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Affiliation |
Engineering educational research section Science Center for Engineering Education |
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Title |
Associate Professor |
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Contact information |
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IZUHARA Hirofumi
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Degree 【 display / non-display 】
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Doctor (Science) ( 2008.3 Hiroshima University )
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修士(理学) ( 2005.3 広島大学 )
Research Areas 【 display / non-display 】
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Natural Science / Basic mathematics / Applied mathematics
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Natural Science / Basic mathematics
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Natural Science / Applied mathematics and statistics
Papers 【 display / non-display 】
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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
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.
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An aggregation model of cockroaches with fast-or-slow motion dichotomy
J. Elias, H. Izuhara, M. Mimura, B. Q. Tang
arXiv 2021.11
Language：English Publishing type：Research paper (other academic)
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Asymptotic stability of two types of traveling waves for some predator-prey models Reviewed
Zhang H., Izuhara H., Wu Y.
Discrete and Continuous Dynamical Systems - Series B 26 ( 4 ) 2323 - 2342 2021.4
Language：English Publishing type：Research paper (scientific journal) Publisher：Discrete and Continuous Dynamical Systems - Series B
This paper is concerned with the asymptotic stability of wave fronts and oscillatory waves for some predator-prey models. By spectral anal- ysis and applying Evans function method with some numerical simulations, we show that the two types of waves with noncritical speeds are spectrally stable and nonlinearly exponentially stable in some exponentially weighted spaces.
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The formation of spreading front: the singular limit of three-component reaction–diffusion models Reviewed
Izuhara H., Monobe H., Wu C.H.
Journal of Mathematical Biology 82 ( 5 ) 2021.4
Authorship：Lead author Publishing type：Research paper (scientific journal) Publisher：Journal of Mathematical Biology
Understanding the invasion processes of biological species is a fundamental issue in ecology. Several mathematical models have been proposed to estimate the spreading speed of species. In recent decades, it was reported that some mathematical models of population dynamics have an explicit form of the evolution equations for the spreading front, which are represented by free boundary problems such as the Stefan-like problem (e.g., Mimura et al., Jpn J Appl Math 2:151–186, 1985; Du and Lin, SIAM J Math Anal 42:377–405, 2010). To understand the formation of the spreading front, in this paper, we will consider the singular limit of three-component reaction–diffusion models and give some interpretations for spreading front from the viewpoint of modeling. As an application, we revisit the issue of the spread of the grey squirrel in the UK and estimate the spreading speed of the grey squirrel based on our result. Also, we discuss the relation between some free boundary problems related to population dynamics and mathematical models describing Controlling Invasive Alien Species. Lastly, we numerically consider the traveling wave solutions, which give information on the spreading behavior of invasive species.
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Spatio-temporal coexistence in the cross-diffusion competition system Reviewed
Izuhara H., Kobayashi S.
Discrete and Continuous Dynamical Systems - Series S 14 ( 3 ) 909 - 933 2021.3
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Discrete and Continuous Dynamical Systems - Series S
We study a two component cross-diffusion competition system which describes the population dynamics between two biological species. Since the cross-diffusion competition system possesses the so-called population pressure effects, a variety of solution behaviors can be exhibited compared with the classical diffusion competition system. In particular, we discuss on the existence of spatially non-constant time periodic solutions. Applying the center manifold theory and the standard normal form theory, the cross-diffusion competition system is reduced to a two dimensional dynamical system around a doubly degenerate point. As a result, we show the existence of stable time periodic solutions in the system. This means spatio-temporal coexistence between two biological species.
Books 【 display / non-display 】
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辻川 亨, 出原 浩史（ Role： Joint author）
学術図書出版社 2017.11
Language：Japanese Book type：Scholarly book
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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
Language：Japanese Book type：Scholarly book
MISC 【 display / non-display 】
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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
Language：Japanese Publishing type：Meeting report
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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
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)
Presentations 【 display / non-display 】
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狭い空間での燃焼の数理モデル解析
出原浩史
九州大学IMI短期共同研究「燃焼・消炎機構の数理に基づく火災・爆発の安全対策」
Event date： 2022.3.8
Language：Japanese Presentation type：Oral presentation (invited, special)
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数学からみた数理モデルあれこれ
出原浩史
明治大学MIMS研究集会「現象と数理モデル~数理モデリング学の形成に向けて~」
Event date： 2022.1.24 - 2022.1.25
Language：Japanese Presentation type：Oral presentation (invited, special)
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Mathematical modeling for derivation of functional responses in prey-predator systems International conference
Hirofumi Izuhara
Online seminar in Warsaw
Event date： 2022.1.17
Language：English Presentation type：Oral presentation (invited, special)
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狭い空間における燃焼の数理モデル-間欠的な燃焼の解明に向けて-
出原浩史
九州大学IMI短期共同研究「燃焼・消炎機構の数理に基づく火災・爆発の安全対策」キックオフミーティング
Event date： 2021.9.6
Language：Japanese Presentation type：Oral presentation (invited, special)
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交差拡散-競争方程式における時間周期的共存について
出原浩史
南大阪応用数学セミナー
Event date： 2021.7.31
Language：Japanese Presentation type：Oral presentation (invited, special)
Grant-in-Aid for Scientific Research 【 display / non-display 】
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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
科学研究費補助金 基盤研究(C)
Authorship：Principal investigator
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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
科学研究費補助金 基盤研究(C)
Authorship：Coinvestigator(s)
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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)
Authorship：Principal investigator
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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)
Authorship：Principal investigator
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生物の集合形成メカニズムに対する数理モデルからの探求
2014.04 - 2017.03
科学研究費補助金 若手研究(B)
Authorship：Principal investigator
バクテリアなどの微生物は集合することにより規則正しいコロニーパターンを形成することがよく知られている. 本研究では, 数理モデルからのアプローチによって生物の自己組織的集合形成のメカニズムを明らかにする.