The objective of this paper is to determine the basic features of the use of mathematical modeling of the system to forecast cryptocurrency exchange rate. The study determines that cryptocurrency is the simplest investment asset being and, at the same time, the riskiest one. Advantages and disadvantages of cryptocurrency use are specified. Advantages include: code openness, anonymity, decentralization, emission, and reliability. Disadvantages include lack of guarantees, instability, risk of prohibition and possible loss. A model to forecast bitcoin cryptocurrency exchange rate is proposed and substantiated mathematically. The observations are the basis to develop a hypothesis: the faster the cryptocurrency (e.g. bitcoin) is mined, the more difficult it is to forecast bitcoin cryptocurrency exchange rate. Certain factors emphasize which may affect the cryptocurrency exchange rate: trade wars of the USA with other export-oriented world economies (China); advent of IEO as the alternative for ICO and new drivers connected with the interest in cryptocurrency; FATF recommendations for market control, the entry of world giants (e.g. Facebook) into the crypto-market and the development of the stablecoin market.

Readily available tetrachloro-2-aza-1,3-butadienes enter into directed cyclocondensation reaction with N-phenyl-1,2-cyclopentanediamine which leads to regioselective cyclopentane annulation by the 1,3,5-triazepine. The formation of the 1,3,5-triazepine derivatives was confirmed proved by 1H- and 13C-NMR spectral study, elemental analysis and, in one case, single-crystal x-ray crystallographic study.

In the context of globalization and fierce competition in world markets, the high level of investment activity in the country is a key to economic and innovative development. The high level of wear and tear of fixed assets in developing countries gives special relevance to solving the problem of attracting investments for production development. Hence, for the investment management system choosing an optimal variant among several available investment projects is one of the most responsible stages of ensuring the stable operation and sustainable development of an enterprise. In this regard, the aim of the article is to develop a comprehensive multi-criteria approach to choose the best investment option. The article analyzes the existing methodological approaches to assess the economic efficiency of the investment projects, identifies their advantages and disadvantages. A multi-criteria method of investment project evaluation is proposed, which is characterized by the absence of restrictions on the number of individual evaluation indicators and the possibility for the investor to determine the significance of every indicator using weights independently. The use of the proposed methodology by enterprises will improve the quality of management decisions at the stage of choosing the optimal investment option.

This paper was retracted based on the authors' request due to errors in the computations.

The quantum-chemical modeling mechanism of the [4+2]-cycloaddition reaction of 2,3 dimethylbuta-1,3-diene and methyl acrylate was conducted. Its qualitative aspects were analyzed at the molecular level by the program MOPAC2012 and semiempirical method RM1. The potential energy surfaces of 2,3 dimethylbuta-1,3-diene and methyl acrylate [4+2] cycloaddition possible reaction pathways were constructed by restricted and unrestricted Hartree-Fock approximation. It has been established that the molecule of the final product methyl-3,4-dimethylcyclohex-3-encarboxylate has the half-chair shape, wherein the carboalkoxyl group is in the exo-orientation. Interaction between molecules of 2,3 dimethylbuta-1,3-diene and methyl acrylate occurs by a two-step mechanism more likely than one-step, since the activation parameters of this interaction maximum coincide with the experimental data.

Ensuring household food security should be a priority goal of state policy. The level of ensuring household food security reflects the state of the country's economic development and the effectiveness of agricultural policy. Household food security is achieved by ensuring a high level of purchasing power of households, which is possible by increasing income. Savings are the “safety cushion” for households during the financial and economic crisis caused by the coronavirus pandemic. The level of household savings is important both for the households themselves and for the country's economy, since savings, on the one hand, help to avoid hunger during crises, and, on the other hand, are an important investment resource for the country's economy. That is why assessing the level of household savings and identifying factors affecting savings are important aspects of building an effective government policy in the field of food security.

