Viser treff 127-146 av 161

    • Some new multidimensional Cochran-Lee and Hardy type inequalities 

      Yimer, Markos Fisseha; Persson, Lars-Erik; Ayele, Tsegaye Gedif (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      A multidimensional Cochran-Lee operator is introduced and investigated in the frame of Hardy-type inequalities with parameters 0<p⩽q<∞. Moreover, for the case p=q and power weights even the sharp constant is derived, thus generalizing the original Cochran-Lee inequality to a multidimensional setting. As applications both several known but also new inequalities are pointed out.
    • SOME NEW REFINEMENTS OF HARDY-TYPE INEQUALITIES 

      Oguntuase, J. A.; Fabelurin, Olanrewaju O; Persson, Lars Erik; Adeleke, EO (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-11)
      We obtain some further refinements of Hardy-type inequalities via superqudraticity technique. Our results both unify and further generalize several results on refinements of Hardy-type inequalities in the literature.
    • Some new refinements of the Young, Hölder, and Minkowski inequalities 

      Nikolova, Ludmila; Persson, Lars-Erik; Varošanec, Sanja (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-21)
      We prove and discuss some new refined Hölder inequalities for any p>1 and also a reversed version for 0<p<1. The key is to use the concepts of superquadraticity, strong convexity, and to first prove the corresponding refinements of the Young and reversed Young inequalities. Refinements of the Minkowski and reversed Minkowski inequalities are also given.
    • Some new restricted maximal operators of Fejér means of Walsh–Fourier series 

      Baramidze, Davit; Baramidze, Lasha; Persson, Lars-Erik; Tephnadze, George (Journal article; Tidsskriftartikkel, 2023-09-12)
      In this paper, we derive the maximal subspace of natural numbers { <i>n<sub>k</sub></i> : <i>k</i> &#8805; 0 }, such that the restricted maximal operator, defined by sup<sub><i>k</i>&#8712;&#8469;</sub> | &sigma;<i><sub>n<sub>k</sub></sub>F</i> | on this subspace of Fejér means of Walsh–Fourier series is bounded from the martingale Hardy space <i>H</i><sub>1/2</sub> to the Lebesgue space ...
    • Some new Two-Sided Inequalities concerning the Fourier Transform 

      Kopezhanova, Aigerim; Nursultanov, Erlan; Persson, Lars Erik (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
      The classical Hausdorff-Young and Hardy-Littlewood-Stein inequalities do not hold for p > 2. In this paper we prove that if we restrict to net spaces we can even derive a two-sided estimate for all p > 1. In particular, this result generalizes a recent result by Liflyand E. and Tikhonov S. [7] (MR 2464253).
    • Some New Weak (Hp- Lp)-Type Inequality for Weighted Maximal Operators of Partial Sums of Walsh–Fourier Series 

      Baramidze, David; Persson, Lars-Erik; Singh, Harpal; Tephnadze, George (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-18)
      In this paper, we introduce some new weighted maximal operators of the partial sums of the Walsh–Fourier series. We prove that for some “optimal” weights these new operators indeed are bounded from the martingale Hardy space H<sub>p</sub>(G) to the Lebesgue space weak−L<sub>p</sub>(G), for 0<p<1. Moreover, we also prove sharpness of this result. As a consequence we obtain some new and well-known ...
    • Some New weak-(Hp-Lp) Type Inequalities For Weighted Maximal Operators Of Fejér Means Of Walsh–Fourier Series 

      Baramidze, Davit; Tephnadze, G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-13)
      We introduce some new weighted maximal operators of the Fejér means of the Walsh–Fourier series. We prove that for some "optimal" weights these new operators are bounded from the martingale Hardy space H<sub>p</sub>(G) to the space weak-L<sub>p</sub>(G), for 0 <p<1/2. Moreover, we also prove sharpness of this result. As a consequence we obtain some new and well-known results.
    • Some sharp inequalities for integral operators with homogeneous kernel 

      Lukkassen, Dag; Persson, Lars Erik; Samko, Stefan G. (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-04-09)
      One goal of this paper is to show that a big number of inequalities for functions in Lp(R+), p ≥ 1, proved from time to time in journal publications are particular cases of some known general results for integral operators with homogeneous kernels including, in particular, the statements on sharp constants. Some new results are also included, e.g. the similar general equivalence result is proved and ...
    • Some weak type inequalities and almost everywhere convergence of Vilenkin–Nörlund means 

