研究者データベース

五十嵐 一(イガラシ ハジメ)
情報科学研究院 システム情報科学部門 システム融合学分野
教授

基本情報

所属

  • 情報科学研究院 システム情報科学部門 システム融合学分野

職名

  • 教授

学位

  • 博士(工学)(北海道大学)

連絡先

  • igarashissi.ist.hokudai.ac.jp

ホームページURL

科研費研究者番号

  • 90212737

ORCID ID

J-Global ID

研究キーワード

  • 環境発電   RFID   設計最適化   Inverse Analysis   Intellectual Computer Aided Engineering   Optimuzation and Generation of Systems Using Soft Computing   計算電磁気学   

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 電力工学
  • 情報通信 / 計算科学
  • 社会基盤(土木・建築・防災) / 安全工学
  • 社会基盤(土木・建築・防災) / 社会システム工学

職歴

  • 2004年04月 - 現在 北海道大学情報科学研究科 教授

所属学協会

  • 日本シミュレーション学会   日本AEM学会   電子情報通信学会   電気学会   International COMPUMAG Society   IEEE   計算数理工学会   

研究活動情報

論文

  • Yoshitsugu Otomo, Hajime Igarashi
    IEEE Transactions on Magnetics 57 6 8203004  2021年06月
  • Yoshitsugu Otomo, Hajime Igarashi
    IEEE Transactions on Power Electronics 36 4 4513 - 4521 2021年04月 [査読有り][通常論文]
     
    This article proposes a method for modeling electric devices based on a Cauer circuit whose circuit parameters are directly determined from measured or computed data using the adjoint variable method. It has been shown that electric devices that are governed by the quasi-static Maxwell's equation can be modeled by the Cauer circuit. From the synthesized Cauer circuit, eddy current losses can be evaluated for a wide frequency range. Moreover, it can be embedded into a circuit simulator to perform the time-domain analysis. It is shown that the Cauer circuit whose parameters are identified using the proposed method works better for a simple numerical model than that whose parameters are identified using a genetic algorithm. Moreover, the Cauer equivalent circuit of a reactor and a power inductor is synthesized from the measured data using the proposed method. It is shown that the input impedance of the reactor and power inductor is well approximated by the Cauer circuit over the frequency domain of interest.
  • 坂本 宏紀, 五十嵐 一
    電気学会論文誌D(産業応用部門誌) 141 2 193 - 198 一般社団法人 電気学会 2021年 [査読有り][通常論文]
     

    This paper proposes simplified model order reduction for the fast dynamic simulation of electric motors. In this method, magnetic fields expressed by reduced variables are stored into memory and restored using interpolation in the current-state space to enable the properties of an electric motor to be computed fast. It is shown that the iron losses considering higher harmonics are computed accurately and effectively usingthe proposed method. Moreover, the proposed method is successfully coupled with flux-based circuit equations.

  • Shingo Hiruma, Makoto Ohtani, Shingo Soma, Yoshihisa Kubota, Hajime Igarashi
    IEEE Transactions on Magnetics 2021年 [査読有り][通常論文]
     
    This paper introduces novel hybridization of parameter optimization (PO) and topology optimization (TO) methods. The proposed method is applied to the optimization of a permanent magnet motor. The magnet shape and topology of the flux barrier of the rotor core are optimized by performing PO and TO simultaneously. In the optimization, automatic mesh generation is adopted to improve the resolution of the shape representation. It is shown that the increase in the average torque resulting from the proposed hybrid optimization is larger than that obtained by the conventional TO in which only the topology of the flux barrier is optimized. The decomposition of the total torque to the magnet and reluctance torques suggests that the reluctance torque is effectively generated in the rotor optimized by the proposed method.
  • Hidenori Sasaki, Yuki Hidaka, Hajime Igarashi
    IEEE Transactions on Magnetics 2021年 [査読有り][通常論文]
     
    This study presents a novel two-step optimization method that incorporates explainable neural networks into topology optimization. The deep neural network (DNN) is trained to infer the torque performance from the input image of the motor cross-section. The sensitive region that has a significant influence on the average torque is extracted using gradient-weighted class activation mapping (Grad-CAM) constructed from the DNN. Then, the optimization with respect to the torque ripple is performed only in the incentive region with little influence on the average torque. The proposed method is shown to increase the average torque of an Interior Permanent Magnet (IPM) motor by 14% and reduce torque ripple by 79% compared to the original model.
  • Hayaho Sato, Hajime Igarashi
    IEEE Transactions on Magnetics 2021年 [査読有り][通常論文]
     
    This paper proposes a method based on three-dimensional discrete element and finite element methods to numerically evaluate the effect of the particle size distribution of soft composite material (SMC) on the electromagnetic property. The three SMC models which obey Gaussian, homogeneous and twin-peak distributions are compared using the proposed method. It is shown that Gaussian model has the highest permeability and lowest loss at high frequencies under the condition that the three models have the same filling rate.
  • 深層学習を用いたトポロジー最適化ー同時および追加学習の比較ー
    佐々木秀徳, 日高勇気, 五十嵐一
    電気学会論文誌B(電力・エネルギー部門誌) 140 12 858 - 865 2020年12月 [査読有り][通常論文]
  • Yuki Sato, Kenji Kawano, Dongbin Hou, Jeffrey Morroni, Hajime Igarashi
    IEEE Transactions on Power Electronics 35 9 9663 - 9670 2020年09月 [査読有り][通常論文]
     
    © 1986-2012 IEEE. This article presents a new method to synthesize the Cauer-equivalent circuit for inductors that can represent the hysteresis, eddy current, anomalous core losses, dc and ac winding losses as well as inductance. Only the measurement of inductor loss under the sinusoidal excitation is required to synthesize the SPICE loss model. The proposed circuit model can be used to evaluate the loss under arbitrary voltage/current excitations. In the proposed approach, the measured loss is subdivided into the ac and hysteresis losses. Then, the Cauer-equivalent circuit for SPICE simulation is synthesized from the loss model. It is shown that the losses evaluated by the proposed model are in good agreement with the measured results under the condition of the sinusoidal and triangular cases with and without dc bias current.
  • Akito Maruo, Hajime Igarashi, Hirotaka Oshima, Satoshi Shimokawa
    IEEE Transactions on Magnetics 56 3 2020年03月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article presents a fast optimization of a 2-D magnetic array using digital annealer, a hardware system which solves quadratic unconstrained binary optimization problems with massive parallelization. The magnetic-array structure, which is used for a vibration energy harvester and a planar motor, is optimized so that the induced voltage in coils placed above the array is maximized. A novel structure of a planar magnet array without the non-magnetic region is obtained as an extension of the Halbach array.
  • Jo Asanuma, Shuhei Doi, Hajime Igarashi
    IEEE Transactions on Magnetics 56 3 2020年03月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article proposes the use of transfer learning for the deep neural network to reduce the computing cost of the topology optimization of electric motors based on a genetic algorithm (GA). The average torque and torque ripple values are shown to be accurately inferred by the transfer learning with small learning data. The individuals on the Pareto front are only evaluated by the finite-element method, while others are fast evaluated only by convolutional neural networks (CNNs). The proposed method makes it possible to reduce the computing cost to less than 15% of the conventional topology optimization method.
  • Shingo Hiruma, Hajime Igarashi
    IEEE Transactions on Magnetics 56 3 2020年03月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article introduces a new model order reduction method for a linear time-invariant system with symmetric positive-definite matrices. The proposed method allows the construction of a reduced model, represented by a Cauer-equivalent circuit, from the original system. The method is developed by extending the Cauer ladder network method for the quasi-static Maxwell's equations, which is shown to be regarded as the Lanczos algorithm with respect to a self-adjoint matrix. As a numerical example, a Cauer-equivalent circuit is generated from a simple mathematical model as well as the finite-element (FE) model of a magnetic reactor that is driven by a pulsewidth modulation voltage wave. The instantaneous power obtained from the circuit analysis is shown to be in good agreement with that obtained from the original FE model.
  • Toshihito Shimotani, Hajime Igarashi, Eiji Hashimoto, Hiroyuki Imanari
    IEEE Transactions on Magnetics 56 2 2020年02月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article presents a method to synthesize the equivalent circuit of an induction heating (IH) machine used in the hot strip mill (HSM) process. The equivalent circuit not only allows to evaluate eddy current losses in different forms, such as iron plate and coils, but also compute the transient responses in online environments. The frequency characteristic of the IH machine is effectively computed by proper orthogonal decomposition. The equivalent circuit of the IH is synthesized through curve fitting to the computed characteristics in conjunction with Tikhonov's regularization. The equivalent circuit is shown to have good accuracy and works much faster than the finite-element method. The proposed equivalent circuit is expected to be used in online control of the HSM process.
  • Hiroki Sakamoto, Kazuya Okamoto, Hajime Igarashi
    IEEE Transactions on Magnetics 56 2 2020年02月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article proposes a simplified model-order reduction for the fast dynamic simulation of electric motors. The magnetic fields are snapshotted for different input currents at each mechanical angle to construct a data matrix. The basis vectors are then computed by the singular value decomposition applied to the data matrix. The interpolation along the mechanical angle is performed by the dynamic mode decomposition. Fast computation of the magnetic field for arbitrary input current and mechanical angle is performed through interpolation of the basis vectors in the space of input currents for the dynamic analysis of motors.
  • Shogo Fujita, Shingo Hiruma, Hajime Igarashi
    IEEE Transactions on Magnetics 56 2 2020年02月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. A magnetically shielded wire (MSW) is effective for the reduction of the eddy-current loss due to the proximity effect. When using the finite-element method (FEM), it is challenging to analyze the electric apparatus, including MSWs, because its radius is much smaller than the overall machine size. This problem can be circumvented by modeling a multiturn MS coil (MSC) as uniform material with the macroscopic complex permeability defined in the frequency domain. This article presents an extension of this homogenization method to the time domain. The inverse Laplace transform is effectively performed by expanding the complex permeability into partial fractions. It is shown that the proposed method is accurate even when the magnetic saturation of the magnetic core is in effect.
  • Shingo Hiruma, Hajime Igarashi
    IEEE Transactions on Magnetics 56 2 2020年02月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article proposes a novel homogenization method based on the unit cell approach which provides the continued fraction and, equivalently, the Cauer circuit representation of the complex permeability of fine structure materials. The proposed method makes it possible to perform the homogenization analysis in time domain. It is shown that the proposed method provides a more accurate resistance factor in comparison to the Dowell method and other classical methods.
  • 五十嵐 一, 比留間 真悟, 佐藤 駿輔
    まぐね = Magnetics Japan 15 3 173 - 178 日本応用磁気学会 2020年 [査読有り][招待有り]
  • Yoshitsugu Otomo, Hajime Igarashi, Yuki Hidaka, Taiga Komatsu, Masaki Yamada
    IEEE Transactions on Magnetics 56 1 2020年01月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article proposes a two-step topology optimization method based on the normalized Gaussian functions. The proposed method is shown to be effective for design of a claw-pole alternator. In this method, the global search using the micro-genetic algorithm (μ GA) is followed by the local search using the sensitivity analysis based on the adjoint variable method. The 3-D structure of the rotor is optimized using the proposed method under low- and high-speed conditions.
  • Shingo Hiruma, Hajime Igarashi
    IEEE Transactions on Magnetics 56 1 2020年01月 [査読有り][通常論文]
     
    © 1965-2012 IEEE. This article presents a new method for time-domain analysis based on the homogenized finite-element method (FEM). The permeability in the homogenized domain is expressed by the Cauer-equivalent circuit. The auxiliary unknowns relevant to the Cauer circuit are then eliminated using the finite-difference method. The homogenized finite-element (FE) equation without the auxiliary unknowns can be effectively solved.
  • Shingo Hiruma, Hajime Igarashi
    IEEJ Transactions on Power and Energy 140 2 134 - 139 2020年 [査読有り][通常論文]
     
    © 2020 The Institute of Electrical Engineers of Japan. This paper introduces a novel method for synthesis of the equivalent circuit of an electromagnetic system described by a homogenized FE equation via model order reduction. The homogenization method replaces fine-structured material such as multi-turn coils, soft magnetic composite and laminated iron sheets with uniform material with complex permeability. The present method reduces the FE equation including the complex permeability to a circuit equation for small variables which can be solved with small computational cost. The present method is effective for time-domain analysis and makes it possible to consider magnetic saturations.
  • 藤田 祥伍, 五十嵐 一
    電気学会論文誌B(電力・エネルギー部門誌) 140 5 402 - 408 一般社団法人 電気学会 2020年 [査読有り][通常論文]
     

    In this paper, a homogenized finite element method for transient analysis of electric apparatus including a multi-turn coil with elliptic cross-section. The tensor-type complex permeability of the multi-turn coil is expanded into partial fractions, which can then be transformed into time-domain. The convolution integral is effectively evaluated using the RC method which does not need large memory storage. It is shown that the power computed by the proposed method is in good agreement with that computed by the conventional finite element method without homogenization.

  • Doi Shuhei, Sasaki Hidenori, Igarashi Hajime
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Fujita Shogo, Igarashi Hajime
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Maruo Akito, Igarashi Hajime, Sato Yuki, Kawano Kenji
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Maruo Akito, Igarashi Hajime
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Otomo Yoshitsugu, Igarashi Hajime
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Sasaki Hidenori, Igarashi Hajime
    IEEE TRANSACTIONS ON MAGNETICS 55 6 2019年06月 [査読有り][通常論文]
  • Fujita Shogo, Igarashi Hajime
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 38 3 999 - 1008 2019年05月07日 [査読有り][通常論文]
  • Ye Fangzhou, Igarashi Hajime
    JOURNAL OF ADVANCED SIMULATION IN SCIENCE AND ENGINEERING 6 1 149 - 156 2019年 [査読有り][通常論文]
  • Sasaki Hidenori, Igarashi Hajime
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 59 1 87 - 96 2019年 [査読有り][通常論文]
  • Maruo Akito, Igarashi Hajime
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 59 2 567 - 575 2019年 [査読有り][通常論文]
  • Hiruma Shingo, Igarashi Hajime
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 60 S79 - S86 2019年 [査読有り][通常論文]
  • Otomo Yoshitsugu, Igarashi Hajime
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 60 S115 - S123 2019年 [査読有り][通常論文]
  • Shogo Fujita, Hajime Igarashi
    Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 205 23 - 31 2018年12月 [査読有り][通常論文]
     
    © 2018 Wiley Periodicals, Inc. Magnetoplated wires (MPW) are effective to reduce eddy current losses in power devices such as converters and contactless power transfer systems. In the conventional finite element analysis (FEA) of MPW, elements must be sufficiently smaller than the skin depth. This results in large number of unknowns. This article proposes a homogenization method using complex permeability for FEA of magnetoplated coils so as to circumvent this problem. The coil impedances obtained by the proposed method with coarse elements are shown to agree well with those computed in the conventional FEA with fine elements.
  • Polyanna Mara Pereira, Felipe Campelo, Takuya Mori, Hajime Igarashi, Ricardo Adriano
    COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 37 1905 - 1917 2018年11月 [査読有り][通常論文]
     
    © 2018, Emerald Publishing Limited. Purpose: This paper aims to present a SPICE model to represent antennas in receiving mode. The model can be used to evaluate the performance of the antenna when it is coupled to several different nonlinear electric circuits. The proposed methodology is particularly suitable for rectenna applications, as it allows the analysis of different configurations for a rectenna more efficiently than using full-wave analysis simulators coupled directly to each rectifier circuit. Design/methodology/approach: The model presented uses reciprocity theory to calculate the ideal voltage source of the Thevenin-equivalent circuit for an antenna. Vector fitting is then used to approximate the model to rational functions that can be converted to Resistor, Inductor and Capacitor circuits. Additional components are added to the circuit to prevent numerical instability. Findings: Two rectennas are used to illustrate the performance of the proposed model, one based on a 2.45-GHz rectangular patch antenna and another based on a planar spiral antenna. The second antenna has impedance with positive and negative real parts along the frequency range, which could lead to numerical instabilities. The proposed method is shown to be stable while working with these negative resistance values, which may appear during circuit parameterization. Research limitations/implications: The equivalent SPICE circuit model for the antenna makes it easy to simulate nonlinear circuits connected to the antenna and perform transient analyses. The computational cost of antenna analysis is reduced, being more computationally efficient than methods that involve full-wave simulation. This characteristic makes it an interesting approach for working with rectennas, or any application where the time constant of the circuit is much longer than the period of the incident wave. Originality/value: For most antenna applications, the numerical stability of the circuit can be achieved using passive enforcement. However, depending on the phase response of the antenna, the impedance that represents its far-field characteristic may present a negative real part, in which case, passive enforcement will fail. In this paper, the problem of numerical instability is solved by introducing an offset resistance and a current-controlled voltage source to the model.
  • Keiichi Itoh, Haruka Nakajima, Hideaki Matsuda, Masaki Tanaka, Hajime Igarashi
    IEICE Transactions on Electronics E101C 784 - 790 2018年10月 [査読有り][通常論文]
     
    Copyright © 2018 The Institute of Electronics, Information and Communication Engineers. This paper reports a novel 3D topology optimization method based on the finite difference time domain (FDTD) method for a dielectric lens antenna. To obtain an optimal lens with smooth boundary, we apply normalized Gaussian networks (NGnet) to 3D topology optimization. Using the proposed method, the dielectric lens with desired radiation characteristics can be designed. As an example of the optimization using the proposed method, the width of the main beam is minimized assuming spatial symmetry. In the optimization, the lens is assumed to be loaded on the aperture of a waveguide slot antenna and is smaller compared with the wavelength. It is shown that the optimized lens has narrower beamwidth of the main beam than that of the conventional lens.
  • Satoshi Shimokawa, Hirotaka Oshima, Koichi Shimizu, Yuji Uehara, Jun Fujisaki, Atsushi Furuya, Hajime Igarashi
    IEEE Transactions on Magnetics 2018年06月 [査読有り][通常論文]
     
    IEEE This paper presents an effective design method for inductors which is based on the multi-objective optimization accelerated by the artificial neural network (ANN). In the learning phase prior to the optimization phase, ANN is trained for 1000 input-output data sets obtained from the finite-element analysis for randomly generated dimensional parameters. The magnetic hysteresis of the ferrite core is modeled by the play model to evaluate the hysteresis losses. The multi-objective optimization problems are solved by the genetic algorithm in which the magnetic loss is effectively computed by the trained ANN to reduce the core volume as well as magnetic loss. The Pareto solutions for an EI-shaped ferrite core are obtained for different inductances. It is shown that the proposed method works much faster than the conventional optimization, and the magnetic loss and the inductance of the optimized inductor agree well with the experimental results.
  • Shingo Hiruma, Yoshitsugu Otomo, Hajime Igarashi
    IEEE Transactions on Magnetics 54 3 2018年03月01日 [査読有り][通常論文]
     
    A new method is introduced to evaluate the macroscopic permeability of a litz wire which is composed of stranded conductors. In this method, an integral equation is solved for the complex magnetization in the litz wire generated due to the proximity effect. The macroscopic permeability computed from the magnetization is used in the homogenization-based finite-element analysis of eddy currents in a litz-wire coil. It is shown that the wire twist has a little effect on the complex permeability.
  • Yoshitsugu Otomo, Yuki Sato, Shogo Fujita, Hajime Igarashi
    IEEE Transactions on Magnetics 54 3 2018年03月01日 [査読有り][通常論文]
     
    In this paper, the multi-turn coil used in a wireless power transfer (WPT) device is modeled as a uniform material using the homogenization method to consider the proximity effect. By fitting the coil impedance to the numerical results, the Cauer equivalent circuit of the multi-turn coil is synthesized for the design and optimization of the power circuits in the WPT device. It is shown that the results obtained from the equivalent circuit and measurement are in good agreement. Moreover, the impedance of a flat WPT coil composed of a Litz wire is shown to be accurately evaluated by the proposed method when the contribution of capacitance is negligible.
  • Hidenori Sasaki, Hajime Igarashi
    IEEE Transactions on Magnetics 54 3 2018年03月01日 [査読有り][通常論文]
     
    This paper presents a new topology optimization method based on basis functions for design of rotating machines. In this method, the core shape of a given rotating machine is represented by the linear combination of the basis functions. The shape is then freely deformed by changing the weighting coefficients to the basis functions to find the optimal shape. The proposed method is compared with the conventional shape optimization based on polygon morphing. The former is shown to outperform the latter in both interior permanent magnet and synchronous motor models.
  • Shogo Fujita, Hajime Igarashi
    IEEE Transactions on Magnetics 54 3 2018年03月01日 [査読有り][通常論文]
     
    A magnetically shielded wire (MSW), which has magnetic-conductive thin layers on the surface of a wire conductor, is expected to reduce the eddy current losses due to the proximity effect. The conventional finite-element method (FEM) needs unacceptably long computational time to analyze eddy currents in multi-turn MSWs. This paper proposes a homogenization method, which models MSW as a uniform material with complex permeability. The coil impedance evaluated by the homogenization-based FEM with coarse elements is shown to agree well with that obtained by the conventional FEM with much finer elements. Moreover, the optimal shield thickness is determined by the proposed method.
  • Hidaka Yuki, Igarashi Hajime
    JOURNAL OF ADVANCED SIMULATION IN SCIENCE AND ENGINEERING 4 1 64 - 77 2018年 [査読有り][通常論文]
  • Takeshi Sugisawa, Hajime Igarashi
    INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 30 5 2017年09月 [査読有り][通常論文]
     
    Energy-harvesting devices have been developed for the use of voltage sources in low-powered wireless sensors. Vibration energy harvesters generate electric power from ambient vibration of constructions such as bridges, tunnel walls, and power pylons. Vibration energy harvesters are required to have high power generation efficiency over a wide vibration frequency. This paper presents a vibration energy harvester in which closed magnetic circuits are formed aiming at high efficiency and double-well potential is formed to have chaotic vibration to realize wide frequency-range power generation. In particular, the conditions for emergence of chaotic vibration are clarified based on numerical analysis and experiments.
  • So Noguchi, Takuto Naoe, Hajime Igarashi, Shinya Matsutomo, Vlatko Cingoski, Akira Ahagon, Akihisa Kameari
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    Mesh quality strongly affects the solution accuracy in electromagnetic finite-element analysis. Hence, the realization of adequate mesh generation becomes a very important task. Several adaptive meshing methods for automatic adjustments of the mesh density in accordance with the shape and complexity of the analyzed problem have been proposed. However, the most of them are not enough robust, some are quite laborious and could not be universally used for adaptive meshing of complex analysis models. In this paper, a new adaptive mesh refinement method based on magnetic field conservation at the border between finite elements is proposed. The proposed error estimation method provides easy mesh refinements, and generates smaller element within regions with large curvature of the magnetic flux lines. The proposed adaptive mesh refinement method based on non-conforming edge finite elements, which could avoid generation of flat or ill-shaped elements, was applied to a simple magnetostatic permanent magnet model. To confirm the validity and accuracy, the obtained results were compared with those obtained by means of the Zienkiewicz-Zhu (ZZ) error estimator. The results show that the computational error using the proposed method was reduced down to 1% compared with that of the ZZ method, which yields error of 8.6%, for the same model.
  • Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    This paper presents a homogenized analysis of soft magnetic composite (SMC), which is composed of small iron particles embedded in insulating medium. The SMC core is modeled by uniform material with the macroscopic complex permeability which is analytically represented in frequency domain. The Cauer-equivalent circuit is synthesized from the macroscopic permeability for time-domain analysis of SMC. The proposed method is shown valid even when SMC is magnetically saturated.
  • Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    This paper presents a homogenization method based on the model order reduction (MOR) for finite element (FE) analysis of multi-turn coils. The multi-turn coils are replaced by a homogenous material with the complex permeability that is expressed by a rational polynomial of frequency. After the MOR process, the complex permeability can readily be computed at any frequency. It is shown that the present method can drastically reduce the computational time without loss of accuracy.
  • Yuki Hidaka, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    The magnetic characteristic of magnetic steel sheets used for rotating machines can be degraded by punching, cutting, or other manufacturing process. This degradation damages the performances of motors. This paper presents topology optimization of rotating machines considering the localized magnetic degradation caused by punching process. It is shown that the optimized synchronous reluctance motors obtained by this method satisfy the torque constraint under the existence of the magnetic degradation.
  • Yuki Sato, Toshihito Shimotani, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    The Cauer-equivalent circuit of electric apparatus is synthesized by applying the model order reduction to the finite-element equations. In this method, the admittance function of a given electric apparatus is expressed by a rational polynomial from which the Cauer-equivalent circuit is directly synthesized. Magnetic saturation in the magnetic core is considered by introducing nonlinearity in the primal inductance of the circuit. The synthesized circuit is shown to express the input-output properties of inductors and induction heating devices in good accuracy.
  • Shingo Hiruma, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 6 2017年06月 [査読有り][通常論文]
     
    Eddy current loss in a litz wire which has 3-D structure is analyzed using the integral equation method considering the proximity effect. In the present method, each wire is modeled as a polygonal line. 1-D integral equation is solved for the dipole magnetization generated by the anti-parallel eddy currents in the wire. The discretized integral equation can effectively be solved using an iterative method solver to compute the eddy current distribution in the wire due to the proximity effect.
  • Yuki Sato, Hajime Igarashi
    IEEJ Transactions on Power and Energy 137 3 202 - 207 2017年 [査読有り][通常論文]
     
    This paper introduces a fast time-periodic eddy current analysis using model order reduction (MOR) and timeperiodic explicit error correction (TP-EEC) method. In this method, the size of the original system is reduced by MOR and simultaneously, the convergence to steady states is accelerated by TP-EEC. It is shown that the speedup ratio of the present method compared with the conventional FEM is more than 30 for a nonlinear test problem.
  • 佐々木 秀徳, 五十嵐 一
    電気学会論文誌. B, 電力・エネルギー部門誌 = IEEJ transactions on power and energy 137 3 245 - 253 電気学会 2017年 [査読有り][通常論文]
     
