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    M. Kindelan

    A methodology is presented for semiautomatically supplying information about the location, shape, dimensions and absolute and relative temperatures in areas with geothermal anomalies. The system uses an aircraft-borne M2S multispectral... more
    A methodology is presented for semiautomatically supplying information about the location, shape, dimensions and absolute and relative temperatures in areas with geothermal anomalies. The system uses an aircraft-borne M2S multispectral scanner mounted on a CASA 212 aircraft. The sensor collects data in 11 wavelength bands, including a thermal infrared band between 8 and 14 microns. The system was tested in
    ... Complex Fourier Series', Math. of Comp. 19,297-301. Darema-Rogers, E, George, DA, Norton, VA, and Pfister, G. E: 1985, ~ VM Parallel Environ-ment', IBM Research Report RCl1225, Yorktown Heights, NY. Di Chio, P and ...
    Research Interests:
    This paper presents a cost-effectiveness analysis of explicit Finite Difference (FD) methods for the numerical integration of the wave equation. Formal notions of computational cost (expressed in floating point operations) and numerical... more
    This paper presents a cost-effectiveness analysis of explicit Finite Difference (FD) methods for the numerical integration of the wave equation. Formal notions of computational cost (expressed in floating point operations) and numerical dispersion error are introduced. Restricting the analysis to leapfrog timemarching, for sake of simplicity, various spatial discrete differentiators are examined. For each scheme, by minimizing the cost at a given error threshold, a cost-effective operating poin (time sampling rate and number of gridpoints per shortest wavelength) is obtained, which is remarkably different from the stability limit. Different schemes, each operated at its cost-effective point, are then compared. High-order dispersion-bounded operators, in the sense of Holberg,1 are found to be competitive with the Pseudo-spectral (PS) method.New optimal schemes improving over the Holberg's spatial differentiators are introduced together with accurate expansions of the convolutional weights is terms of the design error threshold. It is also shown that the composition of two distinct Holberg's operators of consecutive orders, with opposite phase properties, minimizes dispersion and yields cost-effective schemes.Numerical experiments illustrate the suitability of the new methods for large-scale wave-equation seismic modelling.
    Research Interests:
    Finite‐difference (FD) techniques have established themselves as viable tools for the numerical modeling of wave propagation. The accuracy and the computational efficiency of numerical modeling can be enhanced by using high‐order spatial... more
    Finite‐difference (FD) techniques have established themselves as viable tools for the numerical modeling of wave propagation. The accuracy and the computational efficiency of numerical modeling can be enhanced by using high‐order spatial differential operators ( ...
    Recently, very intensive efforts have been devoted to develop meshless or element free methods that eliminate the need of element connectivity in the solution of PDEs. The motivation is to cut down modelling costs in industrial... more
    Recently, very intensive efforts have been devoted to develop meshless or element free methods that eliminate the need of element connectivity in the solution of PDEs. The motivation is to cut down modelling costs in industrial applications by avoiding the labor intensive step of mesh generation. In addition, these methods are particularly attractive in problems with moving interfaces since no
    ABSTRACT
    ... SPE 100291 Simultaneous Characterization of Geological Shapes and Permeability Distributions in Reservoirs Using the Level Set Method R. Villegas, O. Dorn, M. Moscoso, and M. Kindelán, U. Carlos III de Madrid, and F. Mustieles,... more
    ... SPE 100291 Simultaneous Characterization of Geological Shapes and Permeability Distributions in Reservoirs Using the Level Set Method R. Villegas, O. Dorn, M. Moscoso, and M. Kindelán, U. Carlos III de Madrid, and F. Mustieles, Repsol-YPF Page 2. 2 SPE 100291 ...
    ABSTRACT Curing of epoxy resins with aliphatic diamines at low temperatures deviates from the 4EQ mechanism (catalytic and non-catalytic dual path) at relatively low conversions, far from vitrification. Although the Horie mechanism relies... more
    ABSTRACT Curing of epoxy resins with aliphatic diamines at low temperatures deviates from the 4EQ mechanism (catalytic and non-catalytic dual path) at relatively low conversions, far from vitrification. Although the Horie mechanism relies on a third order reaction it is possible a more realistic approach to epoxy curing kinetics if a detailed analysis of auto-acceleration is made. A single parameter dependent only on the nature of the amine is proposed.
    In this paper, we introduce a radial basis function collocation method for computing solutions to the time-dependent radiative transfer equation. For these computations, we use finite differences to discretize the time coordinate, a... more
    In this paper, we introduce a radial basis function collocation method for computing solutions to the time-dependent radiative transfer equation. For these computations, we use finite differences to discretize the time coordinate, a discrete ordinate method to discretize the directional variable, and an expansion in radial basis functions to approximate the spatial dependence of the solution. The main advantages of
    Tunable oscillatory modes of electric-field domains in doped semiconductor superlattices are reported. The experimental investigations demonstrate the realization of tunable, GHz frequencies in GaAs-AlAs superlattices covering the... more
    Tunable oscillatory modes of electric-field domains in doped semiconductor superlattices are reported. The experimental investigations demonstrate the realization of tunable, GHz frequencies in GaAs-AlAs superlattices covering the temperature region from 5 to 300 K. The orgin of the tunable oscillatory modes is determined using an analytical and a numerical modeling of the dynamics of domain formation. Three different oscillatory modes are found. Their presence depends on the actual shape of the drift velocity curve, the doping density, the boundary condition, and the length of the superlattice. For most bias regions, the self-sustained oscillations are due to the formation, motion, and recycling of the domain boundary inside the superlattice. For some biases, the strengths of the low and high field domain change periodically in time with the domain boundary being pinned within a few quantum wells. The dependency of the frequency on the coupling leads to the prediction of a new type...