      Baramidze, Davit; Nadirashvili, Nato; Persson, Lars-Erik; Tephnadze, George (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-04)
      We prove and discuss some new weak type (1, 1) inequalities of maximal operators of Vilenkin–Nörlund means generated by monotone coefficients. Moreover, we use these results to prove a.e. convergence of such Vilenkin–Nörlund means. As applications, both some well-known and new inequalities are pointed out.
    • 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 ...
    • 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. ...
    • Steklov Problems in Perforated Domains with a Coefficient of Indefinite Sign 

      Piatnitski, Andrey L.; Piat, Valeria C.; Nazarov, Sergey S. (Journal article; Peer reviewed; Tidsskriftartikkel, 2012)
    • Study of Acoustics Properties of SK One Component Polyurethane and its Application in Arctic Marine Structures 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba; Sun, Zhiheng; Souli, Mhmed (Conference object; Konferansebidrag, 2016-12-08)
      Marine noise reduction tends to be challenging and requires a comprehensive engineering approach. The soundproofing materials for marine noise reduction are usually exposed to high temperatures, potential fluid or oil spills, engine maintenance and a high airflow environment. This work looks into the acoustic proofing properties of a non-toxic material ‘SK One Component Polyurethane’ developed by ...
    • Study of Ice Adhesion Behavior of SK One Component Polyurethane 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba; Sun, Zhiheng (Conference object; Konferansebidrag, 2016-12)
      Ice adhesion causes many serious problems such as aircraft accidents, navigational issues on ships, and power loss on wind turbines. These challenges are mainly associated with the acute behavior of ice adhesion. The ice adheres when water seeps into the microscopic pores of the material substrate and freezes, thereby, forming an interlocking mechanism. Therefore, surface roughness has a significant ...
    • A study on hybrid sensor technology in winter road assessment 

      Pedersen, Aleksander; Brustad, Tanita Fossli (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-23)
      Road conditions during the winter months in Nordic countries can be highly unstable. Slippery roads combined with heavy haul traffic and ordinary road users can create dangerous, even lethal, situations if road maintenance is unsuccessful. Accidents and critical road conditions may lead to blocked roads, putting strain on a limited number of main roads in many regions, and may in the worst case ...
    • Synaptus: A Matlab/Octave toolbox for synthetic aperture ultrasound imaging. 

      Skjelvareid, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-08)
      Underlying patterns and factors behind suicides of patients in treatment are still unclear and there is a pressing need for more studies to address this knowledge gap. We analysed 278 cases of suicide reported to The Norwegian System of Patient Injury Compensation, drawing on anonymised data, i.e., age group, gender, diagnostic category, type of treatment provided, inpatient vs. outpatient status, ...
    • Thermal Properties of SK One Component Polyurethane using Experiments and Multiphysics Simulations 

      Ahmad, Tanveer; Xue, Hui; Khawaja, Hassan Abbas; Sun, Zhiheng; Linmei, Nie; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2016-12-08)
      This study proposes to determine the thermal conductivity of SK One Component Polyurethane (SKOCP) developed by China Institute of Water Resources & Hydropower Research Beijing IWHR-KHL Co. Ltd. SKOCP provides excellent proof of aging and chemical resistance of this material. It is non-toxic, acts as a good anti-seepage, offers anti-abrasion and good anti-freezing performance. In addition, it has ...
    • Time scale Hardy-type inequalities with ‘broken’ exponent p 

      Oguntuase, James A; Fabelurin, Olanrewaju O; Adeagbo-Sheikh, Abdulaziz G; Persson, Lars Erik (Peer reviewed; Journal article; Tidsskriftsartikkel, 2015-01-16)
      In this paper, some new Hardy-type inequalities involving ?broken? exponents are derived on arbitrary time scales. Our approach uses both convexity and superquadracity arguments, and the results obtained generalize, complement and provide refinements of some known results in literature
    • Topological Singularities in Periodic Media: Ginzburg–Landau and Core-Radius Approaches 

      Alicandro, Roberto; Braides, Andrea; Cicalese, Marco; De Luca, Lucia; Piatnitski, Andrey (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)
      We describe the emergence of topological singularities in periodic media within the Ginzburg–Landau model and the core-radius approach. The energy functionals of both models are denoted by Eε,δ, where ε represent the coherence length (in the Ginzburg–Landau model) or the core-radius size (in the core-radius approach) and δ denotes the periodicity scale. We carry out the -convergence analysis ...
    • Toward Interactive Music Generation: A Position Paper 

      Dadman, Shayan; Bremdal, Bernt Arild; Bang, Børre; Dalmo, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-30)
      Music generation using deep learning has received considerable attention in recent years. Researchers have developed various generative models capable of imitating musical conventions, comprehending the musical corpora, and generating new samples based on the learning outcome. Although the samples generated by these models are persuasive, they often lack musical structure and creativity. For instance, ...