Pub Date : 2024-12-31DOI: 10.1109/JMMCT.2024.3524598
Yuxian Zhang;Yilin Kang;Naixing Feng;Xiaoli Feng;Zhixiang Huang;Atef Z. Elsherbeni
In this article, to breakthrough the constraint from conventional finite-difference time-domain (FDTD) method, we firstly propose a scale-compressed technique (SCT) working for the FDTD method, been called SCT-FDTD for short, to reduce three-dimensional (3-D) into one-dimensional (1-D) processes and capture the propagation coefficients. Combining with Maxwell's curl equations, the transverse wave vectors (kx, ky) can be defined as the fixed values, which let the curl operator become the curl matrix with only z-directional derivative. The obvious advantage demonstrated by above is that it does not require excessive computational processes to obtain high-dimensional numerical results with reasonable accuracy. By comparing with commercial software COMSOL by the TE/TM illumination in multi-layered biaxial anisotropy, those results from SCT-FDTD method are entirely consistent. More importantly, the SCT-FDTD possesses less CPU time and lower computational resources for COMSOL.
{"title":"Scale-Compressed Technique in Finite-Difference Time-Domain Method for Multi-Layered Anisotropic Media","authors":"Yuxian Zhang;Yilin Kang;Naixing Feng;Xiaoli Feng;Zhixiang Huang;Atef Z. Elsherbeni","doi":"10.1109/JMMCT.2024.3524598","DOIUrl":"https://doi.org/10.1109/JMMCT.2024.3524598","url":null,"abstract":"In this article, to breakthrough the constraint from conventional finite-difference time-domain (FDTD) method, we firstly propose a scale-compressed technique (SCT) working for the FDTD method, been called SCT-FDTD for short, to reduce three-dimensional (3-D) into one-dimensional (1-D) processes and capture the propagation coefficients. Combining with Maxwell's curl equations, the transverse wave vectors (<italic>k<sub>x</sub></i>, <italic>k<sub>y</sub></i>) can be defined as the fixed values, which let the curl operator become the curl matrix with only <italic>z</i>-directional derivative. The obvious advantage demonstrated by above is that it does not require excessive computational processes to obtain high-dimensional numerical results with reasonable accuracy. By comparing with commercial software COMSOL by the TE/TM illumination in multi-layered biaxial anisotropy, those results from SCT-FDTD method are entirely consistent. More importantly, the SCT-FDTD possesses less CPU time and lower computational resources for COMSOL.","PeriodicalId":52176,"journal":{"name":"IEEE Journal on Multiscale and Multiphysics Computational Techniques","volume":"10 ","pages":"85-93"},"PeriodicalIF":1.8,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975849","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 : 2024-12-20DOI: 10.1109/JMMCT.2024.3520488
Angelika S. Thalmayer;Keyu Xiao;Paul Wolff;Georg Fischer
The development of trustworthy simulation models is crucial for planning drug administration in magnetic drug targeting (MDT) interventions for future cancer treatment. In the MDT cancer therapy, the drug is bound to magnetic nanoparticles, which act as carriers and are guided through the cardiovascular system into the tumor region using an external magnetic field. Thus, the modeling represents a multiphysical problem and can be approached either by particle-based or concentration-based models. In this paper, both simulation approaches are implemented in COMSOL Multiphysics in a typical magnetic drug targeting scenario, verified by measurements, and compared among each other. Two different particle concentrations with and without an applied magnetic field of a Halbach array consisting of five permanent magnets in a tube flow system with a laminar velocity flow were investigated. Within this scope, an analytical model for calculating the system response for the detection of nanoparticles with a commercial susceptometer is derived, too. Considering the two implemented models and the investigated scenario, the concentration-based model shows a considerably better agreement with the experimental results for both with and without an applied magnetic field. The spatial resolution of the particle-based model is reduced due to the limited number of considered particles resulting in an inaccurate system response. Overall, the high number of new publications shows the need for research in this interdisciplinary research field to improve therapeutic success.
