Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.最新文献
Pub Date : 2004-12-27DOI: 10.1109/DIPED.2004.242683
G. Kevanishvili, I. Kevanishvili, G. V. Kekelia, K. Kotetishvili
An electrodynamic problem is solved. The problem is that of matching waveguide branches, partly filled by dielectric, for an E-plane T-junction with a symmetrical diaphragm at the waveguide junction. In analytical form, the approximate condition is presented for matching, installing the relation between the geometrical parameters of the T-junction, the wavelength and the dielectric permittivity of the layer.
{"title":"About one case of matching of waveguide branches in E-plane T-junction","authors":"G. Kevanishvili, I. Kevanishvili, G. V. Kekelia, K. Kotetishvili","doi":"10.1109/DIPED.2004.242683","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242683","url":null,"abstract":"An electrodynamic problem is solved. The problem is that of matching waveguide branches, partly filled by dielectric, for an E-plane T-junction with a symmetrical diaphragm at the waveguide junction. In analytical form, the approximate condition is presented for matching, installing the relation between the geometrical parameters of the T-junction, the wavelength and the dielectric permittivity of the layer.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"261 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121885395","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242938
I. Shamatava, F. Shubitidze, K. O'Neill, K. Sun, K. Paulsen
Low frequency electromagnetic induction (EMI) sensing, operating from ten's of Hertz up to several hundred's of kHz, has been identified as one of most promising technologies for detection and discrimination of subsurface metallic objects, particularly unexploded ordnance (UXO's). In EMI sensing, which is a pure EM diffusion rather than wave phenomena, displacement currents within an object and its surrounding medium are negligible. Therefore the scattered field outside the object can be represented as a sum of quasi-static magnetic fields radiated by magnetic charges placed on a fictitious surface. This paper presents a simple surface magnetic charge model for fast and accurate representation of EMI signal for any metallic scatterer of interest. The magnetic charges and Green's function associated with them are much simpler than magnetic dipoles and their dyadic Green's functions. The simplicity and computational accuracy of the magnetic charge model makes it an alternative candidate to the simple dipole model for buried metallic object discrimination in EMI frequency range. In addition, for a given object the amplitudes of the magnetic charges are unique and they can be used to discriminate an object of interest from innocuous items. The amplitudes of the responding magnetic charges are determined from measured data. Several numerical results are presented to demonstrate the accuracy and superior computational speed of the proposed method. I. Introduction
{"title":"Simple magnetic charge model for representation of emi responses from a buried UXO","authors":"I. Shamatava, F. Shubitidze, K. O'Neill, K. Sun, K. Paulsen","doi":"10.1109/DIPED.2004.242938","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242938","url":null,"abstract":"Low frequency electromagnetic induction (EMI) sensing, operating from ten's of Hertz up to several hundred's of kHz, has been identified as one of most promising technologies for detection and discrimination of subsurface metallic objects, particularly unexploded ordnance (UXO's). In EMI sensing, which is a pure EM diffusion rather than wave phenomena, displacement currents within an object and its surrounding medium are negligible. Therefore the scattered field outside the object can be represented as a sum of quasi-static magnetic fields radiated by magnetic charges placed on a fictitious surface. This paper presents a simple surface magnetic charge model for fast and accurate representation of EMI signal for any metallic scatterer of interest. The magnetic charges and Green's function associated with them are much simpler than magnetic dipoles and their dyadic Green's functions. The simplicity and computational accuracy of the magnetic charge model makes it an alternative candidate to the simple dipole model for buried metallic object discrimination in EMI frequency range. In addition, for a given object the amplitudes of the magnetic charges are unique and they can be used to discriminate an object of interest from innocuous items. The amplitudes of the responding magnetic charges are determined from measured data. Several numerical results are presented to demonstrate the accuracy and superior computational speed of the proposed method. I. Introduction","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"12 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132645170","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242462
V. Yatsyk
The algorithms for the solution of the nonlinear diffraction problem and the results of a numerical analysis for the transverse non-homogeneous, isotropic, nonmagnetic, linearly polarized, nonlinear (a Kerr-like dielectric nonlinearity) dielectric layer are shown. The effect of non-uniform shift of resonant frequency and the effect of increasing the transparency angle of the nonlinear layer with the growth of the field intensity are found.
{"title":"Intensive electromagnetic fields and resonant scattering of waves by dielectric layer with Kerr-like nonlinearity","authors":"V. Yatsyk","doi":"10.1109/DIPED.2004.242462","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242462","url":null,"abstract":"The algorithms for the solution of the nonlinear diffraction problem and the results of a numerical analysis for the transverse non-homogeneous, isotropic, nonmagnetic, linearly polarized, nonlinear (a Kerr-like dielectric nonlinearity) dielectric layer are shown. The effect of non-uniform shift of resonant frequency and the effect of increasing the transparency angle of the nonlinear layer with the growth of the field intensity are found.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131659858","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242675
R. Jobava, P. Tsereteli, F. Bogdanov, A. Radchenko
Solving modern problems of electromagnetic compatibility (EMC) in large systems involving electronic equipment (such as ships, planes, automobiles), in view of the complexity of the problems, demands enormous computing capacities and machine resources. Actually, solving many problems is impossible on standard personal computers/workstations. Therefore, the construction of high-efficiency cluster systems, allowing uniting in common use the resources of a group of personal computers, is very important. However, in order to exploit the computing power offered by a cluster of personal computers, efficient parallel implementations of 3D electromagnetic solvers, i.e. method of moments (MoM) solvers, using the message-passing paradigm have to be developed. We describe our experience with a parallel MoM solver, TriD (F.G. Bogdanov et al., 2003), for large-scale EMC problems.
