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<article article-type="research-article" dtd-version="1.3" 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" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">mireabulletin</journal-id><journal-title-group><journal-title xml:lang="ru">Russian Technological Journal</journal-title><trans-title-group xml:lang="en"><trans-title>Russian Technological Journal</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2782-3210</issn><issn pub-type="epub">2500-316X</issn><publisher><publisher-name>RTU MIREA</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.32362/2500-316X-2024-12-1-111-122</article-id><article-id custom-type="elpub" pub-id-type="custom">mireabulletin-830</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATHEMATICAL MODELING</subject></subj-group></article-categories><title-group><article-title>Использование сплайнов сложной структуры в проектировании дорожных трасс</article-title><trans-title-group xml:lang="en"><trans-title>The use of complex structure splines in roadway design</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-9801-7454</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Струченков</surname><given-names>В. И.</given-names></name><name name-style="western" xml:lang="en"><surname>Struchenkov</surname><given-names>V. I.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Струченков Валерий Иванович - д.т.н., профессор, кафедра геоинформационных систем Института радиоэлектроники и информатики. Scopus Author ID 36451166800.</p><p>119454, Москва, пр-т Вернадского, д. 78</p></bio><bio xml:lang="en"><p>Valery I. Struchenkov - Dr. Sci. (Eng.), Professor, Department of Geographic Information Systems, Institute of Radio Electronics and Informatics. Scopus Author ID 36451166800.</p><p>78, Vernadskogo pr., Moscow, 119454</p></bio><email xlink:type="simple">str1942@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-3734-7182</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Карпов</surname><given-names>Д. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Karpov</surname><given-names>D. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Карпов Дмитрий Анатольевич - к.т.н., заведующий кафедрой геоинформационных систем Института радиоэлектроники и информатики. Scopus Author ID 57211584863.</p><p>119454, Москва, пр-т Вернадского, д. 78</p></bio><bio xml:lang="en"><p>Dmitry A. Karpov - Cand. Sci. (Eng.), Head of the Department of Geographic Information Systems, Institute of Radio Electronics and Informatics. Scopus Author ID 57211584863.</p><p>78, Vernadskogo pr., Moscow, 119454</p></bio><email xlink:type="simple">karpov@mirea.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>МИРЭА – Российский технологический университет</institution><country>Россия</country></aff><aff xml:lang="en"><institution>MIREA – Russian Technological University</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2024</year></pub-date><pub-date pub-type="epub"><day>02</day><month>02</month><year>2024</year></pub-date><volume>12</volume><issue>1</issue><fpage>111</fpage><lpage>122</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Струченков В.И., Карпов Д.А., 2024</copyright-statement><copyright-year>2024</copyright-year><copyright-holder xml:lang="ru">Струченков В.И., Карпов Д.А.</copyright-holder><copyright-holder xml:lang="en">Struchenkov V.I., Karpov D.A.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.rtj-mirea.ru/jour/article/view/830">https://www.rtj-mirea.ru/jour/article/view/830</self-uri><abstract><sec><title>Цели</title><p>Цели. Цель работы состоит в развитии теории сплайн-аппроксимации последовательности точек на плоскости на случай использования составных сплайнов сложной структуры. В отличие от простого, например, полиномиального сплайна, составной сплайн содержит повторяющиеся связки нескольких элементов. Такая задача возникает в проектировании трасс железных и автомобильных дорог. План (проекция на горизонтальную плоскость) такой трассы – это кривая, состоящая из