Filtry
wszystkich: 7412
wybranych: 4357
-
Katalog
- Publikacje 4357 wyników po odfiltrowaniu
- Czasopisma 1073 wyników po odfiltrowaniu
- Konferencje 106 wyników po odfiltrowaniu
- Wydawnictwa 1 wyników po odfiltrowaniu
- Osoby 1231 wyników po odfiltrowaniu
- Wynalazki 4 wyników po odfiltrowaniu
- Projekty 55 wyników po odfiltrowaniu
- Laboratoria 4 wyników po odfiltrowaniu
- Zespoły Badawcze 4 wyników po odfiltrowaniu
- Aparatura Badawcza 1 wyników po odfiltrowaniu
- Kursy Online 393 wyników po odfiltrowaniu
- Wydarzenia 20 wyników po odfiltrowaniu
- Dane Badawcze 163 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: ocean%20engineering
-
Validation study on a new semi-empirical method for the prediction of added resistance in waves of arbitrary heading in analyzing ship speed trial results
Publikacja -
Full-scale CFD simulations for the determination of ship resistance as a rational, alternative method to towing tank experiments
PublikacjaResults of ship resistance predictions obtained from towing tank experiments are affected by the method used to extrapolate from a model scale to a ship scale. Selection of method to determine a form factor is subjective and the extrapolation method is accurate for typical hull forms. For innovative hull forms the proper method for calculating the form factor is questionable. Moreover, the influence of the extrapolation method...
-
Full scale measurements of pressure field induced on the quay wall by bow thrusters – indirect method for seabed velocities monitoring
PublikacjaThe paper presents the results of full-scale experimental investigation of loads generated on the quay wall by bow thrusters during unberthing of a self-manoeuvring vessel. The presented research allowed for the comparison of the measurements results with generally accepted empirical prediction methods and confirmed the utility of the developed measuring setup for the on-line monitoring of jet induced loads. The conclusions from the...
-
Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker
PublikacjaThis paper aims to present a new approach in the prediction of manoeuvring abilities of pod-driven ships. A new mathematical model of motions based on MMG methodology was developed and a new type of description of forces acting on azimuth drives is presented. Captive model tests of medium-size coastal tanker and pod open water tests were carried out in CTO S.A. (Ship Design and Research Centre S.A.) to obtain hull hydrodynamic derivatives...
-
High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
-
Towards a reliable method for extrapolation of propulsion performance for vessels with twin-crp-pod system
PublikacjaThe study presents power performance prediction of an Ultra Large Container Ship (ULCS) with hybrid twin-crp-pod propulsion system. Twin crp-pod propulsion system is a combination of three concepts: twin screw, contra-rotating propellers (crp) and conventional shaft propellers with pod propulsors behind. The presented study shows the current extrapolation method for crp propulsion systems and tries to point out its weaknesses....
-
Numerical and experimental propeller noise investigations
PublikacjaThe standard propeller has been investigated in model scale, using medium size cavitation tunnel. The hydroacoustic characteristics of propellers under different loading conditions have been investigated. Additionally the presented experimental results have been used for the verification of applied numerical approach. During both numerical and experimental analyses non-uniform inflow propeller’s conditions have been adapted. Good...
-
A decision-making system supporting selection of commanded outputs for a ship's propulsion system with a controllable pitch propeller
PublikacjaThe ship's operators have to make decisions regarding the values of commanded outputs (commanded engine speed and pitch ratio) which ensure maximum vessel speed and minimum fuel consumption. Obviously, the presented decision problems are opposed. Therefore, there is a need for a compromise solution that enables more flexible vessel voyage planning. This paper deals with development of a computer-aided system supporting selection...
-
An analysis of domain-based ship collision risk parameters
PublikacjaAccording to a lot of contemporary research on ship collision avoidance the classic approach parameters – distance at closest point of approach (DCPA) and time to the closest point of approach (TCPA) – are not sufficient for estimating ship collision risk and for planning evasive manoeuvres. Consequently new measures are introduced, often utilizing the concept of a ship domain. Their drawback, up to this point, was the lack of...