    This paper proposes a topology optimization method for rotating machines, in which the rotor shape is represented in terms of the Fourier series. The rotor shape of an IPM motor is optimized to maximize the average torque and minimize radial torque variations using the present method. The proposed method is shown to provide the optimized rotors whose performances are comparable with those obtained by the NGnet-based method. The topology optimization performed by both methods can give useful information on the motor design.
  • 藤田 祥伍, 五十嵐 一
    電気学会論文誌. B, 電力・エネルギー部門誌 = IEEJ transactions on power and energy 137 3 223 - 229 電気学会 2017年 [査読有り][通常論文]
     
    Magnetoplated wires (MPW) are effective to reduce eddy current losses in power devices such as converters and contactless power transfer systems. In the convenient finite element (FE) analysis of MPW, elements must be sufficiently smaller than the skin depth. This results in large number of unknowns. This paper proposes a homogenization method using complex permeability for FE analysis of MP-coils so as to circumvent this problem. The coil impedances obtained by the proposed method with coarse elements are shown to agree well with those computed in the conventional FE analysis with fine elements.
  • 日高 勇気, 五十嵐 一
    電気学会論文誌. B, 電力・エネルギー部門誌 = IEEJ transactions on power and energy 137 3 208 - 215 電気学会 2017年 [査読有り][通常論文]
     
    This paper presents topology optimization of rotating machines using the On-Off method with variable design region. The flux barrier shape is optimized by the present method in which the thin design regions covering the boundary of the flux barriers are adaptively modified during the optimization process. Because the design region is strongly restricted, the optimized flux barrier boundaries are expected to be rather smooth even if the smoothing procedure is not employed. Moreover the present method is based on the evolutionary algorithm which has powerful searching abilities. In order to validate its effectiveness, the flux barrier shapes of the interior permanent magnetic motors and synchronous reluctance motors are optimized by the present method. The performance of the present method is shown to be superior over that of the Rosen-brock method.
  • Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 53 1 2017年01月 [査読有り][通常論文]
     
    Native application of finite-element method (FEM) to the analysis of skin and proximity effects in multi-turn coils results in large equation systems, whose solution needs long computational time. This paper proposes a semi-analytical approach to overcome this problem. For the analysis of the proximity effect, the complex permeability of a round conducting wire immersed in uniform time-harmonic magnetic fields is represented in a closed form. Then, the homogenized complex permeability over the cross section of the multi-turn coil is analytically evaluated using the Ollendorff formula. The magnetoquasistatic problem is thus replaced by the magnetostatic one, in which the multi-turn coil is treated as a uniform material with the homogenized complex permeability. The skin effect is taken into consideration by introducing the corresponding impedance in the circuit equation. The proposed method is shown to give the impedance of multi-turn coils, which is in good agreement with that obtained by the conventional FEM as well as experiments.
  • Yuki Sato, Markus Clemens, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 52 3 2016年03月 [査読有り][通常論文]
     
    This paper presents a novel adaptive subdomain model order reduction (MOR) based on proper orthogonal decomposition (POD) and discrete empirical interpolation (DEI) methods for nonlinear magneto-quasi-static (MQS) problems. In this method, a nonlinear region is decomposed into two regions, where one of the regions includes all those finite elements that have a particularly strong saturation and the other region does not. MOR based on POD and DEI methods is applied only to the latter region. Both the regions are determined automatically at each time step. It is shown that this method can effectively reduce the computational time to solve the nonlinear MQS problems without losing the quality of accuracy.
  • Yasuhisa Ito, Hajime Igarashi, Michiaki Suzuki, Yoshiki Iwasaki, Kenji Kawano
    IEEE TRANSACTIONS ON MAGNETICS 52 3 2016年03月 [査読有り][通常論文]
     
    It is revealed that the contact of magnetic particles in soft magnetic composite (SMC) significantly increases the macroscopic permeability. It is shown that Ollendorff's formula, which assumes homogenous magnetic particles and insulation layers, underestimates the macroscopic permeability of SMC. It is suggested that the excess in the permeability is due to the local contacts among the magnetic particles. The effect of the magnetic contact is evaluated using a magnetic circuit model.
  • Toshihito Shimotani, Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 52 3 2016年03月 [査読有り][通常論文]
     
    This paper presents the generation of equivalent circuits from a finite-element (FE) model of electromagnetic devices using proper orthogonal decomposition (POD). This method effectively computes the frequency response of the reduced FE model constructed by the POD-based model order reduction. Then, the circuit parameters are determined so as to minimize the error between the frequency responses of the reduced FE model and equivalent circuit. The frequency characteristics of an inductor and the induction heating machine evaluated by the equivalent circuit are shown to be in good agreement with those computed from the original FE model.
  • Toshihito Shimotani, Yuki Sato, Takahiro Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 52 3 2016年03月 [査読有り][通常論文]
     
    This paper proposes a model order reduction (MOR) based on the proper orthogonal decomposition (POD) to perform a fast analysis of motors. When a POD-based MOR is applied to the motor analysis, the number of basis vectors has to be increased to express the changes in the magnetic fields due to a rotational movement. Its computational efficiency is, thus, greatly deteriorated. To overcome this difficulty, the block-MOR is first applied to a motor analysis. In this method, a parameter space is subdivided into several blocks, which correspond to angular ranges in the motor analysis, in each of which the basis vectors are constructed from snapshotted fields. The computational time of the block-MOR is shown to be shorter than that of the conventional MOR, while the accuracy of both the methods is almost identical.
  • Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 52 3 2016年03月 [査読有り][通常論文]
     
    This paper proposes an equivalent-circuit generation from the finite-element (FE) model of electromagnetic devices using a model order reduction (MOR). In this method, an equivalent circuit is directly generated from the reduced transfer function obtained using MOR based on Pade approximation via the Lanczos process. It is shown that the generated circuit yields sufficiently accurate results in both frequency and time domains. Moreover, the computational time of the present method is much shorter than that of the circuit generation based on frequency sweep using the conventional FE analysis.
  • Shingo Hiruma, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    Eddy current loss in a Litz wire which has three-dimensional structure is analyzed using integral equation method considering proximity effect. In the present method, one-dimensional integral equation is formulated for the perpendicular component of the complex magnetization vector generated by eddy currents in the wire. It can effectively be solved by iterative methods to compute the eddy currents due to proximity effect.
  • Yuki Sato, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    This paper presents a homogenization method based on the model order reduction for FE analysis of multi-turn coils. In this method, using the Pade approximation via the Lanczos processes method, the macroscopic complex permeability of a multi-turn coil is expressed as a rational polynomial which is an explicit function of frequency. The macroscopic permeability which is used in FE analysis is, therefore, readily obtained for any frequency.
  • Yuki Hidaka, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    This paper presents topology optimization of rotating machine rotors considering localized magnetic degradation in rotor and stator cores caused by the manufacturing process. On the basis of experimental observation, magnetic reluctivity is assumed to exponentially decay as approaching to the processed surfaces. The present topology optimization seeks for optimal rotor shapes which are robust against the material degradation.
  • Yuki Sato, Toshihito Shimotani, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    The Cauer-equivalent circuit of electric apparatuses is synthesized by applying the model order reduction (MOR) to their FE equations. The equivalent circuit is synthesized directly from the rational polynomial expression of the admittance function of an electric apparatus. Nonlinearity in the magnetic core of the electric apparatus can be modeled by the synthesized equivalent circuit, which is shown to accurately express the property of an inductor used in a DC-DC converter.
  • Hidenori Sasaki, Shintaro Furui, Hajime Igarashi, Hiroki Sakamoto, Takashi Abe, Kazuya Ogura
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    A topology optimization method to maximize efficiency of IPM motors is proposed. In this method, the rotor topology is represented using on/off method based on the normalized Gaussian network. To obtain rotor shapes which are easily manufactured, a regularization term is introduced in the objective function. Moreover, a post-processing method which helps users interpret the optimization results is introduced.
  • Yuki Sato, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    This paper presents a homogenized analysis of soft magnetic composite (SMC) which is composed of small metallic magnetic particles embedded in insulating medium. The macroscopic complex permeability of SMC is obtained in frequency domain from complex permeability of the particles expressed in closed form and Ollendorff formula. On the basis of this formulation, the Cauer-equivalent circuit is synthesized for time-domain analysis of SMC.
  • Yuki Hidaka, Hajime Igarashi
    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC) 2016年 [査読有り][通常論文]
     
    This paper presents three-dimensional shape optimization of claw-pole motors. The claw-pole shape is determined from the binary state of hexahedral cells. The cell states are optimized to maximize induced voltage and minimize the field current using micro-genetic algorithm. The optimization is successfully carried out without time-consuming mesh generation.
  • Yuki Sato, Takuya Mori, Toshihito Shimotani, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 52 1-2 649 - 657 2016年 [査読有り][通常論文]
     
    It is known that the proper orthogonal decomposition (POD), which is one of the effective approaches for model order reduction (MOR), can effectively reduce computational time for finite element method (FEM). This paper proposes a new method for generation of equivalent circuits based on POD-based FEM. In this method, the circuit parameters are determined by genetic algorithm so that the input impedance of the equivalent circuit is coincident with that computed by POD-based finite element method (FEM). For test of the proposed method, POD-based FEM is applied to analysis of a dipole antenna which is loaded with the Cockcroft Walton circuit. It is shown that this method can reduce the computational time to generate the equivalent circuit without deterioration of accuracy.
  • Keiichi Itoh, Kento Watanabe, Katsumasa Miyata, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 52 1-2 623 - 630 2016年 [査読有り][通常論文]
     
    This paper reports the performance improvement of the planar waveguide slot array antenna by loading the small spherical dielectric lenses. The proposed lens is sphere and small, and can be loaded on each slot independently. To design the antenna with the proposed lenses, other design parameters are fixed, and the optimal slot length is searched by using the finite difference time domain (FDTD) method. From both the calculated and the measured far-field radiation patterns, the optimized antenna with the proposed lenses shows good performance as the resonant uniformly distribution array. By comparing with the conventional antenna, it is found that the gain increase by loading small lens is estimated by 1.07 dB.
  • Yuta Watanabe, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 52 1-2 609 - 616 2016年 [査読有り][通常論文]
     
    This paper discusses the shape optimization of chipless radio frequency identification (RFID) tags comprising fractal structures. In the proposed optimization process, scattering electromagnetic waves from a chipless RFID tag are analyzed using a finite-difference time-domain (FDTD) method. The shapes of the chipless RFID tags are optimized by a micro-genetic algorithm (m-GA) to determine the frequencies of the subject scattering waves, as well as to maximize their associated amplitudes and quality factors. As such, a self-similar metal line and metal patch comprising fractal structures are assumed to be a chipless RFID tag. The optimized tags obtained using the FDTD method and m-GA ultimately maintain the selective frequencies, high amplitudes, and quality factors of the scattering electromagnetic waves.
  • Takuya Mori, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 52 1-2 631 - 639 2016年 [査読有り][通常論文]
     
    This paper presents optimal shape design of planar array antennas for microwave energy harvesters. The topology optimization of the C-4-symmetric array antenna is conducted to maximize their isotropic gain and minimize the return losses in a frequency band ranging from 1.5 to 3.5 GHz. Then, we design the rectifier by varying the circuit parameter based on measurement results to realize the impedance matching between the optimized antenna and rectifier. It is shown by experiment that the harvester composed of the optimized array antenna and rectifier has higher receiving voltage in comparison with the single one. Moreover, the resultant harvester is found to start operating when the arrival electric field is greater than 0.1 V/m.
  • Toshihito Shimotani, Yuki Sato, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 35 6 2035 - 2044 2016年 [査読有り][通常論文]
     
    Purpose - The purpose of this paper is to propose a fast synthesis method of the equivalent circuits of electromagnetic devices using model order reduction. Finite element method (FEM) has been widely used to design electromagnetic devices. For FE analysis of these devices connected to control and deriving circuits, FE equations coupled with the circuit equations have to be solved for many times in their design processes. If the FE models are replaced by equivalent circuit models, computational time could be drastically reduced. Design/methodology/approach - In the proposed method, a reduced FE model is obtained using proper orthogonal decomposition (POD) in which the size of FE equation is effectively reduced so that the computational time for FE analysis is shortened. Then, the equivalent circuits are directly synthesized from the admittance function of the reduced system. Findings - Accuracy and computational efficiency of the proposed method are compared with those of another POD-based method in which the equivalent circuits are synthesized from fitting of frequency characteristics using optimization algorithm. There are no significant differences in the accuracy of both methods, while the speedup ratio of the former method is found larger than that for the latter method for the same sampling points. Originality/value - The equivalent circuits of electric machines and devices have been synthesized on the basis of physical insight of engineers. This paper proposes a novel method by which the equivalent circuits are automatically synthesized from FE model of the electric machines and devices using POD.
  • T. Mori, Y. Sato, R. Adriano, H. Igarashi
    Sensing and Imaging 16 1 2015年11月04日 [査読有り][通常論文]
     
    This paper presents optimal design of an RF energy harvesting device using genetic algorithm (GA). In the present RF harvester, a planar spiral antenna (PSA) is loaded with matching and rectifying circuits. On the first stage of the optimal design, the shape parameters of PSA are optimized using $$\\mu {\\rm GA}$$μGA. Then, the equivalent circuit of the optimized PSA is derived for optimization of the circuits. Finally, the parameters of RF energy harvesting circuit are optimized to maximize the output power using GA. It is shown that the present optimization increases the output power by a factor of five. The manufactured energy harvester starts working when the input electric field is greater than 0.5 V/m.
  • Yuki Hidaka, Shintaro Furui, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.7401204  2015年03月 [査読無し][通常論文]
     
    This paper presents robust topology optimization of electromagnetic machines by considering the magnetic degradation caused by mechanical and thermal stresses in punching, shrinking fitting, and other manufacturing processes. The topology optimization is performed using two methods: one is the robust genetic algorithm in which random noises are added to the magnetic characteristic parameters and the other takes the deviations in the objective and constraint functions due to the degradation into account. These methods are applied to optimization of the flux barrier shapes in an interior permanent magnetic motor to find that one can successfully realize robust design.
  • Yuki Sato, Felipe Campelo, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.7204304  2015年03月 [査読有り][通常論文]
     
    This paper presents a fast shape optimization method for antennas using proper orthogonal decomposition (POD)-based model order reduction (MOR). In this method, the finite element region is subdivided into design and ambient regions. The former includes antennas, whose shapes are optimized, whereas the latter includes air and perfect matched layer. Since the electromagnetic fields significantly change in the design region during the optimization process, POD-based MOR is only applied to the ambient region. In addition, MOR for both shape and frequency responses is performed for optimization of wideband antennas. It is shown that the present method can effectively reduce the computational time without deteriorating performance in the optimization.
  • Takuya Mori, Ryo Murakami, Yuki Sato, Felipe Campelo, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.8000804  2015年03月 [査読有り][通常論文]
     
    This paper presents parameter and topology optimizations of wideband antennas for microwave energy harvesters based on finite difference time-domain computations. The antenna shapes are optimized to reduce return losses in a specific frequency band using micro-genetic algorithm. The shape parameters of a two-arm planar spiral antenna are optimized. In addition, the topology optimization is performed using normalized Gaussian network, where spatial symmetries are assumed. It is shown that the return losses of the optimized antennas are <-10 dB from 1 to 2 GHz in which they have isotropic directivity.
  • Takahiro Sato, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.7202604  2015年03月 [査読有り][通常論文]
     
    This paper presents a topology optimization method for multimaterial models based on the normalized Gaussian network. In this method, one can determine optimal shapes of machines that are composed of various materials, such as iron, magnetic, and nonmagnetic material. The present method is applied to the optimization of the average torque for interior permanent magnet motor to determine the distributions of magnetic core and flux barrier as well as magnets. The optimization results show that average torque can be improved using as small amount of magnet as possible. In addition, the characteristic of the present method is discussed in detail.
  • Takahiro Sato, Soichiro Aya, Hajime Igarashi, Michiaki Suzuki, Yoshiki Iwasaki, Kenji Kawano
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.8001704  2015年03月 [査読有り][通常論文]
     
    This paper presents a new loss computation method for soft magnetic composite (SMC), which allows us to evaluate the loss for wide operating conditions. A formula for evaluation of eddy current and hysteresis losses is introduced. The effective volume fraction of the magnetic grain is determined from the sampled measured data. It is shown that the formula provides accurate estimate of the total loss in a toroidal SMC core. In addition, the loss of SMC inductor is shown to be also accurately evaluated at small computational burden using the proposed method.
  • Shunpei Sato, Takahiro Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.8200904  2015年03月 [査読有り][通常論文]
     
    This paper presents the topology optimization of a synchronous reluctance motor using the normalized Gaussian network. In the optimization, the average torque and iron loss are considered. In the resultant motor, the area of the rotor surface adjacent to the stator is found to be reduced when the weight for the iron loss is sufficiently large. On the other hand, large flux barriers are present in the rotor when the average torque is maximized without considering the iron loss.
  • Naoya Terauchi, So Noguchi, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 51 3 ROMBUNNO.7202804  2015年03月 [査読無し][通常論文]
     
    High-temperature superconducting quantum interference devices (HTS SQUIDs) have been developed as an extremely sensitive magnetic sensor. The HTS SQUIDs are required to have high robustness with respect to the magnetic noise for stable operation in an unshielded environment and also reduced cost to widen the application range. It is, therefore, necessary to clarify the quantum magnetic behavior of the HTS SQUID. However, a simulation tool, which can consider the quantum magnetic behavior, has not been developed yet. In this paper, an equivalent circuit of a Josephson junction comprising the HTS SQUID is more properly considered to represent the quantum behavior. It can consider the ac and dc Josephson effect. The obtained results are compared with an ordinary simulation using a simplified circuit model, and the results agree well with each other. Using the proposed simulation method instead of the ordinary simulation, the current path is more accurately simulated, so this new method will be used to evaluate the robustness of the SQUID.
  • 佐藤 孝洋, 五十嵐 一, 高橋 慎矢, 内山 翔, 松尾 圭祐, 松橋 大器
    電気学会論文誌D(産業応用部門誌) 135 3 291 - 298 The Institute of Electrical Engineers of Japan 2015年03月01日 [査読有り][通常論文]
     
    This paper presents a new topology optimization method based on normalized Gaussian network (NGnet). In this method, the machine region is subdivided into small elements whose material states are determined from the output of NGnet so that the objective function is extremized under the given constraints. The present method is applied to shape optimization of the rotor in an interior permanent magnet motor. The rotor shape is optimized to minimize the torque ripple while keeping the average torque. It is shown that the optimization halves the torque ripple while the average torque remains unchanged. This result was validated through a comparison between the computed and measured torques.
  • Takahiro Sato, Hajime Igarashi
    Smart Materials and Structures 24 2 025033,1-8  2015年02月 [査読有り][通常論文]
     
    This paper presents a new wideband electromagnetic vibration energy harvester (VEH) composed of a magnetic core embedded into the coil axis. The magnetic core generates a nonlinear magnetic force, which gives rise to the nonlinearity in the behavior of the VEH. Moreover, the magnetic core increases the flux linkage with the coil. These features improve the operational bandwidth and output power of the VEH. Numerical analysis and experimental measurements reveal that the operational bandwidth of the proposed VEH is over 30 Hz in which the output power is kept about 0.1 mW. Moreover, the proposed VEH operates by complicated oscillation due to nonlinear forces acting on the oscillator. Evaluation of the Lyapunov exponent for the measured oscillation suggests that the proposed VEH produces chaotic oscillation.
  • Takahiro Sato, Yuki Sato, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 34 5 1623 - 1636 2015年 [査読有り][通常論文]
     
    Purpose - The finite element method (FEM) for 3D models needs heavy computational cost. The computational cost for FE analysis of moving objects, e.g. Vibration energy harvester, must be reduced to exploit the simulation of the dynamic system in its design. The paper aims to discuss these issues. Design/methodology/approach - To reduce the computational time of FEM, the model order reduction (MOR) based on proper orthogonal decomposition has been proposed. For the moving systems, MOR is modified. Findings - It is shown that proposed MOR makes it possible to drastically reduce the coupling analysis of the energy harvester in which the equations of motion, magnetostatics, and circuit are repeatedly solved. Originality/value - To reduce the computational time of FEM, block-MOR is presented, in which the whole domain is subdivided into N-blocks. As a result computational cost for MOR can be reduced.
  • 佐藤孝洋, 渡辺浩太, 五十嵐一
    計算数理工学論文集 14 13 - 18 2014年12月 [査読有り][通常論文]
  • Yuki Hidaka, Takahiro Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 50 2 2014年02月 [査読有り][通常論文]
     
    This paper proposes a two-step method for topology optimization, in which after global search is performed by the on-off method, and then local search is carried out by the level set approach. The genetic and gradient-based algorithms are employed for the former and latter optimizations, respectively. This present method is applied to two numerical examples; topology optimizations of a magnetic shield system and interior permanent magnetic motor. It is shown that this present method can find solutions with better performances in comparison with the conventional on-off method.
  • Takahiro Sato, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 50 2 2014年02月 [査読有り][通常論文]
     
    This paper presents a coupled analysis of electromagnetic vibration energy harvester (VEH) on the basis of the nonconforming voxel FEM. In this analysis method, the motion, Maxewell, and circuit equations are alternatively solved using the staggered method. The FE models can be generated in this method with low computational costs. By using the coupled analysis method, the characteristics of a VEH model, which contains the magnetic material in the coil, is analyzed changing the geometric parameters. It is shown from the analysis results that the VEH model has chaotic and linear oscillations. It is also shown that output power can be generated for a wide frequency range in the chaotic mode, and in the linear mode, large output power is obtained at the resonance.
  • Rony Teguh, Ryo Murakami, Hajime Igarashi
    ARTIFICIAL INTELLIGENCE AND SOFT COMPUTING ICAISC 2014, PT I 8467 468 - 479 2014年 [査読有り][通常論文]
     
    This paper presents optimization of router deployment based on genetic algorithm for energy- constrained wireless sensor networks which are used for wildfire monitoring. The router positions are optimized so that the total communication distance is minimized to maximize the lifetime of the sensor network. To consider the real geographical features of the target field, the elevation differences are included in fitness evaluation. It is shown that one can reduce the total communication distance as well as the number of disconnected sensors for both flat and irregular terrains using the present optimization method.
  • Takahiro Sato, Takeshi Sugisawa, Hajime Igarashi
    14TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2014) 557 2014年 [査読有り][通常論文]
     
    In this work, to increase magnetic flux passing through the electric coil in a bistable vibration energy harvester, the magnetic circuit is made closed by introducing two coil systems which have magnetic core in their axis holes. The magnetic resistance of the magnetic circuit, composed of silicon steel and thin air gaps, is supressed to be small. The double well potential is realized from the spring force and nonlinear magnetic force between the magnets and the magnetic core. Two harvesters with opened and closed magnetic circuits are manufactured for comparison. It is also shown that the closed magnetic circuit can effectively improve the output power.
  • 五十嵐 一
    電気学会誌 134 10 700 - 703 The Institute of Electrical Engineers of Japan 2014年 [査読無し][招待有り]
     
    電磁界解析による設計最適化:Computer-Aided Inventionに向けて 五十嵐 一
  • 佐藤 孝洋, 五十嵐 一
    日本AEM学会誌 22 3 374 - 379 日本AEM学会 2014年 [査読無し][招待有り]
     
    This paper reports an electromagnetic vibration energy harvester with magnetic material in which nonlinear oscillation results in broadband operation frequency range for power generation. Moreover, the present harvester is shown to have double-well potential which yields chaotic oscillation.
  • Takahiro Sato, Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 33 1-2 181 - 190 2014年 [査読有り][通常論文]
     
    Purpose - Three-dimensional (3D) mesh generation for shape optimizations needs long computational time. This makes it difficult to perform 3D shape optimizations. The purpose of this paper is to present a new meshing method with light computational cost for 3D shape optimizations. Design/methodology/approach - This paper presents a new meshing method on the basis of nonconforming voxel finite element method. The 3D mesh generation is performed with light computational cost keeping the computational accuracy. Findings - It is shown that the computational cost for 3D mesh generation can be reduced without deteriorating numerical accuracy in the FE analysis. It is reported the performance of the present method. Originality/value - The validity of the nonconforming voxel elements is tested to apply it to the optimization of 3D optimizations.
  • Yuki Hidaka, Takahiro Sato, Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 33 6 1904 - 1919 2014年 [査読有り][通常論文]
     
    Purpose - Conventional level-set method tends to fall into local optima because optimization is conducted based on gradient method. The purpose of this paper is to develop a novel topology optimization in which simulated annealing (SA) is introduced to overcome the difficulties in level-set method. Design/methodology/approach - Level-set based topology optimization for two-dimensional optimization problem. Findings - It is shown in the numerical examples, where conventional and present methods are applied to shape optimization of ferrite inductor and Interior Permanent Magnetic (IPM)-motor, the present method can find solutions with better performance than those obtained by the conventional method. Originality/value - SA is introduced to improve the search performances of level-set method.
  • Takahiro Sato, Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 33 3 821 - 833 2014年 [査読有り][通常論文]
     
    Purpose - In the development of electromagnetic devices, multiobjective topology optimisation is effective to obtain diverse design candidates for production models. However, multiobjective topology optimisation has not widely been performed because it is difficult to obtain resultant shapes for engineering realisation due to large search spaces. The purpose of this paper is to present a new multiobjective topology optimisation method. Design/methodology/approach - This paper presents a new multiobjective topology optimisation method in which the Immune Algorithm is modified for multiobjecrive optimisation and a shape modification process based on spatial filtering is employed. Findings - The present method shows that better Pareto solutions can be found in comparison with the conventional methods. Originality/value - A new effective multiobjective topology optimisation is presented. This method enables to diverse design candidates for production models.
  • 日高 勇気, 五十嵐 一
    日本シミュレーション学会論文誌 6 3 37 - 42 日本シミュレーション学会 2014年 [査読有り][通常論文]
     
