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Wyniki wyszukiwania dla: PRESSURE SIGANTURE OF SHIP
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JOURNAL OF SHIP RESEARCH
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VARIANT DESIGNING IN the PRELIMINARY SMALL SHIP DESIGN PROCESS
PublikacjaShip designing is a complex process, as the ship itself is a complex, technical multi-level object which operates in the air/water boundary environment and is exposed to the action of many different external and internal factors resulting from the adopted technical solutions, type of operation, and environmental conditions. A traditional ship design process consists of a series of subsequent multistage iterations, which gradually...
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Hybrid System for Ship-Aided Design Automation
PublikacjaA hybrid support system for ship design based on the methodology of CBR with some artificial intelligence tools such as expert system Exsys Developer along with fuzzy logic, relational Access database and artificial neural network with backward propagation of errors.
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USING ARTIFICIAL NEURAL NETWORKS FOR PREDICTING SHIP FUEL CONSUMPTION
PublikacjaIn marine vessel operations, fuel costs are major operating costs which affect the overall profitability of the maritime transport industry. The effective enhancement of using ship fuel will increase ship operation efficiency. Since ship fuel consumption depends on different factors, such as weather, cruising condition, cargo load, and engine condition, it is difficult to assess the fuel consumption pattern for various types...
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Strategie wzrostowe dla Neptun Ship Service Ltd.
PublikacjaW ekspertyzie przeprowadzono ewaluację strategii wzrostowych dla firmy Neptun Ship Service Ltd.
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COLREGS compliance in Evolutionary Sets of Cooperating Ship Trajectories
PublikacjaIn general, Evolutionary Sets of Cooperating Ship Trajectories combine some of the assumptions of game theory with evolutionary programming and aim to find optimal set of cooperating trajectoriesof all ships involved in an encounter situation. In a two-ship encounter situation the method enables the operator of an on-board collision-avoidance system to predict the most probable behaviour of atarget and to plan the own manoeuvres...
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APPLICATION OF REDUNDANCY IN SHIP POWER PLANTS OF OFFSHORE VESSEL
PublikacjaPower and propulsion systems of offshore units must be of a very high level of reliability. The loss of ability to perform functions of their components causes generally to very high economic losses, which may be increased by unused the weather window resulting to postponing the planned offshore operations. To ensure carrying out so expensive offshore operations in the most reliable way, various types of redundancies are built-in...
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Influence of pitting corrosion on fatigue and corrosion fatigue of ship structures. Part I: pitting corrosion of ship structures.
PublikacjaThe paper is a literature survey focused on pitting corrosion and its influence on fatigue of ship and offshore steels. Mechanisms of short- and long-term pitting corrosion in marine environment have been described including pit nucleation and growth phases. Some models of pit growth versus time of exposure have been presented. Some factors which influence the pit growth have been discussed briefly.
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Modelling of some stealth features for a small navy ship at the concept design stage.
PublikacjaIn this paper the basic research problems associated with modelling the basic stealth features for a small navy ship at the concept design stage are introduced. Amongst the major stealth features considered are: the modification of the immersed ship hull form by a rapid change of the ship loading condition, and modification of the ship boundary layer by the hull skin cover. The other stealth features of the ship are not presented...
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In Search of Naval Beauty. Historical Study of Ship Architecture
PublikacjaDesigning ships is no mean achievement. In the old days, constructors focused on making their ships visually appealing, while paying scant regard to the living conditions of the crew. Such an approach reflected the state of the art in ship building at the time as well as the social order prevalent in those days. A breakthrough came no earlier than at the turn of the 19th / 20th centuries. The industrial revolution brought along...
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Simulation Environment in Python for Ship Encounter Situations
PublikacjaTo assess the risk of collision in radar navigation distance-based safety measures such as Distance at the Closest Point of Approach and Time to the Closest Point of Approach are most commonly used. Also Bow Crossing Range and Bow Crossing Time measures are good complement to the picture of the meeting situation. When ship safety domain is considered then Degree of Domain Violation and Time to Domain Violation can be applied. This...
