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Search results for: VARIABLE SPEED DRIVES
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Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublicationResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
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Sensitivity analysis of simple random beam models by means of Monte Carlo Methods using Variance Reductions Techniques
PublicationA probabilistic sensitivity analysis of two nonlinear bar structures is presented. The analysis is carried out on the basis of the Monte Carlo method. The imperfections of the structures and the applied loads are adapted as random variables. Based on all of the generated input variables, an output response of the system is sought. Afterwards, a coefficient responsible for the structure failure is calculated and the limit state...
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Radionuclides activity and effective doses referred to geological formations
PublicationNaturally occurring radioactive materials (NORM) are present in Earth’s crust and they caused natural background radiation, variable in different regions. Liquid, gas and solid radionuclides emit three types of radiation – alpha, beta and gamma. Fluctuations of natural radioactivity in different geological formations in the world and in Poland were compared in relation to radiological hazard. Also drilling cuttings from boreholes...
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Regression points in non-intrusive polynomial chaos expansion method and D-optimal design
PublicationThe paper addresses selected issues of uncertainty quantification in the modelling of a system containing surgical mesh used in ventral hernia repair. Uncertainties in the models occur e.g. due to variability of abdominal wall properties among others. In order to include them, a non-intrusive regression-based polynomial chaos expansion method is employed. Its accuracy depends on the choice of regression points. In the study a relation...
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Tunable Dielectric Switching of (Quinuclidinium)[MnCl4] Hybrid Compounds
PublicationInorganic−organic hybrid QMnCl (Q = quinuclidinium) crystals were synthesized and characterized. The X-ray and variable-temperature IR/Raman analysis demonstrate that the crystals undergo a reversible structural phase transition, which originates from an order−disorder process and is related to the dynamics of the organic Q cation. Dielectric function measurements disclose a switchability between low (“OFF”) and high (“ON”) dielectric...
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Wpływ zmian dopuszczalnych wartości parametrów geometrycznych i kinematycznych na podatność modernizacyjną układów torowych
PublicationPodatnością modernizacyjną nazywamy stopień przystosowania analizowanego odcinka linii kolejowej do zmiany prędkości eksploatacyjnej. Skala możliwych zmian prędkości (w sensie jej zwiększenia) jest wypadkową istniejącego układu geometrycznego linii w planie, ograniczeń lokalizacyjnych oraz dopuszczalnych wartości parametrów geometrycznych i inematycznych. Jakiekolwiek zmiany tych ostatnich wpływają bezpośrednio na obliczenie elementarnych...
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Broadband Modeling of Motor Cable Impact on Common Mode Currents in VFD
PublicationExamination of conducted EMI generation and propagation in AC motor drives fed by frequency converter requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. AC motor winding voltage transients and related common mode currents are significantly correlated with resonance effects occurring in converter's load circuits. Intensity levels of these phenomena depend...
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Nondestructive global corrosion measurement using guided wavefield data
PublicationMetallic structures often face degradation, and corrosion ranks among the most prevalent forms of deterioration. Accurate quantification of corrosion is crucial, especially for structures exposed to harsh environmental conditions, such as marine vessels and offshore installations. Because the traditional measurement methods based on scanning by ultrasonic gauge are time-consuming and provide only rough information on the thickness...
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Impact of Climate Change on Water Sources and River‐Floodplain Mixing in the Natural Wetland Floodplain of Biebrza River
PublicationThe origins of river and floodplain waters (groundwater, rainfall, and snowmelt) and their extent during overbank flow events strongly impact ecological processes such as denitrification and vegetation development. However, the long-term sensitivity of floodplain water signatures to climate change remains elusive. We examined how the integrated hydrological model HydroGeoSphere and the Hydraulic Mixing-Cell method could help us...
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Enhancing rheological muscle models with stochastic processes
PublicationPurpose: Biological musculoskeletal systems operate under variable conditions. Muscle stiffness, activation signals, and loads change during each movement. The presence of noise and different harmonic components in force production significantly influences the behaviour of the muscular system. Therefore, it is essential to consider these factors in numerical simulations. Methods: This study aims to develop a rheological mathematical...
