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  • 1. Abramovich, S
    et al.
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Some new Hermite-Hadamard and Fejer typeinequalities without convexity/concavityManuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
  • 2. Abravomich, S
    et al.
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Rearrangements andJensen type inequalities related to convexity, superquadracity, strongconvexity and 1-quasiconvexityManuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
  • 3. Ackelh, A.S.
    et al.
    Colombo, R.M.
    Hille, S.C.
    Muntean, Adrian
    Institute for Complex Molecular Systems & Centre for Analysis, Scientific computing and Applications, Eindhoven University of Technology.
    Preface to "modeling with measures"2015Ingår i: Mathematical Biosciences and Engineering, ISSN 1547-1063, E-ISSN 1551-0018, Vol. 12, nr 2Artikel i tidskrift (Refereegranskat)
  • 4.
    Aiki, T.
    et al.
    Japan Womens Univ, Fac Sci, Dept Math, Bunkyo Ku, Tokyo.
    Hulshof, J.
    Vrije Univ Amsterdam, Fac Sci, Dept Math, Amsterdam, Netherlands.
    Kenmochi, N.
    Bukkyo Univ, Sch Educ Math, Kita Ku, Kyoto.
    Muntean, Adrian
    Eindhoven Univ Technol, Dept Math & Comp Sci,.
    Analysis of non-equilibrium evolution problems: Selected topics in material and life sciences2014Ingår i: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, Vol. 7, nr 1Artikel i tidskrift (Refereegranskat)
  • 5. Aiki, T.
    et al.
    Muntean, Adrian
    Eindhoven Univ Technol, Dept Math & Comp Sci.
    A free-boundary problem for concrete carbonation: Front nucleation and rigorous justification of the root t-law of propagation2013Ingår i: Interfaces and free boundaries (Print), ISSN 1463-9963, E-ISSN 1463-9971, Vol. 15, nr 2, s. 167-180Artikel i tidskrift (Refereegranskat)
  • 6. Aiki, T.
    et al.
    Muntean, Adrian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Existence and uniqueness of solutions to a mathematical model predicting service life of concrete structures2009Ingår i: Advances in Mathematical Sciences and Applications, ISSN 1343-4373, Vol. 19, s. 119-129Artikel i tidskrift (Refereegranskat)
  • 7.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Anthonissen, Martijn
    Eindhoven University Technology, Netherlands.
    Muntean, Adrian
    Eindhoven University Technology, Netherlands.
    On a one-dimensional shape-memory alloy model in its fast-temperature- activation limit2012Ingår i: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, Vol. 5, nr 1, s. 15-28Artikel i tidskrift (Refereegranskat)
  • 8.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Muntean, Adrian
    Eindhoven University of Technology.
    Large time behavior of solutions to a moving-interface problem modeling concrete carbonation2010Ingår i: Communications on Pure and Applied Analysis, ISSN 1534-0392, E-ISSN 1553-5258, Vol. 9, nr 5, s. 1117-1129Artikel i tidskrift (Refereegranskat)
  • 9.
    Aiki, Toyohiko
    et al.
    Tokyo Womens University.
    Muntean, Adrian
    Netherlands.
    Large-time asymptotics of moving-reaction interfaces involving nonlinear Henry’s law and time-dependent Dirichlet data2013Ingår i: Nonlinear Analysis, ISSN 0362-546X, E-ISSN 1873-5215, Vol. 93, s. 3-14Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the large-time behavior of the free boundary position capturing the one-dimensional motion of the carbonation reaction front in concrete-based materials. We extend here our rigorous justification of the t-behavior of reaction penetration depths by including nonlinear effects due to deviations from the classical Henry's law and time-dependent Dirichlet data.

  • 10. Aiki, Toyohiko
    et al.
    Muntean, Adrian
    Eindhoven University of Technology.
    Large-time behavior of a two-scale semilinear reaction-diffusion system for concrete sulfatation2014Ingår i: Mathematical methods in the applied sciences, ISSN 0170-4214, E-ISSN 1099-1476, Vol. 38, nr 7, s. 1451-1464Artikel i tidskrift (Refereegranskat)
  • 11.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Muntean, Adrian
    Eindhoven University of Technology.
    On uniqueness of a weak solution of one-dimensional concrete carbonation problem2011Ingår i: Discrete and Continuous Dynamical Systems, ISSN 1078-0947, E-ISSN 1553-5231, Vol. 29, nr 4, s. 1345-1365Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In our previous works we studied a one-dimensional free-boundary model related to the aggressive penetration of gaseous carbon dioxide in unsaturated concrete. Essentially, global existence and uniqueness of weak solutions to the model were obtained when the initial functions are bounded on the domain. In this paper we investigate the well-posedness of the problem for the case when the initial functions belong to a  class. Specifically, the uniqueness of weak solutions is proved by applying the dual equation method.

