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A novel estimation of the equivalent number of looks (ENL) is proposed in statistical modeling of multilook polarimetric synthetic aperture radar (PolSAR) images for the product model, which is based on the log-determinant moments (LDM). The LDM estimators discovered by looking at certain log-cumulants of the intensities of different polarization channels and the multilook polarimetric covariance matrix, which can be used for both the Gaussian model and all product models. This estimator has analytic expressions, and uses the full covariance matrix and intensities as input, which makes more statistical information available. Experiments based on simulated data and real data are performed. The comparisons among the widely used methods of equivalent number of looks (ENL) estimation for the product model such as K and GO distributions show that the performance of the LDM estimator is outstanding. The performance of estimators for the real data of San Francisco and Flevoland is analyzed and the results are according to those of simulated data. Finally, it can be concluded that the LDM estimator is well robust to each product model with low computational complexity and high accuracy. [ABSTRACT FROM AUTHOR]

Highlights: [•] A robust and efficient Lagrangian scheme is applied to soot transport in flames. [•] Advection and source terms are decoupled therefore robustness is enhanced. [•] The Lagrangian scheme do not compromise realizability in moment methods for soot. [•] If stiff source terms are present, the Lagrangian scheme outperforms Eulerian methods. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we study the accuracy and the efficiency of the monopolar divergence-conforming Rao–Wilton–Glisson (RWG) and the monopolar curl-conforming n × RWG basis functions for the magnetic field integral equation (MFIE). Similar to cases using RWG and n × RWG basis functions for the MFIE, there are two impedance matrix elements calculation schemes if the monopolar RWG and monopolar n × RWG basis functions are used to the MFIE, respectively. The monopolar basis functions and the implementation schemes used for the MFIE are discussed. The scattering cross section data as well as the CPU time needed to fill the corresponding impedance matrix obtained from numerical solutions of these implementation schemes using monopolar basis functions are investigated. For the monopolar basis functions and the implementation schemes considered, the first scheme of the MFIE using the monopolar curl-conforming n × RWG basis functions gives most accurate results and it is the best choice for the use of the monopolar basis functions to the MFIE. [Copyright &y& Elsevier]

We demonstrate that measurement of the membrane potential at one or more sites on a branched and tapered neuron following a known transient injection of subthreshold somatic current uniquely determines the cell''s passive electrical properties. That is, knowledge of the potentials allows recovery of the cell''s axial resistance, membrane capacitance, membrane conductance and soma conductance. The argument underlying uniqueness leads immediately to a constructive, robust algorithm that we successfully test on synthetic data. The robustness stems from the fact that the algorithm requires only a few weighted integrals, or moments, of the measured potentials. [Copyright &y& Elsevier]

We describe a methodology that makes the computational intensive boundary element method/the method of moments feasible for analysing transients on PCBs. The methodology uses a combination of three modelling techniques to reduce the computational demand as well as to overcome the numerical difficulty due to the electrically small dimensions at low frequencies. The techniques used are equivalent wires to model the tracks at low frequencies, 2D sheet impedance approximation for the dielectric substrate and dynamic adaptive sampling to obtain the frequency spectrum. The non-uniformly spaced frequency samples are converted into the impulse response by a modified discrete Fourier transform formula. The transient is then obtained by performing the convolution with the excitation source voltage in the time domain. [Copyright &y& Elsevier]

The second-order realizable ζ moment advection scheme developed in Laurent and Nguyen (2017) is extended to the case of unstructured grids with cells of arbitrary shape. The necessary modifications to the scheme and the conditions under which the scheme ensures the realizability of the advected moment set are presented. The implementation of the scheme in the OpenFOAM® CFD toolbox is verified comparing the results obtained in one-dimensional test cases involving moment sets well inside the moment space, and at the boundary of the moment space. Results obtained with the proposed scheme are compared to the corresponding analytical solution. The scheme is then tested considering two-dimensional cases of pure moment advection with an imposed irrotational velocity field. First, a quadrilateral grid is considered to determine the order of the scheme and compare it to the results reported in Laurent and Nguyen (2017) with the same grid resolution. Then, the accuracy of the scheme on two-dimensional triangular grids is determined. • Realizable advection scheme for moment advection. • Implementation on unstructured grids. • Second-order accuracy on both hexahedral and tetrahedral grids. • Successful advection of moment vectors near the boundary of the moment space. • Open-source implementation into OpenFOAM. [ABSTRACT FROM AUTHOR]