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Effective use of multi-precision arithmetic on floating number system of digital computers aiming at numerical computations of differential equations with singulari or ill-posedness

Research Project

Project/Area Number 23K20811
Project/Area Number (Other) 21H00999 (2021-2023)
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeMulti-year Fund (2024)
Single-year Grants (2021-2023)
Section一般
Review Section Basic Section 12040:Applied mathematics and statistics-related
Research InstitutionKyoto University

Principal Investigator

磯 祐介  京都大学, 情報学研究科, 教授 (70203065)

Co-Investigator(Kenkyū-buntansha) 藤原 宏志  京都大学, 情報学研究科, 准教授 (00362583)
川越 大輔  京都大学, 情報学研究科, 助教 (30848073)
木村 正人  金沢大学, 数物科学系, 教授 (70263358)
今井 仁司  同志社大学, 理工学部, 教授 (80203298)
田口 智清  京都大学, 情報学研究科, 教授 (90448168)
Project Period (FY) 2021-04-01 – 2025-03-31
Project Status Granted (Fiscal Year 2024)
Budget Amount *help
¥16,380,000 (Direct Cost: ¥12,600,000、Indirect Cost: ¥3,780,000)
Fiscal Year 2024: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2023: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2022: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2021: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Keywords数値解析学 / 多倍長数値計算 / 逆問題・非適切問題解析 / ひかりトモグラフィー / 流体・弾性体方程式の解の特異性 / ひかりトモグラフィ
Outline of Research at the Start

持続可能な社会の実現とその安定的な継続に重要な諸現象・諸問題の数理モデルの中で、偏微分方程式や積分方程式等の函数方程式で記述されるものを対象とし、数値解析を中心とする数理解析的な研究を行う。具体的には、数理モデルとしての函数方程式の解の特異性や非適切性が本質的となる問題に焦点をあて、方程式の解の構造を明らかにして信頼できる数値計算の実現を目指す。

Outline of Annual Research Achievements

本課題研究では、主として現象の数理モデルとしての偏微分方程式の数値解析と数学解析を論じている。偏微分方程式の数学解析では、解の有する特異性や不安定性をどのように正則化するかが純粋数学としては重要な論点であり、このために様々な概念が提唱され、また種々の函数空間が導入される。一方で、現象の数理モデルとしての微分方程式の議論においては、特異性は単に正則化されるべき「特異」な挙動と考えることは慎重で有らねばならない。実際、解の特異性や不安定性は対象とする系・現象の重要な物理量などと関連している場合が散見され、この特異性を定量的に論じることが重要となる事例も少なくない。しかし解の「特異性」は数値計算の発散や不安定性と表裏一体であるため、特異性を定量的に論じることはきわめて困難である。既存の理論の単純適用では、特異性を定量的に数値計算によって扱うことはきわめて困難である。
本課題研究ではこのような問題意識と現状認識の下で、研究代表者と分担者の過去の研究実績を踏まえて、代表者と分担者が分業によって幾つかの具体的な問題に限定的に取組、数学解析に裏付けられた数値計算法を新たに確立することによって特異性の定量的な議論を行なおうとしている。
2年度は初年度に引き続き1階双曲型方程式の有限要素法解析について成果を得、先行研究を超えたシャープな収束評価を与えるに至った。逆問題解析については医用断層撮影の数値解析にかかる国際共同研究の推進を図った。さらにポテンシャル逆問題を再考し、Zidarov による bubbling アルゴリズムの再検討を行いこの手法の有効性の検証を行った。

Current Status of Research Progress
Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

年度の後半から COVID-19 による様々な制約が徐々に緩和され、国内研究集会の実施、外国人共同研究者の招聘等も当初予定に準じた形で実施できるようになり、順調に研究が進展した。

Strategy for Future Research Activity

2年度に研究を開始した Zidarov の bubbling 法による逆ポテンシャル問題のアルゴリズムの正当性と優位性を数学解析・数値解析の観点から論じる。国際研究集会に関しては、対面形式での開催が延期されている日台の合同ワークショップを対面形式による実施を図る。

Report

(2 results)
  • 2022 Annual Research Report
  • 2021 Annual Research Report
  • Research Products

    (31 results)

All 2023 2022 2021

All Journal Article (18 results) (of which Int'l Joint Research: 15 results,  Peer Reviewed: 16 results,  Open Access: 7 results) Presentation (13 results) (of which Int'l Joint Research: 8 results,  Invited: 5 results)

  • [Journal Article] A Two-Step Lagrange?Galerkin Scheme for the Shallow Water Equations with a Transmission Boundary Condition and Its Application to the Bay of Bengal Region?Part I: Flat Bottom Topography2023