повторяющейся связки элементов «прямая ++ клотоида + окружность + клотоида …», что обеспечивает непрерывность не только кривой и касательной, но и кривизны. Число элементов сплайна неизвестно и должно определяться в процессе решения проектной задачи. Алгоритм решения задачи применительно к сплайну, состоящему из дуг окружностей, сопрягаемых прямыми, реализован и опубликован ранее. Аппроксимирующий сплайн в общем случае – многозначная функция. На координаты точек ее графика могут накладываться ограничения. Еще одним существенным фактором, усложняющим задачу, является наличие клотоид, которые не выражаются аналитически (формулой). Алгоритм определения числа элементов сплайна с клотоидами и построения начального приближения опубликован ранее. В настоящей статье рассматривается следующий этап решения задачи – оптимизация с применением нелинейного программирования сплайна, полученного на первом этапе по методу динамического программирования.</p></sec><sec><title>Методы</title><p>Методы. Для оптимизации параметров сплайна используется новая математическая модель в виде модифицированной функции Лагранжа и специальный алгоритм нелинейного программирования. При этом удается вычислять аналитически производные целевой функции по параметрам сплайна при отсутствии ее аналитического выражения через эти параметры.</p></sec><sec><title>Результаты</title><p>Результаты. Разработаны математическая модель и алгоритм оптимизации параметров составного сплайна, состоящего из дуг окружностей, сопрягаемых клотоидами и прямыми.</p></sec><sec><title>Выводы</title><p>Выводы. Предложенная ранее двухэтапная схема проектирования плана трасс линейных сооружений пригодна и при использовании составных сплайнов с клотоидами.</p></sec></abstract><trans-abstract xml:lang="en"><sec><title>Objectives</title><p>Objectives. The aim of the work is to develop the theory of spline-approximation of a sequence of points on a plane for using compound splines with a complex structure. In contrast to a simple spline (e.g., polynomial), a compound spline contains repeating bundles of several elements. Such problems typically arise in the design of traces for railroads and highways. The plan (projection on the horizontal plane) of such a trace is a curve consisting of a repeating bundle of elements “line + clothoid + circle + clothoid ...,” which ensures continuity not only of curve and tangent but also of curvature. The number of spline elements, which is unknown, should be determined in the process of solving the design problem. An algorithm for solving the problem with respect to the spline, which consists of arcs conjugated by straight lines, was implemented and published in an earlier work. The approximating spline in the general case is a multivalued function, whose ordinates may be limited. Another significant factor that complicates the problem is the presence of clothoids that are not expressed analytically (in a formula). The algorithm for determining the number of elements of a spline with clothoids and constructing an initial approximation was also published earlier. The present work considers the next stage of solving the spline approximation problem: optimization using a nonlinear programming spline obtained at the first stage by means of the dynamic programming method.</p></sec><sec><title>Methods</title><p>Methods. A new mathematical model in the form of a modified Lagrange function is used together with a special nonlinear programming algorithm to optimize spline parameters. In this case, it is possible to calculate the derivatives of the objective function by the spline parameters in the absence of its analytical expression through these parameters.</p></sec><sec><title>Results</title><p>Results. A mathematical model and algorithm for optimization of compound spline parameters comprising arcs of circles conjugated by clothoids and lines have been developed.</p></sec><sec><title>Conclusions</title><p>Conclusions. The previously proposed two-step scheme for designing paths of linear structures is also suitable for the utilization of compound splines with clothoids.