    This paper introduces a new method for multi-objective topology optimization problems. The present method is composed of two steps: global search based on genetic algorithm (GA), which is followed by local search using a gradient-based method. In the global search, the design region is subdivided into small elements, to which either of two states, On (material) or Off (non-material) is assigned. In the optimization process based on multi-objective GA, diverse device shapes are generated by changing these states independently to obtain Pareto solutions. In order to improve performance of the devices corresponding to the Pareto solutions, local search based on the level-set method is performed starting from those solutions.   The present method is applied to multi-objective design problem of IPM (Interior permanent magnet motor). The goal of this design is to maximize the average torque and minimize torque ripple. It is shown from the numerical results that the quality of the Pareto solutions can be improved by the local search. Moreover, it is found that manufacture of the optimized rotor becomes easier after the local search because small flux barriers disappear and the surface of the remained flux barriers becomes smooth. It is possible to obtain diverse IPM motors which have different average torques and torque ripples by the present method. The present method, therefore, gives useful information for the design of devices and machines.
  • Yasuhisa Ito, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 49 5 1953 - 1956 2013年05月 [査読有り][通常論文]
     
    This paper presents a new numerical method to compute the macroscopic electromagnetic properties of the soft magnetic composite (SMC). In present method, SMC is assumed to be composed of homogeneous magnetic bricks with periodicity. The macroscopic electromagnetic properties of SMC are obtained using the finite element method in which it is assumed that the homogenized energy is equal to that stored in a unit domain. We compare the macroscopic electromagnetic properties obtained by the present method with those obtained by Ollendorf's formula and magnetic circuit based on the nonmagnetic grain boundary model. It is shown that the three results are in good agreement when assuming constant permeability. It is also found that there are clear discrepancies among them due to magnetic saturations especially when the demagnetization coefficient is large.
  • Yuta Watanabe, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 49 5 2133 - 2136 2013年05月 [査読有り][通常論文]
     
    The passive RFID tag, which receives energy for its operation from electromagnetic waves radiated by RFID readers, changes the antenna impedance to modulate the back scattering waves caught by the reader. For this reason, during the back-scattering communication, the energy received by the RFID tag much reduces due to the impedance mismatch. To resolve this problem, the double antenna system which consists of receiving and sending antennas has been proposed. In this paper, the double antenna shapes are optimized on the basis of FDTD analysis and genetic algorithm to maximize the communication distance.
  • Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 49 5 1697 - 1700 2013年05月 [査読有り][通常論文]
     
    The model reduction based on the method of snapshots is applied to the finite element analysis of three-dimensional transient eddy current problems. It is known that accuracy of the reduced model highly depends on the number of snapshots. In this paper, we introduce a novel method which determines the adequate number of snapshots automatically. It is shown that the computational time can be reduced when using the model reduction based on the present method.
  • Yuta Watanabe, Yuki Sato, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 49 5 1673 - 1676 2013年05月 [査読有り][通常論文]
     
    The infinite elements for edge based finite-element methods (FEMs) have been shown effective for open boundary problems. In the infinite elements, electromagnetic fields are expressed in terms of radially decaying basis functions. On the other hand, the perfect matched layer has widely been used for FEMs for high-frequency problems. In this paper, numerical performance of both methods is comparably discussed. The numerical experiments show that the former has higher computational efficiency.
  • T. Sato, K. Watanabe, H. Igarashi, T. Matsuo, T. Mifune, K. Kawano, M. Suzuki, Y. Uehara, A. Furuya
    IEEE TRANSACTIONS ON MAGNETICS 49 5 2129 - 2132 2013年05月 [査読有り][通常論文]
     
    This paper presents three-dimensional shape optimization of inductors for the dc-dc converters, in which the nonconforming voxel-based finite element method (FEM) is employed to realize fast FE mesh generation during the optimization. The operating point of the inductor under the bias current condition, which is estimated from the circuit analysis, is obtained by nonlinear FE analysis. Then, the FE equation linearized around the operating point is solved being coupled with the circuit equation to obtain the magnetic fields in the inductor. The hysteresis loss is computed from the Steinmetz formula. Validity of the field computation is tested by comparing the numerical results with measured data. The multiobjective optimization of the inductor shapes is performed to minimize the winding resistance and hysteresis loss. It is shown that the present method can effectively find the Pareto solutions which can lead to improvement in the efficiency of the dc-dc converter.
  • S. Ito, T. Mifune, T. Matsuo, K. Watanabe, H. Igarashi, K. Kawano, Y. Iijima, M. Suzuki, Y. Uehara, A. Furuya
    IEEE Transactions on Magnetics 49 5 1985 - 1988 2013年05月 [査読有り][通常論文]
  • Ryusei Itoh, Yuki Oga, So Noguchi, Hajime Igarashi, Hiroshi Ueda
    Physica C: Superconductivity and its Applications 484 300 - 304 2013年01月15日 [査読有り][通常論文]
     
    In recent years, properties of high temperature superconducting (HTS) tapes, especially in-field performance and mechanical strength, have been continuously improved. The HTS tapes have been widely used for high field (> 20 T) magnet researches and there are several technical challenges including field attenuation of an HTS magnet by screening currents induced within the HTS tapes. Several publications reported that the screening currents, induced by penetration of self magnetic fields into HTS tapes within an HTS magnet, weakened a field constant of the HTS magnet. The result may demonstrate that the screening current changes an overall current density distribution in HTS tapes and, as a consequence, the generated magnetic field. Therefore, it is necessary to investigate the screening current distribution in an HTS tape. This paper reports numerical simulation of the screening current distribution in an HTS tape of high field magnets using 2D finite element method with the E-J characteristic of the HTS tape taken into account. Self magnetic field distribution and its orientation to the HTS tape are also considered to compute critical currents and locally generated electric fields, two key components to figure out the distribution of screening currents.
  • Yuki Sato, Felipe Campelo, Hajime Igarashi
    IEEE Transactions on Magnetics 49 5 1889 - 1892 2013年 [査読有り][通常論文]
     
    This paper presents the optimization of a meander line antenna finite-element model by means of an adaptive genetic algorithm (GA). To search for optimal antenna configurations, the present method employs a GA with an adaptive method that adjusts the characteristics of its selection, crossover, and mutation operators in order to maintain a diverse set of high-quality candidate solutions during its execution. It is shown that the present method can find an optimal solution faster than the conventional GA. Moreover, the fitness values of the optimal solutions obtained by the present method are better than those obtained by conventional GA. © 1965-2012 IEEE.
  • So Noguchi, Atsushi Takada, Fumiaki Nobuyama, Masahiko Miwa, Hajime Igarashi
    IEEE Transactions on Magnetics 49 5 1705 - 1708 2013年 [査読有り][通常論文]
     
    A common mesh smoothing method strives to improve the shape quality of all elements. Generally a mesh consisting of only well-shaped elements is desired in finite element analysis. Although a perfect-shaped element yields short computation time, even a well-shaped element, whose shape is close to a regular polygon, sometimes prolongs the computation time of solving the system of equations derived with the edge-based finite element method. In this paper, we propose a new smoothing scheme of improving a convergence property of the system of equations by applying a common mesh smoothing method to some elements, which cause long computation time of the iterative solver. The proposed smoothing scheme utilizes the condition number of submatrices, into which coefficient matrix derived with the edge-based finite element method is subdivided, in order to choose ill-conditioned elements to be smoothed. As a result, the computation time is shortened applying a smoothing process only to the chosen ill-conditioned elements. © 1965-2012 IEEE.
  • Takahiro Sato, Hajime Igarashi
    13TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2013) 476 2013年 [査読有り][通常論文]
     
    This paper presents a new electromagnetic vibration energy harvester (VEH) which harvests the electric power in wide frequency range. The present VEH contains the ferrite core embedded in the axis hole of the coil bobbin which generates the magnetic force acting on the oscillator. The performance of the present VEH is estimated using the coupled analysis method for VEH in which motion, Ampere, and circuit equations are alternatively solved until convergence. Using the coupled analysis method, the output power characteristic in the present VEH against input frequency is analyzed. It is shown from the analysis results that the present VEH has chaotic oscillation and wide frequency range for power generation. Moreover, the condition that the present VEH has nonlinear oscillation is discussed.
  • Yuta Watanabe, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 43 1-2 77 - 84 2013年 [査読有り][通常論文]
     
    This paper presents shape optimization of patch antennas loaded by the Cockcroft-Walton (CW) circuit for UHF-band passive RFID tags. In the present optimization, the antenna characteristics are analyzed by hybridization of the finite-difference time-domain method and modified nodal method. To accelerate the convergence to the steady state, the unknowns are decomposed into the fast and slowly convergence components, which are separately determined. The shape of patch antennas is optimized by using the micro genetic algorithm in order to maximize the output voltage of the CW circuit and obtain high robustness against the shape changes. The optimized antenna has higher output voltage of the CW circuit in comparison with the half-wave patch antenna.
  • 杉原 慶彦, 本田 敏文, 浦野 雄太, 渡辺 正浩, 野口 聡, 五十嵐 一
    電気学会論文誌C(電子・情報・システム部門誌) 133 11 2118 - 2124 一般社団法人 電気学会 2013年 [査読無し][通常論文]
     
    Usually, there are two processes in wafer inspection. One is detection of defects on a wafer, which is very important. The other is classification of the detected defects, which is done after defect detection as necessary. Recently, it has been necessary to simultaneously detect and classify defects on wafers in order to shorten the wafer inspection time with high resolution. Optical wafer inspection is the most effective method for detecting and classifying a defect and estimating its size in a short time. Optical wafer inspection utilizing scattered light distribution can easily detect and classify a defect since the distribution depends on both the type and size of the defect. The measured scattered light distribution is compared with a database of the previous scattered light distributions using pattern matching in order to classify the defect and estimate its size. Therefore, to achieve optical wafer inspection with scattered light distribution, it is necessary to gather scattered light distribution data for many various samples.The first aim of this study is to develop a defect classification and size estimation method utilizing scattered light distribution. We propose a way for classifying a defect on a wafer and estimating its size. The proposed method uses pattern matching utilizing a parametric eigenspace. The second aim of the paper is to validate the proposed method by applying it to scattered light distribution samples. The light scattering distribution samples are generated by Discrete Dipole Approximation (DDA) simulation. The database of the light scattering distributions is easily created using the simulation.
  • T. Yoshioka, Y. Tawada, K. Tsuzaki, S. Wakao, A. Kameari, T. Tokumasu, Y. Takahashi, H. Igarashi, K. Fujiwara
    IEEE Transactions on Magnetics 49 5 1681 - 1684 2013年 [査読有り][通常論文]
     
    The electromagnetic phenomena intrinsically spread over the infinite space. Thus, the efficient handling of the open boundary is one of the main issues in the electromagnetic field computation. This paper proposes the infinite edge element method (IEEM) with the boundary surface integration to accurately obtain the magnetic field, i.e., the derivatives of vector potentials, in the far-field region. © 1965-2012 IEEE.
  • 津﨑賢大, 多和田義大, 若尾真治, 亀有昭久, 徳増 正, 髙橋康人, 五十嵐 一, 藤原耕二, 石原好之
    電気学会論文誌B 133 5 8 - 472 2013年 [査読有り][通常論文]
     
    The electromagnetic phenomena intrinsically spread over the infinite region. Thus, the efficient handling of open boundary is one of the main issues in the electromagnetic field computations. This paper deals with the orthogonalized infinite edge element method which efficiently performs precise analysis of the infinite region. In this method, there are several parameters to achieve its high accuracy. As one of the parameters, we focus on the reference point and investigate the effect of its position setting on the accuracy. Furthermore, we also evaluate the accuracy of the calculated magnetic field at distance region. By applying boundary element method (BEM) as post-processing, it is found that the high computational accuracy in the region can be effectively achieved. © 2013 The Institute of Electrical Engineers of Japan.
  • Toshifumi Honda, Kenji Obara, Minoru Harada, Hajime Igarashi
    ELECTRONICS AND COMMUNICATIONS IN JAPAN 95 9 44 - 53 2012年09月 [査読有り][通常論文]
     
    A highly sensitive inspection algorithm is proposed that extracts defects in multidimensional vector spaces from multiple images. The proposed algorithm projects subtraction vectors calculated from test and reference images to control the noise by reducing the dimensionality of vector spaces. The linear projection vectors are optimized using a physical defect model, and the noise distribution is calculated from the images. Because the noise distribution varies with the intensity or texture of the pixels, the target image is divided into small regions and the noise distribution of the subtraction images are calculated for each divided region. The bidirectional local perturbation pattern matching (BD-LPPM), which is an enhanced version of the LPPM, is proposed to increase the sensitivity when calculating the subtraction vectors, especially when the reference image contains more high-frequency components than the test image. The proposed algorithm is evaluated using defect samples for three different scanning electron microscopy images. The results reveal that the proposed algorithm increases the signal-to-noise ratio by a factor of 1.32 relative to that obtained using the Mahalanobis distance algorithm. (c) 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(9): 4453, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11390
  • Yuki Oga, So Noguchi, Hajime Igarashi
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 22 3 4701604,1-4  2012年06月 [査読無し][通常論文]
     
    Recently, many HTS-SMES systems have been designed and investigated in many countries. They usually consist of some superconducting element coils owing to effectively storing excessively high energy. If one of the superconducting element coils transition into a resistive state, the energy stored in the resistive superconducting element coil has to be immediately dispersed by a shunt resistor to prevent the superconducting conductor from burning. However, the electromagnetic behavior of the HTS-SMES with some resistive superconducting element coils has not yet been well investigated. Therefore, we have developed a simulation code to investigate the electromagnetic behavior of the HTS-SMES magnet after one or more superconducting element coils transitions into the resistive state. In the simulation, the magnetic field analysis and the electrical circuit analysis are coupled with the critical current calculation considering the B - J - theta characteristics of HTS tape. By the electromagnetic simulation, it is indicated that a chain of quenches is caused by the quench of one element coil.
  • Kota Watanabe, Yosuke Iijima, Kenji Kawano, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 48 2 543 - 546 2012年02月 [査読有り][通常論文]
     
    A homogenization technique in order to improve accuracy of finite element analyses with voxel mesh is proposed. The voxel mesh is one of the effective techniques to reduce costs of mesh generation. However, poor ability of expression for curved surfaces is a drawback to be solved and decreases the accuracy of finite element analyses. In this paper, a homogenization method for the voxel elements on the surfaces of magnetic objects is introduced. The anisotropic permeability determined by the present method improves the accuracy of analyses. The numerical results show that the proposed method has smaller errors of inductance in a three dimensional magnetostatic analysis in comparison with the conventional method.
  • Keiichi Itoh, Katsumasa Miyata, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 48 2 779 - 782 2012年02月 [査読有り][通常論文]
     
    This paper reports novel design method of waveguide slot array antenna with dielectric lenses by using the evolutionary optimization. We adopt the micro-genetic algorithm (MGA) with the real-coded gene as the optimization method and the finite-difference time-domain (FDTD) method to evaluate the objective function. The purpose of this study is to establish the design method of the above antenna by optimizing slot length and offset parameters. In the optimization of the antenna aperture distribution, it is shown that the optimized aperture field becomes sufficiently uniform, and the side-lobe levels (SLL) are improved in comparison with those of conventional antennas. Another optimization in which the objective function is evaluated by the array factor controls directly the side-lobe levels, to design low side-lobe antennas. By using the proposed method, the target antenna is optimized to satisfy the given SLL. It is confirmed that the proposed design method is a promising tool for designing the antennas loaded with dielectric materials.
  • S. Tamitani, K. Tsuzaki, Shinji Wakao, T. Tokumasu, Y. Takahashi, A. Kameari, H. Igarashi, K. Fujiwara, Y. Ishihara
    IEEE TRANSACTIONS ON MAGNETICS 48 2 363 - 366 2012年02月 [査読有り][通常論文]
     
    This paper proposes an orthogonalization of the Hilbert matrix in element matrices of the infinite edge elements. The validity of the infinite edge element is demonstrated in previous researches, but the Hilbert matrix results in extremely slow convergence in the ICCG method, especially when using higher order expansions. The proposed orthogonalization technique improves the convergence drastically and it makes the infinite elements practical in the electromagnetic FEM analysis of the open boundary problems in quasi-static magnetic fields.
  • Hiroki Ito, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 48 2 667 - 670 2012年02月 [査読有り][通常論文]
     
    This paper presents a deflation technique to improve the convergence of finite element (FE) analyses with infinite elements. In FE analyses of electromagnetic fields, large air regions must be discretized into FE meshes. This leads to increases in computational time. The infinite element in which electromagnetic fields in air region are accurately expressed has been introduced in order to solve this problem. However, when using the infinite element, convergence of iterative liner solvers deteriorates because the condition number of FE matrices becomes large. In this paper, a deflation technique to improve convergence of iterative solvers is introduced. Numerical examples show that the proposed technique can improve convergence characteristics in a magnetostatic analysis with finite and infinite elements.
  • Hajime Igarashi, Yuta Watanabe, Yasuhisa Ito
    IEEE TRANSACTIONS ON MAGNETICS 48 2 415 - 418 2012年02月 [査読有り][通常論文]
     
    In this paper, deflation method, A-phi method, explicit and implicit error correction (EC) methods and time-periodic explicit error correction (TP-EEC) method are shown to be based on the same mathematical principle that the slowly converging errors are effectively eliminated through the EC process while the fast converging errors are reduced by iterative linear solvers. The properties of the TP-EEC are discussed in detail and the EC is shown to work as an error filter. The numerical experiments show that the error reduction in the time-periodic eddy current problem is in good agreement with those predicted by the present theory.
  • Yuta Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 60 2 958 - 963 2012年02月 [査読有り][通常論文]
     
    A fast FDTD method for the analysis of antennas loaded by nonlinear electric circuits is introduced. In the present analysis, the modified nodal analysis (MNA) method is coupled with the FDTD method. The time-periodic explicit error correction (TP-EEC) method is applied to the MNA method for accelerated computation of the transient processes. The present method is applied to analysis of simplified models of an RFID tag composed of a nonlinear electric circuit and line antenna. It is shown that the present method can effectively shorten the computational time by accelerating the transient processes.
  • Yasuhisa Ito, Hajime Igarashi, Kota Watanabe, Yosuke Iijima, Kenji Kawano
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 39 1-4 739 - 745 2012年 [査読有り][通常論文]
     
    This paper presents a non-conforming finite element (FE) method with tetrahedral elements, which is applied to 3-D shape optimization. In the present method, continuity of magnetic flux is directly enforced on the interfaces of different domains in which FE meshes are independently generated. The slave unknowns in one side which are linearly dependent on the unknowns in the other side are eliminated. It is shown that the present method yields accurate solutions to 3-D nonlinear magnetostatic problems. Moreover, evolutional shape optimization of an inductor is shown to be successfully carried out using the present method.
  • Kota Watanabe, Yuta Watanabe, Hajime Igarashi, Hiroshi Waki
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 39 1-4 671 - 676 2012年 [査読有り][通常論文]
     
    This paper proposes double antennas which consist of receiver and backscatter antennas for passive long range UHF-band IC (Integrated Circuit) tags. The passive IC tags reply to reader's queries by using backscatter modulation. For this purpose, variable impedance elements are inserted between the antenna and a voltage multiplier which generate dc power. This decreases the efficiency of received power in the voltage multiplier and reduces the communication range. To solve this problem, we propose to use an independent antenna for backscatter modulation. Experimental results and numerical simulation results show that the double antennas successfully reply data from IC tag to the reader.
  • Yuta Watanabe, Kota Watanabe, Hajime Igarashi
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 39 1-4 747 - 752 2012年 [査読有り][通常論文]
     
    This paper presents multi-objective optimization of meander line antennas (MLA) for passive UHF-band Radio Frequency Identification. The characteristics of the MLA loaded by Cockcroft-Walton (CW) circuit are analyzed by hybrid analysis of the finite difference time domain method and modified nodal analysis. The antenna shape is optimized in order to maximize the output voltage of the CW circuit and minimize the antenna size.
  • Takahiro Sato, Kota Watanabe, Hajime Igarashi, Yosuke Iijima, Kenji Kawano
    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 39 1-4 761 - 768 2012年 [査読有り][通常論文]
     
    In parameter optimization using the finite element method (FEM), re-meshing with long computational time must be performed many times. Although voxel-based FEM is one of the effective techniques to avoid the re-meshing, it has less accuracy in comparison with the conventional FEM because of stair-shaped boundaries. In this work, to improve the computational accuracy in the voxel-based FEM, a new homogenization method is presented. In the present method, the effective reluctivity of finite elements at material interfaces is determined on the basis of magnetic circuit. The present method is successfully applied to three dimensional shape optimization of an inductor model.
  • 幸若 完壮, 渡辺 浩太, 五十嵐 一
    電気学会論文誌. C, 電子・情報・システム部門誌 = The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and Systems Society 132 3 15 - 454 電気学会 2012年 [査読有り][通常論文]
     
    In this paper, Rationally oriented Forgettable Profit Sharing method (RFPS) for reinforcement learning is proposed. Although the Profit Sharing (PS) provides good performances in real environments, its learning is often slow in long term tasks because it is difficult to determine the adequate discount rate which satisfies the Miyazaki rational theorem. There are several rationality-relaxed PS methods which work well for such tasks. However, these PS may result in many irrational loops. The proposed method fulfills the rationality by forgetting the reinforced irrational loops. This method can be easily combined with ordinary PS methods and performs well in long term tasks. The simulation results show that the proposed method can learn more efficiently than the conventional PS methods. © 2012 The Institute of Electrical Engineers of Japan.
  • 牧村 英俊, 渡辺 浩太, 五十嵐 一, 和木 浩
    電気学会論文誌. C, 電子・情報・システム部門誌 = The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and Systems Society 132 5 691 - 696 電気学会 2012年 [査読有り][通常論文]
     
    This paper presents a novel temperature measurement system based on passive RFID operating at UHF band for monitoring system of conventional railways. The goal of this study is to realize wireless temperature measurement using UHF-band RFID whose communication distance is several meters under the assumption that the RFID reader/writer (R/W) has 4 W EIRP. A low power temperature measurement circuit, which is vital for the above purpose, has been developed using a thermistor and comparator. The temperature measured by this sensor, ranging from zero to 80 Celsius, is shown to be in good agreem...
  • 渡部 雄太, 牧村 英俊, 渡辺 浩太, 五十嵐 一
    日本AEM学会誌 19 2 286 - 291 日本AEM学会 2011年06月 [査読有り][通常論文]
  • 佐藤 孝洋, 渡辺 浩太, 五十嵐 一
    日本AEM学会誌 19 2 201 - 206 日本AEM学会 2011年06月 [査読有り][通常論文]
  • Yuta Watanabe, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 47 5 1506 - 1509 2011年05月 [査読有り][通常論文]
     
    This paper presents optimization of meander line antennas (MLA) for passive IC tags which contain nonlinear circuits. In the present analysis, the tag antenna loaded by the Cockcroft-Walton circuit is analyzed by solving coupling equations for electromagnetic waves and nonlinear circuit with FDTD method. The antenna shape is optimized so that the output voltage of the Cockcroft-Walton circuit is maximized using the micro genetic algorithm (mu GA). The computational burden in the optimization processes is effectively suppressed by truncating the transient computations. A criterion is introduced to evaluate the errors caused by the truncation. The present method yields the optimal MLA which has the greater output voltage in comparison with the dipole antenna.
  • Hidetoshi Makimura, Yuta Watanabe, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 47 5 1510 - 1513 2011年05月 [査読有り][通常論文]
     
    This paper presents evolutional design of antennas for UHF-band passive IC tags. The wire-antenna shapes are optimized using the genetic algorithm (GA) aiming at maximization of feeding power to the IC tag as well as minimization of the antenna size. The characteristics of the antennas printed on a dielectric substrate are evaluated using the moment method in the optimization processes. The genotypes for GA are introduced to express the shapes of lattice antennas, which include loops and floating lines, and spiral antennas. The present genotypes for the latter are also valid for optimization of spiral structure of, for example, inductors and filters. It is shown that optimized lattice and spiral antennas have smaller sizes in comparison with the conventional meander antennas.
  • Hajime Igarashi, Kota Watanabe
    IEEE TRANSACTIONS ON MAGNETICS 47 5 1438 - 1441 2011年05月 [査読有り][通常論文]
     
    This paper describes deflation of finite element (FE) matrices for electromagnetic fields. The condition of the FE matrices is improved by the matrix deflation which replaces small eigenvalues with zeros. It is known that convergence of linear solvers for FE equations can be improved by using the AV method as well as explicit and implicit error correction (EC) methods which have been derived from the multigrid method. These numerical results are theorized on the basis of the matrix deflation. In particular, augmented matrices appeared in the AV and implicit EC methods are shown to have good conditioning after preconditioning. These results suggest that the above methods are based on a common mathematical principle.
  • Kota Watanabe, Seiji Fujino, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 47 5 1210 - 1213 2011年05月 [査読有り][通常論文]
     
    Multigrid (MG) methods are known to be fast linear solvers for large-scale finite-element analyses. The Gauss-Seidel method is usually adopted as the smoother for MG methods. However, recently, considerable attention has focused on induced dimension reduction (IDR)-based solvers because they are faster. In this paper, we investigate the convergence of IDR-based solvers and evaluate the performance of an MG method with an adaptive IDR-based Jacobi smoother. Numerical results show that this method has good convergence and good efficiency in parallel computations for finite-element analysis of electromagnetic fields.
  • Yuta Watanabe, Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 47 5 1506 - 1509 2011年05月 [査読無し][通常論文]
     
