МЕТОД РАСЧЕТА ПЕРЕХОДНЫХ РЕЖИМОВ ГРЕБНЫХ ЭЛЕКТРОЭНЕРГЕТИЧЕСКИХ УСТАНОВОК ЭЛЕКТРОХОДОВ

The purpose of the work is to develop the method for calculating the transient modes of electric ships’ propelling electric plants during maneuver. This will allow us to evaluate and improve the maneuverability of vessels with electric motion. Methodology. The solution to the problems is proposed to be carried out on the basis of mathematical modeling of maneuvering modes. The duration of transient modes in an electric power plant at electric ships’ maneuvers is commensurable with the transient operation modes of the vessel itself. Therefore, the analysis of the electric power plants’ maneuvering modes should be made in unity with all the components of the ship’s propulsion complex. Results. A specified mathematical model of transient regimes of electric ship’s propulsion complex, including thermal motors, synchronous generators, electric power converters, propulsion motors, propellers, rudder, ship’s hull is developed. The model is universal. It covers the vast majority of modern and promising electric ships with a traditional type of propulsors. It allows calculating the current values of the basic mode indicators and assessing the quality indicators of maneuvering. The model is made in relative units. Dimensionless parameters of the complex are obtained. These parameters influence the main indicators of the quality of maneuvering. The adequacy of the suggested specified mathematical model and the developed computation method based on it were confirmed. To do this, the results of mathematical modeling for a real electric ship were compared with the data obtained in the course of field experiments conducted by other researchers. Originality. The mathematical description of a generator unit, as an integral part of an indivisible ship’s propulsion complex, makes it possible to calculate the dynamic operation modes of electric power sources during electric vessels’ maneuvering. There is an opportunity to design the electric ships’ propulsion power plant according to the final result – according to the indicators characterizing the vessel and its maneuvering properties. The use of a system of dimensionless units provides a generality to the results obtained. Electric ships with equal values of dimensionless parameters will have correspondingly the same values (in relative units) of maneuvering quality indicators. Practical value. The developed mathematical model and the research method constructed on its basis allow calculating the current values of the basic regime parameters of all the components of the ship’s propulsion complex. A mathematical apparatus for estimating the main indicators of the quality of electric ships’ maneuvering is proposed. There is an opportunity to improve the electric ships’ maneuvering characteristics by optimizing the operation of propulsion motors.Целью работы является разработка метода расчета переходных режимов гребных электроэнергетических установок в составе судовых пропульсивных комплексов. Методика. На маневрах продолжительности переходных режимов в электроэнергетической установке соизмеримы с переходными режимами работы судна. Поэтому анализ маневренных режимов ее работы следует проводить в единстве со всеми составными частями судового пропульсивного комплекса.            Результаты. Разработаны уточненная математическая модель и метод расчета переходных режимов всех составных частей пропульсивного комплекса электрохода на маневрах. Найдены безразмерные параметры комплекса. Они определяют основные показатели качества маневрирования. Адекватность модели и метода расчета подтверждены сравнением результатов математического моделирования с натурными экспериментами. Научная новизна. Метод расчета позволяет рассчитывать динамические режимы работы всех составных частей комплекса. Появляется возможность проектирования гребных электроэнергетических установок по конечному результату – по показателям качества маневрирования судна. Практическое значение. Метод расчета позволяет проводить исследования поведения пропульсивных комплексов на маневрах и отыскивать пути повышения маневренности электроходов

OPTIMAL CONTROL OF THE ELECTRIC SHIPS’ PROPULSION MOTORS DURING REVERSAL

Introduction. Reliability and safety of electric ships’ maneuverability depends on the maneuvering characteristics of their propulsion motors (PM). Therefore, the issues of improving the process of controlling propulsion motors at maneuvers are topical. The aim of this paper is to find the optimal laws of control. The indicators estimating electric ships’ maneuvering properties are chosen as criteria of optimality. Methodology. A proportional control law is traditionally used in electrical propelling plants with frequency-controlled PM. However, it does not provide the necessary maneuvering characteristics to the electric ships, since it does not take into account the process of the vessel's movement. To search for the optimal control laws of propulsion motors at maneuvers, the electrical propulsion plant is considered in unity with all the components of the ship’s propulsion complex. The dimensionless parameters of the complex are revealed from the mathematical model of the transient modes of its operation. They determine the numerical values of the optimality criteria. Control signals are formed by frequency and voltage. A method for the formation of optimal control laws is proposed. The nature of the target functions is revealed and a special optimization method is developed. A minimum of the braking distance and a minimum of energy spent on maneuvering are taken as criteria of optimality. Results. The parameters of the complexes that significantly affect the optimality criteria are revealed. For various combinations of the values of these parameters, optimization calculations have been carried out and the optimal control laws of the propulsion motors during electric ships’ reversal have been found. Optimization is carried out by the criterion of the minimum of the braking distance and by the criterion of minimum energy consumption. The results are presented in an analytical form and in a graphical form. The effectiveness of the proposed control laws is illustrated. Scientific novelty. The method of searching for the optimal control laws of the propulsion motors is constructed according to the system principle. This allows us to find the control laws of the propulsion motors on the final result – on the indicators of electric ships’ maneuverability. The proposed recommendations cover a wide class of vessels with electric motion. Practical value. The proposed optimal control laws for propulsion motors can be used both in the design of propulsion power plants and in their operation. The best control law can be selected and incorporated into the control system for any particular electric ship of the considered class, depending on the quality of maneuvering. In particular, the optimal control law for propulsion motors during reversal providing electric ship’s minimum braking distance or minimum energy consumption for maneuvering can be chosen

