ジャーナル

  1. Naoya Okamura, Masataka Ishihara, Kazuhiro Umetani, Kotaro Kobashi, Hiroto Sakai, Yuta Okawauchi, Takuto Hayashi, Eiji Hiraki, “ Measurement-Based Parasitic Inductance Network Identification for Multichip Power Modules Based on Inductance Matrix of Loop Wiring Paths,” IEEE Access, vol. 14, pp. 82069 - 82080, 28 May 2026.

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  2. Masataka Ishihara, Kodai Matsuura, Akihiro Konishi, Kazuhiro Umetani, Eiji Hiraki, “ Multiple Transmitters with Controlled Amplitude and Phase of Transmitter Currents to Eliminate Cross-Interference Effects for Large-Area Wireless Power Transfer Systems,” IEEJ JOURNAL OF INDUSTRY APPLICATIONS, vol. 15, Issue 3, pp. 385-396, 2026.

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  3. Aoi Oyane, Kazuhiro Umetani, Eiji Hiraki, “ Load Observing System Based on Wave Reflection for Soft-Switching Control of MHz-Frequency Resonant Inverter Against Load Fluctuations,” IEEE Access, vol. 13, pp. 127126 - 127141, 10 July 2025.

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  4. Kazuhiro Umetani, Yu Takehara, Masataka Ishihara, and Eiji Hiraki, “ GaN-HEMT power module of aluminum-clad printed circuit boards for small power loop inductance and high cooling performance,” IEEE Trans. Power Electron., vol. 39, no. 10, pp. 12047–12052, Oct. 2024.

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  5. Masataka Ishihara, Kazuhiro Umetani, Akihiro Konishi, and Eiji Hiraki, “ Feasibility of active reactance compensator for autonomously maximizing repeater coil current of wireless power transfer system against variations in resonant frequency and magnetic coupling intensity,” IEEE Access, vol. 12, pp. 98175–98188, Jul. 2024.

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  6. 小西晃央，石原將貴，梅谷和弘，平木英治, “ 非接触給電用中継共振器の共振周波数自律調整回路のためのリアクタンス補償量探索範囲を拡張する新制御方式 ,”パワーエレクトロニクス学会誌，第48巻 (2023).

  7. Akihiro Konishi, Kazuhiro Umetani, Masataka Ishihara,and Eiji Hiraki, “Autonomous Resonant Frequency Tuner for a 6.78MHz Inductive Coupling Wireless Power Transfer System to Stably Maximize Repeater Current (in-press),”電気学会 英文論文誌D, Vol. 12, No. 2 (2023), pp. 215-227, March. 2023.

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  8. T. Kusumi, K. Kobayashi, K. Umetani, and E. Hiraki, “Analytical derivation of phase-current waveform for elimination of torque and input-current ripples of switched reluctance motor operating under magnetic saturation,” IEEE Trans. Ind. Appl., vol. 58, no. 4, pp. 5248-5261, July-Aug. 2022.

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  9. T. Kawakami, K. Yamada, K. Umetani, and S. Morimoto, “Design and analysis of power balance mode control using digital control for boost-type dc-dc converter,” IEEJ Trans. Elect. Electron. Eng., vol. 17, no. 5, pp. 739-748, Feb. 2022.

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  10. H. Senshu, T. Mizuno, K. Umetani, T. Nakura, A. Konishi, A. Ogawa, H. Ikeda, K. Matsumoto, H. Noda, Y. Ishihara, S. Sasaki, N. Tateno, Y. Ikuse, K. Mayuzumi, T. Kase, and H. Kashine, “Light detection and ranging (LIDAR) laser altimeter for the martian moons exploration (MMX) spacecraft,” Earth, Planets and Space, vol. 73, 219, Dec. 2021.

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  11. M. Ishihara, K. Fujiki, K. Umetani, E. Hiraki, “Autonomous system concept of multiple-receiver inductive coupling wireless power transfer for output power stabilization against cross-interference among receivers and resonance frequency tolerance”, IEEE Trans. Industry Applications., vol. 57, no. 4, pp. 3898–3910, Aug. 2021.

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  12. O. Lucia, J. She, V. Huang, A. Chen, S. Yokota, M. Chow, Z. Cheng, L. Dunai, K. Umetani, M. Hilairet, and E. Monmasson,“Emerging trends in industrial electronics: A cross disciplinary view,” IEEE Ind. Electron. Mag., vol. 15, no. 1, pp. 127–139, Mar.2021.

