M. Abdelmoneim, N. Eldabe, Mohamed Ahmed Abouzeid, M. Ouaf
In this study, we focused on the heat transfer through a uniformly inclined rectangular duct caused by the electro-osmotic peristaltic flow of an unsteady non-Newtonian nanofluid. With couple stress, the fluid obeys the Papanastasiou model. The flow is through a porous medium that follows Darcy’s law in a modified form. In addition, Dufour and Soret effects, mixed convection, the impacts of a chemical reaction, and the effects of viscous couple stress dissipation are all considered. The governing equations that explain the velocity, temperature, and concentration of nanoparticles are simplified when wave transformation is used. The homotopy perturbation method was used to solve these equations analytically. Additionally, a collection of figures is used to discuss and visually illustrate the consequences of the physical characteristics. In fact, the modified Darcy’s law makes the velocity gradient appear in the momentum equation, which increases the contribution of the velocity gradient to the velocity profile. In addition, the electro-osmotic parameter and Helmholtz-Smoluchowski velocity have a significant impact on the velocity gradient’s direction, as well as the velocity gradient’s ability to be either positive or negative, depending on their values. In addition, in the case of forced convection, the values of the Nusselt number and the Sherwood number are highly affected by the value of Helmholtz–Smoluchowski velocity. The current findings have applications in biology and medicine, particularly in cancer therapy, which involves peristaltic blood pumps(arteries) and suspended gold nanoparticles (nanofluid). According to our knowledge, no prior studies have merged the couple stress Papanastasiou model and the modified Darcy’s law.
{"title":"Modified Darcy’s law and couple stress effects on electro-osmotic flow of non-Newtonian nanofluid with peristalsis","authors":"M. Abdelmoneim, N. Eldabe, Mohamed Ahmed Abouzeid, M. Ouaf","doi":"10.3233/jae-220287","DOIUrl":"https://doi.org/10.3233/jae-220287","url":null,"abstract":"In this study, we focused on the heat transfer through a uniformly inclined rectangular duct caused by the electro-osmotic peristaltic flow of an unsteady non-Newtonian nanofluid. With couple stress, the fluid obeys the Papanastasiou model. The flow is through a porous medium that follows Darcy’s law in a modified form. In addition, Dufour and Soret effects, mixed convection, the impacts of a chemical reaction, and the effects of viscous couple stress dissipation are all considered. The governing equations that explain the velocity, temperature, and concentration of nanoparticles are simplified when wave transformation is used. The homotopy perturbation method was used to solve these equations analytically. Additionally, a collection of figures is used to discuss and visually illustrate the consequences of the physical characteristics. In fact, the modified Darcy’s law makes the velocity gradient appear in the momentum equation, which increases the contribution of the velocity gradient to the velocity profile. In addition, the electro-osmotic parameter and Helmholtz-Smoluchowski velocity have a significant impact on the velocity gradient’s direction, as well as the velocity gradient’s ability to be either positive or negative, depending on their values. In addition, in the case of forced convection, the values of the Nusselt number and the Sherwood number are highly affected by the value of Helmholtz–Smoluchowski velocity. The current findings have applications in biology and medicine, particularly in cancer therapy, which involves peristaltic blood pumps(arteries) and suspended gold nanoparticles (nanofluid). According to our knowledge, no prior studies have merged the couple stress Papanastasiou model and the modified Darcy’s law.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"4 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80207107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Santiago S. Pérez, Alessandro Bedoya, Luis Miguel Prócel, Ramiro Taco
Spin-transfer torque magnetic random-access memory (STT-MRAM) has been demonstrated to be a leading candidate for on-chip memory technology. In this work, double-barrier magnetic tunnel junction (DMTJ) is exploited to define STT-MRAMs at the circuit-level (i.e. at the bitcell level). The DMTJ-basedbitcells are built from tunnel-FET technology and benchmarked against a calibrated 10 nm-FinFET technology model. STT-MRAM bitcells operate in the ultra-low voltage domain, and are evaluated in terms of energy-efficiency and area. Simulation results points out that the tunnel-FET based solution is the most energy-efficient alternative, in terms of energy-delay-product (EDP), when evaluated at the 6𝜎 corner. Quantitatively, when compared against the FinFET-based design, the TFET-based bitcell exhibits 58% lower EDP, 40% better delay and 34% reduced writing energy. Finally, a leakage analysis was also carried out, showing that TFET-based STT-MRAM bitcells have lower leakage current as compared to the FinFET-based counterpart.