    • Author(s)
      Rasid Md Mamunur、Kimura Masato、Murshed Md Masum、Wijayanti Erny Rahayu、Notsu Hirofumi
    • Journal Title

      Mathematics

      Volume: 11 Issue: 7 Pages: 1633-1633

    • DOI

      10.3390/math11071633

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Cauchy型積分による部分観測のもとでのX線計算機断層撮影法2022

    • Author(s)
      藤原宏志,大石直也,SADIQ Kamran, TAMASAN Alexandru
    • Journal Title

      計算数理工学会レビュー

      Volume: No.2022-2 Pages: 33-48

    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Journal Article] Global in space numerical computation of the ruin probability2022

    • Author(s)
      H. Soutome, N. Ishimura, H. Imai
    • Journal Title

      Advances in Mathematical Sciences and Applications

      Volume: 31(2) Pages: 397-406

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed
  • [Journal Article] 不連続性にもとづく散乱信号からのトモグラフィの数値的実現2022

    • Author(s)
      藤原宏志,川越大輔,陳逸昆
    • Journal Title

      計算工学講演会論文集

      Volume: Vol.27

    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Journal Article] Numerical crack path selection problem based on energy profiles2022

    • Author(s)
      Alifian Mahardhika Maulana、Kimura Masato、Alfat Sayahdin
    • Journal Title

      Japan Journal of Industrial and Applied Mathematics

      Volume: 39 Issue: 3 Pages: 817-841

    • DOI

      10.1007/s13160-022-00523-0

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Comoving mesh method for certain classes of moving boundary problems2022

    • Author(s)
      Sunayama Yosuke、Kimura Masato、Rabago Julius Fergy T.
    • Journal Title

      Japan Journal of Industrial and Applied Mathematics

      Volume: 39 Issue: 3 Pages: 973-1001

    • DOI

      10.1007/s13160-022-00524-z

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Partial inversion of the 2D attenuated X-ray transform with data on an arc2022

    • Author(s)
      Fujiwara Hiroshi、Sadiq Kamran、Tamasan Alexandru
    • Journal Title

      Inverse Problems & Imaging

      Volume: 16 Issue: 1 Pages: 215-228

    • DOI

      10.3934/ipi.2021047

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Phase Field Models for Thermal Fracturing and Their Variational Structures2022

    • Author(s)
      Alfat Sayahdin、Kimura Masato、Maulana Alifian Mahardhika
    • Journal Title

      Materials

      Volume: 15 Issue: 7 Pages: 2571-2571

    • DOI

      10.3390/ma15072571

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] The lewy-stampacchia inequality for the fractional Laplacian and its application to anomalous unidirectional diffusion equations2022

    • Author(s)
      Kow Pu-Zhao、Kimura Masato
    • Journal Title

      Discrete & Continuous Dynamical Systems - B

      Volume: 27 (6) Issue: 6 Pages: 2935-2957

    • DOI

      10.3934/dcdsb.2021167

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Web-based Visualization Framework on FreeFEM2021

    • Author(s)
      LEE, Yu-Hsun, 藤原宏志
    • Journal Title

      計算数理工学論文集

      Volume: Vol.21 Pages: 57-62

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] 部分観測による X 線計算機断層撮影法の数値的実現2021

    • Author(s)
      藤原宏志,大石直也, SADIQ, Kamran, TAMASAN, Alexandru
    • Journal Title

      計算数理工学論文集

      Volume: Vol.21 Pages: 37-43

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Numerical regularity map for simple one-dimensional fractional differential equations with Hoelder continuous solutions2021

    • Author(s)
      Mana Kato, Hiroshi Fujiwara and Hitoshi Imai
    • Journal Title

      Adv. Math. Sci. Appl

      Volume: Vol.30 (No 2) Pages: 499-506

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] A two dimensional source reconstruction method in radiative transport using boundary data measured on an arc2021

    • Author(s)
      H.Fujiwara, K.Sadiq, and A.Tamasan
    • Journal Title

      Inverse Problems

      Volume: 37-11 Issue: 11 Pages: 115005-115005

    • DOI

      10.1088/1361-6420/ac2d75

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Development of three-dimensional integral-type reconstruction formula for magnetic resonance elastography2021

    • Author(s)
      Takeda Tasuku、Fujiwara Hiroshi、Suga Mikio
    • Journal Title

      International Journal of Computer Assisted Radiology and Surgery

      Volume: 16 Issue: 11 Pages: 1947-1956

    • DOI

      10.1007/s11548-021-02517-8

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Multiple-Precision Arithmetic of Biot-Savart Integrals for Reconnections of Vortex Filaments2021

    • Author(s)
      Lee Yu-Hsun、Fujiwara Hiroshi
    • Journal Title

      Lecture Notes in Computer Science book series (LNTCS)