-
A method of determining and visualizing safe motion parameters of a ship navigating in restricted waters
PublikacjaThe paper presents a method of displaying ship collision avoidance information which is based on an unconventional Collision Threat Parameters Area (CTPA) technique. The solution presented here extends CTPA's functionality from past works by supporting navigation in restricted waters and handling ship domains analytically instead of numerically. It visualizes potential navigational threats as well as possible collision avoidance...
-
Experimental investigation of Steel–Concrete–Polymer composite barrier for the ship internal tank construction
PublikacjaTransportation of dangerous cargo by ships demands ensuring an appropriate protection level in case of an accident. Two of the most dangerous accident types resulting in an oil spill are grounding and ship to ship collision. The article presents results of research on a new composite construction for a ship hull that increases structural safety during collision. The concept of semi-elastic Steel–Concrete–Polymer structure is presented....
-
Review of ship safety domains: Models and applications
PublikacjaShip safety domain is a term which is widely used in research on collision avoidance and traffic engineering among others. Classic ship domains have been compared in multiple reports. However, up till now there has been no work summing up contemporary research in this field. The paper offers a systematic and critical review of the newer ship domain models and related research. It discusses multiple differences in approach to ship...
-
Determining and visualizing safe motion parameters of a ship navigating in severe weather conditions
PublikacjaThe paper presents a method of determining, organizing and displaying ship collision avoidance information, which is based on the Collision Threat Parameters Area (CTPA) technique. The method makes it possible to visualize navigational threats as well as possible collision avoidance manoeuvres. The solution is focused on supporting navigation in severe weather conditions. Normally collision avoidance decisions are made taking into...
-
Validation study on a new semi-empirical method for the prediction of added resistance in waves of arbitrary heading in analyzing ship speed trial results
PublikacjaThis paper describes an open and extensive validation study carried out by the Specialist Committee on Ships in Operation at Sea (SOS) of the International Towing Tank Conference (ITTC) on the newly developed SHOPERA-NTUA-NTU-MARIC (SNNM) wave-added resistance prediction method. The SNNM method aims at a simple, fast and transparent determination of the added resistance in regular waves of arbitrary encounter directions, even when...
-
An enhanced method in predicting tensile behaviour of corroded thick steel plate specimens by using random field approach
PublikacjaThe present work investigates the possibility of using random field techniques in modelling the mechanical behaviour of corroded thick steel plate specimens. The nonlinear Finite Element method, employing the explicit dynamic solver, is used to analyse the mechanical properties of typical specimens. A material model considering full nonlinearity is used to evaluate the stress-strain response. The influence of major governing parameters...
-
Modernized cathodic protection system for legs of the production rig – Evaluation during ten years of service
PublikacjaThe modernization of cathodic protection system of the Baltic Beta platform legs is described. It was that the sacrificial anodes cone-shaped groups were to be placed on the seabed at a depth of 80 m. The measurements results of cathodic protection effectiveness during its ten-years operation are presented. The effectiveness was assessed based on the potential value along the entire length of the legs from the sea surface to the...
-
Ship weather routing optimization with dynamic constraints based on reliable synchronous roll prediction
PublikacjaShip routing process taking into account weather conditions is a constrained multi-objective optimization problem and it should consider various optimization criteria and constraints. Formulation of a stability-related, dynamic route optimization constraint is presented in this paper. One of the key objectives of a cross ocean sailing is finding a compromise between ship safety and economics of operation. This compromise should...
-
On ship roll resonance frequency
PublikacjaThe paper deals with the problem of modeling of rolling motion under a variety of excitation parameters. Special emphasis is put on the analysis and prediction of the frequency of the resonant mode of rolling, since it is often an essential issue in terms of motion of a ship related to her safety against capsizing or excessive amplitudes of roll. The research is performed for both free rolling and excited rolling and it is based...