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Reducing Monitoring Costs in Industrially Contaminated Rivers: Cluster and Regression Analysis Approach
PublicationMonitoring contamination in river water is an expensive procedure, particularly for developing countries where pollution is a significant problem. This study was conducted to provide a pollution monitoring strategy that reduces the cost of laboratory analysis. The new monitoring strategy was designed as a result of cluster and regression analysis on field data collected from an industrially influenced river. Pollution sources in...
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Mobile application technology in levelling
PublicationThe topic of this article is the use of mobile application technology in geodetic measurements with an emphasis on levelling. Reference points were registered as data from levelling benchmarks, performed with a traditional dumpy level. The created application allowed the recording of measurements on location, sending them to a remote server for processing and preparing a report to be saved in a database. The project was to decrease...
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Comparative Analysis of Salient and Non-Salient Pole Brushless Synchronous Generator for Application in Autonomous Electric Power System
PublicationThis paper presents a comparative study of two types of brushless synchronous generator for application in autonomous electric power systems (e.g. airplane power grid). Commercially used salient pole and a prototype non-salient pole high speed multi-pole brushless synchronous generator (BSG) have been presented. Comparative analysis of both types of the generator has been performed. Chosen simulation (using FEM and circuit models)...
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Collaboration within the Automotive Value Chain
PublicationThe paper describes new approach to supply chain management in the North American automotive industry, in part influenced by the Japanese model. To survive and prosper all automotive suppliers must face major challenges in supporting their customers including delivering innovative ideas, technology and quality with increasing speed, participating in every aspect of product development and producing entire systems. The authors describe...
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Advances in macromodeling technique
PublicationThe paper discuses recent advances in the finite differencetime domain method employing macromodels. New techniquesfor creating irregularly shaped macromodels, grouping ofmacromodels and advanced macromodel cloning are introduced.The last technique is particularly important for efficient analysisof the structures based on Photonic Crystals (PhC). The methodallows one to shorten considerably the preprocessing time, theRAM usage...
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A Simulative Comparison of Ship Domains and Their Polygonal Approximations
PublicationThe paper investigates the impact of a precise ship domain shape on the size of collision avoidance manoeuvres. The considered collision avoidance manoeuvres include both course and speed alterations. Various ship domains are compared with their polygonal approximations, which vary in the number of points of a domain contour and placement of these points. The best of all considered approximations is determined in the course of...
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Detection of the Oocyte Orientation for the ICSI Method Automation
PublicationAutomation or even computer assistance of the popular infertility treatment method: ICSI (Intracytoplasmic Sperm Injection) would speed up the whole process and improve the control of the results. This paper introduces a preliminary research for automatic spermatozoon injection into the oocyte cytoplasm. Here, the method for detection a correct orientation of the polar body of the oocyte is presented. Proposed method uses deep...
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Parametric method applicable in calculating breakout force and time for lifting axisymmetric objects from seabed.
PublicationThe issue of calculating parameters for lifting objects of axisymmetric shapes from the seabed is studied. The article presents the results of numerical simulation examination of the equation formulated by Foda for the force needed to extricate the object from the seabed depending on soil and water parameters, extrication speed, and object diameter. The simulations were performed within the range of parameters characteristic for...
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Operational Performance and Weld Bead Characteristics of Experimental Tubular-Wires for Underwater Welding
PublicationAiming to evaluate new formulations and their operational behavior underwater, two experimental tubular wires with different chemical compositions in their internal flux were initially manufactured, employing a pilot machine and a unique manufacturing process. Weld beads were deposited on a plate placed in a flat position inside a tank using a mechanized system and the IMC 300 welding power source. The work was done at a depth...
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Prediction of metal deformation due to line heating; an alternative method of mechanical bending, based on artificial neural network approach
PublicationLine heating is one of the alternative methods of forming metals and this kind of forming uses the heating torch as a source of heat input. During the process, many parameters are considered like the size of the substrate, thickness, cooling method, source power intensity, the travel speed of the power source, the sequence of heating, and so on. It is important to analyze the factors affecting the...
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IMAGE CORRELATION AS A TOLL FOR TRACKING FACIAL CHANGES CAUSING BY EXTERNAL STIMULI
PublicationExpressions of the human face bring a lot of information, which are a valuable source in the areas of computer vision, remote sensing and affective computing. For years, by analyzing the movement of the skin and facial muscles scientists are trying to create the perfect tool, based on image analysis, allowing the recognition of emotional states of human beings. To create a reliable algorithm, it is necessary to explore and examine...