{"title":"Exploiting TFET-based technology for energy-efficient STT-MRAM cells","authors":"Santiago S. Pérez, Alessandro Bedoya, Luis Miguel Prócel, Ramiro Taco","doi":"10.3233/jae-220300","DOIUrl":"https://doi.org/10.3233/jae-220300","url":null,"abstract":"Spin-transfer torque magnetic random-access memory (STT-MRAM) has been demonstrated to be a leading candidate for on-chip memory technology. In this work, double-barrier magnetic tunnel junction (DMTJ) is exploited to define STT-MRAMs at the circuit-level (i.e. at the bitcell level). The DMTJ-basedbitcells are built from tunnel-FET technology and benchmarked against a calibrated 10 nm-FinFET technology model. STT-MRAM bitcells operate in the ultra-low voltage domain, and are evaluated in terms of energy-efficiency and area. Simulation results points out that the tunnel-FET based solution is the most energy-efficient alternative, in terms of energy-delay-product (EDP), when evaluated at the 6𝜎 corner. Quantitatively, when compared against the FinFET-based design, the TFET-based bitcell exhibits 58% lower EDP, 40% better delay and 34% reduced writing energy. Finally, a leakage analysis was also carried out, showing that TFET-based STT-MRAM bitcells have lower leakage current as compared to the FinFET-based counterpart.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"71 6","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138503694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the distribution of the air gap magnetic field in the motorized spindle is obtained through theoretical derivation, which is verified by comparing with the finite element simulation results. Based on the original calculation of air gap magnetic field, the rotor eccentricity theory is added, and the distribution of air gap magnetic field after rotor eccentricity is obtained. The correctness of the calculation theory of eccentric air gap magnetic field is verified by the finite element simulation results. Through the electromagnetic force calculation and finite element simulation of asymmetric magnetic field in eccentric state, the influence law of unbalanced electromagnetic force on the fatigue life of motorized spindle rotor is summarized.
{"title":"Analysis of rotor fatigue characteristics of permanent magnet synchronous motor spindle in eccentric state","authors":"Haining Zhao, Shenbo Yu","doi":"10.3233/jae-220236","DOIUrl":"https://doi.org/10.3233/jae-220236","url":null,"abstract":"In this paper, the distribution of the air gap magnetic field in the motorized spindle is obtained through theoretical derivation, which is verified by comparing with the finite element simulation results. Based on the original calculation of air gap magnetic field, the rotor eccentricity theory is added, and the distribution of air gap magnetic field after rotor eccentricity is obtained. The correctness of the calculation theory of eccentric air gap magnetic field is verified by the finite element simulation results. Through the electromagnetic force calculation and finite element simulation of asymmetric magnetic field in eccentric state, the influence law of unbalanced electromagnetic force on the fatigue life of motorized spindle rotor is summarized.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"34 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84011617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main problem with any tomography is the transformation of measurements into images. It is the so-called “inverse problem,” which, due to its indeterminacy, can never be solved perfectly. An additional factor contributing to the deterioration of the quality of tomograms is measurement noise. This article shows how to denoise electrical capacitance tomography measurements using the LSTM autoencoder. The presented model is two-staged. First, the autoencoder is trained using very noisy measurements. Then, the decoder autoencoder generates a training set to using activations ofe the latent layer. In the second stage, the LSTM network is trained, which has encoder latent layer activations at the input and pattern images at the output. The results of the experiments show that using an autoencoder to denoise the measurements improves the reconstruction quality.
