The Experts below are selected from a list of 11427 Experts worldwide ranked by ideXlab platform
Thrasyvoulos N. Pappas - One of the best experts on this subject based on the ideXlab platform.
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Generalized K-Level cutset sampling and reconstruction
2016 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2016Co-Authors: Thrasyvoulos N. PappasAbstract:We propose a family of cutset sampling schemes and a generalized K-Level image reconstruction approach formulated under a minimum mean squared error (MMSE) framework. The K-Level reconstruction approach is a direct generalization of the recently proposed pattern-based approach, and can be applied to periodic samples either on a cutset or on a grid. Our experimental results indicate that the generalization of the K-Level reconstruction approach results in only a small performance loss. For rectangular cutsets, we show that the proposed approach outperforms the cutset-MRF approach as well as two inpainting approaches. Moreover, we show that combining the cutset sampling with an additional point sample inside the periodic structure outperforms K-Level reconstruction from cutset sampling and point sampling under comparable sampling densities.
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ICASSP - Generalized K-Level cutset sampling and reconstruction
2016 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2016Co-Authors: Thrasyvoulos N. PappasAbstract:We propose a family of cutset sampling schemes and a generalized K-Level image reconstruction approach formulated under a minimum mean squared error (MMSE) framework. The K-Level reconstruction approach is a direct generalization of the recently proposed pattern-based approach, and can be applied to periodic samples either on a cutset or on a grid. Our experimental results indicate that the generalization of the K-Level reconstruction approach results in only a small performance loss. For rectangular cutsets, we show that the proposed approach outperforms the cutset-MRF approach as well as two inpainting approaches. Moreover, we show that combining the cutset sampling with an additional point sample inside the periodic structure outperforms K-Level reconstruction from cutset sampling and point sampling under comparable sampling densities.
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ICIP - Pattern-based K-Level cutset reconstruction
2015 IEEE International Conference on Image Processing (ICIP), 2015Co-Authors: Thrasyvoulos N. PappasAbstract:We propose a pattern-based approach for reconstructing K-Level images from cutsets. We construct a database of K-Level cutset block patterns and use it for reconstruction based on fuzzy pattern retrieval and Markov random field (MRF) energy minimization. The proposed approach outperforms previously proposed cutset-MRF approaches as well as inpainting approaches. When integrated into a lossy bilevel image coding scheme that utilizes cutsets, the proposed approach outperforms the state of the art with comparable constraints.
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Pattern-based K-Level cutset reconstruction
2015 IEEE International Conference on Image Processing (ICIP), 2015Co-Authors: Thrasyvoulos N. PappasAbstract:We propose a pattern-based approach for reconstructing K-Level images from cutsets. We construct a database of K-Level cutset block patterns and use it for reconstruction based on fuzzy pattern retrieval and Markov random field (MRF) energy minimization. The proposed approach outperforms previously proposed cutset-MRF approaches as well as inpainting approaches. When integrated into a lossy bilevel image coding scheme that utilizes cutsets, the proposed approach outperforms the state of the art with comparable constraints.
Iain S. Duff - One of the best experts on this subject based on the ideXlab platform.
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Level 3 basic linear algebra subprograms for sparse matrices: a user-level interface
ACM Transactions on Mathematical Software, 1997Co-Authors: Iain S. Duff, Michele Marrone, Giuseppe Radicati, Carlo VittoliAbstract:This article proposes a set of Level 3 Basic Linear Algebra Subprograms and associated kernels for sparse matrices. A major goal is to design and develop a common framework to enable efficient, and portable, implementations of iterative algorithms for sparse matrices on high-performance computers. We have designed the routines to shield the developer of mathematical software from most of the complexities of the various data structures used for sparse matrices. We have kept the interface and suite of codes as simple as possible while at the same time including sufficient functionality to cover most of the requirements of iterative solvers and sufficient flexibility to cover most sparse matrix data structures. An important aspect of our framework is that it can be easily extended to incorporate new kernels if the need arises. We discuss the design, implementation, and use of subprograms for the multiplication of a fully matrix by a sparse one and for the solution of sparse triangular systems with one or more (full) right-hand sides. We include a routine for checking the input data, generating a new sparse data structure from the input, and scaling a sparse matrix. The new data structure for the transformation can be specified by the user or can be chosen automatically by vendors to be efficient on their machines. We also include a routine for permuting the columns of a sparse matrix and one for permuting the rows of a full matrix.