  • 12. Aljinovic, A.A
    et al.
    Peric, I
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Josip Pecaric- andhis life in mathematics and politicsManuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
  • 13.
    Andriash, A. V.
    et al.
    All Russia Res Inst Automat VNIIA, Moscow, Russia.
    Bobylev, Alexander V.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Brantov, A. V.
    All Russia Res Inst Automat VNIIA, Moscow, Russia.;RAS, PN Lebedev Phys Inst, Moscow 117901, Russia.
    Bychenkov, V. Yu.
    All Russia Res Inst Automat VNIIA, Moscow, Russia.;RAS, PN Lebedev Phys Inst, Moscow 117901, Russia.
    Karpov, S. A.
    All Russia Res Inst Automat VNIIA, Moscow, Russia.
    Potapenko, I. F.
    RAS, MV Keldysh Appl Math Inst, Moscow 117901, Russia.
    Stochastic simulation of the nonlinear kinetic equation with high-frequency electromagnetic fields2013Ingår i: PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY, ISSN 1562-6016, nr 4, s. 233-237Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A general approach to Monte Carlo methods for Coulomb collisions is proposed. Its key idea is an approximation of Landau-Fokker-Planck (LFP) equations by Boltzmann equations of quasi-Maxwellian kind. High-frequency fields are included into consideration and comparison with the well-known results are given.

  • 14.
    Barza, Sorina
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    Lind, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    A new variational characterization of Sobolev spaces2015Ingår i: Journal of Geometric Analysis, ISSN 1050-6926, E-ISSN 1559-002X, Vol. 25, nr 4, s. 2185-2195Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We obtain a new variational characterization of the Sobolev space $W_p^1(\Omega)$ (where $\Omega\subseteq\R^n$ and $p>n$). This is a generalization of a classical result of F. Riesz. We also consider some related results.

  • 15.
    Barza, Sorina
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Marcoci, Anca N.
    Department of Mathematics and Computer Science, Technical University of Civil Engineering Bucharest, Romania.
    Marcoci, Liviu G.
    Department of Mathematics and Computer Science, Technical University of Civil Engineering Bucharest, Romania.
    Factorizations of Weighted Hardy Inequalities2018Ingår i: Bulletin of the Brazilian Mathematical Society, ISSN 1678-7544, E-ISSN 1678-7714, Vol. 49, nr 4, s. 915-932Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present factorizations of weighted Lebesgue, Cesàro and Copson spaces, for weights satisfying the conditions which assure the boundedness of the Hardy’s integral operator between weighted Lebesgue spaces. Our results enhance, among other, the best known forms of weighted Hardy inequalities.

  • 16.
    Berg, Marcus
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Buchberger, Igor
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Enander, Jonas
    Stockholm University.
    Mörtsell, Edvard
    Stockholm University.
    Sjörs, Stefan
    Stockholm University.
    Growth Histories in Bimetric Massive Gravity2012Ingår i: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, nr 12, artikel-id 021Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We perform cosmological perturbation theory in Hassan-Rosen bimetric gravity for general homogeneous and isotropic backgrounds. In the de Sitter approximation, we obtain decoupled sets of massless and massive scalar gravitational fluctuations. Matter perturbations then evolve like in Einstein gravity. We perturb the future de Sitter regime by the ratio of matter to dark energy, producing quasi-de Sitter space. In this more general setting the massive and massless fluctuations mix. We argue that in the quasi-de Sitter regime, the growth of structure in bimetric gravity differs from that of Einstein gravity.

  • 17.
    Bergman, Ivar
    Karlstads universitet, Institutionen för ingenjörsvetenskap, fysik och matematik.
    Baire category theorem2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In this thesis we give an exposition of the notion of category and the Baire category theorem as a set theoretical method for proving existence. The category method was introduced by René Baire to describe the functions that can be represented by a limit of a sequence of continuous real functions. Baire used the term functions of the first class to denote these functions.

    The usage of the Baire category theorem and the category method will be illustrated by some of its numerous applications in real and functional analysis. Since the usefulness, and generality, of the category method becomes fully apparent in Banach spaces, the applications provided have been restricted to these spaces.