{"title":"The use of an LSTM-based autoencoder for measurement denoising in process tomography","authors":"G. Kłosowski, T. Rymarczyk, D. Wójcik","doi":"10.3233/jae-230013","DOIUrl":"https://doi.org/10.3233/jae-230013","url":null,"abstract":"The main problem with any tomography is the transformation of measurements into images. It is the so-called “inverse problem,” which, due to its indeterminacy, can never be solved perfectly. An additional factor contributing to the deterioration of the quality of tomograms is measurement noise. This article shows how to denoise electrical capacitance tomography measurements using the LSTM autoencoder. The presented model is two-staged. First, the autoencoder is trained using very noisy measurements. Then, the decoder autoencoder generates a training set to using activations ofe the latent layer. In the second stage, the LSTM network is trained, which has encoder latent layer activations at the input and pattern images at the output. The results of the experiments show that using an autoencoder to denoise the measurements improves the reconstruction quality.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"8 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79019547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng-long Hou, B. Ge, Dajun Tao, Bo Pan, Shuqi Liu
In order to solve the problem that the design of high-speed permanent magnet motor (HSPMM) is constrained by multi-physical fields, this paper starts with the comprehensive study of multi physical fields, introduces the finite element calculation model of rotor strength-rotor dynamics-electromagnetic field-fluid field and temperature field, carries out the comprehensive design of a 100 kW, 18 000 r/min FeCo based HSPMM, and gives the detailed and complete research process of the main parameters of HSPMM under multi-physical field constraints. First, the initial dimensions of the motor are obtained by electromagnetic and mechanical design theory. Secondly, the influence of design parameters on rotor stress is analyzed in detail, including the influence of bearing rigidity, impeller mass, rotor diameter, rotor core length and gyroscopic effect on critical speed. Subsequently, the electromagnetic characteristics of the motor are comprehensively studied, the cooling system is designed in the Flow-Heat coupling calculation model and the temperature field is studied. Finally, the prototype test verifies the correctness and validity of the comprehensive research method of multi physical field.
{"title":"Multi physical comprehensive design of a new type of FeCo based high speed permanent magnet motor","authors":"Peng-long Hou, B. Ge, Dajun Tao, Bo Pan, Shuqi Liu","doi":"10.3233/jae-220190","DOIUrl":"https://doi.org/10.3233/jae-220190","url":null,"abstract":"In order to solve the problem that the design of high-speed permanent magnet motor (HSPMM) is constrained by multi-physical fields, this paper starts with the comprehensive study of multi physical fields, introduces the finite element calculation model of rotor strength-rotor dynamics-electromagnetic field-fluid field and temperature field, carries out the comprehensive design of a 100 kW, 18 000 r/min FeCo based HSPMM, and gives the detailed and complete research process of the main parameters of HSPMM under multi-physical field constraints. First, the initial dimensions of the motor are obtained by electromagnetic and mechanical design theory. Secondly, the influence of design parameters on rotor stress is analyzed in detail, including the influence of bearing rigidity, impeller mass, rotor diameter, rotor core length and gyroscopic effect on critical speed. Subsequently, the electromagnetic characteristics of the motor are comprehensively studied, the cooling system is designed in the Flow-Heat coupling calculation model and the temperature field is studied. Finally, the prototype test verifies the correctness and validity of the comprehensive research method of multi physical field.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"38 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77794567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Rocha-Gómez, O. Susarrey-Huerta, A. Aguilar-Pérez, J.C. Suárez-Calderón, J. A. Flores-Campos, D. Desiderio-Maya, M. Cruz-Deviana, J. Cortés-Pérez, S. G. Torres-Cedillo, A. Reyes-Solís
This article presents an angular position control, based on the Gaussian function, of a Magneto-Rheological fluid disc brake (MR brake) driven by a DC motor. Our proposed control strategy is to apply a continuous magnetic flux density to the MR brake, which will be maximum when the proportional controller of the DC motor reaches the desired position to brake the hybrid device. The MR brake controller activates a braking torque that adopts the behavior of the Gaussian function instead of a pulsed braking torque as provided by other commonly used controllers (On-Off controllers). The response of the MR brake controller, which is presented in a closed-loop feedback system, depends on the angular position error of the shaft and a tuning parameter representing the critical angular position at which the magnetic flux density, which is applied to the MR brake, reaches 60.65% of its maximum value. The advantage is to avoid knowing the dynamic parameters, such as the inertia of the mechanical device or its speed, and to reject these perturbations by a simple tuning parameter of the MR brake. To show the effectiveness of the proposed controller, the dynamic model of a slider-crank mechanism is considered. The results showed similar behavior as conventional controllers, where overshoot and oscillations were minimized. This behavior has been obtained in other research articles using controllers that require a greater amount of data processing.
