A fast parametric modelling algorithm with the Powell method.
Physiol Meas
; 16(3 Suppl A): A39-47, 1995 Aug.
Article
en En
| MEDLINE
| ID: mdl-8528125
ABSTRACT
This paper presents a model that comprises only two parameters (R/S, fr) and the application of three function minimization algorithms (simplex, Powell and modified Powell) to this model to obtain parametric images. Comparisons among the three algorithms in terms of efficiency and reliability were carried out. It was found that, with proper initialization by taking the shape of the modelled data into consideration, the minimization function can be approximated by a quadratic function near the minimum point, therefore the iteration times can be minimized in the modified Powell method. The results show that with the modified Powell method a substantial reduction of computation time can be achieved in the parametric imaging. This makes it possible to obtain a 16 x 16 parametric image in 1 s.
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Bases de datos:
MEDLINE
Asunto principal:
Algoritmos
/
Impedancia Eléctrica
Tipo de estudio:
Clinical_trials
/
Prognostic_studies
Idioma:
En
Revista:
Physiol Meas
Asunto de la revista:
BIOFISICA
/
ENGENHARIA BIOMEDICA
/
FISIOLOGIA
Año:
1995
Tipo del documento:
Article
País de afiliación:
Reino Unido