УПРАВЛЕНИЕ ГРЕБНЫМИ ЭЛЕКТРОДВИГАТЕЛЯМИ ЭЛЕКТРОХОДОВ ПРИ ДВИЖЕНИИ ПО КРИВОЛИНЕЙНОЙ ТРАЕКТОРИИ

Purpose. The aim of the work is to search for the optimal control of the electric ships’ propeller motors (PM) while moving on curvilinear trajectory. The indices characterizing the vessel were selected as the criteria of optimality. Methodology. Optimal control laws of PM providing electric ships’ best maneuverability can be found by joint consideration of the electric propelling plant (EPP), propellers and hull. Results. A method of calculating the transient regimes of the electric ships’ propulsion complexes during maneuver has been developed. A new method of forming the PM control laws is proposed. The nature of the target functions is revealed and a method of optimizing the parameters of control signals is developed. Optimization calculations have been carried out and the optimal control of the electric ships’ propeller motors when moving along curvilinear trajectory has been found. Optimization has been carried out by the criterion of minimum energy consumption and by the criterion of minimum ship’s distance. The optimization efficiency is illustrated. Scientific novelty. The method of searching for the optimal control laws is constructed according to the system principle, which allows optimizing the control of the propulsion motors by the final result. Practical value. The proposed recommendations can be used in the design of electric propelling plants and in their operation. Целью работы является поиск оптимального управления гребными электродвигателями (ГЭД) электроходов при движении по криволинейной траектории. В качестве критериев оптимальности выбраны показатели, характеризующие судно. Методика. Оптимальные законы управления ГЭД, обеспечивающие наилучшие маневренные характеристики электроходов, могут быть найдены при совместном рассмотрении гребной электроэнергетической установки, гребных винтов и корпуса судна. Результаты. Разработан метод расчета переходных режимов пропульсивных комплексов электроходов при маневрировании на криволинейной траектории. Предложен новый способ формирования законов управления ГЭД. Выявлен характер целевых функций и разработан метод оптимизации параметров сигналов управления. Проведены оптимизационные расчеты и найдено оптимальное управление гребными электродвигателями электроходов при движении по криволинейной траектории. Оптимизация проведена по критерию минимума расхода энергии и по критерию минимума выбега судна. Проиллюстрирована эффективность оптимизации. Научная новизна. Метод поиска оптимальных законов управления построен по системному принципу, что позволяет оптимизировать управление гребными электродвигателями по конечному результату. Практическая значимость. Предложенные рекомендации могут использоваться и при проектировании гребных электроэнергетических установок и при их эксплуатации.

Modeling of "information bubbles" in the global information space

The article uses the Sedov-Taylor function to model "information bubbles" formed in the global information space due to information attacks. The authors identify the most relevant determinants that describe information activities related to cyber threats and reactions of economic agents in the global digital economic space. The article hypothesizes about the emergence of "information bubbles" due to increases in information activities and their rupture due to information intrusion, leading to appropriate reactions of economic agents and their subsequent stabilization over time. The empirical data from global web statistics indicates, that four large-scale information overloads were caused by cyberattacks during the study period, which led to the rupture of "information bubbles". Application of autocorrelation functions allows us to determine that the period during which misinformation spreads is, on average, seven days. Solution of the Sedov-Taylor optimization problem and calculations of differential equations, as well as their derivatives, suggest several indicators. Namely, a breakpoint of the second kind, corresponds to the rupture of the "information bubble" with a subsequent adaptation of the system; the inflection point of the function identifies the levels of information activities related to cyber threats, which will change the consequences of the "information bubble" rupture; the minimum possible level of the reactions of economic agents in the global digital economic space

Coat Polymorphism in Eurasian Lynx: Adaptation to Environment or Phylogeographic Legacy?

