Journal of Applied and Industrial Mathematics最新文献

{"title":"Equivalence Relations in Convex Optimization","authors":"E. A. Nurminski","doi":"10.1134/S1990478923020126","DOIUrl":"10.1134/S1990478923020126","url":null,"abstract":"<p> Several useful correspondences between general convex optimization problems, support\u0000functions, and projection operations are established. These correspondences cover the asymptotic\u0000equivalence of projection operations and computation of support functions for general convex sets,\u0000hence the same equivalence for general convex optimization problems, and the equivalence\u0000between least-norm problems and the problem of regularized convex suplinear optimization.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"339 - 344"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Numerical Simulation of the Peripheral and Internal Configurations of a Model Assembly of Fuel Elements","authors":"V. A. Ivashchenko,&nbsp;P. D. Lobanov,&nbsp;N. I. Yavorsky,&nbsp;M. P. Tokarev,&nbsp;R. I. Mullyadzhanov","doi":"10.1134/S1990478923020102","DOIUrl":"10.1134/S1990478923020102","url":null,"abstract":"<p> Owing to the active development of nuclear energy in the world and in Russia, increasing\u0000attention is paid to the issues of energy efficiency and safety of nuclear reactors. Although most of\u0000the reactors operating today have already been well studied, some hydrodynamic questions related\u0000to the flow of the moderator along the fuel elements still remain open. In particular, this paper\u0000considers the equivalence of flow in the peripheral and internal regions of the fuel assembly.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"320 - 325"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4290306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Testing Set for Preparata-Like Codes","authors":"A. Yu. Vasil’eva","doi":"10.1134/S1990478923020205","DOIUrl":"10.1134/S1990478923020205","url":null,"abstract":"<p> The reconstruction of an object of a given class by its intersection with some (so-called\u0000testing) set is studied. For the class, we consider Preparata-like codes, i.e., nonlinear codes of\u0000length\u0000<span>( n=2^{2m}-1 )</span>,\u0000<span>( m=2,3,dots )</span>, with code distance 5 and twice the size of a linear code of the same length\u0000and distance. Conditions are determined under which the union of a few concentric spheres forms\u0000a testing set for Preparata-like codes.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"427 - 432"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4286874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical Modelling of COVID-19 Incidence in Moscow with an Agent-Based Model","authors":"V. V. Vlasov,&nbsp;A. M. Deryabin,&nbsp;O. V. Zatsepin,&nbsp;G. D. Kaminsky,&nbsp;E. V. Karamov,&nbsp;A. L. Karmanov,&nbsp;S. N. Lebedev,&nbsp;G. N. Rykovanov,&nbsp;A. V. Sokolov,&nbsp;M. A. Teplykh,&nbsp;A. S. Turgiyev,&nbsp;K. E. Khatuntsev","doi":"10.1134/S1990478923020217","DOIUrl":"10.1134/S1990478923020217","url":null,"abstract":"<p> The outbreak of the COVID-19 pandemic created an emergency situation in the public\u0000health system in Russia and in the world, which entailed the need to develop tools for predicting\u0000the progression of the pandemic and assessing the potential interventions. In the present day\u0000context, numerical simulation is actively used to solve such problems. The paper considers a\u0000COVID-19 agent-based megalopolis model. The model was developed in 2020 and was further\u0000refined in subsequent years. The capabilities of the model include the description of simultaneous\u0000spread of several virus strains and taking into account data on vaccination and population\u0000activity. The model parameters are calculated using statistical data on the daily number of newly\u0000diagnosed COVID-19 cases.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"433 - 450"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4286886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Analytical Methods for Calculating Wave Fields and Reconstructing the Velocity Characteristics of Inhomogeneous Elastic Media in the Baikal Rift Zone","authors":"M. S. Khairetdinov,&nbsp;A. A. Mikhailov,&nbsp;V. V. Kovalevsky,&nbsp;D. L. Pinigina,&nbsp;A. A. Yakimenko","doi":"10.1134/S1990478923020114","DOIUrl":"10.1134/S1990478923020114","url":null,"abstract":"<p> On the basis of a numerical method for solving direct and inverse problems, a method has\u0000been developed for tracking the dynamics of the propagation of a seismohydroacoustic wave field,\u0000constructing model seismograms, and estimating the velocity characteristics of the complex\u0000geophysical structure of the Baikal rift zone in the area of the Babushkin village (southeastern\u0000Baikal) and the Buguldeika village (northwestern Baikal). The choice of the profile for modeling is\u0000due to the experimental work performed here by the Institute of Physics of the Earth of the\u0000Russian Academy of Sciences, the Institute of Computational Mathematics and Mathematical\u0000Geophysics of the Siberian Branch of the Russian Academy of Sciences, and the Institute of\u0000Geology of the Siberian Branch of the Russian Academy of Sciences in 2021. The algorithm for\u0000solving the direct problem of wave field reconstruction is based on applying the Laguerre integral\u0000transform in time and finite-difference approximation in the spatial coordinates. The numerical\u0000model of the medium used to calculate the propagation of seismic waves is established taking into\u0000account a priori data on the velocity section of the Baikal rift zone obtained by a number of\u0000researchers in the region according to the data of deep seismic sounding of the Earth. The results\u0000of