• Title/Summary/Keyword: ship stability

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EMPIRICAL DESIGN FOR SMALL CONTAINER SHIPS

  • Lee Kwi Joo;Joa Soon Won;Sarath E.S.;Park Na Ra
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.85-89
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    • 2004
  • The paper presents a summary of the multidisciplinary/optimization method for the preliminary design of container feeder vessel. The current scenario in the ship building industry highly focuses on container ship design and construction proving the inherent demand in maritime industry. The design accomplishes the outer circle of the design spiral giving stress in areas of Hull Form Design, Resistance & Propulsion. Empirical relations, model test results, data from built ships, class rules and latest market demands stood as the criteria for the design. Optimization of the design as per the owners requirement. class rules, and the trade route selected are the major challenges met with. Strength. reliability, structural safety and stability have been incorporated in compromising standards.

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Design of Automatic Control System for Ship Stabilization (선박 안정화를 위한 자동제어설계에 대하여)

  • 박정후
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.11 no.1
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    • pp.26-31
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    • 1975
  • Mordern Ocean-going ships utilize stabilization techniques in order to minimize the effects of oscillations due to the unwanted disturbances. In this paper, as an elementary design of automatic control system with linear-state vari;tble feedback and series compensator for ship stabilization, analysis and design is limited to the linear time-invariant single input and output system. In order for the Controlled system to meet the requirements of stability, accuracy and transient response, a model of the automatic control system is proposed. For the analysis and design of this model, the state-space method, that is, the mordern way, or an alternative to the transfer function method of describing a linear system that utilize the state variables and state equations, is applied.

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Developing Chatbot for Training Seafarers for better Understanding and Communication by Using Real VTS Data

  • Choe, Seong-Cheol;Seo, Won-Cheol;Choe, Seung-Hui;Jang, Eun-Gyu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.36-38
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    • 2017
  • The advent of the era of data age and advances inartificial intelligence technology has led to innovations in various business areas. In particular, many attempts have been made to improve the stability of the marine accident, which has not previously been applied by a data-drive approach. Most of the marine accidents happen at a time when the vessel isapproaching a port and preparing for berthing. Although the cause of the accident has many factors, it is often caused by the difficulties of communication between the ship navigator and the control center. In particular, communication in English makes difficulties for navigators, not English astheir first language. To do this, proper English conversation education forsailors is very important. In order to support the issue, this study presents data and framework for the development of a chatbot for ship safety education.

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Added resistance and parametric roll prediction as a design criteria for energy efficient ships

  • Somayajula, Abhilash;Guha, Amitava;Falzarano, Jeffrey;Chun, Ho-Hwan;Jung, Kwang Hyo
    • Ocean Systems Engineering
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    • v.4 no.2
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    • pp.117-136
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    • 2014
  • The increased interest in the design of energy efficient ships post IMO regulation on enforcing EEDI has encouraged researchers to reevaluate the numerical methods in predicting important hull design parameters. The prediction of added resistance and stability of ships in the rough sea environment dictates selection of ship hulls. A 3D panel method based on Green function is developed for vessel motion prediction. The effects of parametric instability are also investigated using the Volterra series approach to model the hydrostatic variation due to ship motions. The added resistance is calculated using the near field pressure integration method.

A Theoretical Study on the Charactersitics of Motion Response of Stern Trawlers (선미식 트롤선의 동요특성에 관한 이론적인 연구)

  • 강일권;윤점동;조효제
    • Journal of the Korean Institute of Navigation
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    • v.22 no.2
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    • pp.89-98
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    • 1998
  • In the field of research of seakeeping quality, much development has been made incent years using the method of calculation based on the strip theory. It is indispensable to grasp quantitatively the seaworthiness of a ship in order to draw correct design at initial stage and to perform proper operations at sea services. In this paper, the responses of three fishing vessels are calculated using statistical and spectral analyzing method to get the characteristics of the motion response. From the theoretical result we know that the significant values of the pitching and rolling motion can be signiicantly affected by not only the ship's tonnage but also the mean wave period in spite of the similar sea environment. So we can apply these expected results to the safe maneuvering and fishing operations in rough weather conditions by combining environmental circumstance with the stability condition of vessels.

