Shlikhta Ganna
@rshu.edu.ua
Faculty of Mathematics and Informatics
Rivne State University of Humanities
RESEARCH, TEACHING, or OTHER INTERESTS
Education, Computer Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Yurii Turbal, Ganna Shlikhta, Mariana Turbal, and Bogdan Turbal
Private Company Technology Center
The object of research in the paper is extrapolation problems based on interpolation polynomials. Polynomial-based prediction methods are well known. However, the problem is that such methods often give very large errors in practice. The permissible error of extrapolation even by one grid step is not ensured by the high accuracy of interpolation using polynomials. The paper proposes an algorithm that allows to significantly improve polynomial forecasts by optimizing the procedure for choosing the power of the polynomial, on the basis of which the forecast is built. The algorithm is based on the procedure for building all polynomial forecasts according to known data and analysis of these forecasts. In particular, the presence of monotonicity and a tendency to convergence allows determining the optimal degree of the polynomial. In the absence of monotonicity, provided that certain ratios are met, the forecast can be constructed as the arithmetic average of all polynomial forecasts. An important result is the estimation of the error of the forecasting method by averaging polynomial forecasts. The development of the algorithm became possible due to the use of a special method of constructing a one-step polynomial forecast. The method differs in that it allows to build a forecast without using the cumbersome procedure of calculating the unknown coefficients of the polynomial. The numerical results presented in the work demonstrate the effectiveness of the forecasting technique based on the average of polynomial forecasts. In particular, for the test functions, the relative error was about 2–5 %, while polynomials of different degrees in the worst case yielded more than 50 %. The obtained results can be useful for building short-term forecasts of series of economic dynamics, forecasting the behavior of arbitrary processes with a dominant deterministic component
Viktor Danchuk, Hanna Shlikhta, Irina Usova, Maiya Batyrbekova, and Gulnara Kuatbayeva
International University of Sarajevo
The topic of project management is relevant since the organisation is obliged to be competitive and promptly respond to market conditions. The main goal of any enterprise is to make a profit and create a successful image. In this regard, the company's strategy is being formed, which is implemented through project management. Project management capabilities affect not only the process of forming a development strategy but also methods of managing innovative and strategic development. When structuring management competencies, special attention should be paid not only to the methods that are implemented in the company's management structure, but also to the technological platform on which the entire management system and the programme for building distributed companies are based. The novelty of the study lies in the structuring of methods to improve the enterprise project management efficiency, taking into account project constraints. To achieve this goal, the authors consider it necessary to analyse the features of enterprise project management. The paper presents theoretical provisions on the effectiveness of project management, identifies factors for increasing the project management efficiency. The paper examines the features of the development of information technology for enterprise multi-project managing. The practical significance of the study is determined by the possibilities of forming a long-term development strategy when implementing project management systems in companies that build their activities not only on a local scale but also plan network growth, which in the context of a lockdown of most world economies becomes the only growth driver.
Natalia Ivanchuk, Petro Martyniuk, Olga Michuta, Yevhenii Malanchuk, and Hanna Shlikhta
Private Company Technology Center
Mathematical modeling and computer simulation methods have been used to investigate the extent of influence exerted by bio-clogging on the dynamics of excess head scattering in the soil massif. To this end, the classical equation of filtration consolidation has been modified for the case of variable porosity resulting from changes in the biomass. The numerical solution to the constructed mathematical model in the form of a nonlinear boundary problem was derived by a finite-element method. Numerical experiments were carried out and their analysis was performed. Specifically, this paper shows the charts of pressure differences in the soil array when neglecting bio-clogging and when estimating the effects exerted by bio-clogging at specific points in time. The numerical experiments demonstrated that in two years after the onset of the consolidation process in the neighborhood of the lower limit of the examined soil mass with a thickness of 10 meters, excess heads fall from the initial value of 10 m to 4 m. The greatest impact from the clogging of pores by microorganisms is revealed in the neighborhood of an upper limit. At a depth of 1 m, at t=180 days, the pressure difference reaches 2.4 m. This is about 200 % of the pressure distribution without taking into account the effects of bio-clogging. Over time, the effect of bacteria on the distribution of pressures in the neighborhood of the upper boundary decreases. However, this effect extends to the entire soil mass, up to the lower limit. Thus, at t=540 days, at the lower limit, the effect of bio-clogging leads to that excess heads are 1.8 m greater than for the case of pure water filtration (a relative increase of about 80 %). Bio-clogging processes are intensified as a result of the development of microorganisms when organic chemicals enter the porous environment. Therefore, from a practical point of view, studying them is especially relevant for household waste storage facilities and the stability of their soil bases. It is advisable to undertake research by using the methods of mathematical modeling and computer simulation