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>план трассы</kwd><kwd>сплайн</kwd><kwd>нелинейное программирование</kwd><kwd>клотоида</kwd><kwd>целевая функция</kwd><kwd>ограничения</kwd></kwd-group><kwd-group xml:lang="en"><kwd>trace plan</kwd><kwd>spline</kwd><kwd>nonlinear programming</kwd><kwd>clothoid</kwd><kwd>objective function</kwd><kwd>constraints</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Карпов Д.А., Струченков В.И. Двухэтапная сплайн-аппроксимация в компьютерном проектировании трасс линейных сооружений. Russ. Technol. J. 2021;9(5):45–56. https://doi.org/10.32362/2500-316X-2021-9-5-45-56</mixed-citation><mixed-citation xml:lang="en">Karpov D.A., Struchenkov V.I. Two-stage spline-approximation in linear structure routing. Russ. Technol. J. 2021;9(5):45−56 (in Russ.). https://doi.org/10.32362/2500-316X-2021-9-5-45-56</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Карпов Д.А., Струченков В.И. Сплайн-аппроксимация многозначных функций в проектировании трасс линейных сооружений. Russ. Technol. J. 2022;10(4):65–74. https://doi.org/10.32362/2500-316X-2022-10-4-65-74</mixed-citation><mixed-citation xml:lang="en">Karpov D.A., Struchenkov V.I. Spline approximation of multivalued function in leaner structures routing. Russ. Technol. J. 2022;10(4):65–74 (in Russ.). https://doi.org/10.32362/2500-316X-2022-10-4-65-74</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Карпов Д.А., Струченков В.И. Оптимизация параметров сплайна при аппроксимации многозначных функций. Russ. Technol. J. 2023;11(2);72–83. https://doi.org/10.32362/2500-316X-2023-11-2-72-83</mixed-citation><mixed-citation xml:lang="en">Karpov D.A., Struchenkov V.I. Optimization of spline parameters in approximation of multi-valued function Russ. Technol. J. 2023;11(2):72–83 (in Russ.). https://doi.org/10.32362/2500-316X-2023-11-2-72-83</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Li W., Pu H., Schonfeld P., et al. A Method for Automatically Recreating the Horizontal Alignment Geometry of Existing Railways. Comput. Aided Civ. Infrastruct. Eng. 2019;34(1):71–94. https://doi.org/10.1111/mice.12392</mixed-citation><mixed-citation xml:lang="en">Li W., Pu H., Schonfeld P., et al. A Method for Automatically Recreating the Horizontal Alignment Geometry of Existing Railways. Comput. Aided Civ. Infrastruct. Eng. 2019;34(1):71–94. https://doi.org/10.1111/mice.12392</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Jha M.K., McCall C., Schonfeld P. Using GIS, genetic algorithms, and visualization in highway development. Comput. Aided Civ. Infrastruct. Eng. 2001;16(6):399–414. https://doi.org/10.1111/0885-9507.00242</mixed-citation><mixed-citation xml:lang="en">Jha M.K., McCall C., Schonfeld P. Using GIS, genetic algorithms, and visualization in highway development. Comput. Aided Civ. Infrastruct. Eng. 2001;16(6):399–414. https://doi.org/10.1111/0885-9507.00242</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Jha M.K., Schonfeld P. A highway alignment optimization model using geographic information systems. Transp. Res. Part A. Policy Pract. 2004;8(6):455–481. https://doi.org/10.1016/j.tra.2004.04.001</mixed-citation><mixed-citation xml:lang="en">Jha M.K., Schonfeld P. A highway alignment optimization model using geographic information systems. Transp. Res. Part A. Policy Pract. 2004;8(6):455–481. https://doi.org/10.1016/j.tra.2004.04.001</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Jong J.C., Jha M.K., Schonfeld P. Preliminary highway design with genetic algorithms and geographic information systems. Comput. Aided Civ. Infrastruct. Eng. 2000;15(4):261–271. https://doi.org/10.1111/0885-9507.00190</mixed-citation><mixed-citation xml:lang="en">Jong J.C., Jha M.K., Schonfeld P. Preliminary highway design with genetic algorithms and geographic information systems. Comput. Aided Civ. Infrastruct. Eng. 2000;15(4):261–271. https://doi.org/10.1111/0885-9507.00190</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Kang