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The existence of Ap_r almost periodic solutions to difference equations and a study of functional ED models due to COVID-19 sequelas

Research Project

Project/Area Number 21K03318
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 12020:Mathematical analysis-related
Research InstitutionOkayama University of Science

Principal Investigator

Hamaya Yoshihiro  岡山理科大学, 研究・社会連携センター, 教授 (40228549)

Co-Investigator(Kenkyū-buntansha) 齋藤 香織  明星大学, 経営学部, 准教授 (10749922)
河野 敏行  岡山理科大学, 情報理工学部, 教授 (90309534)
Project Period (FY) 2021-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2023: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2022: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2021: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
KeywordsCOVID-19のSIR感染症モデル / COVID-19のSEIR感染症モデル / 体内感染症離散モデル / ワニの生存戦略離散モデル / 概周期族解 / COVID‐19のSIRモデル / COVID-19 のSEIRモデル / 拡散型Boom方程式 / 概周期解族 / 時間遅れを持つ拡散反応型モデルの漸近安定性 / テストステロン分泌の時間遅れを持つ制御モデル / COVID-19 後遺症を持つED制御モデル / 大型行列の理論と行列の数値計算 / COVID-19 / 関数差分方程式 / 有界解の漸近挙動 / 関数微分方程式 / 機能性EDモデル
Outline of Research at the Start

COVID-19の後遺症としてテストステロン減衰による機能性ED症候群の発症例が取り沙汰されている.そのため,本研究の目的は,テストステロン制御モデルの多くの既存研究が黄体形成ホルモン放出ホルモンLHRHを表すのに有理型関数を用いている点に対して,COVID-19の後遺症を考慮したLHRTのtanh型のy-軸と対称な関数によるテストステロン制御のより現実的で新しい差分方程式モデルを構築し,その解の安定性を調べ,さらに第1波流行以後の第2,第3波以降と続く感染継続を表す概周期族の解の存在定理を示す.及びこのCOVID-19後遺症による機能性ED症候群モデルの数値実験を行い,解の可視化を行う.

Outline of Final Research Achievements

We show the asymptotic stability of the blood and lymph model of infectious diseases in a body, and SIR and SEIR type of the reaction diffusion partial differential equations with finite delay.
Moreover, we consider the existence theorem of almost periodic solutions and the asymptotic stability of control model with a time lag of testosterone secretion, announced at the International Conference of Difference Equations and Applications of Paris and submitted a paper, in 2022.

Academic Significance and Societal Importance of the Research Achievements

昨今,COVID-19感染の後遺症としてテストステロン減衰による機能性ED症候群の発症例が取
り沙汰されている.その解明対策のため, 既存モデルより現実的な新しいテストステロンの制御モデルを構築し,モデルの定性的性質を数学的に証明して,数値的シミュレーションを行うことで,COVID-19感染の後遺症によるテストステロン減少に伴う機能性ED症候群に現れる概周期的現象, 第2波流行以後の流行継続の現象をとらえ,その時系列的減衰及び,ED回復のメカニズムを研究する点が学術的独自性を持つ意義であること共に社会的重要性のある意義である.

Report

(4 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • 2021 Research-status Report
  • Research Products

    (12 results)

All 2023 2022 2021

All Journal Article (10 results) (of which Peer Reviewed: 9 results,  Open Access: 2 results) Presentation (2 results) (of which Int'l Joint Research: 2 results)

  • [Journal Article] Asymptotic Behavior of Delayed SIR Epidemic Models of COVID-19 with Diffusion2023

    • Author(s)
      Saito Kaori、Kohno Toshiyuki、Hamaya Yoshihiro
    • Journal Title

      Journal of Applied Mathematics and Computation

      Volume: 7 Issue: 1 Pages: 112-127

    • DOI

      10.26855/jamc.2023.03.012

    • Related Report
      2023 Annual Research Report 2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Global attractivity of a delayed SEIR epidemic model of COVID -19 with diffusion2023

    • Author(s)
      Y. Hamaya and K. Saito
    • Journal Title

      Journal of Mathematical Sciences

      Volume: 271 Issue: 3 Pages: 378-399

    • DOI

      10.1007/s10958-023-06527-6

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Global stability properties of virus dynamics discrete models2023

    • Author(s)
      K. Saito and Y. Hamaya
    • Journal Title

      Journal of Mathematics and Statistical Science

      Volume: 9, Issue 9 Pages: 26-39

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed
  • [Journal Article] On the Asymptotic Stability of Discrete Crocodilians Model2023

    • Author(s)
      Saito Kaori、Hamaya Yoshihiro
    • Journal Title

      Advances in Pure Mathematics

      Volume: 13 Issue: 05 Pages: 211-225

    • DOI

      10.4236/apm.2023.135015

    • Related Report
      2023 Annual Research Report 2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] On the global stability of an SIR epidemic discrete model2023

    • Author(s)
      K. Saito and Y. Hamaya
    • Journal Title

      International Journal of Mathematical Analysis

      Volume: 17 Issue: 3 Pages: 119-132

    • DOI

      10.12988/ijma.2023.912517

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Global Stability Properties of Virus Dynamics Discrete Models2023

    • Author(s)
      Saito Kaori、Hamaya Yoshihiro
    • Journal Title

      ー

      Volume: -

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] On the Global Stability of an SIR Epidemic Discrete Model2023

    • Author(s)
      Saito Kaori
    • Journal Title

      ー

      Volume: ー

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Global Attractivity of a Delayed SEIR Epidemic Model of COVID-19 with Diffusion2023

    • Author(s)
      Hamaya Yoshihiro、Saito Kaori
    • Journal Title

      Journal of Mathematical Science

      Volume: -

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Asymptotic behavior of delayed SIR epidemic models of COVID-19 with diffusion2022

    • Author(s)
      K. Saito, T. Kohno and Y. Hamaya
    • Journal Title

      Journal of Applied Mathematics and Computation, to appear

      Volume: To appear

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Asymptotic behavior of delayed SIR epidemic model of COVID-19 with diffusion2021

    • Author(s)
      Y. Hamaya and K. Saito
    • Journal Title

      The Bulletin of the Information Processing Center

      Volume: Vol. 1, No.41-42 Pages: 29-40

    • Related Report
      2021 Research-status Report
    • Open Access
  • [Presentation] Boundedness and global attractivity to three-species cyclic prey-predator of Volterra type difference equations2023

    • Author(s)
      Y. Hamaya
    • Organizer
      International Conference on Difference Equations and Applications 2022
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Boundedness and global attractivity to three-species cyclic prey-predator of Volterra type difference equations2022

    • Author(s)
      Y. Hamaya
    • Organizer
      27th International Conference on Difference Equations and Applications (ICDEA 2022, Paris)
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research

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Published: 2021-04-28   Modified: 2025-01-30  

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