mathematical model

The method of solving problems of mathematical physics, in particular for calculating a non-stationary gas flow in pipelines, is proposed in this article on the basis of the biorthogonal polynomial constructed by the authors. The method of solving the problem by means of the separation of variables in the base of biorthogonal polynomials is investigated. The analytical-approximate and approximate solutions of the problem as the sum of some biorthogonal and quasi-spectral polynomials are found.

The models of gas movement in pipelines and gas filtration processes in complex porous media are considered in entire and fractional derivatives. The method for linearization of equations, which are included in the mathematical model of mass transfer, is suggested as well as an iterative scheme for solving initial systems of nonlinear differential equations is constructed. The finite-element model of the problem with the use of the Petrov-Galerkin method and Grunwald-Letnikov scheme concerning derivatives of the fractional order are implemented.

The paper presents a methodology for improving mathematical model of ultrasonic flowmeter (USM) results through the application of CFD simulation along with experimental reference data on measured consumption. On the basis of the proposed methodology, USM errors research method in terms of distortion of the flow structure has been developed. Using the proposed methodology mathematical model of two-path chordal USM has been improved and its study in terms of distortion of the flow structure after seven types of fittings has been conducted.

This article is about determination adaptation processes of algorithms formulas. The adaptation algorithm of formulas is resulted. Synthesized, minimized, and built mathematical model and probed adaptation algorithm of operation base sign.

In this paper we propose a formalization of ontology-based task execution modeling system. It is built using approach of algebraic systems theory. We show that proposed algebraic system is based on multiple domains, which can be used for ontological models representation and knowledge elucidation, storage and processing

This paper belongs to the field of systems engineering and is aimed at improving the qualitative indices of vector data information technologies (e.g. 2D vector data coding design) with respect to reliability, precision and other significant operating characteristics of the systems based on the combinatorial configurations theory, namely the Ideal Ring Bundles (IRB)s.

This article examines a question of basic factors that affect the efficiency of IT investments. Structural components and the effect on investment were investigated. A multi objective model of investment allocation in IT for the period and election of the initial date of investment was proposed. The methods for making decision and elaborated recommendations for using these methods were analysed.

This article is about determination of properties of unitherms. The algorithm of calculating geometrical parameters of unitherms is introduced. The mathematical model is synthesized. This model is then minimized and built. The algorithm of calculating geometrical parameters of unitherms is probed into.

In the article formed the organizational and institutional model of separation procedure of land in state and municipal property of settlements based on a systematic approach.

The work is dedicated to theoretical and experimental investigations of kinetics and dynamics of filtration drying of capillary and pore materials, and mineral granulated fertilizers, in particular. The proposed physical model of a moist particle and the differential system of equations which describes heat exchange in the second drying period enables to determine the transfer velocity of mass-exchange zone in a dispersion layer of the material during filtration drying.