    To some extent, basic concepts of metric topology will be revised, as the Baire category theorem is formulated and proved by these concepts. In addition to the Baire category theorem, we will give proof of equivalence between different versions of the theorem.

    Explicit examples, of first class functions will be presented, and we shall state a theorem, due to Baire, providing a necessary condition on the set of points of continuity for any function of the first class.

     

  • 18.
    Bernhoff, Niclas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Discrete Velocity Models for Polyatomic Molecules Without Nonphysical Collision Invariants2018Ingår i: Journal of statistical physics, ISSN 0022-4715, E-ISSN 1572-9613, Vol. 172, nr 3, s. 742-761Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An important aspect of constructing discrete velocity models (DVMs) for the Boltzmann equation is to obtain the right number of collision invariants. Unlike for the Boltzmann equation, for DVMs there can appear extra collision invariants, so called spurious collision invariants, in plus to the physical ones. A DVM with only physical collision invariants, and hence, without spurious ones, is called normal. The construction of such normal DVMs has been studied a lot in the literature for single species, but also for binary mixtures and recently extensively for multicomponent mixtures. In this paper, we address ways of constructing normal DVMs for polyatomic molecules (here represented by that each molecule has an internal energy, to account for non-translational energies, which can change during collisions), under the assumption that the set of allowed internal energies are finite. We present general algorithms for constructing such models, but we also give concrete examples of such constructions. This approach can also be combined with similar constructions of multicomponent mixtures to obtain multicomponent mixtures with polyatomic molecules, which is also briefly outlined. Then also, chemical reactions can be added.

  • 19.
    Bernhoff, Niclas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Half-Space Problems for a Linearized Discrete Quantum Kinetic Equation2015Ingår i: Journal of statistical physics, ISSN 0022-4715, E-ISSN 1572-9613, Vol. 159, nr 2, s. 358-379Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study typical half-space problems of rarefied gas dynamics, including the problems of Milne and Kramer, for a general discrete model of a quantum kinetic equation for excitations in a Bose gas. In the discrete case the plane stationary quantum kinetic equation reduces to a system of ordinary differential equations. These systems are studied close to equilibrium and are proved to have the same structure as corresponding systems for the discrete Boltzmann equation. Then a classification of well-posed half-space problems for the homogeneous, as well as the inhomogeneous, linearized discrete kinetic equation can be made. The number of additional conditions that need to be imposed for well-posedness is given by some characteristic numbers. These characteristic numbers are calculated for discrete models axially symmetric with respect to the x-axis. When the characteristic numbers change is found in the discrete as well as the continuous case. As an illustration explicit solutions are found for a small-sized model.

  • 20.
    Bourne, D.
    et al.
    Univ Glasgow, Sch Math & Stat, Glasgow.
    Fatima, T.
    Eindhoven Univ Technol, Dept Math & Comp Sci, NL.
    van Meurs, P.
    Eindhoven Univ Technol, Dept Math & Comp Sci, NL.
    Muntean, Adrian
    Eindhoven University of Technology,.
    Is adding charcoal to soil a good method for CO2 sequestration? -: Modeling a spatially homogeneous soil2014Ingår i: Applied Mathematical Modelling, ISSN 0307-904X, E-ISSN 1872-8480, Vol. 38, nr 9-10, s. 2463-2475Artikel i tidskrift (Refereegranskat)
  • 21.
    Bringedal, Carina
    et al.
    Univ Bergen, Geophys Inst, POB 7803, N-5020 Bergen, Norway.;Univ Hasselt, Fac Sci, Campus Diepenbeek,Agoralaan Bldg D, BE-3590 Diepenbeek, Belgium..
    Kumar, Kundan
    Univ Bergen, Dept Math, POB 7803, N-5020 Bergen, Norway..
    Effective Behavior Near Clogging in Upscaled Equations for Non-isothermal Reactive Porous Media Flow2017Ingår i: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 120, nr 3, s. 553-577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For a non-isothermal reactive flow process, effective properties such as permeability and heat conductivity change as the underlying pore structure evolves. We investigate changes of the effective properties for a two-dimensional periodic porous medium as the grain geometry changes. We consider specific grain shapes and study the evolution by solving the cell problems numerically for an upscaled model derived in Bringedal et al. (Transp Porous Media 114(2):371-393, 2016. doi 10.1007/s11242-015-0530-9). In particular, we focus on the limit behavior near clogging. The effective heat conductivities are compared to common porosity-weighted volume averaging approximations, and we find that geometric averages perform better than arithmetic and harmonic for isotropic media, while the optimal choice for anisotropic media depends on the degree and direction of the anisotropy. An approximate analytical expression is found to perform well for the isotropic effective heat conductivity. The permeability is compared to some commonly used approaches focusing on the limiting behavior near clogging, where a fitted power law is found to behave reasonably well. The resulting macroscale equations are tested on a case where the geochemical reactions cause pore clogging and a corresponding change in the flow and transport behavior at Darcy scale. As pores clog the flow paths shift away, while heat conduction increases in regions with lower porosity.

