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Search results for: PRESSURE SIGANTURE OF SHIP
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Simplified approach to assess the dynamic response of a container ship subjected to bow slamming load
PublicationSimplified approach to assess the dynamic response of a container ship subjected to the bow slamming load, resulting in a transient vibratory response, typically called a 'whip-ping', is presented. The accurate numerical modelling is very complex and involves cou-pling of the hydrodynamic and structural solution at every time step, leading to huge com-putational and workload cost. Thus, the one-way coupling methodology is adopted,...
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Analiza możliwości zastosowania środowiska SCILAB do wspomagania projektowania podsystemów energetycznych statków = Analysis of capability of using SCILAB for adding design of power ship subsystems
PublicationW artykule przedstawiono koncepcję wykorzystania środowiska symulacyjnego Scilab, modeli matematycznych oraz badań symulacyjnych przy projektowaniu podsystemów energetycznych statku. Zredagowano przykładową strukturę zawierającą model wysokoprężnego silnika oraz model śruby okrętowej. Przedstawione procedury oraz modele matematyczne zostaną włączone do systemu ekspertowego wspomagającego projektowanie statków. This paper deals...
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Flow Maps and Flow Patterns of R1233zd(E) in a Circular Minichannel at Low, Medium and High Values of Saturation Pressure
PublicationThere is a gap in knowledge regarding the flow pattern of low-boiling working fluids in the range of high saturation temperatures (above 120°C) and medium and high reduced pressures (0.5-0.9). Data are present in the literature for similar values of reduced pressures, but for lower values of saturation temperature. This is due to the existing refrigeration applications of these working fluids. At high values of reduced pressure,...
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Pressure-induced superconductivity in CaFe2As2
PublicationNowo odkryty związek CaFe2As2 pod wpływem zewnętrznego ciśnienia 0.69 GPa przechodzi w stan nadprzewodnictwa z temperaturą krytyczną powyżej 10K.
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Pressure field in a plane layer
PublicationPraca prezentuje wyniki badań teoretycznych i numerycznych zagadnienia przejścia fal płaskich przez warstwę. Omówiono zagadnienie tworzenia i rozchodzenia się fal w poszczególnych warstwach. Zaproponowano model matematyczny opisujący zmiany ciśnienia wewnątrz warstwy. Analizowano ciśnienie wewnątrz warstwy, fale bieżące i odbite wewnątrz warstwy oraz w ośrodku otaczającym. Przedstawiono wyniki badań numerycznych.
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Signature of Hydrodynamic Pressure Field
PublicationW artykule przedstawiono wyniki obliczeń pola hydrodynamicznego ciśnienia wokół statku jako funkcję przestrzenną, obliczoną metodą brzegowego rozkładu osobliwości. Obliczone pole ciśnienia hydrodynamicznego jest porównywane z pomierzonym polem ciśnienia wokół okrętu na akwenie specjalnym, opis kształtu kadłuba jest przybliżony. Przedstawione wyniki obliczeń uzyskano stosując pojedynczą warstwę o ciągłym rozkładzie źródłowości....
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Signature of Hydrodynamic Pressure Field
PublicationW artykule przedstawiono wyniki obliczeń pola hydrodynamicznego ciśnienia wokół okrętu specjalnego jako funkcji przestrzennej, obliczonej metodą brzegową. Obliczone pola ćiśnienia hydrodynamicznego jest porównywane z pomierzonym polem okrętu na morzu, przy czym opis kształtu kadłuba okrętu jest przybliżony. Przedstawione wyniki obliczeń uzyskano stosując warstwę pojedynczą , którą stanowią źródła o rozkładzie ciągłym. Skonstruowany...
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PREDICTION OF SHIP MOTIONS IN IRREGULAR WAVES BASED ON RESPONSE AMPLITUDE OPERATORS EVALUATED EXPERIMENTALLY IN NOISE WAVES
PublicationThe most common methods for predicting ship roll motions in a specified sea state are direct measurements of motions in a representative irregular wave realisation (time domain) or calculations of motions from response amplitude operators (RAOs) in the frequency domain. The result of the first method is valid only for the tested sea state, whilst the second method is more flexible but less accurate. RAO-based predictions are calculated...
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Karol Niklas dr hab. inż.
PeopleKarol NIKLAS is a university professor at Gdansk University of Technology (Faculty of Mechanical Engineering and Ship Technology, Institute of Naval Architecture). He defended his master's thesis on Naval Architecture, specialty Design of vessels and yachts in 2007. In 2008, he completed postgraduate studies in the specialty 'Novel Simulation Methods in Engineering' at the Faculty of Applied Physics and Mathematics. In 2014 awarded...