The global process of society information has covered almost all countries of the world and is currently the core of scientific, technical and socio-economic development. The effectiveness of the power exercise in any state depends on its information support. Indeed, without information, successful political structure, the development of mass political consciousness as well as the interaction of the subject and the object of government are impossible. That is why this research aims to improve the methodics of evaluation of informational security through theoretical-methodological substantiation, forming and calculation of integral indexes of its competitiveness of a country. Global economic crisis had consequences for almost every country and cannot be ignored by any conditions, that is why the methodic of informational security calculations should be adapted to modern economic conditions. Cardinal changes in political, economic and social conditions in Ukraine causes inaccessibility of approaches to information security level calculations and particularly in the national security system. In modern scientific schools the questions of effective informational security have not been sufficiently studied. The aim of this article is to analyze active methods of state informational safety level calculations in order to adapt their indexes to actual global circumstances in Ukraine and in the world. Integral informational security have been composed of such components (indicators): income of the broadband Internet access market, dynamics of broadband Internet subscribers (connections), penetration rate of fixed broadband access (number of subscribers per 100 people), dynamics of Internet penetration (percentage of Internet users to the total population of the country), Network Readiness Index of the country, ICT Development Index of the state, Global Innovation Index, capital investments in intangible assets of Ukraine (that is, in software and databases). Every component of informational safety has factors of relevance and indispensability of reinforcement of national competitiveness on security foundations are substantiated. A taxonomic indicator is used to measure the level of informational safety. The paper proves that each of the components of the state informational security has almost equal input in forming its integral index.

Two potential energy surfaces 1 ²A1 and 1 ²B1 for linear geometry of F-H-Br system have been computed with aug-cc-pVQZ basis set using dynamically weighted state averaged MCSCF followed by MRCI-F12 method. State 1 ²A1 has smaller barrier height (3.49 kcal/mol) than 1 ²B1. (13.6 kcal/mol). The latter has deep van der Waals well in Br-HF valley (2.12 kcal/mol).

The article simulates the impact of the digital technologies’ development on economic growth, which makes it possible to find ways to improve the quality of various spheres of life and identify areas of the economy, the accelerated digitalization of which will ensure an increase in gross domestic product (GDP). The research used groupings of economic activities that directly influence the development of the digital economy. Using the data of regression models, the coefficients of GDP elasticity from the development of the studied sectors were calculated and used to forecast GDP under the development influence of the studied sectors while maintaining the existing trends. The dynamics of the e-commerce market development in Ukraine, the dynamics of production volumes of products (services) of the main types of economic activities in the field of digital transformation of the economy in Ukraine, the dynamics of financial results of enterprises in the information and telecommunications sector in Ukraine, the dynamics of capital investments in the field of information and communications of Ukraine, the dynamics of foreign investment in the development of the type of economic activity “information and telecommunications” in Ukraine, the dynamics of the development of the main areas of digitalization of the Ukrainian economy in 2010-2018 and the dynamics of GDP in actual prices were revealed. A correlation and regression analysis of the impact of the main indicators of the digital technologies sectors development on Ukraine's GDP is also carried out. The forecast extrapolation trend of production growth volumes of products and services in the information sector of Ukraine was built. A forecast of GDP growth in Ukraine has been constructed, taking into account the processes of digitalization of the economy in accordance with certain trends. The forecast dynamics of changes in GDP under the influence of the IT sector development until 2023 was also illustrated. It was found that Ukraine lags significantly behind most developed countries in terms of the level of industrial production development of information and communication technologies and equipment, Ukraine is completely import-dependent in this area. It has been proved that stimulating the development of information and communication technologies has significant prospects for activating digitalization processes in all spheres of the economy and society and increasing GDP.

The paper reflects the importance of social networks in the organization of social communication processes in public administration. The essence of communication in public administration and its paradigm is determined. The main differences between public administration and object-oriented public administration are shown. The paper also describes the importance of social networks in the conduct of communication processes compared to other communication channels. Research on the use of social networks in public administration is conducted based on the results of research of the Ukrainian Government and users of the Ukrainian social networks. The main trends in the use of social networks in public administration in Ukraine are described. According to the results of the study, the possible directions of social networks development in public administration in the context of preserving democratic values were proposed.

This paper presents a scheme of implementation of the protocol for diagnosing stakeholders of educational space, which aims to meet the needs and interests of both contractors and the university, and makes an efficiency assessment in achieving the goals of the university. The ranking of the social status of the stakeholders in the association is obtained, which demonstrates the importance of each stakeholder in the collaboration. The relationships between university and stakeholders, the degree of communication of stakeholders with each other, the attitude of each stakeholder towards the group of stakeholders as a whole and the total activity of group interaction based on the calculation of sociometric indicators are determined. Finally, the effectiveness of the level of involvement of stakeholders in the activities of the University is also proved.