{"title":"A new modified Bessel-type radial basis function for meshless methods: Utilized in the analysis of free vibration in 2D functionally graded Euler–Bernoulli beams","authors":"Shahram Hosseini, Fatemeh Abbaspour, Romina Nazari","doi":"10.1002/jnm.3287","DOIUrl":"https://doi.org/10.1002/jnm.3287","url":null,"abstract":"<p>Radial basis functions (RBFs) are extensively employed in mesh-free methods owing to their distinct properties. This study presents a novel RBF formulation based on a modified first-kind Bessel function, introduced for the first time. The efficacy and precision of the proposed function are assessed through an examination of the free vibrations of Euler–Bernoulli beams composed of two-directional functionally graded materials. Longitudinal and thickness property variations are modeled in polynomial and exponential forms, respectively. The performance of the novel RBF is scrutinized under various boundary conditions (clamped, simply supported, and free), and comparative analyses are conducted against similar investigations and an RBF based on the first-kind Bessel function. Convergence analysis of the proposed modified first-kind Bessel function-based RBF reveals superior convergence rates compared to the first-kind Bessel function-based RBF. Moreover, a comparison between results obtained from modeling using the proposed RBF and exact solutions underscores the adequacy of this approach, with a maximum discrepancy of 4.933% observed under clamped-free boundary conditions. In essence, the findings suggest that the proposed modified first-kind Bessel function-based RBF holds promise for analyzing the free vibrations of functionally graded Euler–Bernoulli beams. The primary aim of this research is to introduce and validate a new RBF based on a modified first-kind Bessel function for the analysis of free vibrations in Euler–Bernoulli beams made of two-directional functionally graded materials. The study focuses on evaluating the performance and accuracy of this novel RBF in comparison with existing RBFs and exact solutions. By addressing the limitations of conventional RBFs and proposing an innovative approach, this research aims to enhance the accuracy and efficiency of meshless methods in structural vibration analysis.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170167","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}
{"title":"Electromagnetic forces and their finite element computation","authors":"François Henrotte, Christophe Geuzaine","doi":"10.1002/jnm.3290","DOIUrl":"https://doi.org/10.1002/jnm.3290","url":null,"abstract":"<p>This paper introduces the concepts of differential geometry that are necessary to establish a systematic definition for electromagnetic forces by means of a natural thermodynamic approach. It is shown that standard electromagnetic force formulae used in finite element computational electromagnetism are particular instances of that general approach. Finally, the paper offers a complete conceptual framework, as well as a mathematical toolbox, to derive electromagnetic force formulae for multi-physics finite element models with complex materials.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169857","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}
{"title":"A millimeter-wave ultra-wideband triplexer with high isolation and high power","authors":"Dong Li, Zhouyang Wei, Maoyan Wang, Zhenyu Hong, Boqi Wei, Juntao Lin, Lijie Sun, Jun Xu, Xiaochuan Zhang","doi":"10.1002/jnm.3288","DOIUrl":"https://doi.org/10.1002/jnm.3288","url":null,"abstract":"<p>This paper provides a compact, noncontiguous, high isolation, manifold triplexer operating from 25.8 to 49.5 GHz, a 62.95% wide fractional operating bandwidth. The triplexer is composed of three waveguide bandpass filters with Chebyshev responses. The initialization and loop optimization strategy of the triplexer are given. To eliminate undesired high-order mode transmission between common port and filters, ridged-waveguide topology, tuning screws, capacitive windows, and narrowing the wide edges of resonant cavities for the third filter are employed. The measured results and simulated ones are in good agreement. To our knowledge, this is the most broadband, high-power triplexer demonstrated to date.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137712","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}
{"title":"Galerkin boundary element method for simulating lightning response of grounding grid in horizontal multilayered soil model considering soil ionization effect","authors":"Zhong-Xin Li, Peng Li, Xia Zhao","doi":"10.1002/jnm.3285","DOIUrl":"https://doi.org/10.1002/jnm.3285","url":null,"abstract":"<p>This work proposes a novel mathematical model based on the Galerkin time-domain boundary element method for accurately calculating the lightning current distribution and lightning impulse response of the buried substation grounding grid, in a multi-layer horizontal layered soil model, by taking into account the soil ionization effect. To improve computational efficiency, the quasi-static complex image method and its closed form time-domain Green's function have been introduced into the model that has the ability to analytically calculate the mutual inductance coefficient between the branch currents of any two conductor segments and the mutual resistance coefficient between the leakage currents. The Galerkin time-domain boundary element method proposed in this work can simulate the transient lightning impulse response of a substation grounding grid buried in the multi-layer horizontal layered soil.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130408","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}