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Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes
PublicationIn the previous paper the author presented the evolutionary ship trajectory planning method designed to support Traffic Separation Schemes (TSS). This time the extensions of this method are described which allow to combine evolutionary trajectory planning with speed reduction manoeuvres. On TSS regions with higher than usual density of traffic and smaller distances between ships, the course alterations alone are not always sufficient...
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Experimental Comparison of Straight Lines and Polynomial Interpolation Modeling Methods in Ship Evolutionary Trajectory Planning Problem
PublicationPaper presents the application of evolutionary algorithms and polynomial interpolation in ship evolutionary trajectory planning method and its comparison to classic approach, where trajectory is modeled by straight lines. Evolutionary algorithms are group of methods that allows\ to find a collision free trajectory in real time, while polynomial interpolation allows to model smooth trajectory, which keeps continuity of velocity...
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How does stakeholder pressure influence CSR-practices? A construction industry model based on a European sample
PublicationThe stakeholder pressure is one of the most vital powers which determines CSR implementation and can provide organizations with the motivation to adopt corporate social responsibility (CSR) strategy, as the stakeholder theory claims. The current investigation replications Kowalczyk’s (2019) study, who examined the same structure of relations based on the Polish sample. The essence of this replication is to find out whether CSR-...
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Adaptable management for cooling cyclic air in ship power plants by heat conversion – Part 1: Downsizing strategy for cogeneration plants
PublicationThe ship power plants (SPP) are generally based on Diesel engines. Their fuel efficiency is gradually sensible to cyclic air temperatures and drops with their rise. A sustainable performance of ship engines with high fuel efficiency is possible by cooling intake and charge air as two objects in waste heat conversion chillers. The peculiarities of marine engine application are associated with constrained space of machine room. Whereas,...
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Measurements of the coefficients of active power distribution between two generators operating in parallel in a ship power station
Open Research DataThe presented dataset is part of research focusing on the assessment of metrological properties of the instrument, Estimator/Analyzer (E/A v.2), developed and made at the Faculty of Electrical Engineering, Department of Marine Electrical Power Engineering of Gdynia Maritime University. The attached dataset contains processed data, expressing coefficients...
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Energetics of formation and stability in high pressure steam of barium lanthanide cobaltite double perovskites
PublicationThis study concerns energetics of formation and the stability in high water partial pressure of BaLnCo2O6−δ, (Ln = La, Pr, Nd, and Gd) (BLnC) and BaGd1−xLaxCo2O6−δ, where x = 0.2, 0.5, and 0.7 (BGLC) double perovskite cobaltites. Those materials are extensively studied due to their potential applications as a positrode in electrochemical devices. Therefore, their stability under such conditions is a key issue. All investigated...
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Relationships between stakeholder pressure, culture, and CSR-practices in the context of project management in the construction industry in Poland
PublicationThe study aims to investigate how CSR-stakeholder pressure, CSR-company culture, and CSR-practices are related to one another based on the example of the construction industry in Poland. This knowledge will make it possible to assess which of the two factors, i.e., stakeholder culture or the internal company culture have a stronger effect on the CSR-practices. To accomplish the goal of the study a sample composed of 216 cases was...
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The influence of stainless steels microstructure evolution on the mechanical properties of pressure installation elements
PublicationIn this paper results of FEM analysis performed for pipe and 90o elbow, made of super duplex stainless steel, after precipitation of sigma phase (),were presented. Heat treatment conditions simulate accidental overheating that can occur in nuclear installations after cooling circulation fails. For initial and modified microstructure tensile test was performed and numerical description of work hardening curves was done. Verification...
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The influence of stainless steels microstructure evolution on the mechanical properties of pressure installation elements
PublicationIn this paper results of FEM analysis performed for pipe and 90o elbow, made of super duplex stainless steel, after precipitation of sigma phase (s), were presented. Heat treatment conditions simulate accidental overheating that can occur in nuclear installations after cooling circulation fails. For initial and modified microstructure tensile test was performed and numerical description of work hardening curves was done. Verification...
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Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation
PublicationThe presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical...
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The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems
PublicationThe article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability...
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Chemical Pressure Tuning Magnetism from Pyrochlore to Triangular Lattices
PublicationGeometrically frustrated lattices combined with magnetism usually host quantum fluctuations that suppress magnetic orders and generate highly entangled ground states. Three-dimensionally (3D) frustrated magnets generally exist in the diamond and pyrochlore lattices, while two-dimensionally (2D) frustrated geometries contain Kagomé, triangular, and honeycomb lattices. In this work, we reported using chemical pressure to tune the magnetism...
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Krzysztof Wołoszyk dr inż.