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Wykorzystanie algorytmów ewolucyjnych do doboru wzmocnień rozszerzonego obserwatora prędkości maszyny indukcyjnej
PublicationW pracy opisano sposób doboru wzmocnień rozszerzonego obserwatora prędkości maszyny indukcyjnej przy wykorzystaniu algorytmów ewolucyjnych. Zaproponowano funkcję celu opartą na rozkładzie biegunów obserwatora. Ze względu na wpływ prędkości maszyny na dynamikę obserwatora zaproponowano dobór wzmocnień obserwatora dla różnych przedziałów prędkości. Dla poszczególnych przedziałów zaprezentowano wyniki doboru wzmocnień w postaci tabel...
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Wpływ równości nawierzchni i dynamicznego oddziaływania pojazdów ciężkich na trwałość zmęczeniową nawierzchni podatnych
PublicationPodczas ruchu pojazdu obserwuje się odchylenia nacisków osi pojazdów od nacisku statycznego, co jest spowodowane nierównościami nawierzchni. Dynamiczne obciążenia pojazdów w większym stopniu wytężają konstrukcję nawierzchni drogowej. Rozkład obciążeń dynamicznych ma kształt rozkładu normalnego i jest opisywany poprzez obciążenie statyczne oraz wskaźniki dynamiczne DI lub DLC. Wraz z pogorszeniem równości i zwiększeniem prędkości...
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Pompownie dużej mocy z falownikiem wędrującym średniego napięcia
PublicationArtykuł zawiera rys rozwoju napędów przekształtnikowych w stacjach pomp, w szczególności regulacji wydatku kilku pomp, po kolei, przez jeden przemiennik częstotliwości. Omówiono podstawy teoretyczne zjawiska pola niestłumionego i napięcia resztkowego silników, które utrudniają szybkie przełączania silnika pompy pomiędzy zasilaniem regulowanym przez falownik a zasilaniem z sieci. Przedstawiono zasady transferu (przełączania) synchronicznego...
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Satelitowy agregat pompowy
PublicationW artykule opisano najnowszą konstrukcję satelitowego agregatu pompowego charakteryzującego się tym, że pompa satelitowa jest umieszczona wewnątrz silnika elektrycznego i zasysa ciecz poprzez otwór wydrążony osiowo w wale silnika. Zastosowana w agregacie pompa satelitowa jest nowatorską konstrukcją zawierającą mechanizm satelitowy o odwróconej kinematyce znamienny tym, że planeta (wirnik) oraz płyty kompensacyjne (rozrządu) są...
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A novel method of Mycobacterium tuberculosis complex strain differentiation using polymorphic GC-rich gene sequences.
PublicationTuberculosis is one of the leading infectious diseases. In this work, a new genotyping method of Mycobacterium tuberculosis (Mtb) complex strain is presented. 27 Mtb genomes were analyzed for the presence of length polymorphism within polymorphic GC-rich gene sequences. Four genes, Rv3345c, Rv3507, Rv0747 and Rv3511, showing variation in length depending on the Mtb strain were selected for designing primer sequences flanking variable...
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On the Existence of Homoclinic Type Solutions of a Class of Inhomogenous Second Order Hamiltonian Systems
PublicationWe show the existence of homoclinic type solutions of a class of inhomogenous second order Hamiltonian systems, where a C1-smooth potential satisfies a relaxed superquadratic growth condition, its gradient is bounded in the time variable, and a forcing term is sufficiently small in the space of square integrable functions. The idea of our proof is to approximate the original system by time-periodic ones, with larger and larger...
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Approach Manoeuvre During Emergency Ship-to-Ship Transfer Operation with Oil Spill
PublicationOne of the major activities during Ship to Ship (STS) transfer operation at sea is to safe approach the Ship to be Lightered (SBL) which moves on a constant heading with slow speed or drifting. In the paper described the manoeuvring problem for approaching during emergency STS transfer operation with oil spill. The approach manoeuvre is considered as a sequence of navigation manoeuvres in specific navigational environment with...