  • 22.
    Eden, Michael
    et al.
    University of Bremen, Germany.
    Muntean, Adrian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Corrector estimates for the homogenization of a two-scale thermoelasticity problem with a priori known phase transformations2017Ingår i: Electronic Journal of Differential Equations, ISSN 1550-6150, E-ISSN 1072-6691, nr 57, s. 1-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate corrector estimates for the solutions of a thermoelasticity problem posed in a highly heterogeneous two-phase medium and its corresponding two-scale thermoelasticity model which was derived in [11] by two-scale convergence arguments. The medium in question consists of a connected matrix with disconnected, initially periodically distributed inclusions separated by a sharp interface undergoing a priori known phase transformations. While such estimates seem not to be obtainable in the fully coupled setting, we show that for some simplified scenarios optimal convergence rates can be proven rigorously. The main technique for the proofs are energy estimates using special reconstructions of two-scale functions and particular operator estimates for periodic functions with zero average. Here, additional regularity results for the involved functions are necessary.

  • 23.
    Evans, Jonathan D.
    et al.
    Univ Bath, Dept Math Sci, Bath BA2 7AY, Avon, England.
    Fernandez, Andrea
    Univ Bath, Dept Math Sci, Bath BA2 7AY, Avon, England.
    Muntean, Adrian
    Eindhoven University of Technology.
    Single and two-scale sharp-interface models for concrete carbonation - Asymptotics and numerical approximation2012Ingår i: Multiscale Modeling & simulation, ISSN 1540-3459, E-ISSN 1540-3467, Vol. 10, nr 3, s. 874-905Artikel i tidskrift (Refereegranskat)
  • 24.
    Evers, Joep H. M.
    et al.
    Eindhoven University of Technology.
    Hille, Sander C.
    Leiden University.
    Muntean, Adrian
    Eindhoven University of Technology.
    Modelling with measures: Approximation of a mass-emitting object by a point source2015Ingår i: Mathematical Biosciences and Engineering, ISSN 1547-1063, E-ISSN 1551-0018, Mathematical Biosciences and Engineering, Vol. 12, nr 2, s. 357-373Artikel i tidskrift (Refereegranskat)
  • 25.
    Evers, Joep
    et al.
    Netherlands.
    Hille, Sander C.
    Netherlands.
    Muntean, Adrian
    Eindhoven University of Technology, The Netherlands.
    Well-posedness and approximation of a measure-valued mass evolution problem with flux boundary conditions2014Ingår i: Comptes rendus. Mathematique, ISSN 1631-073X, E-ISSN 1778-3569, Vol. 352, nr 1, s. 51-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This Note deals with imposing a flux boundary condition on a non-conservative measure-valued mass evolution problem posed on a bounded interval. To establish the wellposedness of the problem, we exploit particle system approximations of the mass accumulation in a thin layer near the active boundary. We derive the convergence rate for the approximation procedure as well as the structure of the flux boundary condition in the limit problem.

  • 26.
    Evers, Joep H.M.
    et al.
    Eindhoven University of Technology, Netherlands.
    Hille, Sander C.
    Leiden University, Netherlands.
    Muntean, Adrian
    Eindhoven University of Technology, Netherlands.
    Mild solutions to a measure-valued mass evolution problem with flux boundary conditions2015Ingår i: Journal of Differential Equations, ISSN 0022-0396, E-ISSN 1090-2732, Vol. 259, nr 3, s. 1068-1097Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the well-posedness and approximation of mild solutions to a class of linear transport equations on the unit interval [0, 1] endowed with a linear discontinuous production term, formulated in the space M([0, 1]) of finite Borel measures. Our working technique includes a detailed boundary layer analysis in terms of a semigroup representation of solutions in spaces of measures able to cope with the passage to the singular limit where thickness of the layer vanishes. We obtain not only a suitable concept of solutions to the chosen measure-valued evolution problem, but also derive convergence rates for the approximation procedure and get insight in the structure of flux boundary conditions for the limit problem.