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Masked hypertension in type 2 diabetes: never take normotension for granted and always assess out-of-office blood pressure
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The J-curve phenomenon revisited again: SPRINT outcomes favor target systolic blood pressure below 120 mmHg
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Analysis of Organic Rankine Cycle efficiency and vapor generator heat transfer surface in function of the reduced pressure
PublicationIn the paper presented is analysis of the influence of reduced pressure on efficiency and heat transfer area of vapor generator of Organic Rankine Cycle (ORC) in case of subcritical and supercritical parameters of operation. Compared are two cases of subcritical and supercritical ORC featuring a similar arrangement of heat source supply and heat removal, that is featuring the same temperatures of working fluid before the turbine,...
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Four Degree-of-Freedom Hydrodynamic Maneuvering Model of a Small Azipod-Actuated Ship With Application to Onboard Decision Support Systems
PublicationThe main contribution of this paper is a numerical ship motion model of NTNU’s research vessel Gunnerus, capturing the surge, sway, roll, and yaw dynamics when sailing in uniform and steady currents. The model utilizes a crossflow drag formulation for the transverse viscous loads, and it includes a nonlinear formulation for the propulsion and steering loads provided by two azipod thrusters. A wide range of experimental data obtained...
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A CONCEPT OF DETERMINING THE RELATION BETWEEN LOAD AND WEAR OF TRIBOLOGICAL SYSTEMS OF SHIP MAIN SELF-IGNITION ENGINES BY USING PROBABILISTIC APPROACH PROBABILISTIC APPROACH
PublicationThis paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t(0 ≤ t ≤ t) are random variables Qt and Zt, respectively. There was characterized...
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FEM simulations applied to the failure analysis of RC structure under the influence of municipal sewage pressure
PublicationThe paper discusses a failure mechanism of reinforced concrete (RC) structure with steel cover that failed under the influence of municipal sewage pressure. To explain the reasons of failure, in-situ measurements, laboratory experiments and comprehensive Finite Element Method (FEM) computations were performed. Non-destructive in-situ scanning tests were carried out to determine quantity and cover thickness of embedded reinforcement...
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Chuan Bo Li Xue/Journal of Ship Mechanics
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Which Target Blood Pressure in Year 2018? Evidence from Recent Clinical Trials
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A framework for risk analysis of maritime transportation systems: A case study for oil spill from tankers in a ship–ship collision
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Fatigue strength determination of ship structural joints. Part I - Analytical methods for determining fatigue strength of ship tructures
PublicationSpectacular accidents at sea which have happened for a few last years show that hull structures of contemporary sea-going ships are not perfect and must be systematically improved. Fatigue strength is one of the groups of strength problems which affect design of contemporary ship's structures and greatly contribute in their improvement process. In this paper several approaches to estimation of fatigue life of hull structural...
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Non-invasive hemodynamic monitoring as a guide to drug treatment of uncontrolled hypertensive patients: effects on home blood pressure in the BEAUTY study
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Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
PublicationObjective. The aim of the study is to investigate the effect of the signal sampling frequency and low-pass filtering on the accuracy of the localisation of the fiducial points of the photoplethysmographic signal (PPG), and thus on the estimation of the blood pressure (i.e. the accuracy of the estimation). Approach. Statistical analysis was performed on 3,799 data samples taken from a publicly available database. Four PPGfiducial...
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Experimental study on the selected aspects of bow thruster generated flow field at ship zero-speed conditions
PublicationThe paper presents the results of experimental study on the interaction between the bow thrusters understood as the flow field changes generated by bow tunnel thruster in deep water conditions operated as a single and twin units. The research was limited to zero-speed case for the ship dead in the water. The influence of the hull form and jet spread between the neighbouring thrusters for several combinations of the applied bow...
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A CONCEPT DESIGN OF DIESEL – HYDRAULIC PROPULSION SYSTEM FOR PASSENGER SHIP INTENDED FOR INLAND SHALLOW WATER NAVIGATION
PublicationThis paper presents an analysis of environmental and technical conditions necessary for working out a possibly most favourable propulsion system for a two – segment passenger ship intended for navigation between Berlin and Kaliningrad. There are presented various types of propulsion systems for small ships as well as analyzed their possible applications and consequences. In this work there were taken into account system’s reliability,...
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A Framework of A Ship Domain-Based Near-Miss Detection Method Using Mamdani Neuro-Fuzzy Classification
PublicationSafety analysis of navigation over a given area may cover application of various risk measures for ship collisions. One of them is percentage of the so called near- miss situations (potential collision situations). In this article a method of automatic detection of such situations based on the data from Automatic Identification System (AIS), is proposed. The method utilizes input parameters such as: collision risk measure based...
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The effect of high pressure at subzero temperature on proteins solubility, drip loss and texture of fish (cod and salmon) and mammal’s (pork and beef) meat
PublicationOne of the possibilities of using high pressure technique in inactivation of microorganism is conducting this process at subzero temperature. However, for its practical application in meat preservation the appropriate properties of meat should be kept. Therefore, the aim of this work was to examine the effect of pressure at subzero temperature (without freezing of water) on proteins and texture of mammal’s and cold-adapted fish...
