• Additive weighted Lp estimates of some classes of integral operators involving generalized Oinarov kernels 

      Baiarystanov, A.O.; Persson, Lars Erik; Wall, Peter; Abylayeva, A.M. (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
    • Altering perceptions, visualizing sub-ground metal objects 

      Pedersen, Aleksander (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06)
      Smart phones and sensor technology represent a key part of everyday life and are being used in areas such as safety, training, healthcare and others. Utilizing an array of internal sensors and a metal detector requires an evaluation of the precision of the measurements and performance reviews. Metal detectors are versatile, with uses in healthcare as well as recreational, but a common issue often ...
    • Analysis of civil engineering infrastructure in Norway with solutions based on structural health monitoring and artificial intelligence 

      Tangrand, Kristoffer Meyer; Singh, Harpal (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-19)
      Ageing civil infrastructures such as bridges and building causes many consequences from practical and economical point of view. Especially in northern Norway, the impact of extreme arctic conditions is intense on civil engineering infrastructures (see \cite{Singh:2022:hologaland_Bridge}). With the increased loading due to the prosperous seafood industry and increased cargo activity is putting ...
    • Asymptotic Behaviour of Ground States for Mixtures of Ferromagnetic and Antiferromagnetic Interactions in a Dilute Regime 

      Braides, Andrea; Causin, Andrea; Piatnitski, Andrey; Solci, Margherita (Journal article; Peer reviewed, 2018-04-30)
      We consider randomly distributed mixtures of bonds of ferromagnetic and antiferromagnetic type in a two-dimensional square lattice with probability 1−p 1−p and p, respectively, according to an i.i.d. random variable. We study minimizers of the corresponding nearest-neighbour spin energy on large domains in Z 2 Z2 . We prove that there exists p 0 p0 such that for p≤ p 0 p≤p0 such ...
    • Asymptotics of a spectral-sieve problem 

      Amirat, Youcef; Bodart, Olivier; Chechkin, Gregory; Piatnitski, Andrey (Peer reviewed; Journal article; Tidsskriftsartikkel, 2015-11-18)
      In a bounded domain with a thin periodically punctured interface we study the limit behavior of the bottom of spectrum for a Steklov type spectral problem, the Steklov boundary condition being imposed on the perforation surface. For a certain range of parameters we construct the effective spectral problem and justify the convergence of eigenpairs.
    • Asymptotics of fundamental solutions for time fractional equations with convolution kernels 

      Kondratiev, Yuri; Piatnitski, Andrey; Zhizhina, Elena (Journal article; Peer reviewed, 2020-09-11)
      The paper deals with the large time asymptotic of the fundamental solution for a time fractional evolution equation with a convolution type operator. In this equation we use a Caputo time derivative of order α ∈ (0, 1), and assume that the convolution kernel of the spatial operator is symmetric, integrable and shows a super-exponential decay at infinity. Under these assumptions we describe the ...
    • Atomized feedback, an approach to automatic formative assessment 

      Steen, Arild; Movik, Hans Richard (Peer reviewed; Chapter, 2017-11)
      In this article, we describe an approach to give automatic formative evaluation by atomizing the feedback. The mechanics in this approach is a large number of multiple-choice tests. The multiplechoice tests are used as voluntary assignments and gives controlled progression by releasing the tests in an order. Instruction is in the spirit of flipped classroom with short video lectures accompanied by ...
    • Blending functions based on trigonometric and polynomial approximations of the Fabius function 

      Olofsen, Hans (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      Most simple blending functions are polynomials, while more advanced blending functions are, for example, rational or expo-rational fractions. The Fabius function has the required properties of a blending function, but is a nowhere analytic function and cannot be calculated exactly everywhere on the required domain. We present a new set of trigonometric and polynomial blending functions with the shape ...
    • Blending spline surfaces over polygon mesh and their application to isogeometric analysis 

      Kravetc, Tatiana (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-11)
      Finite elements are allowed to be of a shape suitable for the specific problem. This choice defines thereafter the accuracy of the approximated solution. Moreover, flexible element shapes allow for the construction of an arbitrary domain topology. Polygon meshes are a common representation of the domain that cover any choice of the finite element shape. Being an alternative tool for modeling and ...
    • Blending techniques in Curve and Surface constructions 

      Lakså, Arne (Book; Bok, 2022)
    • Blendingsteknikker i kurve- og flatekonstruksjoner 

      Lakså, Arne (Book; Bok, 2022)
    • Boundedness and compactness of a class of Hardy type operators 