-
Towards evaluation of the Second Generation Intact Stability Criteria - examination of a fishing vessel vulnerability to surf-riding, based on historical capsizing
PublikacjaThe Second Generation Intact Stability Criteria (SGISC) are the latest achievements in the field of intact ship stability assessment. The criteria are the result of massive international cooperative efforts and extensive research that lasted more than 15 years. Even though they are based on a solid scientific foundation, the trial period has commenced to collect user experience and further validation. One of possible approaches...
-
Determination of the dynamic critical maneuvering area in an encounter between two vessels: Operation with negligible environmental disruption
PublikacjaThis paper introduces the concept of Collision Avoidance Dynamic Critical Area (CADCA) for onboard Decision Support Systems (DSS). The indicator proposed is derived via identification of a minimum required maneuvering zone in an encounter between two vessels. The CADCA model accounts for ship maneuvering dynamics and associated hydrodynamic actions emerging from different rudder angles and forward speed effects. The method presented...
-
Corrosion degradation monitoring of ship stiffened plates using guided wave phase velocity and constrained convex optimization method
PublikacjaThe study presents an experimental investigation on the corrosion degradation level assessment using nondestructive wave-based methods. The degradation level of ship structural elements has been assessed in two different ways. The first one is based on the spectral decomposition and zero-crossing incorporated reconstruction of the dispersion curve approach of the antisymmetric Lamb wave mode and the best matching of the theoretical...
-
Experimental study on the selected aspects of bow thruster generated flow field at ship zero-speed conditions
PublikacjaThe 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...
-
Indoor accelerated controlled corrosion degradation test of small- and large-scale specimens
PublikacjaThe work presented here is a part of a long-term project analysing the structural behaviour of ageing marine structures. An accelerated corrosion degradation set-up was developed to reproduce corroded marine structural specimens of different degrees of degradation, controlling various natural factors, i.e., temperature, oxygen content, salinity, and flow velocity. The nine stiffened plates of 1.2 m length and 30 small scale specimens...
-
The impact of shipping 4.0 on controlling shipping accidents: A systematic literature review
PublikacjaMaritime shipping, with a significant role in global trade, confronts various accidents leading to loss of lives, properties, and the environment. Shipping 4.0 technologies are scaling up to address this problem by employing real-time data-driven technologies, including cyber-physical systems, advanced tracking and tracing, intelligent systems, and big data analytics. Despite growing attention, there is a general lack of clarity...
-
Impact of thermal loading into the structural performance of ships: A review
PublikacjaThe presented study reviews the recent advances done regarding the impact of thermal loading on the structural performance of ships. Firstly, the studies related to the mechanical and thermal properties of typical materials used in shipbuilding are outlined. Secondly, a brief introduction to the heat transfer analysis, Finite Element modelling and thermal stresses is provided. Finally, the review of papers dealing with the structural...
-
Photogrammetry image-based approach for imperfect structure modelling and FE analysis
PublikacjaThis study aims to model and analyse imperfect tructures using real measurements, employing photogrammetry technique commonly used in the geodesy. The study highlights the capability of the photogrammetry in aiding the structural analysis of imperfect engineering objects. Firstly, the photogrammetry measurements of a stiffened plate are carried out using a specially designed for the purpose experimental stand. Then, the plate surface...
-
Kriging-assisted hybrid reliability design and optimization of offshore wind turbine support structure based on a portfolio allocation strategy
PublikacjaIn recent years, offshore wind power generation technology has developed rapidly around the world, making important contributions to the further development of renewable energy. When designing an Offshore Wind Turbine (OWT) system, the uncertainties in parameters and different types of constraints need to be considered to find the optimal design of these systems. Therefore, the Reliability-Based Design Optimization (RBDO) method...
