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In the paper, a noncontact conductivity detection method based on the eddy current sensors is designed and analyzed. The sensors consist of an excitation coil and a sensing coil. A finite element (FM) model of the two coaxial coils is established for numerical simulation. Numerical analysis and finite element simulations are employed to analyze the relationship between the conductivity of the measured...
Calderon's method was generalized to deal with the image reconstruction of electrical resistance tomography (ERT) from partial boundary measurements. The electrodes of the ERT sensor are located on part of its boundary, which indicates that the Dirichlet-to-Neumann map is obtained on an open subset of the whole boundary. However, the Dirichlet-to-Neumann map is typically approximated from the data...
In this paper, the effects of the geometrical parameters of Electromagnetic Wave Resistivity (EWR) tool are studied. A model composed of three-layer formation, borehole, metallic mandrel, and coils, was built. The studied geometrical parameters include the cross-sectional shape of the antennas, transmitter-receiver spacing and receiver interval. Numerical analysis and simulations were employed to...
A direct reconstruction method for three-dimensional (3-D) electrical resistance tomography was introduced by using the factorization method. Compared with the traditional image reconstruction algorithms based on the sensitivity/Jacobian matrix, the conductivity distribution in any part of the 3-D region of interest can be obtained directly and independently. A new way to calculate the Neumann-to-Dirichlet...
A direct reconstruction method, termed as the dbar method for electromagnetic tomography (EMT) is introduced. It is suitable to reconstruct distributions with high permeability and low conductivity as well as small size distributions of high conductivity. By using the dbar method, the permeability/conductivity distribution in any part of the region of interest can be obtained directly and independently...
A factorization method was introduced to electromagnetic tomography (EMT) in this paper. Compared with the traditional methods based on the sensitivity theorem, the proposed method can generate the reconstructed images directly. Neither matrix inversion nor iterations is needed in the reconstruction process. The reconstruction process is simple, as the test function is calculated according to the...
A direct reconstruction method for electromagnetic tomography (EMT) is introduced. It is suitable to reconstruct the distributions with high permeability and low conductivity. By using the proposed method, the permeability distribution in any part of the region of interest can be obtained directly and independently. Simulated data for EMT with sixteen coils were obtained in two dimensions. Neither...
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