在涉及电子设备(如船舶、飞机、汽车)的大型系统中解决现代电磁兼容问题，由于问题的复杂性，需要巨大的计算能力和机器资源。实际上，在标准的个人电脑/工作站上解决许多问题是不可能的。因此，构建高效的集群系统，统一使用一组个人计算机的资源是非常重要的。然而，为了利用个人计算机集群提供的计算能力，必须开发使用消息传递范式的三维电磁求解器的高效并行实现，即矩量法(MoM)求解器。我们描述了我们使用并行MoM求解器TriD (F.G. Bogdanov et al.， 2003)解决大规模EMC问题的经验。
{"title":"Solving large scale EMC problems using Linux cluster and parallel MoM","authors":"R. Jobava, P. Tsereteli, F. Bogdanov, A. Radchenko","doi":"10.1109/DIPED.2004.242675","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242675","url":null,"abstract":"Solving modern problems of electromagnetic compatibility (EMC) in large systems involving electronic equipment (such as ships, planes, automobiles), in view of the complexity of the problems, demands enormous computing capacities and machine resources. Actually, solving many problems is impossible on standard personal computers/workstations. Therefore, the construction of high-efficiency cluster systems, allowing uniting in common use the resources of a group of personal computers, is very important. However, in order to exploit the computing power offered by a cluster of personal computers, efficient parallel implementations of 3D electromagnetic solvers, i.e. method of moments (MoM) solvers, using the message-passing paradigm have to be developed. We describe our experience with a parallel MoM solver, TriD (F.G. Bogdanov et al., 2003), for large-scale EMC problems.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"440 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123052132","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242569
F. Bogdanov, R. Jobava, P. Tsereteli
A partitioned MoM scheme is suggested for electromagnetically treating assemblies of geometries having a substantial common part. This scheme is applied to compare and optimize the characteristics of various antennas installed on an airplane surface. The effectiveness of the suggested scheme to decrease CPU time efficiently is. demonstrated. The perspectives of the new scheme for the solution of various EM and EMC problems in vehicle design are outlined.
{"title":"A partitioned MoM scheme for solution of EM/EMC problems on assemblies of geometries with a substantial common part","authors":"F. Bogdanov, R. Jobava, P. Tsereteli","doi":"10.1109/DIPED.2004.242569","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242569","url":null,"abstract":"A partitioned MoM scheme is suggested for electromagnetically treating assemblies of geometries having a substantial common part. This scheme is applied to compare and optimize the characteristics of various antennas installed on an airplane surface. The effectiveness of the suggested scheme to decrease CPU time efficiently is. demonstrated. The perspectives of the new scheme for the solution of various EM and EMC problems in vehicle design are outlined.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114518070","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242456
A. Gheonjian, R. Jobava, A. Radchenko, I. Ishmuhametov, R. Kvaratskhelia
There are two ways of treating transient radiation and scattering problems for structures of arbitrary shape: solution of time-dependant Maxwell equations directly in the time domain; solution of these equations in the frequency domain with consequent application of the Fourier transformation to reconstruct the time-dependant signal. Comparative advantages and disadvantages of both approaches are well described in the literature (Poggio, A.J. and Miller, E.K., 1973). The paper aims to increase the effectiveness of the multifrequency approach by performing adaptive frequency sampling (AFS) for spectrum calculation of the electromagnetic system under consideration. The paper demonstrates that the solution of transient problems in the frequency domain with consequent application of FFT becomes very effective if frequency sampling is performed using the AFS technique. Implementation details of the AFS algorithm and examples demonstrating the advantages of applying AFS are also presented.
{"title":"Adaptive frequency sampling for solution of transient problems in frequency domain","authors":"A. Gheonjian, R. Jobava, A. Radchenko, I. Ishmuhametov, R. Kvaratskhelia","doi":"10.1109/DIPED.2004.242456","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242456","url":null,"abstract":"There are two ways of treating transient radiation and scattering problems for structures of arbitrary shape: solution of time-dependant Maxwell equations directly in the time domain; solution of these equations in the frequency domain with consequent application of the Fourier transformation to reconstruct the time-dependant signal. Comparative advantages and disadvantages of both approaches are well described in the literature (Poggio, A.J. and Miller, E.K., 1973). The paper aims to increase the effectiveness of the multifrequency approach by performing adaptive frequency sampling (AFS) for spectrum calculation of the electromagnetic system under consideration. The paper demonstrates that the solution of transient problems in the frequency domain with consequent application of FFT becomes very effective if frequency sampling is performed using the AFS technique. Implementation details of the AFS algorithm and examples demonstrating the advantages of applying AFS are also presented.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116397573","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242807
Yang Ruiliang, Fan Xiaowei
The paper considers the exterior acoustic field produced by an arbitrary structure immersed in an infinite homogeneous fluid and vibrating at constant frequency. The acoustic radiating problem is solved by a combination of the finite element method (FEM) and the infinite element method (IEM). The field information is usually obtained from the Kirchoff integral using the computed surface information. Compared to the boundary element method, this combination method yields significantly greater computational efficiency. Furthermore, the method is easy to understand and extend.