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  13. O. Lucia, J. Martins, Y. Ibrahim, K. Umetani, L. Gomes, H. Zeroug, and M. Manic, “Industrial electronics education: past, present and future perspectives,” IEEE Ind. Electron. Mag. vol. 15, no. 1, pp. 140–154, Mar. 2021.

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  14. K. Umetani, S. Kawahara, Jesús Acero, Héctor Sarnago, Óscar Lucía and E. Hiraki, “Analytical Formulation of Copper Loss of Litz Wire With Multiple Levels of Twisting Using Measurable Parameters”, IEEE Trans. Industry Applications.,vol. 57, no. 3, pp. 2407-2420, March. 2021.

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  15. T. Kusumi, T. Hara, K. Umetani, and E. Hiraki, “Phase-current waveform for switched reluctance motors to eliminate input-current ripple and torque ripple in low-power propulsion below magnetic saturation,” IET Power Electron., vol. 13, no. 15, pp. 3351– 3359, Nov. 2020.

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  16. T. Kusumi, T. Hara, K. Umetani, and E. Hiraki, “Simultaneous Tuning of Rotor Shape and Phase Current of Switched Reluctance Motors for Eliminating Input Current and Torque Ripples with Reduced Copper Loss”, IEEE Trans. Industry Applications., August. 2020.

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  17. M. Ishihara, K. Umetani, and E. Hiraki, “Strategy of topology selection based on quasi-duality between series-series and series parallel topologies of resonant inductive coupling wireless power transfer systems”, IEEE Trans. Power Electron. vol. 35, pp. 6785–6798, July. 2020.

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  18. T. Shirakawa, K. Umetani, and E. Hiraki, “Copper loss reduction for plate shape one turn coil in high step-down center-tapped rectifier”, J. Japan Inst. Power Electron., JIPE-45-12, vol. 45, Mar. 2020.
    (in japanese)白川知秀, 梅谷和弘, 平木英治, 「板状ワンターンコイルを採用した高降圧中点タップ整流方式の銅損低減に関する取り組み」パワーエレクトロニクス学会誌 vol. 45, JIPE-45-12, Mar. 2018.

  19. M. Noah, T. Shirakawa, K. Umetani, J. Imaoka, M. Yamamoto, and E. Hiraki, “Effects of secondary leakage inductance on the LLC resonant converter,” IEEE Trans. Power Electron., vol. 35, no. 1, pp. 835–852, Jan. 2020.

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  20. K. Umetani, T. Honjo, T. Koyama, M. Ishihara, and E. Hiraki, “Receiving-coil structure reducing stray ac resistance for resonant coupling wireless power transfer,” IET Power Electron., vol. 12, no. 9, pp. 2338–2344, Aug. 2019.

    IEEE Xplore

  21. K. Umetani, R. Matsumoto, and E. Hiraki, “Prevention of Oscillatory False Triggering of GaN-FETs by Balancing Gate-Drain Capacitance and Common-Source Inductance”, IEEE Trans. vol. 55, no. 1, pp. 610–619, Feb. 2019.

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  22. 川上太知, 原田敏和, 山本真義, 梅谷 和弘, 「昇圧型DC-DCコンバータにおける高い速応性とロバスト性を有する新制御手法の提案」電気学会論文誌D vol. 138, no. 4, pp. 395–404, Apr. 2018.

    JSTAGE

  23. M. Noah, K. Umetani, J. Imaoka, and M. Yamamoto, “Lagrangian dynamics model and practical implementation of an integrated transformer in multi-phase LLC resonant converter,” IET Power Electron., vol. 11, no. 2, pp. 339–347, Feb. 2018

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  24. M. Noah, K. Umetani, M. Yamamoto, and J. Imaoka, “A winding orientation method to minimize the secondary leakage of a gapped transformer utilized in LLC resonant converter,” IET Electronics Letters, vol. 54, no. 3, pp. 157–159, Feb. 2018.

    IEEE Xplore

  25. M. Noah, S. Endo, H. Ishibashi, M. Yamamoto, K. Umetani, J. Imaoka, “A current sharing method utilizing single balancing transformer for a multiphase LLC resonant converter with integrated magnetics,” IEEE J. Emerg. Sel. Topics Power Electron., vol. 6, no. 2, pp. 977–992, Jun. 2018.

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  26. T. Koyama, K. Umetani, and E. Hiraki, “Design optimization method for the load impedance to maximize the output power in dual transmitting resonator wireless power transfer system,” IEEJ J. Ind. Appl., pp. 49–55, Jan. 2018.

    JSTAGE

  27. T. Shirakawa, K. Umetani, and E. Hiraki, “Extremum co-energy principle for analyzing ac current distribution in parallel-connected wires of high frequency power inductors,” IEEJ J. Ind. Appl., vol. 7, no. 1, pp. 35–42, Jan. 2018.

