Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047337
M. Manguoglu
A solver for sparse linear systems is an important kernel in many areas of science and engineering. Typically, sparse linear systems of equations arise from the discretization of partial differential equations (PDEs), while some sparse systems are not governed by PDEs. Even in the case that the coefficient matrix is dense, applications still require an effective preconditioner, which is often sparse. For solving large problems, one needs to resort to parallel computing in order to reduce the time to solution. Sparse algorithms are well-known for their poor utilization of the cache due to irregular memory access. In addition, traditional algorithms that are designed for sequential platforms usually have inherited limitations for parallelism. Therefore, there is a need for novel algorithms to work on today's multicore clusters. Given a system of equations Ax = f, where A is large and sparse, it is known that hybrid solvers that contain both direct and iterative components are promising in terms of robustness and scalability on parallel computing platforms. In this paper, we review the generalized parallel sparse DS factorization algorithm and its relationship to sparse graphs. We will provide an example of parallel scalability of the hybrid solver compared to other well-known preconditioned Krylov subspace methods.
{"title":"A parallel sparse solver and its relation to graphs","authors":"M. Manguoglu","doi":"10.1109/CEM.2011.6047337","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047337","url":null,"abstract":"A solver for sparse linear systems is an important kernel in many areas of science and engineering. Typically, sparse linear systems of equations arise from the discretization of partial differential equations (PDEs), while some sparse systems are not governed by PDEs. Even in the case that the coefficient matrix is dense, applications still require an effective preconditioner, which is often sparse. For solving large problems, one needs to resort to parallel computing in order to reduce the time to solution. Sparse algorithms are well-known for their poor utilization of the cache due to irregular memory access. In addition, traditional algorithms that are designed for sequential platforms usually have inherited limitations for parallelism. Therefore, there is a need for novel algorithms to work on today's multicore clusters. Given a system of equations Ax = f, where A is large and sparse, it is known that hybrid solvers that contain both direct and iterative components are promising in terms of robustness and scalability on parallel computing platforms. In this paper, we review the generalized parallel sparse DS factorization algorithm and its relationship to sparse graphs. We will provide an example of parallel scalability of the hybrid solver compared to other well-known preconditioned Krylov subspace methods.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115299045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047332
K. Şendur
In this study, the interaction of a spherical nanoparticle with focused beams of various angular spectra is investigated. This study demonstrates that the focused light can be utilized to manipulate the near-field radiation around nanoparticles. Also in this study, the interaction between focused light and nano-antennas is investigated.
{"title":"Optical aspects of the interaction of focused beams with plasmonic nanoparticles","authors":"K. Şendur","doi":"10.1109/CEM.2011.6047332","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047332","url":null,"abstract":"In this study, the interaction of a spherical nanoparticle with focused beams of various angular spectra is investigated. This study demonstrates that the focused light can be utilized to manipulate the near-field radiation around nanoparticles. Also in this study, the interaction between focused light and nano-antennas is investigated.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"2010 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127353361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047349
C. Statz, Gabriel Arnold, S. Hegler, D. Plettemeier, A. Hérique, Wlodek Kofman
The three-dimensional finite-difference time-domain method (FDTD) simulation of electromagnetic wave propagation in large structures, like the cometary nucleus of 67P/Churyumov-Gerasimenko, as well as the inverse problem of reconstructing the permittivity distribution inside the comet nucleus is computationally expensive. With approximative methods not all propagation phenomena can be sufficiently modeled. For the efficient solution of this kind of inverse problem we propose the use of pseudo-spectral time-domain method (PSTD). This method overcomes the computational burdens and memory demands of the FDTD and allows accurate modeling of wave propagation for the CoNSERT case. In combination with optimal checkpointing and a state-of-the-art optimization tool, we demonstrate the solution of inverse problems at a scale of 50 wavelengths.