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A Study on the Snap-through Behaviour According to the Initial Deflection Shape of Plate Members (초기처짐형상에 따른 판부재의 천이거동에 관한 연구)

  • 고재용;이계희;박주신
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.348-356
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    • 2003
  • Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the steel structure and marine structure so that it is wide. Especially, the post-buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct post-buckling behaviour accurately at the stability of the ship structure or marine structure. In this study, examined closely about conduct and snap-through behaviour after initial buckling of thin plate structure which apply compressive load according to various kinds initial deflection shape under all edges simply supported condition that make by buckling formula in each payment in advance rule to place which is representative construction of hull. Analysis method is F.E.M in used ANSYS program and complicated nonlinear behaviour to analyze such as secondary buckling with snap-through behaviour. Nonlinear buckling control is applied between newton-raphson method and arc-length method in this study

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Characteristic of Hydrodynamic Interaction on Tug-Barge (예부선의 유체력 간섭 특성에 관한 연구)

  • Lee, Sang-Min;Jo, Sang-Hui
    • Proceedings of KOSOMES biannual meeting
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    • 2008.05a
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    • pp.43-47
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    • 2008
  • In order to investigate the hydrodynamic interaction between the tug-barge and bank or ship which is crossing to the opposite direction, we have executed the towing simulation of tug-barge transportation. Heading of barge, yaw moment and lateral force of tug boat are obtained by this simulation. We have analyzed the characteristics of results and propose the safety towing method for tug-barge operation.

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A numerical study on manoeuvrability of wind turbine installation vessel using OpenFOAM

  • Lee, Sungwook;Kim, Booki
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.3
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    • pp.466-477
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    • 2015
  • In this study, a numerical prediction method on manoeuvrability of Wind Turbine Installation Vessel (WTIV) is presented. Planar Motion Mechanism (PMM) captive test for the bare hull of WTIV is carried out in the model basin and compared with the numerical results using RANS simulation based on Open-source Field Operation And Manipulation (OpenFOAM) calculation to validate the developed method. The manoeuvrability of WTIV with skeg and/or without skeg is investigated using the numerical approach along with the captive model test. In the numerical calculations, the dynamic stability index which indicates the course keeping ability is evaluated and compared for three different hull configurations i.e. bare hull and other two hulls with center skeg and twin skeg. This paper proves that the numerical approach using RANS simulation can be readily applied to estimate the manoeuvrability of WTIV at the initial design stage.

Performance Assessment of Navigation Seakeeping for Coastal Liquified-Natural-Gas Bunkering Ship (연안선박용 LNG 벙커링 전용선박의 내항성능 평가에 대한 연구)

  • Yi, Minah;Park, Jun-Bum;Lee, Chang-Hee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.7
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    • pp.904-914
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    • 2020
  • Through the Ministry of Trade, Industry, and Energy, South Korea is trying to support the "Building Project for Liquified Natural Gas (LNG) Bunkering Ship," centered on the Korea Gas Corporation, while the Ministry of Maritime Af airs and Fisheries is pushing to construct an LNG bunkering terminal at Busan New Port. LNG bunkering ships are essential for supplying LNG fuel from the terminal to the ships, resulting in the need for safety operation procedures. Therefore, in this study, the stability of a coastal LNG bunkering ship operating from Busan New Port to the anchorage in Busan Port was assessed to investigate the need for operational procedures for coastal LNG bunkering ships. Seakeeping analysis of the LNG bunkering ship was performed for each significant wave height by combining the response amplitude operator from the ship motion analysis under the potential flow theory with the actual observed sea data for five years and Texel, Marsen, and Arsloe (TMA) spectrum suitable for the Busan coast. The results showed that the roll and horizontal acceleration were the main risks that affected the navigation seakeeping performance above a significance wave height of 2 m. The operational periods of the LNG bunkering ship ranged from 83.3% to 99.9% of the total observation period.

Stability of fishing vessel according to the LED luring lamp installation (LED집어등 설치에 따른 연안 채낚기 어선의 복원성능)

  • Jeong, Seong-Jae;An, Heui-Chun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.623-632
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    • 2014
  • In this study, the stability of fishing vessels get some change in accordance with the installation of LED luring lamp in comparison with metal halide luring lamp were investigated. Inclining test for 9.77 ton class of squid jigging and hair-tail angling vessel was performed in order to make a stability evaluation. A performance analysis of the target vessels to the stability on the basis of KST-SHIP program was evaluated. The results were as follows in this study. The stability of the fishing vessel by a metal halide such as LED and the like according to the result obtained by the inclining test is a slightly present difference, and the stability is not affected. The fishing vessel with LED lamp installed satisfies all the stability criteria specified in law and IMO rule. Compared to the metal halide LED lamp the increase of the height of the center of gravity and the initial transverse metacenter was caused. Due to the LED installation, the somewhat wider wind area of the waterline, which appears as a result, does not lead to an actual increase in rolling period. But then it is necessary to be designed on that the LED lamp shape reduces wind pressure area. Because of LED lamp installation, the GM value of vessels is increasing faster rolling cycle so causes a decrease in the sense that the crew is aboard.