The effect of the nonlinearity on GCV applied to conjugate gradients in computerized tomography



Título del documento: The effect of the nonlinearity on GCV applied to conjugate gradients in computerized tomography
Revista: Computational & applied mathematics
Base de datos: PERIÓDICA
Número de sistema: 000310700
ISSN: 0101-8205
Autores: 1
2
Instituciones: 1Universidade Federal de Minas Gerais, Departamento de Matematica, Belo Horizonte, Minas Gerais. Brasil
2Universidade Estadual de Campinas, Departamento de Matematica Aplicada, Campinas, Sao Paulo. Brasil
Año:
Volumen: 25
Número: 1
Paginación: 111-128
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, analítico
Resumen en inglés We study the effect of the nonlinear dependence of the iterate x k of Conjugate Gradients method (CG) from the data b in the GCV procedure to stop the iterations. We compare two versions of using GCV to stop CG. In one version we compute the GCV function with the iterate x k depending linearly from the data b and the other one depending nonlinearly. We have tested the two versions in a large scale problem: positron emission tomography (PET). Our results suggest the necessity of considering the nonlinearity for the GCV function to obtain a reasonable stopping criterion
Disciplinas: Matemáticas
Palabras clave: Matemáticas puras,
Validación cruzada,
Tomografía,
Gradiente conjugado
Keyword: Mathematics,
Pure mathematics,
Cross validation,
Tomography,
Conjugate gradient
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