and Software Design for SuperDARN Radar Systems 

      McWilliams, K.A.; Detwiller, M.; Kotyk, K.; Krieger, K.; Rohel, R.; Billett, D.D.; Huyghebaert, Devin Ray; Ponomarenko, P. (Journal article; Tidsskriftartikkel, 2023-02-17)
      The Borealis radar system is a hardware and software upgrade to the conventional Super Dual Auroral Radar Network radar system, which has been used since the early 1990s. The conventional system has hardware and software that is aging, and many components are no longer supported. Limitations of the conventional system limit radar and data techniques for scientific discovery. Using software defined ...
    • Burst statistics of fluctuations in a simple magnetized torus configuration 

      Rypdal, Kristoffer; Živkovic, Tatjana; Østvand, Lene (Working paper; Arbeidsnotat, 2009-04-19)
      In a toroidal plasma confined by a purely toroidal magnetic field the plasma transport is governed by electrostatic turbulence driven by the flute interchange instability on the low-field side of the torus cross section. In this paper we revisit experimental data obtained from the Blaamann torus at the University of Tromso. On time-scales shorter than the poloidal rotation time, the time series of ...
    • Can Mineral Oil Slicks Be Distinguished From Newly Formed Sea Ice Using Synthetic Aperture Radar? 

      Johansson, Malin; Espeseth, Martine; Brekke, Camilla; Holt, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-18)
      In this feasibility study discriminating oil slicks and newly formed sea ice using SAR imagery is investigated, using imagery from the L-band high-resolution Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne and the satellite C-band RADARSAT-2 (RS-2) systems. To determine the separability of these two varying but similar appearing low backscatter ocean surfaces, multi-polarization ...
    • Can We Automate Diagrammatic Reasoning? 

      Sekh, Arif Ahmed; Dogra, Debi Prasad; Kar, Samarjit; Roy, Partha Pratim; Prosad, Dilip K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-06)
      Diagrammatic reasoning (DR) problems are well known. However, solving DR problems represented in 4 × 1 Raven’s Progressive Matrix (RPM) form using computer vision and pattern recognition has not yet been tried. Emergence of deep learning techniques aided by advanced computing can be exploited to solve such DR problems. In this paper, we propose a new learning framework by combining LSTM and Convolutional ...