All issues

The features of the component circuits method (MCC) in modeling chemical-technological systems (CTS) are considered, taking into account its practical significance. The software and algorithmic implementation of which is currently a set of computer modeling programs MARS (Modeling and Automatic Research of Systems). MARS allows the development and analysis of mathematical models with specified experimental parameters. Research and calculations were carried out using a specialized software and hardware complex MARS, which allows the development of mathematical models with specified experimental parameters. In the course of this work, the model of a perfect-mixing reactor was developed in the MARS modeling environment taking into account the physicochemical features of the uranium extraction process in the presence of nitric acid and tributyl phosphate. As results, the curves of changes of the concentration of uranium extracted into the organic phase are presented. The possibility of using MCC for the description and analysis of CTS, including extraction processes, has been confirmed. The use of the obtained results is planned to be used in the development of a virtual laboratory, which will include the main apparatus of the chemical industry, as well as complex technical controlled systems (CTСS) based on them and will allow one to acquire a wide range of professional competencies in working with “digital twins” of real control objects, including gaining initial experience working with the main equipment of the nuclear industry. In addition to the direct applied benefits, it is also assumed that the successful implementation of the domestic complex of computer modeling programs and technologies based on the obtained results will make it possible to find solutions to the problems of organizing national technological sovereignty and import substitution.

Fault-tolerance of a finite computing net with arbitrary graph, containing elements with certain probability of fault and restore, is analyzed. Algorithm for net growth at each work cycle is suggested. It is shown that if the rate of net increase is sufficiently big then the probability of infinity faultless work is positive. Estimated critical net increase rate is logarithmic over the number of work cycles.

The paper describes a new algorithm of construction of the nonlinear arithmetic triangle on the basis of numerical simulation and the binary system. It demonstrates that the numbers that fill the nonlinear arithmetic triangle may be binomial coefficients of a new type. An analogy has been drawn with the binomial coefficients calculated with the use of the Pascal triangle. The paper provides a geometrical interpretation of binomials of different types in considering the branching systems of rays.

Statement of a problem of management of movement of a body in a viscous liquid is given. Movement bodies it is induced by moving of internal material points. On a basis the numerical decision of the equations of movement of a body and the hydrodynamic equations approximating dependencies for viscous forces are received. With application approximations the problem of optimum control of body movement dares on the set trajectory with application of hybrid genetic algorithm. Possibility of the directed movement of a body under action is established back and forth motion of an internal point. Optimum control movement direction it is carried out by motion of other internal point on circular trajectory with variable speed.

The article is dedicated to choose of method for digital signal filtering with continuous 'on-line' data entry and to use of filtration algorithm based on the fast wavelet transform for special problem.

In the paper we construct the adjoint problem for the explicit and implicit parabolic quazi-linear grid boundary-value problems with one spatial variable; the coefficients of the problems depend on the solution at the same time and earlier times. Dependence on the history of the solution is via the state vector; its evolution is described by the differential equation. Many models of diffusion mass transport are reduced to such boundary-value problems. Having solutions to the direct and adjoint problems, one can obtain the exact value of the gradient of a functional in the space of parameters the problem also depends on. We present solving algorithms, including the parallel one.

In this paper the problem of automated building of a citation graph from a collection of scientific documents is considered as a sequence of machine learning tasks. The overall data processing technology is described which consists of six stages: preprocessing, metainformation extraction, bibliography lists extraction, splitting bibliography lists into separate bibliography records, standardization of each bibliography record, and record linkage. The goal of this paper is to provide a survey of approaches and algorithms suitable for each stage, motivate the choice of the best combination of algorithms, and adapt some of them for multilingual bibliographies processing. For some of the tasks new algorithms and heuristics are proposed and evaluated on the mixed English and Russian documents corpora.

In this paper, we propose a new software for simulation of fluid-structure interaction. The software is designed for solving coupled problems and provides an interface for synchronization synchronisation and data exchange between existing fluid and structural solvers. Algorithms of coupling solvers and mesh deformation are discussed. The software can be used on hybrid CPU/GPU platforms.

The paper considers the problem of increasing the approximation order of transparent boundary conditions for the wave equation while using finite difference schemes up to the sixth order of accuracy in space. As an example, the problem of wave propagation in a semi-infinite rectangular waveguide is formulated. Computationally efficient and highly accurate formulas for discretizing operator of transparent boundary conditions are proposed. Numerical results confirm the accuracy and stability of the obtained difference algorithms.

The approach to parallel implementation of low-frequency PIC-algorithms is proposed, taking into account peculiarity of the nonradiative (Darwin) field approximation. Its advantages and specifics of adaptation to the base computer types for high performance calculations are discussed.