Статті
Постійне посилання на розділhttps://dspace.nuft.edu.ua/handle/123456789/7372
Переглянути
4 результатів
Результати пошуку
Документ The farming costs (including insurance) of the agricultural holdings in the European Union(2023) Arych, Mykhailo; Kuievda, Yulia; Dvořák, Marek; Hinke, JanaThe paper is devoted to exploring the farming costs (including insurance) indicators of the agricultural enterprises in the European Union. The analysis employs the box plot methodology that provides a five-number summary for a set of data. In this paper, we analyse the evidence of interconnection between the indicators of efficiency and competitiveness and insurance costs regarding food market security. This research discusses the dynamic changes of the absolute value of farming costs (including insurance) indicators and different relative indicators derived from the original one for the agricultural enterprise holdings in the European Union for the period of 2004-2019. The results show that farming costs (including insurance) indicators of the agricultural holdings should be considered as an instrument for providing food market security. Based on these research results, we are going to further explore the impact of insurance on the food market security. In addition, these research results could help to clarify the difference between EU countries and dynamic changes in farming costs (including insurance) indicators of agricultural holdings. У статті досліджено показники витрат на ведення сільського господарства (включаючи страхування) сільськогосподарських підприємств у Європейському Союзі. Під час аналізу використовується методологія прямокутної діаграми, яка надає зведення з п’яти чисел для набору даних. У цій статті ми аналізуємо докази взаємозв’язку між показниками ефективності і конкурентоспроможності та витратами на страхування. У статті обговорюються динамічні зміни абсолютного значення показників витрат на ведення сільського господарства (включаючи страхування) та різних відносних показників, отриманих сільськогосподарських підприємств у Європейському Союзі за період 2004-2019 рр. Результати показують, що показники витрат на ведення сільського господарства (включаючи страхування) агрохолдингів слід розглядати як інструмент забезпечення безпеки продовольчого ринку. На основі цих результатів дослідження ми збираємося продовжити дослідження впливу страхування на безпеку продовольчого ринку. Крім того, ці результати дослідження можуть допомогти з’ясувати різницю між країнами ЄС та динамічними змінами показників витрат на ведення сільського господарства (включаючи страхування) сільськогосподарських угідь.Документ Fuzzy logic energy management system of food manufacturing processes(2020) Baliuta, Serhii; Kopylova, Liudmyla; Kuievda, Yulia; Kuyevda, Valery; Kovalchuk, OlenaIntroduction. The research is conducted to justify the method of increasing the efficiency of electrical power use in food production processes, which is based on the algorithms of fuzzy power management system. Materials and methods. The study is based on optimal and fuzzy control methods, such as Mamdani and Sugeno algorithms. Computer simulation was performed using MATLAB Simulink. Results and discussion. The control criterion of power supply of food production is formulated in the form of a functional minimization problem, which depends on the expected value of active and reactive power losses, active and reactive power losses at the level of secondary substations and individual load nodes. Maintaining energy efficient voltages in the power supply system nodes is chosen as a control task. It is determined the dependence of energy efficient voltages on the nominal voltage of the power system, the active resistance of its segments, the power and the coefficient of linearized static load characteristics at the network nodes, the equivalent active resistance, the nominal power, open circuit and short circuit losses of secondary substation transformers. To solve the control problem, an algorithm is synthesized using fuzzy controllers at the levels of the primary and secondary substations. In particular, it is determined that the input signals of the secondary substation fuzzy regulator should be the deviation from the energy efficient voltages and the rate of voltage change, and the output signals should be the transformer voltage and the actuation delay. Using numerical methods it is shown that this algorithm can reduce electricity losses in food production processes up to 7% compared to classical voltage regulation methods. Conclusions. The fuzzy system method under study ensures that energy-efficient voltage levels are maintained at the distribution network nodes when the voltage of the power source or the consumer loads are changed.Документ Identification of mathematical model of turbine generator unit in presence of uncertainty(2021) Baliuta, Serhii; Chernenko, P. O.; Kuyevda, Valery; Kuievda, YuliaAn identification procedure of mathematical model of turbine generator unit in the presence of uncertainty is studied for using in the interconnected robust control automated system. The procedure is based on “worst-case” identification approach. The controlled object is modelled by the matrix transfer function with additive uncertainty. The identification consists of two stages: first is to identify transfer function with nominal parameters with the use of prediction error minimization algorithm, second – to determine weight function in additive uncertainty model using finding the worstcase log magnitude curve of uncertainties. Identification is performed in active way, determining datasets for each control channel from individual experiments. A linear frequency-modulated signal is selected as the input test disturbance. A simulation model of the controlled object is constructed and the numerical experiment is conducted using the identification procedure.Документ Synthesis of robust interconnected power system stabilizers for turbine generators in sugar factories(2017) Kuievda, Yulia; Baliuta, SerhiiThis research aims to develop the method of synthesis of interconnected robust power system stabilizer (IRPSS) for power supply systems of sugar factories with own turbine generators. A model of power supply system with own generator, automatic exciter regulator, turbine and speed governor is constructed. The controlled object nonlinear differential equations model is linearized and simplified by reducing of its order using Schur's method. The model is extended with chosen weighting functions preparing for H∞ synthesis procedure. The LMI region is chosen in the form of a conic sector for satisfying condition of lower oscillability of transient process, which is the main goal of such a regulator to optimize turbine generator operation process. The IRPSS for extended model was synthesized, using H∞ synthesis procedure with poles placement. The regulator is presented in the form of matrix continuous transfer function. The transition process of 3-phase short-circuit fault behind the transformer and subsequent automatic re-closing is simulated with full-order nonlinear model with IRPSS and compared with standard system stabilizer and the system without stabilizer. The graphs of modelled transients demonstrate effectiveness of IRPSS.