{"title":"Position control based on Gaussian function applied on magneto-rheological fluid disc brake of a hybrid mechanical device (MR brake - DC motor)","authors":"I. Rocha-Gómez, O. Susarrey-Huerta, A. Aguilar-Pérez, J.C. Suárez-Calderón, J. A. Flores-Campos, D. Desiderio-Maya, M. Cruz-Deviana, J. Cortés-Pérez, S. G. Torres-Cedillo, A. Reyes-Solís","doi":"10.3233/jae-220302","DOIUrl":"https://doi.org/10.3233/jae-220302","url":null,"abstract":"This article presents an angular position control, based on the Gaussian function, of a Magneto-Rheological fluid disc brake (MR brake) driven by a DC motor. Our proposed control strategy is to apply a continuous magnetic flux density to the MR brake, which will be maximum when the proportional controller of the DC motor reaches the desired position to brake the hybrid device. The MR brake controller activates a braking torque that adopts the behavior of the Gaussian function instead of a pulsed braking torque as provided by other commonly used controllers (On-Off controllers). The response of the MR brake controller, which is presented in a closed-loop feedback system, depends on the angular position error of the shaft and a tuning parameter representing the critical angular position at which the magnetic flux density, which is applied to the MR brake, reaches 60.65% of its maximum value. The advantage is to avoid knowing the dynamic parameters, such as the inertia of the mechanical device or its speed, and to reject these perturbations by a simple tuning parameter of the MR brake. To show the effectiveness of the proposed controller, the dynamic model of a slider-crank mechanism is considered. The results showed similar behavior as conventional controllers, where overshoot and oscillations were minimized. This behavior has been obtained in other research articles using controllers that require a greater amount of data processing.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"62 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88505041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao Jiang, Hongwei Zhang, Jing Chen, Sa Xiao, Xiren Miao, Weiqing Lin
The top oil temperature in ultra-high voltage (UHV) reactors has attracted enormous interest due to its wide applications in fault diagnosis and insulation evaluation. In this work, the precise prediction method based on the Seq2Seq module with the convolutional block attention mechanism is proposed for the UHV reactor. To reduce the influence of vibratility and improve computational efficiency, a combination of the encoding layer and decoding layer named Seq2Seq is performed to reconstruct the complex raw data. The convolutional block attention mechanism (CBAM), composed of spatial attention and channel attention, is utilized to maximize the use of information in data. The Seq2Seq-CBAM is established to forecast the variation tendency of the oil temperatures in the UHV reactor. The experimental results show that the proposed method achieves high prediction accuracy for the top oil temperature in both single-step and multi-step.