    This paper presents optimization of meander line antennas (MLA) for passive IC tags which contain nonlinear circuits. In the present analysis, the tag antenna loaded by the Cockcroft-Walton circuit is analyzed by solving coupling equations for electromagnetic waves and nonlinear circuit with FDTD method. The antenna shape is optimized so that the output voltage of the Cockcroft-Walton circuit is maximized using the micro genetic algorithm (mu GA). The computational burden in the optimization processes is effectively suppressed by truncating the transient computations. A criterion is introduced to evaluate the errors caused by the truncation. The present method yields the optimal MLA which has the greater output voltage in comparison with the dipole antenna.
  • FDTD法による導波管スロットアレーアンテナに装荷した 球形誘電体レンズの効果の解析
    日本AEM学会誌 19 2 378 - 383 2011年 [査読有り][通常論文]
  • 電波型パッシブRFIDのための媒質効果の低減
    日本AEM学会誌 19 2 286 - 291 2011年 [査読有り][通常論文]
  • 中枢パターン生成器と機械学習によるロボットの運動自動獲得
    日本AEM学会誌 19 2 201 - 206 2011年 [査読無し][通常論文]
  • Kota Watanabe, Felipe Campelo, Yosuke Iijima, Kenji Kawano, Tetsuji Matsuo, Takeshi Mifune, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 46 8 3393 - 3396 2010年08月 [査読有り][通常論文]
     
    This paper presents parameter and topology optimization of inductor shapes using evolutionary algorithms. The goal of the optimization is to reduce the size of inductors satisfying the specifications on inductance values under weak and strong bias-current conditions. The inductance values are computed from the finite-element (FE) method taking magnetic saturation into account. The result of the parameter optimization, which leads to significant reduction in the volume, is realized for test, and the dependence of inductance on bias currents is experimentally measured, which is shown to agree well with the computed values. Moreover, novel methods are introduced for topology optimization to obtain inductor shapes with homogeneous ferrite cores suitable for mass production.
  • Hajime Igarashi, Kota Watanabe
    IEEE TRANSACTIONS ON MAGNETICS 46 8 2739 - 2742 2010年08月 [査読有り][通常論文]
     
    This paper presents the adjoint variable method (AVM) for finite-element (FE) analysis of eddy current problems based on complex variables. In the sensitivity analysis based on FE analysis of time-harmonic eddy current fields, the functions for which sensitivity is evaluated are often real-valued, while unknown variables in the FE analysis are complex. When the AVM is applied to such problems, the real-valued functions are differentiated with respect to the complex variables. However, such differentiation cannot be defined because the Cauchy-Riemann equation does not hold. In this paper, the AVM for complex systems is introduced and applied to linear and nonlinear eddy current problems, in the latter of which the harmonic balance method is employed.
  • 丸山 尚之, 渡邊 浩太, 五十嵐 一
    シミュレ-ション 29 1 9 - 16 日鉄技術情報センタ- 2010年03月 [査読有り][通常論文]
  • Kenta Hoshino, Hajime Igarashi
    Proceedings of the IEEE International Symposium on Computer-Aided Control System Design 368 - 373 2010年 [査読有り][通常論文]
     
    This paper describes a genetic algorithm (GA) applied to combinational optimization problems in which the objective functions include uncertain constant parameters. In the present method, noises whose probabilistic distribution is assumed based on the problem environments are added to the parameters during the evaluations process. It is assumed that this allows us to make approximate evaluation of the expected values of the objective function under uncertainties. It is shown that the present method results in the robust solutions, which have higher expectation values than the ones obtained by the conventional GA, to the traveling salesman and knapsack problems with uncertainties. © 2010 IEEE.
  • R. Inoue, K. Watanabe, H. Igarashi
    2010 IEEE INTERNATIONAL SYMPOSIUM ON INTELLIGENT CONTROL 795 - 800 2010年 [査読有り][通常論文]
     
    Actor-critic method based on policy gradient is an effective method for problems with high-dimensional learning space. In walking behavior of robots, the movement of robot's joint is cyclic. For this purpose, we apply closed-loops of B-spline curve to cyclic movement. Hence, we propose a method combined actor-critic method based on policy gradient with B-spline curve. In this method, B-spline curve uses for controlling target such as joints in robot on continuous space. By using B-spline curve, the target for control can move smoothly and flexible. In this paper, we applied this method to a four-legged robot with 12 joints and simulated on the Open Dynamics Engine (ODE) which is a dynamics simulation software. The simulation results show that robots succeeded in getting walking behavior.
  • Kenta Hoshino, Hajime Igarashi
    2010 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS IJCNN 2010 780 - 785 2010年 [査読有り][通常論文]
     
    This paper introduces a novel image recognition method based on the neural oscillator network. In the present method, the dynamics of neurons is determined from neural coupling strengths relevant to the similarities in pixel levels, which have been used in the conventional image segmentation, as well as geometrical local features obtained from the Gabor filtering. Then the image regions under resultant neural synchronization are identified. It is shown that the accuracy of the present method, applied to the image recognition for pairs of identical and different alphabetical letters, is 76.9% and 62.2%, respectively. Moreover, the simple polygons are also correctly recognized by the present method.
  • T. Sato, K. Watanabe, H. Igarashi
    2010 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS IJCNN 2010 552 - 559 2010年 [査読有り][通常論文]
     
    Recently, biologically inspired approaches have received much attention for robot control. A typical example of them is control of rhythmic behaviors by Central Pattern Generator (CPG). However, this control has a problem that there are few theories to determine parameters of CPG. For this reason, they are determined experimentally. In this paper, we propose a combination method of Genetic Algorithm and Reinforcement Learning for determining parameters of CPG, and apply to a quadruped robot with the CPG controller. Simulation results show that the robot obtains walking behaviors automatically through learning process without using the parameters set by knowledge of designers.
  • Takayuki Maruyama, Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 29 6 1524 - 1532 2010年 [査読有り][通常論文]
     
    Purpose - The purpose of this paper is to present a new method to obtain robust solutions to electromagnetic optimization problems, solved with evolutional algorithms, which are insensitive to changes in design parameters such as spatial size, positioning and material constant. Design/methodology/approach - Adjoint variable method is employed to evaluate the sensitivity of individuals in evolutional processes. Findings - It is shown in the numerical examples, where the present method is applied to optimization of a superconducting energy storage system and C-shape magnet, that robust solutions are actually obtained which are insensitive to deviations in spatial sizes. Originality/value - Unlike usual optimization methods, the present method takes into account deviation in the design parameters due to production errors and long-term changes. Moreover, the present method is limited to about twice the computational cost of non-robust optimization methods.
  • Kota Watanabe, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 45 3 1088 - 1091 2009年03月 [査読有り][通常論文]
     
    The multigrid method is known as. the faster linear solver for large scale finite element analysis. In the edge-based finite element analysis, the geometric multigrid (GMG) method requires careful treatment for the stable convergence. In this paper we investigate factors for stable convergence of nested GMG method. The Numerical results show that the unsuitable application of essential boundary condition to the system matrix results in poor convergence of GMG method. We indicate that the appropriate boundary condition for the system or restriction matrix enable the stable convergence.
  • Felipe Campelo, Frederico G. Guimaraes, Jaime A. Ramirez, Hajime Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 45 3 1558 - 1561 2009年03月 [査読有り][通常論文]
     
    In this paper, we introduce an approach for the design of electromagnetic devices based on the use of Estimation of Distribution Algorithms (EDAs), coupled with approximation-based local search around the most promising solutions. The-main idea is to combine the power of EDAs in the solution of hard optimization problems with the faster convergence provided by the local search using local approximations. The resulting hybrid, algorithm is tested on a numerical benchmark problem.
  • 球形誘電体レンズ装荷による導波管スロットアンテナの放射特性改善
    電子情報通信学会論文誌 J92-B 7 1185 - 1192 2009年 [査読有り][通常論文]
  • Felipe Campelo, Frederico G. Guimaraes, Jaime A. Ramirez, Hajime Igarashi
    2008 IEEE CONFERENCE ON SOFT COMPUTING IN INDUSTRIAL APPLICATIONS SMCIA/08 89 - + 2009年 [査読有り][通常論文]
     
    This work analyzes the Real-coded Clonal Selection Algorithm (RCSA) for mono objective optimization in electromagnetics. This algorithm presents a set of features enabling global search as well as the local improvement of the candidate solutions. An analysis of the sensitivity of the algorithm to its basic parameters shows that it is possible to suggest a basic configuration for the RCSA, narrowing the range of variation of the input parameters and simplifying the use of the algorithm. Results obtained on a test problem show that this algorithm is able to find higher-quality solutions, and also presents faster convergence than similar approaches for the problem considered.
  • Frederico G. Guimaraes, Reinaldo M. Palhares, Felipe Campelo, Hajime Igarashi
    INFORMATION SCIENCES 177 20 4368 - 4386 2007年10月 [査読有り][通常論文]
     
    We utilize optimization algorithms inspired by the immune system for treating the mixed H-2/H-infinity control problem. Both precisely known systems and uncertain systems with polytopic uncertainties are investigated. For the latter, a novel methodology is proposed to compute the worst case norms within the polytope of matrices. This methodology consists in defining the worst case norm computation as an implicit optimization problem with a special structure. We exploit this structure of the problem for its solution. The paper presents both mono and multiobjective optimization algorithms developed from the clonal selection principle. The former is the real-coded clonal selection algorithm (RCSA) and the latter is the multiobjective clonal selection algorithm (MOCSA). The complete design process involves the combination of synthesis and analysis. The RCSA is used for analysis, through the worst case norm computation for a given provided controller. The MOCSA is used for synthesis, working on a population of candidate coritrollers, until providing an estimate of the Pareto set for the mixed d H-2/H-infinity control problem. The numerical examples illustrate the power and the validity of the proposed approach for robust control design. Moreover, our approach for worst case norm evaluation is compared with other approaches available in literature. (c) 2007 ElsevierInc. All rights reserved.
  • Hiroshi Waki, Hajime Igarashi, Toshihisa Honma
    ELECTRICAL ENGINEERING IN JAPAN 160 4 7 - 15 2007年09月 [査読有り][通常論文]
     
    This paper describes an effective analysis of magnetic shielding based on homogenization. The analyses become time-consuming if the problems include the magnetic substances having fine structure. The homogenization of the structure makes it possible to analyze effectively the magnetic fields. The authors introduce a method to estimate the effective permeability of the homogenized substance. This method can be applied to any periodic structure made of magnetic substance. The magnetic shielding effects by the structures against direct-current (DC) fields generated by electric railways are analyzed by using the present method. As a result, it is found that the overhead way and the protective fence near the railway work as a magnetic shield, whose effects can be improved by appropriate arrangement of those constructions. (C) 2007 Wiley Periodicals, Inc.
  • So Noguchi, Nobuki Kawawada, Hajime Igarashi, Atsushi Ishiyama, Nagato Yanagi, Shinsaku Imagawa
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 17 2 2490 - 2493 2007年06月 [査読有り][通常論文]
     
    Aluminum stabilized superconductors are used in accelerators, SMES, and fusion devices, such as the LHD helical coils. These superconductors have large cross-sectional area of high purity aluminum to improve their stability. However, one of the important properties of these superconductors is the transient stability, which is caused by a long duration of transport current transfer from the superconducting strands into the aluminum in a normal state region. Once a normal zone is initiated in such superconductors, excess joule heat is generated in a small region of the aluminum stabilizer near the superconducting strands during the transport current diffusion time. It hence deteriorates the transient stability. Therefore, it is important to investigate the characteristics of the transient stability by numerical analysis. The latest experiments of the LHD helical coil conductor showed an asymmetrical propagation of normal zone along the longitudinal direction of the conductor. The Hall effect is clearly one of the causes of this phenomenon. The Hall effect prevents the transport current from transferring between the superconducting strands and the aluminum stabilizer. It causes the asymmetrical transport current distribution, and affects the stability of the superconductor. In order to simulate the normal zone propagation in the superconductor more precisely and to clarify the cause of the asymmetrical propagation, we have developed a 2D finite element analysis code taking account of the Hall effect and investigated the characteristics of the normal zone propagation of large aluminum stabilized superconductors.
  • So Noguchi, Takanori Tanikawa, Hajime Igarashi
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 17 2 1835 - 1838 2007年06月 [査読有り][通常論文]
     
    The resistive Superconducting Fault Current Limiters are very attractive devices for electric power circuits. We have investigated the operating properties of a parallelized superconducting fault current limiter made from YBCO thin film and gold film on sapphire substrate by numerical simulation. In order to improve the operating properties and the stability, the YBCO films need to be parallelized. However, it is necessary to investigate whether a few sheets of YBCO film with different critical current density will deteriorate the device's operating properties and stability. That is, when the fault current occurs in power circuit, all YBCO films with different critical current density have not simultaneously quenched. It causes the deterioration of the operating properties. Therefore, it is necessary to investigate the influence of the imbalanced critical current density on the quench characteristics of the parallelized superconducting fault current limiter by numerical simulation. The simulation is performed by a newly developed code coupling the thermal diffusion and the current circuit. It takes into account the E-J power low depending temperature, obtained by experiments. The current limiting properties and the recovery properties are evaluated from quench behavior when the YBCO films have some inhomogeneities. Moreover, the influence of the thickness of gold film on the current limiting properties is also investigated. To grasp such properties is required when the resistive fault current limiter using YBCO thin film is designed.
  • Kota Watanabe, F. Campelo, H. Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 43 4 1637 - 1640 2007年04月 [査読有り][通常論文]
     
    This paper describes topology optimization of electromagnetic systems using the multigrid method. The topology optimization employs uniform rectangular finite elements, in which the multigrid method works effectively as a fast linear solver. Moreover, the present method uses a new optimization algorithm, based on the artificial immune systems paradigm, in which the multilevel search is carried out.
  • Frederico G. Guimaraes, Felipe Campelo, Hajime Igarashi, David A. Lowther, Jaime A. Ramirez
    IEEE TRANSACTIONS ON MAGNETICS 43 4 1641 - 1644 2007年04月 [査読有り][通常論文]
     
    Evolutionary algorithms can benefit from their association with local search operators, giving rise to hybrid or memetic algorithms. The cost of the local search may be prohibitive, particularly when dealing with computationally expensive functions. We propose the use of local approximations in the local search phase of memetic algorithms for optimization of cost functions. These local approximations are generated using only information already collected by the algorithm during the evolutionary process, requiring no additional evaluations. The local search improves some individuals of the population, hence speeding up the overall optimization process. We investigate the design of a loudspeaker magnet with seven variables. The results show the improvement achieved by the proposed combination of local learning and search within evolutionary algorithms.
  • Hirotomo Fujimori, So Noguchi, Hajime Igarashi, Hideo Yamashita
    IEEE TRANSACTIONS ON MAGNETICS 43 4 1505 - 1508 2007年04月 [査読有り][通常論文]
     
    In this paper, an automatic hexahedral mesh generation method is presented in order to control the element size along each direction. By utilizing Ellipsoidal Bubbles as mesh density data, the present method can generate the mesh with flat elements for analysis, including very thin domain such as eddy current regions of conductor, motor air gaps, and so on. In order to verify the effectiveness of the present method, the finite element analysis was actually performed.
  • 藤森 寛朝, 野口 聡, 五十嵐 一
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 127 3 293 - 299 電気学会 2007年03月 [査読有り][通常論文]
     
    This paper presents an adaptive mesh generation with parameterized learning. The present method does not need to perform iterative processes of field analysis in contrast with the conventional adaptive meshing methods. The present method evaluates mesh qualities for each element by means of evaluation function, which is weighted linear combination of shape and area of elements, distance from material corners and so on. The element which has the worst value of the evaluation function is divided into a few elements according to its shape, and this procedure is repeated until the prescribed nu...
  • 電気学会論文誌B 127 11 1205  2007年 [査読有り][通常論文]
  • Analysis of Planar and Curved Microstrip Antennas
    Journal of Microwaves and Optoelectronics 6 1 96  2007年 [査読有り][通常論文]
  • Felipe Campelo, Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 26 3 677 - 688 2007年 [査読有り][通常論文]
     
    Purpose - The paper introduces an evolutionary algorithm based on the artificial immune systems paradigm for topology optimization (TO) in 3D. Design/methodology/approach - The 3D TO algorithm is described, and experimentally validated on an electromagnetic design problem. Findings - The proposed method is capable of finding an optimal configuration for the validation problem used. Research limitations/implications - More tests are needed in order to fully assert the capabilities of the algorithm. Moreover, further improvements are needed in order to obtain smoother topologies at the end of the optimization procedure. Practical implications - The paper presents a novel tool for the design of electromagnetic devices, using a TO approach. Originality/value - So far most of the TO algorithms did not tackle true 3D problems, and the ones capable of 3D optimization do it at high computational costs. The algorithm presented here is capable of true 3D design at a reasonable computational budget.
  • Kota Watanabe, Hajime Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 26 3 888 - 898 2007年 [査読有り][通常論文]
     
    Purpose - It is important to investigate large-scale numerical analyses of electromagnetic fields in design processes of electromagnetic machines. Thus, faster solvers for eddy current analyses are necessary. Parallel computation methods for linear solvers in electromagnetic field analyses have been investigated. These methods have gained importance due to the diffusion of PC clusters and multi-core CPUs in recent years. Design/methodology/approach - This paper discuses linear solvers for the finite element method in eddy current analyses on parallel computers. The preconditioned conjugate gradient method with overlapping domain decomposition is treated. Some techniques treated to improve the convergence was investigated. Findings - The numerical results show that the overlapping effect results in good convergence in eddy current analyses. Originality/value - The preconditioned conjugate gradient method with overlapping domain decomposition has been treated. The numerical results show that the overlapping method works more efficiently for eddy current analyses. Moreover, this method enables large-scale analyses on popular computers such as PC clusters.
  • 藤森 寛朝, 野口 聡, 五十嵐 一
    電気学会論文誌D 127 3 293 - 299 2007年 [査読有り][通常論文]
  • 下村 昌平, 五十嵐 一, 広井 高志, 細谷 直樹, 中川 泰夫
    電気学会論文誌C 127 6 914 - 921 2007年 [査読有り][通常論文]
  • Felipe Campelo, Frederico G. Guimaraes, Hajime Igarashi
    EVOLUTIONARY MULTI-CRITERION OPTIMIZATION, PROCEEDINGS 4403 937 - + 2007年 [査読有り][通常論文]
     
    Evolutionary algorithms have become a very popular approach for multiobjective optimization in many fields of engineering. Due to the outstanding performance of such techniques, new approaches are constantly been developed and tested to improve convergence, tackle new problems, and reduce computational cost. Recently, a new class of algorithms, based on ideas from the immune system, have begun to emerge as problem solvers in the evolutionary multiobjective optimization field. Although all these immune algorithms present unique, individual characteristics, there are some trends and common characteristics that, if explored, can lead to a better understanding of the mechanisms governing the behavior of these techniques. In this paper we propose a common framework for the description and analysis of multiobjective immune algorithms.
  • Nobuki Kawawada, So Noguchi, Hajime Igarashi, Atsushi Ishiyama, Nagato Yanagi, Shinsaku Imagawa
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 16 2 1717 - 1720 2006年06月 [査読無し][通常論文]
     
    Aluminum stabilized superconductors are used in accelerators, SMES, and fusion devices, such as the LHD helical coils. These superconductors have large-cross sectional area of high purity aluminum to improve their stability. However, one of the important properties of these superconductors is the transient stability, which is caused by a long duration of transport current transfer from the superconducting strands into the aluminum in a normal-state region. Once a normal zone is initiated in such superconductors, excess joule heat is generated in a small region of the aluminum stabilizer near the superconducting strands during the transport current diffusion time. It hence deteriorates the transient stability. Therefore, it is important to investigate the characteristics of the transient stability by numerical analysis. The latest experiments of the LHD helical coil conductor show an asymmetrical propagation of normal zone along the longitudinal direction of the conductor. The Hall current generation is clearly one of the causes of this phenomenon. The Hall current generation prevents the transport current from transferring between the superconducting strands and the aluminum stabilizer. It causes the asymmetrical transport current distribution, and affects the stability of the superconductor. In order to simulate the normal-zone propagation in the superconductor more preciously and to clarify the cause of the asymmetrical propagation, we have developed a 2D finite element analysis code taking account of the Hall effect and investigated the transient stability of large aluminum stabilized superconductors.
  • Felipe Campelo, So Noguchi, Hajime Igarashi
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 16 2 1316 - 1319 2006年06月 [査読無し][通常論文]
     
    When designing high-field superconducting magnets, such as the ones used in nuclear magnetic resonance, one is often interested in using the minimum winding volume, in order to reduce the construction costs. On the other hand, a highly homogeneous, highly regulated magnetic field is an essential requirement for this kind of system. Moreover, small variations in the design parameters are unavoidable in the construction of any equipment, and must be taken into account during the design process. Due to these many requirements, the design of magnets with high field homogencity is a very difficult task for traditional optimization methods. Optimization methods based in the artificial immune systems paradigm are usually able to perform global as well as local exploration of the search space. The local search feature can be used to perform an estimation of the sensitivity of the candidate solutions, thus enabling the algorithm to search for points that represent robust devices at a reasonable computational cost. In this work, we explore the design of a high-field, highly homogeneous superconducting magnets by using an immune-based robust optimization algorithm. The algorithm is described, and applied to the optimization of the device. The analysis of the results shows the validity of the proposed method.
  • FG Guimaraes, F Campelo, RR Saldanha, H Igarashi, RHC Takahashi, JA Ramirez
    IEEE TRANSACTIONS ON MAGNETICS 42 4 1471 - 1474 2006年04月 [査読無し][通常論文]
     
    The TEAM benchmark problem 22 is an important optimization problem in electromagnetic design, which can be formulated as a constrained mono-objective problem or a multiobjective one with two objectives. In this paper, we propose a multiobjective version with three objectives, whose third objective is related to the quench constraint and the better use of the superconducting material. The formulation proposed yields results that provide new alternatives to the designer. We solved the formulation proposed using the multiobjective clonal selection algorithm. After that, we selected a particular solution using a simple decision making procedure.
  • F Campelo, FG Guimaraes, H Igarashi, JA Ramirez, S Noguchi
    IEEE TRANSACTIONS ON MAGNETICS 42 4 1111 - 1114 2006年04月 [査読無し][通常論文]
     
    Some optimization algorithms based on theories from immunology have the feature of finding an arbitrary number of optima, including the global solution. However, this advantage comes at the cost of a large number of objective function evaluations, in most cases, prohibitive in electromagnetic design. This paper proposes a modified version of the artificial immune network algorithm (opt-AINet) for electromagnetic design optimization. The objective of this modified AINet (m-AINet) is to reduce the computational effort required by the algorithm, while keeping or improving the convergence characteristics. Another improvement proposed is to make it more suitable for constrained problems through the utilization of a specific constraint-handling technique. The results obtained over an analytical problem and the design of an electromagnetic device show the applicability of the proposed algorithm.
  • H Igarashi, K Watanabe, A Kost
    IEEE TRANSACTIONS ON MAGNETICS 42 4 739 - 742 2006年04月 [査読無し][通常論文]
     
    This paper describes a method which reduces the number of unknowns in the finite element analysis of steel laminations. In the present method, the global variation in the electromagnetic field is assumed to be piecewise linear or polynomial while periodical, local variation is analyzed by the finite element method. This method allows us to make accurate analysis of the field including edge effects in steel laminations with low memory consumption and short computing time.
  • H Waki, H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 42 4 847 - 850 2006年04月 [査読無し][通常論文]
     
    This paper describes a nonlinear analysis of magnetic field based on homogenization. The analysis of a magnetic field is time-consuming when the problem includes magnetic substance with fine structure. Simplification of the fine structure by homogenization makes it possible to analyze them efficiently. The authors have introduced a homogenization method to estimate effective permeability of magnetic composite structure for a static field. This method can be applied not only for linear problems but also nonlinear ones. In this paper, the magnetic shielding effect of layered nonlinear material is analyzed by using the homogenization method, and the applicability of this method is discussed.
  • H Waki, H Igarashi, T Honma
    PHYSICA B-CONDENSED MATTER 372 1-2 383 - 387 2006年02月 [査読有り][通常論文]
     
    This paper describes a homogenization method for magnetic materials with fine structure. In this method, the structures of the magnetic materials are assumed to be periodic, and the unit cell is defined. The effective permeability is determined on the basis of magnetic energy balance in the unit cell. This method can be applied not only for linear problems but also for non-linear ones. In this paper, estimation of the effective permeability of non-linear magnetic materials by using the homogenization method is described in detail, and then the validity for the non-liner problems is tested for two-dimensional problems. It is shown that this homogenization method gives accurate non-linear effective permeability. (c) 2005 Elsevier B.V. All rights reserved.
  • Frederico G. Guimaraes, Elizabeth F. Wanner, Felipe Campelo, Ricardo H. C. Takahashi, Hajime Igarashi, David A. Lowther, Jaime A. Ramirez
    2006 IEEE CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1-6 2921 - + 2006年 [査読無し][通常論文]
     
    The use of local search in evolutionary techniques is believed to enhance the performance of the algorithms, giving rise to memetic or hybrid algorithms. However, in many continuous optimization problems the additional cost required by local search may be prohibitive. Thus we propose the local learning of the objective and constraint functions prior to the local search phase of memetic algorithms, based on the samples gathered by the population through the evolutionary process. The local search operator is then applied over this approximated model. We perform some experiments by combining our approach with a real-coded genetic algorithm. The results demonstrate the benefit of the proposed methodology for costly black-box functions.
  • F. Campelo, F.G. Guimaraes, H. Igarashi, K. Watanabe, J.A. Ramirez
    Proc. IEEE world congress on computational intelligence 10973  2006年 [査読無し][通常論文]
  • Felipe Campelo, Frederico G. Guimaraes, Hajime Igarashi, Kota Watanabe, Jaime A. Ramirez
    2006 IEEE CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1-6 3189 - + 2006年 [査読有り][通常論文]
     