      Volume: 12953 Pages: 191-201

    • DOI

      10.1007/978-3-030-86976-2_13

    • ISBN
      9783030869755, 9783030869762
    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Weak solutions for unidirectional gradient flows: existence, uniqueness, and convergence of time discretization schemes2021

    • Author(s)
      Kimura Masato、Negri Matteo
    • Journal Title

      Nonlinear Differential Equations and Applications NoDEA

      Volume: 28 Issue: 6

    • DOI

      10.1007/s00030-021-00720-9

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Particle Dynamics with Elastic Collision at the Boundary: Existence and Partial Uniqueness of Solutions2021

    • Author(s)
      Kimura M.、van Meurs P.、Yang Z. X.
    • Journal Title

      Acta Applicandae Mathematicae

      Volume: 174 Issue: 1 Pages: 1-26

    • DOI

      10.1007/s10440-021-00423-4

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Irreversible phase field models for crack growth in industrial applications: thermal stress, viscoelasticity, hydrogen embrittlement2021

    • Author(s)
      Kimura Masato、Takaishi Takeshi、Alfat Sayahdin、Nakano Takumi、Tanaka Yoshimi
    • Journal Title

      SN Applied Sciences

      Volume: 3 Issue: 9

    • DOI

      10.1007/s42452-021-04593-6

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Presentation] On a Cauchy-type singular integral equation for x-ray computerized tomography with partial measurement2023

    • Author(s)
      藤原宏志, Kamran Sadiq, Alexandru Tamasan
    • Organizer
      日本数学会 2023年度年会
    • Related Report
      2022 Annual Research Report
  • [Presentation] A Stokes system with a source/sink-type condition derived from a Boltzmann system with discontinuous boundary data2022

    • Author(s)
      S. Taguchi
    • Organizer
      PDE and Applied Analysis Seminar (POSTECH)
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Motion of a rarefied gas induced by discontinuous boundary data2022

    • Author(s)
      S. Taguchi
    • Organizer
      Japan-France Joint Workshop "Interacting Particle Systems and Fluid Mechanics: Theory and Applications"
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Numerical analysis of a slow rarefied gas flow past a circular disk2022

    • Author(s)
      T. Tomita, S. Taguchi, T. Tsuji
    • Organizer
      The 15th World Congress on Computational Mechanics & 8th Asian Pacific Congress on Computational Mechanics (WCCM-APCOM 2022)
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Numerical analysis of slow uniform flow past a circular disk with sharp edge2022

    • Author(s)
      T. Tomita, S. Taguchi, T. Tsuji
    • Organizer
      32nd International Symposium on Rarefied Gas Dynamics
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Source-sink-type condition for slightly rarefied gas flow driven by a discontinuous wall temperature2022

    • Author(s)
      S. Taguchi, T. Tsuji
    • Organizer
      32nd International Symposium on Rarefied Gas Dynamics
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 特異積分方程式による部分観測でのX線計算機トモグラフィ2022

    • Author(s)
      藤原宏志, K.Sadiq, A.Tamasan
    • Organizer
      日本応用数理学会2022年度年会
    • Related Report
      2021 Annual Research Report
  • [Presentation] On feasibility of numerical reconstruction of the attenuation coefficient in the stationary radiative transport equation2022

    • Author(s)
      H. Fujiwara
    • Organizer
      Practical Inverse Problems and Their Prospects
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] An Efficient Numerical Scheme for Near-Infrared Light Propagation in Turbid Media2021

    • Author(s)
      H.Fujiwara
    • Organizer
      IUTAM symposium computational methods for large-scale and complex wave problems
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 自然境界条件を伴う楕円型正則化による移流方程式の数値計算の不連続性の解析2021

    • Author(s)
      今川真城, 川越大輔, 藤原宏志, 磯祐介
    • Organizer
      日本応用数理学会2021年度年会
    • Related Report
      2021 Annual Research Report
  • [Presentation] 2次元遷音速流問題における Tricomi 方程式の変数分離解の記述する速度場2021

    • Author(s)
      高橋幸聖, 川越大輔, 磯祐介
    • Organizer
      日本応用数理学会2021年度年会
    • Related Report
      2021 Annual Research Report
  • [Presentation] Slip-flow theory for a rarefied gas flow driven by a discontinuous wall temperature2021

    • Author(s)
      S. Taguchi
    • Organizer
      International Workshop: Recent Advances in Kinetic Theory and Non-Equilibrium Fluid Dynamics
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 円板を過ぎる中程度に希薄な流れ:モデル Boltzmann 方程式の数値解析2021

    • Author(s)
      富田卓磨,田口智清,辻徹郎
    • Organizer
      日本流体力学会年会 2021
    • Related Report
      2021 Annual Research Report

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Published: 2021-04-28   Modified: 2024-08-08  

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