We studied the relationship between the variability and contemporary distribution of pelage phenotypes in one of most widely distributed felid species and an array of environmental and demographic conditions. We collected 672 photographic georeferenced records of the Eurasian lynx throughout Eurasia. We assigned each lynx coat to one of five phenotypes. Then we fitted the coat patterns to different environmental and anthropogenic variables, as well as the effective geographic distances from inferred glacial refugia. A majority of lynx were either of the large spotted (41.5%) or unspotted (uniform, 36.2%) phenotype. The remaining patterns (rosettes, small spots and pseudo-rosettes) were represented in 11.0%, 7.4%, and 3.9% of samples, respectively. Although various environmental variables greatly affected lynx distribution and habitat suitability, it was the effect of least-cost distances from locations of the inferred refugia during the Last Glacial Maximum that explained the distribution of lynx coat patterns the best. Whereas the occurrence of lynx phenotypes with large spots was explained by the proximity to refugia located in the Caucasus/Middle East, the uniform phenotype was associated with refugia in the Far East and Central Asia. Despite the widely accepted hypothesis of adaptive functionality of coat patterns in mammals and exceptionally high phenotypic polymorphism in Eurasian lynx, we did not find well-defined signs of habitat matching in the coat pattern of this species. Instead, we showed how the global patterns of morphological variability in this large mammal and its environmental adaptations may have been shaped by past climatic change.publishedVersio

МЕТОД РАСЧЕТА ПЕРЕХОДНЫХ РЕЖИМОВ ГРЕБНЫХ ЭЛЕКТРОЭНЕРГЕТИЧЕСКИХ УСТАНОВОК ЭЛЕКТРОХОДОВ

The purpose of the work is to develop the method for calculating the transient modes of electric ships’ propelling electric plants during maneuver. This will allow us to evaluate and improve the maneuverability of vessels with electric motion. Methodology. The solution to the problems is proposed to be carried out on the basis of mathematical modeling of maneuvering modes. The duration of transient modes in an electric power plant at electric ships’ maneuvers is commensurable with the transient operation modes of the vessel itself. Therefore, the analysis of the electric power plants’ maneuvering modes should be made in unity with all the components of the ship’s propulsion complex. Results. A specified mathematical model of transient regimes of electric ship’s propulsion complex, including thermal motors, synchronous generators, electric power converters, propulsion motors, propellers, rudder, ship’s hull is developed. The model is universal. It covers the vast majority of modern and promising electric ships with a traditional type of propulsors. It allows calculating the current values of the basic mode indicators and assessing the quality indicators of maneuvering. The model is made in relative units. Dimensionless parameters of the complex are obtained. These parameters influence the main indicators of the quality of maneuvering. The adequacy of the suggested specified mathematical model and the developed computation method based on it were confirmed. To do this, the results of mathematical modeling for a real electric ship were compared with the data obtained in the course of field experiments conducted by other researchers. Originality. The mathematical description of a generator unit, as an integral part of an indivisible ship’s propulsion complex, makes it possible to calculate the dynamic operation modes of electric power sources during electric vessels’ maneuvering. There is an opportunity to design the electric ships’ propulsion power plant according to the final result – according to the indicators characterizing the vessel and its maneuvering properties. The use of a system of dimensionless units provides a generality to the results obtained. Electric ships with equal values of dimensionless parameters will have correspondingly the same values (in relative units) of maneuvering quality indicators. Practical value. The developed mathematical model and the research method constructed on its basis allow calculating the current values of the basic regime parameters of all the components of the ship’s propulsion complex. A mathematical apparatus for estimating the main indicators of the quality of electric ships’ maneuvering is proposed. There is an opportunity to improve the electric ships’ maneuvering characteristics by optimizing the operation of propulsion motors.Целью работы является разработка метода расчета переходных режимов гребных электроэнергетических установок в составе судовых пропульсивных комплексов. Методика. На маневрах продолжительности переходных режимов в электроэнергетической установке соизмеримы с переходными режимами работы судна. Поэтому анализ маневренных режимов ее работы следует проводить в единстве со всеми составными частями судового пропульсивного комплекса.            Результаты. Разработаны уточненная математическая модель и метод расчета переходных режимов всех составных частей пропульсивного комплекса электрохода на маневрах. Найдены безразмерные параметры комплекса. Они определяют основные показатели качества маневрирования. Адекватность модели и метода расчета подтверждены сравнением результатов математического моделирования с натурными экспериментами. Научная новизна. Метод расчета позволяет рассчитывать динамические режимы работы всех составных частей комплекса. Появляется возможность проектирования гребных электроэнергетических установок по конечному результату – по показателям качества маневрирования судна. Практическое значение. Метод расчета позволяет проводить исследования поведения пропульсивных комплексов на маневрах и отыскивать пути повышения маневренности электроходов

Search Method Based on Figurative Indexation of Folksonomic Features of Graphic Files

In this paper the search method based on usage of figurative indexation of folksonomic characteristics of graphical files is described. The method takes into account extralinguistic information, is based on using a model of figurative thinking of humans. The paper displays the creation of a method of searching image files based on their formal, including folksonomical clues