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  28. M. Noah, S. Kimura, J. Imaoka, W. Martinez, S. Endo, M. Yamamoto, and K. Umetani, “Magnetic design and experimental evaluation of a commercially available single integrated transformer in three-phase LLC converter,” IEEE Trans. Ind. Appl. (in press)

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  29. W. Martinez, C. Cortes, M. Yamamoto, J. Imaoka, and K. Umetani, “Total volume evaluation of high power density non-isolated DC-DC converters with integrated magnetics for electric vehicles,” IET Power Electronics, vol. 10, no. 14, pp. 2010–2014, Nov. 2017.

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  30. K. Umetani, K. Aikawa, and E. Hiraki, “Straightforward measurement method of common source inductance for fast switching semiconductor devices mounted on-board,” IEEE Trans. Ind. Electron., vol. 64, no. 10, pp. 8258–8267, Oct. 2017.

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  31. M. Onishi, I. Iizawa, K. Umetani, A. Ito, A. Yajima, K. Ono, N. Amemura, and S. Sakai, “Local effective thermal inertia estimated by cloud appearance,” Scientific Online Letters on the Atmosphere, vol. 13, pp. 59–62, Apr. 2017.

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  32. N Nanato, N Kishi, Y Tanaka and M Kondo: Basic study for a large AC current supply with a single phase air-core Bi2223 high temperature superconducting transformer, Journal of Physics: Conference Series, Vol. 871, 012101 (2017)

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  33. N Nanato, S Nakamura and S Tanaka: Detection of normal transitions in a hybrid single-phase Bi2223 high temperature superconducting transformer by using the active power method and a magnetic flux detection coil, Journal of Physics: Conference Series, Vol. 871, 012085 (2017)

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  34. N Nanato, K Okura, H Kumagai and H Aoyama: Locating of normal transitions in a Bi2223 high temperature superconducting coil by using capacitor type voltage terminals and the active power method, Journal of Physics: Conference Series, Vol. 871, 012084 (2017)

    IOP 論文PDF

  35. M. Ishihara, K. Umetani, H. Umegami, E. Hiraki, and M. Yamamoto, “Quasi-duality between SS and SP topologies of basic electric-field coupling wireless power transfer system,” IET Electronics Letters, vol. 52, no. 25, pp. 2057–2059, Dec. 2016.

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  36. K. Umetani, K. Yagyu, and E. Hiraki, “A design guideline of parasitic inductance for preventing oscillatory false triggering of fast switching GaN-FET,” IEEJ Trans. Elect. Electron. Eng., vol. 11, no. S2, pp. S84–S90, Dec. 2016.

    Wiley

  37. K. Umetani, “Lagrangian method for deriving electrically dual power converters applicable to non-planar circuit topologies,” IEEJ Trans. Elect. Electron. Eng., vol. 11, no. 4, pp. 521–530, Jul. 2016.

    Wiley

  38. J. Imaoka, K. Umetani, S. Kimura, W. Martinez, M. Yamamoto, S. Arimura, and T. Hirano, “Magnetic analysis, design and experimental evaluations of integrated winding coupled inductors in interleaved converters,” IEEJ J. Ind. Appl., vol. 5, no. 3, pp. 276–288, May 2016.

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  39. M. Hataya, Y. Oka, K. Umetani, E. Hiraki, T. Hirokawa and M. Imai, “Novel thin heating coil structure with reduced copper loss for high frequency induction cookers,” 2016 19th International Conference on Electrical Machines and Systems (ICEMS), Chiba, Japan, 2016, pp. 1-6.

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  40. I. Iizawa, K. Umetani, A. Ito, A. Yajima, K. Ono, N. Amemura, M. Onishi, and S. Sakai, “Time evolution of an urban heat island from high-density observations in Kyoto city,” Scientific Online Letters on the Atmosphere, vol. 12, pp. 51–54, Feb. 2016.

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  41. J. Imaoka,K. Umetani,S. Kimura,W. Martinez,M. Yamamoto,S. Arimura,T. Hirano: Magnetic Analysis, Design, and Experimental Evaluations of Integrated Winding Coupled Inductors in Interleaved Converters, IEEJ Journal of Industry Applications, Vol. 5 (2016) No. 3 p. 276-288

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  42. K. Umetani, E. Hiraki, and M. Yamamoto, “Lagrangian-based derivation of a novel sliding mode control for synchronous buck converters,” IEEJ J. Ind. Appl., vol. 4, no. 6, pp. 728–729, Nov. 2015.