{"title":"Forecasting top oil temperature for UHV reactor using Seq2Seq model with convolutional block attention mechanism","authors":"Hao Jiang, Hongwei Zhang, Jing Chen, Sa Xiao, Xiren Miao, Weiqing Lin","doi":"10.3233/jae-230022","DOIUrl":"https://doi.org/10.3233/jae-230022","url":null,"abstract":"The top oil temperature in ultra-high voltage (UHV) reactors has attracted enormous interest due to its wide applications in fault diagnosis and insulation evaluation. In this work, the precise prediction method based on the Seq2Seq module with the convolutional block attention mechanism is proposed for the UHV reactor. To reduce the influence of vibratility and improve computational efficiency, a combination of the encoding layer and decoding layer named Seq2Seq is performed to reconstruct the complex raw data. The convolutional block attention mechanism (CBAM), composed of spatial attention and channel attention, is utilized to maximize the use of information in data. The Seq2Seq-CBAM is established to forecast the variation tendency of the oil temperatures in the UHV reactor. The experimental results show that the proposed method achieves high prediction accuracy for the top oil temperature in both single-step and multi-step.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"92 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79426385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Permata, W. Widyawati, H. H. Sinaga, N. Purwasih, S. Widiarto
Natural fiber composite becomes a necessity encountering the issue of eco-friendly materials. The application of natural fiber composite as electromagnetic interference (EMI) shielding enclosures has not been studied extensively. This study aims to investigate the performance of the coconut fiber composite as EMI shielding enclosure material. Enhancement of the electrical volume-conductivity of the composite was made by polymerization of coconut fiber with polyaniline and doping the multiwall carbon nanotubes to epoxy resin. Three types of composites were made with different weight percentages of coconut fiber: 5, 10, and 15 wt%. The highest volume-conductivity and shielding effectiveness of coconut fiber composite are 0,0458 S/m and −7.69 dB from the highest weight percentage of coconut fiber (15 wt%). While the highest tensile strength (26.78 MPa) resulted from the lowest weight percentage (5 wt%). This study shows the coconut fiber composite could potentially be the material of EMI shielding enclosure though their electrical conductivity and tensile strength should be increased.
{"title":"Study of electrical volume-conductivity, tensile strength, and electromagnetic shielding effectiveness of coconut fiber composite","authors":"D. Permata, W. Widyawati, H. H. Sinaga, N. Purwasih, S. Widiarto","doi":"10.3233/jae-220295","DOIUrl":"https://doi.org/10.3233/jae-220295","url":null,"abstract":"Natural fiber composite becomes a necessity encountering the issue of eco-friendly materials. The application of natural fiber composite as electromagnetic interference (EMI) shielding enclosures has not been studied extensively. This study aims to investigate the performance of the coconut fiber composite as EMI shielding enclosure material. Enhancement of the electrical volume-conductivity of the composite was made by polymerization of coconut fiber with polyaniline and doping the multiwall carbon nanotubes to epoxy resin. Three types of composites were made with different weight percentages of coconut fiber: 5, 10, and 15 wt%. The highest volume-conductivity and shielding effectiveness of coconut fiber composite are 0,0458 S/m and −7.69 dB from the highest weight percentage of coconut fiber (15 wt%). While the highest tensile strength (26.78 MPa) resulted from the lowest weight percentage (5 wt%). This study shows the coconut fiber composite could potentially be the material of EMI shielding enclosure though their electrical conductivity and tensile strength should be increased.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"3 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73262334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Moez Hizem, Aymen Ben Saada, Sofiane Ben Mbarek, F. Choubani
Human-Like digital models have been around for quite some time. They significantly contributed to the increase of the accuracy of the whole-body-average specific absorption rate estimations. However, the anatomical and morphological diversity between human beings has not yet been embraced by the actual anthropomorphic models for several reasons such as financial costs, excessive exposure of volunteers to electromagnetic waves, and the required number of technical experts needed to build one voxelized model. Recently, machine learning has been used to reduce the complexity of certain tasks. Yet, at least, having an anthropomorphic model per nation is still far away to achieve. To reduce the building cost of new human-like models, we build on the success of anthropomorphic models and machine learning to derive mathematical equations that make it possible to predict the Whole-body-average SAR from low frequencies up to twice the resonance frequency without any cost and excessive electromagnetic exposure of new volunteers. The completely new machine learning based equations are applicable for any age, ethnic group, and for both genders. They depend only on the human body’s morphological (height and weight) and anatomical parameters (tissue weights). In this work, we first address the whole-body-average SAR peak and we present a set of two estimators. In second, we show that the resonance frequency is not only a function of the height of the human body, to end up with a third estimation for the resonance frequency. These completely new estimators are finally combined into a novel function that links the whole-body-average SAR to the frequency. It shows the accurate prediction for low frequencies (10 MHz) up to twice the resonance frequency. The derived estimators for the maximum WBASAR and the resonance frequencies showed better results for low frequency exposure.
