Loading...
Search for: hardiness
0.005 seconds

    Hardy Inequalities

    , M.Sc. Thesis Sharif University of Technology Tavakkoli, Mohsen (Author) ; Ranjbar Motlagh, Alireza (Supervisor)
    Abstract
    In this thesis, it has been introduced Hardy inequality and it’s extends. The fractional Hardy inequality for Ω ⊆ Rn and f ∈ C ∞ (Ω) is:1f (x) − f ( y)2∫α +n2dx dy ≥ kn,α ∫f (x)dx( )αΩ×Ωx − yΩ M α x In this thesis we are going to introduce the fractional and derivative forms of Hardy inequality then the Hardy inequality will be proved to fractional form on Euclidean and Hyperbolic domains, and finally we will get right into Hardy inequality with remainder.
     

    Null controllability of degenerate/singular parabolic equations

    , Article Journal of Dynamical and Control Systems ; Volume 18, Issue 4 , 2012 , Pages 573-602 ; 10792724 (ISSN) Fotouhi, M ; Salimi, L ; Sharif University of Technology
    Springer  2012
    Abstract
    The purpose of this paper is to provide a full analysis of the null controllability problem for the one dimensional degenerate/singular parabolic equation ut - (a(x)ux)x - λ/x βu = 0, (t,x) ∈ (0, T) × (0,1), where the diffusion coefficient a(·) is degenerate at x = 0. Also the boundary conditions are considered to be Dirichlet or Neumann type related to the degeneracy rate of a(·). Under some conditions on the function a(·) and parameters β, λ, we prove global Carleman estimates. The proof is based on an improved Hardy-type inequality  

    Controllability results for a class of one dimensional degenerate/singular parabolic equations

    , Article Communications on Pure and Applied Analysis ; Volume 12, Issue 3 , 2013 , Pages 1415-1430 ; 15340392 (ISSN) Fotouhi, M ; Salimi, L ; Sharif University of Technology
    2013
    Abstract
    We study the null controllability properties of some degenerate/singular parabolic equations in a bounded interval of ℝ. For this reason we derive a new Carleman estimate whose proof is based on Hardy inequalities  

    Existence of positive solution for nonlocal singular fourth order Kirchhoff equation with Hardy potential

    , Article Positivity ; Volume 21, Issue 4 , 2017 , Pages 1545-1562 ; 13851292 (ISSN) Ansari, H ; Vaezpour, S. M ; Hesaaraki, M ; Sharif University of Technology
    Abstract
    This paper is concerned with the existence of positive solution to a class of singular fourth order elliptic equation of Kirchhoff type (Formula Presented.)▵2u-λM(‖∇u‖2)▵u-μ|x|4u=h(x)uγ+k(x)uα,under Navier boundary conditions, u= ▵u= 0. Here Ω⊂ RN, N≥ 1 is a bounded C4-domain, 0 ∈ Ω, h(x) and k(x) are positive continuous functions, γ∈ (0 , 1) , α∈ (0 , 1) and M: R+→ R+ is a continuous function. By using Galerkin method and sharp angle lemma, we will show that this problem has a positive solution for m0 and 0 < μ< μ∗. Here μ∗=(N(N-4)4)2 is the best constant in the Hardy inequality. Besides, if μ= 0 , λ> 0 and h, k are Lipschitz functions, we show that this problem has a positive smooth... 

    A fractional Laplacian problem with mixed singular nonlinearities and nonregular data

    , Article Journal of Elliptic and Parabolic Equations ; Volume 7, Issue 2 , 2021 , Pages 787-814 ; 22969020 (ISSN) Bayrami Aminlouee, M ; Hesaaraki, M ; Sharif University of Technology
    Birkhauser  2021
    Abstract
    In this note, we study on the existence and uniqueness of a positive solution to the following doubly singular fractional problem: {(-Δ)su=K(x)uq+f(x)uγ+μinΩ,u>0inΩ,u=0in(RN\u03a9).Here Ω ⊂ RN (N> 2 s) is an open bounded domain with smooth boundary, s∈ (0 , 1) , q> 0 , γ> 0 , and K(x) is a positive Hölder continuous function in which behaves as dist (x, ∂Ω) -β near the boundary with 0 ≤ β< 2 s. Also, 0 ≤ f, μ∈ L1(Ω) , or non-negative bounded Radon measures in Ω. Moreover, we assume that 0<βs+q<1, or βs+q>1 with 2 β+ q(2 s- 1) < (2 s+ 1). For s∈(0,12), we take advantage of the convexity of Ω. For any γ> 0 , we will prove the existence of a positive weak (distributional) solution to the above... 

