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 Выпуск 97
- Zverkina G., Farhadov M. Application of the coupling method for the asymptotic analysis of regenerative processes in queuing theory and related problems
In queuing theory (QT) and related problems, it is very important to know the numerical characteristics of an investigated system – both in stationary and non-stationary modes. Sometimes they can be calculating, but this is not possible for all models. However, it is often possible to calculate or estimate the stationary values of the characteristics of the models under study. If for a certain characteristic the rate of convergence (or an upper estimate of the rate of convergence) to a stationary value is known, then its value can be estimated at any time. At the same time, the behavior of many processes in QT and in related fields can be describing by linear Markov processes, which are often regenerative Markov processes (RMPs). If the regeneration period of RMP has a finite average value, then RMP is ergodic. To obtain upper bounds for the rate of convergence of RMP distribution to a stationary distribution, the coupling method may be used. The purpose of this paper is to show the application of the coupling method. This article is a small review of currently actively developing methods for obtaining upper bounds of the rate of convergence of the distribution of regenerative processes and fills the existing gap in the domestic literature.
- Akinfiev V. Sanctions and modeling of the financial stability of companies
The problem of modeling the consequences of sanctions for enterprises and companies is considered. The introduction of economic sanctions against the economy of a particular country leads to a sharp change in the conditions of economic activity and business of companies. Companies have to adapt to the "new reality", make non-standard management decisions and support measures. Under these conditions, the task of studying the impact of sanctions on the financial stability and solvency of companies becomes relevant. Another important task is to model and evaluate the effects of various countermeasures aimed at maintaining financial stability. A comparative analysis of methods for assessing the financial stability and solvency of companies is presented, which can be divided into two groups: direct and indirect methods. It is shown that under the conditions of application of sanctions, the direct method based on the dynamic modeling of the company's financial indicators and cash flows is preferable to the indirect method based on the calculation of a set of coefficients using statistical data. The article describes software tools for building a production and financial model of an enterprise based on the TEO-INVEST software package and, using a good example, shows a methodology for using it to predict the dynamics of an enterprise's financial performance and select management decisions to maintain its financial stability and solvency when sanctions are imposed.
- Chernov A. Evaluation of the effectiveness of the mask regime during the COVID-19 epidemic in Moscow in SEIQRD model
The aim of this work is to evaluate the effectiveness of the widespread use of medical masks to control the epidemic. The epidemic spread is described by the model SEIQRD (susceptible -- exposed -- infected -- quarantined -- recovered -- deaths), where the key variables responsible for the epidemic development are divided into 2 groups: complined and noncomplined to mask regime. The baseline reproduction rate, elasticities to model parameters, and the minimum percentage of the population that needs to adhere to the mask regime to prevent the epidemic are calculated for the model. Model parameters are estimated using statistical data from the COVID-19 epidemic in Moscow and then scenarios of the epidemic development with different degrees of mask compliance are numerically simulated.
- Shiroky A., Krylov P., Novochadov V. Predicting the risks of osteoarthritis development using scenario model
Joint diseases and, first of all, osteoarthritis are critical medical and social problems. The priority healthcare tasks are prevention, early diagnosis, and treatment of such deceases. Thus, an essential problem is increasing the efficiency of osteoarthritis treatment. A traumatologist could optimize the treatment in particular cases with an instrument, allowing to predict the pathology development with sufficient accuracy. This study proposes a model for assessing the risks of osteoarthritis development, considering both the influence of factors external to the joint and the cellular / extracellular processes in it. The model allows examining scenarios of change the balance of cartilage matrix synthesis and loss under three different groups of negative factors: genetic, non-genetic, and environmental ones. The simulation result is a quantitative assessment of the osteoarthritis developing risk. Such assessment allows choosing the composition and the necessary amount of medical intervention in each specific case. We plan to verify the model using retrospective data of traumatology patients diagnosed with osteoarthritis at different stages.
- Kulakova A., Galkin V., Makarenko A. Methoarial analysis of methods of colour calibration of images using RGB ang HSV colour spaces in tasks of intelligent computer vision (for example, images ob-tained in industrial greenhouses
The article analyses the problem of colour distortion of images generated by computer vision systems in industrial greenhouses. Methods of colour calibration of images used to correct such distortions are considered. The analysis of the features of the HSV colour space is carried out. A mathematical model in RGB space and two models in HSV space used to solve the colour correction problem have been compiled. A comparative analysis of the quality of the presented algorithms is carried out. The functioning of the algorithms is demonstrated on the task of correcting colour distortions in images of tomatoes grown in industrial greenhouses, under artificial and natural lighting.
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