  • 27.
    Fabelurin, O.O
    et al.
    Obafemi Awolowo University Ile-Ife, Osun State, Nigeria .
    Oguntuase, J. A
    Federal University of Agriculture P.M.B. 2240, Abeokuta, Ogun State, Nigeria .
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    MULTIDIMENSIONAL HARDY–TYPE INEQUALITIESON TIME SCALES WITH VARIABLE EXPONENTS2019Ingår i: Journal Mathematics Inequalities, ISSN 1846-579X, Vol. 13, nr 3, s. 725-736Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     A new Jensen inequality for multivariate superquadratic functions is derived and proved. The derived Jensen inequality is then employed to obtain the general Hardy-type integral inequality for superquadratic and subquadratic functions of several variables.

  • 28.
    Fatima, Tasnim
    et al.
    Eindhoven University of Technology, Netherlands.
    Ijioma, Ekeoma
    Meiji University, Tokyo.
    Ogawa, Toshiyuki
    Meiji University, Tokyo.
    Muntean, Adrian
    Eindhoven University of Technology, Netherlands.
    Homogenization and dimension reduction of filtration combustion in heterogeneous thin layers2014Ingår i: Networks and Heterogeneous Media, ISSN 1556-1801, E-ISSN 1556-181X, Vol. 9, nr 4, s. 709-737Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the homogenization of a reaction-diffusion-convection system posed in an epsilon-periodic delta-thin layer made of a two-component (solid-air) composite material. The microscopic system includes heat flow, diffusion and convection coupled with a nonlinear surface chemical reaction. We treat two distinct asymptotic scenarios: (1) For a fixed width delta > 0 of the thin layer, we homogenize the presence of the microstructures (the classical periodic homogenization limit epsilon --> 0); (2) In the homogenized problem, we pass to delta --> 0 (the vanishing limit of the layer's width). In this way, we are preparing the stage for the simultaneous homogenization (epsilon --> 0) and dimension reduction limit (delta --> 0) with delta = delta (epsilon). We recover the reduced macroscopic equations from [25] with precise formulas for the effective transport and reaction coefficients. We complement the analytical results with a few simulations of a case study in smoldering combustion. The chosen multiscale scenario is relevant for a large variety of practical applications ranging from the forecast of the response to fire of refractory concrete, the microstructure design of resistance-to-heat ceramic-based materials for engines, to the smoldering combustion of thin porous samples under microgravity conditions.

  • 29. Fatima, Tasnim
    et al.
    Muntean, Adrian
    Technical University Eindhoven.
    Sulfate attack in sewer pipes: Derivation of a concrete corrosion model via two-scale convergence2014Ingår i: Nonlinear Analysis, ISSN 1468-1218, Vol. 15, nr 1, s. 326-344Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We explore the homogenization limit and rigorously derive upscaled equations for a microscopic reaction-diffusion system modeling sulfate corrosion in sewer pipes made of concrete. The system, defined in a periodically-perforated domain, is semi-linear, partially dissipative and weakly coupled via a non-linear ordinary differential equation posed on the solid-water interface at the pore level. First, we show the well-posedness of the microscopic model. We then apply homogenization techniques based on two-scale convergence for a uniformly periodic domain and derive upscaled equations together with explicit formulas for the effective diffusion coefficients and reaction constants. We use a boundary unfolding method to pass to the homogenization limit in the non-linear ordinary differential equation. Finally, we give the strong formulation of the upscaled system.