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Accident susceptibility index for a passenger ship-a framework and case study
PublikacjaThe continuous monitoring and assessment of operational vulnerability and accident susceptibility of passenger ships is crucial from the perspective of ship and passenger safety. Despite the existing solutions for vulnerability monitoring, stemming mainly from watertight door operations, a comprehensive framework for accident susceptibility assessment and monitoring is missing in the literature. Therefore, this paper offers a...
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Advances in Modelling and Analysis of Strength of Corroded Ship Structures
PublikacjaThe present study reviews the recent advances in modelling and analyses the strength of corroded ship structures. Firstly, the time-variant methodologies that consider only the mean structural element thickness loss due to corrosion degradation are identified. Corrosion degradation is regarded as the phenomenon that causes uneven thinning of specimens. This has been captured by various researchers as the loss of mechanical properties...
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Pressure Pulsations in Turbine Blade Seal
PublikacjaThe paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublikacjaThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublikacjaThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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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...
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UNDERWATER NOISE GENERATED BY A SMALL SHIP IN THE SHALLOW SEA
PublikacjaStudy of the sea noise has been a subject of interest for years. The first work of this scope were published at the turn of the twentieth century by Knudsen (KNUDSEN et al., 1948) and G. Wenz (WENZ, 1962). Disturbances called "shipping noise" are one of the important components of the sea noise. In this work the results of an experimental research of underwater noise produced by a small ship of a classic propulsion are...
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Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals
PublikacjaThe paper presents a description of the evaluation phase of the Evolutionary Sets of Safe Ship Trajectories method. In general, the Evolutionary Sets of Safe Ship Trajectories method combines some of the assumptions of game theory with evolutionary programming and finds an optimal set of cooperating trajectories of all ships involved in an encounter situation. While developing a new version of this method, the authors decided to...
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Quantitative risk assessment of new ship designs in damage conditions
PublikacjaThe paper is devoted to safety of ships in damage conditions. The novel contribution of the paper is connected with a new Multi-Task ship (MT-ship) design at the preliminary stage of design. There are a few problems at the preliminary stage that should be considered. One problem is connected with if the quantitative risk-based method is a reliable and formal method for safety assessment of such the new design (MT-ship) in damage...
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Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals
PublikacjaThe paper presents a description of the evaluation phase of the Evolutionary Sets of Safe Ship Trajectories method. In general, the Evolutionary Sets of Safe Ship Trajectories method combines some of the assumptions of game theory with evolutionary programming and finds an optimal set of cooperating trajectories of all ships involved in an encounter situation. While developing a new version of this method, the au-thors decided...
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HYBRID ENERGY SYSTEM FOR A CLASSIC SHIP POWER PLANT
PublikacjaThe article presents a brief overview of hybrid energy systems used on ships. The area of their application is outlined. The benefits of using such systems are also indicated. Then, the classic ship power plant is defined. The most important part of the article is a proposal how to modify a classic engine room by using a hybrid energy system. The idea is: to accumulate a part of electricity in areas where it is allowed to burn...
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Case Study of Stray Current Corrosion of Tall Ship Mast
PublikacjaNowadays, in the present technical civilization there are numerous complex technical systems that may generate various hazards. Large transport units like ships can be considered as the most dangerous systems. Therefore, it is important to eliminate all possible hazards, especially for ship crewmembers. Destruction of ship structural components caused by vast corrosion is one of these hazards. Usually, its activity leads to a decrease...
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Predicting Thrust Loss of Ship Propellers Due to Ventilation and Out-of-Water Effect
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Customized crossover in evolutionary sets of safe ship trajectories
PublikacjaThe paper presents selected aspects of evolutionary sets of safe ship trajectories-a method which applies evolutionary algorithms and some of the assumptions of game theory to solving ship encounter situations. For given positions and motion parameters of the ships, the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The method works in real time and the solutions must be returned within...
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Human Resource Management Digitalisation in Multidisciplinary Ship Design Companies
PublikacjaThe digitalisation in the ship design sector is currently applied to the design process itself and is well defined, partially standardised and practically implemented by both independent design companies and the design departments of shipyards. The situation is similar in other sectors of engineering. However, the requirements for the digitalisation of other processes in design and engineering companies have not previously been...
