Finite element formulation of acoustic scattering phenomena with absorbing boundary condition in the frequency domain

1993 ◽  
Vol 94 (3) ◽  
pp. 1651-1662 ◽  
Author(s):  
H. Gan ◽  
P. L. Levin ◽  
R. Ludwig
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Frequency Domain ◽  
Acoustic Scattering ◽  
Absorbing Boundary Condition ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Absorbing Boundary

Optical Tomography With a Least Square Finite Element Formulation of the Collimated Irradiation in Frequency Domain

2010 ◽  
Author(s):  
Olivier Balima ◽  
Joan Boulanger ◽  
Andre´ Charette ◽  
Daniel Marceau
Keyword(s):  
Finite Element ◽  
Optical Properties ◽  
Frequency Domain ◽  
Complex Geometry ◽  
Numerical Study ◽  
Optical Tomography ◽  
Least Square ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Scattering Media

This paper presents a numerical study of optical tomography in frequency domain for the reconstruction of optical properties of scattering and absorbing media with collimated irradiation light sources. The forward model is a least square finite element formulation of the collimated irradiation problem where the intensity is separated into its collimated and scattered parts. This model does not use any empirical stabilization and moreover the collimated source direction is taken into account. The inversion uses a gradient type minimization method where the gradient is computed through an adjoint formulation. Scaling is used to avoid numerical round errors, as the output readings at detectors are very low. Numerical reconstructions of optical properties of absorbing and scattering media with simulated data (noised and noise-free) are achieved in a complex geometry with satisfactory results. The results show that complex geometries are well handled with the proposed method.

Sign in / Sign up

Export Citation Format

Share Document