Browsing by Subject "Partial differential equations"
Now showing items 1-20 of 70
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3D nurbs-enhanced finite element method
(2009-06-08T10:12:04Z)
Conference report
Open AccessAn improvement of the classical finite element method is proposed in [1], the NURBS-Enhanced Finite Element Method (NEFEM). It is able to exactly represent the geometry by means of the usual CAD description of the boundary ... -
A consistent approximation of the total perimeter functional for topology optimization algorithms
(2022-02-24)
Article
Open AccessThis article revolves around the total perimeter functional, one particular version of the perimeter of a shape O contained in a fixed computational domain D measuring the total area of its boundary ¿O, as opposed to its ... -
A critical comparison of two discontinuous galerkin methods for the navier-stokes equations using solenoidal aproximations
(2009-06-08T07:49:26Z)
Conference report
Open AccessThis paper compares two methods to solve incompressible problems, in particular the Navier-Stokes equations, using a discontinuous polynomial interpolation that is exactly divergence-free in each element. The first method ... -
A free boundary problem of codimension two
(2007-06-18)
Audiovisual
Open AccessConferència presentada dins el marc de la GLOBAL School on PDEs: layers and dislocations (Barcelona, UPC, 18-22 juny 2007). -
A mean field equation on a torus: one-dimensional symmetry of solutions
(2003)
Article
Open AccessWe study the equation $$-\Delta u=\lambda\left(\frac{e^u}{\int_\oep e^u}- \frac{1}{|\oep|}\right)\quad \text{in }\oep$$ for $u\in E$, where $E = \{ u \in H^1(\oep): u \hbox{ is doubly periodic}, \int_{\oep} u = 0 \}$ and ... -
A numerical method for computing unstable quasi-periodic solutions for the 2-D Poiseuille flow
(1999)
Article
Open Access -
A Parameterized multi-step Newton method for solving systems of nonlinear equations
(2016-03-01)
Article
Open AccessWe construct a novel multi-step iterative method for solving systems of nonlinear equations by introducing a parameter. to generalize the multi-step Newton method while keeping its order of convergence and computational ... -
Acoplamiento del modelo regional de calidad de aire (CMAQ) con el modelo de emisiones locales mediante elementos finitos
(2009-06-08T09:47:57Z)
Conference report
Open AccessExisten modelos regionales de calidad del aire que son muy utilizados. Estos modelos tienen modelos para estudiar el aporte de contaminantes provocados por fuentes importantes de contaminación, como pueden ser chimeneas, ... -
An implicit finite-element model for 3D non-hydrostatic mesoscale ocean flows
(2004)
Article
Open AccessWe present in this paper a pressure stabilized, finite element method for the numerical approximation of three-dimensional, non-hydrostatic mesoscale ocean flows. The model considered here incorporates surface wind ... -
An interactive mesh generation environment for geometry-based simulations. Progress updated
(2009-02-16T12:15:10Z)
Conference report
Open AccessWe presented an overview of an interactive mesh generation environment in our previous work that it is being developed in the Laboratori de Càlcul Numèric (LaCàN). We started the development of the software in order to ... -
Analysis of a viscoelastic spring-mass model
(2003)
Article
Open AccessIn this paper we consider a linear wave equation with strong damping and dynamical boundary conditions as an alternative model for the classical spring-mass-damper ODE. Our purpose is to compare analytically these two ... -
Application of the measured equation of invariance to radiation and scattering by flat surfaces
(. IEEE AP-S SYMPOSIUM DIGEST, 1993)
Conference report
Open AccessBecause on flat surfaces the electric currents are confined to two dimensions, a simple vector potential formulation can be used. The problem of radiation and scattering by rectangular strip dipoles is solved, including ... -
Automatic generation of quadrilateral structured meshes using linear programming and transfinite interpolation
(2009-04-30T11:25:15Z)
Conference report
Open AccessThis paper presents an implementation of a structured quadrilateral algorithm called submapping. The meshing procedure splits the geometry into patches and then meshes each patch separately preserving the mesh compatibility ... -
Bounded solutions of some nonlinear elliptic equations in cylindrical domains
(1997)
Article
Open AccessThe existence of a (unique) solution of the second order semilinear elliptic equation $$ \sum^{n}_{i,j=0}a_{ij}(x)u_{x_{i}x_{j}}+f(\nabla u,u,x)=0 $$ with $x=(x_{0},x_{1},\dots, x_{n})\in (s_{0},\infty )\times \Omega '$, ... -
Bounds and adaptivity for 3D limit analysis
(2009-06-08T10:28:14Z)
Conference report
Open AccessIn the present paper we compute upper and lower bounds for limit analysis in two and three dimensions. From the solution of the discretised upper and lower bound problems, and from the optimum displacement rate and stress ... -
Canonical Homotopy Operators for @ in the Ball with Respect to the Bergman Metric
(1995)
Article
Open AccessWe notice that some well-known homotopy operators due to Skoda et. al. for the $\bar\partial$-complex in the ball actually give the boundary values of the canonical homotopy operators with respect to certain weighted Bergman ... -
Conformal marked bisection for local refinement of n-dimensional unstructured simplicial meshes
(Elsevier, 2022)
Article
Open AccessWe present an n-dimensional marked bisection method for unstructured conformal meshes. We devise the method for local refinement in adaptive n-dimensional applications. To this end, we propose a mesh marking pre-process ... -
Constraint algorithm for k-presymplectic hamiltonian systems: application to singular field theories
(World Scientific and Engineering Academy and Society (WSEAS), 2009-08-01)
Article
Open AccessThe k-symplectic formulation of field theories is specially simple, since only tangent and cotangent bundles are needed in its description. Its defining elements show a close relationship with those in the symplectic formulation ... -
Derivation of shallow water models for steady and transient phenomena, required assumptions and resulting equations
(2009-04-07T11:25:00Z)
Conference report
Open AccessThe shallow water models describe water flow in rivers, lakes and shallow seas. They are used to study many physical phenomena of interest, such as, modeling environmental effects, commercial activities on fisheries and ... -
Entire solutions of semilinear elliptic equations in R<sup>3</sup> and a conjecture of De Giorgi
(1999)
Article
Open Access