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Quantitative Assessment of Operation of Ship Main Diesel Engine
PublikacjaOperation of ship propulsion system is associated with realization of definite operational goals. If to elements of the system the operational reliability strategy could be applied, the situation would be very simple as existing conditions would unambiguously determine application of means being on hand. However decision to reject application of the strategy (even if hypothetical) becomes obvious with a view of necessity of ensuring...
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Implementation of 24-hour Blood Pressure Control
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Evolutionary Sets of Safe Ship Trajectories: the Method's Development and Selected Reaserch Results
PublikacjaThe Evolutionary Sets of Safe Ship Trajectories is a method solving ship encounter situations. The method combines evolutionary approach to planning ship trajectory with some of the assumption of game theory. For given positions and motion parameters the method finds a near optimal set of safe trajectories of all ships involved in an encounter. This paper presents framework of the method and its development. Additionally, selected...
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Applying artificial neural networks for modelling ship speed and fuel consumption
PublikacjaThis paper deals with modelling ship speed and fuel consumption using artificial neural network (ANN) techniques. These tools allowed us to develop ANN models that can be used for predicting both the fuel consumption and the travel time to the destination for commanded outputs (the ship driveline shaft speed and the propeller pitch) selected by the ship operator. In these cases, due to variable environmental conditions, making...
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Marine autonomous surface ship - control system configuration
PublikacjaThis paper addresses the problem of marine autonomous surface ship (MASS) control. The contribution of the paper is the development of a control system configuration, done assuming fully autonomous MASS operation under distinct operational conditions. The overview of hardware and software selection is included.
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Microwave Ring Resonator Based Pressure Sensor
PublikacjaThis paper demonstrates a microwave pressure sensor, which is based on microstrip line-fed ring resonators. The first ring resonator is loaded with the concentric cylindrical shafts, while the same number of the hollow shanks as the shafts are mounted on the second ring resonator. The arrangement of the cylindrical shaft and hollow shank allows for mechanical movement between two substrates while maintaining electrical contact....
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Numerical Simulations of Hydrodynamic Open-Water Characteristics of a Ship Propeller
PublikacjaThe paper presents the results of numerical simulations of ship propeller operation bearing the name of Propeller Open Water (POW) Tests. The object of tests was a sample ship propeller (PPTC1), the geometrical and kinematic data of which are available, along with the results of model tests, on the official page of the research centre involved in the measurements. The research aimed at verifying the correctness of results of numerical...
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NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublikacjaOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
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Evolutionary Sets of Safe Ship Trajectories: development of the method
PublikacjaThe Evolutionary Sets of Safe Ship Trajectories is a method solving ship encounter situations. The method combines evolutionary approach to planning ship trajectory with some of the assumption of game theory. For given positions and motion parameters the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The version presented here is an updated one and its authors have tested extensively...
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Evolutionary Planning of Safe Ship Tracks in Restricted Visibility
PublikacjaThe paper presents the continuation of the author's research on ship track planning by means of Evolutionary Algorithms (EA). The presented method uses EA to search for an optimal set of safe tracks for all ships involved in an encounter. Until now the method assumed good visibility – compliance with standard rules of the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS, 1972). However, in restricted...
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Selection Pressure in the Evolutionary Path Planning Problem
PublikacjaThis article compares an impact of using various post-selection methods on the selection pressure and the quality of the solution for the problem of planning the path for a moving object using the evolutionary method. The concept of selection pressure and different methods of post-selection are presented. Article analyses behaviour of post-selection for four options of evolutionary algorithms. Based on the results achieved, waveform...
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Factors Shaping the Working Environment, Living Conditions and Recreation on Board Ship
PublikacjaA seagoing ship is a working place, an accommodation space and a recreation area at the same time. Being exposed to harsh physical conditions, it must satisfy different requirements. The human organism and its qualities become a point of reference here; consequently, the functions and spatial arrangement and interiors of a ship must be subordinated to its needs. The organisation of the space in contemporary ships meant for human...
