Matviychuk A. The Modelling and Analysis of Economic Systems in Terms of Fuzzy Logic

The processes of economic systems functioning under conditions of uncertainty and risk. The developing of methodological-theoretic statements and correspond mathematical models of economic systems analysis and financial indexes forecasting with usage of fuzzy logic tools. The methods of: fuzzy logic theory, financial analysis, Elliott wave theory, neural networks, discriminant analysis, interval mathematics and economic statistics. There are formed the conception and methodology of construction of economic and mathematical models of financial indexes forecasting taking into account the adjusted regularities of economic systems development, securities rating modeling, carrying out of complex analysis of financial state and diagnosing of bankruptcy of enterprise, enterprise's competitiveness assessment, evaluation of risk of tax non-payment and forming of planned schedule for tax audit. It's developed the complex of economic and mathematical models, algorithms and software tools on the basis of proposedconceptual and methodological approaches. The theory and methodology of economic and mathematical modeling, analysis and forecasting of economic systems development with usage of fuzzy logic tools. There are applied the economic and mathematical models of forecasting of budget inpayments by regions for basic kinds of tax, assessment of risk of tax non-payment and forming of planned schedule for tax audit. Financial field, educational process.