Tongxin Zhang, Gaozhe Cai, Zhuo Zhang, Qian Li, Chuanjin Cui
{"title":"Temperature control technology for PCR","authors":"Tongxin Zhang, Gaozhe Cai, Zhuo Zhang, Qian Li, Chuanjin Cui","doi":"10.1002/jnm.3280","DOIUrl":"https://doi.org/10.1002/jnm.3280","url":null,"abstract":"<p>In order to solve the obvious nonlinear problem of temperature and complex structure of PCR instrument during nucleic acid amplification. In this paper, a new nucleic acid amplification device and temperature control algorithm were proposed. In the device, in order to improve the rise and fall rate and make the whole reaction device smaller and simpler, this paper uses a microfluidic chip for nucleic acid reaction. At the same time, in the warming and cooling module, the temperature is controlled by the semiconductor chilling plate, the air-cooled cooling device and the heat sink structure, which greatly improves the speed of nucleic acid amplification. In the algorithm, a hybrid algorithm is designed, using Particle Swarm Optimization (PSO) to optimize PID algorithm parameters, and then based on fuzzy theory, according to the temperature control requirements of nucleic acid amplification, fuzzy rules are analyzed and fuzzy reasoning is carried out, and then combined with PID to achieve rapid response and overshooting control of temperature control. Finally, the measurement noise is filtered by Kalman filter. Finally, COMSOL and MATLAB software are used to simulate and compare, and it is proved that the device has a certain heat dissipation effect in the process of nucleic acid amplification. This algorithm can improve the accuracy and robustness of the control system, improve the response speed, reduce the overshoot, shorten the adjustment time, and restrain the interference.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137818","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}
Yihang Ma, Giovanni Crupi, Jialin Cai, Chao Yu, Shichang Chen, Tao Zhou
{"title":"Behavioral modeling of LMBA with different back-off state using PSO optimized XGBoost method","authors":"Yihang Ma, Giovanni Crupi, Jialin Cai, Chao Yu, Shichang Chen, Tao Zhou","doi":"10.1002/jnm.3286","DOIUrl":"https://doi.org/10.1002/jnm.3286","url":null,"abstract":"<p>In this paper, an optimization technique based on the particle swarm optimization (PSO) algorithm is applied to the eXtreme gradient boosting (XGBoost) method for load modulated balanced amplifiers (LMBAs) modeling, taking into consideration both strong nonlinearity and memory effects. An overview of the basic principles of the proposed modeling technique is provided, as well as a detailed description of how the model is extracted. To improve the performance of the XGBoost model, the hyperparameters are optimized using the PSO algorithm. An in-house designed LMBA was used to perform experimental validation, which demonstrated that the new PSO-XGBoost model provided very efficient and extremely accurate predictions, especially in the case of strong nonlinearities. When compared to traditional Volterra models, canonical piecewise-linear based models, and standard XGBoost models, the proposed PSO-XGBoost model provides improved performance with reasonable complexity.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100038","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}
{"title":"Numerical solution of fractal-fractional differential equations system via Vieta-Fibonacci polynomials fractal-fractional integral operators","authors":"Parisa Rahimkhani, Yadollah Ordokhani, Sedigheh Sabermahani","doi":"10.1002/jnm.3283","DOIUrl":"https://doi.org/10.1002/jnm.3283","url":null,"abstract":"<p>The main idea of this work is to present a numerical method based on Vieta-Fibonacci polynomials (VFPs) for finding approximate solutions of fractal-fractional (FF) pantograph differential equations and a system of differential equations. Although the presented scheme can be applied to any fractional integral, we focus on the Caputo, Atangana-Baleanu, and Caputo-Fabrizio integrals with due to their privileges. To carry out the method, first, we introduce FF integral operators in the Caputo, Atangana-Baleanu, and Caputo-Fabrizio senses. Then, by applying the Vieta-Fibonacci polynomials and their FF integral operators together with the collocation method, the problem becomes reduced to a system of algebraic equations that can be solved by Mathematical software. In the presented scheme, acceptable approximate solutions are achieved by employing only a few number of the basic functions. Moreover, the error analysis of the presented method is investigated. Finally, the accuracy of the presented method is examined through the numerical examples. The proposed scheme is implemented for some famous systems of FF differential equations, such as memristor, which is a fundamental circuit element so called universal charge-controlled mem-element, convective fluid motion in rotating cavity, and Lorenz chaotic system.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142089820","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}
