• 2d gauge theories and generalized geometry 

      Salnikov, Vladimir; Strobl, Thomas; Kotov, Oleksii (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Abelian equations and rank problems for planar webs 

      Goldberg, Vladislav V.; Lychagin, Valentin V. (Journal article; Tidsskriftartikkel; Peer reviewed, 2006-05-04)
      We find an invariant characterization of planar webs of maximum rank. For 4-webs, we prove that a planar 4-web is of maximum rank three if and only if it is linearizable and its curvature vanishes. This result leads ...
    • Almost complex homogeneous spaces with semi-simple isotropy 

      Winther, Henrik (Master thesis; Mastergradsoppgave, 2012-05)
      We classify the almost complex structures on homogeneous spaces M = G/H of real dimension less than or equal to 6 with semi-simple isotropy group H.
    • Anomaly of linearization and auxiliary integrals 

      Kruglikov, Boris (Chapter; Bokkapittel, 2007-12-20)
      In this note we discuss some formal properties of universal linearization operator, relate this to brackets of non-linear differential operators and discuss application to the calculus of auxiliary integrals, used in ...
    • Applying the ICM algorithm for separating pictures consisting of two main parts, background and object application to fMRI recordings and mole pictures 

      Larsen, Are (Master thesis; Mastergradsoppgave, 2009-05-15)
      This work concentrates on using the ICM algorithm for image restoration. The algorithm has been applied to fMRI recordings and mole pictures
    • Arctic tipping points 

      Smolkova, Valentina (Master thesis; Mastergradsoppgave, 2015-05-15)
      The Arctic is warming much faster than the entire planet, and this causes severe melting of sea ice. However, the climate of different regions of the Earth is interconnected, and changes in the amount of ice in the Arctic ...
    • Are there multiple scaling regimes in Holocene temperature records? 

      Nilsen, Tine; Rypdal, Kristoffer; Fredriksen, Hege-Beate (Journal article; Tidsskriftartikkel, 2015-07-17)
      The concept of multiple scaling regimes in temperature time series is examined, with emphasis on the question whether or not a mono-scaling model can be rejected from the data at hand. A model with only one regime is ...
    • Attribution in the presence of a long-memory climate response 

      Rypdal, Kristoffer (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-18)
      Multiple, linear regression is employed to attribute variability in the global surface temperature to various forcing components and prominent internal climatic modes. The purpose of the study is to assess how sensitive ...
    • Attribution in the presence of a long-memory climate response 

      Rypdal, Kristoffer (Journal article; Tidsskriftartikkel, 2015-08-10)
      Multiple, linear regression is employed to attribute variability in the global surface temperature to various forcing components and prominent internal climatic modes. The purpose of the study is to asses how sensitive ...
    • Automatic nematode detection in cod fillets (Gadus morhua L.) by hyperspectral imaging 

      Sivertsen, Agnar Holten; Heia, Karsten; Hindberg, Kristian; Godtliebsen, Fred (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Detection of objects embedded in tissue, using visible light, is difficult due to light scattering. The optical properties of the surrounding tissue will influence the spectral characteristics of the light interacting with ...
    • Automatic Segmentation of Dermoscopic Images by Iterative Classification 

      Zortea, Maciel; Skrøvseth, Stein Olav; Schopf, Thomas Roger Griesbeck; Kirchesch, Herbert M.; Godtliebsen, Fred (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      Accurate detection of the borders of skin lesions is a vital first step for computer aided diagnostic systems. This paper presents a novel automatic approach to segmentation of skin lesions that is particularly suitable ...
    • Bayesian modeling and significant features exploration in wavelet power spectra 

      Divine, Dmitry V; Godtliebsen, Fred (Journal article; Tidsskriftartikkel; Peer reviewed, 2007)
    • Bayesian multiscale analysis of images modeled as Gaussian Markov random fields 

      Thon, Kevin Otto; Rue, Håvard; Skrøvseth, Stein Olav; Godtliebsen, Fred (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      A Bayesian multiscale technique for the detection of statistically significant features in noisy images is proposed. The prior is defined as a stationary intrinsic Gaussian Markov random field on a toroidal graph, which ...
    • Betti numbers associated to the facet ideal of a matroid 

      Johnsen, Trygve; Roksvold, Jan Nyquist; Verdure, Hugues (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-06)
      To a matroid M with n edges, we associate the so-called facet ideal F(M)⊂k[x1,…,xn] , generated by monomials corresponding to bases of M. We show that when M is a graph, the Betti numbers related to an ℕ0-graded minimal ...
    • The Capabilities of the EISCAT Svalbard Radar for Inter-hemispheric Coordinated Studies 

      van Eyken, Tony; Grydeland, Tom; Strømme, Anja; La Hoz, Cesar (Journal article; Tidsskriftartikkel; Peer reviewed, 2002)
      In this article we want to present the EISCAT Svalbard Radar (ESR) in some detail, as well as some of the instruments of interest for ionospheric and magnetospheric research that are located in the vicinity of it. We ...
    • The categorical theory of relations and quantization 

      Lychagin, Valentin V.; Jakobsen, Per K. (Working paper; Arbeidsnotat, 2001-10-30)
      In this paper we develops a categorical theory of relations and use this formulation to define the notion of quantization for relations. Categories of relations are defined in the context of symmetric monoidal categories. They ...
    • Causality in Scale Space as an Approach to Change Detection 

      Skrøvseth, Stein Olav; Godtliebsen, Fred; Bellika, Johan Gustav (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Kernel density estimation and kernel regression are useful ways to visualize and assess the structure of data. Using these techniques we define a temporal scale space as the vector space spanned by bandwidth and a temporal ...
    • Compatibility, multi-brackets and integrability of systems of PDEs 

      Kruglikov, Boris; Lychagin, Valentin V. (Journal article; Tidsskriftartikkel; Peer reviewed, 2008-02-20)
      We establish an efficient compatibility criterion for a system of generalized complete intersection type in terms of certain multi-brackets of differential operators. These multi-brackets generalize the higher Jacobi- Mayer ...
    • Computer-aided decision support for melanoma detection applied on melanocytic and non-melanocytic skin lesions: a comparison of two systems based on automatic analysis of dermoscopic images 

      Møllersen, Kajsa; Kirchesch, Herbert M.; Zortea, Maciel; Schopf, Thomas Roger Griesbeck; Hindberg, Kristian; Godtliebsen, Fred (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
      Commercially available clinical decision support systems (CDSSs) for skin cancer have been designed for the detection of melanoma only. Correct use of the systems requires expert knowledge, hampering their utility for ...
    • COPD in primary lung cancer patients: prevalence and mortality 

      Ytterstad, Elinor; Moe, Per Christian; Hjalmarsen, Audhild (Journal article; Peer reviewed, 2016-03-23)
      Background: Previous studies have relied on international spirometry criteria to diagnose COPD in patients with lung cancer without considering the effect lung cancer might have on spirometric results. The aim of this study ...