    Nonlocal Lazer–McKenna-type problem perturbed by the Hardy’s potential and its parabolic equivalence

    , Article Boundary Value Problems ; Volume 2021, Issue 1 , 2021 ; 16872762 (ISSN) Bayrami Aminlouee, M ; Hesaaraki, M ; Karim Hamdani, M ; Thanh Chung, N ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    In this paper, we study the effect of Hardy potential on the existence or nonexistence of solutions to the following fractional problem involving a singular nonlinearity: {(−Δ)su=λu|x|2s+μuγ+fin Ω,u>0in Ω,u=0in (RN∖Ω). Here 0 < s< 1 , λ> 0 , γ> 0 , and Ω ⊂ RN (N> 2 s) is a bounded smooth domain such that 0 ∈ Ω. Moreover, 0 ≤ μ, f∈ L1(Ω). For 0 < λ≤ Λ N,s, Λ N,s being the best constant in the fractional Hardy inequality, we find a necessary and sufficient condition for the existence of a positive weak solution to the problem with respect to the data μ and f. Also, for a regular datum of f, under suitable assumptions, we obtain some existence and uniqueness results and calculate the rate of... 

    Control of Heat Equations

    , Ph.D. Dissertation Sharif University of Technology Salimi, Leila (Author) ; Fotouhi Firouzabad, Morteza (Supervisor)
    Abstract
    The controllability problem may be formulated roughly as follows. Consider an evolution system (either described in terms of partial or ordinary differential equations) on which we are allowed to act by means of a suitable choice of the control (the right-hand side of the system, the boundary conditions, etc.). Given a time interval 0 < t < T, and initial and final states, the goal is to determine whether there exists a control driving the given initial data to the given final ones in time T. Now, consider the simplest parabolic equation, namely heat equation and suppose that one could act by appropraite controls on this system. The null controllability problem which is one of the very... 

    Semilinear Biharmonic Problem with a Singular Term

    , M.Sc. Thesis Sharif University of Technology Bayrami Aminlouee, Masoud (Author) ; Hesaaraki, Mahmoud (Supervisor)
    Abstract
    The aim of this work is to study the optimal exponent p to have solvability of semilinear biharmonic problem with a singular term in a smooth and bounded domain such that contains origin in Euclidean space with dimension greater than 4. The singular term is related to the Hardy inequality. First of all, it is not difficult to show that any positive supersolution of problem is unbounded near the origin and then additional hypotheses on p are needed to ensure existence of solutions. We will say that problem blows up completely if the solutions to the truncated problems (with a bounded weight instead of the Hardy singularity) tend to infinity for every x in domain as n goes infinity. The main... 

    Singular PDEs with Irregular Data

    , Ph.D. Dissertation Sharif University of Technology Bayrami Aminlouee, Masoud (Author) ; Hesaaraki, Mahmoud (Supervisor) ; Fotouhi Firoozabad, Morteza (Co-Supervisor)
    Abstract
    Singular differential equations have a wide range of applications. Hardy singularities, which are connected to inequalities of the same name and have various extensions, are the most well-known singularities. The application of Hardy inequalities in quantum physics and also in the linearization of reaction-diffusion equations in thermodynamics and combustion theory motivates researchers to examine them. Singularities on a domain's boundary are another well-known type of singularity. In the study of fluid mechanics and pseudoplastic flows, these singularities emerge.Differential equations with coefficients or functions that are simply functions belonging to $ L^1 $, or bounded Radon measures,... 

    High angular resolution diffusion image registration

    , Article Iranian Conference on Machine Vision and Image Processing, MVIP ; Sept , 2013 , Pages 232-236 ; 21666776 (ISSN) ; 9781467361842 (ISBN) Afzali, M ; Fatemizadeh, E ; Soltanian Zadeh, H ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    Diffusion Tensor Imaging (DTI) is a common method for the investigation of brain white matter. In this method, it is assumed that diffusion of water molecules is Gaussian and so, it fails in fiber crossings where this assumption does not hold. High Angular Resolution Diffusion Imaging (HARDI) allows more accurate investigation of microstructures of the brain white matter; it can present fiber crossing in each voxel. HARDI contains complex orientation information of the fibers. Therefore, registration of these images is more complicated than the scalar images. In this paper, we propose a HARDI registration algorithm based on the feature vectors that are extracted from the Orientation... 

    Evaluation of cellular attachment and proliferation on different surface charged functional cellulose electrospun nanofibers

    , Article Carbohydrate Polymers ; Volume 207 , 2019 , Pages 796-805 ; 01448617 (ISSN) Golizadeh, M ; Karimi, A ; Gandomi Ravandi, S ; Vossoughi, M ; Khafaji, M ; Joghataei, M. T ; Faghihi, F ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Fabrication and characterization of different surface charged cellulose electrospun scaffolds including cellulose acetate (CA), cellulose, carboxymethyl cellulose (CMC) and quaternary ammonium cationic cellulose (QACC) for biomedical applications have been reported in this research. Several instrumental techniques were employed to characterize the nanofibers. MTT assay and cell attachment studies were also carried out to determine the cytocompatibility, viability and proliferation of the scaffolds. Fabricated CA, cellulose, CMC and QACC nanofibers had 100–600 nm diameter, −9, −1.75, −12.8, + 22 mV surface potential, 2.5, 4.2, 7.2, 7 MPa tensile strength, 122, 320, 515, 482 MPa Young modules,...