Alejandro Garcia - Academia.edu (original) (raw)

Papers by Alejandro Garcia

Journal of Applied Non-classical Logics, 2003

Computing Research Repository, 2003

The work reported here introduces Defeasible Logic Programming (DeLP), a formalism that combines ... more The work reported here introduces Defeasible Logic Programming (DeLP), a formalism that combines results of Logic Programming and Defeasible Argumentation. DeLP provides the possibility of representing information in the form of weak rules in a declarative manner, and a defeasible argumentation inference mechanism for warranting the entailed conclusions.

Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsis... more Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsistent information. When strong negation is also allowed, contradictory conclusions can arise. A criterion for deciding between them is needed. The aim of this paper is to investigate an inherent and autonomous comparison criterion, based on specificity as defined in . In contrast to other approaches, we consider not only defeasible, but also strict knowledge. Our criterion is context-sensitive, i.e. preference among defeasible rules is determined dynamically during the dialectical analysis. We show how specificity can be defined in terms of two different approaches: activation sets and derivation trees. This allows us to get a more syntactic criterion that can be implemented in a computationally attractive way. The resulting definitions may be applied in general rule-based formalisms. We present theorems linking both characterizations. Finally we discuss other frameworks for defeasible reasoning in which preference handling is considered explicitly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Journal of Computational Physics, 1998

Journal of Computational Physics, 1998

Journal of Computational Physics, 1998

Journal of Applied Non-classical Logics, 2003

Computing Research Repository, 2003

The work reported here introduces Defeasible Logic Programming (DeLP), a formalism that combines ... more The work reported here introduces Defeasible Logic Programming (DeLP), a formalism that combines results of Logic Programming and Defeasible Argumentation. DeLP provides the possibility of representing information in the form of weak rules in a declarative manner, and a defeasible argumentation inference mechanism for warranting the entailed conclusions.

Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsis... more Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsistent information. When strong negation is also allowed, contradictory conclusions can arise. A criterion for deciding between them is needed. The aim of this paper is to investigate an inherent and autonomous comparison criterion, based on specificity as defined in . In contrast to other approaches, we consider not only defeasible, but also strict knowledge. Our criterion is context-sensitive, i.e. preference among defeasible rules is determined dynamically during the dialectical analysis. We show how specificity can be defined in terms of two different approaches: activation sets and derivation trees. This allows us to get a more syntactic criterion that can be implemented in a computationally attractive way. The resulting definitions may be applied in general rule-based formalisms. We present theorems linking both characterizations. Finally we discuss other frameworks for defeasible reasoning in which preference handling is considered explicitly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Journal of Statistical Physics, 1995

A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately contr... more A three-dimensional thermal lattice-Boltzmann model with two relaxation times to separately control viscosity and thermal diffusion is developed. Numerical stability of the model is significantly improved using Lax-Wendroff advection to provide and adjustable time step. Good agreement with a conventional fiitedifference Navier-Stokes solver is obtained in modeling compressible Rayleigh-Bénard convestion when boundary conditions are treated similarly.

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Physical Review Letters, 1995

A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder L... more A Consistent Boltzmann Algorithm. Francis J. Alexander, Alejandro L. Garcia, and Berni J. Alder Lawrence Livermore National Laboratory, Livermore, California 94550. Received 14 February 1995 The direct simulation Monte ...

Physics of Fluids, 2000

Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)].... more Time step truncation error in direct simulation Monte Carlo. [Physics of Fluids 12, 2621 (2000)]. Alejandro L. Garcia, Wolfgang Wagner. Abstract. The time step truncation error in direct simulation Monte Carlo calculations is found ...

Journal of Computational Physics, 1998

Journal of Computational Physics, 1998

Journal of Computational Physics, 1998