    Traditional shape optimization of engineering devices usually starts with an initial user-defined configuration of material. Optimization algorithms are then applied for optimizing objective functions of predefined parameters. While this approach can yield efficient results, it is essentially limited, since limitations in the initial design forbid the computational methods to explore different distributions of material as solutions for a given problem. In other words, the algorithms are not allowed to exhibit creativity in the design process. Topology optimization is a paradigm for optimization that allows such creativity to emerge. Instead of optimizing functions of user-defined parameters, this paradigm optimizes the material properties of each point of the design space, and its methods are theoretically able to describe all possible devices within a limited space. This work presents a new methodology for topology optimization, based on an evolutionary paradigm known as artificial immune systems. The proposed technique is capable of exploring the space locally as well as globally, efficiently searching for the optimal distribution of material. It also incorporates strategies for the evolution of smoother, more regular shapes, in order to generate physically feasible solutions for engineering problems.
  • H Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 41 5 1816 - 1819 2005年05月 [査読無し][通常論文]
     
    In this paper, the self-organizing map is applied for visualization and clustering of optimal solutions in parameter spaces. The present method is tested for the simplified version of De Jong's function and TEAM workshop problem 22. It is shown that the present method successfully visualizes the distribution of optimal solutions, and allows us to classify the optimal solutions into clusters. Moreover, the optimal regions which include clustered optimal solutions in the parameter space can be obtained by the present method.
  • F Campelo, FG Guimaraes, H Igarashi, JA Ramirez
    IEEE TRANSACTIONS ON MAGNETICS 41 5 1736 - 1739 2005年05月 [査読無し][通常論文]
     
    This paper proposes the real-coded clonal selection algorithm (RCSA) for use in electromagnetic design optimization. Some features of the algorithm, such as the number of clones, mutation range, and the fraction of the population selected each generation are discussed. The TEAM Workshop problem 22 is investigated, in order to illustrate the performance of the algorithm in a real electromagnetic problem. The results obtained, a set of optimal solutions representing a broader range of options for the designer, are compared with those achieved by a genetic algorithm, showing the efficiency of the RCSA in practical optimization problems.
  • K Watanabe, H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 41 5 1672 - 1675 2005年05月 [査読無し][通常論文]
     
    This paper discusses the comparison between the geometric multigrid (GMG) method and the algebraic multigrid (AMG) method in edge-based finite-element (FE) analysis. The GMG method requires the hierarchical meshes. On the other hand, the AMG method requires the only a single mesh information. The system matrices of the coarse grids are generated using algebraic operation in AMG. The numerical results show that both multigrid methods are faster than the conventional solvers in large-scale analysis. Although multigrid methods require the setup procedures, the calculation time of these procedures is comparatively short and increase linearly with the number of unknowns.
  • H Waki, H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 41 5 1520 - 1523 2005年05月 [査読無し][通常論文]
     
    This paper describes a method to estimate effective permeability of magnetic composite materials for static field. In the present method, the structures of the composite materials are assumed to be periodic, and the unit cell is defined. The effective permeability is determined on the basis of magnetic energy balance in the unit cell. The present method considers magnetic interaction between inclusions of the composite materials, and is more accurate and useful. Therefore, the present method can be more widely applied than conventional models, for example, the Maxwell-Garnett formula and the Bruggeman formula. Validity of the present method is confirmed by numerical analyses. This approach can be applied also to nonlinear magnetic composite materials.
  • H Waki, H Igarashi, T Honma
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 24 2 566 - 580 2005年 [査読無し][通常論文]
     
    Purpose - To analyze effectively magnetic shielding effects by shields with fine structure. Design/methodology/approach - Simplification of the fine structure makes it possible to analyze them efficiently. The authors have introduced a homogenization method to estimate effective permeability of magnetic composite structure for the static field. The homogenization method is applied to the analysis of magnetic shields composed of steel plates and steel rods against DC power lines to test its feasibility. Findings - The properties of the magnetic shielding are analyzed by using the homogenization method. The errors of the magnetic fields increase in case of very few layers. Originality/value - The simplification of the magnetic shields with fine structure by using the homogenization method makes it possible to analyze efficiently magnetic shielding effects, although the accuracy becomes worse in case of very few layers.
  • K Watanabe, H Igarashi
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 24 2 408 - 417 2005年 [査読無し][通常論文]
     
    Purpose - This paper discusses the robustness of the algebraic multigrid (AMG) method as well as geometric multigrid (GMG) method against mesh distortion in edge-based finite element analysis. Design/methodology/approach - Analyzes a simple magnetostatic problem, in which the model consists of a cubic iron and the surrounding air region. Prepares three meshes which have same number of elements to evaluate the robustness of multigrid against the distortion of mesh. Findings - The AMG method is shown to be more robust against mesh distortion than the GMG method. Originality/value - Shows that the AMG is more robust than the GMG. This result is of practical interest to the researchers in this field.
  • 和木 浩, 五十嵐 一, 本間 利久
    電気学会論文誌A 125 4 309 - 316 2005年 [査読無し][通常論文]
     
    This paper describes an effective analysis of magnetic shielding based on homogenization. The analyses become time-consuming if the problems include the magnetic substances having fine structure. The homogenization of the structure makes it possible to analyze effectively the magnetic fields. The authors introduce a method to estimate the effective permeability of the homogenized substance. This method can be applied to any periodic structure made of magnetic substance. The magnetic shielding effects by the structures against direct-current (DC) fields generated by electric railways are analyzed by using the present method. As a result, it is found that the overhead way and the protective fence near the railway work as a magnetic shield, whose effects can be improved by appropriate arrangement of those constructions. © 2005, The Institute of Electrical Engineers of Japan. All rights reserved.
  • K Watanabe, H Igarashi, T Honma
    ELECTRICAL ENGINEERING IN JAPAN 148 1 75 - 81 2004年07月 [査読有り][通常論文]
     
    The dependence of the multigrid finite element method solving three-dimensional magnetostatic fields on the quality of the finite element mesh is reported. It is shown that the convergence of the multigrid method is strongly influenced by the mesh quality. Moreover, the multigrid method with ICCG smoother is shown to be more robust against mesh distortion than that with Gauss-Seidel and SOR smoothers. (C) 2004 Wiley Periodicals, Inc.
  • H Igarashi, K Watanabe, T Ito, T Fukuda, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 40 2 605 - 608 2004年03月 [査読無し][通常論文]
     
    This paper describes a finite-element analysis of surface microwaves coupled to a cold nonmagnetized plasma for chemical vapor deposition (CVD). The microwave-plasma coupling is taken into account by introducing the frequency-dependent permittivity. The computed resonant modes of the surface wave on the interface between the dielectric and plasma in a cylindrical vessel are shown to be in good agreement with the theoretical ones. Moreover, the computed field distribution for a waveguide loaded cylindrical vessel agrees well with that computed by the finite-difference time-domain (FDTD) method.
  • 渡辺 浩太, 五十嵐 一, 本間 利久
    電気学会論文誌 123 3 257 - 262 2003年09月01日 [査読無し][通常論文]
     
    The dependence of the multigrid-finite element method solving three dimensional magnetostatic fields onthe quality of the finite element mesh is reported. It is shown that the convergence of the muitigrid method is strongly influenced by the mesh quality. Moreover, the muitigrid method with ICCG-smoother is shown to be more robust against mesh distortion than that with Gauss-Seidel and SOR smoothers. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 渡辺 浩太, 五十嵐 一, 本間 利久
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 3 257 - 262 電気学会 2003年09月01日 [査読無し][通常論文]
     
    The dependence of the multigrid-finite element method solving three dimensional magnetostatic fields on the quality of the finite element mesh is reported. It is shown that the convergence of the multigrid method is strongly influenced by the mesh quality. Moreover, the multigrid method with ICCG-smoother is shown to be more robust against mesh distortion than that with Gauss-Seidel and SOR smoothers.
  • 和木 浩, 五十嵐 一, 本間 和久
    日本AEM学会誌 11 2 82 - 87 日本AEM学会 2003年06月10日 [査読無し][通常論文]
  • K Watanabe, H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 39 3 1674 - 1676 2003年05月 [査読無し][通常論文]
     
    This paper discusses robustness of the multigrid (MG) method against distortion of finite elements. The convergence of MG method becomes considerably worse as the finite elements become flat. It is shown that the smoother used in the MG method cannot effectively eliminate the high-frequency component of the residue for flat elements, and this gives rise to deterioration in the convergence. Moreover, the multigrid method with conjugate gradient (CG) smoother is shown to be more robust against mesh distortion than that with Gauss-Seidel smoother.
  • H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 39 3 1705 - 1708 2003年05月 [査読無し][通常論文]
     
    Driven microwave problems can be solved with the finite-element method formulated in terms of the electric field, as well as the vector and scalar potentials. It is known that the latter gives faster convergence of the preconditioned conjugate gradient method than the former. This can be understood from the following facts: namely; the preconditioned finite-element matrix of the former method can contain small negative eigenvalues which make the matrix condition worse. On the other hand, in the latter, such eigenvalues are shown to be composed of zeros and normalized ones.
  • "構造物内部の透磁率分布の逆解析"
    日本AEM学会誌 11 82 - 87 2003年 [査読無し][通常論文]
  • H. Igarashi, K. Ooi and T. Honma, "A Magnetostatic Reconstruction of Permeability Distribution in Material", Inverse Problems in Engineering Mechanics IV, ed. M. Tanaka, 383-388 (Elsevier, Berlin) (2003)*
    2003年 [査読無し][通常論文]
  • H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 38 2 565 - 568 2002年03月 [査読無し][通常論文]
     
    This paper discusses convergence of the incomplete Cholesky conjugate gradient method (ICCG) which solves edge-based finite-element equations for quasi-static electromagnetic fields. It has been observed in numerical computations that convergence of ICCG for the A-V method is faster than that for the A method. This phenomenon is found to be explained by the fact that, in the A-V method, the preconditioning eliminates the small singular values which deteriorate the condition number while they remain after the preconditioning in the case of the A method.
  • Property of Second Order Edge Elements in a Class
    International Journal of Applied Electromagnetics and Mechanics 14 15 - 18 2002年 [査読無し][通常論文]
  • Igarashi, H. and Honma, T.:"A Direct Reconstruction of Magnetic Charge for Non-Destructive Testing ", Electromagnetic Nondestructive Evaluation IV, (IOS Press)29-34(2002)*
    2002年 [査読無し][通常論文]
  • Reconstruction of Planar Magnetic Charge Distribution
    International Journal of Applied Electromagnetics and Mechanics 15 257 - 260 2002年 [査読無し][通常論文]
  • H Igarashi, T Honma
    ELECTROMAGNETIC NONDESTRUCTIVE EVALUATION (VI) 23 29 - 34 2002年 [査読有り][通常論文]
     
    The magnetic charge, which is due to martensite transformation around a crack in ferromagnetic materials, is reconstructed from the magnetic fields measured on a plane above the charge region. It is shown that both Tikhonov method with an appropriate regularization term and iterative regularization based on the CG method solving a modified normal equation yield satisfactory solutions. The regularization parameter for the Tikhonov method can be determined from the L-curve when the noise level is under 10% of measurement data. The residual tolerance of CG iteration, which gives great influence on the solution, can roughly be estimated from the discrepancy principle.
  • H Igarashi
    IEEE TRANSACTIONS ON MAGNETICS 37 5 3129 - 3132 2001年09月 [査読無し][通常論文]
     
    This paper discusses properties of the curl-curl matrix in the finite element formulation with edge elements. Moreover the observed deceleration in convergence of the CG and ICCG methods applied to magnetostatic problems through the tree-cotree gauging is explained on the basis of the eigenvalue separation property. From the eigenvalue separation property it follows that neither minimum nonzero eigenvalue of the curl-curl matrix nor maximum one Increase through the tree-cotree gauging. Hence it is concluded that the condition number of the curl-curl matrix tends to grow by its definition. Moreover the maximum eigenvalue tends to keep constant whereas the minimum nonzero eigenvalue reduces. This property also makes the condition number worse.
  • Igarashi, H. and Honma, T., "On Identification of Magnetic Sources in Materials", Inverse Problems in Engineering Mechanics III, eds. M. Tanaka and G.S. Dulikravich, Elsevier, 403-410 (2001)*
    2001年 [査読無し][通常論文]
  • H Igarashi, T Honma, A Kost
    IEEE TRANSACTIONS ON MAGNETICS 36 4 1168 - 1171 2000年07月 [査読無し][通常論文]
     
    In this paper the magnetization distribution in a cylindrical permanent magnet, called magnet roller, used in copy machines and laser printers, is determined from the magnetic fields measured on a circle outside the roller, The system matrix, which is singular because of luck of uniqueness of the solution, is regularized by the Tikhonov method. The determination of the optimal regularization parameter based on the L-curve method is discussed. It is shown that the uniform and distributed magnetization patterns are successfully reconstructed by the present method.
  • 円筒形永久磁石の順・逆解析
    電気学会論文誌 A 120巻 8/9号 791 - 797 2000年 [査読無し][通常論文]
  • Igarashi, H.:"On the Reconstruction of Magnetic Source in Cylindrical Permanent Magnets", Inverse Problems in Engineering Mechanics II, eds. Tanaka, M. and Dulikravich, G.S., Elsevier: 467-476 (2000)*
    2000年 [査読無し][通常論文]
  • D Lederer, H Igarashi, A Kost, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 35 3 1211 - 1214 1999年05月 [査読有り][通常論文]
     
    The application of the Jiles-Atherton hysteresis model for numerical modelling of measured magnetic hysteresis characteristics of constructional steel is investigated. Parameter identification is done using the stochastic optimization method "simulated annealing". Modifications of the original model, which were proposed to overcome its drawbacks, are examined, resulting in a new combined Jiles-Atherton and scaling model.
  • H Igarashi, T Yoshikawa, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 35 3 1518 - 1521 1999年05月 [査読有り][通常論文]
     
    In this paper the time-dependent Schrodinger equation governing dynamics of single electron in magnetic fields is solved by the finite difference method (FDM) with the explicit central difference scheme and Trotter-Suzuki method (TSM). Motion of a wave packet in rectangular and stadium-shaped domains immersed in uniform magnetic field is analyzed. The performance of the two numerical methods is compared. It is shown that FDM is superior over TSM for accuracy and computing efficiency while TSM is superior for numerical stability. Moreover the probability density of an electron in the stadium is shown to form complex spatial patterns which, suggest quantum chaos.
  • D Lederer, H Igarashi, A Kost, T Honma
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 18 3 410 - 421 1999年 [査読有り][通常論文]
     
    The calculation of magnetic shielding with ferromagnetic material by an effective reluctivity method and a time step method based on the finite element calculation is investigated The calculation results of both methods are compared with measurement results and with each other in order to check their reliability and accuracy. It turns out that both methods give similar results for the field inside the shielding material, whereas in the surrounding air the effective reluctivity method gives more accurate results than the present time step method.
  • H Igarashi, A Kost, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 34 5 2539 - 2542 1998年09月 [査読有り][通常論文]
     
    This paper describes a method for the three dimensional analysis of quasi-static magnetic fields around a thin magnetic conductive layer, The impedance boundary conditions (IBCs) for the vector potential are introduced on both sides of the layer surface. The magnetic field around the layer is numerically determined under the IBCs. The present method does not require numerical analysis of the electromagnetic field inside the layer which is formidable due to its extreme spatial structure. The present method gives reasonable solutions to numerical examples.
  • H Igarashi, D Lederer, A Kost, T Honma, T Nakata
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 17 1-3 357 - 363 1998年 [査読有り][通常論文]
     
    The Preisach and Jiles models for hysteresis are applied to reconstruct BH loops from measurement data for constructional steel St 37. The distribution function for the Preisach model is determined from all the available, 18, measured BH loops starting from the initial curve. The five unknown parameters in Jiles model are determined by the simulated annealing method to minimize the distance between the largest measured BH loop and the corresponding computed loop. Although Jiles model gives differences from the measured BH loops for low applied fields, it provides results fitted well to the largest measured loop for which the parameters are optimized. The Preisach model gives good fitting over a wide range of the applied field.
  • H Igarashi, D Lederer, T Honma, A Kost
    NON-LINEAR ELECTROMAGNETIC SYSTEMS 13 653 - 656 1998年 [査読有り][通常論文]
     
    This paper describes a numerical method for analysis of electromagnetic fields around thin ferromagnetic layers with time-dependent source currents. In this method, the electromagnetic fields inside the thin layer are assumed to obey the one dimensional magnetic-diffusion equation while the field in air around the layer is assumed to be a quasi-static magnetic field in full dimensions. The nonlinearity in the magnetic characteristics of the ferromagnetic material is taken into account. The interior and exterior fields are analyzed by finite and boundary element methods, respectively. The present method gives results similar to experimental results for a shielding thin plate.
  • H Igarashi, A Kost, T Honma
    EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS 1 1 103 - 109 1998年01月 [査読有り][通常論文]
     
    Thin layers of magnetic substance are often used in magnetic shieldings. Since the scale of the spatial change in electromagnetic fields in the direction of the thickness of such a thin layer is considerably different from that in the transverse directions, the numerical treatment of the interior electromagnetic fields is formidable. In this paper, it is shown that the impedance boundary conditions on the surfaces of the thin magnetic layer, which have been written in former papers by the scalar potentials, can be expressed in terms of the vector potentials, Moreover, a new numerical method for analysis of eddy currents on thin magnetic layers is introduced, in which the quasi-static magnetic field in an air region ambient the thin layer is analyzed by solving the boundary integral equations under the impedance boundary conditions without any numerical treatment of the interior field, This formulation has no difficulties even when the skin depth is very short compared with the thickness of the layer. It is shown that the numerical results obtained by the present method in two-dimensional and axisymmetric systems agree well with the results analytically obtained or computed by a conventional numerical method.
  • H Igarashi, A Kost, T Honma
    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 17 5-6 585 - 594 1998年 [査読有り][通常論文]
  • K Tsubota, H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 33 2 1366 - 1369 1997年03月 [査読無し][通常論文]
     
    We report the analysis of plasma sheaths which occur between plasma and the wall. The plasma equation which governs sheaths[1] has been already solved by Bissell et al[2], but the serious numerical errors occur in their results because the singularity exists in the equation, We consider the singularity and develop the method which regularizes the singularity, so that we confirm the errors are improved, We think this method is available for another calculation of the equation which includes the singularity.
  • Kost, A. and Igarashi, H. : "Different Numerical Methods for Electromagnetic Field Calculation with Respect to EMC Problems", Electromagnetic Field Problems and Applications, 276-281 (1997)*
    1997年 [査読無し][通常論文]
  • Lederer, D., Igarashi, H. and Kost, A. : "A Newton-Raphson Method for Complex Systems・h, ACES Journal, 12(2) : 113-116 (1997)*
    1997年 [査読無し][通常論文]
  • Igarashi, H., Honma, T. and Kost, A. : "A Three-Dimensional Analysis of Magnetic Shielding with Thin Layers", ACES Journal, 12(2) : 71-74 (1997)*
    1997年 [査読無し][通常論文]
  • A Kost, H Igarashi
    IEEE 1997 INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY - SYMPOSIUM RECORD 248 - 253 1997年 [査読有り][通常論文]
     
    The disturbance of sensitive measurement and control equipment by electromagnetic fields is a central problem in electromagnetic compatibility. A removal or reduction of such a disturbance is achieved by thin shielding sheets, the optimum design of which nowadays can be found by numerical methods. This paper describes the principles of three new methods for this task. The first method is the conventional hybrid FEM/BEM-method, which analyzes a 3D distribution of the fields numerically in the interior of the shielding sheet as well as in its surroundings, In the case of linear shielding material the 3D discretization can be replaced by a 2D one on the shielding sheet surface in the second and third method. While the second method leads to a more appropriate FEM/BEM formulation for thin shielding sheets than the first one, the third one has the advantage that only a BEM formulation is needed to solve the problem. Some EMC applications and their results illustrate the use of the methods.
  • A Kost, H Igarashi
    ELECTROMAGNETIC FIELD PROBLEMS AND APPLICATIONS (ICEF '96) 276 - 281 1997年 [査読有り][通常論文]
     
    This paper describes two different numerical methods for the analysis of electromagnetic fields with respect to EMC problems. The methods can analyze electromagnetic fields, ranging from static to high-frequency fields, with thin shielding materials. In the methods, FEM is employed to solve a couple of differential equations which express the relation between the magnetic fields on both surfaces of the shielding material. The magnetic fields in vacuum regions are modeled by means of BEM. The FEM-BEM coupled equations are solved to evaluate shielding property. The first method described in this paper employs the potentials and the normal components of magnetic fields on the surfaces of the shielding material for unknowns. It is impossible to apply this method to the analysis of shielding materials with open surfaces unless a fictitious boundary is introduced in vacuum region. One the other hand, the second method, which employs the jump in the potential and normal component of the magnetic fields across the thin shielding material as unknown variables, can analyze shielding materials with both open and closed surfaces. The number of unknowns in the latter is half of that in the former. Though both methods give slight discrepancies in the computed shielding factors at high frequencies, the results computed by them are almost identical.
  • H Igarashi, T Honma
    APPLIED MATHEMATICAL MODELLING 20 11 847 - 852 1996年11月 [査読無し][通常論文]
     
    It is known that the spatial derivatives of a potential function become infinite at corner points on a boundary under certain conditions. Numerical methods such as finite and boundary element methods cannot adequately analyse the potential fields with those field singularities since they conventionally employ piecewise polynomials. This paper presents a boundary element formulation for the accurate analysis of two-dimensional potential fields with the field singularities. In this method boundary integral equations are formulated for unknown regularised functions, which are introduced by subtracting off the field singularities from the original potential function. Moreover at the singular corner points boundary integral equations are formulated to determine the unknown expansion coefficients that characterize the behavior of the potential function around the singular corner points. By simultaneously solving the boundary integral equations for the regularized function and the expansion coefficients the original potential function is accurately determined. (C) 1996 by Elsevier Science Inc.
  • H Igarashi, Y Mizuyama, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 32 3 686 - 689 1996年05月 [査読無し][通常論文]
     
    This paper presents a boundary element analysis of transmission-line parameters on the basis of the quasi-TEM assumption. Singular boundary elements are employed to adequately express the corner singularities at sharp conductor edges. The boundary integrals consisting of the Green function and singular interpolation functions are regularized by a Taylor expansion technique, and are then evaluated using the standard Gaussian quadrature, The numerical results for test problems show the reliability of the present method.
  • H Igarashi, T Honma
    IEEE TRANSACTIONS ON MAGNETICS 32 3 682 - 685 1996年05月 [査読無し][通常論文]
     
    This paper describes a two-dimensional analysis of magnetic fields with thin magnetic materials using hypersingular integral equations. In this analysis, the thin materials are modeled as infinitesimally thin sheets, on which hypersingular integral equations for the vector potential are formulated, The hypersingular integral equation is discretized by boundary element method, on the basis of the Hadamard finite part integral, to numerically compute magnetic fields. The present method is shown to give an accurate magnetic field in a cylindrical magnetic shell with linear permeability. Moreover, numerical results for the shell with non-linear permeability are provided.
  • H. Igarashi, K. Watanabe, T. Honma and A. Kost : "Regularization of Nearly Singular Boundary Integrals in Three-Dimensional Potential Problem", Boundary Element Communications, 7 : 164-170 (1996)*
    1996年 [査読無し][通常論文]
  • H Igarashi, T Honma
    IEICE TRANSACTIONS ON ELECTRONICS E79C 1 131 - 138 1996年01月 [査読無し][通常論文]
     
    This paper describes a finite element method to obtain an accurate solution of the scalar Helmholtz equation with field singularities. It is known that the spatial derivatives of the eigenfunction of the scalar Helmholtz equation become infinite under certain conditions. These field singularities undermine the accuracy of the numerical solutions obtained by conventional finite element methods based on piecewise polynomials. In this paper, a regularized eigenfunction is introduced by subtracting the field singularities from the original eigenfunction. The finite element method formulated in terms of the regularized eigenfunction is expected to improve the accuracy and convergence of the numerical solutions. The finite element matrices for the present method can be easily evaluated since they do not involve any singular integrands. Moreover, the Dirichlet type boundary conditions are explicitly imposed on the variables using a transform matrix while the Neumann-type boundary conditions are implicitly imposed in the functional. The numerical results for three test problems show that the present method clearly improves the accuracy of the numerical solutions.
  • H IGARASHI, T HONMA
    JOURNAL OF COMPUTATIONAL PHYSICS 119 2 244 - 251 1995年07月 [査読有り][通常論文]
     
    This paper describes two strategies for the accurate computations of potential derivatives in boundary element methods. The first method regularizes the quasi singularity in a fundamental solution by referring the potential and its derivatives at the boundary point nearest to a calculation point in a domain. In the second method, a system of coupled equations for an unknown potential and its derivatives at a calculation point is solved to improve accuracy. Green's theorem unifies the derivation of the above methods, which are shown to be suitable for computer implementation. Numerical results show that the present methods considerably improve the accuracy in the computations of potential derivatives. The errors in the present methods are analyzed to evaluate their performance for general cases. Although this paper describes the regularization methods for only two-dimensional problems, it is suggested that those can be easily extended to three-dimensional problems. (C) 1995 Academic Press, Inc.
  • H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 31 3 1492 - 1495 1995年05月 [査読有り][通常論文]
     
