Integral Approach to Vulnerability Assessment of Ship’s Critical Equipment and Systems

The digital transformation of the maritime industry is almost a fait accompli. Merchant ships today use computing and cyber-dependent technologies for navigation, communications, cargo operations, environmental monitoring, and many other purposes. Nowadays, entire industries and businesses are becoming increasingly dependent on data arrays, and the maritime sector is fully experiencing this transformation. A modern commercial ship is unthinkable without digital technology, and the reasons for the deep digitalization of the fleet are numerous. Emergency systems such as safety monitoring, fire detection and alarms are increasingly reliant on cyber technology. Therefore, cybersecurity is a critical component of ship and shipping safety, and cyber-attacks on maritime transport are a very likely problem. These risks will only increase with the further development of information technology. This article proposes approaches to identifying cyber threats as well as a probabilistic assessment of ship cybersecurity, which is based on an integral approach to assessing the vulnerability of shipboard critical equipment and systems. Estimated probabilities of target and non-target cybersecurity breaches of the ship, as well as their overall probability, which allows considering all chains of events leading to a certain consequence associated with potential losses. The model of probability assessment of ship cybersecurity violation and its consequences, which allows evaluation of possible losses as a result of these events, is presented and mathematically described

DEVELOPMENT MEASURES TO ENHANCE THE ECOLOGICAL SAFETY OF SHIPS AND REDUCE OPERATIONAL POLLUTION TO THE ENVIRONMENT

Reduction of ecological risks of shipping is a challenging task that requires methods of legislative and regulatory control, organizational measures, and technical and technological support. Furthermore, the matter concerns not only the reduction of possible risks but also the level of existing impact on the marine environment because of exhaust gas emissions by ships, discharge of waste and ballast water, as well as control of ecological consequences of accidents. The purpose of this study is to analyse possible sources of environmental impact during ship operation cycles, identify significant risks, review existing potentials to reduce the risk of ship accidents and their environmental consequences, and develop solutions to existing problems. This study offers results, which can serve as the initial basis for the formation of comprehensive measures on the reduction of environmental risks, and consequences of possible accidents for the environment caused by ships and international shipping

Автоматизація процесів керування конденсаторами холодильних установок

In the article energy efficient ways of the condensing pressure (temperature) control in refrigeration units for various purposes are considered. The comparative analysis of the circuit solutions of the condensing temperature regulators for air cooling condensers is conducted with simulation methods. Modeling of the single-phase system of the regulator pulse-phase control triac HPC1/4 showed that this system has a low power factor. The feasibility of the condensing temperature regulators implementation on the basis of the three-phase frequency converter with DC chain is substantiated for the low and medium cooling capacity refrigeration units. The disadvantages of the existing systems of the condensing pressure stabilization of the refrigeration units water cooling condensers are highlighted. The research of two proposed control systems of the water-cooled condensers of the medium and high cooling capacity refrigeration units is conducted. It is established that the using of the principles of partial invariance to main disturbances with elements of the nonlinear correction can improve the energy efficiency of refrigeration units. Also it is provided by modeling the processes in the shell and tube capacitor KTP-300 of the ship refrigeration unit that the using of variable structure systems further improves the dynamic quality of control processes with large fluctuations of the heat loads.Методами імітаційного моделювання проведений порівняльний аналіз схемотехнічних рішень регуляторів температури конденсації. Обґрунтовано доцільність реалізації таких регуляторів на базі трифазного перетворювача частоти з ланкою постійного струму. Проведено дослідження двох систем керування охолодженням водяних конденсаторів холодильних установок. Доведено, що використання запропонованих алгоритмів управління дозволить підвищити енергетичну ефективність холодильних установок і якість динамічних процесів управління при значних коливаннях теплових навантажень

