IZUHARA Hirofumi

写真a

Affiliation

Engineering educational research section Science Center for Engineering Education

Title

Associate Professor

Contact information

Contact information

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Degree 【 display / non-display

  • Doctor (Science) ( 2008.3   Hiroshima University )

  • 修士(理学) ( 2005.3   広島大学 )

Research Areas 【 display / non-display

  • Natural Science / Basic mathematics

  • Natural Science / Basic mathematics  / Applied mathematics

  • Natural Science / Applied mathematics and statistics

 

Papers 【 display / non-display

  • CROSS-DIFFUSION PREDATOR–PREY MODEL DERIVED FROM THE DICHOTOMY BETWEEN TWO BEHAVIORAL PREDATOR STATES Reviewed

    Iida M., Izuhara H., Kon R.

    Discrete and Continuous Dynamical Systems - Series B   28 ( 12 )   6159 - 6178   2023.12

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Discrete and Continuous Dynamical Systems - Series B  

    Cross-diffusion may be an important driving force of pattern formation in population models. Recently, a relation between cross-diffusion and reaction-diffusion systems has been revealed from the mathematical modeling point of view. In this paper, we derive a predator–prey model with cross-diffusion from a simple reaction-diffusion system with two behavioral states in the predator population and examine whether cross-diffusion can induce spatial patterns in predator–prey models. We assume that the predators have identical behavioral characteristics except for their mobility and searching activity for preys: we consider two states, namely less mobile predators searching for preys more actively than mobile predators. Our analysis shows that cross-diffusion derived in this situation can induce spatial patterns if the prey-density-dependent conversion rate from less mobile state to mobile one increases more rapidly than that from mobile to less mobile at high prey density.

    DOI: 10.3934/dcdsb.2023098

    Scopus

  • SPATIAL SEGREGATION OF MULTIPLE SPECIES: A SINGULAR LIMIT APPROACH Reviewed International coauthorship

    Izuhara H., Monobe H., Wu C.H.

    Discrete and Continuous Dynamical Systems - Series B   28 ( 12 )   6208 - 6232   2023.12

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Discrete and Continuous Dynamical Systems - Series B  

    The spatial segregation of the populations occurs commonly in ecology. One typical way to understand this phenomenon is to consider strong competition in some species. In this paper, we shall consider multiple-species competition-diffusion models. Under the condition that some interspecies competition rates are large, we show that the segregation phenomenon occurs. Furthermore, we derive some two-phase Stefan-like problems appearing as the singular limit, which may provide some modeling interpretation for free boundary problems studied in the literature.

    DOI: 10.3934/dcdsb.2022215

    Scopus

  • PARTIALLY OVERLAPPING TRAVELLING WAVES IN A PARABOLIC-HYPERBOLIC SYSTEM Reviewed International coauthorship

    Bertsch M., Izuhara H., Mimura M., Wakasa T.

    Discrete and Continuous Dynamical Systems - Series B   28 ( 12 )   5934 - 5966   2023.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Discrete and Continuous Dynamical Systems - Series B  

    We study the existence of travelling wave solutions of a one-dimensional parabolic-hyperbolic system for u(x, t) and v(x, t), which arises as a model for contact inhibition of cell growth. Compared to the scalar Fisher-KPP equation, the structure of the travelling wave solutions is surprisingly rich and strongly parameter-dependent. In the present paper we consider a parameter regime where the minimal wave speed is positive. We show that there exists a branch of travelling wave solutions for wave speeds which are larger than the minimal one. But the main result is more surprising: for certain values of the parameters the travelling wave with minimal wave speed is not segregated (a solution is called segregated if the product uv vanishes almost everywhere) and in that case there exists a second branch of “partially overlapping” travelling wave solutions for speeds between the minimal one and that of the (unique) segregated travelling wave.

    DOI: 10.3934/dcdsb.2023076

    Scopus

  • An aggregation model of cockroaches with fast-or-slow motion dichotomy Reviewed International coauthorship

    Eliaš J., Izuhara H., Mimura M., Tang B.Q.

    Journal of Mathematical Biology   85 ( 3 )   2022.9

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    Authorship:Corresponding author   Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Journal of Mathematical Biology  

    We propose a mathematical model, namely a reaction–diffusion system, to describe social behaviour of cockroaches. An essential new aspect in our model is that the dispersion behaviour due to overcrowding effect is taken into account as a counterpart to commonly studied aggregation. This consideration leads to an intriguing new phenomenon which has not been observed in the literature. Namely, due to the competition between aggregation towards areas of higher concentration of pheromone and dispersion avoiding overcrowded areas, the cockroaches aggregate more at the transition area of pheromone. Moreover, we also consider the fast reaction limit where the switching rate between active and inactive subpopulations tends to infinity. By utilising improved duality and energy methods, together with the regularisation of heat operator, we prove that the weak solution of the reaction–diffusion system converges to that of a reaction-cross-diffusion system.

    DOI: 10.1007/s00285-022-01797-1

    Scopus

  • Oscillations and bifurcation structure of reaction–diffusion model for cell polarity formation Reviewed

    Kuwamura M., Izuhara H., Ei S.i.

