{"title":"Hypergraph Edge Representations with the Use of Homological Paths","authors":"M. N. Vyalyi, V. E. Karpov","doi":"10.1134/S1990478923030201","DOIUrl":"10.1134/S1990478923030201","url":null,"abstract":"<p> We consider the problem of realization of hypergraphs on a graph provided each hyperedge\u0000is realized by a subgraph in which exactly two vertices have odd degree. This problem is related to\u0000Cycle Double Cover conjecture. We prove that checking the existence of realization is\u0000computationally hard. The hardness is proved in various settings: for realizations on all graphs,\u0000on simple graphs, and on graphs from several restricted classes.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 3","pages":"678 - 686"},"PeriodicalIF":0.58,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909134","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":"Decomposition of Singularly Perturbed Optimal Tracking Problems with a Given Reference Trajectory","authors":"V. A. Sobolev","doi":"10.1134/S1990478923030171","DOIUrl":"10.1134/S1990478923030171","url":null,"abstract":"<p> For the first time, the problem of optimal tracking with a given reference trajectory and\u0000an integral quadratic performance criterion in the presence of singular perturbations is considered.\u0000The decomposition method is used to analyze singularly perturbed differential systems that arise\u0000in solving this problem. The method is based on the technique of integral manifolds of fast and\u0000slow motions. A suboptimal control is constructed the use of which leads to a difference in the\u0000values of the minimized functional for the optimal and suboptimal controls by an amount of the\u0000order of the second power of a small parameter characterizing singular perturbations.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 3","pages":"640 - 650"},"PeriodicalIF":0.58,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909127","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 Simulation of a Turbulent Gas Flow over a Wavy Surface","authors":"Yu. S. Apostol, I. S. Vozhakov","doi":"10.1134/S1990478923020011","DOIUrl":"10.1134/S1990478923020011","url":null,"abstract":"<p> We use the <span>OpnFoam</span>\u0000package to numerically study the turbulent flow over a wavy surface for various values of the\u0000amplitude and wavelength of the perturbation of the channel wall. The RANS and LES models\u0000are used to describe turbulent characteristics. The Reynolds number in the flow is 20 000. The\u0000average profiles of velocities and shear stresses on the channel wall are obtained. The values of the\u0000amplitude and phase shift for perturbations of the shear stress are calculated for various\u0000geometrical parameters of the channel. Comparison with the theoretical model and experimental\u0000results is carried out.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"235 - 241"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289367","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":"Stochastic Modeling of Time- and Place-Local Contacts of Individuals in an Epidemic Process","authors":"N. V. Pertsev, V. A. Topchii, K. K. Loginov","doi":"10.1134/S199047892302014X","DOIUrl":"10.1134/S199047892302014X","url":null,"abstract":"<p> A continuous–discrete stochastic model is presented that describes the dynamics of the\u0000number of susceptible and infectious individuals visiting a certain facility. The individuals enter\u0000the facility both separately and as part of groups of individuals arranged according to some\u0000characteristics. The duration of stay of individuals on the territory of the facility is specified using\u0000distributions other than exponential. Individuals who entered the facility as part of a certain\u0000group leave the facility as part of the same group. Infectious individuals spread viral particles\u0000contained in the airborne mixture they secrete. A certain amount of the airborne mixture\u0000containing viral particles settles on the surfaces of various objects in places of the facility that are\u0000generally accessible to individuals. The area of the infected surface (the surface containing the\u0000settled airborne mixture with viral particles) is described using a linear differential equation with\u0000a jumping right-side and discontinuous initial data. Susceptible individuals contacting infectious\u0000individuals and contaminated surfaces may be infected. A probabilistic formalization of the model\u0000is presented, and an algorithm for numerical simulation of the dynamics of the components of the\u0000constructed stochastic process using the Monte Carlo method is described. The results of a\u0000numerical study of the expectations of stochastic variables describing the number of contacts of\u0000susceptible individuals with infectious ones and with infected surfaces per one susceptible\u0000individual for a fixed period of time are presented.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"355 - 369"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289851","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}
O. A. Solnyshkina, N. B. Fatkullina, A. Z. Bulatova
{"title":"Three-Dimensional Simulation of Singleand Multi-Phase Flows in Roughness Microchannels","authors":"O. A. Solnyshkina, N. B. Fatkullina, A. Z. Bulatova","doi":"10.1134/S1990478923020175","DOIUrl":"10.1134/S1990478923020175","url":null,"abstract":"<p> To predict the behavior of reservoir fluids in porous media and their investigation at the\u0000macroscopic level, it is necessary to study in detail the hydrodynamic flows in porous media at the\u0000microscale level from the point of view of the individual pore spaces taking into account their\u0000structural features. This paper deals with the analysis of a periodic flow of a viscous\u0000incompressible fluid and dispersed systems in a flat channel of rectangular cross section with\u0000irregular side walls under a constant pressure drop. Using an efficient numerical approach based\u0000on the 3D Boundary Element Method accelerated by the Fast Multipole Method on heterogeneous\u0000computing architectures, the influence of irregularities of various size and shape present on\u0000microchannel walls on the hydrodynamic flows of the viscous fluid flow and the emulsion droplet\u0000dynamics in a capillary micromodel of the porous medium is studied. The results of the present\u0000paper can also be useful in the design of microfluidic devices.