Автоматизація процесів керування конденсаторами холодильних установок

In the article energy efficient ways of the condensing pressure (temperature) control in refrigeration units for various purposes are considered. The comparative analysis of the circuit solutions of the condensing temperature regulators for air cooling condensers is conducted with simulation methods. Modeling of the single-phase system of the regulator pulse-phase control triac HPC1/4 showed that this system has a low power factor. The feasibility of the condensing temperature regulators implementation on the basis of the three-phase frequency converter with DC chain is substantiated for the low and medium cooling capacity refrigeration units. The disadvantages of the existing systems of the condensing pressure stabilization of the refrigeration units water cooling condensers are highlighted. The research of two proposed control systems of the water-cooled condensers of the medium and high cooling capacity refrigeration units is conducted. It is established that the using of the principles of partial invariance to main disturbances with elements of the nonlinear correction can improve the energy efficiency of refrigeration units. Also it is provided by modeling the processes in the shell and tube capacitor KTP-300 of the ship refrigeration unit that the using of variable structure systems further improves the dynamic quality of control processes with large fluctuations of the heat loads.Методами імітаційного моделювання проведений порівняльний аналіз схемотехнічних рішень регуляторів температури конденсації. Обґрунтовано доцільність реалізації таких регуляторів на базі трифазного перетворювача частоти з ланкою постійного струму. Проведено дослідження двох систем керування охолодженням водяних конденсаторів холодильних установок. Доведено, що використання запропонованих алгоритмів управління дозволить підвищити енергетичну ефективність холодильних установок і якість динамічних процесів управління при значних коливаннях теплових навантажень

Аналіз можливостей підвищення енергетичних показників асинхронних електродвигунів пропульсівних комплексів автономних плавальних апа-ратів

This study proposes additional possibilities to improve, at minimal efforts, a number of technical-economic indicators of three-phase standard industrial induction motors (IM). We suggest that such engines should be used in the propulsion complexes of modern autonomous floating vehicles (AFV). Such a task is to be solved because of the need to provide the propulsion complex of AFV with energy-efficient and inexpensive electric motors. It is proposed to apply four-pole electric motors, instead of bipolar electric motors, at an elevated rated power frequency (100, 150, 200 Hz). Employing the method of analogies of geometrically similar electric machines, it is substantiated to apply the shortened three-phase four-pole IM instead of bipolar IM. We have conducted a detailed analysis of the basic structural and energy characteristics of the modernized general-purpose IM. It was established that in the modernized four-pole IM of the AFV propulsion complex the weight and size parameters are significantly reduced (by approximately 15 %). This is enabled by a simple structural modernization. Given such a modernization, it is not necessary to manufacture new bearing assemblies, lids; in this case, mass of the utilized active materials decreases (by 10...17 %). The research results make it possible to meet the needs of modern AFV production in energy-efficient (power factor of modernized engines is approximately 0.56) and inexpensive electric motors for a propulsion complex.Представлены возможности повышения энергетических показателей трехфазных общепромышленных асинхронных электродвигателей (АД), применяемых в автономных плавательных аппаратах (АПА). На основе метода аналогий обосновывается применение укороченных трехфазных четырехполюсных АД вместо двухполюсных. Рассчитываются основные конструкционные и энергетические характеристики модернизированных АД. Доказано, что для модернизированного четырехполюсного АД АПА существенно снижаются массогабаритные показатели при минимальной его конструкционной модернизацииПредставлені можливості підвищення енергетичних показників трифазних загальнопромислових асинхронних електродвигунів (АД), що використовуються у автономних плавальних апаратах (АПА). На основі методу аналогій обґрунтовано застосування укорочених трифазних чотириполюсних АД замість двополюсних. Розраховані основні конструкційні й енергетичні характеристики модернізованих АД. Доведено, що для модернізованого чотириполюсного АД АПА суттєво знижуються масогабаритні показники при мінімальній його конструкційної модернізаці

Концепція створення системи підтримки прийняття рішень для проектування комбінованих пропульсивних комплексів

It is shown that there are many mathematical models (MM) of ship power plants for various purposes. Such MM are integrated into decision support systems (DSS) and used in the design and power optimization of ship power plants (SPP) of various constructional configurations. Experimental research and scientific literature analysis prove that such integrated MM into DSS are not always adequate to real physical processes in some modes, for example, dynamic ship positioning.That is why integrated MM SPP into DSS need clarification as well as the existing DSS need further development.The approach for the creation of specialized DSS SPP of the ship combined propulsive complexes (CPC) is proposed, which allows predicting the number and type of thrusters (T), pods, power system, and does not require the application of similarity criteria, allows a multiple analysis of the structure at minimal initial data.The designed DSS applies the principles of the construction of DMI-models ships and methods of implementation of characteristic spatial vectors of power processes, gives a possibility to synthesize recommendations to T designers, controllers and power systems for ships operating in the dynamic positioning modes.  Created DSS can be used practically for any type of vessels and adapted for the modes of dynamic ship positioning.It is established for a given rotation speed of the pods, traction, torque and stepper ratio with the help of created DSS, that traction coefficient grows with the change in mutual location of T relative to each another and diametrical plane of the vessel. It is proved that the interelation of thrusts coefficients are correlated better with the power coefficients than with the stepping  pods coefficients, allowing  increasing energy efficiency of SPP CPC in the dynamic positioning modes.The results of the research can be implemented into data bases of similar DSS and provide researchers with verified information needed for creation of new concepts of SPP CPC design for modification of existing systems. Приводятся результаты исследований в рамках совершенствования системы поддержки принятия решений при проектировании судовых энергетических установок (СЭУ) комбинированных пропульсивных комплексов (КПК). СППР построена с использованием системного анализа, оптимизации и технологий моделирования, реализованных на базе DMI-моделей судов. При совершенствовании СППР был применен метод взаимной имплементации характеристических пространственных векторов энергетических процессов в СЭУ и гидродинамических в КПК.Наводяться результати досліджень у рамках удосконалення системи підтримки прийняття рішень при проектуванні суднових енергетичних установок (СЕУ) комбінованих пропульсивних комплексів (КПК). СППР побудована з використанням системного аналізу, оптимізації та технологій моделювання, реалізованих на базі DMI–моделей суден. При удосконаленні СППР було застосовано метод взаємної імплементації характеристичних просторових векторів енергетичних процесів в СЕУ і гідродинамічних в КПК

