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A new finite-difference time-domain (FDTD) formulation for modeling graphene is proposed, in which the graphene is modeled as a resistive sheet with a frequency-dependent conductivity. The formulation is first developed in the context of the vector wave finite-element time-domain and then reduced to the FDTD based on the equivalence between these two techniques. The obtained formulation is easy to implement and does not alter the original FDTD update equations. It can be applied to an existing FDTD code by simply adding a correction term to appropriate variables. One of the main contributions of this paper is analyzing the stability of the proposed formulation, which has not been done previously. [ABSTRACT FROM AUTHOR]

A general framework to combine the finite-difference time-domain (FDTD) and the finite-element time-domain (FETD) formulations, both based on the vector wave equation, is proposed. In contrast to the existing stable hybrid FETD-FDTD, there is no transition layer between two subdomains. In addition, the stability of the proposed approach is analytically proved. This framework allows combining different FDTD and FETD formulations together. Particularly, a fully unconditionally stable hybrid method is proposed, which is proved to be energy conservative too. The key ingredient is a finite-element tearing and interconnecting method for electromagnetic problems with a new interface condition that preserves the stability of the numerical method in each region. Several numerical examples are considered in order to validate the proposed methods. The numerical results match with the reference solutions very well in all cases. [ABSTRACT FROM PUBLISHER]

Scalability and low power consumption are major issues in designing custom hardware platforms for accelerating computation intensive electromagnetic applications. Clustered architectures decreases wire delays, power consumption and enhance scalability. We introduce a new steering algorithm that increases the performance of electromagnetic applications on such architectures, making clustering an even more attractive design alternative. The effectiveness of the new method is illustrated for two representative electromagnetic benchmarks. [ABSTRACT FROM AUTHOR]

Communication strategies in parallel finite element methods can greatly affect system performance. The communication cost for a proposed parallel 3-D mesh refinement method with tetrahedra is analyzed. A Petri Nets-based model is developed for a target mesh refinement algorithm and parallel computing system architecture, which simulates the inter-processor communication. Subsequently, estimates for performance measures are derived from discrete event simulations. The potential benefits of this approach for developing high performance parallel mesh refinement algorithms are demonstrated by optimizing the system communication costs for varying problem size and numbers of processors. [ABSTRACT FROM AUTHOR]

Developing models from computational data is a major focus in electromagnetic design. This paper introduces ways of creating customized neural models based on a fuzzy clustering of responses. Fuzzy-clustered neural network (FCNN) models are explored, leading to increases in accuracy. The information contained within FCNN models can also be applied to space mapping electromagnetic optimization. This optimization approach strives to combine the accuracy of fine models (such as finite elements) with the low cost of coarse models. These FCNN enhancements are demonstrated through a patch antenna test case. [ABSTRACT FROM AUTHOR]

An electromagnetic system can be described in a variety of ways. Coarse models provide fast evaluations but lack the required accuracy in the final stages of design. Fine models are highly accurate, but prohibitively expensive. Finding a compromise between these extremes may assist in overcoming bottlenecks in design automation and optimization. One approach is to carry out optimization in the coarse model space and use fine model simulations to fine-tune the result via space mapping. A new response surface space mapping (RSSM) strategy is presented and applied to an E-shaped patch antenna test case. The solutions that emerge are comparable to full fine model optimization at a fraction of the cost. [ABSTRACT FROM AUTHOR]

The potential benefits of employing optimal discretization-based (ODB) refinement criteria for vector tetrahedra to achieve load balancing in three-dimensional parallel adaptive finite-element electromagnetic analysis are considered. Specifically, the ability of this class of adaption refinement criteria to resolve effective domain decompositions based on initial discretizations with only relatively few tetrahedra is examined for generalized vector Helmholtz systems. The effectiveness of the new load balancing method is demonstrated with adaptively refined finite-element meshes for benchmark systems. [ABSTRACT FROM AUTHOR]

Finite-element (FE) accuracy can be directly affected by mesh quality. The potential benefits and related costs of a family of new mesh quality improvement systems are investigated using a suite of electromagnetic benchmarks and mesh quality measures theoretically linked to FE accuracy. Experimental findings suggest error reductions on the order of 10% for half-second runtimes. [ABSTRACT FROM AUTHOR]