WorldCat Identities

Llorente, Ignacio M.

Overview
Works: 13 works in 42 publications in 2 languages and 402 library holdings
Genres: Conference papers and proceedings 
Roles: Author, Editor, htt, Author of introduction, Other
Classifications: TK5105.875.I57, 004.678
Publication Timeline
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Most widely held works by Ignacio M Llorente
Semicoarsening and implicit smoothers for the simulation of a flat plate at yaw by Ruben S Montero( Book )

5 editions published in 2001 in English and held by 111 WorldCat member libraries worldwide

This paper presents a full multigrid solver for the simulation of flow over a yawed at plate. The two problems associated with this simulation; boundary layers and entering flows with non-aligned characteristics, have been successfully overcome through the combination of a plane-implicit solver and semicoarsening. In fact, this multigrid algorithm exhibits a textbook multigrid convergence rate, i.e., the solution of the discrete system of equations is obtained in a fixed amount of computational work, independently of the grid size, grid stretching factor and non-alignment parameter. Also, a parallel variant of the smoother based on a four-color ordering of planes is investigated
Plane smoothers for multiblock grids : computational aspects by Ignacio M Llorente( Book )

4 editions published in 1999 in English and held by 97 WorldCat member libraries worldwide

Robust multigrid smoothers for three dimensional elliptic equations with strong anisotropies by Ignacio M Llorente( Book )

3 editions published in 1998 in English and held by 95 WorldCat member libraries worldwide

Abstract: "We discuss the behavior of several plane relaxation methods as multigrid smoothers for the solution of a discrete anisotropic elliptic model problem on cell-centered grids. The methods compared are plane Jacobi with damping, plane Jacobi with partial damping, plane Gauss-Seidel, plane zebra Gauss-Seidel, and line Gauss-Seidel. Based on numerical experiments and local mode analysis, we compare the smoothing factor of the different methods in the presence of strong anisotropies. A four-color Gauss-Seidel method is found to have the best numerical and architectural properties of the methods considered in the present work. Although alternating direction plane relaxation schemes are simpler and more robust than other approaches, they are not currently used in industrial and production codes because they require the solution of a two-dimensional problem for each plane in each direction. We verify the theoretical predictions of Thole and Trottenberg that an exact solution of each plane is not necessary and that a single two-dimensional multigrid cycle gives the same result as an exact solution, in much less execution time. Parallelization of the two-dimensional multigrid cycles, the kernel of the three-dimensional implicit solver, is also discussed. Alternating-plane smoothers are found to be highly efficient multigrid smoothers for anisotropic elliptic problems."
Towards a Service-Based Internet : 4th European Conference, ServiceWave 2011, Poznan, Poland, October 26-28, 2011, Proceedings by Witold Abramowicz( )

9 editions published in 2011 in English and German and held by 64 WorldCat member libraries worldwide

This volume constitutes the refereed proceedings of the Fourth European Conference, ServiceWave 2011, held in Poznan, Poland, in October 2011. The 25 revised full papers presented together with 3 invited presentations were carefully reviewed and selected from numerous submissions. They are organized in topical sections on cloud computing, security, privacy and trust, service engineering fundamentals, business services, and FI-PPP. In addition to the scientific track, 14 extended abstracts of demonstrations covering a wide spectrum of technology and application domains were accepted
Towards a Service-Based Internet : 4th European Conference, ServiceWave 2011, Poznan, Poland, October 26-28, 2011. Proceedings( )

2 editions published in 2011 in English and held by 7 WorldCat member libraries worldwide

This volume constitutes the refereed proceedings of the Fourth European Conference, ServiceWave 2011, held in Poznan, Poland, in October 2011. The 25 revised full papers presented together with 3 invited presentations were carefully reviewed and selected from numerous submissions. They are organized in topical sections on cloud computing, security, privacy and trust, service engineering fundamentals, business services, and FI-PPP. In addition to the scientific track, 14 extended abstracts of demonstrations covering a wide spectrum of technology and application domains were accepted
An efficient parallel multigrid solver for 3-D convection-dominated problems by Ignacio M Llorente( Book )

5 editions published in 2000 in English and held by 6 WorldCat member libraries worldwide

Multigrid algorithms are known to be highly efficient in solving systems of elliptic equations. However, standard multigrid algorithms fail to achieve optimal grid-independent convergence rates in solving non-elliptic problems. In many practical cases, the non-elliptic part of a problem is represented by the convection operator. Downstream marching, when it is viable, is the simplest and most efficient way to solve this operator. However, in a parallel setting, the sequential nature of marching degrades the efficiency of the algorithm. The aim of this report is to present, evaluate and analyze an alternative highly parallel multigrid method for 3-D convection-dominated problems. This method employs semi-coarsening, a four-color plane-implicit smoother, and discretization rules allowing the same cross-characteristic interactions on all the grids involved to be maintained. The resulting multigrid solver exhibits a fast grid-independent convergence rate for solving the convection-diffusion operator on cell-centered grids with stretching. The load imbalance below the critical level is the main source of inefficiency in its parallel implementation. A hybrid smoother that degrades the convergence properties of the method but improves its granularity has been found to be the best choice in a parallel setting. The numerical and parallel properties of the multigrid algorithm with the four-color and hybrid smoothers are studied on SGI Origin 2000 and Cray T3E systems
A parallel multigrid solver for viscous flows on anisotropic structured grids by Manuel Prieto( Book )