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Ship Resistance Prediction with Artificial Neural Networks
PublikacjaThe paper is dedicated to a new method of ship’s resistance prediction using Artificial Neural Network (ANN). In the initial stage selected ships parameters are prepared to be used as a training and validation sets. Next step is to verify several network structures and to determine parameters with the highest influence on the result resistance. Finally, other parameters expected to impact the resistance are proposed. The research utilizes...
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Propagation of Ship-Generated Noise in Shallow Sea
PublikacjaContamination of sea environment by noise and any energy radiated to water constitutes today a problem to which more and more attention is paid, in view, a.o., of consequences of an impact of these factors onto marine fauna. European Union has introduced a directive by which EU countries are made responsible to undertake efforts aimed at reaching a good envirenmental status of European seas by 2020. A main source of underwater...
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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...
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Modelling of some stealth features for a small navy ship at the concept design stage - part II
PublikacjaIn the paper a few problems associated with modelling the basic stealth features for a small ship at the concept design stage are introduced. One problem concerns the modification of the immersed ship hull using the rapid change of the ship loading condition. The second is associated with the modification of the ship boundary layer by the hull skin cover. The other stealth features of the ship are not presented in this paper. The...
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Evolutionary Sets Of Safe Ship Trajectories: A New Approach To Collision Avoidance
PublikacjaThe paper introduces a new method of solving multi-ship encounter situations for both open waters and restricted water regions. The method, called evolutionary sets of safe trajectories combines some of the assumptions of game theory with evolutionary programming and aims to find optimal set of safe trajectories of all ships involved in an encounter situation. In a two-ship encounter situation it enables the operator of an on-board...
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Pressure pulsations in turbine blade seal clearance
PublikacjaThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...
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Parametrical Method for Determining Optimal Ship Carrying Capacity and Performance of Handling Equipment
PublikacjaThe paper presents a method of evaluating the optimal value of the cargo ships deadweight and the coupled optimal value of cargo handling capacity. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper second hand ship for a given transportation task. The deadweight and the capacity are determined on the basis of a selected economic...
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Combined Close Range Photogrammetry and Terrestrial Laser Scanning for Ship Hull Modelling
PublikacjaThe paper addresses the fields of combined close-range photogrammetry and terrestrial laser scanning in the light of ship modelling. The authors pointed out precision and measurement accuracy due to their possible complex application for ship hulls inventories. Due to prescribed vitality of every ship structure, it is crucial to prepare documentation to support the vessel processes. The presented methods are directed, combined...
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COMPARISON OF BLOOD PRESSURE PREDICTION METHODS
PublikacjaIn the paper dierent approaches of predicting blood pressure values are presented. Basically, two methods and theirs modifications are considered. In total, seven algorithms have been examined. Tests have been conducted using both synthetic and clinical data. From our study it follows that none of the examined methods is superior to other.
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Investigating Fuel Injection Strategies to Enhance Ship Energy Efficiency in Wave Conditions
PublikacjaThe prediction of fuel consumption and resulting transportation costs is a crucial stage in ship design, particularly for conditions involving motion in waves. This study investigates the real-time fuel consumption of a container ship when sailing in waves. The overall ship performance is evaluated using a novel non-linear coupled hull-engine-propeller interaction model. A series of towing tank experiments for hull resistance in...
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The Influence of Water and Mineral Oil on Pressure Losses in Hydraulic Motor
PublikacjaIn this paper, pressure losses in hydraulic motor supplied with water and mineral oil (two liquids that have significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a hydraulic satellite motor that is dedicated to working with different liquids, including water. The methodology of measuring the pressure drop in internal channels of this motor is also...
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Reservoir Influence on Pressure Wave Propagation in Steel Pipes
PublikacjaThe relation between the length of steel pipe and the pressure wave period in the system, reservoir-pipe-valve, is discussed. Experiments carried out for the short steel pipes showed that in such a system, the pressure wave celerity estimated using the measured wave cycles systematically increases with the increase of the pipe length. The observed differences can exceed even 90 m=s. As the pressure wave traveling in the pipe with...