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JOURNALS // Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy // Archive

Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy, 2021 Volume 8, Issue 1, Pages 37–48 (Mi vspua130)

This article is cited in 1 paper

MATHEMATICS

Monte-Carlo for solving large linear systems of ordinary differential equations

S. M. Ermakov, M. G. Smilovitskiy

St. Petersburg State University, 7-9, Universitetskaya nab., St. Petersburg, 199034, Russian Federation

Abstract: Monte-Carlo approach towards solving Cauchy problem for large systems of linear differential equations is being proposed in this paper. Firstly, a quick overlook of previously obtained results from applying the approach towards Fredholm-type integral equations is being made. In the main part of the paper, a similar method is being applied towards a linear system of ODE. It is transformed into an equivalent system of Volterra-type integral equations, which relaxes certain limitations being present due to necessary conditions for convergence of majorant series. The following theorems are being stated. Theorem 1 provides necessary compliance conditions that need to be imposed upon initial and transition distributions of a required Markov chain, for which an equality between estimate's expectation and a desirable vector product would hold. Theorem 2 formulates an equation that governs estimate's variance, while theorem 3 states a form for Markov chain parameters that minimise the variance. Proofs are given, following the statements. A system of linear ODEs that describe a closed queue made up of ten virtual machines and seven virtual service hubs is then solved using the proposed approach. Solutions are being obtained both for a system with constant coefficients and time-variable coefficients, where breakdown intensity is dependent on t. Comparison is being made between Monte-Carlo and Rungge - Kutta - obtained solutions. The results can be found in corresponding tables.

Keywords: Monte-Carlo, ODE system, integral equation, queuing theory, optimal density, unbiased estimate, statistical modelling.

UDC: 519.245

MSC: 65C05

Received: 03.06.2020
Revised: 27.07.2020
Accepted: 17.09.2020

DOI: 10.21638/spbu01.2021.104


 English version:
Vestnik St. Petersburg University, Mathematics, 2021, 8:3, 28–38


© Steklov Math. Inst. of RAS, 2024