3 editions published in 2001 in English and held by 4 WorldCat member libraries worldwide

Abstract: "This paper presents an efficient parallel multigrid solver for speeding up the computation of a 3-D model that treats the flow of a viscous fluid over a flat plate. The main interest of this simulation lies in exhibiting some basic difficulties that prevent optimal multigrid efficiencies from being achieved. As the computing platform, we have used Coral, a Beowulf-class system based on Intel Pentium processors and equipped with GigaNet cLAN and switched Fast Ethernet networks. Our study not only examines the scalability of the solver but also includes a performance evaluation of Coral where the investigated solver has been used to compare several of its design choices, namely, the interconnection network (GigaNet versus switched Fast-Ethernet) and the node configuration (dual nodes versus single nodes). As a reference, the performance results have been compared with those obtained with the NAS-MG benchmark."
An experimental framework for executing applications in dynamic grid environments by Eduardo Huedo( Book )

4 editions published in 2002 in English and held by 4 WorldCat member libraries worldwide

"The Grid opens up opportunities for resource-starved scientists and engineers to harness highly distributed computing resources. A number of Grid middleware projects are currently available to support the simultaneous exploitation of heterogeneous resources distributed in different administrative domains. However, efficient job submission and management continue being far from accessible to ordinary scientists and engineers due to the dynamic and complex nature of the Grid. This report describes a new Globus framework that allows an easier and more efficient execution of jobs in a 'submit and forget' fashion. Adaptation to dynamic Grid conditions is achieved by supporting automatic application migration following performance degradation, 'better' resource discovery, requirement change, owner decision or remote resource failure. The report also includes experimental results of the behavior of our framework on the TRGP testbed."--NASA Technical Report Server
OpenNebula 3 cloud computing : set up, manage, and maintain your cloud and learn solutions for datacenter virtualization with this step-by-step practical guide by Giovanni Toraldo( Book )

1 edition published in 2012 in English and held by 4 WorldCat member libraries worldwide

This is a step-by-step practical guide to get you started easily with OpenNebula. It guides you to build, maintain, and configure your cloud infrastructure, providing real-world examples in a simple and coherent manner. If you are a GNU/Linux system administrator with no experience with virtualization or cloud computing but eager to learn about it, or you are thwarted by your current virtualized infrastructure, this book is for you. You are expected to have some basic knowledge of GNU/Linux, with knowledge of basic package management tools and system configuration
Robust multigrid algorithms for the incompressible Navier-Stokes equations by Ruben S Montero( Book )

3 editions published in 2000 in English and held by 4 WorldCat member libraries worldwide

Anisotropies occur naturally in CFD where the simulation of small scale physical phenomena, such as boundary layers at high Reynolds numbers, causes the grid to be highly stretched leading to a slow down in convergence of multigrid methods. Several approaches aimed at making multigrid a robust solver have been proposed and analyzed in literature using the scalar diffusion equation. However, they have been rarely applied to solving more complicated models, like the incompressible Navier-Stokes equations. This paper contains the first published numerical results of the behavior of two popular robust multigrid approaches (alternating-plane smoothers combined with standard coarsening and plane implicit smoothers combined with semi-coarsening) for solving the 3-D incompressible Navier-Stokes equations in the simulation of the driven cavity and a boundary layer over a flat plate on a stretched grid. The discrete operator is obtained using a staggered-grid arrangement of variables with a finite volume technique and second-order accuracy is achieved using defect correction within the multigrid cycle. Grid size, grid stretching and Reynolds number are the factors considered in evaluating the robustness of the multigrid methods. Both approaches yield large increases in convergence rates over cell-implicit smoothers on stretched grids. The combination of plane implicit smoothers and semi-coarsening was found to be fully robust in the fiat plate simulation up to Reynolds numbers 10(exp 6) and the best alternative in the driven cavity simulation for Reynolds numbers above 10(exp 3). The alternating-plane approach exhibits a better behavior for lower Reynolds numbers (below to 10(exp 3) in the driven cavity simulation. A parallel variant of the smoother, tri-plane ordering, presents a good trade-off between convergence and parallel properties
Efficient resource provisioning for elastic Cloud services based on machine learning techniques by Rafael Moreno Vozmediano( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Robust multigrid algorithms for incompressible Navier-Stokes equations by Ruben S Montero( Book )

1 edition published in 2000 in English and held by 2 WorldCat member libraries worldwide

Implementation and Provisioning of Federated Networks in Hybrid Clouds by Rafael Moreno Vozmediano( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

 
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Towards a Service-Based Internet : 4th European Conference, ServiceWave 2011, Poznan, Poland, October 26-28, 2011, Proceedings
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OpenNebula 3 cloud computing : set up, manage, and maintain your cloud and learn solutions for datacenter virtualization with this step-by-step practical guide
Alternative Names
Llorente, Ignacio Martín

Languages
English (41)

German (1)