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.

ASSESSMENT OF INDICES OF NONSPECIFIC RESISTANCE OF THE ORGANISM IN CONDITIONS OF NARROWING OF THE LUMEN OF THE TRACHEA IN AN EXPERIMENT

The narrowing of the lumen of the trachea due to cicatricial stenoses of the trachea is one of the urgent problems of the modern surgery.  The processes taking place in the trachea and lungs lead to a change in the state of the immune system. Assessment of the dynamics of  indices of nonspecific resistance is one of the methods for assessing  the severity of the course of the disease. We studied the indices of  nonspecific resistance of the organism in narrowing the lumen of the  trachea in an experiment in the early postoperative period.  The study was carried out on the basis of the scientific department  of experimental surgery with the vivarium of Irkutsk Scientific  Centre of Surgery and Traumatology, on 24 white male Wistar rats  with a body weight of 300–350 g. We simulated narrowing the lumen of the trachea by placing a silicone tube in the lumen of the trachea  for 14 days. The parameters of phagocytosis, the state of phagocytic activity of blood neutrophils, spontaneous NBT-test, induced NBT- test were studied. The animals were withdrawn from the experiment  on the 3rd, 7th and 14th day. We revealed that as a result of  narrowing of the lumen of the trachea with the original procedure,  the nonspecific resistance of the organism was violated with  inhibition of the phagocytic activity of leukocytes. There was  inhibition of phagocytic activity of leukocytes and depletion of the  functional reserve of leukocytes

CHANGES IN THE INDICES OF NONSPECIFIC RESISTANCE OF AN ORGANISM IN MODELING DISTURBED REPARATIVE REGENERATION OF SHIN BONES

The problem of regeneration of bone structure and joint cartilage is one of the priority programs of scientific research. Regulation of bone formation at the damage is carried out by complex set of factors. A reflection of the regeneration processes is the dynamics of blood parameters, among which are the indicators of inflammatory reaction of the organism, and condition of phagocytosis system. One way to control the severity of impaired reparative regeneration is the analysis of immunological tests of the first order. The aim of our study was to investigate nonspecific resistance of the organism for any breach of reparative regeneration of bone in the lower leg. The study was performed on rabbits "Chinchilla" which simulated the breach of the terms of reparative regeneration. We assessed leukocyte profile and indicators of phagocytosis in experimental animals. Status of the phagocytic activity of blood neutrophils was evaluated on the following parameters: phagocytic index, phagocytic number, nitroblue tetrazolium test, the concentration of circulating immune complexes. We found broken shin bone reparative regeneration of rabbit at fiftieth day of observations is accompanied by leukocytosis with increased segmented neutrophils and a decrease in lymphocytes, inhibition of phagocytosis, and violation of the elimination of circulating immune complexes

Effect of single intake of exogenous hepatocytes growth inducer on the indices of non-specific resistance under conditions of postresection liver injury

HGF is one of the factors taking part in regeneration and recovery of liver after injury. The article is dedicated to the study of influence of single HGF intake on the indices of non-specific immune response in rats after 70% liver resection in the early postoperative period. Research was conducted on 42 six-months white male Wistar rats of 250-300 g. It was revealed that level of segmentonuclear neutrophils and lymphocytes in the group with HGF intake stand at normal level on the 2nd day and normalizes to the 11th day that testifies to the decrease of inflammatory response. Increased level of leukocytes and monocytes is registered in the group with HGF intake. Also integrity of non-specific resistance in the early postoperative period on the 2nd day is registered. Suppression of phagocytosis indices with preservation of functional activity of phagocytes was registered to the 11th day

Emerging concepts in biomarker discovery; The US-Japan workshop on immunological molecular markers in oncology

Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations

ALL-SKY CAMERAS FOR OBSERVATION AND INVESTIGATION OF VARIABLE STARS AND METEOR SHOWERS

This paper studies the capabilities of the all-sky weather (meteorological) cameras in investigation of bright variable stars and determination of apparent radiants of meteor showers. This paper studies the capabilities of the all-sky weather (meteorological) cameras in investigation of bright variable stars and determination of apparent radiants of meteor showers.