Application of fuzzy controllers in automatic ship motion control systems

Automatic ship heading control is a part of the automatic navigation system. It is charged with the task of maintaining the actual ship’s course angle or actual ship’s course without human intervention in accordance with the set course or setting parameter and maintaining this condition under the effect of disturbing influences. Thus, the corrective influence on deviations from a course can be rendered by the position of a rudder or controlling influence that leads to the rotary movement of a vessel around a vertical axis that represents a problem, which can be solved with the use of fuzzy logic. In this paper, we propose to consider the estimation of the efficiency of fuzzy controllers in systems of automatic control of ship movement, obtained by analysis of a method of the formalized record of a logic conclusion and structure of the fuzzy controller. The realization of this allows to carry out effective stabilization of a course angle of a vessel taking into account existing restrictions

Epidemiology of the vestibular schwannomas in Ukraine and our experience of surgical and radiosurgical treatment

Aim: Figuring out the occurrence of vestibular schwannomas (VS) and their management tendencies in Ukraine.Materials and methods: Data about VS detection and treatment were collected among all Ukrainian neurosurgical and radiological facilities which are enrolled in providing care for these patients. Together with those who were treated overseas the total number in 2016-2018 was 903 people. There were 665 cases (73.6  %) treated surgically, 124 cases (13.8  %) irradiated and 114 (12.6  %) observed via serial imaging.Results: The prevalence of VS in Ukraine is about 7.27 per 1 million people which corresponds to data around the world (CBTRUS trial suggested VS incidence 10-20 people per 1 million during 2004-2009).Most of verified VSs were treated surgically (73.6  %), lesser part was irradiated (13.8  %) and 12.7 % were followed-up by wait-and-scan strategy. Our data regarding surgical management was higher than worldwide. At the same time, the volume of detected tumors was much larger in comparison to published data. Seventy-three per cent of all cases were Koos T4 tumors as a possible result of poor diagnosis and lack of alertness making surgical interventions more common and difficult.Total and subtotal resection rate was 79  % as the result of combined microsurgical and endoscopic techniques under intraoperative electrophysiological neuromonitoring guidance. The facial nerve was preserved in 94.2  % of cases, cochlear — in 8.5  % of cases. The average mortality rate during 2016-2018 in Ukraine was 3.1  % with 1.3  % in Subtentorial Neurooncology Department of the Romodanov Neurosurgery Institute.Conclusions: For further improvements and development of optimal management strategies for patients with VS, it is necessary to improve earlier diagnosis and reasonable to provide neurosurgical care in high-volume centers based on the profound expertise with further advances in technologies for functionally favorable outcomes

Generation of Localised Vertical Streams in Unstable Stratified Atmosphere

A new model of axially symmetric concentrated vortex generation was developed herein. In this work, the solution of a nonlinear equation for internal gravity waves in an unstable stratified atmosphere was obtained and analysed in the framework of ideal hydrodynamics. The related expressions for the velocities in the inner and outer regions of the vortex were described by Bessel functions and modified zeroth-order Bessel functions. The proposed new nonlinear analytical model allows the study of the structure and dynamics of vortices in the radial region. The formation of jets (i.e., structures elongated in the vertical direction with finite components of the poloidal (radial and vertical) velocities that grow exponentially in time in an unstable stratified atmosphere) was also analysed. The characteristic growth time was determined by the inverse growth rate of instability. It is shown that a seed vertical vorticity component may be responsible for the formation of vortices with a finite azimuthal velocity