    ABSTRACT In this work we explore the applicability of the RBF method to laminar flame propagation modeling. This problem is an interesting challenge for the RBF method since it involves the solution of two coupled nonlinear parabolic... more
    ABSTRACT In this work we explore the applicability of the RBF method to laminar flame propagation modeling. This problem is an interesting challenge for the RBF method since it involves the solution of two coupled nonlinear parabolic equations in temperature and mass fraction. We show the suitability of the method by solving unsteady flame propagation problems in one and two dimensions. We also apply the method to compute the shape of an anchored flame using both equispaced and non-equispaced nodes.
    A method is proposed to improve the accuracy of the numerical solution of elliptic problems with discontinuous boundary conditions using both global and local meshless collocation methods with multiquadrics as basis functions. It is based... more
    A method is proposed to improve the accuracy of the numerical solution of elliptic problems with discontinuous boundary conditions using both global and local meshless collocation methods with multiquadrics as basis functions. It is based on the use of special functions which capture the singular behavior near discontinuities in boundary conditions. In the case of global collocation, the method consists
    ... hard to reconcile with the notion of a structured numerical support, and a mesh or a ... lines or planes rather than isolated singularities has been less explored in meshfree methods. ... solved a turbulent combustion problem, in... more
    ... hard to reconcile with the notion of a structured numerical support, and a mesh or a ... lines or planes rather than isolated singularities has been less explored in meshfree methods. ... solved a turbulent combustion problem, in which the flame is a discontinuous (shock) free boundary ...
    In this paper we consider the problem of injecting a non-Newtonian fluid into a thin cavity. Using the Hele–Shaw approximation the problem reduces to a moving boundary problem in which the pressure is described by a 2D, nonlinear,... more
    In this paper we consider the problem of injecting a non-Newtonian fluid into a thin cavity. Using the Hele–Shaw approximation the problem reduces to a moving boundary problem in which the pressure is described by a 2D, nonlinear, elliptic equation. Mesh-free methods are ...
    ABSTRACT In this work we present a novel level set technique for shape reconstruction in history matching for reservoirs with two or more kinds of rocks (the so-called lithofacies) using stochastic initializations. In the paper we discuss... more
    ABSTRACT In this work we present a novel level set technique for shape reconstruction in history matching for reservoirs with two or more kinds of rocks (the so-called lithofacies) using stochastic initializations. In the paper we discuss the use of sequential Gaussian simulation for the creation of geostatistical initial guesses which will then be applied to an earlier introduced level set based shape reconstruction algorithm for the history matching problem in reservoir characterization. The shapes or regions with sharp interfaces to each other are represented by a level set function which needs to be determined from the production data gathered at few locations of the reservoir. We present numerical results in 2D which demonstrate that our method is able to provide reliable estimates of this structure from these relatively few production data even though the topology of the unknown regions is a priori unknown.
    By asymptotic methods, which treat the ratio of the thermal energy to the activation energy for gasification as a small parameter, the entire temperature-time history is derived for a semi-infinite solid, whose surface is subjected to a... more
    By asymptotic methods, which treat the ratio of the thermal energy to the activation energy for gasification as a small parameter, the entire temperature-time history is derived for a semi-infinite solid, whose surface is subjected to a constant energy flux. It is found that an initial stage of inert heat-conduction is separated from a final stage of transport-controlled gasification by
    In an earlier paper an asymptotic analysis was presented for the radiant ignition of a solid fuel that gasifies endothermically then reacts exothermically in the gas phase through a one-step Arrhenius process. The theory was restricted to... more
    In an earlier paper an asymptotic analysis was presented for the radiant ignition of a solid fuel that gasifies endothermically then reacts exothermically in the gas phase through a one-step Arrhenius process. The theory was restricted to surface absorption of the incoming radiation and to ignitions occurring during the stage of transport-controlled gasification which follows the stage of transition to
    Abstract An asymptotic analysis is presented for the ignition of a solid fuel that gasifies endothermically then reacts exothermically in the gas phase through a one-step Arrhenius process. The endothermic gasification was analyzed in an... more
    Abstract An asymptotic analysis is presented for the ignition of a solid fuel that gasifies endothermically then reacts exothermically in the gas phase through a one-step Arrhenius process. The endothermic gasification was analyzed in an earlier paper; the present ...
    Purpose – The Motz problem can be considered as a benchmark problem for testing the performance of numerical methods in the solution of elliptic problems with boundary singularities. The purpose of this paper is to address the solution of... more
    Purpose – The Motz problem can be considered as a benchmark problem for testing the performance of numerical methods in the solution of elliptic problems with boundary singularities. The purpose of this paper is to address the solution of the Motz problem using the radial basis function (RBF) method, which is a truly meshfree scheme. Design/methodology/approach – Both the global