M.W., Schonfeld P., Yang N. Prescreening and repairing in a genetic algorithm for highway alignment optimization. Comput. Aided Civ. Infrastruct. Eng. 2009;24(2):109–119. https://doi.org/10.1111/j.1467-8667.2008.00574.x</mixed-citation><mixed-citation xml:lang="en">Kang M.W., Schonfeld P., Yang N. Prescreening and repairing in a genetic algorithm for highway alignment optimization. Comput. Aided Civ. Infrastruct. Eng. 2009;24(2):109–119. https://doi.org/10.1111/j.1467-8667.2008.00574.x</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Pushak Y., Hare W., Lucet Y. Multiple-path selection for new highway alignments using discrete algorithms. Eur. J. Oper. Res. 2016;248(2):415–427. https://doi.org/10.1016/j.ejor.2015.07.039</mixed-citation><mixed-citation xml:lang="en">Pushak Y., Hare W., Lucet Y. Multiple-path selection for new highway alignments using discrete algorithms. Eur. J. Oper. Res. 2016;248(2):415–427. https://doi.org/10.1016/j.ejor.2015.07.039</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Sarma K.C., Adeli H. Bilevel parallel genetic algorithms for optimization of large steel structures. Comput. Aided Civ. Infrastruct. Eng. 2001;16(5):295–304. https://doi.org/10.1111/0885-9507.00234</mixed-citation><mixed-citation xml:lang="en">Sarma K.C., Adeli H. Bilevel parallel genetic algorithms for optimization of large steel structures. Comput. Aided Civ. Infrastruct. Eng. 2001;16(5):295–304. https://doi.org/10.1111/0885-9507.00234</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Shafahi Y., Bagherian M. A customized particle swarm method to solve highway alignment optimization problem. Comput. Aided Civ. Infrastruct. Eng. 2013;28(1):52–67. https://doi.org/10.1111/j.1467-8667.2012.00769.x</mixed-citation><mixed-citation xml:lang="en">Shafahi Y., Bagherian M. A customized particle swarm method to solve highway alignment optimization problem. Comput. Aided Civ. Infrastruct. Eng. 2013;28(1):52–67. https://doi.org/10.1111/j.1467-8667.2012.00769.x</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Bosurgi G., D’Andrea A. A polynomial parametric curve (PPC-curve) for the design of horizontal geometry of highways. Comput. Aided Civ. Infrastruct. Eng. 2012;27(4):303–312. https://doi.org/10.1111/j.1467-8667.2011.00750.x</mixed-citation><mixed-citation xml:lang="en">Bosurgi G., D’Andrea A. A polynomial parametric curve (PPC-curve) for the design of horizontal geometry of highways. Comput. Aided Civ. Infrastruct. Eng. 2012;27(4):303–312. https://doi.org/10.1111/j.1467-8667.2011.00750.x</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Cerf R. The quasispecies regime for the simple genetic algorithm with roulette wheel Selection. Cornell University. Adv. Appl. Probability. 2017;49(3):903–926. https://doi.org/10.1017/apr.2017.26</mixed-citation><mixed-citation xml:lang="en">Cerf R. The quasispecies regime for the simple genetic algorithm with roulette wheel Selection. Cornell University. Adv. Appl. Probability. 2017;49(3):903–926. https://doi.org/10.1017/apr.2017.26</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Oudshoorn M., Koppenberg T., Yorke-Smith N. Optimization of annual planned rail maintenance. Comput. Aided Civ. Infrastruct. Eng. 2021;37(6):669–687. https://doi.org/10.1111/mice.12764</mixed-citation><mixed-citation xml:lang="en">Oudshoorn M., Koppenberg T., Yorke-Smith N. Optimization of annual planned rail maintenance. Comput. Aided Civ. Infrastruct. Eng. 2021;37(6):669–687. https://doi.org/10.1111/mice.12764</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Струченков В.И. Новый алгоритм поэлементного расчета трасс в САПР линейных сооружений. Информационные технологии. 2015;21(4):271–276.</mixed-citation><mixed-citation xml:lang="en">Struchenkov V.I. New algorithm for perelement calculation of line structures routes. Informacionnye tekhnologii = Information Technologies. 2015;21(4):271–276 (in Russ.).</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Бородакий Ю.В., Загребаев А.М., Крицына Н.А., Кулябичев Ю.