direct numerical modeling assume the prediction of the complex structure of the wave field and\u0000are intended to facilitate its interpretation. As an approach to solving the inverse problem of\u0000reconstructing the velocity characteristics of an inhomogeneous medium, a computational grid\u0000algorithm based on calculating weighted average velocities in sections of the grid superimposed on\u0000the Earth’s surface is proposed and tested. By choosing the grid step and the method for\u0000approximating the discrete wave travel time curve by cubic splines and taking into account the\u0000curvature of the head wave travel time curve in areas with a pronounced inhomogeneity of the\u0000medium structure, it is possible to determine the velocity characteristic with an increased\u0000accuracy. The consistency of the reconstructed theoretical velocity model of the medium with the\u0000model experimentally obtained by the method of deep seismic sounding is shown.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"326 - 338"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation of the Structure of Turbulent Flow and Heat Transfer in a Planar Channel with Hexagonal Honeycomb of Varying Depth","authors":"A. V. Barsukov,&nbsp;V. V. Terekhov,&nbsp;V. I. Terekhov","doi":"10.1134/S1990478923020023","DOIUrl":"10.1134/S1990478923020023","url":null,"abstract":"<p> The results of a numerical calculation by the RANS method of a separated flow in a\u0000planar channel in the presence of a honeycomb surface are presented. The calculation is performed\u0000for Reynolds numbers (\u0000<span>( 14thinspace 000leqslant mathrm {Re}leqslant 28thinspace 000 )</span>) determined from the average mass velocity and channel height. The\u0000distribution of the local Nusselt number is obtained for various Reynolds numbers and cell depths.\u0000It is shown that the distribution of the Nusselt number on the surface is highly nonuniform; in\u0000particular, the maximum heat transfer is observed near the upper face of the ribs, in the vicinity\u0000of which the largest velocity gradient is observed.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"242 - 250"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4286418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlocal Inverse Problem for Determining the Unknown Coefficient in the Beam Vibration Equation","authors":"U. D. Durdiev,&nbsp;Z. R. Bozorov","doi":"10.1134/S1990478923020060","DOIUrl":"10.1134/S1990478923020060","url":null,"abstract":"<p> The paper is devoted to the study of the direct problem for the vibration of\u0000a homogeneous beam of finite length with nonlocal time conditions. Necessary and sufficient\u0000conditions for the existence of a solution of the direct problem are obtained. For the direct\u0000problem, we study the inverse problem of determining the time-dependent coefficient multiplying\u0000a lower-order derivative. Using the eigenvalues and eigenfunctions, the problem is reduced to\u0000a system of integral equations. The existence and uniqueness of the solution of inverse problems\u0000are shown using the Banach principle.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"281 - 290"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4291015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase Image Decoding Algorithm for Three-Dimensional Geometry Measurements of Dynamic Objects","authors":"S. V. Dvoinishnikov,&nbsp;D. V. Kulikov,&nbsp;V. G. Meledin,&nbsp;V. V. Rakhmanov","doi":"10.1134/S1990478923020072","DOIUrl":"10.1134/S1990478923020072","url":null,"abstract":"<p> We propose an algorithm for decoding phase images that has algorithmic complexity\u0000<span>( O(Nlog N) )</span>. The method is based on an iterative search for the minimum deviation of\u0000the model function from the measurement results. The use of an interval search algorithm\u0000permitted considerably reducing the computational complexity of the algorithm. The error of the\u0000proposed method is comparable to the error of the phase image decoding method based on the\u0000analytical solution of the system of equations describing the intensity in the phase images.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"291 - 295"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation of the Interaction between a Shock Wave and Aqueous Foam with Compaction","authors":"P. A. Chuprov,&nbsp;S. V. Fortova,&nbsp;P. S. Utkin","doi":"10.1134/S1990478923020059","DOIUrl":"10.1134/S1990478923020059","url":null,"abstract":"<p> A numerical study of the interaction of a blast wave with liquid foam is carried out using\u0000the system of Baer–Nunziato equations. This problem is aimed at studying the influence of the\u0000compaction mechanism on the re-reflection wave pattern. A computational algorithm based on the\u0000HLL method is developed. Comparison of the results with computational experiments by other\u0000authors shows that taking into account the compaction mechanism leads to better results.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"272 - 280"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4286887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Solvability of an Initial–Boundary Value Problem for a High Even Order Partial Differential Equation Degenerating on the Domain Boundary","authors":"A. K. Urinov,&nbsp;M. S. Azizov","doi":"10.1134/S1990478923020199","DOIUrl":"10.1134/S1990478923020199","url":null,"abstract":"<p> An initial–boundary value problem is posed in a rectangle for a degenerate partial\u0000differential equation of high even order with a Bessel operator. The existence, uniqueness, and\u0000stability of a solution of the problem under study are proved.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"414 - 426"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}