      Abylayeva, AAkbota M; Oinarov, Ryskul; Persson, Lars Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-13)
      We establish characterizations of both boundedness and of compactness of a general class of fractional integral operators involving the Riemann-Liouville, Hadamard, and Erdelyi-Kober operators. In particular, these results imply new results in the theory of Hardy type inequalities. As applications both new and well-known results are pointed out.
    • Bruk av droner i nordområdene 

      Bakken, Trond; Johnsen, Stig Ole; Holmstrøm, Sture; Merz, Mariann; Transeth, Aksel Andreas; Grøtli, Esten Ingar; Risholm, Petter; Storvold, Rune (Research report; Forskningsrapport, 2020-05-13)
      Formålet med denne rapporten er å vise eksempler på bruk av fjernstyrte og autonome droner i petroleumssektoren og vise hvilke utviklingstrender innen droneteknologi som er viktige. Utfordringer og muligheter for bruk av droner i nordområdene er spesielt vektlagt. Teknologi for og anvendelser av flyvende droner, droner på havoverflaten og droner under vann er behandlet i denne rapporten. Rapporten ...
    • Continuous refinements of some Jensen-type inequalities via strong convexity with applications 

      Nikolova, Ludmila; Persson, Lars-Erik; Varošanec, Sanja (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-23)
      In this paper we prove new continuous refinements of some Jensen type inequalities in both direct and reversed forms. As applications we also derive some continuous refinements of Hermite–Hadamard, Hölder, and Popoviciu type inequalities. As particular cases we point out the corresponding results for sums and integrals showing that our results contain both several well-known but also some new ...
    • Deployment of a Neo-Hookean membrane: experimental and numerical analysis 

      Moatamedi, Mojtaba; Al-Bahkali, Essam; Erchiqui, Fouad; Souli, M (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-03-31)
      The aim of this research is to assess the response of a thin membrane subjected to high-pressure gas loading for inflation. This procedure is applied during the design process of the membrane structure to allow the product to resist high-pressure loading and to further characterize the hyper-elastic material. The simulation in this work considers the standard procedures used in the LS-DYNA software, ...
    • Design of water shock tube for testing shell materials 

      Ji, Hongjuan; Mustafa, Mohamad; Khawaja, Hassan Abbas; Ewan, Bruce C.; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-04-15)
      This paper presents design considerations for a shock tube experimental rig used to investigate the dynamic failure mechanisms of shell geometries subjected to water shock impact loading. In such setup, it is desirable that the drive pressure used within the tube can provide a wide range of impulsive loads on the test structures and some flexibility can be achieved on the applied pulse durations. ...
    • Discretization and Representation of a Complex Environment for On-Policy Reinforcement Learning for Obstacle Avoidance for Simulated Autonomous Mobile Agents 

      Jansson, Andreas Dyrøy (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-12)
      In recent years, the demand for digitalization, automation, and smart systems in the airline industry has accelerated. Furthermore, due to the ongoing global pandemic as of 2022, airlines are faced with the challenge of offering flexibility in both cargo and passenger capacity. Studies show that the use of smart products and autonomous agents are expected to play a key part in the digital transformation ...
    • Dynamic plastic response of beams subjected to localised pulse loads 

      Thil, Nicolas; Mehreganian, Navid; Moatamedi, Mojtaba; Louca, Luke A.; Soleiman Fallah, Arash (Journal article; Peer reviewed, 2018-10-31)
      Localised blast loads give rise to high gradients of overpressure detrimental to structural elements as beams and plates. This article presents an analytical study on the dynamic plastic response of beams made of a ductile metallic material due to close-in pulse pressure loading. The close-in pressure load is characterised by a spatially varying function constant over a central region and exponentially ...
    • E-Mobility and Batteries—A Business Case for Flexibility in the Arctic Region 

      Bremdal, Bernt Arild; Ilieva, Iliana; Tangrand, Kristoffer Meyer; Dadman, Shayan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-28)
      This paper provides a method for determining the economic incentives and limitations for a battery used for peak clipping, with the goal of finding an optimal mix between the battery’s power density and energy density. A ratio called the R-factor has been introduced, which helps determine the energy demand to curb the peak. The paper’s results embrace different investment scenarios showing what ...
    • Economic evaluation of the Power grid tariff for households With solar Power installed 

      Sæle, Hanne; Bremdal, Bernt Arild (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
      This paper focuses on alternative grid tariffs for household customers with roof top PV-panels ("prosumers"), and evaluates how alternative grid tariffs might affect the benefit from investing in a roof top PV-panel. The paper further shows how different orientations of the PV-panels can affect the benefits for the prosumers subjected to different grid tariffs (for example a power grid tariff), where ...