{"title":"Experimental and Numerical Modeling of Magnetic Drug Targeting: Can We Trust Particle-Based Models?","authors":"Angelika S. Thalmayer;Keyu Xiao;Paul Wolff;Georg Fischer","doi":"10.1109/JMMCT.2024.3520488","DOIUrl":"https://doi.org/10.1109/JMMCT.2024.3520488","url":null,"abstract":"The development of trustworthy simulation models is crucial for planning drug administration in magnetic drug targeting (MDT) interventions for future cancer treatment. In the MDT cancer therapy, the drug is bound to magnetic nanoparticles, which act as carriers and are guided through the cardiovascular system into the tumor region using an external magnetic field. Thus, the modeling represents a multiphysical problem and can be approached either by particle-based or concentration-based models. In this paper, both simulation approaches are implemented in COMSOL Multiphysics in a typical magnetic drug targeting scenario, verified by measurements, and compared among each other. Two different particle concentrations with and without an applied magnetic field of a Halbach array consisting of five permanent magnets in a tube flow system with a laminar velocity flow were investigated. Within this scope, an analytical model for calculating the system response for the detection of nanoparticles with a commercial susceptometer is derived, too. Considering the two implemented models and the investigated scenario, the concentration-based model shows a considerably better agreement with the experimental results for both with and without an applied magnetic field. The spatial resolution of the particle-based model is reduced due to the limited number of considered particles resulting in an inaccurate system response. Overall, the high number of new publications shows the need for research in this interdisciplinary research field to improve therapeutic success.","PeriodicalId":52176,"journal":{"name":"IEEE Journal on Multiscale and Multiphysics Computational Techniques","volume":"10 ","pages":"69-84"},"PeriodicalIF":1.8,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938138","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}
Recently, there has been a surge in the development of data-driven propagation models. These models aspire to distill knowledge from propagation solvers or measured data and eventually become capable of predicting characteristics related to radiowave propagation. In this paper, we present the functionality of a generalizable and robust data-driven propagation model that enables efficient and reliable simulations of indoor wireless communication systems (IWCSs). In particular, we modify our previously introduced model, EM DeepRay, to consider the impact of antenna directivity, and we present a training and inference strategy that allows the simulation of large-scale and complicated IWCSs. Our data-driven model is trained over a rich data set comprising diverse building geometries, frequency bands, and antenna radiation patterns. Benchmarking its performance with that of a ray-tracer in complicated IWCSs with real-world measured data yields similar results that have a distinct advantage in terms of computational time. Ultimately, our work paves the way for replacing legacy IWCSs simulators, with high-fidelity artificial intelligence-based models.
{"title":"Rigorous Indoor Wireless Communication System Simulations With Deep Learning-Based Radio Propagation Models","authors":"Stefanos Bakirtzis;Kehai Qiu;Jiming Chen;Hui Song;Jie Zhang;Ian Wassell","doi":"10.1109/JMMCT.2024.3506693","DOIUrl":"https://doi.org/10.1109/JMMCT.2024.3506693","url":null,"abstract":"Recently, there has been a surge in the development of data-driven propagation models. These models aspire to distill knowledge from propagation solvers or measured data and eventually become capable of predicting characteristics related to radiowave propagation. In this paper, we present the functionality of a generalizable and robust data-driven propagation model that enables efficient and reliable simulations of indoor wireless communication systems (IWCSs). In particular, we modify our previously introduced model, EM DeepRay, to consider the impact of antenna directivity, and we present a training and inference strategy that allows the simulation of large-scale and complicated IWCSs. Our data-driven model is trained over a rich data set comprising diverse building geometries, frequency bands, and antenna radiation patterns. Benchmarking its performance with that of a ray-tracer in complicated IWCSs with real-world measured data yields similar results that have a distinct advantage in terms of computational time. Ultimately, our work paves the way for replacing legacy IWCSs simulators, with high-fidelity artificial intelligence-based models.","PeriodicalId":52176,"journal":{"name":"IEEE Journal on Multiscale and Multiphysics Computational Techniques","volume":"10 ","pages":"58-68"},"PeriodicalIF":1.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905782","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 : 2024-11-29DOI: 10.1109/JMMCT.2024.3509773
Aggraj Gupta;Uday K Khankhoje
Deep learning frameworks are gaining prominence in the electromagnetics community for designing microwave and mm-wave devices. This paper presents a computationally efficient transfer learning technique for designing and scaling multi-band microstrip antennas to a desired dielectric and frequency of interest. The proposed methodology involves a two-step process. First, a pre-trained model trained extensively on air-filled microstrip antennas is used for knowledge transfer. This pre-trained model is fine-tuned with a limited set of dielectric simulations, reducing data acquisition costs. In the second step, the developed forward model serves as a surrogate to design dielectric-filled antennas using the Improved Binary Particle Swarm Optimization algorithm. In contrast to conventional methods, this approach enables the design of compact antennas across various dielectrics and frequency ranges, with a significantly reduced number of time-consuming dielectric simulations (88% fewer simulations) and a lower neural network training time (75% lesser time). We analyze the optimal ways of generating dielectric antenna datasets via scaling, and perform sensitivity analysis with respect to the antenna's physical parameters. We report simulation and experimental results for single and double band antennas fabricated using the proposed approach.