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METHOD OF ROUTING SHIPS SAILING IN DEDICATED ENVIRONMENT
PublicationThe method for determining the suboptimal route of sailing vessels operating in a restricted area of the sea are proposed in the paper. The dynamics of the environment including weather conditions and speed characteristics of ships sailing are considered. As optimiza-tion criterion, measure sailing time T, and the number of maneuvers performed ω, are taken into account. An heuristic algorithm, and the appropriate application routing...
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Application of road map of operating condition for estimation of fuel and electric energy consumption from city transport
PublicationThe paper presents procedure of data collecting and generation of road map of operating condition in the selected urban area. This map allows forecasting the selected vehicle operating parameters for the assumed road. The main parameters calculated using the road maps of operating conditions are: total energy spent to drive the selected vehicle, consumed fuel, travel time, average speed of travel, CO2 emissions. Presented example...
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Heuristic Method of Safe Manoeuvre Selection Based on Collision Threat Parameters Areas
PublicationThis paper is a continuation of papers dedicated to a radar-based CTPA (Collision Threat Parameters Area) display designed to support safe manoeuvre selection. The display visualizes all the ships in an encounter and presents situational overview from the own ship’s point of view. It calculates and displays information on unsafe or unrealistic own ship’s course & speed allowing a user to select a safe manoeuvre. So far only the...
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Selected dynamic properties of adaptive proportional observer of induction motor state variables
PublicationThis paper presents problems related to the design and the stability of adaptive proportional observer which is used for estimation of magnetic flux and motor speed in sensorless control systems of induction motor. The gain matrix of the observer was chosen by genetic algorithm and alternatively by pole placement method. It has been shown that adaptive proportional observer is stable if the...
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Slip Compensation Technique In Five-Phase Induction Motors Drive System
PublicationThe article presents a slip compensation method for traditional scalar (V/f) control of a five-phase induction motor. The proposed control method uses the possibility of injecting the third harmonic of voltage to increase the motor’s electromagnetic torque. The solution is characterized by both the simplicity of scalar control and improved speed control efficiency. The paper presents the PLECS simulation results and describes the...
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Prototype and design of six axis robotic manipulator
PublicationThe paper presents a design of six axis manipulator. The design consists of specially designed solutions for housing, planetary gearboxes and electronics. The manipulator is controlled by a supervisory control system. The use of a series of measuring elements allows to track the current position of each axis and use this to create a cascade control loop with velocity and acceleration feed-forward. The implemented control algorithm...
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Human capital quality indicators for measuring regional knowledge economy advances
PublicationBuilding Knowledge Economies (KE) is a long-term process. However, civilizational and technological changes together with EU's Lisbon Strategy help in creating solutions that may speed up economical growth of countries and their regions. This seems to be a very important issue, as during last two centuries history shown, that wisdom and human invention and innovation are the most important factor driving economical growth. In this...
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PRESSURE LOSSES AND POWER BALANCE IN THE UNLOADED SATELLITE PUMP
PublicationThis paper presents the results of laboratory research the pressure drop in the internal channels of unloaded satellite pump pumping tap water. Also shows the characteristics of the increase of pressure in the working chamber of the pump. It has been shown that after reaching cavitation, increase pump speed will increase in torque. This is the moment of inertia caused by the increase of the operating mechanism and the liquid contained...
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The new version of contact-less method for localisation of catenary contact wire – theoretical assumption
PublicationThis article presents the theoretical basic of a new version of contact-less method for localising the catenary contact wires, using the advanced video techniques and image analysis. So far, contact line diagnostic systems exploited nowadays uses the contact measuring methods with special design current collector. This solutions make it impossible to measure the contact line geometry in a static way. The proposed measurement method...
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Pressure losses and power balance in the unloaded satellite pump
PublicationThis paper presents the results of laboratory research the pressure drop in the internal channels of unloaded satellite pump pumping tap water. Also shows the characteristics of the increase of pressure in the working chamber of the pump. It has been shown that after reaching cavitation, increase pump speed will increase in torque. This is the moment of inertia caused by the increase of the operating mechanism and the liquid contained...
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Design, modelling and analysis of a new type of piezoelectric motor. Multicell piezoelectric motor
PublicationThis paper describes a new type of piezoelectric motor. The results, obtained in the field of piezoelectric motors, have pointed out that these motors have potentially high possibilities in the future special applications. The research work presents the design, simulations and parameters of the piezoelectric motor with three rotation-mode actuators. The motor is characterized by a high power, relative high speed and torque. The...
