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Wyniki wyszukiwania dla: marine%20propulsion%20shafting,%20bearing%20lubrication,%20fluid-structure%20interaction,%20finite-element%20method,%20optimization
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Multi-core and Multiprocessor Implementation of Numerical Integration in Finite Element Method
PublikacjaThe paper presents techniques for accelerating a numerical integration process which appears in the Finite Element Method. The acceleration is achieved by taking advantages of multi-core and multiprocessor devices. It is shown that using multi-core implementation with OpenMP and a GPU acceleration using CUDA architecture allows one to achieve the speedups by a factor of 5 and 10 on a CPU and GPUs, respectively.
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Antimicrobial resistance of Pseudomonas spp. isolated from wastewater and wastewater-impacted marine coastal zone
PublikacjaIn this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins,...
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Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from colission of ships
PublikacjaIn this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to...
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EXHAUST GAS TEMPERATURE MEASUREMENTS IN DIAGNOSTICS OF TURBOCHARGED MARINE INTERNAL COMBUSTION ENGINES PART II DYNAMIC MEASUREMENTS
PublikacjaThe second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy) in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment...
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Endoscopic image processing and analysis of pistons' service failures of marine diesel engines
PublikacjaThe paper deals with diagnostic issues concerning endoscopic examinations of working spaces within marine diesel engines. In the beginning, endoscopy apparatus being on laboratory equipment of the Department of Ship Power Plants of Gdansk University of Technology has been characterized. The endoscopy considerations have been focused on theoretical bases of a digital image processing and especially - on the "Shadow" measurement...
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Identification of diagnostic parameter sensitivity during dynamic processes of a marine engine
PublikacjaChanging some parameters of the engine structure alters the emission of harmful components in the exhaust gas. This applies in particular to the damage of charge exchange system as well as fuel system and engine supercharger. These changes are much greater during the dynamic states and their accompanying transitional processes. The different sensitivity of diagnostic parameters to the same force, coming from the engine structure, but...
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GPU-Accelerated 3D Mesh Deformation for Optimization Based on the Finite Element Method
PublikacjaThis paper discusses a strategy for speeding up the mesh deformation process in the design-byoptimization of high-frequency components involving electromagnetic field simulations using the 3D finite element method (FEM). The mesh deformation is assumed to be described by a linear elasticity model of a rigid body; therefore, each time the shape of the device is changed, an auxiliary elasticity finite-element problem must be solved....
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Exhaust gas temperature measurements in diagnostics of turbocharged marine internal combustion engines. Part I. Standard measurements.
PublikacjaThe article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard...
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Large deformation finite element analysis of undrained pile installation
PublikacjaIn this paper, a numerical undrained analysis of pile jacking into the subsoil using Abaqus software suit has been presented. Two different approaches, including traditional Finite Element Method (FEM) and Arbitrary Lagrangian–Eulerian (ALE) formulation, were tested. In the first method, the soil was modelled as a two-phase medium and effective stress analysis was performed. In the second one (ALE), a single-phase medium was assumed...
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JOURNAL OF MARINE SYSTEMS
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Anomalous diffraction approach to the visible spectra of absorption by marine particles with power-law size distributions
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COMPARISON OF INFINITE ELEMENT MODELS
PublikacjaThe main objective of this paper is to show the comparison of two models of infinite ab- sorbing layer with increasing damping in numerical investigations of elastic wave prop- agation in unbounded structures. This has been achieved by the Authors by a careful in- vestigation of two different engineering structures characterised by gradually increasing geometrical and mathematical description complexities. The analysis included...
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Processing of point cloud data retrieved from terrestrial laser scanning for structural modeling by Finite Element Method
PublikacjaFinite Element Method is one most popular contemporary method of strength analysis. The method is an advanced method for solving differential equations, based on discretization, which means that area is divided into finite elements. Each finite element has a solution of the equation approximated by specific functions and performing the actual calculations only for nodes of this division. Finite Element Method is widely used in...
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The Structure of Entrepreneurial Team Members’ Competencies: Between Effectuation and Causation
PublikacjaA conscious shaping of entrepreneurial competence is a relevant element of entrepreneurial education. In order to recognize which of the competencies regarded as entrepreneurial are characteristic of members of entrepreneurial teams, which is crucial for the work of those teams, it is necessary to identify the structure of those competencies. This quantitative study was conducted with the use of a survey method and involved 111...