{"title":"PSTD-based approach to a large-scale inverse scattering problem","authors":"C. Statz, Gabriel Arnold, S. Hegler, D. Plettemeier, A. Hérique, Wlodek Kofman","doi":"10.1109/CEM.2011.6047349","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047349","url":null,"abstract":"The three-dimensional finite-difference time-domain method (FDTD) simulation of electromagnetic wave propagation in large structures, like the cometary nucleus of 67P/Churyumov-Gerasimenko, as well as the inverse problem of reconstructing the permittivity distribution inside the comet nucleus is computationally expensive. With approximative methods not all propagation phenomena can be sufficiently modeled. For the efficient solution of this kind of inverse problem we propose the use of pseudo-spectral time-domain method (PSTD). This method overcomes the computational burdens and memory demands of the FDTD and allows accurate modeling of wave propagation for the CoNSERT case. In combination with optimal checkpointing and a state-of-the-art optimization tool, we demonstrate the solution of inverse problems at a scale of 50 wavelengths.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"534 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123102104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047346
B. Michiels, J. Fostier, I. Bogaert, P. Demeester, D. De Zutter
The development of a scalable parallel multilevel fast multipole algorithm (MLFMA) for three dimensional electromagnetic scattering problems is reported. In the context of this work, the term 'scalable' denotes the ability to handle larger simulations with a proportional increase in the number of parallel processes (CPU cores), without loss of parallel efficiency. The workload is divided among the different processes according to the hierarchical partitioning scheme. Crucial to ensure the parallel scalability of the algorithm, is that the radiation patterns — sampled on the sphere — are partitioned in two dimensions, i.e., both in azimuth and elevation directions.
{"title":"Towards a scalable parallel MLFMA in three dimensions","authors":"B. Michiels, J. Fostier, I. Bogaert, P. Demeester, D. De Zutter","doi":"10.1109/CEM.2011.6047346","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047346","url":null,"abstract":"The development of a scalable parallel multilevel fast multipole algorithm (MLFMA) for three dimensional electromagnetic scattering problems is reported. In the context of this work, the term 'scalable' denotes the ability to handle larger simulations with a proportional increase in the number of parallel processes (CPU cores), without loss of parallel efficiency. The workload is divided among the different processes according to the hierarchical partitioning scheme. Crucial to ensure the parallel scalability of the algorithm, is that the radiation patterns — sampled on the sphere — are partitioned in two dimensions, i.e., both in azimuth and elevation directions.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130431402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047343
L. Jakab, T. Berceli
A method for the broadband measurement of the complex permittivity of barium ferrite (BaF) thick film samples in a partially filled rectangular waveguide is presented. The material characterization is based on the measurement of the reflection and the transmission coefficients of the rectangular waveguide containing the demagnetized ferrite sample. We present the detailed numerical method for the calculation of the complex permittivity from the measured scattering matrix. First the propagation constant is deduced from the scattering parameters followed by the determination of the cutoff wavenumber for the partially filled section of the waveguide. Finally, the material parameters are calculated based on the analytical solution of the partially filled waveguide. The method is verified by 3-D electromagnetic simulation tools and by reference measurements on known samples.
{"title":"Electromagnetic characterization of barium ferrite thick film samples in the KP band","authors":"L. Jakab, T. Berceli","doi":"10.1109/CEM.2011.6047343","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047343","url":null,"abstract":"A method for the broadband measurement of the complex permittivity of barium ferrite (BaF) thick film samples in a partially filled rectangular waveguide is presented. The material characterization is based on the measurement of the reflection and the transmission coefficients of the rectangular waveguide containing the demagnetized ferrite sample. We present the detailed numerical method for the calculation of the complex permittivity from the measured scattering matrix. First the propagation constant is deduced from the scattering parameters followed by the determination of the cutoff wavenumber for the partially filled section of the waveguide. Finally, the material parameters are calculated based on the analytical solution of the partially filled waveguide. The method is verified by 3-D electromagnetic simulation tools and by reference measurements on known samples.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130654571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047347
L. Gurel, O. Ergul
This study considers fast and accurate solutions of extremely large electromagnetics problems. Surface formulations of large-scale objects lead to dense matrix equations involving millions of unknowns. Thanks to recent developments in parallel algorithms and high-performance computers, these problems can easily be solved with unprecedented levels of accuracy and detail. For example, using a parallel implementation of the multilevel fast multipole algorithm (MLFMA), we are able to solve electromagnetics problems discretized with hundreds of millions of unknowns. Unfortunately, as the problem size grows, it becomes difficult to assess the accuracy and efficiency of the solutions, especially when comparing different implementations. This paper presents our efforts to solve extremely large electromagnetics problems with an emphasis on accuracy and efficiency. We present a list of benchmark problems, which can be used to compare different implementations for large-scale problems.