{"title":"Transfer Learning Based Rapid Design of Frequency and Dielectric Agile Antennas","authors":"Aggraj Gupta;Uday K Khankhoje","doi":"10.1109/JMMCT.2024.3509773","DOIUrl":"https://doi.org/10.1109/JMMCT.2024.3509773","url":null,"abstract":"Deep learning frameworks are gaining prominence in the electromagnetics community for designing microwave and mm-wave devices. This paper presents a computationally efficient transfer learning technique for designing and scaling multi-band microstrip antennas to a desired dielectric and frequency of interest. The proposed methodology involves a two-step process. First, a pre-trained model trained extensively on air-filled microstrip antennas is used for knowledge transfer. This pre-trained model is fine-tuned with a limited set of dielectric simulations, reducing data acquisition costs. In the second step, the developed forward model serves as a surrogate to design dielectric-filled antennas using the Improved Binary Particle Swarm Optimization algorithm. In contrast to conventional methods, this approach enables the design of compact antennas across various dielectrics and frequency ranges, with a significantly reduced number of time-consuming dielectric simulations (88% fewer simulations) and a lower neural network training time (75% lesser time). We analyze the optimal ways of generating dielectric antenna datasets via scaling, and perform sensitivity analysis with respect to the antenna's physical parameters. We report simulation and experimental results for single and double band antennas fabricated using the proposed approach.","PeriodicalId":52176,"journal":{"name":"IEEE Journal on Multiscale and Multiphysics Computational Techniques","volume":"10 ","pages":"47-57"},"PeriodicalIF":1.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810340","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 : 2024-11-20DOI: 10.1109/JMMCT.2024.3502830
Eng Leong Tan;Ding Yu Heh
This paper presents the critical-point-based stability analyses of finite-difference time-domain (FDTD) methods for Schrödinger equation incorporating vector and scalar potentials. Most previous FDTD formulations and stability analyses for the Schrödinger equation involve only the scalar potentials. On the other hand, the existing stability conditions that include both vector and scalar potentials were not thoroughly nor rigorously analyzed, hence they are inadequate for general cases. In this paper, rigorous stability analyses of the FDTD methods will be performed for Schrödinger equation in full 3D incorporating both vector and scalar potentials. New stability conditions are derived rigorously based on the critical points within the interior and boundary regions, while considering the local and global extrema across all variables. Two FDTD schemes are considered, of which one is updated entirely in complex form, and the other is decomposed into real and imaginary parts and updated in a leapfrog manner. Comparisons of the new stability conditions are made against those of prior works, highlighting the thoroughness, completeness and adequacy. Numerical experiments further validate the derived stability conditions and demonstrate their applicability in FDTD methods. Using these stability conditions, the FDTD methods are useful for simulations of quantum-electromagnetic interactions involving vector and scalar potentials.
{"title":"Critical-Point-Based Stability Analyses of Finite-Difference Time-Domain Methods for Schrödinger Equation Incorporating Vector and Scalar Potentials","authors":"Eng Leong Tan;Ding Yu Heh","doi":"10.1109/JMMCT.2024.3502830","DOIUrl":"https://doi.org/10.1109/JMMCT.2024.3502830","url":null,"abstract":"This paper presents the critical-point-based stability analyses of finite-difference time-domain (FDTD) methods for Schrödinger equation incorporating vector and scalar potentials. Most previous FDTD formulations and stability analyses for the Schrödinger equation involve only the scalar potentials. On the other hand, the existing stability conditions that include both vector and scalar potentials were not thoroughly nor rigorously analyzed, hence they are inadequate for general cases. In this paper, rigorous stability analyses of the FDTD methods will be performed for Schrödinger equation in full 3D incorporating both vector and scalar potentials. New stability conditions are derived rigorously based on the critical points within the interior and boundary regions, while considering the local and global extrema across all variables. Two FDTD schemes are considered, of which one is updated entirely in complex form, and the other is decomposed into real and imaginary parts and updated in a leapfrog manner. Comparisons of the new stability conditions are made against those of prior works, highlighting the thoroughness, completeness and adequacy. Numerical experiments further validate the derived stability conditions and demonstrate their applicability in FDTD methods. Using these stability conditions, the FDTD methods are useful for simulations of quantum-electromagnetic interactions involving vector and scalar potentials.","PeriodicalId":52176,"journal":{"name":"IEEE Journal on Multiscale and Multiphysics Computational Techniques","volume":"10 ","pages":"38-46"},"PeriodicalIF":1.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798015","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 : 2024-11-19DOI: 10.1109/JMMCT.2024.3502062
Yanan Liu;Hongliang Li;Jian-Ming Jin
In this paper, we present a machine learning technique based on analytic extension of eigenvalues and neural networks for the efficient modeling of high-frequency devices. In the proposed method, neural networks are used to learn the mapping between device's geometry and its modal equivalent circuit parameters. These circuit parameters are extracted from the eigen-decomposition of the deviceâs $Z$