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Full scale CFD seakeeping simulations for case study ship redesigned from V-shaped bulbous bow to X-bow hull form
PublicationIncreasing propulsion efficiency, safety, comfort and operability are of the great importance, especially for small ships operating on windy sites like the North Sea and the Baltic Sea. Seakeeping performance of ships and offshore structures can be analysed by different methods and the one that is becoming increasingly important is CFD RANS. The recent development of simulation techniques together with rising HPC accessibility...
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The voltage on bus bars of the main switchboard of the ro-ro ship electrical power system during a layover at the port
Open Research DataThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results carried out onboard a ro-ro ship during a layover at the port.
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High Pressure Luminescence of Cr-Related Centers in (3CaO-Ga 2 O 3 -3GeO 2 ) Glasses
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Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making.
PublicationThe article presents the three-state semi-Markov model of the process {W(t): t 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application...
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Marek Dzida dr hab. inż.
PeopleHe was born on 6 August 1953 in Bielsko-Biała. He is a graduate of the Institute of Shipbuilding at Gdańsk University of Technology. Since 1978 he has been working at Faculty of Ocean Engineering and Ship Technology at GUT. In 1983 he received the title of Doctor of Technical Sciences, and in 2001 – the title of Doctor with habilitation. He is currently employed as Associate Professor at GUT. He worked as vice-dean for Education...
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The voltage on bus bars of the main switchboard of the ro-ro ship electrical power system during maneuvering
Open Research DataThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results carried out onboard a ro-ro ship during maneuvering.
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Multi-source-supplied parallel hybrid propulsion of the inland passenger ship STA.H. Research work on energy efficiency of a hybrid propulsion system operating in the electric motor drive mode
PublicationIn the Faculty of Ocean Engineering and Ship Technology, Gdansk University of Technology, design has recently been developed of a small inland ship with hybrid propulsion and supply system. The ship will be propelled by a specially designed so called parallel hybrid propulsion system. The work was aimed at carrying out the energy efficiency analysis of a hybrid propulsion system operating in the electric motor drive mode and at...
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A computer system for the complete design of ship propellers
PublicationPraca zawiera opis metody obliczeniowej pozwalającej na zaprojektowanie okrętowej śruby napędowej dla również obliczeniowo wyznaczonego niejednorodnego pola prędkości za kadłubem statku o znanej geometrii i parametrach ruchu. Metoda pozwala na właściwe ujęcie efektu skali i konsekwencji obecności płetwy sterowej za projektowaną śrubą.
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New methods of underwater ship noise classification
PublicationDetekcja, klasyfikacj, identyfikacja i rozpoznanie cech hałasu generowanego przez statki jest bardzo istotna z punku widzenia naukowego i obronnego. Włożono wiele wysiłku w rozwój technologii sonarów pasywnych, która umożliwia zastosowanie hałasów podwodnych do celów praktycznych. Przedstawiono wyniki badań, które ukazują możliwości wykorzystania sieci neuronowej do klasyfikacji źródeł generowanych przez układy mechaniczne, odpowiadających...
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Analysis of reliability of redundant ship power plants
PublicationW referacie przedstawiono możliwości wykorzystania teorii procesów semimarkowskich do określania charakterystyk niezawodnościowych złożonych układów napędowych o zadanym stopniu redundancji. Na przykładzie wybranego układu zaproponowano model niezawodnościowy w formie procesu stochastycznego dyskretnego w stanach i ciągłego w czasie. W oparciu o rozkład graniczny procesu wskazano na praktyczne aspekty wykorzystania uzyskanych w...
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Optimization of transformation of measurements of ship hull blocks
PublicationArtykuł przedstawia analizę wyników pomiarów wykonanych na blokach kadłuba statku, aby ocenić ich przydatność montażową podczas ostatniej fazy montażu w suchym doku lub na pochylni. Analiza realizowana jest w dwóch krokach. Najpierw sprawdza się, czy bloki zostały wykonane z zachowaniem wymaganych tolerancji, a następnie czy istnieje możliwość połączenia ze sobą dwóch sąsiednich bloków. Ponieważ każdy blok jest mierzony w innym...
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Optimization of quadrilateral mesh for ship hull modelling
PublicationArtykuł przedstawia metodę poprawy jakości czworokątnej siatki elementów skończonych, które najlepiej nadają się do modelowania kadłuba statku dla potrzeb analizy MES. W metodzie zakłada się poprawną topologię siatki i stosuje gradient funkcji celu do poszukiwania optymalnego rozwiązania. Funkcja celu może być dowolną funkcją, opisująca jakość elementu (metryka), odpowiednią dla wymagań metody elementów skończonych. W artykule...