  • 30.
    Fatima, Tasnim
    et al.
    Eindhoven University of Technology.
    Muntean, Adrian
    Eindhoven University of Technology.
    Aiki, Toyohiko
    Gifu University Yanagido.
    Distributed space scales in a semilinear reaction-diffusion system including parabolic variational inequality: a well-posedness study2012Ingår i: Advances in Mathematical Sciences and Applications, ISSN 1343-4373, Vol. 22, s. 295-318Artikel i tidskrift (Refereegranskat)
  • 31.
    Fatima, Tasnim
    et al.
    Eindhoven Univ Technol, Ctr Anal Sci Comp & Applicat, Dept Math & Comp Sci, NL-5600 MB Eindhoven, Netherlands.
    Muntean, Adrian
    Eindhoven University of Technology.
    Ptashnyk, Maria
    Univ Dundee, Div Math, Dundee DD1 4HN, Scotland.
    Unfolding-based corrector estimates for a reaction-diffusion system predicting concrete corrosion2012Ingår i: Applicable Analysis, ISSN 0003-6811, E-ISSN 1563-504X, Vol. 91, nr 6, s. 1129-1154Artikel i tidskrift (Refereegranskat)
  • 32.
    Fatima, Tasnin
    et al.
    Technical University Eindhoven, The Netherlands.
    Arab, Nasrin
    Technical University Eindhoven, The Netherlands.
    Zemskov, Evgeny P.
    Computing Centre of the Russian Academy of Sciences, Moscow, Russia.
    Muntean, Adrian
    Technical University Eindhoven, The Netherlands.
    Homogenization of a reaction-diffusion system modeling sulfate corrosion of concrete in locally periodic perforated domains2011Ingår i: Journal of Engineering Mathematics, ISSN 0022-0833, E-ISSN 1573-2703, Vol. 69, nr 2, s. 261-276Artikel i tidskrift (Refereegranskat)
  • 33.
    Gogatishvili, Amiran
    et al.
    Czech Acad Sci, Inst Math, Prague, Czech Republic.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Univ Freiburg, Inst Math.
    Pick, Lubos
    Charles Univ Prague, Czech republic.
    Soudsky, Filip
    Czech Tech Univ; Univ South Bohemia, Czech republic.
    Embeddings of Lorentz-type spaces involving weighted integral means2017Ingår i: Journal of Functional Analysis, ISSN 0022-1236, E-ISSN 1096-0783, Vol. 273, nr 9, s. 2939-2980Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We solve the problem of characterizing weights on (0, infinity) for which the inequality involving two possibly different general inner weighted means (integral(infinity)(0)(integral(t)(0)f*(s)(m2)u(2)(s)ds)(p2/m2) w(2)(t)dt)(1/p2) <= C(integral(infinity)(0)(integral(t)(0)f*(s)(m2)u(1)(s)ds)(p1/m1) w(1)(t)dt)(1/p1) holds, where p(1), p(2), m(1), m(2) is an element of (0, infinity) and p(2) > m(2). The proof is based on a new approach combining duality techniques with sharp weighted estimates for iterated integral and supremum operators. (C) 2017 Elsevier Inc. All rights reserved.

  • 34.
    Hedlund, Sara
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Kan elever utveckla sin taluppfattning vid användandet av digitala spel?: En innehållsanalys av digitala spel med fokus på området taluppfattning2017Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet med studien var att undersöka om digitala spel skapade för underhållning kan erbjuda spelaren färdighetsträning inom området taluppfattning i ämnet matematik. Studien genomfördes på 11 spel som valdes med hjälp av barn i årskurs 4–6 och ramverket baseras på McIntosh tolkning av vad taluppfattning innebär och sex aspekter framarbetades. Ett kodningsschema användes för att undersöka om spelen omfattar situationer som innehåller taluppfattning samt hur spelaren kan använda sig av taluppfattning i dessa situationer. Studien visar att möjligheterna för färdighetsträning finns i spelen men vissa spel särskiljer sig då de erbjuder mer komplexa beräkningssituationer än de andra spelen. Aspekten representationer för olika tal skilde sig från de andra då alla analysenheter inte omfattar denna aspekt. Resultatet av studien innebär att lärare kan använda sig av dessa spel och själva analysera spel för att använda dem i matematiska lärandesituationer.

  • 35.
    Höglund, Karl
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    CAP KC3-12: Design and finite element analysis2007Självständigt arbete på grundnivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    In offshore oil production FMC Subsea systems use a product called cap. The cap´s mainly task is to protect hubface and seal areas on inboard hub against dirt, corrosion and mechanical damage under installation of a subsea system. A new model of a cap has been designed and analysed using finite element method. The model is called KC3-12 and has a new function, emergency release, which is a backup method for the ROV (remote operated vehicle) to release the cap from the hubface when it is placed under water. The cap KC3-12 was found to fulfil the criteria under the test load pressure, according to ASME VIII, div2. The analysis shows that a higher pressure can be allowed on the cap since the collapse load occurs at 7.2 times test pressure and 1.2 times test pressure is allowed.

