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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Discrete and Continuous Models and Applied Computational Science</journal-id><journal-title-group><journal-title xml:lang="en">Discrete and Continuous Models and Applied Computational Science</journal-title><trans-title-group xml:lang="ru"><trans-title>Discrete and Continuous Models and Applied Computational Science</trans-title></trans-title-group></journal-title-group><issn publication-format="print">2658-4670</issn><issn publication-format="electronic">2658-7149</issn><publisher><publisher-name xml:lang="en">Peoples' Friendship University of Russia named after Patrice Lumumba (RUDN University)</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">40099</article-id><article-id pub-id-type="doi">10.22363/2658-4670-2024-32-1-48-60</article-id><article-id pub-id-type="edn">HEYUGO</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Articles</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Статьи</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Solving the eikonal equation by the FSM method in Julia language</article-title><trans-title-group xml:lang="ru"><trans-title>Решение уравнения эйконала методом FSM на языке Julia</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-4092-4326</contrib-id><contrib-id contrib-id-type="researcherid">GLS-1445-2022</contrib-id><name-alternatives><name xml:lang="en"><surname>Stepa</surname><given-names>Christina A.</given-names></name><name xml:lang="ru"><surname>Штепа</surname><given-names>К. А.</given-names></name></name-alternatives><bio xml:lang="en"><p>PhD student of Probability Theory and Cyber Security</p></bio><email>1042210111@pfur.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-3036-0117</contrib-id><contrib-id contrib-id-type="scopus">57219092618</contrib-id><contrib-id contrib-id-type="researcherid">AGY-9849-2022</contrib-id><name-alternatives><name xml:lang="en"><surname>Fedorov</surname><given-names>Arseny V.</given-names></name><name xml:lang="ru"><surname>Фёдоров</surname><given-names>А. В.</given-names></name></name-alternatives><bio xml:lang="en"><p>PhD student of Probability Theory and Cyber Security</p></bio><email>1042210107@rudn.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-4834-4895</contrib-id><contrib-id contrib-id-type="scopus">57190004380</contrib-id><contrib-id contrib-id-type="researcherid">E-9214-2016</contrib-id><name-alternatives><name xml:lang="en"><surname>Gevorkyan</surname><given-names>Migran N.</given-names></name><name xml:lang="ru"><surname>Геворкян</surname><given-names>М. Н.</given-names></name></name-alternatives><bio xml:lang="en"><p>Candidate of Sciences in Physics and Mathematics, Associate Professor of Department of Probability Theory and Cyber Security</p></bio><email>gevorkyan-mn@rudn.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7141-7610</contrib-id><contrib-id contrib-id-type="scopus">36968057600</contrib-id><contrib-id contrib-id-type="researcherid">I-3191-2013</contrib-id><name-alternatives><name xml:lang="en"><surname>Korolkova</surname><given-names>Anna V.</given-names></name><name xml:lang="ru"><surname>Королькова</surname><given-names>А. В.</given-names></name></name-alternatives><bio xml:lang="en"><p>Docent, Candidate of Sciences in Physics and Mathematics, Associate Professor of Department of Probability Theory and Cyber Security</p></bio><email>korolkova-av@rudn.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-0877-7063</contrib-id><contrib-id contrib-id-type="scopus">35194130800</contrib-id><contrib-id contrib-id-type="researcherid">I-3183-2013</contrib-id><name-alternatives><name xml:lang="en"><surname>Kulyabov</surname><given-names>Dmitry S.</given-names></name><name xml:lang="ru"><surname>Кулябов</surname><given-names>Д. С.