-
Selecting cost-effective risk control option for advanced maritime operations; Integration of STPA-BN-Influence diagram
PublikacjaAdvanced maritime operations, such as remote pilotage, are vulnerable to new emergent risks due to increased system complexity and a multitude of interactions. Thus, maritime researchers this decade have combined Systems-Theoretic Process Analysis (STPA) and Bayesian Network (BN) to effectively manage these risks. Although these methods are effective in identifying hazards and analyzing risk levels, none of the STPA-BN studies...
-
Impact of steel grade on a ship colliding with an offshore wind turbine monopile supporting structure
PublikacjaOffshore wind power is experiencing rapid development around the world. The number of installations and their size is growing. Thousands of monopile support structures with diameters of 10 m and weights of 2000 tons will be installed in the coming years. Offshore wind power installations, often located close to the shore and shipping routes, pose a new challenge to ship safety. The study analyses the damages from an accidental...
-
A multiparameter simulation-driven analysis of ship turning trajectory concerning a required number of irregular wave realizations
PublikacjaIn times of progressive automation of the marine industry, accurate modeling of ship maneuvers is of utmost importance to all parties involved in maritime transportation. Despite the existence of modern collisionavoidance algorithms using 6DOF motion models to predict ship trajectories in waves, the impact of stochastic realization of irregular waves is usually neglected and remains under-investigated. Therefore, herein, this phenomenon...
-
Guided wave propagation in debonding detection in CFRP-reinforced steel plate-like structures
PublikacjaThe present study investigates the guided wave propagation in multilayered steel specimens reinforced with carbon fiber reinforced polymer (CFRP) through theoretical, numerical, and experimental means. The effectiveness of externally bonded reinforcement (EBR) relies heavily on the bonding quality between the CFRP and the substrate. Premature debonding, a prevalent and hazardous defect, can arise from suboptimal manufacturing processes,...
-
A multiparameter simulation-driven analysis of ship response when turning concerning a required number of irregular wave realizations
PublikacjaThe growing implementation of Decision Support Systems on modern ships, digital-twin technology, and the introduction of autonomous vessels cause the marine industry to seek accurate modeling of vessel response. Despite the contemporary 6DOF models can be used to predict ship motions in irregular waves, the impact of their stochastic realization is usually neglected and remains under-investigated. Especially in the case of turning, differences...
-
Impact of trajectory simplification methods on modeling carbon dioxide emissions from ships
PublikacjaModels of ship fuel consumption and emissions play an essential role in estimating global shipping’s greenhouse gas emissions. They are also widely used for verification of reported CO2 emissions for systems like EU MRV (Monitoring, Reporting and Verification) or IMO DCS (Data Collection System). Such models achieve high accuracy using historical spatiotemporal information about each ship from AIS data. However, this approach requires substantial...
-
Actual field corrosion rate of offshore structures in the Baltic Sea along depth profile from water surface to sea bed
PublikacjaThe paper presents the results of field electrochemical investigations on the corrosion rate of carbon steel in seawater of the Baltic Sea at the location of the Baltic Beta production rig. The measurements were conducted throughout the year in seawater at different depths from the sea surface to the sea bed (about 75 m). The results revealed corrosion aggressiveness of the seawater along the entire depth profile. There was...
-
Experimental and numerical identification of corrosion degradation of ageing structural components
PublikacjaThe study presents experimental and numerical identification of corrosion degradation of thin-walled structural components employing guided wave propagation. The steel structural components are subjected to through-thickness varying corrosion degradation levels. The developed approach using the non-destructive guided wave-propagation quantifies the equivalent average corrosion degradation level by exploring a limited number of...
-
On reliability assessment of ship machinery system in different autonomy degree; A Bayesian-based approach
PublikacjaAnalyzing the reliability of autonomous ships has recently attracted attention mainly due to epistemic uncertainty (lack of knowledge) integrated with automatic operations in the maritime sector. The advent of new random failures with unrecognized failure patterns in autonomous ship operations requires a comprehensive reliability assessment specifically aiming at estimating the time in which the ship can be trusted to be left unattended....