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Mixed 4-node shell element with assumed strain and stress in 6-parameter theory
PublikacjaWe propose a mixed hybrid 4-node shell elements based on Hu-Washizu principle. Apart from displacements both strains and stress fields are treated as independent fields. The element is derived in the framework of a general nonlinear 6-field shell theory with drilling rotation which is dedicated to the analysis of multifold irregular shells with intersections. The novelty of the presented results stems from the fact that the measures...
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Mixed 4-node shell element with assumed strain and stress in 6-parameter theory
PublikacjaWe propose a mixed hybrid 4-node shell elements based on Hu-Washizu principle. Apart from displacements both strains and stress fields are treated as independent fields. The element is derived in the framework of a general nonlinear 6-field shell theory with drilling rotation which is dedicated to the analysis of multifold irregular shells with intersections. The novelty of the presented results stems from the fact that the measures...
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Development and validation of lumbar spine finite element model
PublikacjaThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
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Verification of algorithms determining wave loads on support structure of wind turbine
PublikacjaThe offshore wind turbines require determination of wave loads on their support structure. This structure is fixed and, therefore, this problem is reduced to solving only the diffraction problem, which is determined by Laplace equation and conditions on the following boundaries: on the support structure, on the sea free surface and on its bottom, and at infinity on free surface. The linear problem was applied to determine the wave...
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Gas turbine: advanced marine propulsion.
PublikacjaPrzedstawiono rys historyczny rozwoju okrętowych turbin gazowych. Omówiono główne problemy zastosowania turbiny gazowej jako głównego silnika okrętowego i współczesne tendencje rozwoju tego napędu.
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Implementation of the Boundary Element Method to Two-Dimensional Heat Transfer with Thermal Bridge Effects
PublikacjaThe work presents an application of the boundary element method applied to a two-dimensional conductive heat transfer. The algorithm of the method is explained and its advantages are outlined. Green's function as a fundamental solution for Poisson's equation in two dimensions was used and the direct approach was applied. The presented results concern building construction elements as typical cases of thermal bridges. Some properties...
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Distribution of the International Marine Traffic Air Pollutant Emissions in the Port of Split
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THE CONCEPT OF MODELING OF SNOW IMPACT ON THE STRUCTURE OF THE SUSPENDED TAURON ARENA ROOF IN CRACOW
PublikacjaThe article presents studies and numerical simulations on modeling snow influence on TAURON ARENA suspended roof structure in Cracow. The scope of work includes experimental tests, functions solutions taking into account various cases of snow impact according to PN and EC, as well as numerical simulations for the sport and entertainment arena in the Czyzyny district. The FEM roof structure model developed in the SOFISITK software...
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Efficient Finite Element Analysis of Axially Symmetrical Waveguides and Waveguide Discontinuities
PublikacjaA combination of the body-of-revolution and finite element methods is adopted for full-wave analysis of waveguides and waveguide discontinuities involving angular field variation. Such an approach is highly efficient and much more flexible than analytical techniques. The method is performed in two different cases: utilizing a generalized impedance matrix to determine the scattering parameters of a single waveguide section and utilizing...
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JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM
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METHOD TO EXTEND OPERATIONABILITY OF WEB-GIS BASED MARINE SERVICES USING SSE PLATFORM
PublikacjaEarth Observation (EO) products are widely used by geospatial society. Over the last years a number of new applications of satellite imagery were proposed. This led to an increased interest in EO products, not only from researchers but also from companies and individuals. The authors constitute the essential part of the team that created the marine, web-GIS system - SafeCity GIS - for dissemination of data obtained from a 1.5...
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The dynamic performance analysis of the Micro-turbine's rotor supparted on slide and roling element bearings
PublikacjaThis article presents the results of investigations of dynamic characteristics of a small-dimension rotor with slide and rolling element bearings. The object of investigations was the rotor-bearing system designed for the ORC based low-power steam micro-turbine. The investigations were performed using MESWIR series programs, as well as commercial FEA software ABAQUS and MADYN 2000. The results of modal analysis of the micro-rotor...
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Entropy function application within the selection process of diagnostic parameters of marine diesel and gas turbine engines
PublikacjaThe paper presents the method of conducting an analysis of the diagnostic informativeness among the parameters characterizing the observed gas dynamic processes carried out within working spaces of marine diesel and gas turbine engines. An entropy function, as the measure of uncertainty of the identified states' set of the engine unfitness was applied. Having evaluated the diagnostic information the most adequate parameters were...