  • 36.
    Ijioma, Ekeoma Rowland
    et al.
    Meiji University,Tokyo, Japan.
    Muntean, Adrian
    Eindhoven University of Technology.
    Ogawa, Toshiyuki
    Meiji University, Tokyo, Japan.
    Pattern formation in reverse smouldering combustion: A homogenisation approach2013Ingår i: Combustion theory and modelling, ISSN 1364-7830, E-ISSN 1741-3559, Vol. 17, nr 2, s. 185-223Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of fingering char patterns on the surface of porous thin materials has been investigated in the framework of reverse combustion. This macroscopic characteristic feature of combustible media has also been studied experimentally and through the use of phenomenological models. However, not much attention has been given to the behaviour of the emerging patterns based on characteristic material properties. Starting from a microscopic description of the combustion process, macroscopic models of reverse combustion that are derived by the application of the homogenisation technique are presented. Using proper scaling by means of a small scale parameter E, the results of the formal asymptotic procedure are justified by qualitative multiscale numerical simulations at the microscopic and macroscopic levels. We consider two equilibrium models that are based on effective conductivity contrasts, in a simple adiabatic situation, to investigate the formation of unstable fingering patterns on the surface of a charred material. The behaviour of the emerging patterns is analysed using primarily the Peclet and Lewis numbers as control parameters.

  • 37.
    Jain, P
    et al.
    South Asian University.
    Kanjilal, S
    South Asian University.
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Hardy-type inequalities over balls in R^N for some bilinear and iterated operators2019Ingår i: Journal of Inequalities and Special Functions, ISSN 2217-4303, E-ISSN 2217-4303, Vol. 10, nr 2, s. 35-48Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Some new multidimensional Hardy-type inequalites are proved and discussed. The cases with bilinear and iterated operators are considered and some equivalence theorems are proved.

  • 38.
    Kanjilal, Saikat
    et al.
    South Asian University.
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Shambilova, G.E
    Peoples' Friendship University of Russia.
    Equivalent Integral Conditions Related to Bilinear Hardy-type Inequalities2019Ingår i: Mathematical Inequalities & Applications, ISSN 1331-4343, E-ISSN 1848-9966Artikel i tidskrift (Refereegranskat)
  • 39.
    Kolyada, Viktor
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    Iterated rearrangements and Gagliardo-Sobolev type inequalities2012Ingår i: Journal of Mathematical Analysis and Applications, ISSN 0022-247X, Vol. 387, nr 1, s. 335-348Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we consider Lorentz type spaces defined in terms of iterated rearrangements of functions of several variables (σ is a permutation of {1,…,n}). Further, we study Fournier–Gagliardo mixed norm spaces V(Rn) closely related to Sobolev spaces . We prove estimate of via ‖fV with the sharp constant. In particular, this gives a refinement of the known Sobolev type inequalities for the space .

  • 40.
    Kolyada, Viktor
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    On Fubini type property in Lorentz spaces2012Ingår i: Recent Advances in Harmonic Analysis and Applications / [ed] Bilyk, D., New York: Springer, 2012, s. 171-179Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    We study Fubini-type property for Lorentz spaces L p,r (R 2 ) . This problem is twofold. First we assume that all linear sections of a function f in directions of coordinate axes belong to L p,r (R) , and their one-dimensional Lp, r-norms belong to L p,r (R). We show that for pr it does not imply that f∈L p,r (R 2 ) (this complements one result by Cwikel). Conversely, we assume that f∈L p,r (R 2 ) , and we show that then for r < p almost all linear sections of f belong to L p,r (R) , but for p < r all linear sections may have infinite one-dimensional Lp, r-norms

  • 41.
    Kolyada, Viktor
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    Lind, Martin
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    On functions of bounded p-variation2009Ingår i: Journal of Mathematical Analysis and Applications, ISSN 0022-247X, E-ISSN 1096-0813, Vol. 356, nr 2, s. 582-604Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We obtain estimates of the total p-variation (1<p<∞) and other related functionals for a periodic function fLp[0,1] in terms of its Lp-modulus of continuity ωp(f;δ). These estimates are sharp for any rate of the decay of ωp(f;δ). Moreover, the constant coefficients in them depend on parameters in an optimal way.

  • 42.
    Kolyada, Viktor
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    Lind, Martin
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik.
    On moduli of p-continuity2012Ingår i: Acta Mathematica Hungarica, ISSN 0236-5294, E-ISSN 1588-2632, Vol. 137, nr 3, s. 191-213Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Moduli of p-continuity provide a measure of fractional smoothness of functions via p-variation. We prove sharp estimates of the modulus of p-continuty in terms of the modulus of q-continuity (1<p<q<\infty).

