Now showing items 41-60 of 88

    • Recognizing Bedside Events Using Thermal and Ultrasonic Readings 

      Danielsen, Asbjørn; Tørresen, Jim (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-09)
      Falls in homes of the elderly, in residential care facilities and in hospitals commonly occur in close proximity to the bed. Most approaches for recognizing falls use cameras, which challenge privacy, or sensor devices attached to the bed or the body to recognize bedside events and bedside falls. We use data collected from a ceiling mounted 80 60 thermal array combined with an ultrasonic sensor ...
    • Multi-source data collection for state-of-the-art data analysis from ground-proximate images in sea ice classification 

      Woltmann, Lucas; Dalmo, Rune; Kristiansen, Raymond (Peer reviewed; Conference object; Konferansebidrag; Bok; Book, 2017-08-08)
      In modern data analysis it is imperative to use well maintained data sources with curated content. This publication gives an approach for research areas, where there is no such central facility. The specific area used here is sea ice classification from images. The publication is split into two parts. The first part describes the integration of discontinuous sources for different aspects of data ...
    • Regression analysis using a blending type spline construction 

      Kravetc, Tatiana; Bang, Børre; Dalmo, Rune (Peer reviewed; Chapter; Bokkapittel, 2017-10-18)
      Regression analysis allows us to track the dynamics of change in measured data and to investigate their properties. A sufficiently good model allows us to predict the behavior of dependent variables with higher accuracy, and to propose a more precise data generation hypothesis. By using polynomial approximation for big data sets with complex dependencies we get piecewise smooth functions. One way ...
    • 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 ...
    • Refinements of some limit hardy-Type Inequalities via Superquadracity 

      Oguntuase, James A; Persson, Lars Erik; Fabelurin, Olanrewaju O; Adeagbo-Sheikh, Abdulaziz G (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-03)
      Refinements of some limit Hardy-type inequalities are derived and discussed using the concept of superquadracity. We also proved that all three constants appearing in the refined inequalities obtained are sharp. The natural turning point of our refined Hardy inequality is p=2 and for this case we have even equality.
    • Pre-evaluation and interactive editing of B-spline and GERBS curves and surfaces 

      Lakså, Arne (Peer reviewed; Bokkapittel; Conference object; Konferansebidrag; Chapter, 2017-12)
      Interactive computer based geometry editing is very useful for designers and artists. Our goal has been to develop useful tools for geometry editing in a way that increases the ability for creative design. When we interactively editing geometry, we want to see the change happening gradually and smoothly on the screen. Pre-evaluation is a tool for increasing the speed of the graphics when doing ...
    • A new look at classical inequalities involving Banach lattice norms 

      Nikolova, Ludmila; Persson, Lars Erik; Varosanec, Sanja (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-12-08)
      Some classical inequalities are known also in a more general form of Banach lattice norms and/or in continuous forms (i.e., for ‘continuous’ many functions are involved instead of finite many as in the classical situation). The main aim of this paper is to initiate a more consequent study of classical inequalities in this more general frame. We already here contribute by discussing some results of ...
    • Stationary convection-diffusion equation in an infinite cylinder 

      Pettersson, Irina; Piatnitski, Andrey (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-21)
      We study the existence and uniqueness of a solution to a linear stationary convection–diffusion equation stated in an infinite cylinder, Neumann boundary condition being imposed on the boundary. We assume that the cylinder is a junction of two semi-infinite cylinders with two different periodic regimes. Depending on the direction of the effective convection in the two semi-infinite cylinders, we ...
    • Fejér and Hermite-Hadamard Type Inequalities for N-Quasiconvex Functions 

      Abramovich, S; Persson, Lars Erik (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-12-28)
      Some new extensions and re finements of Hermite – Hadamard and Fejer type inequalities for functions which are N -quasiconvex are derived and discussed.
    • A NEW GENERALIZATION OF BOAS THEOREM FOR SOME LORENTZ SPACES Λq(ω) 

      Kopezhanova, Aigerim; Nursultanov, Erlan; Persson, Lars Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      Let Λq( ω ), q > 0, denote the Lorentz space equipped with the (quasi) norm [<i>MATHEMATICAL FORMULA</I>] for a function f on [0,1] and with ω positive and equipped with some additional growth properties. A generalization of Boas theorem in the form of a two-sided inequality is obtained in the case of both general regular system [<i>MATHEMATICAL FORMULA</I>] and generalized Lorentz Λq( ω ) spaces
    • On Some Power Means and Their Geometric Constructions 