П., Шумилов Ю.Ю. Нелинейное программирование в современных задачах оптимизации. М.: НИЯУ МИФИ; 2011. 244 с. ISBN 987-5-7262-1451-1</mixed-citation><mixed-citation xml:lang="en">Borodakii Yu.V., Zagrebaev A.M., Kritsyna N.A., Kulyabichev Yu.P., Shumilov Yu.Yu. Nelineinoe programmirovanie v sovremennykh zadachakh optimizatsii (Nonlinear Programming in Modern Optimization Problem). Moscow: NIYAU MEPhI; 2008. 244 р. (in Russ.).</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Поляков В.М., Агаларов З.С. Методы оптимизации. М.: Дашков и К; 2022. 86 с. ISBN 978-5-3940-5003-9</mixed-citation><mixed-citation xml:lang="en">Polyakov V.M., Agalarov Z.S. Metody optimizatsii (Optimization Methods). Moscow: Dashkov i K; 2022. 86 p. (in Russ.). ISBN 978-5-3940-5003-9</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Гасников А.В. Современные численные методы оптимизации. Метод универсального градиентного спуска. М.: МЦНМО; 2021. 272 с. ISBN 978-5-4439-1614-9</mixed-citation><mixed-citation xml:lang="en">Gasnikov A.V. Sovremennye chislennye metody optimizatsii. Metod universal’nogo gradientnogo spuska (Modern Numerical Optimization Methods. Universal Gradient Method Descent). Moscow: MTsNMO; 2021.272 p. (in Russ.). ISBN 978-5-4439-1614-9</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Струченков В.И. Методы оптимизации трасс в САПР линейных сооружений. М.: СОЛОН-Пресс; 2020. 272 с. ISBN 978-5-9135-9139-5</mixed-citation><mixed-citation xml:lang="en">Struchenkov V.I. Metody optimizatsii trass v SAPR lineinykh sooruzhenii (Methods for Route Optimization in CAD of Linear Structures). Moscow: SOLON-Press; 2020. 272 р. (in Russ.). ISBN 978-5-9135-9139-5</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Кохендерфер М. Д., Уилер Т.А. Алгоритмы оптимизации. M.: Вильямс; 2020. 528 с.</mixed-citation><mixed-citation xml:lang="en">Kochenderfer M.D., Wheeler T.A. Algoritmy optimizatsii (Algorithms for Optimization). Moscow: Vil’yams; 2020. 528 p. (in Russ.). [Kochenderfer M.D., Wheeler T.A. Algorithms for Optimization. London: The MIT Press; 2019. 520 p.]</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Audet C., Hare W. Derivative-Free and Blackbox Optimization. Springer Series in Operations Research and Financial Engineering. Springer; 2017. 302 р. https://doi.org/10.1007/978-3-319-68913-5</mixed-citation><mixed-citation xml:lang="en">Audet C., Hare W. Derivative-Free and Blackbox Optimization. Springer Series in Operations Research and Financial Engineering. Springer; 2017. 302 р. https://doi.org/10.1007/978-3-319-68913-5</mixed-citation></citation-alternatives></ref><ref id="cit22"><label>22</label><citation-alternatives><mixed-citation xml:lang="ru">Черноруцкий И.Г. Методы оптимизации. Компьютерные технологии. СПб.: БХВ-Петербург; 2011. 329 с.</mixed-citation><mixed-citation xml:lang="en">Chernorutskii I.G. Metody optimizatsii. Komp’yuternye tekhnologii (Methods of Optimization. Computer Technologies). St. Petersburg: BHV-Petersburg; 2011. 329 p. (in Russ.).</mixed-citation></citation-alternatives></ref><ref id="cit23"><label>23</label><citation-alternatives><mixed-citation xml:lang="ru">Гилл Ф., Мюррей У., Райт М. Практическая оптимизация: пер. с англ. М.: Мир; 1985. 509 c.</mixed-citation><mixed-citation xml:lang="en">Gill Ph.E., Murray W., Wright M.H. Prakticheskaya optimizatsiya (Practical Optimization): transl. from Engl. Moscow: Mir; 1985. 509 p. (in Russ.). [Gill Ph.E., Murray W., Wright M.H. Practical Optimization. London: Academic Press; 1981. 402 p.]</mixed-citation></citation-alternatives></ref><ref id="cit24"><label>24</label><citation-alternatives><mixed-citation xml:lang="ru">Ларичев О.И., Горвиц Г.Г. Методы поиска локальных экстремумов овражных функций. М.: Наука; 1990. 96 с.</mixed-citation><mixed-citation xml:lang="en">Larichev O.I., Gorvits G.G. Metody poiska lokal’nykh ekstremumov ovrazhnykh funktsii (Methods for Finding Local Extrema of Ravine Functions). Moscow: Nauka; 1990. 96 p. (in Russ.).</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