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Elastic wave propagation signals in concrete cube (experimental and calculated using discrete element method)
Dane BadawczeThe DataSet contains the results of the elastic wave propagation. Both experimental and numerical signals were obtained for the concrete cube with dimensions of 50 × 50 × 50 mm3. The specimen was made of concrete with called mortar concrete. The ingredients of the concrete mix were as follows: CEM I 42.5R (500 kg/m3), sand 0 – 2 (1500 kg/m3) and water...
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Adaptive dynamic control allocation for dynamic positioning of marine vessel based on backstepping method and sequential quadratic programming
PublikacjaIt is generally assumed in dynamic positioning of over-actuated marine vessels that the control effectiveness matrix (input matrix) is known and constant, or, in case of fault information, it is estimated by the fault detection and diagnosis system. The purpose of the study is to develop the adaptive dynamic positioning control system for an over-actuated marine vessel in the presence of uncertainties and with emphasis on limited...
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Local mesh morphing technique for parametrized macromodels in the finite element method
PublikacjaThis paper presents a novel approach for enhancing the efficiency of the design process of microwave devices by means of the finite element method. It combines mesh morphing with local model order reduction (MOR) and yields parametrized macromodels that can be used to significantly reduce the number of variables in the FEM system of equations and acceleration of computer simulation. A projection basis for local reduction is generated...
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Jerzy Kowalski dr hab. inż.
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Accelerated large scale test set-up design in natural corrosion marine environment
PublikacjaThe standards for conducting small-scale specimen tests are well developed, but there is a lack of direct guidelines for conducting corrosion tests for large-scale specimens. The objective here is to develop a methodology which may be used in designing an accelerated corrosion test of large-scale structural components subjected to a natural corrosion marine environment. Different factors influencing corrosion degradation of steel...
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Janusz Kozak prof. dr hab. inż.
OsobyDr hab. inż. Janusz Kozak Dziekan Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej Urodzony: 04.07.1953 w Pucku Absolwent Technikum Budowy Okrętów „Conradinum” w Gdańsku, 1973. Absolwent Instytutu Okrętowego PG, 1978. Po ukończeniu studiów praca w Stoczni Gdynia, a od roku 1980 w Katedrze Technologii Okrętów Instytutu Okrętowego a później Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej kolejno na...
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Investigation of the Efficiency of a Dual-Fuel Gas Turbine Combustion Chamber with a Plasma‒Chemical Element
PublikacjaThe study is devoted to the possibility of increasing the efficiency of the working process in dual-fuel combustion chambers of gas turbine engines for FPSO vessels. For the first time, it is proposed to use the advantages of plasma‒chemical intensification of the combustion of hydrocarbon fuels in the dual-fuel combustion chambers, which can simultaneously operate on gaseous and liquid fuels. A design scheme of a combustion chamber...
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Unequally-Spaced Slot Strategy for Radiation Null Reduction in Single SIW-Embedded Antenna Element
PublikacjaThe incorporation of higher-order modes (HOMs) can substantially augment the antenna gain and bandwidth, but this improvement is typically accompanied by compromised radiation performance including radiation nulls and higher side lobe levels. In this study, an inventive strategy is introduced to reduce the radiation nulls and the side lobe levels of a single antenna element by positioning multiple slots of the radiating element...
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GPU-Accelerated Finite-Element Matrix Generation for Lossless, Lossy, and Tensor Media [EM Programmer's Notebook]
PublikacjaThis paper presents an optimization approach for limiting memory requirements and enhancing the performance of GPU-accelerated finite-element matrix generation applied in the implementation of the higher-order finite-element method (FEM). It emphasizes the details of the implementation of the matrix-generation algorithm for the simulation of electromagnetic wave propagation in lossless, lossy, and tensor media. Moreover, the impact...
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Modelling of Longitudinal Elastic Wave Propagation in a Steel Rod Using the Discrete Element Method
PublikacjaThe paper deals with the issue of modelling elastic wave propagation using the discrete element method (DEM). The case of a longitudinal wave in a rod with a circular cross-section was considered. A novel, complex algorithm consisting of the preparation of models and simulation of elastic waves was developed. A series of DEM models were prepared for simulations, differing in discretisation and material parameters. Additional calculations...