    This paper provides new regularized formulas for the boundary element analysis of the modified Helmholtz equation describing eddy current fields. The present formulas are shown to regularize near singularity in the kernels and effectively to improve the accuracy in the computation of fields near boundaries.
  • H IGARASHI, Y SUGAWARA, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 31 3 1642 - 1645 1995年05月 [査読有り][通常論文]
     
    This paper describes a simple numerical method based on the finite element method for the analysis of the resonant frequencies and external Q values of a waveguide loaded cavity. The present method solves a second order proper equation with a damping term, which can be reduced to a linear one. It is shown that the present method provides the reasonable resonant frequencies and corresponding Q values for wide range of the electromagnetic coupling.
  • H IGARASHI, M YOSHIDA, T HONMA
    ADVANCED COMPUTATIONAL AND DESIGN TECHNIQUES IN APPLIED ELECTROMAGNETIC SYSTEMS 6 521 - 524 1995年 [査読有り][通常論文]
  • H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 30 5 3104 - 3107 1994年09月 [査読有り][通常論文]
     
    This paper describes an analysis of electromagnetic waves in a waveguide using the finite element method based on the complementary variational principle. The vector Helmholtz equation is represented in dual forms, in which the solenoidal and irrotational transverse fields are chosen to be unknowns, and they are approximated by the edge and facet elements, respectively. The dual representations are then shown to provide the lower bounds of the eigenfrequencies of a waveguide, with the aid of the complementary variational principle.
  • H IGARASHI, T HONMA
    BOUNDARY ELEMENT TECHNOLOGY VIII 157 - 166 1993年 [査読有り][通常論文]
  • H IGARASHI, T HONMA
    JOURNAL OF APPLIED PHYSICS 71 11 5689 - 5693 1992年06月 [査読有り][通常論文]
     
    This paper describes a vectorial finite element method for the analysis of electromagnetic waves propagating in helical systems. The present method can be as easily used as the methods for guided electromagnetic waves in systems with translational and axial symmetries. The functional for the vector Helmholtz equation is minimized using twisted coordinates in which the problem becomes two-dimensional. The spurious solutions, which do not satisfy the divergence-free condition, are removed on the basis of the penalty method. Two finite element equations for the covariant and contravariant components of electromagnetic fields are derived and boundary conditions for both formulations are described. The present method is applied to the analysis of a twisted waveguide with a rectangular cross section and the numerical solutions are shown to be in good agreement with the perturbed solutions for a small helical pitch.
  • H IGARASHI, T HONMA
    APPLIED MATHEMATICAL MODELLING 16 6 314 - 319 1992年06月 [査読有り][通常論文]
     
    Fundamental solutions to modified Helmholtz-type equations, which often appear in electrostatics and magnetostatics, are investigated. In particular, this paper defines the relation among two-dimensional (or symmetric) fundamental solutions that play an important role in boundary element analyses. The fundamental solutions for axially and helically symmetric systems are derived from the integration of three-dimensional fundamental solutions along a ring and a helix, respectively. These derivations are performed on the basis of the Fourier-Bessel theorem.
  • H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 28 2 1671 - 1674 1992年03月 [査読有り][通常論文]
     
    This paper presents boundary element (BE) and finite element (FE) solutions to open boundary potential problems with helical symmetry. The BE and FE equations are introduced in the twisted coordinates in which helical potential fields can be regarded as being two-dimensional. In the FE analysis, 'transfinite' elements are used for modeling open boundaries. Magnetic fields around a helical solenoid are analyzed using the above mentioned methods and those numerical solutions are shown to be in good agreement with analytic solutions. Moreover, electric fields around a twisted-pair line are calculated and it is shown that the fields come to concentrate in the vicinity of the lines as the helical pitch is increased.
  • H IGARASHI, T HONMA
    ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS 10 2 131 - 136 1992年 [査読有り][通常論文]
     
    This paper presents a boundary element analysis of helically symmetric potential fields. A two dimensional boundary integral equation is introduced in general curvilinear coordinates. On the basis of this formulation, a boundary integral equation for helically symmetric potential problems is obtained using twisted coordinates. Moreover, the boundary element solution by the present scheme is compared with perturbation and finite element solutions for a simple potential problem and it is shown that the boundary element solution is in good agreement with the finite element solution for arbitrary helical pitch values while the perturbed solution becomes inaccurate for large pitch values.
  • H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 27 5 4052 - 4055 1991年09月 [査読有り][通常論文]
     
    In this paper, the scalar Helmholtz equation is solved by the use of finite element methods to analyze the TE mode in the twisted waveguide. For this purpose, on the basis of the weighted residual method, a two dimensional integral equation described in the twisted coordinates is introduced by reducing that in the general curvilinear coordinates. After the finite element formulation, it is shown that the numerical solution monotonously converges with increasing the number of nodes. Moreover, the cut-off constant and the dispersion relation calculated by the present scheme are shown to be in good agreement with those calculated by the perturbation method. Furthermore, on the basis of the numerical results, some comments are offered on the TE mode distributions in a twisted rectangular waveguide and on the influence of the shift of the waveguide on those distributions.
  • H IGARASHI, T HONMA
    BOUNDARY ELEMENT TECHNOLOGY VI 65 - 76 1991年 [査読有り][通常論文]
  • H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 26 5 1774 - 1776 1990年09月 [査読有り][通常論文]
  • S SHIRAKAWA, H IGARASHI, T HONMA
    IEEE TRANSACTIONS ON MAGNETICS 26 2 555 - 558 1990年03月 [査読有り][通常論文]

書籍

講演・口頭発表等

  • トポロジー・深層学習・機械学習を用いた設計技術  [招待講演]
    五十嵐一
    サイエンス&テクノロジーセミナー 2021年04月 公開講演,セミナー,チュートリアル,講習,講義等
  • モーター磁気回路設計へのトポロジー最適化および深層学習の適用  [招待講演]
    五十嵐一
    自動車技術会モータ技術部門委員会 2021年01月 公開講演,セミナー,チュートリアル,講習,講義等
  • 電磁誘導を用いた振動発電機  [招待講演]
    五十嵐 一
    2020 年度 第 3 回 EH コンソーシアム 総会 2020年12月 公開講演,セミナー,チュートリアル,講習,講義等
  • AI技術とデータ駆動による電磁界解析・最適化計算の効率化  [招待講演]
    五十嵐一
    JMAG ユーザ会 2020 2020年12月 口頭発表(基調)
  • AI技術・データを活用した 電気電子機器解析と最適設計  [招待講演]
    五十嵐一
    Panasonic総合技術シンポジウム 専門技術セッション 2020年11月 口頭発表(招待・特別)
  • Data-driven methods for computational electromagnetism  [招待講演]
    Hajime Igarashi
    International Symposium on Numerical Modeling towards Digital Twin in Electrical Engineering 2020年01月 口頭発表(招待・特別)
  • 環境発電デバイスの発電効率を最適設計により向上させる技術を開発  [通常講演]
    五十嵐 一
    日本経済新聞 2019年07月 メディア報道等
  • トポロジー最適化の基礎と応用およびAI技術の適用  [招待講演]
    五十嵐 一
    サイエンス&テクノロジー社セミナー 2019年03月 公開講演,セミナー,チュートリアル,講習,講義等
  • 北大と明電舎,EV用モーターをAIで最適設計  [通常講演]
    五十嵐 一
    日本経済新聞社 2018年11月 メディア報道等
  • Topology Optimization Based on Deep Learning and toward Their Coevolution  [招待講演]
    五十嵐 一
    JSST2018 2018年09月 口頭発表(招待・特別)
  • トポロジー最適化を用いたマイクロ波エネルギーハーベスタの開発  [招待講演]
    五十嵐 一
    第51回野依フォーラム 2018年04月 口頭発表(招待・特別)
  • AI技術と高精度電磁界解析を用いた最適設計  [招待講演]
    五十嵐一, 佐々木秀徳
    平成30年電気学会全国大会シンポジウム講演 2018年03月 シンポジウム・ワークショップパネル(指名)
  • 遺伝的アルゴリズム を用いた電気機器 の最適設計  [招待講演]
    五十嵐 一
    精密工学会「基礎講座 トポロジー最適化 -設計を変える!」」 2017年10月 公開講演,セミナー,チュートリアル,講習,講義等
  • 電磁界解析による最適設計技術  [招待講演]
    五十嵐 一
    エレクトロニクス実装学会サマーセミナー 2017年08月 公開講演,セミナー,チュートリアル,講習,講義等
  • Model Order Reduction, Homogenization and Their Combination  [招待講演]
    五十嵐 一
    COMPUMAG2017 2017年06月 口頭発表(基調)
  • マルチスケール問題の電磁界解析:均質化とモデル縮約法  [招待講演]
    五十嵐 一
    平成28年度磁性流体連合講演会 2016年12月 口頭発表(招待・特別)
  • モータ回転子・固定子のトポロジー最適化  [招待講演]
    五十嵐 一
    第36回モータ技術シンポジウム 2016年04月 公開講演,セミナー,チュートリアル,講習,講義等
  • IPMモータのトポロジー最適化とその実験的検証  [招待講演]
    五十嵐 一
    電気学会第25回電磁界解析に関するセミナー 2015年12月 公開講演,セミナー,チュートリアル,講習,講義等
  • 電磁界解析を用いた最適設計  [招待講演]
    五十嵐 一
    JMAGユーザ会2015 2015年12月 口頭発表(基調)
  • 進化計算を用いた最適化デザイン  [招待講演]
    五十嵐 一
    電子情報通信学会信越支部講演会 2015年10月 公開講演,セミナー,チュートリアル,講習,講義等
  • 渦電流損失を考慮した磁性複合材料のマクロ磁気特性  [招待講演]
    五十嵐 一
    日本ボンド磁性材料協会2014年例会 2014年09月 口頭発表(招待・特別)
  • 電磁界解析による最適設計技術  [招待講演]
    五十嵐 一
    平成25年度電気学会電子・情報・システム部門大会 先端技術セミナー 2013年09月 公開講演,セミナー,チュートリアル,講習,講義等

その他活動・業績

  • 大友 佳嗣, 五十嵐 一 電気学会研究会資料. SA 2019 (73) 41 -45 2021年 [査読無し][通常論文]
     
    This paper proposes a novel topology optimization method using the Gabor filter, which is widely used in the field of image processing. The proposed method is applied to the optimization of a synchronous reluctance motor; its average torque is maximized, and simultaneously, the torque ripple is minimized. It is shown that the proposed method results in a motor with thin layer-shaped flux barriers, which achieves a better torque performance in comparison with a conventional model and a motor optimized using NGnet.
  • 佐々木 秀徳, 日高 勇気, 有田 秀哲, 伊藤 一将, 五十嵐 一 電気学会研究会資料. SA 2020 (51) 51 -56 2020年09月04日
  • 比留間 真悟, 五十嵐 一 電気学会研究会資料. SA 2020 (31) 93 -102 2020年09月03日
  • 佐藤 佑樹, 河野 健二, 五十嵐 一 電気学会研究会資料. SA 2020 (31) 43 -48 2020年09月03日
  • 佐々木 秀徳, 日高 勇気, 伊藤 一将, 田中 敏則, 五十嵐 一 電気学会研究会資料. RM 2020 (16) 25 -30 2020年01月24日
  • 佐々木 真, 丸尾 昭人, 大島 弘敬, 五十嵐 一 電気学会研究会資料. RM 2020 (16) 13 -18 2020年01月24日
  • 丸尾 昭人, 大島 弘敬, 五十嵐 一 電気学会研究会資料. RM 2020 (16) 7 -12 2020年01月24日
  • 岡本和也, 五十嵐一 MAGDAコンファレンス講演論文集 28th 350‐351 2019年10月30日 [査読無し][通常論文]
  • 土居周平, 浅沼丈, 五十嵐一 MAGDAコンファレンス講演論文集 28th 348‐349 2019年10月30日 [査読無し][通常論文]
  • 藤田祥伍, 藤田祥伍, 五十嵐一 MAGDAコンファレンス講演論文集 28th 238‐239 2019年10月30日 [査読無し][通常論文]
  • 大友佳嗣, 大友佳嗣, 五十嵐一 電気学会産業応用部門大会(CD-ROM) 2019-October 4341 -4344 2019年10月 [査読無し][通常論文]
     
    © 2019 IEEE. This paper presents topology optimization of magnetic couplers for wireless power transfer (WPT) device considering electromagnetic shields. In this optimization, the magnetic coupler shape for WPT is represented by the Gaussian basis functions. The coupler shape is optimized so that the coupling factor is maximized while the leakage flux is minimized. Moreover, a robust optimization method is proposed to keep the interlinkage flux as large as possible against misalignment between the coils. It is shown by the computational and experimental results that the optimized coupler outperforms the conventional coupler.
  • 土居周平, 浅沼丈, 五十嵐一 電気学会研究会資料 (SA-19-073-091/RM-19-093-111) 23‐28 2019年09月12日 [査読無し][通常論文]
  • 岡本和也, 五十嵐一, 坂本宏紀 電気学会研究会資料 (SA-19-073-091/RM-19-093-111) 71‐76 2019年09月12日 [査読無し][通常論文]
  • 佐々木秀徳, 佐々木秀徳, 日高勇気, 伊藤一将, 田中敏則, 大友佳嗣, 五十嵐一 電気学会研究会資料 (SA-19-073-091/RM-19-093-111) 29‐34 2019年09月12日 [査読無し][通常論文]
  • 佐藤駿輔, 比留間真悟, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2019 ROMBUNNO.PS3‐6 2019年08月28日 [査読無し][通常論文]
  • 佐々木隆宏, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2019 ROMBUNNO.PS6‐2 2019年08月28日 [査読無し][通常論文]
  • 土居周平, 浅沼丈, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2019 ROMBUNNO.PS3‐5 2019年08月28日 [査読無し][通常論文]
  • 佐藤佑樹, 河野健二, 五十嵐一 電気学会研究会資料 (SA-19-001-015/RM-19-001-015) 7‐12 2019年03月05日 [査読無し][通常論文]
  • 大友佳嗣, 五十嵐一, 日高勇気, 小松大河, 山田正樹 電気学会研究会資料 (SA-19-001-015/RM-19-001-015) 31‐34 2019年03月05日 [査読無し][通常論文]
  • 比留間真悟, 五十嵐一 電気学会研究会資料 (SA-19-001-015/RM-19-001-015) 25‐30 2019年03月05日 [査読無し][通常論文]
  • 石田智和, 五十嵐一, 下谷俊人, 橋本英二, 今成宏幸 電気学会全国大会講演論文集(CD-ROM) 2019 ROMBUNNO.5‐131 2019年03月01日 [査読無し][通常論文]
  • 藤田祥伍, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2019 ROMBUNNO.5‐130 2019年03月01日 [査読無し][通常論文]
  • 大友佳嗣, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2019 ROMBUNNO.4‐034 2019年03月01日 [査読無し][通常論文]
  • 大友 佳嗣, 五十嵐 一 計算力学講演会講演論文集 2019 (0) 43 -43 2019年 

    This paper presents topology optimization of magnetic cores for EV wireless charging device. In this optimization, the magnetic core shape for wireless power transfer (WPT) is represented by the Gaussian basis function. The core shape is optimized so as to maximize the coupling factor. In addition, robustness against misalignment between transmitting and receiving coils is taken into account in the optimization. It is found that the optimized core shape effectively increases the net magnetic flux interlinked with the receiving coil, and outperforms the conventional core shape.

  • 下谷俊人, 下谷俊人, 五十嵐一, 橋本英二, 今成宏幸 MAGDAコンファレンス講演論文集 27th 80‐83 2018年10月20日 [査読無し][通常論文]
  • 伊藤桂一, 滝田和真, 五十嵐一 MAGDAコンファレンス講演論文集 27th 92‐93 2018年10月20日 [査読無し][通常論文]
  • 岡本和也, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2018 ROMBUNNO.MC1‐4 2018年09月05日 [査読無し][通常論文]
  • 土居周平, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2018 ROMBUNNO.MC6‐4 2018年09月05日 [査読無し][通常論文]
  • 丸尾昭人, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2018 ROMBUNNO.MC3‐1 2018年09月05日 [査読無し][通常論文]
  • 比留間真悟, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2018 ROMBUNNO.MC7‐3 2018年09月05日 [査読無し][通常論文]
  • 大友佳嗣, 五十嵐一 電気学会電子・情報・システム部門大会講演論文集(CD-ROM) 2018 ROMBUNNO.MC7‐4 2018年09月05日 [査読無し][通常論文]
  • 丸尾昭人, 五十嵐一 電気学会研究会資料 (SA-18-053-059.061-068/RM-18-072-078.080-087) 23‐28 2018年08月21日 [査読無し][通常論文]
  • 比留間真悟, 五十嵐一 電気学会研究会資料 (SA-18-053-059.061-068/RM-18-072-078.080-087) 51‐56 2018年08月21日 [査読無し][通常論文]
  • 藤田祥伍, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2018 ROMBUNNO.5‐119 2018年03月05日 [査読無し][通常論文]
  • 大友佳嗣, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2018 ROMBUNNO.5‐125 2018年03月05日 [査読無し][通常論文]
  • 丸尾昭人, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2018 ROMBUNNO.5‐129 2018年03月05日 [査読無し][通常論文]
  • 佐々木秀徳, 五十嵐一 電気学会研究会資料 (SA-18-016-031/RM-18-016-031) 29‐33 2018年01月23日 [査読無し][通常論文]
  • 下川聡, 大島弘敬, 清水香壱, 上原裕二, 藤崎淳, 古屋篤史, 五十嵐一 電気学会研究会資料 (SA-18-016-031/RM-18-016-031) 17‐22 2018年01月23日 [査読無し][通常論文]
  • 比留間真悟, 五十嵐一 電気学会研究会資料 (SA-18-001-015/RM-18-001-015) 73‐80 2018年01月23日 [査読無し][通常論文]
  • 杉澤健, 丸尾昭人, 五十嵐一 MAGDAコンファレンス講演論文集 26th 295‐300 2017年10月26日 [査読無し][通常論文]
  • 伊藤桂一, 五十嵐一 電子情報通信学会技術研究報告 117 (244(MW2017 82-110)) 123‐127 2017年10月12日 [査読無し][通常論文]
  • 比留間真悟, 五十嵐一 電気学会静止器研究会資料 SA-17 (52-66) 67‐72 2017年09月21日 [査読無し][通常論文]
  • 大友佳嗣, 五十嵐一, 鈴木理明, 佐野広征, 山田隆, 上田幸平, 西田雄亮 電気学会静止器研究会資料 SA-17 (67-81) 7‐12 2017年09月21日 [査読無し][通常論文]
  • 佐々木秀徳, 五十嵐一 電気学会静止器研究会資料 SA-17 (67-81) 83‐88 2017年09月21日 [査読無し][通常論文]
  • 五十嵐 一, 佐藤 佑樹 電気学会誌 = The journal of the Institute of Electrical Engineers of Japan 137 (8) 545 -548,527 2017年08月 [査読無し][招待有り]
  • 五十嵐 一 電気学会論文誌. B 137 (3) 156 -156 2017年 [査読無し][招待有り]
     
    <p>計算機を用いた電磁界解析手法には,有限要素法,境界要素法,時間領域差分法(FDTD 法),モーメント法,部分要素等価回路法(PEEC)などがあるが,電力・電気機器の電磁界解析には非線形解析に適し,柔軟な形状表現が可能な有限要素法が広く用いられている。有限要素法は1960 年</p>
  • 五十嵐 一 電気学会誌 137 (8) 528 -529 2017年 [査読無し][招待有り]
     
    <p>1.電磁界解析による機器設計の広がり</p><p>研究開発において,理論的方法,実験的方法に加え,第三の方法として数値シミュレーションが活用されてきた。電気機器の設計においても,電磁界解析をはじめとした数値シミュレーションが積極的に導入されてきた。初期には,電磁界解析は現象の解析や可視化など補完的な役割を</p>
  • 五十嵐 一, 阿波根 明, 岡本 吉史, 米津 大吾 電気学会論文誌. B, 電力・エネルギー部門誌 = IEEJ transactions on power and energy 137 (3) 157 -161 2017年 [査読無し][招待有り]
     
    This paper surveys the recent advances in electromagnetic field analysis of electric power apparatus. The model order reduction and homogenization methods are effective to reduce the computational time. The Play model can express vector hysteresis characteristics with small computational burden. The topology optimization can lead to novel design of electric apparatus. The contactless power transfer and induction heat devices are effectively analyzed by the finite element method.
  • 杉澤健, 丸尾昭人, 五十嵐一 日本機械学会計算力学講演会論文集(CD-ROM) 29th ROMBUNNO.108 2016年09月21日 [査読無し][通常論文]
  • 上原雅広, 五十嵐一 日本機械学会計算力学講演会論文集(CD-ROM) 29th ROMBUNNO.167 2016年09月21日 [査読無し][通常論文]
  • 藤田祥伍, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 7‐12 2016年08月31日 [査読無し][通常論文]
  • 佐藤佑樹, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 109‐114 2016年08月31日 [査読無し][通常論文]
  • 佐々木秀徳, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 301‐306 2016年08月31日 [査読無し][通常論文]
  • 伊藤桂一, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 157‐160 2016年08月31日 [査読無し][通常論文]
  • 比留間真悟, 藤田祥伍, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 19‐24 2016年08月31日 [査読無し][通常論文]
  • 日高勇気, 日高勇気, 五十嵐一 電子情報通信学会技術研究報告 116 (212(EST2016 42-55)) 295‐300 2016年08月31日 [査読無し][通常論文]
  • 佐々木秀徳, 古井真太郎, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2016 ROMBUNNO.5‐006 2016年03月05日 [査読無し][通常論文]
  • 佐藤佑樹, 佐藤佑樹, 下谷俊人, 五十嵐一 電気学会静止器研究会資料 SA-16 (18-32.34) 1‐6 2016年01月20日 [査読無し][通常論文]
  • 佐藤孝洋, 藤田真史, 五十嵐一 電気学会静止器研究会資料 SA-16 (18-32.34) 23‐28 2016年01月20日 [査読無し][通常論文]
  • 古井真太郎, 五十嵐一, 坂本宏紀, 阿部崇志, 小倉和也 電気学会静止器研究会資料 SA-16 (18-32.34) 29‐34 2016年01月20日 [査読無し][通常論文]
  • 日高勇気, 日高勇気, 五十嵐一 電気学会静止器研究会資料 SA-16 (18-32.34) 65‐68 2016年01月20日 [査読無し][通常論文]
  • 佐々木秀徳, 五十嵐一 電気学会産業応用部門大会(CD-ROM) 2016 ROMBUNNO.Y‐102 2016年 [査読無し][通常論文]
  • 杉澤健, 五十嵐一 MAGDAコンファレンス講演論文集 24th 307‐312 2015年11月12日 [査読無し][通常論文]
  • 伊藤桂一, 宮田克正, 五十嵐一 MAGDAコンファレンス講演論文集 24th 489‐492 2015年11月12日 [査読無し][通常論文]
  • 杉澤健, 佐藤孝洋, 五十嵐一 電磁力関連のダイナミックスシンポジウム講演論文集 27th 449 -450 2015年05月14日 [査読無し][通常論文]
  • Kenta Tsuzaki, Yoshihiro Tawada, Shinji Wakao, Akihisa Kameari, Tadashi Tokumasu, Yasuhito Takahashi, Hajime Igarashi, Koji Fujiwara, Yoshiyuki Ishihara Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 191 (1) 20 -28 2015年04月01日 [査読無し][通常論文]
     
