SHIMOJI Nobuaki

写真a

Title

Assistant Professor

Researcher Number(JSPS Kakenhi)

20464240

Profile

We are studying computational physics and atmospheric electricity.

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Current Affiliation Organization 【 display / non-display 】

  • Duty   University of the Ryukyus   Faculty of Engineering   School of Engineering_Electrical and Systems Engineering Program   Assistant Professor  

  • Concurrently   University of the Ryukyus   Graduate School of Engineering and Science   Electrical Energy and Systems Control Engineering   Assistant Professor  

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Graduate School 【 display / non-display 】

  • 2004.04
    -
    2007.03

    University of the Ryukyus  Graduate School, Division of Science and Engineering  Interdisciplinary Intelligent Systems Engineering  Doctor's Course  Completed

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Academic degree 【 display / non-display 】

  • University of the Ryukyus -  Doctor (Science)

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External Career 【 display / non-display 】

  • 2008.10
    　
    　

    University of the Ryukyus, Faculty of Engineering, Assistant Professor  

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Affiliated academic organizations 【 display / non-display 】

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    The Physical Society of Japan 

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    Meteorological Society of Japan 

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Research Interests 【 display / non-display 】

  • Computational Physics

  • Atmospheric Electricity

  • Lightning Science

  • Photometry

  • Image Analysis

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Research Areas 【 display / non-display 】

  • Informatics / Mathematical informatics

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Research Theme 【 display / non-display 】

  • Atmospheric Electricity

    　View Summary

    We have analyzed the lightning flashes shownf in digital photographs. In order to evaluate the brightness of the lightning flashes in the digital photographs, we have studied the optical properties of some digital cameras. We have also studied particle dynamics in the thundercloud. Some other research themes are performing.

  • Solid-state Physics(Computational Physics)

    　View Summary

    We have studied solid-state physics using the DV-Xa method, VASP code, and ESPRESSO code. So far, we studied superionic conductors, AgI, AgBr, AgCl, CuI, CuBr, and CuI, carbon tube, carbon sheet, and battery electrode such as LiCoO2.

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Published Papers 【 display / non-display 】

  • Development of a Time-Integration Method for Analyzing the Photoresponse of Image Sensors: Theoretical and experimental verification with digital cameras

    Nobuaki Shimoji, Yuto Suzuki

    Measurement Science Review ( Slovak Academy of Sciences, Institute of Measurement Science )  26 ( 2 ) 46 - 56   2026.04 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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      DOI Open Access

  • Development and field testing of a UHF antenna system for the observation of electrical discharge phenomena in the atmosphere

    Nobuaki Shimoji, Itsuki Tofuku

    Journal of Atmospheric and Solar-Terrestrial Physics ( Elsevier )  280   106754   2026.03 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    In Japan, the digital terrestrial television broadcasting band (470–710 MHz) is legally protected, resulting in extremely low levels of artificial electromagnetic noise within this frequency range. Therefore, when an antenna is directed toward targets such as cumulus clouds, high-voltage transmission towers, volcanic plumes, or trees, the received signals are highly likely to be ultra high frequency (UHF) event signals—discharge emissions—from those targets. Because discharge phenomena last only tens of nanoseconds, developing instruments capable of directly recording them is technically difficult. Considering Japan's radio-wave environment and practical hardware constraints, we developed a UHF antenna system with a sampling interval. A dual-integration system was devised and implemented in the backend, enabling continuous recording with no dead time. Although a interval is long relative to discharge timescales, it becomes a practical method when the objective is not to resolve individual pulses but to detect the collective occurrence of numerous discharge events. The developed system was installed outdoors, and tests confirmed reception of both discharge signals and television broadcasts. Subsequent observations included cumulus clouds, partial discharges from high-voltage transmission towers, small-scale volcanic eruptions, and tree corona discharges. For each target, characteristics consistent with streamers, corona discharges, or partial discharges were obtained. These results suggest that, although improvements are still possible, the compact UHF antenna system developed in this study has the potential to serve as a new observational method for atmospheric discharge phenomena.

  • Development of lightning-leader extraction algorithm for digital photographs applying quartile and deep learning

    Musashi Okizaki, Nobuaki Shimoji

    Journal of Atmospheric and Solar-Terrestrial Physics ( Elsevier )  242   106001   2023.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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      DOI

  • Theoretical formulation and experimental validation of brightness evaluation using digital cameras

    Nobuaki Shimoji, Musashi Okizaki

    Results in Optics ( Elsevier )  2   100050   2021.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Color analysis based on the color indices of lightning channels obtained from a digital photograph

    Nobuaki Shimoji, Takahiro Nakano

    Results in Physics ( Elsevier )  15   102662   2019.12 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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Other Papers 【 display / non-display 】

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Social Activity 【 display / non-display 】

  • 2025.11
    　
    　

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