  • 43.
    Krehel, Oleh
    et al.
    Eindhoven University of Technology, Netherlands.
    Aiki, Toyohiko
    Japan Women's University, Japan.
    Muntean, Adrian
    Eindhoven University of Technology, Netherlands.
    Homogenization of a thermo-diffusion system with smoluchowski interactions2014Ingår i: Networks and Heterogeneous Media, ISSN 1556-1801, E-ISSN 1556-181X, Vol. 9, nr 4, s. 739-762Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the solvability and homogenization of a thermal-diffusion reaction problem posed in a periodically perforated domain. The system describes the motion of populations of hot colloidal particles interacting together via Smoluchowski production terms. The upscaled system, obtained via two-scale convergence techniques, allows the investigation of deposition effects in porous materials in the presence of thermal gradients.

  • 44.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Bilinear weighted Hardy inequality for nonincreasing functions2017Ingår i: Publications mathématiques (Bures-sur-Yvette), ISSN 0073-8301, E-ISSN 1618-1913, Vol. 61, nr 1, s. 3-50Artikel i tidskrift (Refereegranskat)
  • 45.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Charles University in Prague, Department of Mathematical Analysis.
    Boundedness of Hardy-type operators with a kernel: integral weighted conditions for the case $0<q<1\le p<\infty$2017Ingår i: Revista Matemática Complutense, ISSN 1139-1138, E-ISSN 1988-2807, Vol. 30, nr 3, s. 547-587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Boundedness of a fundamental Hardy-type operator with a kernel is characterized between weighted Lebesgue spaces $L^p(v)$ and $L^q(w)$ for $0<q<1\le p<\infty$. The conditions are explicit and have a standard integral form.

  • 46.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Convolution in weighted Lorentz spaces of type Γ2016Ingår i: Mathematica Scandinavica, ISSN 0025-5521, E-ISSN 1903-1807, Vol. 119, nr 1, s. 113-132Artikel i tidskrift (Refereegranskat)
  • 47.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Convolution inequalities in weighted Lorentz spaces2014Ingår i: Mathematical Inequalities & Applications, ISSN 1331-4343, E-ISSN 1848-9966, Vol. 17, nr 4, s. 1201-1223Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We characterize boundedness of a convolution operator with a fixed kernel between the weighted Lorentz spaces Lambda(p)(v) and Gamma(q)(w) for 0 < p <= q <= infinity, 1 <= q < p < infinity and 0 < q <= p = infinity. We provide corresponding weighted Young-type inequalities and also study basic properties of some new involved r.i. spaces.

  • 48.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Charles University in Prague, Department of Mathematical Analysis.
    Convolution inequalities in weighted Lorentz spaces: case 0<q<12017Ingår i: Mathematical Inequalities & Applications, ISSN 1331-4343, E-ISSN 1848-9966, Vol. 20, nr 1, s. 191-201Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We characterize boundedness of a convolution operator between weighted Lorentz spaces $\Lambda^p(v)$and $\Gamma^q(w)$ in the case $0<q<1$.

  • 49.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Forever Young: Convolution Inequalities in Weighted Lorentz-type Spaces2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis is devoted to an investigation of boundedness of a general convolution operator between certain weighted Lorentz-type spaces with the aim of proving analogues of the Young convolution inequality for these spaces.

    Necessary and sufficient conditions on the kernel function are given, for which the convolution operator with the fixed kernel is bounded between a certain domain space and the weighted Lorentz space of type Gamma. The considered domain spaces are the weighted Lorentz-type spaces defined in terms of the nondecreasing rearrangement of a function, the maximal function or the difference of these two quantities.

    In each case of the domain space, the corresponding Young-type convolution inequality is proved and the optimality of involved rearrangement-invariant spaces in shown.

    Furthermore, covering of the previously existing results is also discussed and some properties of the new rearrangement-invariant function spaces obtained during the process are studied.

  • 50.
    Křepela, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Integral conditions for Hardy-type operators involving suprema2017Ingår i: Collectanea Mathematica (Universitat de Barcelona), ISSN 0010-0757, E-ISSN 2038-4815, Vol. 68, nr 1, s. 21-50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The article contains characterizations of boundedness of an iterated supremal Hardy-type operator between weighted Lebesgue spaces, and an supremal Hardy operator restricted to positive decreasing functions between the same spaces. The found condtitions have an explicit integral/supremal form and cover all possible cases of positive exponents of the involved spaces.

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