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JournalISSN: 1070-4698

Progress in Electromagnetics Research-pier 

About: Progress in Electromagnetics Research-pier is an academic journal. The journal publishes majorly in the area(s): Antenna (radio) & Microstrip. It has an ISSN identifier of 1070-4698. It is also open access. Over the lifetime, 3467 publications have been published receiving 87489 citations. The journal is also known as: Electromagnetic waves monograph series on progress in electromagnetics research & PIER.


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Journal ArticleDOI
TL;DR: The Finite Integration Technique (FIT) as discussed by the authors is a consistent discretization scheme for Maxwell's equations in their integral form, which can be used for efficient numerical simulations on modern computers.
Abstract: The Finite Integration Technique (FIT) is a consistent discretization scheme for Maxwell's equations in their integral form. The resulting matrix equations of the discretized fields can be used for efficient numerical simulations on modern computers. In addition, the basic algebraic properties of this discrete electromagnetic field theory allow to analytically and algebraically prove conservation properties with respect to energy and charge of the discrete formulation and gives an explanation of the stability properties of numerical formulations in the time domain.

519 citations

Journal ArticleDOI
TL;DR: Central Force Optimization is a new deterministic multi-dimensional search metaheuristic based on the metaphor of gravitational kinematics that models “probes” that “fly” through the decision space by analogy to masses moving under the influence of gravity.
Abstract: Central Force Optimization (CFO) is a new deterministic multi-dimensional search metaheuristic based on the metaphor of gravitational kinematics. It models “probes” that “fly” through the decision space by analogy to masses moving under the influence of gravity. Equations are developed for the probes’ positions and accelerations using the analogy of particle motion in a gravitational field. In the physical universe, objects traveling through threedimensional space become trapped in close orbits around highly gravitating masses, which is analogous to locating the maximum value of an objective function. In the CFO metaphor, “mass” is a userdefined function of the value of the objective function to be maximized. CFO is readily implemented in a compact computer program, and sample pseudocode is presented. As tests of CFO’s effectiveness, an equalizer is designed for the well-known Fano load, and a 32-element linear array is synthesized. CFO results are compared to several other optimization methods.

390 citations

Journal ArticleDOI
TL;DR: The photoacoustic tomography (PAT) is an emerging imaging modality that shows great potential for preclinical research and clinical practice as mentioned in this paper, which is based on the acoustic detection of optical absorption from either endogenous chromophores, such as oxy-hemoglobin and deoxy-hemoglobaloglobin, or exogenous contrast agents such as organic dyes and nanoparticles.
Abstract: Photoacoustic tomography (PAT) is an emerging imaging modality that shows great potential for preclinical research and clinical practice. As a hybrid technique, PAT is based on the acoustic detection of optical absorption from either endogenous chromophores, such as oxy-hemoglobin and deoxy-hemoglobin, or exogenous contrast agents, such as organic dyes and nanoparticles. Because ultrasound scatters much less than light in tissue, PAT generates high-resolution images in both the optical ballistic and diffusive regimes. Over the past decade, the photoacoustic technique has been evolving rapidly, leading to a variety of exciting discoveries and applications. This review covers the basic principles of PAT and its different implementations. Strengths of PAT are highlighted, along with the most recent imaging results.

368 citations

Journal ArticleDOI
TL;DR: Van den Berg and Abubakar as discussed by the authors discussed the possibility of the presence of local minima of the nonlinear cost functional and under which conditions they can exist, and introduced a new type of regularization, based on a weighted L 2 total variation norm.
Abstract: We discuss the problem of the reconstruction of the profile of an inhomogeneous object from scattered field data. Our starting point is the contrast source inversion method, where the unknown contrast sources and the unknown contrast are updated by an iterative minimization of a cost functional. We discuss the possibility of the presence of local minima of the nonlinear cost functional and under which conditions they can exist. Inspired by the successful implementation of the minimization of total variation and other edgepreserving algorithms in image restoration and inverse scattering, we have explored the use of these image-enhancement techniques as an extra regularization. The drawback of adding a regularization term to the cost functional is the presence of an artificial weighting parameter in the cost functional, which can only be determined through considerable numerical experimentation. Therefore, we first discuss the regularization as a multiplicative constraint and show that the weighting parameter is now completely prescribed by the error norm of the data equation and the object equation. Secondly, inspired by the edge-preserving algorithms, we introduce a new type of regularization, based on a weighted L2 total variation norm. The advantage is that the updating parameters in the contrast source inversion method can be determined explicitly, without the usual line minimization. In addition this new regularization shows excellent edge-preserving properties. Numerical experiments illustrate that the present multiplicative regularized inversion scheme is very robust, handling noisy as well as limited data very well, without the necessity of artificial regularization parameters. 190 Van den Berg and Abubakar

338 citations

Journal ArticleDOI
TL;DR: In this paper, a general framework for the inversion of electromagnetic measurements in cases where parametrization of the unknown configuration is possible is developed, which can advantageously be used over gradient-based approaches.
Abstract: In this paper, we developed a general framework for the inversion of electromagnetic measurements in cases where parametrization of the unknown configuration is possible. Due to the ill-posed nature of this nonlinear inverse scattering problem, this parametrization approach is needed when the available measurement data are limited and measurements are only carried out from limited transmitter-receiver positions (limited data diversity). By carrying out this parametrization, the number of unknown model parameters that need to be inverted is manageable. Hence the Newton based approach can advantageously be used over gradient-based approaches. In order to guarantee an error reduction of the optimization process, the iterative step is adjusted using a line search algorithm. Further unlike the most available Newton-based approaches available in the literature, we enhanced the Newton based approaches presented in this paper by constraining the inverted model parameters with nonlinear transformation. This constrain forces the reconstruction of the unknown model parameters to lie within their physical bounds. In order to deal with cases where the measurements are redundant or lacking sensitivity to certain model parameters causing non-uniqueness of solution, the cost function to be minimized is regularized by adding a penalty term. One of the crucial aspects of this approach is how to determine the regularization parameter determining the relative importance of the misfit between the measured and predicted data and the penalty term. We reviewed different approaches to determine this parameter and proposed a robust and simple way of choosing this regularization parameter with aid of recently developed multiplicative regularization analysis. By combining all the techniques mentioned above we arrive at an effective and robust parametric algorithm. As numerical examples we present results of electromagnetic inversion at induction frequency in the deviated borehole configuration.

329 citations

Performance
Metrics
No. of papers from the Journal in previous years
YearPapers
202314
202225
202114
202044
201969
2018107