{"title":"Accuracy and efficiency considerations in the solution of extremely large electromagnetics problems","authors":"L. Gurel, O. Ergul","doi":"10.1109/CEM.2011.6047347","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047347","url":null,"abstract":"This study considers fast and accurate solutions of extremely large electromagnetics problems. Surface formulations of large-scale objects lead to dense matrix equations involving millions of unknowns. Thanks to recent developments in parallel algorithms and high-performance computers, these problems can easily be solved with unprecedented levels of accuracy and detail. For example, using a parallel implementation of the multilevel fast multipole algorithm (MLFMA), we are able to solve electromagnetics problems discretized with hundreds of millions of unknowns. Unfortunately, as the problem size grows, it becomes difficult to assess the accuracy and efficiency of the solutions, especially when comparing different implementations. This paper presents our efforts to solve extremely large electromagnetics problems with an emphasis on accuracy and efficiency. We present a list of benchmark problems, which can be used to compare different implementations for large-scale problems.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117313705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-17DOI: 10.1109/CEM.2011.6047328
D. Masotti, A. Costanzo, F. Mastri, M. Aldrigo, V. Rizzoli
The purpose of the paper is to demonstrate a general and rigorous computer-aided design (CAD) procedure that can potentially provide a systematic answer to the needs of modern circuit-level microwave system simulation/design by combining nonlinear, electromagnetic (EM), and propagation analysis tools. As examples of application, a systematic approach to a full CAD-based treatment of multi-input multi-output (MIMO) and ultra wide band (UWB) links is presented. The EM theory allows to evaluate a set of Norton equivalent generators to derive a circuit description of the receiver excitation: in the MIMO case one generator for each ray coming from each transmitting antenna; in the UWB case one generator for each harmonic frequency used to describe the spectrum of the impulse-radio (IR)-UWB signal. For the first time, highly-complex radio frequency (RF) links can be otpimized by means of the rigorous circuit-level CAD tool here presented: the selection of both the optimum distance between the receiving antennas and the optimum transmitted pulse shape is numerically performed in the MIMO and UWB case, respectively.
{"title":"Nonlinear/electromagnetic co-design of MIMO and UWB radio links","authors":"D. Masotti, A. Costanzo, F. Mastri, M. Aldrigo, V. Rizzoli","doi":"10.1109/CEM.2011.6047328","DOIUrl":"https://doi.org/10.1109/CEM.2011.6047328","url":null,"abstract":"The purpose of the paper is to demonstrate a general and rigorous computer-aided design (CAD) procedure that can potentially provide a systematic answer to the needs of modern circuit-level microwave system simulation/design by combining nonlinear, electromagnetic (EM), and propagation analysis tools. As examples of application, a systematic approach to a full CAD-based treatment of multi-input multi-output (MIMO) and ultra wide band (UWB) links is presented. The EM theory allows to evaluate a set of Norton equivalent generators to derive a circuit description of the receiver excitation: in the MIMO case one generator for each ray coming from each transmitting antenna; in the UWB case one generator for each harmonic frequency used to describe the spectrum of the impulse-radio (IR)-UWB signal. For the first time, highly-complex radio frequency (RF) links can be otpimized by means of the rigorous circuit-level CAD tool here presented: the selection of both the optimum distance between the receiving antennas and the optimum transmitted pulse shape is numerically performed in the MIMO and UWB case, respectively.","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125866927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1987-10-01DOI: 10.1109/ias.2004.1348766
Copyright and Reprint Permission: Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limit of U.S. copyright law for private use of patrons those articles in this volume that carry a code at the bottom of the first page, provided the per-copy fee indicated in the code is paid through
{"title":"Copyright page","authors":"","doi":"10.1109/ias.2004.1348766","DOIUrl":"https://doi.org/10.1109/ias.2004.1348766","url":null,"abstract":"Copyright and Reprint Permission: Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limit of U.S. copyright law for private use of patrons those articles in this volume that carry a code at the bottom of the first page, provided the per-copy fee indicated in the code is paid through","PeriodicalId":169588,"journal":{"name":"CEM'11 Computational Electromagnetics International Workshop","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133176209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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