    Electromagnetic phenomena intrinsically spread over an infinite region. Thus, effcient handling of open boundaries is one of the main issues in electromagnetic feld computations. This paper deals with the orthogonalized infinite edge element method that effciently performs precise analysis of the infinite region. In this method, several parameters are used to achieve high accuracy. As one of the parameters, we focus on the reference point and investigate the effect of its position setting on accuracy. We also evaluate the accuracy of the calculated magnetic feld in the far region. By applying boundary element method as postprocessing, it is found that high computational accuracy in the region can be effectively achieved.
  • 佐藤孝洋, 渡辺浩太, 五十嵐一 電気学会静止器研究会資料 SA-15 (33-55) 63 -68 2015年03月05日 [査読無し][通常論文]
  • 佐藤佑樹, 五十嵐一, CLEMENS Markus 電気学会静止器研究会資料 SA-15 (9-14.16-17.19-32) 25 -30 2015年03月05日 [査読無し][通常論文]
  • 渡辺浩太, 体阿彌勇樹, 五十嵐一 電気学会静止器研究会資料 SA-15 (9-14.16-17.19-32) 7 -10 2015年03月05日 [査読無し][通常論文]
  • 五十嵐一, 佐藤佑樹, 伊藤泰久 電気学会静止器研究会資料 SA-15 (9-14.16-17.19-32) 111 -115 2015年03月05日 [査読無し][通常論文]
  • 渡部雄太, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2015 ROMBUNNO.1-023 2015年03月05日 [査読無し][通常論文]
  • 杉澤健, 佐藤孝洋, 五十嵐一 電気学会全国大会講演論文集(CD-ROM) 2015 ROMBUNNO.3-117 2015年03月05日 [査読無し][通常論文]
  • 渡辺浩太, 五十嵐一 MAGDAコンファレンス講演論文集 23rd 237 -242 2014年12月04日 [査読無し][通常論文]
  • 佐藤俊平, 佐藤孝洋, 古井真太郎, 五十嵐一 MAGDAコンファレンス講演論文集 23rd 243 -246 2014年12月04日 [査読無し][通常論文]
  • 伊藤桂一, 渡邊健人, 宮田克正, 五十嵐一 MAGDAコンファレンス講演論文集 23rd 55 -58 2014年12月04日 [査読無し][通常論文]
  • 村上稜, 五十嵐一 MAGDAコンファレンス講演論文集 23rd 483 -486 2014年12月04日 [査読無し][通常論文]
  • 安益崇一郎, 伊藤泰久, 佐藤佑樹, 五十嵐一 MAGDAコンファレンス講演論文集 23rd 489 -490 2014年12月04日 [査読無し][通常論文]
  • 佐藤佑樹, 五十嵐一 電気学会静止器研究会資料 SA-13 (59-74) 35 -40 2013年09月26日 [査読無し][通常論文]
  • 佐藤孝洋, 渡辺浩太, 五十嵐一 電気学会静止器研究会資料 SA-13 (59-74) 29 -34 2013年09月26日 [査読無し][通常論文]
  • 佐藤孝洋, 渡辺浩太, 五十嵐一 電気学会静止器研究会資料 SA-13 (15-28) 5 -10 2013年01月24日 [査読無し][通常論文]
  • 日高勇気, 五十嵐一 電気学会静止器研究会資料 SA-13 (1-14) 55 -60 2013年01月24日 [査読無し][通常論文]
  • 上原裕二, 古屋篤史, 藤崎淳, 清水香壱, 大島弘敬, 鈴木理明, 河野健二, 美舩健, 松尾哲司, 渡辺浩太, 五十嵐一 電気学会マグネティックス研究会資料 MAG-12 (146-159) 39 -44 2012年12月06日 [査読無し][通常論文]
  • 佐藤 孝洋, 五十嵐 一, 渡辺 浩太, 河野 健二, 鈴木 理明, 松尾 哲司, 美舩 健, 上原 裕二, 古屋 篤史 電気学会研究会資料. SA, 静止器研究会 2012 (79) 7 -12 2012年09月10日 [査読無し][通常論文]
  • 津崎 賢大, 多和田 義大, 若尾 真治, 亀有 昭久, 徳増 正, 高橋 康人, 五十嵐 一, 藤原 耕二, 石原 好之 電気学会研究会資料. SA, 静止器研究会 2012 (1) 7 -12 2012年01月26日 [査読無し][通常論文]
  • 高田 篤, 野口 聡, 五十嵐 一, 三輪 將彦 電気学会研究会資料. SA, 静止器研究会 2012 (1) 13 -18 2012年01月26日 [査読無し][通常論文]
  • 伊藤 泰久, 五十嵐 一, 渡辺 浩太, 飯島 洋祐, 河野 健二 電気学会研究会資料. SA, 静止器研究会 2012 (23) 17 -22 2012年01月26日 [査読無し][通常論文]
  • 佐藤 孝洋, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2012 (23) 23 -28 2012年01月26日 [査読無し][通常論文]
  • 渡部 雄太, 五十嵐 一, 亀有 昭久 電気学会研究会資料. SA, 静止器研究会 2011 (46) 1 -4 2011年08月25日 [査読無し][通常論文]
  • 佐藤 孝洋, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2011 (46) 23 -28 2011年08月25日 [査読無し][通常論文]
  • 五十嵐 一, 渡部 雄太, 伊藤 泰久 電気学会研究会資料. SA, 静止器研究会 2011 (46) 85 -90 2011年08月25日 [査読無し][通常論文]
  • 高田 篤, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2011 (1) 25 -29 2011年01月20日 [査読無し][通常論文]
  • Sadamori Koujaku, Kota Watanabe, Hajime Igarashi Proceedings - 10th International Conference on Machine Learning and Applications, ICMLA 2011 1 462 -465 2011年 [査読無し][通常論文]
     
    In this paper, an Adaptive Forgettable Profit Sharing reinforcement learning method is introduced. This method enables agents to adapt the environmental changes very quickly. It can be used to learn the robust and effective actions in the uncertain environments which have the non-markov property, especially the partial observable markov process (POMDP). Profit Sharing learns rational policy that is easy to be learned and results in good behavior in POMDP. However, the policy becomes worse in the dynamic and huge environment that changes frequently and require the lots of actions to achieve the goal. In order to handle such kind of environment, the forgetting, which gives the adaptability and rationality to Profit Sharing, is implemented. This method allows the agent to forget past experiences that reduce the rationality of its policy. The usefulness of the proposed algorithm is demonstrated through the numerical examples. © 2011 IEEE.
  • Double Antennas for Passive Long Range UHF-Band RFID,
    Proceedings of 15th international symposium on applied electromagnetics and mechanics 113 -114 2011年 [査読無し][通常論文]
  • Non-conforming Finite Element Method with Tetrahedral Elements
    Proceedings of 15th international symposium on applied electromagnetics and mechanics 357 -358 2011年 [査読無し][通常論文]
  • Three Dimensional Optimization Using the Voxel Based Finite Element Method with Homogenization
    Proceedings of 15th international symposium on applied electromagnetics and mechanics 351 -352 2011年 [査読無し][通常論文]
  • Pareto optimization of antenna for passive UHF-band RFID
    Proceedings of 15th international symposium on applied electromagnetics and mechanics 209 -210 2011年 [査読無し][通常論文]
  • Multi-Objective Topology Optimization Based on Immune Algorithm for Electromagnetic Devices
    Proc. 30th JSST Annual Conference 236 -241 2011年 [査読無し][通常論文]
  • FDTD Analysis of Ultraviolet Waves Scattered from Dielectric Surfaces
    Proc. 30th JSST Annual Conference 166 -170 2011年 [査読無し][通常論文]
  • Evolutional Design of Waveguide Slot Antenna with Dielectric Lenses
    Proceedings of COMPUMAG2011 CMP682 2011年 [査読無し][通常論文]
  • Voxel Based Finite Element Method Using Homogenization
    Proceedings of COMPUMAG2011 CMP704 2011年 [査読無し][通常論文]
  • Orthogonalized Infinite Edge Element Method ?Convergence Improvement by Orthogonalization of Hilbert Matrix in Infinite Edge Element Method
    Proceedings of COMPUMAG2011 CMP696 2011年 [査読無し][通常論文]
  • On Error Correction Methods for Acceleration of Convergence
    Proceedings of COMPUMAG2011 CMP685 2011年 [査読無し][通常論文]
  • Robust Optimization of IC Tag Antennas
    Proceedings of COMPUMAG2011 CMP686 2011年 [査読無し][通常論文]
  • An Improvement of Convergence in Finite element Analysis with Infinite Element Using Deflation
    Proceedings of COMPUMAG2011 CMP787 2011年 [査読無し][通常論文]
  • Accelerated FDTD computation applied to antenna shape
    Proceedings of COMPUMAG2011 CMP627 2011年 [査読無し][通常論文]
  • Topology Optimization of UHF-band Antennas
    Proc. 14th IGTE Symposium 277 -282 2011年 [査読無し][通常論文]
  • On Unphysical Solutions Obtained by Moment Method in Optimization of Wire Antennas
    Proc. 14th IGTE Symposium 44 -49 2011年 [査読無し][通常論文]
  • 飯島 洋祐, 河野 健二, 五十嵐 一 日本電子材料技術協会会報 41 (0) 40 -42 2010年11月 [査読無し][通常論文]
  • 高田 篤, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2010 (76) 21 -26 2010年09月28日 [査読無し][通常論文]
  • 五十嵐 一, 渡邊 浩太 電気学会研究会資料. SA, 静止器研究会 2010 (76) 65 -70 2010年09月28日 [査読無し][通常論文]
  • 渡部 雄太, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2010 (76) 71 -76 2010年09月28日 [査読無し][通常論文]
  • 五十嵐 一 電気学会論文誌. A, 基礎・材料・共通部門誌 = The transactions of the Institute of Electrical Engineers of Japan. A, A publication of Fundamentals and Materials Society 130 (2) 2010年02月01日 [査読無し][通常論文]
  • 米田 憲二, 渡辺 浩太, 荒井 有気, 宮崎 佳樹, 長嶋 賢, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2010 (26) 25 -29 2010年01月29日 [査読無し][通常論文]
  • 本岡 雄一郎, 野口 聡, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2010 (1) 13 -17 2010年01月28日 [査読無し][通常論文]
  • 稲葉 共昭, 野口 聡, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2010 (1) 19 -23 2010年01月28日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2010 (1) 111 -116 2010年01月28日 [査読無し][通常論文]
  • Kota Watanabe, Seiji Fujino, Hajime Igarashi Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010 1689 2010年 [査読無し][通常論文]
     
    The multigrid (MG) method is known as the fast linear solver for large scale finite element analyses. In the iterations of MG, the Gauss-Seidel method is usually adopted as the smoother. Recently, Induced Dimension Reduction (IDR)-based methods receive much attention because these methods solve faster than the other strong solvers such as BiCGStab method. In this paper, we present a performance of MG with adaptive IDR-based Smoother method. Numerical results show that the present method has good convergence and good parallel efficiency in the electromagnetic analyses. © 2010 IEEE.
  • Deflation techniques for computational electromagnetism, Part I: Theoretical considerations
    Proc. of 14th Biennial IEEE Conference on Electromagnetic Field Computation (CD-ROM) 1458 2010年 [査読無し][通常論文]
  • Deflation techniques for computational electromagnetism, Part II: Numerical applications
    Proc. of 14th Biennial IEEE Conference on Electromagnetic Field Computation (CD-ROM) 1459 2010年 [査読無し][通常論文]
  • Hidetoshi Makimura, Yuta Watanabe, Kota Watanabe, Hajime Igarashi Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010 1378 2010年 [査読無し][通常論文]
     
    This paper presents optimal design of antennas for passive IC tags used in UHF-band radio frequency identification. To improve the performance of IC tags, the shape of the meander line antennas and planar lattice antennas are optimized using the genetic algorithm. In the optimization process, the objective function includes the terms relevant to the antenna size, gain and input impedance. The characteristics of the antennas printed on a dielectric substrate are evaluated using the moment method. The optimization results in desirable input impedance for impedance matching and miniaturizing. © 2010 IEEE.
  • Optimization of Meander Line Antenna Considering Coupling between Non-linear Circuit and Electromagnetic Waves for UHF-band RFID
    Proc. of 14th Biennial IEEE Conference on Electromagnetic Field Computation (CD-ROM) 1349 2010年 [査読無し][通常論文]
  • 第19回MAGDAコンファレンス in 札幌 講演論文集
    日本AEM学会 2010年 [査読無し][通常論文]
  • 飯島 洋祐, 河野 健二, 五十嵐 一, 渡辺 浩太, 松尾 哲司, 美舩 健 粉体および粉末冶金 56 (10) 619 -624 2009年10月 [査読無し][通常論文]
     
    Recently, the inductor has become an important component in order to obtain high performance of the electric devices such as mobile telephone, and further improvement of the inductor performance is needed. Especially, the inductance under superimposed DC current is one of key properties for the application using inductor. However, it is difficult to satisfy such high performance only by an improvement of the magnetic material. Therefore it is required to establish the inductor shape design technique considering with the magnetic material properties in order to improve the inductor performance. In this paper, the shape optimization method of inductor using probabilistic optimize algorithm is discussed and the availability of this method is examined through the comparison between the calculation and the experiment. As a result, ̃ 60% downsized shape can be derived from this optimization method maintaining the same performance of the original inductor.
  • 渡辺 浩太, CAMPELO Felipe, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2009 (54) 1 -4 2009年09月16日 [査読無し][通常論文]
  • 五十嵐 一, 渡邊 浩太 電気学会研究会資料. SA, 静止器研究会 2009 (54) 27 -32 2009年09月16日 [査読無し][通常論文]
  • 牧村 英俊, 渡部 雄太, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2009 (54) 33 -36 2009年09月16日 [査読無し][通常論文]
  • 本岡 雄一郎, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2009 (54) 53 -58 2009年09月16日 [査読無し][通常論文]
  • 丸山 尚之, 五十嵐 一 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム 28 (0) 345 -348 2009年06月11日 [査読無し][通常論文]
  • 牧村 英俊, 渡辺 浩太, 渡部 雄太, 五十嵐 一 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム 28 (0) 349 -352 2009年06月11日 [査読無し][通常論文]
  • 渡部 雄太, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2009 (17) 1 -5 2009年01月30日 [査読無し][通常論文]
  • 長谷 篤樹, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2009 (17) 7 -10 2009年01月30日 [査読無し][通常論文]
  • Simple Evaluation of Solution Accuracy on FEA by calculating Magnetic Flux Lines
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 1062 -1063 2009年 [査読無し][通常論文]
  • Visualization Method of Magnetic Flux Lines with Accurate Allocation Applying Tube System
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 867 -868 2009年 [査読無し][通常論文]
  • A Comparison of Parallel Finite Element Analysis Using Domain Decomposition
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 837 -838 2009年 [査読無し][通常論文]
  • Complex Adjoint Variable Method for Finite Element Analysis of Eddy Current Problems
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 695 -696 2009年 [査読無し][通常論文]
  • FDTD Analysis of UHF-band RFID for Metallic Objects
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 476 -477 2009年 [査読無し][通常論文]
  • Quality Evaluation of Automatically Generated Hexahedral Mesh for FEA
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 406 -407 2009年 [査読無し][通常論文]
  • Optimization of Inductors Using Evolutionary Algorithms and Its Experimental Validation
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 324 -325 2009年 [査読無し][通常論文]
  • FDTD Analysis of UHF-band RFID Considering Dielectric Effects
    Proceeding of 8th International Symposium on Electric and Magnetic Fields CD-ROM OB1-2 2009年 [査読無し][通常論文]
  • Optimization of Meander Line Antenna on Dielectric Substrate for UHF-band RFID
    Proceeding of 8th International Symposium on Electric and Magnetic Fields CD-ROM A2-1 2009年 [査読無し][通常論文]
  • A Robust Optimization Method Based on Adjoint Variable Method
    Proc. 8th International Symposium on Electric and Magnetic Fields CD-ROM OB2-3 2009年 [査読無し][通常論文]
  • Design of Conventiona lC-core Magnets Using a Multi-Step Optimization Procedure
    Proceedings of 17th International Conference on the Computation of Electromagnetic Fields 410 -411 2009年 [査読無し][通常論文]
  • 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2008 (49) 7 -12 2008年09月18日 [査読無し][通常論文]
  • 本岡 雄一郎, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2008 (49) 13 -17 2008年09月18日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2008 (49) 67 -70 2008年09月18日 [査読無し][通常論文]
  • 丸山 尚之, 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2008 (49) 89 -92 2008年09月18日 [査読無し][通常論文]
  • 五十嵐 一, 渡辺 浩太, 松尾 哲司, 美舩 健, 河野 健二, 飯島 洋祐 電気学会研究会資料. SA, 静止器研究会 2008 (49) 93 -98 2008年09月18日 [査読無し][通常論文]
  • 渡辺 浩太, 丸山 尚之, 五十嵐 一, 松尾 哲司, 美舩 健 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム 27 (0) 47 -50 2008年06月19日 [査読無し][通常論文]
  • Felipe Campelo, Frederico G. Guimaraes, Hajime Igarashi IEEE TRANSACTIONS ON MAGNETICS 44 (6) 982 -985 2008年06月 [査読無し][通常論文]
     
    The m-AINet is a modified version of the artificial immune network algorithm for single-objective and multimodal optimization (opt-AINet), with constraint-handling capability and improvements aiming to reduce the computational effort required by the original algorithm. In this paper we extend this algorithm for multiobjective problems by using the compromise programming approach to aggregate the objectives in the evaluation step. We adopt a compromise programming formulation that is theoretically able to map the whole Pareto front. The proposed multiobjective m-AINet is tested on the design of a loudspeaker with two objectives, showing promising results.
  • Felipe Campelo, Satoru Ota, Kota Watanabe, Hajime Igarashi IEEE TRANSACTIONS ON MAGNETICS 44 (6) 986 -989 2008年06月 [査読無し][通常論文]
     
    A new hybrid methodology for the design of engineering devices is presented in this paper. This technique employs a topology optimization (TO) algorithm in order to obtain an initial design for a given device under consideration, followed by a parameterization routine which transforms the TO solution into a parametric model. Finally, this model is further optimized by means of a parametric optimization algorithm. The whole process is executed without any user intervention, and is able to deliver innovative solutions to problems in electromagnetic design. Results obtained on the design of a C-core magnet are shown in order to illustrate the applicability of the proposed method.
  • So Noguchi, Youichi Inaba, Hajime Igarashi IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 18 (2) 762 -765 2008年06月 [査読無し][通常論文]
     
    This paper describes an optimal design method for SMES coils wound with high temperature superconducting tapes. Commonly, on the design stage of a SMES coil, its configuration is optimized to reduce the winding' volume and the weight under taking into account the electromagnetic characteristics of high temperature superconducting tapes. The better configuration can be optimally designed to taken into account its thermal characteristics. So, we propose an optimal design method for SMES coils wound with Bi2223/Ag tape taking into account both electromagnetic and thermal characteristics. In this paper, the designs of 72 MJ toroidal SMES coil are investigated using the Simulated Annealing as an optimization method and the Finite Element Method as a thermal analysis method.
  • Takayuki Maruyama, Hajime Igarashi IEEE TRANSACTIONS ON MAGNETICS 44 (6) 990 -993 2008年06月 [査読無し][通常論文]
     
    Although probabilistic optimization methods based on genetic algorithm (GA) provides accurate results, its performance is sometimes considerably sensitive to parameter changes. Moreover, the constraints are violated due to such parameter changes. A robust GA which performs random perturbation during optimization processes has been applied to some mathematical problems to show that it works as fast as the usual GAs. An adequate elite reservation technique for the robust GA is presented and applied to the robust GA for electromagnetic problems. Moreover, this method is shown to find solutions which are kept feasible against parameter changes.
  • Hajime Igarashi, Nobito Yamamoto IEEE TRANSACTIONS ON MAGNETICS 44 (6) 942 -945 2008年06月 [査読無し][通常論文]
     
    This paper discusses mathematical properties of preconditioned finite-element matrices based on vector potential formulation (A method) and vector and scalar potential formulation (A-V method) for eddy-current problems. Numerical results show that A-V method with preconditioning is stable at all frequencies in contrast to A method. In this paper, this property is mathematically discussed by considering the diagonal scaling which is one of the simple preconditioning methods. In addition, regularization of A method is discussed.
  • 平畠 将士, 野口 聡, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2008 (13) 7 -12 2008年01月24日 [査読無し][通常論文]
  • 丸山 尚之, 五十嵐 一 電気学会研究会資料. MAG, マグネティックス研究会 2008 (13) 13 -18 2008年01月24日 [査読無し][通常論文]
  • Robustness of Nested Multigrid Method for Edge-based Finite Element
    Proc. CEFC2008 PA1-18 2008年 [査読無し][通常論文]
  • Hybrid Estimation of Distribution Algorithm Using Local Function Approximations
    Proc. CEFC2008 PF2-6 2008年 [査読無し][通常論文]
  • A Spectral Topology Optimization Approach to the Design of Magnetic
    Proc. CEFC2008 PD3-18 2008年 [査読無し][通常論文]
  • Allocation Method of Magnetic Flux Lines Applying Tube System for
    Proc. CEFC2008 PC1-19 2008年 [査読無し][通常論文]
  • Finite-Difference Time-Domain Analysis of Waveguide Slot Antenna
    Proc. CEFC2008 OC2-3 2008年 [査読無し][通常論文]
  • A Reliability Analysis of Electromagnetic Devices Using Surrogate Model
    Proc. CEFC2008 PB4-7 2008年 [査読無し][通常論文]
  • On Uncertainty Analysis of Three-Dimensional Magnetostatic Systems
    Proc. CEFC2008 PC1-8 2008年 [査読無し][通常論文]
  • 電磁界解析のアプローチと特徴
    シミュレーション学会誌 27 (3) 140 -148 2008年 [査読無し][通常論文]
  • Ralf T. Jacobs, Arnulf Kost, Hajime Igarashi, Alan J. Sangster COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 27 (1) 110 -121 2008年 [査読無し][通常論文]
     
    Purpose - The purpose of this paper is the analysis of the radiation and impedance characteristics of cavity backed patch antennas embedded in a curved surface. Single patch elements and small scale array antennas are considered. The impact of curvature on the performance of the patch antenna is investigated, and the effect of mutual coupling between the elements in an array is examined. Design/methodology/approach - A finite element-boundary integral procedure has been implemented to accurately determine the performance characteristics of the patch radiators on planar and cylindrical surfaces. Simulated results will be shown to be in good agreement with measurements. Findings - Mutual coupling effects between array elements are examined and it can be observed that an active element primarily interacts with the nearest neighbour elements. A comparison of an array element with a single patch radiator shows that the mutual coupling effects cause no significant mismatch between a patch and a feed network in practical applications. Originality/value - The characteristics of conformal microstrip antennas are investigated for single patch radiators and patch elements in array environments. Simulations are supported by measurements.
  • Takayuki Maruyama, Hajime Igarashi INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 28 (1-2) 177 -185 2008年 [査読無し][通常論文]
     
    Robust optimization searches for optimal solutions which remain feasible under the effect of uncertainties. The conventional robust optimization, however, often requires great computational cost to find robust solutions. This paper introduces a novel robust optimization method based on genetic algorithm. In this method, individuals with "good" performance are selected and tested for their robustness for reduction of computational time. It is shown that the present method works in shorter time in comparison with the conventional robust optimization.
  • Felipe Campelo, Kota Watanabe, Hajime Igarashi INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 28 (1-2) 187 -192 2008年 [査読無し][通常論文]
     
    Topology optimization (TO) is a promising field for the design of industrial devices, since it can allow computational tools to develop creative solutions independently of initial topologies. However, the generation of smooth solutions, i.e., solutions that can be physically implemented, remains a challenge for most TO techniques available. In this paper, we discuss a set of operators that allow smoother topologies to be generated by an evolutionary topology optimization algorithm based on the artificial immune systems paradigm. The design of an electromagnetic device is used as a test case for the proposed methodology.
  • 電磁界解析のための前処理付き並列クリロフ部分空間法
    計算数理工学論文集 239 2008年 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2007 (54) 21 -24 2007年09月20日 [査読無し][通常論文]
  • 藤原 耕二, 亀有 昭久, 若尾 真治, 高橋 康人, 五十嵐 一, 松尾 哲司, 岩下 武史, 村松 和弘, 岡本 吉史, 山田 隆, 河瀬 順洋, 山崎 克巳, 平田 勝弘 電気学会研究会資料. SA, 静止器研究会 2007 (54) 91 -97 2007年09月20日 [査読無し][通常論文]
  • 北村 正司, 田島 文男, 赤見 裕介, 内海 典之, 李 友行, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2007 (17) 69 -73 2007年01月26日 [査読無し][通常論文]
  • 藤森 寛朝, 野口 聡, 五十嵐 一, 山下 英生 電気学会研究会資料. SA, 静止器研究会 2007 (1) 13 -18 2007年01月25日 [査読無し][通常論文]
  • 渡辺 浩太, CAMPELO Felipe, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2007 (1) 19 -24 2007年01月25日 [査読無し][通常論文]
  • 平畠 将士, 野口 聡, 五十嵐 一, 山下 英生 電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society 127 (11) 12 -1212 2007年 [査読無し][通常論文]
     
    This paper presents analytical calculation of magnetic flux line from hexahedral edge finite element analysis and its allocation using the Bubble System for visualization. Most of methods to draw magnetic flux lines can't take their distribution into sufficient consideration. As a result, such visualizations bring out observer's misunderstanding about the magnetic field and the phenomenon. Therefore, the method to appropriately allocate the magnetic flux lines in a space using the Bubble System is proposed. In the proposed method, the bubble's radius of the Bubble System depends on the magn...
  • Topology Optimization with Smoothness Considerations
    Proceedings of ISEM2007 303 2007年 [査読無し][通常論文]
  • Reduction of Computational Time for Robust Geneteic Algorithm
    Proceedings of ISEM 301 2007年 [査読無し][通常論文]
  • Generating Parametric Design Models Using Information from Multimodal Topology Optimization
    Proceedings of COMPUMAG2007 961 2007年 [査読無し][通常論文]
  • An Effective Robust Optimization Based on Genetic Algorithm
    Proceedings of COMPUMAG2007 951 2007年 [査読無し][通常論文]
  • Multiobjective Optimization Using Compromise Programming and an Immune Algorithm
    Proceedings of COMPUMAG2007 949 2007年 [査読無し][通常論文]
  • Computation of the Scattering Parameters of a Slot Antenna using FE-BI/FMM
    Proceedings of COMPUMAG2007 507 2007年 [査読無し][通常論文]
  • Allocation Method of Magnetic Flux Lines Using Bubble System for Magnetic Field Visualization
    Proceedings of COMPUMAG2007 81 2007年 [査読無し][通常論文]
  • On effect of preconditioning in edge-based finite element method
    Proceedings of COMPUMAG2007 73 2007年 [査読無し][通常論文]
  • 電磁界解析法の最近の動向
    電気学会誌 711 2007年 [査読無し][通常論文]
  • A Parallel Preconditioned Conjugate Gradient Method for FEM
    Proceedings of COMPUMAG2007 71 2007年 [査読無し][通常論文]
  • 野口 聡, 五十嵐 一, 石山 敦士, 柳 長門, 今川 信作 低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity 75 (0) 2006年11月15日 [査読無し][通常論文]
  • 平畠 将士, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2006 (58) 7 -12 2006年08月24日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2006 (58) 25 -29 2006年08月24日 [査読無し][通常論文]
  • 丸山 尚之, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2006 (58) 37 -42 2006年08月24日 [査読無し][通常論文]
  • 栗林 夏城, 五十嵐 一, 本間 利久 電気学会研究会資料. SA, 静止器研究会 2006 (16) 35 -42 2006年01月27日 [査読無し][通常論文]
  • 亀有昭久, 五十嵐一, 若尾真治, 野口聡, 池田文昭, 石橋一久, 榎園正人, 遠藤久, 大場彰人, 金井靖, 金山寛, 神谷淳, 河本正, 久保武春, 結石友宏, 島崎真昭, かん浩司, 坪井始, 徳増正, 徳良晋, 西口磯春, 羽野光夫, 房安浩嗣, 藤原耕二, 本間利久, 松田哲也, 松原克夫, 村松和弘, 宮田健治, 森田克明, 山下英生, 黄こう宇, 松尾哲司, 美船健, 山田隆, 岩下武史, 島田茂樹, 大神光司, 浜田昌司, 瀬島紀夫 電気学会技術報告 (1043) 120P 2006年01月05日 [査読無し][通常論文]
  • 3D Topology Optimization Using an Immune Algorithm
    Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering 132 2006年 [査読無し][通常論文]
  • On robustness of edge-based FE analysis using algebraic multigrid method
    Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering 90 2006年 [査読無し][通常論文]
  • Automatic Generation of Robust Analogue Filters Using Genetic Algorithm
    Proc. 9th Workshop on Optimization and Inverse Problems in Electromagnetism 201 2006年 [査読無し][通常論文]
  • K. Watanabe, F. Campelo, H. Igarashi 12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006 47 2006年 [査読無し][通常論文]
     