{"title":"Comparative analysis of uncontrollable angles in direct torque and stator flux control and rotor flux control strategies: A numerical and experimental study","authors":"Mussaab Alshbib, Sohayb Abdulkerim, Abdulkader Ghazal","doi":"10.1002/jnm.3282","DOIUrl":"https://doi.org/10.1002/jnm.3282","url":null,"abstract":"<p>The uncontrollable angles (UAs) in direct torque control (DTC) algorithm is an important issue through which the effects of voltage vectors (VEs) on the magnetic flux and the torque are accurately determined. In this paper, a unique analysis of UAs is performed at different operating conditions, including parameters variations in two different strategies: Direct torque and stator flux control (DTC_SC) and (DTC_RC). Values of Those angles were accurately determined for wide speed, stator and rotor variations, and load changes. In addition, a detailed numerical comparison was performed in terms of these angles in the two strategies mentioned above for each operating condition. The comprehensive comparison showed the superiority of the DTC_RC strategy over its DTC_SC counterpart, being the maximum values of UAs in DTC_RC were 8°, 33°, and 21° versus 15°, 45°, and 38° in DTC_RC strategy for the following operations: Variable speed with variable stator resistance, variable speed with variable stator and rotor resistances, variable speed with variable load, respectively. MATLAB/Simulink results of the contributed analysis and comparisons were accomplished and validated. In addition, DS1103-based experimental tests supported and verified the theoretical analysis.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077931","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}
{"title":"Numerical modeling of HTS excited medium-speed wind generators with diode rectifier stator feeding","authors":"Robin Köster, Andreas Binder","doi":"10.1002/jnm.3284","DOIUrl":"https://doi.org/10.1002/jnm.3284","url":null,"abstract":"<p>Medium-speed wind generators in the MW-range with high-temperature superconducting excitation winding are analyzed by means of non-linear 2D and 3D FEM models. Besides an inverter-based sinusoidal stator current feeding, a grid connection via a diode rectifier is analyzed by using coupled FEM and circuit simulations. The newly proposed modeling techniques are used to determine the excitation requirement for speed-variable, unity power factor operation at constant stator voltage, as required for a diode rectifier feeding of the stator winding. 2D FEM models in the <i>H</i>-<i>A</i>-formulation are developed and used for the calculation of the hysteresis loss in the superconducting field winding at stationary operation as well as for an investigation of field current variations in the HTS field winding. The major modeling challenges consist in very long settling times of voltage-fed models, several strong model non-linearities and high requirements on the spatial discretization. Approaches for overcoming these difficulties with reasonable computational efficiency are proposed.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jnm.3284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuman Mao, Xiang Su, Qingzhi Wu, Yan Wang, Xiangyang Duan, Shen Tian, Xuehuan Li, Yuehang Xu
{"title":"Physics-based compact models of GaN HEMTs for high power RF applications: A review (Invited Paper)","authors":"Shuman Mao, Xiang Su, Qingzhi Wu, Yan Wang, Xiangyang Duan, Shen Tian, Xuehuan Li, Yuehang Xu","doi":"10.1002/jnm.3276","DOIUrl":"https://doi.org/10.1002/jnm.3276","url":null,"abstract":"<p>The compact model plays a pivotal role as a critical link between device fabrication and circuit design. While conventional compact model theories and techniques are generally mature, the intricate physical mechanisms of gallium nitride (GaN) high-electron mobility transistors (HEMTs) pose challenges due to their strong non-linearity in high-power radio frequency (RF) applications. This complexity hinders achieving the required precision for applications using traditional modeling methods. Therefore, the development of physics-based compact modeling techniques becomes crucial for a deeper understanding of the intricate features of GaN HEMTs. This paper explores the advancements and the current state-of-the-art in physics-based compact models. The comprehensive review covers both intrinsic core models and real-device effects models. Core models are presented with a focus on fundamental concepts, development overviews, and applications. Additionally, the real-device effects models are introduced, encompassing advanced characterization techniques and modeling methodologies. Furthermore, the paper outlines future trends in physics-based compact modeling, providing valuable insights for individuals engaged in transistor compact modeling work.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002573","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}