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algorithm 679 a set of level 3 basic linear algebra subprograms model implementation and test programs
ACM Transactions on Mathematical Software, 1990Co-Authors: Jack Dongarra, Jermey Du Cruz, Sven Hammarling, Iain S. DuffAbstract:This paper describes a model implementation and test software for the Level 3 Basic Linear Algebra Subprograms (Level3 BLAS). The Level3 BLAS are targeted at matrix-matrix operations with the aim of providing more efficient, but portable, implementations of algorithms on high-performance computers. The model implementation provides a portable set of Fortran 77 Level 3 BLAS for machines where specialized implementations do not exist or are not required. The test software aims to verify that specialized implementations meet the specification of the Level 3 BLAS and that implementations are correctly installed.
Nicolas Chevaugeon - One of the best experts on this subject based on the ideXlab platform.
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a level set based model for damage growth the thick level set approach
International Journal for Numerical Methods in Engineering, 2011Co-Authors: Nicolas Moes, Claude Stolz, Paulemile Bernard, Nicolas ChevaugeonAbstract:In this paper, we introduce a new way to model damage growth in solids. A level set is used to separate the undamaged zone from the damaged zone. In the damaged zone, the damage variable is an explicit function of the level set. This function is a parameter of the model. Beyond a critical length, we assume the material to be totally damaged, thus allowing a straightforward transition to fracture. The damage growth is expressed as a level set propagation. The configurational force driving the damage front is non-local in the sense that it averages information over the thickness in the wake of the front. The computational and theoretical advantages of the new damage model are stressed. Numerical examples demonstrate the capability of the new model to initiate cracks and propagate them even in complex topological patterns (branching and merging for instance).
N. G. Kolin - One of the best experts on this subject based on the ideXlab platform.
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Correlation between energy positions of deep intrinsic point-defect levels and a limiting fermi level in irradiated III–V semiconductors
Russian Physics Journal, 2007Co-Authors: V. N. Brudnyi, S. N. Grinyaev, N. G. KolinAbstract:The energy levels of neutral anion (V_A) and cation (V_C) vacancies and antisite defects are calculated for the anion C_A and cation A_C sublattices of III–V semiconductors. An averaged energy level position for these defects is estimated to be E_av ^abs = 4.9 eV. The position coincides with the local charge electroneutrality level. It is shown that the case, where the total energies of formation of V_A, V_C and antisite C_A, A_C defects in the sublattices of binary semiconductors are similar, corresponds to the point-defect equilibrium condition and stabilization of the Fermi level in the proximity of the local charge electroneutrality level.
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correlation between energy positions of deep intrinsic point defect levels and a limiting fermi level in irradiated iii v semiconductors
Russian Physics Journal, 2007Co-Authors: V. N. Brudnyi, S. N. Grinyaev, N. G. KolinAbstract:The energy levels of neutral anion (VA) and cation (VC) vacancies and antisite defects are calculated for the anion CA and cation AC sublattices of III–V semiconductors. An averaged energy level position for these defects is estimated to be Eav abs = 4.9 eV. The position coincides with the local charge electroneutrality level. It is shown that the case, where the total energies of formation of VA, VC and antisite CA, AC defects in the sublattices of binary semiconductors are similar, corresponds to the point-defect equilibrium condition and stabilization of the Fermi level in the proximity of the local charge electroneutrality level.
Nicolas Moes - One of the best experts on this subject based on the ideXlab platform.
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a level set based model for damage growth the thick level set approach
International Journal for Numerical Methods in Engineering, 2011Co-Authors: Nicolas Moes, Claude Stolz, Paulemile Bernard, Nicolas ChevaugeonAbstract:In this paper, we introduce a new way to model damage growth in solids. A level set is used to separate the undamaged zone from the damaged zone. In the damaged zone, the damage variable is an explicit function of the level set. This function is a parameter of the model. Beyond a critical length, we assume the material to be totally damaged, thus allowing a straightforward transition to fracture. The damage growth is expressed as a level set propagation. The configurational force driving the damage front is non-local in the sense that it averages information over the thickness in the wake of the front. The computational and theoretical advantages of the new damage model are stressed. Numerical examples demonstrate the capability of the new model to initiate cracks and propagate them even in complex topological patterns (branching and merging for instance).