    This paper describes topology optimization of electromagnetic systems using the multi-grid method. The present topology optimization employs uniform rectangular finite elements, in which the multi-grid method effectively works as a fast linear solver. Moreover, the present method uses a new optimization algorithm, based on the artificial immune systems paradigm, in which multi-level search is carried out. ©2006 IEEE.
  • Optimization of Cost Functions Using Evolutionary Algorithms With Local Learning and Local Search
    Proc. Twelfth Biennial IEEE Conference on Electromagnetic Field Computation 165 2006年 [査読無し][通常論文]
  • S. Ota, F. Campelo, H. Igarashi 12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006 163 2006年 [査読無し][通常論文]
     
    This paper describes methods for acquisition of useful knowledge from optimization results of electromagnetic systems. Optimization of those systems on the basis of field computation often yields many quasi-optimal solutions which satisfy given criterion. In this study, such solutions are classified into clusters using the hierarchic method, principal component analysis and self-organizing map to extract useful knowledge for designers about them. ©2006 IEEE.
  • An Automatic Hexhedral Mesh Generation to Control Shape of Elements
    Proc. Twelfth Biennial IEEE Conference on Electromagnetic Field Computation 53 2006年 [査読無し][通常論文]
  • K. Watanabe, H. Igarashi 12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006 48 2006年 [査読無し][通常論文]
     
    This paper describes a liner solver for finite element analyses on parallel computers. The present method of parallel computation is based on the overlapping domain decomposition. This lead to the improvement of convergence as well as reduction of the communication cost between processor elements. The numerical results show that this method has good convergence in the eddy current analysis. © 2006 IEEE.
  • A Topology Optimization Method Based on Immune Algorithm and Multi-Grid Method
    Proc. 9th Workshop on Optimization and Inverse Problems in Electromagnetism 187 2006年 [査読無し][通常論文]
  • 川和田 伸樹, 野口 聡, 五十嵐 一, 石山 敦士, 柳 長門, 今川 信作 低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity 73 (0) 2005年11月21日 [査読無し][通常論文]
  • 五十嵐 一 計算力学講演会講演論文集 2005 (18) 643 -644 2005年11月17日 [査読無し][通常論文]
  • 渡辺浩太, 野口聡, 五十嵐一 電気学会全国大会講演論文集 2005 (5) 5.S11(5)-5.S11(8) 2005年03月17日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一 計算数理工学レビュー 2005 (1) 1 -10 2005年03月 [査読無し][通常論文]
  • CAMPELO Felipe, 野口 聡, 五十嵐 一 電気学会研究会資料. SA, 静止器研究会 2005 (1) 51 -56 2005年01月27日 [査読無し][通常論文]
  • 和木 浩, 五十嵐 一, 本間 利久 電気学会論文誌. A, 基礎・材料・共通部門誌 = The transactions of the Institute of Electrical Engineers of Japan. A, A publication of Fundamentals and Materials Society 125 (4) 309 -316 2005年 [査読無し][通常論文]
     
    This paper describes an effective analysis of magnetic shielding based on homogenization. The analyses become time-consuming if the problems include the magnetic substances having fine structure. The homogenization of the structure makes it possible to analyze effectively the magnetic fields. The authors introduce a method to estimate the effective permeability of the homogenized substance. This method can be applied to any periodic structure made of magnetic substance. The magnetic shielding effects by the structures against direct-current (DC) fields generated by electric railways are ana...
  • An Analysis of Magnetic Shielding Effect of Layered Shields Based on Homogenization
    Proc. COMPUMAG-2005 vol.3 224 2005年 [査読無し][通常論文]
  • Robust Optimization using the Real-coded Clonal Selection Algorithm
    Proc. COMPUMAG-2005 1 58 -59 2005年 [査読無し][通常論文]
  • Convergence of Geometric Multigrid Method for Electromagnetic Field Analysis
    ", Proc. 12th Int. Sympo. Interdisciplinary Electromagnetic, Mechanic and Biomedical Problems 444-445-445 2005年 [査読無し][通常論文]
  • A Multi-Objective Proposal for the TEAM Benchmark Problem 22
    Proc. COMPUMAG-2005 vol.2 270 2005年 [査読無し][通常論文]
  • A Multigrid Method for Large Scale FE Analysis with Effective Memory Usage
    Proc. COMPUMAG-2005 vol.3 82 2005年 [査読無し][通常論文]
  • A Reduced Model for Finite Element Analysis of Steel Laminations
    Proc. COMPUMAG-2005 1 6 -7 2005年 [査読無し][通常論文]
  • Using Self-Organizing Maps for Decision Making in Multiobjective Optimization
    Proc. COMPUMAG-2005 vol.2 62 2005年 [査読無し][通常論文]
  • A Modified Immune Network Algorithm for Multimodal Electromagnetic Problems
    Proc. COMPUMAG-2005 vol.1 60 2005年 [査読無し][通常論文]
  • 本間 利久, 上田 英典, 渡辺 浩太, 五十嵐 一, 福田 正己 自然災害科学 23 (3) 344 -347 2004年11月30日 [査読無し][通常論文]
  • 島津 洋一郎, 大貫 惣明, 小林 幸徳, 蟹江 俊仁, 五十嵐 一 工学・工業教育研究講演会講演論文集 16 473 -474 2004年07月30日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一, 本間 利久 電気学会研究会資料. RM, 回転機研究会 2004 (68) 13 -16 2004年07月08日 [査読無し][通常論文]
  • 和木 浩, 五十嵐 一, 本間 利久 電気学会研究会資料. RM, 回転機研究会 2004 (68) 61 -66 2004年07月08日 [査読無し][通常論文]
  • Watanabe, K., Sato, K., Igarashi, H., Honma, T., "Post Processing for Large Scale Finite Element Analysis using Java Servlet and VRML", Computational Engineering I, JASCOME, 141-146 (2004)*
    2004年 [査読無し][通常論文]
  • Igarashi, H., Yamamoto, A., Honma, T., "A Learnable Mesh Generation Technique Based on Genetic Algorithm", Computational Engineering I, JASCOME, 299-305 (2004)*
    2004年 [査読無し][通常論文]
  • Watanabe, K., Igarashi, H., "On robustness of edge-based FE analysis using algebraic multigrid method", Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering, 90-95 (2004)*
    2004年 [査読無し][通常論文]
  • Jacobs, R.T., Kost, A., Igarashi, H., Honma, T., Sangster, A.J., "Analysis of the Radiation Characteristics of Conformal Microstrip Antennas, Proc. 11th Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2004), 280 (2004)*
    2004年 [査読無し][通常論文]
  • Waki, H., Igarashi, H., Honma, T., "Estimation of Effective Permeability of Magnetic Composite Materials", Proc. 11th Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2004), 86 (2004)*
    2004年 [査読無し][通常論文]
  • Campelo, F., Guimareas, F.G., Saldanha, R.R., Takahashi, R.H.C., Igarashi, H., Noguchi, S., "A novel multiobjective immune algorithm using nondominated sorting", Proc. the 11th international IGTE symposium on numerical field calculation in electrical e・・・
    2004年 [査読無し][通常論文]
     
    Campelo, F., Guimareas, F.G., Saldanha, R.R., Takahashi, R.H.C., Igarashi, H., Noguchi, S., "A novel multiobjective immune algorithm using nondominated sorting", Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering, 308-313 (2004)*
  • 「均質化手法による磁気シールドの解析」
    電気学会研究会資料 SA-04-55 2004年 [査読無し][通常論文]
  • Igarashi, H., Yamamoto, A., "A mesh generation method using machine learning based on genetic algorithm", Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering, 133-137 (2004)*
    2004年 [査読無し][通常論文]
  • Waki, H., Igarashi, H., Honma, T., "An analysis of magnetic shielding against DC power lines based on homogenization", Proc. the 11th international IGTE symposium on numerical field calculation in electrical engineering, 272-275 (2004)*
    2004年 [査読無し][通常論文]
  • Watanabe, K., Igarashi, H. Honma, T., "Comparison of Geometric and Algebraic Multigirid Methods in Edge-based FE Analysis", Proc. 11th Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2004), 107 (2004)*
    2004年 [査読無し][通常論文]
  • Waki, H., Igarashi, H., Honma, T., "Modeling of Reinforced Concrete Structures for Analysis of Environmental Magnetic Fields", Computational Engineering I, JASCOME, 117-124 (2004)*
    2004年 [査読無し][通常論文]
  • Igarashi, H., "Visualization of Quasi-optimal Solutions in Stochastic Optimization", Proc. 11th Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2004), 398 (2004)*
    2004年 [査読無し][通常論文]
  • 五十嵐 一, 本間 利久 数理解析研究所講究録 1320 (0) 171 -178 2003年05月 [査読無し][通常論文]
  • K. Watanabe, H. Igarashi and T. Honma: "Convergence of Multigrid Finite Element Method in Eddy Current Analysis", Proc. Applied Computational Electromagnetics Society (ACES) Conference, 775-778, (2003)*
    2003年 [査読無し][通常論文]
  • Spectra of Finite Element Matrix for Magnetostatic and Quasi-static Electromagnetic Fields
    H. Igarashi, T. Honma Proc. Applied Computational Electromagnetics Society (ACES) Conference 779 -782 2003年 [査読無し][通常論文]
  • K. Watanabe, H. Igarashi and T. Honma: Investigation of Parallel Multigrid Mathod Using Java Language, , COMPUMAG-Saratoga, Proc. vol.4, 34-35 (2003).*
    2003年 [査読無し][通常論文]
  • H. Igarashi, K. Watanabe, T. Ito, T. Fukuda and T. Honma: A Finite Element Analysis of Surface Wave Plasmas, Proc. COMPUMAG-Saratoga, vol.4, 48-49 (2003)*
    2003年 [査読無し][通常論文]
  • H. Igarashi, A. Yamamoto and T. Honma: Mesh Generation Based on Machine Learning, Proc. COMPUMAG-Saratoga, vol.1, 28-29 (2003)*
    2003年 [査読無し][通常論文]
  • H. Igarashi, K. Ooi and T. Honma: Magnetostatic Permeability Tomography, Proc. COMPUMAG-Saratoga, vol.1, 126-127 (2003)*
    2003年 [査読無し][通常論文]
  • 若尾 真治, 五十嵐 一, 藤原 耕二, 亀有 昭久 電気学会研究会資料. RM, 回転機研究会 2002 (58) 37 -42 2002年09月02日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一, 本間 利久 電気学会研究会資料. RM, 回転機研究会 2002 (58) 49 -52 2002年09月02日 [査読無し][通常論文]
  • 五十嵐 一, 福田 鉄平, 本間 利久 電気学会研究会資料. RM, 回転機研究会 2002 (58) 77 -82 2002年09月02日 [査読無し][通常論文]
  • 五十嵐 一, 大井 健太郎, 本間 利久 電気学会研究会資料. RM, 回転機研究会 2002 (58) 95 -100 2002年09月02日 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一, 本間 利久 数理解析研究所講究録 1288 (0) 115 -121 2002年09月 [査読無し][通常論文]
  • 「表面波プロセスプラズマのFDTD解析」<平成14年度電気関係学会北海道支部連合大会,北見>
    2002年 [査読無し][通常論文]
  • 「フライホイールにおける渦電流場の有限要素解析」<平成14年度電気関係学会北海道支部連合大会,北見>
    2002年 [査読無し][通常論文]
  • 「2次辺要素を用いた有限要素行列の条件数について」<平成14年度電気関係学会北海道支部連合大会,北見>
    2002年 [査読無し][通常論文]
  • "計算電磁気学と逆問題手法による構造材の欠陥診断"
    電気学会静止器回転機合同研究会 SA-02-38 RM-02-74 2002年 [査読無し][通常論文]
  • "電磁界数値解析で役立つ解析積分公式集(その1)"
    電気学会静止器回転機合同研究会 SA-02-28 RM-02-64 2002年 [査読無し][通常論文]
  • 3次元静磁場有限要素法解析におけるマルチグリッド法のメッシュ依存性について
    第14回電磁力のダイナミクスシンポジウム講演論文集 93 -96 2002年 [査読無し][通常論文]
  • "駆動源のある高周波問題の有限要素解析-ICCGの収束性-"
    電気学会静止器回転機合同研究会 SA-02-35 RM-02-71 2002年 [査読無し][通常論文]
  • Igarashi, H. and Honma, T.:"Convergence of Conjugate Gradient Method Applied to Driven Microwave Problems", Proc. CEFC-Perugia, 265(2002)*
    2002年 [査読無し][通常論文]
  • 第51回理論応用力学講演会講演論文集 621 -622 2002年 [査読無し][通常論文]
  • 「静磁界による材料中の透磁率の同定」<平成14年度電気関係学会北海道支部連合大会,北見>
    2002年 [査読無し][通常論文]
  • 「磁気ヘッドのアダプティブ有限要素解析」<平成14年度電気関係学会北海道支部連合大会,北見>
    2002年 [査読無し][通常論文]
  • Javaを用いたプラズマ粒子シミュレーション
    第14回電磁力のダイナミクスシンポジウム講演論文集 97 -100 2002年 [査読無し][通常論文]
  • "電磁界解析におけるマルチグリッド法の有限要素法への適用について"
    京都大学数理解析研究所講究録1288 115 -121 2002年 [査読無し][通常論文]
  • 電磁界解析におけるマルチグリッド法の有限要素法への適用について
    115 -121 2002年 [査読無し][通常論文]
  • 高周波電磁界解析における有限要素行列のスペクトル
    平成14年電気学会全国大会 3 (26-29/) 5 -165 2002年 [査読無し][通常論文]
  • "マルチグリッド法を用いた有限要素法の渦電流解析への適用"
    電気学会静止器回転機合同研究会 SA-02-30 RM-02-66 2002年 [査読無し][通常論文]
  • Watanabe, K., Igarashi, H. and Honma, T.:"Convergence of Multigrid Method for Edge-based FEM", Proc. CEFC-Perugia, 76(2002)*
    2002年 [査読無し][通常論文]
  • 「格子ガスオートマトン法による流体解析」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「Pulsed Plasma Thruster(PPT)における電流層の数値シミュレーション」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「要素形状によるマルチグリッド法の収束性に関する検討」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「電磁粒子シミュレーションによる ビームプラズマ不安定性に関する研究」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「PPT(パルス型プラズマスラスタ)プラズマの1次元解析」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • Igarashi, H. and Honma T., "On the Convergence of ICCG Applied to Finite Element Equation for Quasi-Static Fields", Proc. COMPUMAG-Evian, II, 204-205 (2001)*
    2001年 [査読無し][通常論文]
  • Igarashi, H., "On Identification of Magnetic Sources in Materials", Proc. ISIP2001, 202 (2001)*
    2001年 [査読無し][通常論文]
  • 「電磁鋼板の磁区解析‐基礎検討‐」
    電気学会研究会資料 MAG-01-226 2001年 [査読無し][通常論文]
  • 「簡易モデルによるPPT(Pulsed Plasma Thruster)の解析」<原子力学会北海道支部第19回研究発表講演会,札幌>
    2001年 [査読無し][通常論文]
  • 「電気的テザーシステムの性能解析」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「有限要素法におけるマルチグリッド法の収束性について」
    電気学会研究会資料 SA-01-9 (RM-01-77) 2001年 [査読無し][通常論文]
  • 「渦電流解析における有限要素法の性質について」
    電気学会研究会資料 SA-01-07 (RM-01-75) 2001年 [査読無し][通常論文]
  • 「マルチグリッド法を用いたFEMによる3次元静磁場検証モデルの解析」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • 「超伝導テープ線材の微視的解析」<平成13年度電気関係学会北海道支部連合大会,札幌>
    2001年 [査読無し][通常論文]
  • Igarashi, H. and Honma, T., "Property of Second Order Edge Elements in a Class", Proc. ISEM-Tokyo, 243-244 (2001)*
    2001年 [査読無し][通常論文]
  • Igarashi, H., Kost, A. and Honma, T., "Reconstruction of Planar Magnetic Charge Distribution, Proc. ISEM-Tokyo, 621-622 (2001)*
    2001年 [査読無し][通常論文]
  • Igarashi, H. and Honma T., "A Direct Reconstruction of Magnetic Charge for Non-Destructive Testing", Proc. ENDE, 47-48 (2001)*
    2001年 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一, 本間 利久 電気学会基礎・材料・共通部門大会講演論文集 = Proceeding of Annual Conference of Fundamentals and Materials Society, IEE Japan 2000 (0) 2000年09月07日 [査読無し][通常論文]
  • An Inverse Analysis of Permanent Magnets in Motors
    H. Igarashi, A. Kost, T. Honma Digest of the 9th Biennial IEEE Conference of Electromagnetic Field Computation-CEFC2000 445 2000年 [査読無し][通常論文]
  • Bastos, J.A., Kost, A., Jaenicke, L., Sadowski, N. and Igarashi, H. :"Using Very Flat Finite Elements for Plate Shielding Considering Nonlinearity", Proc. ICEF2000: 55-58 (2000)
    2000年 [査読無し][通常論文]
  • Igarashi, H.:"Finite Elements, Circuit Theory and Homology", Proc. JSST2000 Int. Conf. on Modeling, Control and Computation in Simulation: 35-38 (2000)
    2000年 [査読無し][通常論文]
  • 五十嵐 一, 本間 利久, 吉川 智之 シンポジウム電磁力関連のダイナミックス講演論文集 11 (0) 313 -315 1999年10月13日 [査読無し][通常論文]
  • Kost, A. and Igarashi, H. : "Different Numerical Methods for Electromagnetic Field Computation with Thin Shielding Sheets", Proc. IEEE Int. Symposium on Electromagnetic Compatibility, 248-253 (1997)*
    1997年 [査読無し][通常論文]
  • 渡辺 浩太, 五十嵐 一, 本間 利久 電気学会研究会資料. RM, 回転機研究会 1995 (63) 1 -10 1995年08月29日 [査読無し][通常論文]
  • 坪田 圭介, 五十嵐 一, 本間 利久 電気学会研究会資料. RM, 回転機研究会 1995 (63) 11 -20 1995年08月29日 [査読無し][通常論文]
  • 本間 利久, 五十嵐 一, 槌本 昌則 数理解析研究所講究録 744 (0) 239 -247 1991年02月 [査読無し][通常論文]

特許

  • 特願2017-223831:形状最適化結果表示方法及びその装置  2017年11月21日
    五十嵐 一
  • 特願2017-223830:形状最適化結果表示方法及びその装置  2017年11月21日
    五十嵐 一
  • 特許5697233:環境情報計測装置,環境情報計測システム,及び環境情報計測方法    2015年02月20日
    五十嵐 一
  • 特願2014-144653:埋め込み型永久磁石回転機  2014年07月15日
    五十嵐 一
  • インダクタの設計方法
    特開2010-62200

受賞

  • 2019年05月 電気学会 電子・情報・システム部門貢献賞
     
    受賞者: 五十嵐 一
  • 2017年10月 日本AEM学会 功労賞
     
    受賞者: 五十嵐 一
  • 2016年04月 電気学会 電気学術振興賞(論文賞)
     
    受賞者: 五十嵐 一
  • 2016年04月 文部科学省 科学技術分野の文部科学大臣表彰科学技術賞(開発部門)
     
    受賞者: 五十嵐 一
  • 2015年10月 日本シミュレーション学会 論文賞
     
    受賞者: 五十嵐 一
  • 2003年 日本AEM学会 著作賞
     「計算電磁力学」 
    受賞者: 五十嵐 一

共同研究・競争的資金等の研究課題

  • トポロジー最適化による永久磁石モータの新しい3次元構造の創出
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2021年04月 -2024年03月 
    代表者 : 五十嵐 一
  • トポロジー最適化と深層学習の共進化による回転機の高速最適設計の実現
    日本学術振興会:科学研究費補助金 挑戦的研究(萌芽)
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 五十嵐 一
  • ハルバッハアレー振動発電機によるインフラ構造物状態モニタリングの実現
    日本学術振興会:科学研究費補助金(基盤研究(B))
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 五十嵐 一
  • 文部科学省:科学研究費補助金(基盤研究(B))
    研究期間 : 2015年 -2017年 
    代表者 : 五十嵐 一
  • モデル縮約による電磁機器の高速3次元最適化の実現
    日本学術振興会:科学研究費補助金 挑戦的萌芽研究
    研究期間 : 2013年04月 -2016年03月 
    代表者 : 五十嵐 一
  • 環境電磁波のエネルギーで動作する無線センサの開発
    日本学術振興会:二国間交流事業共同研究
    研究期間 : 2013年04月 -2015年03月 
    代表者 : 五十嵐 一
  • 社会インフラの遠隔安全監視を行う振動発電式セミパッシブ無線センサ
    日本学術振興会:科学研究費補助金 基盤研究(B)
    研究期間 : 2012年04月 -2015年03月 
    代表者 : 五十嵐一
  • インフラ安全監視を行う無電源作動ワイヤレスセンサー
    日本学術振興会:科学研究費補助金 基盤研究(C)
    研究期間 : 2009年 -2011年 
    代表者 : 五十嵐 一
  • 発見的最適形状アルゴリズムを用いたインダクタ設計技術の構築
    科学技術振興機構:産学協同イノベーション化事業「顕在化ステージ」A-STEP
    研究期間 : 2007年07月 -2008年06月 
    代表者 : 五十嵐 一
  • Computational Electromagnetism, Soft Computing, System Simulation
    研究期間 : 1989年

教育活動情報

主要な担当授業

  • システム融合学特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学研究科
    キーワード : パワーエレクトロニクス,電力システム,電磁界解析,ヒューマノイドロボット
  • 電磁工学特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学研究科
    キーワード : 偏微分方程式,電磁界解析,有限要素法,差分法,システム最適化,可視化
  • 電磁工学特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学院
    キーワード : 偏微分方程式,電磁界解析,有限要素法,差分法,システム最適化,可視化
  • システム融合学特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学研究科
    キーワード : パワーエレクトロニクス,電力システム,電磁界解析,ヒューマノイドロボット
  • 電磁工学特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学研究科
    キーワード : 偏微分方程式,電磁界解析,有限要素法,差分法,システム最適化,可視化
  • 電磁工学特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学院
    キーワード : 偏微分方程式,電磁界解析,有限要素法,差分法,システム最適化,可視化
  • ソフトコンピューティング
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 確率統計,機械学習,人工知能,ベイズ識別,パターン認識,Parzen窓,カーネル密度推定法,サポートベクターマシン,クラスタリング,主成分分析,特異値分解,脳情報処理,ニューラルネットワーク,深層記憶,連想記憶,遺伝的アルゴリズム,焼きなまし法
  • 応用電磁気学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 誘電体,分極,コンデンサ,磁性体,磁気ヒステリシス,インダクタ,リアクトル,誘導加熱,うず電流,表皮効果,近接効果,非接触給電,電磁波,ポインティングベクトル,電磁界解析,有限要素法,伝送線路,伝送方程式,特性インピーダンス,インピーダンス整合
  • 計算知能工学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 確率統計,機械学習,人工知能,ベイズ識別,パターン認識,Parzen窓,カーネル密度推定法,サポートベクターマシン,クラスタリング,主成分分析,特異値分解,脳情報処理,ニューラルネットワーク,深層記憶,連想記憶,遺伝的アルゴリズム,焼きなまし法
  • 科学技術英語演習
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 科学技術英語 英語論文 英語プレゼンテーション
  • 電気制御システム演習Ⅰ
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 電気回路学,線形システム,電磁気学,最適化理論,システムデザイン

大学運営

委員歴

  • 2014年12月 - 現在   日本AEM学会   論文委員会委員長 理事
  • 2007年 - 現在   International COMPUMAG Society   International COMPUMAG Society, Vice President
  • 2017年09月 - 2018年09月   電気学会   平成30年電子・情報・システム大会委員会 副実行委員長,現地実行委員長
  • 2016年03月 - 2018年03月   電気学会   北海道支部長 理事
  • 2013年04月 - 2016年03月   電気学会   電気学会先進電磁界解析による設計高度化技術調査専門委員会委員長
  • 2009年   日本AEM学会   第19回MAGDAコンファレンス in 札幌 実行委員長   日本AEM学会
  • 2008年   平成21年電気学会全国大会実行委員長
  • 2006年   日本シミュレーション学会   電磁界解析プログラムの並列化技術研究委員会幹事   日本シミュレーション学会

その他

  • 2015年09月 - 2015年09月  ISEM2015 OS オーガナイザ 
    オーガナイズドセッション オーガナイザ
  • 2014年12月 - 2014年12月  MAGDAシンポジウム OS オーガナイザ 
    オーガナイズドセッション オーガナイザ
  • 2014年11月 - 2014年11月  JSST2015 OS オーガナイザ 
    オーガナイズドセッションのオーガナイザ


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