-
Badania i ocena właściwości granulatu asfaltowego stosowanego w recyklingu na gorąco w otaczarkach
PublikacjaZaprojektowanie mieszanki mineralno-asfaltowej, zawierającej granulat asfaltowy, wymaga wiarygodnej informacji, dotyczącej jego właściwości. W artykule przedstawiono informacje dotyczące zalecanych zasad pobierania próbek granulatu oraz omówiono zakres niezbędnych badań. Przedstawiono wymagania normy EN 13108-8 oraz zasady stosowane w wybranych krajach w odniesieniu do oceny właściwości asfaltu i kruszywa zawartych w granulacie...
-
WSTĘPNA OCENA PRAWIDŁOWOŚCI DOBORU BARYŁKOWEGO ŁOŻYSKA PRZESIEWACZA I MOŻLIWYCH PRZYCZYN JEGO PRZYSPIESZONEGO ZUŻYCIA
PublikacjaW pracy przedstawiona analizę przyczyn awarii baryłkowych łożysk tocznych zainstalowanych w wibracyjnych sortownikach węgla. Podczas analizy poddano oględzinom uszkodzone łozysko i wykonano obbliczenia sprawdzające. Istotnym czynnikiem któy przyczynił się do powstania przedwczesnej awarii były zanieczyszczenia i stosowanie nieodpowiedniego gatunku smaru plastycznego.
-
Ocena efektywności procesu dyplomowania na studiach pierwszego stopnia w polskich publicznych uczelniach technicznych
PublikacjaW artykule przedstawiono analizę i ilościową ocenę funkcjonowania 18 polskich uczelni technicznych uwzględniającą dwa podstawowe problemy: rezygnację ze studiów w trakcie pierwszego roku oraz wskaźniki ukończenia studiów w nominalnym czasie. Do oceny efektywności procesu dyplomowania wykorzystano prostą metodę wskaźnikową oraz nieparametryczną metodę Data Envelopment Analysis (DEA). Ocenę przeprowadzono dla studiów pierwszego stopnia...
-
Ocena bezpieczeństwa ruchu drogowego na odcinkach dróg wojewódzkich położonych w obszarze poszczególnych gmin
PublikacjaOcena brd na odcinkach dróg wojewódzkich w poszczególnych gminach woj. kujawsko - pomorskiego. liczba wypadków i ich ofiar, wskaźniki brd.
-
Grupowanie i ocena parametrów elektryczno ruchowych trolejbusowego układu zasilania metodą analizy głównych składowych
PublikacjaJednym z podstawowych typów badań i analiz wykonywanych w różnych gałęziach nauki są analizy porównawcze. W tego typu badaniach mamy do czynienia z wieloma obiektami, które są charakteryzowane za pomocą różnych parametrów, często wyrażonych w różnych jednostkach fizycznych. Celem wielowymiarowej analizy porównawczej jest znalezienie zależności pomiędzy parametrami poszczególnych obiektów i ich grupowanie na podstawie podobieństw....
-
Ocena skuteczności dyskryminacyjnych modeli logitowych, probitowych oraz liniowych w prognozowaniu upadłości spółek giełdowych
PublikacjaW artykule tym autor przeanalizował różnice w sprawności opracowanych przez niego modeli prognozowania upadłości firm na rok i na dwa lata wstecz, przy zastosowaniu trzech różnych technik opracowywania modeli. Przeprowadzone przez autora badania wykazały, że mimo iż modele liniowej wielowymiarowej analizy dyskryminacyjnej są najpopularniejsze na świecie i w Polsce, ich skuteczność w prognozowaniu upadłości firm jest wyraźnie gorsza...