</given-names></name></name-alternatives><bio xml:lang="en"><p>Professor, Doctor of Sciences in Physics and Mathematics, Professor of the Department of Probability Theory and Cyber Security of Peoples’ Friendship University of Russia named after Patrice Lumumba (RUDN University); Senior Researcher of Laboratory of Information Technologies, Joint Institute for Nuclear Research</p></bio><email>kulyabov-ds@rudn.ru</email><xref ref-type="aff" rid="aff1"/><xref ref-type="aff" rid="aff2"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">RUDN University</institution></aff><aff><institution xml:lang="ru">Российский университет дружбы народов</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">Joint Institute for Nuclear Research</institution></aff><aff><institution xml:lang="ru">Объединённый институт ядерных исследований</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2024-06-30" publication-format="electronic"><day>30</day><month>06</month><year>2024</year></pub-date><volume>32</volume><issue>1</issue><issue-title xml:lang="en">VOL 32, NO1 (2024)</issue-title><issue-title xml:lang="ru">ТОМ 32, №1 (2024)</issue-title><fpage>48</fpage><lpage>60</lpage><history><date date-type="received" iso-8601-date="2024-07-19"><day>19</day><month>07</month><year>2024</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2024, Stepa C.A., Fedorov A.V., Gevorkyan M.N., Korolkova A.V., Kulyabov D.S.</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2024, Штепа К.А., Фёдоров А.В., Геворкян М.Н., Королькова А.В., Кулябов Д.С.</copyright-statement><copyright-year>2024</copyright-year><copyright-holder xml:lang="en">Stepa C.A., Fedorov A.V., Gevorkyan M.N., Korolkova A.V., Kulyabov D.S.</copyright-holder><copyright-holder xml:lang="ru">Штепа К.А., Фёдоров А.В., Геворкян М.Н., Королькова А.В., Кулябов Д.С.</copyright-holder><ali:free_to_read xmlns:ali="http://www.niso.org/schemas/ali/1.0/"/><license><ali:license_ref xmlns:ali="http://www.niso.org/schemas/ali/1.0/">https://creativecommons.org/licenses/by-nc/4.0</ali:license_ref></license></permissions><self-uri xlink:href="https://journals.rudn.ru/miph/article/view/40099">https://journals.rudn.ru/miph/article/view/40099</self-uri><abstract xml:lang="en"><p>There are two main approaches to the numerical solution of the eikonal equation: reducing it to asystemofODES(methodofcharacteristics)andconstructingspecializedmethodsforthenumericalsolutionof this equation in the form of a partial differential equation. The latter approach includes the FSM (Fast sweeping method) method. It is reasonable to assume that a specialized method should have greater versatility. The purpose of this work is to evaluate the applicability of the FSM method for constructing beams and fronts. The implementation of the FSM method in the Eikonal library of the Julia programming language was used. The method was used for numerical simulation of spherical lenses by Maxwell, Luneburg and Eaton. These lenses were chosen because their optical properties have been well studied. A special case of flat lenses was chosen as the easiest to visualize and interpret the results. The results of the calculations are presented in the form of images of fronts and rays for each of the lenses. From the analysis of the obtained images, it is concluded that the FSM method is well suited for constructing electromagnetic wave fronts. An attempt to visualize ray trajectories based on the results of his work encounters a number of difficulties and in some cases gives an incorrect visual picture.</p></abstract><trans-abstract xml:lang="ru"><p>Существует два основных подхода к численному решению уравнения эйконала: сведение его к системе ОДУ (метод характеристик) и конструирование специализированных методов для численного решения данного уравнения в виде дифференциального уравнения в частных производных. К последнему подходу относится метод FSM (Fast sweeping method). Резонно предположить, что специализированный метод должен обладать большей универсальностью. Цель данной работы - оценка применимости метода FSM для построения лучей и фронтов. Использовалась реализация метода FSM в библиотеке Eikonal языка программирования Julia. Метод применялся для численного моделирования сферических линз Максвелла, Люнеберга и Итона. Данные линзы были выбраны так как их оптические свойства хорошо изучены. Был выбран частный случай плоских линз, как наиболее простых для визуализации и интерпретации результатов. Результаты вычислений представлены в виде изображений фронтов и лучей для каждой из линз. Из анализа полученных изображений сделан вывод, что метод FSM хорошо подходит для построения фронтов электромагнитных волн. Попытка же по результатам его работы визуализировать траектории лучей наталкивается на ряд трудностей и в некоторых случаях дает неправильную визуальную картину.</p></trans-abstract><kwd-group xml:lang="en"><kwd>eikonal equation</kwd><kwd>geometric optics</kwd><kwd>wave optics</kwd><kwd>Julia language</kwd><kwd>Fast Sweeping Method</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>уравнение эйконала</kwd><kwd>геометрическая оптика</kwd><kwd>волновая оптика</kwd><kwd>Julia language</kwd><kwd>FSM</kwd></kwd-group><funding-group><funding-statement xml:lang="en">This publication has been supported by the RUDN University Scientific Projects Grant System, project No 021934-0-000&#13;
