IMPROVING EFFICIENCY OF THE SUPPLY CHAIN BY OPTIMAL DISTRIBUTION CENTER LOCATION

The solution of a logistic problem to improve the efficiency of the supply chain in order to achieve an optimal delivery strategy is presented. The solution involves the use of mathematical methods to determine the location of the distribution center in the service area. The use of an optimal delivery strategy leads to a decrease in storage and transportation costs, which has a positive effect on the competitiveness of an enterprise in modern market conditions

Verification of the Geomagnetic Field Models Using Historical Satellite Measurements Obtained in 1964 and 1970

In 2019, the WDC for Solar-Terrestrial Physics in Moscow digitized the archive of observations of the Earth’s magnetic field carried out by the Soviet satellites Kosmos-49 (1964) and Kosmos-321 (1970). As a result, the scientific community for the first time obtained access to a unique digital data set, which was registered at the very beginning of the scientific space era. This article sets out three objectives. First, the quality of the obtained measurements is assessed by their comparison with the IGRF reference field model. Secondly, we assess the quality of the models, which at that time were derived from the data of these two satellites and ground-based observations. Thirdly, we propose a new, improved model of the geomagnetic field secular variation based on the scalar measurements of the Kosmos-49 and Kosmos-321 satellites using modern mathematical methods.

USING THE UNIVERSITY'S ENERGY EFFICIENCY KNOWLEDGE HUB FOR ENERGY RENOVATION AND ENERGY MODERNIZATION OF UNIVERSITY BUILDINGS

BACKGROUND AND OBJECTIVES. The most important socio-economic task in the current period is to transfer Ukraine's economy to an intensive way of development in order to improve the level and quality of life of the population and solve the full range of social problems. Implementation of such a policy dictates the need to solve problems of reconstruction and modernization of buildings and structures, primarily related to the public sphere (including higher education institutions), in order to eliminate the existing inconsistency of the technical condition and functional and consumer qualities of public buildings to current standards and consumer requirements. Therefore, one of the most urgent directions of development of higher educational institutions is the task of providing effective overhaul and reconstruction of buildings, increasing their energy efficiency.METHODS. The theoretical and methodological basis of the study were the fundamental and applied developments of leading domestic and foreign scientists in the theory and practice of management of energy modernization and energy reconstruction of buildings, increasing energy efficiency of buildings. The factual basis of research were the legislative acts of Ukraine in the field of energy efficiency, normative and methodical documents on the modernization and reconstruction of buildings, Directive 2010/31/EC in the field of energy saving. When solving specific tasks the methods of system and comparative analysis, economic-mathematical methods of efficiency evaluation of energy reconstruction and energy modernization projects were used.FINDINGS. The method of calculation of the reduced resistance to heat transfer of the enclosing structures and the shell of the 4th building of Kyiv National University of Technology and Design as a whole taking into account the temperature and humidity conditions in the fencing marginal zones. It is shown that in the enclosure edge zones the heat protective properties decrease resulting in a deterioration of the heat protection of the whole building. Practical recommendations for the design of fencing structures of modern buildings taking into account the temperature-moisture regime are proposed.CONCLUSION. For the analysis of complex processes of moisture transfer in enclosures, a mathematical model based on the moisture potential is most convenient. A certain difference from the thermal potential (temperature) to the definition of the moisture potential allows to diagnose the most general assessment of the moisture regime of exterior and interior fences on the basis of HUB knowledge on energy efficiency. At use of this model it is possible to consider process of moisture exchange in a wide range of humidity and temperature taking into account movement of a moisture as a basis of carrying out energy reconstruction and energy modernization of operating buildings of the university.

COVID-19 Spread Forecasting, Mathematical Methods vs. Machine Learning, Moscow Case

To predict the spread of the new coronavirus infection COVID-19, the critical values of spread indicators have been determined for deciding on the introduction of restrictive measures using the city of Moscow as an example. A model was developed using classical methods of mathematical modeling based on exponential regression, the accuracy of the forecast was estimated, and the shortcomings of mathematical methods for predicting the spread of infection for more than two weeks. As a solution to the problem of the accuracy of long-term forecasts for more than two weeks, two models based on machine learning methods are proposed: a recurrent neural network with two layers of long short-term memory (LSTM) blocks and a 1-D convolutional neural network with a description of the choice of an optimization algorithm. The forecast accuracy of ML models was evaluated in comparison with the exponential regression model and one another using the example of data on the number of COVID-19 cases in the city of Moscow.

Risk minimisation methods in shaping the optimal range of treadmills

The article presents a solution to the problem of integrating risk minimisation methods in the process of forming the optimal range of treadmill models in a retail enterprise. The problem of multi-criteria optimisation was solved using the generalised criterion method. The formulated problem was therefore broken down into a number of specific tasks, each of which was solved by selecting specific methods. Risks were minimised by mathematical methods, taking into account the economic performance of the enterprise. Recommendations were also offered for customers wishing to purchase one of the treadmill models chosen from the analysis and the best option for ordering via the online shop with home delivery.

Asumu Fractional Derivative Applied to Edge Detection on SARS-COV2 Images

Edge detection consists of a set of mathematical methods which identifies the points in a digital image where image brightness changes sharply. In the traditional edge detection methods such as the first-order derivative filters, it is easy to lose image information details and the second-order derivative filters are more sensitive to noise. To overcome these problems, the methods based on the fractional differential-order filters have been proposed in the literature. This paper presents the construction and implementation of the Prewitt fractional differential filter in the Asumu definition sense for SARS-COV2 image edge detection. The experiments show that these filters can avoid noise and detect rich edge details. The experimental comparison show that the proposed method outperforms some edge detection methods. In the next paper, we are planning to improve and combine the proposed filters with artificial intelligence algorithm in order to program a training system for SARS-COV2 image classification with the aim of having a supplemental medical diagnostic.

Estimation of the Seismic Damage Potential of RC Frames Using Seismic Parameters

Variation of the fundamental period is regarded as one of the methods to assess the damage of the structures under earthquakes. The inter-relationship among seismic parameters and variation of the fundamental period can identify the potential structural damage of an earthquake. For this purpose, the present paper aimed to study the relations among main seismic parameters, incorporating a variety of information about ground motion and variation of fundamental period. Three RC frames were analyzed under far-fault earthquake records by nonlinear dynamic analyses and mathematical methods applied to assay the correlation between seismic parameters and variation of fundamental period. Based on the results, high correlations were observed between some seismic parameters and variation of fundamental period. Further, based on regression equations, new parameters with a very strong correlation with variations of fundamental periods were achieved, which can be regarded as appropriate indices to estimate the potential structural damage of an earthquake.