{"title":"Finite/infinite element method for the acoustic radiating problem","authors":"Yang Ruiliang, Fan Xiaowei","doi":"10.1109/DIPED.2004.242807","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242807","url":null,"abstract":"The paper considers the exterior acoustic field produced by an arbitrary structure immersed in an infinite homogeneous fluid and vibrating at constant frequency. The acoustic radiating problem is solved by a combination of the finite element method (FEM) and the infinite element method (IEM). The field information is usually obtained from the Kirchoff integral using the computed surface information. Compared to the boundary element method, this combination method yields significantly greater computational efficiency. Furthermore, the method is easy to understand and extend.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123033081","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242803
O. Kusyi, P. Stevrin, N. N. Voitovich, O. Zamorska
A method for reconstructing the shape of an irregular waveguide is proposed. The method uses the amplitudes of the normal modes excited by a point source moving along the irregular part of the waveguide and measured at its output. The mean-square discrepancy of the measured and calculated mode amplitudes integrated over the source path is minimized. The direct problem is solved by the cross-section method. Numerical results concerning a 2D model problem are presented.
{"title":"Reconstruction of irregular waveguide geometry using a moving source","authors":"O. Kusyi, P. Stevrin, N. N. Voitovich, O. Zamorska","doi":"10.1109/DIPED.2004.242803","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242803","url":null,"abstract":"A method for reconstructing the shape of an irregular waveguide is proposed. The method uses the amplitudes of the normal modes excited by a point source moving along the irregular part of the waveguide and measured at its output. The mean-square discrepancy of the measured and calculated mode amplitudes integrated over the source path is minimized. The direct problem is solved by the cross-section method. Numerical results concerning a 2D model problem are presented.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127819824","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242676
N. Gritsenko, A. Bijamov, A. Razmadze, L. Shoshiashvili, R. Zaridze
We investigate thermal effects in the human head exposed to the electromagnetic (EM) radiation of a mobile antenna at 0.9 GHz frequency. Computer simulation of EM and thermal phenomena in the given problem was performed. The simulation code is based on the finite-difference time-domain (FDTD) method for Maxwell's equations (Taflove, A. and Hagness, S., "Computational Electrodynamics: the finite difference time-domain method", 2nd edition, Artech House, 2000) and bio heat equations (Bernardi, P. and Pisa, S., IEEE Trans. Microwave Theory Tech., vol.48, p.1118-26, 1998) for the EM and thermal problems respectively.
{"title":"Simulation of the thermal effects in the human head due to the RF exposure","authors":"N. Gritsenko, A. Bijamov, A. Razmadze, L. Shoshiashvili, R. Zaridze","doi":"10.1109/DIPED.2004.242676","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242676","url":null,"abstract":"We investigate thermal effects in the human head exposed to the electromagnetic (EM) radiation of a mobile antenna at 0.9 GHz frequency. Computer simulation of EM and thermal phenomena in the given problem was performed. The simulation code is based on the finite-difference time-domain (FDTD) method for Maxwell's equations (Taflove, A. and Hagness, S., \"Computational Electrodynamics: the finite difference time-domain method\", 2nd edition, Artech House, 2000) and bio heat equations (Bernardi, P. and Pisa, S., IEEE Trans. Microwave Theory Tech., vol.48, p.1118-26, 1998) for the EM and thermal problems respectively.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126718398","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 : 2004-11-01DOI: 10.1109/ICCEA.2004.1459293
F. Khajepiri, A. Ghorbanii, H. Amindavar
We propose a new method for estimating rain attenuation at high frequencies. Although this method is based on the Mie theory, it is much faster than older methods because of a reduction in the number of calculations. In other words, instead of using the Mie theory on all drop diameters, the calculation is performed on only the mean value as an indicator of distribution. At the end, the answer must be corrected by a factor. We obtain the proper formula and show, through simulation, the adaptation of its result with previous methods.
{"title":"A new method for estimating rain attenuation at high frequencies","authors":"F. Khajepiri, A. Ghorbanii, H. Amindavar","doi":"10.1109/ICCEA.2004.1459293","DOIUrl":"https://doi.org/10.1109/ICCEA.2004.1459293","url":null,"abstract":"We propose a new method for estimating rain attenuation at high frequencies. Although this method is based on the Mie theory, it is much faster than older methods because of a reduction in the number of calculations. In other words, instead of using the Mie theory on all drop diameters, the calculation is performed on only the mean value as an indicator of distribution. At the end, the answer must be corrected by a factor. We obtain the proper formula and show, through simulation, the adaptation of its result with previous methods.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133316686","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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