&#13;
(recipients Anna V. Korolkova; Migran N. Gevorkyan) and has been supported by the RUDN University Strategic Academic Leadership Program (recipient Dmitry S. Kulyabov; Arseny V. Fedorov; Christina A. Stepa).</funding-statement></funding-group></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Zhao, H. A fast sweeping method for Eikonal equations. Mathematics of Computation 74, 603-627 doi:10.1090/s0025-5718-04-01678-3 (May 2004).</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Gremaud, P. A. &amp; Kuster, C. M. Computational Study of Fast Methods for the Eikonal Equation. SIAM Journal on Scientific Computing 27, 1803-1816. doi:10.1137/040605655 (Jan. 2006).</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Jeong, W. &amp; Whitaker, R. A fast eikonal equation solver for parallel systems. SIAM conference 84112, 1-4 (2007).</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Kulyabov, D. S., Gevorkyan, M. N. &amp; Korolkova, A. V. Software Implementation of the Eikonal Equation in Proceedings of the Selected Papers of the 8th International Conference ”Information and Telecommunication Technologies and Mathematical Modeling of High-Tech Systems” (ITTMM-2018), Moscow, Russia, April 16, 2018 (eds Kulyabov, D. S., Samouylov, K. E. &amp; Sevastianov, L. A.) 2177 (Moscow, Apr. 2018), 25-32.</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Kulyabov, D. S., Korolkova, A. V., Velieva, T. R. &amp; Gevorkyan, M. N. Numerical analysis of eikonal equation in Saratov Fall Meeting 2018: Laser Physics, Photonic Technologies, and Molecular Modeling (ed Derbov, V. L.) 11066 (SPIE, Saratov, June 2019), 56. doi:10.1117/12.2525142. arXiv: 1906.09467.</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Févotte, F. Fast Sweeping and Fast Marching methods for the solution of eikonal equations version 0.2.0. https://github.com/triscale-innov/Eikonal.jl (2023).</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Lauwens, B. &amp; Downey, A. Think Julia How to Think Like a Computer Scientist. 229 pp. (O’Reilly Media, Inc., 2019).</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Born, M. &amp; Wolf, E. Principles of Optics 7th. 952 pp. (Cambridge University Press, 1999).</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Fedorov, A. V., Stepa, C. A., Korolkova, A. V., Gevorkyan, M. N. &amp; Kulyabov, D. S. Methodological derivation of the eikonal equation. Discrete and Continuous Models and Applied Computational Science 31, 399-418. doi:10.22363/2658-4670-2023-31-4-399-418 (Dec. 2023).</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Ivanov, D. I., Ivanov, I. E. &amp; Kryukov, I. A. Hamilton-Jacobi equation-based algorithms for approximate solutions to certain problems in applied geometry. Computational Mathematics and Mathematical Physics 45, 1297-1310 (8 2005).</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Kabanikhin, S. I. &amp; Krivorotko, O. I. Numerical solution eikonal equation. Siberian Electronic Mathematical Reports 10, 28-34 (2013).</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Fonseca, N. J. G., Tyc, T. &amp; Quevedo-Teruel, O. A solution to the complement of the generalized Luneburg lens problem. Communications Physics 4. doi:10.1038/s42005-021-00774-2 (2021).</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Abbasi, M. A. B. &amp; Fusco, V. F. Maxwell Fisheye Lens Based Retrodirective Array. Scientific Reports 9. doi:10.1038/s41598-019-52779-1 (Nov. 2019).</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Zeng, Y. &amp; Werner, D. H. Two-dimensional inside-out Eaton Lens. Design technique and TMpolarized wave properties. Optical Express 20, 2335-2345. doi:10.1364/OE.20.002335 (Jan. 2012).</mixed-citation></ref><ref id="B15"><label>15.</label><mixed-citation>Gevorkyan, M. N., Kulyabov, D. S. &amp; Sevastyanov, L. A. Review of Julia programming language for scientific computing in The 6th International Conference ”Distributed Computing and Gridtechnologies in Science and Education” (2014), 27.</mixed-citation></ref><ref id="B16"><label>16.</label><mixed-citation>Phillips, L. Practical Julia. A Hands-On Introduction for Scientific Minds 528 pp. (No Starch Press, Oct. 31, 2023).</mixed-citation></ref></ref-list></back></article>