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  43. K. Umetani, M. Yamamoto and E. Hiraki, “Simple Flux-based Lagrangian Formulation to Model the Non-linearity of Concentrated-winding Switched Reluctance Motors,” IET Electronics Letters, vol. 51, no. 24, pp.1984–1986, Nov. 2015.

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  44. H. Umegami, K. Umetani, M. Yamamoto, and E. Hiraki, “Lagrangian-based equivalent circuit of basic electric-field coupling wireless power transfer system,” IEEJ Trans. Elect. Electron. Eng., vol. 10, no. S1, pp. S168–S170, Oct. 2015.

    Wiley

  45. K. Umetani, T. Tera, and K. Shirakawa, “A magnetic structure integrating differential-mode and common-mode inductors with improved tolerance to DC saturation,” IEEJ J. Ind. Appl., vol. 4, no. 3, pp. 166–173, May 2015.

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  46. W. Martinez, J. Imaoka, M. Yamamoto and K. Umetani, “Parasitic resistance analysis in a novel high step-up interleaved converter for hybrid electric vehicles”, J. Japan Inst. Power Electron., JIPE-40-08, vol. 40, pp. 93–104, Mar. 2015.

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  47. K. Umetani, J. Imaoka, M. Yamamoto, S. Arimura, and T. Hirano, “Evaluation of the Lagrangian method for deriving equivalent circuits of integrated magnetic components: a case study using the integrated winding coupled inductor,” IEEE Trans. Ind. Appl., vol. 51, no. 1, pp. 547–555, Jan. 2015.

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  48. H. Tanaka, T. Tanaka, T. Wakimoto, E. Hiraki, M. Okamoto : "Reduced-Capacity Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders With Reactive Power Control", IEEE Transactions on Industry Applications, Vol. 51, No. 1, pp. 315-324 (2015)

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  49. T. Soe Win, Y. Hisada, T. Tanaka, E. Hiraki, M. Okamoto, S. Ryong Lee, "Novel Simple Reactive Power Control Strategy With DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems", IEEE Transactions on Industry Applications, Vol. 51, No. 5, pp. 4091 - 4099 (2015)

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  50. N. Nanato, K. Nishiyama: Locating of normal transitions in a Bi2223 high temperature superconducting coil by non-contact voltage measurement method, Cryogenics, Vol. 72, pp. 53-56 (2015)

    ScienceDirect

  51. N. Nanato, Y. Kobayashi: Quench Detection and Protection for High Temperature Superconducting Transformers by Using the Active Power Method, Physics Procedia, Vol. 58, pp. 264-267 (2014) (Proceedings of the 26th International symposium on superconductivity)

    ScienceDirect

  52. K. Umetani,M. Yamamoto,E. Hiraki: Lagrangian-Based Derivation of a Novel Sliding-Mode Control for Synchronous Buck Converters, IEEJ Journal of Industry Applications,Vol. 4 (2015) No. 6 p. 728-729

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  53. T. Soe Win,Y. Hisada,T. Tanaka,E. Hiraki,M. Okamoto,S. Ryong Lee: Reactive Power Control Strategy Based on DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems, IEEJ Journal of Industry Applications, Vol. 4 (2015) No. 3 p. 158-165

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  54. K. Umetani,M. Yamamoto,E. Hiraki: Lagrangian-Based Derivation of a Novel Sliding-Mode Control for Synchronous Buck Converters, IEEJ Journal of Industry Applications, Vol. 4 (2015) No. 6 p. 728-729

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  55. N. Nanato, K. Nishiyama: Non-destructive Detection of Normal Transitions in High Temperature Superconducting Coil, Physics Procedia, Vol. 58, pp. 260-263 (2014) (Proceedings of the 26th International symposium on superconductivity)

    ScienceDirect

  56. N. Nanato, N. Takemoto: Time-frequency Analyses of AE Signals in YBCO Superconductors, Physics Procedia, Vol. 58, pp. 256-259 (2014) (Proceedings of the 26th International symposium on superconductivity)

    ScienceDirect

  57. H. Tanaka,T. Wakimoto,T. Tanaka,M. Okamoto,E. Hiraki: Reducing Capacity of Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders with Reactive Power Control, IEEJ Journal of Industry Applications, Vol. 3 (2014) No. 6 p. 437-445

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  58. T. Soe Win,E. Hiraki,M. Okamoto,S. Ryong Lee,T. Tanaka: Novel Control Algorithm for Active Load Balancer in Three-Phase Four-Wire Distribution Systems, IEEJ Journal of Industry Applications, Vol. 3 (2014) No. 3 p. 286-287

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