    Journal of Mathematical Biology   84 ( 4 )   2022.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Journal of Mathematical Biology  

    We investigate the oscillatory dynamics and bifurcation structure of a reaction–diffusion system with bistable nonlinearity and mass conservation, which was proposed by (Otsuji et al., PLoS Comp Biol 3:e108, 2007). The system is a useful model for understanding cell polarity formation. We show that this model exhibits four different spatiotemporal patterns including two types of oscillatory patterns, which can be regarded as cell polarity oscillations with the reversal and non-reversal of polarity, respectively. The trigger causing these patterns is a diffusion-driven (Turing-like) instability. Moreover, we investigate the effects of extracellular signals on the cell polarity oscillations.

    DOI: 10.1007/s00285-022-01723-5

    Scopus

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Books 【 display / non-display

  • 微分積分の押さえどころ

    辻川 亨, 大塚 浩史, 出原 浩史, 伊藤 翼, 矢崎 成俊

    学術図書出版社  2019 

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    Language:Japanese

    CiNii Books

  • 線形代数入門

    辻川 亨, 出原 浩史( Role: Joint author)

    学術図書出版社  2017.11 

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    Language:Japanese Book type:Scholarly book

    CiNii Books

  • パターン形成の数理とバイオメディカルへの応用

    Murray J. D. (James Dickson), 勝瀬 一登, 三村 昌泰, 瀬野 裕美, 吉田 雄紀, 青木 修一郎, 宮嶋 望, 半田 剛久, 清田 正紘, 河内 一樹, 中口 悦史, 梯 正之, 川崎 廣吉, 池田 幸太, 森下 喜弘, 出原 浩史, 関村 利朗, 昌子 浩登, 柴田 達夫, 上田 肇一, 本多 久夫, 稲葉 寿( Role: Joint translator)

    丸善出版  2016 

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    Language:Japanese Book type:Scholarly book

    CiNii Books

MISC 【 display / non-display

  • 第31回日本数理生物学会大会報告

    飯田雅人, 今隆助, 出原浩史

    日本数理生物学会ニュースレター   ( 96 )   2 - 5   2022.2

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    Language:Japanese   Publishing type:Meeting report  

  • 半乾燥地域における植生パターンと数理モデル Invited

    出原浩史

    数理科学 数理モデリングと生命科学   59 ( 9 )   51 - 57   2021.9

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    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

Presentations 【 display / non-display

  • 2成分反応拡散系に現れるHopf-Turing-Turing分岐 Invited

    出原浩史

    神戸非線形解析研究会  2023.3.20 

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    Event date: 2023.3.20

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  • 捕食者−被食者モデルと交差拡散 Invited

    出原浩史

    松江数理生物学・現象数理学ミニ研究会  2023.3.8 

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    Event date: 2023.3.8 - 2023.3.10

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  • 3成分燃焼モデルに現れる一様燃焼の不安定化 Invited

    出原浩史

    九州大学IMI短期共同研究「消炎や振動を含む不安定燃焼の数理」  2023.3.6 

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    Event date: 2023.3.6

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  • 燃焼問題の進行波解について Invited

    出原浩史

    数学と現象 in 長瀞  2023.2.2 

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    Event date: 2023.2.1 - 2023.2.3

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  • Cross-diffusion in predator-prey models with two behavioral states in predators Invited International conference

    Hirofumi Izuhara

    A ReaDiNet seminar day on reaction-diffusion systems in biology  2022.11.21 

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    Event date: 2022.11.21

    Language:English   Presentation type:Oral presentation (invited, special)  

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Awards 【 display / non-display

  • 熱コレ2022 最優秀動画賞

    2022.10   日本機械学会 熱工学コンファレンス2022   様々な紙の燃え方

    中村 愛美, 小林 温斗, 鈴木 啓介, 松岡 常吉, 出原 浩史, 桑名 一徳, 中村 祐二

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    Award type:Award from Japanese society, conference, symposium, etc. 

Grant-in-Aid for Scientific Research 【 display / non-display

  • 個体群の広がりを抑制する障害物問題とその解析

    Grant number:23K03216  2023.04 - 2026.03

    独立行政法人日本学術振興会  科学研究費補助金  基盤研究(C)

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    Authorship:Coinvestigator(s) 

  • 狭い空間における燃焼の数理モデルと理論解析

    Grant number:21K03353  2021.04 - 2024.03

    独立行政法人日本学術振興会  科学研究費補助金  基盤研究(C)

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    Authorship:Principal investigator 

  • 燃焼限界近傍における火炎の燃え拡がり方向を決めるメカニズムの解明

    Grant number:20K05001  2020.04 - 2023.03

    独立行政法人日本学術振興会  科学研究費補助金  基盤研究(C)

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    Authorship:Coinvestigator(s) 

  • 燃焼モデルに現れるパターンの計算機支援解析

    Grant number:17K14237  2017.04 - 2022.03

    科学研究費補助金  若手研究(B)

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    Authorship:Principal investigator 

  • 生命現象における階層を超えるミクロとマクロとをつなぐ理論の構築

    2016.04 - 2019.03

    科学研究費補助金  基盤研究(C)

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    Authorship:Principal investigator 

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