{"title":"Modeling of the interaction between human body and electromagnetic waves near resonance using machine learning","authors":"Moez Hizem, Aymen Ben Saada, Sofiane Ben Mbarek, F. Choubani","doi":"10.3233/jae-230025","DOIUrl":"https://doi.org/10.3233/jae-230025","url":null,"abstract":"Human-Like digital models have been around for quite some time. They significantly contributed to the increase of the accuracy of the whole-body-average specific absorption rate estimations. However, the anatomical and morphological diversity between human beings has not yet been embraced by the actual anthropomorphic models for several reasons such as financial costs, excessive exposure of volunteers to electromagnetic waves, and the required number of technical experts needed to build one voxelized model. Recently, machine learning has been used to reduce the complexity of certain tasks. Yet, at least, having an anthropomorphic model per nation is still far away to achieve. To reduce the building cost of new human-like models, we build on the success of anthropomorphic models and machine learning to derive mathematical equations that make it possible to predict the Whole-body-average SAR from low frequencies up to twice the resonance frequency without any cost and excessive electromagnetic exposure of new volunteers. The completely new machine learning based equations are applicable for any age, ethnic group, and for both genders. They depend only on the human body’s morphological (height and weight) and anatomical parameters (tissue weights). In this work, we first address the whole-body-average SAR peak and we present a set of two estimators. In second, we show that the resonance frequency is not only a function of the height of the human body, to end up with a third estimation for the resonance frequency. These completely new estimators are finally combined into a novel function that links the whole-body-average SAR to the frequency. It shows the accurate prediction for low frequencies (10 MHz) up to twice the resonance frequency. The derived estimators for the maximum WBASAR and the resonance frequencies showed better results for low frequency exposure.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"87 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79378931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to increase the torque performance of the conventional surface-inset Halbach machines, a surface-inset Halbach machine with trapezoidal mixed grade magnets is proposed and investigated. Based on a layered and linear superposition method, the air-gap magnetic fields are analytically obtained from solution of matrix equations. In addition, the dimensions of mid-magnet and the remanences of Halbach magnets are analytically optimized. In order to show its advantages, the optimized performances of the proposed machine model are compared with those of the conventional Halbach and trapezoidal equal grade Halbach machines. The prediction shows that the proposed optimized machine model has the largest electromagnetic torque and the lowest torque ripple. The demagnetization performance is also investigated. Finally, the finite element analysis (FEA) results verify the analytical predictions.
{"title":"Investigation of surface-inset Halbach machines with trapezoidal mixed grade magnets","authors":"Youyuan Ni, Zhiwei Qiu, B. Xiao","doi":"10.3233/jae-220192","DOIUrl":"https://doi.org/10.3233/jae-220192","url":null,"abstract":"In order to increase the torque performance of the conventional surface-inset Halbach machines, a surface-inset Halbach machine with trapezoidal mixed grade magnets is proposed and investigated. Based on a layered and linear superposition method, the air-gap magnetic fields are analytically obtained from solution of matrix equations. In addition, the dimensions of mid-magnet and the remanences of Halbach magnets are analytically optimized. In order to show its advantages, the optimized performances of the proposed machine model are compared with those of the conventional Halbach and trapezoidal equal grade Halbach machines. The prediction shows that the proposed optimized machine model has the largest electromagnetic torque and the lowest torque ripple. The demagnetization performance is also investigated. Finally, the finite element analysis (FEA) results verify the analytical predictions.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":"48 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86591903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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