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Does one currency mean one price? An analysis of the euro effect on price dispersion and convergence
PublicationThis paper examines price differentials in the European Union to investigate whether the European Monetary Union has lowered the degree of price dispersion in the euro zone and increased the speed of price convergence. Both euro effects are evaluated using difference-in-difference methodology. Applied to the issue of introducing a single currency, the euro effects identified are the estimated differences in price dispersion and...
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GPU Acceleration of Multilevel Solvers for Analysis of Microwave Components With Finite Element Method
PublicationThe letter discusses a fast implementation of the conjugate gradient iterative method with ${rm E}$-field multilevel preconditioner applied to solving real symmetric and sparse systems obtained with vector finite element method. In order to accelerate computations, a graphics processing unit (GPU) was used and significant speed-up (2.61 fold) was achieved comparing to a central processing unit (CPU) based approach. These results...
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Vertical motions damping model test of a lifeboat lowered onto a flat sea surface
PublicationThe article presents the experiment’s results of the lifeboat model lowered with an initial speed and then released to fall onto a flat water surface. The purpose of the research is to determine the trajectory of the vertical boat motion and describe it with a mathematical model. This is closely related to determining the damping factor since the vertical motion is damped and the lifeboat gets balanced and stops moving after some...
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The methodology for determining of the value of cutting power for cross cutting on optimizing sawing machine
PublicationIn the article the methodology of forecasting the energy effects of the cross-cutting process using the classical method, which takes into account the specific cutting resistance, is presented. The values of cutting power for the cross-cutting process of two types of wood (softwood and hardwood) were forecasted for the optimizing sawing machine with using presented methodology. The cross-cutting process with high values of feed...
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Embodying Intelligence in Autonomous and Robotic Systems with the Use of Cognitive Psychology and Motivation Theories
PublicationThe article discusses, on a certain level of abstraction and generalization, a coherent anthropological approach to the issue of controlling autonomous robots or agents. A contemporary idea can be based on appropriate modeling of the human mind using the available psychological knowledge. One of the main reasons for developing such projects is the lack of available and effective top-down approaches resulting from the known research...
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Equivalent standard manoeuvres for pod-driven ships
PublicationProcedures for carrying out the manoeuvring tests presented in International Maritime Organisation (IMO) resolution MSC.137(76) are based on the capabilities of ships with conventional steering-propulsion systems. Therefore they do not correspond to ships with other steering-propulsion devices, like pod drives. IMO is aware of this shortcoming and for ships with non-conventional steering and propulsion system may permit the use...
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Embodying Intelligence in Autonomous Systems with the Use of Cognitive Psychology and Motivation Theories
PublicationThe article discusses, on a certain level of abstraction and generalization, a coherent anthropological approach to the issue of controlling autonomous robots or agents. A contemporary idea can be based on appropriate modeling of the human mind using the available psychological knowledge. One of the main reasons for developing such projects is the lack of available and effective top-down approaches resulting from the known research...
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Reliability Analysis of Data Storage Using Survival Signature and Logic Differential Calculus
PublicationThe Data storage system is an important part of any information system. All the necessary data that must be available for the successful operation of the information system are stored here. Therefore, it is advisable to think about the reliability of such a data storage system. As part of reliability engineering, it is possible to perform a reliability analysis of any system. Therefore, the data storage system can be analyzed as...
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Development of a new generation of unmanned surface and underwater vehicles using the advanced technologies and achievements towards the application of control systems by the artificial intelligence AI.
PublicationThe operation of offshore structures at sea requires implementation of the advanced systems of permanent monitoring of work of such the installations. Novel solutions concerning such the systems should be associated with application of unmanned maritime surface and underwater platforms. The unmanned maritime platforms are and will be based on application of the newest achievements of some important technologies. Between these technologies...
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Investigation of the thrust generated by active isolated hydrofoils via wave-induced ship motion
PublicationWave Augmented Hydrofoil Technology (WAHT) aims to convert hydrofoil movement, induced by ship motion, into thrust force, and ship's resistance reduction in waves. Despite the growing interest in WAHT, a significant research gap remains in understanding the complex interactions between hydrofoil design parameters and wave-induced thrust generation. A hydrofoil attached to a ship serves dual roles; reducing the ship resistance in...