-
Ocena efektywności funkcjonowania banków w systemie bankowym w Polsce : wybrane problemy (część I)
PublikacjaW artykule określono efektywność funkcjonowania banków komercyjnych i banków spółdzielczych w Polsce. Uwzględniono metody tradycyjne oraz nowoczesne. Wskazano ich przydatność do oceny funkcjonowania analizowanych banków.
-
Ocena skuteczności płukania przewymiarowanych sieci wodociągowych metodą ukierunkowanego przepływu na podstawie jakości popłuczyn
PublikacjaOcenę skuteczności płukania 77 km sieci przeprowadzono wielokryterialnie na bazie symulacyjnego odwzorowania jego przebiegu, w tym dokonano oszacowania hydraulicznego stanu wybranych rurociągów przed i po płukaniu. Wzrost sprawności hydraulicznej płukanych rurociągów jest zróżnicowany zależnie od funkcji, jaką pełnią w układzie wodociągowym, ich średnicy i rodzaju materiału. Najlepsze efekty uzyskano w płukaniu sieci rozdzielczej...
-
Ocena wpływu zagrożeń hałasowych na częstość występowania chorób słuchu z zastosowaniem systemów teleinformatycznych
Publikacja.
-
Ocena ekotoksyczności próbek osadów portowych z morskiego portu Gdańsk i morskiego portu Gdynia
PublikacjaW pracy przedstawiono wyniki badań ekotoksykologicznych (wobec bakterii Vibrio fischeri i małżoraczka Heterocypris incongruens) osadów z portu w Gdańsku i Gdyni. Osady uśrednione z rdzeni z obu portów można określić jako niestwarzające zagrożenia (poza dwiema próbkami z portu w Gdyni). Wybrane próbki pobierane z określonych głębokości wykazywały znacznie wyższą toksyczność wobec organizmów wskaźnikowych niż próbki uśredniane. Niska...
-
Ocena nośności betonowych dźwigarów wzmocnionych płaskownikiem stalowym na podstawie badań modelowych i numerycznych
PublikacjaKoniec wieku XIX oraz początek XX wieku były okresem, który w budownictwie przyniósł postęp metod obliczeń oraz zaowocował szeregiem nowatorskich rozwiązań konstrukcyjnych. Szczególny wkład w tych dziedzinach wnieśli inżynierowie zajmujący się budową mostów. Pozostawili szereg nowatorskich rozwiązań technicznych i technologicznych. Jednym z nich są ustroje systemu Möllera.Na ziemiach polskich znajduje się jeszcze kilka obiektów...
-
Ocena jakości powietrza atmosferycznego na terenie Aglomeracji Trojmiejskiej = Quality of atmospheric air in the Tricity area
PublikacjaNa terenie Aglomeracji Trójmiejskiej i Tczewa monitoring jakości powietrza prowadzony jest, obok jednostek samorządowych przez fundację: Agencja Monitoringu Regionalnego Atmosfery Aglomeracji Gdańskiej - ARMAAG. Katedra Chemii Analitycznej PG współpracując z fundacją ARMAAG podjęła próbę uzupełnienia informacji na temat stanu atmosfery na terenie Trójmiasta i Tczewa o ocenę pod względem zawartości analitów z grupy BTEX. Celem...
-
Ocena ekotoksyczności próbek osadów portowych z Morskiego Portu Gdańsk i Morskiego Portu Gdynia
PublikacjaPogłębianie basenów portowych jest powszechnie stosowanym procesem we wszystkich krajach świata. Jest to proces przynoszący zyski ekonomiczne oraz stanowi rozwiązanie problemów związanych z odmulaniem kanałów. Niemniej powinniśmy być świadomi negatywnych skutków tego procesu, jakim jest zakłócenie naturalnej flory i fauny a także skażenie terenu składowania wydobytego urobku. Wiele krajów wprowadziło wytyczne dotyczące zagospodarowaniem...
-
Ocena jakości skratek i zawiesiny mineralnej z oczyszczalni ścieków w aspekcie ich unieszkodliwiania
Publikacja