      Høibakk, Ralph; Lukkassen, Dag; Meidell, Annette; Persson, Lars Erik (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
      The main aim of this paper is to further develop the recently initiatedresearch concerning geometric construction of some power means wherethe variables are appearing as line segments. It will be demonstratedthat the arithmetic mean, the harmonic mean and the quadratic meancan be constructed for any number of variables and that all power meanswhere the number of variables are n = 2m, m 1 2 N for all ...
    • Predicting Bedside Falls using Current Context 

      Danielsen, Asbjørn; Bremdal, Bernt Arild (Peer reviewed; Chapter; Bokkapittel, 2018-02-05)
      Each year about a third of the elderly aged 65 or older experience a fall. Many of these falls could be avoided if fall risk assessment and prevention tools where available in the daily living situation. Such tools would need to use the current context as input to predict an imminent fall. This paper presents an approach predicting imminent falls using data from a roof-mounted infrared array combined ...
    • Homogenization of nonisothermal immiscible incompressible two-phase flow in porous media 

      Amaziane, Brahim; Jurak, Murat; Pankratov, Leonid; Piatnitski, Andrey (Journal article; Peer reviewed, 2018-03-15)
      In this paper, we consider nonisothermal two-phase flows through heterogeneous porous media with periodic microstructure. Examples of such models appear in gas migration through engineered and geological barriers for a deep repository for radioactive waste, thermally enhanced oil recovery and geothermal systems. The mathematical model is given by a coupled system of two-phase flow equations, and an ...
    • Local Flexibility Market Design for Aggregators Providing Multiple Flexibility Services at Distribution Network Level 

      Olivella-Rosell, Pol; Lloret-Gallego, Pau; Munne-Collado, Ingrid; Villafafila-Robles, Roberto; Sumper, Andreas; Ottesen, Stig Ødegaard; Rajasekharan, Jayaprakash; Bremdal, Bernt Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-02)
      This paper presents a general description of local flexibility markets as a market-based management mechanism for aggregators. The high penetration of distributed energy resources introduces new flexibility services like prosumer or community self-balancing, congestion management and time-of-use optimization. This work is focused on the flexibility framework to enable multiple participants to compete ...
    • Steady States, Fluctuation-Dissipation Theorems and Homogenization for Reversible Diffusions in a Random Environment 

      Mathieu, P; Piatnitski, A (Journal article; Peer reviewed; Tidsskriftartikkel, 2018-04-02)
      Prolongating our previous paper on the Einstein relation, we study the motion of a particle diffusing in a random reversible environment when subject to a small external forcing. In order to describe the long time behavior of the particle, we introduce the notions of steady state and weak steady state. We establish the continuity of weak steady states for an ergodic and uniformly elliptic environment. ...
    • Hardy-type inequalities in fractional h-discrete calculus 

      Persson, Lars Erik; Oinarov, Ryskul; Shaimardan, Serikbol (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-04)
      The first power weighted version of Hardy’s inequality can be rewritten as [<i>mathematical formula</i>] where the constant <i>C</i> =[<i>p</i> / <i>p</i> - <i><b>a</b></i> - 1]<sup><i>p</i></sup> is sharp. This inequality holds in the reversed direction when<math xmlns="http://www.w3.org/1998/Math/MathML"> <mn>0</mn> <mo>&#x2264;<!-- ≤ --></mo> <mi><i>p</i></mi> <mo>&lt;</mo> <mn>1</mn> ...
    • Pointwise estimates for heat kernels of convolution-type operators 

      Grigor'yan, Alexander; Kondratiev, Yuri; Piatnitski, Andrey; Zhizhina, Elena (Journal article; Peer reviewed; Tidsskriftartikkel, 2018-04-16)
      We study the large‐time behaviour of the fundamental solution of parabolic equations with an elliptic part being non‐local convolution‐type operator. We assume that this operator is a generator of a Markov jump process, and that its convolution kernel decays at least exponentially at infinity. The fundamental solution shows rather different asymptotic behaviour depending on whether | x | ≲ t , or t ...
    • 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 ...
    • A sharp boundedness result for restricted maximal operators of Vilenkin-Fourier series on martingale Hardy spaces 

      Blahota, Istvan; Nagy, Karoly; Persson, Lars Erik; Tephnadze, George (Journal article; Peer reviewed, 2018-09-20)
      The restricted maximal operators of partial sums with respect to bounded Vilenkin systems are investigated. We derive the maximal subspace of positive numbers, for which this operator is bounded from the Hardy space H p to the Lebesgue space L p for all 0<p≤1 . We also prove that the result is sharp in a particular sense.
    • 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 ...