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DIAGNOSTIC INFORMATION ANALYSIS OF QUICKLY CHANGING TEMPERATURE OF EXHAUST GAS FROM MARINE DIESEL ENGINE PART I SINGLE FACTOR ANALYSIS
PublikacjaIn this paper, attention was paid to the problem of low controllability of marine medium- and high-speed engines during operation, which significantly limits the parametric diagnosis. The measurement of quickly changing temperature of engine exhaust gas was proposed, the courses of which can be a source of diagnostic information. The F statistic of the Fisher-Snedecor distribution was chosen as a statistical tool. Laboratory tests...
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Reliable Greedy Multipoint Model-Order Reduction Techniques for Finite-Element Analysis
PublikacjaA new greedy multipoint model-order reduction algorithm for fast frequency-domain finite-element method simulations of electromagnetic problems is proposed. The location of the expansion points and the size of the projection basis are determined based on a rigorous error estimator. Compared to previous multipoint methods, the quality of the error estimator is significantly improved by ensuring the orthogonality of the projection...
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GPU Acceleration of Multilevel Solvers for Analysis of Microwave Components With Finite Element Method
PublikacjaThe 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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Postquarter-Point Case of Ship’s Side-Berthing and Its Influence on Marine Fender Pitch
PublikacjaThis paper presents a critical analysis of some selected codes and practical recommendations used as basic rules in the design procedures of modern marine fender systems. The first part of the discussion pertains to the existing equations used in calculating the eccentricity coefficient in the ship’s kinetic energy equation and the maximum allowable fender pitch (spacing) in a set of fenders installed along a quay wall. A new approach...
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Planning of the green road system as an element of spatial management in suburbs and small towns
PublikacjaThe premise for the development of sustainable forms of road infrastructure in small towns is the appropriate plan at an early stage or modifi cation in the case of existing spaces. A multi-directional approach is extremely important, which takes into account the specifi city of the regional (country) road system, availability, and capacity of traffi c network, but also social and environmental factors. Effi cient management...
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MARINE CHEMISTRY
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Marine Drugs
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Local Mesh Deformation for accelerated parametric studies based on the Finite Element Method
PublikacjaThis paper presents an approach for enhancing the efficiency of two-dimensional Finite Element Method analysis in parametric studies or optimisation process of microwave components. The new approach involves local mesh deformation applied near the elements that are modified during computations. Since in the proposed approach the topology of the mesh remains unchanged, a new mesh does not have to be generated from scratch when the...
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Bioaccumulation of metals in tissues of marine animals, Part II - metal concentrations in animal tissues
PublikacjaThe bioaccumulation of metals in an animal depends on a multitude of factors: biotic ones, like its body dimensions and mass, age, sex, diet, metabolism and position in the trophic web, as well as abiotic ones such as the distribution of metals in its environment, the salinity, temperature and pH of the water, habitat type, interactions with other metals. But it is diet that has the greatest influence on the accumulation of metals...
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Updating Finite Element Model of a Wind Turbine Blade Section Using Experimental Modal Analysis Results
PublikacjaThis paper presents selected results and aspects of themultidisciplinary and interdisciplinary research oriented for the experimental and numerical study of the structural dynamics of a bend-twist coupled full scale section of awind turbine blade structure.Themain goal of the conducted research is to validate finite elementmodel of themodified wind turbine blade section mounted in the flexible support structure accordingly to the...
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Fault diagnosis of marine 4-stroke diesel engines using a one-vs-one extreme learning ensemble
PublikacjaThis paper proposes a novel approach for intelligent fault diagnosis for stroke Diesel marine engines, which are commonly used in on-road and marine transportation. The safety and reliability of a ship's work rely strongly on the performance of such an engine; therefore, early detection of any type of failure that affects the engine is of crucial importance. Automatic diagnostic systems are of special importance because they can...
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Spectral Finite Element Method in Condition Monitoring and Damage Detection
PublikacjaIt is well known that the dynamic behaviour of engineering structures may carry very important and crucial information that can be further used for the assessment of their condition as well as detection of any damage induced. The current interest in monitoring techniques based on the propagation of guided elastic waves requires that numerical techniques used for modelling the phenomena associated must shift into the realm of high...
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Simulations of Shear Zones and Cracks in Engineering Materials Using eXtended Finite Element Method
PublikacjaNumerical simulations of cracks and shear zones in quasi-brittle materials are presented. Extended Finite Element Method is used to describe both cracks and shear zones. In a description of tensile cracks, a Rankine criterion is assumed. A discrete Mohr-Coulomb law is adopted for simulations of shear zones. Results of simple numerical tests: unixial tension, bending and biaxial compression are demonstrated.