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"396 - 404"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289852","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 Mathematical Model of a Wastewater Treatment Filter Using Biofilms","authors":"T. N. Bobyleva, A. S. Shamaev, O. V. Yantsen","doi":"10.1134/S1990478923020035","DOIUrl":"10.1134/S1990478923020035","url":null,"abstract":"<p> The article proposes a mathematical model of wastewater treatment in a filter based on\u0000the use of biofilm. In this model, microorganisms destroy harmful impurities contained in water.\u0000The impurities are “food” for the microorganisms. The filter contains a large number of loading\u0000elements. A system of partial differential equations with boundary conditions is given for one\u0000loading element, which is a cylindrical rod whose surface is covered with a biologically active film.\u0000This system includes a parabolic equation in a three-dimensional domain and a hyperbolic\u0000equation on part of the surface of this domain, the equations being related via the boundary\u0000condition and the potential in the hyperbolic equation. Further, an asymptotic analysis of this\u0000system is carried out, which permits one to reduce the model of an individual element to solving a\u0000simple ordinary differential equation; a rigorous mathematical justification of the proposed\u0000method is given. Here a mathematical method for constructing asymptotics in so-called “thin\u0000domains” is used. The method is a simplification of a complex combined model based on the laws\u0000of hydrodynamics and diffusion. We use this as a basis to propose a model of the operation of the\u0000entire wastewater treatment device containing a large number (millions) of such elements.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"251 - 259"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4285045","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":"S-Blocks of Special Type with Few Variables","authors":"D. A. Zyubina, N. N. Tokareva","doi":"10.1134/S1990478923020229","DOIUrl":"10.1134/S1990478923020229","url":null,"abstract":"<p> When constructing block ciphers, it is necessary to use vector Boolean functions with\u0000special cryptographic properties as S-blocks for the cipher’s resistance to various types of\u0000cryptanalysis. In this paper, we investigate the following S-block construction: let\u0000<span>( pi )</span> be a permutation on\u0000<span>( n )</span> elements, let\u0000<span>( pi ^i )</span> be the\u0000<span>( i )</span>-fold application of the permutation\u0000<span>( pi )</span>, and let\u0000<span>( f )</span> be a Boolean function of\u0000<span>( n )</span> variables. Define a vector Boolean function\u0000<span>( F_{pi }colon mathbb {Z}_2^n to mathbb {Z}_2^n )</span> as\u0000<span>( F_{pi }(x) = (f(x), f(pi (x)), ldots , f(pi _{n-1}(x))) )</span>. We study the cryptographic properties of\u0000<span>( F_{pi } )</span> such as high nonlinearity, balancedness, and low differential\u0000<span>( delta )</span>-uniformity in the dependence on the properties of\u0000<span>( f )</span> and\u0000<span>( pi )</span> for small\u0000<span>( n )</span>. Complete sets of Boolean functions\u0000<span>( f )</span> and vector Boolean functions\u0000<span>( F_{pi } )</span> of few variables with maximum algebraic immunity are also obtained.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"451 - 457"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4291024","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":"Scheduling Problem for Call Center Operators","authors":"A. V. Eremeev, M. A. Sakhno","doi":"10.1134/S1990478923020084","DOIUrl":"10.1134/S1990478923020084","url":null,"abstract":"<p> The paper is devoted to solving the problem of scheduling the work of the call center staff.\u0000A model of integer linear programming is formulated, the problem is shown to be NP-hard, and a\u0000genetic algorithm is proposed that takes into account the specifics of the problem. An\u0000experimental comparison of optimal solutions obtained using the <span>CPLEX</span> package with solutions found by the\u0000genetic algorithm is carried out. The computational experiment has shown the practically\u0000acceptable accuracy of the solutions obtained by the genetic algorithm and its applicability to\u0000large-dimensional problems.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"296 - 306"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289847","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":"The Problem of Determining the Coefficient Multiplying a Power-Law Gradient Nonlinearity in a Semilinear Wave Equation","authors":"V. G. Romanov, T. V. Bugueva","doi":"10.1134/S1990478923020151","DOIUrl":"10.1134/S1990478923020151","url":null,"abstract":"<p> We consider a one-dimensional inverse problem of determining the coefficient multiplying\u0000a power-law gradient nonlinearity in a semilinear wave equation. Theorems on the existence and\u0000uniqueness of the solution of the direct problem and local existence and stability of the solution of\u0000the inverse problem are proved.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"370 - 384"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4286885","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":"Inelastic Collision of Resonant Solitons in a Bubble Medium","authors":"I. A. Ogorodnikov","doi":"10.1134/S1990478923020138","DOIUrl":"10.1134/S1990478923020138","url":null,"abstract":"<p> We study a collision of high-amplitude resonant solitons in a liquid with gas bubbles\u0000moving towards each other. The interaction is of an inelastic nature. The amplitude of the state\u0000of full merging of two resonant solitons is three times their initial amplitudes. Two intense sonic\u0000precursors are emitted during the interaction. After the solitons leave the interaction region,\u0000a space-limited zone of coupled bubble pulsations arises in it. These processes reduce the energy of\u0000solitons, which never restore to their original state.\u0000</p>","PeriodicalId":607,"journal":{"name":"Journal of Applied and Industrial Mathematics","volume":"17 2","pages":"345 - 354"},"PeriodicalIF":0.58,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4289392","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}